Significance of glycosylation in Notch signaling

Notch signaling is essential for cell-fate specification in metazoans, and dysregulation of the pathway leads to a variety of human diseases including heart and vascular defects as well as cancer. Glycosylation of the Notch extracellular domain has emerged as an elegant means for regulating Notch activity, especially since the discovery that Fringe is a glycosyltransferase that modifies O-fucose in 2000. Since then, several other O-glycans on the extracellular domain have been demonstrated to modulate Notch activity. Here we will describe recent results on the molecular mechanisms by which Fringe modulates Notch activity, summarize recent work on how O-glucose, O-GlcNAc, and O-GalNAc glycans affect Notch, and discuss several human genetic disorders resulting from defects in Notch glycosylation.     

Structural features of the Notch ankyrin domain-Deltex WWE2 domain heterodimer determined by NMR spectroscopy and functional implications

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Characterization of Notch3-deficient mice: normal embryonic development and absence of genetic interactions with a Notch1 mutation

The Notch signaling pathway is an evolutionarily conserved signaling mechanism and mutations in its components disrupt cell fate specification and embryonic development in many organisms. To analyze the in vivo role of the Notch3 gene in mice, we created a deletion allele by gene targeting. Embryos homozygous for this mutation developed normally and homozygous mutant adults were viable and fertile. We also examined whether we could detect genetic interactions during early embryogenesis between the Notch3 mutation and a targeted mutation of the Notch1 gene. Double homozygous mutant embryos exhibited defects normally observed in Notch1-deficient embryos, but we detected no obvious synergistic effects in the double mutants. These data demonstrate that the Notch3 gene is not essential for embryonic development or fertility in mice, and does not have a redundant function with the Notch1 gene during early embryogenesis.     

Notch信号通路对免疫细胞的调节作用

Notch家族是一组进化上高度保守的跨膜蛋白,可以广泛调节细胞的发育和分化.越来越多的研究发现,Notch信号通路可以通过调节多种免疫细胞的发育和功能来调节机体的免疫功能.本文综述了Notch家族的组成,其调控因素及其靶基因,Notch信号通路对造血干细胞、固有免疫细胞和适应性免疫细胞的调节作用以及Notch信号通路参与的免疫相关疾病.Notch信号通路对造血干细胞、巨噬细胞、树突状细胞、肥大细胞、T和B淋巴细胞的发育和功能的发挥都有重要的调节作用,并参与肿瘤、病毒感染、炎症反应和自身免疫疾病等免疫相关疾病的发生.     

Notch 通路在大鼠肝纤维化发生发展中作用的初探

目的:研究Notch通路在肝纤维发生发展中作用及可能的分子机制。方法:Wistar大鼠40只随机分为正常对照组与病理模型组,病理模型组皮下注射四氯化碳制备肝纤维化模型。8周后将大鼠处死,取肝组织行病理HE染色评价肝纤维化程度并采用免疫组织化学法检测Notch-1蛋白、E-cadherin蛋白与TGF-β1蛋白的表达。结果:肝组织病理HE染色示肝纤维化大鼠肝脏肝细胞坏死、再生明显,胶原纤维沉积明显增加,肝实质结构紊乱。与正常对照组相比,病理模型组notch-1与TGF-β1蛋白表达明显增加,而E-cadherin蛋白的表达明显下降(P<0.01)。结论:Notch通路在大鼠肝纤维化发生发展中可能起重要作用。     

Notch和Wnt信号通路在血管形成中的协同调控作用

Notch和Wnt信号通路能够调控细胞的分化、增殖、迁移和粘附等多种行为,在胚胎发育、干细胞分化及肿瘤生长等方面发挥多样性的调控作用.血管形成过程中的典型事件包括尖端细胞(tipcell)和柄细胞(stalkcell)分化、柄细胞增殖、内皮细胞迁移和粘附、血管重塑以及动静脉分化等.本文对Notch和Wnt信号通路在血管形成不同阶段的功能作一综述,以期描述Notch和Wnt是怎样在分子水平上协同作用进而调控血管的形成.从两条信号通路的分子水平及复杂信号网络中众多成员协调作用的角度了解血管形成的机制,对于调整肿瘤等涉及血管形成的相关疾病的治疗策略具有一定意义.     

