Expression of interleukin (IL) 1 type I and type II receptors in megakaryocytic cells and enhancing effects of IL-1 beta on megakaryocytopoiesis and NF-E2 expression

Megakaryocytopoiesis is regulated by thrombopoietin (TPO) and cytokines suc h as interleukin 3 (IL-3), IL-6 and IL-11. This study investigated the in v itro effects of IL-1 beta on megakaryocytopoiesis and the expression of IL- 1 type I and type II receptors (IL-1 RI and RII) on megakaryocytic cell lin es and primary cells, Our results demonstrated that IL-1 beta alone or in c ombination with TPO induced megakaryocyte colony forming units (CFU-MK) fro m murine and human haematopoietic cells. Using reverse-transcription polyme rase chain reaction (RT-PCR) and Southern hybridization techniques, the mRN A of IL-1 beta, IL-1 RI, IL-1 RII and the transcription factor NF-E2 were d etected in CD61(+)CD41(+) cells cultured from cord blood and four megakaryo cytic cell lines, Meg-01, DAMI, CHRF-288-11 and M-07e. The expression of IL -1 RI and RU: proteins was confirmed by flow cytometry and immunofluorescen ce staining. In Meg-01 cells, the expression of NF-E2 was increased at both mRNA and protein levels after treatment with IL-1 beta for 4 h, This study demonstrated for the first time the presence of IL-1 receptors on megakary ocytic cells and the induction of NF-E2 by IL-1 beta. The mitogenic effect of IL-1 beta on this lineage could be mediated through IL-1 receptors and t he activation of NF-E2.