bims-axbals 2024-06-16 papers

bims-axbals

Biomed News

on Axonal Biology and ALS

Issue of 2024‒06‒16
twenty-six papers selected by
TJ Krzystek, ALS Therapy Development Institute

Protein Disulfide Isomerase Endoplasmic Reticulum Protein 57 (ERp57) is Protective Against ALS-Associated Mutant TDP-43 in Neuronal Cells.
Cellular and axonal transport phenotypes due to the C9ORF72 HRE in iPSC motor and sensory neurons.
Cell-autonomous role of leucine-rich repeat kinase in the protection of dopaminergic neuron survival.
Elevated nuclear TDP-43 induces constitutive exon skipping.
A designed ankyrin-repeat protein that targets Parkinson's disease-associated LRRK2.
T cell subset composition differs between blood and cerebrospinal fluid in amyotrophic lateral sclerosis.
Frontotemporal dementia-like disease progression elicited by seeded aggregation and spread of FUS.
Diverse Functions of Parkin in Midbrain Dopaminergic Neurons.
Atlastin-1 regulates endosomal tubulation and lysosomal proteolysis in human cortical neurons.
Protein aggregation and therapeutic strategies in SOD1- and TDP-43- linked ALS.
ARHGAP26/GRAF1 orchestrates actin remodeling and membrane dynamics to drive mitochondrial clearance and promote fuel flexibility.
M6A reduction relieves FUS-associated ALS granules.
Modeling the Simultaneous Dynamics of Proteins in Blood Plasma and the Cerebrospinal Fluid in Human In Vivo.
Amygdala TDP-43 pathology is associated with behavioural dysfunction and ferritin accumulation in amyotrophic lateral sclerosis.
Multidisciplinary care for amyotrophic lateral sclerosis.
DOPA-decarboxylase is elevated in CSF, but not plasma, in prodromal and de novo Parkinson's disease.
Nanobiopsy investigation of the subcellular mtDNA heteroplasmy in human tissues.
Author Correction: RIP3 targets pyruvate dehydrogenase complex to increase aerobic respiration in TNF-induced necroptosis.
Deep learning based characterization of human organoids using optical coherence tomography.
Repeated cognitive assessments show stable function over time in patients with ALS.
Single-extracellular vesicle (EV) analyses validate the use of L1 Cell Adhesion Molecule (L1CAM) as a reliable biomarker of neuron-derived EVs.
Early and selective localization of tau filaments to glutamatergic subcellular domains within the human anterodorsal thalamus.
Fully Human Bifunctional Intrabodies Achieve Graded Reduction of Intracellular Tau and Rescue Survival of MAPT Mutation iPSC-derived Neurons.
Pharmacological modulation of developmental and synaptic phenotypes in human SHANK3 deficient stem cell-derived neuronal models.
Ataxia telangiectasia patient-derived neuronal and brain organoid models reveal mitochondrial dysfunction and oxidative stress.
Astragaloside IV mediates radiation-induced neuronal damage through activation of BDNF-TrkB signaling.

Neuromolecular Med. 2024 Jun 11. 26(1): 23

Protein Disulfide Isomerase Endoplasmic Reticulum Protein 57 (ERp57) is Protective Against ALS-Associated Mutant TDP-43 in Neuronal Cells.

Sonam Parakh, Emma R Perri, Marta Vidal, Zeinab Takalloo, Cyril J Jagaraj, Prachi Mehta, Shu Yang, Colleen J Thomas, Ian P Blair, Yuning Hong, Julie D Atkin.

  Amyotrophic Lateral Sclerosis (ALS) is a severe neurodegenerative disease affecting motor neurons. Pathological forms of Tar-DNA binding protein-43 (TDP-43), involving its mislocalisation to the cytoplasm and the formation of misfolded inclusions, are present in almost all ALS cases (97%), and ~ 50% cases of the related condition, frontotemporal dementia (FTD), highlighting its importance in neurodegeneration. Previous studies have shown that endoplasmic reticulum protein 57 (ERp57), a member of the protein disulphide isomerase (PDI) family of redox chaperones, is protective against ALS-linked mutant superoxide dismutase (SOD1) in neuronal cells and transgenic SOD1G93A mouse models. However, it remains unclear whether ERp57 is protective against pathological TDP-43 in ALS. Here, we demonstrate that ERp57 is protective against key features of TDP-43 pathology in neuronal cells. ERp57 inhibited the mislocalisation of TDP-43M337V from the nucleus to the cytoplasm. In addition, ERp57 inhibited the number of inclusions formed by ALS-associated variant TDP-43M337V and reduced the size of these inclusions. ERp57 was also protective against ER stress and induction of apoptosis. Furthermore, ERp57 modulated the steady-state expression levels of TDP-43. This study therefore demonstrates a novel mechanism of action of ERp57 in ALS. It also implies that ERp57 may have potential as a novel therapeutic target to prevent the TDP-43 pathology associated with neurodegeneration.

Keywords:  ALS—Amyotrophic lateral sclerosis; ER stress; ERp57—Endoplasmic reticulum protein 57; PDI—Protein disulphide isomerase; TDP-43 pathology

DOI:  https://doi.org/10.1007/s12017-024-08787-0
Stem Cell Reports. 2024 Jun 06. pii: S2213-6711(24)00150-4. [Epub ahead of print]

Cellular and axonal transport phenotypes due to the C9ORF72 HRE in iPSC motor and sensory neurons.

Jakub Scaber, Iona Thomas-Wright, Alex J Clark, Yinyan Xu, Björn F Vahsen, Mireia Carcolé, Ruxandra Dafinca, Lucy Farrimond, Adrian M Isaacs, David L Bennett, Kevin Talbot.

