bims-axbals Biomed News
on Axonal biology and ALS
Issue of 2025–07–06
48 papers selected by
TJ Krzystek
  1. C9orf72 deficiency impairs the autophagic response to aggregated TDP-25 and exacerbates TDP-25-mediated neurodegeneration in vivo.
  2. Leucine-Rich Repeat Kinase 2: Pathways to Parkinson's Disease.
  3. Restoration of striatal neuroprotective pathways by kinase inhibitor treatment of Parkinson's disease-linked LRRK2-mutant mice.
  4. Cryptic Splicing of GAP43 mRNA is a Novel Hallmark of TDP-43-Associated ALS and AD.
  5. Genetically encoded and modular subcellular organelle probes reveal dysfunction in lysosomes and mitochondria driven by PRKN knockout.
  6. Sephin1 reduces TDP-43 cytoplasmic mislocalization and improves motor neuron survival in ALS models.
  7. Coding and non-coding RNA expression in NSC34 cells following TDP-43 depletion and mutant TDP-43 M337V expression.
  8. Differential response of neurons to autophagy modulation in Huntington's disease.
  9. Induced Pluripotent Stem Cells Derived Cellular Models for Investigating Parkinson's Disease Pathogenesis and Drug Screening.
  10. Modulating mitochondrial dynamics in CMT2A: a multifaceted platform for drug discovery and evaluation.
  11. Generation of Leucine-Rich Repeat Kinase 2 (LRRK2) Knockout Neuroblastoma Cells SH-SY5Y by CRISPR/Cas9-Mediated Genome Editing.
  12. Transmembrane protein 184B (TMEM184B) modulates endolysosomal acidification via the vesicular proton pump.
  13. Plasma membrane remodeling in GM2 gangliosidoses drives synaptic dysfunction.
  14. FABP7 is increased in progressive multiple sclerosis and induces a pro-inflammatory phenotype in monocytes through a glycolytic switch.
  15. Storage and transport of labile iron is mediated by lysosomes in axons and dendrites of hippocampal neurons.
  16. [Development of RNA Hydrogels as a Potential System for Intracellular Biomimicry: A Method for the In Vitro Synthesis of ALS/FTD-related (G4C2)n RNA with over 100 Repeats].
  17. Fisetin Attenuates Mutant SOD1 Aggregation in Amyotrophic Lateral Sclerosis via Nrf2-Mediated Autophagy Activation.
  18. Advances, challenges, and opportunities of human midbrain organoids for modelling of the dopaminergic system.
  19. Protocol for generating and using human iPSC-derived microglia-containing air-liquid-interface cortical organoid cultures.
  20. Metal Ion Nanodepots Orchestrate Neuronal Axon and Dendrite Growth via the Actin-PFN1 Pathway.
  21. Transthyretin abnormalities in amyotrophic lateral sclerosis: High molecular weight species in cerebrospinal fluid and stromal deposits in choroid plexus.
  22. Trimetazidine stimulates intracellular Ca2+ transients and zebrafish locomotor activity in spinal neurons.
  23. Jawbone-like organoids generated from human pluripotent stem cells.
  24. Axonal pathology differentially affects human Purkinje cell subpopulations in the essential tremor cerebellum.
  25. Conformational dynamics and membrane insertion mechanism of B4GALNT1 in ganglioside synthesis.
  26. STING COPII ER Export Trafficking and Signaling Primed by Phosphorylation Switches.
  27. Site-resolved assessment of targeted protein degradation.
  28. Triglycerides are an important fuel reserve for synapse function in the brain.
  29. Critical impact of lysine 136 in TDP-43 phase separation, compartmentalization, and aggregation in living vertebrates.
  30. Injectable borax-loaded alginate hydrogels reduce muscle atrophy, modulate inflammation, and promote neuroprotection in the SOD1G93A mouse model of ALS through mechanisms involving IGF-Akt-mTOR signaling.
  31. Glycoproteomic profiling of serum-derived small extracellular vesicles enriched via ultracentrifugation and affinity-based techniques.
  32. Development of Antibody-Based Strategies for Targeted Degradation of Membrane and Extracellular Proteins.
  33. Parkinson's disease associated with LRRK2-R1441C mutation: Characterization and comparison with other LRRK2 mutations.
  34. Dysbiosis and Neurodegeneration in ALS: Unraveling the Gut-Brain Axis.
  35. The loss of OPA1 accelerates intervertebral disc degeneration and osteoarthritis in aged mice.
  36. Arabidopsis Vacuolar protein sorting 9a (VPS9a) is required for glutamine synthetase/glutamate synthase (GS/GOGAT) cycle and autophagy under nutrient starvation.
  37. Generation of mature epicardium derived from human-induced pluripotent stem cells via inhibition of mTOR signaling.
  38. Rim4-seeded stress granules connect temperature sensing to meiotic regulation.
  39. Familial ALS/FTD-associated RNA-binding deficient TDP-43 mutants cause neuronal and synaptic transcript dysregulation in vitro.
  40. ESCRTing the RABs through conversion.
  41. The mechanisms and functions of mitochondria-encapsulating extracellular vesicles.
  42. Cell-specific mechanisms drive connectivity across the time course of Huntington's disease.
  43. Nucleocytoplasmic HDAC inhibition drives acetylation-dependent TDP-43 mislocalization and disulfide-linked oligomerization.
  44. Visualizing PIEZO1 localization and activity in hiPSC-derived single cells and organoids with HaloTag technology.
  45. Co-occurrence of amyotrophic lateral sclerosis and multiple sclerosis: a rare but interesting association.
  46. Cerebellar pathology contributes to neurodevelopmental deficits in spinal muscular atrophy.
  47. Engine breakdown of lysosomes and related organelles and the resulting physiology.
  48. Tofersen treatment normalizes neurofilament levels in autosomal recessive SOD1 Amyotrophic Lateral Sclerosis.
  1. Acta Neuropathol Commun. 2025 06 28. 13(1): 136
    C9orf72 deficiency impairs the autophagic response to aggregated TDP-25 and exacerbates TDP-25-mediated neurodegeneration in vivo.
    Lilian Tsai-Wei Lin, Marc Shenouda, Philip McGoldrick, Agnes Lau, Janice Robertson.
      Cytoplasmic aggregates of the predominantly nuclear TAR DNA-binding protein 43 (TDP-43) are a pathological hallmark of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) cases caused by G4C2 hexanucleotide repeat expansions in C9orf72 (C9-ALS/FTD). While these repeat expansions are associated with both gain- and loss-of-function mechanisms, the contribution of C9orf72 loss of function to disease pathogenesis remains unclear. C9orf72 has been shown to regulate autophagy, and its deficiency has been shown to exacerbate phenotypes in gain-of-function G4C2 models, implicating impaired autophagic clearance in disease pathogenesis. Here, we directly test whether C9orf72 deficiency exacerbates TDP-43 pathology and neurodegeneration in vivo. Using AAV9-vectors to drive neuron-specific expression of pathologically relevant C-terminal species of TDP-43, TDP-35 and TDP-25, we established models of TDP-43 pathology that recapitulate key disease features, including cytoplasmic aggregates, motor and cognitive decline, and neuronal loss. TDP-25 expression in particular produced robust, abnormally phosphorylated, ubiquitinated and p62-labelled cytoplasmic aggregates, modelling TDP-43 pathology in disease. Loss of C9orf72 in TDP-25-expressing mice accelerated the onset of motor deficits, increased neurodegeneration, and impaired the autophagic response to TDP-25 expression. These findings reveal that C9orf72 deficiency disrupts autophagy and exacerbates TDP-25-mediated toxicity in vivo, supporting a contributory role for C9orf72 loss-of-function in driving neurodegeneration in C9-ALS/FTD.
    Keywords:  Amyotrophic lateral sclerosis; Autophagy; C9orf72; Frontotemporal dementia; Neurodegeneration; Protein aggregation; TAR DNA-binding protein 43
    DOI:  https://doi.org/10.1186/s40478-025-02061-5
  2. Cold Spring Harb Perspect Med. 2025 Jun 30. pii: a041620. [Epub ahead of print]
    Leucine-Rich Repeat Kinase 2: Pathways to Parkinson's Disease.
    Suzanne R Pfeffer, Dario R Alessi.
      The past 10 years have seen tremendous progress in our understanding of leucine-rich repeat kinase 2 (LRRK2) and how mutations activate the kinase and trigger downstream pathology, contributing to Parkinson's disease. A breakthrough came from the identification of key LRRK2 substrates-a subset of small guanosine triphosphatases (GTPases) called Rab proteins. Cryoelectron microscopy has revealed structures of LRRK2 and showed how inhibitors engage and inhibit the kinase. Biochemical experiments have revealed how LRRK2 is recruited to membranes to phosphorylate Rab substrates. LRRK2 activation during lysosomal stress triggers Rab phosphorylation, altering the repertoire of Rab-binding partners. Resulting phospho-Rab-effector complexes have prominent effects in specific cell types, disrupting primary cilia and impairing Hedgehog signaling-effects that can be reversed by LRRK2 inhibitors. This disruption in Hedgehog signaling represents a convergence point linking genetic and idiopathic forms of Parkinson's. Together, these findings support the therapeutic potential of LRRK2 inhibitors in Parkinson's disease.
    DOI:  https://doi.org/10.1101/cshperspect.a041620
  3. Sci Signal. 2025 Jul;18(893): eads5761
    Restoration of striatal neuroprotective pathways by kinase inhibitor treatment of Parkinson's disease-linked LRRK2-mutant mice.
    Ebsy Jaimon, Yu-En Lin, Francesca Tonelli, Odetta Antico, Dario R Alessi, Suzanne R Pfeffer.
      Parkinson's disease is associated with activating mutations in the gene encoding leucine-rich repeat kinase 2 (LRRK2), which suppresses primary cilia formation in cholinergic and parvalbumin interneurons and astrocytes in the striatum. As a result, there is a decrease in the production of neuroprotective glial cell line-derived neurotrophic factor (GDNF) and neurturin (NRTN), which normally support the viability of dopaminergic neurons. MLi-2 is a brain-penetrant, selective, and now experimental inhibitor of LRRK2. Here, we found that dietary administration of MLi-2 to young LRRK2-mutant mice for 3 months restored primary cilia formation and Hedgehog signaling in both cholinergic and parvalbumin interneurons and astrocytes. The treatment also restored the Hedgehog-responsive expression of Gdnf and Nrtn in the neurons. Cilia were also restored on cholinergic neurons of the pedunculopontine nucleus, where their loss correlates with severity of motor impairment in patients. Furthermore, MLi-2 increased the density of fine striatal dopaminergic processes and decreased the amount of stress-associated Sonic Hedgehog RNA expression in nigral dopaminergic neurons. Thus, pathogenic LRRK2-driven cilia loss is reversible in postmitotic neurons and astrocytes, which suggests that early administration of specific LRRK2 inhibitors may therapeutically benefit patients.
