Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201.
Center of Molecular and Translational Medicine and the Institute of Biomedical Sciences, Georgia State University, Atlanta, GA 30303.
Proc Natl Acad Sci U S A. 2023 Jan 3;120(1):e2208541120. doi: 10.1073/pnas.2208541120. Epub 2022 Dec 27.
Impaired endothelial cell (EC)-mediated angiogenesis contributes to critical limb ischemia in diabetic patients. The sonic hedgehog (SHH) pathway participates in angiogenesis but is repressed in hyperglycemia by obscure mechanisms. We investigated the orphan G protein-coupled receptor GPR39 on SHH pathway activation in ECs and ischemia-induced angiogenesis in animals with chronic hyperglycemia. Human aortic ECs from healthy and type 2 diabetic (T2D) donors were cultured in vitro. GPR39 mRNA expression was significantly elevated in T2D. The EC proliferation, migration, and tube formation were attenuated by adenovirus-mediated GPR39 overexpression (Ad-GPR39) or GPR39 agonist TC-G-1008 in vitro. The production of proangiogenic factors was reduced by Ad-GPR39. Conversely, human ECs transfected with GPR39 siRNA or the mouse aortic ECs isolated from GPR39 global knockout (GPR39) mice displayed enhanced migration and proliferation compared with their respective controls. GPR39 suppressed the basal and ligand-dependent activation of the SHH effector GLI1, leading to attenuated EC migration. Coimmunoprecipitation revealed that the GPR39 direct binding of the suppressor of fused (SUFU), the SHH pathway endogenous inhibitor, may achieve this. Furthermore, in ECs with GPR39 knockdown, the robust GLI1 activation and EC migration were abolished by SUFU overexpression. In a chronic diabetic model of diet-induced obesity (DIO) and low-dose streptozotocin (STZ)-induced hyperglycemia, the GPR39 mice demonstrated a faster pace of revascularization from hind limb ischemia and lower incidence of tissue necrosis than GPR39 wild-type (GPR39) counterparts. These findings have provided a conceptual framework for developing therapeutic tools that ablate or inhibit GPR39 for ischemic tissue repair under metabolic stress.
受损的内皮细胞 (EC) 介导的血管生成导致糖尿病患者的肢体严重缺血。声波刺猬 (SHH) 通路参与血管生成,但在高血糖环境下被未知机制所抑制。我们研究了孤儿 G 蛋白偶联受体 GPR39 在 ECs 中的 SHH 通路激活和慢性高血糖动物的缺血诱导血管生成中的作用。在体外培养来自健康和 2 型糖尿病 (T2D) 供体的人主动脉 ECs。T2D 患者的 GPR39 mRNA 表达显著升高。腺病毒介导的 GPR39 过表达 (Ad-GPR39) 或 GPR39 激动剂 TC-G-1008 在体外显著减弱 EC 的增殖、迁移和管形成。Ad-GPR39 降低了促血管生成因子的产生。相反,用 GPR39 siRNA 转染的人 EC 或从 GPR39 全局敲除 (GPR39) 小鼠分离的小鼠主动脉 EC 与各自的对照相比,显示出增强的迁移和增殖。GPR39 抑制了 SHH 效应物 GLI1 的基础和配体依赖性激活,导致 EC 迁移减弱。共免疫沉淀显示,GPR39 可能通过直接结合抑制融合蛋白 (SUFU),一种 SHH 通路内源性抑制剂,实现这一点。此外,在 GPR39 敲低的 EC 中,SUFU 过表达消除了强大的 GLI1 激活和 EC 迁移。在饮食诱导肥胖 (DIO) 和低剂量链脲佐菌素 (STZ) 诱导高血糖的慢性糖尿病模型中,与 GPR39 野生型 (GPR39) 相比,GPR39 小鼠在后肢缺血时更快地实现血管再生,组织坏死的发生率更低。这些发现为开发治疗工具提供了一个概念框架,即在代谢应激下,通过消除或抑制 GPR39 来修复缺血组织。