GLUT12 deficiency during early development results in heart failure and a diabetic phenotype in zebrafish

J Endocrinol. 2015 Jan;224(1):1-15. doi: 10.1530/JOE-14-0539. Epub 2014 Oct 17.

Abstract

Cardiomyopathies-associated metabolic pathologies (e.g., type 2 diabetes and insulin resistance) are a leading cause of mortality. It is known that the association between these pathologies works in both directions, for which heart failure can lead to metabolic derangements such as insulin resistance. This intricate crosstalk exemplifies the importance of a fine coordination between one of the most energy-demanding organs and an equilibrated carbohydrate metabolism. In this light, to assist in the understanding of the role of insulin-regulated glucose transporters (GLUTs) and the development of cardiomyopathies, we have developed a model for glut12 deficiency in zebrafish. GLUT12 is a novel insulin-regulated GLUT expressed in the main insulin-sensitive tissues, such as cardiac muscle, skeletal muscle, and adipose tissue. In this study, we show that glut12 knockdown impacts the development of the embryonic heart resulting in abnormal valve formation. Moreover, glut12-deficient embryos also exhibited poor glycemic control. Glucose measurements showed that these larvae were hyperglycemic and resistant to insulin administration. Transcriptome analysis demonstrated that a number of genes known to be important in cardiac development and function as well as metabolic mediators were dysregulated in these larvae. These results indicate that glut12 is an essential GLUT in the heart where the reduction in glucose uptake due to glut12 deficiency leads to heart failure presumably due to the lack of glucose as energy substrate. In addition, the diabetic phenotype displayed by these larvae after glut12 abrogation highlights the importance of this GLUT during early developmental stages.

Keywords: diabetes; glut12; heart failure; valve dysgenesis; zebrafish.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / embryology
  • Diabetes Mellitus, Type 2 / genetics*
  • Diabetic Cardiomyopathies / complications
  • Diabetic Cardiomyopathies / embryology
  • Diabetic Cardiomyopathies / genetics*
  • Disease Models, Animal*
  • Embryo, Nonmammalian
  • Gene Expression Regulation, Developmental / drug effects
  • Glucose Transport Proteins, Facilitative / deficiency
  • Glucose Transport Proteins, Facilitative / genetics*
  • Heart Failure / genetics*
  • Heart Failure / pathology
  • Insulin / pharmacology
  • Metformin / pharmacology
  • Phenotype
  • Zebrafish / embryology*
  • Zebrafish / genetics
  • Zebrafish Proteins / deficiency
  • Zebrafish Proteins / genetics*

Substances

  • Glucose Transport Proteins, Facilitative
  • Insulin
  • SLC2A12 protein, zebrafish
  • Zebrafish Proteins
  • Metformin