AGINGSCIENCES™ – Anti-Aging Firewalls™

This post is about a relatively older but still-interesting line of research linking the human hormone alpha-melanocyte-stimulating hormone (alpha-MSH) to reduction of inflammation.  Melanocytes are cells which produce the pigment melanin which gives color to the skin, eyes and hair.   In the blog post, More research insight on gray hair and adult stem cell reproduction I discussed how declining numbers of melanocyte stem cells is responsible for the hair of older people turning white or gray.  Melanocytes are found in multiple body tissues in addition to hair follicles, including the skin, meninges, bone and heart.  The role of alpha-MSH in activating  activate melanocytes has been extensively studied for some time(ref)(ref)(ref).  Alpha-MSH is produced in the pituitary gland, in neural cells, monocytes and certain types of skin cells.  For example, consider suntan.  When ultraviolet radiation impacts on keratinocytes, the keratinocytes release alpha-MSH.  Melanocytes have target receptors for alpha-MSH and when alpha-MSH binds to skin melanocytes, they generates the black pigment eumelanin.  The result is suntan. [Actually the situation is a bit more complicated than this since other factors are also involved in producing eumelanin and the melanocytes have other regulatory functions besides producing eumelanin(ref)(ref)(ref)(ref).]

With respect to theories of aging it is interesting that Alpha-MSH inhibits the expression of NF-kappaB and is a powerful anti-inflammatory, affecting what is possibly a key pathway in inflammatory pathologies(ref). “We report that alpha-melanocyte-stimulating hormone(10–9 M) was effective in opposing a tumor necrosis factor- stimulated increase in NF- B DNA binding activity in: (i) normal ocular melanocytes; (ii) cells cultured from ocular melanoma tumors; and (iii) two cutaneous melanoma cell lines(ref).”

  This is quite interesting since runaway expression on NF-kappaB and TNF-alpha seem to be characteristic of melanoma.  Systemic administration of alpha-MSH appears to inhibit inflammation in general.  For example, it has been shown to be capable of inhibiting colonic inflammation in inflammatory bowel disease, at least in rats(ref).  It can inhibit edema in the mouse paw and acute ear inflammation in mice(ref). Another study description indicates “The results suggest that anti-inflammatory influences of neural origin that are triggered by alpha-MSH could be used to treat systemic inflammation. In addition to its central influences, alpha-MSH has inhibitory effects on peripheral host cells, in which it reduces release of pro-inflammatory mediators. Alpha-MSH reduces chemotaxis of human neutrophils and production of TNF-alpha, neopterin, and NO by monocytes. In research on septic patients, alpha-MSH inhibited release of TNF-alpha, interleukin-1 beta (IL-1 beta), and interleukin-8 (IL-8) in whole blood samples in vitro(ref).”  In the nervous system, the anti-inflammatory effects of alpha-MSH are communicated via neurogenic signaling.  One report indicates “We recently found that alpha-MSH can act solely within the brain to inhibit inflammation caused by a general irritant applied to the skin. This activity appears to be shared with salicylate drugs and the combined observations suggest the existence of descending neurogenic anti-inflammatory signals capable of modulating inflammation in peripheral tissues(ref).”The way that alpha-MSH works to limit inflammation appears to be through inhibiting expression of NF-kappaB which is essential for the expression of proinflammatory cytokines.  It appears to do this by prevention of degradation of IkappaBalpha, a protein that keeps NF-kappaB locked up in the cell cytoplasm and out of the nucleus(ref). 

NF-kappaB plays a central role in the Programmed Epigenomic Changes theory of aging.  There does not seem to be much current research action on the anti-inflammatory effects alpha-MSH or use of alpha-MSH as an anti-inflammatory therapy but I would not be surprised to see this thread picked up again at some point in an expanded context.

