In disease states, such as emphysema and aneurysmal degeneration, the degradation of elastin fibers that characterizes these conditions is accompanied by repair processes that are insufficient and fail to prevent disease progression. Towards this goal our objectives are to regenerate elastin in tissue culture systems by crosslinking recombinant tropoelastin (rTE) into damaged elastin and to characterize the effectiveness of this regeneration by assessing the functional mechanical, biochemical, and ultrastructural properties. Our central hypothesis is that elastin can be regenerated in vitro and in vivo by administering rTE to damaged elastin, thereby restoring, at least in part, the pre-existing elastin fiber organization and its mechanical properties. Such repair might prevent mechanical forces from causing failure of the remodeled matrix at loci of stress concentrations.
Aim 1. To identify the separate contributions of elastin, proteoglycans, collagens, and cells to the macroscopic mechanical properties of elastogenic cultures. This will be carried out in well-defined cultures by manipulating the amount of elastin, fibrillar collagen, proteoglycans or by generating cell-free matrices. This will provide essential information on the structural and mechanical properties of the components of extracellular matrices and provide the baseline information for this in vitro model system.
Aim 2. To assess the changes in functional mechanical, biochemical, and ultrastructural properties of the defined elastogenic cultures from Aim 1 during and after treatment with elastases to degrade elastin and proteoglycans or with non-elastolytic enzymes to digest primarily collagen or proteoglycans. The cultures will then be monitored as the endogenous smooth muscle cells effect repair. The information will shed light on how enzymatic injury degenerates structure and mechanical function and the effectiveness of endogenous repair processes.
Aim 3. To determine the mechanical, biochemical and ultrastructural properties of rTE mediated regeneration of elastase-treated matrices in the presence or absence of endogenous tropoelastin production.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21EB000988-02
Application #
6660701
Study Section
Special Emphasis Panel (ZHL1-CSR-O (S1))
Program Officer
Kelley, Christine A
Project Start
2002-09-25
Project End
2005-08-31
Budget Start
2003-09-01
Budget End
2004-08-31
Support Year
2
Fiscal Year
2003
Total Cost
$242,250
Indirect Cost
Name
Boston University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
Black, Lauren D; Allen, Philip G; Morris, Shirley M et al. (2008) Mechanical and failure properties of extracellular matrix sheets as a function of structural protein composition. Biophys J 94:1916-29
Leach, Jennie B; Wolinsky, Jesse B; Stone, Phillip J et al. (2005) Crosslinked alpha-elastin biomaterials: towards a processable elastin mimetic scaffold. Acta Biomater 1:155-64
Black, Lauren D; Brewer, Kelly K; Morris, Shirley M et al. (2005) Effects of elastase on the mechanical and failure properties of engineered elastin-rich matrices. J Appl Physiol 98:1434-41