Notch-Hes1 signaling activation in Caroli disease and polycystic liver disease

The Notch signaling pathway plays a key role in the morphogenesis of the biliary tree, but its involvement in cystic biliary diseases, such as Caroli disease (CD) and polycystic liver disease (PLD), has yet to be determined. Immunostaining was performed using liver sections of CD and PLD, and the results were compared with those of congenital hepatic fibrosis (CHF) and von Meyenburg complex (VMC). The expression of Notch receptor 1 (Notch1) was increased in the nuclei of biliary epithelial cells in all cases of CD and PLD, whereas it remained at a low level in CHF and VMC. In addition, Notch2 and Notch3 were preferably expressed in the nuclei of biliary epithelial cells of PLD. Accordingly, the Notch effector Hes1 was highly expressed in biliary epithelial cells of CD and PLD, and the cell proliferative activity was significantly higher in CD and PLD. The expression of the Notch ligand Delta-like 1 was significantly increased in biliary epithelial cells of CD and PLD, which may be causally associated with the nuclear overexpression of Notch1 and Hes1. These results indicate that aberrant activation of the Notch-Hes1 signaling pathway may be responsible for the progression of biliary cystogenesis in CD and PLD.     

Analysis of gene expression in wild‐type and Notch1 mutant retinal cells by single cell profiling

Results: To examine the molecular underpinnings of this observation, microarray analysis of single retinal cells from wild‐type or Notch1 conditional knockout retinas was performed. In situ hybridization was carried out to validate some of the findings. 相似文献   

低氧环境下Notch信号通路对人牙髓干细胞成牙本质向分化的影响

目的探讨低氧环境下通过低氧诱导因子-1α（HIF-1α）调控Notch信号通路对人牙髓干细胞（HDPSC）成牙本质向分化能力的影响。 方法组织块酶消化法培养HDPSC,给予氯化钴（CoCl₂）诱导的化学性低氧环境,Western blot检测HIF-1α蛋白表达,茜素红染色检测细胞矿化结节形成能力,反转录聚合酶链反应（RT-PCR）检测Notch下游靶基因Hes1与成牙本质相关基因的表达;进一步加入Notch信号通路特异性阻断剂γ分泌酶抑制剂（GSI）,观察以上指标的变化。报告基因方法检测HIF-1α对Notch信号通路的调控作用。采用R version 3.5.3软件进行统计分析,计量资料进行正态检验,多组间比较采用单因素方差分析（方差齐）或Kruskal-Wallis H检验（方差不齐）,两两比较采用LSD-t检验（方差齐）或Mann-Whitney U检验（方差不齐）。 结果（1）CoCl₂诱导的低氧条件下HDPSC中的HIF-1α蛋白水平上调,Notch下游靶基因Hes1 mRNA相对表达量为1.46 ± 0.12,相比常氧组（1.06 ± 0.09）显著增高（t = -4.64,P = 0.012）;GSI处理阻断Notch信号通路后,低氧条件下HDPSC中HIF-1α蛋白水平下调,Hes1 mRNA相对表达量降低至0.82 ± 0.14,与处理前相比差异有统计学意义（t = 5.98,P = 0.004）;常氧条件下GSI处理后的HDPSC中HIF-1α蛋白水平也明显下调,Hes1 mRNA相对表达量（0.30 ± 0.09）相比处理前也显著降低（t = 10.08,P = 0.001）;（2）矿化诱导后的茜素红染色结果显示：低氧处理后,HDPSC细胞成牙本质分化能力下降;GSI处理后,成牙本质向分化能力增强。成骨/牙本质相关基因mRNA表达水平检测结果显示：低氧处理后,BSP、OCN和DSPP的mRNA相对表达量分别为0.53 ± 0.14、0.43 ± 0.20、0.48 ± 0.11,相比常氧组（1.21 ± 0.12、1.08 ± 0.19、1.03 ± 0.13）显著降低（t_BSP = 6.30,P_BSP = 0.003;t_OCN = 4.07,P_OCN = 0.015;t_DSPP = 5.67,P_DSPP = 0.005）;GSI处理后,低氧条件下BSP、OCN和DSPP mRNA相对表达量分别为0.99 ± 0.13、1.09 ± 0.13、0.95 ± 0.16,与处理前相比显著增高（t_BSP = -4.17,P_BSP = 0.014;t_OCN = -4.83,P_OCN = 0.012;t_DSPP = -4.30,P_DSPP = 0.017）,常氧条件下BSP、OCN和DSPP mRNA相对表达量分别为1.73 ± 0.20、1.55 ± 0.08、1.52 ± 0.14,与处理前相比显著增高（t_BSP = -3.84,P_BSP = 0.027;t_OCN = -3.99,P_OCN = 0.035;t_DSPP = -4.43,P_DSPP = 0.011）。（3）荧光素酶报告基因结果显示,HIF-1α可调控NICD启动子,使双荧光素酶相对表达活性为5.37 ± 0.12,与对照组（2.09 ± 0.15）相比显著增强（t = -28.92,P<0.001）,提示HIF-1α可能使Notch信号通路激活。 结论低氧引起HDPSC中HIF-1α升高并可能通过激活Notch信号通路抑制其成牙本质向分化能力。     

Notch信号通路在脑缺血的研究进展

Notch信号通路对中枢神经系统、血管细胞及免疫细胞生长分化发挥重要的调节作用.脑血管疾病引起的脑缺血激活Notch信号通路,活化的Notch信号通路调控神经前体细胞增殖和分化、介导炎症介质释放和促进血管细胞生成等在神经损伤修复、炎症反应、血管缺血区血管生成等起重要的调节作用.此外,Notch还与遗传性疾病CADASIL发病有关.本文就Notch信号通路在脑血管病中的作用及机制进行了分析.     

