This study was aimed to investigate the expression of neuropilin-1 (NRP-1) and NRP-2 mRNA in myeloid leukemia cells and the effect of NRP-1 on cell proliferation and migration. The expressions of NRP-1 and NRP-2 mRNA in bone marrow mononuclear cells of 24 patients with acute myeloid leukemia and in 7 myeloid leukemic cell lines (HL-60, KGIa, NB4, U937, HEL MEG01 and K562) were detected by RT-PCR. The effects of NRP-1 interfered with siRNA on proliferation and migration in leukemic cell line HEL were examined by MTT and migration test. The results showed that the expression of NRP-1 mRNA was found in bone marrow mononuclear cells (BMMNCS) of 24 AML patients, the positive rate was 100% and significantly higher than that in control group (positive rate 67%). The expressions of NRP-2 mRNA were seen in 79% AML patients and in 67% health control, there was no significant difference between them. The increased NRP-1 expression was directly correlated with the blast percentage in both peripheral blood and bone marrow of AML patients (r=05, r=0.4, p<0.05). The expressions of NRP-1 and NRP-2 mRNA were observed in 6/7 and 3/7 myeloid leukemic cell lines respectively. After HEL cells were transfected with siRNA for 24 hours, the expression levels of NRP-1 mRNA and protein decreased obviously. Under VEGF action, the cell number in control group significantly increased, while the cell proliferation in interfered group had been not changed. After being transfected for 24 hours, the migration in interfered group decreased significantly. It is concluded that the higher level of NRP-1 mRNA is expressed in bone marrow mononuclear cells of leukemia patients and plays a pivotal role in proliferation and migration of myeloid leukemic cells. Inhibition of NRP-1 functions may provide a new therapeutic strategy for AML.
Adolescent ; Adult ; Aged ; Cell Movement ; Cell Proliferation ; Child ; Female ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Male ; Middle Aged ; Neuropilin-1 ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; pharmacology ; Tumor Cells, Cultured ; Young Adult

OBJECTIVEThe purpose of the present study was to observe the changes in CD4+CD25+Nrp1+Treg cells after irradiation with different doses and explore the possible molecular mechanisms involved.

METHODSICR mice and mouse lymphoma cell line (EL-4 cells) was used. The expressions of CD4, CD25, Nrp1, calcineurin and PKC-α were detected by flow cytometry. The expressions of TGF-β1, IL-10, PKA and cAMP were estimated with ELISA.

RESULTSAt 12 h after irradiation, the expression of Nrp1 increased significantly in 4.0 Gy group, compared with sham-irradiation group (P<0.05) in the spleen and thymus, respectively, when ICR mice received whole-body irradiation (WBI). Meanwhile the synthesis of Interleukin 10 (IL-10) and transforming growth factor-β1 (TGF-β1) increased significantly after high dose irradiation (HDR) (> or = 1.0 Gy). In addition, the expression of cAMP and PKA protein increased, while PKC-α, calcineurin decreased at 12h in thymus cells after 4.0 Gy X-irradiation. While TGF-β1 was clearly inhibited when the PLC-PIP2 signal pathway was stimulated or the cAMP-PKA signal pathway was blocked after 4.0 Gy X-irradiation, this did not limit the up-regulation of CD4+CD25+Nrp1+Treg cells after ionizing radiation.

CONCLUSIONThese results indicated that HDR might induce CD4+CD25+Nrp1+Treg cells production and stimulate TGF-β1 secretion by regulating signal molecules in mice.

Animals ; Calcineurin ; genetics ; metabolism ; Cyclic AMP ; metabolism ; Dose-Response Relationship, Radiation ; Female ; Gene Expression Regulation ; radiation effects ; Immunosuppression ; Interleukin-10 ; genetics ; metabolism ; Lymphocyte Subsets ; physiology ; Male ; Mice ; Neuropilin-1 ; genetics ; metabolism ; Phosphoinositide Phospholipase C ; genetics ; metabolism ; Protein Kinases ; genetics ; metabolism ; Signal Transduction ; Transforming Growth Factor beta ; genetics ; metabolism ; Whole-Body Irradiation ; adverse effects

Neuropilin 1 (NP1) is a part of essential receptor complexes mediating both semaphorin3A (SEMA3A) and vascular endothelial growth factor (VEGF) which is one of important mediators involved in the pathogenesis of asthma. Therefore, it is possible that SEMA3A plays a role in the pathogenesis of asthma through attenuation of VEGF-mediated effects. In the present study, we aimed to evaluate expression levels of SEMA3A and NP1 using induced sputum of asthmatics and a murine model of asthma. Firstly, SEMA3A and NP1 expressions in induced sputum of asthmatics and SEMA3A and NP1 expression on bronchoalveolar lavage (BAL) cells and lung homogenates of asthmatic mice were determined. Then we evaluated the immunolocalization of VEGF receptor 1 (VEGFR1), VEGF receptor 2 (VEGFR2), and NP1 expressions on asthmatic mice lung tissue and their subcellular distributions using fibroblast and BEAS2B cell lines. Sputum SEMA3A and NP1 expressions were significantly higher in asthmatics than controls. Similarly, SEMA3A and NP1 expressions on BAL cells and lung homogenates were significantly elevated in asthmatic mice compared to control mice. Immunohistochemical analysis showed that VEGFR1, VEGFR2, and NP1 expressions were also uniformly increased in asthmatic mice. Our observations suggest that SEMA3A and NP1 may play important roles in the pathogenesis of asthma.
Animals ; Asthma/metabolism/pathology/*physiopathology ; Bronchoalveolar Lavage Fluid/cytology ; Cell Line ; Disease Models, Animal ; Female ; Fibroblasts/metabolism ; *Gene Expression Regulation ; Immunohistochemistry ; Lung/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Neuropilin-1/*genetics/metabolism ; Semaphorin-3A/*genetics/metabolism ; Sputum/metabolism ; Vascular Endothelial Growth Factor Receptor-1/metabolism ; Vascular Endothelial Growth Factor Receptor-2/metabolism