Cardiomyocytes from human stem cells restore heart rhythm
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《英国医生杂志》
Cardiomyocytes developed from human embryonic stem cells can act as biological pacemakers and restore myocardial mechanical function when transplanted into animal hearts with a slow heart rate, according to research published last week.
Researchers from the Technion-Israel Institute of Technology in Haifa, Israel, generated cardiomyocyte cell grafts from human embryonic cells in vitro. They showed that the cells formed structural and electromechanical connections with cultured rat cardiomyocytes. However, to be clinically useful it is important not just to create such cells but to prove that they can survive and function in the body, making functional connections with existing heart tissue, explained Professor Lior Gepstein, senior lecturer in physiology at the institute and a member of the research group.
Creating large numbers of functioning cardiomyoctes from embryonic stem cells is difficult, so the group focused on replacing cells in the cardiac pacemaker region. They created a pig model with complete atrioventricular block in which the cardiac pacemaker was dysfunctional. They then transplanted the cultured cardiomyocytes into the pacemaker region. The results showed that the transplanted cardiomyocytes successfully paced the pig ventricles. Long term electromechanical integration between host and donor tissues occurred at several levels, according to the study findings, which were published in the 26 September online version of Nature Biotechnology (www.nature.com/nbt/) and will appear in the print edition next week.
The research group commented: "Our proof-of-concept study suggests the use of excitable cell grafts as a biological alternative to implantable devices." The technique could also be used to repair cardiac muscle tissue damaged during myocardial infarction.
"To do this, one needs to create enough healthy heart cells that survive the transplant and connect electrically with existing heart cells so they beat in unison," explained Professor Gepstein. He noted that the concept of a biological pacemaker created from embryonic stem cells was new and that it was too early to predict when it might be used to assist or replace mechanical pacemakers. "We have to prove a biological pacemaker will function non-stop for years in a sickly heart and wouldn抰 be rejected by the recipient抯 immune system," he concluded.(Jerusalem Judy Siegel-Itz)
Researchers from the Technion-Israel Institute of Technology in Haifa, Israel, generated cardiomyocyte cell grafts from human embryonic cells in vitro. They showed that the cells formed structural and electromechanical connections with cultured rat cardiomyocytes. However, to be clinically useful it is important not just to create such cells but to prove that they can survive and function in the body, making functional connections with existing heart tissue, explained Professor Lior Gepstein, senior lecturer in physiology at the institute and a member of the research group.
Creating large numbers of functioning cardiomyoctes from embryonic stem cells is difficult, so the group focused on replacing cells in the cardiac pacemaker region. They created a pig model with complete atrioventricular block in which the cardiac pacemaker was dysfunctional. They then transplanted the cultured cardiomyocytes into the pacemaker region. The results showed that the transplanted cardiomyocytes successfully paced the pig ventricles. Long term electromechanical integration between host and donor tissues occurred at several levels, according to the study findings, which were published in the 26 September online version of Nature Biotechnology (www.nature.com/nbt/) and will appear in the print edition next week.
The research group commented: "Our proof-of-concept study suggests the use of excitable cell grafts as a biological alternative to implantable devices." The technique could also be used to repair cardiac muscle tissue damaged during myocardial infarction.
"To do this, one needs to create enough healthy heart cells that survive the transplant and connect electrically with existing heart cells so they beat in unison," explained Professor Gepstein. He noted that the concept of a biological pacemaker created from embryonic stem cells was new and that it was too early to predict when it might be used to assist or replace mechanical pacemakers. "We have to prove a biological pacemaker will function non-stop for years in a sickly heart and wouldn抰 be rejected by the recipient抯 immune system," he concluded.(Jerusalem Judy Siegel-Itz)