17β-雌二醇与氟维司群抑制蛋白激酶C刺激下系膜细胞纤维化

17β-Estradiol and fulvestrant inhibit glomerular mesangial cell fibrogenesis downstream of protein kinase C activation

为确定雌激素受体(ER)激动剂17β-雌二醇与G蛋白偶联雌激素受体(GPER)激动剂氟维司群在蛋白激酶C(PKC)激活时对系膜细胞纤维化影响,本研究利用十四烷酰佛波醇乙酸酯(PMA)短期刺激以模拟激活PKC,导致Ⅳ型胶原、纤连蛋白、结缔组织生长因子、转化生长因子-β1的基因转录水平上调至基线的2.5±0.5、1.4±0.2、26±11和1.9±0.3倍(P<0.05),而17β-雌二醇及氟维司群可显著抑制上述基因转录水平的上调(P<0.05),并通过抑制Akt磷酸化阻碍PKC下游信号;同时,应用受体抑制剂及基因敲低技术,可明确17β-雌二醇及氟维司群对上述基因表达、信号通过的影响依赖于ER、GPER的激活。本研究表明,ER与GPER激动剂可发挥肾小球保护功能,抑制肾小球系膜细胞在PKC激活后过度表达促纤维化因子及无用的细胞外基质。

To investigate the effect of estrogen receptor（ER）agonist 17β-estradiol and G protein-coupled estrogen receptor 1（GPER）agonist fulvestrant on masangial cell fibrogenesis under protein kinase C（PKC）, we quantified type IV collagen（COL4A1）, fibronectin（FN1）, connective tissue growth factor（CTGF）and transforming growth factor-β1（TGFβ1）gene transcription and semi-quantified phosphorylation of Akt signal upon Phorbol 12-myristate 13-acetate stimulation（which increased COL4A1, FN1, CTGF and TGFβ1 gene transcription to 2. 5±0. 5, 1. 4±0. 2, 26±11 and 1. 9±0. 3 times compared with baseline, P〈 0. 05）when incubated with the two drugs. It was found that 17β-estradiol and fulvestrant down-regulated COL4A1, FN1, CTGF and TGFβ1 genes transcription（P〈 0. 05）and Akt signaling under PKC activation via ER and GPER. ER and GPER agonists are beneficial in protecting the mesangial cells from fibrogenic stimuli by inhibiting PKC signaling and excessive extracellular matrix production.