Adipose Tissue TCF7L2 Splicing Is Regulated by Weight Loss and Associates With Glucose and Fatty Acid Metabolism
- Dorota Kaminska1,2,
- Tiina Kuulasmaa2,
- Sari Venesmaa3,
- Pirjo Käkelä3,
- Maija Vaittinen1,
- Leena Pulkkinen1,
- Matti Pääkkönen3,
- Helena Gylling1,
- Markku Laakso2 and
- Jussi Pihlajamäki1,4⇓
- 1Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
- 2Department of Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
- 3Department of Surgery, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
- 4Clinical Nutrition and Obesity Center, Kuopio University Hospital, Kuopio, Finland
- Corresponding author: Jussi Pihlajamäki, .
We investigated the effects of obesity surgery-induced weight loss on transcription factor 7-like 2 gene (TCF7L2) alternative splicing in adipose tissue and liver. Furthermore, we determined the association of TCF7L2 splicing with the levels of plasma glucose and serum free fatty acids (FFAs) in three independent studies (n = 216). Expression of the short mRNA variant, lacking exons 12, 13, and 13a, decreased after weight loss in subcutaneous fat (n = 46) and liver (n = 11) and was more common in subcutaneous fat of subjects with type 2 diabetes than in subjects with normal glucose tolerance in obese individuals (n = 54) and a population-based sample (n = 49). Additionally, there was a positive correlation between this variant and the level of fasting glucose in nondiabetic individuals (n = 113). This association between TCF7L2 splicing and plasma glucose was independent of the TCF7L2 genotype. Finally, this variant was associated with high levels of serum FFAs during hyperinsulinemia, suggesting impaired insulin action in adipose tissue, whereas no association with insulin secretion or insulin-stimulated whole-body glucose uptake was observed. Our study shows that the short TCF7L2 mRNA variant in subcutaneous fat is regulated by weight loss and is associated with hyperglycemia and impaired insulin action in adipose tissue.
- Received March 5, 2012.
- Accepted May 14, 2012.
- © 2012 by the American Diabetes Association.
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