title: Differential regulation of MMP-13 expression in two models of experimentally induced periodontal disease in rats.
abstract: OBJECTIVE
  Evaluate expression of MMP-13 during the course of two models experimentally induced periodontal disease in rats.
  
  
  METHODS
  Expression of MMP-13 at mRNA and protein levels was studied, respectively, by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Two experimental models were used: LPS injections and ligature placement. 30mug of LPS from Eschericia coli was injected twice a week into the palatal aspect of upper molars. Ligatures were placed at the gingival margin around lower first molars. Controls received injections of PBS vehicle and no ligatures on lower molars. Samples were collected 5, 15 and 30 days after initiation of periodontal disease and processed for extraction of total RNA, total protein, and routinely processed for histology.
  
  
  RESULTS
  Both experimental models produced a significant increase on the inflammatory infiltrate that paralleled elevated levels of MMP-13 mRNA and protein at 5 and 15 days. The LPS model was associated with a sustained level of inflammation and increased MMP-13 mRNA throughout the 30 days, whereas the ligature model showed a decrease on the severity of inflammation and MMP-13 mRNA at the 30-day period. Interestingly, MMP-13 protein levels were diametrically contrary to the mRNA levels.
  
  
  CONCLUSIONS
  MMP-13 expression during LPS- and ligature-induced experimental periodontal disease follows the increase on severity of inflammation at the earliest periods. At 30 days, there is a decrease on the severity of inflammation on the ligature model associated with decreased MMP-13 mRNA. There is a lack of transcription-translation coupling of MMP-13 gene in both experimental models.
authors.affiliation: Department of Diagnosis and Surgery, School of Dentistry at Araraquara, State University of Sao Paulo (UNESP), Araraquara, SP, Brazil.
authors.forename: Sabrina Garcia
authors.initials: SG
authors.lastname: de Aquino
authors.forename: Morgana Rodrigues
authors.initials: MR
authors.lastname: Guimaraes
authors.forename: Dagmar Ruth
authors.initials: DR
authors.lastname: Stach-Machado
authors.forename: Juliete Aparecida Francisco
authors.initials: JA
authors.lastname: da Silva
authors.forename: Luís Carlos
authors.initials: LC
authors.lastname: Spolidorio
authors.forename: Carlos
authors.initials: C
authors.lastname: Rossa
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004195:Disease Models, Animal; D004848:Epithelium / Q000201:enzymology / Q000473:pathology; D004926:Escherichia coli; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D005881:Gingiva / Q000293:injuries; D005891:Gingivitis / Q000201:enzymology / Q000209:etiology / Q000473:pathology; D008026:Ligation / Q000295:instrumentation; D008070:Lipopolysaccharides / Q000009:adverse effects; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000032:analysis* / Q000235:genetics; D008963:Molar; D010510:Periodontal Diseases / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D010518:Periodontitis / Q000201:enzymology / Q000209:etiology / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D008070:Lipopolysaccharides; D012333:RNA, Messenger; D053509:Matrix Metalloproteinase 13; C507083:Mmp13 protein, rat