Cisplatin-induced renal injury in LLC-PK1 cells

Nephrotoxicity is one of the important adverse effects induced by cisplatin (CDDP), a potent anticancer drug. CDDP causes a disorder of renal proximal tubules. So, we evaluated mechanisms of renal tubular injury induced by CDDP using established epithelial cell line, LLC-PK1, which is characteristic of renal proximal tubular epithelium. LLC-PK1 cells were incubated in culture media except CDDP subsequently after exposure to CDDP for five hours. The production of reactive oxygen species (ROS) increased in LLC-PK1 cells which was an earlier event than the increase in the release of LDH occurring at 48 hr after the exposure. CDDP induced also the activation of MAP kinase, ERK1/2. U0126, an ERK inhibitor, inhibited LDH leakage from the cells 48hr after the CDDP exposure. An antioxidant, tempol, significantly prevented CDDP-induced activation of ERK1/2 and cell injury. BAPTA-AM, an intracellular calcium chelator, prevented the increases in production of ROS and cell injury induced by CDDP. The results suggest that CDDP –induced increase in intracellular calcium causes oxidative stress to induce renal tubular injury via ERK1/2 activation leaded by ROS. Furthermore, these results indicate that established renal cell line, LLC-PK1, is very effective method for elucidation of nephrotoxic mechanisms.