Michael Fossel Michael is President of Telocyte

October 10, 2017

Should everyone respond the same to telomerase?

A physician friend asked if a patient’s APOE status (which alleles they carry, for example APOE4, APOE3, or APOE2) would effect how well they should respond to telomerase therapy. Ideally, it may not make much difference, except that the genes you carry (including the APOE genes and the alleles for each type of APOE gene, as well as other genes linked to Alzheimer’s risk) determine how your risk goes up with age. For example, those with APOE4 alleles (especially if both are APOE4) have a modestly higher risk of Alzheimer’s disease (and at a lower age) than those with APOE2 alleles (expecially if both are APOE2).

Since telomerase doesn’t change your genes or the alleles, then while it should reset your risk of dementia to that of a younger person, your risk (partly determined by your genes) would then operate “all over again”, just as it did before. Think of it this way. If it took you 40 years to get dementia and we reset your risk using telomerase, then it might take you 40 years to get dementia again. If it took you 60 years to get dementia and we reset your risk using telomerase, then it might take you 60 years to get dementia again. It wouldn’t remove your risk of dementia, but it should reset your risk to what it was when you were younger. While the exact outcomes are still unknown, it is clear is that telomerase shouldn’t get rid of your risk, but it might be expected to reset that risk to what it was several years (or decades) before you were treated with telomerase. Your cells might act younger, but your genes are still your genes, and your risk is still (again) your risk.

The same could be said for the rate of response to telomerase therapy. How well (and how quickly) a patient should respond to telomerasse therapy should depend on how much damage has already occurred, which (again) is partially determined by your genes (including APOE genes and dozens of others). Compared to a patient with APOE2 alleles (the “good” APOE alleles), we might expect the clinical response for a patient with APOE4 alleles (the “bad” APOE alleles) to have a slightly slower respone to telomerase, a peak clinical effect that was about the same, and the time-to-retreatment to be just a big shorter. The reality should depend on how fast amyloid plaques accumulates (varying from person to person) and how fast we might be able to remove the plaque (again, probably varying from person to person). The vector (slope of the line from normal to onset of dementia) should be slightly steeper for those with two APOE4 alleles than for two APOE3 alleles, which would be slightly steeper than for two APOE2 alleles. Those with unmatched alleles (APOE4/APOE2) should vary depending upon which two alleles they carried.

To give a visual idea of what we might expect, I’ve added an image that shows the theoretical response of three different patients (a, b, and c), each of whom might respond equally well to telomerase therapy, but might then need a second treatment at different times, depending on their genes (APOE and other genes) and their environment (for example, head injuries, infections, diet, etc.). Patient c might need retreatment in a few years, while patient a might not need retreatment for twice as long.


September 20, 2017

Genes and Aging

Several of you have asked why I don’t update this blog more often. My priority is to take effective interventions for age-related diseases to FDA phase 1 human trials, rather than blogging about the process. Each week, Outlook reminds me to update the blog, but there are many tasks that need doing if we are going to get to human trials, which remains our primary target.

In working on age-related disease, however, I am reminded that we can do very little unless we understand aging. Most of us assume we already understand what we mean by aging, but our assumptions prevent us from a more fundamental and valid understanding of the aging process. In short, our unexamined assumptions get in the way of effective solutions. To give an analogy, if we start with the assumption that the Earth is the center of the solar system, then no matter how carefully we calculate the orbits of the planets, we will fail. If we start with the assumption that the plague results from evil spirits rather than Yersinia pestis, then no matter how many exorcisms we invoke, we will fail. We don’t fail because of any lack of effort, we fail because of misdirected effort.

Our assumptions define the limits of our abilities.

When we look at aging, too often we take only a narrow view. Humans age, as do all the mammals and birds (livestock and pets come to mind) that have played common roles in human culture and human history. When most people think of aging, they seldom consider trees, hydra, yeast, bacteria, or individual cells (whatever the species). Worse, even when we do look at these, we never question our quotidian assumptions. We carry our complacent assumptions along with us, a ponderous baggage, dragging us down, restricting our ability to move ahead toward a more sophisticated (and accurate) understanding. If we looked carefully, we would see that not all cells age and not all organisms age. Moreover, of those that age, not all organisms age at the same rate and, within an organism, not all cells age at the same rate. In short, neither the rate of aging, nor aging itself is universal. As examples, dogs age faster than humans and, among humans, progeric children age faster than normal humans. The same is true when we consider cells: somatic cells age faster than stem cells, while germ cells (sperm and ova) don’t age at all. So much for aging being universal.

The key question isn’t “why do all things age?”, but rather “why does aging occur in some cases and not in others, and at widely different rates when it occurs at all?” The answer certainly isn’t hormones, heartbeats, entropy, mitochondria, or free radicals, for none of these can explain the enormous disparity in what ages and what doesn’t, nor why cells age at different rates. Nor is aging genetic in any simplistic sense. While genes play a prominent role in how we age, there are no “aging genes”. Aging is not a “genetic disease”, but rather a matter of epigenetics – it’s not which genes you have, but how those genes are expressed and how their expression changes over time, particularly over the life of the organism or over multiple cell divisions in the life of a cell. In a sense, you age not because of entropy, but because your cells downregulate the ability to maintain themselves in the face of that entropy. Cell senescence effects a broad change in gene expression that results in a gradual failure to deal with DNA repair, mitochondrial repair, free radical damage, and molecular turnover in general. Aging isn’t a matter of damage, it’s a matter of no longer repairing the damage.