One of the more-traditional theories of aging covered in my anti-aging treatise is Lipofuscin accumulation, a theory that has been around for decades.  According to this theory, aging is caused by or contributed to by lipofuscin, metabolic gunk, oxidized cross-linked proteins, that accumulates in postmitotic cells with age and gums up their workings.  It is found in a variety of cell types in a variety of organs including the heart, kidney, liver, eyes and brain.  Levels of lipofuscin are often used as biomarkers of age.  I recently started to wonder if this theory was too stodgy compared to newer sexier theories like Programmed epigenomic changes.  So, I decided to do a check on lipofuscin-related research.  I came up with several items suggesting that despite all the aging-related research in newer areas of genomics and molecular biology, lipofuscin accumulation continues to be of great importance in aging. 

o    Lipofuscin continues to be studied. A search in pubmed.org on “lipofuscin 2009” reveals 150 citations.  According to a review study, “Lipofuscin formation appears to depend on the rate of oxidative damage to proteins, the functionality of mitochondrial repair systems, the proteasomal system, and the functionality and effectiveness of the lysosomes. This review highlights the current knowledge of the formation, distribution, and effects of lipofuscin in mammalian cells(ref).”

o    Cells have mechanisms for protein repair and a mechanism for getting rid of damaged proteins called proteolysis which happens due to specialized protein complexes in cells called proteasomes.  “Therefore, the accumulation of oxidized protein with age can be due to increased protein damage, decreased oxidized protein degradation and repair, or the combination of both mechanisms. The proteasomal system is the major intracellular proteolytic pathway implicated in the degradation of oxidized protein, –(ref).”  In plain language words, lipofuscin accumulation is due to an imbalance in cell metabolic and waste-degradation functions. 

o    Large accumulations of lipofuscin and lipofuscin-like materials in cells can lead to cell death.  “The results of this study are consistent with the conclusion that accumulation of lipofuscin-like materials results in inhibition of the proteasome, which initiates an apoptotic cascade as a result of dysregulation of several proapoptotic proteins(ref).

·         According to Encylopedia Britannica “The pigment lipofuscin accumulates within heart muscle cells; it is not detectable at ten years of age but rises to almost 3 percent of the cell volume by age 90(ref).”

·        ”This review article covers how lipofuscin and neuromelanin, a related substance, accumulated with age in autophagic vacuoles in neurons and the damage created.  “The most striking morphologic change in neurons during normal aging is the accumulation of autophagic vacuoles filled with lipofuscin or neuromelanin pigments. — The pigments arise from incompletely degraded proteins and lipids principally derived from the breakdown of mitochondria or products of oxidized catecholamines.  Pigmented autophagic vacuoles may eventually occupy a major portion of the neuronal cell body volume because of resistance of the pigments to lysosomal degradation –(ref).” 

·        There is a family of at least eight rare and genetically distinct neurodegenerative diseases associated with accumulation of lipofuscin in cells known as neuronal ceroid lipofuscinoses (NCL)(ref)(ref).  “They (the NCL diseases) are associated with variable yet progressive symptoms including seizures, dementia, visual loss, and/or cerebral atrophy(ref).”

·        The tyrosinase gene is involved in the deposition of cardiac lipofuscin, at least in mice(ref).  This is a relatively older (1993) finding.  “Analysis of spontaneous mutants of the tyrosinase gene, encoded by the albino locus, confirmed that the tyrosinase gene itself controls lipofuscin formation.”  “Tyrosinase is a copper-containing enzyme present in plant and animal tissues that catalyzes the production of melanin and other pigments from tyrosine by oxidation, as in the blackening of a peeled or sliced potato exposed to air(ref).”  So it is a good guess that black lipofuscin skin spots on older people are created by a somewhat similar process to that which turns a sliced potato black.

·        Lipofuscin is often considered in a broader context as one of several forms of undesirable protein aggregations, others sometimes being called ceroids, inclusion bodies, plaques, or aggresomes depending on their source and composition.  While possibly being metabolic products, these aggregations may be biologically active.  They may affect proteasomal activity and protein turnover and are common features of neurodegenerative diseases as well as aging(ref).

·        A diagram of how lipofuscin buildup reduces the effectiveness of cellular lysomes capability to degrade damaged mitochondria can be found here.

·        Acumulation of lipofuscin in the retinal pigment epithelium (RPE) has long thought to be a major factor leading to age-related dry macular degeneration(ref)(ref).  There is a substantial literature on this subject.

These and many other research reports I encountered continue to indicate that lipofuscin accumulation is serious issue in aging.

