New breakthrough could help heal 'broken' hearts
Researchers have said that a type of cell that builds mouse hearts can renew itself.
The Johns Hopkins researchers that say the discovery, which likely applies to such cells in humans as well, may pave the way to using them to repair hearts damaged by disease - or even grow new heart tissue for transplantation.
Chulan Kwon, Ph.D., an assistant professor of cardiology and member of the Institute for Cell Engineering at the Johns Hopkins University School of Medicine, research group's first step was figuring out the role of two genes, Numb and Numbl, in CPCs, which others' studies had shown are needed for guiding stem and progenitor cells to their fully mature, specialized functions.
Numb and Numbl are highly conserved, meaning that they're nearly identical in mice, humans and other animals, a sign that they're likely very important. To find out whether these genes are required for heart formation, the group disabled Numb and Numbl in early CPCs in developing mouse embryos.
The researchers next set out to find where CPCs live in the developing embryo. Using embryonic stem cells from mouse embryos, they again disabled Numb and Numbl while also engineering the cells to produce a glowing red protein, which would give away the CPCs' location.
But because the engineered stem cells alone wouldn't grow into a viable embryo, the team injected them into normal mouse blastocysts - a structure formed in the early stage of mammalian development that forms both the embryo and placenta.
When the team checked the hearts of the embryos, they found the glowing red cells in the second pharyngeal arch, which is known for forming parts of the neck and face. Kwon says theirs is the first study to identify it as home to CPCs.
His team took cells surrounding CPCs from this arch and grew them with CPCs in a dish. They found that the CPCs self-renewed without developing into specialized heart cells. This is an important step, he says, toward using CPCs to treat heart disease.
The study is set to be published in an upcoming issue of the journal eLife.
(Posted on 01-05-2014)