Relationship between Notch Receptors and Hyperoxia-induced Lung Injury in Newborn Rats

Summary: To investigate role of Notch1-3 in hyperoxia-induced lung injury in newborn rat exposed to 85% O 2, 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 O 2 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 % O 2 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.

Notch signalling pathway in development of cholangiocarcinoma

Cholangiocarcinoma(CCA)comprises of extra-hepatic cholangiocarcinoma and intrahepatic cholangiocarcinoma cancers as a result of inflammation of epithelium cell lining of the bile duct.The incidence rate is increasing dramatically worldwide with highest rates in Eastern and South Asian regions.Major risk factors involve chronic damage and inflammation of bile duct epithelium from primary sclerosing cholangitis,chronic hepatitis virus infection,gallstones and liver fluke infection.Various genetic variants have also been identified and as CCA develops on the background of biliary inflammation,diverse range of molecular mechanisms are involved in its progression.Among these,the Notch signalling pathway acts as a major driver of cholangiocarcinogenesis and its components(receptors,ligands and downstream signalling molecules)represent a promising therapeutic targets.Gamma-Secretase Inhibitors have been recognized in inhibiting the Notch pathway efficiently.A comprehensive knowledge of the molecular pathways activated by the Notch signalling cascade as well as its functional crosstalk with other signalling pathways provide better approach in developing innovative therapies against CCA.

强力霉素对胃癌细胞增殖及Notch1、MMP-9表达的影响

目的研究强力霉素对胃癌细胞BGC-823细胞的增殖及Notch1、基质金属蛋白酶-9(MMP-9)蛋白表达的影响,为胃癌的治疗提供新的抗肿瘤药物。方法分别以0、5、10、20、40 mg/L终浓度的强力霉素作用于人胃癌细胞系BGC-823,运用MTT法检测细胞增殖程度;流式细胞仪检测细胞周期分布的影响;Western Blot检测Notch1、MMP-9蛋白水平的表达。结果强力霉素能够抑制人胃癌细胞BGC-823细胞的增殖,且有剂量及时间依赖性(P<0.01);强力霉素能够改变胃癌细胞BGC-823周期的分布,随着浓度的增加,S期所占比例降低;并且随着浓度的增加,Notch1的表达增强,MMP-9的表达降低(P<0.01)。结论强力霉素能够抑制胃癌细胞BGC-823的增殖,促进Notch1上调为可能的机制之一。

Notch signaling pathway mediates the immunomodulatory mechanism of Yangfei Huoxue decoction alleviating bleomycin-induced pulmonary fibrosis in rats

OBJECTIVE: To investigate the immunomodulatory mechanism by which Yangfei Huoxue decoction(YHD) alleviates bleomycin(BLM)-induced pulmonary fibrosis(PF) in rats.METHODS: Rats were randomly divided into two time-point groups(day 14 and 28), and each timepoint group comprised the following six subgroups: control, BLM, dexamethasone(DXM), YHD high dose(YHD-H), YHD middle dose(YHD-M), and YHD low dose(YHD-L). Haematoxylin and eosin and Masson staining, flow cytometry, enzymelinked immunosorbent assay, Western blotting and UPLC-QT of analyses were examined.RESULTS: The results showed that YHD reduced the degree of alveolar inflammation and fibrosis;downregulated the expression of CD28, CD80,CD86, Delta-like 1, Notch2, and Notch3;and upregulated the proportions of Th1/Th2 and Tc1/Tc2. The seven components of YHD were detected.CONCLUSION: The current study indicates that YHD mainly functions by regulating the immune system and that the molecular mechanism may be related to the regulation of the Notch signaling pathway.

Efficacy of Banxia Xiexin decoction in a rat model of chronic atrophic gastritis

OBJECTIVE:To investigate the effectiveness of Banxia Xiexin decoction(BXD)in a rat model of chronic atrophic gastritis(CAG).METHODS:Sixty 6-week-old healthy Wistar rats(30 males,30 females)were used in the present study.A rat model of CAG was successfully established using the combined active immunization/ethanol/sodium deoxycholate method.BXD was prepared from a mixture of seven Chinese herbs,and was intragastrically administered to CAG rats at three different doses(6,12,and 24 g·kg^-1·d^-1).Af-ter 24 weeks,the rats were euthanized,and gastric tissue specimens were collected.Gastric mucosal specimens were stained with hematoxylin and eosin for histological examination to evaluate the degree of inflammation and morphological changes.Immunohistochemical staining was performed to examine the mucosal expression of proliferating cell nuclear antigen.Serum gastrin levels were measured using radioimmunoassay.The expression of Notch signaling-associated genes was examined by quantitative polymerase chain reaction and Western blot assay.RESULTS:BXD at all three doses significantly reversed the adverse effects generated by CAG in rats.Compared with control rats,the CAG rats who were administered BXD had an accelerated growth rate,reduced inflammatory cell infiltration,improved gastric mucosal morphology,augmented thickness of the gastric mucosa,increased number of gastric glands,enhanced mucosal expression of proliferating cell nuclear antigen,and elevated serum gastrin levels.