Nguyen Thanh, Baker Jeff M, Obeid Joyce, Raha Sandeep, Parise Gianni, Pedder Linda, Timmons Brian W
Child Health & Exercise Medicine Program, McMaster University, Hamilton, Ontario, Canada.
Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.
Physiol Rep. 2014 Jun 18;2(6):e12042. doi: 10.14814/phy2.12042.
Chronic systemic inflammation is a clinical symptom in children with cystic fibrosis (CF), but the effects on skeletal muscle development are unknown. The aims of this study were to determine (1) the effects of systemic factors from children with CF and healthy controls on myoblast proliferation, and (2) whether exercise serum can have an effect on proliferation in vitro. Eleven children with CF and 11 biological age-matched controls completed two 30-min bouts of cycling at an intensity set at 50% peak mechanical power. Serum samples were collected before exercise (REST), immediately following exercise (EX), and after 60 min of recovery (REC). Serum samples prepared in group-specific pools were used for cell culture experiments. C2C12 myoblasts were incubated in 5% serum and media for 1 h and then immediately harvested for protein and mRNA analysis, or incubated in growth media for 2 days to examine proliferation. C2C12 myoblasts treated with CF serum displayed greater proliferation phenotype than myoblasts treated with control serum. Proliferation did not change with EX or REC serum from children with CF compared to CF REST serum, while proliferation was increased with EX and REC serum from control compared to control REST serum. These findings suggest that systemic factors from children with CF at rest and after exercise can alter myoblast proliferation responses when compared to systemic factors from healthy children, which may have implications on skeletal muscle development.
慢性全身性炎症是囊性纤维化（CF）患儿的一种临床症状，但对骨骼肌发育的影响尚不清楚。本研究的目的是确定：（1）CF患儿和健康对照者的全身因素对成肌细胞增殖的影响；（2）运动血清是否能在体外对增殖产生影响。11名CF患儿和11名生物学年龄匹配的对照者以50%峰值机械功率设定的强度完成了两轮30分钟的骑行。在运动前（静息）、运动后即刻（运动后）和恢复60分钟后（恢复后）采集血清样本。将按组特异性混合制备的血清样本用于细胞培养实验。将C2C12成肌细胞在5%血清和培养基中孵育1小时，然后立即收获用于蛋白质和mRNA分析，或在生长培养基中孵育2天以检测增殖情况。用CF血清处理的C2C12成肌细胞比用对照血清处理的成肌细胞表现出更大的增殖表型。与CF静息血清相比，CF患儿运动后和恢复后的血清处理的成肌细胞增殖没有变化，而与对照静息血清相比，对照者运动后和恢复后的血清处理的成肌细胞增殖增加。这些发现表明，与健康儿童的全身因素相比，CF患儿静息时和运动后的全身因素可改变成肌细胞的增殖反应，这可能对骨骼肌发育有影响。