All of this wouldn’t matter – it’s mere words and theory – were it not for our ability to intervene in age-related disease. Once we understand how aging works, once we look carefully at our assumptions and reconsider them, our more accurate and fundamental understanding allows suggests how we might cure age-related disease, to finally treat the diseases we have so long thought beyond our ability. It is our ability to see with fresh eyes, to look at all organisms and all cells without preconceptions, that permits us to finally do something about Alzheimer’s and other age-related disease.

Only an open mind will allow us to save lives.


January 17, 2017

Intuition and Air Planes

The formulation of a problem is often more essential than its solution, which may be merely a matter of mathematical or experimental skill. To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and marks real advances in science.

— Albert Einstein, 1938


Most “advances” are purely incremental. We make minor advances in current techniques or technology, we marginally improve our existing surgery or drugs, or we precisely define the specifications of previously known molecules. Rarely do we develop a novel technology, an unprecedented therapy, or a distinctively new theory. Truly innovative, unexpected, and compelling changes require that – as Einstein said – we “regard old problems from a new angle.” Genuine advances in science don’t require experimental skill, they require conceptual creativity.

Advances require us to look at things in an entirely new way.

Our ability to cure age-related diseases, such as Alzheimer’s, does not depend on incremental improvements, but on exactly such changes in how we look at things. The same, it turns out, is true of aging and – oddly enough – telomeres. We automatically view the world through our preconceptions, and this has always been true. Upon seeing the world’s first automobile, and unable to grasp the idea of a “horseless carriage”, we asked where the horse was attached. Upon seeing the world’s first television, and unable to grasp the idea of an electron tube, we asked how tiny people fit into that television cabinet. We continually look at new things, but we see them using old eyes.

As an analogy, imagine a group of castaways who have spend years trapped on a large, unexplored, tropical island. Two of the castaways are exploring an unfamiliar beach, when they come upon a large, entirely unexpected, and unfamiliar object. The first castaway, a bright academic, carefully measures the dimensions of every single part of the object. She tells the rest of the castaways about her measurements and they present her with an award for her hard work. To some acclaim, she explains that the unknown object might actually prove useful: the castaways could use it to 1) hang up their laundry, 2) provide shade from the hot tropical sun, and, 3) offer shelter during tropical storms. The second castaway has a more intuitive and creative bent. He carefully looks over the object, announces that it’s a plane, and offers to fly it off the island and save their lives.

Small Jet Plane

Sometimes, it’s not the measurements, it’s the ability to see new possibilities.

In the case of aging and age-related diseases, the odd thing is that most people don’t see how anything can be done. They still want to hang their laundry on the wings of the plane, without realizing that the airplane can fly them to safety. At best, they concede that aging might be slowed down, perhaps with diet, exercise, stress management, and other behavioral changes. The idea that aging can be reversed, or that age-related diseases can be cured, is anathema to their thinking, despite the solid evidence in cells, tissues, and animal studies. I first described the potential of telomeres for clinical therapy 20 years ago and the evidence has been growing steadily since then, yet the general public, the media, and many academics still think of telomeres as a place to hang laundry, provide shade, and offer shelter from the rain. Is it really that hard to recognize a plane? Apparently so.

It would appear that the only way to show people what telomeres can do is to fly the plane and safe lives.


December 29, 2016

The Ethics of Gene Therapy for Alzheimer’s Disease

The Ethics of Telomerase Treatment


The rationale behind telomerase therapy was first published in the medical literature two decades ago1 and has been updated and supported in academic textbooks2 and a more recent book for the public3 as well. The theoretical basis was cogent, even twenty years ago, and evidence has continued to support the hypothesis since then, in human cells, in human tissues, in informal human trials, and in formal animal trials. The potential implications of telomerase interventions in human age-related disease are unprecedented, well-supported, consistent, and feasible. The surprise is not that this approach is practical, but that it has taken so long to get telomerase therapy into clinical trials.

The reasons for the delay are complex and subtle, but are part of human nature.

For one thing, the clinical use of telomerase requires a novel and more sophisticated understanding of the aging process itself – at the genetic and epigenetic level – than has been the case until recently. Whenever a new scientific paradigm comes into play – whether a geocentric solar system, biological evolution, quantum mechanics, relativity, or anything else – it takes time for us to outgrow previous, less accurate models and to accept a more complex, but more accurate understanding of reality. Reality is not a democracy and a consensus is no guarantee of truth.

Putting it bluntly: old theories never die, their proponents do.

A second problem is credibility. In the case of telomerase clinical trials, there have been a number of cases in which individuals or companies (impatient with the regulatory delays so common in modern drug development) have attempted “end runs” of social and regulatory acceptance. Unfortunately (and perhaps unfairly), these off-shore human trials are often judged as lacking credibility and this can also undercut the credibility of other attempts. If a company evades the FDA (or the accepted regulatory agencies in other countries, such as the EMA or CFDA) and runs small off shore trials their results are not only specifically disbelieved, but result in general disbelief, even of serious biotech endeavors that DO attempt to meet FDA requirements. Moreover, the companies that attempt “end runs” often seek publicity and the outcome can be a perception that while there is significant publicity, that’s all there is. Unfairly or accurately, the academic judgement becomes one of “incredible claims, but no credible data”. Fair or unfair, just or unjust, such is human nature and such is the nature of clinical research in today’s world.

A third problem is a general misunderstanding of the role of telomerase in cancer. Telomerase never causes cancer, although small amounts can be necessary to permit cancer. More striking, however, is the role of telomerase in genomic stability: telomerase upregulates DNA repair, drastically lowering the risk of cancer. Dividing cells – including cancer cells – require at least minimal telomerase, yet a significant presence of telomerase (and sufficiently long telomeres) is protective against cancer. Some have even suggested that cancer is a disease of the young, and attribute it to the presence of telomerase, but the clinical reality is that cancer increases exponentially with age and that this increase is directly attributable to the down-regulation of DNA repair due to telomere shortening. In short, telomerase can be used to prevent cancer.

