title: Role of endothelin-1 in periodontal diseases: A structured review.
abstract: OBJECTIVE
  Endothelin-1 (ET-1) is a 21-amino acid peptide and is a potent vasoconstrictor produced by endothelial cells. It plays a role in the development of diseases such as hypertension and atherosclerosis. Previous studies have identified ET-1 in gingival tissues obtained from patients affected by chronic periodontitis or gingival overgrowth. Thus, there is a need to appraise the role of ET-1 in periodontal disease.
  
  
  METHODS
  The electronic search strategy included the databases such as PubMed, PubMed Central, LILACS, MEDLINE, ScienceDirect, MeSH, Cochrane database of systematic reviews, and EMBASE databases. Hand search of relevant journals was also carried out until September 2013. The included studies were both cross-sectional and longitudinal performed in vivo/in vitro, which measures the expression of ET-1 from various cells of the periodontium and in periodontal disease. Further, studies assessing the factors which influence ET-1 expression were included in the study.
  
  
  RESULTS
  A total of 15 articles were found relevant and fulfilled the inclusion criteria posed in this review. Ten studies discussed the concentration of ET-1 in periodontal disease, whereas eight studies investigated the cells expressing ET-1. Nine studies assessed the factors influencing ET-1 expression and two studies evaluated the influence of ET-1 on inflammatory mediators and other cytokines. The results suggested that ET-1 is elevated in periodontal diseases and is influenced by inflammatory cytokines and periodontal pathogens.
  
  
  CONCLUSIONS
  ET-1 was found to have a role in periodontal disease, but further research will be required to substantiate its use as a biomarker.
authors.affiliation: Department of Periodontics, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Waleed
authors.initials: W
authors.lastname: Khalid
authors.affiliation: Department of Periodontics, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Sheeja S
authors.initials: SS
authors.lastname: Vargheese
authors.affiliation: Department of Periodontics, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India.
authors.forename: Reema
authors.initials: R
authors.lastname: Lakshmanan
authors.affiliation: Department of Periodontics, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India.
authors.forename: M
authors.initials: M
authors.lastname: Sankari
authors.affiliation: Department of Periodontics, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India.
authors.forename: N D
authors.initials: ND
authors.lastname: Jayakumar
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D019332:Endothelin-1 / Q000378:metabolism*; D006801:Humans; D010510:Periodontal Diseases / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D016207:Cytokines; D019332:Endothelin-1