    DOI:  https://doi.org/10.1126/scisignal.ads5761
  4. Adv Sci (Weinh). 2025 Jun 29. e12054
    Cryptic Splicing of GAP43 mRNA is a Novel Hallmark of TDP-43-Associated ALS and AD.
    Mingming Yang, Qi Wang, Dongkun Kang, Shijia Wang, Yanli Jiang, Jian-Zhi Wang, Chen Ming, Rong Liu, Jianlan Gu, Xiaochuan Wang.
      Cytoplasmic aggregation of transactive response DNA-binding protein 43 (TDP-43) is a hallmark of amyotrophic lateral sclerosis (ALS) and occurs in 57% of Alzheimer's disease (AD) cases. TDP-43 regulates RNA processing, including cryptic exon splicing. Here, we demonstrate that TDP-43 directly controls growth-associated protein (GAP43) expression by binding to its pre-mRNA. Loss or hyperphosphorylation of TDP-43 disrupts this binding, leading to the inclusion of cryptic exon 4a1, which introduces premature stop codons and reduces GAP43 protein levels. RNA sequencing analysis of ALS and AD brains revealed GAP43 downregulation, while 4a1 is upregulated in AD cases with phosphorylated TDP-43. TDP-43 knockdown impaired axonal regeneration in induced pluripotent stem cell (iPSC)-derived motor neurons, whereas GAP43 restoration rescued this defect. These findings suggest that the loss of GAP43 contributes to neurodegeneration in ALS and AD. The inclusion of GAP43 cryptic exon 4a1 may serve as a hallmark of TDP-43 proteinopathies, highlighting a mechanistic link between TDP-43 dysfunction and neuronal vulnerability.
    Keywords:  GAP43; TDP‐43; cryptic exon; mis‐splicing
    DOI:  https://doi.org/10.1002/advs.202412054
  5. iScience. 2025 Jul 18. 28(7): 112816
    Genetically encoded and modular subcellular organelle probes reveal dysfunction in lysosomes and mitochondria driven by PRKN knockout.
    Camille Goldman, Tatyana Kareva, Lily Sarrafha, Braxton R Schuldt, Abhishek Sahasrabudhe, Tim Ahfeldt, Joel W Blanchard.
      Cellular processes including lysosomal and mitochondrial dysfunction are implicated in the development of many diseases. Quantitative visualization of mitochondria and lysosomes is crucial to understand how these organelles are dysregulated during disease. To address a gap in live-imaging tools, we developed GEM-SCOPe (genetically encoded and modular subcellular organelle probes), a modular toolbox of fluorescent markers designed to inform on localization, distribution, turnover, and oxidative stress of specific organelles. We expressed GEM-SCOPe in differentiated astrocytes and neurons from a human pluripotent stem cell PRKN-knockout model of Parkinson's disease and identified disease-associated changes in proliferation, lysosomal distribution, mitochondrial transport and turnover, and reactive oxygen species. We demonstrate GEM-SCOPe is a powerful panel that provides critical insight into the subcellular mechanisms underlying Parkinson's disease in human cells. GEM-SCOPe can be expanded upon and applied to a diversity of cellular models to glean an understanding of the mechanisms that promote disease onset and progression.
    Keywords:  Cell biology; Molecular biology
    DOI:  https://doi.org/10.1016/j.isci.2025.112816
  6. Life Sci Alliance. 2025 Sep;pii: e202403195. [Epub ahead of print]8(9):
    Sephin1 reduces TDP-43 cytoplasmic mislocalization and improves motor neuron survival in ALS models.
    Emmanuelle Abgueguen, Massimo Tortarolo, Laura Rouviere, Stefania Marcuzzo, Laura Camporeale, Alexandre Henriques, Laura Pasetto, Georgia R Culley, Valentina Bonetto, Anca Marian, Beatrice L Lejeune, Anne Visbecq, Giuseppe Lauria, Edor Kabashi, Noëlle Callizot, Caterina Bendotti, Pierre Y Miniou.
      A pathological hallmark of ALS is the abnormal accumulation of misfolded proteins (e.g., TDP-43) and enlarged endoplasmic reticulum (ER), indicating ER stress. To resolve this stress, cells initiate the Unfolded Protein Response (UPR). However, unresolved stress leads to apoptosis. In ALS, UPR activation fails to resolve proteostasis impairment. UPR activation modulators, among them Sephin1, reduce protein aggregates and improve motor neuron survival in ALS models. We demonstrate that following glutamate intoxication, Sephin1 increases motor neuron survival by reducing mitochondria ROS production and extranuclear TDP-43. Sephin1 reduces abnormal splicing because of TDP-43 nuclear loss of function following oxidative stress. In SOD1G93A mice, Sephin1 treatment decreases TDP-43 in triton-insoluble fraction, improving motor neuron survival in spinal cord. Sephin1 improves motor neurons survival, motor function and survival of mutated TDP-43 transgenic zebrafish. Sephin1 improves motor neuron survival in ALS models by reducing TDP-43 cytoplasmic mislocalization and its toxicity. These findings open new therapeutic opportunities for Sephin1 in neurodegenerative pathologies with TDP-43 proteinopathy, including ALS.
    DOI:  https://doi.org/10.26508/lsa.202403195
  7. Sci Data. 2025 Jul 01. 12(1): 1110
    Coding and non-coding RNA expression in NSC34 cells following TDP-43 depletion and mutant TDP-43 M337V expression.
    Ismail Gbadamosi, Sandra Binias, Bartłomiej Gielniewski, Ramiro Magno, Isabel Duarte, Ali Jawaid.
      Several neurodegenerative disorders (NDDs), notably amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are characterized by pathological cytoplasmic aggregation of TAR DNA-binding protein 43 (TDP-43) in neurons and glia. Primarily localized in the nucleus under physiological conditions, TDP-43 is a critical regulator of RNA processing and metabolism. Therefore, RNA changes induced by TDP-43 depletion or mutation could play an important role in the pathogenesis of ALS and other TDP-43 related NDDs.To investigate these effects in NSC34 motor neuron-like cells, a commonly used cellular model of ALS, we used RNA interference to knock down TDP-43 and overexpressed the ALS-associated TDP-43 M337V mutation. RNA from both these experiments was enriched for small and large transcripts and subsequently analyzed via next-generation sequencing.The resulting transcriptomics datasets offer a valuable resource for studying the impact of TDP-43 depletion and mutant over-expression in motor neurons. These data enable comprehensive differential expression analyses and functional enrichment studies, identifying cellular pathways affected by TDP-43 depletion or mutation. Additionally, the inclusion of non-coding RNAs facilitates the construction of gene regulatory networks, providing insights into the interplay between coding and non-coding RNAs in gene expression regulation under TDP-43 loss-of-function or pathogenic mutation conditions.
    DOI:  https://doi.org/10.1038/s41597-025-05409-7
  8. Autophagy Rep. 2025 ;4(1): 2519102
    Differential response of neurons to autophagy modulation in Huntington's disease.
    Ankit Sharma, Sushma Rao, Ravi Manjithaya, Vasu Sheeba.
      Huntington's disease (HD) is caused by the expansion of poly-glutamine repeats in the Huntingtin (Htt) gene and is associated with a wide variety of motor and physiological (sleep, metabolism, etc.) perturbations. Studies from diverse model organisms have proposed that modulation of autophagy (a key protein homeostatic pathway) can mitigate the toxic effects of mutant HTT protein. However, consistent changes are not observed across studies, and the improvements in phenotypes can be associated with changes in specific circuits/neurons affected by the mutant HTT protein. They suggest that not all neurons respond effectively to autophagy modulation. Hence, it remains to be understood whether diverse circuits/neurons affected by mutant HTT protein respond effectively to this intervention. Using a genetic approach, we expressed mutant HTT protein independently in diverse sets of neurons in male Drosophila melanogaster and asked whether genetic modulation of autophagy pathway through Atg8a overexpression can mitigate the toxic effect of mutant HTT protein. We found that in male flies, not all neurons/circuits expressing mutant HTT protein respond effectively to ATG8a protein. Circadian neurons and neurons regulating carbohydrate and lipid metabolism (Dilp2 +ve) showed improvement, while motor and neurons responding to temperature changes showed no improvement. Using cellular markers we also showed that these phenotypes can be attributed to specific changes in mutant HTT and Ref(2)P proteins (autophagy marker). Our study suggests that not all circuits respond effectively to autophagy modulation and suggests a potential cause for low success of autophagy modulators in clinical trials..
    Keywords:  Drosophila melanogaster; Huntington’s disease; autophagy; circadian rhythm; metabolism; motor neurons; sleep
    DOI:  https://doi.org/10.1080/27694127.2025.2519102
  9. Stem Cell Rev Rep. 2025 Jun 30.
    Induced Pluripotent Stem Cells Derived Cellular Models for Investigating Parkinson's Disease Pathogenesis and Drug Screening.
    Jihong Liu, Wanlin Zhao, Zijuan Zhang, Xilei Ai, Bing Cao, Zhenqiang Zhang, Dongrui Ma.
      Parkinson's disease (PD) is the second most common neurodegenerative disorder, affecting millions worldwide. The complexity of PD has hindered the development of accurate disease models. Induced pluripotent stem cells (iPSCs), derived from patient-specific cells, offer a promising platform for modeling PD. This review discusses the development of PD models using iPSCs from different patient sources, focusing on 2D and 3D culture systems. We also explore the integration of iPSCs with advanced technologies like multi-omics, tissue engineering, and gene editing, and their potential to drive breakthroughs in disease modeling. Co-culture systems of iPSC-derived neurons and glial cells provide insights into cell-cell interactions in PD, while 3D brain region-specific organoids enhance understanding of interregional disease processes. Advances in multi-omics and gene editing have further propelled iPSC-based disease modeling, offering new avenues for investigating disease mechanisms and therapeutic screening.
    Keywords:  Disease modeling; Induced pluripotent stem cells; Organoid; Parkinson’s disease; iPSC-derived neurons
    DOI:  https://doi.org/10.1007/s12015-025-10931-7
  10. Biophys Rep. 2025 Jun 30. 11(3): 143-155
    Modulating mitochondrial dynamics in CMT2A: a multifaceted platform for drug discovery and evaluation.
    Yang Liu, Chen Yan, Borui Cao, Dejun Kong, Jiaqi Li, Wenlei Li, Yingjie Guo, Zhongyang Yuan, Yumiao Gao, Yubo Zhang, Ran Sui, Guo Chen, Xiaojiang Hao, Quan Chen.
