mRNA Expression Levels Of Notch1 Research Articles

Helicobacter pylori Infection of Gastric Epithelial Cells Affects NOTCH Pathway In Vitro.

Helicobacter pylori infection is exceptionally prevalent, and it is an important risk factor for gastritis, gastroduodenal ulcers, and gastric cancer. However, the pathogenic mechanisms of H. pylori are not entirely clear. The aim of this study was to assess which signal pathway is initially activated by H. pylori. Using the Human Signal Transduction Pathway Finder RT(2) Profiler PCR Array, we screened for alterations in the expression of genes encoding members of ten different signal transduction pathways in GES-1 cells co-cultured with H. pylori. qPCR and Western blotting were used to verify the expression of four key genes in NOTCH pathway. Of the 84 genes represented in the array, 22 genes demonstrated more than twofold difference (p<0.05) in GES-1 cells grown in the presence of H. pylori 11637 compared to cells without H. pylori 11637. Ten genes were up-regulated in the co-culture group, whereas 12 appeared to be down-regulated. Further analysis using the SA Biosciences online program revealed that NOTCH pathway was the most significantly affected network. There was a significant reduction in the mRNA expression level of NOTCH1 and NOTCH2, together with a reduced level of active forms of NOTCH1 (NICD1) and NOTCH2 (NICD2). Meanwhile, the expression level of the ligand DLL4 was found to be significantly increased. NOTCH signaling may play an important role in H. pylori-induced gastric carcinogenesis.

Up-regulation of Notch1 inhibits proliferation and differentiation of osteoclast in vitro

This study aimed to explore the effect of the up-regulation of Notch1 on osteoclastogenesis induced to osteoclasts by receptor activator for nuclear factor-kappaB ligand (RANKL) and macrophage colony-stimulating factors (MCSF) in vitro. The bone marrow stem cells (BMSCs) of Rosa(-notch1) mice were cultured and induced to osteoclasts by RANKL and MCSF. The BMSCs were transfected with the Ad-Cre-green fluorescent protein (GFP) virus or Ad-GFP virus. Total RNA from cells was extracted, and the gene expression levels of Notch1, Notch2, Notch3, Notch4, Deltal, Delta3, Delta4, Jagged1, Hes1, and tartrate resistant acid phosphatase (TRAP) were detected at the defined stage by reverse transcription-polymerase chain reaction (RT-PCR). Osteoclast formation was analyzed by TRAP assay. The number of TRAP-positive multinuclear cells of the experimental group significantly decreased compared with that of the control group. The mRNA expression levels of Notch1, Notch3, Jagged1, Delta3, and Hesl of the experimental group were significantly higher than those of the control group, whereas the TRAP mRNA expression of the experimental group was significantly lower than that of the control group (P<0.05). Up-regulation of Notch1 inhibit osteoclastogenesis of BMSCs induced by RANKL and MCSF in vitro.

Expression and Significance of CD4+ CD25+ CDl27low Regulatory T Cells, TGF-β and Notch1 mRNA in Patients with Idiopathic Thrombocytopenic Purpura

