bims-axbals 2026-03-22 papers

bims-axbals

Biomed News

on Axonal biology and ALS

Issue of 2026–03–22
34 papers selected by
TJ Krzystek

TDP-43 impairs glycolysis by sequestering hexokinase 1 in amyotrophic lateral sclerosis.
Ubiquitin signatures on aggregating proteins in neurodegeneration.
Functional validation of the novel KIF5A p.R17Q VUS reveals defective axonal transport in iPSC-motoneurons from a SPG10 patient.
Consequences of the Novel ALS-Associated KIF5A Variant c.2993-6C > A for Exon 27 Splicing and Axonal Transport of SFPQ.
High-throughput screening of ALS patient iPSC-derived spinal motor neurons identifies novel compounds that increase neurofilament light chain expression.
Reduced nuclear TDP-43 and cytoplasmic DLK1 as markers of motor neuron degeneration in amyotrophic lateral sclerosis.
Self-inactivating AAV-CRISPR at different ages enables sustained amelioration of Huntington's disease deficits in BAC226Q mice.
Control of lysosome function by the GTPase-activating protein TBC1D9B and its binding partner TMEM55B.
Splicing the narrative: alternative TARDBP splicing and its relation to neurodegeneration in ALS and FTD.
Biopreservation of a tissue engineered nigrostriatal pathway for tract reconstruction in Parkinson's disease.
Paraspeckle condensation is controlled via TDP-43 polymerization and linked to neuroprotection.
The role of TDP-43 fragments in regular cellular functions and homeostatic failure.
Features of Mitochondrial Dynamics Changes in Large Pyramidal Neurons of the Human Motor Cortex during Aging.
Small heat shock proteins HspB1 and HspB5 differentially alter the condensation and aggregation of the TDP-43 low-complexity domain.
Mitochondria "Shackled" by Mutant Huntingtin: Analysis of Morphological Alterations and Disruptions of Intracellular Transport.
Peripheral inflammation mediates midbrain Lrrk2 kinase activity via Rab32 expression.
Employing an integrated computational simulation strategy to identify high-affinity ligands for TDP-43 amyloid proteins.
Impact of the CYFIP2 R87C variant in a human neuronal model in vitro.
Uncovering NMDA receptor-mediated high firing activity in excitatory human neurons.
Huntingtin (HTT) interactome in regulation of DNA repair/remodeling and RNA processing pathways.
Decoding neurodegeneration one cell at a time.
Presenilin-dependent regulation of neuronal tau pathology via the autophagy and proteasome pathways.
Molecular resilience of neurons to repetitive mechanical compression.
Identification of tofersen PD-response biomarkers in VALOR clinical trial CSF via multiplexed quantitative proteomics.
Neuronal mitochondrial dynamics: roles in brain disorders and therapeutic potential.
Bisphenol-A impairs hippocampal neurogenesis by disrupting Kinesin-1-dependent mitochondrial trafficking.
Mitochondria acidify lysosomes through membrane contacts.
Non-physiological potassium concentrations in commercial culture media trigger acute seizure-like activity in human iPSC-derived neurons.
Intellectual disability-causing mutations in KIF11 impair microtubule dynamics and dendritic arborization.
Human Induced Pluripotent Stem Cell-Based Models for Studying Neural Repair.
The role of autophagy in microwave radiation induced toxicity in iPSC-derived cardiomyocytes.
Lysosomal down-regulation of the mu opioid receptor is opposed by the Retromer complex.
Protocol for measuring lipid membrane fluidity in human iPSC-derived neural cells.
Retrograde Golgi-to-ER transport is regulated by diacylglycerol in Saccharomyces cerevisiae.

Acta Neuropathol. 2026 Mar 16. pii: 26. [Epub ahead of print]151(1):

TDP-43 impairs glycolysis by sequestering hexokinase 1 in amyotrophic lateral sclerosis.

Cassandra Barone, Rihua Wang, Sarah Cooke, Hang Pong Ng, Rodolfo S Ferreira, Helen C Miranda, Xin Qi.

  Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive motor neuron degeneration and cytoplasmic mislocalization of TDP-43. While metabolic dysfunction is increasingly recognized in ALS, the mechanistic link between impaired energy metabolism and TDP-43 pathology remains unknown. Here, we show that cytoplasmic TDP-43 directly disrupts glycolysis by targeting hexokinase 1 (HK1), the first rate-limiting enzyme of the pathway. In cells expressing a TDP-43 variant lacking its nuclear localization signal and in patient-derived iPSC motor neurons, TDP-43 accumulation in the cytoplasm reduces glycolytic capacity, indicating a neuron-intrinsic metabolic defect. Across cellular models including patient-derived neurons, TDP-43 mutant mice, and postmortem spinal cord tissue from ALS patients, we observe consistent decreases in HK1 protein level, mitochondrial association, and enzymatic activity, despite unchanged transcript levels. Mechanistically, cytoplasmic TDP-43 directly binds to HK1, disassociating it from mitochondria and promoting its sequestration into insoluble aggregates. This mislocalization impairs glycolysis and increases neuronal vulnerability. Notably, compensation for HK1 loss reduces cytoplasmic TDP-43 and ubiquitin accumulation, improves motor performance, and prolongs survival in TDP-43-associated ALS models. Together, these findings identify a previously unrecognized mechanism by which TDP-43 impairs glycolysis through HK1 misregulation and highlight glycolytic restoration as a potential therapeutic strategy in ALS.

Keywords:  Glucose; Metabolism; Motor neuron; Spinal cord

DOI:  https://doi.org/10.1007/s00401-026-02996-6
Essays Biochem. 2025 Dec 22. pii: EBC20253046. [Epub ahead of print]69(5):

Ubiquitin signatures on aggregating proteins in neurodegeneration.

Subhashree Sahoo, Amrita Arpita Padhy, Kummari Shivani, Ashish Misra, Parul Mishra.

  The aberrant accumulation of misfolded proteins marked by cellular dysfunction and progressive neuronal loss is the hallmark of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. This review examines the pivotal role of ubiquitin modifications in altering the fate of aggregation-prone proteins such as tau, α-synuclein, mutant huntingtin, TAR DNA-binding protein 43 and superoxide dismutase 1. The ubiquitin signatures identified by their linkage types, chain architectures and site specificities emerge as a complex regulatory language that influences the clearance, aggregation or cellular propagation of these aggregating proteins. The dysregulation of other components of the ubiquitin association pathways, such as impaired E3 ligases and deubiquitinases, also contributes to the inefficient protein disposal and disease progression. Understanding how ubiquitin signatures alter the spatiotemporal dynamics of aggregating proteins is critical for advancing our knowledge of disease biology. Here, we focus on the role of ubiquitin modifications and their associated regulators affecting protein fate and neurotoxicity, and highlight the current therapeutic strategies targeting the degradation of aggregating proteins to uncover potential avenues for treating neurodegenerative diseases.

Keywords:  autophagy; neurodegenerative disease; proteasome; ubiquitin; ubiquitin E3 ligases

DOI:  https://doi.org/10.1042/EBC20253046
Front Genet. 2026 ;17 1774170

Functional validation of the novel KIF5A p.R17Q VUS reveals defective axonal transport in iPSC-motoneurons from a SPG10 patient.

Serena Santangelo, Valeria Casiraghi, Claudia Fallini, Sabrina Invernizzi, Silvia Peverelli, Martina Bertocchi, Monica Feole, Marta Cozzi, Stefania Magri, Angelo Poletti, Patrizia Bossolasco, Franco Taroni, Vincenzo Silani, Antonia Ratti.

