High-dose estrogen administration induces anemia in mammals. In chickens, estrogens stimulate outgrowth of bone marrow-derived erythroid progenitor cells and delay their maturation. This delay is associated with down-regulation of many erythroid cell-specific genes, including alpha- and beta-globin, band 3, band 4.1, and the erythroid cell-specific histone H5. We show here that estrogens also r...

1. Abstract 2. Introduction 3. Signaling Pathways Involved in Megakaryocyte Maturation 3.1. Thrombopoietin 3.2. TPO-Initiated Signaling in Megakaryocytes 3.3. Phosphatidylinositol 3-kinase 3.4. Mitogen Activated Protein Kinases 3.5. Stromal Cell-Derived Factor 1 3.6. Immediate Early Gene X-1 3.7. The Src Family Kinase; Lyn 4. Transcription Factors Associated with Megakaryopoiesis 4.1. GATA-1 an...

Megakaryocytes lacking transcription factor GATA-1 fail to complete maturation in vivo and hyperproliferate. To define how GATA-1 regulates megakaryocyte cell growth we searched for mRNA transcripts expressed in primary wild-type, but not GATA-1(-), megakaryocytes. One differentially expressed transcript encodes inositol polyphosphate 4-phosphatase type I (4-Ptase I). This enzyme hydrolyses pho...

The cytoplamic junctional proteins cingulin and paracingulin have been implicated in the regulation of gene expression in different cultured cell models. In renal epithelial MDCK cells, depletion of either protein results in a Rho-dependent increase in the expression of claudin-2. Here we examined MDCK cell clones depleted of both cingulin and paracingulin (double-KD cells), and we found that u...

The SCL/TAL-1 gene encodes a basic helix-loop-helix transcription factor that is expressed in multipotent hematopoietic progenitors before lineage commitment. Its expression is maintained during differentiation along erythroid, mast, and megakaryocytic lineages, but is repressed after commitment to nonexpressing lineages. To begin to address the molecular mechanisms underlying this complex patt...

Pulmonary fibrosis is a common delayed side effect of radiation therapy. Since its mechanism is almost unknown, little can be done to prevent or treat it. Th2 cytokines have been clearly implicated as mediators of asthma, and evidence is mounting that type 2 immune responses may also promote the development of pulmonary fibrosis. The aim of this study was to investigate whether Th2-like immune ...

BACKGROUND Asthma is a chronic inflammatory disorder in which Th2, Th1 and suppressive T cells (Tregs) play a role. The transcription factor FoxP3 plays a role in Treg differentiation while T-bet is important for Th1 and GATA-3 for Th2 differentiation from naïve T cells. Recent data show that age-related deregulation of Treg cells is a mechanism of senescence affecting several chronic diseases....

GATA-1, a zinc finger transcription factor, has been believed to be indispensable for the survival of proerythroblasts. However, we found that GATA-1-null proerythroblasts could survive and proliferate on OP9 stroma cells in the presence of erythropoietin. Furthermore, myeloid and mast cells were induced from the GATA-1-null proerythroblasts by the stimulation of granulocyte-macrophage colony-s...

Interplay among GATA transcription factors is an important determinant of cell fate during hematopoiesis. Although GATA-2 regulates hematopoietic stem cell function, mechanisms controlling GATA-2 expression are undefined. Of particular interest is the repression of GATA-2, because sustained GATA-2 expression in hematopoietic stem and progenitor cells alters hematopoiesis. GATA-2 transcription i...