麦冬正丁醇提取部位调控人脐静脉血管内皮细胞凋亡相关基因与信号转导通路研究

目的:研究麦冬正丁醇提取部位对H_2O_2造模的人脐静脉血管内皮细胞(HUVEC)凋亡相关基因和信号转导通路调控,探讨其对HUVEC保护作用的分子机制。方法:用H_2O_2构建HUVEC凋亡模型,运用MTT检测细胞增殖情况,流式细胞仪检测凋亡相关基因Bc1-2表达,免疫组化方法观察NF-kB表达情况。结果:麦冬正丁醇提取部位可以减少H_2O_2造模的HUVEC的凋亡,促进Bc1-2的表达,并能降低NF-kB的表达。结论:麦冬正丁醇提取部位可以通过NF-kB路径,促进凋亡抑制基因Bc1-2的表达,从而起到抗HUVEC凋亡的作用。     

菌根共生体形成过程中的信号识别与转导机制

在菌根共生体建立过程中存在信号分子的多重性和信号通路的多样性以及共牛体特异基因的表达调控,从分子水平上揭示了菌根整个发育过程。     

菌根共生体形成过程中的信号识别与转导机制

在菌根共生体建立过程中存在信号分子的多重性和信号通路的多样性以及共牛体特异基因的表达调控,从分子水平上揭示了菌根整个发育过程。     

磷脂酶D(PLD)基因的结构、表达及其表达产物在信号转导中的作用

磷脂酶D(PLDEC 3 .1 .4.4)水解磷脂 (PL) ,磷脂构成生物膜的骨架 ,磷脂酶的激活不仅对细胞的结构和稳定性有很重要的作用 ,而且调控许多重要的细胞生理功能 ,例如PLD在信号转导、小泡运输、有丝分裂、激素作用的发挥、细胞骨架组装、防御反应以及种子萌发和衰老过程中都起重要作用。近年来它在跨膜信号转导中的重要作用 ,越来越引起人们的重视 ,成为新的研究热点。介绍了磷脂酶基因的结构特点、亚细胞定位、表达的激活抑制以及其表达产物作为胞内信号分子在植物信号转导中的重要作用。     

细胞迁移中微丝微管的变化及其信号转导通路研究进展

细胞迁移是一个多步骤协调的过程。在此过程中,细胞骨架蛋白微丝和微管的动态变化提供了细胞运动的主要动力。而迁移的过程又被多种信号分子组成的复杂的网络所调控。本文主要综述了细胞迁移中微丝和微管的变化以及调控此种变化的分子机制。     

植物信号转导与水稻雄性不育机制研究进展(综述)

本文综述 Ca2 、赤霉素、生长素等信使分子与水稻雄性不育的关系的研究概况。     

生长素代谢、运输及信号转导调控水稻粒型研究进展

水稻(Oryza sativa)是世界主要粮食作物。随着我国经济飞速发展, 耕地面积逐年减少, 提高水稻总产量唯有依靠单产的增加。粒重是决定水稻产量的重要因素之一, 其遗传稳定, 受外界环境因素影响较小。粒重由粒型和灌浆程度决定, 而粒型性状包括粒长、粒宽、粒厚和长宽比。水稻种子颖壳和胚乳发育决定了粒型和粒重, 颖壳细胞的增殖和扩张限制籽粒发育, 胚乳占据成熟种子的大部分体积。而生长素调控受精后颖壳和胚乳的发育, 是调控种子发育和影响水稻产量的重要植物激素。生长素的时空分布受生长素代谢、运输和信号转导的动态调节, 以维持生长素在种子发育中的最适水平。该文综述了生长素代谢、运输和信号转导调控水稻粒型的研究进展, 以期为深入探究生长素调控水稻粒型发育机制和提高水稻产量提供线索。     

解毒化瘀汤联合刺络放血疗法对血瘀热结证寻常型银屑病患者血清炎性因子及CREB信号传导通路相关蛋白表达的影响

摘要 目的：探讨解毒化瘀汤联合刺络放血疗法对血瘀热结证寻常型银屑病患者血清炎性因子及cAMP反应元件结合蛋白（CREB）信号传导通路相关蛋白表达的影响。方法：选取2018年5月到2020年5月武警成都支队卫生队和武警四川总队医院收治的寻常型银屑病患者共80例,随机分成对照组（维A酸哈西奈德乳膏治疗）与观察组（解毒化瘀汤联合刺络放血疗法治疗）,各40例。两组均以4周为1个疗程,共治疗2个疗程。对比两组疗效、中医证候积分、血清炎性因子及CREB信号传导通路相关蛋白表达水平。结果： 观察组的临床总有效率高于对照组（P<0.05）。两组治疗后中医证候主证、次证总评分和血清白介素-17（IL-17）、肿瘤坏死因子-α（TNF-α）、干扰素-γ（IFN-γ）、C反应蛋白（CRP）水平以及CREB微小核糖核酸（mRNA）、PKA mRNA、P38 mRNA相对表达量均较治疗前下降,且观察组较对照组低（P<0.05）。结论：解毒化瘀汤联合刺络放血疗法治疗血瘀热结证寻常型银屑病患者,疗效显著,可有效改善临床症状,减轻机体炎性反应,其主要作用机制可能与调节CREB信号传导通路相关蛋白表达有关。     

