Background Type 2 diabetes mellitus (T2DM) is characterized by defects in insulin secretion and action. Impaired glucose uptake in skeletal muscle is believed to be one of the earliest features in the natural history of T2DM, although underlying mechanisms remain obscure. Methods and Findings We combined human insulin/glucose clamp physiological studies with genome-wide expression profiling to identify thioredoxin interacting protein (TXNIP) as a gene whose expression is powerfully suppressed by insulin yet stimulated by glucose. In healthy individuals, its expression was inversely correlated to total body measures of glucose uptake. Forced expression of TXNIP in cultured adipocytes significantly reduced glucose uptake, while silencing with RNA interference in adipocytes and in skeletal muscle enhanced glucose uptake, confirming that the gene product is also a regulator of glucose uptake. TXNIP expression is consistently elevated in the muscle of prediabetics and diabetics, although in a panel of 4,450 Scandinavian individuals, we found no evidence for association between common genetic variation in the TXNIP gene and T2DM. Conclusions TXNIP regulates both insulin-dependent and insulin-independent pathways of glucose uptake in human skeletal muscle. Combined with recent studies that have implicated TXNIP in pancreatic β-cell glucose toxicity, our data suggest that TXNIP might play a key role in defective glucose homeostasis preceding overt T2DM.
TXNIP Regulates Peripheral Glucose Metabolism in Humans
H. Parikh,E. Carlsson,E. Carlsson,William A. Chutkow,Lovisa Johansson,H. Storgaard,P. Poulsen,Richa Saxena,Richa Saxena,C. Ladd,P. Schulze,M. J. Mazzini,C. Jensen,A. Krook,M. Björnholm,H. Tornqvist,J. Zierath,M. Ridderstråle,D. Altshuler,D. Altshuler,Richard T. Lee,A. Vaag,A. Vaag,L. Groop,L. Groop,V. Mootha,V. Mootha
Published 2007 in PLoS Medicine
ABSTRACT
PUBLICATION RECORD
- Publication year
2007
- Venue
PLoS Medicine
- Publication date
2007-05-01
- Fields of study
Biology, Medicine
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- glucose
The circulating sugar used as the metabolic stimulus and substrate in the reported analyses.
- glucose uptake
Cellular uptake of glucose measured as the metabolic outcome in cultured cells and muscle.
- insulin
A peptide hormone used in the clamp experiments to probe insulin-responsive metabolism.
- rna interference
A gene-silencing technique used to reduce TXNIP expression in cultured cells and muscle.
Aliases: RNAi
- skeletal muscle
A major insulin-sensitive tissue analyzed for TXNIP expression and glucose uptake effects.
Aliases: muscle
- txnip
A human gene encoding thioredoxin interacting protein that was measured in metabolic tissues and cells.
Aliases: thioredoxin interacting protein
- txnip genetic variation
Common inherited variation within the TXNIP gene assessed for association with diabetes risk.
Aliases: common genetic variation in the TXNIP gene
- type 2 diabetes mellitus
A metabolic disease characterized by impaired insulin secretion and action, used as the clinical comparison context.
Aliases: T2DM
- whole-body glucose uptake
An organism-level measure of glucose disposal assessed in the human physiological studies.
Aliases: total body glucose uptake
REFERENCES
Showing 1-59 of 59 references · Page 1 of 1