A fourth problem is a naïve conception of the pathology that underlies Alzheimer’s disease (and other age-related diseases). Citing data on mice, genetically altered to express a human amyloid protein, they extrapolate the results to human Alzheimer’s patients without appreciating the complex cascade of pathology that actually occurs in humans, let alone the differences between mice and human patients.

Finally, some people argue with the ethics of treating Alzheimer’s disease in clinical trials at all, let alone by using gene therapy. One wonders whether they have ever spend a year or two watching a loved one slide down into the abyss. I have known hundreds, perhaps thousands, of Alzheimer’s patients and their family members. Almost without exception, most would do literally anything, try literally anything in an effort to find a cure. The pity of AD is that it is 100% fatal and there is NO effective therapy – at the moment. While few of us would risk an experimental gene therapy (even one as promising at telomerase) to treat wrinkles or osteoporosis (particularly since neither one is fatal), all of us would consider such therapy to treat Alzheimer’s disease. It is scarcely surprising that scarcely a day goes by without someone contacting me, asking about potential treatments for Alzheimer’s disease. These are not people who live in ivory towers, these are not people with a “degree in microbiology”, these are people who are deeply and personally affected by the tragedy.

They’ve BEEN there. They UNDERSTAND.

One critic of gene therapy noted that: “there are 7 patients killed by gene therapy clinical trials” (over the past 20 years). Compare this with the seven hundred thousand Alzheimer’s patients who died in 2016 alone of not having had gene therapy. Why would I choose to be one of 700,000 deaths per year?

For those of us who have spent decades treating dying patients, for those of us who have Alzheimer’s disease, and for those of us who are terrified by what is happening to those we love who have Alzheimer’s disease, the ethics of using gene therapy to try curing the most frightening disease on earth are clear enough.

The ethical weight lies on the side of compassion.



  1. Fossel: Reversing Human Aging (1996) . Banks and Fossel: Telomeres, cancer, and aging – Altering the human lifespan (JAMA, 1997). Fossel: Telomerase and the aging cell – Implications for human health (JAMA, 1998).
  2. Fossel: Cells, Aging, and Human Disease (Oxford University Press, 2004).
  3. Fossel: The Telomerase Revolution (BenBella Press, 2015).

November 22, 2016

Teaching Cells to Fish

Aging is the slowing down of active molecular turnover, not the passive accumulation of damage. Damage certainly accumulates, but only because turnover is no longer keeping up with that damage.

It’s much like asking why one car falls apart, when another car looks like it just came out of the showroom. It’s not so much a matter of damage (although if you live up north and the road salt eats away at your undercarriage, that’s another matter), as it is a matter of how well a car is cared for. I’ve see an 80-year-old Duesenberg that looks a lot better than my 4-year-old SUV. It’s not how well either car was made, nor how long either car has been around, but how well each car was cared for. If I don’t care for my SUV, my SUV rusts; if a car collector gives weekly (even daily) care to a Duesenberg, then that Duesenberg may well last forever.

The parallel is apt. The reason that “old cells” fall apart isn’t that they’ve been around a long time, nor even that they are continually being exposed to various insults. The reason “old cells” fall apart is that their maintenance functions slow noticeably and that maintenance fails to keep up with the quotidian damage occurring within living cells. If we look at knees, for example, the reason that our chondrocytes fail isn’t a matter of how many years you’ve been on the planet, nor even a matter of how many miles a day you spend walking around. The reason chondrocytes fail is because their maintenance functions slow down and stop keeping up with the daily damage. As it turns out, that deceleration in maintenance occurs because of changes in gene expression, which occur because telomeres shorten, which occur because cells divide. And, not at all surprisingly, the number of those cell divisions is related to how long you’ve been on the planet (how old you are) and how many miles you walk (or if you play basketball). In short, osteoarthritis is distantly related to your age and to the “mileage” you incur, but not directly so. The problem is not really the age nor is it the mileage; the problem is the failure to repair the routine damage and THAT failure is directly controlled by changes in gene expression.

So what?

The telomeres and gene expression may play a central role, but if your age and the “mileage” is distantly causing all those changes in cell division, telomere lengths, gene expression, and failing cell maintenance, then what’s the difference? Why bother with all the complexity? Why not accept that age and your “mileage” are the cause of aging diseases and stop fussing? Why not simply accept age-related disease?

Because we can change it.

The question isn’t “why does this happen?” so much as “what can we do about it?” We can’t change your age and it’s hard to avoid a certain amount of “mileage” in your daily life, but we CAN change telomeres, gene expression, and cell maintenance. In fact, we can reset the entire process and end up with cells that keep up with damage, just as your cells did when you were younger.

Until now, everyone who has tried to deal with only the damage (or the damaged cells) failed because they focused on damage rather than focusing on repair. For example, if you focus only on cell damage (as most big pharma and biotech companies do when they go after beta amyloid or tau proteins in trying to cure Alzheimer’s disease), then any clinical effect is transient and the disease continues to progress – which is why companies like Eli Lily, Biogen, TauRx, and dozens of other companies are frustrated. And small wonder. Or if you focus only on the damaged cells (and try removing them), then the clinical effect is not only transient, but will end up accelerating deterioration (as discussed in last week’s blog, see figure below) – which is why companies like Unity will be frustrated. Their approaches fail not because they don’t address the damage, but because they fail to understand the deceleration of dynamic cell maintenance that occurs with age – and fail to understand the most effective single clinical target. The key target is not damage, nor damaged cells, but the changes in gene expression that permit that damage, and those damaged cells, to lead to pathology. We can’t cure Alzheimer’s or osteoarthritis by removing senescent cells, but we can cure them by resetting those same cells.