  Cytoskeletal alterations and axonal transport deficits are key factors in many neurodegenerative disorders. The neuronal kinesin family member 5A (KIF5A) is a microtubule-based motor protein critical for anterograde transport of RNA granules, organelles, and neurofilaments along axons and dendrites. Heterozygous missense and nonsense mutations in the N-terminal motor and stalk domains are associated with hereditary spastic paraplegia 10 (SPG10) and Charcot-Marie-Tooth disease type 2 (CMT2), while frameshift mutations in KIF5A C-terminal cargo-binding domain are linked to amyotrophic lateral sclerosis (ALS). We recently reprogrammed an iPSC line from a SPG10 patient carrying the novel missense variant c.50G>A (p.R17Q) in the KIF5A motor domain, classified as variant of unknown significance (VUS) and predicted to affect ATP binding. Here we gene-edited this mutant iPSC line by CRISPR-Cas9 to obtain an isogenic wild-type (WT) KIF5A cell line. We next examined functionally the impact of the p.R17Q VUS on KIF5A protein sub-cellular distribution and on axonal transport of mitochondria and lysosomes in differentiated iPSC-motoneurons (MNs). The presence of neurofilament-positive axonal swellings and an increased distribution of KIF5A protein in distal neurites was observed in the mutant p.R17Q compared to the WT KIF5A iPSC-MNs, indicating a likely defective axonal transport. The anterograde velocity and distance travelled by mitochondria and lysosomes along neurites was indeed significantly reduced in the mutant KIF5A iPSC-MNs compared to the WT ones. These findings demonstrate that the p.R17Q VUS is pathogenic, thereby extending the spectrum of KIF5A mutations causing SPG10 and support the use of patient-derived iPSC-MNs to functionally validate KIF5A-associated VUS.

Keywords:  KIF5A; SPG10; VUS; axonal transport; iPSC; motor neurons

DOI:  https://doi.org/10.3389/fgene.2026.1774170
Neurol Genet. 2026 Apr;12(2): e200362

Consequences of the Novel ALS-Associated KIF5A Variant c.2993-6C > A for Exon 27 Splicing and Axonal Transport of SFPQ.

Guy A Rouleau, Ziqi Yu, Jay P Ross, Daniel Rochefort, Boting Li, Kate Bornais, Marvin Chum, Sali M K Farhan, Patrick A Dion.

Background and Objectives: Recent studies have identified variants in the kinesin family member 5A (KIF5A) gene that predispose to amyotrophic lateral sclerosis (ALS). These ALS-linked KIF5A variants lead to the exclusion of exon 27, resulting in the production of a mutated protein with an altered C-terminal region (KIF5A ΔExon27). Through whole genome sequencing, we identified a novel KIF5A intronic variant, rs1057522322 (c.2993-6C > A; chr12:57582596C > A, GRCh38.p14), in a family segregating ALS. Our goal is to investigate the effect of this variant on exon 27 splicing and to assess its functional consequences on KIF5A-mediated cargo transport.
Methods: Induced pluripotent stem cells (iPSCs) were generated from siblings with and without the c.2993-6C > A variant. RT-PCR was performed on RNA extracted from iPSC-derived neurons to assess exon 27 splicing. Functional studies were conducted on iPSC-derived motor neurons (MNs).
Results: RT-PCR confirmed that the c.2993-6C > A variant induced exon 27 skipping in KIF5A. Immunofluorescent staining showed that KIF5A ΔExon27 abolished the axonal interaction with splicing factor proline- and glutamine-rich, a cargo specifically transported by KIF5A. Under stress conditions, MNs carrying the c.2993-6C > A variant exhibited TDP-43 proteinopathy.
Discussion: KIF5A intronic variant c.2993-6C > A could be a risk factor for ALS. KIF5A ΔExon27 impairs KIF5A-mediated cargo transport and contributes to ALS pathogenesis in a TDP-43-dependent manner.

DOI: https://doi.org/10.1212/NXG.0000000000200362
SLAS Discov. 2026 Mar 14. pii: S2472-5552(26)00009-2. [Epub ahead of print] 100303

High-throughput screening of ALS patient iPSC-derived spinal motor neurons identifies novel compounds that increase neurofilament light chain expression.

Gulcan Semra Sahin, Paul J Guyett, Kaiping Xu, Jennifer Kouznetsova, Wei Zheng, Michael Hendrickson.

  Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease primarily affecting motor neurons both in the spinal cord and brain. The cardinal pathology of ALS is motor neuron-selective inclusion of proteins such as TDP43, SOD1, C9orf72-derived dipeptide repeats, or FUS due to the mutations in the genes encoding them. Both familial and sporadic forms of ALS also show neurofilament (NF) aggregates, attributed to an imbalance in subunit expression, particularly a decrease in neurofilament light chain (NF-L) levels. Current FDA-approved treatments extend survival for only a few months, highlighting the urgent need for new therapies. In this study, we developed a cell-based reporter system for high-throughput screening by engineering induced pluripotent stem cells (iPSCs) derived from ALS patients and differentiating them into spinal motor neurons. We screened over 6,000 compounds using these reporter iPSC-derived motor neurons and identified a novel compound that increases NF-L expression by more than 50%. However, this novel compound also inhibits TGF-β signaling, prompting us to optimize its activity through a hit-to-lead chemistry analysis. In our subsequent investigations, we identified an additional compound that does not affect TGF-β signaling and outperforms the original compound in both in vitro and in vivo drug metabolism and pharmacokinetics assays. Our study highlights the utility of iPSC-derived neurons in disease modeling and illustrates how they can be employed to discover new compounds for therapeutic development through extensive screening in disease-relevant settings.

Keywords:  Amyotrophic lateral sclerosis; drug discovery; drug metabolism and pharmacokinetics; induced pluripotent stem cells, motor neurons, quantitative high throughput screen

DOI:  https://doi.org/10.1016/j.slasd.2026.100303
J Neuropathol Exp Neurol. 2026 Mar 19. pii: nlag017. [Epub ahead of print]

Reduced nuclear TDP-43 and cytoplasmic DLK1 as markers of motor neuron degeneration in amyotrophic lateral sclerosis.

Takahiro Takeda, Ai Ishikawa, Sayuri Kokubun, Yumiko Saito, Sagiri Isose, Kimiko Ito, Kimihito Arai, Satoshi Kuwabara, Kazuhiro Honda.

  Loss of upper and lower motor neurons (MNs) is a defining pathological feature underlying the clinical manifestations of amyotrophic lateral sclerosis (ALS). However, the differences in MN loss and TDP-43 pathology between these areas in ALS patients remain unclear. This study included 7 patients with ALS and 3 controls from consecutive autopsies. The cell density and regional density of TDP-43-positive inclusions in 4 upper MN areas and their anatomically corresponding lower MN areas were measured. The numbers of large cells with loss of nuclear TDP-43 and cytoplasmic delta-like-1 homolog (DLK1) were counted. The results showed severe MN loss in both upper and lower MN areas. However, TDP-43-positive inclusions differed markedly, that is they were rare in upper MNs but abundant in lower MN. In upper MN areas, TDP-43 density was not associated with the residual rate of MNs, whereas in lower MN areas, the density in MNs was associated with the cell residual rate. Significantly higher numbers of MNs lacking nuclear TDP-43 and cytoplasmic DLK1 were observed in the upper and lower MN regions in ALS vs controls. These findings suggest that these morphological changes may be closely related to motor neuron vulnerability and may be mechanistic contributors to ALS development.

Keywords:  DLK1; TDP-43 pathology; amyotrophic lateral sclerosis; cytoplasmic inclusions; motor neuron degeneration; neuropathology

DOI:  https://doi.org/10.1093/jnen/nlag017
Sci Adv. 2026 Mar 20. 12(12): eaea8052

Self-inactivating AAV-CRISPR at different ages enables sustained amelioration of Huntington's disease deficits in BAC226Q mice.

Yuanyi Dai, Zuliayeti Abudujielili, Yunyi Ding, Wanping Huang, Jianhang Yin, Liqiong Ou, Jiazhi Hu, Sushuang Zheng, Chenjian Li.

