Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Kunming Medical University, Kunming City, Yunan Province, 650101, China.
Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Kunming Medical University, Kunming City, Yunan Province, 650101, China.
Eur J Pharmacol. 2021 Jul 15;903:174137. doi: 10.1016/j.ejphar.2021.174137. Epub 2021 Apr 30.
Liver fibrosis (LF) is a common pathological process with high morbidity and mortality. Runt-related transcription factor 1 (RUNX1) is a transcription factor that could cause nephropathy and renal fibrosis, but its role in LF is unclear. Therefore, this study aimed to investigate the role RUNX1 in LF. Briefly, hepatic fibrosis was detected by Sirius Red staining. Transcript levels were quantified by qPCR, and proteins were assessed by western blotting or immunofluorescence. Cell viability and cell migration were measured by CCK8 assays and wound healing assays, respectively. The binding of RUNX1 and ubiquitin-specific protease 9X (USP9X) promoter was validated by ChIP assays and luciferase report assays, while the binding of USP9X and SMAD1 was confirmed by co-immunoprecipitation (Co-IP). Our studies found that the expression of RUNX1 was upregulated in LF mice, and RUNX1 knockdown alleviated CCl4-induced LF. RUNX1 silencing reduced the viability and migration of HSCs. Besides, RUNX1, as a transcription factor, bound to the promoter of USP9X and regulated the expression of USP9X. USP9X is a deubiquitination enzyme and was found to be up-regulated in LF mice. USP9X silencing reduced the viability and migration of HSCs, thereby inhibiting LF. Further studies showed that USP9X could stabilize downstream Smad1 expression. Furthermore, we also found that RUNX1 regulated the expression of SMAD1 by transcriptionally activating the expression of USP9X, thereby regulating the activation of hepatic stellate cells and liver fibrosis.
肝纤维化（LF）是一种常见的病理过程，具有高发病率和死亡率。 runt 相关转录因子 1（RUNX1）是一种转录因子，可导致肾病和肾纤维化，但它在 LF 中的作用尚不清楚。因此，本研究旨在探讨 RUNX1 在 LF 中的作用。简而言之，通过天狼星红染色检测肝纤维化。通过 qPCR 定量转录水平，通过 Western blot 或免疫荧光评估蛋白质。通过 CCK8 测定和划痕愈合测定分别测量细胞活力和细胞迁移。通过 ChIP 测定和荧光素酶报告测定验证 RUNX1 和泛素特异性蛋白酶 9X（USP9X）启动子的结合，通过共免疫沉淀（Co-IP）确认 USP9X 和 SMAD1 的结合。我们的研究发现，RUNX1 在 LF 小鼠中的表达上调，RUNX1 敲低减轻了 CCl4 诱导的 LF。RUNX1 沉默降低了 HSCs 的活力和迁移。此外，RUNX1 作为一种转录因子，与 USP9X 的启动子结合并调节 USP9X 的表达。USP9X 是一种去泛素化酶，在 LF 小鼠中发现上调。USP9X 沉默降低了 HSCs 的活力和迁移，从而抑制 LF。进一步的研究表明，USP9X 通过转录激活 SMAD1 的表达来稳定下游 Smad1 的表达。此外，我们还发现 RUNX1 通过转录激活 USP9X 的表达来调节 SMAD1 的表达，从而调节肝星状细胞的激活和肝纤维化。
