The hsa_circ_0002371/hsa-miR-502-5p/ATG16L1 axis modulates the survival of intracellular Mycobacterium tuberculosis and autophagy in macrophages

Abstract

AbstractBackgroundCircular RNAs (circRNAs) play a critical role in pathological mechanisms ofMycobacterium tuberculosis(Mtb) and can be used as a new biomarker for tuberculosis (TB) diagnosis. Therefore, we identified significantly dysregulated circRNAs in TB patients and healthy controls (HC) and explored the role of hsa_circ_0002371 in TB and its molecular mechanism. Methods RNA sequencing was performed to identify significantly dysregulated circRNAs in TB patients and HC. The diagnostic value of hsa_circ_0002371 was evaluated by receiver operating characteristic (ROC) curve analysis. Real-time quantitative polymerase chain reaction (RT-qPCR), western blot (WB), immunofluorescence, and colony-forming unit (CFU) assay were conducted to investigate the role of hsa_circ_0002371in BCG-infected THP-1 human macrophages. Bioinformatics, fluorescence in situ hybridization (FISH), dual-luciferase reporter gene assay, and WB were used to explore the underlying molecular mechanisms. Results Hsa_circ_0002371 was significantly up-regulated in PBMCs of TB patients and H37Rv- or BCG-infected THP-1 human macrophages. Functional experiments demonstrated that hsa_circ_0002371 inhibited autophagy of BCG-infected THP-1 human macrophages and promoted intracellular BCG survival rate. Mechanistically, hsa_circ_0002371 promoted the expression of hsa-miR-502-5p, and hsa_circ_0002371overexpression-induced protective effects in BCG-infected THP-1 human macrophages was largely overturned by the inhibition of hsa-miR-502-5p. Notably, hsa-miR-502-5p inhibited autophagy via suppressing autophagy related 16 like 1 (ATG16L1) in BCG-infected macrophages and thus promoting intracellular BCG growth. In summation, hsa_circ_0002371 increased the suppression of hsa-miR-502-5p on ATG16L1 and inhibited autophagy to promote Mycobacteria growth in macrophages.ConclusionOur data suggested that hsa_circ_0002371 was significantly up-regulated in the PBMCs of TB patients compared with HC. The hsa_circ_0002371/hsa-miR-502-5p/ATG16L1 axis promoted the survival of intracellularMtband inhibited autophagy in macrophages. Our findings suggested hsa_circ_0002371 could act as a potential diagnostic biomarker and therapeutic target.