The JAK2/STAT3 signal pathway regulates the expression of genes related to skeletal muscle development and energy metabolism in mice and mouse skeletal muscle cells

Abstract

To investigate the effects of the JAK2/STAT3 pathway on skeletal muscle development and energy metabolism, AG490 and IL-11 were used as agonist and inhibitor in treating mice and the mouse skeletal muscle cells. Average body weight (ABW) was reduced significantly in the mice treated with AG490 (p < 0:05), while IL-11 had the opposite effect (p < 0:05), as compared with the controls, average body temperature (ABT) remained at normal levels in both groups. Western blotting was used to determine the protein levels of JAK2, STAT3, p-JAK2, and p-STAT3. AG490 caused significant decreases in p-JAK2 and p-STAT3 (p < 0:05), while IL-11 did the opposite (p < 0:05, p < 0:01). Quantitative RT-PCR also showed significantly decreased expression levels of Myf5, MyoD, LXRa, and UCP3 in the AG490 group (p < 0:01), but in the IL-11 group, the expression of Myf5, MyoD, and UCP3 was increased (p < 0:05), except that LXRa whose expression did not change. In cultured skeletal muscle cells, the expression of MyoD, Myf5, LXRa, and UCP3 (p < 0:05) exhibited the same trend as that in the skeletal muscles of both treated groups (p < 0:05). These results implicate the JAK2/STAT3 in skeletal muscle development and energy metabolism.