The Study Of Thrombocytes Development By A Drug Obtained From Zebrafish Model Screening

The platelets are an essential component of blood cells and play an important role in hemostasis and thrombosis.Mammalian platelets are anucleated cytoplasmic fragments of megakaryocytes(MKs).Zebrafish thrombocytes are small nucleated round cells.Although their morphology is different,their development processes and functions are conserved.When an injury happens,platelets are recruited to the site of injury and activated.Platelets,together with thrombin,convert the soluble fibrin into insoluble fibrin clot which can format the fibrin mesh and strengthens the thrombus.Therefore,the normal development and function of platelets play an important role in normal hemostasis and injury repair.The development and differentiation of platelets are strictly regulated by transcription factors and cytokines.Thrombopoietin TPO and its receptor MPL are the main pathways regulating platelet differentiation and maturation.Defects in platelet development can lead to thrombocytopenia related diseases,such as congenital thrombocytopenia without megakaryocytes.The cause of CAMT is a mutation of MPL,and the only treatment is bone marrow transplantation.Other hereditary thrombocytopenia is also caused by mutations in genes related to megakaryocyte development and is primarily treated with oral thrombopoietin receptor agonists and clinical platelet transfusion.Therefore,it is of great clinical significance to screen and develop therapeutic drugs for thrombocytopenia.The specific features of zebrafish including high fecundity,fertilization,and the embryo transparency make it a great tool for high throughput screening.Taking advantage of the mpl mutant modeling CAMT and Tg(mpl:eGFP),we are looking for some drugs with significant effects on the number of thrombocytes.Moreover,new chemical regulators and molecular mechanisms of thrombocyte development in zebrafish will be found.Through the screening of 560 compounds,we obtained three drugs that can significantly increase the thrombocyte numbers in mpl mutant zebrafish.We found that the drug 102PG could increase the zebrafish thrombocytes specifically,with little effect on other zebrafish definitive hematopoiesis lineages.Drug 102PG can enhance the proliferation of cd41 labeled thrombocytes and thrombocytes progenitor cells at 2.5 dpf.Moreover,we found the molecular mechanism of the drug 102PG on thrombocytes is dependent on jak2a gene.We systematically studied the effects of drug 102PG on thrombocytes development in zebrafish,as well as the cytological and molecular mechanisms.we provide insights for the discover of therapeutic drugs for thrombocytopenia like CAMT,and the new clinical usages of 102PG.we also provided ideas for the discovery of new mechanism of thrombocytes development and pathological mechanism of diseases.