Zhang Mian-zhi, Zhang Min-ying, Zhao Song, Duan Jian-zhao, Zhang Yan-qiu, Zuo Chun-xia, Cheng Xiang-yang, Duan Hui-jun
Department of Nephrology, Tianjin Gongan Hospital, Tianjin 300040, China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2007 Jun;29(3):364-9.
To evaluate the effect of JAK/STAT signaling pathway activation on the transdifferentiation and secretion of transforming growth factor-beta1 (TGF-beta1) induced by high glucose in renal proximal tubular epithelial cells.
Human kidney cells (HKC) were cultured and then divided into four groups: low glucose (LG) group, high glucose (HG) group, high mannitol (LG + M) group, and HG + AG490 group. Immunoprecipitation and Western blot analysis were used to determine the expression of tryosine phosphorylated Janus kinase 2 ( p-JAK2). The protein expressions of STAT1, STAT3, p-STAT1, and p-STAT3 and the expressions of alpha-SMA and E-Cadherin were observed by Western blot. The contents of TGF-B1, fibronectin and type I collagen in the supernatants of the cultured HKC were detected by enzyme-linked immunosorbent assay (ELISA). The expression of TGF-beta1 mRNA was measured by reverse transcription and polymerase chain reaction (RT-PCR).
Compared with LG group, the expressions of JAK2, p-STAT1, p-STAT3, and TGF-beta1, mRNA were significantly increased in HG group from 6 to 72 hours. Meanwhile, the contents of TGF-beta1 and collagen I in the supernatants and the expression of alpha-SMA increased and the expression of E-Cadherin decreased. The expressions of JAK2, p-STAT1, p-STAT3, and TGF-beta mRNA as well as the levels of TGF-beta1 and collagen I in the supernatant s in HG + AG490 group were significantly lower than in the HG group. The expressions of alpha-SMA and E-Cadherin were also decreased in HG + AG490 group.
Activation of JAK/STAT signaling pathway may be involved in the high glucose-induced transdifferentiation and overproduction of TGF-beta1, and ECM proteins in HKCs.
评估JAK/STAT信号通路激活对高糖诱导的肾近端小管上皮细胞转分化及转化生长因子-β1（TGF-β1）分泌的影响。
培养人肾细胞（HKC），然后分为四组：低糖（LG）组、高糖（HG）组、高甘露醇（LG + M）组和HG + AG490组。采用免疫沉淀和蛋白质印迹分析来测定酪氨酸磷酸化的Janus激酶2（p-JAK2）的表达。通过蛋白质印迹观察STAT1、STAT3、p-STAT1和p-STAT3的蛋白表达以及α-SMA和E-钙黏蛋白的表达。采用酶联免疫吸附测定（ELISA）检测培养的HKC上清液中TGF-B1、纤连蛋白和I型胶原的含量。通过逆转录聚合酶链反应（RT-PCR）测量TGF-β1 mRNA的表达。
与LG组相比，HG组在6至72小时内JAK2、p-STAT1、p-STAT3和TGF-β1 mRNA的表达显著增加。同时，上清液中TGF-β1和I型胶原的含量增加，α-SMA的表达增加，E-钙黏蛋白的表达降低。HG + AG490组中JAK2、p-STAT1、p-STAT3和TGF-β mRNA的表达以及上清液中TGF-β1和I型胶原的水平显著低于HG组。HG + AG490组中α-SMA和E-钙黏蛋白的表达也降低。
JAK/STAT信号通路的激活可能参与了高糖诱导的HKCs中TGF-β1转分化及过量产生以及细胞外基质蛋白的形成。
