Fine-scale haplotype mapping of MUT, AACS, SLC6A15 and PRKCA genes indicates association with insulin resistance of metabolic syndrome and relationship with branched chain amino acid metabolism or regulation.
Sara HaydarFlorin GrigorescuMădălina VintilăYannick CogneCorinne LautierYıldız TutuncuJean Frederic BrunJean Marie RobineMichel PugeatChristophe NormandPatrick PoucheretMonica Livia GheorghiuCarmen Emanuela GeorgescuCorin BadiuNicoleta BăculescuEric RenardDorina YlliStephanie BadiouThibault SutraJean Paul CristolJacques MercierRamon GomisJosep Maria MaciasSerghey LitvinovElza K KhusnutdinovaCatalina PoianaRenato PasqualiDavide LauroGiorgio SestiSabrina PrudenteVincenzo TrischittaAgathocles TsatsoulisSonia AbdelhakAbdelhamid BarakatAkila ZenatiAgron YlliIlhan SatmanTimo KanninenYves RinatoSasa MissoniPublished in: PloS one (2019)
Branched chain amino acids (BCAA) are essential elements of the human diet, which display increased plasma levels in obesity and regained particular interest as potential biomarkers for development of diabetes. To define determinants of insulin resistance (IR) we investigated 73 genes involved in BCAA metabolism or regulation by fine-scale haplotype mapping in two European populations with metabolic syndrome. French and Romanians (n = 465) were genotyped for SNPs (Affymetrix) and enriched by imputation (BEAGLE 4.1) at 1000 genome project density. Initial association hits detected by sliding window were refined (HAPLOVIEW 3.1 and PHASE 2.1) and correlated to homeostasis model assessment (HOMAIR) index, in vivo insulin sensitivity (SI) and BCAA plasma levels (ANOVA). Four genomic regions were associated with IR located downstream of MUT, AACS, SLC6A15 and PRKCA genes (P between 9.3 and 3.7 x 10-5). Inferred haplotypes up to 13 SNPs length were associated with IR (e.g. MUT gene with P < 4.9 x 10-5; Bonferroni 1.3 x 10-3) and synergistic to HOMAIR. SNPs in the same regions were also associated with one order of magnitude lower P values (e.g. rs20167284 in the MUT gene with P < 1.27 x 10-4) and replicated in Mediterranean samples (n = 832). In French, influential haplotypes (OR > 2.0) were correlated with in vivo insulin sensitivity (1/SI) except for SLC6A15 gene. Association of these genes with BCAA levels was variable, but influential haplotypes confirmed implication of MUT from BCAA metabolism as well as a role of regulatory genes (AACS and PRKCA) and suggested potential changes in transcriptional activity. These data drive attention towards new regulatory regions involved in IR in relation with BCAA and show the ability of haplotypes in phased DNA to detect signals complimentary to SNPs, which may be useful in designing genetic markers for clinical applications in ethnic populations.
Keyphrases
- genome wide
- insulin resistance
- metabolic syndrome
- copy number
- dna methylation
- amino acid
- genome wide identification
- type diabetes
- transcription factor
- adipose tissue
- high fat diet
- high fat diet induced
- skeletal muscle
- uric acid
- air pollution
- gene expression
- high resolution
- cardiovascular disease
- glycemic control
- weight loss
- genetic diversity
- drug delivery
- working memory
- weight gain
- bioinformatics analysis
- cancer therapy
- ionic liquid