Endogenous antisense <em>walR</em> RNA modulates biofilm organization and pathogenicity of <em>Enterococcus faecalis</em>

Wu,Shizhou; Liu,Yunjie; Lei,Lei; Zhang,Hui

doi:10.3892/etm.2020.9501

Endogenous antisense walR RNA modulates biofilm organization and pathogenicity of Enterococcus faecalis

Authors:
- Shizhou Wu
- Yunjie Liu
- Lei Lei
- Hui Zhang
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Affiliations: Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China, West China School of Public Health, Sichuan University, Chengdu, Sichuan 610041, P.R. China, State Key Laboratory of Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China
Published online on: November 23, 2020 https://doi.org/10.3892/etm.2020.9501
Article Number: 69
Copyright: © Wu et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

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Abstract

Enterococcus faecalis (E. faecalis) is regarded as the major pathogen for persistent periapical periodontitis. The aim of the present study was to investigate the role of antisense walR RNA in the regulation of adjacent downstream genes. Reverse transcription‑PCR assays were performed to validate walR. Adjacent downstream genes walK, EF1195, EF1196, and EF1197 were co‑transcribed and detect antisense walR RNA. Northern blotting and 5'‑rapid amplification of cDNA ends (5'‑RACE) assays were conducted to detect and confirm a novel walR antisense (ASwalR) RNA. ASwalR overexpression mutants were constructed, and the biofilm biomass was determined using a crystal violet microtiter assay. The present study detected and confirmed a 550‑bp noncoding antisense RNA with the potential to attenuate the activities of the essential response regulator WalR. The levels of antisense walR RNA transcripts were inversely associated with the production of WalR protein. It was showed that overexpression of ASwalR leads to reduced biofilm formation and exopolysaccharide synthesis. Furthermore, the pathogenicity of E. faecalis was markedly decreased by ASwalR overexpression in an in vivo periapical periodontitis model. In summary, the present study detected a novel antisense walR RNA that leads to a reduction in biofilm formation and the pathogenicity of E. faecalis. Collectively, the data suggest a role for ASwalR as a post‑transcriptional modulator of the WalR regulator in E. faecalis.

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