Establishment of RANKL-highly sensitive RAW264 subclones in accordance with high expression of TPC2

Abstract

Osteoclast differentiation is one of the critical steps that control bone mass levels during bone remodeling. However, the molecules involved in osteoclastogenesis are still incompletely understood. The pre-osteoclast cell lines RAW264 and 264.7 are widely used to study osteoclast differentiation, however, their response to RANKL stimulation is relatively lower than that of primary pre-osteoclast. Here, we established novel RAW264 subclones. The subclones showed various responses to RANKL stimulation and their tartrate-resistant acid phosphatase (TRAP) activity was strongly correlated with the mRNA expression of two-pore channel subtype 2 (TPC2). TRAP activity in Clone15 and 10 was higher and lower when compared with that of RAW264.7 cells, respectively. We conclude that the subclones established in our study are useful tools to study osteoclast biology. Moreover, we demonstrated that TPC2 expression levels influence osteoclastogenesis in RAW264 subclones.