[Placenta-derived mesenchymal stem cells with HLA-G positive expression induce Treg in vitro].

OBJECTIVE: To study placenta-derived mesenchymal stem cells with HLA-G (Human Leukocyte Antigen, HLA-G) positive expression induce Treg (regulatory T cell, Treg) in vitro. METHODS: placenta-derived mesenchymal stem cells were separated from neonatal placenta; PEGFP - N1 -HLA-G plasmid was transfected in placenta-derived mesenchymal stem cells by liposome transfection.The cells were divided into 3 groups including control group, PEGFP-N1 group and PEGFP-N1-HLA-G group, 5 complex walls in each group. Expression of HLA-G protein was detected by Western Blotting; after identification of cells, healthy human peripheral blood CD4+ T lymphocytes were cultured with placenta-derived mesenchymal stem cells with HLA-G positive expression, and the ratio of CD4+CD25+Foxp3+Treg in T lymphocytes was accounted. RESULTS: After transfection of PEGFP-N1-HLA-G, the placenta-derived mesenchymal stem cells can express HLA-G protein significantly, compared with the control group and PEGFP - N1 group (P<0.01). After HLA-G positive placenta-derived mesenchymal stem cells and CD4 + T lymphocytes were cultured for 24 h, the ratio of CD4+CD25+Foxp3+Treg in T lymphocytes was (16.41±0.94)%. After HLA - G positive placenta-derived mesenchymal stem cells and CD4+ T lymphocytes were cultured for 48 h, the ratio of CD4+CD25+Foxp3+Treg in T lymphocytes was (16.46±0.59)% significantly, compared with the control group and PEGFP - N1 group (P<0.01). CONCLUSIONS: Placenta-derived mesenchymal stem cells modified by HLA-G gene can effectively induce CD4+CD25+Foxp3+Treg in vitro.

[Effect of antagonism of glutamate receptors in the PVN region on baroreflex in conscious rats].

AIM: To investigate the possible involvement of glutamate(Glu) in the paraventricular nucleus (PVN) in the central regulation of baroreflex. METHODS: The baroreflex was induced by intravenous injection of phenylephrine in conscious rats, and the extracellular concentration of Glu in the PVN region was measured by microdialysis and high performance liquid chromatography (HPLC) techniques. To determine whether the observed Glu release was involved in the baroreflex, NMDA and non-NMDA receptor antagonists, MK-801 and CNQX, were perfused in the PVN region during baroreflex. RESULTS: During baroreflex, the Glu concentration in the PVN region immediately increased to 384.82% +/- 91.77% of basal level (P < 0.01). (2) During baroreflex, direct perfusion of MK-801 and CNQX in the PVN were attenuated the increase of blood pressure and enhanced the decrease of HR (P < 0.01),resulting a significant increase in baroreflex sensitivity (P < 0.01). CONCLUSION: Glutamate in PVN is involved in central regulation of baroreflex, which may inhibit baroreflex via ionothopic glutamate receptors.