Why you shouldn't kill senescent cells.

Why you shouldn’t kill senescent cells.

In the cases of removing senescent cells (an approach Unity advocates), wouldn’t it be better to remove the damaged cells and then reset the telomeres of those that remain? But why remove the damaged cells if you can reset them as well, with the result that they can now deal with the damage and remove it – as well as young cells do?

Why remove senescent cells at all?

While you could first remove senescent cells, then add telomerase so that the remaining cells could divide without significant degradation of function, why would you bother? You could much more easily, more simply, and more effectively treat all the cells in an aging tissue, reset their aging process and have no need to ever remove senescent cells in the first place. Instead of removing them, you simply turn them into “younger” and more functional cells. For an analogy, imagine that we have a therapy that could turn cancer cells into normal cells. If that were true, why would anyone first surgically remove a tumor? If you could really “reset” cancer cells into normal cells, there would be no need to do a surgical removal in the first place. While there is no such therapy for cancer cells, the analogy is still useful. Removing senescent cells is not only counter-productive, but (if we reset gene expression) entirely unnecessary.

Removal is unnecessary (both as to cost and pathology), risky, and medically contraindicated. You’d be performing a completely unnecessary procedure when a more cost-effective and reliable procedure was available. It would be exactly like removing your tonsils if you already had overwhelming data showing that an antibiotic was reliable, cheap, and without risk.

A cell with full telomere lengths – regardless of prior history – is already superior. The accumulated damage is not a static phenomenon, but a dynamic one. Reset cells can clean up damage. This is not merely theory, but supported well in fact, based on both human cells and whole animal studies. We shouldn’t think of damage as something that merely accumulates passively. All molecules are continually being recycled. The reason some molecular pools show increased damage isn’t because molecules denature, but because the rate of turnover slows, thereby allowing denatured molecules (damage) to increase within the pool.

Try this analogy: we have two buildings. One is run by a company that invests heavily in maintenance costs, the other is run by a company that cut its maintenance budget by 50%. The first building is clean and well-kept, the second building is dirty and poorly-kept. Would you rather raze the second building and then rebuild it or would you rather increase the maintenance budget back to a full maintenance schedule and end up with a clean building? This is precisely the case with young versus old cells: the problem is not the dirt that accumulates, the problem is that no one is paying for routine maintenance. There are cells that are “too senescent” to save, but almost all the cells in human age-related disease can be reset with good clinical outcome. There is no reason to remove senescent cells any more than (in the case of a dirty building), we need to send in the dynamite and bulldozers.

Too often, we try to approach the damage rather than looking at the longer view. Instead of addressing the process, we address the outcome. It’s like the problem that often occurs in global philanthropy, where we see famine and think we can solve the problem with food alone. While the approach is necessary – as a stopgap – many are surprised to find that simply providing free food for one year, results in bankrupt farmers and recurrent famines in the following years. Or we provide free medical care in a poor nation, then wonder why there is a dearth of medical practitioners in years to come, without realizing we have put them out of business and accidentally encouraged them to emigrate to someplace they can make a living and feed their families. We intend well, but we perpetuate the problem we are desperately trying to solve. Treating famine or medical problems, like treating the fundamental causes of age-related disease, is not simple and cannot be effectively addressed with band aids and superficial interventions, such as addressing damage alone or removing senescent cells. Effective clinical intervention – like effective interventions in famine or global healthcare – require a sophisticated understanding of the complexity of cell function, an understanding of the dynamic changes that underlie age-related pathology.

An adage (variously attributed to dozens of sources) about fish and fishing provides a useful analogy here:

Give a man a fish, and you feed him for a day.

Teach a man to fish, and you feed him for a lifetime.

If we want to intervene effectively in age-related diseases – whether Alzheimer’s, osteoarthritis, or myriad other problems of aging – we shouldn’t throw fish at medical problems.

We should teach our cells to fish.


November 8, 2016

Revolution in Medicine

Every pharmaceutical firm, every biotech company, every hospital, every clinic, and every conference makes revolutionary claims, albeit seldom with any logic or thought behind the claims. Every product is a “revolutionary” therapy, every surgery is a “revolutionary” procedure, and everyone has a “revolutionary” way of looking at clinical medicine. Reality is strikingly different. Despite claims to the contrary, almost all advances in medicine are accretionary, not revolutionary. About sixty percent of all FDA applications for “breakthrough” status are turned down for not being breakthroughs, but merely incremental advances (if that). Even granting a third of these applications is overly kind, but then breakthroughs, like revolutions, are remarkably rare. I am reminded of my years consulting for hospitals around the world, where I was entertained to find every hospital, in every town, in every country, bragging that they were ranked as “one of the best ten hospitals!” Sometimes, they bragged that they were THE best hospital. Somehow, it appears that thousands of hospitals are among the best ten hospitals and hundreds are THE best hospital. In the entire world or on that block?

It clearly depends on who’s counting and on who does the ranking.

Therapies are much the same: they are seldom “the best” (in the world?) and they are almost never revolutionary. To the contrary, almost all current therapy is based on incremental change: we find a slightly better statin, an antibiotic with slightly less resistance (at least this year), and a procedure with a slightly lower risk. We rank our interventions by statistical significance and we deal with percentage points in the adverse effect profile. Scarcely the stuff of revolution.

We can do better; much better. To do so, however, requires both an open mind and a very disciplined one. We need both creativity and intelligence to envision a path to revolutionary therapies. If we do so, we may be able to cure diseases that are thought to be “incurable”, a true revolution I both clinical thinking and clinical practice.

