bims-axbals 2026-09-06 papers

bims-axbals

Biomed News

on Axonal biology and ALS

Issue of 2026–09–06
seventeen papers selected by
TJ Krzystek

A standardized framework resolves ambiguity in motor neuron loss across neurodegenerative diseases.
Mitophagy in neuronal health and disease: from mechanisms to neurodegeneration.
Disrupted astrocyte-neuron metabolic coupling in amyotrophic lateral sclerosis.
Identification of Age-Associated Upstream Regulators to Promote Neuronal Resilience in HD Patient-Derived Neurons.
Glutamatergic neuron degeneration in C. elegans models of Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.
Seeds from ALS patients homozygous for the SOD1 D90A mutation transmit two types of SOD1 aggregation and motor neuron disease.
Age-related disruptions in ubiquitination and mitochondrial proteostasis are associated with neuronal compartment-specific mitochondrial changes.
Chaperone-assisted selective autophagy (CASA) in polyglutamine-related diseases: From mechanisms to therapeutic perspectives.
Axonal pathology and impaired axo-glial crosstalk as early drivers of neurodegeneration.
YTHDC1 functions as a molecular chaperone to suppress ALS-linked hnRNPA1 mutants from aggregation.
Autophagy Deficits in Lower Motor Neuron and Striated Muscle Diseases: From Genetics to Therapeutic Advances.
An Optimized Protocol for the Generation of Vascular Organoids from Human Induced Pluripotent Stem Cells.
The extracellular Zinc-finger ubiquitin-binding domain of histone Deacetylase 6 enhances podosome formation in neuronal cells.
Differential amyloid-beta sensitivity across human and nonhuman primate neurons.
Protocol to quantify LRRK2-mediated Rab10 phosphorylation using high-content imaging.
Real-time tracking of cell death in human intestinal organoids: A quantitative imaging approach.
RAB1 mediates OPTN-dependent mitophagy via ATG9A recruitment.

Acta Neuropathol Commun. 2026 Sep 01. pii: 182. [Epub ahead of print]14(1):

A standardized framework resolves ambiguity in motor neuron loss across neurodegenerative diseases.

Leonie Sowoidnich, Aaron L Norman, Florian Gerstner, Josiane K Siemund, Jannik M Buettner, John G Pagiazitis, Vanessa Dreilich, Konstantin Pilz, Dajun Tian, Charlotte J Sumner, Angela Paradis, George Z Mentis, Christian M Simon.

  Motor neuron (MN) loss is a hallmark of neurodegenerative disorders, yet its assessment remains variable, confounding mechanistic and therapeutic interpretation. To address this, we conducted a systematic review and meta-analysis of spinal muscular atrophy (SMA) mouse studies, revealing 60% variability in reported MN loss, for which spinal cord sampling emerged as a major contributor. Using a whole-segment approach with tissue clearing, MN tracing, and multimodal imaging, we confirmed segment-dependent differences in MN counts. Common MN markers (SMI-32, Nissl) lacked specificity, whereas choline acetyltransferase (ChAT) provided robust labeling in murine and human spinal cords. Deep learning-based whole-mount segmentation enabled unbiased MN quantification and validated manual counts. Integrating analysis with computational modeling established segment sampling as a key driver of variability and revealed degeneration patterns: widespread MN loss in amyotrophic lateral sclerosis (ALS), selective MN loss in severe SMA, and preservation in mild SMA models. These findings establish a framework for reproducible MN quantification.

Keywords:  4-copy SMN2 Type III-like SMA; Amyotrophic lateral sclerosis; Motor neuron diseases; Motor neuron quantification; Neurodegeneration; SMN∆7; SOD1-G93A; Spinal cord; Spinal muscular atrophy

DOI:  https://doi.org/10.1186/s40478-026-02415-7
J Clin Invest. 2026 Sep 01. pii: e199847. [Epub ahead of print]136(17):

Mitophagy in neuronal health and disease: from mechanisms to neurodegeneration.

