Biology subjects

Gentil, C.

Publications and source records attributed to Gentil, C..

9 recordsLinked to original sources

bioRxiv2026

Axonopathy in Duchenne Muscular Dystrophy limits microdystrophin gene therapy efficacy

Duchenne muscular dystrophy (DMD) is classically defined as a primary myopathy, and current AAV-mediated microdystrophin gene therapies are shown to successfully preserve muscle integrity. However, their efficacy in recovering functional outcomes remains to improve. We hypothesized that this limitation stems from an unaccounted vulnerability within the peripheral nerve. Here, we demonstrate that the mdx mouse model exhibits a peripheral axonopathy independently of muscle necrosis. Using single-nucleus RNA sequencing and structural analyses, we have identified an active denervation program and a profound failure of neural repair pathways. Importantly, we revealed that the full-length dystrophin isoform Dp427c is expressed in the healthy peripheral nerve, intimately following the cytoskeletal organization and accumulating at regions of high biomechanical stress, including Schmidt-Lanterman incisures and Nodes of Ranvier. In its absence, nerves of mdx mice loss an essential scaffolding support, leading to localized structural collapse. Furthermore, we showed that muscle-restricted microdystrophin gene therapy rescues sarcolemmal integrity but failed to restore nerve-muscle connectivity or resolved neurotransmission defects. These findings fundamentally redefine DMD as an integrated motor unit pathology, thereby underscoring the absolute necessity of implementing combined therapeutic strategies that target both the muscle and the peripheral nervous system.

physiology↗

bioRxiv2026

GDF5 as a Multimodal Protector of the Motor Unit in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis is characterized by the progressive dismantling of the motor unit. While "dying back" hypothesis suggests that peripheral neuromuscular dysfunction precedes motor neuron loss, the molecular mechanisms limiting endogenous compensatory responses remain poorly understood. We longitudinally examined neuromuscular decline and GDF5-SMAD1/5/8 signaling in SOD1G93A mice. Our findings revealed a translational checkpoint linked to the lncRNA Myoparr that suppresses GDF5 production at symptom onset. To overcome this deficit, we delivered AAV9-GDF5 at the symptomatic stage. GDF5 supplementation restored SMAD signaling balance, shifting the motor unit from a pro-atrophic TGF-{beta}-SMAD2/3 toward a pro-myogenic SMAD1/5 profile. Treatment preserved muscle mass, reduced mitochondrial reactive oxygen species, and maintained neuromuscular junction integrity, including peri-synaptic glial support. GDF5 also promoted molecular recovery of spinal MNs by enhancing homeostatic marker expression. Together, these findings identify GDF5 as a multimodal stabilizer of the motor unit and highlight its potential as therapeutic target in combinatorial strategies aimed at coupling motor unit stabilization with central neuroprotective interventions.

physiology↗

bioRxiv2026

Microchimerism in the human brain, quantitative assessment and single nuclei profiling establish cell types and diversity

Bi-directional maternal-fetal exchange during pregnancy creates a long-term microchimerism (Mc) legacy in both individuals, but its presence and cellular fate in human brain are largely unknown. We studied surgically resected epilepsy brain specimens with targetable maternal polymorphisms using polymorphism-specific quantitative PCR. Maternal Mc was prevalent, detectable in 70% of patients, and often at striking quantities spanning temporal, frontal, parietal, and hippocampal regions. Next, we employed single nucleus RNA profiling using cellector, a genetic demultiplexing tool designed to detect rare allogeneic cells. We identified Mc across major neural and glial populations. Finally, analysis of publicly available snRNA-seq datasets from neurotypical brains from gestation to late adulthood further revealed widespread Mc, persisting into advanced age, and preferentially adopting L2/3 intratelencephalic neuronal or microglial/macrophage-like fates. These data show that naturally acquired Mc is prevalent, diverse, and persistent in human brain, inviting reconsideration of what constitutes "self," with broad implications for health and disease.

neuroscience↗

bioRxiv2025

GDF5 modulation of MuSC pool as a potential therapeutic benefit for DMD

Duchenne muscular dystrophy (DMD) is a fatal disease caused by dystrophin deficiency, leading to degeneration of the entire musculature. To improve muscle pathophysiology and gene therapy for DMD, we investigated the potential of growth differentiation factor 5 (GDF5) in the DMD mdx mouse model. We showed that the overexpression of GDF5 in the muscle improved its histology, reduced inflammation, modulated regeneration and induced the appearance of de novo fibers. We demonstrated that muscle satellite cells (MuSCs) are targeted by GDF5 which enhanced their proliferation and slowed down their myogenic commitment and finally their fusion. When combined with AAV-mediated microdystrophin gene therapy, the leading therapeutic strategy, GDF5 further increased the number of microdystrophin-positive fibers compared to gene therapy alone. These findings highlight GDF5 as a promising modulator of DMD pathology and provide the first evidence of a synergistic effect of the combination of GDF5-based intervention and AAV-microdystrophin treatment.

cell biology↗

bioRxiv2025

Identification of CaVβ1 isoforms required for neuromuscular junction formation and maintenance

