YAMANAKA FACTORS / RIR
Reprogramming-Induced Rejuvenation
(WikiLinks: Yamanaka Factors) - (Last Revision: 10/14/2022)
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The timeline of major scientific advances during the history of stem cell research. Multipotent stem cells were first discovered in 1961, representing the initial breakthrough in stem cell and regenerative medicine. Dolly the sheep was cloned in 1997. The transition from fundamental research, to pre-clinical research, and finally to clinical trials is driven by many discoveries and milestones. Many advances in reprogramming factor combinations, experimental methods, and the elucidation of signaling pathways have recently contributed to the first clinical trials for retinal cell transplants and spinal cord transplants. Red shading represents fundamental research, yellow shading represents pre-clinical work, and green shading represents clinical trials. [18]
◉ Instructions to restart life, to reset the cell back to a prior age-state including age zero, are contained within almost all somatic cells.
◉ Yamanaka factors(YF), constitute a set of protein transcription factors or reprogramming molecules that can rejuvenate cells and reset the molecular clocks found in cells of all multi-cellular organisms.
◉ Epigenetic reprogramming using cyclic expression of Yamanaka factors have demonstrated rejuvenation on a systemic level in animal models with no obvious deleterious e!ects.
◉ Small-molecule, chemical reprogramming has demonstrated improvements in key drivers of aging, including; genomic instability, and epigenetic alterations in aged human cells and organisms.
◉ It has now been determined that only two small-molecules are sufficient to achieve Reprogramming Induced Rejuvenation (RIR), ameliorating aging phenotypes including cellular senescence and oxidative stress.
Development Path to Reprogramming Induced Rejuvenation
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Yamanaka factors consist of (Oct3/4, Sox2, Klf4, c-Myc (OSKM)) a group of protein transcription factors that can revert cellular lineage back to an undifferentiated state. When this cell state is “induced” by exogenous factors or small molecules, the cells are referred to as induced pluripotent stem cells (IPSC). Driving any specialized cell type back to an undifferentiated state is obviously not an ideal result in any systemic therapeutic.
Reprogramming Induced Rejuvenation (RIR) does not change cell identity, but can reverse markers of aging in cells, improve the capacity of an animale to repair tissue injuries, and extend longevity in a rapidly aging mouse model, (progeroid mice). They do so by returning unique patterns of chemicals known as epigenetic markers, which evolve through aging, to their original states. Additionally metabolic and transcriptomic changes occur that drive cells, tissues and blood serum back to a younger state.
Recent research has demonstrated that RIR can now be accomplished by pulsing two drugs, a TGF inhibitor and an MOA inhibitor.
⫸Little is known about the mechanisms involved. Here, we have studied changes in the DNA-methylome, transcriptome, and metabolome in naturally aged mice subject to a single period of transient OSKM expression. We found that this is sufficient to reverse DNA methylation changes that occur upon aging in the pancreas, liver, spleen, and blood. Similarly, we observed reversion of transcriptional changes, especially regarding biological processes known to change during aging. Finally, some serum metabolites and biomarkers altered with aging were also restored to young levels upon transient reprogramming. These observations indicate that a single period of OSKM expression can drive epigenetic, transcriptomic, and metabolomic changes toward a younger configuration in multiple tissues and in the serum. ⫷[10]
⫸Cellular reprogramming has demonstrated the potential of regenerative medicine, but also in the ageing field through the amelioration of both physiological and cellular ageing hallmarks. While partial reprogramming might be used as a catch-all term to describe this type of rejuvenation, it does not reflect the fact that the described interrupted cellular reprogramming techniques are applied with the aim of (epigenetic) rejuvenation as opposed to inducing pluripotency (loss of cell identity). Reprogramming-induced rejuvenation (RIR) is a better term, capturing the nature of the utilised process and final aim of the interventions [131]. RIR has shown promise as a treatment to safely reverse ageing whilst retaining the ability to revert to or maintain original cell identity, both in vivo [74, 127, 129] and in vitro [73, 118, 125]. ⫷⟦3⟧
In 2006 Shinya Yamanaka Identified what are now universally referred to as Yamanaka factors. He published his findings in 2007 and received the 2012 Nobel prize in medicine for an advancement that may shortly become the leader in anti-aging therapeutics.
