结缔组织生长因子诱导人近端肾小管上皮细胞整合素连接激酶的表达及与激酶信号途径的关系  

Connective tissue growth factor induces integrin-linked kinase expression in human proximal tubular epithelial cells and its relationship with MEK/ERK and PI3-K signaling pathway

作　　者：刘小聪[1] 刘必成[1] 张晓良[1] 李敏侠[1] 张建东[1] 

机构地区：[1]东南大学肾脏病研究所东南大学附属中大医院肾脏科,南京210009

出　　处：《中华肾脏病杂志》2007年第9期570-574,共5页Chinese Journal of Nephrology

基　　金：国家自然科学基金（30471732）

摘　　要：目的探讨结缔组织生长因子（CTGF）对人近端肾小管上皮细胞系HK-2整合素连接激酶（ILK）表达的影响，以及丝裂原激活蛋白激酶（MAPK）和磷脂酰肌醇3激酶（P13-K）途径对该因子表达的影响。方法用不同浓度的CTGF作用HK-2细胞24h及50μg／L的CTGF作用HK-2细胞不同时间，以实时PCR和Western印迹方法检测ILKmRNA及蛋白的表达。用信号通路特异性抑制剂预处理，观察其对CTGF的干预作用。结果CTGF呈时间及浓度依赖性诱导人近端肾小管上皮细胞ILK蛋白表达。5、20、50μg／L的CTGF可使ILK表达量分别增加为对照组的3．284、5．103、5．638倍。50μg／LCTGF使ILK的表达在6h开始升高，高峰在48h（为对照组5．740倍），MEK抑制剂PD98059和P13．K抑制剂LY294002显著降低CTGF诱导的HK-2细胞ILK基因和蛋白的表达（P均〈0．05）。p38MAPK抑制剂SB203580对CTGF诱导的ILK表达无显著影响。结论CTGF能诱导HK-2细胞ILK蛋白的表达，该作用可能与ERK1／2和P13-K信号途径激活有关。Objective To investigate the effect of connective tissue growth factor （CTGF） on integrin-linked kinase （ILK） expression and its relationship with activation of MAPK, PI3-K signaling pathways in renal proximal tubular epithelial cells （PTEC）. Methods Time and dose response of CTGF-stimulated ILK protein expression was measured in PTEC. After 24 h of serum depletion, the cells were incubated in serum-free medium containing different concentrations of CTGF （0, 1, 5, 20, 50 μg/L） for 24 h or were incubated in serum-free medium containing 50μg/L CTGF for different times （0, 6, 24, 48, 72 h）. The cells were pretreated with MEK inhibitor PD98059 （10 μmol/L）, PI3-K inhibitor LY294002 （5 μmol/L） and P38 MAPK inhibitor SB203580 （10 μmol/L） respectively for 45 min before adding CTGF, then the cells were incubated for additional 12 h （real-time PCR） or 24 h （Western blotting）. Results CTGF up-regulated ILK expression in a concentration-dependent manner, with a plateau at 50 μg/L by 5.638-fold as compared to the control （P〈0.05）. CTGF stimulated expression of ILK in a time-dependent manner as well. After exposure to CTGF （50 μg/L）, the maximal level of ILK expression was reached at 48 h by 5.740-fold as compared to the control （P〈0.05）. Blockade of MAPK pathway and PI3-K pathway with PD98059 and LY294002 respectively could markedly inhibit CTGF-induced ILK expression （ILK mRNA CTGF：5.130±0.920, CTG＋PD98059：3.006±0.477, CTGF＋LY294002： 3.700±0.387, all P〈0.05）. Inhibition of p38 MAPK pathway by SB203580 did not exert any effect on CTGF-induced ILK expression. Conclusion CTGF can induce the expression of ILK in time- and dose-dependent manner in PTEC, which is partially dependent on MEK/ERK1, 2 and PI3-K signaling pathways and independent on p38 MAPK signaling.

关 键 词：结缔组织生长因子 整合素连接激酶 信号传导 上皮问充质转分化 小管间质纤维化 

分 类 号：R686[医药卫生—骨科学]