Neurons Created Directly From Skin Cells 231
alx5000 writes "The Times is running a story about a neurologic breakthrough that could revolutionise treatments for conditions such as Parkinson's disease and Alzheimer's: Neurons have been created directly from skin cells for the first time. Quoting neurobiologist Professor Jack Price: 'This suggests that there are no great rules — you can reprogramme anything into anything else.' The article also points out that this method could work around the ethical issues surrounding embryonic stem-cell research."
Re:Perfect explanation (Score:3, Informative)
So that's why they cut of the foreskin.
Actually, yes. The foreskin contains about 90% of the nerve endings on the penis. It's rather barbaric that this country is one of the few in the western world that routinely mutilates male anatomy -- many parents often not even knowing why it's done, only that everybody else does it. more info [indra.com]. For the very few men that have been circumsized as an adult and had an opportunity to experience sex both ways -- they say that sex is very disappointing after. Some become suicidally depressed.
Embryonic stem cells shouldn't be replaced (Score:5, Informative)
Re:That's awesome! (Score:5, Informative)
No. The beta-amyloid plaques that damage and ultimately kill bain cells would still be present. The plaques themselves must be destroyed, not just throw billions of new neurons at the problem.
Cancer incidence (Score:2, Informative)
Re:Fetal Stem Cells Need Not Apply (Score:2, Informative)
Nature is only organic if it has carbon in it.
Article (Score:5, Informative)
For those of you trying to find the actual nature article, here. [nature.com] I know we hate paywalls, but it should really be required for submission to slashdot that a link to the real paper, not preview, be included.
I am not a stem cell biologist, nor am I a neurobiologist, and I will need to read the paper more carefully when I’m at home, but some of my thoughts:
There do seem to be some hurdles to using this in humans, but many are trivial in comparison, and the reason the authors didn’t do them yet is because they wanted to get this out there before anyone else did. For one thing, they haven’t shown this in humans yet, but it should work in human cells that’s their stated next step. These cells were grown using dead mouse “feeder cells” which is common in cell culture, but complicates things for human therapy. You don’t want even dead mouse cells or other people’s dead cells in something that is going to go into your brain. People are working on culturing without feeder cells, I’m not sure where they are on that. The method of getting the 3 genes in is also an issue. These guys used lentiviral transfection, which is not something you want for human cells. Earlier work on IPSC got it done by incubating cells with transcription factor –protein- modified to penetrate cells. That might be a good next step here, though it would probably decrease the efficiency.
A bigger issue to me is what they are transfecting. They’re putting in three transcription factors, Ascl1, Brn2 (also called Pou3f2) and Myt1l. One of them, Ascl1, is found in many cancers (according to wiki anyway) and might be tumorgenic. Especially if they find they can’t get it to work without viral transfection, that could be a concern. The other two though aren’t tumorgenic apparently. Brn2 (also called Pou3f2) and Myt1l are both associated with neuron differentiation, which is interesting.
They did overcome a big hurdle: these are not pluripotent, which probably means there’s less chance of causing tumors, teratomas. With induced pluripotent cells, that is a concern. If you were to inject IpsC into your brain, you don’t know what you’re going to get. You could get bone cells growing in there, cells which aren’t supposed to be there that could potentially cause tumor formation. This doesn’t seem like that will be an issue here, they apparently get all neurons, neurons which appear not to continue dividing. I do find it a little hard to believe though that these only produce neurons and never glial cells, though I’ll need to reread it a few more times.
This is also a interesting paradigm shift for developmental biologists: apparently you don’t have to go back to square one to switch cell fates, it will take longer and be less efficient to do so. IpsC take about a month to become pluripotent and then be grown back into neurons, and only about 1% of the cells do that if I recall correctly. These take a week.
For much of the study, they seem to be using 5 different factors, not the 3 minimal ones. They state that Ascl1 alone was sufficient to make these cells start looking like neurons, but the other two were needed for them to look and behave like mature neurons. Most of the figures were working with a combination of 5 factors. With all 5, they showed a good mix of different types of neurons, but that had less efficient conversion than the minimal 3. I’m wondering if you’d actually be able to get all the different types of mature neurons with just the 3. I’d guess it’s not that they intentionally did it that way, but they wanted to hurry up and publish ASAP, so they skipped doing that characterization for now.
One problem facing all these therapies eventually, as I understand it, is that you want to get one specific type of neuron for therapy. I have no idea what strategies there are to direct differentiation into specific types of neurons, but this seems like it would be the bigger hurdle.
I don't know if I'd go as far as that quote (Score:3, Informative)
Re:sweet (Score:3, Informative)
insert dickhead joke here