Heparin induces eNOS phosphorylation and TMEM184A-dependent internalization in vascular smooth muscle cells, a process requiring TMEM184A, Ca2+, and TRPV4.
Heparin-induced eNOS activation and internalization in vascular cells requires the heparin receptor TMEM184A and calcium.
Published studies indicate that TMEM184A is a heparin receptor that interacts with and transduces stimulation from heparin in vascular cells. Previous studies have indicated that heparin increases endothelial nitric oxide synthase (eNOS) activity in bovine endothelial cells. However, the precise mechanism remains unknown. In this study, we investigated the impact of heparin treatment and TMEM184A on eNOS’s activation and the role of eNOS in heparin signaling in the cloned A7r5 rat vascular smooth muscle cell line and confirmed results in endothelial cells. We employed a combination of TMEM184A knockdown A7r5 cells along with transient eNOS knockdown and enzyme inhibitor strategies. The results indicate that heparin induces phosphorylation of eNOS. eNOS can be immunoprecipitated with TMEM184A and is internalized to the perinuclear region in a TMEM184A-dependent manner in response to heparin. We also examined how heparin treatment leads to phosphorylation of eNOS and confirmed that TMEM184A and Ca 2+ were required to mediate heparin-elicited eNOS phosphorylation. Evidence supporting the involvement of transient receptor potential cation channel subfamily V member 4 with TMEM184A in this eNOS activation process is also presented.
Li et al. (Tue,) conducted a other in Vascular smooth muscle cell signaling. Heparin was evaluated on eNOS phosphorylation and internalization. Heparin induces eNOS phosphorylation and TMEM184A-dependent internalization in vascular smooth muscle cells, a process requiring TMEM184A, Ca2+, and TRPV4.