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.]
Alida de Flamingh and her team are collecting elephant dung. It holds a trove of information about animal health, diet and genetic diversity.
Approximately 27 percent of mammals and 28 percent of all assessed species are close to dying out. The IUCN Red List of threatened species, simply called the Red List, is the world’s most comprehensive record of animals’ risk of extinction status. The more information scientists gather, the better their chances of reducing those risks. In Africa, populations of vertebrates declined 69 percent between 1970 and 2022, according to the World Wildlife Fund (WWF).
“We put on sterile gloves and use a sterile swab to collect wet mucus and materials from the outside of the dung ball,” says Alida de Flamingh, a postdoctoral researcher at the University of Illinois Urbana-Champaign.
“When people talk about species, they often talk about ecosystems, but they often overlook genetic diversity,” says Christina Hvilsom, senior geneticist at the Copenhagen Zoo. “It’s easy to count (individuals) to assess whether the population size is increasing or decreasing, but diversity isn’t something we can see with our bare eyes. Yet, it’s actually the foundation for the species and populations.” DNA analysis can provide this critical information.
Assessing elephants’ health
“Africa’s elephant populations are facing unprecedented threats,” says de Flamingh, the postdoc, who has studied them since 2009. Challenges include ivory poaching, habitat destruction and smaller, more fragmented habitats that result in smaller mating pools with less genetic diversity. Additionally, de Flamingh studies the microbial communities living on and in elephants – their microbiomes – looking for parasites or dangerous microbes.
Approximately 415,000 elephants inhabit Africa today, but de Flamingh says the number would be four times higher without these challenges. The IUCN Red List reports African savannah elephants are endangered and African forest elephants are critically endangered. Elephants support ecosystem biodiversity by clearing paths that help other species travel. Their very footprints create small puddles that can host smaller organisms such as tadpoles. Elephants are often described as ecosystems’ engineers, so if they disappear, the rest of the ecosystem will suffer too.
There’s a process to collecting elephant feces. “We put on sterile gloves (which we change for each sample) and use a sterile swab to collect wet mucus and materials from the outside of the dung ball,” says de Flamingh. They rub a sample about the size of a U.S. quarter onto a paper card embedded with DNA preservation technology. Each card is air dried and stored in a packet of desiccant to prevent mold growth. This way, samples can be stored at room temperature indefinitely without the DNA degrading.
Earlier methods required collecting dung in bags, which needed either refrigeration or the addition of preservatives, or the riskier alternative of tranquilizing the animals before approaching them to draw blood samples. The ability to collect and sequence the DNA made things much easier and safer.
“Our research provides a way to assess elephant health without having to physically interact with elephants,” de Flamingh emphasizes. “We also keep track of the GPS coordinates of each sample so that we can create a map of the sampling locations,” she adds. That helps researchers correlate elephants’ health with geographic areas and their conditions.
Although de Flamingh works with elephants in the wild, the contributions of zoos in the United States and collaborations in South Africa (notably the late Professor Rudi van Aarde and the Conservation Ecology Research Unit at the University of Pretoria) were key in studying this method to ensure it worked, she points out.
Protecting chimpanzees
Genetic work with chimpanzees began about a decade ago. Hvilsom and her group at the Copenhagen Zoo analyzed DNA from nearly 1,000 fecal samples collected between 2003 and 2018 by a team of international researchers. The goal was to assess the status of the West African subspecies, which is critically endangered after rapid population declines. Of the four subspecies of chimpanzees, the West African subspecies is considered the most at-risk.
In total, the WWF estimates the numbers of chimpanzees inhabiting Africa’s forests and savannah woodlands at between 173,000 and 300,000. Poaching, disease and human-caused changes to their lands are their major risks.
By analyzing genetics obtained from fecal samples, Hvilsom estimated the chimpanzees’ population, ascertained their family relationships and mapped their migration routes.
“One of the threats is mining near the Nimba Mountains in Guinea,” a stronghold for the West African subspecies, Hvilsom says. The Nimba Mountains are a UNESCO World Heritage Site, but they are rich in iron ore, which is used to make the steel that is vital to the Asian construction boom. As she and colleagues wrote in a recent paper, “Many extractive industries are currently developing projects in chimpanzee habitat.”