Many people, in a totally practical vein, think of diseases in three categories. The first includes those diseases that we have “cures” for, by means of vaccines, antibiotics, and routine surgeries (think of tetanus, cellulitis, and appendicitis). The second category includes diseases for which we have no cure yet, but for which we see a cure on the horizon (think of treating sickle cell anemia with gene therapy). This second category includes type 1 diabetes: while we use insulin to good effect, we eagerly imagine the days when we simply replace the missing cells in the pancreas and truly cure diabetes. While we have – or imagine that we may soon have – true cures for these diseases in both the first two categories, the third category brings a sense of futility. When it comes to age-related disease (think of Alzheimer’s disease, cardiovascular disease, osteoporosis, etc.), we are caught up by the assumption that while we can treat symptoms, use grafts or stents, lower the risk factors, or replace the damaged part (a total knee replacement comes to mind), we will never be able to entirely prevent or cure the underlying disease. After all, they’re simply the outcome of aging, yes? And who could possibly change the aging process?

Oddly enough, we already have.

We first showed we could reverse cell aging in 1999, followed by the reversal of tissue aging (in the laboratory) in the following few years. The question isn’t “can we reverse the aging process in human cells or tissues”, but “can we reverse the aging process in human patients”? Can we take someone with age-related disease, treat them, and reverse the disease reverse at the cellular and genetic levels? Can we prevent and cure age-related disease? Based on both theory and animal data, the answer is almost certainly to be “yes, we can”. All it requires is intelligence, a modicum of work, and a small commitment of funding.

Instead of treating Alzheimer’s as something to live with, we can treat it and have it be something we can live without. Only then we will have a true revolution.

November 1, 2016

Making Things Worse

Imagine a factory which is operating at capacity, with a thousand workers. Some of the workers are doing a great job, but some are ill and not working hard. In fact, they are actively interfering with those who are working hard. In this factory, you can’t hire anyone new, so you have two choices: you can fire the bad workers or you try to improve their health. If you simply fire the bad workers, you have increased the work load for those who remain. Not surprisingly, they begin to get tired and ill as well, so the factory ends up failing even faster and before you know it, everyone is out of a job. On the other hand, if you can improve the health (and the attitude) of the workers who are tired and ill, the factory can become a success.

The factory is human tissue; the workers are your cells.

Let’s look at an example, such as the cells in your knee. Over time, the chondrocytes divide, become gradually more senescent, and begin to fail. The result is osteoarthritis. If you have mild osteoarthritis, you might (naively) consider simply removing senescent cells. This reliefs some of the inflammation and removes the cells that aren’t doing a good job (the tired workers), but the result is that you’ve just asked all the remaining cells to take up the slack (increased the work load for the remaining factory workers). In order to replace the cells that you’ve removed, the remaining cells now have to divide, which accelerates their own senescent changes, and hastens the failure of the entire tissue. In the case of the knee joint, the osteoarthritis improves temporarily, but you’ve just accelerated osteoarthritic changes in the long run. Instead of a slow joint failure, you’ve ensured that it fails even faster.

Several people have, in a charming burst of innocence, recommended that we do just that. Instead of resetting senescent cells and restoring cell and tissue function, they want to remove senescent cells in older tissues. Their hope is understandable, but their understanding is simplistic. Studies show that you may see temporary improvement in inflammation and secretory profiles, but what about long term risks? The problem is that those who want to kill off senescent cells lack a full appreciation of the dynamic pathology and the cellular consequences. They offer a simplistic view, but biology is seldom simplistic.

Why you shouldn't kill senescent cells.

Why you shouldn’t kill senescent cells.


Consider the knee again. A common concern is that of chondrocyte senescence (leading to osteoarthritis) in professional basketball players. Because of repetitive high-impact trauma, they lose chondrocytes at an accelerated rate compared to people whose knees are not subject to traumatic cell loss. The remaining chondrocytes divide to replace the lost chondrocytes, accelerating telomere loss, and accelerating osteoarthritic changes. The clinical result is due to tissue failure at an early age.

Those who are trying to treat tissue senescence by selectively removing senescent cells (instead of resetting them to a normal pattern of gene expression) are causing a transient improvement in tissue function, coincident upon the removal of dysfunctional, senescent cells (temporarily decreasing inflammatory biomarkers, for example), but the longer-term result is to accelerate cell senescence in all remaining cells. The result is a transient hiatus in inflammation and other biomarkers of cell senescence, followed by a more rapid decline in cell and tissue function. In the case of OA, for example, the outcome is to relief symptoms temporarily, only to then ensure a more rapid failure of the joint.

Our analogy remains apt. If you have a group of workers in a factory, some of whom are suffering from fatigue and are no longer producing, you have two possible interventions. Intervention #1 might be to fire all the tired workers, but the long-term result is that you increase the workload and failure rate among the remaining workers. Intervention #2 would be to find a way to restore the energy and interest among those workers who are fatigued. The analogy is a loose one, but the outcomes are predictable. Removing the “tired” cells within a tissue will accelerate pathology. Resetting the “tired” cells within a tissue will resolve pathology.

If you want to cure age-related disease, the solution is not to kill senescent cells, but to reset their gene expression to that of young cells.


August 8, 2016

Regenerative Medicine: What Is It? Where Is It Going?

What is regenerative medicine?

To bystanders, regenerative medicine might be merely a catch-all category or simply a current medical fashion. The reality, however, is that regenerative medicine represents a conceptual, material, and historical transformation of human medical care. Even the key researchers and clinicians who are moving this field ahead are often so busy in advancing the technology that they are less aware of the extraordinary changes that they represent, changes that are about to change the face of human medicine forever.