To detect the expression levels of CD4(+) CD25(+) CDl27(low) Treg cells, TGF-β and Notch1 mRNA in peripheral blood of the patients with idiopathic thrombocytopenic purpura (IPT) before and after treatment, and to investigate their significance in the pathogenesis of ITP. Peripheral blood was collected from 30 newly diagnosed patients with ITP and 20 normal controls, then the number of CD4(+) CD25(+) Treg and CD4(+) CD25(+) CDl27(low) Treg were detected by the flow cytometry. Plasma TGF-β level was determined by ELISA. Total RNA was extracted and the expression level of Notch1 mRNA was measured by real-time Q-PCR. The expression levels of CD4(+) CD25(+) CDl27(low) Treg and CD4(+) CD25(+) Treg in newly diagnosed ITP group were significantly lower than those in normal controls. After treatment, the proportion of Tregs increased to (5.17% ± 0.74%) and (4.16% ± 0.68%), and was higher than that in newly diagnosed patients. The TGF-β level in peripheral blood of newly-diagnosed patients was obviously lower than that in normal controls, and was (961.53 ± 60.10) ng/L after treatment and was significantly higher than that in newly diagnosed patients; the expression level of Notch1 mRNA in peripheral blood of patients in newly-diagnosed group was obviously lower than that in control, and was (1.35 ± 0.10) after treatment that was higher than that in newly-diagnosed group. After treatment, the proportion of Treg cells, level of TGF-β and erpression level of Notch1 mRNA in effective group were higher than those in effective group, improved group and ineffective group, and there was significant difference (P <0.01). The expression level of TGF-β and Notch1 mRNA in ITP patients possitively correlated to CD4(+) CD25(+) CDl27(low) (P <0.01). The levels of CD4(+) CD25(+) CDl27(low) Treg, TGF-βand Notch1 mRNA in peripheral blood of the patients with ITP are significantly lower than those of normal control, suggesting that there is significant abnormal immunoregulation in ITP patients. In the ITP patients the levels of CD4(+) CD25(+) CDl27(low) Treg postively correlated with Notch1 mRNA expression, indicating that Notch signal may be revalent to Treg's immunosuppression function.

Abnormal expression of the Notch and Wnt/β-catenin signaling pathways in stem-like ALDHhiCD44+ cells correlates highly with Ki-67 expression in breast cancer.

Previous studies have reported that breast cancer stem cells may be closely associated with tumor metastasis, recurrence, and even the failure of chemotherapy and radiotherapy. The aim of the present study was to investigate whether important cell signaling pathways associated with drug resistance are activated in stem-like acetaldehyde dehydrogenase (ALDH)hi cluster of differentiation (CD)44+ cells, and to analyze the association between ALDHhiCD44+ cells and specific pathological features. ALDHhiCD44+ cells and non-stem-like ALDHlowCD44+ cells were separated from MDA-MB-231 cells by fluorescence-activated cell sorting, and the mRNA expression levels of Notch1 and β-catenin were estimated by performing quantitative polymerase chain reaction in the stem-like and non-stem-like cells. Line correlation analysis was used to evaluate the correlation between an immunohistochemical panel of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67, and ALDHhiCD44+ cells from patients with invasive breast carcinoma. The mRNA levels of Notch1 and β-catenin were significantly higher in the ALDHhiCD44+ cells compared with those in the ALDHlowCD44+ cells (P<0.05); furthermore, the present study determined a high correlation (P<0.05) between the ALDHhiCD44+ cells and Ki-67 expression (P=0.007), but no correlation (P≥0.05) with ER (P=0.065), PR (P=0.107) and HER2 (P=0.050). Overall, these data clearly indicate that ALDHhiCD44+ cells may serve as novel diagnostic and prognostic factors in breast cancer.

Effect of notch signaling pathway on VEGF promoting rat mesenchymal stem cell proliferation

This study was purposed to investigate the effect of Notch signaling pathway on VEGF promoting the proliferation of rat mesenchymal stem cells (MSC). Rat MSC were cultured in vitro, and the cells in logarithmic growth phase were used for experiments. The inhibitor DAPT was used to block Notch signaling pathway, and the effect of the pathway on VEGF promoting proliferation of MSC was observed. The experiment was divided into 4 groups: control, VEGF, DAPT and VEGF+DAPT. The CCK-8 was used to assay the cells proliferation of each group, while RT-PCR was used to detect the changes of related genes (Notch1, Notch2, Flk-1, Hes-1) at mRNA levels. The results indicated that the cells survival rate MSC in DAPT group and VEGF+DAPT group was low in each time point (24 h, 48 h, 72 h), the cell number decreased, and the cells became rounded. The survival rate of MSC in VEGF group was the highest; the difference of cell survival rate was statistically significant between the groups (P < 0.01); Compared with the control group, the mRNA expression level of Notch1, Notch2 and Flk-1 in VEGF group was raised, while the expression level of Notch1 and Notch2 in DAPT group and VEGF+DAPT group come down, with statistically significant differences (P < 0.05); whereas the mRNA expression level of Hes-1 in VEGF group was down-regulated, but that in DAPT group and VEGF+DAPT group was up-regulated, and the difference was statistically significant (P < 0.05). Flk-1 mRNA level in DAPT group and VEGF+DAPT group was slightly lower, but the difference was not statistically significant (P > 0.05). It is concluded that Notch signaling pathway plays an important role in promoting the proliferation of rat MSC, treated with VEGF, however, the DAPT can weaken this effect.

