title: Platelet-derived growth factor (PDGF) isoform and PDGF receptor expression in drug-induced gingival overgrowth and hereditary gingival fibrosis.
abstract: OBJECTIVE
  To investigate possible associations between platelet-derived growth factor (PDGF), PDGF receptor expression and macrophages in drug-induced and hereditary gingival overgrowth.
  
  
  METHODS
  Tissues from patients with drug-induced gingival overgrowth (DIGO) (n = 10) and hereditary gingival fibrosis (n = 10) were studied and compared with 'control' gingiva (n = 10). Expression of PDGF and its alpha and beta receptors was investigated immunohistochemically and by RT-PCR. Macrophages were identified by immunostaining for CD68.
  
  
  RESULTS
  PDGF isoforms and receptors were detected in most cells within all specimens. There were no differences in the numbers of macrophages, or fibroblasts expressing PDGF or receptors, between groups. The level of PDGF expression by fibroblasts, determined by absorbance measurements, was similar between groups for PDGF A. Significantly lower levels of total PDGF and the receptors were detected in drug-induced overgrowth compared to those in hereditary fibrosis (P < 0.004) and control specimens (P < 0.034). All specimens expressed mRNA for PDGF A, PDGF B and alpha and beta receptors.
  
  
  CONCLUSIONS
  These data do not support a pivotal role for macrophage-derived PDGF B in the pathogenesis of DIGO. They suggest that fibroblasts in drug-induced lesions have a lowered capacity to produce, and respond to, PDGF, a property not shared by fibroblasts associated with hereditary fibrosis.
authors.affiliation: Unit of Oral Biology & Pathology, Periodontal Research Group, School of Dentistry, University of Birmingham, Birmingham, UK.
authors.forename: H J
authors.initials: HJ
authors.lastname: Wright
authors.forename: I L C
authors.initials: IL
authors.lastname: Chapple
authors.forename: P
authors.initials: P
authors.lastname: Cooper
authors.forename: J B
authors.initials: JB
authors.lastname: Matthews
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D005351:Fibromatosis, Gingival / Q000378:metabolism*; D005881:Gingiva / Q000378:metabolism; D019214:Gingival Overgrowth / Q000139:chemically induced / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis*; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000032:analysis; D017479:Receptors, Platelet-Derived Growth Factor / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric
chemical_list: D010982:Platelet-Derived Growth Factor; D020033:Protein Isoforms; D012333:RNA, Messenger; D017479:Receptors, Platelet-Derived Growth Factor