title: Expression of inducible nitric oxide synthase and heat shock proteins in periapical inflammatory lesions.
abstract: BACKGROUND
  The mechanisms responsible for activation and proliferation of lining epithelium involved in inflammatory processes in periapical inflammatory lesions remain unclear. In this study, the expression and distribution of inducible nitric oxide synthase (iNOS) and heat shock proteins (HSPs) were immunohistochemically investigated in periapical inflammatory lesions.
  
  
  METHODS
  Control specimens of periodontal ligaments including Malassez epithelial rests from seven teeth and periapical inflammatory lesions (15 apical granulomas (AGs), 16 radicular cysts (RCs), and 10 residual radicular cysts (RRCs)) were prepared and examined by the standard streptavidin-biotin peroxidase complex method using anti-iNOS rabbit polyclonal antiserum, and anti-HSP27, -HSP60, -HSP70 mouse monoclonal antibodies.
  
  
  RESULTS
  Immunoreactivity for iNOS was detected in macrophages, lymphocytes, and endothelial cells of granulation tissue and in lining epithelium of periapical inflammatory lesions. Malassez epithelial rests showed no or slight staining for iNOS. The epithelial staining intensity of iNOS in RCs was greater than that in Malassez epithelial rests and RRCs. Immunoreactivity for HSP27 was recognized in inflammatory cells, endothelial cells and lining epithelium of periapical inflammatory lesions and in Malassez epithelial rests. HSP60 was detected in some lymphocytes of granulation tissue and in lining epithelium of periapical inflammatory lesions, whereas Malassez epithelial rests showed no staining for HSP60. Epithelial HSP60 reactivity was more intense in RCs than in RRCs. HSP70 was expressed in lymphocytes, endothelial cells and lining epithelium of periapical inflammatory lesions and in Malassez epithelial rests. The staining intensity of HSP70 in Malassez epithelial rests was slightly lower than that in lining epithelium of RCs and RRCs.
  
  
  CONCLUSIONS
  These data demonstrate that the expressions of iNOS, HSP60, and HSP70 are involved in inflammatory processes and might play a role in the activation and proliferation of lining epithelium, leading to progression of periapical inflammatory lesions.
authors.affiliation: Department of Oro-Maxillofacial Surgical Science, Division of Maxillofacial and Plastic Surgery, Tohoku University Graduate School of Dentistry, Sendai, Japan. takahiro@mail.cc.tohoku.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kumamoto
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ooya
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Motegi
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000032:analysis; D002455:Cell Division; D018834:Chaperonin 60 / Q000032:analysis / Q000235:genetics; D004396:Coloring Agents; D018450:Disease Progression; D004727:Endothelium / Q000473:pathology; D004847:Epithelial Cells / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D015971:Gene Expression Regulation, Enzymologic; D006097:Granulation Tissue / Q000473:pathology; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis / Q000235:genetics; D006360:Heat-Shock Proteins / Q000032:analysis* / Q000235:genetics; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008214:Lymphocytes / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000032:analysis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D010483:Periapical Diseases / Q000473:pathology*; D010484:Periapical Granuloma / Q000473:pathology; D011842:Radicular Cyst / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D018834:Chaperonin 60; D004396:Coloring Agents; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II