bims-axbals 2025-01-19 papers

bims-axbals

Biomed News

on Axonal biology and ALS

Issue of 2025–01–19
thirty papers selected by
TJ Krzystek, ALS Therapy Development Institute

Evaluation of a biomarker for amyotrophic lateral sclerosis derived from a hypomethylated DNA signature of human motor neurons.
Motor cortical neuronal hyperexcitability associated with α-synuclein aggregation.
Targeting mitophagy in neurodegenerative diseases.
The Primary Cilia are Associated with the Axon Initial Segment in Neurons.
C9ORF72 poly-PR induces TDP-43 nuclear condensation via NEAT1 and is modulated by HSP70 activity.
ATXN2 polyglutamine intermediate repeats length expansions in Malaysian patients with amyotrophic lateral sclerosis (ALS).
A STING-CASM-GABARAP pathway activates LRRK2 at lysosomes.
C9orf72 role in myeloid cells: new perspectives in the investigation of the neuro-immune crosstalk in amyotrophic lateral sclerosis and frontotemporal dementia.
Alpha-synuclein inhibits the secretion of extracellular vesicles through disruptions in YKT6 lipidation.
Maintenance of neuronal TDP-43 expression requires axonal lysosome transport.
Protocol for live imaging of axonal transport in iPSC-derived iNeurons.
Peripheral proteinopathy in neurodegenerative diseases.
Beyond the Synapse: FMR1 and FMRP Molecular Mechanisms in the Nucleus.
The VAPB Axis Precisely Coordinates the Timing of Motoneuron Dendritogenesis in Neural Map Development.
ATAD1 Regulates Neuronal Development and Synapse Formation Through Tuning Mitochondrial Function.
Unbiased identification of cell identity in dense mixed neural cultures.
The α-Synuclein Seeding Amplification Assay for Parkinson's Disease.
Neurodegenerative and neurodevelopmental roles for bulk lipid transporters VPS13A and BLTP2 in movement disorders.
Tofersen for SOD1 amyotrophic lateral sclerosis: a systematic review and meta-analysis.
Neuronal LAG3 facilitates pathogenic α-synuclein neuron-to-neuron propagation.
Recycling of endocytic BDNF through extracellular vesicles in astrocytes.
Unifying biology of neurodegeneration in lysosomal storage diseases.
Human neural rosettes secrete bioactive extracellular vesicles enriched in neuronal and glial cellular components.
Engineering organoids as cerebral disease models.
Opposing roles of p38α-mediated phosphorylation and PRMT1-mediated arginine methylation in driving TDP-43 proteinopathy.
Microfluidic Cultures of Basal Forebrain Cholinergic Neurons for Assessing Retrograde Cell Death by Live Imaging.
Neuroinflammation and neurodegeneration in Huntington's disease: genetic hallmarks, role of metals and organophosphates.
Neuron-tumour networks targeted.
Pros and Cons of Human Brain Organoids to Study Alzheimer's Disease.
Human brain organoids identify glioma inhibitors.

BMC Med Genomics. 2025 Jan 14. 18(1): 10

Evaluation of a biomarker for amyotrophic lateral sclerosis derived from a hypomethylated DNA signature of human motor neurons.

Calum Harvey, Alicja Nowak, Sai Zhang, Tobias Moll, Annika K Weimer, Aina Mogas Barcons, Cleide Dos Santos Souza, Laura Ferraiuolo, Kevin Kenna, Noah Zaitlen, Christa Caggiano, Pamela J Shaw, Michael P Snyder, Jonathan Mill, Eilis Hannon, Johnathan Cooper-Knock.

  Amyotrophic lateral sclerosis (ALS) lacks a specific biomarker, but is defined by relatively selective toxicity to motor neurons (MN). As others have highlighted, this offers an opportunity to develop a sensitive and specific biomarker based on detection of DNA released from dying MN within accessible biofluids. Here we have performed whole genome bisulfite sequencing (WGBS) of iPSC-derived MN from neurologically normal individuals. By comparing MN methylation with an atlas of tissue methylation we have derived a MN-specific signature of hypomethylated genomic regions, which accords with genes important for MN function. Through simulation we have optimised the selection of regions for biomarker detection in plasma and CSF cell-free DNA (cfDNA). However, we show that MN-derived DNA is not detectable via WGBS in plasma cfDNA. In support of our experimental finding, we show theoretically that the relative sparsity of lower MN sets a limit on the proportion of plasma cfDNA derived from MN which is below the threshold for detection via WGBS. Our findings are important for the ongoing development of ALS biomarkers. The MN-specific hypomethylated genomic regions we have derived could be usefully combined with more sensitive detection methods and perhaps with study of CSF instead of plasma. Indeed we demonstrate that neuronal-derived DNA is detectable in CSF. Our work is relevant for all diseases featuring death of rare cell-types.

Keywords:  Amyotrophic lateral sclerosis (ALS); Biomarker; Cell-free DNA; DNA methylation; IPSC-derived motor neuron; Whole-genome bisulfite sequencing

DOI:  https://doi.org/10.1186/s12920-025-02084-w
NPJ Parkinsons Dis. 2025 Jan 15. 11(1): 18

Motor cortical neuronal hyperexcitability associated with α-synuclein aggregation.

Liqiang Chen, Hiba Douja Chehade, Hong-Yuan Chu.

ΑBSTRACT: In Parkinson's disease (PD), Lewy pathology deposits in the cerebral cortex, but how the pathology disrupts cortical circuit integrity and function remains poorly understood. To begin to address this question, we injected α-synuclein (αSyn) preformed fibrils (PFFs) into the dorsolateral striatum of mice to seed αSyn pathology in the cortical cortex and induce degeneration of midbrain dopaminergic neurons. We reported that αSyn aggregates accumulate in the motor cortex in a layer- and cell-subtype-specific pattern. Specifically, αSyn aggregates-bearing intratelencephalic neurons (ITNs) showed hyperexcitability, increased input resistance, and decreased cell capacitance, which were associated with impaired HCN channel function. Morphologically, the αSyn aggregates-bearing ITNs showed shrinkage of cell bodies and loss of dendritic spines. Last, we showed that partial dopamine depletion is not sufficient to alter thalamocortical transmission to cortical pyramidal neurons. Our results provide a novel mechanistic understanding of cortical circuit dysfunction in PD.

