Background
Oxidative stress is an important mechanism in liver ischemia/reperfusion (I/R) injury. Hepatocyte apoptosis and proliferation occur in parallel with liver I/R injury, and the degree of apoptosis and proliferation determines the effects on hepatocytes. Vitamin D receptor (VDR) can lessen liver I/R injury, but previous studies focused mostly on inflammation and immunity.
Conclusions
VDR mediates hepatocyte apoptosis and proliferation through autophagy.
Methods
H2O2 was used to induce hepatocyte injury. Before treatment with H2O2, Hep-3B cells were pretreated with paricalcitol (PC) and siRNA-VDR. Rapamycin and chloroquine were also applied in the study.
Results
The number of apoptotic cells was measured with an annexin V (AV) -fluorescein isothiocyanate apoptosis detection kit. Expression of proteins was measured by western blotting. As compared with the H2O2+Hep-3B group, levels of AV/PI, cleaved caspase-3, and p62 were lower, and expression levels of Bcl-2, proliferating cell nuclear antigen, and VDR were higher, in the PC+H2O2+Hep-3B group. When the VDR gene was silenced by siRNA-VDR in the siRNA-VDR+H2O2+Hep-3B group, expressions of AV/PI, cleaved caspase-3, and p62 were upregulated, and expressions of Bcl-2, proliferating cell nuclear antigen, and VDR were downregulated, as compared with values for the siRNA-NC+H2O2+Hep-3B group. Treatment with rapamycin or chloroquine partially reversed the effect of PC and siRNA-VDR on apoptosis and proliferation. Conclusions: VDR mediates hepatocyte apoptosis and proliferation through autophagy.