Rat Heart Reanimated
By Jamie Lawson
The pitched battle between Science and the Forces of Nature has been raging for some centuries now, with heavy losses on both sides and neither showing any indication that they are likely to be surrendering any time soon. It is with great pleasure, then, that I find myself able to report that we (the Scientists) have scored a palpable victory against that most ancient of foes; the Reaper, Death himself.The old boney bastard has been spoiling our fun here on Earth pretty much since our first ancestor did the mitosis mambo in that far off stagnant pond and, frankly, we’ve all had about enough of his nonsense by now. Doris Taylor and her team at the University of Minnesota Center for Cardiovascular Repair have certainly had enough anyway, and have picked up their weapons to show Death that we are tired of being pushed about. Fixed to their battle standard: a beating, reanimated rat heart.
Stem cells have been the weapon of choice in a battle against the Reaper for some years now. You are probably familiar with the theory; stem cells are unspecialised cells that are capable of growing in to pretty much any other kind of cell in the body. They are vital in adults as part of the body’s self-repair mechanism and vital in embryos as starting points for every other specialised cell within the developing organism and, thereby, pretty much every organ in your body.
Big DealImpressive, yes, but what’s the big deal? Well, the thing is that if you can fool a stem cell into thinking what it’s meant to be doing right now is growing a liver, then you can grow a new liver for someone (assuming you happen to be in possession of embryonic stem cells for that individual) and transplant it in to them if their liver has failed. This is handy, as it avoids the trauma of having your immune system suppressed in order that you can accept a transplanted liver from someone else’s body and neatly sidesteps the tedious ethical problems of having to wait for someone to die so that you can have their organs. (more about stem cells)
Using stem cells would also mean we can abandon the prospect of hiding entire colonies of cloned people, produced as walking spare-part repositories for the wealthy and weird, in high-tech, underground facilities, thereby utterly avoiding the inevitable crisis when one of the clones breaks free and runs amok in the world above. Which is a shame, I think, in many ways.
But I digress.
So. Last month a British group reported that they had forced some stem cells to make heart cells. These cells were capable of beating and could be used to patch up someone’s heart, should someone’s heart require patching. This was good news and everyone was excited. The group at the University of Minnesota, however, have gone one step further and used stem cell technology to reanimate dead rat hearts.
Re-Rat-imationDoris Taylor and her colleagues wondered if they could use the structure of an existing heart to grow a new one. “We recognised that nature has created the perfect scaffold,” she explains, “and wondered whether there is a way in the lab to give nature the tools and get out of the way".
What is this scaffold of which she speaks? Why it is the network of collagen fibres, fibronectin and laminin along which the cells of the heart are normally strung. The team hung the hearts of rats and pigs in their lab (yes, that said hung, charming image isn’t it?) and then proceeded to wash all the cells from the organs, using a process called ‘decellurisation’. The remaining gelatinous scaffolds look like “ghost tissue” says Taylor, and it is these ghosts that are then injected with embryonic stem cells, fed a nutrient rich solution and allowed to do their stuff.
Four days after the process had begun, Taylor’s team had some rat and pig hearts that could contract. Eight days later and they could attach one of the new hearts to a pacemaker, fill it with some fluid (at roughly blood pressure) and step back to watch it beat. The team were understandably thrilled and reported their finding in Nature Medicine, though they didn’t mention the bit about the pig hearts... well, there’s no need to show off, is there?
Bright future
“The hope ultimately,” says Taylor, “although we've got a way to go, is that we could take a scaffold from a pig or a cadaver and then take stem or progenitor cells from your body and actually grow a self-derived organ... [the research] opens a door to this notion that you can make any organ: kidney, liver, lung, pancreas - you name it and we hope we can make it."
Sounds good to me, and I hear that the opposition is so concerned he’s stopped playing chess with Scandinavians and is sharpening his scythe as we speak. It may come as some comfort to him to know that my nights are haunted at the moment by the images of ghost hearts hanging from my ceiling. Great.
Read more of Jamie's articles:
- Interesting - When hairy was good
- Pay attention - I tawt I taw a puddy tat
- All round daft - Phones 4 UR safety
Image: Victor Maltby
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