Résumé
OBJECTIVE: To investigate the anti-oxidant mechanism of andrographolide on HaCaT cells via Nrf2/ARE signal pathway. METHODS: The effect of andrographolide on the viability of HaCaT cells and the effect of H2O2-induced cell viability were measured by CCK-8. HaCaT cells were pretreated with andrographolide of different concentration for 24 h. The protein and mRNA expression levels of Nrf2, HO-1, AKR1C1 and NQO1 in HaCaT cells were detected by Western blot and RT-qPCR, respectively. The expression of Nrf2 protein in the nucleus was analyzed by nuclear cytoplasmic separation and immunofluorescence. RESULTS: Andrographolide had no significant effect on cell viability and dose-dependently decreased H2O2-induced cell death, the difference was statistically significant. Andrographolide significantly enhanced the expression of protein and mRNA of antioxidant enzymes Nrf2, HO-1, AKR1C1, NQO1, increased the distribution of Nrf2 in the nucleus, and up-regulated the expression of ARE. Besides, andrographolide upregulated the phosphorylation level of the upstream protein kinase AMPKα (p-AMPKα). CONCLUSION: Andrographolide could decrease H2O2-induced cell death, and its mechanism may be through the activation of Nrf2/ARE signaling pathway, thereby regulating the expression levels of HO-1, AKR1C1, and NQO1.
Résumé
The NADPH-dependent reduction activities of two paralogous pig AKR1C1s with and without 19 additional amino acid residues in C-terminus were evaluated against steroid hormones including 5a-dihydrotestosterone, testosterone, progesterone, androstenedione and 5a-androstane-3,17-dione, which act as substrates of the AKR1C1s. Among the hormones, the AKR1C1s exhibited the highest activity against 5a-dihydrotestosterone and the lowest activity against testosterone and progesterone. Furthermore, the AKR1C1s showed the largest differential activities against 5a-dihydrotestosterone, but no such change of activities was found against progestrone and testosterone. These results suggest that the C-terminal region of AKR1C1 plays an important effect in the reduction activities of pig AKR1C1. Thus, the differential activities of two AKR1C1 paralogs observed in the present study provide important insights in understanding the molecular evolution.