title: SMAD3 Is Upregulated in Human Osteoarthritic Cartilage Independent of the Promoter DNA Methylation.
abstract: OBJECTIVE
  To compare SMAD3 gene expression between human osteoarthritic and healthy cartilage and to examine whether expression is regulated by the promoter DNA methylation of the gene.
  
  
  METHODS
  Human cartilage samples were collected from patients undergoing total hip/knee joint replacement surgery due to primary osteoarthritis (OA), and from patients with hip fractures as controls. DNA/RNA was extracted from the cartilage tissues. Real-time quantitative PCR was performed to measure gene expression, and Sequenom EpiTyper was used to assay DNA methylation. Mann-Whitney test was used to compare the methylation and expression levels between OA cases and controls. Spearman rank correlation coefficient was calculated to examine the association between the methylation and gene expression.
  
  
  RESULTS
  A total of 58 patients with OA (36 women, 22 men; mean age 64 ± 9 yrs) and 55 controls (43 women, 12 men; mean age 79 ± 10 yrs) were studied. SMAD3 expression was on average 83% higher in OA cartilage than in controls (p = 0.0005). No difference was observed for DNA methylation levels in the SMAD3 promoter region between OA cases and controls. No correlation was found between SMAD3 expression and promoter DNA methylation.
  
  
  CONCLUSIONS
  Our study demonstrates that SMAD3 is significantly overexpressed in OA. This overexpression cannot be explained by DNA methylation in the promoter region. The results suggest that the transforming growth factor-β/SMAD3 pathway may be overactivated in OA cartilage and has potential in developing targeted therapies for OA.
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Erfan
authors.initials: E
authors.lastname: Aref-Eshghi
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Seyd Babak
authors.initials: SB
authors.lastname: Razavi-Lopez
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Hirasawa
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Harper
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Glynn
authors.initials: G
authors.lastname: Martin
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Furey
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Roger
authors.initials: R
authors.lastname: Green
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Guang
authors.initials: G
authors.lastname: Sun
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
authors.forename: Proton
authors.initials: P
authors.lastname: Rahman
authors.affiliation: From the Discipline of Genetics, Division of Biomedical Science, Division of Orthopedics, Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; and the Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.E. Aref-Eshghi, MD, PhD Candidate; M. Liu, MSc, Research Assistant, Discipline of Genetics; S. Razavi-Lopez, BSc, Research Assistant; K. Hirasawa, PhD, Professor, Division of Biomedical Science; P.E. Harper, BSc, Master's Student, Discipline of Genetics; G. Martin, MD, Orthopedic Surgeon; A. Furey, MD, Associate Professor of Surgery, Division of Orthopedics; R. Green*, PhD, Honorary Research Professor, Discipline of Genetics; G. Sun, PhD, Professor; P. Rahman, MD, Professor of Medicine (Rheumatology), Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada; G. Zhai, PhD, Associate Professor, Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland; Department of Twin Research and Genetic Epidemiology, King's College London, London, UK. guangju.zhai@med.mun.ca.
authors.forename: Guangju
authors.initials: G
authors.lastname: Zhai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002358:Cartilage, Articular / Q000378:metabolism*; D019902:Chondrocytes / Q000378:metabolism; D019175:DNA Methylation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000235:genetics* / Q000378:metabolism / Q000601:surgery; D020370:Osteoarthritis, Knee / Q000235:genetics* / Q000378:metabolism / Q000601:surgery; D011401:Promoter Regions, Genetic; D051900:Smad3 Protein / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D051900:Smad3 Protein
keywords: CARTILAGE; DNA METHYLATION; GENE EXPRESSION; OSTEOARTHRITIS; SMAD3