P85磷酯肌醇-3激酶-蛋白激酶C-ζ复合物对血管紧张素Ⅱ激活平滑肌细胞p70核蛋白体S6激酶的调节作用

作者以前的研究发现蛋白激酶C-ζ介导血管紧张素Ⅱ经Ras-MEK途径激活血管平滑肌细胞丝裂素活化的蛋白激酶MAPK或细胞外信号调节激酶ERK1/2.本文研究了P85磷酯肌醇-3激酶-蛋白激酶C-ζ复合物核蛋白体激酶p70S6激酶活性的调节作用及其信号传递途径. Western Blot分析显示正常培养的血管平滑肌细胞表达p70S6激酶、p85磷酯肌醇-3激酶和蛋白激酶C-ζ.100 nmol血管紧张素Ⅱ和 10 μg/L 血小板源生长因子刺激并不影响p70S6激酶、p85磷酯肌醇-3激酶和蛋白激酶C-ζ表达. p70S6激酶磷酸转移酶活性分析发现血管紧张素Ⅱ与血管平滑肌细胞作用5 min 即开始激活p70S6激酶, 20 min达高峰, 并呈剂量依赖性.磷酯肌醇-3激酶抑制剂wortmannin (10 nmol)、蛋白激酶C-ζ抑制剂Pseudo Z (50 μmol) 和p70S6激酶抑制剂rapamycin (100 μg/L) 均可明显阻断血管紧张素Ⅱ诱导的p70S6激酶激活.有趣的是,我们观察到p85磷酯肌醇-3激酶和蛋白激酶C-ζ受血管紧张素Ⅱ和血小板源生长因子刺激后均向Ras转位并与之结合, 抗Ras抗体可将p85磷酯肌醇-3激酶或蛋白激酶C-ζ混合沉淀, 抗p85磷酯肌醇-3激酶抗体亦可使蛋白激酶C-ζ沉淀下来. 提示Ras、p85磷酯肌醇-3激酶和蛋白激酶C-ζ三种蛋白结合在一起形成一个功能复合体,Wortmannin和Pseudo Z可阻断这个功能复合体的形成.此外,血管紧张素Ⅱ和血小板源生长因子与血管平滑肌细胞孵育24 h 明显促进细胞增殖,氚标胸腺嘧啶脱氧核苷掺入率增加约50%, Wortmannin和非特异性蛋白激酶C抑制剂Chelerythine均抑制血管紧张素Ⅱ和血小板源生长因子对血管平滑肌细胞的促增殖作用.综合上述结果, 说明血管紧张素Ⅱ通过Ras-磷酯肌醇-3激酶-蛋白激酶C-ζ途径激活p70S6激酶和刺激血管平滑肌细胞增殖, p85磷酯肌醇-3激酶-蛋白激酶C-ζ复合物在其中起重要调节作用.     

缬沙坦对血管平滑肌细胞增殖与迁移及丝裂原活化蛋白激酶的影响

目的:观察缬沙坦对血管紧张素Ⅱ(AngⅡ)刺激下大鼠胸主动脉平滑肌细胞(VSMC)的增殖与迁移及磷酸化P42/44丝裂原活化蛋白激酶(MAPK)表达的影响。方法:组织贴块法培养大鼠胸主动脉平滑肌细胞,应用丝裂原活化蛋白激酶(MTT)分析检测细胞的增殖能力,transwell小室检测细胞的迁移能力,Western blot检测磷酸化P42/44MAPK蛋白表达的水平。结果:(1)AngII能明显促进血管平滑肌细胞的增殖与迁移,该作用可被缬沙坦和MAPK激酶的特异性抑制剂PD98059所抑制。(2)AngⅡ刺激血管平滑肌细胞5min时,磷酸化P42/44MAPK的表达量最大,该作用也可被缬沙坦和P     

血管紧张素-(1-7)、血管紧张素Ⅱ和p38丝裂原活化蛋白激酶关系的研究进展

血管紧张素-(1-7)是肾素-血管紧张素系统家族中新发现的终末活性产物,与血管紧张素Ⅱ的多种作用相拮抗;血管紧张素Ⅱ可激活p38丝裂原活化蛋白激酶通路,介导炎症反应.现就血管紧张素-(1-7)、血管紧张素Ⅱ和p38丝裂原活化蛋白激酶信号转导通路的关系进行简要综述.     

