Abstract 357: Cardiac Fibroblasts as a Support Cell for Endothelial Cell Sprout Formation in Engineered Cardiac Tissue
Cardiac tissue engineering offers a promising approach to regenerating post-MI myocardial tissue; however, a primary impediment lies in the inability to adequately vascularize a tissue scaffold. Endothelial cells (ECs) require a support cell to form mature patent lumens and it has been demonstrated that pericytes, vascular smooth muscle cells and mesenchymal stem cells (MSCs) are able to support the formation of mature tubules/vessels. Cardiac fibroblasts (CFs) provide important electrical and mechanical components to the myocardium and are present in the native cardiac cell population, but to date have not been sufficiently studied for their role in angiogenesis in the heart. As a model of myocardial tissue, we co-cultured different concentrations of various cell types in fibrin hemispheres in appropriate combinations of their specific media, to determine the optimal sprout formation through DNA analysis, flow cytometry and immunohistology (IH). For flow cytometry, endothelial cells and mesenchymal stem cells were marked with CD31 and CD90, respectively. The highest total cell count was found in the fetal CF co-cultured populations (Fig 1A p<0.05), but ECs proliferated best with the adult and neonatal CFs (Fig 1B p<0.001). Analysis of IH images (Fig 1C, D) demonstrated that ECs formed the longest (Fig 1E p<0.05) and most numerous sprouts (p<0.002) with CFs as compared to MSCs. However, ECs were able to produce more multicellular sprouts when in culture with the MSCs (Fig 1F p<0.001). In summary, CFs provide a better support system for EC proliferation and sprout formation than MSCs, while MSCs allow for more multicellular sprouts, which is more indicative of the in vivo process.
- © 2012 by American Heart Association, Inc.