Exopolysaccharides metabolism and cariogenesis of Streptococcus mutans biofilm regulated by antisense vicK RNA

ABSTRACT

Background

Streptococcus mutans (S. mutans) is a pivotal cariogenic pathogen contributing to its multiple virulence factors, one of which is synthesizing exopolysaccharides (EPS). VicK, a sensor histidine kinase, plays a major role in regulating genes associated with EPS synthesis and adhesion. Here we first identified an antisense vicK RNA (ASvicK) bound with vicK into double-stranded RNA (dsRNA).

Objective

This study aims to investigate the effect and mechanism of ASvicK in the EPS metabolism and cariogenesis of S. mutans.

Methods

The phenotypes of biofilm were detected by scanning electron microscopy (SEM), gas chromatography-mass spectrometery (GC-MS) , gel permeation chromatography (GPC) , transcriptome analysis and Western blot. Co-immunoprecipitation (Co-ip) assay and enzyme activity experiment were adopted to investigate the mechanism of ASvicK regulation. Caries animal models were developed to study the relationship between ASvicK and cariogenicity of S. mutans.

Results

Overexpression of ASvicK can inhibit the growth of biofilm, reduce the production of EPS and alter genes and protein related to EPS metabolism. ASvicK can adsorb RNase III to regulate vicK and affect the cariogenicity of S. mutans.

Conclusions

ASvicK regulates vicK at the transcriptional and post-transcriptional levels, effectively inhibits EPS synthesis and biofilm formation and reduces its cariogenicity in vivo.

KEYWORDS:

• Streptococcus mutans
• Antisense RNA
• vicK gene
• biofilm growth
• exopolysaccharides
• dental caries
• bacterial genetics

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions

Y.T. Sun., H. Chen. and H.C. Mao. contributed to conception, design, data acquisition, analysis, and interpretation, drafted and critically revised the manuscript; S.Y. Yang., M.M. Xu. And X. Qiao., contributed to data acquisition, analysis, and interpretation, critically revised the manuscript; L.W. He., contributed to data acquisition and analysis, critically revised the manuscript; D.Q. Yang, contributed to conception, design, data acquisition, analysis, and interpretation, critically revised the manuscript. All authors gave final approval and agree to be accountable for all aspects of the work.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/20002297.2023.2204250

Additional information

Funding

This research was funded by the National Natural Science Foundation of China under Grant Agreement (No. 31970783 and No. 32270888). This work was supported by a grant from National Science Fund for Distinguished Young Scholars (No. 82100991). This research was funded by the Top Talent Distinguished Professor from Chongqing Medical University [No. (2021) 215] and Program for Youth Innovation in Future Medicine from Chongqing Medical University (No. W0060). This research was funded by the Natural Science Foundation Project of Chongqing Science and Technology Commission (cstc2021jcyj-bshX0211) and the Basic Research and Frontiers Exploration Project of Science and Technology Committee of Yuzhong District (No. 20210124).