Comparison Between the Timing of JNK activation, c-Jun Phosphorylation, and Onset of Death Commitment in Sympathetic Neurones

Abstract: We have investigated the relationship between c-Jun N-terminal kinase (JNK) activity, apoptosis, and the potential of survival factors to rescue primary rat sympathetic neurones deprived of trophic support. Incubation of sympathetic neurones in the absence of nerve growth factor (NGF) caused a time-dependent increase in JNK activity, which became apparent by 3 h and attained maximal levels that were three- to fourfold higher than activity measured in neurones maintained for the same periods with NGF. Continuous culture in the presence of either NGF or the cyclic AMP analogue 4-(8-chlorophenylthio) cyclic AMP (CPTcAMP) not only prevented JNK activation from occurring, but also suppressed JNK activity that had been elevated by prior culture of the neurones in the absence of trophic support. When either NGF or CPTcAMP was added to cultures that had been initially deprived of neurotrophic support for up to 10 h, this resulted in complete suppression of total JNK activity, arrest of apoptosis, and rescue of >90% of the neurones that did not display apoptotic morphology by this time. However, when either agent was added after more protracted periods of initial neurotrophin deprivation (≥ 14 h), although this also resulted in near-complete suppression of total JNK activity and short-term arrest of apoptosis, not all of the neurones that appeared to be nonapoptotic at the time of agent addition were rescued. The lack of death commitment after 10 h of maintained JNK activity was not due to a late induction of c-Jun expression, because the majority of newly isolated sympathetic neurones had already been expressing high levels of c-Jun in their nuclei for several hours, yet were capable of being rescued by NGF. Elevation of JNK activity as a result of neurotrophic-factor deprivation was also associated with enhanced phosphorylation of c-Jun, assessed by immunoblot analysis and immunocytochemistry, and addition of NGF to cultures previously deprived of neurotrophic support resulted in a reversion of the state of phospho-c-Jun to that observed in cultures that had been maintained in the continuous presence of trophic support. We conclude that activation of JNK and c-Jun phosphorylation are not necessarily rate-limiting for apoptosis induction. In some neurones undergoing prolonged NGF deprivation, suppression of JNK activity and c-Jun dephosphorylation by NGF may be insufficient to effect their rescue. Thus, if c-Jun mediates death by increasing the expression of “death” genes, these must become effective very close to the death commitment point.     

Complex Structure and Biochemical Characterization of the Staphylococcus aureus Cyclic Diadenylate Monophosphate (c-di-AMP)-binding Protein PstA,the Founding Member of a New Signal Transduction Protein Family

Signaling nucleotides are integral parts of signal transduction systems allowing bacteria to cope with and rapidly respond to changes in the environment. The Staphylococcus aureus PII-like signal transduction protein PstA was recently identified as a cyclic diadenylate monophosphate (c-di-AMP)-binding protein. Here, we present the crystal structures of the apo- and c-di-AMP-bound PstA protein, which is trimeric in solution as well as in the crystals. The structures combined with detailed bioinformatics analysis revealed that the protein belongs to a new family of proteins with a similar core fold but with distinct features to classical PII proteins, which usually function in nitrogen metabolism pathways in bacteria. The complex structure revealed three identical c-di-AMP-binding sites per trimer with each binding site at a monomer-monomer interface. Although distinctly different from other cyclic-di-nucleotide-binding sites, as the half-binding sites are not symmetrical, the complex structure also highlighted common features for c-di-AMP-binding sites. A comparison between the apo and complex structures revealed a series of conformational changes that result in the ordering of two anti-parallel β-strands that protrude from each monomer and allowed us to propose a mechanism on how the PstA protein functions as a signaling transduction protein.     