Huntington's disease (HD) is a monogenic autosomal dominant neurodegenerative disorder caused by a CAG repeat expansion in exon 1 of the HTT gene, yielding a gain-of-toxic-function mutant Huntingtin protein (mHTT). CRISPR-Cas9 is a potentially powerful therapeutic strategy for HD by eliminating mutant HTT (mHTT) gene. We developed a specific SaCas9 guide RNA to target human mHTT and a self-inactivating gene editing system that abolishes SaCas9 after a short transient expression for high gene editing efficiency and maximal safety to prevent off-target effects. Both conventional and the self-inactivating gene editing systems successfully eliminated mHTT gene, 60 to 90% mHTT protein and 90% of mHTT aggregation in BAC226Q mouse brains, which resulted in significant long-term rescue of neuropathology, motor deficits, weight loss, and shortened life span. These beneficial effects were observed when gene editing was applied before, at, and well after the onset of pathological and behavioral abnormalities. These proof-of-concept data demonstrate that gene editing can be a highly effective therapeutic approach for HD.

DOI: https://doi.org/10.1126/sciadv.aea8052
Nat Commun. 2026 03 14. pii: 2487. [Epub ahead of print]17(1):

Control of lysosome function by the GTPase-activating protein TBC1D9B and its binding partner TMEM55B.

Valentin Duhay, Miaomiao Tian, Klaudia Kosieradzka, Michael Ebner, Wen-Ting Lo, Michael Krauss, Henner-Linus Sprengel, Matthias Voss, Mara Riechmann, Jeffrey N Savas, Michael Schwake, Volker Haucke, Markus Damme.

Lysosomes are highly dynamic organelles that serve antagonistic functions as terminal catabolic stations for the degradation of macromolecules and as central metabolic decision centers for anabolic growth signaling. Lysosome dysfunction is implicated in various human diseases. The physiological roles of lysosomes are linked to the control of lysosome position and dynamics via the activity of the kinesin-activating small GTPase ARL8. How the activity of ARL8 is regulated remains poorly understood. Here, we identify the GTPase-activating Tre-2/Bub2/Cdc16 (TBC) domain protein TBC1D9B as a critical negative regulator of ARL8B function. We demonstrate that TBC1D9B is associated with the lysosomal membrane protein TMEM55B, directly binds to ARL8B-GTP, and stimulates its GTPase activity. Knockout of TBC1D9B or its binding partner TMEM55B causes lysosome dispersion, defective autophagic flux, and impairs the adaptive degradative response of cells to limiting nutrient supply. These lysosomal phenotypes of TBC1D9B loss are occluded by concomitant depletion of ARL8 in cells. Collectively, our data unravel a key role for TBC1D9B in controlling lysosome function by serving as a negative regulator of ARL8 activity.

DOI: https://doi.org/10.1038/s41467-026-70345-y
J Clin Invest. 2026 Mar 16. pii: e199846. [Epub ahead of print]136(6):

Splicing the narrative: alternative TARDBP splicing and its relation to neurodegeneration in ALS and FTD.

Morgan R Miller, Megan Dykstra, Sami Barmada.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are progressive neurodegenerative diseases characterized by the nuclear clearance and cytoplasmic aggregation of transactive response DNA/RNA-binding protein of 43 kDa (TDP43). Alternative splicing of TARDBP, the gene encoding TDP43, leads to a surprising diversity of RNA and protein isoforms with unique functions and potential implications for disease pathogenesis. Here, we review the production, properties, and functional consequences of alternative splicing in the development of ALS and FTD, focusing primarily on TDP43 due to its integral connection with the pathogenesis of sporadic as well as familial forms of these diseases. We synthesize current evidence on the biology of alternative TARDBP splicing, highlight key questions regarding its role in TDP43 proteinopathies such as ALS and FTD, and touch on the larger phenomenon of alternative splicing and its relationship to disease.

DOI: https://doi.org/10.1172/JCI199846
Acta Biomater. 2026 Mar 18. pii: S1742-7061(26)00180-7. [Epub ahead of print]

Biopreservation of a tissue engineered nigrostriatal pathway for tract reconstruction in Parkinson's disease.

Dimple Chouhan, Kevin D Browne, Wisberty J Gordián Vélez, Saarang P Karandikar, Ronit Patel, Kiera N A Yankson, Robert B Shultz, John E Duda, D Kacy Cullen.

  The typical motor symptoms of Parkinson's disease (PD) are caused by selective loss of dopaminergic neurons in the substantia nigra (SN). Although conventional pharmacotherapies can temporarily alleviate symptoms, no approved therapies exist to slow or reverse the underlying pathologic processes. To address this gap, cell transplantation therapies are being pursued; however, restoration of the original neuroanatomical circuit is not a goal of traditional ectopic intra-striatal neuronal transplantations. To address this, we developed an implantable tissue engineered nigrostriatal pathway (TE-NSP) containing human stem cell derived dopaminergic neurons with pre-formed long-projecting axonal bundles to replace the circuitry connecting the SN and the striatum. However, a challenge in the translation of tissue engineered medical products is the need for storage and transportation following biofabrication to enable point-of-care surgical implantation. Herein, we describe successful creation of TE-NSPs using a commercially-available human iPSC-derived dopaminergic neuronal source and describe growth characteristics for a range of neuronal and axonal densities. We also established protocols for the biopreservation of these fully-grown, human neuron-based TE-NSPs under hypothermic (4°C) conditions for up to 2 days. Subsequent assessment of neuronal viability and maintenance of axonal-tract architecture out to 12-weeks in vitro demonstrate that short-term hibernation of TE-NSPs consisting of 55,000 neurons did not reduce neuronal viability, axonal health, structural integrity, or survival in physioxia conditions (5% O2) when compared to non-biopreserved controls. The long-term survival of biopreserved TE-NSPs in vitro provides proof-of-concept supporting hypothermic storage during transportation for future safety and efficacy studies. STATEMENT OF SIGNIFICANCE: Degeneration of dopaminergic neurons and their axonal projections comprising the nigrostriatal pathway leads to Parkinson's disease, the second most common neurodegenerative disease globally. To address the shortcomings of the current cell transplantation therapies that primarily focus on ectopic cell transplantation, we have generated an engineered microtissue with pre-formed axon tracts using human neurons. Our tissue engineered nigrostriatal pathways (TE-NSPs) are implantable engineered microtissue that structurally and functionally resemble the native nigrostriatal pathway. For future translational applications, we established their preservation under hypothermic conditions, facilitating storage and transportation to the clinical setting. The study provides proof-of-concept that biopreserved 'living neural tissue' survive under hypothermic and simulated physioxic conditions, demonstrating their translational potential in the human brain.

Keywords:  Parkinson’s disease; axonal pathway; living scaffold; neurodegeneration; tissue engineering

DOI:  https://doi.org/10.1016/j.actbio.2026.03.031
Nat Cell Biol. 2026 Mar 18.

Paraspeckle condensation is controlled via TDP-43 polymerization and linked to neuroprotection.

Project MinE ALS Sequencing Consortium

The paraspeckle is a disease-relevant biomolecular condensate assembled from long non-coding RNA (lncRNA) NEAT1_2 ribonucleoprotein particles. Paraspeckle biogenesis is suppressed in normal tissues, yet it can be rapidly upregulated under stress. Here we demonstrate that a neurodegeneration-linked RNA-binding protein TDP-43 inhibits NEAT1_2 ribonucleoprotein particle condensation into the paraspeckle, in a concentration-dependent manner, which requires its intact polymerization and RNA binding. This effect is counterbalanced by core paraspeckle proteins such as FUS. Below disruptive concentrations, TDP-43 can be recruited into paraspeckles, forming non-liquid clusters. Under stress, TDP-43 sequestration into de novo nuclear condensates alleviates paraspeckle suppression and increases their dynamism. NEAT1_2 middle-part and 3'-end UG repeats mediate paraspeckle regulation by TDP-43 cotranscriptionally and post assembly, respectively. The deletion of the 3'-end UG repeat increases paraspeckle stability and cytoprotection in stressed human neurons. Consistently, longer 3'-end UG repeats are linked to shorter survival in the neurodegenerative disease amyotrophic lateral sclerosis. Thus, TDP-43 is a critical regulator of paraspeckle condensates linked to cytoprotection.

