[Interference of hexavalent chromium on VDAC1 mRNA expression or ATP level and their potential association]

To explore the interference of hexavalent chromium-Cr(VI) on voltage-dependent anion channel (VDAC1) mRNA expression and intracellular adenosine triphosphate (ATP) level in cells and their potential association.

Cultured L-02 hepatocytes were treated with 2, 4, 8, 16 and 32 micromol/L of Cr(VI) for 12, 24 and 36 hours (h). The expression of VDAC1 mRNA was measured by reverse transcription quantitative polymerase chain reaction (RT-qPCR), whereas the levels of intracellular ATP was determined by an ATP-specific bioluminescence assay.

(1) The expression of VDAC1 mRNA in cells of treated groups was less than that of control group at 12h, and then showed slight increase at 24h, and increased significantly after 36 h of treatment. (2) After being treated by Cr(VI) for 12 h, ATP level in cells increased, especially in higher dose groups, and the ATP level then decreased significantly at 24h except in the lowest dosage (2 micromol/L) group, and increased again at 36h in 2 micromol/L and 4 micromol/L groups, but the ATP level in 8, 16 and 32 micromol/L groups remained less than that in the control group. (3) Correlation analysis showed a moderate negative relationship between VDAC1 mRNA expression and intracellular ATP level during Cr (VI) treatment (r = -0.604, P < 0.05).

The interference of Cr(VI) on ATP level was associated with abnormal expression of VDAC1 mRNA, over-expression of VDAC1 mRNA may be one of molecular mechanisms for the decrease of ATP level induced by heavy metal-Cr(VI).