Publications (2)2.7 Total impact
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ABSTRACT: Investigation of the response of mesenchymal stem cells (MSCs) to vascular mechanical forces is very important in the field of cardiovascular intervention. Ser/Thr-protein kinase Pim-1 is a novel transducer of cell survival and the cell cycle that promotes signals in the hematopoietic cell system. Current studies aim to foster an understanding of Pim-1 expression and regulation in MSCs in response to different durations and strengths of laminar shear stress (SS) and to investigate the role of Pim-1 in SS-induced cell proliferation. A parallel-plate flow chamber was used to control the strength and duration of SS. Proliferation was measured with the BrdU cell proliferation assay. The expressions of Pim-1 mRNA and protein were evaluated by reverse transcription-polymerase chain reaction and western blotting, respectively. RNA interference was used to knock down the Pim-1 gene. The results showed that SS up-regulation of Pim-1 mRNA and protein was time-dependent. Pim-1 induction was SS strength-dependent, and the expression level reached a maximum at 30 dynes/cm(2). Inhibitors of p38MAPK and ERK attenuated the SS-induced expression of Pim-1. In addition, SS significantly increased BrdU-uptake, which was effectively blocked by the silencing of Pim-1. These results demonstrated that Pim-1 is expressed in MSCs and plays an important role in the SS-induced proliferation of MSCs.
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ABSTRACT: To investigate the effect of human angiotensin II (AngII) type 1 receptor (AT(1)R) antisense cDNA (ahAT(1)) on migration, proliferation, and apoptosis of cultured human pulmonary artery smooth muscle cells (PASMC). Two recombinant adenoviral vectors, AdCMVahAT(1) containing full length antisense cDNA targeting to human AT(1)R mRNA, and AdCMVLacZ containing LacZ, were constructed by orientation clone technology and homologous recombination. The PASMC was divided into 3 groups (DMEM, AdCMVLacZ, AdCMVahAT(1)) and different interventions were given to different groups. AT(1)R expression was detected by RT-PCR and immunohistochemistry method; migration of PASMC was measured by Boyden's Chamer method. Other PASMC was divided into 4 groups (DMEM, AngII, AdCMVLacZ + AngII and AdCMVahAT(1) + AngII), and only the last 2 groups were respectively transfected with AdCMVLacZ and AdCMVahAT(1) before administration of AngII. From 6 h to 96 h after stimulation by AngII (10(-7) mol/L), proliferation index (PI) and apoptosis of PASMC were determined by flow cytometry. At the 48 h the level of AT(1)R mRNA was significantly less in PASMC transfected AdCMVahAT(1) than that in group DMEM and in group AdCMVLacZ. The protein level showed a same difference (P < 0.01). At 24 h the migration distance of PASMC also was significantly less in group AdCMVahAT(1) than that in group DMEM and Group AdCMVLacZ (P < 0.01). Stimulated by AngII for 48 h, in group AngII the PI of PASMC markedly increased (P < 0.01 vs group DMEM). But in Group AdCMVahAT(1) + AngII PI of PASMC clearly decreased (P < 0.01 vs group AngII and group DMEM respectively). There was no statistic difference of PI between group AdCMVLacZ + AngII and group AngII. Moreover, apoptosis peak emerged only in group AdCMVahAT(1) + AngII. The rate of apoptosis in those PASMC used AdCMVahAT(1) and AngII was 24.70 +/- 4.04 (P < 0.01 vs the other 3 groups respectively). These results indicate that AngII stimulates proliferation via AT(1) receptors in human PASMC, and antisense cDNA targeting to human AT(1)R transfection mediated by adenoviral vector has powerful inhibitory effects on AngII-induced migration and proliferation of human PASMC by attenuating AT(1)R mRNA and protein expression. Also, it can promote apoptosis of human PASMC. That demonstrate that AT(1)R antisense cDNA is a potent inhibitors of the actions of AngII on PASMC. Antisense inhibition targeting to AT(1)R has therapeutic potential for the treatment of pulmonary vascular diseases.