Age-related changes in the mitotic and metabolic characteristics of muscle-derived cells
Journal of applied physiology
Barani, Aude E., Anne-Cé cile Durieux, Odile Sabido, and Damien Freyssenet. Age-related changes in the mitotic and metabolic characteristics of muscle-derived cells. J Appl Physiol 95: 2089-2098, 2003; 10.1152/japplphysiol. 00437.2003.-Age-related sarcopenia could partly result from cumulative repeated episodes of incomplete repair and regeneration. We hypothesized that mitotic and metabolic events associated with satellite cell activation and proliferation could be altered with aging.
... rived cells (mdc) were isolated from gastrocnemius and quadriceps muscles of young (3 wk old), adult (9 mo old), and old (24 mo old) Sprague-Dawley male rats (n ϭ 10/group). The mdc from young growing rats started to proliferate earlier compared with adult and old animals. Cell cycle duration was significantly reduced with aging from 36.5 Ϯ 3.2 to 28.0 Ϯ 2.2 h. However, the proportion of noncycling (G0 phase) and cycling (G1 ϩ S ϩ G2 ϩ M phases) cultured mdc was statistically unchanged among the three age groups. Significantly lower increase in c-met and proliferating cell nuclear antigen expression were observed in cultured mdc of old rats upon serum stimulation. Major changes in the expression of citrate synthase, lactate dehydrogenase, proteasome, caspase 3, plasminogen activators (PAs), and matrix metalloproteinase 2-9 (MMP2-9) were observed upon serum stimulation, but no age-related difference was noted. However, when measured on crushed muscle extracts, PAs and MMP2-9 enzyme activities were significantly decreased with aging. Our results show that cellular and biochemical events associated with the control of mdc activation and proliferation occur with aging. These alterations may participate in the accumulation of repeated episodes of incomplete repair and regeneration throughout the life span, thus contributing to the loss of skeletal muscle mass and function with aging. aging; energetic and proteolytic metabolism; extracellular matrix; hepatocyte growth factor; mitochondria; mitotic activity SARCOPENIA IS A term that refers to a loss of skeletal muscle mass associated with a decrease in muscle strength and an increased fatigability. Sarcopenia is the common denominator of the aging process, responsible for a general and substantial decline in physical performance, which leads ultimately to physical dis-Original submission in response to a call for papers on "Physiology of Aging."