Implanting embryonic cardiac cells prevents arrhythmias

When researchers at Cornell, the University of Bonn and the University of Pittsburgh **transplanted living embryonic heart cells** into cardiac tissue of mice that had suffered heart attacks, the mice became resistant to cardiac arrhythmias, thereby avoiding one of the most dangerous and fatal consequences of heart attacks. The discovery, reported in "Nature":[ http://nature.com], has profound implications for using cell-transplant therapies to restore damaged heart tissue. The researchers, including Michael Kotlikoff, the Austin O. Hooey Dean of Cornell's College of Veterinary Medicine, one of the paper's senior authors, discovered that a protein called **connexin43**, expressed by the transplanted embryonic heart cells, improved electrical connections to other heart cells. The researchers showed that the improved connections helped activate the transplanted cells deep within the damaged section of the heart tissue. The technique reversed the risk of developing ventricular arrhythmias after a heart attack, the number one cause of sudden death in the Western world. #img_826#.> *Cells implanted within damaged heart tissue (darker area) express a green fluorescent molecular sensor. Implantation of these cells, which express the protein connexin43, reduces the risk of the damaged heart developing fatal arrhythmias by enhancing electrical conduction (arrows). The fluorescent molecular sensor is activated when the cells contract, demonstrating conduction of electrical waves into the damaged area. Credit: Michael Simmons* In the past, scientists have transplanted a variety of cell types into failing hearts with modest improvement of function, although transplanting skeletal muscle cells made things worse and led to more **arrhythmias**. Surprisingly, when co-author Bernd Fleischmann at the University of Bonn and colleagues transplanted embryonic cardiac cells, the hearts' electrical stability and function returned to normal. Scientists recognize the untapped potential of using **cell-based therapies** to counter many debilitating diseases, but they have not had tools to assess the function of the cells once transferred. In Kotlikoff's laboratory, the researchers determined that the **transplanted embryonic cells** were making electrical connections with normal heart cells. Using genetically modified heart cells that express a fluorescent sensor, they established that transplanted heart cells were activated during normal heart contractions. "For the first time we were able to see how cells used in therapy are working with other cells in a complex organ within a living animal, establishing the mechanism of the therapeutic effect," Kotlikoff said. Whole article: "http://physorg.com":[ http://physorg.com/news116085966.html]

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