title: Elevated serum osteoprotegerin levels in women: friend or foe?
abstract: BACKGROUND
  osteoprotegerin has emerged as a new candidate for the treatment of osteoporosis. However, high levels of osteoprotegerin have been linked to vascular calcification, an independent and well-defined risk factor for cardiovascular disease (CVD) and mortality. Thus, the action of osteoprotegerin in these situations has been questioned.
  
  
  OBJECTIVE
  to evaluate the effect of osteoprotegerin (OPG) on the human body, especially in bone tissue and in vascular diseases.
  
  
  METHODS
  the scientific databases consulted were PubMed-Medline and Cochrane, using keywords (MeSH terms) grouped into the following syntaxes: (Osteoprotegerin OR Osteoclastogenesis Inhibitory Factor OR Receptors, Tumor Necrosis Factor, Member 11b OR Tumor Necrosis Factor Receptor Superfamily, Member 11b OR FDCR-1 Protein OR FDCR 1 Protein OR OCIF Protein OR Follicular Dendritic Cell-Derived Receptor-1) AND (Bones AND Bone OR Bones AND Bone Tissue OR Bones OR Bone Tissue OR Cardiovascular Diseases).
  
  
  RESULTS
  Osteoprotegerin is present in various organs and binds to two ligands: nuclear factor kB (RANKL) related to the differentiation of osteoclasts, and tumor necrosis factor related to the apoptosis-inducing ligand (TRAIL). OPG inhibits the regulation effects of nuclear factor kB on inflammation and on the skeletal and vascular systems, preventing the apoptosis induced by TRAIL, being related to the preservation of bone tissue.
  
  
  CONCLUSIONS
  a deeper knowledge of the mechanisms involved in the association between OPG serum levels, bone integrity and cardiovascular disease can provide important data for future therapeutic interventions.
authors: Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
authors: Gisela Rodrigues da Silva
authors: GR
authors: Sasso
authors: Department of Morphology and Genetics, Unifesp, São Paulo, SP, Brazil.
authors: Rinaldo
authors: R
authors: Florencio-Silva
authors: Department of Obstetrics and Gynecology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: Ricardo Santos
authors: RS
authors: Simões
authors: Department of Obstetrics and Gynecology, FM, USP, São Paulo, SP, Brazil.
authors: Maria Cândida Pinheiro
authors: MC
authors: Baracat
authors: Department of Obstetrics and Gynecology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: José Maria
authors: JM
authors: Soares Júnior
authors: Department of Obstetrics and Gynecology, FM, USP, São Paulo, SP, Brazil.
authors: Edmund Chada
authors: EC
authors: Baracat
mesh_terms: D016723:Bone Remodeling / Q000502:physiology; D001842:Bone and Bones / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000097:blood / Q000378:metabolism; D005260:Female; D006801:Humans; D053244:Osteoprotegerin / Q000097:blood* / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism; D012307:Risk Factors; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism; D061205:Vascular Calcification / Q000097:blood / Q000378:metabolism
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand