IGF-1 controls GLUT3 expression in muscle via the transcriptional factor Sp1.

Glucose transporter 3 (GLUT3), while first found in human fetal muscle, is predominantly expressed in brain and neural tissue. By several independent techniques we have previously shown that GLUT3 is expressed in human skeletal muscle cells. The structure of the human GLUT3 gene has not been previously reported nor has there been any evaluation of the 5'-untranslated region (UTR).

Distribution of insulin receptor substrate-2 in brain areas involved in energy homeostasis.

Body weight regulation depends on neuronal signaling by adiposity-related hormones such as insulin and leptin. Activation of receptors for these hormones induces cell signaling via the insulin receptor substrate/phosphatidylinositol 3-kinase (IRS-PI3K) pathway, and growing evidence from knockout models implicates IRS-2 as a key component of this signal transduction mechanism. As a first step towards the identification of brain areas that utilize IRS-PI3K signaling in the control of energy homeostasis, we used immunohistochemical techniques to investigate the neuronal distribution of IRS-2 protein in rat brain.

Discovery of a high molecular weight complex of calcium, phosphate, fetuin, and matrix gamma-carboxyglutamic acid protein in the serum of etidronate-treated rats.

In the present study we report the discovery of a novel protein-mineral complex in the serum of rats treated with doses of the bone-active bisphosphonate etidronate that inhibit normal bone mineralization. The composition of this high molecular mass protein-mineral complex consists of about 18% mineral, 80% fetuin, and 2% matrix Gla protein (MGP) by weight, and the presence of the complex in serum after an injection of 8 mg etidronate/100 g of body weight elevates calcium by 1.8-fold (to 4.