人白细胞介素10对血管紧张素Ⅱ诱导的大鼠血管平滑肌细胞增殖的作用

目的观察重组人白介素10 (rhIL-10) 对血管紧张素Ⅱ(AngⅡ)刺激下离体大鼠胸主动脉血管平滑肌细胞增殖及对p44/p42 丝裂素活化蛋白激酶的影响. 方法体外培养大鼠主动脉血管平滑肌细胞,采用MTS/PES(methoxyphenyl-tetrazolium salt/phenazine ethosulfate)法确定血管平滑肌细胞的增殖状态.利用p44/p42磷酸化抗丝裂素活化蛋白激酶抗体的蛋白免疫印迹法测定丝裂素活化蛋白激酶蛋白的表达;对照组为未用AngⅡ刺激的血管平滑肌细胞. 结果 AngⅡ对大鼠血管平滑肌细胞增殖具有明显的刺激作用(1.311±0.201 对 0.781 ±0.236, P<0.05).rhIL-10单独应用对血管平滑肌细胞生长没有影响(0.783±0.170 对 0.781±0.236, P>0.05).在AngⅡ刺激下,1、10、100 ng/ml的rhIL-10均可抑制血管平滑肌细胞的生长 (分别为0.984±0.172、 0.932±0.134、 0.784±0.097对1.311±0.201, P<0.05).AngⅡ对p44/p42 丝裂素活化蛋白激酶蛋白表达有显著的增强作用(512±78对100,P< 0.01), 此作用可被rhIL-10抑制 (512±78对329±59, P< 0.01). 结论 rhIL-10可抑制AngⅡ诱导的血管平滑肌细胞增殖及p44/p42 丝裂素活化蛋白激酶蛋白的表达.     

血管紧张素(1-7)对血管紧张素Ⅱ诱导的人脐静脉内皮细胞血凝素样氧化型低密度脂蛋白受体1表达的影响

目的 观察血管紧张素(1-7)对血管紧张素Ⅱ诱导的人脐静脉内皮细胞血凝素样氧化型低密度脂蛋白受体1表达水平的影响并探讨其可能作用机制.方法 采用胰蛋白酶消化法原代培养人脐静脉内皮细胞,取2～5代用于实验,培养的人脐静脉内皮细胞随机分为对照组、血管紧张素Ⅱ组、血管紧张素(1-7)组、血管紧张素Ⅱ+血管紧张素(1-7)组、血管紧张素Ⅱ+血管紧张素(1-7)+血管紧张素(1-7)特异性受体拮抗剂A-779组,通过半定量逆转录聚合酶链反应和流式细胞术分别检测血凝素样氧化型低密度脂蛋白受体1基因和蛋白表达水平;用免疫印迹法检测p38丝裂原活化蛋白激酶磷酸化的表达水平.结果 血管紧张素Ⅱ(10-6mol/L)可以诱导血凝素样氧化型低密度脂蛋白受体1表达增加(P<0.05),血管紧张素(1-7)(10-9～10-6mol/L)随着浓度的增加抑制血管紧张素Ⅱ诱导的血凝素样氧化型低密度脂蛋白受体1表达水平增强(P<0.05);血管紧张素(1-7)特异性受体拮抗剂A-779可阻断血管紧张素(1-7)的上述效应(P<0.05).与对照组相比,血管紧张素Ⅱ(10-6 mol/L)诱导后p38丝裂原活化蛋白激酶磷酸化表迭水平显著增加(P<0.05);血管紧张素(1-7)(10-9～10-6 mol/L)随着浓度的增加抑制血管紧张素Ⅱ诱导的p38丝裂原活化蛋白激酶磷酸化表达水平增强(P<0.05),血管紧张素(1-7)特异性受体拮抗剂A-779可阻断血管紧张素(1-7)的上述效应(P<0.05).结论 血管紧张素Ⅱ可诱导血凝素样氧化型低密度脂蛋白受体1及p38丝裂原活化蛋白激酶磷酸化表达增加,血管紧张素(1-7)抑制血管紧张素Ⅱ的上述效应,并且是通过其特异性受体发挥作用.     

