ID: 26697887
Title: Defective PITRM1 mitochondrial peptidase is associated with Aβ amyloidotic neurodegeneration.
Abstract: Mitochondrial dysfunction and altered proteostasis are central features of neurodegenerative diseases. The pitrilysin metallopeptidase 1 (PITRM1) is a mitochondrial matrix enzyme, which digests oligopeptides, including the mitochondrial targeting sequences that are cleaved from proteins imported across the inner mitochondrial membrane and the mitochondrial fraction of amyloid beta (Aβ). We identified two siblings carrying a homozygous PITRM1 missense mutation (c.548G>A, p.Arg183Gln) associated with an autosomal recessive, slowly progressive syndrome characterised by mental retardation, spinocerebellar ataxia, cognitive decline and psychosis. The pathogenicity of the mutation was tested in vitro, in mutant fibroblasts and skeletal muscle, and in a yeast model. A Pitrm1(+/-) heterozygous mouse showed progressive ataxia associated with brain degenerative lesions, including accumulation of Aβ-positive amyloid deposits. Our results show that PITRM1 is responsible for significant Aβ degradation and that impairment of its activity results in Aβ accumulation, thus providing a mechanistic demonstration of the mitochondrial involvement in amyloidotic neurodegeneration.

ID: 29183787
Title: Mechanism of Peptide Binding and Cleavage by the Human Mitochondrial Peptidase Neurolysin.
Abstract: Proteolysis plays an important role in mitochondrial biogenesis, from the processing of newly imported precursor proteins to the degradation of mitochondrial targeting peptides. Disruption of peptide degradation activity in yeast, plant and mammalian mitochondria is known to have deleterious consequences for organism physiology, highlighting the important role of mitochondrial peptidases. In the present work, we show that the human mitochondrial peptidase neurolysin (hNLN) can degrade mitochondrial presequence peptides as well as other fragments up to 19 amino acids long. The crystal structure of hNLNE475Q in complex with the products of neurotensin cleavage at 2.7Å revealed a closed conformation with an internal cavity that restricts substrate length and highlighted the mechanism of enzyme opening/closing that is necessary for substrate binding and catalytic activity. Analysis of peptide degradation in vitro showed that hNLN cooperates with presequence protease (PreP or PITRM1) in the degradation of long targeting peptides and amyloid-β peptide, Aβ1-40, associated with Alzheimer disease, particularly cleaving the hydrophobic fragment Aβ35-40. These findings suggest that a network of proteases may be required for complete degradation of peptides localized in mitochondria.

ID: 29764912
Title: Mitochondrial PITRM1 peptidase loss-of-function in childhood cerebellar atrophy.
Abstract: To identify the genetic basis of a childhood-onset syndrome of variable severity characterised by progressive spinocerebellar ataxia, mental retardation, psychotic episodes and cerebellar atrophy. Identification of the underlying mutations by whole exome and whole genome sequencing. Consequences were examined in patients' cells and in yeast. Two brothers from a consanguineous Palestinian family presented with progressive spinocerebellar ataxia, mental retardation and psychotic episodes. Serial brain imaging showed severe progressive cerebellar atrophy. Whole exome sequencing revealed a novel mutation: pitrilysin metallopeptidase 1 (PITRM1) c.2795C>T, p.T931M, homozygous in the affected children and resulting in 95% reduction in PITRM1 protein. Whole genome sequencing revealed a chromosome X structural rearrangement that also segregated with the disease. Independently, two siblings from a second Palestinian family presented with similar, somewhat milder symptoms and the same PITRM1 mutation on a shared haplotype. PITRM1T931M carrier frequency was 0.027 (3/110) in the village of the first family evaluated, and 0/300 among Palestinians from other locales. PITRM1 is a mitochondrial matrix enzyme that degrades 10-65 amino acid oligopeptides, including the mitochondrial fraction of amyloid-beta peptide. Analysis of peptide cleavage activity by the PITRM1T931M protein revealed a significant decrease in the degradation capacity specifically of peptides ≥40 amino acids. PITRM1T931M results in childhood-onset recessive cerebellar pathology. Severity of PITRM1-related disease may be affected by the degree of impairment in cleavage of mitochondrial long peptides. Disruption and deletion of X linked regulatory segments may also contribute to severity.

ID: 32632204
Title: Loss of function of the mitochondrial peptidase PITRM1 induces proteotoxic stress and Alzheimer's disease-like pathology in human cerebral organoids.
Abstract: Mutations in pitrilysin metallopeptidase 1 (PITRM1), a mitochondrial protease involved in mitochondrial precursor processing and degradation, result in a slow-progressing syndrome characterized by cerebellar ataxia, psychotic episodes, and obsessive behavior, as well as cognitive decline. To investigate the pathogenetic mechanisms of mitochondrial presequence processing, we employed cortical neurons and cerebral organoids generated from PITRM1-knockout human induced pluripotent stem cells (iPSCs). PITRM1 deficiency strongly induced mitochondrial unfolded protein response (UPRmt) and enhanced mitochondrial clearance in iPSC-derived neurons. Furthermore, we observed increased levels of amyloid precursor protein and amyloid β in PITRM1-knockout neurons. However, neither cell death nor protein aggregates were observed in 2D iPSC-derived cortical neuronal cultures. On the other hand, over time, cerebral organoids generated from PITRM1-knockout iPSCs spontaneously developed pathological features of Alzheimer's disease (AD), including the accumulation of protein aggregates, tau pathology, and neuronal cell death. Single-cell RNA sequencing revealed a perturbation of mitochondrial function in all cell types in PITRM1-knockout cerebral organoids, whereas immune transcriptional signatures were substantially dysregulated in astrocytes. Importantly, we provide evidence of a protective role of UPRmt and mitochondrial clearance against impaired mitochondrial presequence processing and proteotoxic stress. Here, we propose a novel concept of PITRM1-linked neurological syndrome whereby defects of mitochondrial presequence processing induce an early activation of UPRmt that, in turn, modulates cytosolic quality control pathways. Thus, our work supports a mechanistic link between mitochondrial function and common neurodegenerative proteinopathies.

ID: 33220280
Title: A novel hypothesis on metal dyshomeostasis and mitochondrial dysfunction in amyotrophic lateral sclerosis: Potential pathogenetic mechanism and therapeutic implications.
Abstract: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by motor dysfunctions resulting from the loss of upper (UMNs) and lower (LMNs) motor neurons. While ALS symptoms are coincidental with pathological changes in LMNs and UMNs, the causal relationship between the two is unclear. For example, research on the extra-motor symptoms associated with this condition suggests that an imbalance of metals, including copper, zinc, iron, and manganese, is initially induced in the sensory ganglia due to a malfunction of metal binding proteins and transporters. It is proposed that the resultant metal dyshomeostasis may promote mitochondrial dysfunction in the satellite glial cells of these sensory ganglia, causing sensory neuron disturbances and sensory symptoms. Sensory neuron hyperactivation can result in LMN impairments, while metal dyshomeostasis in spinal cord and brain stem parenchyma induces mitochondrial dysfunction in LMNs and UMNs. These events could prompt intracellular calcium dyshomeostasis, pathological TDP-43 formation, and reactive microglia with neuroinflammation, which in turn activate the apoptosis signaling pathways within the LMNs and UMNs. Our model suggests that the degeneration of LMNs and UMNs is incidental to the metal-induced changes in the spinal cord and brain stem. Over time psychiatric symptoms may appear as the metal dyshomeostasis and mitochondrial dysfunction affect other brain regions, including the reticular formation, hippocampus, and prefrontal cortex. It is proposed that metal dyshomeostasis in combination with mitochondrial dysfunction could be the underlying mechanism responsible for the initiation and progression of the pathological changes associated with both the motor and extra-motor symptoms of ALS.

ID: 33835239
Title: In-frame deletion in canine PITRM1 is associated with a severe early-onset epilepsy, mitochondrial dysfunction and neurodegeneration.
Abstract: We investigated the clinical, genetic, and pathological characteristics of a previously unknown severe juvenile brain disorder in several litters of Parson Russel Terriers. The disease started with epileptic seizures at 6-12 weeks of age and progressed rapidly to status epilepticus and death or euthanasia. Histopathological changes at autopsy were restricted to the brain. There was severe acute neuronal degeneration and necrosis diffusely affecting the grey matter throughout the brain with extensive intraneuronal mitochondrial crowding and accumulation of amyloid-β (Aβ). Combined homozygosity mapping and genome sequencing revealed an in-frame 6-bp deletion in the nuclear-encoded pitrilysin metallopeptidase 1 (PITRM1) encoding for a mitochondrial protease involved in mitochondrial targeting sequence processing and degradation. The 6-bp deletion results in the loss of two amino acid residues in the N-terminal part of PITRM1, potentially affecting protein folding and function. Assessment of the mitochondrial function in the affected brain tissue showed a significant deficiency in respiratory chain function. The functional consequences of the mutation were modeled in yeast and showed impaired growth in permissive conditions and an impaired respiration capacity. Loss-of-function variants in human PITRM1 result in a childhood-onset progressive amyloidotic neurological syndrome characterized by spinocerebellar ataxia with behavioral, psychiatric and cognitive abnormalities. Homozygous Pitrm1-knockout mice are embryonic lethal, while heterozygotes show a progressive, neurodegenerative phenotype characterized by impairment in motor coordination and Aβ deposits. Our study describes a novel early-onset PITRM1-related neurodegenerative canine brain disorder with mitochondrial dysfunction, Aβ accumulation, and lethal epilepsy. The findings highlight the essential role of PITRM1 in neuronal survival and strengthen the connection between mitochondrial dysfunction and neurodegeneration.

ID: 33951271
Title: Gain of PITRM1 peptidase in cortical neurons affords protection of mitochondrial and synaptic function in an advanced age mouse model of Alzheimer's disease.
Abstract: Mitochondrial dysfunction is one of the early pathological features of Alzheimer's disease (AD). Accumulation of cerebral and mitochondrial Aβ links to mitochondrial and synaptic toxicity. We have previously demonstrated the mechanism by which presequence peptidase (PITRM1)-mediated clearance of mitochondrial Aβ contributes to mitochondrial and cerebral amyloid pathology and mitochondrial and synaptic stress in adult transgenic AD mice overexpressing Aβ up to 12 months old. Here, we investigate the effect of PITRM1 in an advanced age AD mouse model (up to 19-24 months) to address the fundamental unexplored question of whether restoration/gain of PITRM1 function protects against mitochondrial and synaptic dysfunction associated with Aβ accumulation and whether this protection is maintained even at later ages featuring profound amyloid pathology and synaptic failure. Using newly developed aged PITRM1/Aβ-producing AD mice, we first uncovered reduction in PITRM1 expression in AD-affected cortex of AD mice at 19-24 months of age. Increasing neuronal PITRM1 activity/expression re-established mitochondrial respiration, suppressed reactive oxygen species, improved synaptic function, and reduced loss of synapses even at advanced ages (up to 19-24 months). Notably, loss of PITRM1 proteolytic activity resulted in Aβ accumulation and failure to rescue mitochondrial and synaptic function, suggesting that PITRM1 activity is required for the degradation and clearance of mitochondrial Aβ and Aβ deposition. These data indicate that augmenting PITRM1 function results in persistent life-long protection against Aβ toxicity in an AD mouse model. Therefore, augmenting PITRM1 function may enhance Aβ clearance in mitochondria, thereby maintaining mitochondrial integrity and ultimately slowing the progression of AD.

