Objective:To establish the intestinal microflora imbalance mouse model to construct a novel allergic airway response model induced by dermatophagoides pteronyssinus allergens. Methods:Sixty BALB/c mice were divided into six groups. Mice in two groups were prepared for the analysis of the quantity of the intestinal bacterial flora and mice in other four groups for the analysis of allergic airway response. Results:Intestinal microflora of mice in antibiotic therapy group presented the weight loss and feces moisture increase. For the mice with intestinal microflora imbalance and induced by dermatophagoides pteronyssinus allergens,the number of total cells,lymphocytes,neutrophils and eosinophils in bronchoalveolar lavage fluid(BALF)significantly increased,the expression level of IL-4 increased,and the expression of GATA-3 mRNA in the lung tissue were upregulated. Conclusions:An allergic airway response model was established successfully by using dermatophagoides pteronyssinus allergens to induce mice with intestinal microflora disruption.

Objective:To study the effects of intestinal flora dysregulation induced by antibiotic on immune function and toll-like receptor(TLR)2,4.Methods:Sixty BALB/c mice were divided into two groups:antibiotic and control group.The mice in antibiotic group were treated with cefoperazone orally for consecutive 7 days.After 7 days,mice were inoculated with Candida albicans.Results:The quantity of Enterobacteriaceae,Enterococcus,Bifidobacterium and Lactobacillus in antibiotic therapy group was significantly lower than that in the control group.The quantity of Candida albicans increased in the antibiotic therapy group.Spleen index,lymphocytic transformation rate induced by PHA,delayed-type hypersensitivity and the number of antibody secreting cells,the gene expression of TLR2 and TLR4 mRNA in spleen were lower than those in the control group.Conclusions:The intestinal flora dysregulation induced by antibiotic may decrease the immune function and toll-like receptor 2,4 gene expression in mice.

Objective To explore the effects of BCG and Poly I:C co-vaccination on the development of spleen T cell subsets of neonatal BALB/c mice. Methods Neonatal BALB/c mice were inoculated with BCG and/or Poly I:C intraperitoneally within 2-3 d after birth. Four weeks later, spleen cells of mice were isolated and the percentage of CD3+ CD8+ IFN-γ+,CD3+ CD8-IFN-γ+,CD3+ CD8+ IL-4+,CD3+ CD8- IL-4+,CD4+ Foxp3+ T cells,which represent Tc1,TH1,Tc2,TH2,Treg cells,respectively,were tested by flow cytometry at single cell level,and the ratios of TH 1/TH 2 and Tc1/Tc2 were calculated. Results The percentages of TH1 and Tc1 cells of BCG-vaccinated mice,Poly I:C-vaccinated mice and BCG plus Poly I:C-vaccinated mice were significantly higher than that of control mice(P＜0.05 or P＜0.01),and there was no difference among the three vaccinated group. The ratios of TH1/TH2 and total IFN-γ/IL-4 of the three vaccinated groups were higher than that of control group,but not the ratio of Tc1/Tc2. The TH1/TH2 ratio of BCG plus Poly I:C-vaccinated group was higher than that of BCG-vaccinated group(P＜0.05).The percentages of Trge cells showed no difference among the four groups(P＞0.05). Conclusion BCG and Poly I:C co-vaccination can significantly increase the number of Tc1 and TH 1 cells and TH 1/TH2 ratio in spleen cells. BCG and Poly I:C vaccination may have a synergistic effect on TH 1/TH2 ratio of spleen cells in neonataI mice. The percentage of CD4+ Foxp3+ T cells among four groups showed no significant difference.

AIM:To investigate the role of microRNA-486-5p (miR-486-5p) in the apoptosis of human bone marrow mesenchymal stem cells (hMSCs) induced by hydrogen peroxide (H2O2).METHODS: The hMSCs were cul-tured in vitro and exposed to serum-free medium and H2O2(10 mmol/L).The changes of miR-486-5p expression in oxida-tive stress-related apoptosis of hMSCs were measured by real-time PCR.The hMSCs were transfected with miR-486-5p mimic or inhibitor at concentration of 30 nmol/L by Lipofectamine RNAiMAX.The effect of miR-486-5p on H2 O2-induced decrease in cell viability was evaluated by MTT assay.Hoechst 33342 staining and flow cytometry were applied to determine the role of miR-486-5p in the apoptosis of hMSCs.The protein expression was evaluated by Western blotting.Caspase-3 ac-tivity was determined using a caspase-3 activity kit.RESULTS:Compared with control group, the expression of miR-486-5p significantly decreased after treated with H2O2(P<0.05).In addition, over-expression of miR-486-5p in the hMSCs reduced the cell viability, accelerated apoptosis, down-regulated Bcl-2/Bax ratio, caspase-3 enzyme precursor content and phosphorylation of Akt, and activated caspase-3 activity.Conversely, down-regulation of miR-486-5p significantly inhibited H2 O2-induced cell apoptosis and the caspase-3 activity, increased cell viability and up-regulated Bcl-2/Bax ratio and phos-phorylation level of Akt.CONCLUSION:Over-expression of miR-486-5p promotes H2 O2-induced hMSCs apoptosis, and repression of miR-486-5p protects hMSCs from H2 O2-induced cellular apoptosis, which may be mediated by regulating Akt signaling pathway.

Objective:To compare peripheral blood tenascin-C (TN-C) level in patients with Kawasaki disease (KD) on admission, after treatment and at recovery, and to assess the potential of TN-C as a novel predictor for coronary artery lesion.Methods:Retrospective study.Blood samples of 44 KD patients [including 21 patients with coronary artery lesions (CAL + group) and 23 patients without coronary artery lesions(CAL - group)], 39 anaphylactoid purpura patients and 36 non-infected and non-vasculitis controls in the Affiliated Hospital of North Sichuan Medical College during January 1, 2018 and November 1, 2018 were collected.TN-C level was measured by enzyme-linked immunosorbent assay.Normally distributed data were compared by the t test; otherwise, they were compared by the Mann- Whitney U test. Pearson product-moment correlation coefficient or Spearman rank correlation coefficient was used to analyze the correlation between TN-C and other laboratory indexes. Results:For KD patients, TN-C levels on admission [(32.0±13.8) μg/L] and after treatment [(33.5±11.4) μg/L] were significantly higher than that at recovery [(23.3±10.8) μg/L](all P<0.01), which was positively correlated with C-reactive protein ( r=0.317, P=0.038), and negatively correlated with sodium level ( r=-0.472, P=0.004). No significant difference in TN-C level was found between CAL + group and CAL - group [on admission: (31.7±15.4) μg/L vs.(32.3±12.5) μg/L; after treatment: (32.2±11.6) μg/L vs.(34.8±11.3) μg/L; at recovery: (22.6±7.3) μg/L vs.(24.0±13.4) μg/L; all P>0.05]. In addition, TN-C level in patients with KD [(32.0±13.8) μg/L] and anaphylactoid purpura [(37.2±18.2) μg/L] was significantly higher than that of control children [(24.0±8.05) μg/L] (all P<0.01). Conclusions:The study findings are able to prove the potential of peripheral blood TN-C as a predictor for coronary artery lesion in KD patients, nor as a maker of vascular injury.Nevertheless, it may be used as an indicator of immune response in the acute phase of KD.