DOI: https://doi.org/10.1038/s41531-024-00867-z
Nat Rev Drug Discov. 2025 Jan 14.

Targeting mitophagy in neurodegenerative diseases.

Odetta Antico, Paul W Thompson, Nicholas T Hertz, Miratul M K Muqit, Laura E Parton.

Mitochondrial dysfunction is a hallmark of idiopathic neurodegenerative diseases, including Parkinson disease, amyotrophic lateral sclerosis, Alzheimer disease and Huntington disease. Familial forms of Parkinson disease and amyotrophic lateral sclerosis are often characterized by mutations in genes associated with mitophagy deficits. Therefore, enhancing the mitophagy pathway may represent a novel therapeutic approach to targeting an underlying pathogenic cause of neurodegenerative diseases, with the potential to deliver neuroprotection and disease modification, which is an important unmet need. Accumulating genetic, molecular and preclinical model-based evidence now supports targeting mitophagy in neurodegenerative diseases. Despite clinical development challenges, small-molecule-based approaches for selective mitophagy enhancement - namely, USP30 inhibitors and PINK1 activators - are entering phase I clinical trials for the first time.

DOI: https://doi.org/10.1038/s41573-024-01105-0
Adv Sci (Weinh). 2025 Jan 13. e2407405

The Primary Cilia are Associated with the Axon Initial Segment in Neurons.

Han Wang, Yu Li, Xin Li, Zehui Sun, Fengdan Yu, Abolghasem Pashang, Don Kulasiri, Hung Wing Li, Huan Chen, Hongwei Hou, Yan Zhang.

  The primary cilia serve as pivotal mediators of environmental signals and play crucial roles in neuronal responses. Disruption of ciliary function has been implicated in neuronal circuit disorders and aberrant neuronal excitability. However, the precise mechanisms remain elusive. To study the link between the primary cilia and neuronal excitability, manipulation of somatostatin receptor 3 (SSTR3) is investigated, as an example of how alterations in ciliary signaling may affect neuronal activity. It is found that aberrant SSTR3 expression perturbed not only ciliary morphology but also disrupted ciliary signaling cascades. Genetic deletion of SSTR3 resulted in perturbed spatial memory and synaptic plasticity. The axon initial segment (AIS) is a specialized region in the axon where action potentials are initiated. Interestingly, loss of ciliary SSTR3 led to decrease of Akt-dependent cyclic AMP-response element binding protein (CREB)-mediated transcription at the AIS, specifically downregulating AIS master organizer adaptor protein ankyrin G (AnkG) expression. In addition, alterations of other ciliary proteins serotonin 6 receptor (5-HT6R)and intraflagellar transport protein 88 (IFT88) also induced length changes of the AIS. The findings elucidate a specific interaction between the primary cilia and AIS, providing insight into the impact of the primary cilia on neuronal excitability and circuit integrity.

Keywords:  5‐HT6R; SSTR3; axon initial segment; ciliary GPCR; primary cilia

DOI:  https://doi.org/10.1002/advs.202407405
Cell Rep. 2025 Jan 12. pii: S2211-1247(24)01524-9. [Epub ahead of print]44(1): 115173

C9ORF72 poly-PR induces TDP-43 nuclear condensation via NEAT1 and is modulated by HSP70 activity.

Diksha Agnihotri, Chi-Chang Lee, Po-Chao Lu, Ruei-Yu He, Yung-An Huang, Hung-Chih Kuo, Joseph Jen-Tse Huang.

  The toxicity of C9ORF72-encoded polyproline-arginine (poly-PR) dipeptide is associated with its ability to disrupt the liquid-liquid phase separation of intrinsically disordered proteins participating in the formation of membraneless organelles, such as the nucleolus and paraspeckles. Amyotrophic lateral sclerosis (ALS)-related TAR DNA-binding protein 43 (TDP-43) also undergoes phase separation to form nuclear condensates (NCs) in response to stress. However, whether poly-PR alters the nuclear condensation of TDP-43 in ALS remains unclear. In this study, we find that the poly-PR dipeptide enhances the formation of TDP-43 NCs with decreased fluidity. While the non-coding RNA, nuclear-enriched abundant transcript 1 (NEAT1), is essential for the formation of TDP-43 NCs, heat shock protein 70 (HSP70) chaperone maintains their fluidity. Under prolonged poly-PR stress, HSP70 delocalizes from TDP-43 NCs, leading to the oligomerization of TDP-43 within these condensates. This phenomenon is accompanied with TDP-43 mislocalization and increasing cytotoxicity. Our study demonstrates the role of NEAT1 and HSP70 in the aberrant phase transition of TDP-43 NCs under poly-PR stress.

Keywords:  ALS; C9ORF72; CP: Cell biology; HSP70 chaperone; NEAT1 lncRNA; TDP-43; TDP-43 oligomerization; TDP-43 proteinopathy; liquid-liquid phase separation; nuclear condensates; oligomerization; poly-GR dipeptide; poly-PR dipeptide; proteinopathy

DOI:  https://doi.org/10.1016/j.celrep.2024.115173
Neurogenetics. 2025 Jan 13. 26(1): 19

ATXN2 polyglutamine intermediate repeats length expansions in Malaysian patients with amyotrophic lateral sclerosis (ALS).

Suzanna Edgar, Nurul Angelyn Zulhairy-Liong, Melina Ellis, Shuchi Trivedi, Danqing Zhu, Jeffrey Ochieng Odongo, Khean-Jin Goh, David Paul Capelle, Nortina Shahrizaila, Marina L Kennerson, Azlina Ahmad-Annuar.

