黄芪当归合剂对大鼠肾间质纤维化的影响及机制探讨

目的探讨黄芪当归合剂（A＆A）对肾间质纤维化模型大鼠的影响并探讨其可能的作用机制。方法采用单侧输尿管结扎（UUO）致大鼠肾间质纤维化模型。将大鼠随机分为3组：假手术组、模型组、黄芪当归合剂治疗组。手术后第9d处死各组大鼠,分别经免疫组化方法观察各组大鼠肾组织的血小板源性生长因子-B（PDGF-B）的表达部位、表达水平及铲平滑肌肌动蛋白（α-SMA）、增殖细胞核抗原（PCNA）的表达情况。Masson染色评定各组肾小管间质损害程度。结果模型组PDGF-B、α-SMA、PCNA的表达及肾小管间质损伤指数明显高于假手术组（P〈0．05）,而黄芪当归合剂组均明显低于模型组（P〈0．05）。各项指标作相关分析PDGF-B与肾小管间质损伤指数（r=0．870,P〈0．01）、α-SMA（r=0．956,P〈0．01）、PCNA（r=0．881,P〈0．01）呈显著正相关。结论黄芪当归合剂可能通过下调PDGF-B的表达减轻肾小管间质纤雏化。     

SiO2对大鼠肺泡巨噬细胞原癌基因c-sis表达影响的体外研究

目的　探讨SiO2 对大鼠肺泡巨噬细胞原癌基因c sis表达的影响以期进一步了解原癌基因c sis在矽肺发病中的作用。方法　采用支气管肺泡灌洗方法获得肺泡巨噬细胞 (alveolarmacrophage ,AM)。体外予SiO2 对AM进行不同时间的处理 ,利用RT PCR方法检测c sismRNA表达 ,结果用计算机自动分析系统进行定量分析。结果　AM中c sis在SiO2 处理后存在高表达 ,处理时间不同其表达量也不同 ,3 0min即有表达 ,1h表达达高峰 ,以后随处理时间的延长表达量逐渐下降 ,各时间点结果与不加SiO2 处理的同期对照组相比差异均有显著性 (P <0 0 1)。结论　SiO2 可诱导AM原癌基因c sis出现高表达 ,提示原癌基因c sis可能参与矽肺纤维化早期的形成。     

转染PDGF-B mRNA的反义寡肽核酸抑制狗冠状动脉搭桥术吻合口再狭窄

目的探讨PDGF-B mRNA反义寡肽核酸对冠状动脉搭桥术吻合口再狭窄的影响。方法建立狗冠状动脉搭桥吻合口再狭窄模型;用合成的反义寡PNA以外科涤纶线携带并辅助治疗性超声波转导吻合口局部血管平滑肌细胞;分别用原位分子杂交和LSAB免疫组织化学法检测PDGF-B mRNA和PCNA表达;用形态测量法检测吻合口局部冠状动脉内膜厚度和面积。结果PNA显著抑制术后第4周吻合口局部冠状动脉内膜vSMCs表达PCNA和PDGF-B mRNA,与对照组相比抑制率分别为75.37%和71.64%;显著减少血管内膜厚度和面积。结论合成的反义寡PNA可部分抑制狗冠状动脉搭桥术吻合口再狭窄。     

Pro-fibrogenic potential of PDGF-D in liver fibrosis

BACKGROUND/AIMS: We analyzed the expression of platelet-derived growth factor D (PDGF-D) in an experimental bile duct-ligated (BDL) rat model and assessed its biological function in cultured hepatic stellate cells (HSC) and myofibroblasts (MFB). METHODS: The mRNA for PDGF-A, -B, -C, -D and for PDGF receptor-alpha and -beta chains (PDGFRalpha and PDGFRbeta) in normal and fibrotic rat livers was assessed quantitatively. Protein levels of PDGF-D were quantified by immunoblotting and immunohistochemistry. RESULTS: The relative mRNA expression of all PDGF isoforms and receptors upregulated upon BDL and PDGF-A, -B and -D expression was significantly higher than that of PDGF-C. PDGF-D and PDGFRbeta protein also increased markedly. Immunostaining revealed that PDGF-D is localized along the fibrotic septa of the periportal- and perisinusoidal areas. Besides PDGF-B, PDGF-D is the second most potent PDGF isoform in PDGFRbeta signaling within HSC/MFB, evidenced by PDGFRbeta autophosphorylation and activation of the downstream signaling molecules ERK1/2-, JNK-, p38 MAPK, and PKB/Akt while PDGF-C effects were minimal. PDGF-D exerted mitogenic and fibrogenic effects in both cultured HSC and MFB comparable to PDGF-B but PDGF-A and -C showed only marginal fibrogenic effects. CONCLUSIONS: PDGF-D possesses potential pathogenetic properties for HSC activation and matrix remodeling in liver fibrosis.     

Regulation of PDGF and PDGF receptor in cultured dermal papilla cells and follicular keratinocytes of the human hair follicle

Platelet-derived growth factor (PDGF) is a potent mitogenic factor for many cell types and has been shown to be important in follicular development and vasculogenesis. In this study, we examined the expression pattern of both PDGF factors and their corresponding receptors in mesenchyme-derived dermal papilla cells (DPCs) and epithelial follicular keratinocytes (FKs). Both types of PDGF receptors are expressed in FKs, whereas DPCs only express PDGF receptor beta on the protein level, a finding also seen in whole organ cultures. By examining the expression of PDGF ligands, we were able to show that cultured FKs synthesize both PDGF-A and PDGF-B, whereas, DPCs only express PDGF-A. As immunomodulatory cytokines were shown to affect hair growth, we investigated the effects of IL-1beta, IL-4, TNF-alpha, TGF-beta and IFN-gamma on the expression levels of PDGF factors in cultured DPCs and FKs. Interestingly, we could show a significant down-regulatory effect by catagen-inducing cytokines like IL-1beta or IFN-gamma, suggesting a possible involvement of PDGF signaling in the induction of catagen. The question concerning the latter hypothesis remains to be elucidated in further studies on whole organ cultures.     

