Cyr61对缺血性急性肾损伤后间质纤维化的影响及机制研究

Cyr61 is a cysteine-rich secretory protein, an immediate early gene product, which is secreted into the renal interstitial tubular epithelial cells in acute kidney injury. It has been proven valuable for the diagnosis of acute kidney injury, but its function in renal interstitial fibrosis follwing ischemic acute kidney injury is still not well known.Our previous research demonstrated that Cyr61 is protective for ischemia acute kidney injury.We propose that Cyr61, as a kind of extracellular matrix proteins, could delay renal interstitial fibrosis through inhibiting apoptosis of tubular epithelial cells, inducing apoptosis of interstitial fibroblasts and promoting growth of interstitial vascular. We established human renal tubular epithelial primary cells, human renal interstitial fibroblast primary cells, human umbilical vein endothelial cells and rat acute renal ischemic injury experimental models, through methods such as Lentiviral vector-transfection, RNA interference, ELISA, Western blot, to explore the function and mechanisim of Cyr61 in renal interstitial fibrosis following ischemic acute kidney injury by inhibiting endoplasmic reticulum stress, regulating cell cycle proteins, promoting vascular endothelial cell proliferation and sprouting, to provide experimental evidence for early intervention of renal interstitial fibrosis following ischemic acute kidney injury.

Cyr61是一种富含半胱氨酸的分泌蛋白，在缺血性急性肾损伤时由肾小管上皮细胞分泌进入肾小管和间质，对肾损伤有诊断价值，但它对肾损伤后间质纤维化的作用尚不明确。我们的研究结果显示:Cyr61对缺血性急性肾损伤具有一定的保护作用。为此，我们提出假说：Cyr61作为细胞外基质蛋白，可能通过抑制肾小管上皮细胞凋亡、诱导间质成纤维细胞的衰老凋亡、促进间质血管的生长、减缓间质纤维化进程。为了验证这一假说，我们将通过人肾小管上皮原代细胞、人肾间质成纤维原代细胞、人脐静脉内皮细胞和大鼠缺血性急性肾损伤模型，采用慢病毒载体转染、RNA干扰、ELISA、Western blot等手段，多方面探讨Cyr61在缺血性急性肾损伤后肾纤维化中的重要作用，明确Cyr61通过抑制内质网应激、调节细胞周期蛋白、促进血管内皮细胞增殖、出芽减缓肾损伤后间质纤维化。本研究将探讨Cyr61对缺血性急性肾损伤后肾间质纤维化的改善作用。

急性肾损伤是临床常见危重疾病，缺血再灌注损伤是急性肾损伤最常见的病因之一；肾间质纤维化是各种肾脏损害发展到终末期肾衰竭的共同途径和主要病理基础，在急性肾损伤发生并超出机体代偿时即开始启动，肾间质纤维化的范围和程度与肾功能减退具有高度相关性。即刻早期基因产物富含半胱氨酸61（Cyr61）是一种富含半胱氨酸的分泌蛋白，在急性缺血性肾损伤动物模型肾组织中表达显著增高。本研究通过制备Cyr61真核表达质粒和RNA干扰质粒，分别转染缺血性急性肾损伤大鼠动物和细胞模型，观察肾损伤组织肾小管上皮细胞凋亡指数、间质成纤维细胞活化增殖程度、间质血管密度的变化；同时表达纯化人Cyr61蛋白，观察Cyr61蛋白和Cyr61 RNA干扰对缺氧时人肾小管上皮细胞内质网应激与凋亡、成纤维细胞活化增殖与衰老和血管内皮细胞增殖、迁移及管状结构形成的影响，探讨Cyr61蛋白对缺血性急性肾损伤后肾间质纤维化的改善作用及机制，为缺血性急性肾损伤后间质纤维化的早期干预治疗提供实验依据。