Biology subjects

Ohana, J.

Publications and source records attributed to Ohana, J..

3 recordsLinked to original sources

bioRxiv2025

EMILIN1 emerges as a TGFbeta/SETDB1-regulated secreted biomarker in Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD) is an incurable muscle-wasting disorder characterized by chronic membrane damage, inflammation, and progressive fibrosis. Fibrosis in DMD is driven by sustained TGF{beta} signaling, which promotes extracellular matrix (ECM) accumulation. We previously showed that SETDB1 sustains the TGF{beta}-induced fibrotic response in DMD myotubes. Here, we further show that SETDB1 modulates the TGF{beta}-induced secretome, particularly by regulating ECM-related proteins. Comparison of the basal secretome from DMD patient-derived myotubes and healthy controls revealed a distinct disease-specific profile. Integrating both secretome analyses, we identified EMILIN1, an ECM glycoprotein not previously studied in skeletal muscle, as a robust shared candidate; EMILIN1 is enriched in the DMD secretome, further upregulated by TGF{beta}, and downregulated upon SETDB1 depletion. We confirmed EMILIN1 overexpression in DMD patient muscle biopsies, validating its pathological relevance. Functionally, EMILIN1 depletion modulated myogenic differentiation and reduced expression of the fibrotic marker SERPINE1. These findings establish EMILIN1 as a novel secreted regulator of myogenesis and fibrosis, and implicate SETDB1 in shaping the TGF{beta}-dependent secretome in DMD. Our integrative proteomic approach provides new insights into the molecular drivers of impaired regeneration in DMD and highlights potential therapeutic targets.

genetics↗

bioRxiv2025

MicroAge Mission: Experimental Design, Hardware Development and Operational Considerations for a Bespoke Culture System to Support Tissue-Engineered Skeletal Muscle Constructs.

Microgravity provides a unique model for understanding accelerated skeletal muscle loss, and potentially a model of muscle ageing, offering insights into the molecular mechanisms underlying reductions in muscle mass and function. During spaceflight, astronauts experience pronounced skeletal muscle atrophy. These effects appear similar to age-related muscle decline on Earth but on a significantly shorter timescale. Despite the incorporation of daily aerobic and resistance exercise on the International Space Station (ISS), countermeasures remain suboptimal, reflecting analogous challenges in exercise efficacy observed in ageing populations. The MicroAge Mission aimed to exploit microgravity conditions aboard the ISS to determine whether the molecular mechanisms underpinning reduced adaptive responses to contractile activity during ageing are analogous to those induced by spaceflight. The mission also explored proof-of-concept genetic interventions, including overexpression of Heat Shock Protein 10 (HSP10), a mitochondrial chaperone, to mitigate muscle atrophy and functional loss. To conduct these investigations, a tissue-engineering approach was employed to fabricate human skeletal muscle constructs, which were secured to custom-designed 3D-printed scaffolds. The scaffolds featured integrated microfluidic channels designed to interface with the fluid handling system within the flight hardware. The hardware, developed by Kayser Space Ltd, was specifically designed to interface with the European Space Agencys (ESA) Kubik incubator located within the Columbus module of the ISS. This research addresses critical methodological constraints in low Earth orbit (LEO) experimentation, providing a detailed account of pre-flight protocol development, muscle construct biofabrication techniques, and operational considerations. The findings establish a translational framework for future investigations into musculoskeletal degeneration, with implications for therapeutic strategies targeting both terrestrial ageing and astronaut musculoskeletal health.

bioengineering↗

bioRxiv2023

Deletion of exons 45 to 55 in the DMD gene: from the therapeutic perspective to the in vitro model

Gene editing therapies in development for correcting out-of-frame DMD mutations in Duchenne muscular dystrophy aim to replicate benign spontaneous deletions. Deletion of 45-55 DMD exons (del45-55) was described in asymptomatic subjects, but recently serious skeletal and cardiac complications have been reported. Uncovering why a single mutation like del45-55 is able to induce diverse phenotypes and grades of severity may impact the strategies of emerging therapies. Cellular models are essential for this purpose, but their availability is compromised by scarce muscle biopsies. Here, we have introduced through CRISPR-Cas9 edition, a del45-55 mimicking the intronic breakpoints harboured by a subset of patients of this form of dystrophinopathy, into a Duchenne patients cell line. Dystrophin expression was restored in edited myoblasts and the myogenic defects were ameliorated. Besides confirming the potential of CRISPR-Cas9 to create tailored mutations as a useful approach to generate in vitro models, we also generated an immortalized myoblast line derived from a patient with a specific del45-55. Overall, we provide helpful resources to deepen into unknown factors responsible for DMD-pathophysiology. SUMMARY STATEMENTWe restored dystrophin expression in a DMD culture by replicating the exact deletion in exons 45-55 harboured by mild patients, testing this therapeutic approach, and creating a new cell model.

cell biology↗