ID: 33968923
Title: Recovery of Depleted miR-146a in ALS Cortical Astrocytes Reverts Cell Aberrancies and Prevents Paracrine Pathogenicity on Microglia and Motor Neurons.
Abstract: Reactive astrocytes in Amyotrophic Lateral Sclerosis (ALS) change their molecular expression pattern and release toxic factors that contribute to neurodegeneration and microglial activation. We and others identified a dysregulated inflammatory miRNA profile in ALS patients and in mice models suggesting that they represent potential targets for therapeutic intervention. Such cellular miRNAs are known to be released into the secretome and to be carried by small extracellular vesicles (sEVs), which may be harmful to recipient cells. Thus, ALS astrocyte secretome may disrupt cell homeostasis and impact on ALS pathogenesis. Previously, we identified a specific aberrant signature in the cortical brain of symptomatic SOD1-G93A (mSOD1) mice, as well as in astrocytes isolated from the same region of 7-day-old mSOD1 mice, with upregulated S100B/HMGB1/Cx43/vimentin and downregulated GFAP. The presence of downregulated miR-146a on both cases suggests that it can be a promising target for modulation in ALS. Here, we upregulated miR-146a with pre-miR-146a, and tested glycoursodeoxycholic acid (GUDCA) and dipeptidyl vinyl sulfone (VS) for their immunoregulatory properties. VS was more effective in restoring astrocytic miR-146a, GFAP, S100B, HMGB1, Cx43, and vimentin levels than GUDCA, which only recovered Cx43 and vimentin mRNA. The miR-146a inhibitor generated typical ALS aberrancies in wild type astrocytes that were abolished by VS. Similarly, pre-miR-146a transfection into the mSOD1 astrocytes abrogated aberrant markers and intracellular Ca2+ overload. Such treatment counteracted miR-146a depletion in sEVs and led to secretome-mediated miR-146a enhancement in NSC-34-motor neurons (MNs) and N9-microglia. Secretome from mSOD1 astrocytes increased early/late apoptosis and FGFR3 mRNA in MNs and microglia, but not when derived from pre-miR-146a or VS-treated cells. These last strategies prevented the impairment of axonal transport and synaptic dynamics by the pathological secretome, while also averted microglia activation through either secretome, or their isolated sEVs. Proteomic analysis of the target cells indicated that pre-miR-146a regulates mitochondria and inflammation via paracrine signaling. We demonstrate that replenishment of miR-146a in mSOD1 cortical astrocytes with pre-miR-146a or by VS abrogates their phenotypic aberrancies and paracrine deleterious consequences to MNs and microglia. These results propose miR-146a as a new causal and emerging therapeutic target for astrocyte pathogenic processes in ALS.

ID: 34968496
Title: Prolyl oligopeptidase acts as a link between chaperone-mediated autophagy and macroautophagy.
Abstract: The accumulation of aggregated α-synuclein (α-syn) has been identified as the primary component of Lewy bodies that are the pathological hallmarks of Parkinson's disease (PD). Several preclinical studies have shown α-syn aggregation, and particularly the intermediates formed during the aggregation process to be toxic to cells. Current PD treatments only provide symptomatic relief, and α-syn serves as a promising target to develop a disease-modifying therapy for PD. Our previous studies have revealed that a small-molecular inhibitor for prolyl oligopeptidase (PREP), KYP-2047, increases α-syn degradation by accelerating macroautophagy (MA) leading to disease-modifying effects in preclinical PD models. However, α-syn is also degraded by chaperone-mediated autophagy (CMA). In the present study, we tested the effects of PREP inhibition or deletion on CMA activation and α-syn degradation. HEK-293 cells were transfected with α-syn and incubated with 1 & 10 µM KYP-2047 for 24 h. Both 1 & 10 µM KYP-2047 increased LAMP-2A levels, induced α-syn degradation and reduced the expression of Hsc70, suggesting that the PREP inhibitor prevented α-syn aggregation by activating the CMA pathway. Similarly, KYP-2047 increased the LAMP-2A immunoreactivity and reduced the Hsc70 levels in mouse primary cortical neurons. When LAMP-2A was silenced by a siRNA, KYP-2047 increased the LC3BII/LC3BI ratio and accelerated the clearance of α-syn. Additionally, KYP-2047 induced CMA effectively also when MA was blocked by bafilomycin A1. Based on our results, we suggest that PREP might function as a core network node in MA-CMA crosstalk, and PREP inhibition can reduce α-syn levels via both main autophagy systems.

ID: 35388015
Title: DELE1 tracks perturbed protein import and processing in human mitochondria.
Abstract: Protein homeostatic control of mitochondria is key to age-related diseases and organismal decline. However, it is unknown how the diverse types of stress experienced by mitochondria can be integrated and appropriately responded to in human cells. Here we identify perturbations in the ancient conserved processes of mitochondrial protein import and processing as sources of DELE1 activation: DELE1 is continuously sorted across both mitochondrial membranes into the matrix and detects different types of perturbations along the way. DELE1 molecules in transit can become licensed for mitochondrial release and stress signaling through proteolytic removal of N-terminal sorting signals. Import defects that occur at the mitochondrial surface allow DELE1 precursors to bind and activate downstream factor HRI without the need for cleavage. Genome-wide genetics reveal that DELE1 additionally responds to compromised presequence processing by the matrix proteases PITRM1 and MPP, which are mutated in neurodegenerative diseases. These mechanisms rationalize DELE1-dependent mitochondrial stress integration in the human system and may inform future therapies of neuropathies.

ID: 37002885
Title: Presequence protease reverses mitochondria-specific amyloid-β-induced mitophagy to protect mitochondria.
Abstract: Amyloid-β (Aβ) peptide is accumulated in the mitochondria and has been shown to play a central role in the development of Alzheimer's disease (AD). It has been shown that exposure of neurons to aggregated Aβ can result in damaged mitochondria and dysregulated mitophagy, indicating that changes in the Aβ content of mitochondria may affect the levels of mitophagy and interfere with the progression of AD. However, the direct influence of mitochondrial Aβ on mitophagy has not been elucidated. In the present study, the effect of the mitochondria-specific Aβ was assessed following a direct change of Aβ content in the mitochondria. We directly change mitochondrial Aβ by transfecting cells with mitochondria-associated plasmids, including the mitochondrial outer membrane protein translocase 22 (TOMM22) and 40 (TOMM40) or presequence protease (PreP) overexpression plasmids. The changes in the levels of mitophagy were assessed by TEM, Western blot, mito-Keima construct, organelle tracker, and probe JC-1 assay. We demonstrated that increased mitochondrial Aβ content enhance mitophagy levels; overexpression of PreP could reverse the mitochondrial Aβ-induced mitophagy levels in vivo and in vitro by reversing the levels of reactive oxygen species (ROS) and the mitochondrial membrane potential. The data provide novel insight into the role of mitochondria-specific Aβ in the progression of AD pathophysiology.

ID: 37576821
Title: PPAR-gamma agonist pioglitazone recovers mitochondrial quality control in fibroblasts from PITRM1-deficient patients.
Abstract: Introduction: Biallelic variants in PITRM1 are associated with a slowly progressive syndrome characterized by intellectual disability, spinocerebellar ataxia, cognitive decline and psychosis. The pitrilysin metallopeptidase 1 (PITRM1) is a mitochondrial matrix enzyme, which digests diverse oligopeptides, including the mitochondrial targeting sequences (MTS) that are cleaved from proteins imported across the inner mitochondrial membrane by the mitochondrial processing peptidase (MPP). Mitochondrial peptidases also play a role in the maturation of Frataxin, the protein affected in Friedreich's ataxia. Recent studies in yeast indicated that the mitochondrial matrix protease Ste23, which is a homologue of the human insulin-degrading enzyme (IDE), cooperates with Cym1 (homologue of PITRM1) to ensure the proper functioning of the preprotein processing machinery. In humans, IDE could be upregulated by Peroxisome Proliferator-Activated Receptor Gamma (PPARG) agonists. Methods: We investigated preprotein processing, mitochondrial membrane potential and MTS degradation in control and patients' fibroblasts, and we evaluated the pharmacological effect of the PPARG agonist Pioglitazone on mitochondrial proteostasis. Results: We discovered that PITRM1 dysfunction results in the accumulation of MTS, leading to the disruption and dissipation of the mitochondrial membrane potential. This triggers a feedback inhibition of MPP activity, consequently impairing the processing and maturation of Frataxin. Furthermore, we found that the pharmacological stimulation of PPARG by Pioglitazone upregulates IDE and also PITRM1 protein levels restoring the presequence processing machinery and improving Frataxin maturation and mitochondrial function. Discussion: Our findings provide mechanistic insights and suggest a potential pharmacological strategy for this rare neurodegenerative mitochondrial disease.

ID: 38906862
Title: Enhancing mitochondrial proteolysis alleviates alpha-synuclein-mediated cellular toxicity.
Abstract: Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by mitochondrial dysfunction and accumulation of alpha-synuclein (α-Syn)-containing protein aggregates known as Lewy bodies (LB). Here, we investigated the entry of α-Syn into mitochondria to cause mitochondrial dysfunction and loss of cellular fitness in vivo. We show that α-Syn expressed in yeast and human cells is constitutively imported into mitochondria. In a transgenic mouse model, the level of endogenous α-Syn accumulation in mitochondria of dopaminergic neurons and microglia increases with age. The imported α-Syn is degraded by conserved mitochondrial proteases, most notably NLN and PITRM1 (Prd1 and Cym1 in yeast, respectively). α-Syn in the mitochondrial matrix that is not degraded interacts with respiratory chain complexes, leading to loss of mitochondrial DNA (mtDNA), mitochondrial membrane potential and cellular fitness decline. Importantly, enhancing mitochondrial proteolysis by increasing levels of specific proteases alleviated these defects in yeast, human cells, and a PD model of mouse primary neurons. Together, our results provide a direct link between α-synuclein-mediated cellular toxicity and its import into mitochondria and reveal potential therapeutic targets for the treatment of α-synucleinopathies.

ID: 38907103
Title: Single-nucleus sequencing reveals enriched expression of genetic risk factors in extratelencephalic neurons sensitive to degeneration in ALS.
Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by a progressive loss of motor function linked to degenerating extratelencephalic neurons/Betz cells (ETNs). The reasons why these neurons are selectively affected remain unclear. Here, to understand the unique molecular properties that may sensitize ETNs to ALS, we performed RNA sequencing of 79,169 single nuclei from cortices of patients and controls. In both patients and unaffected individuals, we found significantly higher expression of ALS risk genes in THY1+ ETNs, regardless of diagnosis. In patients, this was accompanied by the induction of genes involved in protein homeostasis and stress responses that were significantly induced in a wide collection of ETNs. Examination of oligodendroglial and microglial nuclei revealed patient-specific downregulation of myelinating genes in oligodendrocytes and upregulation of an endolysosomal reactive state in microglia. Our findings suggest that selective vulnerability of extratelencephalic neurons is partly connected to their intrinsic molecular properties sensitizing them to genetics and mechanisms of degeneration.

