With the use of fetal cardiac surgical techniques, Core C is designed to provide PPG investigators with rigorously defined and reproducible novel ovine models of congenital heart disease (CHD). To this end, Core C will comprehensively generate, manage and provide all animal-related experiments, resources, and expertise. In addition, Core C will obtain peri-operative blood samples from neonates, infants, children, and adults with a wide range of differing congenital heart defects, to be utilized by PPG investigators. A secure database is already established that contains banked samples and clinical data on >300 patients. In this context, Core C will be defined by providing six services: 1) Ovine models of CHD. This will include our well-established Shunt model and our newly created LPA ligation model. Tissues (peripheral lung and isolated vessels) and primary pulmonary artery endothelial and smooth muscle cells (both proximal and microvascular) will be available to PPG investigators. 2) Acquisition and analysis of data. This will include the evaluation of cardiopulmonary hemodynamics, pulmonary vascular reactivity (both in vivo and in vitro), the assessment of pulmonary vascular remodeling, advanced in vivo imaging, the effect of cardiopulmonary bypass on hemodynamics and vascular function, and the effect of different therapies. 3) Biochemical, proliferation, apoptosis, and angiogenesis determinations. This will include the measurement of various reactive oxygen and nitrogen species of oxygen or nitrogen oxide in vascular cells and tissues, indices of cell proliferation, apoptosis, and tube formation. 4) The in vitro assessment of differing biomechanical forces. This includes the utilization of a novel microfluidic chamber (UCSD) that allows the simultaneous and independent variation of pressure, cyclic stretch, and flow-induced shear stresses on the vascular endothelial cells. 5) Use of the CAR peptide to target therapeutics to the damaged pulmonary endothelium. To reduce the potential of off-target effects, we will utilize IV co-delivery of our therapies with the CARSKNKDC (CAR) peptide. 6) A bio-repository and corresponding clinical database of neonates, infants, children, and adults with CHD. Blood samples from patients with CHD will be obtained before and after surgical repair for human confirmation of aberrant pathways initially identified in animals and for metabolic screening. Correlation between the identified aberrations, with the type of CHD (+/- flow; +/- pressure), and degree of pre-operative and post-operative pulmonary vascular disease will be sought. Core C will enhance the scientific work for all three projects by assuring that all animal models are standardized and performed in a uniform manner by highly experienced and trained personnel. Investigators who have had many years of experience using these techniques run Core C. They have developed or adapted several of the techniques and applied them to perform physiological studies in in vitro and in vivo systems. As a central dedicated analytical resource Core C will ensure these analyses are also carried out in a cost-efficient manner with minimal animal morbidity and mortality.
Congenital Heart Disease (CHD) remains one of the most common worldwide causes of pulmonary vascular disease (PVD), and represents 45-55% of all pediatric PVD. The current proposal is based on large animal, clinically relevant models of CHD that result in abnormal pulmonary blood flow (PBF) patterns and early PVD. These unique ovine models require complex fetal cardiac surgical techniques and sophisticated hemodynamic monitoring, services that are best centralized given their inherent difficulty, reliance on specialized and sophisticated equipment and expertise, as well as the requirements of all three projects-Core C will provide these services for all three projects.
