title: Polymorphisms in Toll-like receptors 2 and 4 genes and their expression in chronic suppurative otitis media.
abstract: OBJECTIVE
  Toll-like receptors (TLRs) have a prominent role in inducing innate immune response. It has been suggested that regulation of TLRs is involved in the pathogenesis of chronic otitis media. TLR 2 and TLR 4 polymorphisms were connected with susceptibility to acute otitis and chronic otitis with effusion. The objective of this study was to establish expression of TLR 2 and 4 on middle ear mucosa in different types of chronic suppurative otitis media (CSOM), and the influence of gene polymorphisms TLR 2 Arg753Gln and TLR 4 Thr399Ile and Asp299Gly to susceptibility to CSOM.
  
  
  METHODS
  Middle ear mucosa and full blood samples were obtained from 85 patients with chronic suppurative otitis media with and without cholesteatoma. Control group for mucosal TLR expression consisted of 71 samples of middle ear mucosa taken from patients with otosclerosis, and control group for DNA polymorphism consisted of 100 full blood samples in healthy subjects. DNA polymorphism detection was done with restriction fragment length polymorphism in RT PCR. Expression of TLR 2 and 4 was determined with immunohistochemical staining.
  
  
  RESULTS
  TLR 2 and TLR 4 expression on the middle ear mucosa was not influenced by age of the patients with chronic otitis media. Incidence of TLR 2 Arg753Gln polymorphism was significantly higher in patients with chronic otitis media, compared to control group. Significant association between TLR 2 Arg753Gln polymorphism and different types of mucosal changes in patients with chronic otitis media was established. TLR 2 and 4 expression on experimental group mucosa was significantly different compared to control group, where there was no expression (p=0.000). Strong dependence of TLR 2 and TLR 4 expression on middle ear mucosa with different mucosal changes and immunohistochemical activity after staining was detected.
  
  
  CONCLUSIONS
  Certain polymorphisms in TLR genes could be indicative for susceptibility to chronic otitis media. Expression of TLR 2 and 4 on middle ear mucosa was more dependable on different types of mucosal changes and type of CSOM than on bacteria found in the specimens. This can indicate that the type of mucosal changes are closely correlated with TLRs activity in middle ear.
authors.affiliation: Medical Faculty Belgrade, University of Belgrade, Serbia; Clinic for Otorhinolaryngology and Maxillofacial Surgery, Clinical Centre of Serbia, Belgrade, Serbia. Electronic address: anajotic@yahoo.com.
authors.forename: Ana
authors.initials: A
authors.lastname: Jotic
authors.affiliation: Medical Faculty Belgrade, University of Belgrade, Serbia; Clinic for Otorhinolaryngology and Maxillofacial Surgery, Clinical Centre of Serbia, Belgrade, Serbia.
authors.forename: Snezana
authors.initials: S
authors.lastname: Jesic
authors.affiliation: Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia.
authors.forename: Maja
authors.initials: M
authors.lastname: Zivkovic
authors.affiliation: Institute of Pathology, Medical Faculty Belgrade, University of Belgrade, Serbia.
authors.forename: Nada
authors.initials: N
authors.lastname: Tomanovic
authors.affiliation: Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia.
authors.forename: Jovana
authors.initials: J
authors.lastname: Kuveljic
authors.affiliation: Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Stankovic
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D018424:Cholesteatoma, Middle Ear / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D002908:Chronic Disease; D004432:Ear, Middle / Q000378:metabolism*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism*; D010035:Otitis Media, Suppurative / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D051195:Toll-Like Receptor 2 / Q000235:genetics* / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000235:genetics* / Q000378:metabolism; D055815:Young Adult
chemical_list: C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4
keywords: Chronic otitis media; TLR 4; Toll-like receptor (TLR) 2