Lipofuscin accumulation is closely associated with things that happen according to other major theories of aging such as Oxidative Damage and Chronic or Excess Inflammation.   For example, in the case of AMD (adult macular degeneration), “These findings link four factors that have been posited as being associated with: inflammation, oxidative damage, drusen, and RPE lipofuscin(ref).” 

Protection against oxidative damage is one key strategy for minimizing the production of li[pofuscin.  See the firewall for the oxidative damage theory of aging, both lifestyle elements and dietary supplements.  Fortunately, there are several supplements with serve either to reduce levels of lipofuscin accumulation or to help pump lipofuscin out of cells.  They are listed in the firewall for the lipofuscin accumulation theory of aging.

Research in induced pluripotent stem cells (iPSCs) is rapidly moving forward, this being probably the most fast-moving area of stem cell research, a field which itself is proceeding at express speed.  I posted a blog entry Rebooting cells and longevity describing iPSCs way back in March of this year (now a time in ancient history) and have referred to them subsequently in various posts.  Again, an iPSC is a stem cell that is created by resetting a normal somatic cell, say a skin cell, back to the ground-zero state of an embryonic stem cell by introducing four critical proteins that wipe out the accumulated epigenomic information in that cell.  It seems an iPSCs can do most everything an embryonic stem cell (ESC) can do.  So, three months later, what are the currently hot issues with respect to iPSCs?  Here is what I think they are:

·        Creating iPSCs that are genomically stable and free of cancer genes

There is a fair amount of research going on in this area, particularly focused on means for making sure that portions of gene sequences from viral vectors are not integrated into the final iPSCs(ref)(ref)(ref).  This is important since such segments might turn out to be oncogenic.  The proteins used to create iPSCs can be Oct4, Sox2, Nanog, and Lin28 or  Oct4, Sox2, Klf4, and c-Myc.  All of these proteins are traditionally known to be oncogenic and that is also a cause for serious concern. If the proteins are activated by inserting genes for them in order to create the iPSCs, it is important to get rid of those genes before the iPSCs are used for therapeutic purposes.  

The actions of the proteins can be quite complex, for example see the comments here about the multiple actions of Lin28.  This story tells about four current research approaches to getting rid of the cancer genes from iPSCs.  Progress in this area is rapid and the expectation is that in a year or two standardized methods will be available for creating iPSCs that are absolutely genomically stable and free of cancer genes.  In the meanwhile most experimentation with iPSCs has been with cells that may or may not be safe for human use.    

·        Determining similarities and differences between embryonic stem cells (ESCs) and iPSCs

This is a very important issue from several viewpoints.  A lot more is known about ESCs since they have been studied for several years.  If this knowledge can be applied to iPSCs, years of research could be saved.  Apart from the religious objections to using fetus-derived ESCs for human therapeutic purposes, there is a compelling reason to use iPSCs instead if they are truly equivalent and safe.  The reason is that iPSCs are genetically a patient’s own cells and will not be rejected by the immune system when reintroduced into a patient.  Unlike some current stem cell treatments based on using other people’s stem cells, there is no need to wipe out a patient’s immune system before introducing iPSCs.  Current research suggests that there may be some differences between ESCs and iPSCs, but exactly what these are and how they play out is still to be explored.

·        Getting iPSCs to differentiate reliably into somatic cell types and adult somatic stem cells types 

On this front, a recent research report demonstrated that iPSCs can differentiate into functional cardiomyocytes.  The author states “We conclude that human iPS cells can differentiate into functional cardiomyocytes, and thus iPS cells are a viable option as an autologous cell source for cardiac repair and a powerful tool for cardiovascular research.”  There are a number of earlier reports related to ESCs being able to differentiate into cardiomyocytes.  This work on human iPS cells confirms earlier research results with mouse iPS cells(ref).  Other reports confirming the pluripotent differentiation capabilities of  iPS cells keeps rolling in.  For example, scientists at UCLA report creating functional neurons from iPSCs.  As time progresses I expect to see reports on more and more tissue types being created from iPSCs.

