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Resumen La vía de señalización Notch es una vía conservada evolutivamente y está involucrada en el control de diversos eventos durante el desarrollo de las células eucariotas. Esta vía se ha relacionado con la expresión y la diferenciación de las células inmunes; por lo tanto, su activación es fundamental en la expresión de la respuesta inmune innata y adquirida, que permite a los mamíferos defenderse frente antígenos externos.
Abstract The Notch signaling pathway is evolutionarily preserved and is involved in the control of several events during the development of eukaryotic cells. This pathway has been linked to expression and differentiation of immune cells, therefore it´s activation is critical in the expression of the innate immune and acquired response that allows mammals to defend themselves against external antigens.
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AIM:To explore the effect of Delta-like ligand 4 (Dll4)-Notch signaling pathway blockade on the development of Thelper 17(Th17) cells in the asthmatic mice.METHODS:Male BALB/c mice were randomly divided into 5 groups:control group, asthma group, normal saline group, anti-Dll4 antibody group, and immunoglobulin G group.The protein expression of Dll4 was detected by immunohistochemical staining.The proportion of Th17 cells in mouse spleen isolated CD4+ T cells was measured by flow cytometry.The protein expression of Th17 transcription factor retinoid-related orphan receptor γt (RORγt) was determined by Western blot.The serum level of interleukin (IL)-17 was measured by enzyme-linked immunosorbent assay (ELISA).RESULTS:The expression of Dll4 in the lung tissues from asthma group significantly increased as compared with anti-Dll4 antibody group.The proportion of Th17 cells in CD4+ T cells was significantly down-regulated, and the protein expression of RORγt in the lung tissues was significantly reduced in anti-Dll4 antibody group compared with asthma group (P<0.05).Moreover, the serum level of IL-17 in anti-Dll4 antibody group was significantly reduced compared with asthma group (P<0.01).CONCLUSION:The blockade of Dll4-Notch signaling pathway inhibits the differentiation of Th17 cells in asthmatic mice.
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Objective To explore whether hypertonic saline would partake in regulating Notch signaling in microglia in experimentally induced cerebral ischemic rats.Methods Male SD rats were randomly divided into sham group, cerebral ischemia group, normal saline group ( NS group ) , 10%hypertonic saline group (10%HS group) , the model of cerebral ischemia were established in all rats except the sham group by using middle cerebral artery occlusion ( MCAO) .After 2 hours of MCAO, the rats were through reperfusion for 24 h.In addition, rats in the normal saline group and 10% HS group were respectively treated with a continuous intravenous injection of normal saline (0.3 mL/h) and 10%HS (0.3 mL/h) by tail vein for 24 h.Immunofluorescence methods, RT-PCR and Western blot were used to detect the expression of Notch1 and intracellular Notch receptor domain ( NICD) .All data was analyzed by one-way analysis of variance ( ANOVA) , The intergroup comparisons were analyzed by the least-significant-difference (LSD) tests.Differences were considered statistically significant if P<0.05.Results Immunofluorescence showed that the expression of Notch1 and NICD were significantly increased in the microglia around peri-ischemia area in cerebral ischemia group and normal saline group compared to sham group;the expression of Notch1 and NICD in the microglia around peri-ischemia area were significantly reduced in 10% HS group compared to ischemia group and NS group.RT-PCR showed that the mRNA expression of Notch1 was significantly increased in ischemia group and NS group compared to sham group ( sham group: 1.000 ± 0.076; ischemia group: 2.203 ±0.283; NS group: 1.616 ±0.185; P <0.01 ); however, it was significantly reduced in 10% HS group compared to ischemia group and NS group ( ischemia group:2.203 ±0.283; NS group: 1.616 ±0.185; 10%HS group: 1.202 ±0.177; P <0.05 ) .Western blot showed that the protein expression of Notch1 was significantly increased in ischemia group and NS group compared to sham group ( sham group: 0.290 ±0.079; ischemia group: 0.750 ±0.029; NS group:0.765 ±0.182;P<0.01);but was significantly reduced in 10%HS group compared to ischemia group and NS group ( ischemia group:0.750 ±0.029; NS group:0.765 ±0.182;10%HS group:0.390 ±0.195;P<0.05 ) .The protein expression of NICD was significantly increased in ischemia group and NS group compared to sham group ( sham group: 0.401 ±0.196; ischemia group: 0.906 ±0.359; NS group:0.847 ±0.153;P<0.01);but was significantly reduced in 10%HS group compared to ischemia group and NS group ( ischemia group:0.906 ±0.359; NS group:0.847 ±0.153;10%HS group:0.561 ±0.165;P<0.05 ) .Conclusion Our results suggest that HS markedly suppresses Notch signaling in microglia around the ischemia tissue area in experimental induced cerebral ischemic rats.
