Klotho overexpression protects human cortical neurons from ?-amyloid induced neuronal toxicity
Klotho,a well-known aging suppressor protein,has been implicated in neuroprotection and the regulation of neuronal senescence. While previous studies have demonstrated its anti-aging properties in human brain organoids,its potential to mitigate neurodegenerative processes triggered by ?-amyloid remains underexplored. In this study,we utilised human induced pluripotent stem cells (iPSCs) engineered with a doxycycline-inducible system to overexpress KLOTHO and generated 2D cortical neuron cultures from these cells. These neurons were next exposed to pre-aggregated ?-amyloid 1–42 oligomers to model the neurotoxicity associated with Alzheimer’s disease. Our data reveal that upregulation of KLOTHO significantly reduced ?-amyloid-induced neuronal degeneration and apoptosis,as evidenced by decreased cleaved caspase-3 expression and preservation of axonal integrity. Additionally,KLOTHO overexpression prevented the loss of dendritic branching and mitigated reductions in axonal diameter,hallmark features of neurodegenerative pathology. These results highlight Klotho’s protective role against ?-amyloid-induced neurotoxicity in human cortical neurons and suggest that its age-related decline may contribute to neurodegenerative diseases such as Alzheimer’s disease. Our findings underscore the therapeutic potential of Klotho-based interventions in mitigating age-associated neurodegenerative processes.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13041-025-01199-6.
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(Jun 2024)
Nature Communications 15
BiœmuS: A new tool for neurological disorders studies through real-time emulation and hybridization using biomimetic Spiking Neural Network
Characterization and modeling of biological neural networks has emerged as a field driving significant advancements in our understanding of brain function and related pathologies. As of today,pharmacological treatments for neurological disorders remain limited,pushing the exploration of promising alternative approaches such as electroceutics. Recent research in bioelectronics and neuromorphic engineering have fostered the development of the new generation of neuroprostheses for brain repair. However,achieving their full potential necessitates a deeper understanding of biohybrid interaction. In this study,we present a novel real-time,biomimetic,cost-effective and user-friendly neural network capable of real-time emulation for biohybrid experiments. Our system facilitates the investigation and replication of biophysically detailed neural network dynamics while prioritizing cost-efficiency,flexibility and ease of use. We showcase the feasibility of conducting biohybrid experiments using standard biophysical interfaces and a variety of biological cells as well as real-time emulation of diverse network configurations. We envision our system as a crucial step towards the development of neuromorphic-based neuroprostheses for bioelectrical therapeutics,enabling seamless communication with biological networks on a comparable timescale. Its embedded real-time functionality enhances practicality and accessibility,amplifying its potential for real-world applications in biohybrid experiments. Beaubois et al. introduce a real-time biomimetic neural network for biohybrid experiments,providing a tool to study closed-loop applications for neuroscience and neuromorphic-based neuroprostheses.
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Human induced pluripotent stem cell-derived myotubes to model inclusion body myositis
Inclusion body myositis (IBM) is an inflammatory myopathy that displays proximal and distal muscle weakness. At the histopathological level,the muscles of IBM patients show inflammatory infiltrates,rimmed vacuoles and mitochondrial changes. The etiology of IBM remains unknown,and there is a lack of validated disease models,biomarkers and effective treatments. To contribute to unveil disease underpins we developed a cell model based on myotubes derived from induced pluripotent stem cells (iPSC-myotubes) from IBM patients and compared the molecular phenotype vs. age and sex-paired controls (n?=?3 IBM and 4 CTL). We evaluated protein histological findings and the gene expression profile by mRNA-seq,alongside functional analysis of inflammation,degeneration and mitochondrial function. Briefly,IBM iPSC-myotubes replicated relevant muscle histopathology features of IBM,including aberrant expression of HLA,TDP-43 and COX markers. mRNA seq analysis identified 1007 differentially expressed genes (DEGs) (p-value adj?0.01; 789 upregulated and 218 downregulated),associated with myopathy,muscle structure and developmental changes. Among these,1 DEG was related to inflammation,28 to autophagy and 28 to mitochondria. At the functional level,inflammation was similar between the IBM and CTL groups under basal conditions (mean cytokine expression in IBM 4.6?±?1.4 vs. 6.7?±?3.4 in CTL),but increased in IBM iPSC-myotubes after lipopolysaccharide treatment (72.5?±?21.8 in IBM vs. 13.0?±?6.7 in CTL). Additionally,autophagy was disturbed,with 40.14% reduction in autophagy mediators. Mitochondrial dysfunction was strongly manifested,showing a conserved respiratory profile and antioxidant capacity,but a 56.33% lower cytochrome c oxidase/citrate synthase ratio and a 66.59% increase in lactate secretion. Overall,these findings support patient-derived iPSC-myotubes as a relevant model for IBM,reflecting the main muscle hallmarks,including inflammation,autophagy dysfunction and mitochondrial alterations at transcriptomic,protein and functional levels.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40478-025-01933-0. Transcriptomic and functional validation of iPSC-derived myotubes from IBM patients revealed that they displayed the main hallmarks of the disease.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40478-025-01933-0.