  Intermediate CAG repeats from 29 to 33 in the ATXN2 gene contributes to the risk of amyotrophic lateral sclerosis (ALS) in European and Asian populations. In this study, 148 ALS patients of multiethnic descent: Chinese (56.1%), Malay (24.3%), Indian (12.8%), others (6.8%) and 100 neurologically normal controls were screened for the ATXN2 CAG repeat expansion. The most common repeat length in both the controls and patients was 22. No familial ALS patients were positive for the intermediate repeat sizes (29-33), while four sporadic patients (2.8%) were positive, with one harbouring a rare ATXN2 homozygous 32 repeat expansion, and a likely pathogenic variant in SPAST. All four patients had limb-onset ALS. Despite representing the smallest ethnic group in our patient cohort, three of the four patients with intermediate repeat sizes were of Indian ancestry. This study, which is the first in Malaysia and Southeast Asia, shows that ATXN2 intermediate risk expansions are relevant to ALS in these populations and will help to inform future genetic testing strategies in the clinic.

Keywords:   ATXN2 ; Amyotrophic lateral sclerosis; Homozygous repeat expansion; Intermediate repeat length; Malaysia

DOI:  https://doi.org/10.1007/s10048-024-00798-0
J Cell Biol. 2025 Feb 03. pii: e202310150. [Epub ahead of print]224(2):

A STING-CASM-GABARAP pathway activates LRRK2 at lysosomes.

Amanda Bentley-DeSousa, Agnes Roczniak-Ferguson, Shawn M Ferguson.

Mutations that increase LRRK2 kinase activity have been linked to Parkinson's disease and Crohn's disease. LRRK2 is also activated by lysosome damage. However, the endogenous cellular mechanisms that control LRRK2 kinase activity are not well understood. In this study, we identify signaling through stimulator of interferon genes (STING) as an activator of LRRK2 via the conjugation of ATG8 to single membranes (CASM) pathway. We furthermore establish that multiple chemical stimuli that perturb lysosomal homeostasis also converge on CASM to activate LRRK2. Although CASM results in the lipidation of multiple ATG8 protein family members, we establish that LRRK2 lysosome recruitment and kinase activation are highly dependent on interactions with the GABARAP member of this family. Collectively, these results define a pathway that integrates multiple stimuli at lysosomes to control the kinase activity of LRRK2. Aberrant activation of LRRK2 via this pathway may be of relevance in both Parkinson's and Crohn's diseases.

DOI: https://doi.org/10.1083/jcb.202310150
Ann Transl Med. 2024 Dec 24. 12(6): 120

C9orf72 role in myeloid cells: new perspectives in the investigation of the neuro-immune crosstalk in amyotrophic lateral sclerosis and frontotemporal dementia.

Maria Elena Cicardi, Davide Trotti.



Keywords:  C9orf72; Neurodegenerative diseases (NDs); microglia; myeloid cells; neuroinflammation

DOI:  https://doi.org/10.21037/atm-24-86
J Neurosci. 2025 Jan 10. pii: e2350232024. [Epub ahead of print]

Alpha-synuclein inhibits the secretion of extracellular vesicles through disruptions in YKT6 lipidation.

Taiji Tsunemi, Yuta Ishiguro, Asako Yoroisaka, Dou Feng, Tomoyo Shimada, Shunichi Niiyama, Yukiko Sasazawa, Keiichi Ishikawa, Wado Akamatsu, Nobutaka Hattori.

Parkinson's disease is characterized by the presence of α-synuclein (α-syn) primarily containing Lewy bodies in neurons. Despite decades of extensive research on α-syn accumulation, its molecular mechanisms have remained largely unexplored. Recent studies by us and others have suggested that extracellular vesicles (EVs), especially exosomes, can mediate the release of α-syn from cells, and inhibiting this pathway could result in increased intracellular α-syn levels. In this study, we have discovered that elevated levels of α-syn themselves lead to reduced α-syn -containing EVs in α-syn inducible H4 cells and induced pluripotent stem cell-derived dopaminergic (DA) neurons from both sexes. Our investigations have revealed that the impairment in EV secretion is not due to their generation but rather a consequence of changes in a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein, YKT6. Specifically, as α-syn levels increase, membrane-associated YKT6 is reduced. Pharmacological inhibition of farnesylation using FTI has led to decreased EV secretion and subsequent elevated levels of α-syn. In summary, our findings suggest that increased levels of α-syn impair YKT6-mediated EV secretion, establishing a detrimental cycle of intracellular α-syn accumulation in human DA neurons.Significance Statement Neurodegenerative disorders, including Parkinson's disease (PD), are characterized by the pathological accumulation of insoluble proteins, primarily in neurons. Regulating intracellular levels of these proteins is critical. Despite extensive research for decades, the precise mechanism of these protein deposits remains unexplained. In this study, we discovered that extracellular vesicles (EVs) play a pivotal role in regulating alpha-synuclein (a-syn) levels through release from neurons. Furthermore, increased levels of a-syn impede its EV secretion, creating a pathological loop. Elevated levels of a-syn interfere with the localization of YKT6, a SNARE protein, to the vesicle membrane by inhibiting YKT6 palmitoylation. These findings illustrate a novel mechanism of a-syn accumulation in neurons and provide a target to potentially mitigate PD pathology.

DOI: https://doi.org/10.1523/JNEUROSCI.2350-23.2024
bioRxiv. 2024 Oct 01. pii: 2024.09.30.615241. [Epub ahead of print]

Maintenance of neuronal TDP-43 expression requires axonal lysosome transport.

Veronica H Ryan, Sydney Lawton, Joel F Reyes, James Hawrot, Ashley M Frankenfield, Sahba Seddighi, Daniel M Ramos, Faraz Faghri, Nicholas L Johnson, Jizhong Zou, Martin Kampmann, John Replogle, Hebao Yuan, Kory R Johnson, Dragan Maric, Ling Hao, Mike A Nalls, Michael E Ward.

TDP-43 mislocalization and pathology occurs across a range of neurodegenerative diseases, but the pathways that modulate TDP-43 in neurons are not well understood. We generated a Halo-TDP-43 knock-in iPSC line and performed a genome-wide CRISPR interference FACS-based screen to identify modifiers of TDP-43 levels in neurons. A meta-analysis of our screen and publicly available screens identified both specific hits and pathways present across multiple screens, the latter likely responsible for generic protein level maintenance. We identified BORC, a complex required for anterograde lysosome transport, as a specific modifier of TDP-43 protein, but not mRNA, levels in neurons. BORC loss led to longer half-life of TDP-43 and other proteins, suggesting lysosome location is required for proper protein turnover. As such, lysosome location and function are crucial for maintaining TDP-43 protein levels in neurons.

