A birthday celebration in the future for someone reaching 150 years old.
Dr. Michael West has a storied legacy in the world of aging research. Twenty years ago, the company he started, Geron, hit upon a major breakthrough when his scientists isolated the active component for the gene that confers immortality to cells, called telomerase.
In the twenty years since, a new field has emerged: the science of extending the human "healthspan."
He was in the lab when scientists for the first time artificially turned on the gene in some skin cells donated by Dr. Leonard Hayflick, the man who had discovered back in 1965 that human cells age over time. Sure enough, with Geron's intervention, Hayflick's skin cells became immortal in the dish, and the landmark paper was published in Science in 1998.
In the twenty years since, a new field has emerged: the science of extending the human "healthspan" – the length of time people can live free of diseases related to aging. A substantial amount of preclinical and some clinical research is now underway, backed by heavy investments from some of the world's largest companies.
Today, Dr. West is the CEO of AgeX Therapeutics, a biotech company that is developing novel therapeutics to target human aging and age-related degenerative diseases using pluripotent stem cells. Dr. West recently shared some key insights with Editor-in-Chief Kira Peikoff about what's happening in this exciting space.
1) Pluripotent stem cells have opened the door for the first time in human history to manufacturing young cells and young tissue of any kind.
These are the body's master cells: They are self-replicating, and they can potentially give rise to any cell or tissue the body needs to repair itself. This year marks the 20th anniversary since their isolation for the first time in a lab.
"People in biotech say that the time from lab to discovery in products is about 20 years," West says. "But the good news is we're at that 20-year mark now, so you're seeing an explosive growth of applications. We can now make all cell types of the human body in a scalable manner."
2) Early human development could hold the key to unlocking the mystery of aging.
West believes that two things occur when the body forms in utero: telomerase, the immortalizing gene, gets turned off very early in development in the body cells like skin, liver, and nerves. Additionally, he thinks that a second genetic switch gets turned off that holds the potential for regeneration after injury.
"These insights open the door to intervention by the transfer of telomerase into the cells of the body."
"Very early when the body is first forming, if you cut the skin, it will not respond by scarring, but will regenerate scarlessly," he says. "But that potential gets turned off once the body is formed, about 8 weeks after fertilization. Then, you accumulate damage over a lifetime. Not only do cells have a finite capacity to replicate, but you have tissue damage."
However, there are animals in nature whose telomerase is never turned off, or whose regenerative ability is never turned off. The flatworm, for example, can regenerate its own head if it gets cut off, and it also shows no detectable aging. Lobsters are believed to be similar. (That's not to say it can't get caught and eaten for dinner.)
"These insights open the door to intervention by the transfer of telomerase into the cells of the body, or understanding how regeneration gets turned off, and then turning it back on," West says. "That's well within the power of modern medical research to understand."
3) Companies are investing tremendous resources into the anti-aging gold rush.
Devising interventions is the mission of AgeX, a subsidiary of BioTime, as well as a number of other companies.
"We're seeing a mad rush," West says. There's Google's Calico, which recently announced, with AbbVie Inc., another $1 billion into research for age-related diseases, on top of the previous $1.5 billion investment.
Other notable players include Unity Biotechnology, Samumed, Human Longevity Inc., RestorBio, Rejuvenate Bio,and Juvenescence (which is also an investor in AgeX).
"These are products in development by our company and others that the baby boomers can reasonably anticipate being available within their lifetimes."
4) The majority of clinical applications are still years away.
"What we've learned about turning back on this regenerative state, called induced tissue regeneration, is that the majority of the clinical implications are years away and will require years of clinical trials before potential FDA approval and marketing to the public," West says. "But we have found some potential near-term applications that we think may have a much faster track to commercialization. As you can imagine, we are all over those."
BioTime, Inc., AgeX's parent, has a regenerative medicine product in clinical trials for age-related macular degeneration, the leading cause of blindness in an aging population. While not yet approved by the FDA, BioTime has reported continued progress in the clinical development of the product now in Phase II trials.
Citi recently issued a major report, Disruptive Innovations VI, that included "Anti-Aging Medicines" as the number two innovation for investors to keep an eye on, and predicted that the first anti-aging therapies could receive regulatory approval by 2023.
5) Few, if any, medical interventions are available today that are proven to markedly slow aging - yet. But the Baby Boomers are not necessarily out of luck.
Buyer beware of any claims in the marketplace that a given skin cream or stem cell product will extend your life. More than likely, they won't.
"There are a lot of people trying to cash in on the aging baby boom population," West warns.
"When you hear claims of stem cell products that you can get now, it's important to understand that they are likely not based on pluripotent stem cell technology. Also, they are usually not products approved by the FDA, having gone through clinical trials to demonstrate safety and efficacy."
However, an array of young pluripotent stem cell-derived therapies are on a development track for future approvals.
One example is another program at AgeX: the manufacture of brown fat cells; these cells burn calories rather than store them. They burn circulating fat like triglycerides and sugar in the blood and generate heat.
"You lose brown fat in aging, and animal models suggest that if you restore that tissue, you can restore a metabolic balance to be more like what you had when you were young," says West. "When I was 18, I could drink milkshakes all day long and not gain an ounce. But at 50 or 60, most of us would rapidly put on weight. Why? We believe that one important factor is that with age, you lose this brown fat tissue. The loss throws your metabolism off balance. So the solution is conceptually simple, we plan to make young brown fat cells for transplantation to reset the balance, potentially to treat Type II diabetes or even obesity.
"These are products in development by our company and others that the baby boomers can reasonably anticipate being available within their lifetimes."
6) There is an ethical debate about how far to apply this new science.
Some people are speculating about whether genetic engineering might one day be used to program longer lifespans into humans at the earliest stages of development. (Note: it is against the law across the Western world to edit human embryos intended for reproduction, although just last week, Chinese scientists used CRISPR to repair a disease-causing mutation in viable human embryos.)
West sounds a cautionary note about such interventions meant to lengthen life. "For people who think not just about the science, but the ethics, safety is a major concern. It's entirely possible to genetically engineer babies, but when you make such modifications, it's an experiment, not just in human cells in a dish, but in a human being. I have a great reticence to put any human at risk unless it's a case where the person is suffering with a life-threatening disease, and the potential therapy is their last best hope."
"I have no doubt, zero doubt, that in the foreseeable future, we'll hear of a person who has lived to about 150."
7) The biggest challenge of intervening in human aging is cultural denial.
"The prospect of intervening in a profound way in human aging is still not seen as credible by the vast majority of thoughtful people around the world," West laments.
"Aging is a universal phenomenon, it's mankind's greatest enemy, but as a species we've adapted to the realities of finite lifespans and death. We have a whole infrastructure of belief systems around this, and many people see it as inevitable."
8) The lifespan for healthy children born today could surpass anything humanity has ever seen.
"It is at least 150 years of age," West predicts. "I have no doubt, zero doubt, that in the foreseeable future, we'll hear of a person who has lived to about 150. We know now it's possible. I've never said that publicly before, but I am comfortable now with the prediction. And, of course, if some people now living could live to 150 years of age, we have the prospect of them living to see even more powerful therapies. So, the question now is, what kind of a world are we going to make for future generations?"
[Editor's Note: Check out our latest video, which was inspired by Dr. West's exclusive prediction to leapsmag.]
Indigenous people in Australia dig pits next to a honeypot colony. Scientists think the honey can be used to make new antimicrobial drugs.
These hunts have become rarer, as many of the Tjupan people have moved away and, up until now, the exact antimicrobial properties of the ant honey remained unknown. But recently, scientists Andrew Dong and Kenya Fernandes from the University of Sydney, joined Ulrich, who runs the Honeypot Ants tours in Kalgoorlie, a city in Western Australia, on a honey-gathering expedition. Afterwards, they ran a series of experiments analyzing the honey’s antimicrobial activity—and confirmed that the Indigenous wisdom was true. The honey was effective against Staphylococcus aureus, a common pathogen responsible for sore throats, skin infections like boils and sores, and also sepsis, which can result in death. Moreover, the honey also worked against two species of fungi, Cryptococcus and Aspergillus, which can be pathogenic to humans, especially those with suppressed immune systems.
In the era of growing antibiotic resistance and the rising threat of pathogenic fungi, these findings may help scientists identify and make new antimicrobial compounds. “Natural products have been honed over thousands and millions of years by nature and evolution,” says Fernandes. “And some of them have complex and intricate properties that make them really important as potential new antibiotics. “
In an era of growing resistance to antibiotics and new threats of fungi infections, the latest findings about honeypot ants are helping scientists identify new antimicrobial drugs.
Danny Ulrich
Bee honey is also known for its antimicrobial properties, but bees produce it very differently than the ants. Bees collect nectar from flowers, which they regurgitate at the hive and pack into the hexagonal honeycombs they build for storage. As they do so, they also add into the mix an enzyme called glucose oxidase produced by their glands. The enzyme converts atmospheric oxygen into hydrogen peroxide, a reactive molecule that destroys bacteria and acts as a natural preservative. After the bees pack the honey into the honeycombs, they fan it with their wings to evaporate the water. Once a honeycomb is full, the bees put a beeswax cover on it, where it stays well-preserved thanks to the enzymatic action, until the bees need it.
