title: Salivary peptidome profiling for diagnosis of severe early childhood caries.
abstract: Severe early childhood caries (s-ECC), which has quite high prevalence among children, is a widespread problem with significant impacts among both developing and developed countries. At present, it is widely known that no early detective techniques and diagnostic tests could have high sensitivity and specificity when using for clinical screening of s-ECC. In this study, we had applied magnetic bead (MB)-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to screen distinctive candidate biomarkers of this disease, so as to establish protein profiles and diagnostic models of s-ECC.
  
  
  
  Firstly, we used the technique mentioned above to detect specifically expressed peptides in saliva samples from ten children with s-ECC, separately at the time point of before, 1 and 4 weeks after dental treatment. Then a diagnostic model for s-ECC was established with the K nearest-neighbour method, which was validated in another six children in the next stage of study. After that, linear ion trap-orbitrap-mass spectrometry (LTQ-Orbitrap-MS) was performed to identify which of the proteins in saliva might be the origination of these peptides.
  
  
  
  We found that seven peptide peaks were significantly different when comparing the three time points, among them two were higher, while other five were lower in the pre-treatment s-ECC group compared with post-treatment. The sensitivity and specificity of the diagnostic model we built were both 83.3 %. Two of these peptides were identified to be segments of histatin-1, which was one important secretory protein in saliva.
  
  
  
  Hereby we confirmed that MB-based MALDI-TOF MS is an effective method for screening distinctive peptides from the saliva of junior patients with s-ECC, and histatin-1 may probably be one important candidate biomarker of this common dental disease. These findings might have bright prospect in future in establishing new diagnostic methods for s-ECC.
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China.|Stomatological Hospital of Guizhou Medical University, Guiyang, 550004, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: Tan
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Si
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China.
authors.forename: Xiaozhe
authors.initials: X
authors.lastname: Wang
authors.affiliation: Central Laboratory, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China. moleculecf@gmail.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China. zhengsg86@gmail.com.
authors.forename: Shuguo
authors.initials: S
authors.lastname: Zheng
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002675:Child, Preschool; D003731:Dental Caries / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D054808:Histatins / Q000378:metabolism; D006801:Humans; D008297:Male; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D012463:Saliva / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D054808:Histatins; D010455:Peptides
keywords: Biomarker; Early diagnosis; Histatin-1; MALDI-TOF MS; Proteomics; Saliva; s-ECC