Partial Neuronal Reprogramming via Modified Yamanaka Cocktail

Proposed by etl-backfill

OCT4 neurodegeneration market 77% debated
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Composite
67%
Novelty
95%
Feasibility
20%
Impact
80%
Mechanistic
40%
Druggability
15%
Safety
25%
Confidence
50%

Mechanistic description

Mechanistic Overview

Partial Neuronal Reprogramming via Modified Yamanaka Cocktail starts from the claim that modulating OCT4 within the disease context of neurodegeneration can redirect a disease-relevant process. The original description reads: "The hypothesis of partial neuronal reprogramming via a modified Yamanaka cocktail represents a paradigm shift in approaching neurodegeneration through epigenetic rejuvenation while preserving neuronal identity. This approach leverages the fundamental principle that cellular aging is largely driven by progressive epigenetic modifications rather than irreversible genetic damage, making it theoretically reversible through controlled reprogramming interventions. Molecular Mechanism of Action: The central mechanism involves OCT4-mediated chromatin remodeling operating through multiple interconnected pathways. OCT4, as a POU-domain transcription factor, functions as a pioneer transcription factor capable of binding to nucleosomal DNA and recruiting chromatin remodeling complexes including SWI/SNF, NuRD, and CoREST complexes. In the context of neuronal reprogramming, OCT4 expression at 10-30% of pluripotency levels initiates chromatin relaxation without triggering the full pluripotency gene regulatory network. The modified cocktail excludes c-MYC to prevent oncogenic transformation and includes SOX2 and KLF4 at reduced levels (20-40% of standard reprogramming concentrations). SOX2, sharing heterodimerization capacity with OCT4, enhances chromatin accessibility at neuronal enhancer regions while KLF4 facilitates the removal of repressive histone marks, particularly H3K9me3 and H3K27me3. The addition of ASCL1 serves as a neuronal-specific pioneer factor that maintains chromatin accessibility at neuronal gene loci, while BRN2 (POU3F2) acts as a neuronal identity safeguard, preventing dedifferentiation beyond intermediate progenitor states. Upstream Regulators and Downstream Effectors: Upstream regulation involves the controlled activation of reprogramming factors through doxycycline-inducible promoter systems, allowing precise temporal control. The pathway is modulated by endogenous neuronal factors including REST/NRSF, which maintains neuronal gene silencing in non-neuronal contexts but becomes permissive under partial reprogramming conditions. MicroRNA networks, particularly miR-124 and miR-9 families, provide additional regulatory layers that favor neuronal identity maintenance. Downstream effectors include the TET family enzymes (TET1, TET2, TET3) which are recruited by OCT4 to promote active DNA demethylation at CpG sites associated with youthful neuronal function. The pathway activates DNMT3L and inhibits DNMT1/3A to reset DNA methylation patterns. Chromatin remodeling leads to reactivation of silenced neuronal genes including BDNF, CREB, ARC, and synaptic plasticity genes while simultaneously rejuvenating mitochondrial biogenesis through PGC-1α activation. Connection to Disease Pathology: Neurodegeneration involves progressive accumulation of repressive epigenetic marks that silence neuroprotective genes and activate inflammatory pathways. In Alzheimer’s disease, hypermethylation of BDNF and CREB promoters contributes to synaptic dysfunction, while altered H3K4me3 patterns affect tau and amyloid processing genes. The partial reprogramming approach specifically targets these age-associated epigenetic changes, potentially reversing the molecular basis of neurodegeneration rather than merely treating symptoms. The mechanism addresses multiple pathological hallmarks simultaneously: restoring synaptic plasticity genes, reactivating stress response pathways, improving mitochondrial function through epigenetic control of OXPHOS genes, and reducing neuroinflammation by resetting microglial activation states through paracrine signaling from rejuvenated neurons. Therapeutic Window and Dosing Considerations: The therapeutic window requires precise optimization of factor levels and timing to achieve rejuvenation without losing neuronal identity. Based on preliminary studies, OCT4 expression should be maintained at 15-25% of embryonic stem cell levels for 48-72 hour pulses, followed by 96-120 hour rest periods. This pulsed approach allows epigenetic remodeling while permitting neuronal identity factors to reassert control. Dosing considerations involve vector copy number (optimal range 2-5 copies per cell), induction timing (3-4 cycles for maximal benefit without toxicity), and regional specificity (hippocampal neurons may require different protocols than cortical neurons due to distinct chromatin landscapes). The approach requires careful monitoring of reprogramming depth using established biomarkers including methylation age clocks and chromatin accessibility profiles. Comparison with Existing Approaches: Current neurodegeneration treatments focus on symptomatic relief or single pathway modulation (cholinesterase inhibitors, amyloid-targeting therapies), whereas partial reprogramming addresses fundamental aging processes. Unlike stem cell replacement strategies that require cell transplantation, this approach rejuvenates endogenous neurons in situ, preserving established neural circuits and avoiding integration challenges. Compared to small molecule approaches targeting individual