      Mitochondrial dynamics, encompassing fusion and fission processes, plays a crucial role in regulating mitochondrial distribution, motility, and material exchange within cells, particularly in the nervous system. Mitofusin-2 (MFN2), a GTPase localized to the outer mitochondrial membrane, mediates mitochondrial fusion through dimerization and conformational changes. Mutations in MFN2 are causal for Charcot-Marie-Tooth disease type 2A (CMT2A), an inherited peripheral neuropathy for which no curative treatment currently exists. Herein, we have developed a comprehensive mitochondrial drug-screening and evaluation platform to facilitate the identification of potential therapeutic candidates. This work builds upon our previous research with S89, a small molecule agonist derived from spiramine alkaloids that promotes mitochondrial fusion by interacting with endogenous MFN1 and effectively mitigates axonal degeneration in CMT2A patient-derived motor neurons. This platform integrates three sequential stages of assessment: (1) initial screening in Mfn knockout mouse embryonic fibroblasts (MEFs) to identify compounds capable of reversibly rescuing mitochondrial fragmentation; (2) evaluation in primary neuronal cultures derived from CMT2A mouse dorsal root ganglia and cortex to assess the compounds' efficacy in restoring mitochondrial morphology, axonal transport, and neurite outgrowth; and (3) final assessment in CMT2A patient-derived induced pluripotent stem cell (iPSC)-differentiated motor neurons to determine the candidates' therapeutic potential in human peripheral nervous system cells. This multi-tiered approach facilitates rapid compound screening with increasing physiological relevance, enhancing the efficiency and translational potential of identifying therapeutic candidates for CMT2A.
    Keywords:  CMT2A neuronal system; Charcot-Marie-Tooth disease type 2A (CMT2A); Mitochondrial fusion; Mitofusin-2 (MFN2); Screening and evaluation platform; Small molecule compounds
    DOI:  https://doi.org/10.52601/bpr.2024.240037
  11. Biochem Genet. 2025 Jul 02.
    Generation of Leucine-Rich Repeat Kinase 2 (LRRK2) Knockout Neuroblastoma Cells SH-SY5Y by CRISPR/Cas9-Mediated Genome Editing.
    Hui-Lan Jong, Kit-San Yuen, Dong-Yan Jin, Susan Ling Ling Hoe, Aini Ideris, Chee-Hong Tan, Sau-Kuen Lam, Yang-Mooi Lim, Soon-Keng Cheong.
      Leucine-rich repeat kinase 2 (LRRK2) is associated with Parkinson's disease, despite its low expression in the brain. Pathogenic mutations in LRRK2 enhance kinase activity and contribute to the disease's pathogenesis. Neuroblastoma SH-SY5Y cells, which also exhibit low LRRK2 expression, are extensively used as a model for Parkinson's disease. While less prominent, low-expression genes can play crucial roles in cellular processes, development, and disease. Knocking out such genes poses specific challenges, including difficulties in detection, incomplete knockout, and compensatory mechanisms that can obscure phenotypic changes. This study develops a strategy to knockout low-expression LRRK2 in SH-SY5Y cells effectively. Our approach employs a double-cut and multiple guide RNAs strategy, optimized electroporation parameters to enhance CRISPR/Cas9 plasmid delivery, refined clonal expansion technique, and a sensitive protein detection protocol. We successfully generate LRRK2 knockout SH-SY5Y cells using CRISPR/Cas9, with the knockout efficiency validated by PCR analysis, sequencing, and Western blot analysis.
    Keywords:  CRISPR/Cas9; Knockout; LRRK2; Neuroblastoma cells; Parkinson’s disease; SH-SY5Y
    DOI:  https://doi.org/10.1007/s10528-025-11174-4
  12. J Cell Sci. 2025 Jun 30. pii: jcs.263908. [Epub ahead of print]
    Transmembrane protein 184B (TMEM184B) modulates endolysosomal acidification via the vesicular proton pump.
    Elizabeth B Wright, Erik G Larsen, Marco Padilla-Rodriguez, Paul R Langlais, Martha R C Bhattacharya.
      Disruption of endolysosomal acidification causes toxic protein accumulation and neuronal dysfunction linked to neurodevelopmental and neurodegenerative disorders. However, the molecular mechanisms regulating neuronal endolysosomal pH remain unclear. TMEM184B is a conserved 7-pass transmembrane protein essential for synaptic function, and sequence disruption is associated with neurodevelopmental disorders. Here we identify TMEM184B as a key regulator of endolysosomal acidification. TMEM184B localizes to early and late endosomes, and proteomic analysis confirms that TMEM184B interacts with endosomal proteins, including the vacuolar ATPase (V-ATPase), a multi-subunit proton pump critical for lumenal acidification. Tmem184b-mutant mouse cortical neurons have reduced endolysosomal acidification compared to wild type neurons. We find reductions in V-ATPase complex assembly in Tmem184b-mutant mouse brains, suggesting TMEM184B facilitates endosomal flux by promoting V-ATPase activity. These findings establish TMEM184B as a regulator of neuronal endosomal acidification and provide mechanistic insight into its role in TMEM184B-associated nervous system disorders.
    Keywords:  Acidification; Endosome; Lysosome; Neuron; TMEM184B; V-ATPase
    DOI:  https://doi.org/10.1242/jcs.263908
  13. PLoS Biol. 2025 Jul 03. 23(7): e3003265
    Plasma membrane remodeling in GM2 gangliosidoses drives synaptic dysfunction.
    Alex S Nicholson, David A Priestman, Robin Antrobus, James C Williamson, Reuben Bush, Shannon J McKie, Henry G Barrow, Emily Smith, Kostantin Dobrenis, Nicholas A Bright, Frances M Platt, Janet E Deane.
      Glycosphingolipids (GSL) are important bioactive membrane components. GSLs containing sialic acids, known as gangliosides, are highly abundant in the brain and diseases of ganglioside metabolism cause severe early-onset neurodegeneration. The ganglioside GM2 is processed by β-hexosaminidase A and when non-functional GM2 accumulates causing Tay-Sachs and Sandhoff diseases. We have developed i3Neuron-based disease models demonstrating storage of GM2 and severe endolysosomal dysfunction. Additionally, the plasma membrane (PM) is significantly altered in its lipid and protein composition. These changes are driven in part by lysosomal exocytosis causing inappropriate accumulation of lysosomal proteins on the cell surface. There are also significant changes in synaptic protein abundances with direct functional impact on neuronal activity. Lysosomal proteins are also enriched at the PM in GM1 gangliosidosis supporting that lysosomal exocytosis is a conserved mechanism of PM proteome change in these diseases. This work provides mechanistic insights into neuronal dysfunction in gangliosidoses highlighting that these are severe PM disorders with implications for other lysosomal and neurodegenerative diseases.
    DOI:  https://doi.org/10.1371/journal.pbio.3003265
  14. Nat Commun. 2025 Jul 01. 16(1): 6049
    FABP7 is increased in progressive multiple sclerosis and induces a pro-inflammatory phenotype in monocytes through a glycolytic switch.
    Rohit Patel, Devin King, Brenna LaBarre, Hrishikesh Lokhande, Danielle Caefer, Johnna F Varghese, Keturah Warner, Marc A Bouffard, Shrishti Saxena, Alena Zhirova, Rohit Bakshi, Tanuja Chitnis.
      Multiple sclerosis (MS) involves dysregulation of innate immune cells including monocytes, especially in progressive MS. Fatty acid binding proteins (FABP) are essential for fatty acid transport and metabolism in multiple cell types. FABP7, a brain-FABP, maintains metabolic function in astrocytes and neural stem cells, but the effect of FABP7 on monocytes is unknown. Here we find elevated levels of FABP7 in the serum and cerebrospinal fluid of patients with secondary progressive MS. Elevated serum FABP7 levels positively correlate with higher disability scores, brain lesion volumes, and lower brain volumes. FABP7 levels are increased in astrocytes from MS postmortem brain lesion. Mechanistically, in vitro treatment of FABP7 induces CD16, CD80 and IL-1β expression in monocytes via increased glycolysis. FABP7-induced gene expression reflects enhanced inflammation, chemotaxis and glucose metabolism in monocytes. In conclusion, we find that FABP7 induces pro-inflammatory profiles in monocytes, correlates with disability and represents a potential biomarker and therapeutic target for progressive MS.
    DOI:  https://doi.org/10.1038/s41467-025-60747-9
  15. Metallomics. 2025 Jul 02. pii: mfaf021. [Epub ahead of print]
    Storage and transport of labile iron is mediated by lysosomes in axons and dendrites of hippocampal neurons.
    Aiyarin Kittilukkana, Asuncion Carmona, Léa Normand, Coline Gibout, Andrea Somogyi, Chalermchai Pilapong, Richard Ortega.
      Iron dyshomeostasis in neurons, involving iron accumulation and abnormal redox balance, is implicated in neurodegeneration. In particular, labile iron, a highly reactive pool of intracellular iron, plays a prominent role in iron-induced neurological damage. However, the mechanisms governing the detoxification and transport of labile iron within neurons are not fully understood. This study investigates the storage and transport of labile ferrous iron Fe(II) in cultured primary rat hippocampal neurons. Iron distribution was studied using live cell fluorescence microscopy with a selective labile Fe(II) fluorescent dye, and synchrotron X-ray fluorescence microscopy (SXRF) for total iron distribution. Fluorescent labelling of the axon initial segment and of lysosomes allowed iron distribution to be correlated with these subcellular compartments. The results show that labile Fe(II) is stored in lysosomes within somas, axons and dendrites and that lysosomal labile Fe(II) is transported retrogradely and anterogradely along axons and dendrites. In addition, SXRF imaging of total iron confirms iron uptake and iron distribution in the form of iron-rich dots in the soma and neurites. These results suggest that after exposure to Fe(II), labile Fe(II) is stored in lysosomes and can be transported along dendrites and axons. These storage and transport mechanisms could be associated with the detoxification of reactive Fe(II) in lysosomes, which protects cellular structures from oxidative stress. They could also be associated with the metabolic functions of iron in the soma, axons and dendrites. In this case, easily exchangeable Fe(II) is transported in lysosomes to the neuronal compartments where iron is required.
    DOI:  https://doi.org/10.1093/mtomcs/mfaf021
  16. Yakugaku Zasshi. 2025 ;145(7): 601-607
    [Development of RNA Hydrogels as a Potential System for Intracellular Biomimicry: A Method for the In Vitro Synthesis of ALS/FTD-related (G4C2)n RNA with over 100 Repeats].
    Lala Ito, Josephine Galipon.
      In the motor neurons of amyotrophic lateral sclerosis (ALS) patients, excessive (G4C2)n repeats in the intronic region of the C9orf72 gene are transcribed to RNA, forming G-quadruplexes that sequester RNA-binding proteins, leading to gelation within the cytoplasm as one of the many mechanisms leading to pathogenesis. While ALS patients frequently harbor over 700 repeats, this kind of 100% GC-rich region is very difficult to clone, and past studies report the necessity to add additional sequences in the middle to clone more than a few dozen repeats. The goal of this study was the in vitro production of the longest repetitive RNA to date consisting solely of (G4C2)n repeats. T4 DNA ligase was used to connect (G4C2)10 stretches of DNA with 3nt overhangs. Then, using a heat-resistant T7 RNA polymerase, the RNA obtained contained transcripts over 100 repeats. Artificial biomimetic RNA gels generated by scaling up this synthesis method are expected to contribute to elucidating the molecular mechanisms of repetitive sequence-related pathogenesis, as well as screening for drugs that can disrupt the gel structure.