ID: 39080331
Title: Investigating copy number variants in schizophrenia pedigrees using a new consensus pipeline called PECAN.
Abstract: Copy number variants (CNVs) have been implicated in many human diseases, including psychiatric disorders. Whole genome sequencing offers advantages in CNV calling compared to previous array-based methods. Here we present a robust and transparent CNV calling pipeline, PECAN (PEdigree Copy number vAriaNt calling), for short-read, whole genome sequencing data, comprised of a novel combination of four calling methods and structural variant genotyping. This method is scalable and can incorporate pedigree information to retain lower-confidence CNVs that would otherwise be discarded. We have robustly benchmarked PECAN using gold-standard CNV calls for two well-established evaluation samples, NA12878 and HG002, showing that PECAN performs with high precision and recall on both datasets, outperforming another pedigree-based CNV calling pipeline. As part of this work, we provide a list of high-confidence gold standard CNVs for the NA12878 reference sample, curated from multiple studies. We applied PECAN to a collection of pedigrees multiply affected with schizophrenia and identified a rare deletion that perfectly co-segregates with schizophrenia in one of the pedigrees. The CNV overlaps the gene PITRM1, which has been implicated in a complex phenotype including ataxia, developmental delay, and schizophrenia-like episodes in affected adults.

ID: 39557152
Title: Mitochondrial DAMPs: Key mediators in neuroinflammation and neurodegenerative disease pathogenesis.
Abstract: Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) are increasingly linked to mitochondrial dysfunction and neuroinflammation. Central to this link are mitochondrial damage-associated molecular patterns (mtDAMPs), including mitochondrial DNA, ATP, and reactive oxygen species, released during mitochondrial stress or damage. These mtDAMPs activate inflammatory pathways, such as the NLRP3 inflammasome and cGAS-STING, contributing to the progression of neurodegenerative diseases. This review delves into the mechanisms by which mtDAMPs drive neuroinflammation and discusses potential therapeutic strategies targeting these pathways to mitigate neurodegeneration. Additionally, it explores the cross-talk between mitochondria and the immune system, highlighting the complex interplay that exacerbates neuronal damage. Understanding the role of mtDAMPs could pave the way for novel treatments aimed at modulating neuroinflammation and slowing disease progression, ultimately improving patient outcome.

ID: 39617881
Title: Dysregulation of protein degradation and alteration of secretome in α-synuclein-exposed astrocytes: implications for dopaminergic neuronal dysfunction.
Abstract: A key factor in the propagation of α-synuclein pathology is the compromised protein quality control system. Variations in membrane association and astrocytic uptake between different α-synuclein forms suggest differences in exocytosis or membrane cleavage, potentially impacting the secretome's influence on dopaminergic neurons. We aimed to understand differences in protein degradation mechanisms of astrocytes for both wild-type (WT) and mutant forms of α-synuclein, specifically during periods of reduced degradation efficiency. We also investigated α-synuclein release into the secretome and its effects on healthy dopaminergic neurons. Cellular models used were rat primary astrocytes alongside hiPSC-derived astrocytes, whose impact on rat primary dopaminergic neurons and the human SH-SY5Y cell line was investigated. We examined the release and accumulation of α-synuclein resulting from impaired degradatory pathways, including matrix metalloprotease-MMP9, the ubiquitin proteasomal pathway-UPS, and the autophagy-lysosomal pathway-ALP, using immunocytochemical analysis and flow cytometry. Additionally, we explored the effect of astrocytic secretome on dopaminergic-neuronal survival, neurite collapse and function. At early stages, astrocytes were able to deal efficiently with monomeric α-synuclein (via UPS), and larger aggregates (through MMP9 and autophagy), clearing extracellular α-synuclein and maintaining neuronal health. However, extended exposure to extracellular monomeric and aggregated α-synuclein compromised their proteasomal activity, inhibiting MMP9 and destabilizing autophagy, transforming astrocytes from protectors to promoters of neurodegeneration. This study is the first to elucidate the astrocytes' preferred degradation pathways for both monomeric and aggregated forms of α-synuclein, along with the subsequent effects of these payloads on the cellular degradation machinery. The astrocytic transformation is characterized by α-synuclein expulsion, increased release of inflammatory cytokines, and diminished secretion of growth factors leading to dopaminergic neuronal apoptosis and dysfunction, particularly neurite collapse, intracellular Ca2+ response and vesicular dopamine release. The presence of phosphorylated and nitrated α-synuclein species in astrocytes also suggests their potential involvement in modifying both forms of the protein. The initial protective action of astrocytes in clearing and degrading extracellular α-synuclein is severely compromised at latter stages, leading to astrocytic dysfunction and impairing neuron-glia cross-talk. This study underscores the criticality of integrating astrocytes into treatment paradigms in synucleinopathies.

ID: 39708673
Title: Vaccination with formulations targeting Eimeria maxima and Clostridium perfringens conferred comprehensive protection using a dual-infection challenge model of necrotic enteritis.
Abstract: With increasing regulations restricting antibiotic use in animal feed, the need for alternative strategies to prevent and manage necrotic enteritis (NE) has become imperative. As a result, developing effective vaccines has emerged as a top priority for broiler chicken health management. Coccidial infections are a well-established predisposing factor for NE, underscoring the importance of controlling coccidiosis to help mitigate NE outbreaks. This research aimed to investigate the protective efficacy of vaccine preparations containing Eimeria maxima elongation factor-1α and a multicomponent antigen cocktail of Clostridium perfringens, including a single collagen adhesion protein (CpCna) and two chimeric proteins: CpNA (NetB-Alpha-toxin) and CpFZ (Fructose-1,6-bisphosphate aldolase-Zinc metalloprotease). Two vaccine preparations-recombinant subunit vaccines and DNA vaccines-were developed to assess their immunoprotective effects, determined by relative body weight gain rate, lesion scores, survival rates, and antigen-specific IgY levels using a dual-infection NE challenge model involving E. maxima and C. perfringens. Broilers were administered two subcutaneous immunizations with either adjuvanted proteins or eukaryotic expression plasmids on Days 7 and 17. Chickens vaccinated with the five antigens exhibited significantly higher serum antigen-specific IgY levels, improved weight gains, zero mortality, and reduced lesion scores following the lethal dual-infection challenge. These results indicated that vaccine preparations targeting both C. perfringens and E. maxima represent a promising approach for controlling and preventing coccidiosis-induced NE in chickens.

ID: 39744160
Title: Exploiting Mitochondria by Triggering a Faulty Unfolded Protein Response Leads to Effective Cardioprotection.
Abstract: This study investigates the role of Fundc1 in cardiac protection under high-altitude hypoxic conditions and elucidates its underlying molecular mechanisms. Using cardiomyocyte-specific Fundc1 knockout (Fundc1CKO ) mice, we demonstrated that Fundc1 deficiency exacerbates cardiac dysfunction under simulated high-altitude hypoxia, manifesting as impaired systolic and diastolic function. Mechanistically, we identified that Fundc1 regulates cardiac function through the mitochondrial unfolded protein response (mito-UPR) pathway. Fundc1 deficiency led to significant downregulation of multiple mito-UPR-related factors, including ATF5, Chop, and PITRM1. Further investigation revealed that Fundc1 deficiency results in increased cardiomyocyte apoptosis, calcium dysregulation, reduced cell viability, and impaired mitochondrial function, characterized by decreased ATP production, reduced membrane potential, and increased ROS production. Notably, activation of mito-UPR with oligomycin significantly ameliorated these cardiac abnormalities in Fundc1-deficient mice. We identified ATF5 as a key downstream effector of Fundc1, as ATF5 overexpression effectively reversed cardiac dysfunction and restored mito-UPR-related gene expression in Fundc1-deficient hearts. Additionally, we discovered that Fundc1-mediated cardioprotection involves regulation of mitophagy, where its activation improved cardiac function and mitochondrial homeostasis in Fundc1-deficient mice. Our findings reveal a novel Fundc1-ATF5-mito-UPR axis in cardioprotection against high-altitude hypoxia and highlight the crucial role of mitophagy in this protective mechanism, providing new insights into potential therapeutic strategies for high-altitude heart disease.

ID: 39934413
Title: Poldip2 promotes mtDNA elimination during Drosophila spermatogenesis to ensure maternal inheritance.
Abstract: Maternal inheritance of mitochondrial DNA (mtDNA) is highly conserved in metazoans. While many species eliminate paternal mtDNA during late sperm development to foster maternal inheritance, the regulatory mechanisms governing this process remain elusive. Through a forward genetic screen in Drosophila, we identified 47 mutant lines exhibiting substantial retention of mtDNA in mature sperm. We mapped one line to poldip2, a gene predominantly expressed in the testis. Disruption of poldip2 led to substantial mtDNA retention in mature sperm and subsequent paternal transmission to progeny. Further investigation via imaging, biochemical analyses and ChIP assays revealed that Poldip2 is a mitochondrial matrix protein capable of binding mtDNA. Moreover, we showed that ClpX, the key component of a major mitochondrial protease, interacts with Poldip2 to co-regulate mtDNA elimination in Drosophila spermatids. This study sheds light on the mechanisms underlying mtDNA removal during spermatogenesis and underscores the pivotal role of this process in safeguarding maternal inheritance.

ID: 39984111
Title: The prolyl oligopeptidase and α-synuclein connection revisited.
Abstract: The aim of this work was to revisit the connection between prolyl oligopeptidase (PREP) and α-synuclein (aSyn) by presenting novel data from cell free and cellular assays and to discuss the results in a contemporary context. The aSyn aggregation process was studied using fluorescence correlation spectroscopy and thioflavin-T fluorescence. Binding sites for PREP on the aSyn sequence were determined using peptide arrays. Subcellular localisation of PREP and stress markers were studied using double staining immunofluorescence microscopy in SH-SY5Y cells with and without overexpression of aSyn and PREP, before and after differentiation, and with or without proteolytic stress induced by proteasome inhibition. The interaction between PREP and aSyn was found to be weak and transient. It promotes the early phases of aggregation but does not affect the rate of β-fibril formation. Moreover, this interaction is not dependent upon the C-terminal prolines of aSyn, but is affected by PREP inhibitors and interferes with PREP substrate binding. Although present in the same cellular compartments, there is little evidence for a strong physical association of PREP with aggresomes and stress markers. Instead, there is colocalization with aSyn in the cell periphery and neurites. There is evidence for a binding site for peptides much longer than the usual PREP substrates. The modular assembly of molecular machines and the observation that PREP's protein-protein interactions are tuneable by active site inhibitors, lead to the hypothesis that this binding site features in the cross-talk between autophagy and neuron-specific pathways involving vesicle transport and protein secretion.

