all Mark T. Keating stories

Broken hearts may mend after all

70652986 — Mon, 26 Mar 2007 06:18:30 -0400

Although adult muscle cells become inflexible after differentiation, these cells temporarily loosen the structure to divide in fetal development. Mark T. Keating found that in some lower vertebrates, heart tissue regenerates without the scarring seen in mammals. This seems to occur by proliferation of existing cardiomyocytes, not stem cells.

Felix Engel, an HMS research fellow in Keating's lab, set out to accomplish this in mammals. Engel first identified a growth factor that could specifically stimulate cardiomyocytes.

Researchers induce heart cells to proliferate

50443248 — Tue, 24 Jul 2007 14:23:18 -0400

In the best-documented effort to date, researchers from the Howard Hughes Medical Institute at Children's Hospital Boston and Harvard Medical School have successfully induced adult heart-muscle cells to divide and multiply.

Researchers regenerate zebrafish heart muscle

70652986 — Mon, 26 Mar 2007 05:28:39 -0400

A research team led by Mark T. Keating showed that zebrafish can regenerate heart muscle within two months after a severe injury. The team, from the Howard Hughes Medical Institute at Children's Hospital Boston, also identified a possible genetic and molecular model for regeneration in zebrafish that could help direct further research in humans. The findings, while still in an early stage, might someday benefit millions of people who suffer heart attacks or experience other forms of cardiac injury. The zebrafish is the subject of active study because of its ability to regenerate spinal cord, retina, and fins. This finding points to the study of zebrafish heart regeneration as a means to understand and reduce cardiac injury in humans. When a human heart is injured, it cannot "grow back" the damaged muscle, which is instead replaced by scar tissue. Too much scarring can impair the heart's ability to pump and can lead to life-threatening arrhythmias. Keating and his colleagues believe that zebrafish, unlike humans, have especially vigorous development of new heart-muscle cells, or cardiomyocytes. This proliferation of cells regenerates the heart muscle with little or no scarring. The research was reported in the Dec. 13, 2002 issue of Science.

Cell development is reversed

70652986 — Mon, 26 Mar 2007 05:07:13 -0400

After years of setbacks, researcher Mark Keating has taken a giant step toward understanding the potential for regrowth of limbs and organs. He and his colleagues have managed to manipulate fully developed mouse muscle cells to the point where they revert to stem cells, uncommitted cells capable of growing into any type of cell. Further, he coaxed these cells into starting their lives over again as bone, cartilage, and fat cells. In other words, he did what everyone thought was impossible. "It's work that should change the way people think about dedifferentiation (restarting development)," Keating says. Mice, like humans, are mammals.