Ciliogenesis during zebra fish heart regeneration.

Abstract

Cardiac ischemic injury, a heart attack, occurs when blood flow through the coronary arteries is obstructed. As a result in humans, necrotic tissue is replaced by hard, inelastic scar tissue that impairs the heart’s ability to function. The human heart possesses little to no regenerative capacity on its own to recovery from ischemic injury. Zebrafish, however, are capable of robust cardiac regeneration after injury to the heart. Through a series of remarkable heart-localized events that mirror embryonic development, the zebrafish can replace damaged or lost heart tissue within a month. We noticed the similarity between the regeneration and development of cardiac tissue may implicate cilia are involved during regeneration. Cilia are microtubule-based organelles that serve important sensory functions during embryonic development and organ homeostasis. It is well established that sensory cilia regulate Hedgehog and Wnt signaling pathways to aid in differentiating tissues during embryogenesis. Recent studies provide evidence that cilia are present during cardiogenesis and are necessary for proper cardiomyocyte differentiation and cardiac morphology. Thus, we hypothesized cilia may play similar roles during zebrafish heart regeneration. In the current study, we tested heart tissue for the presence of cilia using immunofluorescent confocal microscopy. Our preliminary data suggest cilia are abundant in regenerating cardiac tissue 7 days after removing a portion of the ventricular apex. In addition, we began to implement the surgical procedures necessary to injure the zebrafish ventricle at Wheaton College.