Dll3 is expressed in developing hair cells in the mammalian cochlea.

Notch mediates the process of lateral inhibition that controls the production of hair cells in the inner ear. Hair cells are known to express Notch ligands Dll1 and Jag2, which signal through Notch1 in adjacent supporting cells. However, recent genetic and pharmacological studies indicate that the level of Notch-mediated lateral inhibition is greater than can be accounted for by Dll1 and Jag2. Here, we report that another Notch ligand, Dll3, is expressed in developing hair cells, in a pattern that overlaps that of Dll1 and Jag2. We analyzed the cochleae of Dll3(pu) mutant mice, but did not detect any abnormalities. However, earlier studies have demonstrated that there is functional redundancy among Notch ligands in cochlear development and loss of one ligand can be at least partially compensated for by another. Thus Dll3 may play a role in lateral inhibition similar to that of Dll1 and Jag2.     

Notch1 expression on T cells is not required for CD4+ T helper differentiation

Notch1 proteins are involved in binary cell fate decisions. To determine the role of Notch1 in the differentiation of CD4(+) Th1 versus Th2 cells, we have compared T helper polarization in vitro in naive CD4(+) T cells isolated from mice in which the N1 gene is specifically inactivated in all mature T cells. Following activation, Notch1-deficient CD4(+) T cells transcribed and secreted IFN-gamma under Th1 conditions and IL-4 under Th2 conditions at levels similar to that of control CD4(+) T cells. These results show that Notch1 is dispensable for the development of Th1 and Th2 phenotypes in vitro. The requirement for Notch1 in Th1 differentiation in vivo was analyzed following inoculation of Leishmania major in mice with a T cell-specific inactivation of the Notch1 gene. Following infection, these mice controlled parasite growth at the site of infection and healed their lesions. The mice developed a protective Th1 immune response characterized by high levels of IFN-gamma mRNA and protein and low levels of IL-4 mRNA with no IL-4 protein in their lymph node cells. Taken together, these results indicate that Notch1 is not critically involved in CD4(+) T helper 1 differentiation and in resolution of lesions following infection with L. major.     

miR-146a-5p regulates autophagy and NLRP3 inflammasome activation in epithelial barrier damage in the in vitro cell model of ulcerative colitis through the RNF8/Notch1/mTORC1 pathway

Ulcerative colitis (UC) is a chronic inflammatory disease affecting the colon that can be influenced by microRNAs (miRNAs). This study aims to investigate the impact of miR-146a-5p on lipopolysaccharide (LPS)-induced Caco-2/HT-29 cell autophagy and NLRP3 inflammasome activation and the underlying mechanism, with the aim of identifying potential therapeutic targets. We used LPS to establish Caco-2/HT-29 cell models and measured cell viability by CCK-8. The levels of miR-146a-5p, RNF8, markers of NLRP3 inflammasome activation and autophagy, proteins involved in the Notch1/mTORC1 pathway, and inflammatory factors were assessed by RT-qPCR, Western blot, and ELISA. Intestinal epithelial barrier function was evaluated by measuring transepithelial electrical resistance. Autophagic flux was measured using tandem fluorescent-labeled LC3. miR-146a-5p was highly-expressed in LPS-induced Caco-2/HT-29 cells, and autophagy flux was blocked at the autolysosomal stage after LPS induction. Inhibition of miR-146a-5p suppressed NLRP3 inflammasome activation, reduced intestinal epithelial barrier damage, and facilitated autophagy inhibition in LPS-induced Caco-2/HT-29 cells. The autophagy inhibitor NH4Cl partially nullified the inhibitory effects of miR-146a-5p inhibition on NLRP3 inflammation activation. miR-146a-5p targeted RNF8, and silencing RNF8 partly abrogated the action of miR-146a-5p inhibition on promoting autophagy and inhibiting NLRP3 inflammasome activation. miR-146a-5p inhibition suppressed the Notch1/mTORC1 pathway activation by upregulating RNF8. Inhibition of the Notch1/mTORC1 pathway partially nullified the function of silencing RNF8 on inhibiting autophagy and bolstering NLRP3 inflammasome activation. In conclusion, miR-146a-5p inhibition may be a potential therapeutic approach for UC, as it facilitates autophagy of LPS-stimulated Caco-2/HT-29 cells, inhibits NLRP3 inflammasome activation, and reduces intestinal epithelial barrier damage by upregulating RNF8 and suppressing the Notch1/mTORC1 pathway.     

