The stringent expression of the hypoxia inducible factor-1α (HIF-1α) is critical to a variety of pathophysiological conditions. We reveal that, in normoxia, enzymatic action of cystathionine β-synthase (CBS) produces H₂S, which persulfidates prolyl hydroxylase 2 (PHD2) at residues Cys²¹ and Cys³³ (zinc finger motif), augmenting prolyl hydroxylase activity. Depleting endogenous H₂S either by hypoxia or by inhibiting CBS via chemical or genetic means reduces persulfidation of PHD2 and inhibits activity, preventing hydroxylation of HIF-1α, resulting in stabilization. Our in vitro findings are further supported by the depletion of CBS in the zebrafish model that exhibits axis defects and abnormal intersegmental vessels. Exogenous H₂S supplementation rescues both in vitro and in vivo phenotypes. We have identified the persulfidated residues and defined their functional significance in regulating the activity of PHD2 via point mutations. Thus, the CBS/H₂S/PHD2 axis may provide therapeutic opportunities for pathologies associated with HIF-1α dysregulation in chronic diseases.

缺氧诱导因子 1α (HIF-1α) 的严格表达对于多种病理生理状况至关重要。我们发现，在常氧条件下，胱硫醚 β-合酶 (CBS) 的酶作用会产生 H ₂ S，使脯氨酰羟化酶 2 (PHD2) 在残基 Cys ²¹和 Cys ³³ （锌指基序）处过硫化，从而增强脯氨酰羟化酶活性。通过缺氧或通过化学或遗传手段抑制 CBS 来消耗内源性 H ₂ S 可减少 PHD2 的过硫化并抑制活性，防止 HIF-1α 的羟基化，从而实现稳定。我们的体外研究结果得到了斑马鱼模型中 CBS 消耗的进一步支持，该模型表现出轴缺陷和异常节间血管。外源性 H ₂ S 补充可挽救体外和体内表型。我们已经鉴定了过硫化残基并定义了它们在通过点突变调节 PHD2 活性中的功能意义。因此，CBS/H ₂ S/PHD2 轴可能为慢性疾病中与 HIF-1α 失调相关的病理学提供治疗机会。