The aim of our study was to gain insight into the molecular and cellular mechanisms of post-angioplasty restenosis using balloon catheter-induced injury model in the rat carotid artery. SD rats were subjected balloon catheterization at one side carotid artery as study group and another side as control group. Six rats were killed on the 6 h, and 3rd, 7th, 14th, 28th day after balloon-induced injury respectively. The intimal thickness and the expression of NF-κB and I-κB were detected by HE-staining, gel electrophoretic mobility shift assay (EMSA) and Western-blot methods. The results showed that: (1) The thickening of intima was observed on the 3rd day after balloon-induced injury, and it became more significant on the 7th, 14th and 28th day. The area ratio of intima/media was increased significantly (P<0.05); (2) The expression of NF-κB was not detectable in the control group, however, in study group, the expression of NF-κB was detected on the 6th h after balloon-induced injury, reached the peak on the 14th day, and on 28th day, strong expression of NF-κB was observed; (3) The expression of I-κB protein was reduced after balloon-induced injury, and there were significant differences between the study group and the control group (P<0.05). It was concluded that the alteration of NF-κB/I-κB system might play an important role in aberrant proliferation within the intima and vascular remodeling following vascular injury. To block NF-κB activation and its role in arterial restenosis initiation may potentially provide a novel therapeutic tool for the treatment and prevention of arterial restenosis.
To develop a more efficient antithrombotic way after coronary artery bypass grafting (CABG), the anticoagulant effects were compared of human tissue factor pathway inhibitor (TFPI) gene transfection and aspirin oral administration (traditional method) on vein grafts. An eukaryotic expression plasmid pCMV-(Kozak) TFPI was prepared. Animal model of carotid artery bypass grafting was constructed. In operation, endothelial cells of vein grafts in TFPI group and empty plasmid control group were transfected with pCMV-(Kozak) TFPI and empty plasmid pCMV respectively, while no transfection was conducted in aspirin control group. After operation, aspirin (2 mg·kg−1·−1) was administered (i.g.) in aspirin control group. Three days later, grafts (n=10) were harvested for RT-PCR, Western blotting and immunohistochemical analyses of exogenous gene expression and for pathological, scanning electron microscopic observation of thrombus. Thirty days later, the patency rates of remnant grafts (n=10) were recorded by vessel Doppler ultrasonography. Human TFPI gene products were detected in gene transferred vein grafts. Three days later, thrombi were found in 7 animals of aspirin control group and in 8 animals of empty plasmid control group, but in only 1 of TFPI group (P<0.01). Thirty days later, 5 grafts were occluded in empty plasmid control group, but none of grafts was occluded in the other groups (P<0.05). The endothelial surfaces of grafts in both of the control groups were covered with aggregated erythrocytes and platelets, and it were not seen in TFPI group. It was suggested that the anticoagulant effects on vein grafts of human TFPI gene transfection are better than those of aspirin.
In order to screen potential mRNA locations of P gene in which targeting siRNAs can effectively inhibit HBV expression, 5 recombinant plasmids containing 4 targeting-specific siRNA fragments and a control were prepared and transfected into 2.2.15 cells respectively. The expression levels of HBx mRNA, HBs mRNA and HBc mRNA were detected by RT-PCR. The concentrations of the hepatitis B virus antigens, including HBsAg and HBeAg harvested from the culture supernatant of transfected 2.2.15 cells, were measured by ELISA. X protein was tested by Western blot. The results showed that four siRNAs against distinct mRNA locations of HBV polymerse gene had different inhibitory effects on their targeted mRNA. The plasmid-derived psiRNA1 and psiRNA2 could effectively inhibit the transcription and translation of HBs gene, whereas the inhibitory efficiency of psiRNA3, psiRNA4 for HBe gene was much higher than that of psiRNA1 and psiRNA2. In comparison to the rest of psiRNAs in this study, psiRNA4 was the most effective to suppress the transcirption and translation of HBx. It is suggested that siRNA can be considered as a powerful therapeutic agent for reducing HBV expression. The siRNAs against HBV polymerase are effective largely depending on the location of targeted sites. To enhance inhibitory efficiency, hunting for high effective target in polymerase gene is necessary and feasible.
