COMP (Cartilage Oligomeric Matrix Protein), a Novel PIEZO1 Regulator That Controls Blood Pressure
Hui Wang, Ze Yuan, Bianbian Wang, Bochuan Li, Huizhen Lv, Jinlong He, Yaqian Huang, Zhen Cui, Qiannan Ma, Ting Li, Yi Fu, Xiaoli Tan, Yangping Liu, Shengpeng Wang, Changhe Wang, Wei Kong, Yi Zhu
Abstract
Background: Vascular endothelial cells are critical for maintaining blood pressure (BP) by releasing biologically active molecules, such as nitric oxide. A non-endothelial cell resident matricellular protein, COMP (cartilage oligomeric matrix protein), plays a pivotal role in maintaining cardiovascular homeostasis, but little is known about its regulatory effect on BP. Methods: Mice were infused with AngII (angiotensin II; 450 ng/kg per minute) for 3 days via an osmotic minipump, and BP was monitored by a tail-cuff system. Second-order mesenteric arteries were isolated from mice for microvascular tension measurement. Nitric oxide was detected by an electron paramagnetic resonance technique. Small-interfering RNA transfection, co-immunoprecipitation, bioluminescence resonance energy transfer assays, and patch-clamp electrophysiology experiments were used for further detailed mechanism investigation. Results: COMP −/− mice displayed elevated BP and impaired acetylcholine-induced endothelium-dependent relaxation compared with wild-type mice with or without AngII. Inhibition of eNOS (endothelial nitric oxide synthase) abolished the difference in endothelium-dependent relaxation between wild-type and COMP −/− mice. Furthermore, COMP directly interacted with the C-terminus of Piezo1 via its C-terminus and activated the endogenous Piezo1 currents, which induced intracellular Ca 2+ influx, Ca 2+ /calmodulin-dependent protein kinase type II and eNOS activation, and nitric oxide production. The Piezo1 activator, Yoda1, reduced the difference in endothelium-dependent relaxation and BP in wild-type and COMP − /− mice. Moreover, COMP overexpression increased eNOS activation and improved endothelium-dependent relaxation and BP. Conclusions: Our study demonstrated that COMP is a novel Piezo1 regulator that plays a protective role in BP regulation by increasing cellular Ca 2+ influx, eNOS activity, and nitric oxide production.