  Induced pluripotent stem cell (iPSC)-derived motor neurons (MNs) from patients with amyotrophic lateral sclerosis (ALS) and the C9ORF72 hexanucleotide repeat expansion (HRE) have multiple cellular phenotypes, but which of these accurately reflect the biology underlying the cell-specific vulnerability of ALS is uncertain. We therefore compared phenotypes due to the C9ORF72 HRE in MNs with sensory neurons (SNs), which are relatively spared in ALS. The iPSC models were able to partially reproduce the differential gene expression seen between adult SNs and MNs. We demonstrated that the typical hallmarks of C9ORF72-ALS, including RNA foci and dipeptide formation, as well as specific axonal transport defects, occurred equally in MNs and SNs, suggesting that these in vitro phenotypes are not sufficient to explain the cell-type selectivity of ALS in isolation.

Keywords:  amyotrophic lateral sclerosis; induced pluripotent stem cells; motor neuron; selective vulnerability; sensory neuron

DOI:  https://doi.org/10.1016/j.stemcr.2024.05.008
Elife. 2024 Jun 10. pii: RP92673. [Epub ahead of print]12

Cell-autonomous role of leucine-rich repeat kinase in the protection of dopaminergic neuron survival.

Jongkyun Kang, Guodong Huang, Long Ma, Youren Tong, Anu Shahapal, Phoenix Chen, Jie Shen.

  Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of Parkinson's disease (PD). However, whether LRRK2 mutations cause PD and degeneration of dopaminergic (DA) neurons via a toxic gain-of-function or a loss-of-function mechanism is unresolved and has pivotal implications for LRRK2-based PD therapies. In this study, we investigate whether Lrrk2 and its functional homolog Lrrk1 play a cell-intrinsic role in DA neuron survival through the development of DA neuron-specific Lrrk conditional double knockout (cDKO) mice. Unlike Lrrk germline DKO mice, DA neuron-restricted Lrrk cDKO mice exhibit normal mortality but develop age-dependent loss of DA neurons, as shown by the progressive reduction of DA neurons in the substantia nigra pars compacta (SNpc) at the ages of 20 and 24 months. Moreover, DA neurodegeneration is accompanied with increases in apoptosis and elevated microgliosis in the SNpc as well as decreases in DA terminals in the striatum, and is preceded by impaired motor coordination. Taken together, these findings provide the unequivocal evidence for the cell-intrinsic requirement of LRRK in DA neurons and raise the possibility that LRRK2 mutations may impair its protection of DA neurons, leading to DA neurodegeneration in PD.

Keywords:  LRRK1; LRRK2; Parkinson's disease; conditional knock-out mice; dopaminergic neuron; mouse; neuroscience; substantia nigra pars compacta

DOI:  https://doi.org/10.7554/eLife.92673
Mol Neurodegener. 2024 Jun 09. 19(1): 45

Elevated nuclear TDP-43 induces constitutive exon skipping.

Rogger P Carmen-Orozco, William Tsao, Yingzhi Ye, Irika R Sinha, Koping Chang, Vickie T Trinh, William Chung, Kyra Bowden, Juan C Troncoso, Seth Blackshaw, Lindsey R Hayes, Shuying Sun, Philip C Wong, Jonathan P Ling.

BACKGROUND: Cytoplasmic inclusions and loss of nuclear TDP-43 are key pathological features found in several neurodegenerative disorders, suggesting both gain- and loss-of-function mechanisms of disease. To study gain-of-function, TDP-43 overexpression has been used to generate in vitro and in vivo model systems.METHODS: We analyzed RNA-seq datasets from mouse and human neurons overexpressing TDP-43 to explore species specific splicing patterns. We explored the dynamics between TDP-43 levels and exon repression in vitro. Furthermore we analyzed human brain samples and publicly available RNA datasets to explore the relationship between exon repression and disease.
RESULTS: Our study shows that excessive levels of nuclear TDP-43 protein lead to constitutive exon skipping that is largely species-specific. Furthermore, while aberrant exon skipping is detected in some human brains, it is not correlated with disease, unlike the incorporation of cryptic exons that occurs after loss of TDP-43.
CONCLUSIONS: Our findings emphasize the need for caution in interpreting TDP-43 overexpression data and stress the importance of controlling for exon skipping when generating models of TDP-43 proteinopathy.

DOI: https://doi.org/10.1186/s13024-024-00732-w
J Biol Chem. 2024 Jun 12. pii: S0021-9258(24)01970-7. [Epub ahead of print] 107469

A designed ankyrin-repeat protein that targets Parkinson's disease-associated LRRK2.

Verena Dederer, Marta Sanz Murillo, Eva P Karasmanis, Kathryn S Hatch, Deep Chatterjee, Franziska Preuss, Kamal R Abdul Azeez, Landon Vu Nguyen, Christian Galicia, Birgit Dreier, Andreas Plückthun, Wim Versees, Sebastian Mathea, Andres E Leschziner, Samara L Reck-Peterson, Stefan Knapp.

