植物促分裂原活化蛋白激酶(mapk)的研究进展

植物促分裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)是一类存在于各种真核生物体中的丝氨酸/苏氨酸型蛋白激酶。它与其它一些信号分子组成MAPK级联信号通路,接受外界刺激信号,将信号传入细胞内,影响特定基因的表达,从而在植物的生长、发育、分化和凋亡等多方面起着重要的作用。而它的作用也受到不同因子的凋节。本文就植物中MAPK的基本组成、分类和功能的最新进展作了综述。     

紫花苜蓿(medicago sativa)抗旱相关促分裂原活化蛋白激酶mapk基因的克隆

用异硫氰酸胍方法提取紫花苜蓿超级阿菠萝(Apollo Supreme)植株嫩叶和幼根的总RNA;采用RT-PCR的方法获得紫花苜蓿超级阿菠萝抗旱相关促分裂原活化蛋白激酶MAPK基因中MMK4基因的cDNA序列全长.cDNA序列测定表明:我们克隆到的MMK4基因的cDNA序列全长1116bp,由此推导的氨基酸序列与GeneBank上MMK4(X82270)基因的cDNA序列所编码的氮基酸序列完全相同,但其中有14个氛基酸的密码子有所不同.     

紫花苜蓿抗旱相关促分裂原活化蛋白激酶植物表达载体的构建

本实验在前期用RT-PCR法克隆出紫花苜蓿促分裂原活化蛋白激酶MMK4基因cDNA的基础上以其为基因供体与诱导型启动子构建植物表达载体,并分别通过三亲本杂交法和冻融法将重组质粒导入根癌农杆菌LBA4404中,为通过农杆菌介导法将MMK4基因导入植物奠定基础。     

热解活化法制备椰壳活性炭的方法和机理研究(摘要)

研究了一种制备活性炭的新方法,在不添加任何活化气体或化学试剂的情况下,依靠原料自身热解产生的气体作为活化剂,原料吸附的空气以及反应器内部自带的空气作为活化助剂,自活化造孔.意在研究一种绿色环保,工艺简单,清洁节能的制备活性炭的快速制备方法.     

定性比较分析(QCA)与新闻传播学研究

作为一种案例导向的研究方法,定性比较分析(QCA)于最近的二十多年中在社会科学研究领域得到普及和应用。本文对这一方法的研究逻辑、适用情境进行了介绍及分析,并就其在新闻传播研究中的应用前景予以展望,提出了四个话题方向。文章同时介绍了该方法的操作步骤,以期将其引入到新闻传播学的研究中,拓展现有的方法论体系。     

有限长圆柱状催化剂内扩散效率因子多态研究(Ⅰ)——研究方法的开发

对有限长圆柱状催化剂内发生强放热反应时的多态特性,本文提出了较为完整的研究方法,包括:(1)将有限北方法与非线性连续性算法及奇性理论结合,开发了有限元全区域分析方法,作为研究非线性偏微分方程多解的基本工具;(2)在高数值效率因子计算中,改进传统方法,开发了高效、准确的新方法,通过实验数据检验了有限元全区域分析方法的可靠性,结果令人满意。     

新农药创新方法与应用(1)—中间体衍生化方法

介绍了一种发现新农药的创新研究方法——中间体衍生化方法。新农药创新涉及多领域间的合作,其过程非常复杂,中间体衍生化方法是从化学的角度出发,把复杂问题简单化,应用效果很好。通过多年的实践,总结其内涵有三:利用中间体进行化学反应,设计合成新化合物,然后筛选,发现先导化合物,再经优化发现新农药品种;利用简单的原料,通过化学反应合成新的中间体,利用该中间体替换已知农药或医药品种化学结构中的一部分,得到新的化合物,经进一步研究,得到新农药品种;利用已知的具有活性的化合物或农药品种作为中间体,进行化学反应,设计合成新化合物,经筛选、优化研究发现新农药品种。     

TRIZ理论的研究应用概况(Ⅰ)

介绍了TRIZ理论的三个核心思想和九项主要内容,综述了俄罗斯、美国、德国、日本、韩国、新加坡、瑞典、欧州、中国等的TRIZ理论研究和应用概况.     

