Abstract

Highlights

  • High F aggravates Cd-mediated disruption of the antioxidant system in cells.
  • High F enhances the Cd-induced apoptosis in cells.
  • High F strengthens the Cd-induced mitochondrial autophagy in cells.
  • High F aggravated Cd-mediated nephrotoxicity of cells via ROS-PINK1/Parkin pathways.

Fluoride (F) and cadmium (Cd) as well known environmental pollutants can cause nephrotoxicity to damage human health, while the joint toxicity of F and Cd to the renal tubular epithelial cells remains still elusive. The interactive influence between F and Cd in oxidative stress, apoptosis, and mitochondrial autophagy of renal tubular epithelial cells was explored. Cells were submitted to varying concentrations with of NaF (1, 5, 10, and 15 ug/mL) combined with CdCl2·2.5H2O (1 ug/mL) for 12 h. Following this, the combined cytotoxicity was assessed. Our results show that different doses of F had varying effects on Cd-mediated nephrotoxicity, with a synergistic effect observed in the high F (15 ug/mL) co-treated with Cd. In response to the Cd induction, the high F treatment resulted in the formation of multiple autophagosomes and notably increased the levels of LDH, ROS, and MMP. It also elevated the MDA contents while decreasing the activities of SOD, GSH-Px, and CAT. Additionally, it yielded a higher Bax/Bcl-2 ratio, which further promotes the apoptotic process. The treatment also disturbed energy metabolism, resulting in a reduction of both ATP and ADP. Furthermore, autophagy-related genes and proteins, including PINK1, Parkin, LC3A, LC3B, and SQSTM1, were significantly improved. In brief, high F of 15 ug/mL aggravated Cd-mediated nephrotoxicity of renal tubular epithelial cells via the ROS-PINK1/Parkin pathway.