  Leucine rich repeat kinase 2 (LRRK2) is a large multidomain protein containing two catalytic domains, a kinase and a GTPase, as well as protein interactions domains, including a WD40 domain. The association of increased LRRK2 kinase activity with both the familial and sporadic forms of Parkinson's disease (PD) has led to intense interest in determining its cellular function. However, small molecule probes that can bind to LRRK2 and report on or affect its cellular activity are needed. Here, we report the identification and characterization of the first high-affinity LRRK2-binding designed ankyrin-repeat protein (DARPin), named E11. Using cryo-EM, we show that DARPin E11 binds to the LRRK2 WD40 domain. LRRK2 bound to DARPin E11 showed improved behavior on cryo-EM grids, resulting in higher resolution LRRK2 structures. DARPin E11 did not affect the catalytic activity of a truncated form of LRRK2 in vitro but decreased the phosphorylation of Rab8A, a LRRK2 substrate, in cells. We also found that DARPin E11 disrupts the formation of microtubule-associated LRRK2 filaments in cells, which are known to require WD40-based dimerization. Thus, DARPin E11 is a new tool to explore the function and dysfunction of LRRK2 and guide the development of LRRK2 kinase inhibitors that target the WD40 domain instead of the kinase.

Keywords:  DARPin; LRRK2; Parkinson’s disease; Rab8a; WD40; cryo-electron microscopy; kinase; kinase inhibitor; microtubule

DOI:  https://doi.org/10.1016/j.jbc.2024.107469
Clin Immunol. 2024 Jun 07. pii: S1521-6616(24)00379-6. [Epub ahead of print]265 110270

T cell subset composition differs between blood and cerebrospinal fluid in amyotrophic lateral sclerosis.

Solmaz Yazdani, Anikó Lovik, Christina Seitz, Caroline Ingre, Fang Fang, John Andersson.

  Inflammation is a hallmark of amyotrophic lateral sclerosis (ALS) and is often assessed through biological samples. Due to the easier access, peripheral blood is more commonly phenotyped instead of cerebrospinal fluid (CSF) or affected tissues in ALS. Here, using flow cytometry, we compared the composition of T cell subsets in blood and CSF in ALS patients. We found consistent but weak correlations between blood and CSF for all T cell subsets examined. This finding implies that blood and CSF offer complementary information when characterizing T cell immunity in ALS and blood may not be used as a surrogate for CSF.

Keywords:  Adaptive immunity; Amyotrophic lateral sclerosis; Epidemiology; Longitudinal correlation analysis; Neurodegenerative disease; Statistical analysis; T cell responses

DOI:  https://doi.org/10.1016/j.clim.2024.110270
Mol Neurodegener. 2024 Jun 11. 19(1): 46

Frontotemporal dementia-like disease progression elicited by seeded aggregation and spread of FUS.

Sonia Vazquez-Sanchez, Britt Tilkin, Fatima Gasset-Rosa, Sitao Zhang, Diana Piol, Melissa McAlonis-Downes, Jonathan Artates, Noe Govea-Perez, Yana Verresen, Lin Guo, Don W Cleveland, James Shorter, Sandrine Da Cruz.

  RNA binding proteins have emerged as central players in the mechanisms of many neurodegenerative diseases. In particular, a proteinopathy of fused in sarcoma (FUS) is present in some instances of familial Amyotrophic lateral sclerosis (ALS) and about 10% of sporadic Frontotemporal lobar degeneration (FTLD). Here we establish that focal injection of sonicated human FUS fibrils into brains of mice in which ALS-linked mutant or wild-type human FUS replaces endogenous mouse FUS is sufficient to induce focal cytoplasmic mislocalization and aggregation of mutant and wild-type FUS which with time spreads to distal regions of the brain. Human FUS fibril-induced FUS aggregation in the mouse brain of humanized FUS mice is accelerated by an ALS-causing FUS mutant relative to wild-type human FUS. Injection of sonicated human FUS fibrils does not induce FUS aggregation and subsequent spreading after injection into naïve mouse brains containing only mouse FUS, indicating a species barrier to human FUS aggregation and its prion-like spread. Fibril-induced human FUS aggregates recapitulate pathological features of FTLD including increased detergent insolubility of FUS and TAF15 and amyloid-like, cytoplasmic deposits of FUS that accumulate ubiquitin and p62, but not TDP-43. Finally, injection of sonicated FUS fibrils is shown to exacerbate age-dependent cognitive and behavioral deficits from mutant human FUS expression. Thus, focal seeded aggregation of FUS and further propagation through prion-like spread elicits FUS-proteinopathy and FTLD-like disease progression.

Keywords:  Aggregation; Amyotrophic lateral sclerosis (ALS); FUS-proteinopathy; Frontotemporal lobar degeneration (FTLD); Spreading

DOI:  https://doi.org/10.1186/s13024-024-00737-5
Mov Disord. 2024 Jun 10.

Diverse Functions of Parkin in Midbrain Dopaminergic Neurons.

Pingping Song, Dimitri Krainc.

  Parkinson's disease (PD) is characterized by preferential degeneration of midbrain dopaminergic neurons that contributes to its typical clinical manifestation. Mutations in the parkin gene (PARK2) represent a relatively common genetic cause of early onset PD. Parkin has been implicated in PINK1-dependent mitochondrial quantity control by targeting dysfunctional mitochondria to lysosomes via mitophagy. Recent evidence suggests that parkin can be activated in PINK1-independent manner to regulate synaptic function in human dopaminergic neurons. Neuronal activity triggers CaMKII-mediated activation of parkin and its recruitment to synaptic vesicles where parkin promotes binding of synaptojanin-1 to endophilin A1 and facilitates vesicle endocytosis. In PD patient neurons, disruption of this pathway on loss of parkin leads to defective recycling of synaptic vesicles and accumulation of toxic oxidized dopamine that at least in part explains preferential vulnerability of midbrain dopaminergic neurons. These findings suggest a convergent mechanism for PD-linked mutations in parkin, synaptojanin-1, and endophilin A1 and highlight synaptic dysfunction as an early pathogenic event in PD. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Keywords:  Parkin functions; Parkinson's disease; dopaminergic neurons; synaptic terminal

DOI:  https://doi.org/10.1002/mds.29890
Neurobiol Dis. 2024 Jun 06. pii: S0969-9961(24)00155-4. [Epub ahead of print] 106556

Atlastin-1 regulates endosomal tubulation and lysosomal proteolysis in human cortical neurons.

