Michael Fossel Michael is President of Telocyte

February 13, 2018

Aging and Disease: 1.2 – Aging, What We Have to Explain

Our understanding is limited by our vision.

If we look locally, our understanding is merely local; if we look globally, our understanding becomes more global; and if we look at our entire universe, then our understanding will be universal. When we attempt to understand our world, we often start with what we know best: our own, local, provincial view of the world around us, and this limits our understanding, particularly of the wider world beyond our local horizon.

Trying to explain the shape of our world, I look at the ground around me and – perhaps not surprisingly – conclude that the world is probably flat. After all, it looks flat locally. Trying to understand the heavens, I look up at the sky around me and – perhaps not surprisingly – conclude that the sun circles the earth. After all, the sun appears to circle over me locally. Trying to understand our physical reality, I look at everyday objects and – perhaps not surprisingly – conclude that “classical physics” accounts for my universe. After all, classical physics accounts for typical objects that are around me locally. As long as we merely look around, look up, and look at quotidian objects, these explanations appear sufficient.

But it is only when we look beyond our purely local neighborhood – when we move beyond our provincial viewpoint, when we give up our simple preconceptions – that can we begin to understand reality. Taking a broader view, we discover that the Earth is round, that the sun is the center of our local star system, and that quantum and relativity physics are a minimum starting point in trying to account for our physical universe.

To truly understand requires that we step back from our parochial, day-to-day, common way of seeing world and open our minds to a much wider view of reality. We need to look at the broader view, the larger universe, the unexpected, the uncommon, or in the case of modern physics, the extremely small and the extremely fast. Time, mass, energy, and other concepts may become oddly elusive and surprisingly complicated, but our new understanding, once achieved, is a lot closer to reality than the simple ideas we get from restricting our vision to the mere commonplace of Newtonian physics. This is true of for branch of science, and for human knowledge generally.

The wider we cast our intellectual nets, the more accurately we understand our world.

To understand aging demands a wide net. If our knowledge of aging is restricted to watching our friends and neighbors age, then our resulting view of aging is necessarily naïve and charmingly unrealistic. If we expand our horizons slightly, to include dogs, cats, livestock, and other mammals, then we have a marginally better view of aging. But even if we realize that different species age at different rates, our understanding is only marginally less naive. To truly understand aging, we need to look at all of biology. We need to look at all species (not just common mammals), all diseases (e.g., the progerias and age-related diseases in all animals), all types of organisms (e.g., multicellular and unicellular organims, since some multicellular organisms don’t age and some unicellular organisms do age), all types of cell within organisms (since somatic cells age, germ cells don’t, and stem cells appear to lie in between the two extremes), and all the cellular components of cells. In short, to understand aging – both what aging is and what aging isn’t – we need to look at all life, all cells, and all biological processes.

Only then, can we begin understand aging.

To open our minds and examine the entire spectrum of aging – so that we can begin to understand what aging is and how to frame a consistent concept of “aging” in the first place – let’s contrast the small sample we would examine in the narrowest, common view of aging with the huge set of biological phenomena we must examine if we want to gain comprehensive and accurate view of aging, a view that allows us to truly understand aging.

The narrow view, the most common stance in considering aging, examines aging as we encounter it in normal humans (such as people we know or people we see in the media) and in normal animals (generally pets, such as dogs and cats, and for some people, domesticated animals, such as horses, cattle, pigs, goats, etc.). This narrow view leaves out almost all species found on our planet. This sample is insufficient to make any accurate statements about the aging process, with the result that most people believe that “everything ages”, “aging is just wear and tear”, and “nothing can be done about aging”. Given the narrow set of data, none of these conclusions are surpring, but then it’s equally unsurprising that all of these conclusion are mistaken.

A broad view has a lot more to take into consideration (see Figure 1), which is (admittedly) an awful lot of work. The categories that we need to include may help us see how broad an accurate and comprehensive view has to be. We need to examine and compare aging:

  1. Among all different organisms,
  2. Within each type of organism,
  3. Among all different cell types, and
  4. Within each type of cell.

 

Lets look at these categories in a bit more detail.

When we look at different organisms, we can’t stop at humans (or even just mammals). We have to account for aging (and non-aging) in all multicellular organisms, including plants, lobsters, hydra, naked rats, bats, and everything else. And not only do we need to look at all multicellular organisms, we also need to account for aging (and non-aging) in all unicellular organisms, including bacteria, yeast, amoebae, and everything else. In short, we need to consider every species.

When we look within organisms, we need to account for all age-related diseases (and any lack of age-related diseases or age-related changes) within organisms. Diseases will include all human (a species that is only one tiny example, but that happens to be dear to all of us) age-related diseases, such as Alzheimer’s disease and all the other CNS age-related diseases, arterial aging (including coronary artery disease, strokes, aneurysms, peripheral vascular disease, cogestive heart failure, etc.), ostoarthritis, osteoporosis, immune system aging, skin aging, renal aging, etc. But we can’t stop there by any means. In addition to age-related diseases within an organism, we need to look at aging changes (and non-aging) whether they are seen as diseaeses or not, for example graying hair, wrinkles, endocrine changes, myastenia, and hundreds of other systemic changes in the aging organism.

