Looks like a good progress after trials on the equally very debilitating AMD and PD diseases:
Reprogrammed’ stem cells to treat spinal-cord injuries for the first time
Posted 26 February 2019 - 07:13 AM
Looks like a good progress after trials on the equally very debilitating AMD and PD diseases:
Reprogrammed’ stem cells to treat spinal-cord injuries for the first time
Posted 04 March 2019 - 06:03 PM
This looks promising for regenerative medicine, mainly for safety, via a clever usage (dissemination) of iPSC in vivo in therapeutic applications:
"...We hypothesized that when iPSCs dominate the local microenvironment, given their pluripotent nature, they can grow and differentiate to form a tumor containing unwanted differentiated cells. In contrast, disseminated iPSCs are controlled by their local microenvironment so that their differentiation and proliferation properties are shaped by the needs of the local lesion, which would also prevent subsequent teratoma formation. Intravenously or topically administered iPSCs spread widely and evenly across large lesions. The disseminated cells fulfill the requirement of being dominantly influenced by their local microenvironment. Intravenous and topical administrations are crucially important for cell therapies not only because of their convenience, but also because stem cell differentiation controlled by the local microenvironment at the site of injury may best meet the cellular and structural needs of disease repair and recovery..."
"...Teratoma can be easily and completely avoided by disseminating the cells. Direct in vivo iPSC application is feasible and can be safe..."
Xiang M, Lu M, Quan J, et al. Direct application of induced pluripotent stem cells is feasible and can be safe. Theranostics. 2019;9(1):290-310.
I did not know about Theranostics: what is the relative impact of the Journal?
Posted 11 March 2019 - 04:03 PM
I am not likely following this area as long as you are doing but I wonder: is David Sinclair basically changing a bit his research focus and going more to epigenetics and reprogramming? This interview might, between others I have been following and also posting, also indicate so. I realize he has hands on many different topics and companies. Is his research now converging small molecules approach and in vivo reprogramming? I heard several times Belmonte and others of his collaborators going likely to a small molecules drugable approach. Or am I mixing things. Just a thought ...
Posted 12 March 2019 - 10:57 AM
I am not likely following this area as long as you are doing but I wonder: is David Sinclair basically changing a bit his research focus and going more to epigenetics and reprogramming? This interview might, between others I have been following and also posting, also indicate so. I realize he has hands on many different topics and companies. Is his research now converging small molecules approach and in vivo reprogramming? I heard several times Belmonte and others of his collaborators going likely to a small molecules drugable approach. Or am I mixing things. Just a thought ...
There is a good presentation by David Sinclair at Xapiens at MIT (start ~1:28) where he also mentions his work (~1:40, ~1:44) on using OSK (no oncogenic c-Myc) vectored using adeno-associated viruses to regenerate the optic nerve after induced injury on mice and looking also at lifespan:
https://twitter.com/...762977637822464
Posted 22 March 2019 - 11:20 AM
Wonderful ! The all field is progressing! I was following here the work of Sebastiano and Sarkar. Here a new work, includes also Rando and Horvath between the authors. We have also a new name in the paper (ERA - Epigenetic Reprogramming of Aging). Look also the company turn.bio.
"Aging is characterized by a gradual loss of function occurring at the molecular, cellular, tissue and organismal levels1-3. At the chromatin level, aging is associated with the progressive accumulation of epigenetic errors that eventually lead to aberrant gene regulation, stem cell exhaustion, senescence, and deregulated cell/tissue homeostasis3. The technology of nuclear reprogramming to pluripotency, through over-expression of a small number of transcription factors, can revert both the age and the identity of any cell to that of an embryonic cell by driving epigenetic reprogramming2,4,5. Recent evidence has shown that transient transgenic reprogramming can ameliorate age-associated hallmarks and extend lifespan in progeroid mice6. However, it is unknown how this form of ‘epigenetic rejuvenation’ would apply to physiologically aged cells and, importantly, how it might translate to human cells. Here we show that transient reprogramming, mediated by transient expression of mRNAs, promotes a rapid reversal of both cellular aging and of epigenetic clock in human fibroblasts and endothelial cells, reduces the inflammatory profile in human chondrocytes, and restores youthful regenerative response to aged, human muscle stem cells, in each case without abolishing cellular identity. Our method, that we named Epigenetic Reprogramming of Aging (ERA), paves the way to a novel, potentially translatable strategy for ex vivo cell rejuvenation treatment. In addition, ERA holds promise for in vivo tissue rejuvenation therapies to reverse the physiological manifestations of aging and the risk for the development of age-related diseases."
Posted 22 March 2019 - 02:49 PM
albedo,
nothing I like more than a brand new study on the epigenetics of aging that brings with it new data.