DOI: https://doi.org/10.1101/2024.09.30.615241
STAR Protoc. 2025 Jan 12. pii: S2666-1667(24)00721-4. [Epub ahead of print]6(1): 103556

Protocol for live imaging of axonal transport in iPSC-derived iNeurons.

Dan Dou, Erika L F Holzbaur, C Alexander Boecker.

  Studies of human induced pluripotent stem cell (iPSC)-derived neurons promise important insights into neurodegenerative diseases. Here, we present a protocol for live imaging of axonal transport in glutamatergic iPSC-derived neurons (iNeurons). We describe steps for the differentiation of iPSCs into iNeurons via PiggyBac-mediated neurogenin 2 (NGN2) delivery, iNeuron culture and transfection, and the acquisition and analysis of time-lapse images. Our protocol is optimized for the widely available catalog of KOLF2.1J iPSCs with mutations relevant to neurodegenerative diseases but is also applicable to other iPSC lines. For complete details on the use and execution of this protocol, please refer to Dou et al.1,2.

Keywords:  cell biology; microscopy; stem cells

DOI:  https://doi.org/10.1016/j.xpro.2024.103556
Transl Neurodegener. 2025 Jan 16. 14(1): 2

Peripheral proteinopathy in neurodegenerative diseases.

Bin Xu, Xia Lei, Ying Yang, Jiayi Yu, Jun Chen, Zhi Xu, Keqiang Ye, Jing Zhang.

  Proteinopathies in neurology typically refer to pathological changes in proteins associated with neurological diseases, such as the aggregation of amyloid β and Tau in Alzheimer's disease, α-synuclein in Parkinson's disease and multiple system atrophy, and TAR DNA-binding protein 43 in amyotrophic lateral sclerosis and frontotemporal dementia. Interestingly, these proteins are also commonly found in peripheral tissues, raising important questions about their roles in neurological disorders. Multiple studies have shown that peripherally derived pathological proteins not only travel to the brain through various routes, aggravating brain pathology, but also contribute significantly to peripheral dysfunction, highlighting their crucial impact on neurological diseases. Investigating how these peripherally derived proteins influence the progression of neurological disorders could open new horizons for achieving early diagnosis and treatment. This review summarizes the distribution, transportation pathways, and pathogenic mechanisms of several neurodegenerative disease-related pathological proteins in the periphery, proposing that targeting these peripheral pathological proteins could be a promising strategy for preventing and managing neurological diseases.

Keywords:  Amyloid β; Neurodegenerative diseases; Peripheral proteinopathies; TDP-43; Tau; α-Synuclein

DOI:  https://doi.org/10.1186/s40035-024-00461-6
Int J Mol Sci. 2024 Dec 30. pii: 214. [Epub ahead of print]26(1):

Beyond the Synapse: FMR1 and FMRP Molecular Mechanisms in the Nucleus.

Nicole Hansen, Anna Dischler, Caroline Dias.

  FMR1 (Fragile X messenger ribonucleoprotein 1), located on the X-chromosome, encodes the multi-functional FMR1 protein (FMRP), critical to brain development and function. Trinucleotide CGG repeat expansions at this locus cause a range of neurological disorders, collectively referred to as Fragile X-related conditions. The most well-known of these is Fragile X syndrome, a neurodevelopmental disorder associated with syndromic facial features, autism, intellectual disabilities, and seizures. However, CGG expansions of different sizes also confer a risk of neuropsychiatric and neurodegenerative disorders throughout the lifespan, through distinct molecular mechanisms. Although Fragile X syndrome is associated with downstream synaptic deficits and neuronal hyperexcitability, work in the past decade has demonstrated that both the causative FMR1 trinucleotide repeat expansion and FMRP itself play important roles in nuclear function and regulation, including non-canonical nucleic acid structure formation and chromatin dynamics. These effects are critical to cellular pathophysiology, although the full extent of their contribution to clinical phenotypes is only just emerging. Here, we present a focused review on some of the nuclear consequences of FMR1/FMRP dysregulation, including parallels in other repeat expansion disorders, ranging from studies in model systems to human cells and tissues.

Keywords:  FMR1; FMRP; Fragile X; R-loops; chromatin; nucleus

DOI:  https://doi.org/10.3390/ijms26010214
Res Sq. 2024 Dec 31. pii: rs.3.rs-5684747. [Epub ahead of print]

The VAPB Axis Precisely Coordinates the Timing of Motoneuron Dendritogenesis in Neural Map Development.

Daichi Kamiyama, Yuri Nishida, Rie Kamiyama, Anthony Sego, George Vining, Kathy Bui, Miyuki Fitch, Hy Do, Oshri Avraham, Takahiro Chihara.

In Drosophila motoneurons, spatiotemporal dendritic patterns are established in the ventral nerve cord. While many guidance cues have been identified, the mechanisms of temporal regulation remain unknown. Previously, we identified the actin modulator Cdc42 GTPase as a key factor in this process. In this report, we further identify the upstream factors that activate Cdc42. Using single-cell genetics, FRET-based imaging, and biochemical techniques, we demonstrate that the guanine nucleotide exchange factor Vav is anchored to the plasma membrane via the Eph receptor tyrosine kinase, enabling Cdc42 activation. VAMP-associated protein 33 (Vap33), an Eph ligand supplied non-cell-autonomously, may induce Eph autophosphorylation, initiating downstream signaling. Traditionally known as an ER-resident protein, Vap33 is secreted extracellularly at the onset of Cdc42 activation, acting as a temporal cue. In humans, VAPB-the ortholog of Vap33-is similarly secreted in the spinal cord, and its dysregulation leads to amyotrophic lateral sclerosis type 8 (ALS8) and spinal muscular atrophy (SMA). Our findings provide a framework linking VAPB signaling to motor circuitry formation in both health and disease.