Notch1 is an important mediator for enhancing of B‐cell activation and antibody secretion by Notch ligand

The roles of Notch1 and Notch2 in T‐cell function have been well studied, but the functional roles of Notch in B cells have not been extensively investigated, except for Notch2 involvement in peripheral marginal zone B‐cell differentiation. This study examined the roles of Notch1 in murine primary B cells. During B‐cell activation by B‐cell receptor ligation, Notch1 was up‐regulated while Notch2 was not. In addition, Notch1 up‐regulation itself did not contribute to the further activation of B cells, but the Notch ligand was important for Notch1‐mediated further B‐cell activation. Moreover, Notch1 deficiency significantly decreased B‐cell activation and antibody secretion under the presence of Notch ligand. These data suggest that Notch1 is an important mediator for enhancing B‐cell activation and antibody secretion by Notch ligand.     

Notch Signaling May Be Involved in the Abnormal Differentiation of Epidermal Keratinocytes in Psoriasis

Localization of each keratin isoform differs among epidermal layers. Proliferating basal cells synthesize keratin 14 (K14) and suprabasal cells express keratin 10 (K10) in normal skin. Notch signaling is essential for keratinocyte differentiation. Notch1 is expressed in all epidermal layers, Notch2 in the basal cell layer and Notch3 in basal cell and spinous cell layers in normal epidermis. It has been poorly elucidated how localization and expression levels of Notch molecules are related to epidermal molecular markers K10 and K14 in psoriatic skin with abnormal differentiation of epidermal tissue. This study aimed to investigate the relationship between abnormal differentiation of epidermal cells in psoriatic skin and expression of Notch molecules. We investigated keratins (K14 and K10) and Notches (1, 2, 3 and 4) using immunohistochemistry in psoriatic skin (n=30) and normal skin (n=10). In normal skin, K14 and K10 were discretely observed in the basal cell layer and suprabasal layer, respectively. In psoriatic skin, K14 was expressed in the pan epidermal layer while it and K10 were co-expressed in some middle suprabasal layer cells. Notch1, 2, 3, and 4 localized in all epidermal layers in normal skin. In psoriatic skin, Notch1, 2, and 4 mainly localized in suprabasilar layers and Notch3 is lacalized in pan epidermal, suprabasilar, and basilar layers. Protein and mRNA of Notch1, 2, and 3 isoforms decreased in psoriatic epidermis compared with normal epidermis. These data suggest that decrements in these Notch molecules might cause aberrant expression of K10 and K14 leading to anomalous differentiation of the epidermis in psoriatic lesions.     

松龄血脉康对大鼠脑动脉粥样硬化血管内皮功能的影响及其脑保护机制

目的 探究松龄血脉康对大鼠脑动脉粥样硬化(CAS)血管内皮功能的影响和脑保护机制。方法 将SD大鼠分为对照组、CAS组和松龄血脉康组。CAS组和松龄血脉康组大鼠建立高血压和高血脂诱导的CAS模型,松龄血脉康组大鼠以松龄血脉康灌胃干预。比较各组大鼠血压和血脂指标。苏木精-伊红染色(HE)检测基底动脉和脑组织病理形态学变化。酶联免疫吸附法检测血清一氧化氮(NO)和内皮素1(ET-1)水平。Western blot检测Notch1和Hes1蛋白表达水平。结果 CAS组大鼠血压和血脂水平均显著高于对照组(P＜0.05),松龄血脉康组血压和血脂水平显著低于CAS组(P＜0.05)。对照组基底动脉形态学正常,CAS组血管内膜出现损伤,动脉中膜平滑肌细胞排列紊乱,松龄血脉康组的病理形态介于对照组和CAS组之间。CAS组NO水平显著低于对照组而ET-1显著高于对照组(P＜0.05),松龄血脉康组NO水平显著高于CAS组而ET-1显著低于CAS组(P＜0.05)。对照组大鼠脑组织结构完整,细胞正常,核仁明显,胞质丰富;CAS组大鼠脑组织细胞排列异常,核仁不明显,细胞质出现空晕;松龄血脉康组形态和排列基本正常。CAS组Notch1和Hes1水平显著高于对照组(P＜0.05),松龄血脉康组Notch1和Hes1水平显著低于CAS组(P＜0.05)。结论 松龄血脉康具有保护高血压和高血脂引起的血管内皮细胞和拮抗脑损伤的作用,这种作用可能与抑制Notch通路有关。