    Keywords:  amyotrophic lateral sclerosis (ALS); repetitive RNA; transcription
    DOI:  https://doi.org/10.1248/yakushi.24-00209-3
  17. J Mol Neurosci. 2025 Jun 28. 75(3): 84
    Fisetin Attenuates Mutant SOD1 Aggregation in Amyotrophic Lateral Sclerosis via Nrf2-Mediated Autophagy Activation.
    Tianhang Wang, Ying Wang, Yueqing Yang, Shuyu Wang, Xudong Wang, Honglin Feng.
      Dysregulated autophagy and copper/zinc superoxide dismutase (SOD1) protein aggregation play a crucial role in amyotrophic lateral sclerosis (ALS). Here, we used stably transfected NSC34 motor neuron-like cells: (1) SOD1G93A mutants (G93A), (2) wild-type SOD1 (WT) controls, and (3) empty vector (EV) controls to observe the effects of fisetin. Pharmacological autophagy inhibition (Bafilomycin A1, 40 nM) and nuclear factor erythroid 2-related factor 2 (Nrf2) gene silencing (siRNA transfection) were employed to dissect molecular pathways. Protein aggregation dynamics and autophagy markers (LC3, p62/SQSTM1) were quantified through immunofluorescence and immunoblotting. SOD1G93A models exhibited impaired autophagic flux evidenced by elevated LC3-II and p62 levels, correlating with increased detergent-insoluble SOD1 aggregates. Fisetin treatment (1-10 μ M) dose-dependently reduced both soluble and aggregated SOD1G93A protein, concomitantly with restored autophagic flux. Mechanistically, fisetin promoted nuclear translocation while decreasing cytoplasmic Nrf2. After administration of an autophagy inhibitor and interference with Nrf2, the regulation of fisetin on p62 and mutant hSOD1 protein was inhibited. Our findings demonstrate that fisetin ameliorates mutant SOD1 proteotoxicity through coordinated activation of Nrf2-mediated autophagy pathways, suggesting therapeutic potential for SOD1-associated ALS pathologies.
    Keywords:  Amyotrophic lateral sclerosis; Antioxidant; Autophagy; Copper/zinc superoxide dismutase; Fisetin; Neurodegenerative disease
    DOI:  https://doi.org/10.1007/s12031-025-02376-x
  18. EMBO J. 2025 Jul 02.
    Advances, challenges, and opportunities of human midbrain organoids for modelling of the dopaminergic system.
    Alessandro Fiorenzano, Edoardo Sozzi, Rahel Kastli, Maria Roberta Iazzetta, Andreas Bruzelius, Paola Arlotta, Malin Parmar.
      Dopaminergic neurons in the ventral midbrain are critical for regulating movement, cognition, and emotion. Ventral midbrain organoids can be used to model both development and diseases of the dopaminergic system, especially Parkinson's disease. Here, we summarize recent advances and remaining challenges in developing such three-dimensional organoids from human pluripotent stem cells. We outline how ventral midbrain organoid systems have progressed from early three-dimensional culture models to sophisticated, engineered, multiregional systems that more accurately replicate the complex network of dopaminergic neurons. Furthermore, we examine how the development of organoid models from other brain regions, particularly the forebrain, provides complementary insights that can accelerate progress also in the field of midbrain organoids, towards the generation of more advanced in vitro systems for midbrain dopaminergic neurons and their circuitry. Such cutting-edge human stem cell-based models offer powerful platforms for investigating dopaminergic neuron generation, function, and connectivity, thereby enhancing disease modelling, drug discovery, and the development of targeted cell-based therapies.
    Keywords:  Disease Modeling; Dopaminergic Neurons; Human Pluripotent Stem Cells; Midbrain Development; Single-cell Sequencing
    DOI:  https://doi.org/10.1038/s44318-025-00494-1
  19. STAR Protoc. 2025 Jun 30. pii: S2666-1667(25)00321-1. [Epub ahead of print]6(3): 103915
    Protocol for generating and using human iPSC-derived microglia-containing air-liquid-interface cortical organoid cultures.
    Marta Cañizares Luna, Mayte Mars, Channa E Jakobs, Christiaan F M Huffels, Arthur Ermakov, Elly M Hol, R Jeroen Pasterkamp.
      Here, we present a protocol for generating long-term microglia-containing air-liquid-interface cortical organoid (MG-ALI-CO) cultures. This approach minimizes necrotic core formation, a common limitation of extended organoid cultures, favoring microglia survival and homeostasis. We describe steps for generating air-liquid-interface cortical organoids (ALI-COs), integrating macrophage precursors, and maintaining MG-ALI-COs. Additionally, we outline several experimental analyses of MG-ALI-COs, including immunostaining, imaging, and patch-clamp electrophysiological recordings. This model provides a physiologically relevant system to investigate human neuroimmune interactions in a 3D brain-like environment.
    Keywords:  Cell Biology; Cell Differentiation; Cell culture; Cell isolation; Immunology; Molecular Biology; Neuroscience; Organoids; Stem Cells
    DOI:  https://doi.org/10.1016/j.xpro.2025.103915
  20. ACS Appl Mater Interfaces. 2025 Jun 30.
    Metal Ion Nanodepots Orchestrate Neuronal Axon and Dendrite Growth via the Actin-PFN1 Pathway.
    Yuanyuan Yang, Jiapan Hu, Fan Mei, Yangyang Gan, Qiang Ma, Chuanda Zhu, Lidong Gong, Zhiqiang Lin.
      Neurodevelopment is a highly coordinated process involving cell differentiation, neurite extension, axon guidance, and dendritic formation, forming the structural basis for cognitive function. Metal ions such as silver and zinc play essential roles in neuronal disease; however, their precise function in neurodevelopment remains elusive. Due to the solubility characteristics of metal ions and the presence of ion channels on the cell membrane, studying the effects of metal ions within cells presents certain challenges. Recent advances in nanotechnology have enabled the effective delivery of goods into cells in a receptor-independent manner. In this study, we developed 11 types of metal ion nanodepots, NanoMIs, a novel class of nanoparticle-based metal ion delivery systems capable of effective intracellular metal ion release and lysosomal escape. These NanoMIs were applied to primary neuronal cells to investigate their effects on neuronal morphology. Our results show that NanoMIs primarily enhance axon elongation by modulating the PFN1-actin-cytoskeleton pathway. These findings suggest that NanoMIs offer a promising approach for exploring the role of metal ions in neuronal development and provide insights into the molecular mechanisms underlying metal-ion-mediated effects in neuronal cells.
    Keywords:  PFN1; axon; cytoskeleton; metal ions nanodepots; neurodevelopment
    DOI:  https://doi.org/10.1021/acsami.5c07533
  21. J Neuropathol Exp Neurol. 2025 Jul 03. pii: nlaf076. [Epub ahead of print]
    Transthyretin abnormalities in amyotrophic lateral sclerosis: High molecular weight species in cerebrospinal fluid and stromal deposits in choroid plexus.
    Mahlon Collins, Heather Kwapiszeski, Jiyan An, Deyri Garcia, Danielle Peller, Shafeeq Ladha, Robert Bowser, Nadine Bakkar.
      Transthyretin (TTR) is a plasma and cerebrospinal fluid (CSF) protein involved in transporting thyroid hormone and retinol, with additional roles in the central nervous system (CNS). The tetrameric structure of TTR is essential for its functions and tetramer dissociation and aggregation into pathological amyloid fibrils is implicated in multiple diseases. Altered levels of TTR have previously been described in amyotrophic lateral sclerosis (ALS) in both CSF and CNS tissue. However, whether altered TTR levels in ALS reflect TTR pathology in CSF or in the choroid plexus (CP) cells that synthesize CNS TTR is unknown. Here, we comprehensively assayed native and aggregated TTR in ALS patient CSF and postmortem ALS CP. Using a nondenaturing native polyacrylamide gel electrophoresis-based assay, we identified high molecular weight TTR aggregates in the CSF of ALS patients. We also observed increased levels of TTR RNA and protein in ALS CP, as well as TTR granule deposits in CP stroma of ALS but not control cases. Taken together, our results reveal new forms of TTR dysfunction in ALS and uncover TTR-related morphological abnormalities in the CP in ALS patients.
    Keywords:  amyotrophic lateral sclerosis; cerebrospinal fluid; choroid plexus; proteoforms; transthyretin
    DOI:  https://doi.org/10.1093/jnen/nlaf076
  22. Sci Rep. 2025 Jul 02. 15(1): 22854
    Trimetazidine stimulates intracellular Ca2+ transients and zebrafish locomotor activity in spinal neurons.
    Sara Bernardi, Sara Vitolo, Chiara Gabellini, Maria Marchese, Elisabetta Ferraro.
      The metabolic modulator trimetazidine (TMZ) is an antianginal recently found to improve skeletal muscle performance in mice models of sarcopenia and of amyotrophic lateral sclerosis (ALS). The mechanism underlying the effect of TMZ on locomotor activity has been proposed to rely on its ability to enhance metabolic efficiency with a consequent improvement of myogenesis and of neuromuscular junction (NMJ) and muscle function. However, although promising and therefore under clinical trials, the mechanism of action of TMZ has not been clearly disclosed; here we hypothesized that it might involve the modulation of neuronal Ca2+ flows. We studied the effect of TMZ on Ca2+ dynamics in vivo, by using the transgenic zebrafish line Tg(neurod1:GCaMP6f) in which the neuronal expression of the Ca2+ indicator GCaMP allows to visualize Ca2+ dynamics in neurons of zebrafish larvae. By this elegant tool, we demonstrated, for the first time, that TMZ promotes an increase of intracellular Ca2+ transients in zebrafish spinal neurons likely enhancing motor neuron firing, which correlates with enhanced motor performance induced by this drug. Even though elevated intracellular Ca2+ levels have often been associated to neurotoxicity, it is unclear if the neuronal excitability features in some neuro-muscular disorders are compensatory or pathological. Therefore, this newly reported effect of TMZ which transiently and selectively enhances spinal neuron firing deserves to be further detailed and taken into account when the possible repurposing of this drug is proposed for the treatment of neuro-muscular disorders.
    Keywords:  Aging; Amyotrophic lateral sclerosis; Motor neuron disease; Neuro-muscular junction; Skeletal muscle; Spinal cord; Trimetazidine
    DOI:  https://doi.org/10.1038/s41598-025-06065-y
  23. Nat Biomed Eng. 2025 Jul 02.
    Jawbone-like organoids generated from human pluripotent stem cells.