ID: 40019378
Title: Accumulation of Damaging Lipids in the Arf1-Ablated Neurons Promotes Neurodegeneration through Releasing mtDNA and Activating Inflammatory Pathways in Microglia.
Abstract: Lipid metabolism disorders in both neurons and glial cells have been found in neurodegenerative (ND) patients and animal models. However, the pathological connection between lipid droplets and NDs remains poorly understood. The recent work has highlighted the utility of a neuron-specific Arf1-knockout mouse model and corresponding cells for elucidating the nexus between lipid metabolism disorders and amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). In this study, it is found that Arf1 deficiency first induced surplus fatty acid synthesis through the AKT-mTORC1-SREBP1-FASN axis, which further triggered endoplasmic reticulum (ER)-mitochondrial stress cascade via calcium flux. The organelle stress cascade further caused mitochondrial DNA (mtDNA) to be released into cytoplasm. Concurrently, the FASN-driven fatty acid synthesis in the Arf1-deficient neurons might also induce accumulation of sphingolipids in lysosomes that caused dysfunction of autophagy and lysosomes, which further promoted lysosomal stress and mitochondria-derived extracellular vesicles (MDEVs) release. The released MDEVs carried mtDNA into microglia to activate the inflammatory pathways and neurodegeneration. The studies on neuronal lipid droplets (LDs) and recent studies of microglial LDs suggest a unified pathological function of LDs in NDs: activating the inflammatory pathways in microglia. This finding potentially provides new therapeutic strategies for NDs.

ID: 40081988
Title: The late-onset Alzheimer's disease risk factor RHBDF2 is a modifier of microglial TREM2 proteolysis.
Abstract: The cell surface receptor TREM2 is a key genetic risk factor and drug target in Alzheimer's disease (AD). In the brain, TREM2 is expressed in microglia, where it undergoes proteolytic cleavage, linked to AD risk, but the responsible protease in microglia is still unknown. Another microglial-expressed AD risk factor is catalytically inactive rhomboid 2 (iRhom2, RHBDF2), which binds to and acts as a non-catalytic subunit of the metalloprotease ADAM17. A potential role in TREM2 proteolysis is not yet known. Using microglial-like BV2 cells, bone marrow-derived macrophages, and primary murine microglia, we identify iRhom2 as a modifier of ADAM17-mediated TREM2 shedding. Loss of iRhom2 increased TREM2 in cell lysates and at the cell surface and enhanced TREM2 signaling and microglial phagocytosis of the amyloid β-peptide (Aβ). This study establishes ADAM17 as a physiological TREM2 protease in microglia and suggests iRhom2 as a potential drug target for modulating TREM2 proteolysis in AD.

ID: 40125820
Title: Clioquinol induces mitochondrial toxicity in SH-SY5Y neuroblastoma cells by affecting the respiratory chain complex IV and OPA1 dynamin-like GTPase.
Abstract: Clioquinol has been thought of as the causative drug of subacute myelo-optic neuropathy (SMON). The underlying mechanisms of clioquinol toxicity, however, have not been elucidated in detail. Here, we revealed that clioquinol (20 μm) suppressed the expression of SCO1 and SCO2 copper chaperones for mitochondrial respiratory chain Complex IV (cytochrome c oxidase) in SH-SY5Y neuroblastoma cells. The assembly of Complex IV components and Complex IV activity were suppressed in clioquinol-treated cells. Clioquinol (10-50 μm) decreased cellular ATP levels in glucose-free media. Clioquinol (10-50 μm) induced OMA1 mitochondrial protease-dependent degradation of the dynamin-related GTPase OPA1 and suppressed the expression of CHCHD10 and CHCHD2 involved in the maintenance of cristae structure. These results suggest that mitochondrial toxicity is one of the mechanisms of clioquinol-induced neuronal cell death.

ID: 40339440
Title: Curcumin induces IL-6 receptor shedding via the ADAM10 proteinase.
Abstract: Proteolytic cleavage and release of single-spanning transmembrane receptors, a process called shedding, is vital for normal physiological functions and pathological responses, including inflammation and cancer. Interleukin-6 receptor (IL-6R) is one of the principal single-spanning transmembrane receptors expressed in hepatocytes and subpopulations of leukocytes, including monocytes and macrophages. Soluble IL-6R (sIL-6R) is also present in human plasma. Herein, we report that membrane-modulating agents including curcumin, enhance IL-6R shedding in human monocytes via a mechanism involving a disintegrin and metalloprotease 10 (ADAM10). Furthermore, amphiphilic derivatives of turmeric curcuminoids increased sIL-6R levels in culture supernatants and altered the membrane domains formed on giant vesicles. These findings offer insights into the mechanism underlying the induction of ectodomain cleavage of IL-6R and ascertain the function of liberated sIL-6R. They can provide a novel strategy to develop therapeutic intervention using membrane-active compounds, such as curcuminoids, for diseases such as inflammation and cancer.

ID: 40523161
Title: Clinical Validation of ADAM9 as a Prognostic Biomarker in Oral Cancer.
Abstract: Oral cancer has a high incidence in Taiwan, and identifying prognostic biomarkers is crucial. This study investigated the role of a disintegrin and metalloprotease 9 (ADAM9) in oral cancer progression and outcomes. This study investigated ADAM9 protein expression in 353 oral cancer tissue specimens through immunohistochemical (IHC) analysis. The analysis revealed that, among the 353 patients, 21 (6%) exhibited low ADAM9 expression, while the remaining 332 patients (94%) showed high ADAM9 expression, which correlated with advanced T status, poor overall survival, and unfavorable prognosis. Kaplan-Meier analysis confirmed that higher ADAM9 expression predicted significantly worse survival. Univariate and multivariate analyses identified ADAM9, histological grade, and AJCC stage as independent prognostic factors. Functionally, ADAM9 silencing in SAS and OC2 cells inhibited invasion and migration, downregulating matrix metalloproteinase 9 (MMP9) and matrix metalloproteinase 14 (MMP14). siRNA-mediated ADAM9 knockdown also reduced cell viability and migration, as confirmed by cell counting kit-8 and transwell assays. The Cancer Genome Atlas (TCGA) analysis further revealed a positive correlation between ADAM9 mRNA levels and matrix metalloproteinase 2 (MMP2) or MMP14 expression in oral cancer patients. This study identifies ADAM9 as a key driver of oral cancer in a Taiwanese cohort and highlights its diagnostic and therapeutic potential.

ID: 40868276
Title: Systemic Neurodegeneration and Brain Aging: Multi-Omics Disintegration, Proteostatic Collapse, and Network Failure Across the CNS.
Abstract: Neurodegeneration is increasingly recognized not as a linear trajectory of protein accumulation, but as a multidimensional collapse of biological organization-spanning intracellular signaling, transcriptional identity, proteostatic integrity, organelle communication, and network-level computation. This review intends to synthesize emerging frameworks that reposition neurodegenerative diseases (ND) as progressive breakdowns of interpretive cellular logic, rather than mere terminal consequences of protein aggregation or synaptic attrition. The discussion aims to provide a detailed mapping of how critical signaling pathways-including PI3K-AKT-mTOR, MAPK, Wnt/β-catenin, and integrated stress response cascades-undergo spatial and temporal disintegration. Special attention is directed toward the roles of RNA-binding proteins (e.g., TDP-43, FUS, ELAVL2), m6A epitranscriptomic modifiers (METTL3, YTHDF1, IGF2BP1), and non-canonical post-translational modifications (SUMOylation, crotonylation) in disrupting translation fidelity, proteostasis, and subcellular targeting. At the organelle level, the review seeks to highlight how the failure of ribosome-associated quality control (RQC), autophagosome-lysosome fusion machinery (STX17, SNAP29), and mitochondrial import/export systems (TIM/TOM complexes) generates cumulative stress and impairs neuronal triage. These dysfunctions are compounded by mitochondrial protease overload (LONP1, CLPP), UPR maladaptation, and phase-transitioned stress granules that sequester nucleocytoplasmic transport proteins and ribosomal subunits, especially in ALS and FTD contexts. Synaptic disassembly is treated not only as a downstream event, but as an early tipping point, driven by impaired PSD scaffolding, aberrant endosomal recycling (Rab5, Rab11), complement-mediated pruning (C1q/C3-CR3 axis), and excitatory-inhibitory imbalance linked to parvalbumin interneuron decay. Using insights from single-cell and spatial transcriptomics, the review illustrates how regional vulnerability to proteostatic and metabolic stress converges with signaling noise to produce entropic attractor collapse within core networks such as the DMN, SN, and FPCN. By framing neurodegeneration as an active loss of cellular and network "meaning-making"-a collapse of coordinated signal interpretation, triage prioritization, and adaptive response-the review aims to support a more integrative conceptual model. In this context, therapeutic direction may shift from damage containment toward restoring high-dimensional neuronal agency, via strategies that include the following elements: reprogrammable proteome-targeting agents (e.g., PROTACs), engineered autophagy adaptors, CRISPR-based BDNF enhancers, mitochondrial gatekeeping stabilizers, and glial-exosome neuroengineering. This synthesis intends to offer a translational scaffold for viewing neurodegeneration as not only a disorder of accumulation but as a systems-level failure of cellular reasoning-a perspective that may inform future efforts in resilience-based intervention and precision neurorestoration.

ID: 40870005
Title: Dual Nature of Mitochondrial Integrated Stress Response: Molecular Switches from Protection to Pathology.
Abstract: The mitochondrial integrated stress response (ISR) represents a fundamental cellular adaptation mechanism with dual protective and pathological roles. We critically analyzed current literature on ISR mechanisms, focusing on recent paradigm shifts including the 2020 discovery of the OMA1-DELE1-HRI axis, emerging controversies over context-dependent activation patterns, and the January 2025 clinical trial failures that have reshaped the therapeutic landscape. We reviewed recent literature (2020-2025) examining ISR mechanisms, clinical trials, and therapeutic developments through comprehensive database searches. The field has evolved from simple linear pathway models to recognition of complex, context-dependent networks. Recent findings reveal that ISR activation mechanisms vary dramatically based on cellular metabolic state, with distinct pathways operating in proliferating versus differentiated cells. The "dark microglia" phenotype in neurodegeneration and DR5-mediated apoptotic switches exemplify pathological ISR manifestations, while adaptive responses include metabolic reprogramming and quality control enhancement. The 2025 failures of DNL343 and ABBV-CLS-7262 in ALS trials underscore the need for precision medicine approaches that account for context-dependent ISR functions, temporal dynamics, and disease-specific mechanisms.

ID: 40896259
Title: ADAM17 Inhibition Protects Cognition in Intermittent Hypoxia: The Role of TREM2.
Abstract: The triggering receptor expressed on myeloid cells 2 (TREM2) is a new therapeutic target in Alzheimer's disease. However, its role in obstructive sleep apnea (OSA)-related cognitive impairment is still unclear. This study aimed to investigate the effect and regulatory mechanism of TREM2 on cognitive impairment related to OSA. Since intermittent hypoxia (IH) is the primary pathophysiologic characteristic of OSA, we conducted IH animal and BV2 cell model to investigate the mechanism. Trem2 knockdown and Trem2 overexpression cells were created by Lentivirus transfection. A disintegrin and metalloprotease 17 (ADAM17) is the primary enzyme for TREM2 shedding, we used TAPI-1 to inhibit its activity. Morris water maze, Nissl staining, real-time PCR, immunofluorescence, Western blotting, fluorometric assay kit, and enzyme-linked immunosorbent assay were used to explore the molecular mechanism. The TREM2 levels were decreased in BV2 cells exposed to IH for 24 hours. IH elevated the levels of IL-1β, TNF-α and CD86 in BV2 cells, as well as the levels of p-Tau in conditioned media-cultured HT-22 cells. Conversely, IH reduced the levels of IL-10 and CD206 in BV2 cells. However, these effects were exacerbated in BV2 cells with Trem2 knockdown, whereas they were mitigated in those with Trem2 overexpression. Additionally, the ADAM17 activity and soluble TREM2 (sTREM2) levels were increased in BV2 cells subjected to IH. Treatment with TAPI-1, suppressed ADAM17 activity and restored TREM2 expression both in vitro and in vivo. Inhibition of ADAM17 led to a reduction in the expression of CD86, IL-1β, TNF-α and p-Tau levels, while enhancing the expression of CD206, IL10 and cognitive functions. TREM2 played a protective role in IH-induced neuroinflammation and neuronal injury by promoting microglia M2 polarization. IH caused excessive activation of ADAM17 and resulted in augmented degradation of TREM2. Restoring TREM2 expression by inhibiting ADAM17 indicates a potentially promising therapeutic strategy for cognitive impairment in OSA.

