Effect Of Leptin On Expression Of Myoblast Proliferation And Differentiation Associated Genes In Duck

Leptin is a protein secreted by fat tissue. Its main function is the regulation of body weight and energy balance. Leptin regulation of cell proliferation by cell cycle and MyoD. Leptin can also inhibit the cell differentiation by reducing the amount of CK activity and reducing muscle cells from producing proteins. Also, leptin can regulate cell growth by PI3K/Akt/mTOR, AMPK, JAK/STAT and MEK signal pathway. However, there is few studies about the function of leptin in duck myoblasts. In this experiment, the effects of leptin on the duck skeletal myoblasts was investigated using in vitro cultured myoblasts and fluorescence quantitative PCR technology for detection of mRNA expression of cell proliferation and differentiation related genes in duck.The main results are as follows:1) Low concentration of leptin (1 ng/mL) have the function of the promoting to duck myoblasts proliferation, but the role will not keep with the increase of time. Long time of treatment can inhibit the proliferation. High levels of leptin (10 ng/mL, 100 ng/mL) have no promoting effects to duck myoblasts proliferation.2) Different concentrations of leptin can inhibit the mRNA expression of duck myoblasts differentiation related genes, and the inhibition can be gradually strengthened with the time of treatment increasing.3) With the inhibition of PI3K/Akt/mTOR signaling pathways, the promoting effect of leptin to the myoblast proliferation changes. It suggests that the regulation of leptin on the myoblast proliferation is associated with PI3K/Akt/mTOR signaling pathway. With the inhibition of PI3K/Akt/mTOR signaling pathways, the inhibitory effects of leptin on myoblast differentiation is reduced, but the inhibition has not disappeared. It suggests that leptin can regulate duck myoblast differentiation by the PI3K/Akt/mTOR signaling pathways, but this pathway is not the only way for leptin suppressing the myoblast differentiation.4) When inhibited the AMPK, the inhibition effect of leptin on myoblast proliferation and myoblast differentiation have changed dramatically. It suggests that the role of leptin may mainly affected by AMPK.