TGF-β2与妊娠期高血压疾病

妊娠期间母胎界面存在着复杂的免疫调控关系,蜕膜及绒毛作为母体及胎儿的直接接触面,是发生免疫反应的重要部位。多种细胞因子如转化生长因子-β、肿瘤坏死因子-α及血管内皮细胞等具有营养细胞、调控滋养细胞侵入、免疫抑制、防止母胎排斥等多种功能,他们在正常妊娠的维持中起着重要的作用。目前转化生长因子-β2的作用已越来越受重视,本文将从转化生长因子-β2与妊娠期高血压疾病存在的关系作如下综述。     

转化生长因子-β1及Sirt1/2参与高血压诱导的血管平滑肌细胞缝隙连接蛋白-43的表达及细胞增殖

为探讨转化生长因子-β1及组蛋白去乙酰化酶Sirt1和Sirt2在高血压诱导的血管平滑肌细胞缝隙连接蛋白-43表达及细胞增殖中的作用,研究了腹主动脉窄缩诱导高血压大鼠和正常大鼠胸主动脉转化生长因子-β1、缝隙连接蛋白-43、Sirt1和Sirt2,以及细胞增殖标志蛋白增殖细胞核抗原表达的变化;观察Sirt1和Sirt2在转化生长因子-β1刺激大鼠VSMCs缝隙连接蛋白-43的表达及细胞增殖中的作用。结果显示,高血压大鼠胸主动脉的转化生长因子-β1、缝隙连接蛋白-43、TGF-β1、Sirt1和Sirt2的表达及细胞增殖较正常大鼠均明显升高;转化生长因子-β1促进了大鼠血管平滑肌细胞缝隙连接蛋白-43的表达和增殖,Sirt1与Sirt2的抑制剂Salermide有效抑制了转化生长因子-β1诱导的血管平滑肌细胞缝隙连接蛋白-43的表达与细胞增殖。结果表明,高血压通过上调转化生长因子-β1来诱导VSMCs缝隙连接蛋白-43的表达和细胞增殖,而Sirt1和Sirt2可能在其中起调控作用。     

母-胎界面T细胞功能研究进展

母-胎界面免疫耐受是成功妊娠建立和维持的基础,T细胞是子宫蜕膜免疫细胞的重要组成细胞,既要介导抗感染免疫,保护胚胎免遭外来病原体攻击,同时又要参与母体接受同种异体胚胎的复杂免疫调节过程,在调控胚胎植入和维持妊娠过程中发挥重要作用,其功能失调可能会导致早期妊娠失败或中晚期妊娠并发症。本文就近年来关于妊娠期母-胎界面T细胞亚群的组成、表型特征及其功能进行介绍,并进一步阐述蜕膜CD4~+与CD8~+T细胞在母-胎免疫调节中的作用,以及异常调控致早期妊娠失败的分子机制,有助于深入理解母-胎免疫耐受机制,为妊娠相关疾病的防治提供新的线索。     

转化生长因子β作用机理研究新进展

转化生长因子β(TGF-β)是一类多功能的生长因子,参与体内多种过程,对细胞增殖和发育、转化和分化都有一定的调节作用。但其作用机理至今仍不清楚。本文从TGF-β前体的激活、TGF-β受体、基因的调控,以及与原癌基因表达、细胞外基质、生长因子和信号传递系统的关系等方面,综述了近几年来该领域取得的一些重要结果。     

中药基于TGF-β/Smad信号转导通路调控肿瘤细胞

转化生长因子-β(transforming growth factor-β, TGF-β)是一类具有多种生物学功能的多肽类细胞因子,对细胞生长、分化发挥重要作用,与肿瘤的发生、发展具有十分密切的关系。Smads蛋白作为TGF-β信号转导通路下游重要的信号分子,可直接或与其他通路协同将TGF-β通路的信号从细胞外转导到细胞核内,调控TGF-β在细胞水平介导的多种生物学效应。我国抗癌药物研究中的大量资料表明,中药成分可以延缓肿瘤的发生进程,中药或其提取物可通过TGF-β1、Smads或其他效应因子影响TGF-β/Smad通路的信号转导从而调控肿瘤细胞的活动。本文就国内对中药成分基于TGF-β/Smad信号转导通路调控肿瘤细胞生长方面的研究进展予以综述。     

