FADS1 genotype is distinguished by human subcutaneous adipose tissue fatty acids, but not inflammatory gene expression

Int J Obes (Lond). 2019 Aug;43(8):1539-1548. doi: 10.1038/s41366-018-0169-z. Epub 2018 Aug 6.

Abstract

Background: Single nucleotide polymorphisms (SNPs) in FADS1/FADS2 genes are associated with changes in serum and tissue polyunsaturated fatty acid (PUFA) content. PUFA regulate inflammatory signaling pathways in adipose tissue; however, the effect of SNPs in FADS1/FADS2 on adipose tissue inflammation is equivocal. The present study examined if SNPs in FADS1/FADS2 modify human subcutaneous adipose tissue (SAT) fatty acid profiles and the expression of genes associated with inflammation/immune function, lipid metabolism, and cellular differentiation.

Methods: SAT fatty acids and the expression of 117 genes were measured in 174 men and women from the DiOGenes Study using gas chromatography and qRT-PCR, respectively. Associations between fatty acids, gene expression, and SNPs in FADS1/FADS2 were investigated by linear regression and multivariate analysis.

Results: Four SNPs (rs174537, rs174546, rs174556, rs174601) in FADS1/FADS2 were significantly associated with SAT fatty acids. All SNPs were in high linkage disequilibrium with the commonly reported rs174537 SNP in FADS1. Minor allele carriers for rs174537 (GT+TT) had reduced 20:4n-6 (p = 1.74E-5), lower delta-5 desaturase enzyme activity (p = 2.09E-9), and lower FADS1 gene expression (p = 0.03) compared to major GG carriers. Multivariate analysis revealed that 20:4n-6 and 20:3n-6 explained ~19% of the variance between rs174537 genotypes, while gene expression explained <7%. Receiver operating characteristic (ROC) curves indicated that rs174537 genotype can be distinguished with SAT fatty acids (AUC = 0.842), but not gene expression (AUC = 0.627). No differences in SAT inflammatory gene expression were observed between rs174537 genotypes. SAT 20:3n-6 levels were positively correlated with the expression of several inflammatory genes, and inversely correlated with FADS1 expression.

Conclusion: This study showed that FADS1 genotype is distinguished by SAT fatty acid profiles, but not inflammatory gene expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cell Differentiation / genetics
  • Delta-5 Fatty Acid Desaturase
  • Fatty Acid Desaturases / genetics*
  • Fatty Acid Desaturases / metabolism
  • Fatty Acids / genetics*
  • Female
  • Gene Expression
  • Genotype
  • Humans
  • Immune System
  • Inflammation / genetics*
  • Linear Models
  • Lipid Metabolism / genetics
  • Male
  • Middle Aged
  • Multigene Family / genetics
  • Multivariate Analysis
  • Obesity / genetics
  • Polymorphism, Single Nucleotide
  • Subcutaneous Fat / metabolism*

Substances

  • Delta-5 Fatty Acid Desaturase
  • Fatty Acids
  • Fatty Acid Desaturases
  • FADS1 protein, human
  • FADS2 protein, human