Friday, December 01, 2006

Heart Stem Cells Discovered!

` I don't know what it is with me and stem cells lately, but I am dredging up yet another Nature article draft about them. Wanna see? It's from Master cell could mend a broken heart: Stem-cell research uncovers the heart's foundations by Narelle Towie.

` Two completely different U.S. research teams have been studying the stem cells that build mouse embryo heart muscles. Both of them discovered that there are two cell types which are absolutely fundamental in growing a heart: One of these cells directly gives rise to all three of the major tissue types in the heart, as well as - they suspect - creating the other.
` It was previously assumed that different source cells would most likely be needed for each different cardiac muscle type, but now we know that a heart-attack victim could potentially benefit from being implanted with only one type of stem cell!

` Hooray for being wrong! According to the article:

"We are going to take the tools that we have learned from embryonic stem cells in the mouse and work out how to use them in humans," says Kenneth Chien of Harvard Medical School, who led one of the two teams. "We believe we could take this cell and engineer tissue for specific components of the heart," he says.
` Of course, says Deepak Srivastava (director of the Gladstone Institute of Cardiovascular Disease at the University of California, San Francisco), that's a long way off, so people should not be led to believe that there are any promises anytime soon.

` With what technique were these cells discovered? Accoring to the medical journal Cell, Chien's team traced the cells expressing a gene already linked with heart muscle called islet-1. Placing markers on the genes, they found that the cells it was expressed in turned into a cell type that produced all the major cardiac muscle types!
` The other group, which was led by Harvard's Stuart Orkin, marked cells that instead contained a gene called Nkx2.5. (This gene is also called 'tinman', because when it is turned off in fruit flies, they are in more dire need of a heart than the character from The Wizard of Oz.) According to their paper - also in Cell - this gene is responsible for two types of heart muscle in the first part of the heart that develops.
` They suspect that cells acting on islet-1 are the parent cells of these, though much work is needed to learn more.
"It now appears that cardiac cells develop in the same way that blood cells do, with a master stem cell giving rise to the entire range of cells," says Chien.
` For now, the stem cells in bone marrow are being injected into the heart to create more muscle, though it is still unclear as to whether this really works or not. However well it does work, it would appear that Chien's team's stem cells would probably be a better fit for something that repairs damaged heart tissue. The biggest problem now is; how to efficiently grow these cells in a lab? And, more importantly, how to get a hold of them to begin with?
` Research shall continue. And if you're really sick of this now like most people, then you may be more interested in these talking cats.
` Good morning and good muffle-flavored waffins. Wait... that sounded vaguely dirty. Maybe it was. I don't know. I'm not the one who made it up!!

3 comments:

Anonymous said...

So glad there's yet more hope on the horizon!

Spoony Quine said...

` Thank you for the spam, Defibrillator Man!

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