(Peer-Reviewed) The vicK gene of Streptococcus mutans mediates its cariogenicity via exopolysaccharides metabolism
Yalan Deng 邓雅兰, Yingming Yang 杨英明, Bin Zhang 张斌, Hong Chen 陈虹, Yangyu Lu, Shirui Ren, Lei Lei 雷蕾, Tao Hu 胡涛
State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, 610041, Chengdu, China
中国 成都 四川大学华西口腔医学院 口腔疾病研究国家重点实验室 国家口腔疾病临床医学研究中心
Abstract
Streptococcus mutans (S. mutans) is generally regarded as a major contributor to dental caries because of its ability to synthesize extracellular polysaccharides (EPS) that aid in the formation of plaque biofilm. The VicRKX system of S. mutans plays an important role in biofilm formation. The aim of this study was to investigate the effects of vicK gene on specific characteristics of EPS in S. mutans biofilm.
We constructed single-species biofilms formed by different mutants of vicK gene. Production and distribution of EPS were detected through atomic force microscopy, scanning electron microscopy and confocal laser scanning microscopy. Microcosmic structures of EPS were analyzed by gel permeation chromatography and gas chromatography-mass spectrometry. Cariogenicity of the vicK mutant was assessed in a specific pathogen-free rat model. Transcriptional levels of cariogenicity-associated genes were confirmed by quantitative real-time polymerase chain reaction.
The results showed that deletion of vicK gene suppressed biofilm formation as well as EPS production, and EPS were synthesized mostly around the cells. Molecular weight and monosaccharide components underwent evident alterations. Biofilms formed in vivo were sparse and contributed a decreased degree of caries. Moreover, expressional levels of genes related to EPS synthesis were down-regulated, except for gtfB.
Our report demonstrates that vicK gene enhances biofilm formation and subsequent caries development. And this may due to its regulations on EPS metabolism, like synthesis or microcosmic features of EPS. This study suggests that vicK gene and EPS can be considered as promising targets to modulate dental caries.
Multiplexed stimulated emission depletion nanoscopy (mSTED) for 5-color live-cell long-term imaging of organelle interactome
Yuran Huang, Zhimin Zhang, Wenli Tao, Yunfei Wei, Liang Xu, Wenwen Gong, Jiaqiang Zhou, Liangcai Cao, Yong Liu, Yubing Han, Cuifang Kuang, Xu Liu
Opto-Electronic Advances
2024-07-05