As for the critical task of regenerating adult stem cells from iPSCs, my cursory scan of the literature has not picked up anything significant yet.  It is one thing to get iPSCs to differentiate into neurons; it would be something else to get them to replenish a body’s declining stock of neural stem cells.  I believe this is a crucial issue, not only from the viewpoint of designing stem cell therapies but also from the viewpoint of longevity.  The fourteenth theory of aging characterized in my treatise on aging is Decline In Adult Stem Cell Differentiation.  Having a good available supply of adult (somatic) stem cells is critical for organ damage repair and constant tissue regeneration. Examples mentioned or discussed previously in this blog include mesenchymal stem cells, neural stem cells, endothelial stem cells, dental pulp stem cells, and hematopoietic stem cells. With aging the population of adult stem cells declines due to replicative senescence attrition and oxidative damage, and the rates of differentiation into somatic cells also declines.  I would imagine that if iPSCs can be induced to differentiate into nerve or heart cells, they can also be induced to differentiate into the corresponding adult stem cell types which by all logic should be intermediate cell types.

The literature is full of curiosities.  For example a very recent study reports that iPSCs created from Tibetian miniature pigs more resemble human iPSCs than those from any other animals.  A fascinating related area of research involves direct reprogramming of cell types without intermediation of stem cells.  For example, it is possible to transformed human skin cells into mouse muscle cells and vice versa(ref)(ref).  The bottom line is far from in yet, and I will continue to watch and report on news related to iPSCs.

Three of the principal theories of aging articulated in my are treatise ANTI-AGING FIREWALLS – THE SCIENCE AND TECHNOLOGY OF LONGEVITY are Chronic or Excess Inflammation, Susceptibilities to Cancers, and Decline In Adult Stem Cell Differentiation. Recent research suggests an underlying mechanism that links inflammation, cancer and the role of adult stem cells, at least in the case of autoimmune diseases such as rheumatoid arthritis, Lupus erythematosus, scleroderma and Sjögren’s syndrome.   For some time, it has been noted that these inflammation-promoting autoimmune diseases are associated with elevated probabilities for incidences of cancer, lung cancer in the case of rheumatoid arthritis and lymphoma in the case of lupus for example(ref)(ref)(ref).  However, the reason for this association remained unclear.  Recent research suggests that what might be happening is a) adult stem cells are attracted to the sites of inflammation associated with the disease, basically on a repair mission b) in the abnormal signaling environment of the inflammation  sites, other things are going on possibly leading some of these stem cells to mutate and become cancerous.  “Recent studies have underscored a striking connection between tissue injury, repair and malignancy that may be of significant importance to the pathogenesis of systemic rheumatic diseases.  At the center of this connection lies the stem cell, the effector of tissue repair and regeneration that can arise from the tissue itself or be recruited from immigrant precursors(ref).”

For example, it is well known that lupus can lead to lung inflammation associated with interstitial lung disease and idiopathic pulmonary fibrosis (ref).  Tissue damage ensues which recruits stem cells to the sites of injury, endothelial progenitor cells being among them(ref).  However, the inflammation may also promote the recruitment of circulating tumor cells to the same sites(ref).  What exactly can happens next is unclear, but one theory gaining traction is that the environment is mutantogenic for the stem cells.  The title of one research publication telegraphs the message:

Stem Cells in Inflammatory Disease: Chronic Inflammation and Tissue Damage Recruits Stem Cells, Which Accumulate Mutations and May Become Transformed.

“A recent study by Houghton and colleagues using a mouse model demonstrates a very striking connection between chronic inflammation, hematopoietic stem-cell recruitment and mutation, and cancer formation in the inflamed target tissue. These authors showed that chronic Helicobacter pylori infection stimulates the recruitment of bone marrow derived stem cells (BMDC) into the gastric mucosa, which engraft permanently into the tissue stem-cell niche, assuming functions of the former. In the inflammatory microenvironment generated by H. pylori, the engrafted BMDCs accumulate mutations, and appear to be the cells that give rise to the gastric tumors arising in these animals(ref).”  Another publication reports “Data from emerging studies provide a growing body of evidence that stem cells play critical roles at the injury-repair interface. While performing the function of regeneration so critical for life, they may also be inadvertent partners in pathology, through their ability to self-renew and express various autoantigens also expressed in tumors.”