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Oral cancer is one of the common cancer cases identified in the developing countries. Genetic mutation and overexpression of certain genes and proteins have been associated in the development of this cancer. Notch signalling pathway is normally involved in controlling the development process of vertebrates and invertebrates; however, deregulation of this pathway was found to be responsible in the formation of certain cancers including oral cancers. Activation of this pathway requires binding of the ligands to its receptors. Four NOTCH receptors (NOTCH 1, 2, 3 and 4) have been identified in mammals. Disruptions within these molecules might interfere with the normal functions of Notch signalling pathway. Hence, this study was conducted to detect mutations of NOTCH1 and NOTCH2 receptor genes which might be occurring in the oral cancer cases obtained from the local population. DNA extracted from fresh-frozen tissue biopsy of the tongue and buccal mucosa from 10 confirmed cases of oral cancer were subjected for polymerase chain reaction (PCR) amplification using the specific sets of primers. The PCR products were sent for sequencing before final results were analysed. Due to time and cost limitation, only two out of four NOTCH receptor genes; NOTCH1 and NOTCH2, were used in this analysis. The results revealed absence of nucleotide changes for both NOTCH receptor genes amplified from these oral cancer samples. More samples and further analysis looking into other regions in these genes are required to conclude the involvement of NOTCH receptor genes mutation in causing oral cancer.
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PURPOSE: Vascular endothelial growth factor (VEGF) is known as a growth factor of endothelium and fibroblast. The purpose is to know the VEGF effects on fibroblast proliferation and fibroblast's notch receptor expression. METHODS: CCD-986sk fibroblast was purchased from the Korean Cell Bank and was used in XTT assay for proliferation and wound healing assay for migration. Immunofluorescent (IF) staining and western blotting were used in testing notch expression of fibroblast. Semiquantitative RT-PCR was used in checking notch 1 mRNA production by fibroblast. Student-t test was used for analyzing results. RESULTS: Cell proliferation assay using XTT showed significant higher proliferation in VEGF treated fibroblast, 2.324 +/- 0.0026 vs. 2.463 +/- 0.017 (p=0.002). Wound healing assay showed longer migration in VEGF treated fibroblast (p=0.062). The fluorescence was brighter in VEGF treated cells of notch 1 IF staining. Notch 1 expressions and mRNA productions increased more in VEGF treated cells. CONCLUSION: VEGF stimulates fibroblast to proliferate, migrate and to express Notch 1 simultaneously. Notch receptor could be related to VEGF mediated wound healing.
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Western Blotting , Proliferación Celular , Endotelio , Fibroblastos , Fluorescencia , ARN Mensajero , Factor A de Crecimiento Endotelial Vascular , Cicatrización de HeridasRESUMEN
To investigate role of Notch1-3 in hyperoxia-induced lung injury in newborn rat exposed to 85% O2, SD rat litters born on the 22th day were randomly divided into two groups: room air group and hyperoxia group. The animals were sacrificed 1, 4, 7, 10, 14 and 21 days after continued exposure to oxygen (n=40, oxygen＞0.85) or room air (n=40). 6 rats each group were used to assess lung histological changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from frozen lung tissues. Notch mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that 7, 14 and 21 days after O2 exposure, hyperoxia group showed lung injury characterized by pulmonary edema, hemorrhage and lung development arrest. Positive staining for Notch1,Notch 2 in hyperoxia group was much lower than those in room air group at all time points (P＜0.01, P＜0.05), but compared with the controls, the hyperoxia group showed higher expression of Notch3 (P＞0.05). Immunostained cells were typically airways epithelia, alveolar epithelial and inflammatory cells, and fibroblasts in hyperoxia group (P＜0.01). Notch mRNA levels showed similar change as protein level (P＜ 0.01). It is concluded that the prolonged exposure to 85 % O2 resulted in abnormal expression of Notch receptors, which might contribute to the pathogenesis of hyperoxia-induced lung injury in newborn rats. The decreased inhibition of Notch1 might be one of the protective reaction and major mechanisms for proliferation/differentiation of type Ⅱ alveolar epithelial cells. The up-regulation of Notch3 activity might result in the lung development arrest of the newborn rats.