Calcific aortic valve disease (CAVD) is an increasingly prevalent and life-threatening condition for which there are currently no clinically useful biological targets or therapeutic agents. Several compelling recent studies have identified common signaling pathways present in both aortic valve formation and calcific aortic stenosis, but our understanding of how these signals are integrated and coordinated at the cell and tissue level is very limited. The cellular mechanisms controlling elongation, condensation, and matrix stratification of the valve primordia are of highest clinical importance but are almost completely unknown. Further complicating matters is that these morphogenic and remodeling behaviors occur within a dynamic mechanical environment, the effects of which have been challenging to investigate due to a lack of research tools. Cadherin-11 is a cell-cell adhesion protein that regulates of collective mesenchymal cell migrations and their subsequent differentiation to osteogenic lineages, making it an attractive candidate for regulating valve formation and homeostasis. Cadherin-11 is strongly and specifically expressed in both the endocardium and mesenchyme of the endocardial cushions, but progressively downgrades in the mesenchyme as cushions elongate into valves. The preliminary data in this proposal demonstrates that deletion of cadherin-11 results in significant lethality during key valve remodeling periods. Conversely, valve specific overexpression of CDH11 is viable but with thickened aortic valves with regions of hypercellular interstitial aggregation and calcification typical of lesions seen in human CAVD. This proposal will test the hypothesis that a tight range of Cadherin-11 expression is essential for proper coordination of fetal valve cellularization, remodeling, and maturation for long-term homeostatic function.
The first aim of the proposal will be to determine the mechanobiological role of cadherin- 11 in cellularization and remodeling of the embryonic aortic valve.
Aim 2 will test how cadherin-11 regulates postnatal valve remodeling and calcification.
Aim 3 of the proposal will test whether cadherin-11 rebalancing can rescue and/or prevent the development of aortic valve CHD and/or calcification. The results of this study will elaborate a novel tightly controlled and mechanically sensitive mechanism responsible for fetal valve maturation and postnatal homeostasis. The combinatorial approach presented will accelerate the development of molecular strategies that diagnose and control clinically accessible functional deficiencies in valve development and calcification risk.

Public Health Relevance

Several molecular mechanisms guiding malformation of the aortic valve appear reactivated during adult calcific valve degeneration. This proposal tests how cadherin-mediated adhesive transitions mediate cellular decisions to create mature aortic valves and maintain tissue homeostasis. Novel conditional mouse genetics models will be combined with in vitro culture systems to dissect how each contributes to mechanical sensation based tissue remodeling in the fetal and adult aortic valve.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL128745-03
Application #
9312882
Study Section
Cardiovascular Differentiation and Development Study Section (CDD)
Program Officer
Evans, Frank
Project Start
2015-08-17
Project End
2019-06-30
Budget Start
2017-07-01
Budget End
2018-06-30
Support Year
3
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Cornell University
Department
Engineering (All Types)
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
872612445
City
Ithaca
State
NY
Country
United States
Zip Code
14850
Sraeyes, Sridhar; Pham, Duc H; Gee, Terence W et al. (2018) Monocytes and Macrophages in Heart Valves: Uninvited Guests or Critical Performers? Curr Opin Biomed Eng 5:82-89
Richards, Jennifer M; Kunitake, Jennie A M R; Hunt, Heather B et al. (2018) Crystallinity of hydroxyapatite drives myofibroblastic activation and calcification in aortic valves. Acta Biomater 71:24-36
Pagnozzi, Leah A; Butcher, Jonathan T (2017) Mechanotransduction Mechanisms in Mitral Valve Physiology and Disease Pathogenesis. Front Cardiovasc Med 4:83
Kang, Laura Hockaday; Armstrong, Patrick A; Lee, Lauren Julia et al. (2017) Optimizing Photo-Encapsulation Viability of Heart Valve Cell Types in 3D Printable Composite Hydrogels. Ann Biomed Eng 45:360-377
Sung, Derek C; Bowen, Caitlin J; Vaidya, Kiran A et al. (2016) Cadherin-11 Overexpression Induces Extracellular Matrix Remodeling and Calcification in Mature Aortic Valves. Arterioscler Thromb Vasc Biol 36:1627-37
Farrar, Emily J; Pramil, Varsha; Richards, Jennifer M et al. (2016) Valve interstitial cell tensional homeostasis directs calcification and extracellular matrix remodeling processes via RhoA signaling. Biomaterials 105:25-37
Duan, Bin; Yin, Ziying; Hockaday Kang, Laura et al. (2016) Active tissue stiffness modulation controls valve interstitial cell phenotype and osteogenic potential in 3D culture. Acta Biomater 36:42-54
Gould, Russell A; Yalcin, Huseyin C; MacKay, Joanna L et al. (2016) Cyclic Mechanical Loading Is Essential for Rac1-Mediated Elongation and Remodeling of the Embryonic Mitral Valve. Curr Biol 26:27-37
Gregg, Chelsea L; Butcher, Jonathan T (2016) Comparative analysis of metallic nanoparticles as exogenous soft tissue contrast for live in vivo micro-computed tomography imaging of avian embryonic morphogenesis. Dev Dyn 245:1001-10
Bowen, Caitlin J; Zhou, Jingjing; Sung, Derek C et al. (2015) Cadherin-11 coordinates cellular migration and extracellular matrix remodeling during aortic valve maturation. Dev Biol 407:145-57