乳腺癌中PKCζ、MMP-2、MMP-9的表达及相关性

目的：探讨乳腺癌中蛋白激酶C灼(protein kinase C灼, PKC灼)、基质金属蛋白酶-2( matrix metalloproteinase-2, MMP-2)、基质金属蛋白酶-9(matrix metalloproteinase-9, MMP-9)的表达及三者与其侵袭、转移的关系。方法应用免疫组化PV 9000两步法检测PKC灼、MMP-2、MMP-9在100例乳腺癌组织及对应癌旁正常乳腺组织中的表达,并分析三者表达的相关性。应用RNAi技术将合成的PKC灼-siRNA转染入乳腺癌细胞株MDA-MB-231中,即siPKC灼/MDA-MB-231细胞组,以转染空载质粒的scr/MDA-MB-231的细胞组作为对照组,应用Transwell侵袭实验检测细胞的体外侵袭能力。利用Western blot法检测转染细胞中PKC灼蛋白的表达。酶联免疫吸附实验( enzyme-linked immunosorbent assay, ELISA)检测培养基中MMP-2、MMP-9的含量。结果 PKC灼、MMP-2、MMP-9在乳腺浸润性导管癌中的阳性率分别为62.5%、37.5%、32.5%,明显高于乳腺导管内癌和癌旁正常乳腺组织(P均<0.05)。 PKC灼蛋白表达与淋巴结转移、远处转移有关(P均<0.01),与患者年龄、肿瘤大小、临床分期、ER、PR等无关( P均>0.05);转染 siRNA的 siPKC灼/MDA-MB-231细胞组与 scr/MDA-MB-231组相比,体外侵袭能力以及PKC灼蛋白的表达水平明显下降(P均<0.05),培养基中MMP-2、MMP-9蛋白表达量亦明显下降(P均<0.05)。结论 PKC灼通过影响乳腺癌细胞中MMP-2、MMP-9的分泌来促进乳腺癌的侵袭、转移。     

米哚妥林对急性白血病细胞株HL-60细胞抑制效应的研究

目的:探讨蛋白激酶C(PKC)抑制剂米哚妥林(PKC412)对HL-60细胞株增殖和凋亡的影响及作用机制.方法:采用CCK-8法检测不同浓度PKC412对HL-60细胞增殖的影响;瑞士吉姆萨染色法鉴定PKC412对HL-60细胞凋亡的影响;qRT-PCR检测BCL-2、P53基因的mRNA表达,Western blot...     

广西、海南、云南微小按蚊3种同工酶谱比较研究

目的　探索我国微小按蚊复合体同工酶谱鉴别指标。　方法　选择广西微小按蚊 (A .m .G)、海南微小按蚊(A .m .H)和云南微小按蚊 (A .m .Y)的单雌线雌蚊匀浆 ,采用不连续性聚丙烯酰胺凝胶垂直板状电泳法分离 ,特异性底物染色 ,比较观察乳酸脱氢酶 (LDH)、醇脱氢酶 (ADH)和酯酶 (EST) 3种同工酶谱。　结果　三地微小按蚊的LDH同工酶谱相同 ,均具 1条Rm14酶带 ;ADH酶谱中三地微小按蚊均显一条酶带 ,A .m .G与A .m .H具相同酶带Rm 3 4,而A .m .Y则是 1条Rm 40酶带 ;EST的主带谱A .m .G与A .m .H基本相似 ,前者显示Rm18、3 5和 61,后者显示Rm18、3 5、5 9和 61。而A .m .Y明显不同于A .m .G和A .m .H ,显示Rm18、3 9、43、5 0、5 6和 5 9六条主带。　结论　ADH和EST同工酶谱在不同种的微小按蚊中存在明显差别 ,可能在区别我国微小按蚊姐妹种中有较大的应用价值。     

Intercellular communication via gap junctions in activated rat hepatic stellate cells

BACKGROUND AND AIMS: Gap junctional communication was studied in quiescent and activated hepatic stellate cells. METHODS: Connexin expression and intercellular dye transfer were studied in rat hepatic stellate cells in culture and in vivo. RESULTS: Protein expression of connexin 43 was up-regulated in activated hepatic stellate cells in vivo and in vitro and was mainly localized on the cell surface, whereas connexin 26 was found intracellularly. In contrast to hepatocytes, hepatic stellate cells do not express connexin 32. Confluent hepatic stellate cells in culture communicate via gap junctions, resulting in lucifer yellow transfer and propagation of intracellular calcium signals. Phorbol ester induces a protein kinase C-dependent hyperphosphorylation and degradation of connexin 43 and inhibits intercellular communication on a short-term time scale. At the long-term level, vitamin D(3) , lipopolysaccharide, thyroid hormone T(3), dexamethasone, platelet-derived growth factor, endothelin 1, and interleukin 1beta up-regulate connexin 43 protein and messenger RNA expression and enhance intercellular communication. Slight down-regulation of connexin 43 is observed in response to vitamin A. Connexin 43 induction by endothelin 1 is inhibited by both endothelin A and endothelin B receptor antagonists. In coculture systems, hepatic stellate cells communicate with each other, which is suggestive of a syncytial organization, but no communication was found between hepatic stellate cells and other liver cell types. As shown by immunohistochemistry and electron microscopy, gap junctions are formed between activated hepatic stellate cells in vivo. CONCLUSIONS: Gap junctional communication occurs between hepatic stellate cells, is enhanced after activation, and underlies complex regulation by cytokines, hormones, and vitamins.     

