Washington: American scientists have claimedto have identified the source of cells that develop intocoronary arteries, a discovery that can help millions ofpeople struggling with heart diseases.
"I thought, as many others did, that these cells(coronary arteries) would arise from the proepicardium. Thesecond surprise came when we realised the cells werede-differentiating from venous cells and becoming arteries." To confirm the finding, the team cultured developinghearts from mouse embryos in a dish. They observed that, incontrast to controls, the chambers of hearts from which thesinus venosus was removed kept beating but never developedcoronary vessels. The scientists then used a cell-marking technology tolabel individual cells in the developing hearts of mouseembryos with different colours.
The found that a single cell from the sinus venosusmigrated across the heart and became not only the lining ofthe coronary arteries, but also of the veins and capillarieson the heart. "This is a beautiful example of natural reprogramming,"said Mark Krasnow, senior author of the study. "The heart is somehow telling these venous cells to leavethe sinus venosus and convert into coronary arteries. If wecan identify these molecular signals, we might be able to usethem to construct coronary arteries for bypass surgery, whichcould be very important therapeutically," Krasnow said.
The team is now trying to identify these signals andstudy how they can change the cells` gene expression patternsas they undergo this conversion. The next step will be to see whether they can inducehuman cells to undergo a similar transformation. Krasnow said: "During the past several years, somescientists have made great progress in understanding howorgans develop. Others have made significant advances intissue engineering and regenerative medicine. But the twogroups don`t talk to each other much. "Now we`re trying to apply what we`ve learned about how abody builds a vessel or an entire organ to building vesselsand organs in the laboratory," he said. "If we can learn about how coronary arteries developnormally, we may be able to take that information and engineerbetter coronary bypass grafts, or even learn how to increaseblood flow to the heart muscle without surgery," Krasnow said. Coronary arteries are the vessels that deliver blood tonourish the continuously pumping heart muscle. PTI
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