👤 Sarah E Innis

Sex differences in adipose tissue distribution and function are associated with sex differences in cardiometabolic disease. While many studies have revealed sex differences in adipocyte cell signaling and physiology, there is a relative dearth of information regarding sex differences in transcript abundance and regulation. We investigated sex differences in subcutaneous adipose tissue transcriptional regulation using omic-scale data from ∼3000 geographically and ethnically diverse human samples. We identified 162 genes with robust sex differences in expression. Differentially expressed genes were implicated in oxidative phosphorylation and adipogenesis. We further determined that sex differences in gene expression levels could be related to sex differences in the genetics of gene expression regulation. Our analyses revealed sex-specific genetic associations, and this finding was replicated in a study of 98 inbred mouse strains. The genes under genetic regulation in human and mouse were enriched for oxidative phosphorylation and adipogenesis. Enrichment analysis showed that the associated genetic loci resided within binding motifs for adipogenic transcription factors (e.g., PPARG and EGR1). We demonstrated that sex differences in gene expression could be influenced by sex differences in genetic regulation for six genes (e.g., Show less

The FADS1/FADS2 gene cluster encodes Delta-5 and Delta-6 desaturase, rate-limiting enzymes in metabolism of linoleic (LA) to arachidonic (ARA) and alpha-linolenic to eicosapentaenoic and docosahexaenoic acid (DHA). Single nucleotide polymorphisms (SNPs) in FADS1/FADS2 contribute to variability in blood lipid fatty acids. Altered n-6 and n-3 fatty acids have been related to perinatal depression (PPD). We genotyped rs174553, rs99780, rs174575, and rs174583 in FADS1/FADS2, analyzed blood lipid fatty acids and assessed PPD risk as an Edinburgh Postnatal Depression Scale (EPDS) score > or =10 for 69 pregnant women. 21, 12 and 15% women had an EPDS score > or =10 at 36 weeks' gestation, 2 and 6 months postpartum, respectively. Quantitative trait analysis showed an association between rs174575 and PPD risk at 36 weeks' gestation and 6 months postpartum. With haplotype ACCC (major alleles) for rs174553, rs99780, rs174575, rs174583, respectively, as reference, GTCT was positively associated with PPD risk at 36 weeks' gestation, p = 0.028, and higher LA and lower ARA in plasma (p = 0.0001, p < 0.0001) and RBC ethanolamine phospholipids (p = 0.007, p = 0.005). We show that SNPs in FADS1/FADS2 are associated with higher blood lipid LA and lower ARA and PPD risk. Show less

The enzymes encoded by fatty acid desaturase (FADS) 1 and FADS2 are rate-limiting enzymes in the desaturation of linoleic acid [LA; 18:2(n-6)] to arachidonic acid [ARA; 20:4(n-6)], and alpha-linolenic acid [ALA; 18:3(n-3)] to eicosapentaenoic acid [EPA; 20:5(n-3)] and docosahexaenoic acid [DHA; 22:6(n-3)]. ARA, EPA, and DHA play central roles in infant growth, neural development, and immune function. The maternal ARA, EPA, and DHA status in gestation influences maternal-to-infant transfer and breast milk provides fatty acids for infants after birth. We determined if single nucleotide polymorphisms in FADS1 and FADS2 influence plasma phospholipid and erythrocyte ethanolamine phosphoglyceride (EPG) (n-6) and (n-3) fatty acids of women in pregnancy or their breast milk during lactation. We genotyped rs174553, rs99780, rs174575, and rs174583 in the FADS1 FADS2 gene cluster and analyzed plasma and erythrocyte fatty acids and dietary intake for 69 pregnant women and breast milk for a subset of 54 women exclusively breast-feeding at 1 mo postpartum. Minor allele homozygotes of rs174553(GG), rs99780(TT), and rs174583(TT) had lower ARA but higher LA in plasma phospholipids and erythrocyte EPG and decreased (n-6) and (n-3) fatty acid product:precursor ratios at 16 and 36 wk of gestation. Breast milk fatty acids were influenced by genotype, with significantly lower 14:0, ARA, and EPA but higher 20:2(n-6) in the minor allele homozygotes of rs174553(GG), rs99780(TT), and rs174583(TT) and lower ARA, EPA, 22:5(n-3), and DHA in the minor allele homozygotes G/G of rs174575. We showed that genetic variants of FADS1 and FADS2 influence blood lipid and breast milk essential fatty acids in pregnancy and lactation. Show less