岗松(精)油质量标准研究

对岗松(精)油质量标准进行研究。采用气相色谱、薄层色谱技术和理化指标对岗松(精)油进行分析。确定其各项指标,并用气相色谱面积归一化法测定特征性组分与代表性组分的相对含量。研究制订岗松(精)油质量标准的技术要求及试验方法,为岗松(精)油的质量控制提供科学基础和方法参考。     

Receptor-Mediated Vascular Smooth Muscle Migration Induced by LPA Involves p38 Mitogen-Activated Protein Kinase Pathway Activation

Lysophosphatidic acid (LPA), a naturally occurring glycerophospholipid, can evoke various biological responses, including cell migration, proliferation and survival, via activation of G protein-coupled receptors (GPCRs). However, the role of LPA receptors and details of LPA signaling in migration are largely unexplored. In this study we detect the expression of LPA1 and LPA3 receptors in rat aortic smooth muscle cells (RASMCs). LPA stimulated RASMCs migration in a dose-dependent manner and induced the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK) and extracellular signal-regulated kinase (ERK). LPA-induced cell migration was significantly inhibited by specific LPA1/LPA3-receptor antagonist Dioctylglycerol pyrophosphate (8:0) (DGPP8.0) at higher concentration. Migration of cells toward LPA was partially, but significantly, reduced in the presence of SB-203580, a p38 MAPK inhibitor, but not PD98059, an ERK inhibitor. In addition, pertussis toxin (PTX), a Gi protein inhibitor, induced an inhibitory effect on p38 MAPK, ERK phosphorylation and RASMCs migration. These data suggest that LPA-induced migration is mediated through the Gi-protein-coupled LPA1 receptor involving activation of a PTX-sensitive Gi / p38MAPK pathway.     

Cell Signaling through Protein Kinase C Oxidation and Activation

Due to the growing importance of cellular signaling mediated by reactive oxygen species (ROS), proteins that are reversibly modulated by these reactant molecules are of high interest. In this context, protein kinases and phosphatases, which act coordinately in the regulation of signal transduction through the phosphorylation and dephosphorylation of target proteins, have been described to be key elements in ROS-mediated signaling events. The major mechanism by which these proteins may be modified by oxidation involves the presence of key redox-sensitive cysteine residues. Protein kinase C (PKC) is involved in a variety of cellular signaling pathways. These proteins have been shown to contain a unique structural feature that is susceptible to oxidative modification. A large number of scientific studies have highlighted the importance of ROS as a second messenger in numerous cellular processes, including cell proliferation, gene expression, adhesion, differentiation, senescence, and apoptosis. In this context, the goal of this review is to discuss the mechanisms by which PKCs are modulated by ROS and how these processes are involved in the cellular response.     

Polydatin Attenuates Hypoxic Pulmonary Hypertension and Reverses Remodeling through Protein Kinase C Mechanisms

Hypoxic pulmonary hypertension is a life-threatening emergency if untreated. Consistent pulmonary hypertension also leads to arteries and ventricular remodeling. The clinical therapeutic strategy for pulmonary hypertension and the corresponding remodeling mainly interacts with NO, angiotensin II (Ang II) and elevated endothelin (ET) targets. In the present study, we evaluated the effects of polydatin on hypoxia-induced pulmonary hypertension. It was observed that polydatin attenuated hypoxic pulmonary hypertension, reversed remodeling, and regulated NO, Ang II, ET contents in the serum and lung samples. However, forced activation of PKC signaling by its selective activator thymeleatoxin (THX) could abate the effects of polydatain. These results suggest that polydatin might be a promising candidate for hypoxic pulmonary treatment through interaction with PKC mechanisms.     

Compartmentalization Role of A-Kinase Anchoring Proteins (AKAPs) in Mediating Protein Kinase A (PKA) Signaling and Cardiomyocyte Hypertrophy

The Beta-adrenergic receptors (β-ARs) stimulation enhances contractility through protein kinase-A (PKA) substrate phosphorylation. This PKA signaling is conferred in part by PKA binding to A-kinase anchoring proteins (AKAPs). AKAPs coordinate multi-protein signaling networks that are targeted to specific intracellular locations, resulting in the localization of enzyme activity and transmitting intracellular actions of neurotransmitters and hormones to its target substrates. In particular, mAKAP (muscle-selective AKAP) has been shown to be present on the nuclear envelope of cardiomyocytes with various proteins including: PKA-regulatory subunit (RIIα), phosphodiesterase-4D3, protein phosphatase-2A, and ryanodine receptor (RyR2). Therefore, through the coordination of spatial-temporal signaling of proteins and enzymes, mAKAP controls cyclic-adenosine monophosphate (cAMP) levels very tightly and functions as a regulator of PKA-mediated substrate phosphorylation leading to changes in calcium availability and myofilament calcium sensitivity. The goal of this review is to elucidate the critical compartmentalization role of mAKAP in mediating PKA signaling and regulating cardiomyocyte hypertrophy by acting as a scaffolding protein. Based on our literature search and studying the structure–function relationship between AKAP scaffolding protein and its binding partners, we propose possible explanations for the mechanism by which mAKAP promotes cardiac hypertrophy.     

