NF-κB-dependent increase in tissue factor expression is responsible for hypoxic podocyte injury.
NF-κB-dependent increase in tissue factor expression is responsible for hypoxic podocyte injury.
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NF-κB 依赖性组织因子表达增加是缺氧足细胞损伤的原因。
DOI：
10.1007/s10157-015-1214-z
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Okumura K.
中科院分区：
文献类型：
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作者：
Narita I;Shimada M;Yamabe H;Kinjo T;Tanno T;Nishizaki K;Kawai M;Nakamura M;Murakami R;Nakamura N;Tomita H;Saleem MA;Mathieson PW;Okumura K.
肾活检标本中常可见肾小球内纤维蛋白沉积，提示凝血活性增强。组织因子(Tf)是一种凝血因子，也与多种生物学效应有关，在肿瘤细胞中，低氧可上调组织因子的表达。最近有人提出足细胞缺氧性损伤，因此，我们研究了TF在低氧中的表达。方法将永生化的人足细胞在低氧或常氧条件下进行分化和处理。用定量RT-PCR方法检测组织因子途径抑制物(TFPI)和组织因子途径抑制物(TFPI)的表达。采用双抗体夹心酶联免疫吸附试验检测Tf、TFPI蛋白水平。我们利用小干扰RNA暂时抑制早期生长反应蛋白-1(Egr-1)、低氧诱导因子-1α(HIF-1α)和转铁蛋白。结果与正常对照组相比，低氧组大鼠足细胞TFmRNA表达增加(6h：2.3h：2.3h±0.05倍，p<；0.001，24h：5.6h±22.4倍，p<；0.001)，组织因子抑制(6h：0.54h±0.04倍，p<；0.05，0.24h±0.06倍，p<；0.001)。类似地，Tf蛋白水平升高，TFPI降低。EGR-1 siRNA不改变Tf基因的表达。核转录因子kappaB(κB)抑制剂吡咯烷二硫代氨基甲酸酯可显著降低缺氧诱导的Tf表达，而HIF1α基因敲除可进一步增加Tf的表达。低氧可导致足细胞CD2AP和肌动蛋白重组减少，这种改变可被TFsiRNA减弱。结论低氧可依赖地增加人足细胞中Tf-κB的表达。Tf可能在缺氧性足细胞损伤中起关键作用。
BackgroundFibrin deposition within glomeruli is commonly seen in kidney biopsy specimens, suggesting enhanced coagulant activity. Tissue factor (TF) is a coagulation factor which is also related to various biological effects, and TF is upregulated by hypoxia in cancer cells. Recently, hypoxic podocyte injury has been proposed, therefore, we investigated TF expression in hypoxia.MethodsConditionally immortalized human podocytes were differentiated and treated under hypoxic or normoxic conditions. mRNA expressions of TF and tissue factor pathway inhibitor (TFPI) were analyzed by quantitative RT-PCR. Protein levels of TF and TFPI were tested by enzyme-linked immunosorbent assay. We employed small interfering RNA (siRNA) to temporary knockdown early growth response protein 1 (Egr-1), hypoxia-inducible factor-1α (HIF-1α) and TF. The expression of CD2-associated protein (CD2AP) mRNA and phalloidin staining was examined to assess podocyte injury.ResultsHypoxia increased mRNA expression of TF (6 h: 2.3 ± 0.05 fold,p< 0.001, 24 h: 5.6 ± 2.4 fold,p< 0.05) and suppressed TFPI (6 h: 0.54 ± 0.04 fold,p< 0.05, 24 h: 0.24 ± 0.06 fold,p< 0.001) compared with normoxia. Similarly, protein levels of TF were increased and TFPI were decreased. Egr-1 siRNA did not change TF mRNA expression. Pyrrolidine dithiocarbamate (PDTC), a nuclear factor kappa B (NF-κB) inhibitor, significantly reduced hypoxia induced TF expression, and HIF-1α knockdown further increased TF. Hypoxia resulted in decreased CD2AP and actin reorganization in podocytes, and these changes were attenuated by TF siRNA.ConclusionHypoxia increased the expression of TF in human podocytes NF-κB dependently. TF may have a critical role in the hypoxic podocyte injury.