Ike Takeshi, Doi Shigehiro, Nakashima Ayumu, Sasaki Kensuke, Ishiuchi Naoki, Asano Tomoichiro, Masaki Takao
Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan.
Department of Stem Cell Biology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Am J Physiol Renal Physiol. 2022 Nov 1;323(5):F539-F552. doi: 10.1152/ajprenal.00083.2022. Epub 2022 Sep 8.
The transcription factors hypoxia-inducible factor-1α and -2α (HIF-1α/2α) are the major regulators of the cellular response to hypoxia and play a key role in renal fibrosis associated with acute and chronic kidney disease. Jumonji domain-containing 1a (JMJD1A), a histone H3 lysine 9 (H3K9) demethylase, is reported to be an important target gene of HIF-α. However, whether JMJD1A and H3K9 methylation status play a role in renal fibrosis is unclear. Here, we investigated the involvement of HIF-α, JMJD1A, and monomethylated/dimethylated H3K9 (H3K9me1/H3K9me2) levels in unilateral ureteral obstruction (UUO)-induced renal fibrosis in mice. Intraperitoneal administration of FG4592, an inhibitor of HIF-α prolyl hydroxylase, which controls HIF-α protein stability, significantly attenuated renal fibrosis on and following UUO. FG4592 concomitantly increased JMJD1A expression, decreased H3K9me1/me2 levels, reduced profibrotic gene expression, and increased erythropoietin expression in renal tissues of UUO mice. The beneficial effects of FG4592 on renal fibrosis were inhibited by the administration of JMJD1A-specific siRNA to mice immediately following UUO. Incubation of normal rat kidney-49F and/or -52E cells with transforming growth factor-β1 (TGF-β1) in vitro resulted in upregulated expression of α-smooth muscle actin and H3K9me1/me2, and these effects were inhibited by cotreatment with FG4592. In contrast, FG4592 treatment further enhanced the TGF-β1-stimulated upregulation of JMJD1A but had no effect on TGF-β1-stimulated expression of the H3K9 methyltransferase euchromatic histone-lysine -methyltransferase 2. Collectively, these findings establish a crucial role for the HIF-α1/2-JMJD1A-H3K9me1/me2 regulatory axis in the therapeutic effect of FG4592 in renal fibrosis. Using a mouse model of renal fibrosis and transforming growth factor-β1-stimulated rat cell lines, we show that treatment with FG4592, an inhibitor of hypoxia-inducible factor-1α and -2α (HIF-1α/2α) prolyl hydroxylase decreases renal fibrosis and concomitantly reduces methylated lysine 9 of histone H3 (H3K9) levels via upregulation of Jumonji domain-containing 1a (JMJD1A). The results identify a novel role for the HIF-1α/2α-JMJD1A-H3K9 regulatory axis in suppressing renal fibrosis.
转录因子缺氧诱导因子-1α和-2α（HIF-1α/2α）是细胞对缺氧反应的主要调节因子，在与急慢性肾病相关的肾纤维化中起关键作用。含Jumonji结构域1a（JMJD1A）是一种组蛋白H3赖氨酸9（H3K9）去甲基化酶，据报道是HIF-α的重要靶基因。然而，JMJD1A和H3K9甲基化状态是否在肾纤维化中起作用尚不清楚。在此，我们研究了HIF-α、JMJD1A和单甲基化/二甲基化H3K9（H3K9me1/H3K9me2）水平在小鼠单侧输尿管梗阻（UUO）诱导的肾纤维化中的作用。腹腔注射FG4592，一种控制HIF-α蛋白稳定性的HIF-α脯氨酰羟化酶抑制剂，在UUO后第7天和第14天显著减轻了肾纤维化。FG4592同时增加了JMJD1A的表达，降低了H3K9me1/me2水平，减少了促纤维化基因的表达，并增加了UUO小鼠肾组织中促红细胞生成素的表达。在UUO后立即给小鼠注射JMJD1A特异性siRNA可抑制FG4592对肾纤维化的有益作用。在体外将正常大鼠肾-49F和/或-52E细胞与转化生长因子-β1（TGF-β1）孵育导致α-平滑肌肌动蛋白和H3K9me1/me2的表达上调，而FG4592共处理可抑制这些作用。相反，FG4592处理进一步增强了TGF-β1刺激的JMJD1A上调，但对TGF-β1刺激的H3K9甲基转移酶常染色质组蛋白赖氨酸-甲基转移酶2的表达没有影响。总的来说，这些发现确立了HIF-α1/2-JMJD1A-H3K9me1/me2调节轴在FG4592治疗肾纤维化中的关键作用。使用肾纤维化小鼠模型和转化生长因子-β1刺激的大鼠细胞系，我们表明用缺氧诱导因子-1α和-2α（HIF-1α/2α）脯氨酰羟化酶抑制剂FG4592治疗可减少肾纤维化，并通过上调含Jumonji结构域1a（JMJD1A）同时降低组蛋白H3赖氨酸9（H3K9）的甲基化水平。结果确定了HIF-1α/2α-JMJD1A-H3K9调节轴在抑制肾纤维化中的新作用。