DOI: https://doi.org/10.21203/rs.3.rs-5684747/v1
Int J Mol Sci. 2024 Dec 24. pii: 44. [Epub ahead of print]26(1):

ATAD1 Regulates Neuronal Development and Synapse Formation Through Tuning Mitochondrial Function.

Hao-Hao Yan, Jia-Jia He, Chuanhai Fu, Jia-Hui Chen, Ai-Hui Tang.

  Mitochondrial function is essential for synaptic function. ATAD1, an AAA+ protease involved in mitochondrial quality control, governs fission-fusion dynamics within the organelle. However, the distribution and functional role of ATAD1 in neurons remain poorly understood. In this study, we demonstrate that ATAD1 is primarily localized to mitochondria in dendrites and, to a lesser extent, in spines in cultured hippocampal neurons. We found that ATAD1 deficiency disrupts the mitochondrial fission-fusion balance, resulting in mitochondrial fragmentation. This deficiency also impairs dendritic branching, hinders dendritic spine maturation, and reduces glutamatergic synaptic transmission in hippocampal neuron. To further investigate the underlying mechanism, we employed an ATP hydrolysis-deficient mutant of ATAD1 to rescue the neuronal deficits associated with ATAD1 loss. We discovered that the synaptic deficits are independent of the mitochondrial morphology changes but rely on its ATP hydrolysis. Furthermore, we show that ATAD1 loss leads to impaired mitochondrial function, including decreased ATP production, impaired membrane potential, and elevated oxidative stress. In conclusion, our results provide evidence that ATAD1 is crucial for maintaining mitochondrial function and regulating neurodevelopment and synaptic function.

Keywords:  ATAD1; mitochondrial dysfunction; neuronal development; synapse formation

DOI:  https://doi.org/10.3390/ijms26010044
Elife. 2025 Jan 17. pii: RP95273. [Epub ahead of print]13

Unbiased identification of cell identity in dense mixed neural cultures.

Sarah De Beuckeleer, Tim Van De Looverbosch, Johanna Van Den Daele, Peter Ponsaerts, Winnok H De Vos.

  Induced pluripotent stem cell (iPSC) technology is revolutionizing cell biology. However, the variability between individual iPSC lines and the lack of efficient technology to comprehensively characterize iPSC-derived cell types hinder its adoption in routine preclinical screening settings. To facilitate the validation of iPSC-derived cell culture composition, we have implemented an imaging assay based on cell painting and convolutional neural networks to recognize cell types in dense and mixed cultures with high fidelity. We have benchmarked our approach using pure and mixed cultures of neuroblastoma and astrocytoma cell lines and attained a classification accuracy above 96%. Through iterative data erosion, we found that inputs containing the nuclear region of interest and its close environment, allow achieving equally high classification accuracy as inputs containing the whole cell for semi-confluent cultures and preserved prediction accuracy even in very dense cultures. We then applied this regionally restricted cell profiling approach to evaluate the differentiation status of iPSC-derived neural cultures, by determining the ratio of postmitotic neurons and neural progenitors. We found that the cell-based prediction significantly outperformed an approach in which the population-level time in culture was used as a classification criterion (96% vs 86%, respectively). In mixed iPSC-derived neuronal cultures, microglia could be unequivocally discriminated from neurons, regardless of their reactivity state, and a tiered strategy allowed for further distinguishing activated from non-activated cell states, albeit with lower accuracy. Thus, morphological single-cell profiling provides a means to quantify cell composition in complex mixed neural cultures and holds promise for use in the quality control of iPSC-derived cell culture models.

Keywords:  cell biology; cell painting; computational biology; cyclic imaging; deep learning; human; iPSC culture; morphological phenotyping; neural differentiation; systems biology

DOI:  https://doi.org/10.7554/eLife.95273
Int J Mol Sci. 2025 Jan 04. pii: 389. [Epub ahead of print]26(1):

The α-Synuclein Seeding Amplification Assay for Parkinson's Disease.

Ling-Xiao Yi, Eng King Tan, Zhi Dong Zhou.

  Parkinson's disease (PD) is the second most common neurodegenerative disease in the world. Currently, PD is incurable, and the diagnosis of PD mainly relies on clinical manifestations. The central pathological event in PD is the abnormal aggregation and deposition of misfolded α-synuclein (α-Syn) protein aggregates in the Lewy body (LB) in affected brain areas. Behaving as a prion-like seeding, the misfolded α-syn protein can induce and facilitate the aggregation of native unfolded α-Syn protein to aggravate α-Syn protein aggregation, leading to PD progression. Recently, in a blood-based α-Syn seeding amplification assay (SAA), Kluge et al. identified pathological α-Syn seeding activity in PD patients with Parkin (PRKN) gene variants. Additionally, pathological α-syn seeding activity was also identified in sporadic PD and PD patients with Leucine-rich repeat kinase 2 (LRRK2) or glucocerebrosidase (GBA) gene variants. Principally, the α-Syn SAA can be used to detect pathological α-Syn seeding activity, which will significantly enhance PD diagnosis, progression monitoring, prognosis prediction, and anti-PD therapy. The significance and future strategies of α-Syn SAA protocol are highlighted and proposed, whereas challenges and limitations of the assay are discussed.

Keywords:  Parkinson’s disease; biomarker; neurodegeneration; seeding amplification assay; α-synuclein

DOI:  https://doi.org/10.3390/ijms26010389
bioRxiv. 2024 Dec 30. pii: 2024.12.30.630795. [Epub ahead of print]

Neurodegenerative and neurodevelopmental roles for bulk lipid transporters VPS13A and BLTP2 in movement disorders.

Sarah D Neuman, Rajan S Thakur, Scott J Gratz, Kate M O'Connor-Giles, Arash Bashirullah.

