Mutations in sarcoglycan, a dystrophin-associated protein complex, cause cardiomyopathy and muscular dystrophy in humans. Through gene targeting, we have generated mice lacking different sarcoglycan subunits to understand better the mechanism by which the loss of these proteins produces membrane instability and cardiac muscle damage. Gamma-sarcoglycan and delta-sarcoglycan are highly related 35 KD, transmembrane proteins. Mice lacking either these sarcoglycans develop cardiomyopathy and show membrane defects characteristic of those seen in humans with mutations in these genes. Gamma-sarcoglycan is expressed exlusively in cardiac and skeletal muscle, yet mice lacking gamma-sarcoglycan appear to have smooth muscle vascular alterations similar to those seen in mice lacking delta-sarcoglycan. Thus, such defects may be a secondary consequence of the primary loss of sarcoglycan in the cariomyocyte. To investigate this, we will compare mice lacking gamma- or delta-sarcoglycan. We will rescue smooth muscle expression of delta-sarcoglycan. We will investigate the role of nitric oxide synthase since unopposed vasoconstriction has been identified as a mediator of abnormal vascular tone in the absence of dystrophin. Lastly, we will study whether cardiomyocyte degeneration produces vascular changes by studying other models of cardiomyopathy.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
1F32HL010432-01
Application #
6208599
Study Section
Experimental Cardiovascular Sciences Study Section (ECS)
Project Start
2000-09-15
Project End
Budget Start
2000-09-15
Budget End
2001-09-14
Support Year
1
Fiscal Year
2000
Total Cost
$37,516
Indirect Cost
Name
University of Chicago
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
225410919
City
Chicago
State
IL
Country
United States
Zip Code
60637
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Wheeler, M T; Allikian, M J; Heydemann, A et al. (2002) The sarcoglycan complex in striated and vascular smooth muscle. Cold Spring Harb Symp Quant Biol 67:389-97
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