There is much current research activity in the associated fields of autoimmune diseases, stem cell activities, oncogenesis and inflammation.  So, I expect there will be further clarification of the phenomena described here as time progresses.  Meanwhile, a general message for both healthy people and ones with autoimmune diseases appears to be “keep the inflammation down as much as possible.”  For someone in the midst of a roaring lupus flare, this could require a medical intervention such as prescribing a strong corticosteroid like prednisone.  For healthy people, there is my suggested anti-aging Firewall against Chronic or Excess Inflammation.

Little Jane asks “Daddy, where will they get the stem cells to make me better?”

Daddy’s answer now “They will get some from your bone marrow.  They stick in a big needle to get it.”

Previous posts on this blog have discussed applications of adult stem cells for tissue regeneration, for example the recent post Simple but powerful non-invasive adult stem cell cures.  Many of these feature the use of autologous mesenchymal stem/progenitor cells extracted from a patient’s own bone marrow.  Mesenchymal stem/progenitor cells are an important category of stem cells which self-renew and are capable of differentiating into bone, adipose and cartilage tissue.  Traditionally these cells have been extracted from bone marrow although they have been known to exist also in placenta, lung and other tissues.  Recently there has been increasing interest in Dental Pulp Stem Cells (DPSCs) for dental tissue restoration, including regeneration of dental pulp and dentine(ref)(ref)(ref)(ref). 

Beyond dental applications, there may be a number of other applications of DPSCs for repair or regeneration of other body tissues.  DPSCs appear to be functionally equivalent to mesenchymal stem/progenitor cells, are relatively easy to collect, have an extensive differentiation capability and offer several other advantages(ref)(ref).  DPSCs “have been demonstrated to answer all of these issues: access to the collection site of these cells is easy and produces very low morbidity; extraction of stem cells from pulp tissue is highly efficiency; they have an extensive differentiation ability; and the demonstrated interactivity with biomaterials makes them ideal for tissue reconstruction. SBP-DPSCs are a multipotent stem cell subpopulation of DPSCs which are able to differentiate into osteoblasts, synthesizing 3D woven bone tissue chips in vitro and that are capable to synergically differentiate into osteoblasts and endotheliocytes. Several studied have been performed on DPSCs and they mainly found that these cells are multipotent stromal cells that can be safety cryopreserved, used with several scaffolds, that can extensively proliferate, have a long lifespan and build in vivo an adult bone with Havers channels and an appropriate vascularization(ref).”  In other words, for many tissue repair and regeneration applications DPSCs might offer a better choice that bone-marrow extracted mesenchymal stem cells.  And there are likely to be a lot of such applications.

In the future little Jane asks: “Daddy, where will they get the stem cells to make me better?”

Daddy’s answer:  “The tooth fairy collects it.  Just leave your baby tooth under your pillow when it comes out.”

Since I started taking 600mg a day of trans-resveratrol, my bowel movements have become reliably punctual, sometimes almost overly so.  If you are taking large doses of resveratrol and are experiencing the same phenomenon or worse, it may be due to emodin, an impurity commonly found in commercial resveratrol supplements.  Among other properties, it is a laxative.  Emodin is a phyto plant substance present in rhubarb and in aloe vera leaves.  Emodin is also present in Japanese knotweed (Polygonum cuspidatum), the source ingredient of most  resveratrol   supplements.  It may not all be removed in refining resveratrol and can represent more than 5% of the content of a marketed resveratrol supplement capsule.  Discussion of this impurity has appeared in an Imminst.org forum on resveratrol. 

The amount of the impurity varies significantly by product.  Most popular suppliers of resveratrol (including Swanson Vitamins, NSI, Country Life, Biotivia, Life Extension InstituteJarrow Formulas, source Naturals and Puritan’s Pride) do not disclose emodin content in their resveratrol labels.  Revgenetics is an exception and has posted laboratory analyses showing emodin is .1% present in their “99% pure” resveratrol product(ref) and .7% present in their “50% pure” product(ref).  Some grape-based resveratrol products avoid emodin completely(ref). 