抗血管紧张素Ⅱ受体1型和α1-肾上腺素受体自身抗体在高血压患者检测结果分析

目的探讨抗血管紧张素Ⅱ受体1型(AT1-受体)和α1-肾上腺素受体自身抗体在高血压发病中的作用.方法收集2级以上高血压病患者194例,给予规范抗高血压联合药物治疗,根据治疗效果,将高血压病患者分为降压达标组和降压未达标组,40例正常血压志愿者作为对照.以合成的抗AT1-受体和α1-肾上腺素受体多肽片段为抗原,酶联免疫吸附法检测血清抗AT1-受体和α1-肾上腺素受体自身抗体.同时检测血浆肾素活性、血管紧张素Ⅱ和儿茶酚胺浓度.结果高血压病组抗AT1-和α1-受体抗体阳性率分别为26.8%(52/194)和 25.3%(49/194),较正常血压组(7.5% 和 5.0%)明显升高(P<0.01).进一步分析表明,降压未达标组抗AT1-受体和α1-肾上腺素受体抗体阳性率分别为42.9%(42/98)和36.7%(36/98),明显高于降压达标组(10.4%和13.5%)(P<0.01).降压未达标组血浆血管紧张素Ⅱ水平、儿茶酚胺水平、蛋白尿和血清肌酐水平等指标亦明显高于降压达标组.结论高血压病患者血清存在抗AT1-受体和α1-肾上腺素受体自身抗体,这些抗体主要在难治性高血压病患者中检出,可能是高血压发病的机制之一.     

缬沙坦对血管平滑肌细胞迁移及丝裂原活化蛋白激酶的影响

目的观察缬沙坦（Val）对血管紧张素Ⅱ（AngⅡ）刺激下大鼠血管平滑肌细胞（VsMC）迁移及磷酸化42／44丝裂原活化蛋白激酶（p42／44MAPK）表达的影响。方法组织贴块法培养大鼠胸主动脉平滑肌细胞,tran-sweⅡ小室检测细胞的迁移能力,免疫印迹法检测p42／44MAPK蛋白表达的水平。结果（1）AngⅡ能明显促进VSMC迁移,该作用可被Val和MAPK激酶的特异性抑制剂PD98059所抑制。（2）AngⅡ刺激VSMC5min时,p42／44MAPK的表达量最大,该作用可被Val和PD98059所抑制。（3）Val单独作用于VSMC时,对细胞的迁移及p42／44MAPK的表达均无明显影响。结论Val抑制AngⅡ诱导的VSMC迁移与其抑制AngⅡ诱导的p42／44MAPK的表达相关。     

血管紧张素Ⅱ对血管内皮细胞骨架的损伤作用

目的探讨血管紧张素Ⅱ对内皮细胞肌动蛋白骨架的影响及其作用机制。方法血管紧张素Ⅱ(10-6mol/L)处理人脐静脉内皮细胞不同时间(0、5、15、30及60 min)。激光共聚焦显微镜下观察细胞纤维状肌动蛋白骨架的形态学变化。Western blotting检测丝裂原活化蛋白激酶磷酸化水平。结果正常组内皮细胞的纤维状肌动蛋白主要富集于细胞膜周边,分布均匀。血管紧张素Ⅱ处理组细胞膜周边的纤维状肌动蛋白消失,胞浆中出现密集的应力纤维,细胞间隙形成,且呈明显的时间依赖性。血管紧张素Ⅱ上调p38丝裂原活化蛋白激酶、c-Jun氨基末端激酶和热休克蛋白27的磷酸化水平,但对细胞外信号调节激酶无明显影响。p38丝裂原活化蛋白激酶特异性抑制剂SB203580阻断血管紧张素Ⅱ引起的纤维状肌动蛋白重排和细胞间隙形成。c-Jun氨基末端激酶特异性抑制剂SP600125则无明显作用。结论血管紧张素Ⅱ通过激活p38丝裂原活化蛋白激酶/热休克蛋白27信号通路引起内皮细胞的纤维状肌动蛋白重排,导致细胞骨架损伤。     

