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41.
蛋白酪氨酸磷酸酶SHP-2在乳腺癌细胞移动及粘附中的作用 总被引:2,自引:0,他引:2
探讨蛋白酪氨酸磷酸酶SHP 2在乳腺癌细胞MCF 7的移动及粘附中的作用 .利用基因重组技术分别将野生型SHP 2与突变型SHP 2与绿色荧光蛋白GFP的基因片段构成重组质粒 (SHP 2 GFP、SHP 2C >S GFP) .脂质体转染法分别转入MCF 7中 ,表达成功后筛选并建立SHP 2 GFP和SHP 2C >S GFP细胞株 .荧光显微镜观察细胞移动情况 ,免疫印迹法检测粘附分子E 钙粘蛋白和金属蛋白酶MMP 1及MMP 9的表达 .实验后建立SHP 2 GFP及SHP 2C >S GFP细胞株 ,同时观察到SHP 2C >S GFP细胞的形态发生明显改变 :从梭形状态变成圆形状态 .荧光显微镜发现 ,MCF 7细胞和SHP 2 GFP、SHP 2C >S GFP转染的细胞在 3h、6h、9h的移动情况分别是MCF 7为 10 %、2 3%、5 4% ,SHP 2 GFP为 15 %、4 9%、98% ,SHP 2C >S GFP为 4 %、11%、30 % .免疫印迹结果表明 ,SHP 2C >S GFP细胞的E 钙粘蛋白表达比SHP 2 GFP细胞明显升高 (P <0 0 5 ) .MMP 1及MMP 9的表达量在SHP 2 GFP细胞中有所增强 (P <0 0 5 ) .实验表明 ,SHP 2可能通过调节粘附分子和基质金属磷酸酶而在细胞移动、粘附中发挥重要作用 相似文献
42.
Evidence suggests that humans might have neurological specializations for music processing, but a compelling adaptationist
account of music and dance is lacking. The sexual selection hypothesis cannot easily account for the widespread performance
of music and dance in groups (especially synchronized performances), and the social bonding hypothesis has severe theoretical
difficulties. Humans are unique among the primates in their ability to form cooperative alliances between groups in the absence
of consanguineal ties. We propose that this unique form of social organization is predicated on music and dance. Music and
dance may have evolved as a coalition signaling system that could, among other things, credibly communicate coalition quality,
thus permitting meaningful cooperative relationships between groups. This capability may have evolved from coordinated territorial
defense signals that are common in many social species, including chimpanzees. We present a study in which manipulation of
music synchrony significantly altered subjects’ perceptions of music quality, and in which subjects’ perceptions of music
quality were correlated with their perceptions of coalition quality, supporting our hypothesis. Our hypothesis also has implications
for the evolution of psychological mechanisms underlying cultural production in other domains such as food preparation, clothing
and body decoration, storytelling and ritual, and tools and other artifacts.
Edward Hagen is a research scientist at the Institute for Theoretical Biology, Humboldt University, Berlin. Gregory Bryant
is a doctoral candidate in the Department of Psychology, University of California, Santa Cruz. 相似文献
43.
《Free radical research》2013,47(9):1085-1094
AbstractMitochondrial superoxide flash (mitoflash) reflects quantal and bursting superoxide production and concurrent membrane depolarization triggered by transient mitochondrial permeability transition in many types of cells, at the level of single mitochondria. Here we investigate reactive oxygen species (ROS)-mediated modulation of mitoflash activity in cardiac myocytes and report a surprising finding that hypochlorite ions potently and preferentially triggered mitoflashes in the subsarcolemmal mitochondria (SSM), whereas hydrogen peroxide (H2O2) elicited mitoflash activity uniformly among SSM and interfibrillar mitochondria (IFM). The striking SSM mitoflash response to hypochlorite stimulation remained intact in cardiac myocytes from NOX2-deficient mice, excluding local NOX2-mediated ROS as the major player. Furthermore, it occurred concomitantly with SSM Ca2+ accumulation and local Ca2+ and CaMKII signaling played an important modulatory role by altering frequency and unitary properties of SSM mitoflashes. These findings underscore the functional heterogeneity of SSM and IFM and the oxidant-specific responsiveness of mitochondria to ROS, and may bear important ramifications in devising therapeutic strategies for the treatment of oxidative stress-related heart diseases. 相似文献
44.
45.
The ubiquitin-proteasome system (UPS) in plants, like in other eukaryotes, targets numerous intracellular regulators and thus modulates almost every aspect of growth and development. The well-known and best-characterized outcome of ubiquitination is mediating target protein degradation via the 26S proteasome, which represents the major selective protein degradation pathway conserved among eukaryotes. In this review, we will discuss the molecular composition, regulation and function of plant UPS, with a major focus on how DELLA protein degradation acts as a key in gibberellin signal transduction and its implication in the regulation of plant growth. 相似文献
46.
Bonny Breckinridge DiNovo Richard Doan Roy B. Dyer Samuel Baron Norbert K. Herzog David W. Niesel 《FEMS immunology and medical microbiology》1996,15(2-3):149-158
Abstract Pathogenesis mediated by Shigella flexneri requires invasion of the gastrointestinal epithelium. It has been previously shown that HeLa cells challenged with S. flexneri show alterations in their phosphotyrosine-containing protein profile. In this report, we demonstrated that bacterial water extracts (WE) abrogated the invasion of HeLa cells by S. flexneri in a dose-dependent manner. A proteinaceous component of S. flexneri was shown to be responsible for this inhibitory activity. Proteins encoded on the 140-MDa plasmid were not responsible for the observed inhibition. WE from other Gram-negative bacteria also inhibited Shigella invasion of HeLa cells. HeLa cells pretreated with WE showed changes in the profile and the intensity of phosphotyrosine-containing protein bands. These data were consistent with a surface protein component in WE which initiated aberrant host cell signaling at the membrane which may account for the inhibition of bacterial entry. 相似文献
47.
48.
Involvement of dying beta cell originated messenger molecules in differentiation of pancreatic mesenchymal stem cells under glucotoxic and glucolipotoxic conditions 下载免费PDF全文
49.
Kenyi Saito-Diaz Hassina Benchabane Ajit Tiwari Ai Tian Bin Li Joshua J. Thompson Annastasia S. Hyde Leah M. Sawyer Jeanne N. Jodoin Eduardo Santos Laura A. Lee Robert J. Coffey R. Daniel Beauchamp Christopher S. Williams Anne K. Kenworthy David J. Robbins Yashi Ahmed Ethan Lee 《Developmental cell》2018,44(5):566-581.e8
50.
Mitochondria sense and shape cytosolic Ca2+ signals by taking up and subsequently releasing Ca2+ ions during physiological and pathological Ca2+ elevations. Sustained elevations in the mitochondrial matrix Ca2+ concentration are increasingly recognized as a defining feature of the intracellular cascade of lethal events that occur in neurons during cerebral ischemia. Here, we review the recently identified transport proteins that mediate the fluxes of Ca2+ across mitochondria and discuss the implication of the permeability transition pore in decoding the abnormally sustained mitochondrial Ca2+ elevations that occur during cerebral ischemia. 相似文献