This does look like a unique protocol since they are using mRNA and OSKMLN.
The most intriguing part of the paper is that they then measure how this affected the other hallmarks of aging. It's long been my contention that epigenetic reprogramming should cover most or all the other hallmarks, thus drastically cutting down the number of interventions needed to reverse aging. Although there is no neat graph, from what I read, the reprogramming showed measures of Mitochondrial, Nutrient Sensing, Senescent cells, and Proteostasis /Autophagy, Stem Cells to levels that approximated the levels seen in youth. The interesting exception was telomere length, which I had always assumed was restored as well. They explain this by the partial nature of the reprogramming. Ultimately, this is a good thing since further reprogramming would restore telomeres, but you don't want to go that far. Maintaining telomeres should be enough.
And the icing on the cake, no cancer detected. All we need is a good delivery system and we're off to the races.
Posted 22 March 2019 - 04:58 PM
Posted 22 March 2019 - 05:22 PM
Two points about that. The previous study was not trying to reprogram to a completely embryonic state. The entire article about not doing that, since it would have major consequences. Secondly, Belmonte has already shown that in vivo cellular reprogramming works to restore tissue in every tissue they tested. The game of in vitro reprogramming has been going on for quite some time, and it's always been quite inefficient. Now, with a lot of the evidence coming in, it looks like that inefficiency is either irrelevant to how things work in vivo, or that the in vivo milieu is actually a necessary part of cellular functioning. I would guess the latter also based on the evidence from tissue generation in the lab. They have made progress with organoids mainly by mimicking the way organs work in vivo. Sometimes something as simple as the recent case where creating a fold just like pancreatic cells are used to in vivo, had quite dramatic effect on the behavior of the cells and the quality of the generated tissue.
Posted 22 March 2019 - 07:05 PM
Two points about that. The previous study was not trying to reprogram to a completely embryonic state.
Oh, I agree, this article was about cell fitness and it's been observed that many reprogrammed cells are not fit for duty. Apparently, not all cells can resume an active competitive state.
The broad issues I see come from epigenetic memory. Partially reprogram a cell to a younger state and old aged epigenetic markers have a tendency to revert to their previous cellular state. I believe there may be a possible solution to this in the process used to epigenetically reprogram sperm. Sperms start their journey with the father's epigenetic imprint. However, shortly following their creation they are stripped of the initial imprint and undergo an erasure and 2nd reprogramming.
We've brought up extracellular vesicles before on this thread. I believe we might want to think about creating circulating white blood cells reprogramed in the lab to express the desired cell signaling RNA's to hold particular segments of DNA active or dampen activity at other epigenetic sites.
Sometimes it takes an army and we can now begin to think about creating new specialized cells to do the legwork.
Just my thoughts.
Bryan
Posted 25 March 2019 - 10:13 PM
OK, connecting the sperm analogy to Extracellular Vesicles (EV)'s didn't land as I expected. Let's review a link to demonstrate its relevance to this topic. See https://www.smithson...perm-180969760/
As these little guys make their journey down the vas deferens between the start and finish they undergo epigenetic reprogramming. They acquire this reprogramming via Extracellular Vesicles (EV's,) released by the winding epididymis—which, in a human male, is about six meters long when unfurled. What the article reveals is that immature, "non-swimming" sperm before entering the vas deferens can produce a viable embryo thru In Vitro Fertilization (IVF), but this ability to produce a viable embryo is lost to sperm as they first begin their journey down the vas deferens. The basic epigenome is wiped and important developmental instructions are lost as a result. Then the fathers latest epigenetic updates are added during its six-meter journey emerging as viable sperm again. The researcher comments; "It’s very bizarre to see them lose [viability] and gain it back,” In addition, if epididymis EV's are collected then added to the nonviable sperm during the IVF process, embryo viability is once again regained.
The researcher also notes; "[The epididymis] is the least studied organ in the body."
So in a general context sense, we see epigenetic reprogramming giving our children the latest environmental updates for the challenges ahead. I also assume a similar process is happening in the female ovaries or fallopian tubes. Now as our understanding of epigenetics expands, the IVF process may come to include specialized RNA's to silence genes causing hereditary diseases. In the same sense, longevity genes could also be beefed up, immunities added and a host of other epigenetically controlled attributes turned on or off. So I would expect to see advancements in this fledgling field of medicine as our understanding grows.
So from a simple inheritance standpoint, we see the application of epigenetic reprogramming and through observation and experiment, a new field of medicine emerges. Extracellular Vesicles are at work wiping and reprograming the father's and mothers epigenetic contribution.
So what are Extracellular Vesicles (EV)'s?
