Department of Surgery, University of Texas Medical Branch, Galveston, Texas.
Department of Neurobiology, University of Texas Medical Branch, Galveston, Texas.
J Surg Res. 2024 Jun;298:14-23. doi: 10.1016/j.jss.2023.12.056. Epub 2024 Mar 26.
INTRODUCTION: Activated hepatic stellate cells (HSCs) are the primary effector cells in hepatic fibrosis, over depositing extracellular matrix (ECM) proteins. Our previous work found oridonin analog CYD0682 attenuates proliferation, Transforming Growth Factor β (TGFβ)-induced signaling, and ECM production in immortalized HSCs. The underlying mechanism behind these reductions is unclear. The Signal Transduction and Activator of Transcription 3 (STAT3) pathway plays a central role in HSC activation and has been found to be overexpressed in models of hepatic injury. In this study, we will examine the effect of CYD0682 on STAT3 signaling. METHODS: Immortalized human (LX-2) and rat (HSC-T6) HSC lines were treated with CYD0682 or Tanespimycin (17-AAG) with or without TGF-β. Nuclear and cytosolic proteins were extracted. Protein expression was analyzed with Western blot. DNA binding activity was assessed with STAT3 DNA Binding ELISA. Cell viability was assessed with Alamar blue assay. RESULTS: CYD0682 treatment inhibited STAT3 phosphorylation at tyrosine 705 in a dose-dependent manner in LX-2 and HSC-T6 cells. STAT3 DNA binding activity and STAT3 regulated protein c-myc were significantly decreased by CYD0682. Notably, TGFβ-induced STAT3 phosphorylation and ECM protein expression were inhibited by CYD0682. STAT3 is reported to be a Heat Shock Protein 90 (HSP90) client protein. Notably, CYD0682 attenuated the expression of endogenous STAT3 and other HSP90 client proteins FAK, IKKα, AKT and CDK9. HSP90 specific inhibitor 17-AAG suppressed endogenous and TGFβ-induced STAT3 phosphorylation and ECM protein production. CONCLUSIONS: CYD0682 attenuates endogenous and TGFβ-induced STAT3 activation and ECM production via an HSP90 dependent pathway in HSCs. Further study of this pathway may present new targets for therapeutic intervention in hepatic fibrosis.
简介：激活的肝星状细胞（HSCs）是肝纤维化的主要效应细胞，过度沉积细胞外基质（ECM）蛋白。我们之前的工作发现，冬凌草甲素类似物 CYD0682 可减弱永生化 HSCs 的增殖、转化生长因子β（TGFβ）诱导的信号转导和 ECM 产生。这些减少的潜在机制尚不清楚。信号转导和转录激活因子 3（STAT3）通路在 HSC 激活中起核心作用，并在肝损伤模型中发现其过度表达。在这项研究中，我们将研究 CYD0682 对 STAT3 信号转导的影响。 方法：用 CYD0682 或 Tanespimycin（17-AAG）处理永生化人（LX-2）和大鼠（HSC-T6）HSC 系，有或无 TGF-β。提取核和胞浆蛋白。用 Western blot 分析蛋白表达。用 STAT3 DNA 结合 ELISA 评估 DNA 结合活性。用 Alamar blue 测定法评估细胞活力。 结果：CYD0682 处理以剂量依赖性方式抑制 LX-2 和 HSC-T6 细胞中 STAT3 酪氨酸 705 的磷酸化。CYD0682 显著降低 STAT3 DNA 结合活性和 STAT3 调节蛋白 c-myc。值得注意的是，CYD0682 抑制 TGFβ诱导的 STAT3 磷酸化和 ECM 蛋白表达。STAT3 被报道为热休克蛋白 90（HSP90）的客户蛋白。值得注意的是，CYD0682 减弱了内源性 STAT3 和其他 HSP90 客户蛋白 FAK、IKKα、AKT 和 CDK9 的表达。HSP90 特异性抑制剂 17-AAG 抑制内源性和 TGFβ诱导的 STAT3 磷酸化和 ECM 蛋白产生。 结论：CYD0682 通过 HSP90 依赖途径减弱内源性和 TGFβ诱导的 HSCs 中 STAT3 激活和 ECM 产生。对该途径的进一步研究可能为肝纤维化的治疗干预提供新的靶点。
J Surg Res. 2015-12
J Surg Res. 2014-3-20
J Pharmacol Exp Ther. 2009-7
Mol Cell Biochem. 2015-12
Zotero 插件