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Effects of micro RNA ‐133b on retinal vascular endothelial cell proliferation and apoptosis through angiotensinogen‐mediated angiotensin II‐ extracellular signal‐regulated kinase 1/2 signalling pathway in rats with diabetic retinopathy
Author(s) -
Liu TaoTao,
Hao Qian,
Zhang Yan,
Li ZhaoHui,
Cui ZhiHua,
Yang Wei
Publication year - 2018
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/aos.13715
Subject(s) - apoptosis , cell growth , biology , angiotensin ii , retinal , kinase , signal transduction , cell cycle , microbiology and biotechnology , medicine , endocrinology , biochemistry , blood pressure
Purpose This study aimed to explore the effects of micro RNA ‐133b (miR‐133b) on diabetic retinopathy ( DR ) by targeting angiotensinogen (AGT) through the angiotensin‐II (Ang II ) extracellular signal‐regulated kinase 1/2 ( ERK 1/2) signalling pathway in rats. Methods The DR rat model was established using retinal tissues of DR rats and normal rats. Immunohistochemistry was performed to detect the protein expressions of AGT and CD 34 in retinal tissues. Quantitative real‐time polymerase chain reaction ( qRT ‐ PCR ) and Western blotting were applied to detect miR‐133b expression, AGT , Ang II , ERK 1/2 mRNA , and protein expressions in tissues and cells after transfection. Retinal vascular endothelial cells were cultured and divided into normal, blank, miR‐133b mimics, miR‐133b mimics negative control ( NC ), miR‐133b inhibitors, miR‐133b inhibitors NC , si RNA NC , si RNA ‐ AGT , and miR‐133b inhibitors + si RNA ‐ AGT groups. 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide (MTT) assay was performed to detect cell proliferation. Cell cycle and apoptosis were evaluated using flow cytometry. Results Compared with normal rats, AGT and CD 34 were expressed more frequently in DR rats. MicroRNA (miR)‐133b expression was downregulated but AGT , Ang II , ERK 1 and ERK 2 mRNA expressions were upregulated in retinal tissues of DR rats. When compared to the normal group, all other groups displayed decreased cell proliferation, increased cell number in G0/G1, decreased cell number in S stage, increased cell apoptosis rate and declined miR‐133b expression. As well, significant increased expressions of AGT and the Ang II ‐ ERK 1/2 pathway‐related proteins were observed in retinal vascular endothelial cells in all groups except the normal group. The miR‐133b mimics and si RNA ‐ AGT groups had increased cell proliferation, decreased cell number in the G0/G1 phase, increased cell number in S stage, decreased cell apoptosis rate and decreased expressions of AGT and Ang II ‐ ERK 1/2 pathway‐related proteins than the miR‐133b inhibitors + si RNA ‐ AGT group. The miR‐133b inhibitors group exhibited opposite trends compared with the miR‐133b mimics and si RNA ‐ AGT groups. Conclusion The study provides data to suggest that miR‐133b induces proliferation and inhibits apoptosis of retinal vascular endothelial cells by targeting AGT through the Ang II ‐ ERK 1/2 signalling pathway in DR rats.