title: The frog trefoil factor Bm-TFF2 activates human platelets via Gq and G12/13 signaling pathway.
abstract: Bm-TFF2 is an amphibian trefoil factor purified from the Bombina maxima skin secretion that is highly toxic to mammals. We previously reported that Bm-TFF2 activates human platelets via protease-activated receptor 1. In this study, for a better understanding of platelet activation induced by Bm-TFF2, we used affinity chromatography and pharmacological inhibitors to investigate the downstream signaling pathway. Using Bm-TFF2-affinity chromatography, Gq was specifically eluted from the Bm-TFF2-coulped column. Pharmacological inhibitors such as U73122, Xestospongin C, BAPTA-AM and Gö6976 can significantly inhibit Bm-TFF2-induced platelet aggregation. These results suggested that Gq activation and the downstream PLCβ-IP3 receptor-cytoplasmic Ca(2+)-PKC signaling pathway is crucial for Bm-TFF2 to stimulate platelet aggregation. Furthermore, Bm-TFF2 induced strong platelet shape change at the concentrations of 5nM, in which the Ca(2+) mobilization of the platelets stimulated was not detectable. The p160(ROCK) inhibitorY27632 totally inhibited the shape change, indicating that Bm-TFF2 may activate the G12/13 pathway which leads to the activation of RhoA-p160(ROCK). In conclusion, Bm-TFF2 induced platelet activation mainly via the Gq and G12/13 signaling pathway. This study on the signaling pathway of Bm-TFF2 stimulation may help us understand the toxicity of B. maxima skin secretion to the human platelets.
authors.affiliation: Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao Chang Road, Kunming, Yunnan 650223, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Lei
authors.forename: Youguang
authors.initials: Y
authors.lastname: Huang
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guoyu
authors.initials: G
authors.lastname: Yu
authors.forename: Shaogui
authors.initials: S
authors.lastname: Wan
authors.forename: Wenhui
authors.initials: W
authors.lastname: Lee
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000664:Amphibian Venoms / Q000737:chemistry*; D000818:Animals; D001001:Anura; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D002846:Chromatography, Affinity; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D044365:GTP-Binding Protein alpha Subunits, G12-G13 / Q000378:metabolism*; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism*; D006801:Humans; D021962:Membrane Microdomains / Q000187:drug effects; D008954:Models, Biological; D010455:Peptides / Q000302:isolation & purification / Q000494:pharmacology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D010974:Platelet Aggregation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects*; D000071164:Trefoil Factor-2
chemical_list: D000664:Amphibian Venoms; D010455:Peptides; C000604007:TFF2 protein, human; D000071164:Trefoil Factor-2; D019869:Phosphatidylinositol 3-Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D044365:GTP-Binding Protein alpha Subunits, G12-G13; D043802:GTP-Binding Protein alpha Subunits, Gq-G11