Thermal injury initiates pervasive fibrogenesis in skeletal muscle.

Thermal injury initiates pervasive fibrogenesis in skeletal muscle. Am J Physiol Cell Physiol. 2020 May 20;: Authors: Brightwell CR, Hanson ME, El Ayadi A, Prasai A, Wang Y, Finnerty CC, Fry CS Abstract Severe burn injury induces a myriad of deleterious effects to skeletal muscle, resulting in impaired function and delayed recovery. Following burn, catabolic signaling and myofiber atrophy are key fiber-intrinsic determinants of weakness; less well understood are alterations in the interstitial environment surrounding myofibers. Muscle quality, specifically alterations in the extracellular matrix (ECM), modulates force transmission and strength. We sought to determine the impact of severe thermal injury on adaptation to the muscle ECM and quantify muscle fibrotic burden. After a 30% total body surface area dorsal burn, spinotrapezius muscle was harvested from mice at 7 (7d, n=5), 14 (14d, n=4), and 21 days (21d, n=4), and a sham control group was also examined (Sham, n=4). Expression of TGFb, myostatin, and downstream effectors and proteases involved in fibrosis and collagen remodeling were measured by immunoblotting, and immunohistochemical and biochemical analyses assessed fibrogenic cell abundance and collagen deposition. Myostatin signaling increased progressively through 21 days post-burn alongside fibrogenic/adipogenic progenitor cell expansion, with abundance peaking at 14 days post-burn. Post-burn, elevated expression of tissu...
Source: Am J Physiol Cell Ph... - Category: Cytology Authors: Tags: Am J Physiol Cell Physiol Source Type: research