Effects of Bofu-Tsusho-San on Diabetes and Hyperlipidemia Associated with AMP-Activated Protein Kinase and Glucose Transporter 4 in High-Fat-Fed Mice

This study was undertaken to examine the effect and mechanism of Bofu-tsusho-san formula (BO) on hyperglycemia and hyperlipidemia and in mice fed with a high-fat (HF) diet. The C57BL/6J mice were received control/HF diet for 12 weeks, and oral administration of BO (at three doses) or rosiglitazone (Rosi) or vehicle for the last 4 weeks. Blood, skeletal muscle and tissues were examined by means of measuring glycaemia and dyslipidaemia-associated events. BO treatment effectively prevented HF diet-induced increases in the levels of triglyceride (TG), free fatty acid (FFA) and leptin (p < 0.01, p < 0.01, p < 0.01, respectively). BO treatment exhibited reduced both visceral fat mass and hepatic triacylglycerol content; moreover, BO treatment displayed significantly decreased both the average area of the cut of adipocytes and ballooning of hepatocytes. BO treatment exerted increased the protein contents of glucose transporter 4 (GLUT4) in skeletal muscle, and caused lowered blood glucose levels. BO treatment displayed increased levels of phosphorylated AMP-activated protein kinase (AMPK) in both skeletal muscle and liver tissue. Furthermore, BO reduced the hepatic expression of glucose-6-phosphatase (G6Pase) and phosphenolpyruvate carboxykinase (PEPCK) and glucose production. Therefore, it is possible that the activation of AMPK by BO leads to diminished gluconeogenesis in liver tissue. BO increased hepatic expressions of peroxisome proliferator-activated receptor α (PPARα), whereas down-regulating decreasing expressions of fatty acid synthesis, including sterol regulatory element binding protein 1c (SREBP1c) and fatty acid synthase (FAS), resulting in a decrease in circulating triglycerides. This study originally provides the evidence that amelioration of dyslipidemic and diabetic state by BO in HF-fed mice occurred by regulation of GLUT4, SREBP1c, FAS, PPARα, adiponectin and AMPK phosphorylation.     

抗原抗体之间的相互反应及其研究方法

抗原抗体的反应在生物学研究、临床诊断等方面具有重要应用,本文论述了抗原抗体之间的相互反应及其研究方法,并重点阐述了当今抗原抗体反应研究方法的新领域。     

Boesenbergia pandurata Attenuates Diet-Induced Obesity by Activating AMP-Activated Protein Kinase and Regulating Lipid Metabolism

Obesity, a chronic metabolic disorder, is characterized by enlarged fat mass and dysregulation of lipid metabolism. The medicinal plant, Boesenbergia pandurata (Roxb.) Schltr., has been reported to possess anti-oxidative and anti-inflammatory properties; however, its anti-obesity activity is unexplored. The present study was conducted to determine whether B. pandurata extract (BPE), prepared from its rhizome parts, attenuated high-fat diet (HFD)-induced obesity in C57BL/6J mice. The molecular mechanism was investigated in 3T3-L1 adipocytes and HepG2 human hepatoma cells. BPE treatment decreased triglyceride accumulation in both 3T3-L1 adipocytes and HepG2 hepatocytes by activating AMP-activated protein kinase (AMPK) signaling and regulating the expression of lipid metabolism-related proteins. In the animal model, oral administration of BPE (200 mg/kg/day for 8 weeks) significantly reduced HFD-induced body weight gain without altering the amount of food intake. In addition, elevated serum levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides were suppressed by BPE administration. Fat pad masses were reduced in BPE-treated mice, as evidenced by reduced adipocyte size. Furthermore, BPE protected against the development of nonalcoholic fatty liver by decreasing hepatic triglyceride accumulation. BPE also activated AMPK signaling and altered the expression of lipid metabolism-related proteins in white adipose tissue and liver. Taken together, these findings indicate that BPE attenuates HFD-induced obesity by activating AMPK and regulating lipid metabolism, suggesting a potent anti-obesity agent.     

Development of Selective Bisubstrate‐Based Inhibitors Against Protein Kinase C (PKC) Isozymes By Using Dynamic Peptide Microarrays

Kinase inhibitors are increasingly important in drug development. Because the majority of current inhibitors target the conserved ATP‐binding site, selectivity might become an important issue. This could be particularly problematic for the potential drug target protein kinase C (PKC), of which twelve isoforms with high homology exist in humans. A strategy to increase selectivity is to prepare bisubstrate‐based inhibitors that target the more selective peptide‐binding site in addition to the ATP‐binding site. In this paper a generally applicable, rapid methodology is presented to discover such bisubstrate‐based leads. Dynamic peptide microarrays were used to find peptide‐binding site inhibitors. These were linked with chemoselective click chemistry to an ATP‐binding site inhibitor, and this led to novel bisubstrate structures. The peptide microarrays were used to evaluate the resulting inhibitors. Thus, novel bisubstrate‐based inhibitors were obtained that were both more potent and selective compared to their constituent parts. The most promising inhibitor has nanomolar affinity and selectivity towards PKCθ amongst three isozymes.