Bishal Basak, Julia F Riley, Neha M Nataraj, Erika Lf Holzbaur.

Regulation of mitochondrial health is critical for maintaining cellular homeostasis in the nervous system. Damaged mitochondria can have detrimental effects on neuronal health and are thought to be key contributors to the progression of neurodegenerative disorders including Parkinson's disease and amyotrophic lateral sclerosis. To mitigate this damage, multiple quality control mechanisms have evolved to eliminate aged or damaged mitochondria. One such quality control process is autophagy, a process that involves turnover of mitochondria at presynaptic sites and the axon terminal under basal conditions. This highly conserved mechanism sequesters mitochondria from the cytosol within autophagosomes followed by degradation upon fusion with a lysosome. Acute mitochondrial damage activates a selective form of autophagy called mitophagy that involves receptor-mediated engulfment and degradation of the damaged organelle. Multiple mechanisms have been shown to drive efficient mitophagy in neurons and glia, including PTEN induced kinase 1 (PINK1)/Parkin-dependent mitophagy and receptor-mediated mitophagy. Genetic, pathological, and experimental evidence all implicate defects in the removal of damaged mitochondria in the onset or progression of neurodegenerative disease. Both the initiation of PINK1/Parkin-dependent mitophagy and deficits in the removal of damaged mitochondria are linked to activation of neuroinflammatory pathways, including NF-κB and cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling. In this Review, we discuss the molecular pathways governing mitophagy in neurons and glial cells and how deficits in these pathways may lead to neurodegeneration. We also highlight emerging therapeutic strategies aimed at restoring mitophagy to preserve neuronal homeostasis and function.

DOI: https://doi.org/10.1172/JCI199847
Front Cell Dev Biol. 2026 ;14 1899307

Disrupted astrocyte-neuron metabolic coupling in amyotrophic lateral sclerosis.

Áine Bríd Heffernan, Florence Do, Eleanor Carter, Farah Al-Tameemi, Bhuvaneish T Selvaraj, Maria Stavrou.

  Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterised by progressive loss of motor neurons. In addition to neurodegeneration, ALS is increasingly recognised as a disorder associated with widespread metabolic dysfunction, including hypermetabolism, weight loss, and dyslipidaemia, all of which correlate with disease progression and survival. Astrocytes play a central role in maintaining metabolic homeostasis in the central nervous system by supporting neuronal energy demands, regulating glutamate levels, buffering oxidative stress, and maintaining lipid balance. Emerging evidence suggests that disruption of these supportive astrocytic functions may contribute directly to motor neuron vulnerability in ALS. In this mini-review, we discuss how alterations in astrocyte metabolism may impair astrocyte-neuron metabolic coupling in ALS. We summarise work from human studies and experimental models demonstrating abnormalities in astrocytic glycolysis, mitochondrial function, lactate shuttling, lipid metabolism, and glutamate homeostasis. We highlight growing evidence implicating mitochondrial dysfunction and impaired lipid handling in astrocytes as important contributors to disease progression. We explore how these changes may deprive motor neurons of metabolic and antioxidant support while also promoting excitotoxicity, oxidative stress, and lipotoxicity. We also discuss how recent advances in human induced pluripotent stem cell models, metabolomics, and single-cell transcriptomics are improving our understanding of astrocyte dysfunction in ALS. Finally, we consider current and emerging therapeutic strategies aimed at restoring astrocytic metabolic function. Together, these findings support the idea that progressive failure of astrocyte-mediated metabolic support is an important component of ALS pathogenesis and may represent a promising therapeutic target.

Keywords:  amyotrophic lateral sclerosis; astrocyte; bioenergetics; cell crosstalk; metabolism; neuron

DOI:  https://doi.org/10.3389/fcell.2026.1899307
Neurosci Bull. 2026 Sep 04.

Identification of Age-Associated Upstream Regulators to Promote Neuronal Resilience in HD Patient-Derived Neurons.

