替米沙坦通过过氧化物酶体增殖物激活受体γ(PPAR-γ)抑制转化生长因子-β1(TGF-β1)诱导的人近端肾小管上皮细胞上皮-间质转化。
Telmisartan counteracts TGF-β1 induced epithelial-to-mesenchymal transition via PPAR-γ in human proximal tubule epithelial cells.
作者信息
Chen Yumin, Luo Qiong, Xiong Zibo, Liang Wei, Chen Li, Xiong Zuying
机构信息
Shenzhen Hospital, Health Science Center, Peking University, Shenzhen, PR China.
出版信息
Int J Clin Exp Pathol. 2012;5(6):522-9. Epub 2012 Jul 17.
Chronic renal failure (CRF) mainly results from kidney fibrosis. Epithelial-to-mesenchymal transition (EMT) occurs in stressed tubular epithelial cells and contributes to renal fibrosis. Transforming growth factor-β1 (TGF-β1) has been shown to initiate and complete the whole EMT process. Peroxisome proliferators-activated receptor-γ (PPAR-γ) exerts anti-inflammatory, anti-fibrotic and vaculo-protective effects on different renal diseases. Telmisartan is a member of angiotensin II (Ang II) receptor blocker (ARB) family. Recent studies show that Telmisartan has a partial agonistic effect on PPAR-γ. Therefore, we tested the hypothesis that Telmisartan reverses the progression of induced EMT by TGF-β1 in cultured human renal proximal tubular epithelial (HK-2) cells. Cultured HK-2 cells were treated with TGF-β1 (3 ng/ml), a combination of TGF-β1 and Telmisartan (10-200 umol/L) and a combination of TGF-β1, Telmisartan and GW9662, a PPAR-γ antagonist for 48 hours. EMT was determined by quantitative real-time PCR analysis of E-cadherin (E-cad), Connective Tissue Growth Factor (CTGF) and PPAR-γ transcript expression and immunocytochemical analysis of E-cad, α-Smooth Muscle Actin (α-SMA) and PPAR-γ protein expression. TGF-β1 induced phenotypic EMT in cultured HK-2 cell line via significantly reduced E-cad expression and significantly increased CTGF, α-SMA expression in association with the loss of epithelial morphology. Telmisartan reversed all EMT markers in a dose-dependent manner which was inhibited by PPAR antagonist GW9662. In the present study, it was suggested that Telmisartan attenuated TGF-β1 induced EMT by agonistic activation of PPAR-γ.
慢性肾衰竭(CRF)主要由肾纤维化引起。上皮-间质转化(EMT)发生于应激的肾小管上皮细胞,并促进肾纤维化。已表明转化生长因子-β1(TGF-β1)启动并完成整个EMT过程。过氧化物酶体增殖物激活受体-γ(PPAR-γ)对不同的肾脏疾病发挥抗炎、抗纤维化和血管保护作用。替米沙坦是血管紧张素II(Ang II)受体阻滞剂(ARB)家族的一员。最近的研究表明,替米沙坦对PPAR-γ具有部分激动作用。因此,我们检验了以下假设:替米沙坦可逆转TGF-β1在培养的人肾近端小管上皮(HK-2)细胞中诱导的EMT进程。将培养的HK-2细胞用TGF-β1(3 ng/ml)、TGF-β1与替米沙坦(10 - 200 μmol/L)的组合以及TGF-β1、替米沙坦与PPAR-γ拮抗剂GW9662的组合处理48小时。通过对E-钙黏蛋白(E-cad)、结缔组织生长因子(CTGF)和PPAR-γ转录本表达进行定量实时PCR分析以及对E-cad、α-平滑肌肌动蛋白(α-SMA)和PPAR-γ蛋白表达进行免疫细胞化学分析来确定EMT。TGF-β1通过显著降低E-cad表达以及显著增加CTGF、α-SMA表达并伴有上皮形态丧失,在培养的HK-2细胞系中诱导表型EMT。替米沙坦以剂量依赖性方式逆转了所有EMT标志物,而这被PPAR拮抗剂GW9662所抑制。在本研究中,提示替米沙坦通过PPAR-γ的激动性激活减轻TGF-β1诱导的EMT。