Vascular diseases such as atherosclerosis are characterized by abnormal accumulation of vascular smooth muscle cells (VSMCs) within the intimal lining. The intimal VSMCs exhibit an increased expression of peroxisome proliferator-activated receptor (PPAR), and the administration of pharmacological PPAR agonists attenuates vascular lesion formation. The factors that regulate PPAR expression in the vasculature are poorly defined. Here we report that platelet-derived growth factor (PDGF) upregulates PPAR by the phosphatidylinositol 3-kinase (PI3-kinase)/Akt signaling pathway. Using Northern-blotting and Western-blotting analyses, we observed that the levels of PPAR mRNA and protein were increased by 2-to 3.5-fold in human aortic smooth muscle cells (HASMCs) treated with PDGF (20ng/mL). This was abolished by preincubation of HASMCs with a PI3-kinase inhibitor (LY294002, 50mol/L), and partially inhibited by a MEK1 inhibitor (U0126, 10mol/L), but not affected by a p38 kinase inhibitor (SB202190, 10mol/L). In addition, overexpression of the dominant-negative p85 subunit of PI3-kinase or Akt proteins blocked the PDGF-induced PPAR expression. Taken together, our results suggest that PDGF induces PPAR expression in VSMCs by a PI3-kinase/Akt signaling pathway. The characterization of factors and signaling pathways that modulate PPAR expression in VSMCs may have important implications for understanding the pathogenesis of vascular diseases.

Although peroxisome proliferator-activated receptor (PPAR) is widely expressed in many tissues, the role of PPAR is poorly understood. In this study, we report that PPAR was up-regulated in vascular smooth muscle cells (VSMC) during vascular lesion formation. By using Northern blot analysis, we demonstrated that PPAR was increased by 3-4-fold in VSMC treated with platelet-derived growth factor (PDGF) (20ng/ml). In addition, PDGF-induced PPAR mRNA expression neither needs de novo protein synthesis nor affects the stability of PPAR mRNA in VSMC. Preincubation of VSMC with phosphatidylinositol 3-kinase inhibitor (LY294002, 50mol/liter) or infection of VSMC with an adenovirus carrying the gene for a dominant negative form of Akt abrogated PDGF-induced PPAR mRNA expression, suggesting that phosphatidylinositol 3-kinase/Akt signaling pathway is involved in the regulation of PDGFinduced PPAR mRNA expression in VSMC. To explore the role of PPAR in VSMC, we generated rat vascular smooth muscle cells (A7r5) stably overexpressing PPAR and the control green fluorescent protein. Overexpression of PPAR in VSMC increased post-confluent cell proliferation by increasing the cyclin A and CDK2 as well as decreasing p57kip2. Taken together, the results suggest that PPAR plays an important role in the pathology of diseases associated with VSMC proliferation, such as primary atherosclerosis and restenosis.

目的 观察人间质胶原酶（MMPl）基因高效表达对体外肝纤维化的影响。方法 利用DNA重组技术构建了pcDNA3-MMPl真核表达重组质粒。经脂质体包裹后，转染张氏传代人肝细胞，Westem blot检测MMPl蛋白表达量。在体外乙醇诱导纤维化培养条件下，抗生蛋白链菌素一生物索复合物标志（ISAB）免疫组织化学法检测肝细胞周围Ⅰ、Ⅲ型胶原生成状况，图象分析仪半定量分析胶原纤维的相对含量（RCC）。结果 成功构建真核表达质粒pcDNA3-MMPl，检测Rcc显示未转染组为132.6±5.7，转染组为118.8±4.8；统计学分析表明未转染组明显高于转染组（P<O.01）。结论 本研究证明重组质粒pcDNA3-MMPl能在体外致纤维化培养条件下拮抗肝细胞间质过多胶原产生。

目的：通过观察IFN-alb对肝星状细胞（HSC）形态和表达CIGF的影响，探讨IFN-alb在治疗纤维化中的作用机制。方法：采用体外培养大鼠肝星状细胞，分别加入IFN-alb、TGF-β1，观察肝星状细胞的形态学及CTGF表达的改变。结果：透射电镜观察到IFN-alb作用组肝星状细胞有明显的凋亡现象发生；RT-PCR观察到正常组和1GF-β1诱导肝星状细胞表达的CTGF mRNA随IFN-alb的作用而减少。结论：IFN-alb对肝星状细胞表达CT-GF的抑制作用机制可能是通过诱导肝星状细胞凋亡和抑制TGF-β1诱导肝星状细胞表达CTGF。

目的 观察3种半离体体外肝手术方式对肝脏缺血再灌注损伤的影响。方法 SD大鼠随机分为对照组（A组）、单纯离断肝下下腔静脉手术组（B组）、单纯离断肝上下腔静脉手术组（C组）和联合离断肝上、肝下下腔静脉手术组（D组），每组各10只，手术后4、24h分组收集血清和肝组织，分别进行血清谷丙转氨酶（ALT）监测、病理切片、免疫组织化学和逆转录-聚合酶链反应（RT-PCR）检测。结果 ALT随各组手术复杂程度和再灌注时间的增加而升高；病理切片见各手术组肝脏炎症反应随手术复杂程度和再灌注时间的增加而有所加重；B组术后4和24h肝组织中过氧化物酶体增殖激活受体（PPAR）α的表达无明显变化，但术后24h原癌基因B淋巴瘤-xL（bclxL）的表达最强；C、D组肝组织术后4hPPARα和bcl-xL的表达增加，术后24hPPARα的表达明显强于4h组，而bcl-xL的表达较4h明显下降。结论 PPARα和bcl-xL参与体外肝手术后肝组织缺血再灌注损伤，两者的表达在一定程度上反应了肝细胞受损的程度。B组手术方式简单、对肝脏的损伤较小；C、D两组手术复杂，对肝组织的再灌注损伤较重。

目的 评价改良全肝血流阻断法在肝切除术中的安全性及应用价值。方法 回归分析近年11例常规方法不能切除的中央型肝肿瘤病例，采用全肝血流阻断法，2例同时利用静脉一静脉转流方法，1例利用体外循环静脉转流技术。结果 1例术中不能耐受全肝血流阻断术中死亡，其余10例顺利切除肿瘤，手术时间327.3±117.8min，3例术后出现右胸积液，1例心房纤颤。结论 全肝血流阻断方法对减少术中出血无优势，且术后并发症发生率高，宜仅选择性应用于肿瘤侵犯肝静脉主干、腔静脉或伴有腔静脉癌栓者。