Construction and assessment of short-hairpin RNA eukaryotic expression vector targeting TGF-beta1 labeled by GFP / 中国应用生理学杂志

<p><b>AIM</b>To construct short hairpin RNA (shRNA) eukaryotic expression vectors targeting TGF-beta1 for further research on the effects of TGF-beta1 on vasculogenesis and angiogenesis.</p><p><b>METHODS</b>Three pairs of siRNA target sequences coding from the mRNA of TGF-beta1 gene were designed and three pairs of nucleotides were synthesized. After annealing, the double-strand DNA products were ligated into the pEN_mH1c entry vector, and in turn into the shRNA eukaryotic expression vector pDS_hpEy labled by GFP through the LR recombination reaction. After sequencing successfully, the three resulting TGF-beta1 shRNA expression vectors were transfected into the mouse fibroblast cell line (NIH/3T3), and then cell clones stably expressing TGF-beta1 shRNA were screened. Reverse Transcript-Polymerase Chain Reaction (RT-PCR) and Western blot were used to detect the mRNA and protein expression.</p><p><b>RESULTS</b>RT-PCR and Western blot showed that one of the TGF-beta1 shRNA expression vectors pDS_Tc downregulated TGF-pl mRNA and protein expression markedly in NIH/3T3 cells.</p><p><b>CONCLUSION</b>ShRNA eukaryotic expression vectors targeting TGF-beta1 are successfully constructed which can be used for further investigation on the mechanism through which TGF-beta1 regulates vasculogenesis and angiogenesis.</p>

Expression of vascular smooth muscle cell markers during early stage of embryonic stem cell-derived embryoid bodies differentiation / 中国应用生理学杂志

<p><b>AIM</b>To observe expression regularity of SMalpha-actin, SM22alpha, myocardin and SMMHC during early embryonic vascular development, and to initially investigate the differentiation effect of platelet derived growth factor-BB (PDGF-BB) on vascular smooth muscle cells (VSMCs) during that period.</p><p><b>METHODS</b>Murine embryonic stem cell line expressing the enhanced green fluorescent protein (GFP) under the transcriptional control of the smooth-muscle-specific SM22alpha promoter was used to make embryoid bodies,and to analyze the expression regularity of SMalpha-actin, SM22alpha, myocardin and SMMHC by immunofluorescence stainings, RT-PCR and Western blot. Then AG1296 (PDGF receptor inhibitor) 0 micro-mol/L(control group), 10 micromol/L and 50 micromol/L were used to treat EBs respectively in order to analyze the differences of SMa-actin, SM22alpha, myocardin and SMMHC at gene and protein levels among the three groups.</p><p><b>RESULTS</b>SMalpha-actin, myocardin, SM22alpha and SMMHC expression in EBs were found to begin at day 0 (ESCs), 8, 11, 13 respectively during early embryonic vascular development. There were no clear differences in SMa-actin, SM22alpha, myocardin and SMMHC protein expression and SM22alpha, myocardin and SMMHC mRNA level among the three groups of different concentrations of AG1296.</p><p><b>CONCLUSION</b>A spontaneous VSMCs differentiation occurs during EBs development, SMalpha-actin is the first to be detected,the following are myocardin, SM22a and SMMHC. PDGF-BB may not be indispensable for the regulation of expression of VSMCs markers during early EBs differentiation.</p>

Effect of CagA(+) helicobacter pylori strain on the expression of connexin 43 and cell proliferation in BGC-823 cells / 中南大学学报(医学版)

