AIM To investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β4(AAV-Tβ4) on murine colitis via intracolonic administration.METHODS AAV-Tβ4 was prepared and intracolonically use...AIM To investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β4(AAV-Tβ4) on murine colitis via intracolonic administration.METHODS AAV-Tβ4 was prepared and intracolonically used to mediate the secretory expression of Tβ4 in mouse colons. Dextran sulfate sodium(DSS) was applied to induce the murine ulcerative colitis, and 2,4,6-trinitrobenzene sulfonic acid(TNBS) was used to establish a mouse colitis model resembling Crohn's disease. The disease severity and colon injuries were observed and graded to reveal the effects of AAV-Tβ4 on colitis. The activities of myeloperoxidase(MPO) and superoxide dismutase(SOD) and the content of malondialdehyde(MDA) were determined using biochemical assays. Colonic levels of tumor necrosis factor-α(TNF-α), interleukin(IL)-1β and IL-10 were measured using ELISA, and mucosal epithelial cell apoptosis andproliferation were detected by TUNEL assay and immunochemistry, respectively.RESULTS Recombinant AAVs efficiently delivered Lac Z and Tβ4 into the colonic tissues of the mice, and AAV-Tβ4 led to a strong expression of Tβ4 in mouse colons. In both the DSS and TNBS colitis models, AAV-Tβ4-treated mice displayed distinctly attenuated colon injuries and reduced apoptosis rate of colonic mucosal epithelia. AAV-Tβ4 significantly reduced inflammatory cell infiltrations and relieved oxidative stress in the inflamed colons of the mice, as evidenced by decreases in MPO activity and MDA content and increases in SOD activity. AAV-Tβ4 also modulated colonic TNF-α, IL-1β and IL-10 levels and suppressed the compensatory proliferation of colonic epithelial cells in DSS- and TNBS-treated mice.CONCLUSION Tβ4 exerts a protective effect on murine colitis, indicating that AAV-Tβ4 could potentially be developed into a promising agent for the therapy of inflammatory bowel diseases.展开更多
Objective:To assess the effects of nebulized inhaled Mycobacterium vaccae on allergic airway inflammation,airway hyperresponsiveness,and Th1/Th2 cell imbalance in mice with ovalbumin(OVA)-induced asthma.Methods:Mice r...Objective:To assess the effects of nebulized inhaled Mycobacterium vaccae on allergic airway inflammation,airway hyperresponsiveness,and Th1/Th2 cell imbalance in mice with ovalbumin(OVA)-induced asthma.Methods:Mice received OVA sensitization and challenge for establishment of the asthmatic model.For intervention,mice received Mycobacterium vaccae nebulization once every other day from the first day of sensitization to the day before challenge.After challenge,pulmonary histological analysis and airway responsiveness measurement were performed.In addition,Th1/Th2 cytokines and OVA-specific IgE levels in bronchoalveolar lavage fluid were measured by ELISA.Th1/Th2 subset ratios and the expression of interferon-regulatory factor 4(IRF4),IRF8 and Toll-like receptor 4(TLR4)in dendritic cells were evaluated by flow cytometry.Results:Severe inflammatory infiltration and airway hyperresponsiveness were observed in OVA-induced asthmatic mice.Asthmatic mice showed higher Th2 cytokine concentration and increased percentage of Th2 cells,along with lower Th1 cytokine concentration and reduced percentage of Th1 cells compared with the normal control.Moreover,an imbalance of IRF4^(+)and IRF8^(+)in dendritic cells was found in asthmatic mice.Nebulized inhaled Mycobacterium vaccae reduced airway hyperresponsiveness and inflammation in OVA-induced asthmatic mice.In addition,nebulized inhaled Mycobacterium vaccae enhanced TLR4 and IRF8 expression,and alleviated the imbalance of Th1/Th2 as well as IRF4^(+)and IRF8^(+)in dendritic cells.Conclusions:Nebulized inhaled Mycobacterium vaccae protects against asthma by alleviating the imbalance of Th1/Th2 and IRF4/IRF8 in OVA-induced asthmatic mice.展开更多