血管紧张素Ⅱ对人内皮细胞转录因子NF-κB的激活机制及其对PDGF-B基因转录的影响

目的　研究血管紧张素Ⅱ对ECV304细胞中转录因子NF-κB的作用和对PDGF-B 基因表达的影响.方法　采用电泳迁移率移动分析法(EMSA)和免疫组化方法,包括共聚焦显微镜及金颗粒标记免疫电镜技术；荧光素酶报告基因与变异型激酶质粒共转染的方法及Northern 印迹法研究血管紧张素Ⅱ激活NF-κB的信号传递路径和检测了血管紧张素Ⅱ刺激前后PDGF-B mRNA的表达水平.结果　血管紧张素Ⅱ刺激后,在ECV304细胞内有NF-κB的激活及核易位过程,应用免疫荧光共聚焦显微镜,免疫电镜及Northern 印迹等方法均可观察到PDGF-B或其基因表达增高.变异型激酶质粒IKKα-KM,IKKβ-KM 及 NIK-KM 可抑制经AngⅡ刺激的转染细胞内与NF-κB启动相连的荧光素酶的表达.结论　AngⅡ可激活胞浆内NF-κB并出现核易位,激酶NIK、IKKα和IKKβ参与了此信号传递路径.血管紧张素Ⅱ刺激后PDGF-B链mRNA水平增高.     

EGR-1基因转染对环境中小鼠肾小球系膜细胞TGF-β及PDGF-B表达的影响

目的:观察EGR-1基因转染对高糖环境中小鼠肾小球系膜细胞TGF-β及PDGF-B表达的影响,探讨EGR-1在糖尿病肾病发病机制中的作用。方法:高糖环境中培养小鼠肾小球系膜细胞,采用LipofectamineTM2000瞬时转染EGR-1质粒,于培养12、24、48小时末,应用MTT法检测细胞增殖程度,免疫细胞化学和Western印迹法检测系膜细胞EGR-1、TGF-β及PDGF-B蛋白表达水平,酶联免疫吸附法(ELISA)检测细胞培养上清Ⅳ型胶原浓度。结果:高糖环境中肾小球系膜细胞EGR-1、TGF-β及PDGF-B表达增强,细胞增殖明显,细胞上清液中Ⅳ型胶原浓度升高,EGR-1基因转染后上述变化较高糖组更加显著。结论:EGR-1可上调TGF-β及PDGF-B表达,促进系膜细胞增殖及系膜外基质积聚,是加速肾小球硬化的可能机制之一。     

LHT7, a chemically modified heparin,inhibits multiple stages of angiogenesis by blocking VEGF,FGF2 and PDGF-B signaling pathways

Despite the therapeutic benefits of the angiogenesis inhibitors shown in the clinics, they have encountered an unexpected limitation by the occurrence of acquired resistance. Although the mechanism of the resistance is not clear so far, the upregulation of alternative angiogenic pathways and stabilization of endothelium by mural cells were reported to be responsible. Therefore, blocking multiple angiogenic pathways that are crucial in tumor angiogenesis has been highlighted to overcome such limitations. To develop an angiogenesis inhibitor that could block multiple angiogenic factors, heparin is an excellent lead compound since wide array of angiogenic factors are heparin-binding proteins. In previous study, we reported a heparin-derived angiogenesis inhibitor, LHT7, as a potent angiogenesis inhibitor and showed that it blocked VEGF signaling pathway. Here we show that LHT7 could block the fibroblast growth factor 2 (FGF2) and platelet-derived growth factor B (PDGF-B) in addition to VEGF. Simultaneous blockade of these angiogenic factors resulted in inhibition of multiple stages of the angiogenic process, including initial angiogenic response to maturation of the endothelium by pericyte coverage in vitro. In addition, the treatment of LHT7 in vivo did not show any sign of vascular normalization and directly led to decreased blood perfusion throughout the tumor. Our findings show that LHT7 could effectively inhibit tumor angiogenesis by blocking multiple stages of the angiogenesis, and could potentially be used to overcome the resistance.     

益气活血汤抑制实验兔PDGF表达和血管平滑肌细胞表型转变的研究

目的:观察益气活血汤对高脂饲料喂养的实验兔机械损伤后血管平滑肌细胞(VSMC)表型转变和血小板衍生生长因子-B(PDGF-B)表达的研究。方法:将32只健康新西兰大耳白兔随机分为4组:正常对照组(A)、模型组(B)、西药组(C)和中药组(D),分别给予普通饲料、高脂饲料、高脂饲料加来适可胶囊和高脂饲料加益气活血汤灌胃喂饲。实验第5周,B、C、D组均行右侧腹-髂动脉内膜球囊损伤术。7周末采取球囊损伤血管以及正常组相对应部位血管在透射电镜下进行病理形态学观察并用逆转录-聚合酶链反应方法观察PDGF-B的表达。结果:PDGF-B模型组表达量高于中药组及西药组(P<0.05)。模型组家兔血管平滑肌细胞表型由收缩型转变为合成型。结论:动脉损伤后PDGF表达增加,益气活血汤组家兔PDGF表达与模型组比较明显减少,提示益气活血汤对PDGF表达一定抑制作用。模型组血管平滑肌细胞由收缩型转变为合成型,而益气活血汤组家兔表型转变不明显,提示益气活血汤可能通过影响PDGF表达影响平滑肌细胞表型转变。