[Angiotensin-(1-7) inhibits hypoxia-induced renal tubular epithelial-to-mesenchymal transition in rats].

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.