A small number of small molecules that replicate the functionality of the 4 original Yamanaka factors hold the real possibility of a therapeutic being readily available in the near future and without commercial development limitations.
A proof-of-principle study demonstrates that somatic reprogramming toward pluripotency can be manipulated using only small-molecule compounds. It reveals that the endogenous pluripotency program can be established by the modulation of molecular pathways nonspecific to pluripotency via small molecules rather than by exogenously provided "master genes." These findings increase our understanding about the establishment of cell identities and open up the possibility of generating functionally desirable cell types in regenerative medicine by cell fate reprogramming using specific chemicals or drugs, instead of genetic manipulation and difficult-to-manufacture biologics. To date, the complete chemical reprogramming approach remains to be further improved to reprogram human somatic cells and ultimately meet the needs of regenerative medicine.
[2013] Pluripotent Stem Cells Induced from Mouse Somatic Cells by Small-Molecule Compounds
Yamanaka’s transcription factors originally consisted of four chemical factors that were capable of regressing samontic cells back to a pluripotent state. This was the first time an intact differentiated somatic cell could be reprogrammed to become pluripotent. In 2020 David Sinclair demonstrated that the sight of mice could be restored utilizing just three of the original Yamanaks factors introduced by viral transduction. He accomplished this safely by carefully controlling dose and interval.
[2020] Reprogramming to recover youthful epigenetic information and restore vision
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In 2016 a group at the Salk Institute led by Juan Carlos Izpisua Belmonte, demonstrated that cellular reprogramming by transient expression of Yamanaka factors ameliorates age-associated symptoms, prolongs lifespan in an excellerated mouse model of aging (progeroid mice), and improves tissue homeostasis in older mice. These mice lived longer than the controls, but also had an improved Healthspan.
[2016] In Vivo Amelioration of Age-Associated Hallmarks by Partial Reprogramming
In 2022 this work was repeated and expanded using normal, wild type mice. Now, researchers have show that long-term partial reprogramming leads to rejuvenating effects in different tissues of mice and at the organismal level. In addition, they show that duration of the treatment determined the extent of the beneficial effects. Transient, pulsed administration of Yamanaka factors was both safe and effective in mice. The rejuvenating effects, the authors note, were associated with a reversion of the epigenetic clock and metabolic and transcriptomic changes, including reduced expression of genes involved in the inflammation, senescence and stress response pathways. The blood of treated animals did not show normal age-related changes. This work is being commercially developed by Altos Labs, a new biotechnology company “focused on cellular rejuvenation programming to restore cell health and resilience, with the goal of reversing disease to transform medicine.”
More information on Altos Lab as an investment opportunity can be found here.
Abstract:
Partial reprogramming by expression of reprogramming factors (Oct4, Sox2, Klf4 and c-Myc) for short periods of time restores a youthful epigenetic signature to aging cells and extends the life span of a premature aging mouse model. However, the effects of longer-term partial reprogramming in physiologically aging wild-type mice are unknown. Here, we performed various long-term partial reprogramming regimens, including different onset timings, during physiological aging. Long-term partial reprogramming lead to rejuvenating effects in different tissues, such as the kidney and skin, and at the organismal level; duration of the treatment determined the extent of the beneficial effects. The rejuvenating effects were associated with a reversion of the epigenetic clock and metabolic and transcriptomic changes, including reduced expression of genes involved in the inflammation, senescence and stress response pathways. Overall, our observations indicate that partial reprogramming protocols can be designed to be safe and effective in preventing age-related physiological changes. We further conclude that longer-term partial reprogramming regimens are more effective in delaying aging phenotypes than short-term reprogramming.
