Beaker bytes: Getting hearts to heal themselves
The cells that make up heart muscle in mammals have been thought incapable of replicating after birth. That's why heart attacks are such a problem: once killed, heart tissue can't grow back and is instead replaced by scar tissue. Now, in the best-documented effort to-date, Felix Engel, PhD, in Children's Hospital Boston's Department of Cardiology, has successfully gotten heart-muscle cells to divide and multiply—the first step in regenerating heart tissue. Engel's work, one of three prize-winning entries on Children's Research Day on June 1, could lead to new strategies for treating cardiac patients.
Reporting in the May 15 issue of Genes & Development, Engel and colleagues showed that an enzyme called p38 MAP kinase suppresses heart-cell replication in rodents, and that inhibiting this enzyme enables cell replication to proceed. p38 proved to have a role in every major step of replication—DNA synthesis, division of the cell nucleus (mitosis) and splitting of the whole cell into two new cells (cytokinesis). Engel is now investigating whether compounds that inhibit p38 can improve heart function after cardiac injury. Preliminary results in rodents are encouraging, he reports.