Formation of the heart requires the interaction of several cell types including myocytes, fibroblasts, smooth muscle cells and endothelial cells, as well as the components of the extracellular matrix (ECM). Organization of these cellular and acellular components is necessary to respond to a variety of physiological signals in the adult. The interaction of cardiac fibroblasts with myocytes and the ECM is poorly understood and it is the main theme of the proposed studies. The specific arrangement the cellular components is critical for communication by chemical, mechanical and electrical signals. Three different models that show changes in cell number, ECM content and physiological parameters will be used to examine the hypothesis that interaction between myocytes, fibroblasts and the ECM is critical in the regulation of cardiac growth and remodeling during both normal and adaptive situations. The interaction between fibroblasts and myocytes, which is regulated by mechanical and chemical signals, is essential to the proper form and function of the heart.
The specific aims that will address this hypothesis are:
Specific Aim 1. Determine the effects of pressure overload hypertrophy, IL-6-loss and periostin-loss on fibroblast-myocyte interactions. The interactions of fibroblasts with myocytes and the ECM will be examined both in vivo and in vitro to determine if cell number varies with changes in the expression of cytokines (specifically IL-6) and periostin.
Specific Aim 2. Determine how mechanical stimulation affects myocyte-fibroblast interactions. Using a unique 3-D culture system, the effects of mechanical signaling and cytokine stimulation will be used to measure fibroblast proliferation, apoptosis, interactions with myocytes and ECM expression.
Specific Aim 3. Determine the junctional proteins and ECM receptors that regulate the interaction between fibroblasts and myocytes. These investigations will employ a variety of cellular and molecular approaches to examine cell characterization, proliferation, turnover and interaction of fibroblasts with myocytes and the ECM during normal neonatal growth, pressure overload hypertrophy and altered cardiac remodeling in periostin-/- mice and IL-6-/- mice, which display altered cardiac physiology and phenotype. Moreover, these studies will utilize a 3-D culture system that displays an in vivo-like myocyte-fibroblast-ECM phenotype. The data generated from these studies will lead to significant new information on the role of the cardiac fibroblast and its interactions with myocytes in the regulation of cardiac remodeling, as well as providing novel therapeutic targets to control the adverse affects of cardiac remodeling.

Public Health Relevance

The proposed studies will examine the dynamic interaction between cardiac fibroblasts, myocytes and the extracellular matrix. Experimental approaches will be used to understand the chemical, mechanical and electrical signaling between these cell types and the ECM under normal growth and under pathophysiological conditions.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL085847-05
Application #
8242805
Study Section
Special Emphasis Panel (ZRG1-CVS-P (02))
Program Officer
Adhikari, Bishow B
Project Start
2008-04-01
Project End
2014-03-31
Budget Start
2012-04-01
Budget End
2014-03-31
Support Year
5
Fiscal Year
2012
Total Cost
$361,159
Indirect Cost
$113,659
Name
Medical University of South Carolina
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29425
Yang, Huaxiao; Borg, Thomas K; Schmidt, Lucas P et al. (2014) Laser cell-micropatterned pair of cardiomyocytes: the relationship between basement membrane development and gap junction maturation. Biofabrication 6:045003
Yang, Huaxiao; Borg, Thomas K; Wang, Zhonghai et al. (2014) Role of the basement membrane in regulation of cardiac electrical properties. Ann Biomed Eng 42:1148-57
Ma, Zhen; Yang, Huaxiao; Liu, Honghai et al. (2013) Mesenchymal stem cell-cardiomyocyte interactions under defined contact modes on laser-patterned biochips. PLoS One 8:e56554
Lindsey, Merry L; Borg, Thomas K (2012) Introduction: Extracellular matrix and cardiovascular remodeling-using microscopy to delineate mechanisms. Microsc Microanal 18:1-2
Souders, Colby A; Bowers, Stephanie L K; Banerjee, Indroneal et al. (2012) c-Myc is required for proper coronary vascular formation via cell- and gene-specific signaling. Arterioscler Thromb Vasc Biol 32:1308-19
Bowers, Stephanie L K; McFadden, William A; Borg, Thomas K et al. (2012) Desmoplakin is important for proper cardiac cell-cell interactions. Microsc Microanal 18:107-14
Borg, Thomas K; Baudino, Troy A (2011) Dynamic interactions between the cellular components of the heart and the extracellular matrix. Pflugers Arch 462:69-74
Bowers, Stephanie L K; Banerjee, Indroneal; Baudino, Troy A (2010) The extracellular matrix: at the center of it all. J Mol Cell Cardiol 48:474-82
Lindsey, Merry L; Borg, Thomas K (2010) Understanding the role of the extracellular matrix in cardiovascular development and disease: where do we go from here? J Mol Cell Cardiol 48:431-2
Bowers, Stephanie L K; Borg, Thomas K; Baudino, Troy A (2010) The dynamics of fibroblast-myocyte-capillary interactions in the heart. Ann N Y Acad Sci 1188:143-52

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