miR-128 plays a critical role in murine osteoclastogenesis and estrogen deficiency-induced bone loss
Gengyang Shen, Hui Ren, Qi Shang, Zhida Zhang, Wenhua Zhao, Xiang Yu, Jingjing Tang, Zhidong Yang, De Liang, Xiaobing Jiang
Abstract
Postmenopausal osteoporosis (PMOP) is a severe health issue faced by postmenopausal women. microRNA-128 (miR-128) is associated with aging, inflammatory signaling, and inflammatory diseases, such as PMOP. It has also been reported to modulate in vitro osteogenic/adipogenic differentiation. However, its function in osteoclast formation is unknown. Methods: First, the expression of miR-128 and nuclear factor of activated T cells 1 (Nfatc1, bone resorption master marker) was investigated in bone tissues derived from PMOP patients, while their correlation to each other was also investigated. The levels of miR-128 and Nfatc1 in bone specimens and bone marrow-derived macrophages (BMMs) from mice subjected to ovariectomy (OVX) were also assayed. Next, we employed mice BMMs modified for overexpression and inhibition of miR-128 levels to determine its effect on osteoclast differentiation. Moreover, we generated osteoclastic miR-128 conditional knockout (miR-128 Oc-/-) mice and isolated miR-128 deletion-BMMs to observe its biological function on bone phenotype and osteoclastogenesis in vivo, respectively. The miR-128 Oc-/-BMMs were used to explore the downstream regulatory mechanisms using pull-down, luciferase reporter, and western-blotting assays. Finally, the impact of miR-128 deficiency on OVX-induced bone loss in mice was evaluated.