Expression of phosphofructokinase in skeletal muscle is influenced by genetic variation and associated with insulin sensitivity.
Author(s)
Type
Journal Article
Abstract
Using an integrative approach in which genetic variation, gene expression, and clinical phenotypes are assessed in relevant tissues may help functionally characterize the contribution of genetics to disease susceptibility. We sought to identify genetic variation influencing skeletal muscle gene expression (expression quantitative trait loci [eQTLs]) as well as expression associated with measures of insulin sensitivity. We investigated associations of 3,799,401 genetic variants in expression of >7,000 genes from three cohorts (n = 104). We identified 287 genes with cis-acting eQTLs (false discovery rate [FDR] <5%; P < 1.96 × 10(-5)) and 49 expression-insulin sensitivity phenotype associations (i.e., fasting insulin, homeostasis model assessment-insulin resistance, and BMI) (FDR <5%; P = 1.34 × 10(-4)). One of these associations, fasting insulin/phosphofructokinase (PFKM), overlaps with an eQTL. Furthermore, the expression of PFKM, a rate-limiting enzyme in glycolysis, was nominally associated with glucose uptake in skeletal muscle (P = 0.026; n = 42) and overexpressed (Bonferroni-corrected P = 0.03) in skeletal muscle of patients with T2D (n = 102) compared with normoglycemic controls (n = 87). The PFKM eQTL (rs4547172; P = 7.69 × 10(-6)) was nominally associated with glucose uptake, glucose oxidation rate, intramuscular triglyceride content, and metabolic flexibility (P = 0.016-0.048; n = 178). We explored eQTL results using published data from genome-wide association studies (DIAGRAM and MAGIC), and a proxy for the PFKM eQTL (rs11168327; r(2) = 0.75) was nominally associated with T2D (DIAGRAM P = 2.7 × 10(-3)). Taken together, our analysis highlights PFKM as a potential regulator of skeletal muscle insulin sensitivity.
Date Issued
2014-03-01
Date Acceptance
2013-11-29
Citation
Diabetes, 2014, 63 (3), pp.1154-1165
ISSN
0012-1797
Publisher
American Diabetes Association
Start Page
1154
End Page
1165
Journal / Book Title
Diabetes
Volume
63
Issue
3
Copyright Statement
© 2014 by the American Diabetes Association.
Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details.
Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details.
Identifier
PII: db13-1301
Subjects
Adult
Aged
Aged, 80 and over
Aminopeptidases
Cation Transport Proteins
Diabetes Mellitus, Type 2
Female
Genetic Variation
Genome-Wide Association Study
Humans
Insulin Resistance
Male
Middle Aged
Muscle, Skeletal
Phosphofructokinase-1, Muscle Type
Polymorphism, Single Nucleotide
Quantitative Trait Loci
Publication Status
Published