Embryonic heart in mouse shows regenerative capacityOctober 14th, 2008 - 2:51 pm ICT by IANS
Washington, Oct 14 (IANS) Embryonic mouse heart has an astounding capacity to regenerate, a phenomenon observed only in non-mammalian species, according to a new study.The research describes the previously unrecognised potential of the embryonic heart to replace diseased tissue through compensatory creation of healthy cells.
Disorders of the mitochondria, a cell structure required for energy production, are one of the leading causes of fatal early onset cardiomyopathies, the “heart muscle disease”, causing the functioning of the actual heart to deteriorate.
To investigate how mutations that interfere with mitochondrial function impact the heart during development, Timothy C. Cox (University of Washington, Seattle) and colleagues used a heart-specific knockout approach in mice to inactivate a gene crucial for normal mitochondrial function.
Their experimental methods established embryonic female mice with hearts composed of mixed cell populations: half normal and half “diseased” (lacking the gene). However, surprisingly, at birth the diseased cells represented only about 10 percent of the cardiac tissue.
The authors went on to show that increased proliferation of healthy heart cells was responsible for this change and led to a fully functional heart, according to a release of the Cell Press.
Nevertheless, despite normal cardiac function early in life, over 40 percent of adult mice prematurely developed cardiac pathologies which may indicate a hitherto unsuspected embryological origin for early onset cardiac disease in humans.
“Our findings reveal an impressive regenerative capacity of the foetal heart that can compensate for an effective loss of half of the cardiac tissue,” concluded Cox. “To the best of our knowledge, this represents the first in vivo demonstration of selection against diseased tissue during embryonic heart development”.
The work also suggests that some cell populations within the heart are better able to regenerate than others.
These findings were published Monday in Developmental Cell.