Notch 信号通路与淋巴细胞发育

Notch 信号通路为一广泛应用且高度保守的信号转导途径,决定多能祖细胞的分化方向,其中在共同淋巴祖细胞向 T 淋巴细胞或 B 淋巴细胞分化选择中具有决定性作用 . Notch 信号通路参与淋巴细胞的发育过程,促进 Tαβ细胞的形成、诱导处女型 T 细胞变为调节型 T 细胞、阻止 CD4+T 细胞向 Th1 类型分化,以及增加外周免疫器官边缘区 B 细胞的数量 . 在分析 Notch 蛋白结构的基础上,综合最新进展,系统阐明了 Notch 信号通路的组成、作用机制、参与的淋巴细胞发育过程以及所起的作用 .     

Loss of Notch2 and Notch3 in vascular smooth muscle causes patent ductus arteriosus

The overlapping roles of the predominant Notch receptors in vascular smooth muscle cells, Notch2 and Notch3, have not been clearly defined in vivo. In this study, we use a smooth muscle‐specific deletion of Notch2 together with a global Notch3 deletion to produce mice with combinations of mutant and wild‐type Notch2/3 alleles in vascular smooth muscle cells. Mice with complete loss of Notch3 and smooth muscle‐expressed Notch2 display late embryonic lethality and subcutaneous hemorrhage. Mice without smooth muscle‐Notch2 and only one wild‐type copy of Notch3 die within one day of birth and present with vascular defects, most notably patent ductus arteriosus (DA) and aortic dilation. These defects were associated with decreased expression of contractile markers in both the DA and aorta. These results demonstrate that Notch2 and Notch3 have overlapping roles in promoting development of vascular smooth muscle cells, and together contribute to functional closure of the DA. genesis 53:738–748, 2015. © 2015 Wiley Periodicals, Inc.     

泛素连接酶对Notch 信号途径的调节作用

Notch信号途径是生物进化过程中高保守的信号通路,对细胞的定向发育及成熟起到决定性的作用。Notch信号途径受到多种分子机制的严格调控。近年来,多项研究均突出了泛素化在调控Notch信号途径活性中的重要性。本文就四种E3泛素连接酶Su(dx)/Itch、Sel-10、LNX以及Neuralized对于调控Notch受体及Notch信号途径配体的研究现况作一综述。     

泛素连接酶对Notch信号途径的调节作用

Noah信号途径是生物进化过程中高保守的信号通路,对细胞的定向发育及成熟起到决定性的作用。Notch信号途径受到多种分子机制的严格调控。近年来,多项研究均突出了泛素化在调控Noah信号途径活性中的重要性。本文就四种E3泛素连接酶Su（dx）Itch、Sel-10、LNX以及Neuralized对于调控Noah受体及Notch信号途径配体的研究现况作一综述。     

Notch信号通路与肺纤维化

Notch信号通路是在进化上非常保守的单次跨膜信号受体蛋白家族,广泛表达于脊椎动物与无脊椎动物中,主要由Notch受体、Notch配体及细胞内效应分子CSL蛋白组成。Notch信号通路是多种组织和器官早期发育所必需的细胞间调节信号,参与对细胞增殖、分化、凋亡的调控。近年的研究表明,Notch信号通路参与肺纤维化的发生发展,阻断或激活这一途径可以影响肺纤维化的进展,本文就Notch信号通路与肺纤维化的关系的研究进展做一综述。     