I remember a good overview I'll share; Exosome Explosion | The Scientist Magazine®
"Secreted vesicles known as exosomes were first discovered nearly 30 years ago. But, considered little more than garbage cans whose job was to discard unwanted cellular components, these small vesicles remained little studied for the next decade. Over the past few years, however, evidence has begun to accumulate that these dumpsters also act as messengers, actually conveying information to distant tissues. Exosomes contain cell-specific payloads of proteins, lipids, and genetic material that are transported to other cells, where they alter function and physiology."
Here is another;
Extracellular Vesicles, Ageing, and Therapeutic Interventions
https://www.ncbi.nlm...les/PMC6115766/
Highly Purified Human Extracellular Vesicles Produced by Stem Cells Alleviate Aging Cellular Phenotypes of Senescent Human Cells
https://doi.org/10.1002/stem.2996
So if you've followed EV research, EV's stand to become one of the hottest areas of medicine. There has been continued efforts to delineate longevity pathways conserved among all eukaryotes and specifically mammalian cellular physiology. So the race to find which epigenetic sites produce the best longevity strategies is progressing.
As we look at the hurdles to overcome in the "in-vivo amelioration of age-associated hallmarks by partial reprogramming" experiment, we find that reaching every cell required an OSKM cassette installed in each cell. This approach required a single cell embryo to ensure each cell would divide pass on and later respond to a drug administered in the mouse's water. In a human sense, attempting to infect enough cells in a mature adult with the OSKM cassette is not practical or possible.
Next issue, the effect was short-term. Meaning that cells still retained an epigenetic memory of their previous state. Hence repeated OSKM treatments were required. So the question is how long does epigenetic memory last? Scientists Have Observed Epigenetic Memories Being Passed Down For 14 Generations That's an inheritance scenario, what about Epigenetic memory in Induced Pluripotent Stem Cells (iPSC)? First off, Embryonic tissues are the most efficiently reprogrammed cells with the least reversion issues, producing iPSC that are nearly identical to Fetal Embryonic Stem Cells (fESC.) Different tissues show variable susceptibility to reprogramming and this constitutes an issue as we examine "in vivo amelioration of age-associated hallmarks by partial reprogramming." As the experiment title suggests they used "partial reprogramming." In the iPSC experiments epigenetic tissue identity was retained and reversion possible on many epigenetic markers. But from a longevity standpoint, we cant strip tissue identity markers without the consequences of cancer or tumors. I feel the answers are revealing themselves within Extracellular Vesicle i.e. exosome research.
There are 37.2 Trillion Cells in Your Body
How do we address so many individual cells if we can't practically install something like an OSKM cassette in each? Answer; one cell at a time. So where do we start? I believe the body already has a triage method installed so let's go with the evolutionary design.
Who are the first responders to injury, let us take one example leukocytes. These include neutrophils, basophils, eosinophils, monocytes, and lymphocytes. These cells are mobile, they make house calls, many are circulating freely or reside dormant in tissues until cell signaling cytokines and other messengers warn of injury and call for action.
See CAR T-Cell Immunotherapy as one approach.
So I would enlist the help of these and other cell types to create an army to get the job done. Make a few modifications to their epigenome to specialize them, and add the release of rejuvenating EV's to boost tissue recovery and add longevity. These cells could also be equipped with drug-induced cassette much like the OSKM cassette if these features needed external control or a suicide switch. So a multitude of tasks could be programmed into different cell groups and lay in wait until needed.
JMHO
Bryan
Edited by Bryan_S, 25 March 2019 - 10:16 PM.
Posted 27 March 2019 - 07:52 AM
They discuss "mediated by transient expression of mRNAs" and "Epigenetic Reprogramming of Aging (ERA), paves the way to a novel, potentially translatable strategy for ex vivo cell rejuvenation treatment."
Great article albedo. However, I could find no mention about epigenetic reversion after treatment or a followup maintenance protocol. This appears to be a good start towards an ex vivo regenerative cell treatment but obviously full body treatments with ERA will need further investigation.
As I read the results, in vivo experiments with ERA treated/transplanted cells appeared positive. I wanted to see long term survival of the ERA treated cells beyond the 11 days after transplantation. Still, long-term strength tests showed a retention of muscle improvement, even if they didn't do a florescence test beyond the 11 days.
Here was a recent review.
https://www.fightagi...rapy-for-aging/
Thanks
Posted 27 March 2019 - 12:24 PM
OK, connecting the sperm analogy to Extracellular Vesicles (EV)'s didn't land as I expected. Let's review a link to demonstrate its relevance to this topic ...
