Exosomes and their Potential for Rejuvenation

Extracellular Vesicles (EVs) have only been studied in the 21st century. Think of them as natural lipid nanoparticles, or endogenous viruses. They transmit information around the body and they’re small enough to be exhaled and carried in the air to communicate with other individuals and even other species. EVs are encapsulated in fats that facilitate entry into cells, and inside they contain proteins, RNA, DNA, lipids — all of which carry information. EVs are a universal biological language, a barely-explored medium of communication.

Last week, an extraordinary paper was published demonstrating the rejuvenation potential of EVs from very young animals injected into old animals. The authors come from Smidt Heart Institute in Los Angeles, and their primary field is cardiology, not gerontology, so they focus on heart-derived EVs and benefits for rejuvenating the heart. But the benefits they observe go well beyond the heart and include lifespan in rodents and rejuvenation of human cells from rat-derived EVs.

This research should be understood in the light of parabiosis experiments by the ConboysRando, and others and in particular to the rejuvenation technology of Harold Katcher. I am grateful to Harold’s partner, Akshay Sanghavi, for alerting me to this publication. Katcher’s blood-derived rejuvenation serum is called E5, and Akshay has told me that E5 includes EVs as well as a wide range of proteins. The current article suggests the possibility that it is wholly the EVs that are responsible for the benefits of E5. Indeed, the authors repeated their experiments with (1) whole blood plasma, (2) plasma with the EVs removed, and (3) just EVs. They found rejuvenation effects associated with whole plasma and with EVs alone, but not with plasma minus EVs. If this holds up, it is the study’s most important finding. Akshay told me that EVs are easier and cheaper to isolate than the molecular constituents of E5 (proteins).

For all those involved in parabiosis and plasma exchange research, I suggest that it should be an immediate priority to replicate the Smidt findings that all of the rejuvenating power of young blood is contained in EVs. The Conboys might be interested in asking whether the pro-aging effect of plasma infusions from old to young animals is also an effect of EVs.

The state-of-the-art EV separation technique for large throughput is called an acoustic nanofilter. Ultrasound pressure can be tuned to separate a particular size of particle in a specially-designed medium. If I were advising Yuvan, I would suggest that they develop an expertise in acoustic nanofiltration ASAP as a next generation replacement for their plasma fractioning technology.

Exosomes

Exosomes are the most common type of EV, and probably the most relevant to aging applications. They seem to be a general vehicle for inter-cellular and inter-individual communication. The study of exosomes is in its infancy, but it is already known that exosomes are tagged in a way that recipient cells can distinguish and choose which exosomes to pick up and “read the message”.

One area of exosome activity that has been studied is the communication of antigens to the immune system. A particular type of exosome includes foreign proteins that are potential invaders, and they are shared not just within the body but through the air. When you think of herd immunity, consider not just the contagion of people who carry disease but also the information about what diseases are in the air that is transmitted in social interactions.

When communities and whole countries were locked down during COVID, one consequence was to prevent uninfected individuals from learning and preparing an immune response to the virus through the sharing of exosomes.

“In the nervous system, exosomes have been found to help in myelin formation, neurite growth, and neuronal survival, thus playing a role in tissue repair and regeneration.” [refrefrefrefrefref] “It has been demonstrated that the mesenchymal stem cell exosomes themselves can act as a therapeutic agent to help [repair] tissue injury.” [refrefrefrefrefref]

“Microvesicles” are, as far as I can tell, a kind of fat exosome. They are as large as bacteria, whereas exosomes are closer to the size of viruses, but the range of contents and hypothesized functions is the same.

Apoptotic Bodies — another potential target for EV therapies

There is also a specific EV type that apoptotic cells send to induce apoptosis in other cells. Apoptosis is programmed cell death, playing an important role in self-destruction of diseased and cancerous cells. However, aging involves a cascade of apoptosis in healthy cells that leads to loss of muscle tissue (sarcopenia) and brain cells (neurodegeneration). Apoptotic bodies are the type of EV that triggers the apoptosis cascade, and I speculate that removing apoptotic bodies from the blood will have future potential as an anti-aging therapy. Apopototic bodies are even larger than “jumbo” microvesicles, so it should not be difficult to separate them in medical applications. It is a reasonable guess that the effectiveness of senolytic therapies is directly related to a reduction in apoptotic bodies, which are secreted by senescent cells. (These are my own speculations, not mentioned in the paper that I’m reviewing here.)