    Souta Motoike, Yoshiko Inada, Junya Toguchida, Mikihito Kajiya, Makoto Ikeya.
      Engineering jawbone tissues from pluripotent stem cells presents a challenge owing to the lack of protocols for selectively inducing the jawbone progenitor, the first pharyngeal arch (PA1) ectomesenchyme, and for recapitulating three-dimensional osteocyte networks. Here we present a method for generating jawbone-like organoids from human induced pluripotent stem cells through PA1 ectomesenchyme of the mandibular prominence (mdEM). A three-dimensional culture system enables sequential differentiation of induced pluripotent stem cells into neural crest cells and mdEM. The mdEM exhibits proximal-distal patterning from the centre outwards, mirroring mandibular development. The introduction of exogenous pharyngeal epithelial signals induces mandibular prominence-specific regional patterning in the mdEM. When cultured under osteogenic conditions, the mdEM forms jawbone-like organoids comprising osteoblasts and network-forming osteocytes embedded in self-produced mineralized bone matrices. Moreover, these organoids promote bone regeneration when transplanted into jaws containing bone defects and recapitulate phenotypes of osteogenesis imperfecta, a genetic disorder characterized by fragile bones, using patient-derived induced pluripotent stem cells. Our protocols establish a foundation for investigating human jaw embryology and pathophysiology.
    DOI:  https://doi.org/10.1038/s41551-025-01419-3
  24. Proc Natl Acad Sci U S A. 2025 Jul 08. 122(27): e2502024122
    Axonal pathology differentially affects human Purkinje cell subpopulations in the essential tremor cerebellum.
    James Widner, Phyllis L Faust, Elan D Louis, Hirofumi Fujita.
      The cerebellar cortex is organized into discrete regions populated by molecularly distinct Purkinje cells (PCs), the sole cortical output neurons. While studies in animal models have shown that PC subtypes differ in their vulnerability to disease, our understanding of human PC subtype and vulnerability remains limited. Here, we demonstrate that human cerebellar regions specialized for motor vs. cognitive functions (lobule HV vs. Crus I) contain distinct PC populations characterized by specific molecular and anatomical features, which show selective vulnerability in essential tremor (ET), a cerebellar degenerative disorder. Using a known PC subtype marker, neurofilament heavy chain (NEFH), we found that motor lobule HV contains PCs with high NEFH expression, while cognitive lobule Crus I contains PCs with low NEFH expression in postmortem samples from healthy controls. In the same cerebella, PC axons in lobule HV were 2.2-fold thicker than those in Crus I. Across lobules, axon caliber positively correlated with NEFH expression. In ET cerebella, we identified motor lobule-specific PC axon pathology with a 1.5-fold reduction in caliber and increased axon variability in lobule HV, while Crus I axons were unaffected. Tremor severity and duration in ET correlated with axon diameter variability selectively in lobule HV PCs. Given that axonal caliber is a major determinant of neural signaling capacity, our results 1) suggest that disrupted cerebellar corticonuclear signaling is occurring in ET, and 2) provide evidence of region-specific PC populations in the human cerebellum and offer insight into how different PC subpopulations may contribute to the pathophysiology of cerebellar degeneration.
    Keywords:  Purkinje cell; essential tremor; human cerebellum; movement disorder; neurodegeneration
    DOI:  https://doi.org/10.1073/pnas.2502024122
  25. Nat Commun. 2025 Jul 01. 16(1): 5442
    Conformational dynamics and membrane insertion mechanism of B4GALNT1 in ganglioside synthesis.
    Jack W J Welland, Henry G Barrow, Phillip J Stansfeld, Janet E Deane.
      Glycosphingolipids (GSLs) are crucial membrane components involved in essential cellular pathways. Complex GSLs, known as gangliosides, are synthesised by glycosyltransferase enzymes and imbalances in GSL metabolism cause severe neurological diseases. B4GALNT1 synthesises the precursors to the major brain gangliosides. Loss of B4GALNT1 function causes hereditary spastic paraplegia, while its overexpression is linked to cancers including childhood neuroblastoma. Here, we present crystal structures of the human homodimeric B4GALNT1 enzyme demonstrating dynamic remodelling of the substrate binding site during catalysis. We show that processing of lipid substrates by B4GALNT1 is severely compromised when surface loops flanking the active site are mutated from hydrophobic residues to polar. Molecular dynamics simulations support that these loops can insert into the lipid bilayer explaining how B4GALNT1 accesses and processes lipid substrates. By combining structure prediction and molecular simulations we propose that this mechanism of dynamic membrane insertion is exploited by other, structurally distinct GSL synthesising enzymes.
    DOI:  https://doi.org/10.1038/s41467-025-60593-9
  26. Adv Sci (Weinh). 2025 Jul 01. e03660
    STING COPII ER Export Trafficking and Signaling Primed by Phosphorylation Switches.
    Yanan Nan, Dongxiao Cui, Jiajian Guo, Xiaojing Ma, Jiaming Wang, Linyue Guo, Tianyu Li, Mingrui Yang, Guangrui Huang, Anlong Xu, Wenfu Ma.
      Despite advances in understanding the STING signaling pathway, mechanisms governing cyclic GMP-AMP (cGAMP)-induced STING trafficking out of the endoplasmic reticulum (ER) remain unclear. This study reveals that STING localization is regulated by the balance between coat protein II (COPII)- and coat protein I (COPI)-mediated trafficking, maintaining ER residency in the inactive state or promoting transport to the cis-Golgi via enhanced COPII-mediated export upon activation. Two novel TANK-binding kinase 1 (TBK1)-regulated phosphorylated COPII sorting signals on STING-a conserved pSGME motif and a primate-specific pFS motif-are biochemically and structurally identified. These cGAMP-induced signals drive activated STING toward the ER-Golgi intermediate compartment (ERGIC) and the cis-Golgi complex. Using a cell-free COPII vesicle reconstitution system, TBK1 activation is shown to occur on COPII vesicles, while IRF3 phosphorylation is confined to the ERGIC or the cis-Golgi complex post-uncoating, due to the competitive binding of COPII Sec24 and IRF3 to phosphorylated STING. A class of compounds is also identified that attenuates IRF3 phosphorylation by inhibiting phosphorylated STING packaging into COPII vesicles. These findings elucidate STING trafficking mechanisms and offer therapeutic potential for diseases linked to dysregulated STING activation.
    Keywords:  COPII vesicle trafficking; ER export; IRF3; STING; TBK1; interferon; phosphorylated motifs
    DOI:  https://doi.org/10.1002/advs.202503660
  27. Cell Chem Biol. 2025 Jul 02. pii: S2451-9456(25)00197-7. [Epub ahead of print]
    Site-resolved assessment of targeted protein degradation.
    Ricardo Moreno-Ballesteros, Thomas Pembridge, Gaurav Beniwal, Satpal Virdee.
      Induced proximity using small molecules, exemplified by targeted protein degradation (TPD), represents a highly promising therapeutic strategy with significant untapped potential. However, evaluating an induced proximity event that accurately reflects drug binding typically requires the challenging and costly development of specific ligands, which limits the advancement of medicines based on this modality. To overcome this bottleneck, we combine genetic code expansion with ultra-fast bioorthogonal chemistry to sensitize specific protein sites at single-residue resolution to a generic bioorthogonal proximity inducer (BPI) molecule. Mammalian cells expressing sensitized mutants of the ubiquitin E3 ligases VHL and CRBN exhibit neosubstrate degradation in the presence of a BPI equipped with a ligand targeting bromodomain and extraterminal (BET) proteins. Furthermore, we demonstrate E3-independent degradation through recruitment of an upstream E2 conjugating enzyme. We anticipate that this approach will have broad applicability, enabling comprehensive assessment of the scope of induced proximity.
    Keywords:  E2 conjugating enzymes; E3 ligases; PROTAC; bioorthogonal chemistry; degrader; genetic code expansion; glues; induced proximity; targeted protein degradation; ubiquitin
    DOI:  https://doi.org/10.1016/j.chembiol.2025.06.002
  28. Nat Metab. 2025 Jul 01.
    Triglycerides are an important fuel reserve for synapse function in the brain.
    Mukesh Kumar, Yumei Wu, Justin Knapp, Catherine L Pontius, Daehun Park, Rose E Witte, Rachel McAllister, Kallol Gupta, Kartik N Rajagopalan, Pietro De Camilli, Timothy A Ryan.
      Proper fuelling of the brain is critical to sustain cognitive function, but the role of fatty acid (FA) combustion in this process has been elusive. Here we show that acute block of a neuron-specific triglyceride lipase, DDHD2 (a genetic driver of complex hereditary spastic paraplegia), or of the mitochondrial lipid transporter CPT1 leads to rapid onset of torpor in adult male mice. These data indicate that in vivo neurons are probably constantly fluxing FAs derived from lipid droplets (LDs) through β-oxidation to support neuronal bioenergetics. We show that in dissociated neurons, electrical silencing or blocking of DDHD2 leads to accumulation of neuronal LDs, including at nerve terminals, and that FAs derived from axonal LDs enter mitochondria in an activity-dependent fashion to drive local mitochondrial ATP production. These data demonstrate that nerve terminals can make use of LDs during electrical activity to provide metabolic support and probably have a critical role in supporting neuron function in vivo.
    DOI:  https://doi.org/10.1038/s42255-025-01321-x
  29. iScience. 2025 Jul 18. 28(7): 112761
    Critical impact of lysine 136 in TDP-43 phase separation, compartmentalization, and aggregation in living vertebrates.
    Cindy Maurel, Natalie M Scherer, Luan Luu, Rowan A Radford, Alison Hogan, Jessica Merjane, Andres Vidal-Itriago, Emily K Don, Tyler Chapman, Stephen Cull, Patrick Vourc'h, Leszek Lisowski, Albert Lee, Roger S Chung, Marco Morsch.
      TDP-43 is a nuclear RNA-binding protein that undergoes liquid-liquid phase separation (LLPS) and forms insoluble aggregates in neurodegenerative diseases. By studying TDP-43 in living vertebrates, we confirmed that TDP-43 undergoes LLPS and forms dynamic biomolecular condensates in spinal motor neurons. We validated in vivo that interfering with the lysine residue at position 136 altered the phase separation behavior of TDP-43 by reducing cytoplasmic mislocalization and aggregation. These alterations were post-translational modification (PTM) independent, highlighting that residue 136 is a key structural regulator of TDP-43 function. We further established an adeno-associated virus (AAV)-mediated expression approach in mice that confirmed altered nuclear condensation characteristics of lysine-modified TDP-43. These assessments exposed the formation of dynamic nuclear TDP-43 condensates and emphasize the important role of lysine 136 in maintaining TDP-43 function. Altogether, we establish lysine 136 as a molecular regulator for phase separation and TDP-43 aggregation in amyotrophic lateral sclerosis (ALS) in two in vivo platforms.