Despite its laxative effects, emodin may offer health benefits of its own such as a cancer-preventative ones. It may inhibit cell growth and angiogenesis in human colon cancers(ref), It “could be a useful chemotherapeutical agent for treatment of hepatocellular carcinoma(ref),”  “Emodin affects the expression of genes involved in various cellular functions and plays important roles in cell apoptosis, tumor metastasis and chemotherapy-resistance, which suggests emodin might become an effective chemopreventive or chemotherapeutic agent for small cell lung cancer(ref),” “Emodin induces apoptosis in human promyeloleukemic HL-60 cells—(ref).”  Further, Emodin has unique antibacterial properties, “taking into account its unique cytotoxicity profile and mode of action, aloe-emodin might represent a conceptually new lead antitumor drug(ref).” And emodin is “a potential lead compound for further anti-bacterial drug discovery(ref).”  To sum it up, emodin appears to be another phyochemical whose possibly important health properties are just-now being systematically explored.

Personally I am taking a resveratrol supplement with less than 1% emodin content and find the laxative effect definitely present but tolerable.  If you are experiencing diarrhea due to taking a large amounts of resveratrol, you might want to switch to a different brand with lower emodin content. 

The longevity research literature citations that appear in this blog or in my treatise are increasingly likely to refer to recombinant DNA laboratory analysis techniques like Western blot analysis, PCR, Alkaline lysis, Column chromatography, Sanger sequencing, Agarose gel electrophoresis, Radio-immune precipitation, and Sodium dodecyl (lauryl) sulfate-polyacrylamide gel electrophoresis.     If you have not studied these, after repeatedly coming across some of them you may wonder what in the dickens they are, how they work and what they are good for.  I recently came across Mama Ji’s Molecular Kitchen, a web site that explains a number of these basic techniques in simple language.  Further, it tells you in a cookbook fashion how to go about doing each of them if you are so inclined.  The site also covers a few key molecular genetic entities like Plasmids and Restriction Enzymes.

My basic message is that if you are reading a research report of otherwise great interest but come across entities you know nothing about, you don’t necessarily have to let yourself be thrown.  In many cases the concept behind an arcane technical term is quite simple: 

·        Take PCR (polymerase chain reaction) for example.  “Let’s say you have a biological sample with trace amounts of DNA in it. You want to work with the DNA, perhaps characterize it by sequencing, but there isn’t much to work with. This is where PCR comes in. PCR is the amplification of a small amount of DNA into a larger amount. It is quick, easy, and automated. Larger amounts of DNA mean more accurate and reliable results for your later techniques(ref).”  

·        Restriction Enzymes, another example, are used as scissors for cutting DNA.  “Restriction enzymes, also known as restriction endonucleases, are enzymes that cut a DNA molecule at a particular place. They are essential tools for recombinant DNA technology. The enzyme “scans” a DNA molecule, looking for a particular sequence, usually of four to six nucleotides. Once it finds this recognition sequence, it stops and cuts the strands. This is known as enzyme digestion(ref).”

I have created a 39-slide PowerPoint presentation THE SCIENCE OF AGING AND PRACTICAL ANTI-AGING INTERVENTIONS that provides an overview of the content in my treatise ANTI-AGING FIREWALLS – THE SCIENCE AND TECHNOLOGY OF LONGEVITY.  It is a good introduction to my anti-aging work and is recommended for readers who have not read the treatise.  The presentation also contains hyperlinks to multiple topics covered in more detail in the treatise and to selected items in this Blog.

Online PowerPoint presentations use scripts.  Because of this feature in PowerPoint, you may have to give your browser security permission to view the presentation.  If a warning bar comes up on your browser, click on it.  And then you might be asked “Install active X control” and/or “Allow blocked content.”  You will then get another security warning and if you click “Yes” the full presentation will come up.  Unfortunately, you will probably have to do at least one of these steps every time you navigate away to a hyperlink and then return to the PowerPoint presentation. 

Like both the Blog and treatise, this presentation is a work in progress.  As time goes on I expect to update its contents and I may add additional multimedia features. 

While most popular discussion has centered around the disease-curing potential of embryonic stem cells and induced pluripotent stem cells, small-scale experiments are beginning to show the power of very simple, inexpensive and non-invasive techniques using a patient’s own (autologous) adult stem cells to clear up formerly intractable disease conditions.  I briefly describe two examples of preliminary but promising applications here.

