蛋白酪氨酸磷酸酶SHP-1、SHP-2在γ射线诱发的小鼠胸腺淋巴瘤中表达的研究

目的　探讨蛋白酪氨酸磷酸酶SHP 1、SHP 2在γ射线体外诱发的小鼠胸腺淋巴瘤中的表达情况 ,为从细胞信号转导途径入手研究辐射致癌的分子机理奠定一定的基础。方法　 338只BALB c小鼠随机分为照射组及对照组 ,照射组经6 0 Coγ射线全身照射 ,病理证实出现胸腺淋巴瘤者为癌变组 ,未出现任何肿瘤者为未癌变组 ;对照组不经γ射线照射 ,与照射组同步喂养。分离胸腺细胞 ,应用Westernblot方法检测其SHP 1及SHP 2蛋白质的表达。结果　癌变组SHP 1蛋白 (吸光度A值为 15 2 7)的表达明显 ,而对照组 (吸光度A值为 3 80 )及未癌变组 (吸光度A值为 1 0 1)表达非常弱甚至无表达 ;SHP 2蛋白的表达总体上呈现癌变组 (吸光度A值为 2 88)明显高于对照组 (吸光度A值为 0 33)及未癌变组 (吸光度A值为 0 99) ,未癌变组略高于对照组的趋势 ;应用Westernblot分析SHP 2的表达时 ,癌变组除了SHP 2蛋白表达明显外 ,同时出现另外 1条表达明显的条带 ,相对分子质量约 5 5× 10 3,该蛋白的表达总体上明显高于对照组及未癌变组。结论　蛋白酪氨酸磷酸酶SHP 1、SHP 2在γ射线诱发的小鼠胸腺淋巴瘤中表达明显增强 ,说明SHP 1、SHP 2可能与辐射致癌的发生有关 ,但有待进一步通过实验证实。     

微机化胎儿心电图仪的研制

本文介绍一种微机化胎儿心电图仪。它采用前后台机结构，前端机以TMS32010数字信号处理器为核心，采用自适应噪声抵消软件算法，无创无损提取胎儿心电信号，并通过通讯接口送至后台微机实时显示，分析和记录处理结果。临床试验表明仪器设计合理，操作简便，可灵活应用于多种场合。     

Tumor cell adhesion to the extracellular matrix and signal transduction mechanisms implicated in tumor cell motility,invasion and metastasis

Summary The relationship between tumor cell adhesion to the extracellular matrix (ECM) and invasion and metastasis formation is one of the most intensively studied topics in cancer biology within the last 10–15 years. The aberrant molecular relationships between malignant tumor cells and their surrounding ECM have been implicated at virtually every stage of the metastatic process; ranging from steps that involve the local invasion of tumor cells away from the primary tumor to those that are involved in mediating extravasation through microvessel-associated basement membranes at the site(s) of metastasis formation. The complexity of tumor metastasis has required that a reductionist approach be taken in order to identify and relate specific molecular mechanisms involved in tumor cell adhesion to various aspects of tumor metastasis. The intensive research efforts into cell adhesion and tumor cell biology have generated many significant new concepts towards our understanding of the molecular aspects of tumor cell adhesion and metastasis. Our purpose in this article is to briefly summarize the relationship of ECM-stimulated tumor cell adhesion to the processes of tumor cell motility and invasion. This is followed by a discussion of certain aspects of signal transduction pathways that may impact on cell motility, with an emphasis on the relationship between phosphatidylinositol hydrolysis and actin polymerization, as well as certain GTP-binding protein-(G-protein) mediated events that could influence cytoskeletal organization and cell motility. Our emphasis is based on increasing evidence that implicates members of the signal transduction G-proteins in the motility and invasion of many normal and transformed cells.     

