Objective: To investigate the effect of angiotensin-(1-7) [Ang(1-7)] on the transdifferentiation of normal rat kidney proximal tubular epithelia cells (NRK52E) under hypoxic condition induced by cobaltous chloride (Co) and the underlying mechanism.
Methods: NRK52E cells were divided into control group, Co group, Co+Ang-(1-7) group and Ang-(1-7) group and cultured for 6 d. Expression levels of hypoxia-inducible factor-1α (HIF-lα) and α-smooth muscle actin (α-SMA) were detected by immunocytochemistry. Immunohistochemistry and Western blotting were used to determine the expression of p-ERK1/2 and ELISA to measure the content of collagen type 1 (Col I) in the culture supernatant.
Results: Compared with the control group, the expressions of HIF-lα, α-SMA, Col Iand p-ERK1/2 in the Co group and the Co+Ang-(1-7) group increased significantly (P<0.05) 6 d later. Compared with the Co group, the expressions of HIF-lα, α-SMA, Col Iand p-ERK1/2 in the Co+Ang-(1-7) group decreased significantly (P<0.05).
Conclusion: Ang-(1-7) can inhibit Co-induced rats' tubular epithelial-to-mesenchymal transition and reduce the production of extracellular matrix. Inhibition of ERK1/2 pathway may play an important role in this process.