Biology subjects

Couttet, P.

Publications and source records attributed to Couttet, P..

3 recordsLinked to original sources

bioRxiv2025

Transcriptional changes in non-human primate tissues after intrathecal delivery of serotype 9 adeno-associated viral vector: insights into organ toxicities

Adeno associated virus (AAV)-based gene transfer has brought transformative therapeutic benefits to patients with otherwise untreatable genetic diseases. However, treatment-related organ toxicities, particularly for high doses, remain a safety concern in the clinic with some translatability in preclinical species. In the present study, we conducted an RNAseq analysis in non-human primates administered intrathecally with scAAV9-CBA-GFP, empty viral capsid particles, or a Promoterless vector. This analysis revealed a broad and long-lasting (4 weeks after dosing) transcriptional impact of the viral transduction/transgene expression on tissues. Liver and DRG, known to be primary sites of toxicity induced by AAV9, had the highest viral load and the most significant transcriptional changes. Our analysis revealed that most of the differentially expressed genes were upregulated, and common gene signatures belonged to immune pathways (innate and adaptive), demonstrating a persistent low-grade immune response up to four weeks post-dosing. Interestingly and across all tissues considered, the impact of empty capsids or of the Promoterless vector was minimal, suggesting that both the presence of the capsid and of a productive viral genome contributed to the observed changes. This study provides a unique insight into the transcriptional responses to AAV9 in key tissues primarily exposed by the vector.

molecular biology↗

bioRxiv2025

Exercise-Induced Myostimulin Enhances Muscle Function in Health and Disease

Musculoskeletal diseases are a leading contributor to years lived with disability worldwide1,2. While exercise offers significant benefits for people with these conditions, many individuals do not engage in adequate physical activity3. Consequently, there is growing interest in pharmacological interventions that can emulate essential health-promoting effects of exercise4,5. By integrating transcriptomics data of exercised skeletal muscle, we identified C1orf54/C1ORF54 as a novel exercise-responsive gene in mice and humans. We demonstrate that removal of the first sixteen N-terminal amino acids of C1ORF54 gives rise to a previously uncharacterized protein that stimulates the proliferation of muscle precursor cells and which we named myostimulin. Intriguingly, repeated intermittent treatment of mice with recombinant myostimulin boosts maximal isometric strength in mice within a week. Moreover, we have engineered a variant with improved biophysical properties, increased biological activity in vitro and enhanced efficacy in vivo. This variant even accelerates the recovery of muscle strength from axonotmesis, a condition associated with pronounced muscle weakness. Our data ascribe to myostimulin a role for enhancing the regenerative capacity of skeletal muscle and mediating functional adaptations characteristic of sustained resistance training. Therefore, myostimulin could be an innovative, fast acting therapeutic for certain human musculoskeletal diseases, injuries and other disorders that improve with exercise.

physiology↗

bioRxiv2023

Drug-induced eRF1 degradation promotes readthrough and reveals a new branch of ribosome quality control

Suppression of premature termination codons (PTC) by translational readthrough is a promising strategy to treat a wide variety of severe genetic diseases caused by nonsense mutations. Here, we present two novel and potent readthrough promoters - NVS1.1 and NVS2.1 - that restore substantial levels of functional full-length CFTR and IDUA proteins in disease models for cystic fibrosis and Hurler syndrome, respectively. In contrast to other readthrough promoters that affect stop codon decoding, the NVS compounds stimulate PTC suppression by triggering rapid proteasomal degradation of the translation termination factor eRF1. Our results show that this occurs by trapping eRF1 in the terminating ribosome, causing ribosome stalls and subsequent ribosome collisions, activating a novel branch of the ribosome-associated quality control (RQC) network that involves the translational stress sensor GCN1 and the catalytic activity of the E3 ubiquitin ligases RNF14 and RNF25.

molecular biology↗