| Object: Aspergillus fumigatus(A.fumigatus)is a common opportunistic pathogenic fungus found in nature,whose spores can germinate in the alveoli and cause invasive pulmonary aspergillosis when human immune function is impaired.Diabetes mellitus is an endocrine metabolic disease characterized by hyperglycemia,which can impair the innate immunity of diabetic patients,and in turn increases the risk of serious infections.Invasive pulmonary aspergillosis has been shown to be more prevalent in diabetic patients than in immunocompromised patients,and so diabetes mellitus was considered to be an important risk factor for A.fumigatus infection.A.fumigatus often forms a hypoxic microenvironment at the site of infection.Previous studies by our group had shown that the transcription factor hypoxia inducible factor-1?(HIF-1?)plays an important regulatory role in this microenvironment,and hyperglycemia inhibits the function of HIF-1? leads to the deterioration of infection.Among them,micro RNA-210(miR-210)is one of the most representative micro RNAs regulated by HIF-1?,which participates in the regulation of various immune cell functions,but its role in anti-pulmonary Aspergillus fumigatus infection is still unclear.Existing studies have shown that miR-210 can affect the course of infection by participating in the recruitment and differentiation of various immune cells and also the regulation of inflammatory factors,but its role in the regulation of pulmonary aspergillosis infection in diabetes mellitus is unclear.The aim of this study aims to explore the characteristics of the infection and the regulatory mechanism of miR-210 during the infection process by establishing an animal model of diabetes complicated with A.fumigatus infection,and to provide new therapeutic ideas for patients with diabetes complicated with pulmonary A.fumigatus infection.Methods: 1.The infection characteristics of diabetes mellitus combined with pulmonary A.fumigatus infection and the differences in miR-210 expression in different infection models.In this part,we selected healthy SPF adult C57/bl6 male mice and randomly divided them into Nondiabetic group(n=25),Nondiabetic,A.f group(n=25),Diabetic group(n=25),Diabetic,A.f group(n=25).According to previous literature,we established the diabetic murine model by intraperitoneal injecting of streptozotocin(STZ)at a dose of 180mg/kg.Experimental mice with A.fumigatus infection were inoculated with 50 ?l of spore suspension by bronchial intubation,while the uninfected group was injected with the same amount of sterile saline.Experimental mice in each group were catheterized and samples were collected 1,2,3,4 and 7 days after inoculation.The survival rate,colony count of lung tissue homogenate,and immunofluorescence staining of A.fumigatus spores were used to evaluate the infection status.In histopathological lung sections,leukocytic infiltration was observed in H&E staining.Mi R-210 expression in lung tissue was detected by RT-q PCR.2.The role of miR-210 in diabetes mellitus complicated with pulmonary A.fumigatus infection.In this part,we selected healthy SPF adult C57/bl6 male mice and randomly divide them into Diabetes co-infection therapy group(FG-4592 group,n=20),and Diabetic co-infection control group(vehicle group,n=20).According to previous literature,we established the diabetic murine model by intraperitoneal injecting of streptozotocin(STZ)at a dose of 180mg/kg.We instilled 50 ul of A.fumigatus spores into all experimental mice via the bronchial intubation technique to infect them with A.fumigatus.The therapy group received intraperitoneal injection of Roxadustat(FG-4592)to increase the expression of miR-210.The mice in each group were sacrificed on the 1,2,3,and 4 days after intubation.The survival rate,colony count of lung tissue homogenate,and immunofluorescence staining of A.fumigatus spores were used to evaluate the infection status.In histopathological lung sections,leukocytic infiltration was observed in H&E staining.Mi R-210 expression in lung tissue was detected by RT-q PCR.Results: 1.The infection characteristics of diabetes mellitus combined with pulmonary A.fumigatus infection and the differences in miR-210 expression in different infection models.1.1 The mortality of mice in the Diabetic,A.f group was significantly higher compared with other groups,and the first three days after infection was a high-risk period.(P<0.05)1.2 Spore clearance was significantly slower in the mice of Diabetic,A.f group compared with the Nondiabetic,A.f group,and the number of colonies in the lung homogenate and the immunofluorescence of A.fumigatus antigens in the lung pathology remained positive on day 7 after infection.(P<0.05)1.3 The inflammatory reaction was more severe in the mice of Diabetic,A.f group compared with the Nondiabetic,A.f group.The lungs of mice in the Diabetic,A.f group showed diffuse inflammatory cell infiltration with delayed regression after infection.(P<0.05)1.4 After infection,the expression of miR-210 was significantly higher in the lungs of Nondiabetic,A.f group compared with the other groups(P<0.05),while the expression was not significantly different between the Diabetic,A.f group and the Diabetic control group.2.The function of miR-210 in the diabetic mice complicated with A.fumigatus infection and its possible mechanism.2.1 After treatment with FG-4592,the mortality rate of the experimental mice in Diabetic co-infection therapy group was significantly reduced,the spores in lungs of the experimental mice were rapidly cleared,and the number of colonies in the homogenized lung tissue and the immunofluorescence intensity of A.fumigatus antigen were significantly reduced on day 4 after infection.(P<0.05)2.2 After the application of FG-4592,the inflammatory response of Diabetic co-infection therapy group was alleviated.The level of inflammatory cell infiltration in the lungs decreased and regressed on time.(P<0.05)2.3 After the use of FG-4592,the expression of miR-210 in lung tissues of mice in the treatment group was significantly higher compared with the control group.(P<0.05)Conclusions: 1.Lung infection with A.fumigatus is exacerbated by the presence of diabetes.Mainly manifested as higher mortality,the stronger inflammatory response and slower spore clearance in mice.2.The expression of miR-210 was suppressed in diabetes combined with pulmonary A.fumigatus infection.3.Overexpression of miR-210 can alleviate the infection of diabetes complicated by A.fumigatus,accelerate A.fumigatus spore removal from the lungs,reduce mortality,and prevente cytokine storm. |
PDF Full Text Request