Kidney and Hypertension Specialists, Manassas, Virginia, USA.
Bernard J Dunn School of Pharmacy, Shenandoah University, Fairfax, Virginia, USA.
Pharmacol Res Perspect. 2021 Oct;9(5):e00872. doi: 10.1002/prp2.872.
Elevation of hypoxia-inducible factor 1 protein has been shown to be protective in acute kidney injury and HIF1α enhancing drug therapies are currently in clinical trials for the treatment of anemia of chronic kidney disease. Despite its benefits, long-term HIF1 elevation seems to be associated with additional effects in the kidneys such as tubulointerstitial fibrosis. To better understand the effects of prolonged HIF1 exposure, assessment of baseline and post-therapy levels of HIF1α and other related biomarkers is essential. In this study, we assessed the effect of HIF1α enhancement using prolyl hydroxylase inhibitor (PHD-I) DMOG, on a key profibrotic marker of kidney disease. In specific, we examined the change in expression of Collagen 4 subunit A2 in cultured urinary cells of CKD patients pre and post 24-hour exposure to 1mM DMOG. Our results show that besides HIF1α enhancement, COL4A2 protein is suppressed in presence of DMOG. To determine if this effect is mediated by HIF1, we used HIF1α gene silencing in HEK293 cells and examined the effect of DMOG on protein and gene expression of COL4A2 post 24-hour exposure. We showed that silencing HIF1α reverses and amplifies the expression of COL4A2 in HEK293 cells. Our data suggest that HIF1 directly regulates the expression of COL4A2 in kidney cells and that HIF1α enhancing therapy has suppressive effects on COL4A2 that may be clinically relevant and must be considered in determining the safety and efficacy of these drugs in the treatment of anemia.
缺氧诱导因子 1 蛋白（HIF1）的升高已被证明对急性肾损伤具有保护作用，目前正在临床试验中，使用 HIF1α 增强药物治疗慢性肾脏病贫血。尽管有其益处，但长期 HIF1 升高似乎与肾脏的其他影响有关，例如肾小管间质纤维化。为了更好地了解长期 HIF1 暴露的影响，评估基线和治疗后 HIF1α 及其他相关生物标志物的水平是必不可少的。在这项研究中，我们使用脯氨酰羟化酶抑制剂（PHD-I）DMOG 评估了 HIF1α 增强对肾脏病关键成纤维指标的影响。具体来说，我们检查了慢性肾脏病患者培养的尿液细胞中，在 1mM DMOG 暴露 24 小时前后，COL4A2 基因的表达变化。我们的结果表明，除了 HIF1α 增强外，DMOG 还会抑制 COL4A2 蛋白的表达。为了确定这种作用是否由 HIF1 介导，我们在 HEK293 细胞中使用 HIF1α 基因沉默，并检查了 DMOG 对 COL4A2 蛋白和基因表达的影响。结果表明，沉默 HIF1α 逆转并放大了 HEK293 细胞中 COL4A2 的表达。我们的数据表明，HIF1 直接调节肾细胞中 COL4A2 的表达，HIF1α 增强治疗对 COL4A2 具有抑制作用，这可能具有临床相关性，在确定这些药物治疗贫血的安全性和有效性时必须考虑到这一点。
