Insulin resistance contributes to the pathogenesis of several disease states including obesity and type 2 diabetes mellitus . We have investigated the nature of the genetic factors that predipose to the development of insulin resistance. Previously, we have identified mutations in the insulin receptor gene in patients with several genetic syndromes associated with insulin resistance. More recently, several variant sequences have been identified in the gene encoding insulin receptor substrate-1 (IRS-1); these variant sequences have been reported to be more prevalent among patients with noninsulin-dependent diabetes mellitus. To investigate the signficance of these amino acid substitutions, we have expressed several of the mutant proteins by transfection in mammalian cells. However, under our experimental conditions, none of the amino acid substitutions (including the most common variant, Gly972Arg-IRS-1) caused a functional defect in recombinant IRS-1. These negative observations do not support the hypothesis that polymorphisms in the amino acid sequence of IRS-1 contribute to the cause of insulin resistance in patients with type 2 diabetes. We are also carrying out clinical investigation of patients with various forms of lipoatrophy, most of whom also have insulin resistant diabetes. We have initiated therapy with troglitazone in order to determine whether this agent will improve metabolic control in these patients with a paucity of adipose tissue. In the course of follow-up, we will also determine whether troglitazone leads to an increase in body fat. Finally, we are establishing cell lines as a source of DNA from these patients in order to identify the genes that cause lipoatrophy in patients with genetic forms of the syndrom (especially Dunnigan's syndrome, a form of partial lipoatrophy transmitted with an autosomal dominant from of inheritance).

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Intramural Research (Z01)
Project #
1Z01DK047022-19
Application #
6105561
Study Section
Special Emphasis Panel (DB)
Project Start
Project End
Budget Start
Budget End
Support Year
19
Fiscal Year
1998
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Javor, Edward D; Moran, Stephanie Ann; Young, Janice Ryan et al. (2004) Proteinuric nephropathy in acquired and congenital generalized lipodystrophy: baseline characteristics and course during recombinant leptin therapy. J Clin Endocrinol Metab 89:3199-207
Musso, Carla; Cochran, Elaine; Moran, Stephanie Ann et al. (2004) Clinical course of genetic diseases of the insulin receptor (type A and Rabson-Mendenhall syndromes): a 30-year prospective. Medicine (Baltimore) 83:209-22
Moran, Stephanie Ann; Patten, Nicole; Young, Janice Ryan et al. (2004) Changes in body composition in patients with severe lipodystrophy after leptin replacement therapy. Metabolism 53:513-9
Cochran, Elaine; Young, Janice Ryan; Sebring, Nancy et al. (2004) Efficacy of recombinant methionyl human leptin therapy for the extreme insulin resistance of the Rabson-Mendenhall syndrome. J Clin Endocrinol Metab 89:1548-54
Agarwal, Anil K; Simha, Vinaya; Oral, Elif Arioglu et al. (2003) Phenotypic and genetic heterogeneity in congenital generalized lipodystrophy. J Clin Endocrinol Metab 88:4840-7
Gorden, Phillip; Gavrilova, Oksana (2003) The clinical uses of leptin. Curr Opin Pharmacol 3:655-9
Petersen, Kitt Falk; Oral, Elif Arioglu; Dufour, Sylvie et al. (2002) Leptin reverses insulin resistance and hepatic steatosis in patients with severe lipodystrophy. J Clin Invest 109:1345-50
Bolan, Charles; Oral, Elif Arioglu; Gorden, Phillip et al. (2002) Intensive, long-term plasma exchange therapy for severe hypertriglyceridemia in acquired generalized lipoatrophy. J Clin Endocrinol Metab 87:380-4
Oral, Elif Arioglu; Simha, Vinaya; Ruiz, Elaine et al. (2002) Leptin-replacement therapy for lipodystrophy. N Engl J Med 346:570-8
Oral, Elif Arioglu; Ruiz, Elaine; Andewelt, Alexa et al. (2002) Effect of leptin replacement on pituitary hormone regulation in patients with severe lipodystrophy. J Clin Endocrinol Metab 87:3110-7

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