阿托伐他汀对心肌缺血再灌注损伤病人内皮前体细胞及血管功能的保护作用

目的:评价阿托伐他汀对于改善心肌缺血损伤病症的临床疗效,同时对给药前后病人外周血中内皮前体细胞及心肌血管功能的变化进行比较分析,探讨其作用机制。方法:入选急性心肌梗死患者60例,随机分为对照组与观察组。两组患者均行常规PCI术,观察组给予阿托伐他汀药物治疗,对照组给予生理盐水做参照。以患者胸部疼痛症状变化、心电图ST段值、心肌酶峰值变化及再灌注心律失常症状为标准,判断两组患者冠脉再通情况;检测患者肱动脉血流介导的扩张反应(FMD),判断血管内皮功能变化情况;检测患者外周血中内皮前体细胞的含量。结果:阿托伐他汀观察组患者冠脉再通率显著高于对照组,且观察组患者心律失常症状明显少于对照组(P<0.05)。术后给药2、24、48、72h后,观察组患者肱动脉FMD、外周血中内皮前体细胞数目较对照组均显著增加,差异具有统计学意义(P<0.05)。结论:阿托伐他汀给药治疗可以改善心肌缺血再灌注引发的血管功能障碍,其作用机制可能与对内皮前体细胞的调控有关。

Endothelial precursor cells promote angiogenesis in hepatocellular carcinoma

AIM:To investigate the role of bone marrow-derived endothelial progenitor cells(EPCs) in the angiogenesis of hepatocellular carcinoma(HCC).METHODS:The bone marrow of HCC mice was reconstructed by transplanting green fluorescent protein(GFP) + bone marrow cells.The concentration of circulating EPCs was determined by colony-forming assays and fluorescence-activated cell sorting.Serum and tissue levels of vascular endothelial growth factor(VEGF) and colony-stimulating factor(CSF) were quantified by enzyme-linked immunosorbent assay.The distribution of EPCs in tumor and tumor-free tissues was detected by immunohistochemistry and real-time polymerase chain reaction.The incorporation of EPCs into hepatic vessels was examined by immunofluorescence and immunohistochemistry.The proportion of EPCs in vessels was then calculated.RESULTS:The HCC model was successful established.The flow cytometry analysis showed the mean percentage of CD133CD34 and CD133VEGFR2 double positive cells in HCC mice was 0.45% ± 0.16% and 0.20% ± 0.09% respectively.These values are much higher than in the sham-operation group(0.11% ± 0.13%,0.05% ± 0.11%,n = 9) at 14 d after modeling.At 21 d,the mean percentage of circulating CD133CD34 and CD133VEGFR2 cells is 0.23% ± 0.19%,0.25% ± 0.15% in HCC model vs 0.05% ± 0.04%,0.12% ± 0.11% in control.Compared to the transient increase observed in controls,the higher level of circulating EPCs were induced by HCC.In addition,the level of serum VEGF and CSF increased gradually in HCC,reaching its peak 14 d after modeling,then slowly decreased.Consecutive sections stained for the CD133 and CD34 antigens showed that the CD133+ and CD34+ VEGFR2 cells were mostly recruited to HCC tissue and concentrated in tumor microvessels.Under fluorescence microscopy,the bone-marrow(BM)-derived cells labeled with GFP were concentrated in the same area.The relative levels of CD133 and CD34 gene expression were elevated in tumors,around 5.0 and 3.8 times that of the tumor free area.In frozen liver sections from HCC mice,cells co-expressing CD133 and VEGFR2 were identified by immunohistochemical staining using anti-CD133 and VEGFR2 antibodies.In tumor tissue,the double-positive cells were incorporated into vessel walls.In immunofluorescent staining.These CD31 and GFP double positive cells are direct evidence that tumor vascular endothelial cells(VECs) come partly from BM-derived EPCs.The proportion of GFP CD31 double positive VECs(out of all VECs) on day 21 was around 35.3% ± 21.2%.This is much higher than the value recorded on day 7 group(17.1% ± 8.9%).The expression of intercellular adhesion molecule 1,vascular adhesion molecule 1,and VEGF was higher in tumor areas than in tumor-free tissues.CONCLUSION:Mobilized EPCs were found to participate in tumor vasculogenesis of HCC.Inhibiting EPC mobilization or recruitment to tumor tissue may be an efficient strategy for treating HCC.

Bone marrow-originated endothelial progenitor cells contribute to neovasculature of tumor

Objective: Neovascularization of tumor is a complex process. In this study, we aimed to reveal whether the bone marrow-originated endothelial progenitor cells (EPCs) contributed to neovasculature in tumor and the angiogenesis-associ-ated factors, VEGF and B-FGF, enhanced this process. Methods: We had established a mouse model, which were deprived of bone marrow by radiation and transplanted with bone marrow of syngenetic GFP (Green Fluorescence Protein)-transgened mice, then implanted Lewis cells. Immunohistochemical and immunoflourensence proved the EPCs location in tumors by indentifying colocalization of GFP expression in cells staining with endothelial progenitor cell markers, CD 133, ICAM-1, CD31. The growth statue and MVD of tumor was observed after injection of VEGF or B-FGF. ICAM-1 and VE-cadherin in tumor were detected by Western blot. Results: By immunohistochemical and immunoflourensence, we proved part of bone marrow precursors located in area of tumor angiogenesis and VEGF or B-FGF increased the MVD of tumor. In Western blot, it was found and VEGF or B-FGF up-regulate the expression of ICAM-1, VE-Cadherin. Conclusion: Bone marrow-derived endothelial progenitor cell seem to be recruited in neovasculature induced by tumor. VEGF and B-FGF are key regulators of this process.