Zhu Xiao-Na, Wang Yu-Huan, Wu Juan-Juan, Dong Peng, Zhang Min
Department of Nuclear Medicine, The Second Affiliated Hospital of Xi'an Jiao Tong University, Xi'an 710004, China. E-mail:
Nan Fang Yi Ke Da Xue Xue Bao. 2018 Mar 20;38(3):296-304. doi: 10.3969/j.issn.1673-4254.2018.03.09.
To analyze the correlation between the expressions of vascular endothelial growth factor (VEGF) and transient receptor potential canonical 6 (TRPC6) and their role in podocyte injury in rats with diabetic nephropathy.
Forty SD rats with diabetic nephropathy induced by intraperitoneal injection of 65 mg/kg streptozotocin were randomized equally into 5 groups, including a diabetic nephropathy model group and 4 treatment groups, with 8 normal SD rats as the normal control group. In the 4 treatment groups, the rats received intraperitoneal injections with SU5416 at 5 mg/kg or 10 mg/kg twice a week or with LY294002 at 1 mg/kg or 2 mg/kg once daily for 8 weeks. Blood glucose, serum creatinine, blood urea nitrogen, and 24-h urinary protein levels of the rats were detected at different time points, and the pathologies in the renal tissue were observed using HE staining, PAS staining and immunohistochemistry. The expressions of VEGF, nephrin, and TRPC6 at mRNA and protein levels were detected using RT-PCR and Western blotting.
Compared with normal control rats, the diabetic rats showed significantly increased fasting blood glucose, serum creatinine, blood urea nitrogen and 24-h urinary protein levels with decreased expressions of nephrin mRNA and protein (P<0.05) and increased expressions of VEGF and TRPC6 (P<0.05). Compared with the untreated diabetic rats, the rats with SU5416 treatment showed increased 24-h urinary protein, urea nitrogen, and nephrin expression and decreased TRPC6 expression without significant changes in fasting blood glucose, serum creatinine, or VEGF expression. The rats treated with LY294002 showed decreased 24-h urinary protein and TRPC6 expression without significant changes in fasting blood glucose, serum creatinine, urea nitrogen, or expressions of nephrin and VEGF.
The regulatory effect of VEGF on TRPC6 can be blocked by inhibiting VEGFR-2 or blocking PI3K/Akt signaling pathway.
分析血管内皮生长因子（VEGF）与瞬时受体电位阳离子通道蛋白6（TRPC6）的表达相关性及其在糖尿病肾病大鼠足细胞损伤中的作用。
将40只腹腔注射65 mg/kg链脲佐菌素诱导的糖尿病肾病SD大鼠随机均分为5组，包括糖尿病肾病模型组和4个治疗组，另取8只正常SD大鼠作为正常对照组。4个治疗组大鼠分别每周两次腹腔注射5 mg/kg或10 mg/kg的SU5416，或每日一次腹腔注射1 mg/kg或2 mg/kg的LY294002，持续8周。在不同时间点检测大鼠的血糖、血清肌酐、血尿素氮和24小时尿蛋白水平，并用苏木精-伊红（HE）染色、过碘酸-雪夫（PAS）染色和免疫组织化学观察肾组织病理变化。采用逆转录-聚合酶链反应（RT-PCR）和蛋白质免疫印迹法（Western blotting）检测VEGF、nephrin和TRPC6在mRNA和蛋白质水平的表达。
与正常对照大鼠相比，糖尿病大鼠空腹血糖、血清肌酐、血尿素氮和24小时尿蛋白水平显著升高，nephrin mRNA和蛋白质表达降低（P<0.05），VEGF和TRPC6表达升高（P<0.05）。与未治疗的糖尿病大鼠相比，接受SU5416治疗的大鼠24小时尿蛋白、尿素氮和nephrin表达增加，TRPC6表达降低，空腹血糖、血清肌酐或VEGF表达无显著变化。接受LY294002治疗的大鼠24小时尿蛋白和TRPC6表达降低，空腹血糖、血清肌酐、尿素氮或nephrin和VEGF表达无显著变化。
抑制血管内皮生长因子受体-2（VEGFR-2）或阻断磷脂酰肌醇-3激酶/蛋白激酶B（PI3K/Akt）信号通路可阻断VEGF对TRPC6的调节作用。