ID: 41009700
Title: An Expendable Player in Positive Vascular Remodeling? ADAMTS13 Deficiency Does Not Affect Arteriogenesis or Angiogenesis.
Abstract: Peripheral artery disease is a common manifestation of atherosclerosis, characterized by insufficient tissue perfusion and chronic ischemia. Arteriogenesis and angiogenesis are essential endogenous mechanisms to restore blood flow and limit ischemic injury. The metalloprotease ADAMTS13, known for cleaving ultra-large von Willebrand factor, has been implicated in thrombotic and inflammatory regulation. However, its role in ischemic vascular remodeling remains unclear. Using a murine hind limb ischemia model, we investigated the effect of ADAMTS13 deficiency on arteriogenesis and angiogenesis by comparing male ADAMTS13-/- and wild-type control mice. Perfusion recovery, vascular cell proliferation, immune cell infiltration, and thrombotic activity were evaluated using laser Doppler measurements, immunohistochemical analysis of adductor and gastrocnemius muscle tissues, and in vivo microscopy. ADAMTS13 deficiency did not impair perfusion recovery, collateral artery growth, or capillarization. While platelet adhesion was slightly increased in ADAMTS13-/- mice, no thrombotic occlusions were observed. Inflammatory responses, including macrophage and neutrophil infiltration as well as macrophage polarization, were largely unaffected. Despite previous in vitro evidence indicating an angiogenic role for ADAMTS13, its absence did not compromise angiogenesis in vivo. Our findings suggest that ADAMTS13 does not play a critical role in ischemia-related angiogenesis and arteriogenesis under sterile conditions and may be relevant only in contexts involving acute and sufficiently strong thromboinflammatory stimuli.

ID: 41106721
Title: KDM6A/MMP-3 epigenetic axis governs macrophage senescence after spinal cord injury for mediating the regenerative niche to promote neurological repair.
Abstract: Spinal cord injury (SCI) stands as the primary cause of disability, still lacking a clear pathogenesis and effective treatment. The role of macrophages is particularly unclear in SCI, especially regarding cellular senescence. Additionally, the mechanisms driving macrophage senescence after SCI, the release of senescence-associated secretory phenotype (SASP) factors that affect the regenerative niche, and their contributions to SCI progression remain elusive. To investigate the role and underlying mechanism of Ubiquitously transcribed Tetratricopeptide repeat, X chromosome (UTX) in regulating macrophage senescence following SCI. A contusive SCI model was constructed to explore the presence of senescent macrophages. After screening for UTX by a PCR array, conditioned knockout UTX mice (LysM-Cre; UTXflox/flox) was constructed to explore the effect of UTX on macrophage senescence to influence angiogenesis and neurological function. Furthermore, RNA-seq and ChIP-seq were carried out to screen the downstream target gene Matrix Metalloprotease-3 (MMP-3). At last, RNA-seq was performed to explore the effect of MMP-3 on endothelial cells in vitro. An elevated presence of lysine demethylase 6A (KDM6A/UTX), a special epigenetic regulatory modifier, was observed in macrophage senescence after SCI. Conditional deletion of UTX not only prevented macrophage senescence, but also enhanced the formation of a regenerative niche that protected endothelial cells from senescence and improved their proliferation. Mechanistically, UTX epigenetically regulated MMP-3 transcription through demethylating histone H3 lysine di/trimethylation (H3K27me2/3) at its promoter region. This led to senescent macrophages releasing MMP-3, a key SASP factor that disrupts the local microenvironment and impairs spinal cord repair post-injury. Notably, MMP-3 could act as a pro-senescent agent by senescent macrophages to propagate cellular senescence in endothelial cells (ECs), exacerbating cellular senescence in the injured region. Our findings elucidate the KDM6A/MMP-3 epigenetic regulatory axis, which governs macrophage senescence and creates an inhibitory microenvironment for regeneration after SCI. Targeting this pathway promotes angiogenesis and facilitates neural repair, highlighting its potential as a therapeutic target for improving functional recovery after SCI.

ID: 41377971
Title: Distributional genetic effects reveal context-dependent molecular regulation in human brain aging and Alzheimer's disease.
Abstract: Molecular QTL studies quantify whether genetic variants affect molecular traits, but non-linear effects including distributional patterns, variance, and interactions provide mechanistic insights beyond mean-level associations. Methods for detecting distributional effects have been developed for eQTL analysis, yet applications have focused on method demonstrations rather than large-scale biological discovery. We comprehensively mapped quantile, variance, and interaction QTLs across 34 data-set from 22 molecular contexts in >2,300 human brain donors, revealing that 48.7% of quantile QTLs (qQTLs) exhibit context-dependent regulation invisible to linear models, with enrichment at phenotypic extremes and in cell-type-specific regulatory elements, chromatin accessibility regions, and long-range chromosomal contacts. qQTL variants explained additional trait heritability beyond linear QTLs for brain-related traits. At Alzheimer's disease (AD) risk loci, qQTL analysis revealed complex regulatory architecture including variance effects at PITRM1, lower-quantile-specific effects at TMEM106B partially explained by APOE ε4 interactions, and coordinated epigenetic regulation at loci harboring CHRNE/SCIMP/RABEP1. Quantile-based transcriptome-wide association studies identified 34 AD risk genes and additional aging-related genes beyond standard TWAS, with enrichment in immune regulation and telomere maintenance pathways where distributional effects may reflect threshold-dependent mechanisms. Our non-linear QTL atlas and qTWAS resource enable characterization of context-dependent regulatory effects in complex disease genetics.

ID: 41430713
Title: Disrupting α-Synuclein-ClpP interaction restores mitochondrial function and attenuates neuropathology in Parkinson's disease models.
Abstract: Mitochondrial dysfunction and α-Synuclein (αSyn) aggregation are defining features of Parkinson's disease (PD), yet the mechanistic link between them remains poorly understood. Although our previous findings suggest that the interaction between αSyn and ClpP (a mitochondrial matrix protease) contributes to PD progression, the pathogenic and therapeutic relevance of this interaction remains elusive. We employed biochemical and cell biological approaches to investigate how αSyn and ClpP are mutually regulated. Additionally, we determined the pathogenic impact of αSyn-ClpP interaction by using decoy peptide CS2 in αSyn-PFF inoculated primary neurons, PD patient iPSC-derived dopaminergic neurons, and a transgenic mouse model of PD carrying αSyn-A53T mutation. We identified mitochondrial protease ClpP as a key regulator of αSyn pathology. We show that αSyn interacts with ClpP through its non-amyloid-β component (NAC) domain, leading to impaired ClpP activity and mitochondrial proteotoxic stress. ClpP, in turn, negatively regulates αSyn aggregation and propagation by stabilizing its native tetrameric form. To interrupt this pathogenic interaction, we developed a decoy peptide, CS2, which binds the NAC domain of αSyn and restores ClpP function. CS2 treatment reduced mitochondrial oxidative stress and αSyn neurotoxicity in neuronal cultures, primary cortical neurons inoculated with αSyn preformed fibrils, and dopaminergic neurons derived from PD patient iPSCs. In mThy1-hSNCA transgenic mice, subcutaneous administration of CS2 restored ClpP levels, decreased αSyn pathology and neuroinflammation, and improved both cognitive and motor function. These findings highlight the αSyn-ClpP interaction as a druggable target and support CS2 as a potential disease-modifying therapy for PD and related synucleinopathies.

ID: 41572998
Title: A novel compound heterozygous mutation in ADAMTS17 identified in a Chinese family with Weill-Marchesani syndrome.
Abstract: To investigate the genetic basis of Weill-Marchesani syndrome (WMS) in a Chinese family and clarify the pathogenic mechanism of novel ADAMTS17 mutations. Comprehensive clinical assessments and genetic analyses were performed on a Chinese family with two affected siblings. Whole-exome sequencing (WES) was conducted for the proband and other family members. Bioinformatics tools were used to evaluate the conservation, predicted pathogenicity, and structural effects of the identified ADAMTS17 variants. In addition, protein structure modeling was applied to assess the functional impacts of the mutations. The proband (a 32-year-old male) and his elder sister (42y) presented typical clinical features of WMS, including short stature, brachydactyly, high myopia, ectopia lentis, and secondary glaucoma. WES identified a novel compound heterozygous mutation in ADAMTS17: a splicing mutation (c.451-2A>G) inherited from the father and a missense mutation (c.1043G>A; p.C348Y) inherited from the mother. The splicing mutation disrupted normal mRNA splicing and processing, leading to premature translation termination. The missense mutation, which is located in the metalloprotease catalytic domain, was predicted to abolish a critical disulfide bond, thereby impairing protein stability. Both mutations exhibited high evolutionary conservation and were predicted to be pathogenic by multiple bioinformatics algorithms. A novel compound heterozygous mutation in ADAMTS17 is identified in this WMS-affected Chinese family, and its pathogenicity is verified via bioinformatics analysis and protein structural modeling. These findings are expected to facilitate the genetic diagnosis of WMS and deepen the understanding of its molecular pathogenesis.

ID: 41610845
Title: A type I interferon-mitochondrial axis regulates efferocytosis and interferon-stimulated gene induction in macrophages.
Abstract: Macrophage metabolism is intricately linked to cellular function. Contrasting with Toll-like receptor (TLR) stimulation, cytosolic nucleic acid sensing induced a decrease in mitochondrial membrane potential (MMP) while maintaining mitochondrial respiration. Interferon α/β (IFN-I) receptor (IFNAR) signaling was necessary and sufficient for this metabolic response. IFNAR signaling induced interferon-stimulated gene 15 (ISG15) expression and ISGylation of mitochondrial proteins, including subunits of mitochondrial complex V, increasing ATP production and decreasing MMP, thus enhancing macrophage efferocytic capacity. Moreover, the IFNAR-ISG15-mediated drop in MMP activated the mitochondrial protease OMA1, inducing mitochondrial fission and decreasing endoplasmic reticulum-mitochondria communication, thus dampening IFN-stimulated gene (ISG) induction. Loss of ISG15 or OMA1 enhanced histone acetylation and ISG induction upon IFN-I stimulation, in a manner dependent on mitochondrial calcium uptake. This increase in ISG induction provided protection against acute viral infections. These data indicate that IFNAR-ISG15 signaling boosts efferocytosis while limiting ISG induction, thereby promoting the resolution of inflammation.

