Diagnostic Value And Function Of Exosome-Derived MiRNA-185-5p In Active Tuberculosis

According to the "Global Tuberculosis Report 2019" released by the WHO,TB remains one of the top 10 causes of death worldwide,and China is still the second largest emerging country of TB,with approximately 900,000 new cases each year.The key to controlling tuberculosis lies in timely detection and treatment.However,the existing diagnostic methods take a long time and the positive rate is low,which prevents patients from getting timely and accurate diagnosis and delays treatment.Therefore,it is important to find a diagnostic method that is fast,accurate,efficient,and easy to operate.The purpose of this study was to screen and identify exosomal mi RNAs specifically expressed in patients with active tuberculosis and to provide new biomarkers for the development of tuberculosis diagnostic methods.In this study,we first established a BCG-infected human THP-1 cell model,used ultracentrifugation to obtain cell culture supernatant exosomes and performed transcriptome sequencing analysis.A total of 24 differentially expressed exosomal mi RNAs were screened.Through data analysis and comparison,4 mi RNAs were identified as biomarker candidate molecules(mi RNA-185-5p,mi RNA-222-3p,mi RNA-146b-5p,mi RNA-126-3p).Then verified by q RT-PCR in THP-1 derived macrophages,only mi RNA-185-5p was differentially expressed.In addition,the study further found that mi RNA-185-5p was still differentially expressed in BCG-infected PBMCs-derived macrophages and plasma exosomes in patients with active tuberculosis,and its expression level was significantly higher than in uninfected BCG groups or healthy volunteers.It can be used as a biomarker for active tuberculosis.Finally,a mi RNA-185-5p lentiviral overexpression vector was constructed and transfected into THP-1 cells.The expression levels of cytokines related to inflammation were detected by q RT-PCR and ELISA methods.We have initially explored the mechanism of action of mi RNA-185-5p and found that over-expressed mi RNA-185-5p can significantly promote the expression of inflammatory factor IL-6 m RNA and protein levels in THP-1 cells.This study indicates that mi RNA-185-5p can be used as a biomarker for active tuberculosis,laying a foundation for the development of diagnostic methods for tuberculosis.Enhancing the expression of mi RNA-185-5p can promote the expression of the inflammatory cytokine IL-6 in THP-1 cells.The molecule may play a role in active tuberculosis by regulating lipid metabolism pathways,which provides a new direction for its research in tuberculosis.