FRANCL, J.*; LIU, Q.; BAGATTO, B.; University of Akron; University of Akron; University of Akron: Cadherin-2 Expression in Regenerating Cardiac Tissue of Zebrafish

A popular model for studying the cardiovascular system is zebrafish due to rapid, transparent development and ease of drug administration. Zebrafish are also capable of regenerating many body structures and tissues. Cadherins are cell adhesion molecules that are commonly expressed during development and have been shown to be expressed during tissue regeneration. In this study cadherin-2 expression was analyzed in regenerating adult zebrafish cardiac tissue, and physiological function (blood pressure and heart rate) was recorded during the repair/regeneration process. To stimulate regeneration, adult fish were injured by opening the body cavity and pinching the apex of the heart with metal forceps. Control fish received the same surgical procedure excluding injuring the heart. Animals were then allowed to recover for 24 hrs., 48 hrs., 4 days, 1 week, 2 weeks, 1 month, and 2 months. Hearts were harvested and fixed at these times, followed by sectioning and immunocytochemistry staining for cadherin-2. Blood pressure and heart rate of 48 hr. recovery fish were measured using a WPI micro-pressure system. Results show cadherin-2 expression increased in the injured area of the cardiac tissue compared to surrounding areas, while control tissue exhibited general cadherin-2 expression. Preliminary physiological data show a general trend of decreased heart rate and blood pressure in 48 hr. recovery animals compared to controls. Cadherin-2 appears to be up-regulated during tissue regeneration, while physical function of the regenerating heart appears to be compromised.