OBJECTIVE@#To determine the effect of CagA(+) Helicobacter pylori(H.pylori)strain and anti-H.pylori drugs on the expression of connexin 43(Cx43) and cell proliferation of BGC-823 cells in vitro,and to investigate the relation between the changes of Cx43 expression, cell proliferation of BGC-823 cells and CagA(+)H.pylori.@*METHODS@#BGC-823 cells were co-cultured with CagA(+) H.pylori strain(NCTC J99) or CagA(-) H.pylori strain(NCTC 12908)at bacteria/cells ratio of 20:1,100:1 and 500:1 for 24 hours and 48 hours respectively. anti-H.pylori drugs was given in the group co-cultured at bacteria/cells ratio of 100:1 after 16 hours. In the control group, BGC-823 cells were cultured for 24 hours and 48 hours respectively,but without H.pylori or antij H.pylori drugs. Immunocytochemical SABC method and the image analysis of the computer were applied to detect the changes of Cx43 expression in BGC-823 cells. The cell proliferation was examined by methyl tetrazolium (MTT) method.@*RESULTS@#(1)The expression of Cx43 in the control group after cultivation for 48 hours was higher than that for 24 hours (P0.05). Cx43 expression in the groups co-cultured with CagA(-) H.pylori strain at the ratio of 100:1 and 500:1 was lower than that in the control group, and Cx43 expression at the ratio of 500:1 was lower than that at the ratio of 20:1 for 24 hours and 48 hours. Cx43 expression increased after the intervention with anti-H.pylori drugs for 48 hours. (2) In the groups co-cultured with CagA(+)H.pylori strain, the optical density value of MTT indicated that the cell proliferation at the bacteria/cells ratio of 100:1 was higher than that in the control group, but no significant difference was found in other two groups co-cultured for 24 hours. After co-culturing for 48 hours, the cell proliferation at the bacteria/cells ratio of 20:1 and 100:1 was significantly accelerated, while the cell proliferation at 500:1 was inhibited. In the groups co-cultured with CagA(-) H.pylori strain,there was no change in the cell proliferation. Intervention with anti-H.pylori drugs could suppress the cell proliferation.@*CONCLUSION@#CagA(+) H.pylori can down-regulate the expression of Cx43 in BGC-823 cells,which is related to the reaction time and the density of H.pylori. Low density of CagA(+)H.pylori suspensions can accelerate the proliferation of BGC-823 cells, while high density can suppress the cell proliferation. The CagA(-) H.pylori has no effect on the cell proliferation. Intervention with anti-H.pylori drugs can up-regulate the expression of Cx43,and suppress the cell proliferation of BGC-823 cells.

Role of MAPK in the migration of human coronary artery smooth muscle cell into three-dimensional fibrin gel / 中国应用生理学杂志

<p><b>AIM</b>To investigate the role of MAPK in the migration of human coronary artery smooth muscle cells(HCASMC ) into three-dimensional fibrin gels.</p><p><b>METHODS</b>HCASMC were primarily cultured. HCASMC migration was measured with a phase-contrast microscope in the presence or absence of PD98059, SB203580, and SP600125, the inhibitors of ERK, p38, and JNK, respectively. Phosphorylation of ERK, p38 and JNK were analyzed by Western blotting in the presence or absence of PD98059, SB203580 or SP600125.</p><p><b>RESULTS</b>HCASMC that migrated into the three-dimensional fibrin gel exhibited a characteristic elongated spindle-shaped appearance and formed vessel-like structure. The number of migrated HCASMC increased with incubation time and concentration of fibrinogen in the range between 0.8 g/L and 6.4 g/L. Western blot showed that fibrin induced phosphorylation of ERK, p38 and JNK time dependently and PD98059, SB203580 and SP600125 could inhibit their activation, respectively. Migration of HCASMC into the fibrin gels was inhibited by SP600125 20 micromol/L and SB203580 10 micromol/L, respectively. Furthermore, inhibition of SP600125 20 micromol/L had a more profound effect. PD98059 50 ,mol/L, however, failed to influence migration of HCASMC. Hence, migration of HCASMC into the fibrin gels is JNK- and p38-dependent, but not ERK-dependent.</p><p><b>CONCLUSION</b>Fibrin gel induces HCASMC migration into itself by activation of JNK and p38, but not ERK, which may play an important role in pathogenesis of atherothrombosis and restenosis.</p>