Voltage-gated Ca{superscript 2} channels (VGCCs) are regulated by four CaV{beta} subunits (CaV{beta}1-CaV{beta}4), each showing specific expression patterns in excitable cells. While primarily known for regulating VGCC function, CaV{beta} proteins also have channel-independent roles, including gene expression modulation. Among these, CaV{beta}1 is expressed in skeletal muscle as multiple isoforms. The adult isoform, CaV{beta}1D, localizes at the triad and modulates CaV1 activity during Excitation-Contraction Coupling (ECC). In this study, we investigated the lesser-known embryonic/perinatal CaV{beta}1 isoforms and their roles in neuromuscular junction (NMJ) formation, maturation, and maintenance. We found that CaV{beta}1 isoform expression is developmentally regulated through differential promoter activation. Specifically, CaV{beta}1A is expressed in embryonic muscle and reactivated in denervated adult muscle, alongside the known CaV{beta}1E isoform. Nerve injury in adult muscle triggers a shift in promoter usage, resulting in re-expression of embryonic/perinatal Cacnb1A and Cacnb1E transcripts. Functional analyses using aneural agrin-induced AChR clustering on primary myotubes demonstrated that these isoforms contribute to NMJ formation. Additionally, their expression during early postnatal development is essential for NMJ maturation and long-term maintenance. These findings reveal previously unrecognized roles of CaV{beta}1 isoforms beyond VGCC regulation, highlighting their significance in neuromuscular system development and homeostasis.

physiology↗

bioRxiv2023

TET2 lesions enhance the aggressiveness of CEBPA-mutant AML by rebalancing GATA2 expression

The myeloid transcription factor CEBPA is recurrently biallelically mutated (i.e., double mutated; CEBPADM) in acute myeloid leukemia (AML) with a combination of hypermorphic N-terminal mutations (CEBPANT), promoting expression of the leukemia-associated p30 isoform, and amorphic C-terminal mutations. The most frequently co-mutated genes in CEBPADM AML are GATA2 and TET2, however the molecular mechanisms underlying this co-mutational spectrum are incomplete. By combining transcriptomic and epigenomic analyses of CEBPA-TET2 co-mutated patients with models thereof, we identify GATA2 as a conserved target of the CEBPA-TET2 mutational axis, providing a rationale for the mutational spectra in CEBPADM AML. Elevated CEBPA levels, driven by CEBPANT, mediate recruitment of TET2 to the Gata2 distal hematopoietic enhancer thereby increasing Gata2 expression. Concurrent loss of TET2 in CEBPADM AML induces a competitive advantage by increasing Gata2 promoter methylation, thereby rebalancing GATA2 levels. Of clinical relevance, demethylating treatment of Cebpa-Tet2 co-mutated AML restores Gata2 levels and prolongs disease latency.

cancer biology↗

bioRxiv2021

Rev-erb-α controls skeletal muscle calcium homeostasis through myoregulin repression: implications in Duchenne Muscular Dystrophy

The sarcoplasmic reticulum (SR) plays an important role in calcium homeostasis. SR calcium mishandling is described in pathological conditions such as myopathies. Here, we investigated whether the nuclear receptor Rev-erb- regulates skeletal muscle SR calcium homeostasis. Our data demonstrate that Rev-erb invalidation in mice impairs SERCA-dependent SR calcium uptake. Rev-erb- acts on calcium homeostasis by repressing the SERCA inhibitor Myoregulin, through direct binding to its promoter. Restoration of Myoregulin counteracts the effects of REV-ERB- overexpression on SR calcium content. Interestingly, myoblasts from Duchenne myopathy patients display downregulated REV-ERB expression, whereas pharmacological Rev-erb activation ameliorates SR calcium homeostasis, and improves muscle structure and function in dystrophic mdx/Utr+/- mice. Our findings demonstrate that Rev-erb- regulates muscle SR calcium homeostasis, pointing to its therapeutic interest for mitigating myopathy.

cell biology↗

bioRxiv2019

A Quantitative Single-Cell Proteomics Approach to Characterize an Acute Myeloid Leukemia Hierarchy

Large-scale single-cell analyses are of fundamental importance in order to capture biological heterogeneity within complex cell systems, but have largely been limited to RNA-based technologies. Here we present a comprehensive benchmarked experimental and computational workflow, which establishes global single-cell mass spectrometry-based proteomics as a tool for large-scale single-cell analyses. By exploiting a primary leukemia model system, we demonstrate both through pre-enrichment of cell populations and through a non-enriched unbiased approach that our workflow enables the exploration of cellular heterogeneity within this aberrant developmental hierarchy. Our approach is capable of consistently quantifying approximately 1000 proteins per cell across thousands of individual cells using limited instrument time. Furthermore, we developed a computational workflow (SCeptre) that effectively normalizes the data, integrates available FACS data and facilitates downstream analysis. The approach presented here lays a solid foundation for implementing global single-cell proteomics studies across the world.

systems biology↗

bioRxiv2018

Clathrin plaques form mechanotransducing platforms

Large flat clathrin plaques are stable features of the plasma membrane associated with sites of strong adhesion suggesting that they could also play a role in force transduction. Here, we analyzed how clathrin plaques interact with the cytoskeleton and how they respond to mechanical cues in skeletal muscle myotubes. We show that branched actin networks surrounding clathrin plaques are directly regulated by dynamin 2, anchor intermediate filaments and sequester YAP at the plasma membrane. Dynamin 2, clathrin and desmin intermediate filaments are all required for basal YAP nucleocytoplasmic distribution and efficient nuclear translocation in response to mechanical stimuli. Dynamin 2 mutations that are responsible for centronuclear myopathy in humans disorganize the desmin network and deregulate YAP signaling both in vitro and in vivo. Thus, clathrin plaques and associated dynamin 2 are defined here as a new sensor conveying mechanical cues and integrate cell signaling with cytoskeletal regulation.

cell biology↗