Young Mi Oh, Emily A Bacallao, Shin-Ae Lee, Jihyun Kim, Samuel Swinford, Genevieve E Smith, Bryce Britt, Shaymaa Madbouli Abdalla, Seong Won Lee.

  Aging is a risk factor for neurodegenerative disorders, but the molecular link between neuronal aging and neurodegeneration remains unclear. Huntington's disease (HD) is an inherited neurodegenerative disorder with adult-onset clinical symptoms. Striatal medium spiny neurons (MSNs) are mainly affected in HD, but how aging contributes to MSN degeneration remains uncertain. Using directly converted MSNs from fibroblasts of HD patients (HD-MSNs), we studied age-related pathological features, including neuronal cell death, mutant huntingtin (mHTT) aggregation, and DNA damage in HD. In this study, through transcriptomic analysis of longitudinally aged MSNs and HD-MSNs, we identified four upstream regulators, NFKB1, SOD1, IRF3, and REST, that modulate downstream gene expression in aged MSNs. Among these, knocking down NFKB1 significantly reduced HD pathologies in HD-MSNs, while overexpressing NFKB1 reversed these protective effects. Overall, these results identify NFKB1 as a key age-associated upstream regulator whose downregulation confers neuronal resilience and is a potential therapeutic target in HD.

Keywords:  Age-associated upstream regulator; Huntington’s disease; Medium spiny neurons; MicroRNA-mediated direct neuronal conversion; Neurodegeneration; Neurodegenerative disease; Neuronal aging; Patient-derived neurons

DOI:  https://doi.org/10.1007/s12264-026-01711-5
MicroPubl Biol. 2026 ;2026

Glutamatergic neuron degeneration in C. elegans models of Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.

Lexi-Amber Hassell, Mika Gallati, Monica Thoma, Selamawit Asfaw, Anne Church Hart.

Frontotemporal Dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS) overlap considerably in genetic origin and pathology. Multiple C. elegans models of ALS/FTD have been developed, but the integrity of glutamatergic neurons in these models has not been thoroughly evaluated. Here, we report degeneration of glutamatergic phasmid neurons in animals expressing either wild-type or disease variant V337M human tau, and mild degeneration in animals expressing disease variant M337V human TDP-43. Defects caused by ectopic expression of tau were suppressed by loss of the known modifier, spop-1 , suggesting that SPOP-1-dependent pathways are also involved in glutamatergic neuron degeneration.

DOI: https://doi.org/10.17912/micropub.biology.002301
Acta Neuropathol. 2026 Sep 01. pii: 27. [Epub ahead of print]152(1):

Seeds from ALS patients homozygous for the SOD1 D90A mutation transmit two types of SOD1 aggregation and motor neuron disease.

Caitlin Henne, Isabelle Sigfridsson, Thomas Brännström, Karin M E Forsberg, Stefan L Marklund, Per Zetterström, Peter M Andersen.

  Mutations in superoxide dismutase-1 (SOD1) are a common cause of amyotrophic lateral sclerosis (ALS). Inheritance is as a rule dominant, but in carriers of the most prevalent mutation, D90A, disease primarily develops in homozygotes. Increasing evidence suggests that prion-like propagation of SOD1 aggregation is the central pathogenic mechanism. Two structurally different strains of aggregates have been found to arise in human SOD1 (hSOD1) transgenic (Tg) mouse models of ALS. Strain A is formed by most mutants including hSOD1G85R and homozygous hSOD1WT Tg mice, whereas homozygous hSOD1D90A Tg mice form a distinct strain B, but also A. Inoculation of strain A and B seed preparations from Tg mice into lumbar spinal cord of adult hSOD1G85R mice induced templated spreading hSOD1 aggregation and premature ALS-like disease. Seeds from an ALS patient carrying the hSOD1G127X truncation mutation likewise transmitted strain A aggregation and disease. In the present study, we investigated whether seeds prepared from spinal ventral horns from six patients homozygous for the hSOD1D90A mutation could transmit aggregation and disease to adult hSOD1G85R Tg mice. Despite the extensive degeneration and loss of motor neurons in the long-lived D90A patients, two of the seeds significantly shortened the survival of the Tg mice, one transmitting A and the other B-pattern hSOD1 aggregation. Nine different preparations from four human controls lacked effects. The results demonstrate that two distinct aggregate strains can arise and propagate in homozygous hSOD1D90A ALS patients, further supporting the hypothesis that prion-like transmission of hSOD1 aggregation is the primary pathogenic mechanism in SOD1-linked ALS.

