Elevated transcriptional co-activator p102 mediates angiotensin II type 1 receptor up-regulation and extracellular matrix overproduction in the high glucose-treated rat glomerular mesangial cells and isolated glomeruli.
Elevated transcriptional co-activator p102 mediates angiotensin II type 1 receptor up-regulation and extracellular matrix overproduction in the high glucose-treated rat glomerular mesangial cells and isolated glomeruli.
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DOI：
10.1016/j.ejphar.2013.01.031
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发表时间：
2013-02
影响因子：
5
通讯作者：
Zhen Wang;Jun Ni;De-cui Shao;Jia Liu;Yang Shen;Li Zhou;Yu Huang;Chen Yu;Jun Wang;H. Xue;Li-min Lu
中科院分区：
文献类型：
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作者：
Zhen Wang;Jun Ni;De-cui Shao;Jia Liu;Yang Shen;Li Zhou;Yu Huang;Chen Yu;Jun Wang;H. Xue;Li-min Lu
P102是一种多功能的转录辅激活因子。本实验旨在探讨p102在糖尿病肾病中激活肾素-血管紧张素系统（RAS）进而导致细胞外基质（ECM）过度合成中的作用。将大鼠肾小球系膜细胞（MCs）或分离的肾小球培养于正常葡萄糖（NG，5.5mM）或高糖（HG，25 mM）DMEM中。用2′，7 ′-二氯二氢荧光素二乙酸酯（DCFH-DA）荧光探针法测定活性氧的产生。蛋白质水平通过Western印迹分析，mRNA水平通过实时PCR评估。HG处理诱导活性氧产生增加。高糖培养48 h，p102 mRNA和蛋白、血管紧张素Ⅱ 1型受体（AT 1 receptor）mRNA、转化生长因子β1（TGF-β1）和纤维连接蛋白（FN）蛋白表达均显著增加。NADPH氧化酶抑制剂DPI可阻断HG诱导的p102、TGF-β1和fibronetcin的升高。siRNA抑制p102表达可抑制HG诱导的AT 1受体表达上调以及TGF-β1和纤连蛋白的增加。而AT 1受体拮抗剂坎地沙坦对NG和HG诱导的p102表达无影响，但能阻断HG诱导的TGF-β1和FN的升高。结果表明，HG刺激肾小球p102表达，与MC的结果一致。这些结果表明，在HG孵育的早期阶段，过量产生的活性氧刺激p102的合成，这反过来又上调AT 1受体的表达。RAS的激活刺激TGF-β1和纤连蛋白的产生，这进一步导致ECM积累。
P102 is a multifunctional transcriptional co-activator. This experiment is designed to investigate the role of p102 in the activation of renin–angiotensin system (RAS) and sequentially extracellular matrix (ECM) over synthesis in diabetic nephropathy. Rat glomerular mesangial cells (MCs) or isolated glomeruli were cultured in normal glucose (NG, 5.5mM) or high glucose (HG, 25mM) DMEM. The generation of reactive oxygen species was measured by 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe assay. The protein levels were analyzed by Western blot and the mRNA levels were evaluated by real-time PCR. HG treatment induced an increase in reactive oxygen species production. Culturing the cells in HG for 48h, p102 mRNA and protein, angiotensin II type 1 receptor (AT1receptor) mRNA, transforming growth factor-β1 (TGF-β1) and fibronectin proteins were significantly increased. NADPH oxidase inhibitor DPI blocked the HG-induced p102, TGF-β1 and fibronetcin elevations. Knockdown on p102 expression by siRNA depressed the HG-induced AT1receptor up-regulation as well as the increases in TGF-β1 and fibronectin. In contrast, AT1receptor antagonist candesartan did not influence p102 levels under either NG or HG condition, but blocked the HG-induced TGF-β1 and fibronectin increases. The results from isolated glomeruli were consistent with that of MCs, which showed that HG exposure stimulated the expression of p102. These results suggest that the overproduction of reactive oxygen species at the early stage of HG incubation stimulates p102 synthesis, which in turn up-regulates AT1receptor expression. The activation of RAS stimulates TGF-β1 and fibronectin production, which further results in ECM accumulation.