The hope is that reversing the decline of a protein in the blood will make the aging body partially rejuvenate itself. Can GDF11 partially reverse the aging process?
Cambridge, MA, May 4 - Harvard Stem Cell Institute (HSCI) researchers have shown that a protein they previously demonstrated can make the failing hearts in aging mice appear more like those of young health mice, similarly improves brain and skeletal muscle function in aging mice.
In two separate papers given early online release today by the journal Science – which is publishing the papers this coming Friday, Professors Amy Wagers and Lee Rubin, of Harvard's Department of Stem Cell and Regenerative Biology (HSCRB), report that injections of a protein known as GDF11, which is found in humans as well as mice, improved the exercise capability of mice equivalent in age to that of about a 70-year-old human, and also improved the function of the olfactory region of the brains of the older mice – they could detect smell as younger mice do.
Clinical trials in 3 to 5 years. Sound exciting?
Rubin and Wagers each said that, baring unexpected developments, they expect to have GDF11 in initial human clinical trials within three to five years. Postdoctoral fellow Lida Katsimpardi is the lead author on the Rubin group's paper, and postdocs Manisha Sinha and Young Jang are the lead authors on the paper from the Wagers group.
Why to temper your enthusiasm: All those cells that damped down their activity due to declining GDF11 with age are dangerous. They are a far greater risk every time they divide than is the case with young cells. Why does GDF11 decline with age? Same reason I suspect many hormones (e.g. testosterone) decline with age: on average it is safer that way.
The body's many cells accumulate damage with age. Turn up the metabolic knobs on those cells and you run the risk of turning them cancerous. Also, even when cancer becomes curable we'll still face at least one other problem from stimulating old cells to divide a lot: if cells are stimulated to divide more times they'll wear out sooner (due to shortening telomere caps) and go senescent (stop dividing at all and become dysfunctional). I've made these points back in 2003, again in 2005 (about research that used young blood to serve the same role to stimulate cell growth in old rodents), again in 2006 and since then.
I'd really like to get as excited by GDF11 as many other reports have. But we need cures for cancer as well as ways to kill senescent cells (since killing senescent cells delays old age diseases in mice). Plus, we need ways to extract cells from our bodies, select for cells with little DNA damage, and then rejuvenate and convert the cells into stem cells of various types. Then we could introduce these cells back into the body, feed in the GDF11 (and likely other as yet undiscovered growth factors as well)
The cancer risk is not decisive in all cases. Imagine yourself at, say, age 60 and with early signs of heart disease or some other generation of an organ. Your risk of dying from something side from cancer could be judged so high that turning up aged repair systems in your body could lead to overall odds of longer life. If your ticker isn't going to let you reach 65 then why not run some marginally higher risk of getting cancer?
Some existing drugs reduce various components of romantic attraction.
Instead of comforting a friend after a break up with ice cream and a movie, bioethicist Brian D. Earp foresees the possibility of an anti-love drug, which could nip those regretful feelings in the bud.
Imagine being able to turn down lust, obsession, or attachment with a pill.
But what can be suppressed and also be stoked. Turning on the genes for vasopressin and oxytocin receptors cause prairie voles to form a lasting bond. Some day we'll have the biotechnology to turn up lust, attachment, and obsessive thoughts.
Imagine where this could lead. A guy could kidnap the woman of his desire, inject drugs or gene therapy, and then force her to stare at him. After a while the woman will develop an obsession and wont want to leave.
If we reach the point where a person's preferences, attachments, and loyalties are susceptible to reprogramming religious cults and harems will be built up using biotechnology. Dictators will use biotech to create loyal servants.
David S. Ludwig and Mark I Friedman lay out an argument for why the demonization of fats in foods has been a health disaster.
They advocate lower glycemic index foods. If you want to lower the glycemic index of the carbohydrates you eat you really need to look at glycemic index tables of foods. Their glycemic indexes are not intuitive. So, for example, sweet potatoes get digested more slowly than russet potatoes and carbohydrates from yams are broken down in digestion even more slowly than sweet potatoes.
Rice eaters: The rices vary greatly by glycemic index. The sticky rices are worse, broken down and absorbed very rapidly. One of the lowest glycemic indexes of rices is Uncle Ben's Converted Rice.
The woman chose a partner based on her biochemical tuning at the time the relationship started. When the woman's brain gets changed by stopping or starting the pill while in a relationship she then goes thru an alteration in her preference that usually lowers her satisfaction with her partner. The alteration makes her ideal male become someone who the current guy isn't.
This opens up all sorts of possibilities. A woman who is deeply satisfied with her man might some day want to get (and will be able to get a treatment that keeps her that way even when she goes off the pill.
Alternatively, a woman might want to alter her preferences in order to shift her preferences toward men she'd be better off with.
Then there is the possibility of a man surreptitiously using biotechnology to make his love interest find him more appealing. Just like magic love potions.