Keywords:  ALS; D90A; Prion; SOD1; Transmission

DOI:  https://doi.org/10.1007/s00401-026-03078-3
Exp Gerontol. 2026 Sep 02. pii: S0531-5565(26)00282-2. [Epub ahead of print]224 113303

Age-related disruptions in ubiquitination and mitochondrial proteostasis are associated with neuronal compartment-specific mitochondrial changes.

Margaret-Jade Searles, Debanjali Dasgupta, Trace A Christensen, Gary C Sieck, Matthew J Fogarty.

  Declining aerodigestive neuromotor function is a major aspect of human aging, with impaired airway defense and swallow manoeuvres implicated in pneumonia and dysphagia. Hypoglossal motor neurons (MNs) innervate tongue muscles, essential for these behaviours. Their degeneration contributes to age-related aerodigestive dysfunctions. In neurodegenerative diseases, the ubiquitin-proteasome system (UPS) is altered, disturbing mitochondrial proteostasis. We have previously shown reduced mitochondrial abundance, dysfunction and mitochondrial fragmentation in aging hypoglossal MN somas and dendrites. However, the relationship between the UPS (pUBS65 and ubiquitinated proteins), mitochondrial fragmentation (pDRP1S616) and fusion promoting proteins (MFN2) in MN aging is unexplored. In other neurons, aging changes mitochondria within axons in an opposite way to somas and dendrites. We used Western blotting to show impairment in mitophagy-related pUBS65, increased fragmentation-promoting pDRP1S616 and unchanged MFN2. Serial Block-Face Scanning Electron Microscopy showed increased mitochondrial volume density and larger, more simplistic mitochondria in old, myelinated hypoglossal axons, while somas and dendrites showed reduced mitochondrial volume density and increased fragmentation. Our results suggest that a more nuanced compartment-specific evaluation of mitochondrial structure and function is required to fully elucidate the pathophysiology underlying age-related neuromotor dysfunction.

Keywords:  Aging; Axon; Brainstem; Dendrite; Hypoglossal; Mitochondria; Motor neuron; Proteostasis

DOI:  https://doi.org/10.1016/j.exger.2026.113303
J Huntingtons Dis. 2026 Sep 03. 18796397261478173

Chaperone-assisted selective autophagy (CASA) in polyglutamine-related diseases: From mechanisms to therapeutic perspectives.

Barbara Tedesco, Marta Chierichetti, Riccardo Cristofani, Angelo Poletti.

  Chaperone-assisted selective autophagy (CASA) is a crucial process aimed at maintaining proteostasis in several neurodegenerative diseases associated with protein misfolding, including polyglutamine (polyQ) diseases. Autophagy is a critical lysosome-mediated degradation pathway, particularly essential in neurons, which are highly susceptible to proteotoxic stress due to their post-mitotic nature. Selective autophagy pathways, including CASA, ensure the targeted removal of misfolded proteins and damaged organelles, thereby preserving cellular homeostasis. CASA is based on the intersection of chaperones and autophagy, where HSPB8 and BAG3 interact with HSPA and STUB1 forming a complex that identifies, ubiquitinates, and directs aberrant proteins toward autophagosomes for subsequent lysosomal degradation. In polyQ diseases, such as spinal and bul muscular atrophy (SBMA) and Huntington's disease (HD), mutant proteins accumulate, overwhelming the protein quality control systems. The CASA components are upregulated as a compensatory response, promoting toxic aggregates clearance and cellular damage mitigation. However, chronic proteotoxic stress and progressive impairment of autophagic and lysosomal pathways eventually limit CASA efficiency, contributing to disease progression. The review highlights how CASA exerts its protective activities in polyQ diseases and reports therapeutic strategies aimed at enhancing CASA activity, including pharmacological inducers and combinatorial approaches targeting autophagy and the ubiquitin-proteasome system. Overall, CASA emerges as a crucial adaptive mechanism and a promising therapeutic target in polyQ-related neurodegeneration.