A Randomized Clinical Trial to Determine the Efficacy of Regimens Containing Clarithromycin, Metronidazole, and Amoxicillin Among Histologic Subgroups for Helicobacter pylori Eradication in a Developing Country

Background: Most treatments deemed effective for Helicobacter pylori eradication in developed countries are less effective in developing countries. Regimens containing clarithromycin, metronidazole, and amoxicillin seem efficacious despite antibiotic resistance, and may be a viable option in developing countries. Materials and Methods: We evaluated the efficacy of a 14‐day regimen with 500 mg clarithromycin b.i.d., 500 mg metronidazole t.i.d., and 500 mg amoxicillin t.i.d. (with and without a proton pump inhibitor), and a 10‐day regimen containing 500 mg clarithromycin b.i.d., 1 g amoxicillin b.i.d., and 20 mg omeprazole b.i.d. in Pasto, Colombia, using a randomized, single‐blind design stratified by presence of atrophic gastritis. Results: H. pylori was eradicated in 86.8% and 85.3% of the participants randomized to a clarithromycin‐metronidazole‐amoxicillin and clarithromycin‐amoxicillin‐omeprazole regimens, respectively (p = .79). Per‐protocol analyses indicated greater efficacy for the clarithromycin‐metronidazole‐amoxicillin regimen (97%) versus the clarithromycin‐amoxicillin‐omeprazole regimen (86%) (p = .04), particularly for participants with atrophic gastritis (clarithromycin‐metronidazole‐amoxicillin = 100%, clarithromycin‐amoxicillin‐omeprazole = 81%; p = .02). Adverse events were mild, but adverse event‐related non‐compliance was reported more often for regimens containing clarithromycin, metronidazole, and amoxicillin. Conclusions: Our results suggest that an eradication rate of > 85% can be achieved with 14‐day clarithromycin, metronidazole, and amoxicillin and 10‐day clarithromycin, amoxicillin, and omeprazole regimens in Pasto, Colombia. The regimens containing clarithromycin, metronidazole, and amoxicillin appear to be superior to the clarithromycin, amoxicillin, and omeprazole regimen for compliant participants and those with atrophic gastritis. Our findings provide treatment options for a population in a developing country with a high prevalence of H. pylori infections and antibiotic resistance.     

Nutrient-induced signal transduction through the protein kinase A pathway and its role in the control of metabolism, stress resistance, and growth in yeast

Yeast cells growing in the presence of glucose or a related rapidly-fermented sugar differ strongly in a variety of physiological properties compared to cells growing in the absence of glucose. Part of these differences appear to be caused by the protein kinase A (PKA) and related signal transduction pathways. Addition of glucose to cells previously deprived of glucose triggers cAMP accumulation, which is apparently mediated by the Gpr1-Gpa2 G-protein coupled receptor system. However, the resulting effect on PKA-controlled properties is only transient when there is no complete growth medium present. When an essential nutrient is lacking, the cells arrest in the stationary phase G0. At the same time they acquire all characteristics of cells with low PKA activity, even if there is ample glucose present. When the essential nutrient is added again, a similar PKA-dependent protein phosphorylation cascade is triggered as observed after addition of glucose to glucose-deprived cells, but which is not cAMP-mediated. Because the pathway involved requires a fermentable carbon source and a complete growth medium, at least for its sustained activation, it has been called “fermentable growth medium (FGM)-induced pathway.”     

非小细胞肺癌组织KIF2A、KIF2C、KIF20A mRNA表达与临床病理特征和预后的关系

摘要 目的：探讨非小细胞肺癌（NSCLC）组织驱动蛋白超家族成员2A（KIF2A）、驱动蛋白超家族成员2C（KIF2C）、驱动蛋白超家族成员20A（KIF20A）信使核糖核酸（mRNA）表达与临床病理特征和预后的关系。方法：选择2016年9月至2019年9月天津医科大学总医院手术切除的NSCLC患者106例,取其癌组织及其对应的癌旁组织,应用荧光定量聚合酶链式反应（RT-qPCR）检测组织中KIF2A、KIF2C、KIF20A mRNA表达,分析其与临床病理特征的关系。应用 Pearson相关性分析NSCLC组织中KIF2A、KIF2C、KIF20A mRNA表达间的关系。随访3年,应用Kaplan-Meier生存曲线分析KIF2A、KIF2C、KIF20A mRNA表达与患者预后关系。结果：NSCLC癌组织中KIF2A、KIF2C、KIF20A mRNA表达水平显著高于癌旁组织（P<0.05）。低分化、淋巴结转移、临床分期Ⅲ A 期NSCLC癌组织中KIF2A、KIF2C、KIF20A mRNA表达水平显著高于中高分化、无淋巴结转移及临床分期I、II期NSCLC癌组织（P<0.05）。Pearson相关分析显示,NSCLC癌组织中KIF2A mRNA表达与KIF2CmRNA、KIF20A mRNA表达呈正相关,KIF2C mRNA表达与KIF20A mRNA表达呈正相关（P<0.05）。Kaplan-Meier法分析显示KIF2A mRNA低表达组、KIF2C mRNA低表达组、KIF20A mRNA低表达组3年生存率分别为（84.78%,86.27%,81.48%）显著高于KIF2A mRNA高表达组、KIF2C mRNA高表达组、KIF20A mRNA高表达组（59.62%,55.32%,59.09%）（P<0.05）。结论：KIF2A、KIF2C、KIF20A mRNA在NSCLC组织中存在高表达,且与低分化、淋巴结转移、临床分期及预后有关。