title: Comparative study of serum proteomes in Legg-Calve-Perthes disease.
abstract: BACKGROUND
  Legg-Calve-Perthes Disease (LCPD) is an idiopathic osteonecrosis of the developing femoral head complicated by pain and disability of the hip joint. To date, the pathological mechanisms of LCPD are not well-known. This study screened the changes in serum protein expression in patients with LCPD.
  
  
  METHODS
  Age- and sex-matched serum samples from 10 control subjects and 10 patients with LCPD were compared using the isobaric tags for relative and absolute quantification (iTRAQ) technique. Gene ontology analyses, KEGG pathway and functional network analyses were performed. Proteins of interest with large differences in expression, S100-A8, alpha-1-acid glycoprotein 1, haptoglobin and apolipoprotein E, were compared by western blotting.
  
  
  RESULTS
  The disease/control ratios showed 26 proteins were significantly differentially expressed (all p < 0.05). Including higher abundances of complement factor H (1.44), complement C4-B (1.45), isocitrate dehydrogenase [NAD] subunit alpha (2.7) alpha-1-acid glycoprotein 1 (1.87), heptoglobin (1.53) and Ig lambda-2 chain C regions (1.46), and lower levels of apolipoprotein E (0.50), apolipoprotein F (0.60), apolipoprotein C-III (0.69), S100-A8 (0.73), S100-A9 (0.75) and prothrombin (0.77) in LCPD than in controls. The alpha-1-acid glycoprotein 1 and haptoglobin increases, and apolipoprotein E and S100-A8 decreases were confirmed by western blot. KEGG pathway analysis revealed these proteins were related to the complement and coagulation cascades, Staphylococcus aureus infection, PPAR signaling, fat digestion and absorption, and vitamin digestion and absorption. Functional network analysis suggested that the proteins were involved in lipid regulation.
  
  
  CONCLUSIONS
  The complement and coagulation cascades, and abnormal lipid metabolism may be involved in the pathogenesis of LCPD.
authors.affiliation: Department of Orthopaedic, the Second Hospital Affilicated to Medical College, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, Shaanxi, 710004, P. R China. liuryu@126.com.
authors.forename: Ruiyu
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Orthopaedic, the Second Hospital Affilicated to Medical College, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, Shaanxi, 710004, P. R China. drfan2140@163.com.
authors.forename: Lihong
authors.initials: L
authors.lastname: Fan
authors.affiliation: Department of Orthopaedic, the Second Hospital Affilicated to Medical College, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, Shaanxi, 710004, P. R China. 591499454@qq.com.
authors.forename: Longbin
authors.initials: L
authors.lastname: Yin
authors.affiliation: Department of Orthopaedic, the Second Hospital Affilicated to Medical College, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, Shaanxi, 710004, P. R China. kunzheng_wang@126.com.
authors.forename: Kunzheng
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Pediatric Orthopaedic, Hong-Hui Hospital, Medical College of Xi'an Jiaotong University, No. 76 Nanguo Road, Nanshao Men, Beilin District, Xi'an, 710054, P. R China. dy513@126.com.
authors.forename: Wusheng
authors.initials: W
authors.lastname: Miao
authors.affiliation: Department of Orthopaedic, the Second Hospital Affilicated to Medical College, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, Shaanxi, 710004, P. R China. songdaifu@qq.com.
authors.forename: Qichun
authors.initials: Q
authors.lastname: Song
authors.affiliation: Department of Orthopaedic, the Second Hospital Affilicated to Medical College, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, Shaanxi, 710004, P. R China. dang_xiaoqian@sohu.com.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Dang
authors.affiliation: Research Center for Proteome Analysis, Shanghai Institutes for Biological5 Sciences, Chinese Academy of Sciences, Shanghai, P. R China. gaohang@sibs.ac.cn.
authors.forename: Hang
authors.initials: H
authors.lastname: Gao
authors.affiliation: Department of Orthopaedic, the Second Hospital Affilicated to Medical College, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, Shaanxi, 710004, P. R China. baichuanyiyx@sina.com.
authors.forename: Chuanyi
authors.initials: C
authors.lastname: Bai
mesh_terms: D015153:Blotting, Western; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D020869:Gene Expression Profiling; D063990:Gene Ontology; D006801:Humans; D007873:Legg-Calve-Perthes Disease / Q000097:blood*; D008297:Male; D020543:Proteome; D040901:Proteomics / Q000379:methods
chemical_list: D020543:Proteome