DOI: https://doi.org/10.1038/s41556-026-01895-y
Neurobiol Dis. 2026 Mar 15. pii: S0969-9961(26)00094-X. [Epub ahead of print] 107349

The role of TDP-43 fragments in regular cellular functions and homeostatic failure.

Regina Dahlhaus, Ralf J Braun.

  Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of motor neurons, leading to severe muscle weakness, loss of voluntary movement, and respiratory failure. A widely noted feature of the disease is the presence of TDP-43 proteinopathies. Under homeostatic conditions, the RNA/DNA-binding protein TDP-43 mainly resides in the nucleus, where it functions to regulate gene expression, controlling not only RNA transcription and splicing, but also stability and transport to the cytoplasm. Upon the arrival at ribosomes, TDP-43 may further moderate translation, acting as a global repressor of protein synthesis. However, in over 95% of ALS cases, TDP-43 mislocalies from the nucleus to the cytoplasm, where it enriches in cytoplasmic inclusions that are marked by the presence of misfolded, ubiquitinated, phosphorylated and fragmented protein species of TDP-43. Although recent studies have tried to untangle the relationship between TDP fragments on the one hand, and cytotoxicity as well as neurodegeneration on the other, the results are still a matter of debate. Here, we review our current understanding of the different TDP fragments derived from proteolytic cleavage as well as alternative splicing, addressing the different N-terminal and C-terminal species and evaluating differences in rodent and primate models. We focus our analysis on the potential homeostatic functions of TDP fragments in the context of viral infections and myelination control, which are potentially pivotally interconnected. The findings illustrate several facets of fragmented TDP-43 protein species in scenarios of enhanced cellular stress. Gaining a detailed understanding could help to reveal new treatment options for ALS and other TDP-43 proteinopathies.

Keywords:  Amyotrophic lateral sclerosis; Glial function; Neuronal function; Proteases; TDP-43 fragments; TDP-43 proteinopathies

DOI:  https://doi.org/10.1016/j.nbd.2026.107349
Biochemistry (Mosc). 2026 Feb;91(2): 380-387

Features of Mitochondrial Dynamics Changes in Large Pyramidal Neurons of the Human Motor Cortex during Aging.

Tatiana I Baranich, Dmitry N Voronkov, Kseniia M Okulova, Ekaterina V Shcherbak, Anna V Egorova, Olga V Velts, Maria S Ryabova, Kristina A Skvortsova, Zainab M Omarova, Dmitry A Kharlamov, Valeria V Glinkina, Vladimir S Sukhorukov.

  Brain aging is a physiological process characterized by various neurodegenerative manifestations, largely driven by mitochondrial dysfunctions, including changes in mitochondrial metabolism and dynamics. Conflicting reports in the literature regarding mitochondrial fusion and fission in the human cerebral cortex during aging underscore the need to elucidate the mechanisms of this dysfunction. The aim of this study was to assess features of mitochondrial dynamics in the large pyramidal neurons of the human motor cortex during aging. The study was conducted on autopsy material from the motor cortex of individuals aged 75 years and older. The control group consisted of similar material from individuals aged 35-44 years who died from sudden cardiac death. Intensity of immunohistochemical staining for TOMM20, Drp1, Mfn1, Mfn2, and Opa1 proteins in the large pyramidal neurons of the human motor cortex was evaluated. Decrease in the staining intensity of TOMM20 and Opa1 markers and increase in the staining intensity of the Drp1 marker were observed, indicating enhanced mitochondrial fragmentation in the pyramidal neurons of layer V of the motor cortex, possibly associated with reduction in the mitochondrial pool volume due to dysfunction in the mitochondrial fusion process, which impedes organelle growth.

Keywords:  adaptation; aging; brain; fission; fusion; mitochondrial dynamics; motor cortex; neurodegeneration

DOI:  https://doi.org/10.1134/S0006297925604447
Protein Sci. 2026 Apr;35(4): e70539

Small heat shock proteins HspB1 and HspB5 differentially alter the condensation and aggregation of the TDP-43 low-complexity domain.

Thomas B Walker, Joshua W Trowbridge, Shannon McMahon, Nicholas R Marzano, Lauren Rice, Justin J Yerbury, Heath Ecroyd, Luke McAlary.

  TAR DNA-binding protein 43 (TDP-43) is a nucleic acid-binding protein that regulates processes of mRNA metabolism, during which it undergoes condensation mediated by its C-terminal low-complexity domain (TDP-43LCD). TDP-43 aggregation and condensation are associated with neurodegenerative disease. However, the proteostasis mechanisms that regulate these processes remain elusive. Some evidence has shown that the molecular chaperone small heat shock protein HspB1 binds to and regulates the cytoplasmic phase separation of TDP-43, indicating that other small heat shock proteins may have similar effects. Here, we demonstrate divergent behaviors for HspB1 and its homolog HspB5 on TDP-43LCD condensation and aggregation. In addition to inhibiting TDP-43LCD aggregation, HspB1 partitions into TDP-43LCD condensates and increases the dynamic exchange of TDP-43LCD within condensates and with the surrounding solution. Phosphorylation-mimicking mutations within HspB1 enhance these effects. HspB5 inhibits TDP-43LCD aggregation more effectively than HspB1 and partitions into TDP-43LCD condensates, where it delays the pathological transition of the condensate to a gel/solid. We identify the N- and C-terminal regions of HspB1 and HspB5 to be crucial for the chaperone effects, and highlight the role of sequence diversity within these regions in defining small heat shock protein function. These findings demonstrate that HspB1 and HspB5 are regulators of TDP-43 phase separation and aggregation and may be potential therapeutic targets in mitigating toxic TDP-43 aggregation in neurodegenerative disease.

Keywords:  amyotrophic lateral sclerosis; chaperones; fibrillation; liquid–liquid phase separation; proteostasis

DOI:  https://doi.org/10.1002/pro.70539
Biochemistry (Mosc). 2026 Feb;91(2): 253-273

Mitochondria "Shackled" by Mutant Huntingtin: Analysis of Morphological Alterations and Disruptions of Intracellular Transport.

Vyacheslav I Pasko, Aleksandra S Churkina, Lilia D Belikova, Anton S Shakhov, Svetlana V Lavrushkina, Anton V Burakov, Alexandra N Bogomazova, Maria A Lagarkova, Irina B Alieva.

  Mitochondria are semi-autonomous, multifunctional organelles that supply cells with energy. They are highly dynamic structures, capable of moving, fusing, dividing, and forming branched networks. The number, density, and complexity of mitochondrial network are unique to each cell type and reflect cellular demands for ATP and other mitochondria-dependent metabolites. Mitochondrial dysfunction is a hallmark of many neurodegenerative diseases; however, the relationships between neurodegeneration and mitochondrial morphogenesis, intracellular localization, and dynamics remain incompletely understood. Interpretation and comparison of published data are complicated by the diversity of analytical approaches used to study mitochondrial behavior. In this research, we investigated the effects of a pathogenic mutation in the huntingtin protein (HTT), which causes Huntington's disease (HD), on mitochondrial morphology and motility, with particular emphasis on associated disruptions in the cytoskeletal organization. We performed a systematic evaluation of automated mitochondrial analysis tools and selected MiNA, TrackMate, and JACoP as the optimal platforms for quantitative assessment of the effects of mutant HTT (mHTT) on the mitochondrial morphology, motility, and interaction with cytoskeletal components and identification of specific disruptions directly related to HD pathogenesis. Our analysis revealed that mitochondria in mHTT-expressing cells are significantly shorter, more branched, and less motile than in control cells. Moreover, their interactions with microtubules and vimentin intermediate filaments are markedly altered. Together, these findings establish a link between HD and specific defects in the mitochondrial network, thus contributing to understanding cellular mechanisms of HD development, and suggest that mHTT disrupts the interaction of mitochondria with cytoskeletal components responsible for their movement and distribution in the cell, thereby negatively affecting mitochondrial motility and morphology.