The cytokine repertoire of ADP/ATP carrier-specific humoral immune responses and the cytokine-dependent anti-ADP/ATP carrier antibody IgG subclasses were examined in a cohort of ADP/ATP carrier-immunized BALB/c mice treated with anti-CD4 monoclonal antibody. Eighteen male BALB/c mice (6–8 weeks old) were randomized into 3 groups: dilated cardiomyopathy (DCM) group, DCM-tolerance (Tol) group and control group. The mice in DCM group were immunized with the peptides derived from human ADP/ATP carrier protein for 6 months and mice in the control group were sham-immunized, while the mice in DCM-Tol group were immunized with ADP/ATP carrier protein and anti-CD4 McAb simultaneously. Serum autoantibody against ADP/ATP carrier and IgG subclasses were measured by ELISA, intracellular cytokines IFN-γ and IL-4 of Th cells were monitored with flow cytometry, and splenic T cell cytokines IFN-γ, IL-2, IL-4 and IL-6 were detected by using real-time fluorescent quantitative PCR. The results showed that the autoantibody against ADP/ATP carrier was found in all mice in DCM group, and the antibody level, serum IgG1 and IgG2a subclasses, cytokines in T cells and Th cells were all elevated in DCM group, as compared with those in control group (P<0.01). On the other hand, in DCM-Tol group, the autoantibody level and contents of all the cytokines were significantly different from those in DCM group (P<0.01), and were close to those in control group. And the levels of IgG1, IgG2a, IgG2b and IgG3 were influenced, to varying degrees, by anti-CD4 McAb as compared with those in DCM group. All these four types of IgG subclasses were substantially decreased in DCM-Tol group as compared with DCM group. It is concluded that the treatment with anti-CD4 McAb could prevent the activation of T cells, reverse the abnormal secretion of cytokines and the imbalance between Th1/Th2 cell subsets and abnormal production of autoantibody against ADP/ATP carrier, and eventually avoid myocardial injuries.
The inhibitory effects of parthenolide (PTL) on angiogenesis induced by multiple myeloma (MM) cells in vitro and the mechanism were investigated. Human MM line RPMI8226 cells were cultured in vitro. The effects of MM culture supernatant on the migration and tubule formation ability of human umbilical vein endothelial cells (HUVECs) treated with PTL were observed. By using Western blot, the expression of p65 and IκB-α in MM cells was detected. RT-PCR was used to assay the expression of VEGF, IL-6, MMP2 and MMP9 mRNA in MM cells. ELISA was used to measure the levels of VEGF and IL-6 in MM cell culture supernatant. The expression of MMP2 and MMP9 in MM cells was examined by immunohistochemistry. (1) In 3.5, 5.0, 7.5 and 10 μmol/L PTL groups the number of migrated cells was 310±56, 207±28, 127±21 and 49±10 respectively, which was significantly different from that in positive control group (598±47) (P<0.01). In 3.5 and 5.0 μmol/L PTL groups the areas of capillary-like structures were 0.092±0.003 and 0.063±0.002 mm2, significantly less than in positive control group (0.262±0.012 mm2) (P<0.01), but in 7.5 and 10 μmol/L PTL groups no capillary-like structures were found; (2) After treatment with different concentrations of PTL for 48 h, the expression of p65 protein was gradually decreased, while that of IκB-α was gradually enhanced with the increased concentration of PTL; (3) After treatment with 3.5, 5.0, 7.5 and 10 μmol/L PTL for 48 h, the VEGF levels in the supernatant were 2373.4±392.2, 1982.3±293.3, 1247.0±338.4 and 936.5±168.5 pg/mL respectively, significantly different from those in positive control group (2729±440.0 pg/mL) (P<0.05). After treatment with 7.5 and 10 μmol/L PTL, the IL-6 levels in the culture supernatant were 59.6±2.8 and 41.4±9.8 pg/mL respectively, significantly lower than in positive control group (1287.3±43.5 pg/mL) (P<0.05); (4) RT-PCR revealed that PTL could significantly inhibit the expression of VEGF and IL-6 mRNA in MM cells, but not influence the expression of MMP2 and MMP9 mRNA.; (5) Immunohistochemistry indicated that PTL had no significant effects on the expression of MMP2 and MMP9 protein in MM cells. It was concluded that the abilities of the culture supernatant of MM cells treated with PTL to induce endothelial cells migration and tubule formation were significantly reduced, suggesting PTL could obviously inhibit the angiogenesis induced by MM cells. PTL could decrease NF-kappaB activity and significantly suppress the expression of VEGF and IL-6 mRNA and protein, which might contribute to the mechanism by which PTL inhibited the angiogenesis induced by MM cells.