...So I would enlist the help of these and other cell types to create an army to get the job done. Make a few modifications to their epigenome to specialize them, and add the release of rejuvenating EV's to boost tissue recovery and add longevity. These cells could also be equipped with drug-induced cassette much like the OSKM cassette if these features needed external control or a suicide switch. So a multitude of tasks could be programmed into different cell groups and lay in wait until needed.
Great post Bryan, as usual (sorry to cut it for easiness of reading but each line counts!). I am likely missing the the point but just wonder if tacking with leukocytes is a good strategy as you tackle with with immune response and we know semen contains immunosuppressive agents protecting from parental response in the process of fertilization. But maybe here we are talking about a specially designed leukocyte, which would retain the broadly circulating characteristics, delivering the rejuvenating exosomes messages, sort of dedicated nanobot.
In any case a deep understanding of the epigenetics of fertilization, growth and then ageing together with putting in contrasts with each other every single phase could lead to the emergence of therapeutic potentials.
(edit: add last line)
Edited by albedo, 27 March 2019 - 12:50 PM.
Posted 15 April 2019 - 04:21 PM
They discuss "mediated by transient expression of mRNAs" and "Epigenetic Reprogramming of Aging (ERA), paves the way to a novel, potentially translatable strategy for ex vivo cell rejuvenation treatment."
Great article albedo. However, I could find no mention about epigenetic reversion after treatment or a followup maintenance protocol. This appears to be a good start towards an ex vivo regenerative cell treatment but obviously full body treatments with ERA will need further investigation.
As I read the results, in vivo experiments with ERA treated/transplanted cells appeared positive. I wanted to see long term survival of the ERA treated cells beyond the 11 days after transplantation. Still, long-term strength tests showed a retention of muscle improvement, even if they didn't do a florescence test beyond the 11 days.
Here was a recent review.
https://www.fightagi...rapy-for-aging/
Thanks
Yes, also maybe your comments will be made by peer reviewers as the paper is still unpublished and on bioRxiv. I also connect their mRNA approach to your EV idea meaning as a possible vehicle for the mRNA. Is that what Oisin is doing? LEAF interviewed Sebastiano at the Undoing Aging meeting in Berlin a couple of weeks ago and you might have seen it already here: https://www.leafscie...no-of-turn-bio/ (Sebastiano also contrasts his work with Ocampo et al but agree on the pioneering approach of the latter)
Edited by albedo, 15 April 2019 - 04:24 PM.
Posted 15 April 2019 - 06:14 PM
Instead of trying to avoid inducing pluripotent stem cells, teratoma risk can be avoided by supplying them by IV. That way their signalling is diluted and instead they go wherever they are needed in the body and differentiate as required.Conclusion: Teratoma can be easily and completely avoided by disseminating the cells. Direct in vivo iPSC application is feasible and can be safe.
Edited by QuestforLife, 15 April 2019 - 06:14 PM.
Posted 27 April 2019 - 11:30 AM
An interesting workshop. Maybe useful to follow some of the featured researchers:
https://www.unil.ch/...m_April2019.pdf
Posted 27 April 2019 - 02:52 PM
This, in my opinion, is a more viable route to rejuvenation:
https://www.ncbi.nlm...les/PMC6332789/
Instead of trying to avoid inducing pluripotent stem cells, teratoma risk can be avoided by supplying them by IV. That way their signalling is diluted and instead they go wherever they are needed in the body and differentiate as required.
ok yes this is fascinating
Intravenously administered iPSCs were therapeutic with a dose as low as 5×106/kg and some iPSCs differentiated into somatic cells in injured organs. Disseminated iPSCs trafficked into injured tissue and survived significantly longer in injured than uninjured organs. In disease-free animals, no intravenously administered cell differentiated into an unwanted long-lasting cell or survived as a quiescent stem cell. In coculture, the stem cell medium and dominant cell-type status were critical for iPSCs to form cell masses.
Unclear if this is mice, monkeys or humans?
Posted 27 April 2019 - 03:42 PM
ok yes this is fascinating
Unclear if this is mice, monkeys or humans?
Posted 27 April 2019 - 03:47 PM
Tables 2+3 in the paper summarise the MAMMOTH number of experiments they did; mostly in mice and monkeys; some used human iPSCs.
Ok so if they did this in humans what would be the source of iPSCs? Where would they come from?
Posted 27 April 2019 - 04:24 PM
Ok so if they did this in humans what would be the source of iPSCs? Where would they come from?
Edited by QuestforLife, 27 April 2019 - 04:26 PM.
Posted 27 April 2019 - 06:24 PM
So how does this differ from those places in Panama that currently offer stem cell treatments?
As I understand it they use the patients own stem cells, culture them, then inject them back into your body.
Posted 27 April 2019 - 06:58 PM
So how does this differ from those places in Panama that currently offer stem cell treatments?
As I understand it they use the patients own stem cells, culture them, then inject them back into your body.
Posted 27 April 2019 - 07:17 PM
Simple. They are not pluripotent stem cells. Various adult stem cells can only operate in their own particular environment, are not small enough to travel around the body through tissue boundaries to where they are needed, although they may have some efficacy for specific injury(anyone tried them?).
On the lyme disease forums a number of folks have tried it and almost universally they say it works great for about 3 months then effects wear off. Its usually injected into the knee or other joint.
So what is the difference in harvesting pluripotent sc then vs what these stem cell clinics are doing? Is it a question of how the harvesting is performed?
Posted 27 April 2019 - 08:11 PM
On the lyme disease forums a number of folks have tried it and almost universally they say it works great for about 3 months then effects wear off. Its usually injected into the knee or other joint.
So what is the difference in harvesting pluripotent sc then vs what these stem cell clinics are doing? Is it a question of how the harvesting is performed?
Posted 11 May 2019 - 01:42 AM
Here is a good article demonstrating the effect of introducing younger cells
https://www.nature.c...2003-019-0298-5
I "believe" younger mRNA expression is the key, the more the better. Maybe the trick is to rejuvenate a hosts bone marrow cells or fibroblasts in the lab and reintroduce these back into the host. The experiment published in the February 20th Nature is a flashback to heterochronic parabiosis. Only here they installed the cells that produce blood and plasma products.
I "believe" in the "In Vivo Amelioration of Age-Associated Hallmarks by Partial Reprogramming" experiment, the cell products, the extracellular vesicles and growth factors released were major contributors in the rejuvenation. But the reprogramming is temporary and the old epigenetics begin to reassert their old programming. This is why they developed a cyclic treatment.
So what would happen if a hosts marrow cells or fibroblasts could be brought back to a pluripotent state and be guided back to a "progenitor stem cell state" then reintroduced into the host? Here is one such concept experiment to see if this can be done in the host. Rejuvenation wasn't the objective See In Situ Modification of Tissue Stem and Progenitor Cell Genomes
There will be a multitude of paths created but I "believe" you need to rejuvenate some yet unknown percentage of cells producing the younger cell signaling and the rest will follow. The most cost-effective method will win out.
Edited by Bryan_S, 11 May 2019 - 02:04 AM.
Posted 14 May 2019 - 08:18 PM
The following can fit many places in the Forum but thought to post (or re-post) here in case you have missed it. An excellent and kept up-to-date chart of rejuvenation efforts and research/clinical phases progress, incl. of course epigenetic alterations and stem cells exhaustion:
https://www.lifespan...nation-roadmap/
Posted 15 May 2019 - 02:00 PM
Remember this study?
2016-12-16, In Vivo Amelioration of Age-Associated Hallmarks by Partial Reprogramming
Summary
Aging is the major risk factor for many human diseases. In vitro studies have demonstrated that cellular reprogramming to pluripotency reverses cellular age, but alteration of the aging process through reprogramming has not been directly demonstrated in vivo. Here, we report that partial reprogramming by short-term cyclic expression of Oct4, Sox2, Klf4, and c-Myc (OSKM) ameliorates cellular and physiological hallmarks of aging and prolongs lifespan in a mouse model of premature aging. Similarly, expression of OSKM in vivo improves recovery from metabolic disease and muscle injury in older wild-type mice. The amelioration of age-associated phenotypes by epigenetic remodeling during cellular reprogramming highlights the role of epigenetic dysregulation as a driver of mammalian aging. Establishing in vivo platforms to modulate age-associated epigenetic marks may provide further insights into the biology of aging.
I've resurfaced after that deep dive into the evidence about Near InfraRed (NIR) Light. After catching my breath and some reflection, a question begging to be asked has become clear.
Are the beneficial health effects triggered by Near Infrared light exposure mediated by epigenetic reprogramming?
Consider the information in the draft chart below. I've provided study links for the first 3 Study Effects by Near Infrared Light exposure up thread. I don't know if a study of NIR and lifespan has been done. We do know that NIR triggers Heat Shock Protein expression and we know that HSP expression can increase survival probability.
Is there a larger evidence-based explanation of the effects of NIR that suggests epigenetic reprogramming is going on?
Yes. There is.
The title of this forum thread is...
An Ancient "Heat Shock"/NRF2/Pluripotency Related Epigenetic Turn* Accelerates Human Aging** and These can be Modulated
- Links to studies demonstrating that Heat Shock Proteins "manage" the induction of pluripotent stem cells were provided in the opening post.
- Links to studies showing that HSP expression can increase survival probability appear upthread.
- And there's this study, among others, showing that NIR triggers HSP expression via TRP Channels.