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(Feb 2024)
Scientific Reports 14
Characterization of enhancer activity in early human neurodevelopment using Massively Parallel Reporter Assay (MPRA) and forebrain organoids
Regulation of gene expression through enhancers is one of the major processes shaping the structure and function of the human brain during development. High-throughput assays have predicted thousands of enhancers involved in neurodevelopment,and confirming their activity through orthogonal functional assays is crucial. Here,we utilized Massively Parallel Reporter Assays (MPRAs) in stem cells and forebrain organoids to evaluate the activity of ~ 7000 gene-linked enhancers previously identified in human fetal tissues and brain organoids. We used a Gaussian mixture model to evaluate the contribution of background noise in the measured activity signal to confirm the activity of ~ 35% of the tested enhancers,with most showing temporal-specific activity,suggesting their evolving role in neurodevelopment. The temporal specificity was further supported by the correlation of activity with gene expression. Our findings provide a valuable gene regulatory resource to the scientific community.
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(May 2024)
Cell reports 43 6
Macrophages enhance contractile force in iPSC-derived human engineered cardiac tissue
SUMMARY Resident cardiac macrophages are critical mediators of cardiac function. Despite their known importance to cardiac electrophysiology and tissue maintenance,there are currently no stem-cell-derived models of human engineered cardiac tissues (hECTs) that include resident macrophages. In this study,we made an induced pluripotent stem cell (iPSC)-derived hECT model with a resident population of macrophages (iM0) to better recapitulate the native myocardium and characterized their impact on tissue function. Macrophage retention within the hECTs was confirmed via immunofluorescence after 28 days of cultivation. The inclusion of iM0s significantly impacted hECT function,increasing contractile force production. A potential mechanism underlying these changes was revealed by the interrogation of calcium signaling,which demonstrated the modulation of ?-adrenergic signaling in +iM0 hECTs. Collectively,these findings demonstrate that macrophages significantly enhance cardiac function in iPSC-derived hECT models,emphasizing the need to further explore their contributions not only in healthy hECT models but also in the contexts of disease and injury. In brief Lock and Graney et al. develop a human engineered cardiac tissue with an incorporated iPSC-derived macrophage population to better mimic the complex cell landscape of the native myocardium. Macrophage inclusion leads to increased contractile function of the tissue,which is attributed to macrophage stimulation of the cardiomyocyte ?-adrenergic signaling pathway. Graphical Abstract
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(Feb 2024)
Cell Death & Disease 15 2
CHCHD2 up-regulation in Huntington disease mediates a compensatory protective response against oxidative stress
Huntington disease (HD) is a neurodegenerative disease caused by the abnormal expansion of a polyglutamine tract resulting from a mutation in the HTT gene. Oxidative stress has been identified as a significant contributing factor to the development of HD and other neurodegenerative diseases,and targeting anti-oxidative stress has emerged as a potential therapeutic approach. CHCHD2 is a mitochondria-related protein involved in regulating cell migration,anti-oxidative stress,and anti-apoptosis. Although CHCHD2 is highly expressed in HD cells,its specific role in the pathogenesis of HD remains uncertain. We postulate that the up-regulation of CHCHD2 in HD models represents a compensatory protective response against mitochondrial dysfunction and oxidative stress associated with HD. To investigate this hypothesis,we employed HD mouse striatal cells and human induced pluripotent stem cells (hiPSCs) as models to examine the effects of CHCHD2 overexpression (CHCHD2-OE) or knockdown (CHCHD2-KD) on the HD phenotype. Our findings demonstrate that CHCHD2 is crucial for maintaining cell survival in both HD mouse striatal cells and hiPSCs-derived neurons. Our study demonstrates that CHCHD2 up-regulation in HD serves as a compensatory protective response against oxidative stress,suggesting a potential anti-oxidative strategy for the treatment of HD.
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(Aug 2024)
Cell Death & Disease 15 8
Heterozygous knockout of Synaptotagmin13 phenocopies ALS features and TP53 activation in human motor neurons
Spinal motor neurons (MNs) represent a highly vulnerable cellular population,which is affected in fatal neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). In this study,we show that the heterozygous loss of SYT13 is sufficient to trigger a neurodegenerative phenotype resembling those observed in ALS and SMA. SYT13+/? hiPSC-derived MNs displayed a progressive manifestation of typical neurodegenerative hallmarks such as loss of synaptic contacts and accumulation of aberrant aggregates. Moreover,analysis of the SYT13+/? transcriptome revealed a significant impairment in biological mechanisms involved in motoneuron specification and spinal cord differentiation. This transcriptional portrait also strikingly correlated with ALS signatures,displaying a significant convergence toward the expression of pro-apoptotic and pro-inflammatory genes,which are controlled by the transcription factor TP53. Our data show for the first time that the heterozygous loss of a single member of the synaptotagmin family,SYT13,is sufficient to trigger a series of abnormal alterations leading to MN sufferance,thus revealing novel insights into the selective vulnerability of this cell population.
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(Mar 2024)
Nature 628 8006
Mitochondrial complex I activity in microglia sustains neuroinflammation
Sustained smouldering,or low-grade activation,of myeloid cells is a common hallmark of several chronic neurological diseases,including multiple sclerosis1. Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells2. However,how these metabolic features act to perpetuate inflammation of the central nervous system is unclear. Here,using a multiomics approach,we identify a molecular signature that sustains the activation of microglia through mitochondrial complex I activity driving reverse electron transport and the production of reactive oxygen species. Mechanistically,blocking complex I in pro-inflammatory microglia protects the central nervous system against neurotoxic damage and improves functional outcomes in an animal disease model in vivo. Complex I activity in microglia is a potential therapeutic target to foster neuroprotection in chronic inflammatory disorders of the central nervous system3. Blocking mitochondrial complex I in pro-inflammatory microglia protects the central nervous system against neurotoxic damage and improves functional outcomes in vivo in an animal disease model.
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(Jun 2024)
Frontiers in Cell and Developmental Biology 12
Optimizing Nodal, Wnt and BMP signaling pathways for robust and efficient differentiation of human induced pluripotent stem cells to intermediate mesoderm cells
Several differentiation protocols have enabled the generation of intermediate mesoderm (IM)-derived cells from human pluripotent stem cells (hPSC). However,the substantial variability between existing protocols for generating IM cells compromises their efficiency,reproducibility,and overall success,potentially hindering the utility of urogenital system organoids. Here,we examined the role of high levels of Nodal signaling and BMP activity,as well as WNT signaling in the specification of IM cells derived from a UCSD167i-99-1 human induced pluripotent stem cells (hiPSC) line. We demonstrate that precise modulation of WNT and BMP signaling significantly enhances IM differentiation efficiency. Treatment of hPSC with 3 ?M CHIR99021 induced TBXT+/MIXL1+ mesoderm progenitor (MP) cells after 48 h of differentiation. Further treatment with a combination of 3 ?M CHIR99021 and 4 ng/mL BMP4 resulted in the generation of OSR1+/GATA3+/PAX2+ IM cells within a subsequent 48 h period. Molecular characterization of differentiated cells was confirmed through immunofluorescence staining and RT-qPCR. Hence,this study establishes a consistent and reproducible protocol for differentiating hiPSC into IM cells that faithfully recapitulates the molecular signatures of IM development. This protocol holds promise for improving the success of protocols designed to generate urogenital system organoids in vitro,with potential applications in regenerative medicine,drug discovery,and disease modeling.