Eliska Zlamalova, Catherine Rodger, Francesca Greco, Samuel R Cheers, Julia Kleniuk, Aishwarya G Nadadhur, Zuzana Kadlecova, Evan Reid.

  Mutation of the ATL1 gene is one of the most common causes of hereditary spastic paraplegia (HSP), a group of genetic neurodegenerative conditions characterised by distal axonal degeneration of the corticospinal tract axons. Atlastin-1, the protein encoded by ATL1, is one of three mammalian atlastins, which are homologous dynamin-like GTPases that control endoplasmic reticulum (ER) morphology by fusing tubules to form the three-way junctions that characterise ER networks. However, it is not clear whether atlastin-1 is required for correct ER morphology in human neurons and if so what the functional consequences of lack of atlastin-1 are. Using CRISPR-inhibition we generated human cortical neurons lacking atlastin-1. We demonstrate that ER morphology was altered in these neurons, with a reduced number of three-way junctions. Neurons lacking atlastin-1 had longer endosomal tubules, suggestive of defective tubule fission. This was accompanied by reduced lysosomal proteolytic capacity. As well as demonstrating that atlastin-1 is required for correct ER morphology in human neurons, our results indicate that lack of a classical ER-shaping protein such as atlastin-1 may cause altered endosomal tubulation and lysosomal proteolytic dysfunction. Furthermore, they strengthen the idea that defective lysosome function contributes to the pathogenesis of a broad group of HSPs, including those where the primary localisation of the protein involved is not at the endolysosomal system.

Keywords:  Atlastin; Endoplasmic reticulum morphology; Endosomal traffic; Endosomal tubulation; Hereditary spastic paraplegia; Lysosomal proteolysis; Lysosome

DOI:  https://doi.org/10.1016/j.nbd.2024.106556
Front Mol Biosci. 2024 ;11 1383453

Protein aggregation and therapeutic strategies in SOD1- and TDP-43- linked ALS.

Maria Tsekrekou, Maria Giannakou, Katerina Papanikolopoulou, Georgios Skretas.

  Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with severe socio-economic impact. A hallmark of ALS pathology is the presence of aberrant cytoplasmic inclusions composed of misfolded and aggregated proteins, including both wild-type and mutant forms. This review highlights the critical role of misfolded protein species in ALS pathogenesis, particularly focusing on Cu/Zn superoxide dismutase (SOD1) and TAR DNA-binding protein 43 (TDP-43), and emphasizes the urgent need for innovative therapeutic strategies targeting these misfolded proteins directly. Despite significant advancements in understanding ALS mechanisms, the disease remains incurable, with current treatments offering limited clinical benefits. Through a comprehensive analysis, the review focuses on the direct modulation of the misfolded proteins and presents recent discoveries in small molecules and peptides that inhibit SOD1 and TDP-43 aggregation, underscoring their potential as effective treatments to modify disease progression and improve clinical outcomes.

Keywords:  SOD1; TDP-43; amyotrophic lateral sclerosis; neurotoxicity; protein aggregation; protein misfolding; therapeutics

DOI:  https://doi.org/10.3389/fmolb.2024.1383453
Autophagy. 2024 Jun 10. 1-3

ARHGAP26/GRAF1 orchestrates actin remodeling and membrane dynamics to drive mitochondrial clearance and promote fuel flexibility.

Qiang Zhu, Joan M Taylor.

  The serine/threonine kinase, PINK1, and the E3 ubiquitin ligase, PRKN/Parkin facilitate LC3-dependent autophagosomal encasement and lysosomal clearance of dysfunctional mitochondria, and defects in this pathway contribute to the pathogenesis of numerous cardiometabolic and neurological diseases. Although dynamic actin remodeling has recently been shown to play an important role in governing spatiotemporal control of mitophagy, the mechanisms remain unclear. We recently found that the RhoGAP, ARHGAP26/GRAF1 is a PRKN-binding protein that is rapidly recruited to damaged mitochondria where upon phosphorylation by PINK1 it serves to coordinate phagophore capture by regulating mitochondrial-associated actin remodeling and by facilitating PRKN-LC3 interactions. Because ARHGAP26 phosphorylation on PINK1-dependent sites is dysregulated in human heart failure and ARHGAP26 depletion in mouse hearts blunts mitochondrial clearance and attenuates compensatory metabolic adaptations to stress, this enzyme may be a tractable target to treat the many diseases associated with mitochondrial dysfunction.

Keywords:  Actin dynamics; GRAF1; PINK1; Parkin; mitophagy

DOI:  https://doi.org/10.1080/15548627.2024.2361576
Nat Commun. 2024 Jun 12. 15(1): 5033

M6A reduction relieves FUS-associated ALS granules.