2015, Role of TRP channels in the induction of heat shock proteins (Hsps) by heating skin
Transient receptor potential (TRP) channels in skin are crucial for achieving temperature sensitivity to maintain internal temperature balance and thermal homeostasis, as well as to protect skin cells from environmental stresses such as infrared (IR) or near-infrared (NIR) radiation via heat shock protein (Hsp) production. However, the mechanisms by which IR and NIR activate TRP channels and produce Hsps intracellularly have been independently reported. In this review, we discuss the relationship between TRP channel activation and Hsp production, and introduce the roles of several skin TRP channels in the regulation of HSP production by IR and NIR exposure.
A tentative model of Hsp production by heat[/size]
We discuss the roles of several skin TRP channels in the regulation of Hsps production via increased intracellular calcium induced ROS generation after IR and NIR exposure. Thus, the coexistence of TRPV1 and TRPA1 potentially supports a model to explain how hyperthermia can produce Hsps in the cell. This coexistence fulfills the necessary and sufficient conditions to produce Hsps; for Hsp production in the nucleus, an IP3 signal is needed. For IP3 production, PLC β must be activated; the Nishizuka school has already established that a rapid increase in Ca2+ is enough for PLC β activation in vitro. Also for in vivo study, a conditional tissue specific knockout mice are established, blocking TRPV1 or TRPA1 in skin to further detect the production of Hsps after IR/NIR exposure. Therefore, we hypothesize that the activation of TRP channels induces several types of Hsp proteins via intracellular calcium elevation to protect human skin (the largest organ of the human body) and maintain skin homeostasis from harmful EMW and high temperature.
So... the question is...
Are the beneficial health effects triggered by Near Infrared light exposure mediated by epigenetic reprogramming?
When a falsifying experiment is performed to determine the answer to the question, I believe the answer will turn out to be yes.
Oh... I forgot to remind about one last thing, a difference between the 2016 reprogramming study and the NIR effects studies...
The 2016 reprogramming study showed positive In-Vivo effects in mice. The NIR studies showing rapid skin and cognition improvement focused on Wild-Type Humans...
I guess that's an important difference, right?
Edited by HighDesertWizard, 15 May 2019 - 02:13 PM.
Posted 23 May 2019 - 02:05 PM
Here is a good article demonstrating the effect of introducing younger cells
https://www.nature.c...2003-019-0298-5
I "believe" younger mRNA expression is the key, the more the better. Maybe the trick is to rejuvenate a hosts bone marrow cells or fibroblasts in the lab and reintroduce these back into the host. The experiment published in the February 20th Nature is a flashback to heterochronic parabiosis. Only here they installed the cells that produce blood and plasma products.
I "believe" in the "In Vivo Amelioration of Age-Associated Hallmarks by Partial Reprogramming" experiment, the cell products, the extracellular vesicles and growth factors released were major contributors in the rejuvenation. But the reprogramming is temporary and the old epigenetics begin to reassert their old programming. This is why they developed a cyclic treatment.
...
Thank you. I think this is possibly supportive of your point:
"Extracellular vesicles (EVs), including exosomes and microvesicles, mediate intercellular communications and exert various biological activities via delivering unique cargos of functional molecules such as RNAs and proteins to recipient cells. Previous studies showed that EVs produced and secreted by human mesenchymal stem cells (MSCs) can substitute intact MSCs for tissue repair and regeneration. In this study, we examined properties and functions of EVs from human induced pluripotent stem cells (iPSCs) that can be cultured infinitely under a chemically defined medium free of any exogenous EVs. We collected and purified EVs secreted by human iPSCs and MSCs. Purified EVs produced by both stem cell types have similar sizes (∼150 nm in diameter), but human iPSCs produced 16‐fold more EVs than MSCs. When highly purified iPSC‐EVs were applied in culture to senescent MSCs that have elevated reactive oxygen species (ROS), human iPSC‐EVs reduced cellular ROS levels and alleviated aging phenotypes of senescent MSCs. Our discovery reveals that EVs from human stem cells can alleviate cellular aging in culture, at least in part by delivering intracellular peroxiredoxin antioxidant enzymes"
Liu S, Mahairaki V, Bai H, et al. Highly Purified Human Extracellular Vesicles Produced by Stem Cells Alleviate Aging Cellular Phenotypes of Senescent Human Cells. Stem Cells. 2019;
Posted 26 May 2019 - 05:03 AM
"Extracellular vesicles (EVs), including exosomes and microvesicles, mediate intercellular communications and exert various biological activities via delivering unique cargos of functional molecules such as RNAs and proteins to recipient cells. Previous studies showed that EVs produced and secreted by human mesenchymal stem cells (MSCs) can substitute intact MSCs for tissue repair and regeneration. In this study, we examined properties and functions of EVs from human induced pluripotent stem cells (iPSCs) that can be cultured infinitely under a chemically defined medium free of any exogenous EVs. We collected and purified EVs secreted by human iPSCs and MSCs. Purified EVs produced by both stem cell types have similar sizes (∼150 nm in diameter), but human iPSCs produced 16‐fold more EVs than MSCs. When highly purified iPSC‐EVs were applied in culture to senescent MSCs that have elevated reactive oxygen species (ROS), human iPSC‐EVs reduced cellular ROS levels and alleviated aging phenotypes of senescent MSCs. Our discovery reveals that EVs from human stem cells can alleviate cellular aging in culture, at least in part by delivering intracellular peroxiredoxin antioxidant enzymes"
