r cardiology," said the study's senior author, Kenneth Chien, M.D., Ph.D., director of the UCSD Institute of Molecular Medicine. "Traditionally, pediatric cardiologists and cardiac surgeons have relied on mechanical devices, human and synthetic tissue grafts, and artificial and animal derived valves to surgically repair heart defects. While progenitor cells won't grow a whole new heart, our research has shown that they can spontaneously become cells from specific parts of the heart by simple co-exposure to other heart cells, which could augment existing surgical procedures. If the cells maintain pacemaker function when placed in the intact heart, they might serve as biological pacemakers for infants born with heart block, which could also be valuable."
After the isl1+ cells were found in newborn rats, the UCSD team used sophisticated genetic methods to tag the progenitor cells in living embryonic tissue and in the newborn heart of mice. With these techniques, they were able to show that the isl1+ progenitor cells were spontaneously able to form cardiac muscle tissue.
"Furthermore, the cardiac muscle cells formed were totally mature and had the complete array of function that one would expect in completely differentiated heart tissue," said the study's co-first author Jason Lam, Ph.D. candidate in the IMM. The cells exhibited contractility, pumping ability, the correct electrical physiology and normal heart structure. In addition, the progenitor cells coupled with neighboring cardiac muscle cells with resulting normal electrical heart beats.
"Another important discovery was the ability to expand the few cells found in a newborn heart, into millions of cells in lab culture dishes," Laugwitz said. "This implies that the isl1+ cells potentially could be harvested from an individual's heart tissue, multiplied in a laboratory setting, then re-implanted into the patient. Furthermore, the developmental lineage marker which identifies undifferentiatedPage: 1 2 3 Related biology news :1
Source:University of California, San Diego
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