Changes of myogenic reactive oxygen species and interleukin-6 in contracting skeletal muscle cells

Abstract

The aim of this study was to measure changes in myotube reactive oxygen species (ROS) and the production of interleukin (IL)-6 in electrically stimulated mouse C2C12 skeletal muscle cells. After five days of differentiation, myotubes were stimulated using an electrical stimulator set at 45V at a frequency of 5Hz, with a pulse width of 20ms. Acute stimulations were performed for 45, 60, 75, 90, or 120min in each dish. ROSs were detected in the extracted cells directly using a fluorescent probe. IL-6 mRNA expression in C2C12 myotubes and IL-6 concentration in C2C12 myotube supernatants were determined using real-time PCR and ELISA, respectively. Compared with control cells, ROS generation was significantly increased at 45min after the onset of stimulation (P < 0.01) and continued to increase, reaching a maximum at 120min. IL-6 mRNA expression and IL-6 concentration in C2C12 cells were significantly increased after 75min (P < 0.01) and 120min (P < 0.05) of electrical stimulation (ES) compared with the control cells. Our data show that a specific ES intensity may modulate ROS accumulation and affect IL-6 gene expression in contracting skeletal muscle cells. © 2012 Hongying Pan et al.