The new research

Rejuvenating effects of young extracellular vesicles in aged rats and in cellular models of human senescence by Grigorian-Shamagian et al, in Nature Scientific Reports. Senior author = Eduardo Marbán.


The authors extracted EVs from neonatal rat hearts, and applied them to cell cultures and injected them into older live rats (22 months). They used whole plasma and plasma minus EVs as controls, establishing that it is the EVs that carry the benefits. They extracted corresponding EVs from heart cells of neonatal humans, and applied them to cultures of human cells.

They found EKG evidence that hearts were functioning better in treated animals. Insulin resistance was blood sugar were reduced.

Exercise endurance increased in treated animals, while declining progressively in controls.

They found that pliability of tissue was restored toward young levels. Hearts, lungs, muscles, and kidneys all improved their function in treated rats.

Tissue samples (muscle and heart) look better in ways that I don’t pretend to understand.

Old rats were treated with four monthly infusions, then kept for 16 weeks more before sacrificing all animals. During those 16 weeks, 6 of 14 control rats died and only 3 of 36 treated rats. My calculation (Fisher’s exact test) indicates life extension with a 99% confidence level.

Tests were conducted on two human cell cultures: fibroblasts from middle-aged donors treated with human EVs, and cardiac cells treated with rat EVs. Fibroblasts increased reproductive capacity, decreased apoptosis, and a more youthful transcriptome. Similarly, cardiac cells exhibited better self-assembly and a more youthful transcriptome.

The bottom line

In case you haven’t yet read between the lines, I’m excited about this work. I would have liked to see results of some Horvath clocks and a hat tip to the Katcher preprint, but in other respects, I find the research quite thorough and convincing. A major question in plasma exchange research has been the identification of the active component, out of thousands of protein species. This is only one study, but it suggests that researchers look at the activity of EVs rather than proteins or RNAs.

 

A crucial question is whether EVs from other mammals can be used to rejuvenate human tissues. This study suggests yes, but the demonstration was limited to cell cultures and no direct comparison was made between treatment with human-derived and rat-derived EVs. The author has not responded to my email requesting any data relevant to this question. If animal EVs work in humans, the therapeutic market may soon open; EVs should be easy to extract from the blood of young animals that are being slaughtered for meat. If not, we face a major ethical dilemma, as aborted and stillborn infants will support only a tiny fraction of the potential demand for rejuvenating EVs. EVs from young human donors can probably be extracted but it’s a lot to ask of our children. The authors suggest that EVs could be manufactured from human cell cultures. “Given that allogeneic CDCs [cardiosphere-derived cells] are already in advanced testing and have proven safe to date, such cells can be used as manufacturing platforms for EVs, enabling rapid progress to clinical testing in a variety of aging-related disorders.”

34 thoughts on “Exosomes and their Potential for Rejuvenation

  1. Thank you for another great article, Josh, and for all the researchers that have taken on these important topics. Now if we can just open people’s eyes to all the chicanery in health, “viruses”, immunity, and public policy in recent history … not that they want to after all the nonsense (and that’s being nice) you and I have pointed out.

    Keep up the good work, JM.

  2. young Fresh Frozen Plasma: 1.84 billion exosomes per ml + peak-of-fertility hormones, proteins and peptides. As the “elixir” experiments continue, Mother Nature simply says, “been there, done that…”

    • We need to be exploring alternatives in advance before we start sticking needles into babies in our quest to live longer. The authors of the article suggest that human cell cultures can be used to manufacture exosomes in quantity.

  3. Dr Sandra Kaufman says in recent interviews that she receives exosomes on a monthly basis. Where would these exosomes be derived from? She is a huge believer in their rejuvenation qualities

    • Hi Dan, we spoke with Dr Kaufmann in the past and she mentioned exosomes. I had a follow up question with her about them and she directed me to Dr Duncan Ross of Kimera Labs. We also talked to Dr Ross and he said that he used placenta derived MSCs.

      • Some other companies, such as Wellbeingint, claim that extracellular vesicles are the true agents of repair and regeneration, not stem cells themselves.

  4. I would have to assume that Yuvan Research does not have the resources to test whether an EV-only E5 produces the same effects in rats as the original version, but it certainly would be informative.

    Am I to understand that the E5 plasma protein fraction needs to be from young sources? My old brain missed that requirement, if indeed that is the case.