Background: Bridge-like lipid transfer proteins (BLTPs) mediate bulk lipid transport at membrane contact sites. Mutations in BLTPs are linked to both early-onset neurodevelopmental and later-onset neurodegenerative diseases, including movement disorders. The tissue specificity and temporal requirements of BLTPs in disease pathogenesis remain poorly understood.
Objectives: To determine the age-of-onset and tissue-specific roles of VPS13A and BLTP2 in movement disorder pathogenesis using Drosophila models.
Methods: We generated tissue-specific knockdowns of the VPS13A ortholog ( Vps13 ) and the BLTP2 ortholog ( hobbit ) in neurons and muscles of Drosophila . We analyzed age-dependent locomotor behavior, neurodegeneration, and synapse development and function.
Results: Neuron-specific loss of the VPS13A ortholog caused neurodegeneration followed by age- onset movement deficits and reduced lifespan, while muscle-specific loss affected only lifespan, revealing neurodegeneration and myopathy as independent comorbidities in VPS13A disease. In contrast, neuronal loss of the BLTP2 ortholog resulted in severe early-onset locomotor defects without neurodegeneration, while muscle loss impaired synaptogenesis and neurotransmission at the neuromuscular junction (NMJ).
Conclusions: VPS13A maintains neuronal survival, while BLTP2 orchestrates synaptic development. VPS13A function in muscle does not play a role in movement defects. The phenotypic specificity of BLTP function provides mechanistic insights into distinct disease trajectories for BLTP-associated movement disorders.

DOI: https://doi.org/10.1101/2024.12.30.630795
Neurol Sci. 2025 Jan 17.

Tofersen for SOD1 amyotrophic lateral sclerosis: a systematic review and meta-analysis.

Abdullah Ashraf Hamad, Ibraheem M Alkhawaldeh, Abdulqadir J Nashwan, Mostafa Meshref, Yahia Imam.

   OBJECTIVE: Tofersen, an antisense oligonucleotide, has recently received FDA and EMA approval for treating amyotrophic lateral sclerosis (ALS) in adults with SOD1 gene mutations. This systematic review and meta-analysis synthesized evidence on tofersen's safety and efficacy in patients with SOD1-related ALS.
METHODS: A comprehensive search of three databases was conducted from inception through October 2024. Eligible studies included clinical trials, observational studies, and case studies. Meta-analyses were conducted using a random-effects model in RevMan.
RESULTS: Twelve studies involving 195 patients treated with tofersen met the inclusion criteria, comprising two randomized controlled trials (RCTs), five cohort studies, one case series, and four case reports. Tofersen demonstrated promising effects, notably reducing SOD1 levels in cerebrospinal fluid and neurofilament light chain (NfL) in plasma, a biomarker strongly correlated with ALS progression and survival. Meta-analysis of RCTs showed a significantly lower rate of decline in ALS Functional Rating Scale-Revised (ALSFRS-R) scores from baseline in the tofersen group compared to placebo (SMD = 0.44, 95% CI [0.05 to 0.83], P = 0.03) and a significant reduction in the decline of predicted Slow Vital Capacity (P = 0.005). In a pre-post meta-analysis of five studies, a significant decrease in ALS progression rate (ALSFRS-R decline rate) was observed (MD = -0.28, 95% CI [-0.40 to -0.15], P < 0.0001). Reported adverse events were consistent with ALS progression or procedural effects.
CONCLUSION: Current evidence suggests that tofersen effectively reduces SOD1 and NfL levels and slow disease progression in SOD1 ALS, showing promise as a targeted therapeutic option.

Keywords:   SOD1 ; ALS; Amyotrophic lateral sclerosis; Antisense oligonucleotide; Tofersen

DOI:  https://doi.org/10.1007/s10072-025-07994-2
bioRxiv. 2025 Jan 03. pii: 2025.01.03.631221. [Epub ahead of print]

Neuronal LAG3 facilitates pathogenic α-synuclein neuron-to-neuron propagation.

Xiuli Yang, Deok Jeong, Graziella Madeo, Ramhari Kumbhar, Ning Wang, Lili Niu, Junkai Hu, Shuya Li, Kundlik Gadhave, Rong Chen, Fatih Akkentli, Creg J Workman, Dario A A Vignali, Mingyao Ying, Antonello Bonci, Valina L Dawson, Ted M Dawson, Xiaobo Mao.

Lymphocyte activation gene 3 (LAG3) is a key receptor involved in the propagation of pathological proteins in Parkinson's disease (PD). This study investigates the role of neuronal LAG3 in mediating the binding, uptake, and propagation of α-synuclein (αSyn) preformed fibrils (PFFs). Using neuronal LAG3 conditional knockout mice and human induced pluripotent stem cells-derived dopaminergic (DA) neurons, we demonstrate that LAG3 expression is critical for pathogenic αSyn propagation. Our results show that the absence of neuronal LAG3 significantly reduces αSyn pathology, alleviates motor dysfunction, and inhibits neurodegeneration in vivo . Electrophysiological recordings revealed that αSyn PFFs induce pronounced neuronal hyperactivity in wild-type (WT) neurons, increasing firing rates in cell-attached and whole-cell configurations, and reducing miniature excitatory postsynaptic currents. In contrast, neurons lacking LAG3 resisted these electrophysiological effects. Moreover, treatment with an anti-human LAG3 antibody in human DA neurons inhibited αSyn PFFs binding and uptake, preventing pathology propagation. These findings confirm the essential function of neuronal LAG3 in mediating αSyn propagation and associated disruptions, identifying LAG3 as a potential therapeutic target for PD and related α-synucleinopathies.

DOI: https://doi.org/10.1101/2025.01.03.631221
Sci Rep. 2025 Jan 15. 15(1): 2011

Recycling of endocytic BDNF through extracellular vesicles in astrocytes.

Jeongho Han, Hyungju Park.

