Up-regulation of transcription factors NF-E2, c-jun and c-fos of AP-1 family induced by Panax Notoginosides in hematopoietic cells / 中国实验血液学杂志

To observe the effects of Panax Notoginosides (PNS) on up-regulation of AP-1 family transcription factors NF-E2, c-jun and c-fos for exploring intracellular signal pathway of PNS in hematopoietic cells, four human hematopoietic cells lines including myeloid HL-60, erythroid K562, megakaryoid CHRF-288 and Meg-01 were incubated in the presence of PNS for 14 days. The nuclear protein of cells were extracted and analyzed by Western blot with antibodies against NF-E2, c-fos and c-jun. Electrophoretic mobility shift assay (EMSA) was performed by using (32)P labeled AP-1 consensus oligonucleotide which contains binding site for NF-E2, c-jun and c-fos. The results showed that the transcription factors NF-E2, c-jun and c-fos of AP-1 family could be induced by PNS. Western blot demonstrated that the nuclear protein of both NF-E2 and c-jun in four cell lines treated by PNS were increased by 1.5-2.5- and 2.0-3.0-fold over untreated cells respectively. The c-fos protein in three cell lines of K562, CHRF-288 and Meg-01 was also elevated by 2.0-3.0-fold respectively, while c-fos protein in HL-60 cells was no detectable difference after PNS treatment. EMSA results in four cell lines indicated that AP-1 binding activity initiated by PNS was apparently elevated to form higher density band of AP-1-DNA complex. In conclusion, the intracellular transcription regulation initiated by PNS was involved in transcription factors NF-E2, c-jun and c-fos of AP-1 family members, which could play an important role in the up-regulation of genes expression related to proliferation and differentiation of hematopoietic cells.

A novel erythroid differentiation related gene EDRF1 upregulating globin gene expression in HEL cells / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To further characterize the differentiation inducing properties of EDRF1 and demonstrate its functional pathway involved in regulation of globin gene expression.</p><p><b>METHODS</b>By transfecting EDRF1 sense and antisense constructs into HEL cells, we identified the expression of globin and erythropoietin receptor genes by Northern blot analysis. RT-PCR and EMSA (electrophoresis mobility shift assay) were performed to monitor the expression and DNA-binding activity of erythroid specific transcription factors GATA-1 and NF-E2.</p><p><b>RESULTS</b>It was shown that when EDRF1 was overexpressed, production of alpha-globin increased. In antisense EDRF1, overexpression of HEL cells, significant loss of alpha-, gamma-globin mRNA synthesis was observed. The transcription of endogenous GATA-1 and NF-E2 mRNA expression were maintained at the same levels compared with control experiments. However, the transcription activity of GATA-1 was severely impaired. Expression of erythropoietin receptor gene was not influenced by EDRF1 gene overexpression.</p><p><b>CONCLUSION</b>The results suggested that EDRF1 regulated alpha- and gamma-globin gene synthesis by modulating DNA-binding activity of GATA-1 transcription factor.</p>

The role of cytokines and transcription factors in megakaryocytopoiesis / 中国实验血液学杂志

The role of cytokines and transcription factors on the regulation of megakaryocy topoiesis and platelet production are reviewed in this article. Megakaryocytopoiesis involves the proliferation and differentiation of megakaryocytic pro genitor cells into immature megakaryocytes, and the differentiation of immature megakaryocytes to mature megakaryocytes which produce platelets. The former is regulated mainly by thrombopoietin (TPO) and to a lesser degree by other cytokines such as interleukin-1 (IL-1), IL-3 and platelet-derived growth factor (PDGF), the later by TPO and probably IL-6 and IL-11. A number of transcription factors have been implicated in the control of megakaryocyte differentiation. GATA-1, FOG-1 and Fli-1 are essential regulators in early- and mid-stages of megakaryocytopoiesis. NF-E2 regulates late-stage of megakaryocytopoiesis and platelet production. However, the platelet release mechanism is poorly understood. Nitric oxide (NO) may act in the stage of platelet release through induction of apoptosis in megakaryocytes.