LIM结构域蛋白FHL1C抑制Notch信号途径的转录激活研究

目的：克隆人表达FHL1C基因以及建立真核表达载体和慢病毒载体。方法：从人的骨骼肌细胞来源的cDNA中扩增并克隆人FHL1C基因的编码区,连接至pMD-18T载体酶切鉴定后测序。序列测定确认后,双酶切pMD18T-FHL1C回收片段,插入真核表达载体,构建真核表达载体pCMV-Myc-FHL1C酶切鉴定正确后,转染Hela细胞及Cos7细胞,用Western Blot检测其在转染细胞中的表达,用双荧光素报告基因系统检测其对Notch信号作用。构建FHL1C-IRES-GFP表达单元,建立慢病毒表达载体plen-ti6/V5-FHL1C-IRES-GFP,包装慢病毒后感染培养的细胞,用免疫荧光显微镜、Western Blot检测分析其在被感染的细胞中的表达。结果：通过PCR方法成功扩增了人FHL1C基因的编码区。通过转染Hela及Cos7细胞,使用Western Blot检测其蛋白水平表达,双荧光报告基因系统分析均能够下调激活的Notch信号。成功构建了FHL1C慢病毒表达载体pLenti6/V5-FHL1C-IRES-GFP,包装慢病毒,把获取的慢病毒感染细胞后通过荧光显微镜证实被感染的细胞绿色荧光蛋白正确表达,Western Blot检测证实其表达。结论：成功建立起FHL1C真核表达载体及慢病毒表达系统,为研究急性T淋巴细胞白血病与Notch信号转导通路之间的关系奠定了基础。     

Notch3对促进胰腺星形细胞活化的基因表达及信号通路的影响

目的:分离培养小鼠胰腺星形细胞(PSCs),检测Notch3对促进PSCs活化的基因表达及信号通路的影响.方法:对小鼠PSCs进行分离培养及传代.采用免疫荧光染色检测活化的小鼠PSCs中α-SMA,fibronectin及collagen Ⅰ的表达;细胞分组为空白对照组(MOCK组),阴性对照组(转染Notch3 si...     

Notch 信号通路与Neuralized蛋白

Notch信号通路在脊椎动物和无脊椎动物许多组织的发育过程和细胞间通讯中都发挥了关键的作用,包括调控细胞命运,调节细胞迁移,分化和增殖.Notch信号通路由Notch受体及其跨膜配体如Delta（Dl）和Serrate组成.Neuralized 蛋白（Neur）编码1个E3泛素连接酶,是Notch配体D1内吞所必需的.Neur蛋白包括3个从线虫到人高度保守的结构域：2个Neur同源重复结构域（NHR1和NHR2）和1个C端RING结构域.本文就Notch信号通路主要元件和Neru的结构与功能及其关系进行综述.     

b-Annulated 1,4-dihydropyridines as Notch inhibitors

The Notch signaling pathway is involved in cell proliferation and differentiation, and has been recognized as an active pathway in regenerating tissue and cancerous cells. Notch signaling inhibition is considered a viable approach to the treatment of a variety of conditions including colorectal cancer, pancreatic cancer, breast cancer and metastatic melanoma. The discovery that the b-annulated dihydropyridine FLI-06 (1) is an inhibitor of the Notch pathway with an EC50?≈?2.5?μM prompted us to screen a library of related analogs. After structure activity studies were conducted, racemic compound 7 was identified with an EC50?=?0.36?μM. Synthesis of individual enantiomers provided (+)-7 enantiomer with an EC50?=?0.13?μM, or about 20-fold the potency of 1.     

LIM结构域蛋白FHL1C抑制Notch信号途径的转录激活研究

目的:克隆人表达FHL1C基因以及建立真核表达载体和慢病毒载体。方法:从人的骨骼肌细胞来源的cDNA中扩增并克隆人FHL1C基因的编码区,连接至pMD-18T载体酶切鉴定后测序。序列测定确认后,双酶切pMD18T-FHL1C回收片段,插入真核表达载体,构建真核表达载体pCMV-Myc-FHL1C酶切鉴定正确后,转染Hela细胞及Cos7细胞,用Western Blot检测其在转染细胞中的表达,用双荧光素报告基因系统检测其对Notch信号作用。构建FHL1C-IRES-GFP表达单元,建立慢病毒表达载体plen-ti6/V5-FHL1C-IRES-GFP,包装慢病毒后感染培养的细胞,用免疫荧光显微镜、Western Blot检测分析其在被感染的细胞中的表达。结果:通过PCR方法成功扩增了人FHL1C基因的编码区。通过转染Hela及Cos7细胞,使用Western Blot检测其蛋白水平表达,双荧光报告基因系统分析均能够下调激活的Notch信号。成功构建了FHL1C慢病毒表达载体pLenti6/V5-FHL1C-IRES-GFP,包装慢病毒,把获取的慢病毒感染细胞后通过荧光显微镜证实被感染的细胞绿色荧光蛋白正确表达,Western Blot检测证实其表达。结论:成功建立起FHL1C真核表达载体及慢病毒表达系统,为研究急性T淋巴细胞白血病与Notch信号转导通路之间的关系奠定了基础。     