    • Antoine Béchamp was a contemporary of Pasteur in France. Some claim that Pasteur stole his research, and others say that Pasteur had it wrong, while Bechamp was more accurate. https://en.wikipedia.org/wiki/Antoine_B%C3%A9champ

      Bechamp argued that all cells have tiny “molecular granulations” — which he referred to as microzymas — that serve to build and recycle an organism. The argument further states that the microzymas respond to changes, such as pH, in the cellular environment. In this regard, microzymas are both beneficent and maleficent depending on the state of our internal environment. If the environment is compromised, the microzymas lead to illnesses. The microzyma being thus the fundamental element of corporate life, it may become morbid through a change in function and thus be the starting point of disease.

    • I wonder why the hypothalamus doesn’t get as big an effect from E5. Would the blood brain barrier interfere some with the young EVs being able to reach the hypothalamus?

        • If I understand correctly from The Illusion of Knowledge, E5 fixes the regulation of anabolism at a cellular level and therefore repairs cell defects. It does this by “tricking” the cell, so ostensibly the hypothalamus wouldn’t be the issue in this case.

          • You have any guesses on why it doesn’t reverse the hypothalamus epigenetic age nearly as much as those other things in the body?

          • System didn’t give me a reply button after you reply @Mike Best. My non expert guess would be that the hypothalamus evolved as a regulator of other cells, over the course of life of complex organisms a regulator will break it’ll easily for evolutionary selective pressures due to getting hit by occasional off target signals. The easiest way for nature to fix that I think is to make sure it responds to the off target signals more slowly than other cells. That provides a fudge factor. It could also be dosage dependent, but my guess is that’s less likely above a certain threshold of dosage because that gets the cell saturated and doesn’t account for the developmental nature of a cell’s biology, so the other solution is simpler.

  5. I think the jury is still out as to what is the exact source of aging/youth, something in old blood, something in young blood or, as I believe, both.
    It appears that aging is a very preserved function across 99.99% of species.
    What I find interesting is that the blood plasma (anti-) aging function seems to work cross species.
    The Katcher E5 experiment used porcine plasma on rats, there was another experiment done at Harvard a few years ago that used young volunteer students plasma on rats that also worked.
    At that time in a Reddit thread, I proposed that we should use bovine plasma. This could be harvested from young cows when they start their life of producing milk. A permanent dual shunt could be inserted/place in the neck and at one of the regular milkings they could be attached to a blood plasma machine to extract plasma to be processed. The infrastructure of farming docile large mammals, extraction, refrigeration and distribution is already in place.

    Time to buy stock ?

    • Last I heard they were doing a trial with Beagles given E5 and might give some early results around September. I think they were starting another topical E5 skin trial around this time also.

  6. I think people just don’t receive notifications for the new posts/comments, that would explain the lack of activity. Can anyone confirm (or not) that I’m not the only one with this problem?

  7. Hi UnUtilisateur,

    I can confirm that I am not getting the posts.
    Neither of the replies to my post showed up in my email.
    By the way thanks for the E5 update, Mike.
    I will again check both boxes.

  8. BTW Josh, they DID use rat EVs on human cells – that was the bit of the paper where they tested whole blood vs. EV sreum vs. EV less serum.

  9. Also. Regarding your comments on senolyrics removing apoptotic factors – I’m sure EVs (or their like) are also the transporters of BAD things. It might be worth considering plasma dilution straight after senolytics if you don’t want the rest of your body to be taking up the dead cells’ contents (for example cells free chromatin)

  10. And finally, I couldn’t let this paper pass without mentioning that EVs increased cardiac TELOMERE LENGTH. Its been known for some time cells can ‘share’ telomeres via vesicles
    and also that conditional reprogramming of cells in culture is dependent on feeder cells, whom supply the telomerase.

    I supplied references, but the post then was held in approval purgatory…

  11. With the potential of Porcine endogenous retrovirus, Theoretically it is possible that the surface of the exosomes, viral proteins, specifically surface envelope protein gp70, may be expressed which could direct the exosomes to the receptor of PERV on target cells in the living organism or the immunosuppressive transmembrane envelope protein p15E which may distribute immunosuppressive properties. In addition, the viral genome may be transported to target cells. Investigating PERV genomic RNA, purified exosomes are checked by RT-PCR and for the presence of viral proteins by Western blot analysis using specific sera against p15E and gp70.

  12. Hi Akshay

    I saw this study on exosomes being eaten.

    The RNA cargo in small extracellular vesicles from chicken eggs is bioactive in C57BL/6 J mice and human peripheral blood mononuclear cells ex vivo.

    Do you think that there might be a supplement version of E5 in the future?

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