Background Inflammatory bowel disease(IBD)is closely associated with intestinal microbiota dysbiosis and metabolic dysfunction.The aim of this study was to explore the protective effects and mechanisms of the probioti...Background Inflammatory bowel disease(IBD)is closely associated with intestinal microbiota dysbiosis and metabolic dysfunction.The aim of this study was to explore the protective effects and mechanisms of the probiotic Bacillus velezensis MZ09,which produces branched-chain short-chain fatty acids(BSCFAs),against the dextran sulfate sodium(DSS)-induced colitis in piglets.Results In this study,a DSS-induced piglet colitis model was established to explore the impact of MZ09.Pretreatment with MZ09 significantly alleviated the symptoms of colitis in piglets.For example,the disease activity index(DAI)score decreased,the length of the colon was restored,and splenomegaly was alleviated.MZ09 enhanced intestinal barrier integrity by upregulating the expression of tight junction proteins such as Claudin-1,Occludin,and ZO-1.Using 16S rRNA analysis,we found that MZ09 could remodel the intestinal microbiota.MZ09 increased the abundance of beneficial bacteria such as Firmicutes and Lactobacillus while suppressing the growth of harmful bacteria such as Proteobacteria and Escherichia-Shigella.MZ09 also increased the levels of short-chain fatty acids(SCFAs)in the colon.The increased SCFA content activated G-protein-coupled receptor 43(GPR43),which increased the phosphorylation of signal transducer and activator of transcription 3(STAT3)and promoted the production of the antiinflammatory cytokine interleukin-10(IL-10).Mechanistically,MZ09 mitigated mitochondrial damage via the STAT3/hypoxia-inducible factor 1α(HIF-1α)axis.This action inhibits nucleotide-binding oligomerization domain,leucinerich repeat and pyrin domain-containing 3(NLRP3)inflammasome-mediated pyroptosis,thus reducing the release of the proinflammatory cytokines IL-1βand IL-18.Conclusions B.velezensis MZ09 alleviates DSS-induced colitis in piglets through multiple pathways,including gut microbiota remodeling,SCFAs–GPR43–STAT3 axis activation,and NLRP3 inflammasome-mediated pyroptosis suppression.These findings provide a new theoretical basis for the development of targeted intervention strategies for IBD,suggesting that MZ09 represents a potentially promising therapeutic agent for IBD treatment.展开更多
Lactobacillus species have excellent abilities to reduce intestinal inflammation and enhance gut barrier function.This study elucidated the potential mechanisms through which Lactobacillus mitigates lipopolysaccharide...Lactobacillus species have excellent abilities to reduce intestinal inflammation and enhance gut barrier function.This study elucidated the potential mechanisms through which Lactobacillus mitigates lipopolysaccharide(LPS)-induced intestinal injury from the perspective of macrophage-intestinal epithelial cell interactions.Lactobacillus intervention improved the histopathological score;elevated ZO-1 and Occludin protein production;reduced CD16^(+)cell numbers;diminished IL-1β,IL-6,and TNF-αlevels;decreased inducible nitric oxide synthase(iNOS)expression;increased CD163^(+)cell numbers;elevated IL-10 concentration;and increased arginase-1(Arg1)expression in LPS-challenged piglets.Lactobacillus pretreatment also altered the colonic microbiota,thereby increasing the butyric acid concentration and GPR43 expression in the LPS-challenged piglets.Compared with those in the LPS group,sodium butyrate(SB)pretreatment decreased IL-1β,IL-6 and TNF-αsecretion and iNOS expression but increased IL-10 secretion and Arg1 expression in macrophages.The SB-pretreated macrophages reduced the protein expression of TLR4,MyD88,and phosphorylated NF-κB p65 but increased the protein expression of ZO-1 and Occludin in intestinal epithelial cells.Moreover,GLPG0974 blocked the beneficial effects of SB on macrophages and intestinal epithelial cells.This study demonstrated that Lactobacillus improves intestinal barrier function by regulating the macrophage phenotype through the control of butyric acid and GPR43 levels to further control inflammation.展开更多
