title: The expression of SIRT1 in articular cartilage of patients with knee osteoarthritis and its correlation with disease severity.
abstract: BACKGROUND
  The study aims to investigate the expression of SIRT1 in articular cartilage of patients with primary knee osteoarthritis (OA) and its relationship with disease severity.
  
  
  METHODS
  Cartilage tissue samples were collected from 38 knee OA patients and 9 normal healthy controls and then ascribed to normal, mild, moderate, and severe groups on the basis of the improved Mankin grading system. The expression of SIRT1 in articular cartilage was detected by immunohistochemistry and western blots. The expression of p53 and acetylated p53 (Ac-p53) was also measured by western blots.
  
  
  RESULTS
  The mutual comparisons of the SIRT1 expression levels in all groups have statistical significance except the one between the mild and moderate groups. Moreover, western blot results showed that the SIRT1 was decreased and p53/Ac-p53 were increased in the OA group. The average gray level of SIRT1 increases with the improving grade of the improved Mankin grading system scorers.
  
  
  CONCLUSIONS
  The expression of SIRT1 in articular cartilage is negatively associated with severity of knee OA, indicating that SIRT1 may act as a monitoring indicator for determining development and progression of knee OA.
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Department of Emergency Medicine, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Zhenhan
authors.initials: Z
authors.lastname: Deng
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zeng
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Tuo
authors.initials: T
authors.lastname: Yang
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China. lgh9640@sina.cn.
authors.forename: Guanghua
authors.initials: G
authors.lastname: Lei
mesh_terms: D000368:Aged; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D012720:Severity of Illness Index; D056564:Sirtuin 1 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C447939:SIRT1 protein, human; D056564:Sirtuin 1
keywords: Articular cartilage; Improved Mankin scoring; Knee; Osteoarthritis; SIRT1