Keywords:  Huntington’s disease; huntingtin; mitochondrial dynamics; neurodegenerative diseases

DOI:  https://doi.org/10.1134/S0006297925602850
bioRxiv. 2026 Mar 05. pii: 2025.09.05.674552. [Epub ahead of print]

Peripheral inflammation mediates midbrain Lrrk2 kinase activity via Rab32 expression.

Jordan Follett, Isaac Bul Deng, Robert C Sharp, Shannon Wall, Adamantios Mamais, Matthew J Farrer.

Mutations that increase leucine-rich repeat kinase 2 (LRRK2) activity confer significant risk for Parkinson's disease (PD), yet incomplete disease penetrance suggest additional factors are required to manifest disease. We recently identified RAB32 Ser71Arg as a Mendelian gene for PD. Here, we establish Rab32 as a key mediator linking peripheral inflammation to Lrrk2 activation. We show that Rab32 and Rab38 expression are modestly, but inversely, correlated with their homolog Rab29. In vivo , peripheral lipopolysaccharide (LPS)-induced inflammation selectively induced Rab32 expression in midbrain Iba1 + microglia but not dopaminergic neurons, where it localized to Lamp1 + lysosomal compartments and correlated with Lrrk2 kinase activity. LPS similarly induces Rab32 expression in human induced pluripotent stem cell-derived microglia, demonstrating a unified biological response to inflammation across species. Promoter analysis identified Tfe3, a master regulator of lysosomal biogenesis and autophagy, as a key driver of Rab32 expression induced Lrrk2 kinase activation. During inflammation, Tfe3 translocated to the nucleus of midbrain Iba1 + microglia to induce Rab32 expression and Lrrk2 kinase activity. Knockdown of Tfe3, but not Tfeb, mitigates these effects, establishing Rab32 as a physiological rheostat of Lrrk2 activity. This mechanistic pathway enables peripheral inflammation to modulate LRRK2 activity and highlights Rab32/Tfe3 as a therapeutic targeting for neuroprotection in PD.

DOI: https://doi.org/10.1101/2025.09.05.674552
Bioorg Med Chem. 2026 Mar 14. pii: S0968-0896(26)00090-8. [Epub ahead of print]137 118634

Employing an integrated computational simulation strategy to identify high-affinity ligands for TDP-43 amyloid proteins.

Yunqing Gao, Zhenghao Sun, Qiumei Wei, Chenyuan She, Yafeng Wang, Jingyun Chen, Mengxuan Wang, Xinrui Gui, Xue Xia, Yang Liu, Xin Wang.

  Developing high-affinity ligands targeting TDP-43 amyloid species is a potential therapeutic approach for amyotrophic lateral sclerosis (ALS). Here, we propose an integrated computational simulation strategy, which integrates multiple virtual screening methods, molecular dynamics simulations and binding free energy evaluations. Using this strategy, we successfully identified TDPL1, a high-affinity ligand for TDP-43 amyloid proteins. In vitro affinity assays confirmed the computational predictions. Based on the MD simulation results, we further investigated the binding mode between TDPL1 and TDP-43 amyloid proteins. Additionally, steered molecular dynamics simulations were employed to assess the impact of TDPL1 on the stability of β-sheet interactions within the TDP-43 amyloid structure. Our data demonstrate that TDPL1 not only binds effectively to TDP-43 amyloid proteins but also possesses the potential to disrupt the stability of amyloid aggregates. These findings provide a molecular foundation for the future development of diagnostic agents or targeted therapeutics for ALS and related diseases.

Keywords:  ALS; MD simulations; Steered molecular dynamics simulation; TDP-43 amyloid proteins; Virtual screening

DOI:  https://doi.org/10.1016/j.bmc.2026.118634
Sci Rep. 2026 Mar 18.

Impact of the CYFIP2 R87C variant in a human neuronal model in vitro.

Isabelle Zaboroski-Silva, Evelin da Silva Brandão, Bianca de Freitas Brenha, Curran Landry, João Carrara, Rodolfo Sanches Ferreira, Isadora May Vaz, Valderez Ravaglio Jamur, Ashleigh E Schaffer, Helen Cristina Miranda, Patrícia Shigunov.

  Mutations in the CYFIP2 gene, particularly the R87C variant, are associated with severe epileptic encephalopathy, and present challenges for therapeutic development. This study utilized CRISPR/Cas9-edited human pluripotent stem cell (hPSC) lines to investigate the impact of R87C variant on neuronal morphology and function. hPSCs were differentiated into neural progenitor cells (NPCs), cortical neurons (CNs), and cortical organoids. Phenotypic characterization included immunofluorescence, scanning electron microscopy (SEM), high-throughput scanning (HTS), multi-electrode array (MEA) recordings, and Western blotting. Edited hPSC lines maintained pluripotency, and neurogenic differentiation yielded NPCs and CNs without significant differences in neural progenitor marker expression. However, mutated NPCs exhibited reduced motility in cell tracking assays, and SEM revealed altered cell morphology, suggesting an impact on lamellipodia formation. While both mutant and wild-type CNs expressed appropriate neuronal and glial markers and showed similar electrophysiological properties, R87C/R87C cortical organoids displayed decreased CYFIP2 protein levels and, by day 30, showed increased size alongside an absence of SOX2 + cells, suggesting premature depletion of the progenitor pool. These findings highlight a marked divergence between 2D and 3D models, with organoids revealing neurodevelopmental abnormalities not evident in monolayer cultures. Together, our results suggest that the CYFIP2 R87C variant impacts NPC cytoskeletal dynamics and early cortical development, warranting further investigation into its role in epileptic encephalopathy.

Keywords:  CYFIP2 variant; Disease modeling; Human pluripotent stem cell; Neurodevelopment

DOI:  https://doi.org/10.1038/s41598-026-44176-2
iScience. 2026 Mar 20. 29(3): 115061

Uncovering NMDA receptor-mediated high firing activity in excitatory human neurons.

Isabel Gameiro-Ros, Adam J Tengolics, Iya Prytkova, Chella Kamarajan, Zhiping P Pang, Alison M Goate, Ronald P Hart, Paul A Slesinger.

  Human iPSC-derived glutamatergic (iGlut) neurons provide a promising platform for studying neuronal function and modeling CNS diseases, but assessing large populations of neurons from multiple donors remains challenging. We developed a protocol that targets N-methyl-D-aspartate receptors (NMDA-Rs) and enhances neuronal activity, revealing functional phenotypes. Using the calcium indicator GCaMP8f, we demonstrate that Mg2+-free ACSF significantly increases neuronal activity, and is enhanced by glycine but inhibited by the NMDA-R antagonist AP-V. Multi-electrode array recordings also show robust firing in Mg2+-free ACSF. Lastly, patch-clamp electrophysiology confirms the higher firing rates in Mg2+-free ACSF across multiple donor lines, uncovering donor-specific firing phenotypes. This protocol facilitates functional analyses of iGlut neurons while preserving single-cell resolution, enabling detailed characterization of iGlut neurons in diverse applications such as CNS disease modeling and drug screening. This protocol establishes a versatile framework for large-scale studies of neuronal network dynamics and individual excitability in iPSC-derived iGlut neurons.

Keywords:  Cell biology; Genomics; Human; Neuroscience

DOI:  https://doi.org/10.1016/j.isci.2026.115061
Life Sci Alliance. 2026 Jun;pii: e202503424. [Epub ahead of print]9(6):

Huntingtin (HTT) interactome in regulation of DNA repair/remodeling and RNA processing pathways.

Tamara Ratovitski, Chloe D Holland, Robert N O'Meally, Alexey V Shevelkin, Siddhi V Kamath, Tianze Shi, Matthew J Rodriguez, Robert N Cole, Mali Jiang, Christopher A Ross.

