Mouse interleukin-20 receptor 1a targets renal epithelial cells and is associated with renal calcium deposition

Abstract

We previously identified a novel transcript, mouse (m)IL-20R1a, generated by alternative splicing of the mIL-20R1 gene and studied its possible in vitro functions. However, the function of mIL-20R1a in vivo is unknown. Overexpression of mIL-20R1a in transgenic FvB/N mice resulted in the pathological change of excess calcium deposited in the kidneys. The interplay between renal epithelial cells and calcium oxalate (CaOx) was important in the crystallization involved in the formation of renal stones (nephrolithiasis). Thus, we investigated and compared the responses of mouse renal proximal (TKPTS) and collecting (M-1) tubule cell lines to CaOx with or without mIL-20R1a. The renal epithelial cell lines exposed to CaOx in the presence of mIL-20R1a showed significantly increased lactate dehydrogenase release; loss of cell viability through apoptosis; increased CaOx internalization; higher tumor necrosis factor (TNF)-alpha, MCP-1 and RANTES expression; and higher reactive oxygen species production. Interleukin-6, TNF-alpha and MCP-1 were also upregulated in the kidneys of mIL-20R1a transgenic mice. These effects of mIL-20R1a on CaOx-exposed renal epithelial cells showed that mIL-20R1a functioned as an aggravating factor in promoting calcium deposition in kidney of mice.