title: Analysis of Small RNAs in Streptococcus mutans under Acid Stress-A New Insight for Caries Research.
abstract: Streptococcus mutans (S. mutans) is the major clinical pathogen responsible for dental caries. Its acid tolerance has been identified as a significant virulence factor for its survival and cariogenicity in acidic conditions. Small RNAs (sRNAs) are recognized as key regulators of virulence and stress adaptation. Here, we constructed three libraries of sRNAs with small size exposed to acidic conditions for the first time, followed by verification using qRT-PCR. The levels of two sRNAs and target genes predicted to be bioinformatically related to acid tolerance were further evaluated under different acid stress conditions (pH 7.5, 6.5, 5.5, and 4.5) at three time points (0.5, 1, and 2 h). Meanwhile, bacterial growth characteristics and vitality were assessed. We obtained 1879 sRNAs with read counts of at least 100. One hundred and ten sRNAs were perfectly mapped to reported msRNAs in S. mutans. Ten out of 18 sRNAs were validated by qRT-PCR. The survival of bacteria declined as the acid was increased from pH 7.5 to 4.5 at each time point. The bacteria can proliferate under each pH except pH 4.5 with time. The levels of sRNAs gradually decreased from pH 7.5 to 5.5, and slightly increased in pH 4.5; however, the expression levels of target mRNAs were up-regulated in acidic conditions than in pH 7.5. These results indicate that some sRNAs are specially induced at acid stress conditions, involving acid adaptation, and provide a new insight into exploring the complex acid tolerance for S. mutans.
authors.affiliation: Department of Preventive Dentistry, Guanghua School of Stomatology, Sun Yat-Sen University, 56 Ling Yuan Road West, Guangzhou 510055, China. liushanshancan@163.com.|Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China. liushanshancan@163.com.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Preventive Dentistry, Guanghua School of Stomatology, Sun Yat-Sen University, 56 Ling Yuan Road West, Guangzhou 510055, China. taoye18@aliyun.com.|Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China. taoye18@aliyun.com.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tao
authors.affiliation: Department of Preventive Dentistry, Guanghua School of Stomatology, Sun Yat-Sen University, 56 Ling Yuan Road West, Guangzhou 510055, China. yuu_lx@163.com.|Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China. yuu_lx@163.com.
authors.forename: Lixia
authors.initials: L
authors.lastname: Yu
authors.affiliation: Department of Preventive Dentistry, Guanghua School of Stomatology, Sun Yat-Sen University, 56 Ling Yuan Road West, Guangzhou 510055, China. pelion@163.com.|Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China. pelion@163.com.
authors.forename: Peilin
authors.initials: P
authors.lastname: Zhuang
authors.affiliation: Department of Preventive Dentistry, Guanghua School of Stomatology, Sun Yat-Sen University, 56 Ling Yuan Road West, Guangzhou 510055, China. zhiqinghui@hotmail.com.|Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China. zhiqinghui@hotmail.com.
authors.forename: Qinghui
authors.initials: Q
authors.lastname: Zhi
authors.affiliation: Department of Preventive Dentistry, Guanghua School of Stomatology, Sun Yat-Sen University, 56 Ling Yuan Road West, Guangzhou 510055, China. zhouy10.3@163.com.|Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China. zhouy10.3@163.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Preventive Dentistry, Guanghua School of Stomatology, Sun Yat-Sen University, 56 Ling Yuan Road West, Guangzhou 510055, China. lin_hc@163.net.|Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China. lin_hc@163.net.
authors.forename: Huancai
authors.initials: H
authors.lastname: Lin
mesh_terms: D000143:Acids / Q000737:chemistry; D001426:Bacterial Proteins / Q000235:genetics; D003731:Dental Caries / Q000382:microbiology / Q000517:prevention & control*; D018865:Dental Research / Q000379:methods; D015723:Gene Library; D006801:Humans; D006863:Hydrogen-Ion Concentration; D012329:RNA, Bacterial / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D058727:RNA, Small Untranslated / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013295:Streptococcus mutans / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D058727:RNA, Small Untranslated
keywords: Streptococcus mutans; dental caries; gene expression; sRNAs; virulence