Proapoptotic factor Bax is increased in satellite cells in the tibialis anterior muscles of old rats

Abstract

Aging impairs the ability of muscle to adapt to exercise or injury. The goal of this study was to determine whether age-related changes in muscle adaptability could be the result of satellite cell apoptosis. Ten days after exposure to an injury protocol, estimates of edema in the exposed tibialis anterior muscles were higher in old (30 months) than young (3 months) rats, and isometric force levels were lower in old rats. Both young and old rats displayed an increase in MyoD labeling in the exposed muscle, indicating that injury induced satellite-cell activation. However, there were more MyoD-labeled cells that coexpressed the proapoptotic factor, Bax, in old than in young rats, suggesting that decrements in muscle recovery may be associated with an increase in satellite-cell apoptosis. Based on these findings we conclude that reducing satellite-cell apoptosis in aged animals may improve muscle recovery after injury.

National occupational research agenda (NORA) future directions in occupational musculoskeletal disorder health research

“…This field of inquiry will help elucidate the factors that produce acute (Hunter and Faulkner, 1997;Cutlip et al, 2004Cutlip et al, , 2005Baker et al, 2007;Faulkner et al, 1989;Geronilla et al, 2003) and chronic Barbe et al, 2003) soft tissue injury, characterize the resultant physiological response due to injurious mechanical exposure (Geronilla et al, 2003;Baker et al, 2006aBaker et al, , b, 2007Krajnak et al, 2006), and describe the reparative mechanisms that result after tissue injury (Lapointe et al, 2002a, b;Peterson et al, 2003;Rabinovsky et al, 2003;Sheehan and Allen, 1999;Trappe et al, 2001Trappe et al, , 2002. Improvements in pathomechanics have allowed better understanding of the response of tissues to repeated mechanical exposures .…”

Characterization of Frequency-Dependent Responses of the Vascular System to Repetitive Vibration

“…16 The transcripts examined and all primer sequences are presented in Table 1. Briefly, RNA was isolated and purified and firststrand complementary DNA was synthesized from 1 εg of total RNA using Invitrogen's Reverse Transcription System (Invitrogen, Carlsbad, CA).…”

Nuclear Apoptosis Contributes to Sarcopenia

“…Furthermore, the agerelated decrement in muscle recovery after stretch-shortening-induced injury in rodents has also been shown to be associated with the increase in satellite cell apoptosis (12). We have recently examined the susceptibility of satellite cells to nuclear apoptosis in aging muscles during unloading (27).…”