Gaia Di Timoteo, Andrea Giuliani, Adriano Setti, Martina C Biagi, Michela Lisi, Tiziana Santini, Alessia Grandioso, Davide Mariani, Francesco Castagnetti, Eleonora Perego, Sabrina Zappone, Serena Lattante, Mario Sabatelli, Dante Rotili, Giuseppe Vicidomini, Irene Bozzoni.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease due to gradual motoneurons (MN) degeneration. Among the processes associated to ALS pathogenesis, there is the formation of cytoplasmic inclusions produced by aggregation of mutant proteins, among which the RNA binding protein FUS. Here we show that, in neuronal cells and in iPSC-derived MN expressing mutant FUS, such inclusions are significantly reduced in number and dissolve faster when the RNA m6A content is diminished. Interestingly, stress granules formed in ALS conditions showed a distinctive transcriptome with respect to control cells, which reverted to similar to control after m6A downregulation. Notably, cells expressing mutant FUS were characterized by higher m6A levels suggesting a possible link between m6A homeostasis and pathological aggregates. Finally, we show that FUS inclusions are reduced also in patient-derived fibroblasts treated with STM-2457, an inhibitor of METTL3 activity, paving the way for its possible use for counteracting aggregate formation in ALS.

DOI: https://doi.org/10.1038/s41467-024-49416-5
J Proteome Res. 2024 Jun 10.

Modeling the Simultaneous Dynamics of Proteins in Blood Plasma and the Cerebrospinal Fluid in Human In Vivo.

Pierre Giroux, Jérôme Vialaret, Jana Kindermans, Audrey Gabelle, Luc Bauchet, Christophe Hirtz, Sylvain Lehmann, Jacques Colinge.

  The analysis of protein dynamics or turnover in patients has the potential to reveal altered protein recycling, such as in Alzheimer's disease, and to provide informative data regarding drug efficacy or certain biological processes. The observed protein dynamics in a solid tissue or a fluid is the net result of not only protein synthesis and degradation but also transport across biological compartments. We report an accurate 3-biological compartment model able to simultaneously account for the protein dynamics observed in blood plasma and the cerebrospinal fluid (CSF) including a hidden central nervous system (CNS) compartment. We successfully applied this model to 69 proteins of a single individual displaying similar or very different dynamics in plasma and CSF. This study puts a strong emphasis on the methods and tools needed to develop this type of model. We believe that it will be useful to any researcher dealing with protein dynamics data modeling.

Keywords:  cerebrospinal fluid; pharmacokinetics; physiology; protein dynamics; proteomics; systems biology

DOI:  https://doi.org/10.1021/acs.jproteome.4c00059
bioRxiv. 2024 Jun 01. pii: 2024.06.01.596819. [Epub ahead of print]

Amygdala TDP-43 pathology is associated with behavioural dysfunction and ferritin accumulation in amyotrophic lateral sclerosis.

Olivia M Rifai, Fergal M Waldron, Judi O'Shaughnessy, Fiona L Read, Martina Gilodi, Annalisa Pastore, Neil Shneider, Gian Gaetano Tartaglia, Elsa Zacco, Holly Spence, Jenna M Gregory.

Background: Cognitive and behavioural symptoms associated with amyotrophic lateral sclerosis and frontotemporal spectrum disorders (ALSFTSD) are thought to be driven, at least in part, by the pathological accumulation of TDP-43.Methods: Here we examine post-mortem tissue from six brain regions associated with cognitive and behavioural symptoms in a cohort of 30 people with sporadic ALS (sALS), a proportion of which underwent standardized neuropsychological behavioural assessment as part of the Edinburgh Cognitive ALS Screen (ECAS).
Results: Overall, the behavioural screen performed as part of the ECAS predicted accumulation of pathological phosphorylated TDP-43 (pTDP-43) with 100% specificity and 86% sensitivity in behaviour-associated brain regions. Notably, of these regions, pathology in the amygdala was the most predictive correlate of behavioural dysfunction in sALS. In the amygdala of sALS patients, we show variation in morphology, cell type predominance, and severity of pTDP-43 pathology. Further, we demonstrate that the presence and severity of intra-neuronal pTDP-43 pathology, but not astroglial pathology, or phosphorylated Tau pathology, is associated with behavioural dysfunction. Cases were also evaluated using a TDP-43 aptamer (TDP-43 APT ), which revealed that pathology was not only associated with behavioural symptoms, but also with ferritin levels, a measure of brain iron.
Conclusions: Intra-neuronal pTDP-43 and cytoplasmic TDP-43 APT pathology in the amygdala is associated with behavioural symptoms in sALS. TDP-43 APT staining intensity is also associated with increased ferritin, regardless of behavioural phenotype, suggesting that ferritin increases may occur upstream of clinical manifestation, in line with early TDP-43 APT pathology, representing a potential region-specific imaging biomarker of early disease in ALS.
Key Messages: What is already known on this topic: The amygdala is a key brain region in regulating behavior and emotional cognition and has been shown recently, through imaging studies, to be affected in ALS and FTD patients.What this study adds: Here we examine the underlying pathology driving the association between the amygdala and behavioural symptoms in sporadic ALS demonstrating that region specific TDP-43 pathology and brain iron accumulation could represent potential early biomarkers of dysfunction.How this study might affect research, practice, or policy: The correlation between early TDP-43 pathology (detected by RNA aptamer) and increased ferritin (brain iron accumulation) occurring upstream of clinical manifestation represents a potential, region-specific (amygdala), early imaging biomarker in ALS. This means that people at risk could be identified early and stratified for clinical trials prior to substantial neuronal cell loss and symptom onset.

DOI: https://doi.org/10.1101/2024.06.01.596819
Lancet Neurol. 2024 Jul;pii: S1474-4422(24)00227-8. [Epub ahead of print]23(7): 649

Multidisciplinary care for amyotrophic lateral sclerosis.

The Lancet Neurology.

DOI: https://doi.org/10.1016/S1474-4422(24)00227-8
Transl Neurodegener. 2024 Jun 11. 13(1): 31

DOPA-decarboxylase is elevated in CSF, but not plasma, in prodromal and de novo Parkinson's disease.

