Inhibition of HIF-la activity is a novel strategy for the treatment of tubulointerstitial fibrosis

慢性缺氧是小管间质纤维化进展的主要因素。在这项研究中，我们研究了缺氧诱导因子1α (HIF-1α)在体内和体外介导上皮-间质转化（EMT）的程度，采用小鼠模型，选择性地删除肾近端上皮HIF-1α的表达，并评估了HIF-1α在EMT介导的肾纤维化中的作用。此外，我们开发了一种体外检测EMT的方法，使用cree重组酶激活的β-半乳糖苷酶（LacZ）来识别和跟踪原代小管上皮细胞（TECs）。为了确定HIF-la是否参与体内小管间质纤维化的发生，我们在HIF-la突变型和野生型小鼠中通过单侧尿道梗阻（UUO）诱导肾纤维化。UUO后8天采集肾脏进行免疫组织化学，并使用改良的abc过氧化物酶法对FSP1（成纤维细胞特异性蛋白1，EMT的标记物）进行染色。hif -1α-突变小鼠梗阻肾中FSP1+细胞数量明显低于野生型小鼠。此外，暴露于缺氧（1% O_2）而不是常氧（20.9% O_2） 5天后，培养的永久标记有LacZ的TECs呈现成纤维细胞样形态。LacZ和FSP1的双染色显示，在常氧条件下，8.2%的tec进行了EMT (LacZ+/FSP1+)，而在缺氧条件下，28.3%的tec进行了EMT。我们还发现，YC-1（3-(5'-羟甲基1-2'-呋喃1)-1-苄基茚唑）作为抗HIF-1α药物，通过抑制上皮-间质转化（EMT），阻断HIF-1α活性可能是治疗小管间质纤维化的一种新方法。综上所述，我们的研究结果表明，通过激活HIF-1，缺氧在体外和体内诱导EMT和EMT介导的肾纤维化中起着关键作用，抗HIF-1α药物可以通过抑制EMT来治疗小管间质纤维化。少

Chronic hypoxia is a main contributor to the progression of tubulointerstitial fibrosis. In this study, we investigated the extent to which hypoxia-inducible factor 1α (HIF-1α) mediates epithelial-mesenchymal-transition (EMT) in vivo and in vitro using a mouse model in which renal proximal epithelial HIF-1α expression was selectively deleted and assessed the role of HIF-1α in EMT-mediated renal fibrosis. In addition, we developed a method with which to detect EMT in vitro, using Cre-recombinase activated β-galactosidase (LacZ) to identify and track primary tubular epithelial cells (TECs). To determine whether HIF-la is involved in the development of tubulointerstitial fibrosis in vivo, renal fibrosis was induced by unilateral urethral obstruction (UUO) in HIF-la-mutant and wild-type mice. Kidneys were harvested for immunohistochemistry 8 days after UUO and stained for FSP1 (fibroblast-specific protein 1, a marker for EMT) using a modified ABC-peroxidase method. Numbers of FSP1+ cells w … More ere significantly lower in obstructed kidneys from HIF-1α-mutant than wild type mice. Moreover, after exposure to hypoxia (1% O_2), but not normoxia (20.9% O_2), for 5 days cultured TECs permanently marked with LacZ assumed a fibroblast-like morphology. And double staining for LacZ and FSP1 revealed that whereas 8.2% of TECs underwent EMT (LacZ+/FSP1+) under normoxic conditions, 28.3% underwent EMT under hypoxic conditions. We also determined that blockade of HIF-1α activity can be a novel approach for the treatment of tubulointerstitial fibrosis through the inhibition of epithelial-mesenchymal-transition (EMT) in vitro and in vivo, using YC-1(3-(5'-hydroxymethy1-2'-fury1)-1-benzyl indazole) as an anti-HIF-1α agent.Taken together, our results suggest that, through activation of HIF-1, hypoxia plays a key role in the induction of EMT and in EMT-mediated renal fibrosis in vitro and in vivo and anti-HIF-1α agents may be utilized for the treatment of tubulointerstitial fibrosis through the inhibition of EMT. Less