Huntington's disease (HD), an uncurable neurodegenerative disorder, is caused by CAG repeat expansion in the HD gene encoding mutant huntingtin protein. DNA damage response is implicated in HD pathogenesis. We used multiple approaches to assess normal and mutant HTT interactomes in the context of genotoxic stress. We show that double-strand break (DSB) repair response is impaired in HD neurons, which are more vulnerable to DSB-induced stress. We found that S1181 phosphorylation of HTT is regulated by DSB, and can be carried out by DNA-PK. Functional interaction of HTT with a major DSB kinase DNA-PKcs and association of both proteins with nuclear speckles suggest a role of HTT in DSB repair mechanism; however, physiological outcome of these interactions remains to be examined. We revealed HTT interactions with other proteins associated with nuclear speckles, TCERG1 and MED15, whose loci are genetic modifiers for HD, and with chromatin remodeling complex BAF. These interactions may position HTT as an important scaffolding intermediary providing integrated regulation of gene expression and RNA processing in the context of DNA repair mechanisms.

DOI: https://doi.org/10.26508/lsa.202503424
J Clin Invest. 2026 Mar 16. pii: e199841. [Epub ahead of print]136(6):

Decoding neurodegeneration one cell at a time.

Olivia Gautier, Thao P Nguyen, Aaron D Gitler.

Neurodegenerative diseases are characterized by protein misfolding and the selective vulnerability of specific neuronal subtypes. This selective vulnerability presents a paradox; most neurodegenerative disease genes are expressed broadly throughout the brain, and some ubiquitously, but only certain types of neurons are lost while others are resistant. The molecular basis for selective neuronal vulnerability has remained a mystery, but recent genomics technological innovations are starting to provide mechanistic insights. Here, we review how single-cell genomics techniques - single-cell transcriptomics, single-cell epigenomics, and spatial transcriptomics - advance our molecular understanding of selective vulnerability and neurodegeneration across Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, frontotemporal dementia, and Huntington disease. Together, these approaches reveal the cell types affected in disease, define disease-associated molecular states, nominate candidate determinants of vulnerability and degeneration, and situate degenerating neurons within their local tissue context. Continued development and application of these techniques, including single-cell perturbation screens, will expand descriptive atlases of relevant cell types in health and disease and identify causal mechanisms, revealing the molecular basis of vulnerability and degeneration and informing therapeutic development.

DOI: https://doi.org/10.1172/JCI199841
Acta Neuropathol Commun. 2026 Mar 20.

Presenilin-dependent regulation of neuronal tau pathology via the autophagy and proteasome pathways.

Anna Del Ser-Badia, Carlos M Soto-Faguás, Rebeca Vecino, Carles Vendrell, Laura Molina-Porcel, Raquel Sánchez-Valle, José Rodríguez-Alvarez, Carlos Vicario, Carlos A Saura.

  Mutations in the presenilin (PS/PSEN) genes cause early-onset familial Alzheimer's disease (AD) by enhancing cerebral accumulation of amyloid-β (Aβ) peptides and microtubule-associated protein tau (MAPT). How PS mutations affect Aβ generation is well characterized, but the precise cellular mechanisms by which PS dysfunction drives neuronal tau pathology are not fully understood. Here, we investigated the mechanisms linking PS/γ-secretase-dependent tau pathology and autophagy/proteasome by employing pathological, imaging and molecular approaches in human brains, fibroblasts and induced pluripotent stem cells (iPSC)-derived neurons from PSEN1-linked familial AD carriers, and in a novel neuronal PS-deficient tauopathy transgenic mouse. We found enhanced levels and colocalization of pathological phosphorylated tau (pTau) and ubiquitin factor p62 in the hippocampus of dementia patients with familial AD-linked PSEN1 mutations, corticobasal degeneration and Pick's disease, suggesting disrupted proteasomal degradation in tauopathies. Human primary fibroblasts from PSEN1 G206D and/or L286P carriers showed elevated LC3-I and autolysosomes indicating autophagy flux alterations. Human iPSC-derived neurons harboring the familial-AD linked PSEN1 G206D mutation showed increased aggregated tau and reduced secreted tau, whereas pharmacological proteasome inhibition reduced significantly total and pTau (Ser396/404) while increasing its release. Consistently, proteasomal inhibition decreased intracellular tau and pTau and promoted tau release in human tau-expressing neurons through a mechanism that partially depends on PS. In the hippocampus of neuronal PS-deficient mice, Akt activation and GSK3β inhibition were associated with elevated levels of phosphorylated and aggregated tau and the ubiquitin-binding protein p62. In conclusion, PS function is required for autophagy/proteasome-mediated tau elimination in neurons, whereas that FAD-linked PSEN1 mutations cause progressive tau pathology by disrupting the proteasome and autophagy/lysosomal pathways.

Keywords:  Alzheimer’s disease; Autophagy; Neurodegeneration; Proteasome; Proteostasis; Tauopathies; γ-Secretase

DOI:  https://doi.org/10.1186/s40478-026-02270-6
Commun Biol. 2026 Mar 17. pii: 392. [Epub ahead of print]9(1):

Molecular resilience of neurons to repetitive mechanical compression.

Allegra Coppini, Valentina Cappello, Syeda Rubaiya Nasrin, Alessandro Falconieri, Oz Mualem, Gadiel Saper, Orit Shefi, Henry Hess, Akira Kakugo, Vittoria Raffa.

Cells and organs constantly experience mechanical forces. Neurons, in particular, are exposed to such stimuli during development, aging, disease, and normal activities like movement and homeostasis. Recent studies highlight the key role of microtubules (MTs) in mechanotransduction, adjusting cytoskeletal dynamics in response to mechanical cues. While the effects of acute forces on MTs are known, the impact of repetitive mechanical stimuli over time remains unclear. In this study, we applied repetitive mechanical motion to neurons from the dorsal root ganglia and analyzed responses at varying strain levels. A 10% strain caused MT and organelle damage, leading to cell death. In contrast, a 2.5% strain did not harm cells and instead stabilized MTs. A 5% strain caused damage to the MT structure and leads to MT destabilization, but neurons activate a molecular response to counteract and recover from this damage, suggesting the involvement of the Ras pathway in response to injury. These findings suggest that neurons can adapt to repetitive mechanical stress, maintaining homeostasis when strain is below a certain threshold. Our results improve understanding of how mechanical forces influence neuronal structure and function, and how cells respond to injury by initiating protective pathways.

DOI: https://doi.org/10.1038/s42003-026-09661-4
Cell Rep Med. 2026 Mar 17. pii: S2666-3791(26)00065-0. [Epub ahead of print]7(3): 102648

Identification of tofersen PD-response biomarkers in VALOR clinical trial CSF via multiplexed quantitative proteomics.

Amanda J Guise, Kyle L Ferber, Damon Young, Amanda L Edwards, Somayeh Sabouri, Kyle B Fraser, Eric Milliman, Edward D Plowey, Jad Zoghbi, Stephanie M Fradette, Danielle L Graham.

  Tofersen, the first approved genetically targeted therapy for amyotrophic lateral sclerosis (ALS), demonstrates significant lowering of plasma neurofilament in adults carrying mutations in the superoxide dismutase 1 (SOD1) gene; however, additional biomarkers of treatment response in ALS are lacking. Here, we analyze longitudinally collected cerebrospinal fluid (CSF) samples from the phase 3 VALOR clinical trial to identify candidate tofersen treatment-response biomarkers in SOD1-ALS via quantitative proteomics. We observe significant modulation from baseline abundance for 56 proteins in tofersen-treated participants relative to placebo, including CSF GPNMB, which is significantly and continuously elevated across all post-baseline timepoints. We orthogonally confirm this observation by GPNMB immunoassay in independent tofersen-treated cohorts. Taken together, these data identify pharmacodynamic-response biomarkers of tofersen treatment that can be measured as early as 4 weeks post-treatment in SOD1-ALS patients and demonstrate the utility of leveraging unbiased proteomic screening integrated with targeted validation methods to identify pharmacodynamic-response biomarkers in clinical trial patient samples.

