1. Nuclear localized Akt limits skeletal muscle derived fibrotic signaling
- Author
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Indranil Sinha, Debalina Bagchi, Ronald L. Neppl, and Eleonora Guadagnin
- Subjects
0301 basic medicine ,Muscle Fibers, Skeletal ,Biophysics ,Muscle Development ,Transfection ,Biochemistry ,Cell Line ,Mice ,03 medical and health sciences ,Paracrine signalling ,0302 clinical medicine ,Fibrosis ,Paracrine Communication ,medicine ,Animals ,Myocyte ,Muscle, Skeletal ,Molecular Biology ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Cell Nucleus ,Myogenesis ,Chemistry ,Regeneration (biology) ,Skeletal muscle ,Cell Biology ,medicine.disease ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Proto-Oncogene Proteins c-akt ,Signal Transduction - Abstract
Skeletal muscle regeneration following injury is a complex multi-stage process involving the recruitment of inflammatory cells, the activation of muscle resident fibroblasts, and the differentiation of activated myoblasts into myocytes. Dysregulation of these cellular processes is associated with ineffective myofiber repair and excessive deposition of extracellular matrix proteins leading to fibrosis. PI3K/Akt signaling is a critical integrator of intra- and intercellular signals connecting nutrient availability to cell survival and growth. Activation of the PI3K/Akt pathway in skeletal muscle leads to hypertrophic growth and a reversal of the changes in body composition associated with obesity and advanced age. Though the molecular mechanisms mediating these effects are incompletely understood, changes in paracrine signaling are thought to play a key role. Here, we utilized modified RNA to study the biological role of the transient translocation of Akt to the myonuclei of maturing myotubes. Using a conditioned medium model system, we show that ectopic myonuclear Akt suppresses fibrogenic paracrine signaling in response to oxidative stress, and that interventions that increase or restore myonuclear Akt may impair fibrosis.
- Published
- 2019