Dynamic changes of the expression of Notch(1) and Jagged(1) in the hippocampus after focal ischemia: experiment with rats

To detect the expression patterns of Notch(1) and Jagged(1) in the hippocampus of focal ischemia and find out whether the Notch pathway is involved in the regulation of the differentiation of the proliferated neural precursor cells in the dentate gyrus under ischemic conditions. 42 SD rats were randomly divided into 3 equal groups: middle cerebral artery occlusion (MCAO) group undergoing MCAO by intraluminal thread technique so as to cause focal cerebral infarction, sham operation group, and normal control group.19 and 28 days after the operation 6 rats in each group were killed with their hippocampus taken out. The protein and mRNA levels of Notch(1) and Jagged(1) in hippocampus were assayed respectively by Western blotting and real-time reverse-transcription PCR. The protein and mRNA expression levels of Notch(1) on the 19th day of the MCAO group were up-regulated, both significantly higher than those of the sham operation and control groups (all P < 0.05). The protein and mRNA expression levels of Notch(1) on the 28th day of the MCAO group were both significantly lower than those of the same group on the 19th day (both P < 0.01), and were lower than those of the sham operation and control groups on the 28th day, however, not significantly (all P > 0.05). The protein and mRNA expression levels of Jagged(1) on the 19th and 28th days of the MCAO group were significantly higher than those of the sham and control groups (all P < 0.05), however, there were not significant differences in the protein and mRNA expression levels of Jagged(1) on the 19th and 28th days of the MCAO group (all P > 0.05). The protein and gene expression of Notch(1) and Jagged(1) vary dynamically in the hippocampus of focal ischemia, which suggests that the Notch pathway may be a potential mechanism in the regulation of the neurogenesis in the dentate gyrus of hippocampus.

Differential expression of cell fate determinants in neurons and glial cells of adult mouse spinal cord after compression injury

Cellular responses after spinal cord injury include activation of astrocytes, degeneration of neurons and oligodendrocytes, and reactions of the ependymal layer and meningeal cells. Because it has been suggested that tissue repair partially recapitulates morphogenesis, we have investigated the expression of several developmentally prominent molecules after spinal cord injury of adult mice where neurogenesis does not occur after injury. Cell fate determinants Numb, Notch-1, Shh and BMPs are abundantly expressed during development but mostly decline in the adult. In the present study, we investigated whether these genes are triggered by spinal cord injury as a sign of attempted recapitulation of development. Expression of Numb, Notch, Shh, BMP2/4 and Msx1/2 was analysed in the adult mouse spinal cord after compression injury by in situ hybridization up to 1 month after injury. The mRNA expression levels of Notch-1, Numb, Shh, BMP4 and Msx2 increased in the grey matter and/or white matter and in the ependyma rostral and caudal to the lesion site after injury. However, BMP2 and Msx1 were not up-regulated. Combining immunohistochemistry of cell type-specific markers with in situ hybridization we found that all the up-regulated genes were expressed in neurons. Moreover, Numb, BMP4 and Msx2 were also expressed by GFAP-positive astrocytes, while Shh was expressed by MBP-positive oligodendrocytes. In conclusion, the cell fate determinants Notch-1, Numb, Shh, BMP4 and Msx2 are expressed in neurons and/or glial cells after injury in a time-dependent manner, suggesting that these genes reflect to some extent an endogenous self-repair potential by recapitulating some features of development.