Use of GLUT-4 null mice to study skeletal muscle glucose uptake.
1. The present review focuses on the effects of varying levels of GLUT-4, the insulin-sensitive glucose transporter, on insulin sensitivity and whole body glucose homeostasis. 2. Three mouse models are discussed including myosin light chain (MLC)-GLUT-4 mice which overexpress GLUT-4 specifically in skeletal muscle, GLUT-4 null mice which express no GLUT-4 and the MLC-GLUT-4 null mice which express GLUT-4 only in skeletal muscle. Overexpressing GLUT-4 specifically in the skeletal muscle results in increased insulin sensitivity in the MLC-GLUT-4 mice. In contrast, the GLUT-4 null mice exhibit insulin intolerance accompanied by abnormalities in glucose and lipid metabolism. Restoring GLUT-4 expression in skeletal muscle in the MLC-GLUT-4 null mice results in normal glucose metabolism but continued abnormal lipid metabolism. 3. The results of experiments using these mouse models demonstrates that modifying the expression of GLUT-4 profoundly affects whole body insulin action and consequently glucose and lipid metabolism.
Charron
Maureen J
MJ
Department of Obstetrics and Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York 10461, USA. charron@aecom.yu.edu
Gorovits
Naira
N
Laidlaw
J Skye
JS
Ranalletta
Mollie
M
Katz
Ellen B
EB
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D001786:Blood Glucose / Q000378:metabolism; D015870:Gene Expression / Q000235:genetics; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000097:blood; D050356:Lipid Metabolism; D008055:Lipids / Q000097:blood; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000502:physiology*; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000502:physiology*; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000502:physiology; D018994:Myosin Light Chains / Q000235:genetics
D001786:Blood Glucose; D051275:Glucose Transporter Type 4; D007328:Insulin; D008055:Lipids; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D018994:Myosin Light Chains; C495693:Slc2a4 protein, mouse; D005947:Glucose