Regenerative medicine has marked differences, both conceptual and concrete differences, when compared to previous approaches to clinical intervention. These differences not only define the field, but they point our way to future progress and, frankly, to improvements in our health and in our lives.

The conceptual key is that regenerative medicine results in long-term (rather than transient) clinical improvements. Regenerative medicine is just that: an intervention that re-generates. Effective regenerative interventions change the body itself – and not merely a set of biomarkers or symptoms. Bluntly, regenerative medicine aims to improve biological function, rather than merely attempting to normalize abnormal biomarkers or symptoms of biological dysfunction. Even admitting the often impressive utility and efficacy of our standard medical interventions to date – for certainly we have come a long way in our ability to treat human disease – such approaches act as pharmacological Band-Aids. In contrast, regenerative medicine seeks to optimize the underlying genetic, cellular, and tissues processes that go awry.

Nor is this the only conceptual difference, for the time course is equally different. Standard clinical interventions generally have transient effects, for example in modifying inflammation, cholesterol, glucose levels, etc., while regenerative interventions generally have long-term (even permanent) changes to tissue and organ function. When most standard interventions may last for hours to days, regenerative interventions may last for years to decades. Even “definitive” surgical approaches (CABG, joint replacements, etc) have no effect upon the underlying disease process and are often merely recurrent stopgaps. Why replace an artificial joint (every decade or so), if we can possibly regrow a normal joint that might last a lifetime?

At its conceptual core, regenerative medicine offers us a more accurate and enlightened view of biological function. Regenerative medicine encompasses a view of biology that is active and dynamic, a view in which we aim to alter the processes rather than the products of biology. Consider diabetes, in which a regenerative approach strives to recreate normal islet cell function, where standard approaches strive to manage glucose levels. The difference is critical to understanding the efficacy of regenerative medicine: it views pathology as a dynamic process and aims to alter the process itself, rather than focusing on the products of such processes and aiming to alter the clinical results of those processes. The same pertains to surgical interventions in which regenerative medicine aims to alter the process of joint failure, rather than the product of joint failure. Regenerative medicine would regenerate a normal joint, where standard approaches implant an artificial joint.

Essentially, regenerative medicine aims to reset biological processes to those of a normal, healthy body.

The material features of regeneration medicine are equally distinctive. Instead of employing what are current called “small molecular” approaches, regenerative medicine uses “large molecular” approaches, generally by employing genes, stem cells, and other large biological structures. We might legitimately include immunization in this category: it not only employs a large biological structure (i.e.., an active virus or a complex set of antibodies), but it also results in a long-term change to the organism (i.e., improved immunity). Contrast this approach to the more common “small molecular” approach, typified by the use of non-steroidal anti-inflammatories, statins, blood pressure medications, antibiotics, etc. While many such molecules are fairly complex and certainly not simple, nor are they large-scale biological structures such as viral vectors, plasmids, genes, or stem cells.

Regeneration medicine is typified by two common approaches: genes and cells. In either case, these interventions are large and active biological structures rather than small and passive chemical structures. Genes and cells do not merely interact with biological structures, they ARE biological structures. They not only interact with genes and cells, they ARE genes and cells.

The historical perspective on regenerative medicine is enlightening. What can the past tell us and what does the future hold? An apt historical analogy is that of infectious disease, particularly when we compare antibiotics and immunization. No one would be so naïve as to underestimate the value of antibiotics, but nor should we underestimate the limits of antibiotics. Faced with most viral infections, such as polio, tetanus, or diphtheria, antibiotics are ineffective. Those same viral infections are readily preventable, however, by immunization, using large and active biological structures (whether antigens or live virus).

Immunization is essentially a form of regenerative medicine, in that it results in a long-term change in the human body, a change that results in long-term health. The one difference is that immunizations don’t “re-generate” so much as they “generate” a healthier organism. Nonetheless, the similarity in addressing basic biological functions, in having a long-term effect, and in using large, active biological structures places immunization an historical forerunner for regenerative medicine. Consider a further analogy, that of Ebola. During the height of the Ebola epidemic, small molecular approaches (IV fluid, pressor support, etc) were useful, but far from optimal. Only an effective Ebola vaccine promises to lower the fatality rate into the single digit percent range. In viral infections (as we look backwards) and for the entirety of medicine (as we look forward) standard small molecular approaches are simply not good enough.

Such is the past, but what of the future? Our current standards of medical care cannot reasonably be considered optimal standards of care. We can do better, but only by moving to a regenerative approach. The upcoming standards of medical care will encompass two main approaches: genetic interventions and cellular interventions. In the first case, we will deliver both genes meant to replace pathologic genes and genes that are intended to reset gene expression. In the second case, we will deliver cells that are meant to replace pathologic (or absent) cells.

Genetic interventions encompass both genetic and epigenetic optimization. While the bulk of interest is currently focused on gene changes, remember that genes that regulate expression are far more important than genes that express proteins, both clinically and in terms of percentage of genes in our genome (we have 10-20 times more regulatory genes than we have protein-expressing genes). Although 20th century medicine has made dramatic inroads in our understanding of genes and disease, it remains to the 21st century to move into the far more difficult – and more important – task of understanding patterns of gene expression. In short, it is not genetics, but epigenetics that will prove to be the key to medical interventions. Viral delivery, telomere effects, cell senescence, and a host of other factors will define what we will soon be capable of. We have scarcely begun to enter this complex and confusing field.

Cellular interventions encompass a spectrum of cells, from somatic cells to pluripotent stem cells – and the entire gamut in between those extremes. It has become clear that pluripotent stem cells need not derive from fetal sources, but equally clear that our understanding of the complex path from stem cell to somatic cell is still inadequate – although increasing by the month.