Keywords:  CAG repeat expansions; Huntington disease; chaperone-assisted selective autophagy; polyglutamine diseases; protein misfolding; spinal and bul muscular atrophy

DOI:  https://doi.org/10.1177/18796397261478173
Neural Regen Res. 2026 Aug 29.

Axonal pathology and impaired axo-glial crosstalk as early drivers of neurodegeneration.

Bastian Bues, Andrew Octavian Sasmita, Shuying Mao, Lina Komarek, Katie O'Mahony, Katja Burk.

   ABSTRACT: Axonal dysfunction is a critical event in neurodegenerative diseases, which can precede neuronal loss. For instance, in multiple sclerosis, chronic demyelination leads to axonal transection and downstream neurological deficits, yet in other neurodegenerative conditions, the causal relationship between axonal pathology and disease progression remains elusive. While defects in axonal transport, cytoskeletal integrity, and organelle trafficking are observed in Alzheimer's disease and the frontotemporal dementia-amyotrophic lateral sclerosis spectrum, a question remains: Are axonal defects merely downstream consequences of somatic neurodegeneration, or do they actively drive pathogenesis? Emerging evidence suggests that early axonal dysfunction may accelerate disease progression through disrupted connectivity, retrograde degeneration, and neuroinflammation. Here, we highlight current evidence on axonal pathophysiology across Alzheimer's disease and frontotemporal dementia-amyotrophic lateral sclerosis. We first outline the makeup of the mature axonal compartment, as well as the processes related to axonal maintenance, which include myelination, glial support, and microtubule-dependent transport mechanisms. We further compare axonal perturbations in Alzheimer's disease and frontotemporal dementia-amyotrophic lateral sclerosis, exploring commonalities as potential convergent mechanisms. Therapeutic strategies to stabilize axons by maintaining microtubule dynamics, restoring energetics, or modulating glial support could therefore theoretically offer neuroprotection if performed selectively on vulnerable neuronal subsets and early in the disease course. Ultimately, by reframing axonal pathology as a primary driver rather than an epiphenomenon, this review underscores the importance of targeting axonal health in neurodegenerative diseases.

Keywords:  Alzheimer’s disease; amyotrophic lateral sclerosis; axonal pathology; axons; frontotemporal dementia; glia; myelin; neuroinflammation

DOI:  https://doi.org/10.4103/NRR.NRR-D-26-00462
Nat Commun. 2026 08 21. pii: 9357. [Epub ahead of print]17(1):

YTHDC1 functions as a molecular chaperone to suppress ALS-linked hnRNPA1 mutants from aggregation.

Kang Ren, Mingjie Cheng, Qiudan Luo, Boxin Zhang, Haosheng Zhang, Zhe Li, Yuxin Liu, Yujie Wang, Ting Kang, Xiaoming Dai, Jiong Chen, Yuanming Cheng, Liangqian Huang.

