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Liming Pei, a research associate at the Salk Institute for Biological Studies, who coauthored an editorial on the paper in Cell Metabolism, cautions that applying this specific approach to humans is many steps away. But the study is important in terms of finding new strategies to target obesity. Previous approaches, Pei says, "focused on stimulating existing natural pathways" for burning fat. The idea of introducing a strategy from another organism that is not present in the body is a novel one.
"This opens up an opportunity for understanding metabolism and finding new therapeutic applications," Liao says. Someday, it may be possible to actually introduce these bacterial genes or proteins into humans, although Pei points out that such a feat poses many challenges, including a potential immune response to foreign genes. Another possibility would be to search for drugs that could mimic the effects of these enzymes. Furthermore, earlier studies reported glyoxylate shunt activity in chickens and rats, suggesting that higher organisms might retain the genes for this pathway but don't use them; it might be possible to activate dormant genes.
Liao says that the study borrows strategies from synthetic biology, a field that has for the most part focused on engineering new functions into bacteria and other lower organisms. The study suggests that the same concepts could be applied to mammals: just as we create bacteria that produce biofuels, we could introduce new abilities into the bodies of humans and other animals.
"What I found fascinating is that it shows how you could use synthetic biology for human therapies in a highly novel way," says James Collins, a synthetic biologist at Boston University. Current strategies for gene and protein therapy largely focus on single molecules--replacing a missing substance like insulin or inhibiting a harmful protein in cancer. Instead, Collins says, scientists might consider introducing an engineered pathway that allows the body to do something that it couldn't before.
A new drug proves effective in fighting obesity and related diseases while increasing stamina in mice.
Researchers believe that they might be able to combat obesity by blocking a nerve that helps regulate digestion.
So do you have a useful suggestion? Or are you just going to complain about a possible way to help obese people be healthier?
It strikes me as somewhat humorous when the authors on studies like this say we're a long way to use in humans. When you're talking about introducing foreign genes the only way to get away with it (i.e. overcome the immune system) is via injecting them into the embryo i.e. germline changes. Basically you'd have to create a new subsect of humans that would permanently pass down these genes. "Instead, Collins says, scientists might consider introducing an engineered pathway that allows the body to do something that it couldn't before." Jim why don't you expand on what this statement really means.
Not true. If you'd read the headlines, you'd know of recent breakthroughs allowing gene therapy to be applied to tissue samples, which are then subsequently de-differentiated into stem cells. Obviously implanting stem cells doesn't require germline modification.
@gabrielg01 "These are intracellular changes, so the immune system does not see them." If these cells are expressing unnatural proteins even if they aren't excreting them it could result in a catastrophic immune response.
@sanman true you could introduce unnatural genes via stem cells, but you'd run into the exact same problem as if you used normal gene therapy. Recently gene therapy (using natural genes) has been done on skin cells to turn them into stem cells, then reimplanted.
However even though these genes are natural there's risk that overexpression of these genes could cause result in cancer. Recently Sheng Ding at Scripps and others have reprogrammed stem cells using proteins which is an attempt to get around this problem.
Either way there is no safe way to introduce unnatural genes into humans without germline modifications.
@ajh20: "Whether through stem cells or somatic line gene therapy there is no safe way to introduce unnatural genes into humans without germline modifications."
This strikes me as a pretty arrogant statement. How do you know that there is NO safe way? Simply because it hasn't been found yet? I would wager that you will be eating your own words within a decade.
@ajh20...if the cells do not display these antigens on their surface, then how exactly would that "catastrophic immune response"occur?...Somebody needs to take Biology 101 again...or perhaps, just shut up, and not pretend to have all the answers.
I agree with ajh20 in that we do need to be cautious when introducing these new technologies into humans (law of unintended consequences), but you have to admit that the rate of progress is astounding. Look at the discoveries in just the last 5 years and think about what we will discover in the next 20.
@gabrielg01 this isn't biology 101 it's actually pretty complicated immunology. Anyway just because a protein isn't excreted or expressed on the surface of a cell does not mean that it will not result in a phenotype that is not immunogenic. Other than the fact that an unnatural protein can effect the expression of those that do show up outside the cell there's also the fact that all proteins can wind up outside the cell. That's because all cells break down and die and when they do, they lyse.
@enantiomer2000 it's not arrogance it's more frustration that there currently no way to introduce foreign genes without serious immunological risk. Here's to anyone that can think of a way around it.
@ajh20 - I suggest you wait for the actual data, which will come from animal experiments, and try not to draw sweeping conclusions based on vague assumptions. Let the data speak first.
