The interleukin-17 (IL-17) is a pro-inflammatory cytokine that are involved in the immune response of tissues but also play a role in bone metabolism. It was previously shown that IL-17 accelerated osteogenic differentiation of human mesenchymal stem cells while inhibited osteoblast differentiation and bone regeneration in rats. To delineate the apparent discrepancy, we evaluated the effect of IL-17 on osteogenesis in mice both in vitro and in vivo. When mouse calvarial osteoblast precursor cells were cultured for in osteogenic medium in the presence of IL-17, the alkaline phosphatase activity and the expression of alkaline phosphatase, osteocalcin, and osterix were significantly enhanced. Moreover, IL-17 significantly accelerated bone regeneration in mouse calvarial defect model. Interestingly, the expression profile of mouse osteoblast IL-17 receptor genes was similar to that of human mesenchymal stem cells, while contradicted with that of rat cells. Our results suggest a species or cell type-specific role for IL-17 in bone formation.
Disclosure: The authors declared no competing interests. This work was supported by grants from the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning.