title: Dioxin-induced thrombocyte aggregation in zebrafish.
abstract: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a canonical member of a group of dioxins which are byproducts of industrial combustion and are dangerous environmental pollutants. TCDD has been shown to cause several abnormalities in humans and wildlife, and recently, some dioxins have been found to activate platelets. However, TCDD-mediated platelet activation pathways are elusive and virtually nothing is known about TCDD activation of fish thrombocytes. To investigate TCDD effect on thrombocyte function, we tested zebrafish blood in presence of TCDD using a thrombocyte functional assay. We found that TCDD activated thrombocytes. Further experiments showed that thrombocytes of fish treated with TCDD formed both aggregates and filopodia. To investigate the mechanism of TCDD-mediated activation of thrombocytes we used inhibitors for Gq, cyclooxygenase-1, aryl hydrocarbon receptor (AHR), c-src, Akt, and ERK1/2. We found that TCDD induces AHR which activates c-src and signals the activation of Akt and ERK1/2 which are ultimately involved in generation of thromboxane A2. Furthermore, we found that ADP potentiates TCDD action, which led to the discovery that ADP itself activates AHR in the absence of TCDD. Taken together, these results resolved the pathway of TCDD activation of thrombocytes and led to the finding that ADP is an activator of AHR.
authors.affiliation: Department of Biological Sciences, University of North Texas, 1510 Chestnut, Denton TX 76203, USA.
authors.forename: Seongcheol
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, University of North Texas, 1510 Chestnut, Denton TX 76203, USA.
authors.forename: Hemalatha
authors.initials: H
authors.lastname: Sundaramoorthi
authors.affiliation: Department of Biological Sciences, University of North Texas, 1510 Chestnut, Denton TX 76203, USA. Electronic address: jag@unt.edu.
authors.forename: Pudur
authors.initials: P
authors.lastname: Jagadeeswaran
mesh_terms: D000818:Animals; D004785:Environmental Pollutants / Q000009:adverse effects* / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects*; D000072317:Polychlorinated Dibenzodioxins / Q000009:adverse effects* / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D013928:Thromboxane A2 / Q000378:metabolism; D015027:Zebrafish / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000378:metabolism*
chemical_list: D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D029961:Zebrafish Proteins; D013928:Thromboxane A2; D051057:Proto-Oncogene Proteins c-akt; D048052:Mitogen-Activated Protein Kinase 3
keywords: ADP; Signaling; TCDD; Thrombocyte; Zebrafish