@gabrielg01
The data is "out." If you actually read the paper you would see they used nude C57BL/6 mice. If you're not familiar with immunology nude mice are mice without or with heavily reduced immune systems. The likelyhood they could get away with this in normal mammals i.e. mammals with a functioning immune system is negligible, which is why they didn't do it and likely will never attempt it.
http://en.wikipedia.org/wiki/C57BL/6
For people who actually read papers before talking about them. http://brokenscience.com/fat.pdf
Dear ajh20, you need to understand once and for all that logic is not optional. You can't just turn it on/off as you wish - and sorry to sound "preachy".
As for the "nude C57BL/6 mice" you are talking about...perhaps you should read the paper again, (and again, if necessary). The C57BL/6 mice are not nude, and they have a very good immune system.
If you want to know what the real nude mice are, then here is a starter:
http://en.wikipedia.org/wiki/Nude_mouse
I have to wonder what happens to these mice if they have this modification and don't consume ton of unhealthy crap? Would they starve to death because all their sugar was going up in smoke?
I'm 35 and thin as a wire. The less exercise I get and the more food I eat, the skinnier I get.
As calorie restriction is yet the best path to a prolonged life, I would like to know the impact of this new pathway on the mice longevity. Besides, what about the strength, activity and cognitive abilities of those engineered mice? I guess only a longitudinal study of 2 to 3 years (usual mice lifespan) will tell us.
I wonder how the physical fitness industry will respond to this..
Besides, genetic modification/ manipulation may not be widely acceptable anytime soon.. We will need another more viable method...
Though I, of course, think it's a shame that so many people in the world are allowed to starve or be undernourished, there is no rational correlation between what I eat , whether too much or too little, and the amount of food that people in other countries receive to eat.
This problem is much closer to home than people ever want to admit. While I am willing to take action to feed the needy near me, I don't think it's arguable that it's my personal fault they are hungry because I have a weight problem (which by the way is TOTALLY hereditary for me, and most overweight people are burdened with some element of heredity, even if it's a psychosomatic family trait. Be grateful if you are not so burdened, and stop judging what you couldn't possibly understand!), but I do what I can because it's right to do it. They like myself are subject to powers beyond their control and need a bit of compassion. Considering the fact that I am not a megalomaniac billionaire industrialist, nor a member of the World Bank, nor any such mega-entity controlling the world's economies, I don't think I can be held responsible for the hunger of people in the Third World. But, neither am I a sweat shop owning Third World business tycoon exploiting my own community, or a corrupt Third World government official taking bribes to help and allow foreign companies to exploit my own country. I believe that, as ironic as it may sound, we have to stop thinking globally, at least when it comes to resolving a problem as personal and direct as hunger, and start thinking locally. I'd be willing to share with the children in India, just as I do with people here, but I can't help noticing that it would be a practical impossibility, and that there are people a lot closer who are failing to do that, also. I'll state plainly that I think their failure is much worse than mine, though it receives no notice in such discussions as these. I'm so sick of being blamed for what's happening on the other side of the world. I'd like to point out that greed is a universal human failing, and not limited to "Westerners". If it weren't, wealthy people in the "third world" would make sure that everyone around them had enough to eat. Instead they allow a level of disparity to exist that rivals anything we have created here in the "West", at least, around us in our communities. Charity should begin at home, and if it did many of the world's problems would be eased, or even overcome. Let them take some responsibility for the people within their arms reach. It has always been greed at the highest economic levels in every country that creates such problems. Not my personal relationship with ice cream, however troubled. That is such a reach! Come on. Blame the fat people for world hunger?! Please!
As far as the breathing "carbon signature" issue, please, now you are going to say fat people would be responsible for global warming if they use this technology? We are a planet full of carbon-based life forms, it's all going to come out one way or the other. And they always poo-poo the complaint that fat people are discriminated against. Why not blame us for the Middle East conflict while you're at it? I have no doubt that's next, and it makes as much "sense".
Re: "Starving children in India"
Ravenrose,
I sighed when i saw the length of your post, but started reading it anyway. I also finished reading it. Bravo.
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hachi
10 Comments
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enantiomer2000
66 Comments
Re: That's funny
Yes, the distribution of resources in the world is not fair and there is absolutely nothing you can do about it. Would you rather us only work on helping the have-nots before researching to help the haves? As a selfish capitalist, I prefer to look after myself first ;)
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Fabrizio
4 Comments
That's funny? no, UNETHICAL
That's even worse than funny. I am stunned by the feat but I think the chosen application is revolting. While the world is striving for making available enough food for its (too many) billions of people, and for reducing C02 emissions, researchers are focusing on techniques to burn excess fat in the body releasing C02!!! This is a good example of research which should be called "UNETHICAL". The best solution to this problem is well known since many years and, for most people, it consists in healthy diet and physical exercise.
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ChrisCooper
3 Comments
Mice with central heating
Must make the animal warmer which may help it survive in a colder climate.
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