2. Academic Validation
  3. Novel Oridonin Analog CYD0682 Inhibits Hepatic Stellate Cell Activation via the Heat Shock Protein 90-Dependent STAT3 Pathway

Novel Oridonin Analog CYD0682 Inhibits Hepatic Stellate Cell Activation via the Heat Shock Protein 90-Dependent STAT3 Pathway

  • J Surg Res. 2024 Jun:298:14-23. doi: 10.1016/j.jss.2023.12.056.
Jana E Dejesus 1,  Xiaofu Wang 1,  Yanping Gu 2,  Jia Zhou 3,  Ravi S Radhakrishnan 4
Affiliations

Affiliations

  • 1 Department of Surgery, University of Texas Medical Branch, Galveston, Texas.
  • 2 Department of Neurobiology, University of Texas Medical Branch, Galveston, Texas.
  • 3 Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas.
  • 4 Department of Surgery, University of Texas Medical Branch, Galveston, Texas. Electronic address: rsradhak@utmb.edu.
PMID: 38537450 DOI: 10.1016/j.jss.2023.12.056
Abstract

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.

Keywords

HSP90; Hepatic fibrosis; Hepatic stellate cells; Myofibroblasts; Oridonin; STAT3.

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Products
  • Cat. No.
    Product Name
    Description
    Target
    Research Area
  • HY-162605
    STAT3 Inhibitor