Effect of monoamine neurotransmitter on megakaryocytopoiesis and platelet functions / 中国实验血液学杂志

The nervous system directly regulates immunity through neurotransmitter receptors expressed on immune cells to participate in host defense and body reparation. Expression of neurotransmitter receptors on blood cells provides important evidence for a direct functional link between the nervous and hematopoietic systems. Our previous studies showed that 5-hydroxytryptamine, as a monoamine neurotransmitter, plays an important role in regulating megakaryocytopoiesis. This review summarizes recent findings of the effect of monoamine neurotransmitter on megakaryocytopoiesis and platelet function, focusing on the receptor expression on hematopoietic stem cells, megakaryocytes/platelets and their functions in order to explore the intrinsic relation of nervous system and hematopoietic system. Based on the existing research results, we find that the monoamine neurotransmitter participates in regulation of megakaryocytopoiesis, and affects on aggregation and functions activation of platelets. Moreover, it has a close link with the specific regulatory factor of megakaryocytopoiesis-TPO. Thus those results also support the "brain-bone marrow-blood-axis" viewpoint of some researchers. At present, the study of the nervous system regulating hematopoiesis is still in its infancy, the exact mechanism remains to be further studied.

Anti-apoptotic effect of Astragalus Polysaccharide on myeloid cells / 中国实验血液学杂志

This study was aimed to assess the effect of Astragalus Polysaccharide (ASPS) on in-vitro hematopoiesis. CFU-GM assays were used to determine the effect of ASPS and thrombopoietin (TPO) on granulocytic-monocyte progenitor cells. The CFU assays were also used to investigate the effect of ASPS on the proliferation of HL-60 cells.HL-60 cells were cultured with serum-free RPMI 1640 medium and treated with or without of different concentrations of ASPS. After 72 h incubation, the number of cells were counted.In addition, the caspase-3 and JC-1 expression was determined by flow cytometry with Annexin V/PI double staining. The results showed that ASPS (100, 200 µg/ml) and TPO (100 ng/ml) significantly promoted CFU-GM formation in vitro. Various concentrations of ASPS and TPO also promoted the colony formation of HL-60 cells, the largest effect of ASPS was observed at a concentration of 100 µg/ml. There were no synergistic effects between TPO and ASPS on cellular proliferation. The results also showed that ASPS significantly protected HL-60 cells from apoptosis in condition of serum-free medium culture, suppressed caspase 3 activation, and reduced the cell apoptosis. It is concluded that ASPS can significantly promote the formation of bone marrow CFU-GM and the proliferation of HL-60 cells, the optimal concentration of ASPS is at 100 µg/ml. In the absence of serum inducing apoptosis, ASPS also significantly reduced the apoptosis of HL-60 cells via suppressing the activation of caspase-3.