When we look at different cells, we need to account for the fact that some cells (e.g., the germ cell lines, including ova and sperm) within multicellular organisms don’t age, while other cells in those same organims (e.g., most somatic cells) do age, and some cells (e.g., stem cells) appear to be intermediate between germ and somatic cells in their aging changes.

When we look within cells, we need to account for a wild assortment of age-related changes in the cells that age, while accounting for the fact that other cells may show no such changes, even in the same species and the same organism. In cells that age – cells that senesce – we need to account for telomere shortening, changes in gene expression, methylation (and other epigenetic changes), a decline in DNA repair (including all four “families” of repair enzymes), mitochondrial changes (including the efficacy of aerobic metabolism enzymes deriving from the nucleus, leakier mitochondrial lipid membranes, increases in ROS production per unit of ATP, etc.), decreased turnover of proteins (enzymatic, structural, and other proteins), decreased turnover of other intracellular and extracellular molecules (lipids, sugars, proteins, and mixed types of molecules, such as glycoproteins, etc.), increased accumulation of denatured molecules, etc. The list is almost innumerable and still growing annually.

If we are truly to understand aging, we cannot look merely at aging humans and a few aging mammals, then close our minds and wave our hands about “wear and tear”. If we are to understand aging accurately and with sophistication, then we must not only look at a broader picture, but the entire picture. In short, to understand aging, we must stand back all the way in both time and space, and look at all of biology.

To understand aging, we must understand life.

January 23, 2018

Aging and Disease: 0.1 – A Prologue

Aging and Disease

0.1 – A Prologue

Over the past 20 years, I have published numerous articles, chapters, and books explaining how aging and age-related disease work, as well as the potential for intervention in both aging and age-related disease. The first of these publications was Reversing Human Aging (1996), followed by my articles in JAMA (the Journal of the American Medical Association) in 1997 and 1998. Twenty years ago, it was my fervent hope that these initial forays, the first publications to ever describe not only how the aging process occurs, but the prospects for effective clinical intervention, would trigger interest, growing understanding, and clinical trials to cure age-related disease. Since then, I have published a what is still the only medical textbook on this topic (Cells, Aging, and Human Disease, 2004), as well as a more recently lauded book (The Telomerase Revolution, 2015) that explains aging and disease, as well as how we can intervene in both. While the reality of a clinical intervention has been slow to come to fruition, we now have the tools to accomplish those human trials and finally move into the clinic. In short, we now have the ability to intervene in aging and age-related disease.

Although we now have the tools, understanding has lagged a bit for most people. This knowledge and acceptance have been held back by any number of misconceptions, such as the idea that “telomeres fray and the chromosomes come apart” or that aging is controlled by telomere length (rather than the changes in telomere lengths). Academics have not been immune to these errors. For example, most current academic papers persist in measuring peripheral blood cell telomeres as though such cells were an adequate measure of tissue telomeres or in some way related to the most common age-related diseases. Peripheral telomeres are largely independent of the telomeres in our coronary arteries and in our brains and it is our arteries and our brains that cause most age-related deaths, not our white blood cells. The major problem, howevere, lies in understanding the subtlety of the aging process. Most people, even academics, researchers, and physicians, persist in seeing aging as mere entropy, when the reality is far more elusive and far more complex. Simplistic beliefs, faulty assumptions, and blindly-held premises are the blinders that have kept us powerless for so long.

It is time to tell the whole story.

While my time is not my own – I’d rather begin our upcoming human trials and demonstrate that we can cure Alzhiemer’s disease than merely talk about all of this – I will use this blog for a series of more than 30 mini-lectures that will take us all the way from “chromosomes to nursing homes”. We will start with an overview of aging itself, then focus in upon what actually happens in human cells as they undergo senesceence, then finally move downstream and look at how these senescent changes result in day-to-day human aging and age-relate disease. In so doing, when we discuss cell aging, we will get down into the nitty-gritty of ROS, mitochondria, gene expression, leaky membranes, scavenger molecules, molecular turnover, collagen, beta amyloid, mutations, gene repair, as well as the mathematics of all of this. Similarly, when we discuss human disease, we will get down into the basic pathology of cancer, atherosclerosis, Alzheimer’s, osteoporosis, osteoarthritis, and all “the heart-ache and the thousand natural shocks that flesh is heir to”. We will look at endothelial cells and subendothelial cells, glial cells and neurons, osteoclasts and osteoblasts, fibroblasts and keratinocytes, chondrocytes, and a host of other players whose failure results in what we commonly think of aging.

I hope that you’ll join me as we, slowly, carefully, unravel the mysteries of aging, the complexities of age-related disease, and the prospects for effective intervention.

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.

 

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