NADPH oxidases (NOXs) are a predominant mediator of redox homeostasis in hepatic stellate cells (HSCs), and oxidative stress plays an important role in the pathogenesis of liver fibrosis. Ursolic acid (UA) is a pentacyclic triterpenoid with various pharmacological activities, but the molecular targets and underlying mechanisms for its antifibrotic effect in the liver remain elusive. This study aimed to computationally predict the molecular interactome and mechanistically investigate the antifibrotic effect of UA on oxidative stress, with a focus on NOX4 activity and cross-linked signaling pathways in human HSCs and rat liver. Drug–drug interaction via chemical–protein interactome tool, a server that can predict drug–drug interaction via chemical–protein interactome, was used to predict the molecular targets of UA, and Database for Annotation, Visualization, and Integrated Discovery was employed to analyze the signaling pathways of the predicted targets of UA. The bioinformatic data showed that there were 611 molecular proteins possibly interacting with UA and that there were over 49 functional clusters responding to UA. The subsequential benchmarking data showed that UA significantly reduced the accumulation of type I collagen in HSCs in rat liver, increased the expression level of MMP-1, but decreased the expression level of TIMP-1 in HSC-T6 cells. UA also remarkably reduced the gene expression level of type I collagen in HSC-T6 cells. Furthermore, UA remarkably attenuated oxidative stress via negative regulation of NOX4 activity and expression in HSC-T6 cells. The employment of specific chemical inhibitors, SB203580, LY294002, PD98059, and AG490, demonstrated the involvement of ERK, PI3K/Akt, and p38 MAPK signaling pathways in the regulatory effect of UA on NOX4 activity and expression. Collectively, the antifibrotic effect of UA is partially due to the oxidative stress attenuating effect through manipulating NOX4 activity and expression. The results suggest that UA may act as a promising antifibrotic agent. More studies are warranted to evaluate the safety and efficacy of UA in the treatment of liver fibrosis.

Gastric cancer is a considerable health burden worldwide. DNA methylation, a major epigenetic phenomenon, is closely related to the pathogenesis of cancer. Neuronal pentraxin II (NPTX2) has been found to be hypermethylated in several cancers such as glioblastoma and pancreatic cancer. However, the roles of NPTX2 in gastric cancer have not been reported. To explore this issue, NPTX2 expression in gastric cancer cells was assessed by western blot and quantitative real-time polymerase chain reaction (qRT-PCR). The methylation analysis of NPTX2 was performed by qRT-PCR as well as methylation-specific PCR (MS-PCR). The effects of NPTX2 on gastric cancer cell proliferation, apoptosis and cell cycle were detected by colony formation, CCK-8 and flow cytometry assays, respectively. The interaction of NPTX2 with the p53 signaling pathway was evaluated by western blot. Our study found the down-regulated expression of NPTX2 in gastric cancer cells compared with human gastric mucosal cells. In addition, the hypermethylation of NPTX2 was observed in gastric cancer cells, which was correlated with the low expression of NPTX2. Moreover, NPTX2 inhibited gastric cancer cell proliferation, inhibited apoptosis and induced cell cycle arrest. Furthermore, NPTX2 enhanced the protein expression of p53, p21 and PTEN to activate the p53 signaling pathway. Therefore, NPTX2 hypermethylation caused the downregulation of NPTX2 expression, which could promote cell proliferation, inhibit apoptosis and cause cell cycle arrest in gastric cancer cells by suppressing the p53 signaling pathway. Therefore, NPTX2 may be crucial for the progression of gastric cancer.

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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.

Gastric carcinoma (GC) is a malignant tumor that has high mortality and morbidity worldwide. Although many efforts have been focused on the development and progression of GC, the underlying functional regulatory mechanism of GC needs more clarification. Metallothionein 1G (MT1G) is a member of the metallothionein family (MTs), and hypermethylation of MT1G occurred in a variety of cancers, including gastric cancer. However, the functional mechanism of MT1G in GC remains unclear. Here, we demonstrated that MT1G was down-regulated in GC tissues and cells. Overexpression of MT1G inhibited cell proliferation, foci formation and cell invasion, while knockdown of MT1G increased cell proliferation, foci formation and cell invasion. In addition, MT1G overexpression inhibited cell cycle progression and MT1G deficiency exerted opposite phenotype. p-AKT was negatively regulated by MT1G. In summary, our study reveals that MT1G exerts crucial role in regulating of cell proliferation and migration of gastric cancer, providing new insights for MT1G-related pathogenesis and a basis for developing new strategies for treatment of GC.