Myostatin (MSTN) is a secreted protein that normally acts to suppress muscle growth. Mice genetically engineered to lack MSTN activity have dramatic increases in muscle mass as a result of a combination of muscle fiber hypertrophy and increased fiber numbers. Moreover, administration of a number of different MSTN inhibitors to wild type mice can also promote muscle growth, demonstrating that MSTN plays a critical role in regulating muscle growth in adult animals. As a result, there has been considerable interest in the possibility that inhibitors of MSTN signaling might be effective in enhancing muscle strength and regeneration in patients with muscle wasting. Although most of the focus on MSTN inhibitors as potential therapeutic agents has focused on their ability to promote muscle growth, several studies have demonstrated that loss of MSTN signaling leads to significant reductions in levels of fibrosis in mouse models of muscular dystrophy. Whether these reductions in fibrosis result indirectly from the anabolic effects of MSTN loss or whether MSTN signals directly to fibroblasts to regulate fibrosis in vivo is not known. The overall aims of this project are to elucidate the mechanisms by which MSTN regulates fibrosis in vivo and to identify the most optimal strategies for exploiting this signaling pathway for the development of new therapies to prevent or reverse the development of muscle fibrosis.
The Specific Aims are: to identify the direct cellular targets for signaling by MSTN and related proteins in skeletal muscle responsible for mediating effects on fibrosis, to assess the potential beneficial effects of targeting BMP-1/tolloid metalloproteases for modulating the fibrotic response in muscle, and to test biologies targeting MSTN and other TGFB family members for their ability to prevent or reverse fibrosis in mouse models of muscular dystrophy. Taken together, these studies should provide fundamental insights into the cellular and molecular mechanisms underlying the beneficial effect of MSTN loss on the pathogenesis of fibrosis and provide valuable information for translating these findings into the development of a therapeutic to combat muscle fibrosis in patients with muscle degenerative diseases.

Public Health Relevance

Fibrosis has long been recognized as a major exacerbating factor in the pathogenesis of muscle degenerative diseases. The regulatory mechanisms underlying the development of fibrosis in muscle are poorly understood, and few therapeutic strategies have been developed for combating muscle fibrosis. Here, we will investigate the potential beneficial effects of targeting myostatin and related pathways to prevent or reverse fibrosis in muscular dystrophy.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Program Projects (P01)
Project #
5P01NS072027-03
Application #
8484888
Study Section
National Institute of Neurological Disorders and Stroke Initial Review Group (NSD)
Project Start
Project End
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
3
Fiscal Year
2013
Total Cost
$333,602
Indirect Cost
Name
University of Chicago
Department
Type
DUNS #
005421136
City
Chicago
State
IL
Country
United States
Zip Code
60637
Molkentin, Jeffery D (2014) Letter by Molkentin regarding article, "The absence of evidence is not evidence of absence: the pitfalls of Cre Knock-Ins in the c-Kit Locus". Circ Res 115:e21-3
Rainer, Peter P; Hao, Scarlett; Vanhoutte, Davy et al. (2014) Cardiomyocyte-specific transforming growth factor ? suppression blocks neutrophil infiltration, augments multiple cytoprotective cascades, and reduces early mortality after myocardial infarction. Circ Res 114:1246-57
Swaggart, Kayleigh A; McNally, Elizabeth M (2014) Modifiers of heart and muscle function: where genetics meets physiology. Exp Physiol 99:621-6
Davis, Jennifer; Molkentin, Jeffery D (2014) Myofibroblasts: trust your heart and let fate decide. J Mol Cell Cardiol 70:9-18
Fahrenbach, John P; Andrade, Jorge; McNally, Elizabeth M (2014) The CO-Regulation Database (CORD): a tool to identify coordinately expressed genes. PLoS One 9:e90408
Puckelwartz, Megan J; Pesce, Lorenzo L; Nelakuditi, Viswateja et al. (2014) Supercomputing for the parallelization of whole genome analysis. Bioinformatics 30:1508-13
Swaggart, Kayleigh A; Demonbreun, Alexis R; Vo, Andy H et al. (2014) Annexin A6 modifies muscular dystrophy by mediating sarcolemmal repair. Proc Natl Acad Sci U S A 111:6004-9
Kwong, J Q; Davis, J; Baines, C P et al. (2014) Genetic deletion of the mitochondrial phosphate carrier desensitizes the mitochondrial permeability transition pore and causes cardiomyopathy. Cell Death Differ 21:1209-17
Demonbreun, Alexis R; McNally, Elizabeth M (2014) Dynamin 2 the rescue for centronuclear myopathy. J Clin Invest 124:976-8
Golbus, Jessica R; Puckelwartz, Megan J; Dellefave-Castillo, Lisa et al. (2014) Targeted analysis of whole genome sequence data to diagnose genetic cardiomyopathy. Circ Cardiovasc Genet 7:751-9

Showing the most recent 10 out of 14 publications