Reg基因蛋白家族的研究进展

Reg基因蛋白（regenerating gene protein）属于钙依赖的植物血凝素超家族,其功能类似应激蛋白、抗凋亡因子或生长因子。Reg基因蛋白的促进胰岛β细胞分裂和诱导再生作用最早是在糖尿病研究中被发现。Reg基因蛋白在人体多种组织中均表达,与细胞增殖、炎症创伤、感染和神经系统发育关系密切。随着研究的深入,Reg基因蛋白在胰腺损伤修复、神经系统损伤、消化系统肿瘤、脓毒血症及其他疾病中的作用逐渐引起人们重视。     

P53基因研究新进展

肿瘤抑制基因在肿瘤发生过程中有重要作用,其中P53基因最引现人注目,P53基因的突变与人类一半以上的肿瘤发生相关,P53基因参与细胞生长的负调控,研究发生P53基因编码的P53蛋白可通过调控Cipl基因表达而调控细胞生长,即P53蛋白可刺激Cipl基因产生分子量为21kD的蛋白,这种蛋白能够有效抑制某些促使细胞通过细胞周期进入有丝分裂的酶活性,从而抑制细胞生长,这就解释了为什么正常的P53基因的缺失可导致细胞的无限生长,此外,P53基因与DNA损伤药物诱导的细胞凋亡有关,与非DNA损伤药物诱导的细胞调亡无关。     

Reg基因家族蛋白对胰岛β细胞生长的影响

Reg基因家族蛋白,属于C型凝集素超家族,具有相同的钙依赖性碳水化合物识别域,在损伤、感染、糖尿病及肿瘤中发生作用.近年来,已有18个Reg基因家族成员被克隆和鉴定.本文综述Reg基因家族蛋白的分类和基因表达调节,以及Reg基因家族蛋白对胰岛β细胞增殖与在自身免疫中的作用.Reg I和人胰岛再生相关蛋白(INGAP)在体外或体内参与胰腺的再生.在1型糖尿病发生中,Reg I和Reg II可做为自身抗原.尽管Reg基因蛋白的功能尚不清楚,但为1型糖尿病的治疗带来新的希望.     

DEK对人子宫内膜蜕膜化的调节作用

为探讨DNA结合蛋白果蝇Eph激酶(Drosophila Eph kinase,DEK)对人子宫内膜基质蜕膜化的调节作用和途径,该研究采用qPCR(Real-time quantitative polymerase chain reaction)、免疫组化(immunohistochemical)和蛋白印迹(Western blot)分别检测人子宫内膜增生期、分泌期和蜕膜组织中DEK基因和蛋白的表达;利用siRNA抑制基质细胞和蜕膜细胞的DEK,再用细胞流式技术、细胞免疫荧光、qPCR、细胞碱性磷酸酶脂显色和Western blot检测DEK沉默后细胞的变化。结果显示,蜕膜组织中DEK mRNA表达水平低于增生期和分泌期(P0.05),蜕膜组织中DEK蛋白表达水平高于增生期和分泌期(P0.05);抑制基质细胞DEK会使细胞增殖和分化能力降低,从而抑制基质细胞蜕膜化;抑制蜕膜细胞DEK可使细胞凋亡增加,DNA损伤情况加剧,导致蜕膜细胞的维持和发展受到影响。综上,该研究初步证实,DEK可能通过调控细胞蜕膜化而参与胚胎着床过程,其可能途径与其通过调控细胞增殖、分化、凋亡和核损伤有关。     

新的凋亡抑制因子Survivin的研究进展

Survivin是近年来发现的一种凋亡抑制因子,属于凋亡抑制蛋白（inhibitor of apoptosis proteins,IAP）家族的新成员;主要通过抑制caspase-3和caspase-7的活性而阻断细胞凋亡过程. Survivin选择性地表达于胚胎发育组织和大多数肿瘤组织,而正常成人终末分化组织中不表达. Survivin参与了细胞周期调控,与肿瘤的发生、发展和预后密切相关,可作为肿瘤治疗的新靶点.     

