Small RNA Profiling in Mycobacterium Provides Insights Into Stress Adaptability

Abstract

Mycobacteria encounter a number of environmental changes during infection and respond using different mechanisms. Small RNA (sRNA) is a post-transcriptionally regulatory system for gene functions and has been investigated in many other bacteria. This study used Mycobacterium tuberculosis and Mycobacterium bovis Bacillus Calmette-Guérin (BCG) infection models and sequenced whole bacterial RNAs before and after host cell infection. A comparison of differentially expressed sRNAs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) and target prediction was carried out. Six pathogenically relevant stress conditions, growth rate, and morphology were used to screen and identify sRNAs. From these data, a subset of sRNAs was differentially expressed in multiple infection groups and stress conditions. Many were found associated with lipid metabolism. Among them, ncBCG427 was significantly downregulated when BCG entered into macrophages and was associated with increased biofilm formation. The reduction of virulence possibility depends on regulating lipid metabolism.

sRNA21, a novel small RNA, protects Mycobacterium abscessus against oxidative stress

“…In Mycobacterium, numerous sRNAs differentially affect bacterial viability in hostlike conditions. [25][26][27] In the present study, we discovered that overexpression of sRNA21 in M. abscessus ATCC_19977 resulted in an increased ability to infect macrophages and significantly induced resistance to oxidative stress in vitro. Biofilm plays an important role in M. abscessus pathogenicity and also drug resistance, and the biofilmforming ability influences bacterial existence in adverse environments.…”

“…Because overexpression of sRNA21 improved bacterial growth viability the most among all recombinant strains, we chose to investigate the role of sRNA21 in M. abscessus further. In Mycobacterium , numerous sRNAs differentially affect bacterial viability in host‐like conditions 25–27 . In the present study, we discovered that overexpression of sRNA21 in M. abscessus ATCC_19977 resulted in an increased ability to infect macrophages and significantly induced resistance to oxidative stress in vitro.…”

“…Biofilm plays an important role in M. abscessus pathogenicity and also drug resistance, and the biofilmforming ability influences bacterial existence in adverse environments. 25,28 The biofilm-forming ability of the sRNA21 overexpression strain was significantly improved. These results suggest that high expression of sRNA21 enhances the survivability of M. abscessus in response to environmental stimuli.…”

“…In the present study, we discovered that overexpression of sRNA21 in M. abscessus ATCC_19977 resulted in an increased ability to infect macrophages and significantly induced resistance to oxidative stress in vitro. Biofilm plays an important role in M. abscessus pathogenicity and also drug resistance, and the biofilm‐forming ability influences bacterial existence in adverse environments 25,28 . The biofilm‐forming ability of the sRNA21 overexpression strain was significantly improved.…”

Mycobacterium tuberculosis complex molecular networks and their regulation: Implications of strain heterogeneity on epigenetic diversity and transcriptome regulation

“…Early pathogen-specific M. tuberculosis transcriptome studies [ [26] , [27] , [28] ] further indicated regulation of stress-response pathways and unique gene regulation profiles associated with clinical isolates of MTBC, implying strain-specific transcriptional regulatory mechanisms. Furthermore, NGS technologies have recently identified many other regulatory non-coding sRNAs [ [29] , [30] , [31] , [32] , [33] , [34] ], and MTBC-specific methylation patterns [ [35] , [36] , [37] , [38] , [39] , [40] , [41] ] that govern the molecular networks of these notorious pathogens. Therefore, the current review provides an update on all the known non-coding regulatory RNAs and their associated transcripts, together with the methylome data of M. tuberculosis .…”