Genetic polymorphisms of the main transcription factors for adiponectin gene promoter in regulation of adiponectin levels: association analysis in three European cohorts

PLoS One. 2012;7(12):e52497. doi: 10.1371/journal.pone.0052497. Epub 2012 Dec 21.

Abstract

Adiponectin serum concentrations are an important biomarker in cardiovascular epidemiology with heritability etimates of 30-70%. However, known genetic variants in the adiponectin gene locus (ADIPOQ) account for only 2%-8% of its variance. As transcription factors are thought to play an under-acknowledged role in carrying functional variants, we hypothesized that genetic polymorphisms in genes coding for the main transcription factors for the ADIPOQ promoter influence adiponectin levels. Single nucleotide polymorphisms (SNPs) at these genes were selected based on the haplotype block structure and previously published evidence to be associated with adiponectin levels. We performed association analyses of the 24 selected SNPs at forkhead box O1 (FOXO1), sterol-regulatory-element-binding transcription factor 1 (SREBF1), sirtuin 1 (SIRT1), peroxisome-proliferator-activated receptor gamma (PPARG) and transcription factor activating enhancer binding protein 2 beta (TFAP2B) gene loci with adiponectin levels in three different European cohorts: SAPHIR (n = 1742), KORA F3 (n = 1636) and CoLaus (n = 5355). In each study population, the association of SNPs with adiponectin levels on log-scale was tested using linear regression adjusted for age, sex and body mass index, applying both an additive and a recessive genetic model. A pooled effect size was obtained by meta-analysis assuming a fixed effects model. We applied a significance threshold of 0.0033 accounting for the multiple testing situation. A significant association was only found for variants within SREBF1 applying an additive genetic model (smallest p-value for rs1889018 on log(adiponectin) = 0.002, β on original scale = -0.217 µg/ml), explaining ~0.4% of variation of adiponectin levels. Recessive genetic models or haplotype analyses of the FOXO1, SREBF1, SIRT1, TFAPB2B genes or sex-stratified analyses did not reveal additional information on the regulation of adiponectin levels. The role of genetic variations at the SREBF1 gene in regulating adiponectin needs further investigation by functional studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adiponectin / blood*
  • Adiponectin / genetics*
  • Adult
  • Aged
  • Cohort Studies
  • Female
  • Genetic Association Studies*
  • Humans
  • Linear Models
  • Linkage Disequilibrium / genetics
  • Male
  • Middle Aged
  • Polymorphism, Single Nucleotide / genetics*
  • Promoter Regions, Genetic / genetics*
  • Transcription Factors / metabolism*
  • White People / genetics*

Substances

  • Adiponectin
  • Transcription Factors

Grants and funding

The SAPHIR population was supported by: Kamilo-Eisner Stiftung, Salzburger Forschungsgesellschaft, OeNB Nr.13339 and FFF-PMU Nr. E-09/09/055-PAU. The KORA study was supported by: “Austrian Genome Research Program GEN-AU” for the project “Genomics of Lipid-associated Disorders – GOLD.” The CoLaus study was supported by: grants from GlaxoSmithKline, the Swiss National Science Foundation (Grant 33CSCO-122661) and the Faculty of Biology and Medicine of Lausanne. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.