TO HEAL A BROKEN HEART
A zebrafish is unlikely to die of a broken heart. The fish, about the size of your pinky, can lose a fifth of its heart and grow it back. Now William Chen and colleagues from the University of Pittsburgh have traced its secret, as reported in
Science Advances last November. It lies not with the heart cells but the scaffolding that supports them, known as extracellular matrix (ECM).
Mice that suffered heart attacks made a remarkable recovery once injected with a powder of zebrafish heart ECM. Normally, mouse heart cells rarely multiply, but they kicked in, repopulating the damaged heart muscle and restoring its elasticity. Some of the powder’s properties appear attributable to neuregulin-1 and Erbb2, proteins which regulate cell proliferation.
The powder also stimulated human heart cells growing in a dish to proliferate. The authors are now testing to see if the zebrafish powder can mend the hearts of larger animals.