丝氨酸/苏氨酸蛋白激酶hFIST/HIPK2的表达纯化磷酸化

目的　观察一个新近克隆的丝氨酸 苏氨酸蛋白激酶hFIST HIPK2 (HumanFasinteractingsignaltransducer homeo domaininteractingproteinkinase)的表达、纯化、磷酸化。方法　用瞬时转染技术、Westernblotting检测hFIST HIPK2野生型及其变异型蛋白 (点突变型hFIST HIPK2K2 2 1A ,C 端缺失型hFIST HIPK2△C、N 端缺失型hFIST HIPK2△N)在 2 93T细胞中的表达、磷酸化 ,及从E coli中纯化GST hFIST HIPK2△C融合蛋白。结果　hFIST HIPK2全长序列cDNA长 4kb ,编码分子质量为 13 0× 10 3的hFIST HIPK2蛋白 ;hFIST HIPK2K2 2 1A的分子质量略小于hFIST HIPK2野生型 ,hFIST HIPK2△C、hFIST HIPK2△N的分子质量分别为 5 9× 10 3、69× 10 3。hFIST HIPK2野生型及其变异型蛋白的丝氨酸残基可自我磷酸化 ,其苏氨酸、酪氨酸残基不被磷酸化 ;hFIST HIPK2蛋白可自我降解 ,尤以hFIST HIPK2K2 2 1A蛋白最为明显 ;从E coli中纯化了一个分子质量为 84× 10 3的GST hFIST HIPK2△C融合蛋白。hFIST HIPK2与小鼠HIPK2、仓鼠PKM具有高度的同源性 ,分别为 96 1%、96 5 %。结论　hFIST HIPK2为一新的丝氨酸 苏氨酸蛋白激酶 ,是DYRK激酶分支家族中的一员 ,也是新近发现的核蛋白激酶HIPKs (Homeodomaininteractingproteinkinases     

Expression of Inositol 1,4,5—trisphosphate Receptor mRNA in Myocardium of Spontaneous Hypertension Rats and Cultured Vascular Smooth Muscle Cells of Rats

Ｔｈｅｉｎｏｓｉｔｏｌ 1,4,5 ｔｒｉｓｐｈｏｓｐｈａｔｅ (ＩＰ3)ｉｓｃｏｎｓｉｄｅｒｅｄａｓａｋｅｙｓｅｃｏｎｄｍｅｓｓｅｎｇｅｒｏｒｏｎｅｏｆｔｈｅｅｌｅｍｅｎｔｓｏｆｓｉｇｎａｌｔｒａｎｓｄｕｃｔｉｏｎ .Ｔｈｅｒａｐｉｄｒｅ ｌｅａｓｅｏｆＣａ2 + ｆｒｏｍｉｎｔｒａｃｅｌｌｕｌａｒＣａ2 + ｓｔｏｒｉｎｇｐｏｏｌｌｉｋｅｔｈｅｅｎｄｏｐｌａｓｍｉｃｒｅｔｉｃｕｌｕｍａｎｄｔｈｅｓａｒｃｏｐｌａｓ ｍｉｃｒｅｔｉｃｕｌｕｍｔｈｒｏｕｇｈｔｗｏｔｙｐｅｓｏｆｉｎｔｒａｃｅｌｌｕｌａｒｃａｌｃｉｕｍｒ…     

COMPETITION BY SECOND MESSENGER SYSTEMS FOR RECEPTOR INTERACTION AND ACTIVATION: IMPLICATIONS FOR TISSUE-SPECIFIC RESPONSES AND DISEASE THERAPY

1. At any one instant, most receptors are now recognized to be able to stimulate multiple signal transduction pathways in a cell when activated by an appropriate hormone. These different signalling pathways appear to allow for distinct cellular responses, such as cell proliferation, differentiation, and shape change. 2. In addition, many different types of cell will possess the same type of receptor. Therefore, for a hormone to be able to transmit differential signals to the various cell types able to respond to it, cells must discriminate the stimulus at some point. Such discrimination would seem to be an absolute requirement to allow a tissue-specific response to an identical initial stimulus. In theory, this specificity could occur at many points in the receptor signal transduction cascade, including cytosolic receptor coupling systems and tissue/cell-specific responsive genes. 3. The present paper summarizes our work and that of others which has determined some of the coupling systems of G-protein-coupled receptors and tyrosine kinase receptors and how these systems may be interacting. 4. In addition to these theoretical considerations, a potential therapeutic strategy underlies the ability of receptors to couple to more than one signal transduction system. If a response to a hormone were, for example, either cell proliferation or cell morphological change or differentiation and separate receptor-coupled signalling systems were responsible for these effects, pharmacological intervention may allow the transfer from one signalling system to another. If such a change allowed a permanent change to the differentiated phenotype, this could potentially form the basis of a signal-based cancer therapy.     