Using an historical perspective to project forward, we begin to see where we can – finally – begin to address diseases that we have long ignored as being “facts of life”, such as the diseases of aging. Although public understanding (indeed, even academic understanding) lags behind the tantalizing and growing data, there is mounting evidence that we will be able to slow, stop, prevent, and even reverse diseases that we have no current treatment for. Consider, for example, osteoporosis. Until now, we have had no therapy that alters the clinical course that begins in the aging osteocyte and the bony matrix. Likewise, our treatment for osteoarthritis, joint replacement, may have value to the patient, but is an admission of failure when we realize that we have no therapy that alters the clinical course of this pathology, that begins in the aging chondrocyte and its matrix either. Arterial disease, Alzheimer’s disease, and a host of other diseases, almost all of which appear to be linked to basic cellular-related aging processes, are fast becoming viable targets for the advances of regenerative medicine.

From a purely practical perspective, how will a regenerative approach change medical care? Currently, medicine is – to a large extent – organized by organ (nephrology, neurology, cardiology, dermatology, etc.), although with an overlay based on the type of intervention (surgical versus medical). At the moment, regenerative medicine is something of a step-child, although gaining traction yearly. Although the approach is innovative, the tools themselves are adaptable within the current framework of medical specialties. There is, for instance, no reason that gene or cell therapy cannot be adopted by and adapted to most current medical specialties, a process that will come to completion within the coming two decades. Regenerative medical techniques equally become the intervention-of-choice for the pulmonologist, the gastroenterologist, or the endocrinologist. For medical specialties, regenerative medicine is an approach which is largely specialty-agnostic.

Surgical specialties, however, will fare a bit differently: where is the need for cardiovascular or orthopedic surgical approaches when we can regenerate both normal coronary arteries and normal joints? Over the next two decades, the face of surgical practice will change rapidly and will lose many of the most common procedures, as regenerative medicine makes effective inroads. Yet there will remain a place for both standard medical care (small molecular drugs) and for surgical procedures, even within a transformed medical landscape. The landscape will continue to change, requiring rapid adaptation for specialties and their practitioners as our knowledge and our capacity to intervene evolve.

Ultimately – if the word is even remotely appropriate to the future of medicine – medical care will still be left with two prongs: a medical approach that fixes the genetic, epigenetic, and cellular problems and a surgical approach that deals with acute, externally imposed disasters, such as trauma. The role of the first specialty will be to deal with non-emergent and known problems at cellular levels. The role of the second specialty will be to deal with emergent and largely unpredictable problems at the organ (rather than cellular) level. The parallel with the modern division between medicine and surgery is apt, but the tools will have evolved, as will the ability to not merely ameliorate, but actually cure disease and to optimize health.

If we are to define regenerative medicine, we might best understand its conceptual underpinnings, its materially different approach, or the historical inflection point that it now represents. In the venue of human disease, regenerative medicine thinks differently, uses different tools, and represents an historic sea-change. Looking at it practically, however, the most striking feature – and perhaps the defining feature – of regenerative medicine is that it offers all of us a more compassionate and a far more effective medical future.

This article is cross-posted at Regenera Global: http://bit.ly/2aMPKIq


July 20, 2016

Curing Disease: More Insight Instead of Mere Effort


Curing disease correlates with insight, not blind effort.

There is an eternal trade-off between insight and effort. If we think carefully, understand the problem, and plan, then effort is minimized. If (as too often happens) we think carelessly, misunderstand the problem, and rely on hope instead of planning, then effort is not only maximized, but is usually a complete waste. Lacking insight, we foolishly flush both money and effort down the drain. In the case of clinical trials for Alzheimer’s disease – and in fact, all age-related diseases – this is precisely the case.

The major problem is a naïve complaisance that we already understand aging pathology.

If there was a single concept that is key to all of aging, it is the notion that everything in our organs, in our tissues, and in our cells is dynamically and actively in flux, rather than being a set of organs, tissues, cells, and molecules that statically and passively deteriorate. Aging isn’t just entropy; aging is entropy with insufficient biological response. Senescent cells no longer keep up with entropy, while young cells manage entropy quite handily. At the tissue level, the best example might be bone. We don’t form just bone and then leave it to the mercy of entropy, rather we continually recycle bony tissue throughout our lives – although more-and-more slowly as our osteocytes lose telomere length. This is equally true at the molecular level, for example the collagen and elastin molecules in our skin. We don’t finish forming collagen and elastin in our youth and then leave it to the vagaries of entropy, rather we continually recycle collagen and elastin molecules throughout our lives, although more-and-more slowly as our skin cells lose telomere length. Aging is not a process in which a fixed amount of bone, collagen, or elastin gradually erodes, denatures, or becomes damaged. Rather, aging is a process in which the rate of recycling of bone, collagen, or elastin gradually slows down as our shortening telomeres alter gene expression, slowing the rate of molecular turnover, and allowing damage to get ahead of the game. We don’t age because we are damaged, we age because cells with shortening telomeres no longer keep up with the damage.

The same is true not only of biological aging as a general process, but equally true of every age-related disease specifically. Vascular disease is not a disease in which our arteries are a static tissue that gradually gives way to an erosive entropy, but an active and dynamic set of cells that gradually slow their turnover of critical cellular components, culminating in the failure of endothelial cell function, the increasing pathology of the subendothelial layer, and the clinical outcomes of myocardial infarction, stroke, and a dozen other medical problems. Merely treating cholesterol, blood pressure, and hundreds of other specific pathological findings does nothing to reset the epigenetic changes that lie upstream and that cause those myriad changes. Small wonder that we fail to change the course of arterial disease if our only interventions are merely “stents and statins”.