AIM： To investigate the effect of short-chain fatty acids （SCFAs） on production of prostaglandin E2 （PGE2）, cytokines and chemokines in human monocytes. METHODS： Human neutrophils and monocytes were isolated fro...AIM： To investigate the effect of short-chain fatty acids （SCFAs） on production of prostaglandin E2 （PGE2）, cytokines and chemokines in human monocytes. METHODS： Human neutrophils and monocytes were isolated from human whole blood by using 1-Step Polymorph and RosetteSep Human Monocyte Enrichment Cocktail, respectively. Human GPR41 and GPR43 mRNA expression was examined by quantitative realtime polymerase chain reaction, The calcium flux assay was used to examine the biological activities of SCFAs in human neutrophils and monocytes. The effect of SCFAs on human monocytes and peripheral blood mononuclear cells （PBMC） was studied by measuring PGE2, cytokines and chemokines in the supernatant. The effect of SCFAs in vivo was examined by intraplantar injection into rat paws. RESULTS： Human GPR43 is highly expressed in human neutrophils and monocytes. SCFAs induce robust calcium flux in human neutrophils, but not in human monocytes. In this study, we show that SCFAs can induce human monocyte release of PGE2 and that this effect can be enhanced in the presence of lipopolysaccharide （LPS）. In addition, we demonstrate that PGE2 production induced by SCFA was inhibited by pertussis toxin, suggesting the involvement of a receptor-mediated mechanism. Furthermore, SCFAs can specifically inhibit constitutive monocyte chemotactic protein-1 （MCP-1） production and LPS-induced interleukin-10 （IL-10） production in human monocytes without affecting the secretion of other cytokines and chemokines examined. Similar activities were observed in human PBMC for the release of PGE2, MCP-1 and IL-10 after 5CFA treatment. In addition, SCFAs inhibit LPS-induced production of tumor necrosis factor-α and interferon-7 in human PBIVlC. Finally, we show that SCFAs and LPS can induce PGE2 production in vivo by intraplantar injection into rat paws （P 〈 0.01）. CONCLUSION： SCFAs can have distinct antiinflammatory activities due to their regulation of PGE2, cytokine and chemokine release from human immune cells.展开更多
Numerous physiological and pathological processes are controlled by free fatty acids, which act as signaling molecules in mammals. We hypothesized that oleic acid (Ole) might stimulate the formation of satellite-cell-...Numerous physiological and pathological processes are controlled by free fatty acids, which act as signaling molecules in mammals. We hypothesized that oleic acid (Ole) might stimulate the formation of satellite-cell-derived intramuscular adipose tissue. The role of Ole as a ligand of <em>G-protein-coupled receptor 43</em> (<em>GPR4</em>3) was previously identified. Thus, the objective of the current study was to determine the effect of Ole on <em>GPR43</em> and factors related to the adipogenic differentiation of bovine satellite cells (BSC). Treatments of 100 μM and 500 μM Ole tended to induce greater (P < 0.10) mRNA expression of <em>CCAAT/enhancer-binding protein β</em> (<em>C/EBPβ</em>) compared to all other doses. The mRNA abundance of peroxisome proliferator-activated receptor γ (<em>PPARγ</em>) was not altered (<em>P</em> > 0.10) by treatment. The addition of 100 μM and 500 μM of Ole upregulated (<em>P</em> < 0.05) <em>GPR43</em> mRNA expression. Protein level of GPR43 was increased (<em>P</em> < 0.05) by 100 μM of Ole treatments. Addition of Ole to BSC cultures induced transformation of myogenic cells into adipocyte-like cells that formed cytoplasmic lipid droplets. Increased expression of<em> C/EBPβ</em> in response to Ole might suppress myogenic differentiation. After the treatment of cells with Ole, increased expression of GPR43 could lead to phosphorylation of 5’ AMP-activated protein kinase α (AMPKα). Altogether, the results indicated that increased Ole might stimulate adipose tissue accumulation within the skeletal muscle of cattle by promoting adipogenic differentiation and activation of GPR43 in satellite cells.展开更多
基金supported by the National Natural Science Foundation of China(32372924)the Major Industrialisation of Scientific and Technological Achievements in Heilongjiang Province(CG24019).