ID: 41666516
Title: iRhom2 deletion protects against diabetic neuropathy by suppressing neuroinflammation.
Abstract: Diabetic peripheral neuropathy (DPN) is a major complication of diabetes, characterized by progressive nerve damage and debilitating pain. Neuroinflammation plays a critical role in its pathogenesis, but therapeutic options remain limited. A disintegrin and metalloprotease 17 (ADAM17) regulates inflammatory signaling, but its ubiquitous expression makes it a difficult target. This study examined the role of inactive rhomboid protein 2 (iRhom2), a cofactor essential for ADAM17 activation, in the development of DPN. Diabetes was induced in wild-type (WT) and iRhom2 knockout (KO) mice using streptozotocin. Both groups developed hyperglycemia (>300 mg/dL); however, only WT mice exhibited significant mechanical and thermal hyposensitivity, characteristic of DPN. iRhom2 KO mice were protected from these deficits, suggesting a glucose-independent protective mechanism. In sciatic nerves of diabetic WT mice, expression of ADAM17, iRhom2, and tumor necrosis factor-α increased by 5.3-, 7.7-, and 48-fold, respectively; these changes were attenuated in KO mice. Histological analysis showed preservation of nerve fiber structure and reduced inflammatory infiltration in diabetic iRhom2 KOs. In cultured human microglial cells, high glucose triggered oxidative stress and induction of inflammatory mediators, including cyclooxygenase-2, interleukin-6, interleukin-8, tumor necrosis factor-α, and monocyte chemoattractant protein-1. Silencing of iRhom2 reduced these responses. These findings identify iRhom2 as a critical mediator of diabetic neuropathy, acting by regulating neuroinflammation. Deletion of iRhom2 confers glucose-independent protection against neuropathic pain, highlighting iRhom2 as a promising therapeutic target for preventing or treating DPN. SIGNIFICANCE STATEMENT: This study identifies iRhom2 as a key mediator of diabetic peripheral neuropathy by driving neuroinflammation and oxidative stress. Deletion of iRhom2 provided protection against neuropathic changes, without altering glucose levels, revealing a glucose-independent mechanism. These findings establish iRhom2 as a promising therapeutic target, offering new translational opportunities to prevent or treat diabetic neuropathy.

ID: 41760807
Title: Stress adaptation of mitochondrial protein import by OMA1-mediated degradation of DNAJC15.
Abstract: Mitochondria dynamically adapt to cellular stress to ensure cell survival. The stress-regulated mitochondrial peptidase OMA1 orchestrates these adaptive responses, which limit mitochondrial fusion and promote mitochondrial stress signaling and metabolic rewiring. Here, we show that cellular stress adaptation involves OMA1-mediated regulation of mitochondrial protein import and OXPHOS biogenesis. OMA1 cleaves the mitochondrial chaperone DNAJC15 and promotes its degradation by the m-AAA protease AFG3L2. Loss of DNAJC15 impairs mitochondrial protein import and restricts OXPHOS biogenesis under conditions of mitochondrial dysfunction. Non-imported mitochondrial preproteins accumulate at the endoplasmic reticulum, inducing an unfolded protein response. Our results demonstrate stress-dependent changes in mitochondrial protein import as part of the OMA1-mediated mitochondrial stress response and highlight the interdependence of proteostasis regulation between different organelles.

ID: 41966055
Title: Genetic contributions to mitochondrial dysfunction in amyotrophic lateral sclerosis etiology.
Abstract: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with multiple genetic causes. Given the strong evidence of mitochondrial dysfunction in ALS, this study aimed to identify genetic contributors to ALS by focusing on genes involved in mitochondrial function. Whole-genome and whole-exome sequencing data from 1,034 individuals with ALS were analyzed using two distinct computational tools, which ranked candidate genes based on functional relevance to ALS. POLG, the sole mitochondrial DNA (mtDNA) polymerase, emerged as a top candidate gene. RNA sequencing (RNA-seq) analysis revealed that among genes upregulated in samples with a POLG variant, there was an enrichment for mitochondrial pathways, including translation, localization, and mitophagy. It also revealed variants in POLG and SOD1, a well-known ALS gene, to be the most enriched in samples with expression profiles of mitochondrial-related genes that differed most from those of unaffected control subjects. POLG variant carriers also exhibited an increased burden of mitochondrial genome variants, a pattern shared by carriers of variants in other genes involved in mtDNA maintenance. Additionally, POLG variant carriers had elevated mtDNA copy number (mtDNA-CN), similar to carriers of variants in mitophagy-related genes, suggesting impaired mitophagy. Together, these findings implicate POLG as an ALS-associated gene and link mtDNA maintenance defects, altered expression of mitochondrial-related pathways, and impaired mitophagy to the ALS etiology.

ID: 42020662
Title: Investigating the role of serum NfL, FGF21, NCAM1 and GDF15 as disease biomarkers for Charcot-Marie-Tooth type 2A.
Abstract: Charcot-Marie-Tooth disease type 2A (CMT2A) is the most common axonal form of inherited peripheral neuropathy, caused by mutations in the mitofusin 2 (MFN2) gene that impair mitochondrial fusion and axonal transport, ultimately leading to progressive neurodegeneration. The identification of accessible molecular biomarkers may improve diagnostic accuracy, enable patient stratification, and support the development and monitoring of emerging therapies. We investigated serum levels of neurofilament light chain (NfL), neural cell adhesion molecule 1 (NCAM1), growth differentiation factor 15 (GDF15), and fibroblast growth factor 21 (FGF21) in CMT2A patients (n = 15), healthy controls (n = 10), and neurological disease controls (n = 16; amyotrophic lateral sclerosis [ALS], n = 10, spinal muscular atrophy type 3 [SMA3], n = 6), evaluating their utility as diagnostic and monitoring biomarkers. In parallel, serum NfL levels were assessed in transgenic Thy1-MFN2*R94Q mice, a validated preclinical model of CMT2A. Serum NfL levels were significantly elevated in CMT2A patients compared to healthy controls, a finding corroborated in transgenic mice. Notably, NfL levels in CMT2A patients were higher than in SMA3 but lower than in ALS patients, supporting the ability of this biomarker to discriminate between clinically overlapping neuromuscular conditions. Higher NfL levels were associated with younger age, earlier disease onset, and shorter disease duration, suggesting a role as a marker of early disease burden. However, no significant correlation was observed with clinical severity scores or electrophysiological measures. Serum FGF21 levels were also significantly elevated in CMT2A patients compared to controls, whereas NCAM1 and GDF15 levels did not differ significantly between groups. These findings support the role of serum NfL as a translational biomarker of axonal damage in CMT2A, capable of distinguishing affected individuals from both healthy and neurological disease controls. The concomitant elevation of FGF21 further underscores the contribution of mitochondrial dysfunction to CMT2A pathophysiology. Together, these results highlight the potential of serum biomarkers to refine diagnostic workflows and facilitate therapeutic development and future clinical trials for CMT2A.

ID: 42059038
Title: Immunomodulatory Effects of Human Breast Milk-Derived Exosomes on Myeloid Cells and Chondrocytes.
Abstract: Human breast milk (HBM) is an ideal nutritional source for the growth and development of infants. In addition, HBM contains hormones, growth factors, microRNAs and exosomes that perform various physiological functions. This study investigates the immunomodulatory effects of HBM-derived exosomes on myeloid cells and chondrocytes, and implications for juvenile idiopathic arthritis. HBM-derived exosomes were isolated and characterized using nanoparticle track analyzer and Western blotting. The HBM-derived exosomes treatment decreased the expression of inflammatory mediators and proinflammatory cytokines in mouse peritoneal macrophages upon lipopolysaccharide stimulation. Flow cytometry analysis of bone marrow-derived macrophages indicated that exosomes promoted M2 polarization, as evidenced by a decrease in cells expressing CD80 (M1 marker) and a concurrent increase in cells expressing M2 marker CD206. In addition, exosome treatment attenuated the mitogen-activated protein kinase signaling pathway by reducing the phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, and IκB-α, thereby reducing the expression of inducible nitric oxide synthase, cyclooxygenase-2, metalloprotease (MMP)-1, MMP-3, and MMP-13 in SW1353 chondrocytes following IL-1β stimulation. These findings suggest that HBM-derived exosomes promote macrophage polarization toward an anti-inflammatory M2 phenotype and exert significant immunomodulatory effects.

ID: 42169138
Title: Tumor-associated protease-activated anti-CD47 antibody precisely maintains phagocytic ability of macrophages with minimal effect on healthy tissue.
Abstract: CD47 is highly expressed on many cancer cells and acts as an innate immune checkpoint. Its binding to signal regulatory protein alpha (SIRPα) on macrophages enables cancer cells to evade phagocytosis. Although anti-CD47 antibody (αCD47 Ab) has been employed to restore phagocytic capacity, the ubiquitous expression of CD47 on normal cells results in significant toxicities during Ab treatment, such as anemia, thrombocytopenia, and sepsis. To mitigate these side effects, we used an autologous hinge region as a spatial-hindrance-based Ab lock and connected it to the N-terminal of the light chain and heavy chain via matrix metalloprotease substrate peptides (i.e., MMP-2) to cover the complementarity-determining regions (CDR) of αCD47 Ab to generate Pro-αCD47 Ab. The Ab lock is selectively removed only in disease regions with overexpressed proteases, thereby reducing the non-selective on-target effect. Our results showed that Pro-αCD47 Ab exhibits a 225.9-fold weaker binding ability compared to parental αCD47 Ab but fully recovers its binding function following MMP-2 treatment. Significantly, Pro-αCD47 Ab exhibits a 100.2-fold and 83.7-fold reduction in binding affinity toward red blood cells and neutrophils, respectively, thereby minimizing the risk of hematological toxicities. Furthermore, in vivo xenograft studies confirmed that Pro-αCD47 Ab achieves dose-dependent and near-complete tumor suppression equivalent to the parental antibody, while maintaining a stable systemic safety profile as evidenced by consistent animal body weight. Besides, it was successfully demonstrated that Pro-αCD47 Ab can be activated by endogenous MMP-2 within clinical tumor specimens, specifically showing promising activation in triple-negative breast cancer (TNBC) samples, thereby restoring its ability to bind CD47. In summary, we developed a protease-activated Pro-αCD47 Ab that avoids the undesired interactions with normal tissues, thereby addressing the most challenging issue limiting clinical efficacy. This advancement may provide patients with better medical care by enhancing therapeutic efficacy and improving overall treatment quality.