Ellen Appleton, Shervin Khosousi, Michael Ta, Michael Nalls, Andrew B Singleton, Andrea Sturchio, Ioanna Markaki, Wojciech Paslawski, Hirotaka Iwaki, Per Svenningsson.

DOI: https://doi.org/10.1186/s40035-024-00421-0
Sci Rep. 2024 Jun 14. 14(1): 13789

Nanobiopsy investigation of the subcellular mtDNA heteroplasmy in human tissues.

Alexander Bury, Angela Pyle, Amy E Vincent, Paolo Actis, Gavin Hudson.

Mitochondrial function is critical to continued cellular vitality and is an important contributor to a growing number of human diseases. Mitochondrial dysfunction is typically heterogeneous, mediated through the clonal expansion of mitochondrial DNA (mtDNA) variants in a subset of cells in a given tissue. To date, our understanding of the dynamics of clonal expansion of mtDNA variants has been technically limited to the single cell-level. Here, we report the use of nanobiopsy for subcellular sampling from human tissues, combined with next-generation sequencing to assess subcellular mtDNA mutation load in human tissue from mitochondrial disease patients. The ability to map mitochondrial mutation loads within individual cells of diseased tissue samples will further our understanding of mitochondrial genetic diseases.

DOI: https://doi.org/10.1038/s41598-024-64455-0
Nat Cell Biol. 2024 Jun 14.

Author Correction: RIP3 targets pyruvate dehydrogenase complex to increase aerobic respiration in TNF-induced necroptosis.

Zhentao Yang, Yan Wang, Yingying Zhang, Xiadi He, Chuan-Qi Zhong, Hengxiao Ni, Xin Chen, Yaoji Liang, Jianfeng Wu, Shimin Zhao, Dawang Zhou, Jiahuai Han.

DOI: https://doi.org/10.1038/s41556-024-01455-2
Biomed Opt Express. 2024 May 01. 15(5): 3112-3127

Deep learning based characterization of human organoids using optical coherence tomography.

Bingjie Wang, Razieh Ganjee, Irona Khandaker, Keevon Flohr, Yuanhang He, Guang Li, Joshua Wesalo, José-Alain Sahel, Susana da Silva, Shaohua Pi.

Organoids, derived from human induced pluripotent stem cells (hiPSCs), are intricate three-dimensional in vitro structures that mimic many key aspects of the complex morphology and functions of in vivo organs such as the retina and heart. Traditional histological methods, while crucial, often fall short in analyzing these dynamic structures due to their inherently static and destructive nature. In this study, we leveraged the capabilities of optical coherence tomography (OCT) for rapid, non-invasive imaging of both retinal, cerebral, and cardiac organoids. Complementing this, we developed a sophisticated deep learning approach to automatically segment the organoid tissues and their internal structures, such as hollows and chambers. Utilizing this advanced imaging and analysis platform, we quantitatively assessed critical parameters, including size, area, volume, and cardiac beating, offering a comprehensive live characterization and classification of the organoids. These findings provide profound insights into the differentiation and developmental processes of organoids, positioning quantitative OCT imaging as a potentially transformative tool for future organoid research.

DOI: https://doi.org/10.1364/BOE.515781
J Neurol. 2024 Jun 09.

Repeated cognitive assessments show stable function over time in patients with ALS.

Linn Öijerstedt, Juliette Foucher, Anikó Lovik, Solmaz Yazdani, Alexander Juto, Ulf Kläppe, Fang Fang, Caroline Ingre.

  BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a multisystem disorder with not only motor symptoms but also extra-motor features including cognitive impairment. The most common cognitive profile observed in patients with ALS includes deficits in executive function, language, and social cognition. However, longitudinal studies on cognitive changes over time in ALS are sparse. We aimed to investigate the presence and nature of cognitive impairment at the time of ALS diagnosis and its association with survival as well as explore longitudinal cognitive change.METHOD: Patients (n = 216) were recruited at the Karolinska University Hospital in Stockholm, Sweden. Follow-up visits (n = 307 in total) were performed every 6 months. Cognitive impairment was assessed using the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and/or Montreal Cognitive Assessment (MoCA).
RESULTS: Cognitive impairment was observed in 38% of the patients at the time of ALS diagnosis, and the majority of these patients had deficits in executive function and/or language. Patients with cognitive impairment at the time of diagnosis had a more rapid decline in ALSFRS-R at 12- and 18-months follow-up, and a shorter survival. Cognitive function was stable during the first 2 years after diagnosis, and did not follow the trajectories of decline in motor functions.
CONCLUSION: Cognitive impairment in ALS was associated with a faster decline of motor functions, and shorter survival. However, cognitive function did not deteriorate over time. Cognitive assessment is essential for the patients and caregivers to understand the phenotypic expression of ALS.

Keywords:  Amyotrophic lateral sclerosis; Cognitive impairment; ECAS; Longitudinal; Survival

DOI:  https://doi.org/10.1007/s00415-024-12479-x
J Extracell Vesicles. 2024 Jun;13(6): e12459

Single-extracellular vesicle (EV) analyses validate the use of L1 Cell Adhesion Molecule (L1CAM) as a reliable biomarker of neuron-derived EVs.

Carlos J Nogueras-Ortiz, Erden Eren, Pamela Yao, Elizabeth Calzada, Christopher Dunn, Olga Volpert, Francheska Delgado-Peraza, Maja Mustapic, Alexey Lyashkov, F Javier Rubio, Michael Vreones, Lesley Cheng, Yang You, Andrew F Hill, Tsuneya Ikezu, Erez Eitan, Edward J Goetzl, Dimitrios Kapogiannis.