龙胆泻肝汤抑制葡萄膜炎大鼠Notch信号通路活化的作用

目的　探讨龙胆泻肝汤（Longdan Xiegan Decoction，LXD）对实验性自身免疫性葡萄膜炎（experimental autoimmune uveitis，EAU）大鼠Notch信号通路活化的抑制作用及其对辅助性T细胞17（T helper 17，Th17）和调节性T细胞（regulatory T cell，Treg）表达水平的影响。方法　随机将雌性Lewis大鼠分为正常对照（NC）组、EAU模型组、LXD干预组。EAU模型组和LXD干预组大鼠诱导EAU，免疫后LXD干预组大鼠每天给予LXD灌胃处理，EAU模型组大鼠给予等量生理盐水灌胃。免疫后12 d观察大鼠眼部炎症表现，取三组大鼠眼球进行病理切片，观察病理学变化；实时荧光定量PCR（quantitative polymerase chain reaction，QT-PCR）和酶联免疫吸附实验（enzyme-linked immunosorbent assay，ELISA）检测免疫后12 d三组大鼠脾脏、淋巴结及眼组织中Notch1、DLL4、白细胞介素10（interleukin 10,IL-10）和IL-17 mRNA及蛋白的表达；流式细胞仪检测三组大鼠各组织中Th17、Treg细胞的表达。结果　病理检查结果表明，LXD对EAU大鼠眼部组织结构有明显的保护作用。QT-PCR和ELISA检测结果发现，与NC组相比，LXD干预组大鼠脾脏、淋巴结和眼组织中Notch1、DLL4、IL-10、IL-17 mRNA和蛋白表达水平均升高，但除IL-10外，其他明显低于EAU模型组（均为P<0.05）；流式细胞仪检测结果发现，EAU模型组大鼠的各组织中Th17/Treg比例均高于NC组，经LXD干预后，Th17细胞表达水平下降，Treg表达水平升高，两者比例趋向平衡。结论　LXD可有效降低EAU大鼠脾脏、淋巴结、眼组织中Notch1、DLL4、IL-10和IL-17 mRNA和蛋白的表达水平，改善Th17/Treg细胞比例的平衡，从而有效减轻EAU大鼠的眼部炎症，保护眼部组织结构，调节全身及眼部的免疫状态。     

川芎赤芍对脑缺血再灌注大鼠模型GFAP、VEGF及Notch1表达的影响

目的：本研究主要观察川芎赤芍对大鼠脑梗死再灌注后外周血胶质纤维酸性蛋白（GFAP）、血管内皮生长因子（VEGF）和脑内Notch1表达的影响。方法：采用线栓法制备大鼠脑缺血再灌注模型,将健康SD大鼠按随机数字表法随机分为空白组、模型组、川芎赤芍低剂量组、川芎赤芍高剂量组、银杏叶片组。采用ELISA法测定大鼠外周血GFAP、VEGF含量,采用real-time PCR法检测缺血脑组织Notch1 mRNA表达。结果：与模型组相比,川芎赤芍能够提高外周血GFAP、VEGF水平,上调脑组织Notch1 mRNA 的表达。结论：川芎赤芍可升高缺血再灌注大鼠外周血GFAP、VEGF的水平及缺血脑组织Notch1 mRNA的表达。     

Notch信号通路与肿瘤的关系

Notch信号转导通路对于细胞的生长发育具有广泛影响,主要是通过调控细胞的分化、增殖和凋亡影响正常生长.Notch信号通路与其他肿瘤发生、发展的关键性通路相互作用.其与肿瘤的相关性最先在由点突变或染色体易位引起的T细胞白血病中确立.随着研究的深入,大量实验证明Notch信号通路的活性变化与其他肿瘤的发生、发展也有密切的关系,如皮肤癌、肝癌、脑肿瘤和乳腺癌等.Notch信号通路对一些肿瘤(如脑肿瘤和乳腺癌)起促癌作用,对另外一些(如皮肤癌和肝癌)则体现为抑癌作用,并且与肿瘤干细胞关系密切.另外,Notch信号通路在同一肿瘤的不同类型或不同发展阶段起的作用也可能不同.     

Notch信号通路与肿瘤的发生及其靶向抗肿瘤疗法

综述Notch信号通路的组成、生理作用和转导途径,探讨Notch信号通路紊乱与肿瘤发生的关系及诱导肿瘤形成的机制,并概述Notch信号通路靶向肿瘤疗法的研究,包括对γ-分泌酶抑制剂、Notch受体拮抗剂和Notch-l小分子干扰RNA的研发。Notch信号通路在决定细胞命运中发挥着重要作用,它参与调控许多与肿瘤发生有关的细胞功能和微环境,包括细胞增殖、凋亡、黏附、上皮一间质转化以及血管发生等生物学过程,有望成为肿瘤治疗的新靶点。