Proteostasis failure drives multiple neurodegenerative disorders (NDs), and ATP-independent chaperone pathways that support neuronal proteostasis remain poorly defined. Here, we identify the N6-methyladenosine (m6A)-binding protein YTHDC1 as an ATP-independent molecular chaperone, whose activity is mediated by a highly acidic polyaspartate/glutamate (polyD/E) segment. YTHDC1 prevents protein misfolding and aggregation, unfolds kinetically trapped substrates, and resolubilizes pre-formed aggregates. Deletion of the polyD/E segment abolishes these activities, whereas aromatic-cage mutants retain chaperone activity, demonstrating independence from m6A recognition. We identify the amyotrophic lateral sclerosis (ALS)-associated RNA-binding protein hnRNPA1 as a YTHDC1 client. YTHDC1 maintains liquid-like hnRNPA1 condensates, delays fibrillization of disease-associated mutants, and limits stress-granule sequestration, while mitigating mutant hnRNPA1-induced neurite growth defects in primary neurons. These findings define a proteostatic function of YTHDC1 and highlight its chaperone activity as a potential target for mitigating protein aggregation in ALS-related NDs.

DOI: https://doi.org/10.1038/s41467-026-77016-y
Annu Rev Pathol. 2026 Sep 03.

Autophagy Deficits in Lower Motor Neuron and Striated Muscle Diseases: From Genetics to Therapeutic Advances.

Angela Sisto, Freke Mertens, Mélissa Lallier, Rani Robeyns, Alexander L N van Nuijs, Pieter Van der Veken, Wim Martinet, Vincent Timmerman.

The degradation and recycling of damaged proteins and organelles through autophagy is a vital process to maintain terminally differentiated cells under energy-demanding physiological conditions and mechanical stress. Clinical and molecular studies of numerous congenital disorders of striated muscle and inherited neuropathies have reported severe autophagy defects as an underlying pathological mechanism. In this review, we investigate the genetic mutations underlying lower motor neuron diseases, skeletal muscle dystrophies, and (cardio)myopathies and how these mutations disrupt autophagy pathways. Through an in-depth analysis of the defective step of the autophagy pathway, we propose pharmacological targets that are able to correct the autophagy defects, thereby improving disease pathology. Finally, we discuss the current limitations in the development of autophagy-modulating drugs and propose novel technologies to support this growing field. By outlining key mechanisms and targets, this review supports the development of more effective autophagy modulators for rare diseases.

DOI: https://doi.org/10.1146/annurev-pathmechdis-032125-020448
J Vis Exp. 2026 Sep 03.

An Optimized Protocol for the Generation of Vascular Organoids from Human Induced Pluripotent Stem Cells.

Qian Song, Yuqing Zhu, Shoudong Ye.

Vascular organoids derived from human pluripotent stem cells (hPSCs) have emerged as powerful three-dimensional models for studying vascular development, disease mechanisms, and drug responses. Current vascular organoid protocols enable the generation of self-organizing endothelial-pericyte networks; however, batch-to-batch variability, inconsistent organoid formation, and inadequate pericyte coverage can compromise reproducibility and scalability. This study presents an optimized protocol for generating vascular organoids from human induced pluripotent stem cells (hiPSCs) with improved reproducibility and structural consistency. Key modifications include refined embryoid body formation conditions, optimized growth factor concentrations and timing during mesoderm induction and vascular specification, and improved three-dimensional culture conditions that promote robust pericyte recruitment and endothelial-pericyte interactions. The optimized organoids exhibit highly branched CD31-positive endothelial networks consistently ensheathed by PDGFR-β-positive pericytes, with significantly reduced batch-to-batch variability compared with the original protocol. Detailed, step-by-step procedures are provided for organoid generation, whole-mount immunofluorescence characterization, and quality control assessment. This optimized method enables the scalable production of high-quality vascular organoids suitable for studying vascular cell interactions, modeling disease, and screening compounds, thereby lowering the technical barrier for laboratories seeking to adopt this model system.

DOI: https://doi.org/10.3791/73561
Methods Enzymol. 2026 ;pii: S0076-6879(26)00188-6. [Epub ahead of print]734 301-326

The extracellular Zinc-finger ubiquitin-binding domain of histone Deacetylase 6 enhances podosome formation in neuronal cells.

Tazeen Qureshi, Abhishek Ankur Balmik, Subashchandrabose Chinnathambi.

