Effects of Boron on Cytotoxicity, Apoptosis, and Cell Cycle of Cultured Rat Sertoli Cells In vitro.

Abstract

The present study aimed to investigate the effects of the administration of boron on viability, apoptosis, and cell cycle of primary rat Sertoli cells (SCs) in vitro. SCs were aseptically isolated from 18-22-day-old male Sprague-Dawley (SD) rats. SCs were identified with immunofluorescence using anti-vimentin antibody. Further, to investigate the effects of boron on Sertoli cells, SCs of the boron treatment group were exposed to different concentrations (0.25, 0.5, 1, 5, 10, 40, and 80mmol/L) of boric acid. Using MTT and Cell Counting Kit-8 assays, the impact of boron on SCs viability was analyzed. Cell apoptosis and cycle of SCs were analyzed using flow cytometry. A concentration of 0.5mmol/L boric acid resulted in the highest viability and lowest necrosis and apoptosis. Above this concentration (even 1.0mmol/L) showed lower viability and higher levels of necrosis and apoptosis. Administration of < 0.5mmol/L boron significantly promoted the viability of Sertoli cells (P < 0.01); however, the exposure to high dose (> 10mmol/L) of boron exhibited significant adverse effects on Sertoli cells (P < 0.01) and even toxic effects, inhibiting cell viability compared to the control group. Flow cytometry analysis showed that treatment with 0.5mmol/L of boron significantly inhibited the apoptosis of Sertoli cells and the proportion of cells in S and G2/M phases was markedly increased; however, a higher concentration of 40 and 80mmol/L of boron promoted Sertoli cell apoptosis and cells were completely arrested at G0/G1 phase. Boron at doses below 0.5mmol/L could significantly improve the viable capacity of testicular Sertoli cells in vitro and inhibit their apoptosis. However, high dose of boron (at a concentration higher than 5.0mmol/L) exhibited noticeable toxic effects, inhibiting cell viability, accelerating apoptosis of Sertoli cells, and arresting cell cycle at G0/G1 phase.