Analyzing DNA allows researchers to identify individual chimpanzees more accurately than simply observing them, she says. Normally, field researchers would install cameras and manually inspect each picture to determine how many chimpanzees were in an area. But, Hvilsom says, “That’s very tricky. Chimpanzees move a lot and are fast, so it’s difficult to get clear pictures. Often, they find and destroy the cameras. Also, they live in large areas, so you need a lot of cameras.”
By analyzing genetics obtained from fecal samples, Hvilsom estimated the chimpanzees’ population, ascertained their family relationships and mapped their migration routes based upon DNA comparisons with other chimpanzee groups. The mining companies and builders are using this information to locate future roads where they won’t disrupt migration – a more effective solution than trying to build artificial corridors for wildlife.
“The current route cuts off communities of chimpanzees,” Hvilsom elaborates. That effectively prevents young adult chimps from joining other groups when the time comes, eventually reducing the currently-high levels of genetic diversity.
“The mining company helped pay for the genetics work,” Hvilsom says, “as part of its obligation to assess and monitor biodiversity and the effect of the mining in the area.”
Of 50 toucan subspecies, 11 are threatened or near-threatened with extinction because of deforestation and poaching.
Identifying toucan families
Feces aren't the only substance researchers draw DNA samples from. Jeffrey Coleman, a Ph.D. candidate at the University of Texas at Austin relies on blood tests for studying the genetic diversity of toucans---birds species native to Central America and nearby regions. They live in the jungles, where they hop among branches, snip fruit from trees, toss it in the air and catch it with their large beaks. “Toucans are beautiful, charismatic birds that are really important to the ecosystem,” says Coleman.
Of their 50 subspecies, 11 are threatened or near-threatened with extinction because of deforestation and poaching. “When people see these aesthetically pleasing birds, they’re motivated to care about conservation practices,” he points out.
Coleman works with the Dallas World Aquarium and its partner zoos to analyze DNA from blood draws, using it to identify which toucans are related and how closely. His goal is to use science to improve the genetic diversity among toucan offspring.
Specifically, he’s looking at sections of the genome of captive birds in which the nucleotides repeat multiple times, such as AGATAGATAGAT. Called microsatellites, these consecutively-repeating sections can be passed from parents to children, helping scientists identify parent-child and sibling-sibling relationships. “That allows you to make strategic decisions about how to pair (captive) individuals for mating...to avoid inbreeding,” Coleman says.
Jeffrey Coleman is studying the microsatellites inside the toucan genomes.
Courtesy Jeffrey Coleman
The alternative is to use a type of analysis that looks for a single DNA building block – a nucleotide – that differs in a given sequence. Called single nucleotide polymorphisms (SNPs, pronounced “snips”), they are very common and very accurate. Coleman says they are better than microsatellites for some uses. But scientists have already developed a large body of microsatellite data from multiple species, so microsatellites can shed more insights on relations.
Regardless of whether conservation programs use SNPs or microsatellites to guide captive breeding efforts, the goal is to help them build genetically diverse populations that eventually may supplement endangered populations in the wild. “The hope is that the ecosystem will be stable enough and that the populations (once reintroduced into the wild) will be able to survive and thrive,” says Coleman. History knows some good examples of captive breeding success.
The California condor, which had a total population of 27 in 1987, when the last wild birds were captured, is one of them. A captive breeding program boosted their numbers to 561 by the end of 2022. Of those, 347 of those are in the wild, according to the National Park Service.
Conservationists hope that their work on animals’ genetic diversity will help preserve and restore endangered species in captivity and the wild. DNA analysis is crucial to both types of efforts. The ability to apply genome sequencing to wildlife conservation brings a new level of accuracy that helps protect species and gives fresh insights that observation alone can’t provide.
“A lot of species are threatened,” Coleman says. “I hope this research will be a resource people can use to get more information on longer-term genealogies and different populations.”