血管紧张素-(1-7)对人脐动脉平滑肌细胞p38MAPK通路的抑制作用

目的 探讨血管紧张素-(1-7)[Ang-(1-7)]阻断血管紧张素Ⅱ(AngⅡ)致炎作用的可能机制.方法 用DMEM培养基培养血管平滑肌细胞(VSMCs),待细胞生长至80％融合时无血清培养12小时后分为两组:Ⅰ组:对照组、AngⅡ组、Ang-(1-7)组、AngⅡ+Ang-(1-7)组、AngⅡ+ Ang-(1-7)+ A-779组、A-779组;Ⅱ组:对照组、AngⅡ组、AngⅡ+不同浓度Ang-(1-7)组.上述两组作用一定时间后收集细胞,用Western blot方法测定细胞p38丝裂原活化蛋白激酶(p38MAPK)蛋白磷酸化表达.结果 Ang-(1-7)(1000 nmol/L)可拮抗AngⅡ(100 nmol/L)诱导的VSMCs p38MAPK磷酸化表达,且呈剂量依赖性,随着Ang-(1-7)剂量的增加,p38MAPK磷酸化表达逐渐减弱.结论 Ang-(1-7)呈剂量依赖性抑制AngⅡ激活人脐动脉平滑肌细胞p38MAPK通路的作用,从而可能拮抗AngⅡ的致炎作用.     

p38丝裂素活化蛋白激酶介导自发性高血压大鼠血管平滑肌细胞增殖

目的 研究p38丝裂素活化蛋白激酶(p38MAPK)信号传导通路在血管紧张素Ⅱ(Ang Ⅱ)与血小板源性生长因子-BB(PDGF-BB)诱导的自发性高血压大鼠(SHR)血管平滑肌细胞(VSMC)增殖中的作用.方法 本实验采用体外培养SHR胸主动脉平滑肌细胞,用3H-胸腺嘧啶核苷([3H]-TdR)掺入法测定细胞增殖状况.用特异性的Phospho-p38MAPK抗体的蛋白免疫印迹法(Western blot)检测p38MAPK的活性.结果 1)Ang Ⅱ、PDGF成剂量依赖性促进SHR血管平滑肌细胞[3H]-TdR掺入率,当Ang Ⅱ为10-7 mol/L、PDGF为10 ng/L时,[3H]-TdR掺入率显著增加[Ang Ⅱ组:(11 588±1322)比对照组(2546±207)计数/min;PDGF:(5279±391)比对照组(2587±230)计数/min,P＜0.05].p38MAPK选择性阻断剂SB202190(10-9～10-7 mol/L)呈浓度依赖性地降低Ang Ⅱ、PDGF诱导的VSMC增殖活度.2)Ang Ⅱ、PDGF对p38MAPK的磷酸化均有显著增强作用,此作用同样被SB202190抑制.3者作用都呈剂量依赖性.结论 Ang Ⅱ、PDGF能激活SHR血管平滑肌细胞的p38MAPK发生磷酸化,进而导致血管平滑肌细胞增殖.     

Chromosome 17p and p53 changes in lymphoma

The clinical course of lymphoma patients in whom rearrangements or deletions of the short arm of chromosome 17 (17p) were evident by cytogenetics was rapidly progressive with a short survival. The gene for the protein designated p53 resides in 17p. We studied four lymphoma cell lines derived from human tumours, and 25 tumour samples of patients with lymphomas, for any evidence of p53 genomic changes by Southern blot technique. The four cell lines and four of the 25 tumour samples showed numerical changes of chromosome 17 or structural abnormalities of 17p (translocations or deletions). Allelic loss of the p53 gene was found in two of the four cell lines, and one of these in addition showed a rearrangement of the 3' end of the gene. Of the four tumours known to have chromosome 17 abnormality, one specimen showed allelic loss of the p53 gene. None of the remaining tumour samples showed any significant change. These studies suggest that acquisition of changes in the short arm of chromosome 17, which may be interrelated with the p53 gene, may carry a poor prognosis in patients with non-Hodgkin's lymphoma.     

Immunohistochemical Expression of p16, p53, and p63 in Colorectal Adenomas and Adenocarcinomas

