Protopine alleviates lipopolysaccharide-triggered intestinal epithelial cell injury through retarding the NLRP3 and NF-kB signaling pathways to reduce inflammation and oxidative stress

Background Inflammatory bowel disease (IBD) is a common chronic intestinal disease. Protopine isolated from different plants has been investigated to understand its special functions on varied diseases. However, the regulatory effects of protopine on the progression of IBD remain unclear. Our study is aimed to explore the effects of protopine on the progression of IBD and its underlying regulatory mechanism of action. Methods The cell viability was assessed through MTT colorimetric assay. The protein expressions of genes were examined by Western blot analysis. The cell apoptosis and reactive oxygen species level were measured using flow cytometry. The levels of inflammation and oxidative stress-related proteins were tested through enzyme-linked-immunosorbent serologic assay. The intracellular Ca2+ concentration and mitochondrial membrane potential were measured through immunofluorescence assay. Results First, different concentrations of lipopolysaccharide (LPS) were treated with NCM460 cells to establish IBD cell model, and 5-μg/mL LPS was chosen for followed experiments. In this study, we discovered that protopine relieved the LPS-induced inhibited intestinal epithelial cell viability and enhanced cell apoptosis. Moreover, protopine attenuated LPS-stimulated inflammation activation and oxidative stress. Further experiments illustrated that the increased intracellular Ca2+ concentration and decreased mitochondrial membrane potential stimulated by LPS were reversed by protopine treatment. Finally, through Western blot analysis, it was demonstrated that protopine retarded the activated NLR family pyrin domain containing 3 (NLRP3) and nuclear factor kappa B (NF-κB) signaling pathways mediated by LPS. Conclusion Protopine alleviated LPS-triggered intestinal epithelial cell injury by inhibiting NLRP3 and NF-κB signaling pathways to reduce inflammation and oxidative stress. This discovery may provide a useful drug for treating IBD (AU)

Changes of aquaporin expression in blood-brain barrier induced by glioma cells / 中国病理生理杂志

AIM: To investigate the effects of glioma cells on aquaporin expression in blood-brain barrier and their importance in pathophysiology. METHODS: A blood-brain barrier model was established by coculture of ECV304 and astrocytes in vitro . HPLC was used to determine the change of water transport of in vitro blood-brain barrier model after the influence of glioma cells. The expression levels of AQP1 and AQP4 were analyzed by semiquatitative RT-PCR. RESULTS: Glioma cells decreased expression level of AQP4 of astrocytes and induced abnormal expression of aquaporin-1 in endothelial cell line. The water transport of in vitro blood-brain barrier model from luminal side to abluminal side was increased after coculture with glioma cells. CONCLUSION: The vasogenic brain edema induced by glioma cells may not be the result of hyperpermeability of blood-brain barrier to macromolecules in plasma. The changes of aquaporin expression may be the molecular basis of brain edema induced by glioma cells.