The first application involves clearing up Scleradactyly, a condition featuring chronic fingertip or toetip hardening and often accompanied by lack of circulation and painful  infections.  Scleradactyly often occurs in people with auto-immune disorders, particularly with scleroderma, CREST syndrome and mixed connective tissue disease.  Up until now, there has been no known way to clear it up.  Dr. Vincent Falanga, working at the Roger Williams Medical Center, in Providence, Rhode Island has developed a procedure that uses mesenchymal stem cells derived from a patient’s bone marrow. “ The cells are cultured ex vivo and their numbers are expanded greatly. A solution of the stem cells and fibrinogen is placed in 1 chamber of a double-chambered syringe, and the second chamber is filled with a solution of dilute thrombin.  “The 2 solutions combine when ejected from the syringe as a spray over the wound. The mix begins to polymerize, and that “clotting” helps to hold the stem cells in place in the wound. The wound is then covered with 2-layer bioengineered skin, containing a layer of keratinocytes and a layer of fibroblasts(ref).”  Except for extracting the cells from bone marrow, there is nothing invasive about the procedure. “This proof-of-concept procedure has been applied to 9 patients with nonhealing ulcers without scleroderma and to 3 patients with nonhealing wounds related to scleroderma. After 6 months of follow-up, 4 patients healed completely and the others improved significantly, “with improved quality of life.”  Dr. Falanga is following up with additional patients and is refining his technique.

The second application is cure of blindness caused by corneal disease.  (Thanks to blog participant Brian Hart who put me onto this one via a comment.)  The technique again seems ridiculously simple for the amazing results achieved.  Work so far in Australia has been only with three patients that were blind in one eye with one healthy eye.  The process is very simple.  “The researchers extracted stem cells from the working eye, cultured them in contact lenses for 10 days, and gave them to the patients to wear. Within 10 to 14 days of use, the stem cells began recolonizing and repairing the cornea(ref).”  Apparently, the stem cells migrate readily into the cornea.  Of the three patients, two were legally blind but can now read the big letters on an eye chart, while the third, who could previously read the top few rows of the chart, is now able to pass the vision test for a driver’s license.”  The procedure can most likely be used to repair a variety of forms of corneal damage due to infections, burns or chemotherapy.  See this web site for a short video on the process.

I think simple autologous stem cell therapies like these will proliferate and soon become part of mainstream medicine significantly contributing to health.  As to their contribution to extraordinary longevity, however, effectiveness of these techniques depends on a supply in the body of healthy adult stem cells and the techniques will not work without them.  In the recent post More research insight on gray hair and adult stem cell reproduction, for example, I cited research indicating that gray hair was ultimately due to depletion of melanocyte stem-cells(MSCs) which in turn is the result of DNA damage.  Other approaches must be used to assure continuing active supplies of adult stem cells, such as taking antioxidants and telomerase activation.  In the longer run, induced pluripotent stem cells might be induced to differentiate in a controlled manner into specific lines of adult stem cells.  See the discussion for the Decline is Stem Cell Differentiation theory of aging. 

I cite a sampling of research studies here related to the quality of human male semen as a function of age and the possible impacts of dietary supplementation. This topic is increasingly important because of the trend in our society for men to have children at more advanced ages. 

First of all, there is a general inverse relationship between sperm quality and age of the donor.  A study report on The effects of male age on sperm DNA damage in healthy non-smokers looked at 80 non-smoking men (mean age: 46.4 years, range: 22–80 years).  The researchers concluded: “Our findings indicate that (i) older men have increased sperm DNA damage associated with alkali-labile sites or single-strand DNA breaks and (ii) independent of age, men with substantial daily caffeine consumption have increased sperm DNA damage associated with double-strand DNA breaks. DNA damage in sperm can be converted to chromosomal aberrations and gene mutations after fertilization, increasing the risks of developmental defects and genetic diseases among offspring.”  Being both old and a coffee drinker this would be bad news for me if I were planning to have additional children, which I am not.