Kinase inhibitors for cardiovascular disease

Over the last decade, there has been substantial progress toward understanding the pathophysiology and treatment of cardiovascular diseases (CVDs). Elucidating cellular responses to the extracellular environment and signal transduction mechanisms have provided the opportunity to explore novel molecular therapeutic approaches for the treatment of CVDs. Neurohormonal stimulation has been implicated in these diseases; blockade of the renin-angiotensin and beta-adrenergic systems are examples of therapeutic effectiveness. There are multiple cell signaling cascades, some of which are beneficial or compensatory and others deleterious. The balance between these pathways, which in large part is dictated by the cellular environment, determines the outcome as a diseased or non-diseased state. Selective targeting of signaling pathways using protein kinase inhibitors, would have a potential advantage over receptor blockers. We review potential protein kinase targets and recent evidence supporting therapeutic interventional value in CVDs.     

小檗碱抑制机械牵张力诱导的小鼠血管平滑肌细胞PKCδ磷酸化及增殖/迁移

目的 观察机械牵张力(SS)是否通过激活PKCδ诱导小鼠血管平滑肌细胞(VSMC)增殖和迁移,并进一步探究小檗碱(BBR)对其的影响及作用机制.方法 体外常规培养小鼠VSMC分为6组:阴性对照组(NC)、小檗碱组(BBR)、PKCδ抑制剂Sotrastaurin组(Sotras)、SS组、SS+BBR组和SS+Sotr...     

AQP4与PKC在大鼠CIR后脑水肿模型中的变化及作用

目的通过研究大鼠局灶性脑缺血再灌注后水通道蛋白4（AQP4）、蛋白激酶C（PKC）表达水平的变化,来探讨两者与脑水肿之间的关系。方法通过线栓法复制大鼠大脑中动脉缺血（MCAO）再灌注模型,动物随机分为正常对照组（Norm）、假手术组（Sham）、缺血再灌注组（CIR）。参照Garcia JH法进行神经功能缺损评分、用Elliot法检测脑组织含水量、免疫组化法检测AQP4及PKC的表达。结果 CIR后6h即有神经功能缺损,脑含水量在CIR12h明显升高,1~3d时达到高峰;AQP4表达在早期水平降低,从12h逐渐升高,至CIR 24h明显升高,3d达高峰;PKC在CIR后6h开始持续性升高,至第5d仍保持较高水平。结论早期的细胞源性脑水肿可能和PKC的升高有关,后期的血管源性脑水肿可能和AQP4的升高相关。     

线粒体型天门冬氨酸氨基转移酶同工酶测定及其应用价值

目的建立免疫抑制法测定各类心脏和肝脏疾病的m-AST,观察其应用价值。方法提取纯化心肌细胞质型天门冬氨酸氨基转移酶同工酶(s-AST)酶蛋白,免疫羊制备抗人s-AST抗体,应用免疫抑制原理抑制标本中的s-AST活性,测定m-AST活性。结果血清m-AST参考值4~15 u/L,急性心肌梗死60~310、陈旧心肌梗死10~20、无梗死冠心病7~15、无心衰7~18、心衰8~25、心包炎10~16、心肌炎18~30 u/L;急性肝炎56~410、慢迁肝炎12~17、慢活肝炎18~90、有腹水肝硬化18~50、无腹水肝硬化12~30、原发性肝癌11~64、继发性肝癌16~95、肝脓肿15~21 u/L。有坏死的心、肝病m-AST明显升高。非心肝性恶性肿瘤和其他疾病基本在参考值范围内。结论测定m-AST可协助判定心、肝疾病的严重性和有无坏死。     

Ammonia metabolism,the brain and fatigue; revisiting the link

This review addresses the ammonia fatigue theory in light of new evidence from exercise and disease studies and aims to provide a view of the role of ammonia during exercise. Hyperammonemia is a condition common to pathological liver disorders and intense or exhausting exercise. In pathology, hyperammonemia is linked to impairment of normal brain function and the onset of the neurological condition, hepatic encephalopathy. Elevated blood ammonia concentrations arise due to a diminished capacity for removal via the liver and lead to increased exposure of organs, such as the brain, to the toxic effects of ammonia. High levels of brain ammonia can lead to deleterious alterations in astrocyte morphology, cerebral energy metabolism and neurotransmission, which may in turn impact on the functioning of important signalling pathways within the neuron. Such changes are believed to contribute to the disturbances in neuropsychological function, in particular the learning, memory, and motor control deficits observed in animal models of liver disease and also patients with cirrhosis. Hyperammonemia in exercise occurs as a result of an increased production by contracting muscle, through adenosine monophosphate (AMP) deamination (the purine nucleotide cycle) and branched chain amino acid (BCAA) deamination prior to oxidation. Plasma concentrations of ammonia during exercise often achieve or exceed those measured in liver disease patients, resulting in increased cerebral uptake. In this article we propose that exercise-induced hyperammonemia may lead to concomitant disturbances in brain function, potentially through similar mechanisms underpinning pathology, which may impact on performance as fatigue or reduced function, especially during extreme exercise.