基金Supported by National Foundation of Natural Sciences,China,No.81300293
文摘AIM To investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β4(AAV-Tβ4) on murine colitis via intracolonic administration.METHODS AAV-Tβ4 was prepared and intracolonically used to mediate the secretory expression of Tβ4 in mouse colons. Dextran sulfate sodium(DSS) was applied to induce the murine ulcerative colitis, and 2,4,6-trinitrobenzene sulfonic acid(TNBS) was used to establish a mouse colitis model resembling Crohn's disease. The disease severity and colon injuries were observed and graded to reveal the effects of AAV-Tβ4 on colitis. The activities of myeloperoxidase(MPO) and superoxide dismutase(SOD) and the content of malondialdehyde(MDA) were determined using biochemical assays. Colonic levels of tumor necrosis factor-α(TNF-α), interleukin(IL)-1β and IL-10 were measured using ELISA, and mucosal epithelial cell apoptosis andproliferation were detected by TUNEL assay and immunochemistry, respectively.RESULTS Recombinant AAVs efficiently delivered Lac Z and Tβ4 into the colonic tissues of the mice, and AAV-Tβ4 led to a strong expression of Tβ4 in mouse colons. In both the DSS and TNBS colitis models, AAV-Tβ4-treated mice displayed distinctly attenuated colon injuries and reduced apoptosis rate of colonic mucosal epithelia. AAV-Tβ4 significantly reduced inflammatory cell infiltrations and relieved oxidative stress in the inflamed colons of the mice, as evidenced by decreases in MPO activity and MDA content and increases in SOD activity. AAV-Tβ4 also modulated colonic TNF-α, IL-1β and IL-10 levels and suppressed the compensatory proliferation of colonic epithelial cells in DSS- and TNBS-treated mice.CONCLUSION Tβ4 exerts a protective effect on murine colitis, indicating that AAV-Tβ4 could potentially be developed into a promising agent for the therapy of inflammatory bowel diseases.
基金supported by the National Natural Science Foundation of China under grants(No.81470230)the Natural Science Foundation of Guangxi Zhuang Autonomous Region under grants(No.2020GXNSFDA238003).
文摘Objective:To assess the effects of nebulized inhaled Mycobacterium vaccae on allergic airway inflammation,airway hyperresponsiveness,and Th1/Th2 cell imbalance in mice with ovalbumin(OVA)-induced asthma.Methods:Mice received OVA sensitization and challenge for establishment of the asthmatic model.For intervention,mice received Mycobacterium vaccae nebulization once every other day from the first day of sensitization to the day before challenge.After challenge,pulmonary histological analysis and airway responsiveness measurement were performed.In addition,Th1/Th2 cytokines and OVA-specific IgE levels in bronchoalveolar lavage fluid were measured by ELISA.Th1/Th2 subset ratios and the expression of interferon-regulatory factor 4(IRF4),IRF8 and Toll-like receptor 4(TLR4)in dendritic cells were evaluated by flow cytometry.Results:Severe inflammatory infiltration and airway hyperresponsiveness were observed in OVA-induced asthmatic mice.Asthmatic mice showed higher Th2 cytokine concentration and increased percentage of Th2 cells,along with lower Th1 cytokine concentration and reduced percentage of Th1 cells compared with the normal control.Moreover,an imbalance of IRF4^(+)and IRF8^(+)in dendritic cells was found in asthmatic mice.Nebulized inhaled Mycobacterium vaccae reduced airway hyperresponsiveness and inflammation in OVA-induced asthmatic mice.In addition,nebulized inhaled Mycobacterium vaccae enhanced TLR4 and IRF8 expression,and alleviated the imbalance of Th1/Th2 as well as IRF4^(+)and IRF8^(+)in dendritic cells.Conclusions:Nebulized inhaled Mycobacterium vaccae protects against asthma by alleviating the imbalance of Th1/Th2 and IRF4/IRF8 in OVA-induced asthmatic mice.