Liu S, Mahairaki V, Bai H, et al. Highly Purified Human Extracellular Vesicles Produced by Stem Cells Alleviate Aging Cellular Phenotypes of Senescent Human Cells. Stem Cells. 2019;
2016, The Production of ExtraCellular Vesicles Is Increased after Heat Shock
When organisms are exposed to extreme conditions or stresses homeostasis is compromised. The natural cellular response to changes in homeostasis is mediated by the expression of a family of proteins coined heat shock proteins (hsp). These proteins are involved in the stabilization of basic cellular processes to preserve cell viability and to guaranty the return to homeostasis. In addition, they protect cells from subsequent insults in a time-dependent fashion. The bulk of hsp function occurred within the cytosol and subcellular compartments. However, hsp have also been found outside cells acting as signaling molecules directed at activating a systemic response to stress. Extracellular hsp are released after cell death by necrosis in a soluble form. Hsp are also exported by an active mechanism independent of cell death, in which hsp are associated with extracellular vesicles (ECV). Indeed, hsp have been detected in numerous preparations of ECV from different sources. We investigated the release of ECV after heat shock (HS) in human hepatoblastoma cells (HepG2). We observed a rapid production of ECV within a few hours after the insult. There were no differences in the size of vesicles derived from HS and control cells. However, HS cells produced between 2–3 folds more ECV than non-stressed cells. Analysis of the biochemical composition of ECV after HS revealed the presence of Hsp70, the major inducible form of hsp. Stress ECV were highly enriched in other cellular components, including tubulin and actin, in comparison with vesicles derived from stressed cells. These observations suggest that the mechanism of ECV release is different between stress and normal conditions. Finally, we propose that stress ECV induce a systemic response directed at avoiding the propagation of the insult, which has been named the “stress observation system” (SOS).
2018, Extracellular cell stress (heat shock) proteins-immune responses and disease: an overview
Extracellular cell stress proteins are highly conserved phylogenetically and have been shown to act as powerful signalling agonists and receptors for selected ligands in several different settings. They also act as immunostimulatory 'danger signals' for the innate and adaptive immune systems. Other studies have shown that cell stress proteins and the induction of immune reactivity to self-cell stress proteins can attenuate disease processes. Some proteins (e.g. Hsp60, Hsp70, gp96) exhibit both inflammatory and anti-inflammatory properties, depending on the context in which they encounter responding immune cells. The burgeoning literature reporting the presence of stress proteins in a range of biological fluids in healthy individuals/non-diseased settings, the association of extracellular stress protein levels with a plethora of clinical and pathological conditions and the selective expression of a membrane form of Hsp70 on cancer cells now supports the concept that extracellular cell stress proteins are involved in maintaining/regulating organismal homeostasis and in disease processes and phenotype. Cell stress proteins, therefore, form a biologically complex extracellular cell stress protein network having diverse biological, homeostatic and immunomodulatory properties, the understanding of which offers exciting opportunities for delivering novel approaches to predict, identify, diagnose, manage and treat disease.This article is part of the theme issue 'Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective'.
2019, Chaperone activation and client binding of a 2-cysteine peroxiredoxin
Many 2-Cys-peroxiredoxins (2-Cys-Prxs) are dual-function proteins, either acting as peroxidases under non-stress conditions or as chaperones during stress. The mechanism by which 2-Cys-Prxs switch functions remains to be defined. Our work focuses on Leishmania infantum mitochondrial 2-Cys-Prx, whose reduced, decameric subpopulation adopts chaperone function during heat shock, an activity that facilitates the transition from insects to warm-blooded host environments. Here, we have solved the cryo-EM structure of mTXNPx in complex with a thermally unfolded client protein, and revealed that the flexible N-termini of mTXNPx form a well-resolved central belt that contacts and encapsulates the unstructured client protein in the center of the decamer ring. In vivo and in vitro cross-linking studies provide further support for these interactions, and demonstrate that mTXNPx decamers undergo temperature-dependent structural rearrangements specifically at the dimer-dimer interfaces. These structural changes appear crucial for exposing chaperone-client binding sites that are buried in the peroxidase-active protein.
