title: Diabetes may affect the expression of matrix metalloproteinases and their inhibitors more than smoking in chronic periodontitis.
abstract: OBJECTIVE
  No previous study has directly compared the levels of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) between smokers and individuals with diabetes mellitus (DM) with periodontitis. Therefore, the aim of this study was to evaluate the gene expression of MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1 and TIMP-2 in tissues with chronic periodontitis (ChP) of smokers and individuals with type 2 DM.
  
  
  METHODS
  Gingival biopsies were harvested from: non-smokers and non-diabetic individuals with ChP (n = 18) (ChP group); non-diabetic smokers (≥ 10 cigarettes per day for at least the past 5 years) with ChP (n = 18) (SChP group); non-smoking individuals with type 2 diabetes (glycated hemoglobin levels ≥ 7.5%) and ChP (n = 18) (DMChP group). The tissue levels of mRNA of MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1 and TIMP-2 were evaluated by quantitative real-time polymerase chain reaction.
  
  
  RESULTS
  The MMP-8 expression was the lowest in the ChP group (p < 0.05). The DMChP group presented increased mRNA levels of MMP-2 and MMP-9, when compared to the SChP group (p < 0.05). MMP-1 expression and the MMP-1/TIMP-1, MMP-2/TIMP-1, MMP-8/TIMP-1, MMP-9/TIMP-1, MMP-1/TIMP-2 and MMP-2/TIMP-2 ratios were higher in the DMChP group than in the ChP and SChP groups (p < 0.05). The DMChP group presented lower mRNA levels of TIMP-1 than the ChP group (p < 0.05). The MMP-8/TIMP-2 ratio was the highest in the SChP group (p < 0.05).
  
  
  CONCLUSIONS
  Uncontrolled type 2 DM upregulates the ratio of MMP/TIMPs in sites with ChP more than smoking, which may contribute to a greater extracellular matrix degradation and periodontal breakdown in DM-related periodontitis.
authors.affiliation: Dental Research Division, Department of Periodontology, Guarulhos University, Guarulhos, SP, Brazil.
authors.forename: M F
authors.initials: MF
authors.lastname: Bastos
authors.affiliation: Dental Research Division, Department of Periodontology, Guarulhos University, Guarulhos, SP, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Tucci
authors.affiliation: Dental Research Division, Department of Periodontology, Guarulhos University, Guarulhos, SP, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: de Siqueira
authors.affiliation: Dental Research Division, Department of Periodontology, Guarulhos University, Guarulhos, SP, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: de Faveri
authors.affiliation: Dental Research Division, Department of Periodontology, Guarulhos University, Guarulhos, SP, Brazil.
authors.forename: L C
authors.initials: LC
authors.lastname: Figueiredo
authors.affiliation: Dental Research Division, Department of Periodontology, Guarulhos University, Guarulhos, SP, Brazil.
authors.forename: P C
authors.initials: PC
authors.lastname: Vallim
authors.affiliation: Dental Research Division, Department of Periodontology, Guarulhos University, Guarulhos, SP, Brazil.
authors.forename: P M
authors.initials: PM
authors.lastname: Duarte
mesh_terms: D000328:Adult; D055113:Chronic Periodontitis / Q000150:complications* / Q000201:enzymology / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000201:enzymology / Q000378:metabolism; D005260:Female; D005881:Gingiva / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020784:Matrix Metalloproteinase 8 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008875:Middle Aged; D012907:Smoking / Q000009:adverse effects*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D020782:Matrix Metalloproteinases; D020778:Matrix Metalloproteinase 2; D020784:Matrix Metalloproteinase 8; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1
keywords: diabetes mellitus; metalloproteinase; periodontitis; smoking; tissue inhibitors of MMPs