文摘Background Inflammatory bowel disease(IBD)is closely associated with intestinal microbiota dysbiosis and metabolic dysfunction.The aim of this study was to explore the protective effects and mechanisms of the probiotic Bacillus velezensis MZ09,which produces branched-chain short-chain fatty acids(BSCFAs),against the dextran sulfate sodium(DSS)-induced colitis in piglets.Results In this study,a DSS-induced piglet colitis model was established to explore the impact of MZ09.Pretreatment with MZ09 significantly alleviated the symptoms of colitis in piglets.For example,the disease activity index(DAI)score decreased,the length of the colon was restored,and splenomegaly was alleviated.MZ09 enhanced intestinal barrier integrity by upregulating the expression of tight junction proteins such as Claudin-1,Occludin,and ZO-1.Using 16S rRNA analysis,we found that MZ09 could remodel the intestinal microbiota.MZ09 increased the abundance of beneficial bacteria such as Firmicutes and Lactobacillus while suppressing the growth of harmful bacteria such as Proteobacteria and Escherichia-Shigella.MZ09 also increased the levels of short-chain fatty acids(SCFAs)in the colon.The increased SCFA content activated G-protein-coupled receptor 43(GPR43),which increased the phosphorylation of signal transducer and activator of transcription 3(STAT3)and promoted the production of the antiinflammatory cytokine interleukin-10(IL-10).Mechanistically,MZ09 mitigated mitochondrial damage via the STAT3/hypoxia-inducible factor 1α(HIF-1α)axis.This action inhibits nucleotide-binding oligomerization domain,leucinerich repeat and pyrin domain-containing 3(NLRP3)inflammasome-mediated pyroptosis,thus reducing the release of the proinflammatory cytokines IL-1βand IL-18.Conclusions B.velezensis MZ09 alleviates DSS-induced colitis in piglets through multiple pathways,including gut microbiota remodeling,SCFAs–GPR43–STAT3 axis activation,and NLRP3 inflammasome-mediated pyroptosis suppression.These findings provide a new theoretical basis for the development of targeted intervention strategies for IBD,suggesting that MZ09 represents a potentially promising therapeutic agent for IBD treatment.
基金supported by the National Nature Science Foundation of China(32272898)the National Key Research and Development Program(2021YFA0805904)the Fundamental Research Funds for the Central Universities(2662020DKQD004).
文摘Lactobacillus species have excellent abilities to reduce intestinal inflammation and enhance gut barrier function.This study elucidated the potential mechanisms through which Lactobacillus mitigates lipopolysaccharide(LPS)-induced intestinal injury from the perspective of macrophage-intestinal epithelial cell interactions.Lactobacillus intervention improved the histopathological score;elevated ZO-1 and Occludin protein production;reduced CD16^(+)cell numbers;diminished IL-1β,IL-6,and TNF-αlevels;decreased inducible nitric oxide synthase(iNOS)expression;increased CD163^(+)cell numbers;elevated IL-10 concentration;and increased arginase-1(Arg1)expression in LPS-challenged piglets.Lactobacillus pretreatment also altered the colonic microbiota,thereby increasing the butyric acid concentration and GPR43 expression in the LPS-challenged piglets.Compared with those in the LPS group,sodium butyrate(SB)pretreatment decreased IL-1β,IL-6 and TNF-αsecretion and iNOS expression but increased IL-10 secretion and Arg1 expression in macrophages.The SB-pretreated macrophages reduced the protein expression of TLR4,MyD88,and phosphorylated NF-κB p65 but increased the protein expression of ZO-1 and Occludin in intestinal epithelial cells.Moreover,GLPG0974 blocked the beneficial effects of SB on macrophages and intestinal epithelial cells.This study demonstrated that Lactobacillus improves intestinal barrier function by regulating the macrophage phenotype through the control of butyric acid and GPR43 levels to further control inflammation.