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(Oct 2024)
Cell Death & Disease 15 10
Deciphering the impact of PROM1 alternative splicing on human photoreceptor development and maturation
Alternative splicing (AS) is a crucial mechanism contributing to proteomic diversity,which is highly regulated in tissue- and development-specific patterns. Retinal tissue exhibits one of the highest levels of AS. In particular,photoreceptors have a distinctive AS pattern involving the inclusion of microexons not found in other cell types. PROM1 whose encoded protein Prominin-1 is located in photoreceptor outer segments (OSs),undergoes exon 4 inclusion from the 12th post-conception week of human development through adulthood. Exon 4 skipping in PROM1 is associated with late-onset mild maculopathy,however its role in photoreceptor maturation and function is unknown. In this study retinal organoids,a valuable model system,were employed in combination with phosphorodiamidate morpholino oligos (PMOs) to assess the role of exon 4 AS in the development of human retina. Retinal organoids were treated with the PMOs for four weeks after which RT-PCR,western blotting and immunofluorescence analysis were performed to assess exon 4 exclusion and its impact on photoreceptors. The transcriptome of treated ROs was studied by bulk RNA-Seq. Our data demonstrate that 55% skipping of PROM1 exon 4 resulted in decreased Prominin-1 expression by 40%,abnormal accumulation of cones in the basal side of the retinal organoids as well as detectable cone photoreceptor cilium defects. Transcriptomic and western blot analyses revealed decreased expression of cone,inner segment and connecting cilium basal body markers,increased expression of genes associated with stress response and the ubiquitin-proteasome system,and downregulation of autophagy. Importantly,the use of retinal organoids provides a valuable platform to study AS and unravel disease mechanisms in a more physiologically relevant context,opening avenues for further research and potential therapeutic interventions. Together our data indicate that cones may be more sensitive to PROM1 exon 4 skipping and/or reduced Prominin-1 expression,corroborating the pathogenesis of late-onset mild maculopathy.
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(Jul 2025)
Scientific Reports 15 suppl 3
Chronic haloperidol exposure impairs neurodevelopment via Notch1 signaling in human stem cell-derived brain organoids
Haloperidol is a typical antipsychotic used to treat schizophrenia and induces dopamine D2 receptor antagonism. Long-term use of haloperidol can reduce brain size in animals and humans; however,the underlying mechanism of this effect remains unclear. Notch1 signaling regulates the development and function of the nervous system by balancing stem cell proliferation and differentiation. Therefore,we investigated the effects of long-term exposure to haloperidol on human-derived brain organoids,which served as sophisticated in vitro models of human brain development. Long-term exposure to haloperidol reduced the size of brain organoids and decreased the ventricular zone and Notch1 signaling. When propionate,which protects against haloperidol-induced toxicity,was combined with haloperidol,it rescued both the overall size of brain organoids and Notch1 expression levels. Additionally,treatment with valproic acid,a Notch1 activator,partially restored the size of brain organoids and the thickness of the ventricular layer. Taken together,these data suggest that long-term exposure to haloperidol impairs neurodevelopment via Notch1 signaling in brain organoids. These findings contribute to our understanding of antipsychotic drug safety and provide information for new neurodevelopmental toxicity assessments.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-08855-w.
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(Feb 2024)
iScience 27 3
Homozygous ALS-linked mutations in TARDBP/TDP-43 lead to hypoactivity and synaptic abnormalities in human iPSC-derived motor neurons
SummaryCytoplasmic mislocalization and aggregation of the RNA-binding protein TDP-43 is a pathological hallmark of the motor neuron (MN) disease amyotrophic lateral sclerosis (ALS). Furthermore,while mutations in TARDBP (encoding TDP-43) have been associated with ALS,the pathogenic consequences of these mutations remain poorly understood. Using CRISPR-Cas9,we engineered two homozygous knock-in induced pluripotent stem cell lines carrying mutations in TARDBP encoding TDP-43A382T and TDP-43G348C,two common yet understudied ALS TDP-43 variants. Motor neurons (MNs) differentiated from knock-in iPSCs had normal viability and displayed no significant changes in TDP-43 subcellular localization,phosphorylation,solubility,or aggregation compared with isogenic control MNs. However,our results highlight synaptic impairments in both TDP-43A382T and TDP-43G348C MN cultures,as reflected in synapse abnormalities and alterations in spontaneous neuronal activity. Collectively,our findings suggest that MN dysfunction may precede the occurrence of TDP-43 pathology and neurodegeneration in ALS and further implicate synaptic and excitability defects in the pathobiology of this disease. Graphical abstract Highlights•Mutant MNs maintain viability but are more vulnerable to cellular stress•Mutant MNs do not show TDP-43 pathology•TDP-43 variants lead to a progressive decline in spontaneous neuronal activity•Functional impairments are accompanied by abnormal synaptic marker expression Molecular neuroscience; Cellular neuroscience
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