转化生长因子—β超家族成员的信号传导通路

转化生长因子-β超家族是在无脊椎动物和脊椎动物中高度保守的一类细胞因子,其家族成员参与调节细胞的增殖、凋亡、分化和发育等多种生命活动。具有丝氨酸／苏氨酸激酶活性的Ⅰ型受体和Ⅱ型受体共同介导了转化生长因子-β超家族成员的跨膜信号传导。新近克隆鉴定的Smad蛋白家族负责将信号由细胞膜传导到细胞核。Smad介导的信号传导通路同其他信号传导通路之间存在相互调节。转化生长因子-β超家族的信号传导通路异常与肿瘤的发生有密切关系。     

TGF-β1对人正常胎盘滋养层细胞表达E-钙粘素的调节

E-钙粘素是在胚胎发育中最早表达的分子之一,它可以与Catenin家族成员形成钙粘素/Catenin复合物参与多种细胞功能,对于胚胎植入和胎盘发生具有重要作用.通过RT-PCR、免疫组织化学、细胞粘附分析等方法,在人正常妊娠和输卵管妊娠母胎界面上,发现E-钙粘素主要定位于绒毛细胞滋养层细胞和滋养层细胞柱,从滋养层细胞柱近端向远端,其蛋白质水平逐渐降低.正常胎盘组织中E-钙粘素水平在妊娠早期较高,妊娠中期直至分娩期均维持低水平.在体外培养的人正常胎盘细胞滋养层细胞系(NPC细胞)中,转化生长因子β(TGFβ1)显著上调E-钙粘素蛋白和mRNA的表达,并呈现时间和剂量依赖性,同时,TGFβ1促进NPC细胞之间的粘附.上述结果表明,胎盘中存在E-钙粘素的旁分泌调节机制,E-钙粘素可通过调节滋养层细胞粘附而参与细胞侵润的有节制调控.     

TGF-β/Smads信号转导通路的研究进展

转化生长因子（TGF）-β超家族成员的重要生物学功能正日益引起人们的重视。受体介导的胞内信号转导研究近年有较大进展,特别是Smads蛋白介导的信号转导通路为阐明TGF-β超家族的作用机理提供了一条重要线索。TGF-β/Smads信号的转导受到机体严密的调控,并与其他信号通路存在着广泛的交叉对话效应。综述了对TGF-β/Smads信号转导通路的机制、调控,及其在维持机体正常生理功能和疾病发生中的作用的研究进展。     

TGF-β1受体1和2在TGF-β1调节细胞增殖中的作用

转化生长因子β1(transforming growth factor-β1,TGF-β1)是一种多功能细胞因子,在细胞增殖、分化、伤口愈合和肿瘤生成转移等过程中均发挥重要调控作用。TGF-β1对细胞增殖的调节可因细胞类型、刺激剂量不同而不同,但其差异调节的机制还不清楚。现普遍认为,TGF-β1在TGFBR2/TGFBR1二聚体参与下通过经典的Smad信号通路抑制增殖,而通过非Smad信号通路促进细胞周期,但是机体是如何调控这种不同增殖调节作用转化的还不明确。TGFBR1和TGFBR2在细胞中的分布和比例变化可能是TGF-β1差异性调控细胞增殖作用的一个重要机制。     

ERK1/2信号通路参与人滋养层细胞中转化生长因子-β1对MMP-9表达的抑制作用(英文)

正常滋养层细胞的侵润受转化生长因子-β(TGF-β)的调控。该文研究了人正常细胞滋养层细胞(CTB)中TGF-β1对MMP-2和-9表达的调控。结果表明,TGF-β1抑制CTB细胞中MMP-9mRNA的表达和酶原MMP-9的分泌,但不影响MMP-2 mRNA和蛋白的表达。IL-1β和TGF-β1均能抑制MMP-9 mRNA的表达和酶原MMP-9的分泌,但二者的效应互相拮抗。抑制ERK1/2信号通路导致TGF-β1对MMP-9 mRNA和酶原MMP-9的抑制作用受阻。以上结果表明ERK1/2信号通路参与TGF-β31对人滋养层细胞MMP-9表达的抑制作用。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV