Effects Of G Protein Mediated Apelin Subtype And ELABELA On Platelet Aggregation And Thrombosis

Purpose:Apelin is the endogenous ligand of G protein-coupled receptor APJ.Previous studies have shown that apelin12,17,36 and ELABELA induce platelet aggregation and thrombosis in a concentration-dependent manner,while apelin13inhibit ADP-induced platelet aggregation and thrombosis.This study further clarified the effects of different G protein and?arrestin pathways on platelet aggregation and thrombosis mediated by apelins and ELABELA.Method:1.The platelet aggregation rate of human,New Zealand rabbits and APLNR^+/-mice was measured by turbidimetry;2.Thrombus formation in vitro was analyzed by in vitro thrombus detector;3.The expression of APJ in human platelets was compared by Western bolt assay;4.Immunofluorescence detection of the expression of rabbit platelet upper half-channel protein pannexin-1;5.The contents of?arrestin in platelets were measured by ELASA;Results:1.APJ receptor was expressed on human platelets,and the expression of APJ receptor on platelets with high aggregation rate was up-regulated;2.Apelin12,17,36 and ELABELA induced human platelet aggregation,and Apelin13 inhibited human platelet aggregation induced by ADP;3.Knockdown of APJ receptor weakens the regulation of apelin on platelet activity;4.Gq protein inhibitor YM254890 inhibits apelin12,apelin17,apelin36,and ELABELA induced rabbits platelet aggregation and thrombosis,but has no effect on the inhibition of apelin13 to ADP-induced platelet aggregation and thrombosis in vitro;5.Gi protein inhibitor PTX significantly abolishes the inhibition of apelin13 on ADP-induced rabbits platelet aggregation and thrombosis,but has no effect in apelin12,apelin17,apelin36,and ELABELA induced platelet aggregation and thrombosis in vitro;6.The PLC inhibitor U-73122 inhibits apelin 12,17,36 and ELABELA induced platelet aggregation in rabbits;7.Pannexin 1 is expressed on rabbit platelets.Spironolactone,a novel pannexin-1 inhibitor,inhibits rabbit platelet aggregation induced by apelin12,17,36 and ELABELA;8.The ATPase apyrase inhibits apelin 12,17,36 and ELABELA induced platelet aggregation in rabbits;9.Apelin13 induced the recruitment of rabbit platelet?arrestin level.Conclusion:Apelin12,apelin17,apelin36 and ELABELA induce platelet aggregation and thrombosis in vitro through APJ-Gq-PLC pathway,while apelin13 inhibits ADP-induced platelet aggregation and thrombosis in vitro through APJ-Gi-?arrestin pathway.