  Isolation of neuron-derived extracellular vesicles (NDEVs) with L1 Cell Adhesion Molecule (L1CAM)-specific antibodies has been widely used to identify blood biomarkers of CNS disorders. However, full methodological validation requires demonstration of L1CAM in individual NDEVs and lower levels or absence of L1CAM in individual EVs from other cells. Here, we used multiple single-EV techniques to establish the neuronal origin and determine the abundance of L1CAM-positive EVs in human blood. L1CAM epitopes of the ectodomain are shown to be co-expressed on single-EVs with the neuronal proteins β-III-tubulin, GAP43, and VAMP2, the levels of which increase in parallel with the enrichment of L1CAM-positive EVs. Levels of L1CAM-positive EVs carrying the neuronal proteins VAMP2 and β-III-tubulin range from 30% to 63%, in contrast to 0.8%-3.9% of L1CAM-negative EVs. Plasma fluid-phase L1CAM does not bind to single-EVs. Our findings support the use of L1CAM as a target for isolating plasma NDEVs and leveraging their cargo to identify biomarkers reflecting neuronal function.

Keywords:  Alzheimer's disease; L1CAM; blood biomarkers; extracellular vesicles; neuron‐derived extracellular vesicles

DOI:  https://doi.org/10.1002/jev2.12459
Acta Neuropathol. 2024 Jun 11. 147(1): 98

Early and selective localization of tau filaments to glutamatergic subcellular domains within the human anterodorsal thalamus.

Barbara Sárkány, Csaba Dávid, Tibor Hortobágyi, Péter Gombás, Peter Somogyi, László Acsády, Tim J Viney.

  Widespread cortical accumulation of misfolded pathological tau proteins (ptau) in the form of paired helical filaments is a major hallmark of Alzheimer's disease. Subcellular localization of ptau at various stages of disease progression is likely to be informative of the cellular mechanisms involving its spread. Here, we found that the density of ptau within several distinct rostral thalamic nuclei in post-mortem human tissue (n = 25 cases) increased with the disease stage, with the anterodorsal nucleus (ADn) consistently being the most affected. In the ADn, ptau-positive elements were present already in the pre-cortical (Braak 0) stage. Tau pathology preferentially affected the calretinin-expressing subpopulation of glutamatergic neurons in the ADn. At the subcellular level, we detected ptau immunoreactivity in ADn cell bodies, dendrites, and in a specialized type of presynaptic terminal that expresses vesicular glutamate transporter 2 (vGLUT2) and likely originates from the mammillary body. The ptau-containing terminals displayed signs of degeneration, including endosomal/lysosomal organelles. In contrast, corticothalamic axon terminals lacked ptau. The data demonstrate the involvement of a specific cell population in ADn at the onset of the disease. The presence of ptau in subcortical glutamatergic presynaptic terminals supports hypotheses about the transsynaptic spread of tau selectively affecting specialized axonal pathways.

Keywords:  Alzheimer’s disease; Paired helical filaments; Tau; Thalamus; vGLUT2

DOI:  https://doi.org/10.1007/s00401-024-02749-3
bioRxiv. 2024 Jun 01. pii: 2024.05.28.596248. [Epub ahead of print]

Fully Human Bifunctional Intrabodies Achieve Graded Reduction of Intracellular Tau and Rescue Survival of MAPT Mutation iPSC-derived Neurons.

Lianna D'Brant, Natasha Rugenstein, Su Kyoung Na, Michael J Miller, Timothy F Czajka, Nicole Trudeau, Emily Fitz, Lindsay Tomaszek, Elizabeth S Fisher, Ethan Mash, Shona Joy, Steven Lotz, Susan Borden, Katherine Stevens, Susan K Goderie, Yue Wang, Taylor Bertucci, Celeste M Karch, Sally Temple, David C Butler.

Tau protein aggregation is a hallmark of several neurodegenerative diseases, including Alzheimer's disease, frontotemporal dementia (FTD) and progressive supranuclear palsy (PSP), spurring development of tau-lowering therapeutic strategies. Here, we report fully human bifunctional anti-tau-PEST intrabodies that bind the mid-domain of tau to block aggregation and degrade tau via the proteasome using the ornithine decarboxylase (ODC) PEST degron. They effectively reduced tau protein in human iPSC-derived cortical neurons in 2D cultures and 3D organoids, including those with the disease-associated tau mutations R5L, N279K, R406W, and V337M. Anti-tau-hPEST intrabodies facilitated efficient ubiquitin-independent proteolysis, in contrast to tau-lowering approaches that rely on the cell's ubiquitination system. Importantly, they counteracted the proteasome impairment observed in V337M patient-derived cortical neurons and significantly improved neuronal survival. By serial mutagenesis, we created variants of the PEST degron that achieved graded levels of tau reduction. Moderate reduction was as effective as high reduction against tau V337M-induced neural cell death.

DOI: https://doi.org/10.1101/2024.05.28.596248
Transl Psychiatry. 2024 Jun 10. 14(1): 249

Pharmacological modulation of developmental and synaptic phenotypes in human SHANK3 deficient stem cell-derived neuronal models.

Amandine Thibaudeau, Karen Schmitt, Louise François, Laure Chatrousse, David Hoffmann, Loic Cousin, Amélie Weiss, Aurore Vuidel, Christina B Jacob, Peter Sommer, Alexandra Benchoua, Johannes H Wilbertz.