Brain-derived neurotrophic factor (BDNF) plays an essential role in regulating diverse neuronal functions in an activity-dependent manner. Although BDNF is synthesized primarily in neurons, astrocytes can also supply BDNF through various routes, including the recycling of neuron-derived BDNF. Despite accumulating evidence for astrocytic BDNF uptake and resecretion of neuronal BDNF, the detailed mechanisms underlying astrocytic BDNF recycling remain unclear. Here, we report that astrocytic resecretion of endocytosed BDNF is mediated by an extracellular vesicle (EV)-dependent secretory pathway. In cultured primary astrocytes, extracellular BDNF was endocytosed into CD63-positive EVs, and stimulation of astrocytes with ATP could evoke the release of endocytosed BDNF from CD63-positive vesicles. Downregulation of vesicle-associated membrane protein 3 (Vamp3) led to an increase in the colocalization of endosomal BDNF and CD63 but a decrease in extracellular vesicle release, suggesting the necessity of Vamp3-dependent signaling for EV-mediated BDNF secretion. Collectively, our findings demonstrate that astrocytic recycling of neuronal BDNF is dependent on the EV-mediated secretory pathway via Vamp3-associated signaling.

DOI: https://doi.org/10.1038/s41598-025-86200-x
J Inherit Metab Dis. 2025 Jan;48(1): e12833

Unifying biology of neurodegeneration in lysosomal storage diseases.

Anna M Ludlaim, Simon N Waddington, Tristan R McKay.

  There are currently at least 70 characterised lysosomal storage diseases (LSD) resultant from inherited single-gene defects. Of these, at least 30 present with central nervous system (CNS) neurodegeneration and overlapping aetiology. Substrate accumulation and dysfunctional neuronal lysosomes are common denominator, but how variants in 30 different genes converge on this central cellular phenotype is unclear. Equally unresolved is how the accumulation of a diverse spectrum of substrates in the neuronal lysosomes results in remarkably similar neurodegenerative outcomes. Conversely, how is it that many other monogenic LSDs cause only visceral disease? Lysosomal substance accumulation in LSDs with CNS neurodegeneration (nLSD) includes lipofuscinoses, mucopolysaccharidoses, sphingolipidoses and glycoproteinoses. Here, we review the latest discoveries in the fundamental biology of four classes of nLSDs, comparing and contrasting new insights into disease mechanism with emerging evidence of unifying convergence.

Keywords:  Fabry disease; Gaucher disease; Krabbe disease; Nieman‐Pick; Sandhoff; Tay‐Sachs; lysosomal storage disease; metachromatic leukodystrophy; mucopolysaccharidosis; neuronal ceroid lipofuscinosis

DOI:  https://doi.org/10.1002/jimd.12833
Sci Rep. 2025 Jan 15. 15(1): 1987

Human neural rosettes secrete bioactive extracellular vesicles enriched in neuronal and glial cellular components.

Malena Herrera Lopez, Matías Bertone Arolfo, Mónica Remedi, Laura Gastaldi, Carlos Wilson, Gonzalo G Guendulain, Danilo Ceschin, Andrés Cardozo Gizzi, Alfredo Cáceres, Ana Lis Moyano.

  Extracellular vesicles (EVs) play a critical role in the development of neural cells in the central nervous system (CNS). Human neural rosettes (hNRs) are radial cell structures that assemble from induced pluripotent stem cells (hiPSCs) and recapitulate some stages of neural tube morphogenesis. Here we show that hiPSCs and hNRs secrete EVs (hiPSC-EVs and hNR-EVs) with distinctive protein cargoes. Remarkably, hNR-EVs carry neuronal and glial cellular components involved in human CNS development. Importantly, hNR-EVs stimulate stem cells to change their cellular morphology and promote neurite growth in human and murine neurons with a significant dysregulation of SOX2 levels. This transcription factor modulates both neural differentiation and pluripotency. Interestingly, these effects were inhibited by antibodies against an unexpected neuroglial cargo of hNR-EVs: the major proteolipid protein (PLP). These findings show that hNRs secrete bioactive EVs containing neural components and might contribute as trophic factors during human neurodevelopment.

Keywords:  CNS; Extracellular vesicles; Myelin; Neurite outgrowth; Neurodevelopment; PLP; SOX2; Stem cells

DOI:  https://doi.org/10.1038/s41598-025-86094-9
Curr Opin Biotechnol. 2025 Jan 13. pii: S0958-1669(24)00189-7. [Epub ahead of print]92 103253

Engineering organoids as cerebral disease models.

Alexander Geidies, Marija Lj Medar, Hannes M Beyer.

Cerebral organoids pioneered in replicating complex brain tissue architectures in vitro, offering a vast potential for human disease modeling. They enable the in vitro study of human physiological and pathophysiological mechanisms of various neurological diseases and disorders. The trajectory of technological advancements in brain organoid generation and engineering over the past decade indicates that the technology might, in the future, mature into indispensable solutions at the horizon of personalized and regenerative medicine. In this review, we highlight recent advances in the engineering of brain organoids as disease models and discuss some of the challenges and opportunities for future research in this rapidly evolving field.

DOI: https://doi.org/10.1016/j.copbio.2024.103253
Cell Rep. 2025 Jan 14. pii: S2211-1247(24)01556-0. [Epub ahead of print]44(1): 115205

Opposing roles of p38α-mediated phosphorylation and PRMT1-mediated arginine methylation in driving TDP-43 proteinopathy.

Mari Aikio, Hana M Odeh, Heike J Wobst, Bo Lim Lee, Úna Chan, Jocelyn C Mauna, Korrie L Mack, Bradley Class, Thomas A Ollerhead, Alice F Ford, Edward M Barbieri, Ryan R Cupo, Lauren E Drake, Joshua L Smalley, Yuan-Ta Lin, Stephanie Lam, Reuben Thomas, Nicholas Castello, Ashmita Baral, Jenna N Beyer, Mohd A Najar, John Dunlop, Aaron D Gitler, Ashkan Javaherian, Julia A Kaye, George M Burslem, Dean G Brown, Christopher J Donnelly, Steven Finkbeiner, Stephen J Moss, Nicholas J Brandon, James Shorter.

  Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder typically characterized by insoluble inclusions of hyperphosphorylated TDP-43. The mechanisms underlying toxic TDP-43 accumulation are not understood. Persistent activation of p38 mitogen-activated protein kinase (MAPK) is implicated in ALS. However, it is unclear how p38 MAPK affects TDP-43 proteinopathy. Here, we show that p38α MAPK inhibition reduces pathological TDP-43 phosphorylation, aggregation, cytoplasmic mislocalization, and neurotoxicity. Remarkably, p38α MAPK inhibition mitigates aberrant TDP-43 phenotypes in diverse ALS patient-derived motor neurons. p38α MAPK phosphorylates TDP-43 at pathological S409/S410 and S292, which reduces TDP-43 liquid-liquid phase separation (LLPS) but allows pathological TDP-43 aggregation. Moreover, we establish that PRMT1 methylates TDP-43 at R293. Importantly, S292 phosphorylation reduces R293 methylation, and R293 methylation reduces S409/S410 phosphorylation. Notably, R293 methylation permits TDP-43 LLPS and reduces pathological TDP-43 aggregation. Thus, strategies to reduce p38α-mediated TDP-43 phosphorylation and promote PRMT1-mediated R293 methylation could have therapeutic utility for ALS and related TDP-43 proteinopathies.

Keywords:  ALS; CP: Molecular biology; CP: Neuroscience; PRMT1; TDP-43; arginine methylation; p38α; phosphorylation

DOI:  https://doi.org/10.1016/j.celrep.2024.115205
Bio Protoc. 2025 Jan 05. 15(1): e5149

Microfluidic Cultures of Basal Forebrain Cholinergic Neurons for Assessing Retrograde Cell Death by Live Imaging.

Srestha Dasgupta, Mansi A Pandya, Wilma J Friedman.

  Neurons are highly polarized cells, with axons that may innervate distant target regions. In the brain, basal forebrain cholinergic neurons (BFCNs) possess extensive axons that project to several target regions such as the cortex, hippocampus, and amygdala, and may be exposed to a specific microenvironment in their axon targets that may have retrograde effects on neuronal health. Interestingly, BFCNs express the pan-neurotrophin receptor p75NTR throughout life while also concomitantly co-expressing all Trk receptors, making them capable of responding to both mature and precursor neurotrophins to promote survival or apoptosis, respectively. Levels of these trophic factors may be modulated in the BFCN axon or soma microenvironment under neurodegenerative conditions such as seizure and brain injury. In this protocol, BFCNs are established in microfluidic devices for compartmental culture, with the aim of studying the effects of axon- or soma-specific stimulation of BFCNs for an in vitro representation of distal axon vs. soma environments as seen in vivo. This study further establishes a novel method of tracing and imaging live BFCNs exposed to stimuli in their distal axons with the aim of assessing retrograde cell death. The in vitro compartmental culture system of BFCNs that allows live imaging may be applied to investigate various effects of axon- or soma-specific stimuli that affect BFCN health, maintenance, and death, to model events that occur in the context of brain injury and neurodegenerative disorders. Key features • Separation of axons and soma of basal forebrain primary neurons in vitro using microfluidic chambers. • Compartmental/localized treatment of axons or somas of BFCNs. • Live imaging of retrogradely labeled BFCNs to assess cell death.

Keywords:  Basal forebrain; Cell death; Live imaging; Microfluidics

DOI:  https://doi.org/10.21769/BioProtoc.5149
Neurogenetics. 2025 Jan 17. 26(1): 21

Neuroinflammation and neurodegeneration in Huntington's disease: genetic hallmarks, role of metals and organophosphates.

Omkar Kumar Kunwar, Shamsher Singh.

  Huntington's disease (HDs) is a fatal, autosomal dominant, and hereditary neurodegenerative disorder characterized by progressive motor dysfunction, cognitive decline, and psychiatric disturbances. HD is well linked to mutation in the HTT gene, which leads to an abnormal expansion of trinucleotide CAG repeats, resulting in the production of the mHTT protein and responsible for abnormally long poly-Q tract. These abnormal proteins disrupt cellular processes, including neuroinflammation, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction, ultimately leading to selective neuronal loss in the brain. Epidemiological studies reveal significant regional variability in HDs prevalence, with the highest rates observed in North America and the lowest in Africa. In addition to genetic factors, environmental influences such as exposure to metals, and chemicals, and lifestyle factors like alcohol and tobacco use may exacerbate disease progression. This review explores the molecular mechanisms underlying HDs and emphasize the role of neuroinflammatory mediators and environmental factors, in HD research. Understanding these complex interactions is crucial for developing targeted interventions that can slow or halt the progression of this devastating disease.

Keywords:  Chlorpyrifos; Dopamine dysfunction; Excitotoxicity; Huntington’s disease; Neuroinflammation

DOI:  https://doi.org/10.1007/s10048-025-00801-2
Nat Rev Neurol. 2025 Jan 17.

Neuron-tumour networks targeted.

Ian Fyfe.

DOI: https://doi.org/10.1038/s41582-025-01059-w
Aging Dis. 2025 Jan 09.

Pros and Cons of Human Brain Organoids to Study Alzheimer's Disease.

Andrea Sainz, Fernando Pérez, Alberto Pérez-Samartín, Mitradas Panicker, Asier Ruiz, Carlos Matute.

There is increasing pressure for researchers to reduce their reliance on animals, particularly in early-stage research. The main reason for that change arises from the different biological behavior of humans that leads to frequent failure of translating data from bench to bed. The advent of organoid technology ten years ago, along with the feasibility of obtaining brain organoids in most laboratories, has created considerable expectations not exempting frustration. In this review, we make a critical appraisal of the advantages and limitations of studying Alzheimer's disease in brain cortical organoids derived from inducible pluripotent stem cells (iPSCs). While dealing with human neurons and glia in 3D poses a tremendous advantage versus murine brain cells, organoids typically lack microglia, blood vessels, immune interactions as well as proper CNS neuropil. In turn, they have relatively few oligodendrocytes and low myelination. In addition, lengthy procedures to get proper mature organoids constitute an additional limitation that may also affect the native biological properties of neurons and glia. We conclude that human brain organoids, while popular and useful, remain a model that needs further refinement before bringing substantial value to study Alzheimer's disease.

DOI: https://doi.org/10.14336/AD.2024.1409
Nat Rev Drug Discov. 2025 Jan 10.

Human brain organoids identify glioma inhibitors.

Sarah Crunkhorn.

DOI: https://doi.org/10.1038/d41573-025-00007-z