Irisin enhances osteogenic differentiation of mouse MC3T3-E1 cells via upregulating osteogenic genes.

Osteoporosis affects millions of individuals and remains a clinical challenge in terms of prevention and treatment. The present study aimed to investigate the effect of irisin on osteogenic differentiation by exposing MC3T3-E1 cells to different concentrations of irisin. Treated cells were assayed for osteoblast proliferation and osteogenic differentiation by measuring alkaline phosphatase (ALP) activity, calcium deposition, formation of mineralized nodules and the expression of osteogenic genes using reverse transcription-quantitative PCR. The proliferation of MC3T3-E1 cells was unaffected by irisin at the concentrations tested of up to 100 ng/ml (P>0.05). ALP activity and mineralized nodule formation were significantly enhanced by irisin in a dose- and time-dependent manner, indicating that irisin promotes osteoblast differentiation of MC3T3-E1 cells. The expression of osteogenic genes, including ALP, collagen I, runt-related transcription factor 2, osterix, osteopontin, osteocalcin, osteoprotegerin and estrogen receptor α, increased significantly after irisin treatment. The present study demonstrated that irisin promoted the osteogenic differentiation of MC3T3-E1 cells, possibly by upregulating the expression of osteogenic genes and markers. Therefore, irisin may be worthy of further investigation as a potential therapeutic agent for osteoporosis.