Endogenous hydrogen sulfide persulfidates endothelin type A receptor to inhibit pulmonary arterial smooth muscle cell proliferation

• DOI: 10.1016/j.redox.2025.103493
• Publication Date: 2025-01-11T07:38:28Z
• Authors: Yanan Zhang; Xiaoyu Tian; Liangyi Chen; Shiqun Zhao; Xinjing Tang; Xin Liu; Dan Zhou; Chaoshu Tang; Bin Geng; Junbao Du; Hongfang Jin; Yaqian Huang
• Keywords: Medicine (General); R5-920; Endothelin type A receptor; Hydrogen sulfide; QH301-705.5; Persulfidation; Cysteine; Biology (General); Pulmonary arterial smooth muscle cell proliferation; Research Paper

BACKGROUND: The binding of endothelin-1 (ET-1) to endothelin type A receptor (ETAR) performs a critical action in pulmonary arterial smooth muscle cell (PASMC) proliferation leading to pulmonary vascular structural remodeling. More evidence showed that cystathionine γ-lyase (CSE)-catalyzed endogenous hydrogen sulfide (H(2)S) was involved in the pathogenesis of cardiovascular diseases. In this study, we aimed to explore the effect of endogenous H(2)S/CSE pathway on the ET-1/ETAR binding and its underlying mechanisms in the cellular and animal models of PASMC proliferation. METHODS AND RESULTS: Both live cell imaging and ligand-receptor assays revealed that H(2)S donor, NaHS, inhibited the binding of ET-1/ETAR in human PASMCs (HPASMCs) and HEK-293A cells, along with an inhibition of ET-1-activated HPASMC proliferation. While, an upregulated Ki-67 expression by the pulmonary arteries, a marked pulmonary artery structural remodeling, and an increased pulmonary artery pressure were observed in CSE knockout (CSE-KO) mice with a deficient H(2)S/CSE pathway compared with those in the wild type (WT) mice. Meanwhile, NaHS rescued the enhanced binding of ET-1 with ETAR and cell proliferation in the CSE-knockdowned HPASMCs. Moreover, the ETAR antagonist BQ123 blocked the enhanced proliferation of CSE-knockdowned HPASMCs. Mechanistically, ETAR persulfidation was reduced in the lung tissues of CSE-KO mice compared to that in WT mice, which could be reversed by NaHS treatment. Similarly, NaHS persulfidated ETAR in HPASMCs and HEK-293A cells. Whereas a thiol reductant dithiothreitol (DTT) reversed the H(2)S-induced ETAR persulfidation and further blocked the H(2)S-inhibited binding of ET-1/ETAR and HPASMC proliferation. Furthermore, the mutation of ETAR at cysteine (Cys) 69 abolished the persulfidation of ETAR by H(2)S, and subsequently blocked the H(2)S-suppressed ET-1/ETAR binding and HPASMC proliferation. CONCLUSION: Endogenous H(2)S persulfidated ETAR at Cys69 to inhibit the binding of ET-1 to ETAR, subsequently suppressed PASMC proliferation, and antagonized pulmonary vascular structural remodeling.