Biology subjects

Jaber, A.

Publications and source records attributed to Jaber, A..

4 recordsLinked to original sources

bioRxiv2025

Targeting lysosomal damage is a new therapeutic perspective for Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD), a muscle degenerative disease affecting young boys, arises from the loss of dystrophin. Current gene therapy approaches aim to restore a shortened form of dystrophin (microdystrophin) via Adeno-Associated Vector (AAV) delivery, but clinical studies show limited efficacy, emphasizing the need for improved strategies such as combined therapies. In this study, we identified lysosomal perturbations in the myofibers of DMD patients and animal models, an overlooked mechanism of cellular damage in muscular dystrophies. These were notably marked by the upregulation and recruitment of Galectin-3, a known biomarker of lysosomal membrane permeabilization, to damaged lysosomes, alongside alterations in lysosome number, morphology, and activation of endolysosomal damage response. Importantly, microdystrophin therapy in Dmdmdx mice fails to fully correct these damages. However, combining it with trehalose, a lysosome-protective disaccharide, significantly improves outcome, enhancing muscle function, histology and transcriptome. These findings highlight lysosomal damage as a novel mechanism in DMD pathogenesis and suggest that combining trehalose with gene therapy could enhance therapeutic efficacy. TeaserLysosomal damage contributes to DMD pathology and is an interesting therapeutic target worth considering for current and future approaches.

physiology↗

bioRxiv2023

Fibroblasts-dependent maturation and phenotype exacerbation of dystrophic hiPSC-derived MYOtissues enables muscle strength evaluation for gene therapy screening

Current gene therapy approaches for Duchenne muscular dystrophy (DMD) using AAV-mediated delivery of microdystrophin ({micro}Dys) have shown limited efficacy in patients, contrasting with the favorable outcomes observed in animal models. This discrepancy is partly due to the lack of models that replicate key pathogenic features associated with the severity of the human disease, such as fibrosis and muscle dysfunction. To tackle the translational gap, we develop a human disease model that recapitulates these critical hallmarks of DMD for a more predictive therapeutic investigation. Using a muscle engineering approach, we generate MYOrganoids from iPSC-derived muscle cells co-cultured with fibroblasts that enable functional maturation for muscle force analysis upon contractions. Incorporation of DMD fibroblasts within DMD iPSC-derived muscle cells allows phenotypic exacerbation by unraveling of fibrotic signature and fatiguability through cell-contact-dependent communication. Although {micro}Dys gene transfer partially restores muscle resistance, it fails to fully restore membrane stability and reduce profibrotic signaling. These findings highlight the persistence of fibrotic activity post-gene therapy in our human DMD system, an unparalleled aspect in existing DMD models, and provide the opportunity to explore the underlying mechanisms of dysregulated cellular communication to identify anti-fibrotic strategies empowering gene therapy efficacy.

bioengineering↗

bioRxiv2021

FGFR inhibitor mediated dismissal of SWI/SNF complexes from YAP-dependent enhancers induces adaptive therapeutic resistance

How cancer cells adapt to evade the therapeutic effects of drugs targeting oncogenic drivers is poorly understood. Here we report an epigenetic mechanism leading to the adaptive resistance of triple-negative breast cancer (TNBC) to fibroblast growth factor receptor (FGFR) inhibitors. Prolonged FGFR inhibition suppresses the function of BRG1-dependent chromatin remodeling leading to an epigenetic state that derepresses YAP-associated enhancers. These chromatin changes induce the expression of several amino acid transporters resulting in increased intracellular levels of specific amino acids that reactivate mTORC1. Collectively, these findings reveal a novel feedback loop involving an epigenetic state transition and metabolic reprogramming that leads to adaptive therapeutic resistance.

cancer biology↗

bioRxiv2021

Expression levels of long noncoding natural antisense transcripts overlapping the UGT73C6 gene affect rosette size of Arabidopsis thaliana

Natural antisense long noncoding RNAs (lncNATs) are involved in the regulation of gene expression in plants, modulating different relevant developmental processes and responses to various stimuli. We identified and characterized two lncNATs (NAT1UGT73C6 and NAT2UGT73C6, collectively NATsUGT73C6) in Arabidopsis thaliana that are transcribed from a gene overlapping UGT73C6, a member of the UGT73C subfamily of genes encoding UDP-glycosyltransferases (UGTs). Expression of both NATsUGT73C6 is developmentally controlled and occurs independently of the transcription of UGT73C6 in cis. Downregulation of NATsUGT73C6 levels through artificial microRNAs results in a reduction of the rosette area, while constitutive overexpression of NAT1UGT73C6 or NAT2UGT73C6 leads to the opposite phenotype, an increase in rosette size. This activity of NATsUGT73C6 relies on its RNA sequence, and, although modulation of UGT73C6 in cis cannot be excluded, the observed phenotypes are not a consequence of the regulation of UGT73C6 in trans. The NATsUGT73C6 levels were shown to affect cell proliferation and thus individual leaf size. Consistent with this concept, our data suggest that the NATsUGT73C6 modulate the expression levels of key transcription factors involved in regulating leaf growth by modulating cell proliferation. These findings thus reveal an additional regulatory layer on the process of leaf growth.

plant biology↗