Another study Advancing age has differential effects on DNA damage, chromatin integrity, gene mutations, and aneuploidies in sperm brings additional bad news for older would-be fathers.  The study looked at 97 nonsmoking men aged 22-80 years.  The researchers report:  “Our findings predict that as healthy males age, they have decreased pregnancy success with trends beginning in their early reproductive years, increased risk for producing offspring with achondroplasia mutations, and risk of fathering offspring with Apert syndrome that may vary across cohorts, but with no increased risk for fathering aneuploid offspring (Down, Klinefelter, Turner, triple X, and XYY syndromes) or triploid embryos.”

Implicated in deterioration of sperm quality are some of the same factors that affect cell health and drive aging, for example Oxidative Damage and Cell DNA Damage.  One study entitled Antioxidant intake is associated with semen quality in healthy men based on study of sperm from 97 men reports: “–, higher antioxidant intake was associated with higher sperm numbers and motility.”  For another study of 114 subjects (60 infertile patients and 54 age-matched healthy workers), the researchers report: “Data from this study thus indicate that oxidative damage to sperm DNA may be important in the etiology of male infertility – .“  This review article looks more broadly at the relationship between oxidative stress and male infertility. “ — oxygen ions, free radicals and peroxides (ROS) — produce infertility by two key mechanisms. First, they damage the sperm membrane, decreasing sperm motility and its ability to fuse with the oocyte. Second, ROS can alter the sperm DNA, resulting in the passage of defective paternal DNA on to the conceptus.” 

A very recent study looked at the Effect of parental age at birth on the accumulation of deficits, frailty and survival in older adults.  “Data was collected on individuals aged 65 (or greater) using a Self-Assessed Risk Factor Questionnaire and screening interview. In this secondary analysis, 5112 participants had complete data for parental age, frailty status and 10-year survival. Parental age was divided into three groups, with cut-offs at 25 and 45 for fathers and at 25 and 40 for mothers. Frailty was defined by an index of deficits.” The researchers reported “There was no effect of maternal or paternal age on survival for either sons or daughters. Similarly, there was no association between parental age and subject frailty in old age.” This time the news was good.  On the other hand since all the participants had already made it to age 65, the study does not tell us what effect parental age at time of birth might have on survival to 65.

The activities of DNA repair mechanisms seem to be age-dependent.  This study Age-Dependent Usage of Double-Strand-Break Repair Pathways looks at DNA repair in the premeiotic germ cells of Drosophila (fruit flies) as a function of age.  The results suggest that at least one repair pathway gets more active with age “We used Rr3, a repair reporter system in Drosophila  to show that the relative usage of DSB repair mechanisms can change substantially as an organism ages. Homologous repair increased linearly in the male germline from 14% in young individuals to more than 60% in old ones, whereas two other pathways showed a corresponding decrease. Furthermore, the proportion of longer conversion tracts (>156 bp) also increased nearly 2-fold as the flies aged.”  I speculate that a similar situation exists for humans: the older the person the more there is a need for repair and actual repair of germline cells.

Among the most widely recognized genetic disorders is Aneuploidy, a condition where there are missing or extra chromosomes.  Testing for aneuploidy may be warranted for men with a serious record of infertility or where his mate has experienced unexplained recurrent pregnancy loss(ref).  

This study investigated the impact of supplementation by zinc, folate, vitamin C, vitamin E and beta-carotene on aneuploidy using sperm samples from 89 healthy, non-smoking men.  Interestingly, the researchers concluded:  “Men with high folate intake had lower overall frequencies of several types of aneuploid sperm.”  There did not seem to be a correlation of use of the other supplements with aneuploidy.

The research literature related to male fertility is extensive and growing and the nine citations above just scratch the surface.  The most obvious implications for normal older men planning to have children are 1.  Protect against oxidative stress and cell DNA damage.  See the protective firewalls for the Oxidative Damage  and the Cell DNA Damage theories of aging, 2.  Include folic acid in your supplement regimen.  And one more point: 3.  Keep yourself young; in today’s world having a father around can be very useful until a child is 30 or older. 

I will return to this topic it at a later time.  It is bound to become more important when extraordinary longevity becomes possible and there will be a demand for interventions that make it possible, safe and easy for a man to father children at the age of 100, 150 or later.