Keywords:  SOD1-ALS; amyotrophic lateral sclerosis; antisense oligonucleotide therapy; cerebrospinal fluid biomarkers; glycoprotein non-metastatic melanoma protein B; motor neuron disease; neurofilament; pharmacodynamic-response; superoxide dismutase; tofersen

DOI:  https://doi.org/10.1016/j.xcrm.2026.102648
Acta Pharmacol Sin. 2026 Mar 16.

Neuronal mitochondrial dynamics: roles in brain disorders and therapeutic potential.

Xing-Xian Zhang, Jia-Min Du, Shen-Zhan Wang, Xin-Lei Mo, Xiang-Nan Zhang.

  Mitochondrial dynamics - processes that include fission, fusion, transport, and mitophagy - are essential for shaping mitochondrial form and function to meet neuronal homeostatic demands. Growing evidence links imbalances in these processes to the pathogenesis of multiple brain disorders. In this review we comprehensively summarize the molecular mechanisms that govern mitochondrial dynamics and clarify their roles in key neuronal functions, including synaptic transmission, vesicle recycling, and calcium buffering. We also examine how disruptions in mitochondrial dynamics drive synaptic dysfunction and neuronal injury, with specific implications for neurodegenerative and psychiatric disorders. Finally, we evaluate emerging therapeutic strategies that target mitochondrial dynamics - both pharmacological and genetic - and highlight their promise as novel therapies for brain disorders. This synthesis provides an in-depth perspective on mitochondrial dynamics in brain health and disease and aims to guide future research and drug development.

Keywords:  mitochondrial dynamics; neurodegenerations; neuron; neuropsychiatric disorders; therapeutic strategy

DOI:  https://doi.org/10.1038/s41401-025-01746-w
J Biol Chem. 2026 Mar 14. pii: S0021-9258(26)00245-0. [Epub ahead of print] 111375

Bisphenol-A impairs hippocampal neurogenesis by disrupting Kinesin-1-dependent mitochondrial trafficking.

Phoolmala, Saurabh Tiwari, Ranjeet Kumar Yadav, Shweta Singh Chauhan, Rajnish Kumar Chaturvedi.

  Mitochondrial trafficking ensures proper distribution of mitochondria in energy-demanding neural stem cells (NSCs) and neurons, by supplying ATP for neuronal function and survival. We studied the effects of xenoestrogen bisphenol-A (BPA), found in consumable plastic products, on axonal bi-directional mitochondrial trafficking/movement in neurons. Time-lapse live-cell imaging revealed that BPA exposure impaired anterograde and retrograde axonal mitochondrial trafficking, resulting in altered mitochondrial distribution and density in hippocampal NSCs-derived neurons. In silico docking studies identified plausible binding of BPA with Kinesin-1, Dynein, and Syntaphilin (SNPH). BPA postnatal exposure reduced mRNA expression and protein levels of mitochondrial trafficking motor proteins Kinesin-1(KIF5A) and Dynein, and increased mitochondrial static anchor protein SNPH in the rat hippocampus. BPA significantly reduced co-localization of KIF5A and Dynein with TOMM20, Nestin & β-III tubulin in vitro and Sox-2 & NeuN in vivo, and increased SNPH co-localization with TOMM20, Nestin & Sox-2, indicating impaired mitochondrial trafficking during NSCs proliferation and differentiation. Transmission Electron Microscopy revealed reduced axonal mitochondrial density, synaptic density, increased damaged mitochondria, and synaptic loss following BPA exposure. Pharmacological inhibition (Monastrol) and activation (Kinesore) of KIF5A mediated mitochondrial transport caused aggravated and mitigated BPA-mediated impairments in NSCs proliferation and neuronal differentiation. BPA-mediated inhibition of mitochondrial distribution, bioenergetics, and synaptic function was reversed by Kinesore, by increasing mitochondrial & synaptic density, mitochondrial movement, and reducing damaged synapses & mitochondria, leading to cognitive improvements. These findings implicate the role of Kinesin-1(KIF5A) in reversing BPA-mediated impaired mitochondrial transport, reduced hippocampal neurogenesis, and cognitive deficits in rats.

Keywords:  Bisphenol-A (BPA); Dynein; Hippocampus; Kinesin-1(KIF5A); Mitochondrial trafficking; Neurogenesis; Neurotoxicity; SNPH; Xenoestrogen

DOI:  https://doi.org/10.1016/j.jbc.2026.111375
Cell Rep. 2026 Mar 15. pii: S2211-1247(26)00190-7. [Epub ahead of print]45(3): 117112

Mitochondria acidify lysosomes through membrane contacts.

Zhiqi Tian, Rui Chen, Guiqian Fang, Kangqiang Qiu, Weijun Wu, Xintian Shao, Daili Liu, Huilin Que, Xueqian Wang, Ji Gao, Jianyu Zhang, Bidyut Kundu, Qixin Chen, Jun-Lin Guan, Yueguang Rong, Ben Zhong Tang, Kai Li, Yujie Sun, Jiajie Diao.

  The acidic environment within the lysosome lumen is essential for its digestive function. However, the source of protons responsible for acidification has remained elusive. Here, using a molecular probe to monitor lysosomal digestion, we discovered enhanced lysosome content degradation at mitochondria-lysosome contact (MLC) sites, which was caused by lysosomal acidification. Using a mitochondrial probe, we observed a proton flux from mitochondria to lysosomes at these MLC sites. Furthermore, we found that physically bringing mitochondria and lysosomes into close proximity can increase lysosome acidification to enhance content digestion under disease conditions. These findings unveil a crucial physiological role of MLCs in cellular functions.

Keywords:  CP: cell biology; lysosome acidification; mitochondria-lysosome contact; proton flux

DOI:  https://doi.org/10.1016/j.celrep.2026.117112
Sci Rep. 2026 Mar 18. pii: 9229. [Epub ahead of print]16(1):

Non-physiological potassium concentrations in commercial culture media trigger acute seizure-like activity in human iPSC-derived neurons.

Tim Lyckenvik, Julia Izsak, Erik Arthursson, My Forsberg, Kalle Johansson, Henrik Zetterberg, Markus Axelsson, Pontus Wasling, Eric Hanse, Stephan Theiss, Sebastian Illes.



Keywords:  Cell culture media; Extracellular ion concentrations; Microelectrode arrays (MEAs); Seizure-like activity; iPSC-derived neurons

DOI:  https://doi.org/10.1038/s41598-026-43094-7
Nat Commun. 2026 Mar 18.

Intellectual disability-causing mutations in KIF11 impair microtubule dynamics and dendritic arborization.

Jenna L Wingfield, Lukas Niese, Yosef Avchalumov, Xiaodan Liu, Rahul Grover, Yoshihisa Nakahata, Bindu L Raveendra, Adrian E Gonzalez-Santiago, Jackson P Carter, Ryohei Yasuda, Jason X-J Yuan, Stefan Diez, Sathyanarayanan V Puthanveettil.

Microcephaly with or without chorioretinopathy, lymphedema, or intellectual disabilities (MCLID) is a rare disease caused by mutations in the mitotic motor KIF11. However, the specific neuronal functions of KIF11, its mechanisms of microtubule (MT) regulation, and the impact of MCLID mutations on KIF11 function remain underexplored. Here, using live-imaging, we find that KIF11 depletion in postmitotic neurons increases minus-end-out MT dynamics in both axons and dendrites. Introducing MCLID-associated KIF11 mutations, KIF11Y82F and KIF11ΔCterm, significantly reduces MT dynamics, impairs dendritic arborization, and decreases mEPSC frequency. Biochemical analyses reveal that the KIF11ΔCterm mutant disrupts tetramer formation and MT crosslinking, while the KIF11Y82F mutant reduces MT sliding velocity and ATP affinity. Temporal inhibition of KIF11 using a photo-controllable KIF11 increases MT dynamics and dendritic growth. Together, these data reveal that KIF11 is a MT dynamics rheostat and regulator of dendritic arborization in mature neurons, providing essential insights into the molecular mechanisms driving MCLID.

DOI: https://doi.org/10.1038/s41467-026-70522-z
Prog Neurobiol. 2026 Mar 17. pii: S0301-0082(26)00033-X. [Epub ahead of print] 102907

Human Induced Pluripotent Stem Cell-Based Models for Studying Neural Repair.