    Keywords:  Biochemistry; Neuroscience; Properties of biomolecules
    DOI:  https://doi.org/10.1016/j.isci.2025.112761
  30. Int J Biol Macromol. 2025 Jun 30. pii: S0141-8130(25)06200-2. [Epub ahead of print]319(Pt 4): 145645
    Injectable borax-loaded alginate hydrogels reduce muscle atrophy, modulate inflammation, and promote neuroprotection in the SOD1G93A mouse model of ALS through mechanisms involving IGF-Akt-mTOR signaling.
    Ana Rodriguez-Romano, Juan Gonzalez-Valdivieso, Laura Moreno-Martinez, Juan Francisco Vázquez Costa, Rosario Osta, Patricia Rico.
      Amyotrophic Lateral Sclerosis (ALS) is a prevalent condition characterized by motor neuron loss and skeletal muscle paralysis. Despite being associated to mutations in over 40 genes, its etiology remains elusive without a cure or effective treatment. ALS, historically considered a motor neuron disease, is defined today as a multisystem disorder involving non-neuronal cell types, including early muscle pathology independent of motor neuron degeneration (dying back hypothesis), thus skeletal muscle actively contributes to disease pathology, making it a viable therapeutic target for ALS. Our previous research has shown that boron transporter NaBC1 (encoded by the SLC4A11 gene), after activation co-localizes with integrins and growth factor receptors synergistically enhancing muscle repair. Here we investigate the effects of injectable alginate-based hydrogels for controlled local borax release in Amyotrophic Lateral Sclerosis muscle. Treated mice showed improved motor function, prolonged survival, and activation of essential muscle metabolic pathways, leading to enhanced muscle repair and reduced atrophy and inflammation. Interestingly, local muscle repair activation provided retrograde neuroprotection by preserving motor neurons and reducing neuro-inflammation. This study highlights the role of muscle tissue in ALS pathology, supporting its targeting with NaBC1-based therapies for muscle regeneration.
    Keywords:  ALS; Alginate hydrogel; Borax; Muscle regeneration; NaBC1 transporter (SLC4A11)
    DOI:  https://doi.org/10.1016/j.ijbiomac.2025.145645
  31. Sci Rep. 2025 Jul 01. 15(1): 21565
    Glycoproteomic profiling of serum-derived small extracellular vesicles enriched via ultracentrifugation and affinity-based techniques.
    Mojibola Fowowe, Cristian D Gutierrez Reyes, Judith Nwaiwu, Joy Solomon, Oluwatosin Daramola, Sherifdeen Onigbinde, Joseph Andrew Whitley, Houjian Cai, Yehia Mechref.
      Small extracellular vesicles (sEVs) are gaining recognition as potential biomarkers for diseases, including cancer, due to their involvement in key pathophysiological processes. However, the glycosylation of EVs and the specific roles of their glycans remain poorly understood. While several methods exist for isolating sEVs from complex biological samples, achieving sufficient purity and quantity for mass spectrometry-based glycoproteomic analysis remains a significant challenge. In this study, we compared two commonly used isolation methods, ultracentrifugation (UC) and immunoaffinity capture (MagCapture kit), across different starting volumes of human serum (200 µL and 500 µL) to evaluate their performance for downstream glycoproteomic analysis. While prior studies have examined protein content across isolation methods, our work uniquely investigates how isolation technique and sample volume affect glycoproteomic yield and quality. We show that UC, particularly at higher sample volumes, enables deeper glycoproteomic coverage, whereas MagCapture is advantageous when serum availability is limited. Notably, we report for the first time site-specific glycan microheterogeneity on sEV glycoproteins derived from human serum, including multiple glycoforms at the same glycosylation site. These findings highlight the complexity and biological relevance of glycosylation in sEV proteins and offer practical guidance for optimizing isolation protocols based on specific omics applications.
    Keywords:  EVs; Glycoproteomics; Immunoaffinity capture; Proteomics; Small extracellular vesicles; Ultracentrifugation
    DOI:  https://doi.org/10.1038/s41598-025-05430-1
  32. Chembiochem. 2025 Jun 30. e202500184
    Development of Antibody-Based Strategies for Targeted Degradation of Membrane and Extracellular Proteins.
    Xiaoqing Cai, Huanhuan Sun, Na Li.
      Membrane and extracellular proteins are essential components in various biological processes that ensure cellular function and homeostasis. Their dysregulation is linked to a wide range of diseases, making them pivotal therapeutic targets. Recent innovations in therapeutic strategies have concentrated on targeted protein degradation, particularly via the endocytosis-lysosome pathway, offering a novel approach to restoring balance within cellular systems. This review elucidates recent advancements in antibody-based therapeutics designed for the targeted degradation of membrane and extracellular proteins, specifically emphasizing three key mechanisms: lysosomal targeting receptors, transmembrane E3 ligases, and lysosome-sorting signals that facilitate the degradation of disease-relevant proteins. We focus on various construction strategies for these antibody-based therapeutics, highlighting the potential of antibody-ligand conjugates, bispecific antibodies, and antibody fusion proteins. By leveraging the natural endocytic pathway for efficient protein internalization and subsequent lysosomal degradation, these antibody-based platforms hold significant promise for developing targeted therapies for a variety of diseases. Through this review, we aim to provide insights into the exciting field of antibody-enabled lysosomal degradation and its implications for future therapeutic interventions.
    Keywords:  Antibody * Membrane proteins * Extracellular protein * Targeted protein degradation * Lysosome
    DOI:  https://doi.org/10.1002/cbic.202500184
  33. J Parkinsons Dis. 2025 Jul 04. 1877718X251354986
    Parkinson's disease associated with LRRK2-R1441C mutation: Characterization and comparison with other LRRK2 mutations.
    Rafi Hadad, Roy N Alcalay, Inna Senderova, Maria Nassar, Andjelika Milicic, Judith Aharon Peretz, Isabel Elaine Allen, Rachel Ben-Hayun, Natalia Chasnyk, Ilham Morani, Nadav Elkoshi, Victor Valcour, Ilana Schlesinger.
      Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene associate with familial and sporadic Parkinson's disease (PD). While various LRRK2 allelic variants have been studied, characteristics of R1441C carriers remain underexplored. We compared PD patients carrying the R1441C mutation (90% Israeli Arabs) to those carrying the G2019S (70% Ashkenazi Jews) and R1441G (42% Basque) variants. R1441C carriers exhibited a distinct clinical phenotype characterized by severe motor and non-motor symptoms and worse scores on the Montreal Cognitive Assessment. These findings highlight the importance of ethnic diversity and genetic stratification in PD research. These results need confirmation in larger, more diverse samples.
    Keywords:  LRRK2 protein; Parkinson’s disease; cognitive dysfunction; genetic variation; human; mutation
    DOI:  https://doi.org/10.1177/1877718X251354986
  34. Neuromolecular Med. 2025 Jul 03. 27(1): 50
    Dysbiosis and Neurodegeneration in ALS: Unraveling the Gut-Brain Axis.
    Vivek Kumar Sharma.
      Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a neurodegenerative disorder marked by the progressive degeneration of motor neurons in the brain and spinal cord. Despite decades of research, ALS remains incurable, diagnostically elusive, and is accompanied by rapid clinical decline, morbidity, and mortality. Its pathophysiology involves a complex interplay of genetic mutations (SOD1, C9/f72), environmental triggers, oxidative stress, neuroinflammation, and the accumulation of misfolded proteins, such as TDP-43 and SOD1. These factors disrupt cellular homeostasis aggravates excitotoxicity and neuronal death. Existing treatments, such as riluzole (a glutamate release modulator) and edaravone (a free radical scavenger), offer limited benefits, modestly prolonging survival or slowing functional decline without halting progression. Investigational approaches include antisense oligonucleotides targeting mutant SOD1 or C9orf72 genes, stem cell-based motor neuron replacement, and biomarker discovery to enable earlier diagnosis and progression monitoring. ALS patients frequently exhibit gastrointestinal (GI) symptoms, including dysphagia, sialorrhea, constipation, delayed gastric emptying, and pancreatic/parotid deficiencies. These observations underscore a close association between GI dysfunction and ALS pathogenesis. Also, recent studies implicate the gut-brain-microbiota axis in disease evolution, with microbial metabolites influencing neuroimmune interactions, synaptic plasticity, myelination, and skeletal muscle function. These studies indicate that dysbiosis-an imbalance in gut microbiota-may have a crucial role in ALS progression by impairing intestinal barrier integrity, promoting endotoxemia, and driving systemic inflammation. Conversely, ALS progression itself worsens dysbiosis, creating a vicious cycle of neuroinflammation and neurodegeneration. Preclinical and clinical evidence suggests that interventions targeting gut microbiota-such as prebiotics, probiotics, antibiotics, or phage therapy-could alleviate symptoms and slow disease progression and specific probiotic strains have also shown promise in reducing oxidative stress and inflammation in animal models. These findings highlight the urgent need to elucidate the functional role of gut microbiota in ALS to unlock novel diagnostic and therapeutic avenues. This review synthesizes current knowledge on the pathophysiology of ALS, with a focus on the emerging role of the gut-brain-microbiota axis. It highlights how dysbiosis influences diverse disease markers and neurodegenerative mechanisms, offering insights into potential therapeutic strategies and identifying key research gaps and future directions.
    Keywords:  Amyotrophic lateral sclerosis; Microbiota; Neuroinflammation; Oxidative stress; SCFA
    DOI:  https://doi.org/10.1007/s12017-025-08870-0
  35. Nat Commun. 2025 Jul 01. 16(1): 5996
    The loss of OPA1 accelerates intervertebral disc degeneration and osteoarthritis in aged mice.
    Vedavathi Madhu, Miriam Hernandaz-Meadows, Ashley Coleman, Kimheak Sao, Kameron Inguito, Owen Haslam, Paige K Boneski, Hiromi Sesaki, Ruteja A Barve, John A Collins, Makarand V Risbud.
      Recent studies have highlighted the importance of mitochondria in NP cells and articular chondrocyte health. Since the understanding of mechanisms governing mitochondrial dynamics in these tissues is lacking, we investigated the role of OPA1, a mitochondrial fusion protein, in their homeostasis. OPA1 knockdown in NP cells altered mitochondrial size and cristae shape and increased the oxygen consumption rate. OPA1 governed the morphology of multiple organelles, including peroxisomes, early endosomes and cis-Golgi and loss resulted in the dysregulation of autophagy. Metabolic profiling and 13C-flux analyses revealed TCA cycle anaplerosis and altered metabolism in OPA1-deficient NP cells. Noteworthy, Opa1AcanCreERT2 mice showed age-dependent disc degeneration, osteoarthritis, and vertebral osteopenia. RNA-Sequencing of Opa1cKO NP tissue revealed dysregulation of metabolism, autophagy, cytoskeletal reorganization, and extracellular matrix and shared strong thematic similarities with a subset of human degenerative NP samples. Our findings underscore that maintenance of mitochondrial dynamics and multi-organelle cross-talk is critical in preserving metabolic homeostasis of disc and cartilage.