p53与细胞畸变的抑制

有关p53蛋白的研究,近年来开展得极为广泛。p53蛋白作为一种极其重要的肿瘤抑制子不但在细胞凋亡和细胞生长抑制中起着重要的作用,而且还参与了细胞衰老的调控,并与细胞分化关系密切。本文对当前在有关p53分子研究方面取得的成果进行了综述,希望它有助于这方面研究工作的进一步开展。     

酿酒酵母Cdk1抑制蛋白的研究进展

细胞周期蛋白依赖性激酶1(cyclin-dependent kinase 1,Cdk1)是真核生物细胞周期调控的核心,也是维持基因组稳定性的重要激酶,其活性受到严格调控.CDK抑制蛋白(cyclin-dependent kinase inhibitor,CKI)是调节其活性的一类关键负调控因子,CKI功能失活导致细胞不受控制地增殖,促进癌症的发生发展.酿酒酵母作为细胞周期研究的重要模式生物,在揭示CDK活性调控机制中发挥着重要作用.酿酒酵母中已发现的Cdk1抑制蛋白CKI包括Far1、Sic1以及最近鉴定的Cip1蛋白.这三个CKI蛋白在不同细胞时期中,通过抑制Cdk1活性调控细胞周期的进程.此外,CKI还在应对环境胁迫,保持基因组稳定性中发挥重要作用.本文对酿酒酵母Cdk1抑制蛋白CKI的研究进展,尤其是CKI在细胞周期运转及胁迫应答中的作用做出综述,以期为细胞周期及癌症的基础研究提供模式依据.     

衣原体抗宿主细胞凋亡调控机制研究进展

衣原体为完成发育周期以及逃避宿主免疫,进化形成一整套机制以实现持续性感染并对宿主细胞进行调控,抑制宿主细胞凋亡。细胞感染衣原体后,早期可以抑制Caspase酶系,抑制相关信号转导途径,且胞内线粒体发生一系列结构和功能的变化,抑制凋亡因子释放,一系列因子协同作用,抑制宿主细胞凋亡。本文从凋亡途径、凋亡蛋白、凋亡信号通路三个主要方面作了衣原体抑制宿主细胞凋亡机制概述,对进一步了解衣原体发育及其致病机制提供了新的研究思路。     

调控p53蛋白的转录因子

肿瘤抑制因子p53被称为"分子警察",它在维持细胞正常生长及抑制恶性增殖过程中起重要作用。p53的表达水平受多种因素影响,其中转录水平的调控是基因发挥功能的一个重要步骤。因此,针对调控p53蛋白的转录因子这一环节阐明p53发挥功能的分子机理,有望为肿瘤治疗、预防和新药研发提供新的靶标。本文着重对调控p53蛋白的转录因子进行综述。     

XIAP在胰腺癌化疗耐药及治疗中的研究进展

X连锁的凋亡抑制蛋白(X-linked inhibitor of apoptosis protein,XIAP)是凋亡抑制蛋白家族中的一员,具有抗凋亡作用.研究发现XIAP在胰腺癌中呈高表达,并且能诱导胰腺癌细胞及组织对化疗耐药.通过在基因水平及蛋白水平降低XIAP的表达对胰腺癌的治疗具有重要意义.AEG 35156是针对XIAP的反义寡核苷酸分子,能够抑制胰腺癌细胞及组织生长.RNAi能够稳定下调胰腺癌细胞中XIAP水平,从而加强TRAIL诱导的细胞凋亡,并能提高胰腺癌细胞对化疗的敏感性.针对XIAP的小分化合物能够抑制XIAP的功能,释放被XIAP抑制的凋亡起始和效应分子以及XIAP抑制的其他促凋亡蛋白,提高多种肿瘤细胞的凋亡指数及对放化疗的敏感性.XAFl能抑制XIAP的抗凋亡作用.本文就XIAP在胰腺癌化疗耐药及治疗中的研究进展做一综述.     

