title: The effect of smoking on the mRNA expression of MMPs and TIMP-1 in untreated chronic periodontitis patients: a cross-sectional study.
abstract: OBJECTIVE
  Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are important for extracellular matrix. Expression of MMPs has been evaluated in gingiva without studying smoking. The aim of this study was to explore the effect of smoking on mRNA expression of MMP-1, -3, -8, -9 and -13 and TIMP-1 in untreated chronic periodontitis and in periodontal health.
  
  
  METHODS
  Gingival samples were harvested from 30 subjects with untreated chronic periodontitis (15 nonsmokers and 15 smokers) and 30 periodontally healthy subjects (15 nonsmokers and 15 smokers). Full-mouth plaque score, gingival index, bleeding on probing, probing depth and clinical attachment level were recorded. Total RNA was isolated, and the mRNA expression of MMPs and TIMP-1 was assessed by RT-PCR.
  
  
  RESULTS
  Periodontitis groups were comparable in clinical measurements. Nonsmoker subjects with periodontitis had statistically significantly higher MMP-1, lower MMP-9 and TIMP-1 expression and higher MMP-1/TIMP-1 ratio than smokers; and higher MMP-8 expression and MMP-8/TIMP-1 and MMP-1/TIMP-1 ratios than healthy nonsmokers. Healthy nonsmokers had statistically significantly higher MMP-13 expression than healthy smokers. Smoker periodontitis and healthy subjects had similar expression levels of MMPs and TIMP-1 and MMPs/TIMP-1 ratios. There was correlation among the MMPs only for smoker periodontitis subjects. Expression of MMP-13 was correlated with mean clinical attachment level.
  
  
  CONCLUSIONS
  Within its limits, this study demonstrated that smoking affected mRNA expression of MMPs and TIMP-1, MMPs/TIMP-1 ratios and relationships among MMPs in untreated chronic periodontitis and expression of MMPs in health. In the absence of smoking, chronic periodontitis affected expression of MMPs and MMPs/TIMP-1 ratios.
authors: Department of Periodontology, School of Dentistry, University of Athens, Greece. bettymouzakiti@hotmail.com
authors: E
authors: E
authors: Mouzakiti
authors: E
authors: E
authors: Pepelassi
authors: G
authors: G
authors: Fanourakis
authors: C
authors: C
authors: Markopoulou
authors: S
authors: S
authors: Tseleni-Balafouta
authors: I
authors: I
authors: Vrotsos
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000201:enzymology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000096:biosynthesis* / Q000235:genetics; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis; D012907:Smoking / Q000009:adverse effects*; D018709:Statistics, Nonparametric; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D020782:Matrix Metalloproteinases