    DOI:  https://doi.org/10.1038/s41467-025-60933-9
  36. Plant J. 2025 Jul;123(1): e70289
    Arabidopsis Vacuolar protein sorting 9a (VPS9a) is required for glutamine synthetase/glutamate synthase (GS/GOGAT) cycle and autophagy under nutrient starvation.
    Baiyang Yu, Yanhui Zhou, Yunfeng Shi, Shengshu Wang, Qing Pang, Chao Yang, Thomas Roitsch, Weiming Hu, Yizhou Wang, Fen Liu.
      Plants have developed complex endomembrane systems in response to environmental challenges such as nutrient deficiency. This study focused on the role of Vacuolar protein sorting 9 (VPS9a), a key regulatory gene involved in the endosomal sorting process in Arabidopsis thaliana. Loss of VPS9a function results in stress-sensitive phenotypes under carbon and nitrogen starvation. First, we investigated the changes in the Glutamine Synthetase/Glutamate Synthase (GS/GOGAT) cycle under nitrogen starvation and conducted a co-expression network analysis based on transcriptomic profiles. These results indicate that the endocytic pathway and the majority of the degradation processes are related to GS and NADH-GOGAT activity. Genes related to autophagy and endocytic pathways showed diverse response trends in Col-0, vps9a-2, and 35S:VPS9a-GFP/vps9a-2. Several autophagy- and endocytosis-related genes, including Autophagy-related protein 1 (ATG1), Autophagy-related protein 8 (ATG8), Thylakoid lumen protein (TLP18.3), Autoinhibited Ca(2+)-ATPase, Isoform 4 (ACA4), MAP kinase 2 (AtMKK2), and Extensin 21 (EXT21), were identified as hub genes. Further, we found that the loss of VPS9a function leads to reduced accumulation of autophagic bodies and a marked decrease in ATG8a protein levels but does not affect autophagic flux or the accumulation of ATG8 with phosphatidylethanolamine (PE). Interestingly, VPS9a appears to exert differential effects on various ATG8 Homologs. In summary, our results established a connection between autophagy, endocytic pathways, and nitrogen metabolism processes, identifying key hub genes involved in these processes. Among these hub genes, VPS9a was found to affect ATG8a levels, suggesting that VPS9a selectively regulates specific ATG8 proteins involved in autophagic processes.
    Keywords:  autophagy; endocytosis; glutamine synthetase/glutamate synthase (GS/GOGAT) cycle; nutrient deprivation; vacuolar protein sorting 9 (VPS9a)
    DOI:  https://doi.org/10.1111/tpj.70289
  37. Nat Commun. 2025 Jul 01. 16(1): 5902
    Generation of mature epicardium derived from human-induced pluripotent stem cells via inhibition of mTOR signaling.
    Yu Tian, Antonio Lucena-Cacace, Kanae Tani, Amanda Putri Elvandari, Rodolfo S Allendes Osorio, Megumi Narita, Yasuko Matsumura, Ian Costa Paixao, Yutaro Miyoshi, Azusa Inagaki, Julia Junghof, Yoshinori Yoshida.
      Reactivating the human epicardium post-cardiac injury holds promise for cardiac tissue regeneration. Despite successful differentiation protocols yielding pure, self-renewing epicardial cells from induced pluripotent stem cells (iPSCs), these cells maintain an embryonic, proliferative state, impeding adult epicardial reactivation investigation. We introduce an optimized method that employs mammalian target of rapamycin (mTOR) signaling inhibition in embryonic epicardium, inducing a quiescent state that enhances multi-step epicardial maturation. This yields functionally mature epicardium, valuable for modeling adult epicardial reactivation. Furthermore, we assess cardiac organoids with cardiomyocytes and mature epicardium, probing molecular mechanisms governing epicardial quiescence during cardiac maturation. Our results highlight iPSC-derived mature epicardium's potential in investigating adult epicardial reactivation, pivotal for effective cardiac regeneration. Additionally, the cardiac organoid model offers insight into intricate cardiomyocyte-epicardium interactions in cardiac development and regeneration.
    DOI:  https://doi.org/10.1038/s41467-025-60934-8
  38. Nat Commun. 2025 Jul 01. 16(1): 5566
    Rim4-seeded stress granules connect temperature sensing to meiotic regulation.
    Rudian Zhang, Shunjin Li, Wenzhi Feng, Suhong Qian, Akshay John Chellappa, Fei Wang.
      Meiosis is more vulnerable to heat than mitosis in many species including humans. In Saccharomyces cerevisiae, we discovered that stress granule formation halts meiosis at high temperatures. Meiotic stress granules appear at lower temperatures (33-42 °C) than mitotic stress granules (~46 °C), requiring the meiosis-specific RNA binding protein Rim4. Heat triggers site-specific Rim4 dephosphorylation, causing it to self-assemble into stress granule seeds. These recruit other stress granule components like Pab1 and mRNAs, pausing meiosis. Normally, 14-3-3 proteins block this assembly by binding phosphorylated Rim4. After temperature drops, Hsp104 assists to break down stress granules. Longer stress granule persistence correlates with better recovery, suggesting stress granules might provide temporal insulation for cellular repair processes prior to meiotic resumption.
    DOI:  https://doi.org/10.1038/s41467-025-60645-0
  39. Hum Mol Genet. 2025 Jun 30. pii: ddaf111. [Epub ahead of print]
    Familial ALS/FTD-associated RNA-binding deficient TDP-43 mutants cause neuronal and synaptic transcript dysregulation in vitro.
    Molly Magarotto, Richard T Gawne, Gabriele Vilkaite, Marcello Beltrami, Andrew S Mason, Han-Jou Chen.
      TDP-43 is an RNA-binding protein constituting the pathological inclusions observed in ~ 95% of ALS and ~ 50% of FTD patients. In ALS and FTD, TDP-43 mislocalises to the cytoplasm and forms insoluble, hyperphosphorylated and ubiquitinated aggregates that enhance cytotoxicity and contribute to neurodegeneration. Despite its primary role as an RNA/DNA-binding protein, how RNA-binding deficiencies contribute to disease onset and progression are little understood. Among many identified familial mutations in TDP-43 causing ALS/FTD, only two mutations cause an RNA-binding deficiency, K181E and K263E. In this study, we used CRISPR/Cas9 to knock-in the two disease-linked RNA-binding deficient mutations in SH-SY5Y cells, generating both homozygous and heterozygous versions of the mutant TDP-43 to investigate TDP-43-mediated neuronal disruption. Significant changes were identified in the transcriptomic profiles of these cells, in particular, between K181E homozygous and heterozygous cells, with the most affected genes involved in neuronal differentiation and synaptic pathways. This result was validated in cell studies where the neuronal differentiation efficiency and neurite morphology were compromised in TDP-43 cells compared to unmodified control. Interestingly, divergent neuronal regulation was observed in K181E-TDP-43 homozygous and heterozygous cells, suggesting a more complex signalling network associated with TDP-43 genotypes and expression level which warrants further study. Overall, our data using cell models expressing the ALS/FTD disease-causing RNA-binding deficient TDP-43 mutations at endogenous levels show a robust impact on transcriptomic profiles at the whole gene and transcript isoform level that compromise neuronal differentiation and processing, providing further insights on TDP-43-mediated neurodegeneration.
    Keywords:  RNA-binding protein; TDP-43; amyotrophic lateral sclerosis; frontotemporal dementia; neurodegeneration
    DOI:  https://doi.org/10.1093/hmg/ddaf111
  40. Biochem Soc Trans. 2025 Apr 30. 53(2): 431-445
    ESCRTing the RABs through conversion.
    Jachen A Solinger, Daniel P Ott, Anne Spang.
      The endosomal system is essential for the intra- and intercellular communication in cells and multicellular organisms. It is involved in the secretion of signaling factors and serves as a venue for signaling receptors from the plasma membrane, which are endocytosed after ligand binding. Many internalized receptor-ligand complexes and numerous other endocytosed proteins arrive at the Rab5-positive early endosome, where they will be sorted. Cargoes marked with ubiquitin are bound by endosomal sorting complex required for transport (ESCRT)-0 and ESCRT-I complexes to initiate their degradation. The remaining cargoes are recycled back to the plasma membrane or the trans-Golgi network. To degrade ubiquitinated cargoes, the early endosome has to mature into a late endosomal structure, the multivesicular body (MVB). This procedure requires the Rab5-to-Rab7 conversion, mediated by the RABEX5-MON1/CCZ1 RabGEF cascade. Moreover, cargoes destined for degradation have to be packaged into intraluminal vesicles (ILVs) through ESCRT-III and Vps4. The matured late endosome or MVB finally fuses with a lysosome to degrade the cargo. Although ESCRT-mediated ILV formation and Rab conversion are well-characterized processes during endosome maturation, it remained until recently unclear whether these processes are connected. Lately, several studies were published illuminating the relationship of ESCRT functions and Rab conversion. Here, we review the current knowledge on the role of the ESCRT machinery in cargo degradation and RABEX5 regulation and MON1/CCZ1-mediated Rab conversion during endosome maturation. Moreover, we propose a model on the regulatory role of ESCRT functions during endosome maturation.
    Keywords:  ESCRT; RABEX5; Rab GTPases; Rab conversion; endosome maturation
    DOI:  https://doi.org/10.1042/BST20253007
  41. Sci China Life Sci. 2025 Jul 02.
    The mechanisms and functions of mitochondria-encapsulating extracellular vesicles.
    Danli Sheng, Xiangyu Chen, Jing Shi, Hongyun Tang.
      Extracellular vesicles (EVs) are membrane-bound subcellular entities that perform crucial roles in cellular communication and the release of intracellular contents. Traditionally, EVs have been recognized for encapsulating a variety of biomolecules, including DNA, RNA, proteins, and metabolites. However, recent advancements in research have revealed that EVs can also encapsulate organelles, with mitochondria emerging as a significant cargo. This review delves into the burgeoning field of mitochondria-encapsulating EVs, such as mitophers, migrasomes, and exophers, along with other mitochondria-harboring EVs that are less characterized. We explore the discovery, distinctive features, and functional roles of these EVs in regulating mitochondrial quality and quantity, under both physiological and pathological conditions. The mechanisms underlying the generation of these vesicles are also examined. Additionally, we discuss the challenges and future directions in the study of mitochondria-containing EVs. Given their potential to serve as diagnostic biomarkers and therapeutic tools, these mitochondria-embedded vesicles represent a promising frontier in molecular and cell biology, with significant implications for understanding and treating a range of diseases.