Regenerating islet-derived protein (Reg)3β plays a crucial role in attenuation of ileitis and colitis in mice

Regenerating islet-derived protein (Reg)3β belongs to a member of the Reg family of proteins and has pleiotropic functions, including antimicrobial activity and tissue repair. However, whether Reg3β plays a protective role in the development of colitis and ileitis has not been fully investigated. We generated transgenic mice expressing a short form of cellular FLICE-inhibitory protein (cFLIPs) that promotes necroptosis, a regulated form of cell death. cFLIPs transgenic (CFLARs Tg) mice develop severe ileitis in utero. Although Reg3β is undetectable in the small intestine of wild-type embryos, its expression is aberrantly elevated in the small intestine of CFLARs Tg embryos. To test whether elevated Reg3β attenuates or exacerbates ileitis in CFLARs Tg mice, we generated a Reg3b^?/? strain. Reg3b^?/? mice grew to adulthood without apparent abnormalities. Deletion of Reg3b in CFLARs Tg mice exacerbated the embryonic lethality of CFLARs Tg mice. Dextran sulfate sodium-induced colitis, characterized by body weight loss and infiltration of neutrophils, was exacerbated in Reg3b^?/? compared to wild-type mice. Moreover, the expression of Interleukin 6, an inflammatory cytokine and Chitinase-like 3, a marker for tissue repair macrophages was elevated in the colon of Reg3b^?/? mice compared to wild-type mice after DSS treatment. Together, these results suggest that attenuation of colitis and ileitis is a result of Reg3β′s real function.     

Reg I protein in healthy and seminoma human testis

Regenerating gene (Reg), encodes a secretory protein with growth and differentiation stimulating effects mostly in digestive tissues. Overexpression of Reg proteins and specifically of Reg I, one member of the Reg family, is associated with several human diseases and cancers. In the present study we analyzed the expression of Reg I in normal rodent and human testes where germ cells normally proliferate and differentiate into spermatozoa, and in seminoma testis, the most common cancer of young men. Western blot analyses demonstrated the presence of a specific band at 19 kDa in human and rodent testis extracts. Immunofluorescence and deconvolution microscopy demonstrated that Reg I was present within the seminiferous tubules in both Sertoli and germ cells. By using a Sertoli cell line we demonstrated that Reg I was localized at the plasma membrane even in the absence of contact between neighboring cells and appeared before the tight junction associated protein ZO-1 was revealed at this location. Reg I was strongly expressed in human seminoma testis tissue and in a human tumor germ cell line where the immunoreactive signal was mainly detected at the plasma membrane level. These data showing for the first time the weak presence of Reg I in the normal testis and its strong expression in the testis cancer suggest a potential role of Reg I in normal and neoplastic germ cell proliferation.     

Reg3b在大鼠耳蜗的分布及噪声刺激后的表达变化

目的：探讨Reg3b在大鼠耳蜗中的分布情况及在噪声刺激前后的表达变化,为治疗噪声性聋提供新思路。方法：30只健康成年SD大鼠,分为噪声暴露组和正常对照组,利用110dBSPL宽频稳态白噪声对噪声组进行噪声暴露,通过免疫组织荧光技术,观察Reg3b在正常及噪声刺激后成年sD大鼠耳蜗内的分布情况。采用实时定量PCR技术（Realtime-PCR）方法检测大鼠接受噪声刺激前后Reg3b在耳蜗内的表达变化。结果：免疫组织荧光技术提示,Reg3b在噪声暴露后主要表达于大鼠耳蜗的内毛细胞、外毛细胞,以及螺旋神经节处,而正常大鼠耳蜗中Reg3b表达不明显或呈阴性表达。与噪声刺激前相比,噪声刺激后,Reg3b在mRNA水平表达较噪声前明显提高。结论：Reg3b在耳蜗内的分布及在噪声刺激后的表达显著升高提示其在噪声诱导的细胞死亡及对抗噪声损伤方面具有一定作用,可能成为治疗感音神经性聋的新靶点。     

