BMP7 plays a critical role in TMEM100-inhibited cell proliferation and apoptosis in mouse metanephric mesenchymal cells in vitro

Kidney mainly arises from the induction of metanephric mesenchymal cells (MM cells) and the ureteric bud (UB). Transmembrane protein-100 (Tmem100) consists of two transmembrane regions with strong temporal and spatial expression characteristics during renal development. However, the function of Tmem100 in mouse embryonic kidney-derived cells remained unclear. We provided qPCR to verify the relationship between Tmem100 and the BMP signal pathway. To clarify the role of Tmem100 in cell proliferation and apoptosis, we carry out EdU incorporation, annexin V- fluorescein isothiocyanate (FITC) apoptosis assay. Here, we find that the knockdown of Tmem100 increases the proliferation and apoptosis of mouse embryonic kidney-derived cells, and this promotion can be inhibited by knockdown of BMP7 at the same time; these results suggest that BMP7 plays a crucial role in Tmem100-regulated cell proliferation and apoptosis. qRT-PCR results further demonstrate that the deficiency of Tmem100 leads to BMP7 upregulation and overexpression could get opposite results. In BMP7-depleted MK3 cells, Tmem100 is highly upregulated and BMPR-II is downregulated. And in BMP7-overexpressed MK3 cells, the expression of Tmem100 is decreased. In BMPR-II-depleted MK3 cells, Tmem100 is downregulated and BMP7 expression remains still. These findings indicate that both BMP7 and BMPR-II can regulate Tmem100 and vice versa, and BMPR-II expression is regulated by BMP7. However, BMP7 has no association with BMPR-II in MK3 cells. Our data demonstrated the significant role of BMP7 in Tmem100-regulated cell proliferation and apoptosis and revealed the complicated regulation network among Tmem100, BMP7, and BMPR-II in mouse embryonic kidney-derived cells.