Phelan-McDermid syndrome (PMDS) arises from mutations in the terminal region of chromosome 22q13, impacting the SHANK3 gene. The resulting deficiency of the postsynaptic density scaffolding protein SHANK3 is associated with autism spectrum disorder (ASD). We examined 12 different PMDS patient and CRISPR-engineered stem cell-derived neuronal models and controls and found that reduced expression of SHANK3 leads to neuronal hyperdifferentiation, increased synapse formation, and decreased neuronal activity. We performed automated imaging-based screening of 7,120 target-annotated small molecules and identified three compounds that rescued SHANK3-dependent neuronal hyperdifferentiation. One compound, Benproperine, rescued the decreased colocalization of Actin Related Protein 2/3 Complex Subunit 2 (ARPC2) with ß-actin and rescued increased synapse formation in SHANK3 deficient neurons when administered early during differentiation. Neuronal activity was only mildly affected, highlighting Benproperine's effects as a neurodevelopmental modulator. This study demonstrates that small molecular compounds that reverse developmental phenotypes can be identified in human neuronal PMDS models.

DOI: https://doi.org/10.1038/s41398-024-02947-3
Neurobiol Dis. 2024 Jun 12. pii: S0969-9961(24)00161-X. [Epub ahead of print] 106562

Ataxia telangiectasia patient-derived neuronal and brain organoid models reveal mitochondrial dysfunction and oxidative stress.

Hannah C Leeson, Julio Aguado, Cecilia Gómez-Inclán, Harman Kaur Chaggar, Atefah Taherian Fard, Zoe Hunter, Martin F Lavin, Alan Mackay-Sim, Ernst J Wolvetang.

  Ataxia Telangiectasia (AT) is a rare disorder caused by mutations in the ATM gene and results in progressive neurodegeneration for reasons that remain poorly understood. In addition to its central role in nuclear DNA repair, ATM operates outside the nucleus to regulate metabolism, redox homeostasis and mitochondrial function. However, a systematic investigation into how and when loss of ATM affects these parameters in relevant human neuronal models of AT was lacking. We therefore used cortical neurons and brain organoids from AT-patient iPSC and gene corrected isogenic controls to reveal levels of mitochondrial dysfunction, oxidative stress, and senescence that vary with developmental maturity. Transcriptome analyses identified disruptions in regulatory networks related to mitochondrial function and maintenance, including alterations in the PARP/SIRT signalling axis and dysregulation of key mitophagy and mitochondrial fission-fusion processes. We further show that antioxidants reduce ROS and restore neurite branching in AT neuronal cultures, and ameliorate impaired neuronal activity in AT brain organoids. We conclude that progressive mitochondrial dysfunction and aberrant ROS production are important contributors to neurodegeneration in AT and are strongly linked to ATM's role in mitochondrial homeostasis regulation.

Keywords:  Ataxia telangiectasia; Brain organoids; Cellular senescence; Mitochondria; Neurodegeneration; Oxidative stress

DOI:  https://doi.org/10.1016/j.nbd.2024.106562
Phytomedicine. 2024 Jun 08. pii: S0944-7113(24)00461-6. [Epub ahead of print]132 155803

Astragaloside IV mediates radiation-induced neuronal damage through activation of BDNF-TrkB signaling.

Xin Liu, Yanping Ding, Chenxin Jiang, Yuanyuan Xin, Xin Ma, Min Xu, Qianhao Wang, Boru Hou, Yingdong Li, Shengxiang Zhang, Baoping Shao.

  BACKGROUND: Electromagnetic radiation is relevant to human life, and radiation can trigger neurodegenerative diseases by altering the function of the central nervous system through oxidative stress, mitochondrial dysfunction, and protein degradation. Astragaloside IV (AS-IV) is anti-oxidative, anti-apoptotic, activates the BDNF-TrkB pathway and enhances synaptic plasticity in radiated mice, which can exert its neuroprotection. However, the exact molecular mechanisms are still unclear.PURPOSE: This study investigated whether AS-IV could play a neuroprotective role by regulating BDNF-TrkB pathway in radiation damage and its underlying molecular mechanisms.
METHODS: Transgenic mice (Thy1-YFP line H) were injected with AS-IV (40 mg/kg/day body weight) by intraperitoneal injection daily for 4 weeks, followed by X-rays. PC12 cells and primary cortical neurons were also exposed to UVA after 24 h of AS-IV treatment (25 μg/ml and 50 μg/ml) in vitro. The impact of radiation on learning and cognitive functions was visualized in the Morris water maze assay. Subsequently, Immunofluorescence and Golgi-Cox staining analyses were utilized to investigate the structural damage of neuronal dendrites and the density of dendritic spines. Transmission electron microscopy was performed to examine how the radiation affected the ultrastructure of neurons. Finally, western blotting analysis and Quantitative RT-PCR were used to evaluate the expression levels and locations of proteins in vitro and in vivo.
RESULTS: Radiation induced BDNF-TrkB signaling dysregulation and decreased the levels of neuron-related functional genes (Ngf, Bdnf, Gap-43, Ras, Psd-95, Arc, Creb, c-Fos), PSD-95 and F-actin, which subsequently led to damage of neuronal ultrastructure and dendrites, loss of dendritic spines, and decreased dendritic complexity index, contributing to spatial learning and memory deficits. These abnormalities were prevented by AS-IV treatment. In addition, TrkB receptor antagonists antagonized these neuroprotective actions of AS-IV. 7,8-dihydroxyflavone and AS-IV had neuroprotective effects after radiation.
CONCLUSION: AS-IV inhibits morphological damage of neurons and cognitive dysfunction in mice after radiation exposure, resulting in a neuroprotective effect, which were mediated by activating the BDNF-TrkB pathway.

Keywords:  Astragaloside IV; BDNF-TrkB signaling pathway; Neuronal damage; Radiation

DOI:  https://doi.org/10.1016/j.phymed.2024.155803