Purpose The aim of this study was to investigate the immunohistochemical expression of p16, p53, and p63 proteins according to some pathologic parameters related to colorectal adenomas and adenocarcinomas such as grade of dysplasia and histologic type. Methods Immunohistochemistry with the antibodies p16, p53, and p63 was performed in tubular, tubular-villous, and villous adenomas (n = 30) and in well, moderately, and poorly differentiated adenocarcinomas (n = 30). The p63-positive cases were submitted to double immunolabeling with the cytokeratin 5 (CK5). Results The p16 and p53 labelings were observed in some adenomas and adenocarcinomas but without any association with p63 expression, histologic type, or grade of differentiation of the neoplasm. P63 expression was found mainly in the villous adenomas and in the poorly differentiated adenocarcinomas. The poorly differentiated adenocarcinomas also exhibited coexpression of CK5 and p63. Conclusions Despite both p16 and p53 having been detected in colorectal neoplasms, they were not related to the different histologic variables nor to the expression of p63. However, p63 expression was closely associated with villous adenomas and poorly differentiated adenocarcinomas. Thus, p63 may represent a marker of poor differentiation in colorectal neoplasms. The coexpression of p63 and CK5 observed in this study could be related to divergent differentiation during the development of colorectal cancer, although further studies are warranted to refine the understanding of this process.     

Structure of the Sec23p/24p and Sec13p/31p complexes of COPII

COPII-coated vesicles carry proteins from the endoplasmic reticulum to the Golgi complex. This vesicular transport can be reconstituted by using three cytosolic components containing five proteins: the small GTPase Sar1p, the Sec23p/24p complex, and the Sec13p/Sec31p complex. We have used a combination of biochemistry and electron microscopy to investigate the molecular organization and structure of Sec23p/24p and Sec13p/31p complexes. The three-dimensional reconstruction of Sec23p/24p reveals that it has a bone-shaped structure, (17 nm in length), composed of two similar globular domains, one corresponding to Sec23p and the other to Sec24p. Sec13p/31p is a heterotetramer composed of two copies of Sec13p and two copies of Sec31p. It has an elongated shape, is 28-30 nm in length, and contains five consecutive globular domains linked by relatively flexible joints. Putting together the architecture of these Sec complexes with the interactions between their subunits and the appearance of the coat in COPII-coated vesicles, we present a model for COPII coat organization.     

食管内反流物成分与p53、细胞周期素D1、p21、p16表达的相关性研究

目的 研究胃及十二指肠液食管反流对食管内抑癌基因、癌基因表达的影响及与黏膜损伤的关系。方法 制作单纯胃食管反流（G组）、单纯十二指肠食管反流（D组）、十二指肠胃混合食管反流（DG组）及无反流对照组（C组）动物模型,用免疫组化法（SABC）检测各组不同时期食管上皮P53、细胞周期素D1（Cyclin D1）、p21、p16等基因的表达。结果 反流组食管组织中p53、CyclinD1基因表达均显著高于C组,并随病程延长而明显增强,D组表达又强于G组;各组不同时期p16表达无明显差异;p21表达在D组、DG组较C组为低,且与p53蛋白表达呈负相关。结论 食管内胃及十二指肠反流物均可改变食管上皮p53、Cyclin、p21基因的表达,十二指肠内容物的作用更明显。但反流对p16基因的表达影响不大。p53、CyclinD1、p21等癌基因或抑癌基因的表达改变可能参与反流性食管炎及其并发症的发生。     

Sensitization to grass allergens: Phl p1, Phl p5 and Phl p7 Phl p12 in adult and children patients in Beja (Southern Portugal)

BackgroundIn Portugal, the pollen types most implicated in respiratory allergy are grasses, olive and parietaria. The knowledge of sensitizations to molecular allergens in children and adults can contribute to better diagnosis and treatment of this pathology.MethodsImmunoCAP singleplex technology was used for molecular allergens and Phadia 250® automatic equipment. g205 (Phl p1); g215 (Phl p5b); g210 (Phl p7); and g212 (Phl p12) allergen determinations were made in 45 patients with positive grass sensitization tests.ResultsThe majority of patients are sensitized to Phl p1 (91%) and Phl p1+/Phl p5−/Phl p7−/Phl p12− was the most dominant profile (40%). In the adult group, the IgE averages for Phl p1 were approximately 10.46, while they were 8.43 for Phl p5, 0.69 for Phl p7, and 0.06 for Phl p12. In the child group, these values were higher: 22.49, 20.23, 3.89, and 0.35, respectively. For allergens Phl p1, Phl p5, and Phl p7, these differences between the child and adult population were not statistically significant (p = 0.754, p = 0.806 and p = 0.102, respectively), but for Phl p12, a statistically significant difference (p = 0.018) was observed.ConclusionsIgE antibodies Phl p1 is the most important allergic marker and sensitivities caused by Phl p12 give rise to higher IgE values in children.