Less is known about the chemistry of ants’ honey-making. Similarly to bees, they collect nectar. They also collect the sweet sap of the mulga tree. Additionally, they also “milk” the aphids—small sap-sucking insects that live on the tree. When ants tickle the aphids with their antennae, the latter release a sweet substance, which the former also transfer to their colonies. That’s where the honey management difference becomes really pronounced. The ants don’t build any kind of structures to store their honey. Instead, they store it in themselves.
The workers feed their harvest to their fellow ants called repletes, stuffing them up to the point that their swollen bellies outgrow the ants themselves, looking like amber-colored honeypots—hence the name. Because of their size, repletes don’t move, but hang down from the chamber’s ceiling, acting as living feedstocks. When food becomes scarce, they regurgitate their reserves to their colony’s brethren. It’s not clear whether the repletes die afterwards or can be restuffed again. “That's a good question,” Dong says. “After they've been stretched, they can't really return to exactly the same shape.”
These replete ants are the “treat” the Tjupan women dug for. Once they saw the round-belly ants inside the chambers, they would reach in carefully and get a few scoops of them. “You see a lot of honeypot ants just hanging on the roof of the little openings,” says Ulrich’s mother, Edie Ulrich. The women would share the ants with family members who would eat them one by one. “They're very delicate,” shares Edie Ulrich—you have to take them out carefully, so they don’t accidentally pop and become a wasted resource. “Because you’d lose all this precious honey.”
Dong stumbled upon the honeypot ants phenomenon because he was interested in Indigenous foods and went on Ulrich’s tour. He quickly became fascinated with the insects and their role in the Indigenous culture. “The honeypot ants are culturally revered by the Indigenous people,” he says. Eventually he decided to test out the honey’s medicinal qualities.
The researchers were surprised to see that even the smallest, eight percent concentration of honey was able to arrest the growth of S. aureus.
To do this, the two scientists first diluted the ant honey with water. “We used something called doubling dilutions, which means that we made 32 percent dilutions, and then we halve that to 16 percent and then we half that to eight percent,” explains Fernandes. The goal was to obtain as much results as possible with the meager honey they had. “We had very, very little of the honeypot ant honey so we wanted to maximize the spectrum of results we can get without wasting too much of the sample.”
After that, the researchers grew different microbes inside a nutrient rich broth. They added the broth to the different honey dilutions and incubated the mixes for a day or two at the temperature favorable to the germs’ growth. If the resulting solution turned turbid, it was a sign that the bugs proliferated. If it stayed clear, it meant that the honey destroyed them. The researchers were surprised to see that even the smallest, eight percent concentration of honey was able to arrest the growth of S. aureus. “It was really quite amazing,” Fernandes says. “Eight milliliters of honey in 92 milliliters of water is a really tiny amount of honey compared to the amount of water.”
Similar to bee honey, the ants’ honey exhibited some peroxide antimicrobial activity, researchers found, but given how little peroxide was in the solution, they think the honey also kills germs by a different mechanism. “When we measured, we found that [the solution] did have some hydrogen peroxide, but it didn't have as much of it as we would expect based on how active it was,” Fernandes says. “Whether this hydrogen peroxide also comes from glucose oxidase or whether it's produced by another source, we don't really know,” she adds. The research team does have some hypotheses about the identity of this other germ-killing agent. “We think it is most likely some kind of antimicrobial peptide that is actually coming from the ant itself.”
The honey also has a very strong activity against the two types of fungi, Cryptococcus and Aspergillus. Both fungi are associated with trees and decaying leaves, as well as in the soils where ants live, so the insects likely have evolved some natural defense compounds, which end up inside the honey.
It wouldn’t be the first time when modern medicines take their origin from the natural world or from the indigenous people’s knowledge. The bark of the cinchona tree native to South America contains quinine, a substance that treats malaria. The Indigenous people of the Andes used the bark to quell fever and chills for generations, and when Europeans began to fall ill with malaria in the Amazon rainforest, they learned to use that medicine from the Andean people.
The wonder drug aspirin similarly takes its origin from a bark of a tree—in this case a willow.
Even some anticancer compounds originated from nature. A chemotherapy drug called Paclitaxel, was originally extracted from the Pacific yew trees, Taxus brevifolia. The samples of the Pacific yew bark were first collected in 1962 by researchers from the United States Department of Agriculture who were looking for natural compounds that might have anti-tumor activity. In December 1992, the FDA approved Paclitaxel (brand name Taxol) for the treatment of ovarian cancer and two years later for breast cancer.
In the era when the world is struggling to find new medicines fast enough to subvert a fungal or bacterial pandemic, these discoveries can pave the way to new therapeutics. “I think it's really important to listen to indigenous cultures and to take their knowledge because they have been using these sources for a really, really long time,” Fernandes says. Now we know it works, so science can elucidate the molecular mechanisms behind it, she adds. “And maybe it can even provide a lead for us to develop some kind of new treatments in the future.”
