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Gagnon, D.

Publications and source records attributed to Gagnon, D..

2 recordsLinked to original sources

Peripheral Skeletal Muscle Alterations in Adults Born Preterm: An Observational Comparative Study

Prematurity is associated with reduced exercise capacity, which relies on the integrity of the cardiovascular, pulmonary, and skeletal muscle systems. Our animal model mimicking prematurity-associated conditions showed altered muscle composition and atrophy in adulthood. This study aimed to compare muscle composition and strength in adults born preterm versus full-term controls. This observational cohort study recruited 55 adults born preterm, [≤]29 weeks of gestation and 53 full-term controls who underwent musculoskeletal ultrasound imaging to assess morphology of the rectus femoris at rest and during a maximal voluntary contraction. Maximal voluntary contraction of the hands and legs were measured by manual dynamometry. In adults born preterm, there was a reduction in muscle strength (handgrip: -4.8 kg, 95% CI -9.1, -0.6; knee extensor: -44.6 N/m, 95% CI -63.4, -25.8) and muscle area (-130 mm2, 95% CI -207, -53), which was more pronounced with a history of bronchopulmonary dysplasia. Muscle stiffness was increased in the preterm group (0.4 m/s, 95% CI 0.04, 0.7). Prematurity is associated with alterations in skeletal muscle composition, area, and function in adulthood. These findings highlight the necessity to implement preventive and/or curative approaches to improve muscle development and function following preterm birth to enhance overall health in this population. Whats known on This SubjectPreterm birth is associated with reduced exercise capacity. However, the impact of preterm birth on skeletal muscle, a critical player of exercise capacity, in adulthood remains unclear. What This Study AddsOur findings provide novel insights into the potential long-term effects of preterm birth and the contributions of bronchopulmonary dysplasia on peripheral muscle-related health outcomes, such as muscle composition (reduced muscle area and increased muscle stiffness) and function (reduced muscle strength).

physiology↗

The dynamic interplay between ATP/ADP levels and autophagy sustain neuronal migration in vivo

Cell migration is a dynamic process that entails extensive protein synthesis and recycling, structural remodeling, and a considerable bioenergetic demand. Autophagy is one of the pathways that maintain cellular homeostasis. Time-lapse imaging of autophagosomes and ATP/ADP levels in migrating cells in the rostral migratory stream of mice revealed that decrease in ATP levels force cells into the stationary phase and induce autophagy. Genetic impairment of autophagy in neuroblasts using either inducible conditional mice or CRISPR/Cas9 gene editing decreased cell migration due to the longer duration of the stationary phase. Autophagy is modulated in response to migration-promoting and inhibiting molecular cues and is required for the recycling of focal adhesions. Our results show that autophagy and energy consumption act in concert in migrating cells to dynamically regulate the pace and periodicity of the migratory and stationary phases in order to sustain neuronal migration. HighlightsO_LIADP levels dynamically change during cell migration C_LIO_LIA decrease in ATP levels leads to cell pausing and autophagy induction via AMPK C_LIO_LIAutophagy is required to sustain neuronal migration by recycling focal adhesions C_LIO_LIAutophagy level is dynamically modulated by migration-promoting and inhibiting cues C_LI

neuroscience↗