  Neurodegenerative disorders are characterized by progressive synaptic failure, neuronal loss, and the accumulation of pathological protein aggregates. A critical but often overlooked driver of this decline is cytoskeletal dysregulation, which compromises essential cellular functions ranging from intracellular transport to morphological stability. Histone Deacetylase 6 (HDAC6) is a central regulator of these dynamics, yet its role in neurodegeneration remains controversial: while its deacetylase activity is often linked to microtubule instability and toxicity, its ubiquitin-binding functions are essential for aggregate clearance. We have previously demonstrated that the ZnF-UBP domain acts as a direct modulator of cytoskeletal architecture, enhancing the formation of actin-rich migratory structures-such as podosomes and lamellipodia-and promoting neuritic outgrowth. It does this by inducing increased localization of actin remodelling proteins to the podosomes, ultimately conferring enhanced migration potential to cells. This chapter highlights the protocols essential for understanding the therapeutic potential of the HDAC6 Zinc Finger Ubiquitin-Binding Protein (ZnF-UBP) domain, in the context of actin remodelling through podosome structures.

Keywords:  Alzheimers disease; Cytoskeleton; Histone deacetylase 6; Podosomes; Tau; Zinc-finger ubiquitin-binding domain (ZnF UBP)

DOI:  https://doi.org/10.1016/bs.mie.2026.05.060
J Hum Evol. 2026 Aug 31. pii: S0047-2484(26)00082-5. [Epub ahead of print]219 103888

Differential amyloid-beta sensitivity across human and nonhuman primate neurons.

Isabel August, Sheila Steiner, Ruth Oefner, Maria Carolina Marchetto.

  The human brain has undergone a threefold increase in size as well as changes in cytoarchitecture and neurochemical organization since the split with the last common ancestor with chimpanzees and bonobos. These changes have likely promoted increased cognitive flexibility but may also have come at the cost of increased vulnerability to neurodegenerative diseases like Alzheimer's disease (AD). Alzheimer's disease is the most common form of age-dependent dementia, and previous research suggests that humans may be uniquely vulnerable to AD. Primate comparative induced pluripotent stem cell models offer a unique opportunity to study the cellular and molecular mechanisms underlying this vulnerability. Plaques composed of amyloid-beta (aβ) are a hallmark pathology of AD, and while the exact role of aβ in disease pathogenesis remains incompletely understood, it is clear that aβ can have a neurotoxic effect and plays a role in the characteristic loss of neurons and synapses. Here we investigate susceptibility to aβ-induced toxicity in induced pluripotent stem cell-derived neurons from humans-both with and without AD, the two Pan species-a chimpanzee and a bonobo, and a rhesus macaque. To measure toxicity, we looked at cell death, along with other metrics of neuronal health and connectivity (neuritic beading and synaptic puncta density, respectively). We also employed transcriptomic approaches (RNA sequencing) to investigate molecular mechanisms underlying observed species differences. Our findings show that macaque neurons are less sensitive to aβ than human and ape neurons, and RNA sequencing points to molecular mechanisms that may underlie potentially protective responses in both macaque and ape neurons relative to humans. This work highlights the importance of studying AD from a comparative lens and provides insights into variation in susceptibility to AD among primates.

Keywords:  Alzheimer’s disease; Evolution; NHPs; Plaques; iPSC

DOI:  https://doi.org/10.1016/j.jhevol.2026.103888
STAR Protoc. 2026 Sep 04. pii: S2666-1667(26)00472-7. [Epub ahead of print]7(3): 104819

Protocol to quantify LRRK2-mediated Rab10 phosphorylation using high-content imaging.

Beatrice Masotti, Paolo Lorenzon, Giuseppina Covello, Elisa Greggio.

  Rab10 phosphorylation at Thr73 (pRab10) is a well-established readout of the kinase LRRK2, a protein whose mutations are associated with Parkinson's disease. Here, we present a protocol for high-content quantification of endogenous pRab10-positive vesicles in primary astrocyte-enriched cultures using the Operetta CLS system. We describe steps for cell culture, immunofluorescence, image acquisition, and quantitative analysis using Harmony software. This protocol is applicable to other LRRK2-expressing cells and offers a scalable platform for quantitative studies of LRRK2 physiological and pathological activity.