Notch signaling in pancreatic endocrine cell and diabetes

Recent studies have improved our understanding of the physiological function of Notch signaling pathway and now there is compelling evidence demonstrating that Notch is a key regulator of embryonic development and tissue homeostasis. Although further extensive studies are necessary to illustrate the molecular mechanisms, new insights into the role of Notch signaling in pancreas development and diabetes have been achieved. Importantly, the ability to regulate Notch signaling intensity both positively and negatively may have therapeutic relevance for diabetes. Thus, this paper reviews the current knowledge of the roles of Notch signaling in the pancreatic endocrine cell system.     

Down-regulation of Notch1 by gamma-secretase inhibition contributes to cell growth inhibition and apoptosis in ovarian cancer cells A2780

The release of Notch intracellular domain (NICD) is mediated by γ-secretase. γ-Secretase inhibitors have been shown to be potent inhibitors of NICD. We hypothesized that Notch1 is acting as an oncogene in ovarian cancer and that inhibition of Notch1 would lead to inhibition of cell growth and apoptotic cell death in ovarian cancer cells. In this study, expressions of Notch1 and hes1 in four human ovarian cancer (A2780, SKOV3, HO-8910, and HO-8910PM), and one ovarian surface (IOSE 144) cell lines were detected by Western blot and quantitative real-time RT-PCR. The effects of γ-secretase inhibition (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester, DAPT) were measured by MTT assay, flow cytometry, ELISA and colony-forming assay. Our results showed that Notch1 and hes1 were found in all the four human ovarian cancer and IOSE 144 cell lines, and they were significantly higher in ovarian cancer cells A2780 compared to another four ovarian cells. Down-regulation of Notch1 expression by DAPT was able to substantially inhibit cell growth, induce G1 cell cycle arrest and induce cell apoptosis in A2780 in dose- and time-dependent manner. In addition, hes1 was found to be down-regulated in dose- and time-dependent manner by DAPT in A2780. These results demonstrate that treatment with DAPT leads to growth inhibition and apoptosis of A2780 cells in dose- and time-dependent manner. These findings also support the conclusion that blocking of the Notch1 activity by γ-secretase inhibitors represents a potentially attractive strategy of targeted therapy for ovarian cancer.     

厄贝沙坦对糖尿病大鼠心肌损伤中Notch1信号通路的影响

目的：观察厄贝沙坦对糖尿病大鼠心肌损伤的作用,分析Notch1信号通路在其中的变化。方法：实验分4组：正常对照组（CON）、高糖高脂组（HC）、糖尿病组（DM）和厄贝沙坦+糖尿病组（Ir+DM）。制作2型糖尿病（T2DM）大鼠模型成功后,第8周开始检测大鼠空腹血糖水平（FBG）、全心质量及左心室重量,计算心脏指数（H/B）及左室重量指数（LVWI）,检测大鼠血浆甘油三酯（TG）、胆固醇（TC）水平,检测心肌组织超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量变化,免疫组化检测Bcl-2、Bax表达变化,Western blot检测大鼠心肌组织Notch1、Hes-1及Jagged-1的蛋白表达。结果：与CON组相比,HC组H/B、LVWI、FBG无明显变化,血脂、MDA含量明显升高,SOD活性、Bcl-2/Bax及Notch1、Hes-1、Jagged-1蛋白表达降低;与HC组相比,DM组H/B、LVWI、FBG、MDA含量增加明显,血脂水平无明显变化,SOD活性、Bcl-2/Bax及Notch1信号通路蛋白表达进一步降低;与DM组相比,厄贝沙坦干预组H/B、LVWI明显降低,血脂、血糖水平无明显变化,但SOD活性、Bcl-2/Bax增加,MDA含量降低,同时Notch1信号通路相关蛋白表达增加。结论：糖尿病可导致大鼠发生心肌损伤,厄贝沙坦可能通过增强Notch1信号通路的表达发挥心肌保护作用。