Manasi Agrawal, Meghal Desai, Shruti Ghumra, Yashashree Bhorkar, Pabitra K Sahoo.

  Injuries and degenerative diseases of the human nervous system result in irreversible functional loss, reflecting the limited regenerative capacity of the central nervous system and the slow repair rate of the peripheral nervous system. Progress has been hindered by the lack of human-relevant experimental models that accurately capture the cellular diversity, long axonal architecture, and species-specific regulatory mechanisms underlying neural injury and repair. Human induced pluripotent stem cells (iPSCs) have emerged as a transformative platform to bridge this gap, enabling the generation of diverse neuronal and glial subtypes, reconstruction of complex neural circuits, and modeling of injury and regeneration in a human-specific context. In this review, we discuss the recent advances in the use of human iPSC-derived systems to study neural repair, spanning two-dimensional cultures, three-dimensional organoids and assembloids, microengineered axon injury platforms, and in vivo transplantation models. We highlight how these approaches have revealed key intracellular regulators of neurite growth, clarified the impact of disease-associated mutations on axonal integrity, and enabled high-throughput screening of neuroprotective and pro-regenerative compounds. We further discuss the role of iPSC-derived glial cells, Schwann cells, and neuromuscular junction models in elucidating axon-glia interactions, remyelination, and circuit-level repair mechanisms. Together, human iPSC-based models offer unprecedented insight into the cellular and molecular determinants of human neural regeneration, thereby overcoming the limitations of animal systems. While challenges remain in standardization, maturation, and clinical translation, these platforms are redefining regenerative neuroscience and hold promise for the development of patient-specific therapies aimed at restoring function after nervous system injury.

Keywords:  axon growth; glial cells; iPSCs; neural repair; neuromuscular junctions; organoids and assembloids; regeneration

DOI:  https://doi.org/10.1016/j.pneurobio.2026.102907
Curr Res Toxicol. 2026 ;10 100288

The role of autophagy in microwave radiation induced toxicity in iPSC-derived cardiomyocytes.

Chenjing Zhang, Zhanming Liu, Yingxin Wang, Weilin Deng, Hailong Wang, Jing Zhang, Qilong Feng.

  This study aims to explore the impact of microwave radiation on the electrophysiological functions of human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) and to focus on the critical role and underlying mechanism of autophagy in this process. The iPSC-CMs were irradiated with S-band microwaves at a power of 30 mw/cm2. Through techniques such as immunofluorescence, Western blotting, electrophysiological recording, scanning electron microscopy, and transcriptomic analysis, the changes in electrophysiological indicators, ultrastructure, and autophagy levels of iPSC-CMs after microwave radiation were systematically evaluated. Further intervention with Acadesine (AICAR) was conducted to verify the role of autophagy in radiation-induced damage. After microwave radiation, iPSC-CMs exhibited significant electrophysiological dysfunction. Ultrastructural observations revealed aggravated mitochondrial damage after radiation, manifested as vacuolization, loss of cristae, and increased mitochondrial autophagy, accompanied by decreased ATP content and mitochondrial membrane potential. At the molecular level, transcriptomic analysis suggested that autophagy-related genes such as ULK1 were key regulatory nodes. After radiation, the expression of autophagy marker LC3II/I was upregulated while p62 expression was downregulated, indicating activation of the autophagic flux. Inhibition of autophagy with AICAR significantly improved the radiation-induced electrophysiological disorders. Microwave radiation can cause severe electrophysiological dysfunction in iPSC-CMs, and the mechanism is closely related to the abnormally elevated autophagy level induced by radiation. Inhibiting autophagy can effectively alleviate the electrophysiological damage caused by radiation, suggesting that targeting the autophagy pathway may be a potential strategy for protecting against the cardiotoxic effects of microwave radiation.

Keywords:  Autophagy; Electrophysiology; Microwave; Mitochondria; iPSC-CMs

DOI:  https://doi.org/10.1016/j.crtox.2026.100288
Sci Adv. 2026 Mar 20. 12(12): eadx8715

Lysosomal down-regulation of the mu opioid receptor is opposed by the Retromer complex.

Aleksandra Dagunts, Hayden Adoff, Brandon Novy, Lamya Ben Ameur, Monica De Maria, Arpiar Saunders, Braden T Lobingier.

A critical homeostatic mechanism for regulating G protein-coupled receptor (GPCR) activity is agonist-induced GPCR endocytosis and trafficking to the lysosome for proteolytic down-regulation. The mu opioid receptor (MOR) is a notable example of this type of cellular regulation, where prolonged exposure to high-efficacy opioid drugs causes MOR to traffic to the lysosome. Here, we used functional genomics to identify cellular proteins that control MOR lysosomal down-regulation. We found that the central regulator of MOR postendocytic trafficking is the Retromer complex, which rescues MOR from opioid-induced down-regulation by promoting MOR recycling from endosomes to the plasma membrane. Critically, MOR accesses the Retromer recycling pathway through its noncanonical bileucine recycling motif, and this mechanism controls how MOR is regulated following chronic exposure to opioid drugs. Additionally, we show that this bileucine pathway for Retromer-based recycling is present in other classes of membrane proteins including the glucose transporter GLUT4.

DOI: https://doi.org/10.1126/sciadv.adx8715
STAR Protoc. 2026 Mar 18. pii: S2666-1667(26)00093-6. [Epub ahead of print]7(2): 104440

Protocol for measuring lipid membrane fluidity in human iPSC-derived neural cells.

Satoshi Morita, Takayuki Kondo, Haruhisa Inoue.

  Here, we present a protocol for describing the differentiation of human cortical neurons from induced pluripotent stem cells (iPSCs) and the subsequent analysis of lipid membrane fluidity using the LipiORDER fluorescent probe. We describe steps for embryoid body formation, neuronal induction with adherent culture maturation, and live-cell membrane fluidity measurement. This approach allows for investigation of the effects of lipid membrane fluidity on neuronal function and pathophysiology. For complete details of the use and execution of this protocol, please refer to Morita et al.1.

Keywords:  Cell Membrane; Cell-based Assays; Stem Cells

DOI:  https://doi.org/10.1016/j.xpro.2026.104440
J Cell Sci. 2026 Mar 13. pii: jcs.264537. [Epub ahead of print]

Retrograde Golgi-to-ER transport is regulated by diacylglycerol in Saccharomyces cerevisiae.

Yujia Yang, Shuyin Yang, Shiori Ito, Hangqing Li, Takefumi Karashima, Kazuki Hanaoka, Philipp Schlarmann, Kuya Matsunaga, Qihao Jin, Kouichi Funato.

  Coat protein complex (COP) I (COPI)-mediated retrograde transport from the Golgi apparatus to the endoplasmic reticulum (ER) plays a crucial role not only in recycling mislocalized and/or misfolded proteins to the ER but also in maintaining ER and Golgi structure and function. This pathway is tightly coordinated with COPII-mediated anterograde transport to ensure cellular homeostasis. In the regulation of bidirectional vesicular trafficking, lipids act as indispensable structural components of vesicles. Among these, the cone-shaped lipid diacylglycerol (DAG) has long been known to be involved in COPI function in mammalian cells. However, whether this regulatory mechanism is conserved across species remains unknown. In this study, we identify diacylglycerol (DAG) as a key modulator of COPI-mediated retrograde transport in budding yeast, demonstrating that DAG accumulation rescues both lethality and transport defects in COPI retrieval mutants. Notably, DAG levels decrease upon inhibition of retrograde transport and increase upon its restoration. These findings suggest that DAG regulates retrograde transport in a manner that promotes COPI vesicle formation, underscoring its potential role as a lipid mediator in cellular trafficking.

Keywords:   Saccharomyces cerevisiae ; Budding yeast; COPI; Diacylglycerol; Lipid; Retrograde Golgi-to-ER transport

DOI:  https://doi.org/10.1242/jcs.264537