Search

Background: Macrophages substantially shape the development, progression, and complications of inflammation-driven diseases. Although numerous researches support a critical role for Notch signaling in most inflammatory diseases, there is limited data on the role of Notch signaling in TLR4-induced macrophage activation and the interaction of Notch signaling with other signaling pathways(e.g., the NF-kB pathway during inflammation) in macrophages. Methods and Results: In this study, we confirmed that stimulation with TLR4 ligand LPS up-regulates Notch1 expression in RAW264.7 monocyte/macrophage-like cell line. LPS also induced the expression of Notch target genes Notch1 and Hes1 mRNA in macrophages, suggesting that TLR4 signaling enhances Notch pathway activation. The upregulation of Notch1, NICD, and Hes1 protein by LPS treatment was inhibited by the Notch1 inhibitor of DAPT. The increase of TNF-a, IL-6, and IL-1b induced by LPS was inhibited by DAPT while jagged1, the Notch1 ligand, rescued them. Furthermore, the suppression of Notch signaling by DAPT up-regulated CYLD expression but down-regulated TRAF6, IKKa/bphosphorylation, and subsequently phosphorylation and degradation of IκB-α, indicating the inhibition of TLR4-triggered NF-kB activation by DAPT. Interestingly, DAPT showed no inhibitory effect on the increase of MyD88 expression induced by LPS in our study. Conclusions: Our study shows that the stimulation of macrophages via the TLR4 signaling cascade triggers the activation of Notch1 signaling, which regulates the expression patterns of genes involved in pro-inflammatory responses through by activating NF-kB. It may be dependent on the CYLD-TRAF6-IKK pathway. The Notch1 signaling may be considered as a potential therapeutic target against infectious and inflammatory driven diseases.

Pancreatic cancer (PCa) is one of the most fatal cancers worldwide. Recently, many studies have confirmed that long non-coding RNAs (lncRNAs) play crucial roles in the development of many human cancers, including PCa. The purpose of the present study was to investigate the biological role and underlying mechanisms of lncRNA small nucleolar RNA host gene 1 (SNHG1) in PCa progression. The results demonstrated that the expression levels of SNHG1 were increased in PCa cell lines and human tissue samples. High SNHG1 expression was notably correlated with adverse characteristics and poor survival of PCa patients. Knockdown of SNHG1 suppressed PCa cell proliferation in vitro and PCa tumor growth in vivo, and these effects might be associated with the induction of cell cycle arrest. We further confirmed that, in PCa cells, SNHG1 can negatively regulate miR-195 expression by acting as a ceRNA, and Cyclin D1 is a direct target of miR-195. Overexpression of miR-195 abrogated the oncogenic role of SNHG1 in PCa cells. Collectively, our results identified SNHG1 as a novel oncogenic lncRNA in PCa, and indicated that SNHG1/miR-195/Cyclin D1 axis might be a potential therapeutic target for PCa patients.

OBJECTIVE To explore the protective effects and mechanism of ethanol extract of Inonotus obliquus (EEIO) injection on asthmatic mice. METHOD OVA was injected intraperitoneally and inhaled to produce the asthmatic model. Thirty two mice were randomly divided into four groups: control group, asthma group and I. obliquus groups of high and low dose. The concentrations of IL-4, IL-5, IL-13 and IFN-gamma in BALF, the phosphor-p38 MAPK in lung tissues were respectively measured by ELISA and Western blotting. The number of inflammatory cells in BALF and histopathology changes were observed. RESULT In asthmatic group, the number of inflammatory cells and the concentrations of IL-4, IL-5, IL-13 in BALF and phospho-p38 MAPK in lung tissue were higher, while IFN-gamma were lower than those in normal control mice (P < 0.05). In I. obliquus group, the number of inflammatory cells, the concentrations of IL-4, IL-5, IL-13 in BALF and phosphor-p38 MAPK in lung tissue were lower, but were higher than those in normal control mice (P < 0.05), and histropathology damage was alleviated significantly. There was no significant difference observed among the efficacies in the I. obliquus groups of high and low dose. CONCLUSION p38 MAPK may play a role in pathological process of asthma. I. obliquus effectively treats asthma by inhibiting the expression of phosphor-p38 MAPK, correcting the unbalance of IFN-gamma/IL-4 and decreasing the number of inflammatory cells.