Study On The Mechanism Of Interaction Between Megakaryocytes And Polymorphonuclear Neutrophils And The Promotion Of Megakaryocytopoiesis/thrombopoiesis

With the development of exploiting nuclear energy in peace, radiation combined injury may not only occur on wartime nuclear bomb explosion and depleted uranium(DU) weapon impact but also on serious nuclear accident (or radiation leakage )concurring with explosion or fire disaster, medical exposure and possible assault of terrorist dirty bomb. Refractory, obduracy, multiplicity and extensive bleeding is one of pathological features of radiation combined injury and is one of the main reasons for death. More attentions have been paid to the study on myeloid and erythroid lineages after radiation combined injury and more understanding has been obtained when comparing with megakaryocytopoiesis. Some hematopoietic growth factors have been used in clinic to effectively promote the recovery of erythrocytopoiesis and myelopoiesis, but not of thrombopoiesis. In our previous research, the phenomenon of interaction between megakaryocytes and polymorphonuclear neutrophils(PMN) has been found in bone marrow of dogs with acute combined injury such as trauma, burns or impact injury. This invading and phagocytic phenomenon of PMN to megakaryocytes we designated megakaryocytophagia (MP). Megakaryocytophagia, of which the molecule mechanism of is unclear, is one of the causes of thrombocytopenia after injury. In this study we screen bone marrows from different species, with various traumas and diseases for megakaryocytophagia. Primary megakaryocytes (or DAMI cell line) and PMN were isolated from donors with different diseases and co-incubated under different condition in order to establish an in vitro MP model, which was applied to study the character of MP. As confirmed before that dogs injured with lager than 25% TBSAâ…¢degree burns was a typical in vitro model of megakaryocytophagia. On this model, the expression of IL-8, IL-3, nuclear factor GATA-1,Fli-1 and NF-E2 were examined. To counteract thrombocytopenia, for which MP is one the causes, recombinant TPO-mimic peptide (L203) was tested for its efficacy of promoting thrombopoiesis in vivo and in vitro...