文摘AIM： To investigate the effect of short-chain fatty acids （SCFAs） on production of prostaglandin E2 （PGE2）, cytokines and chemokines in human monocytes. METHODS： Human neutrophils and monocytes were isolated from human whole blood by using 1-Step Polymorph and RosetteSep Human Monocyte Enrichment Cocktail, respectively. Human GPR41 and GPR43 mRNA expression was examined by quantitative realtime polymerase chain reaction, The calcium flux assay was used to examine the biological activities of SCFAs in human neutrophils and monocytes. The effect of SCFAs on human monocytes and peripheral blood mononuclear cells （PBMC） was studied by measuring PGE2, cytokines and chemokines in the supernatant. The effect of SCFAs in vivo was examined by intraplantar injection into rat paws. RESULTS： Human GPR43 is highly expressed in human neutrophils and monocytes. SCFAs induce robust calcium flux in human neutrophils, but not in human monocytes. In this study, we show that SCFAs can induce human monocyte release of PGE2 and that this effect can be enhanced in the presence of lipopolysaccharide （LPS）. In addition, we demonstrate that PGE2 production induced by SCFA was inhibited by pertussis toxin, suggesting the involvement of a receptor-mediated mechanism. Furthermore, SCFAs can specifically inhibit constitutive monocyte chemotactic protein-1 （MCP-1） production and LPS-induced interleukin-10 （IL-10） production in human monocytes without affecting the secretion of other cytokines and chemokines examined. Similar activities were observed in human PBMC for the release of PGE2, MCP-1 and IL-10 after 5CFA treatment. In addition, SCFAs inhibit LPS-induced production of tumor necrosis factor-α and interferon-7 in human PBIVlC. Finally, we show that SCFAs and LPS can induce PGE2 production in vivo by intraplantar injection into rat paws （P 〈 0.01）. CONCLUSION： SCFAs can have distinct antiinflammatory activities due to their regulation of PGE2, cytokine and chemokine release from human immune cells.
文摘Numerous physiological and pathological processes are controlled by free fatty acids, which act as signaling molecules in mammals. We hypothesized that oleic acid (Ole) might stimulate the formation of satellite-cell-derived intramuscular adipose tissue. The role of Ole as a ligand of <em>G-protein-coupled receptor 43</em> (<em>GPR4</em>3) was previously identified. Thus, the objective of the current study was to determine the effect of Ole on <em>GPR43</em> and factors related to the adipogenic differentiation of bovine satellite cells (BSC). Treatments of 100 μM and 500 μM Ole tended to induce greater (P < 0.10) mRNA expression of <em>CCAAT/enhancer-binding protein β</em> (<em>C/EBPβ</em>) compared to all other doses. The mRNA abundance of peroxisome proliferator-activated receptor γ (<em>PPARγ</em>) was not altered (<em>P</em> > 0.10) by treatment. The addition of 100 μM and 500 μM of Ole upregulated (<em>P</em> < 0.05) <em>GPR43</em> mRNA expression. Protein level of GPR43 was increased (<em>P</em> < 0.05) by 100 μM of Ole treatments. Addition of Ole to BSC cultures induced transformation of myogenic cells into adipocyte-like cells that formed cytoplasmic lipid droplets. Increased expression of<em> C/EBPβ</em> in response to Ole might suppress myogenic differentiation. After the treatment of cells with Ole, increased expression of GPR43 could lead to phosphorylation of 5’ AMP-activated protein kinase α (AMPKα). Altogether, the results indicated that increased Ole might stimulate adipose tissue accumulation within the skeletal muscle of cattle by promoting adipogenic differentiation and activation of GPR43 in satellite cells.
