title: High levels of CXC ligand 12/stromal cell-derived factor 1 in apical lesions of endodontic origin associated with mast cell infiltration.
abstract: BACKGROUND
  CXC ligand 12/stromal-derived factor-1 (CXCL12/SDF-1) is a pleiotropic chemokine that regulates the influx of a wide range of leukocytes. The aim of this study was to characterize CXCL12/SDF-1 in apical lesions (ALs) of endodontic origin, with special emphasis in associated immune cell populations.
  
  
  METHODS
  In this case-control study, 29 individuals with chronic apical periodontitis and 21 healthy volunteers were enrolled. ALs and healthy periodontal ligament samples were obtained for tissue homogenization, immune Western blotting, and enzyme-linked immunosorbent assay to determine CXCL12/SDF-1 forms and levels. Anatomopathologic diagnosis, immunostaining for CXCL12/SDF-1, CD117-CXCL12/SDF-1, and toluidine blue were also performed to identify tissue and cell localization. Finally, a set of tissue samples were digested and analyzed by flow cytometry to identify CXCL12/SDF-1 in different immune cell populations. Data were analyzed with Stata v11 and WinDi 2.9 software, and significance was considered if P < .05.
  
  
  RESULTS
  CXCL12/SDF-1 was predominantly identified as monomers; levels of CXCL12/SDF-1 were significantly higher in ALs compared with controls, and it was primarily localized to inflammatory infiltrates. Expression of CXCL12/SDF-1 was colocalized to mast cells in tissue sections. Furthermore, CD117(+) mast cells were the second most frequent infiltrating cells and the main CXCL12/SDF-1 expressing cells, followed by CD4(+) lymphocytes, monocytes/macrophages, neutrophils, and dendritic cells.
  
  
  CONCLUSIONS
  ALs of endodontic origin demonstrated higher levels of CXCL12/SDF-1 compared with controls. CXCL12/SDF-1 was identified in immune cell populations, whereas mast cells represented the major CXCL12/SDF-1 expressing cells, suggesting that this chemokine might play a central role in apical tissue destruction, most probably inducing persistent recruitment of immune cells, particularly of mast cells.
authors.affiliation: Laboratorio de Biología Periodontal, Facultad de Odontología, Universidad de Chile, Santiago, Chile.
authors.forename: Franco
authors.initials: F
authors.lastname: Cavalla
authors.forename: Montserrat
authors.initials: M
authors.lastname: Reyes
authors.forename: Rolando
authors.initials: R
authors.lastname: Vernal
authors.forename: Carla
authors.initials: C
authors.lastname: Alvarez
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Paredes
authors.forename: Jocelyn
authors.initials: J
authors.lastname: García-Sesnich
authors.forename: Magdalena
authors.initials: M
authors.lastname: Infante
authors.forename: Valeska
authors.initials: V
authors.lastname: Fariña
authors.forename: Ignacio
authors.initials: I
authors.lastname: Barrón
authors.forename: Marcela
authors.initials: M
authors.lastname: Hernández
mesh_terms: D000293:Adolescent; D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D060833:Cellular Microenvironment / Q000276:immunology; D054377:Chemokine CXCL12 / Q000032:analysis*; D002648:Child; D003713:Dendritic Cells / Q000276:immunology; D003788:Dental Pulp Diseases / Q000276:immunology*; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D008297:Male; D008407:Mast Cells / Q000276:immunology*; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D010484:Periapical Granuloma / Q000276:immunology / Q000473:pathology; D010485:Periapical Periodontitis / Q000276:immunology* / Q000473:pathology; D010513:Periodontal Ligament / Q000276:immunology; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D011842:Radicular Cyst / Q000276:immunology / Q000473:pathology
chemical_list: C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019009:Proto-Oncogene Proteins c-kit
keywords: Apical periodontitis; CXCL12/SDF-1; mast cells