ID: 42190894
Title: From protector to perpetrator: The cGAS-STING pathway at the intersection of neurodegeneration and neuroinflammation.
Abstract: The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, a cornerstone of the innate immune system designed to combat pathogens, is now implicated as a critical driver of sterile inflammation in the brain. This review synthesizes compelling evidence that in the aging and diseased central nervous system, endogenous cytosolic DNA, sourced from genomic instability, mitochondrial dysfunction, and activated retrotransposons, hijacks this pathway. Chronic cGAS-STING activation transforms microglia into inflammatory amplifiers, instigates neurotoxic astrocyte programs, and directly compromises neuronal health, creating a self-perpetuating cycle of neuroinflammation. We dissect the cell-type specific consequences within the neurovascular unit and establish the pathway's role in the pathogenesis of ALS/FTD, Alzheimer's, Parkinson's, and Huntington's diseases. Crucially, we evaluate the therapeutic potential of targeting this axis, discussing small-molecule inhibitors, oligonucleotide therapies, and upstream interventions to quell the source of immunogenic DNA. We also explicitly examine contradictory preclinical data, including the retracted PINK1-Parkin-STING report and context-dependent neurovascular findings, to provide a balanced appraisal of STING biology in the CNS. By reconciling its dual protective and pathogenic roles, this review posits cGAS-STING as a pivotal mechanism-based therapeutic node for halting the progression of neurodegenerative disorders.

ID: 42236747
Title: Targeting mitophagy for neuroprotection: mechanisms and therapeutic opportunities.
Abstract: Mitochondria are essential for neuronal energy production, cellular homeostasis, and overall neuronal function. Due to their high metabolic demands and limited regenerative capacity, neurons are particularly vulnerable to mitochondrial dysfunction, which leads to ATP depletion, excessive reactive oxygen species (ROS) production, and calcium imbalance-ultimately causing oxidative stress, metabolic disruption, and neuronal death. Mitophagy is a selective process that removes damaged mitochondria through the autophagy-lysosome pathway. As a key mechanism of mitochondrial quality control, mitophagy preserves energy production, limits oxidative damage, and maintains mitochondrial network integrity. This process is regulated by pathways such as PINK1-Parkin and receptor-mediated mechanisms involving BNIP3 and FUNDC1, all of which help sustain cellular health by preventing mitochondrial dysfunction. Impaired mitophagy is a common feature of several neurodegenerative diseases, including Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS), and Huntington's disease, exacerbating mitochondrial damage and neuronal stress. Emerging therapeutic strategies that target mitophagy-ranging from pharmacological agents and gene therapies to dietary interventions-show promise in restoring mitochondrial quality and protecting neurons from degeneration. Nevertheless, challenges remain in translating these findings into effective clinical treatments. Mitophagy represents a critical mechanism for preserving neuronal integrity and offers a compelling target for innovative therapies against neurodegenerative disorders.

ID: 42302176
Title: Elevated mitochondrial protein import in acute myeloid leukemia increases reliance on mitochondrial protease LONP1.
Abstract: Most mitochondrial proteins are nuclear encoded, translated in the cytosol, and imported into the mitochondria. Through gene expression analysis and functional assays, we demonstrated that mitochondrial protein import is increased in acute myeloid leukemia (AML) cells compared to normal hematopoietic cells. Increased mitochondrial protein import was positively correlated with increased mitochondrial unfolded protein response (UPRmt), a stress activated pathway of mitochondrial proteases and chaperones that maintains protein solubility and prevents the formation of toxic aggregates. The UPRmt protease LONP1 (Lon Peptidase 1) was upregulated in AML and positively correlated with increased mitochondrial protein import and UPRmt. Genetically or chemically inhibiting the LONP1 ATPase domain induced mitochondrial protein aggregation and selectively killed AML cells with high LONP1 expression while sparing AML cells with low LONP1 expression and normal hematopoietic cells in vitro and in vivo. Thus, we uncovered a critical role of the UPRmt protease LONP1 in buffering stress from mitochondrial protein import in AML.

ID: 42321946
Title: Mitochondrial proteases maintain cellular protein homeostasis and tissue integrity.
Abstract: Mitochondrial proteases are essential for mitochondrial protein import and constitute the core of the organelle's intrinsic protein quality control system. However, their physiological functions across tissues, as well as their influence on cytosolic proteostasis, remain incompletely understood. We generated loss- and gain-of-function alleles for 15 conserved mitochondrial proteases in Drosophila melanogaster to systematically dissect their in vivo functions. Disruption of specific proteases caused male sterility or organismal lethality, whereas tissue-specific knockouts in the eye, muscle, or fat body led to mitochondrial protein aggregates, structural defects, and age-dependent degeneration. Loss of UQCR-C1 or Afg3l2 robustly increased mitophagy, while overexpression of several proteases severely impaired muscle integrity. Loss of UQCR-C1, Mppa, or CG11771 promoted HTT72Q aggregation, and reducing UQCR-C1 or Afg3l2 markedly elevated cytosolic HTT72Q levels. Conversely, overexpressing Mppa-but with reduced efficacy in its disease-associated variants-suppressed HTT96Q aggregation and neuronal toxicity. Mppa forms a complex with UQCR-C1 to regulate mitochondrial pre-protein processing and import, indicating that enhancing mitochondrial protein import is sufficient to alleviate cytosolic proteotoxic stress caused by HTT polyglutamine (polyQ) proteins. This work establishes a comprehensive in vivo resource for mitochondrial protease functions and their roles in shaping cytosolic proteostasis.

ID: 42331015
Title: Malnutrition as a Risk Factor for Cerebral and Glaucomatous Neurodegeneration - Mechanisms and Therapeutic Strategies.
Abstract: BACKGROUND: Neurodegenerative diseases are an increasing challenge for healthcare systems in the context of demographic change. They affect the central nervous system, including the brain-manifesting, for example, as dementia-as well as the retina, as seen in glaucoma or age-related macular degeneration. Malnutrition-defined as quantitative or qualitative under- or overnutrition-affects key mechanisms that contribute to neuronal and retinal neurodegeneration. OBJECTIVE: The aim of this study is to systematically present the pathophysiological mechanisms of malnutrition-related neurodegeneration, to evaluate the current evidence on dietary patterns and cognitive health, and to derive practical clinical strategies for nutritional optimization. METHODS: Narrative literature review based on peer-reviewed publications from the fields of nutritional medicine, geriatrics, neurology, ophthalmology, and public health. RESULTS: Malnutrition promotes oxidative stress, mitochondrial dysfunction, chronic neuroinflammation, and vascular dysregulation, and it influences neurotransmitter synthesis. These mechanisms are relevant to both cerebral and ocular neurodegenerative processes. The Mediterranean diet and the MIND diet are associated with a significantly reduced risk of cognitive impairment; for ocular diseases, interventional studies in age-related macular degeneration in particular demonstrate protective effects of antioxidant supplementation, whereas evidence for glaucoma is currently based predominantly on observational data. Screening approaches and micronutrient diagnostics enable early identification of at-risk individuals. Building on this, individualised dietary interventions and targeted supplementation of selected nutrients could be potentially preventive and stabilising therapeutic strategies. CONCLUSION: Malnutrition is a key modifiable risk factor for neurodegenerative diseases of the brain and retina. More intense integration of nutritional diagnostics and therapy into neurological, geriatric, and ophthalmological care structures appears warranted. Neurodegenerative Erkrankungen stellen angesichts des demografischen Wandels eine zunehmende Herausforderung für das Gesundheitswesen dar. Sie betreffen das zentrale Nervensystem, einschließlich des Gehirns, etwa in Form von Demenz, sowie die Retina, wie beim Glaukom oder bei der altersabhängigen Makuladegeneration. Fehlernährung – verstanden als quantitative oder qualitative Unter- bzw. Überversorgung – beeinflusst zentrale Mechanismen, die zur neuronalen und retinalen Neurodegeneration beitragen. Ziel dieser Arbeit ist es, die pathophysiologischen Mechanismen fehlernährungsbedingter Neurodegeneration systematisch darzustellen, die aktuelle Evidenzlage zu Ernährungsmustern und kognitiver Gesundheit zu bewerten sowie praxisnahe klinische Strategien zur Ernährungsoptimierung abzuleiten. Narrative Literaturübersicht basierend auf Publikationen mit Peer-Review-Verfahren aus den Bereichen Ernährungsmedizin, Geriatrie, Neurologie, Ophthalmologie und Public Health. Fehlernährung fördert oxidativen Stress, mitochondriale Dysfunktion, chronische Neuroinflammation sowie vaskuläre Dysregulation und beeinflusst die Neurotransmittersynthese. Diese Mechanismen sind sowohl für zerebrale als auch für okuläre Neurodegenerationsprozesse relevant. Mediterrane Ernährung und MIND-Diät sind mit einem signifikant reduzierten Risiko kognitiver Beeinträchtigung assoziiert; für okuläre Erkrankungen zeigen insbesondere Interventionsstudien bei AMD protektive Effekte antioxidativer Supplementierung, während für das Glaukom bislang vorwiegend beobachtende Daten vorliegen. Screening-Ansätze und Mikronährstoffdiagnostik ermöglichen die frühzeitige Identifikation von Risikopersonen. Darauf aufbauend stellen individualisierte diätetische Maßnahmen sowie die gezielte Supplementierung ausgewählter Nährstoffe potenziell präventive und stabilisierende therapeutische Strategien dar. Fehlernährung ist ein zentraler, modifizierbarer Risikofaktor neurodegenerativer Erkrankungen des Gehirns und der Retina. Eine stärkere Integration ernährungsmedizinischer Diagnostik und Therapie in neurologischen, geriatrischen und ophthalmologischen Versorgungsstrukturen erscheint sinnvoll.

ID: 42343420
Title: Immune checkpoint LAG-3 governs stage-dependent and disease-associated microglial modules in ALS model mice.
Abstract: Immune checkpoint molecules, inhibitory receptors originally characterized in T cell biology, have recently emerged as regulators of microglial function in neurodegeneration, yet their roles in amyotrophic lateral sclerosis (ALS) remain unexplored. Here, we investigated LAG-3, an inhibitory immune checkpoint receptor, in microglial regulation during ALS pathogenesis using SOD1G93A mice. LAG-3 expression was progressively upregulated in spinal cord microglia during disease progression, and LAG-3-high microglia exhibited a disease-associated microglia (DAM) transcriptional signature. Genetic deletion of LAG-3 produced a biphasic phenotype, with accelerated disease onset but significantly prolonged disease duration. LAG-3 deficiency enhanced inflammatory microglial responses at the early disease stage, whereas at the late stage it suppressed inflammatory signaling while selectively preserving phagocytic effector gene expression, demonstrating that LAG-3 dissociates the inflammatory and phagocytic modules within the DAM program in a stage-dependent manner. These transcriptional changes translated into enhanced phagocytic capacity in primary microglia and amelioration of the spinal cord environment through suppression of inflammatory pathways and restoration of oxidative phosphorylation. Our findings identify LAG-3 as a stage-dependent regulator of microglial functional states in ALS and support the concept that immune checkpoint molecules constitute a class of module-level regulators of microglial function in neurodegeneration.