A Dramatic Advancement in the Clinical and Commercial Availability of Yamanaka Factors in Future Treatment Paradigms
Now a group out of Switzerland led by Alejandro Ocampo has demonstrated that only two small molecules can accomplish the benefit of regressing not just cells, but whole organisms back to a more youthful state. The first authors of this study; Patrick Paine and Lucas Schoenfeldt, demonstrated that by controlling dose and interval, the two agents can be utilized while simultaneously reducing the risk of driving cells into an undifferentiated or oncogenic state.
The most amazing and compelling element of this research are the two chemical agents utilized to accomplish these results are readily available; a TGFbeta-1, ALK5 inhibitor (RepSox) and a prescription antidepressant; Tranycypromine, a monoamine oxidase inhibitor with a brand name of Parnate.
There is a large body of research demonstrating the efficacy of utilizing inhibitors to the ALK5 pathway. A prime example is the Conboy’s paper: [2018] Rejuvenation of brain, liver and muscle by simultaneous pharmacological modulation of two signaling determinants, that change in opposite directions with age. A large number of potent and effective, nutritional supplement inhibitors of ALK5 exists. See this page: (Transforming Growth Factor beta-1(TGFb-1))
Multiple groups and researchers have also demonstrated anti-aging benefits from drugs that inhibit the monoamine oxidase (MAO) pathway. This research dates back to the 1940’s by professor Ana Aslan’s, with procaine hydrochloride, a drug developed as a safe alternative / derivative of cocaine in 1905. A large amount of information has been catalogued on this site ( PROCAINE HCI ) describing that research.
We do not currently know if this combination is effective or safe in mammals. I would propose that the answers to those questions will come quickly, if not from clinical research, then from biohackers. Potential insights into dosage, interval, effect and safety are contained in the Belmonte mouse studies.
Harold Katcher has already demonstrated a fast and effective way to determine one level of efficacy by utilizing ( E5 ) topically. If the rejuvenative effects of two Ocampo factors (2OF) are effective, then that simple, fast and effective experiment may provide us with our first insights into the safety and effectiveness of a new leader in the race to effectively regress aging.
The paper that describes accomplishing RIR with two small molecules is linked below.
[2022] Chemical reprogramming ameliorates cellular hallmarks of aging and extends lifespan
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MAO-A AS AN IMMUNE REGULATOR
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⫸ MAO-A was recently discovered to be upregulated in TIIs, especially in exhausted intratumoral CD8 T cells. This led to the hypothesis that MAO-A may be a negative regulator of antitumor T cell immunity through some unknown mechanism, so further studies examining the functions of knockout MAO-A T cells in tumor-challenged mice were conducted to determine whether there was any impact on oncolytic activity. Wang et al. reported that MAO-A-KO mice exhibited significantly suppressed tumor growth in two syngeneic mouse tumor models (5). This improved tumor-suppression response was accompanied by an increase in cytokine and cytotoxic molecule release in MAO-A-KO mice, indicating that the knockout of MAO-A results in increased cytotoxic lymphocyte (CTL) activity. To further dissect the mechanisms underlying the antitumor effects of MAO-A-KO T cells, researchers demonstrated that MAO-A-KO CD8 T cells produce higher levels of serotonin, which acts as an autocrine immune regulator to activate the downstream immunostimulatory mitogenactivated protein kinase (MAPK) pathway through 5-HTRs (5). This signaling pathway in turn “cross-talks” with the T cell receptor (TCR) signaling pathway, resulting in the enhanced effector function observed in MAO-A-KO T cells (Figure 1A) (5).
In addition to MAO-A’s role as a T cell regulator, another recent study revealed that MAO-A activity in tumor-associated macrophages (TAMs) was positively correlated with immune suppression (14). A knockout study comparing tumor-laden MAO-A-deficient mice and WT mice revealed that MAO-AKO TAMs expressed lower levels of immunosuppressive markers and higher levels of immunostimulatory molecules (14). This led to the elucidation of a novel immunosuppressive mechanism of action associated with MAO-A in TAMs in addition to its role in T cells (5). The oxidation of monoamines in neurotransmitters such as serotonin by MAO-A results in the intracellular accumulation of reactive oxygen species (ROS) (14, 15). These ROS cause oxidative stress that polarizes the TME through the stimulation of the immunosuppressive JAK-Stat6 pathway and the production of immunosuppressive cytokines (Figure 1A) (16, 17). This demonstrated the multifaceted effects that MAO-A has on immune function in the TME. ⫷ [20]
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Click [√] to Enlarge Source: Developmental signaling network regulated by endogenous Yamanaka factors.
(A) Pathway classification for the target genes of each endogenous Yamanaka factor using KOBAS. All enriched pathways are categorized into developmental signaling, cancers, metabolism, and others. The numbers in the figure represent the number of signaling pathways regulated by each of the Yamanaka factors.
(B) The signaling regulatory network of endogenous Yamanaka factors shows autoregulation, interconnectivity, and feed-forward regulation. Regulation of each Yamanaka factor on the known pluripotency-associated pathways is also shown ronroccod known nlurinatonav_accncintod nathwavd If (pink: Yamanaka factors; yellow: the activated known pluripotency-associated pathways; green: the repressed known pluripotency-associated pathways).
(C) Endogenous Yamanaka factors regulated other developmental signaling pathways, whose association with ES cell pluripotency is not yet established. The dashed arrows show the potential association with ES cell pluripotency (yellow: the activated known pluripotency-associated pathways; green: the repressed known pluripotency-associated pathways).
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References:
[2] [2020] Reprogramming to recover youthful epigenetic information and restore vision
[3] [2021] Cellular reprogramming and epigenetic rejuvenation
[5] [2022] Aging Delayed in Mice through Longer-Term Partial Reprogramming
[6] [2022] Cellular Rejuvenation Therapy Safely Reverses Signs of Aging in Mice
[7] [2022] Chemical reprogramming ameliorates cellular hallmarks of aging and extends lifespan
[9] [2022] Multi-omic rejuvenation of human cells by maturation phase transient reprogramming
[11] [2016] In Vivo Amelioration of Age-Associated Hallmarks by Partial Reprogramming
[14] [2022] The hypothetical utilisation of Entomopoxvirus to achieve rejuvenation through cyclic expression of Yamanaka factors
[15] [2022] Cellular reprogramming and the rise of rejuvenation biotech
[16] [2014] Reprogramming Can Be a Transforming Experience
[18] [2019] Advances in Pluripotent Stem Cells: History, Mechanisms, Technologies, and Applications
[19] [2018] Human pluripotent reprogramming with CRISPR activators
[20] [2022] MAOI Antidepressants- Could They Be a Next-Generation ICB Therapy
Cancer: Returning cancer cells to normal cell function
As indicated above, Reprogramming-induced rejuvenation (RIR) has shown promise as a treatment to safely revert old cells back you a younger state while retaining the ability to revert to or maintain original cell identity. One of the significant utilities of cancer cell reprogramming is the therapeutic potential of retrieving normal cell functions from various malignancies. Currently, it is only feasible to conduct such reprogramming in laboratory settings, but there is an increasing number of studies that are focusing on optimizing cancer cell reprogramming so that it can be safely, specifically and effectively used in clinical treatments [96]. Various approaches, including transcription factors, small molecules, microRNAs, and exosome-mediated cancer cell reprogramming, have achieved tremendous accomplishments, making it increasing versatile and convenient in preclinical as well as clinical practices.
[2019] Cancer cell reprogramming: a promising therapy converting malignancy to benignity
Reference [13] “Premature termination of reprogramming in vivo leads to cancer development through altered epigenetic regulation.” is a strong indication that the development of RIR is at a very early stage of development. Clinical studies in animal models will be required prior to any human clinical trials making them years in the future.