Nor is Alzheimer’s a disease in which beta amyloid and tau proteins passively accumulate over time as they become denatured, resulting in neuronal death and cognitive failure. Alzheimer’s is a disease in which the turnover – the binding, the uptake, the degradation, and the replacement – of key molecules gradually slows down with telomere shortening, culminating in the failure of both glial cell and neuron function, the accumulation of plaques and tangles, and ending finally in a profound human tragedy. The cause is the change in gene expression, not the more obvious plaques and tangles.

Our lack of insight, even when we exert Herculean efforts – enormous clinical trials, immense amounts of funding, and years of work – is striking for a complete failure of every clinical trial aimed at Alzheimer’s disease. Naively, we target beta amyloid, tau proteins, phosphodiesterase, immune responses, and growth factors, without ever understanding the subtle upstream causes of these obvious downstream effects. Aging, aging diseases, and especially Alzheimer’s disease are not amenable to mere well-intended efforts. Without insight, our funding, our time, and our exertions are useless. Worse yet, that same funding time, and exertion could be used quite effectively, if used intelligently. If our target is to cure the diseases of aging, then we don’t need more effort, but more thought. However well intentioned, however much investment, however many grants, and however many clinical trials, all will be wasted unless we understand the aging process. Aging is not a passive accumulation of damage, but an active process in which damage accumulates because cells change their patterns of gene expression, patterns which can be reset.

Curing Alzheimer’s requires insight and intelligence, not naive hope and wasted effort.



May 12, 2016

Telomeres: Are They Worth Measuring?

It’s funny how often we make assumptions that are not only wrong, but that we are completely unaware of making. Having spent more than twenty years dealing with the clinical implications of cell aging, telomeres come to mind as an immediate example of this mistake.

Hardly a week goes by without another claim that some particular intervention alters telomere lengths in human patients. Without exception, they are measuring telomeres in peripheral white blood cells. It’s easy to get blood samples and measure telomeres in circulating white cells. Unfortunately, not only are these telomeres the ones that matter least, but (if you’re trying to prove the value of your intervention) they’re almost worthless.

Measuring telomeres in your blood to see how old you are is a bit like looking at your hat size to figure out how tall you are. Whether it’s your peripheral blood telomeres or your hat size, it’s still the wrong measurement for the job.

There are two problems with measuring telomeres in blood cells (even totally ignoring arguments about technical methods, unreliable laboratories, and the mean length versus the shortest lengths of those telomeres).

The first problem is that the blood cells aren’t the key cells when it comes to aging and age-related diseases. If you really want to know where you stand clinically, you should be measuring the telomeres in the endothelial cells lining your coronary arteries, the glial cells in your brain, the chondrocytes in your joints, or several other places more closely related to the most common (and fatal) aging diseases. Few of us are willing to have biopsies taken from our coronary arteries, our brain, or our joints, but just because we are a lot more relaxed about giving a blood sample doesn’t mean that the blood sample is worth getting. It barely reflects what’s going on in your white cells, let alone what is going to end up causing disease and death.

The second problem is a more subtle, but more important. It boils down to this: most of your white cells aren’t circulating in your blood and the ones that do circulate are changing and dividing all the time, making them a poor reflection of what’s happening to the stem cells in your marrow. I wrote an academic review article about this in 2012 and discussed it in The Telomerase Revolution, but let’s look at it here. Imagine you can instantly and accurately measure every telomere in the body, including those in the bone marrow and peripheral venous circulation. Oddly enough, you’d discover that the blood tests aren’t reliable indicators of what’s happening in the marrow.

Let’s say that you measure all of the telomeres at time A and again at time B. In between A and B, you use an intervention such as gene therapy, TA65, mediation, dietary change, or whatever you think might be effective. At time A, you find that the telomeres in the hematopoietic cells of the marrow are 12 kbp long. At the same time (due to stress, infection, poor diet, inflammation, and generally poor health habits) there is rapid peripheral turnover, cell division, and telomere loss in the peripheral blood. As a result, the mean telomere length in the blood sample is only 8 kbp.

We then intervene.

At time B, you find that the telomeres in the hematopoietic stem cells in the marrow are now only 11 kbp long (showing that the patient has gotten older). Also at time B, since we might now have lowered stress, removed infections, decreased inflammation, and generally made the patient “healthier” with whatever intervention we may have chosen, their peripheral cells are now turning over more slowly, dividing less frequently, and losing less telomere lengths once they leave the marrow and enter peripheral circulation, so that the mean telomere length in the peripheral blood sample is now 9 kbp.

We could claim (as many articles do) that our clinical intervention “lengthened the peripheral telomeres!” The truth is that our intervention didn’t lengthen anything and we’re deluding ourselves (and whoever believes our claims). The peripheral telomeres that we sample at time B might be longer than the ones we sampled at time A, but the telomeres of the cells back in the marrow now have shorter telomeres. Our intervention may well have made the patient healthier and we might actually have slowed down the rate of telomere loss, but we definitely didn’t lengthen any telomeres, no matter how proudly we pat ourselves on the back.

Peripheral leukocytes are routinely used to assess telomere lengths (which is fine as far as it goes) and then used to assess clinical interventions, which is overreaching. If we do serial measures of peripheral telomeres every few months for a few years, then the validity will increase somewhat, but peripheral telomere measurements (no matter how often you measure them) are intrinsically an unreliable and invalid biomarker for what we really want to assess, which is “whole body telomere changes” or at least “marrow telomere changes” (in the case of blood cells).

Most of the available literature which suggests that we can slow or reverse telomere losses is – if it’s based on peripheral blood samples – misleading at best and unethical at worst.

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