    Keywords:  exopher; extracellular vesicles; migrasome; mitochondrial quality control; mitochondrial quantity control; mitocytosis; mitopher
    DOI:  https://doi.org/10.1007/s11427-024-2905-5
  42. Nat Commun. 2025 Jul 01. 16(1): 5519
    Cell-specific mechanisms drive connectivity across the time course of Huntington's disease.
    Carlos Estevez-Fraga, Isaac Sebenius, Justine Y Hansen, Benjamin Hänisch, Paul Zeun, Rachael I Scahill, Sarah Gregory, Eilanoir B Johnson, Edward J Wild, Lauren M Byrne, Alexandra Durr, Bernhard Landwehrmeyer, Blair R Leavitt, Bratislav Misic, Sofie Louise Valk, Geraint Rees, Sarah J Tabrizi, Peter McColgan.
      Hyperconnectivity in functional brain networks occurs decades before disease onset in Huntington's disease. However, the biological mechanisms remain unknown. We investigate connectivity in Huntington's disease using Morphometric INverse Divergence (MIND) in three Huntington's disease cohorts (N = 512) spanning from two decades before the onset of symptoms through to functional decline. Here, we identify stage-specific profiles, with hyperconnectivity 22 years from predicted motor onset, progressing to hypoconnectivity through the late premanifest and manifest stages, showing that hypoconnectivity is correlated with neurofilament light concentrations. To understand the biological mechanisms, we investigate associations with cortical organization principles including disease epicentres and cell-autonomous systems, in particular neurotransmitter distribution. The contribution from disease epicentres is limited to late premanifest while cell-autonomous associations are demonstrated across the Huntington's disease lifespan. Specific relationships to cholinergic and serotoninergic systems localized to granular and infragranular cortical layers are identified, consistent with serotoninergic layer 5a neuronal vulnerability previously identified in post-mortem brains.
    DOI:  https://doi.org/10.1038/s41467-025-60556-0
  43. J Mol Biol. 2025 Jul 01. pii: S0022-2836(25)00384-5. [Epub ahead of print] 169318
    Nucleocytoplasmic HDAC inhibition drives acetylation-dependent TDP-43 mislocalization and disulfide-linked oligomerization.
    Nataliia Lukianenko, Dong Min Kang, Aybuke Bekci, Yun Kyung Kim, Sungsu Lim.
      TDP-43 proteinopathies, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), are characterized by aberrant cytoplasmic mislocalization and aggregation of TDP-43. Here, we established a live-cell TDP43-BiFC model to visualize TDP-43 oligomerization in real time and screened diverse cellular stressors. Histone deacetylase (HDAC) inhibition emerged as the most potent trigger of TDP-43 oligomerization. In particular, selective inhibition of the shuttling HDAC4/5 with LMK-235 induced an early and robust formation of cytoplasmic TDP-43 oligomers, comparable to or even exceeding the effect of the pan-HDAC inhibitor apicidin. In contrast, nuclear-restricted HDAC1/3 inhibition by MS-275 prolonged TDP-43 retention in the nucleus with minimal cytoplasmic mislocalization or oligomerization, underscoring distinct roles for nuclear versus nucleocytoplasmic HDACs. Inhibition of cytoplasmic HDAC6 (tubastatin A) had no significant effect. Notably, both shuttling and pan-HDAC inhibition increased TDP-43 acetylation and promoted the accumulation of stable, disulfide-linked TDP-43 oligomers. These findings identify lysine acetylation as a key regulator of disulfide bond-dependent TDP-43 oligomerization and suggest that targeting nucleocytoplasmic HDACs could be a novel therapeutic strategy in TDP-43 proteinopathies.
    Keywords:  Shuttling HDACs; TDP-43 oligomerization; TDP43-BiFC; cytoplasmic mislocalization; disulfide-bond formation
    DOI:  https://doi.org/10.1016/j.jmb.2025.169318
  44. Nat Commun. 2025 Jul 01. 16(1): 5556
    Visualizing PIEZO1 localization and activity in hiPSC-derived single cells and organoids with HaloTag technology.
    Gabriella A Bertaccini, Ignasi Casanellas, Elizabeth L Evans, Jamison L Nourse, George D Dickinson, Gaoxiang Liu, Sayan Seal, Alan T Ly, Jesse R Holt, Tharaka D Wijerathne, Shijun Yan, Elliot E Hui, Jerome J Lacroix, Mitradas M Panicker, Srigokul Upadhyayula, Ian Parker, Medha M Pathak.
      PIEZO1 is critical to numerous physiological processes, transducing diverse mechanical stimuli into electrical and chemical signals. Recent studies underscore the importance of visualizing endogenous PIEZO1 activity and localization to understand its functional roles. To enable physiologically and clinically relevant studies on human PIEZO1, we genetically engineered human induced pluripotent stem cells (hiPSCs) to express a HaloTag fused to endogenous PIEZO1. Combined with advanced imaging, our chemogenetic platform allows precise visualization of PIEZO1 localization dynamics in various cell types. Furthermore, the PIEZO1-HaloTag hiPSC technology facilitates the non-invasive monitoring of channel activity across diverse cell types using Ca2+-sensitive HaloTag ligands, achieving temporal resolution approaching that of patch clamp electrophysiology. Finally, we use lightsheet microscopy on hiPSC-derived neural organoids to achieve molecular scale imaging of PIEZO1 in three-dimensional tissue. Our advances establish a platform for studying PIEZO1 mechanotransduction in human systems, with potential for elucidating disease mechanisms and targeted drug screening.
    DOI:  https://doi.org/10.1038/s41467-025-59150-1
  45. J Neural Transm (Vienna). 2025 Jun 28.
    Co-occurrence of amyotrophic lateral sclerosis and multiple sclerosis: a rare but interesting association.
    Kurt A Jellinger.
      Multiple sclerosis (MS) is an inflammatory demyelinating disease with highly variable clinical course and usual onset in younger age, caused by genetic and environmental factors. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that affects motor neurons in the brain and spinal cord, resulting in gradual loss of voluntary muscle and respiratory control. Both ALS and MS exhibit distinct underlying causes and disease mechanisms, despite some shared clinical effects. About 10% of ALS are linked to genetic factors, such as C9orf72, the remaining sporadic ones being potentially influenced by environmental, toxic and oxidative stress, while MS is an autoimmune disorder where the immune system leads to inflammation and attacks the myelin sheath, genetic predisposition and viral infections playing a role in its susceptibility. The co-occurrence of ALS and MS is extremely rare, with 46 cases being reported in the available literature from 1986 to 2024, while in the earlier literature, cases with coincidental muscular atrophy simulating ALS were described. In the overwhelming majority, ALS manifested between one and 41 years after the onset of MS; only in four cases was ALS present before detection of MS. The concurrence of MS and ALS can be explained by similarities in their pathogenesis related to neurodegeneration, inflammation, and/or genetic susceptibility. The role of rare genetic ALS forms in this comorbidity deserves further studies. The shared inflammatory component with a cascade of oxidative stress and other noxious mechanisms leads to progressive motor and bulbar or other symptoms that underscore the potential for cross-disease research to yield insights applicable to both conditions and their relations to immune-mediated disorders.
    Keywords:  Amyotrophic lateral sclerosis; Genetic markers; Multiple sclerosis; Neuroinflammation
    DOI:  https://doi.org/10.1007/s00702-025-02975-3
  46. Res Sq. 2025 Jun 23. pii: rs.3.rs-6819992. [Epub ahead of print]
    Cerebellar pathology contributes to neurodevelopmental deficits in spinal muscular atrophy.
    Florian Gerstner, Sandra Wittig, Christian Menedo, Sayan Ruwald, Maria J Carlini, Adela Vankova, Leonie Sowoidnich, Gerardo Martín-López, Vanessa Dreilich, Andrea Alonso Collado, John G Pagiazitis, Oumayma Aousji, Chloe Grzyb, Amy Smith, Mu Yang, Francesco Roselli, George Z Mentis, Charlotte J Sumner, Livio Pellizzoni, Christian M Simon.
      Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by ubiquitous SMN deficiency and loss of motor neurons. The persistence of motor and communication impairments, together with emerging cognitive and social deficits in severe Type I SMA patients treated early with SMN-restoring therapies, suggests a broader dysfunction involving neural circuits of the brain. To explore the potential supraspinal contributions to these emerging phenotypes, we investigated the cerebellum, a brain region critical for both motor and cognitive behaviors. Here, we identify cerebellar pathology in both post-mortem tissue from Type I SMA patients and a severe mouse model, which is characterized by lobule-specific Purkinje cell (PC) death driven by cell-autonomous, non-apoptotic p53-dependent mechanisms. Loss and dysfunction of excitatory parallel fiber synapses onto PC further contribute to cerebellar circuit disruption and altered PC firing. Furthermore, we identified impaired ultrasonic vocalization (USV) in a severe SMA mouse model-a proxy for early-developing social communication skills that depend on cerebellar function. Cell-specific rescue experiments demonstrate that intrinsic cerebellar pathology contributes to motor and social communication impairments independently of spinal motor circuit abnormalities. Together, these findings establish cerebellar dysfunction as a pathogenic driver of motor and social deficits, providing a link between brain involvement and the emerging neurodevelopmental phenotypes of SMA.
    DOI:  https://doi.org/10.21203/rs.3.rs-6819992/v2
  47. Front Cell Dev Biol. 2025 ;13 1575571
    Engine breakdown of lysosomes and related organelles and the resulting physiology.
    Nina Bakker, Marlieke L M Jongsma, Jacques Neefjes.
      Late endosomes/lysosomes (LE/Lys) and lysosome related organelles (LROs) move dynamically through cells which involves many levels of regulation. To reach their destination, they need to connect to the motor proteins dynein-dynactin, kinesin or myosin for long-range bidirectional transport along microtubules and short-range movement along actin filaments. This connection depends on various factors at the microtubule, including the MAP- and tubulin-code, as well as adaptors, Rab GTPases and effector proteins marking the LE/Lys and LRO membranes. Mutations affecting this transport results in defective LE/Lys or LRO cargo delivery often resulting in skin, neurological and/or immunological diseases. How LE/Lys and LRO transport is orchestrated and how it fails in disease states, will be discussed.
    Keywords:  disease; dynein; kinesin; lysosome-related organelles (LROs); lysosomes; microtubules; transport
    DOI:  https://doi.org/10.3389/fcell.2025.1575571
  48. Can J Neurol Sci. 2025 Jul 03. 1-6
    Tofersen treatment normalizes neurofilament levels in autosomal recessive SOD1 Amyotrophic Lateral Sclerosis.
    Bram De Wel, Theodore Mobach, Gerald Pfeffer, Gordon Jewett.
      
    DOI:  https://doi.org/10.1017/cjn.2025.10350
This page is being maintained by Thomas Krichel. It was last updated on 2025‒07‒13 at 13:32.