BV Reduces H₂O₂-induced Apoptosis Of NRK52E Cells Via The PI3K/AKT Pathways

Objective: To investigate the protective effects and mechanisms of biliverdin （BV）against H₂O₂-induced apoptosis on NRK52E cells.Methods: Cultured NRK52E cells in vitro were divided into six groups, namely controlgroup, BV group, LY294002（PI3K inhibitor） group, H₂O₂group, H₂O₂+BV group andH₂O₂+BV+LY294002group. NRK52E cells were pretreated respectively with BV（30μmol/L） and LY294002（15μmol/L） for30min, and then stimulated by H₂O₂（200μmol/L）. NRK52E cells were stained by Annexin V-FITC/PI Kit and apoptosis wasevaluated by FACS. The expression of Biliverdin reductase （BVR） and P-AKT weredetermined by western blot, the expression of BVR on external plasma membrane ofNRK52E was determined by western blot and immunofluorescence, the tyrosinephosphorylation of BVR was determined by immunoprecipitation.Result:（1）30μmol/L BV pretreated for30min reduced apoptosis significantly（p<0.01）,the proportion of apoptosis in H₂O₂+BV+LY group was increased as compared toH₂O₂+BVgroup（P<0.05）.（2）BV prolonged the activation of P-AKT（p<0.05）, LY294002significantly suppressed the phosphorylation of P-AKT（p<0.01）.（3）BV could not changethe expression of BVR on NRK52E cells（P>0.05）, but increased the expression of BVR on the external plasma membrane of NRK52E（p<0.05）, and then prolonged the activationof P-AKT（p<0.01）. Moreover, BV increased the tyrosine phosphorylation of BVR.Conclusion: BV could increase the expression of BVR on the external plasma membraneand reduce H₂O₂-induced apoptosis of NRK52E cells via the tyrosine phosphorylation ofBVR and PI3K/AKT signal pathway.