Reg genes are CCK2 receptor targets in ElasCCK2 mice pancreas

We previously demonstrated that expression of the gastrin receptor, CCK2R, in pancreatic acini of transgenic ElasCCK2 mice induced alteration of acinar morphology and differentiation, increased sensitivity to a carcinogen and development of preneoplastic lesions and tumours. Reg proteins are suggested to be involved in pancreatic cancer and in regeneration of endocrine pancreas. Reg I gene is a known target of gastrin. We examined whether an expression of CCK2R in the pancreatic acini of ElasCCK2 mice is linked to induction of Reg proteins expression. We analyzed Reg expression by Western-blot and immunohistochemistry in pancreas from ElasCCK2 and control mice. Islet neogenesis, glucose homeostasis, insulin secretion and content were also evaluated. Reg I is exclusively produced in acini in ElasCCK2 and control mice. In tumoral pancreas, Reg I and Reg III proteins are expressed in duct-like cells in preneoplastic lesions or in the periphery of tumours and in adjacent acini. The expression of Reg III proteins is increased in ElasCCK2 pancreas before the development of preneoplastic lesions in a subpopulation of islet cells and in small islet-like cell clusters dispersed within the acinar tissue. Several criteria of an enhanced neogenesis are fulfilled in ElasCCK2 pancreas. Moreover, ElasCCK2 mice have an improved response to glucose load, an increased insulin secretion and a doubling of insulin content compared to control mice. We show that Reg proteins are targets of CCK2R activation and are induced during early steps of carcinogenesis in ElasCCK2 mice pancreas. Alterations of exocrine tissue homeostasis in ElasCCK2 pancreas concomitantly activate regenerative responses of the endocrine pancreas possibly linked to paracrine actions of Reg III proteins.     

Natural versus adaptive regulatory T cells

The regulation of immune responses to self-antigens is a complex process that involves maintaining self-tolerance while retaining the capacity to mount robust immune responses against invading microorganisms. Over the past few years, many new insights into this process have been gained, leading to the re-emergence of the idea that regulatory T (T(Reg)) cells are a central mechanism of immune regulation. These insights have raised fundamental questions concerning what constitutes a T(Reg) cell, where they develop and what signals maintain T(Reg)-cell populations in a functional state. Here, we propose the existence of two subsets of CD4+ T(Reg) cells--natural and adaptive--that differ in terms of their development, specificity, mechanism of action and dependence on T-cell receptor and co-stimulatory signalling.     

Isolation and characterization of a cDNA encoding a novel member of the human regenerating protein family: Reg IV

Human Reg and Reg-related genes constitute a multi-gene family belonging to the calcium (C-type) dependent lectin superfamily. Regenerating gene family members are expressed in the proximal gastrointestinal (GI) tract and ectopically at other sites in the setting of tissue injury. By high-throughput sequence analysis of a large inflammatory bowel disease library, two cDNAs have been isolated which encode a novel member of this multigene family. Based on primary sequence homology, tissue expression profiles, and shared exon-intron junction genomic organization, we assign this gene to the regenerating gene family. Specific protein structural differences suggest that the current three regenerating gene subtypes should be expanded to four. We demonstrate that Reg IV has a highly restricted tissue expression pattern, with prominent expression in the gastrointestinal tract. Reg IV mRNA expression is significantly up-regulated by mucosal injury from active Crohn's disease or ulcerative colitis.     

Establishment of a pancreatic β cell proliferation model in vitro and a platform for diabetes drug screening

Diabetes, a disease resulting from loss of functional β cells, is globally an increasingly important condition. Based on the islet-differentiation ability of ductal epithelial cells and stimulating β cell proliferation ability of the Reg Iα gene, we aimed to establish an in vitro pancreatic β cell proliferation model for screening therapeutic drugs of diabetes in the future. Pancreatic ductal epithelial cells were isolated from male Wistar rats, and induced to differentiate into pancreatic β cells. Immunofluorescence staining assay, western blot, RT-PCR analysis, and dithizone staining were used to characterize the cells. Rat Reg Iα protein was transiently expressed in vitro by transfection of HEK 293 cells with the PCMV6-entry-REG Ia plasmid, and expression was verified by RT-PCR analysis, proliferation assay, and apoptosis assay. The pancreatic β cell proliferation model was further validated by a proliferation assay using differentiated pancreatic β cells treated with transfection supernatant. Finally, we have successfully established an in vitro pancreatic β cells proliferation model using transiently expressed rat Reg Iα protein and differentiated pancreatic β cells from pancreatic ductal epithelial cells. This model could be used as a platform to screen new drugs for islet neogenesis to cure diabetes, especially Chinese herbal drugs in the future.