See Tyler Cowen's post The commons are still tragic.
Some people have a more optimistic outlook on the future than I do. Take for example, Ramez Naam's book The Infinite Resource: The Power of Ideas on a Finite Planet. It is an excellent well-researched book. I recommend it to your attention. Ramez does a good job of outlining the prospects for many promising technological advances. But technology that avoids major sacrifices does not seem sufficient for the problem. I believe human nature (or, rather, human natures) and incentives lead to outcomes that make me not share that optimism.
One problem is the tragedy of the commons. Under what scenario might be handled effectively on a global scale? Global government might do it. But that is a long ways off andit is not clear the powers in a global government would handle the problem effectively.
Can we avoid political solutions? The optimists see technology as providing substitutes to reduce demand on limited resources. But new technologies do not just play the role of substitutes. They can just add more ways to build up more resource extraction capabilities.
I see technology playing a very large role to accelerate resource depletion (e.g. factory fishing ships with sonar to track fish, robotic mining equipment, computer models to find oil more rapidly). It is not clear to me that technological advances will, on net, reduce resource usage. The opposite seems more likely. Our ability to harness more of nature to do human bidding may continue to accelerate resource depletion and habitat damage in much of the globe.
Another problem looms that the optimists do not address at all: natural selection. Selection for higher fertility seems inevitable to me and I suspect we are already seeing signs of it (e.g. the rise of religious groups that are totally immune to the fertility-lowering effects of modern civilization). I do not see how technology will solve that without dictatorial power to alter which genes get passed on to offspring.
Did you know that the international body that regulates thoroughbred racing lifted its ban against clones in 2012? Secretariat could ride again. Thoroughbreds aren't getting any faster. How boring.
Faster is better. I would like to see new race horses bred using many horse breeds rather than just thoroughbreds. Next I'd like to sequencing of millions of horses to identify genetic variants that are purely harmful. This is known as genetic load. Then do extensive genetic testing and sequencing of the edited cell lines to make sure no bad genetic edit happened.
What would be ways better: Identify all the genetic load mutations in a group of fertile humans. Then edit out the genetic load of their embryos. The result would be super humans. Super humans would be brilliant and extremely healthy.
In another 10 or so years might be a lower risk way to cut down genetic load in humans: Take dozens of sample skin cells from a man, preferably from areas with little sun exposure (so less genetic damage from the sun). Grow up each sample in a separate cell culture. Genetically test cells from each culture to identify the least genetically damaged ones. To the ones with little genetic damage do CRISPR genetic editing to get rid of every known harmful mutation (and in 10 yearrs we will know thousands of harmful mutations if not more). Then turn the cells into sperm cells. The babies would have no paternal genetic load.
Your own cells genetically edited in culture to fix all their genetic load mutations would have another big benefit: They'd be great starting points for creating cell therapies. Send in new muscle cell precursors that can function better than your own muscles did when you were young. Grow a better kidney, liver, or pancreas than you ever had. Fix whatever has given you a skin condition, an easily upset stomach, or easily injured tendons. The cell therapies would be like a software update embedded in a hardware update.
In Kunming China scientists are genetically editing macaque monkey embryos to create genetic variants of interest to study. Since monkeys have many genes in common with humans this work will also accelerate the rate at which we figure out how human genes work.
The Chinese scientists used the fairly new and highly disruptive CRISPR gene editing technique (and that article surveys a number of enhancements to CRISPR that make it more accurate). Since CRISPR makes it much easier to do to do germ line genetic engineering there is a strong possibility that it will eventually be used to do human germ line genetic engineering. Since we all have hundreds (or more?) genetic variations that are each mildly harmful we could create much more highly functional, healthier, and more robust humans if we could edit out all those harmful genetic variants in the genes we pass on to progeny.
The plunging costs of genome sequencing is producing an explosion in the number of genetic variants of interest. Cheap and easy genome editing with CRISPR will make it possible to study interactions of combinations of genetic variants.
Click thru and read all about it.
Five people who suffered serious leg injuries have been able to regrow muscle tissue in their legs thanks to a new regenerative medicine treatment.
In a major advance, researchers at the University of Washington have successfully restored damaged heart muscle of monkeys using heart cells created from human embryonic stem cells.
A key piece of their advance: They were able to grow up much larger numbers of cells, 10 times more than have been used in previous therapy development attempts.
The researchers found that over subsequent weeks, the stem-cell derived heart muscle cells infiltrated into the damaged heart tissue, then matured, assembled into muscle fibers and began to beat in synchrony with the macaque heart cells. After three months, the cells appear to have fully integrated into the macaque heart muscle.
On average the transplanted stem cells regenerated 40 percent of the damaged heart tissue, said Laflamme, UW assistant professor of pathology, whose team was principally responsible for generating the replacement heart muscle cells.
I wonder whether any of these cells integrated with leg and arm muscles. Could we rejuvenate aged muscles just by injecting large numbers of stem cells?