Chronic stress is known to promote inflammatory bowel disease (IBD), but the underlying mechanism remains largely unresolved. Here, we found chronic stress to sensitize mice to dextran sulfate sodium (DSS)-induced colitis; to increase the infiltration of B cells, neutrophils, and proinflammatory ly6C macrophages in colonic lamina propria; and to present with decreased thymus and mesenteric lymph node (MLN) coefficients. Circulating total white blood cells were significantly increased after stress, and the proportion of MLN-associated immune cells were largely changed. Results showed a marked activation of IL-6/STAT3 signaling by stress. The detrimental action of stress was not terminated in IL-6 mice. Interestingly, the composition of gut microbiota was dramatically changed after stress, with expansion of inflammation-promoting bacteria. Furthermore, results showed stress-induced deficient expression of mucin-2 and lysozyme, which may contribute to the disorder of gut microbiota. Of note is that, in the case of cohousing, the stress-induced immune reaction and decreased body weight were abrogated, and transferred gut microbiota from stressed mice to control mice was sufficient to facilitate DSS-induced colitis. The important role of gut microbiota was further reinforced by broad-spectrum antibiotic treatment. Taken together, our results reveal that chronic stress disturbs gut microbiota, triggering immune system response and facilitating DSS-induced colitis.

In this study, we found that pretreatment with low dose of lipopolysaccharide (LPS), also known as lipoglycans and endotoxin, obviously attenuated liver injury caused by diethylnitrosamine (DEN) in mice. This protective effect was described by decreased ALT, TNF-α, and IL-1β and increased TGF-β production. However, Toll-like receptor 4-deficient (TLR4(-/-)) or macrophages depletion abolished this protection in mice, which revealed Kupffer cells (KCs) and TLR4 to be crucial for the prevention of LPS against DEN-induced damage. Further study revealed that LPS pretreatment induced the KCs to M2 polarization and impaired the signaling of MAPKs and NF-κB that mediated the production of inflammatory cytokines. Moreover, T regulatory cells (Tregs) were also recruited to the liver, which may mediate immunosuppression and participate in the prevention of DEN-induced injury. Our results suggested that LPS protected against DEN-induced hepatitis via induction of M2 Kupffer cells and recruitment of Tregs, which contributes to liver tolerance in TLR4-dependent mechanism.

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Background: Prostate cancer is the leading cause of disease and death in men. Long non-coding RNAs (lncRNAs), microRNA (miRNAs) and mRNAs networks mediate prostate cancer progression. Here, we aim to investigate functions of lncRNA AC008972.1/miR-143-3p/thousand-and-one-amino acid 2 kinase (TAOK2) in prostate cancer. Methods: The expression levels of lncRNA AC008972.1, miR-143-3p and TAOK2 are detected in prostate cancer tissues and cell lines by RT-qPCR. PC3 and LNCaP cells are used to establish lncRNA AC008972.1-knockdown, miR-143-3p-overexpressing, and TAOK2-down-regulated cells. Cell viability is examined by MTT and cell proliferation is detected by clone formation assay. Cell migration and invasion are tested by wound scratch assay and transwell chamber assay. The rate of apoptosis was analyzed by flow cytometry. The protein expression is detected by western blot assay. The target is validated by RNA binding protein immunoprecipitation (RIP) assay and dual luciferase activity assay. A mouse xenograft model was conducted to investigate the oncogenic effect of lncRNA AC008972.1 on prostate cancer. Results: High expression of lncRNA AC008972.1 was associated with low overall survival in prostate cancer. Down-regulation of lncRNA AC008972.1 delayed prostate cancer process by inhibiting cell viability, proliferation, migration and invasion, as well as altering protein expression，whereas cell apoptosis was markedly promoted. LncRNA AC008972.1 negatively regulated miR-143-3p expression and miR-143-3p overexpression promoted prostate cancer process in vitro. TAOK2 expression was decreased by miR-143-3p through the complementary targeting of TAOK2 mRNA. Down-regulation of lncRNA AC008972.1 mitigated prostate cancer process in vitro based on miR-143-3p/TAOK2 node. Furthmore, the data of xenograft model experiment showed that inhibition of lncRNA AC008972.1 suppressed tumor growth in vivo. Conclusions: Collectively, knockdown of lncRNA AC008972.1 inhibits prostate cancer cell growth based on down-regulation of TAOK2 induced by miR-143-3p. Here, we identify that lncRNA AC008972.1 exerts essential roles in the progression of prostate cancer and serves as a novel therapeutic target for prostate cancer.