体内蛋白转导的研究进展

简要综述了几种能够携带药物跨越血脑屏障和细胞生物膜屏障的蛋白结构域的研究进展。     

肝刺激物促肝细胞增殖信号转导途径的初步研究

目的：探讨新生牛肝肝刺激物(hepatic stimulator substance，HSS)促进SMMC7721肝癌细胞增殖的信号转导途径。方法：对新生牛肝进行多步分离，采用^3H-Td RDNA掺入法检测分离物的促增殖活性，从而获得具增殖刺激活性的HSS；Western印迹方法检测其对肝癌细胞MAPK Thr202／Tyr204的磷酸化作用并检测其对SPK的激活作用。结果：经多步分离纯化，获得了活性较高的HSS粗提物，Western印迹法结果显示HSS粗提物能明显提高MAPK的磷酸化水平，并能激活细胞内的SPK活性。结论：HSS对细胞的增殖刺激可能是通过SPK和MAPK途径发挥作用。     

阻断PI3K信号通路显著抑制成骨前体细胞MC3T3-E1的分化

目的：研究PI3K信号通路对成骨前体细胞MC3T3-E1分化的调控作用。方法：首先通过Western印迹试验检测到PI3K信号通路参与成骨细胞分化的调控。应用PI3K激酶的特异性抑制剂LY294002药物阻断PI3K信号通路的活化，通过碱性磷酸酶(ALP)和von Kossa染色观察成骨前体细胞MC3T3-E1分化的改变。结果：Western印迹试验显示，成骨细胞分化过程中PI3K信号通路明显活化。阻断该信号通路的活化显著抑制成骨细胞碱性磷酸酶的活性，同时降低成骨细胞体外形成骨结节结构的能力。结论：PI3K信号通路参与了成骨细胞分化的调控，而这种调控作用是成骨细胞分化所必需的。     

Adenylyl cyclase activity in Alzheimer's disease brain: stimulatory and inhibitory signal transduction pathways are differently affected

Adenylyl cyclase (AC) activity was studied in post mortem hippocampus and cerebellum from eight patients with Alzheimer's disease/senile dementia of the Alzheimer type (AD/SDAT) and seven non-demented control patients. AC was stimulated via stimulatory guanine nucleotide binding proteins (Gs) using guanosine triphosphate (GTP) and GppNHp (both 10⁻⁴M) or directly with either forskolin (10⁻⁴M) or Mn²⁺ (10⁻²M). Inhibition of AC via A₁-receptors was performed with N⁶-cyclohexyladenosine (CHA) under basal conditions and in the presence of forskolin (10⁻⁵M). In both brain regions AC activity was significantly reduced in AD/SDAT when compared to controls. Under basal conditions and after stimulation via Gs mean reduction in hippocampus and cerebellum was 47.7% and 58.2%, respectively. The reduction was less pronounced after direct activation of the AC, amounting to 21.8% in hippocampus and 28.1% in cerebellum. CHA inhibited basal and forskolin-stimulated AC concentration-dependently by about 20% (basal) and 30% (forskolin). Inhibition by CHA was similar in hippocampus and cerebellum and tended to be more pronounced in AD/SDAT than in controls. Since the reduction of AC activity in AD/SDAT is greater after stimulation via Gs than after direct activation of the catalytic subunit, we suggest that both Gs and the catalytic subunit seem to be impaired. The fact that CHA-mediated inhibition of AC is not significantly different in AD/SDAT and controls, indicates that in contrast to Gs-, inhibitory G-proteins (Gi) coupling to AC remains intact in Alzheimer's disease.