Sublytic complement C5b-9 complexes induce thrombospondin-1 production in rat glomerular mesangial cells via PI3-k/Akt:: association with activation of latent transforming growth factor-β1
Sublytic complement C5b-9 complexes induce thrombospondin-1 production in rat glomerular mesangial cells via PI3-k/Akt:: association with activation of latent transforming growth factor-β1
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DOI：
10.1111/j.1365-2249.2006.03069.x
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发表时间：
2006-05-01
影响因子：
4.6
通讯作者：
Tong, J
中科院分区：
文献类型：
--
作者：
Gao, L;Qiu, W;Tong, J
系膜细胞增生是多种不同类型肾小球损伤的常见细胞反应。补体C5b-9是介导系膜细胞增殖的主要候选者，尤其是亚溶C5b-9，它可以诱导多种炎症因子和细胞因子的产生。转化生长因子(TGF)- β 1在细胞外基质（ECM）的积累中起主要作用，而血栓反应蛋白(TSP)-1在体外系统中已被确定为潜在TGF- β 1的激活剂。我们以大鼠肾小球系膜细胞（glomerular mesangial cells, GMCs）为模型系统，评估亚溶C5b-9对TSP-1和tgf - β 1表达的影响，并探讨其相关信号转导途径。首先，我们确定了抗thy1抗体和补体的浓度，将其视为亚溶C5b-9剂量，并分别通过实时聚合酶链反应（PCR）和酶联免疫吸附试验（ELISA）检测亚溶C5b-9是否诱导大鼠GMCs中TSP-1的表达，进而激活潜伏的tgf - β 1。然后，通过Western blot分析，我们研究了PI3-k/Akt通路在大鼠gmc亚裂解c5b -9诱导的TSP-1产生中的作用。在大鼠GMCs中加入亚溶C5b-9（5%抗thy1抗体和4%正常血清），通过TSP-1诱导潜在tgf - β 1活化。亚溶C5b-9的加入明显增加了Akt磷酸化蛋白，而PI3-k抑制剂LY294002可以明显降低亚溶C5b-9诱导的TSP-1的升高。这些结果表明，TSP-1是亚溶解c5b -9诱导的大鼠GMCs中潜伏tgf - β 1的激活剂；此外，PI3-k/Akt信号转导通路可能在亚溶c5b -9诱导的TSP-1产生中发挥关键作用。
Mesangial cell proliferation is a common cellular response to a variety of different types of glomerular injury. Complement C5b-9 is a prime candidate to mediate mesangial cell proliferation, especially sublytic C5b-9, which can induce the production of multiple inflammatory factors and cytokines. Transforming growth factor (TGF)-beta 1 plays a major role in the accumulation of extracellular matrix (ECM), while thrombospondin (TSP)-1 has been identified as an activator of latent TGF-beta 1 in an in vitro system. Using rat glomerular mesangial cells (GMCs) as a model system, we assessed the effect of sublytic C5b-9 on the expression of TSP-1 and TGF-beta 1 and explored the relevant pathway of signal transduction. First, we ensured the concentrations of anti-Thy1 antibody and complement, which were regarded as a sublytic C5b-9 dose, and examined whether the sublytic C5b-9 induced expression of TSP-1 in rat GMCs which, in turn, activated latent TGF-beta 1 by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Then, we investigated the role of the PI3-k/Akt pathway in sublytic C5b-9-induced TSP-1 production in rat GMCs by Western blot analysis. The addition of sublytic C5b-9 (5% anti-Thy1 antibody and 4% normal serum) to rat GMCs induced activation of latent TGF-beta 1 via TSP-1. The addition of sublytic C5b-9 apparently increased the protein of Akt phosphorylation, whereas PI3-k inhibitor LY294002 could clearly reduce the increase of TSP-1 induced by sublytic C5b-9. These results indicate that TSP-1 is an activator of latent TGF-beta 1 in sublytic C5b-9-induced rat GMCs; furthermore, the PI3-k/Akt signal transduction pathway may play a key role in sublytic C5b-9-induced TSP-1 production.