A functional and genetic analysis of SOD2 promoter variants and their contribution to age-related hearing loss

Mech Ageing Dev. 2013 Jul-Aug;134(7-8):298-306. doi: 10.1016/j.mad.2013.02.009. Epub 2013 Mar 13.

Abstract

Genetic variation in superoxide dismutase 2 (SOD2) is implicated in several ageing pathologies and with noise-induced hearing loss. Here, we have investigated the role of SOD2 promoter variants in age related hearing loss (ARHL).

Methods: Putative regulatory variants identified in the SOD2 promoter using bioinformatics were functionally evaluated in an inner-ear-derived cell line (OC-2). Variants with effects on transcription factor binding were then tested in association studies in discovery and replication cohorts (London ARHL and ELSA cohorts, n=2177).

Results: The rs5746092 (-38C>G) and rs2758343 (-299C>A) SNPs alter the affinity of the SOD2 promoter for AP-2α and SP1 respectively. Evidence of an association between the -38C>G SNP and ARHL was detected in the London cohort only; p=0.0436, OR=1.35 [1.05-1.73]. This effect was strongest in males reporting family history of ARHL (p=0.0095) and was independent of reported noise exposure. The rs2758343 (-299C>A) rSNP was found to be in complete LD with the well characterised functional variant rs4880 (Ala16Val) and was not associated with hearing loss.

Conclusion: This study describes the effect of common SOD2 promoter variation on SOD2 promoter regulation and links it to ARHL risk in men. However, due to lack of replication, this association should be regarded as suggestive only.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging* / genetics
  • Aging* / metabolism
  • Cell Line
  • Cohort Studies
  • Hearing Loss* / genetics
  • Hearing Loss* / metabolism
  • Humans
  • Male
  • Middle Aged
  • Polymorphism, Single Nucleotide*
  • Response Elements / genetics*
  • Sp1 Transcription Factor / genetics
  • Sp1 Transcription Factor / metabolism
  • Superoxide Dismutase
  • Transcription Factor AP-2 / genetics
  • Transcription Factor AP-2 / metabolism

Substances

  • Sp1 Transcription Factor
  • Transcription Factor AP-2
  • Superoxide Dismutase
  • superoxide dismutase 2