ID: 42353109
Title: Research Advances in the Pathogenesis of Sepsis-Associated Encephalopathy.
Abstract: Sepsis-associated encephalopathy (SAE) is a frequent neurological complication of sepsis, driven by six interconnected pathophysiological components: (1) systemic inflammation-triggered neuroinflammatory cascades, initiated by systemic recognition of pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) and propagated by pro-inflammatory mediators; (2) central nervous system (CNS) immune cell-mediated neuroinflammation, wherein microglia, regulatory T cells, and neutrophils dynamically regulate inflammatory progression; (3) blood-brain barrier (BBB) disruption, progressing from functional disturbance to structural damage via tight junction degradation and immune infiltration; (4) multimodal programmed cell death, encompassing autophagy, apoptosis, pyroptosis, and ferroptosis driven by mitochondrial dysfunction; (5) neurotransmitter network imbalance, manifesting as cholinergic deficiency and glutamate excitotoxicity; and (6) gut-brain axis dysregulation, characterized by reduced microbiota-derived metabolites such as butyrate and indolepropionic acid. These components are organized along a core pathological axis comprising four sequential stages: neuroinflammatory storm (encompassing components 1 and 2) → BBB disruption and microcirculatory disturbances (component 3) → multimodal programmed cell death (component 4) → neurotransmitter imbalance (component 5), with the gut-brain axis (component 6) functioning as a bidirectional regulatory node that intersects and modulates all four stages. Mitochondrial dysfunction serves as the central converging node linking these pathological axes. Targeted interventions against neuroinflammation, immune cell modulation, BBB restoration, inhibition of aberrant cell death, neurotransmitter homeostasis, and gut microbiota remodeling hold therapeutic promise. Elucidating the crosstalk among these pathways will accelerate the clinical translation of precision therapies for SAE.

ID: 42387204
Title: Microglial tunneling nanotubes: an intercellular transfer facilitating mitochondrial dysfunction and neuroinflammation in experimental cerebral malaria.
Abstract: Cerebral malaria (CM), the most severe neurological manifestation of Plasmodium infection, is characterized by microglial activation that plays a pivotal role in initiating pathogenic neuroinflammatory cascades. Tunneling nanotubes (TNTs) are dynamic F-actin-based intercellular connections which transfer mitochondria and pathogenic factors. Although TNTs have been implicated in various neuropathological conditions, their precise involvement in CM pathogenesis, particularly in relation to microglial activation, remains undefined. In this study, single-cell RNA-sequencing (scRNA-seq) revealed significant dysregulation of TNT-associated genes and actin cytoskeleton pathway remodeling in microglia of ECM model. In vitro studies demonstrated that Plasmodium-infected red blood cells (pRBCs)-stimulated primary microglia formed extensive F-actin-rich tunneling nanotubes, which mediated the bidirectional transfer for mitochondria and facilitated intercellular trafficking of lysosomal contents and malarial pigment. These TNT-mediated intercellular communication amplified microglial activation, as evidenced by: (i) lipid peroxidation, (ii) mitochondrial dysfunction, and (iii) autophagosome (LC3+) accumulation. This process further amplifies neuroinflammation through TNFα/IL-6 secretion and expansion of CD45high microglial populations. Pharmacological TNT inhibition restores microglial homeostasis in ECM model. In conclusion, TNTs mediate neuroinflammation in the ECM model by transferring mitochondria and malarial pigment between microglia. Although mitochondrial transfer may transiently support cellular homeostasis, progressive malarial pigment accumulation triggers lipid metabolism dysregulation and amplified neuroinflammation. Inhibiting TNTs formation attenuates microglial hyperactivation, highlighting targeted regulation of TNT-mediated intercellular communication as a potential therapeutic approach for CM-associated neuropathology.

ID: 42393712
Title: The mitochondrial protease, LonP1, is a potential cardioprotective target for attenuating doxorubicin-induced cardiomyocyte death.
Abstract: Doxorubicin (DOX), a first-line chemotherapeutic agent, has been linked to severe off-target cardiotoxicity in the clinic. Previous works suggest that mitochondria are key mediators of this cardiotoxicity. Leakage of mitochondrial contents after DOX treatment, including mitochondrial DNA (mtDNA), is thought to activate apoptotic and inflammatory signaling pathways implicated in cardiomyocyte cell death. Whether the master mitochondrial protease, LonP1, can dampen these pathways and improve cardiomyocyte viability following DOX treatment remains unknown. Human cardiac cells (AC-16) and primary (1°) human cardiomyocytes were subjected to DOX treatment, followed by bulk RNA-Seq, RT-qPCR, qPCR, and immunoblotting to assess apoptotic signaling, inflammatory signaling, mtDNA release, and LonP1 expression, respectively. Lentivirus transduction of AC-16 cells was used to generate both knockdown (KD) and overexpression (OE) LonP1 cell lines to determine the effects of altered LonP1 levels on DOX-induced apoptosis and mtDNA release. Further, levels of mitochondrial DNA (mtDNA) were measured using qPCR from serum samples obtained from patients undergoing DOX treatment to assess the clinical relevance of released mtDNA as a potential biomarker for the development of DOX cardiotoxicity. DOX treatment of AC-16 cells, as well as 1° human cardiomyocytes, upregulated both apoptotic and inflammatory signaling in both cell models. Increased LonP1 levels were also observed under DOX treatment in AC-16 cells and 1° human cardiomyocytes. Likewise, DOX increased mtDNA release from both cell lines, both prior to, and as a sequel to cell death. Decreasing LonP1 levels exacerbated DOX-mediated apoptotic signaling and mtDNA release, whereas overexpression of LonP1 attenuated these effects. Furthermore, DOX treatment in cancer patients increases plasma mtDNA levels. These findings suggest LonP1 plays a protective role in the heart following DOX treatment, supporting LonP1 as a potential novel therapeutic target for prevention of DOX cardiotoxicity. Patterns of mtDNA release within patients undergoing DOX treatment also highlight the potential of mtDNA as a potential biomarker and target for prevention of DOX cardiotoxicity, justifying the need for more extensive, prospectively monitored cohort studies to expand upon these findings and statistically model mtDNA release patterns.

ID: 42398881
Title: Mitochondrial Dysfunction and Diabetic Retinopathy: Research Progress from Pathogenic Mechanisms to Therapeutic Targets.
Abstract: Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes mellitus (DM) and remains a major cause of visual impairment and blindness in adults. Accumulating evidence indicates that DR is not merely a microvascular disorder, but a complex neurovascular disease driven by long-standing hyperglycemia, metabolic dysregulation, oxidative stress, chronic inflammation, neurodegeneration, and impaired neurovascular coupling. Mitochondria are central regulators of cellular energy metabolism and redox homeostasis, and mitochondrial dysfunction is increasingly recognized as a pivotal mechanism linking hyperglycemia-induced metabolic abnormalities to retinal neurovascular unit injury. Under persistent hyperglycemic conditions, excessive glucose flux and metabolic overload promote mitochondrial reactive oxygen species (ROS) overproduction, mitochondrial DNA (mtDNA) damage, impaired oxidative phosphorylation, mitochondrial fusion-fission imbalance, defective mitochondrial biogenesis, dysregulated mitophagy, metabolic reprogramming, and epigenetic alterations. These abnormalities lead to ATP depletion, inflammatory amplification, and activation of multiple forms of programmed cell death, including apoptosis, ferroptosis, pyroptosis, necroptosis, and poly(ADP-ribose) polymerase 1 (PARP1)-dependent cell death. Mitochondrial injury affects retinal endothelial cells, pericytes, Muller cells, microglia, retinal ganglion cells, photoreceptors, and retinal pigment epithelial cells in a cell-type-specific manner, ultimately contributing to blood-retinal barrier disruption, capillary occlusion, neurovascular coupling impairment, retinal neurodegeneration, and progression from non-proliferative to proliferative DR. This review summarizes recent advances in mitochondrial dysfunction in DR, focusing on oxidative stress, mtDNA injury, mitochondrial metabolic reprogramming, mitochondrial dynamics, mitochondrial biogenesis, mitophagy, epigenetic regulation, mitochondria-associated cell death, and neurovascular unit dysfunction. Emerging mitochondria-targeted therapeutic strategies, including mitochondrial antioxidants, modulation of mitochondrial biogenesis and dynamics, mitophagy regulation, mtDNA protection, ferroptosis and inflammasome inhibition, epigenetic intervention, are also discussed. A deeper understanding of mitochondrial mechanisms may provide new therapeutic targets and translational opportunities for DR prevention and treatment.

ID: 42412280
Title: Dysfunctional Mitochondria in Microglia Drive Cognitive Aging and Neurodegeneration via cGAS-STING.
Abstract: Mitochondrial dysfunction induces metabolic dysregulation in immune cells that is etiologically associated with age-related brain disorders. However, how dysfunctional mitochondria in microglia-the brain-resident immune cells-initially affect neurological function remains incompletely understood. Here, we demonstrate that dysfunctional mitochondria in microglia, induced by the conditional knockout of mitochondrial transcription factor A, act as triggers of metabolic dysregulation, cognitive aging, and neurodegeneration in adult mice. Notably, this metabolic disturbance induces a microglial transition to states associated with neuroinflammatory activation and neurodegenerative disease, thereby triggering multiple layers of pathological cascade reactions among other brain cell types and shaping a neuroinflammaging state at single-cell resolution. Mechanistically, mitochondrial dysfunction activates the innate immune cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, which mediates immune sensing of cytosolic DNA in microglia and contributes to inflammaging. We further present evidence that combined treatment aimed at restoring metabolic homeostasis and inhibiting neuroinflammatory cGAS-STING partially rescues age-related neurological dysfunction in mice. Collectively, our findings reveal a link between mitochondrial dysfunction in microglia and cognitive aging, underscoring the significance of tightly regulated metabolism in age-associated neurological diseases.

ID: 42425696
Title: The absence of ADAMTS13 improves early outcomes in an experimental model of trauma with uncontrolled hemorrhage.
Abstract: Bleeding after trauma is aggravated by trauma-induced coagulopathy (TIC). In trauma patients with shock, ADAMTS13 (a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13) antigen is decreased, but its activity can be increased, possibly due to specific cleavage by plasmin. Increased ADAMTS13 activity could aggravate TIC and bleeding. Therefore, this study aimed to determine whether knocking-out ADAMTS13 is protective after trauma with uncontrolled bleeding. Furthermore, we examined the effect of plasmin inhibition with tranexamic acid (TXA) on ADAMTS13 antigen and activity. Wild-type and ADAMTS13 knockout (ADAMTS13KO) mice were anesthetized, mechanically ventilated, and subjected to traumatic injury with uncontrolled hemorrhage. In a separate experiment, wild-type mice underwent the same traumatic injury, but with additional blood withdrawal to induce shock and treatment with a single dose of TXA or vehicle. Outcomes included mortality, ADAMTS13 activity, von Willebrand factor (VWF) multimers, and rotational thromboelastometry (ROTEM). ADAMTS13KO mice showed significantly lower mortality rates after trauma compared with wild-type mice (13% vs. 47%, P=0.046), with significantly higher VWF multimers. ROTEM parameters did not differ significantly between ADAMTS13KO and wild-type mice. In the wild-type mice subjected to trauma and shock, there was a significant increase in ADAMTS13 activity, which correlated with shock severity. Treatment with TXA significantly reduced mortality, but had no significant effect on ADAMTS13 antigen or activity. Knocking-out ADAMTS13 is associated with improved early survival following trauma, demonstrating a role for ADAMTS13 in contributing to early TIC and bleeding. While ADAMTS13 activity increases after trauma and shock, its levels appear unaffected by TXA. (J Trauma Acute Care Surg 2026;00:000-000 © 2026 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Surgery of Trauma.). Level V.