Keywords:  Cell Biology; Molecular Biology; Neuroscience

DOI:  https://doi.org/10.1016/j.xpro.2026.104819
Methods Cell Biol. 2026 ;pii: S0091-679X(26)00160-3. [Epub ahead of print]210 137-156

Real-time tracking of cell death in human intestinal organoids: A quantitative imaging approach.

Jiyi Pang, Hojin Chang, Lachlan Whitehead, James E Vince.

  Organoids are self-renewing three-dimensional tissue models that can be derived from patient samples. Their recapitulation of the structure and function of native tissues makes them powerful tools for studying development, physiology, disease mechanisms and personalized medicine in vitro. However, quantitative assessment of cell death in organoid systems remains challenging due to their structural complexity and dynamic responses. Here, we present a robust pipeline combining real-time Incucyte® live-cell imaging with ImageJ-based quantitative analysis to measure cell death kinetics in human intestinal organoids. Organoids are cultured in the low-viscosity matrix suspension culture method, labelled with cell death-specific Incucyte® Cytotox Red Dye, and imaged via brightfield and fluorescence channels. A custom ImageJ analysis pipeline enables calculation of cell death overtime with high sensitivity and reproducibility. This approach overcomes the limitations of endpoint assays, delivering precise kinetic quantification of organoid cell death in response to cytokine stimulation, drug treatments, or genetic perturbations. The workflow is broadly applicable across diverse organoid systems and offers a scalable, standardized platform for interrogating cell death dynamics in basic and translational research.

Keywords:  Apoptosis; Cell death; Intestinal organoids; Live cell imaging; Necroptosis; Pyroptosis

DOI:  https://doi.org/10.1016/bs.mcb.2026.05.004
Autophagy. 2026 Sep 01.

RAB1 mediates OPTN-dependent mitophagy via ATG9A recruitment.

Waka Kojima, Ryu Endo, Kei Okatsu, Hiroki Kinefuchi, Tomoko Tokita, Reika Kikuchi, Noriyuki Matsuda, Shuya Fukai, Koji Yamano.

  Damaged mitochondria are selectively eliminated through mitophagy, a critical quality control process. A kinase PINK1 and an E3 ubiquitin ligase PRKN/Parkin, both of which are mutated in familial Parkinson disease, amplify ubiquitin signals on the damaged mitochondria. The autophagy receptor OPTN plays a pivotal role in mitophagy by bridging ubiquitinated mitochondria with autophagy components. Although OPTN is known to recruit ATG9A-positive vesicles to facilitate mitophagy progression, the precise molecular mechanisms governing this recruitment remain poorly understood. In this study, we identify the small RAB GTPases RAB1A and RAB1B as direct binding partners of the OPTN leucine zipper (LZ) domain. We demonstrate that RAB1A/1B is required for the recruitment of ATG9A vesicles to mitochondria during the initial stages of mitophagy. Knockdown of RAB1A and RAB1B significantly impaired the assembly of OPTN at phagophore formation sites, leading to a profound inhibition of mitophagy progression. Mechanistically, we found that RAB1A/1B associate with ATG9A-positive vesicles via their C-terminal prenylation, thereby tethering these vesicles to the OPTN-bound mitochondria. Our findings establish a novel OPTN-RAB1-ATG9A axis that drives the de novo synthesis of phagophore membranes in close proximity to damaged mitochondria. This work clarifies how selective autophagy receptors spatially coordinate membrane trafficking to ensure the efficient clearance of dysfunctional organelles.

Keywords:  Autophagy; Optineurin; PINK1; Parkin; RAB GTPase; mitochondria; ubiquitin

DOI:  https://doi.org/10.1080/15548627.2026.2728346