RESUMO
[Objective] To investigate the effects of airway dysbacteriosis on the development of murine atlergic airway diseases (AAD).[Methods] Female C57BL/6 mice were neubulized with Vancomycin for 10 days and then were sacrificed.The bacterial population in bronchoalveolar lavage fluid (BALF) were evaluated using 16S rRNA high-throughput sequencing technology,exploriug the method of establishing an airway dysbacteriosis mouse model.After the mouse model was established successfully,airway dysbacteriosis mouse models were established by the same method,and based on that,the mice were sensitized and challenged with ovalbumin (OVA) to induce airway allergic inflammation.The frequency of nasal rubbing behaviors per mice was counted;the total cell number and eosinophil relative abundance in BALF were evaluated;the lung tissue inflammation and goblet cell metaplasia were assessed according to histopathological features;and the IgE level in serum,IFN-γ,IL-4 and IL-5 levels in BALF,and IL-33 levels in serum,BALF and intestine tissue were measured by ELISA.[Results] Nebulization of Vancomycin increased Bradyrhizobium,Sphingopyxis,Cupriavidus,Pelomonas,and decreased Akkermansia and Prevotella_6 in airway,inducing significant airway dysbacteriosis.Using the animal model,further study found that airway dysbacteriosis exacerbated OVA-induced airway allergic inflammation,including increased nasal rubbing frequency,higher serun IgE level,more total cell count especially eosinophil infiltration,more serious lung tissue inflammation and goblet cell metaplasia.Additionally,compared to OVA group,mice in Dysbacteriosis and OVA group had significantly increased level of Th2 cytokine IL-4 and IL-5,and significantly decreased Thl cytokine IFN-γin BALF,which revealed that mice in Dysbacteriosis and OVA group had mote remarkable Thl/Th2 imbalance.Furthermore,IL-33 level showed a significant increase in BALF,but didn't change in serum or intestine tissue in Dysbacteriosis and OVA group compared to OVA group.Indicating that airway dysbacteriosis may only affect the local production of IL-33.[Conclusions] An airway dysbacteriosis mouse model was established by Vancomycin nebulization successfully.Airway dysbacteriosis may activate innate lymphoid cells (ILC) and Th2 cell by inducing local IL-33 secreting,which leads to the imbalance of Th1/Th2,and in turn promotes the development of AAD.
RESUMO
BACKGROUND:In the process of cardiac stem cel culture in vitro, the growth microenvironment may have some effects on the cel proliferation. OBJECTIVE:To investigate the possible mechanism of proliferation and migration of rat cardiac stem cel s cultured in vitro. METHODS:Cardiac tissues from 10 Sprague-Dawley rats were obtained for primary culture and subculture. Passage 3 cel s were col ected for immunofluorescence staining, and stem cel growth factor receptor (c-kit) and CD45, CD90 were detected. Cultured tissues were col ected and randomly divided into two groups:in group 1, paraformaldehyde fixation, paraffin embedding, hematoxylin-eosin staining, Masson staining, and detecting apoptotic cel s using TUNEL method were conducted;in group 2, EdU labeling of proliferated cel s, immunofluorescent detection of c-kit positive expression, matrix metal oproteinases 2, 9 and transforming growth factorβ1 using immunofluorescent staining were done. RESULTS AND CONCLUSION:After 7-10 days of myocardial tissue culture, bright and round cel s were visible, and after adhesion, fusiform cel s exhibited strong growth and proliferation ability. Immunofluorescence staining showed a large number of c-kit, CD45 positive cel s but CD90 negative cel s. After culture, a great number of newborn cel s were found, accompanied by apoptosis of myocardial cel s. After EdU staining, the positive cel s were distributed in the myocardial gap, and showed a smal amount of matrix metal oproteinases 2, 9 and transforming growth factorβ1, while in the surrounding myocardium there was a large number of matrix metal oproteinases 2, 9 and transforming growth factorβ1. Taken together, our findings show that cardiac stem cel s could be obtained through myocardial tissue culture in vitro, accompanied by cel proliferation and migration. The mechanism is related to the expression of matrix metal oproteinases 2, 9 and transforming growth factorβ1.