Edited by HighDesertWizard, 26 May 2019 - 05:06 AM.
Posted 26 May 2019 - 05:31 AM
< SNIP >
I "believe" younger mRNA expression is the key, the more the better. Maybe the trick is to rejuvenate a hosts bone marrow cells or fibroblasts in the lab and reintroduce these back into the host. The experiment published in the February 20th Nature is a flashback to heterochronic parabiosis. Only here they installed the cells that produce blood and plasma products.
I "believe" in the "In Vivo Amelioration of Age-Associated Hallmarks by Partial Reprogramming" experiment, the cell products, the extracellular vesicles and growth factors released were major contributors in the rejuvenation. But the reprogramming is temporary and the old epigenetics begin to reassert their old programming. This is why they developed a cyclic treatment.
< SNIP >
There will be a multitude of paths created but I "believe" you need to rejuvenate some yet unknown percentage of cells producing the younger cell signaling and the rest will follow. The most cost-effective method will win out.
Bryan... I like that you're thinking out-of-the-box and in terms of some quantitative threshold of cells impacted that must be achieved to stop "the old epigenetics ... [from] reassert[ing] their old programming".
We've been exploring at least 5 conjectures... I've restated and listed them below in a new order...
- “Heat Shock” Expression Declines in Humans During Aging but can be Modulated for Benefit
- Posts about practical, healthy longevity benefiting, heat shock protein-related interventions fall into this category.
- “Heat Shock”, OSKM, iPSC, and Epigenetic Reprogramming are Related Biological Processes
- study evidence supporting this conjecture was noted in the opening post of this thread
- An ancient "Heat Shock"-related aging switch exists in c elegans and is triggered in early adulthood
- A set of genes in mice and humans related to PSD-95 and Schizophrenia can be used to predict biological age and expression of these genes dramatically turns in early adulthood
- The Ancient "Heat Shock"-Related Aging Switch in c Elegans (conjecture #3) is the Ortholog ("comparable") Biological Process of gene expression turn in mice and humans highlighted in conjecture #4
- this is a conjecture I've been writing about in this forum thread with varying, hopefully increasing, degrees of clarity
Edited by HighDesertWizard, 26 May 2019 - 05:37 AM.
Posted 02 August 2019 - 11:47 AM
Long waited preprint on this work by D Sinclair and a host of well known researchers. Good progress in the area of reprogramming:
bioRxiv 710210; doi: https://doi.org/10.1101/710210
Ageing is a degenerative process leading to tissue dysfunction and death. A proposed cause of ageing is the accumulation of epigenetic noise, which disrupts youthful gene expression patterns that are required for cells to function optimally and recover from damage. Changes to DNA methylation patterns over time form the basis of an 'ageing clock', but whether old individuals retain information to reset the clock and, if so, whether this would improve tissue function is not known. Of all the tissues in the body, the central nervous system (CNS) is one of the first to lose regenerative capacity. Using the eye as a model tissue, we show that expression of Oct4, Sox2, and Klf4 genes (OSK) in mice resets youthful gene expression patterns and the DNA methylation age of retinal ganglion cells, promotes axon regeneration after optic nerve crush injury, and restores vision in a mouse model of glaucoma and in normal old mice. This process, which we call recovery of information via epigenetic reprogramming or REVIVER, requires the DNA demethylases Tet1 and Tet2, indicating that DNA methylation patterns don't just indicate age, they participate in ageing. Thus, old tissues retain a faithful record of youthful epigenetic information that can be accessed for functional age reversal.
Community →
News & Resources →
Interviews →
Hacking Aging - Genomic Failure HypothesisStarted by johnhemming , 08 Apr 2024 epigenetics |
|
|
||
Science & Health →
AgingResearch →
William Shatner and stem cell therapyStarted by osris , 08 Jan 2024 stem cells |
|
|
||
Science & Health →
AgingResearch →
Aging Theories →
Methylation showing gradual reduction in genomic functionStarted by johnhemming , 25 Dec 2023 epigenetics |
|
|
||
Science & Health →
AgingResearch →
Aging Theories →
The (new) telomere theory of agingStarted by hplus , 29 Apr 2023 telomeres, senescent cells and 1 more... |
|
|
||
Science & Health →
Supplements →
Vorinostat (HDAC inhibitor) source?Started by Guest_Funiture2_* , 31 Mar 2023 hdac, inhibitor, dnmt and 5 more... |
|
|
0 members, 2 guests, 0 anonymous users