The effect of Pterostilbene on endoplasmic reticulum stress and apoptosis in HK-2 cells induced by oxalate / 中华泌尿外科杂志

ABSTRACT

Objective:To study the effect of Pterostilbene on endoplasmic reticulum stress and apoptosis in human renal tubular epithelial cells (HK-2 cells) induced by oxalate.Methods:From January 2019 to January 2020, HK-2 cells were divided into a control group (cultured with normal medium), an oxalate group (cultured with a medium containing 4 mmol/L of oxalate), and an intervention group of Pterostilbene (containing 4 mmol/L of oxalate + Pterostilbene 5, 10, and 20 μmol/L mixed medium were cultured at the same time), and the following tests were performed after 12 hours of treatment. Pterostilbene (5, 10, and 20 μmol/L) intervention group for cell viability test, lactate dehydrogenase cytotoxicity test, reduced glutathione, superoxide dismutase, malondialdehyde, hydrogen peroxide enzyme, total antioxidant capacity detection experiments to explore the degree of oxidative damage, and Western blotting experiments to explore the protein expression of ATF6, GRP78, DDIT3, caspase12, Clevead caspase 3/9; Pterostilbene (10 μmol/L) intervention group to detect mitochondrial membrane potential, caspase 3 enzyme activity, apoptosis rate, reactive oxygen detection to detect the apoptosis, reactive oxygen level, and qRT-PCR to detect ATF6, GRP78, DDIT3 of cells mRNA expression.Results:CCK-8 and lactate dehydrogenase toxicity test results showed that the cell activity of the oxalate group was significantly lower than that of the control group [(45.6±3.1)% vs. 100.0%, P<0.001]; the lactate dehydrogenase [(330.2±11.1)U/L vs. (2.6±6.7) U/L, P<0.001] of the oxalate group was higher than that of the control group increased obviously; the cell viability[ (57.2±1.7)%, (67.2±3.4)%, (78.9±1.8)%] of Pterostilbene intervention group (5, 10, 20 μmol/L) significantly increased compared with oxalate group ( P<0.05); lactate dehydrogenase [(288.1±4.3)U/L, (260.9±5.5)U, (202.7±10.2)U/L] in Pterostilbene intervention group (5, 10, 20 μmol/L ) was significantly lower than oxalate group ( P<0.05). The results of the five biochemical indexes of malondialdehyde, reduced glutathione, total superoxide dismutase, catalase, and total antioxidant capacity showed that the cell damage state was consistent with the experimental results of CCK-8 and lactate dehydrogenase. The active oxygen test results showed that the oxalate group had a significantly higher active oxygen level (76.3±4.9 vs. 6.2±1.7, P<0.01); the active oxygen level (39.5±5.4) of the Pterostilbene intervention group(10 μmol/L) was significantly lower than oxalate group ( P<0.01). The flow cytometry and caspase3 enzyme activity showed an increase in apoptosis rate and caspase3 activity in line with the trend of reactive oxygen levels. Mitochondrial membrane potential results showed that the oxalate group had a significantly lower mitochondrial membrane potential (0.76±0.15 vs. 7.84±0.26, P<0.01), and the mitochondrial membrane potential (2.26±0.27) of the Pterostilbene intervention group (10 μmol/L) was significantly higher than oxalate group( P<0.01). Western blot analysis showed that the relative expression of ATF6, DDIT3, GRP78, caspase12 and Cleaved caspase3/9 protein in the oxalate group was significantly higher than that in the control group. The relative expression of ATF6, DDIT3, GRP78, caspase12, Cleaved caspase3/9 protein in the Pterostilbene intervention group was significantly lower than that in the oxalate group ( P<0.05). qRT-PCR results showed that the mRNA expression trends of ATF6, DDIT3 and GRP78 in the three groups were consistent with the results of Western blotting. Conclusion:Pterostilbene can effectively inhibit the endoplasmic reticulum stress and apoptosis of HK-2 cells induced by oxalate.