epigenetic enzymes (HDAC inhibitors, DNMT inhibitors), partial reprogramming provides coordinated, comprehensive epigenetic remodeling. The approach offers advantages over gene therapy targeting single factors by addressing the multifactorial nature of neuronal aging through coordinated transcriptional network reset. Potential Biomarkers for Efficacy: Epigenetic age biomarkers include the Horvath clock and neural-specific methylation clocks measuring biological age reversal. Functional biomarkers encompass synaptic protein expression (PSD95, synaptophysin, SNAP25), dendritic spine density measurements, and electrophysiological parameters including long-term potentiation magnitude and action potential properties. Molecular biomarkers include chromatin accessibility changes measured by ATAC-seq, histone modification patterns (H3K4me3/H3K27me3 ratios), and single-cell RNA sequencing profiles demonstrating youthful gene expression patterns while maintaining neuronal identity markers. Functional outcomes include cognitive assessments, neuroimaging measures of brain volume and connectivity, and CSF biomarkers reflecting neuronal health. Testable Predictions: The hypothesis predicts that partial reprogramming will: (1) reduce DNA methylation age by 20-40% in treated neurons while maintaining >95% neuronal marker expression, (2) restore synaptic plasticity to youthful levels as measured by LTP amplitude and duration, (3) improve mitochondrial function indicated by increased ATP production and reduced ROS levels, (4) enhance cognitive performance in aged animal models by 30-50% across multiple domains, and (5) demonstrate dose-dependent effects with optimal efficacy at specific factor concentration ranges. Additional predictions include restoration of circadian rhythm gene expression, improved stress resistance, and enhanced neurogenesis in neurogenic niches through paracrine effects from rejuvenated neurons. Key Experimental Model Systems: Primary experimental models include aged primary neurons from 18-24 month old mice and rats, allowing assessment of reprogramming in naturally aged cells. Human iPSC-derived neurons subjected to aging protocols (oxidative stress, mitochondrial dysfunction) provide translational relevance. Organotypic brain slice cultures from aged animals enable assessment of reprogramming effects within preserved neural circuit architecture. In vivo models encompass naturally aged mice (18-24 months), accelerated aging models (SAMP8, progerin-expressing mice), and disease-specific models (5xFAD Alzheimer’s mice, MPTP Parkinson’s models). Non-human primate studies using aged macaques would provide critical translational data given the evolutionary conservation of reprogramming mechanisms and brain structure similarity to humans. Advanced model systems include brain organoids derived from aged human fibroblasts, allowing assessment of species-specific responses, and microfluidic culture systems enabling precise factor delivery control and real-time monitoring of reprogramming progression. These models collectively provide the experimental framework necessary to validate, optimize, and translate partial neuronal reprogramming approaches toward clinical application. Challenges and Risk Mitigation Challenge 1: Oncogenic Risk. Even modified Yamanaka factors carry theoretical cancer risk. OCT4, SOX2, and KLF4 are expressed in various cancers. Mitigation: The modified cocktail excludes c-MYC. Use self-limiting expression systems with built-in kill switches (inducible caspase-9). Implement strict temporal control through doxycycline-responsive promoters. Long-term safety monitoring in non-human primates (minimum 2 years) before human trials. Challenge 2: Loss of Neuronal Identity. Excessive reprogramming could push neurons into dedifferentiation, losing established synaptic connections. Mitigation: ASCL1 and BRN2 serve as neuronal identity safeguards. Monitor neuronal identity markers (NeuN, MAP2, synapsin) in real-time. If neuronal marker expression drops below 90% of baseline, terminate the reprogramming cycle. Single-cell RNA sequencing at each cycle endpoint confirms identity preservation. Challenge 3: Immune Response to Viral Vectors. AAV-mediated delivery may trigger immune responses, limiting repeated dosing. Mitigation: Use non-viral delivery systems (lipid nanoparticles carrying mRNA) for repeatable dosing without immunogenicity concerns. mRNA-based delivery provides inherently transient expression, adding a natural safety layer. Challenge 4: Heterogeneous Response Across Neuronal Subtypes. Different neuronal populations have distinct chromatin landscapes and may respond differently. Mitigation: Develop subtype-specific promoter systems. Characterize response heterogeneity in organoid models before in vivo application. Accept that initial applications may target specific populations (e.g., hippocampal neurons in AD, dopaminergic neurons in PD). Resource Requirements and Timeline - Cocktail optimization in human iPSC-derived neurons: 18 months, 4-6M - Safety validation in rodent models (12-month follow-up): 24 months, 8-12M - Delivery platform development (LNP-mRNA or AAV): 24 months, 10-15M - Non-human primate studies (24-month follow-up): 36 months, 15-25M - IND-enabling studies and regulatory interactions: 18 months, 8-12M - Phase 1/2a first-in-human trial: 36 months, 30-50M - Total to proof-of-concept: $75-120M over 10-12 years Competitive Landscape - Altos Labs: Well-funded startup focused on cellular rejuvenation through reprogramming. Primary focus on peripheral tissues; neuronal applications in early research. - Turn Biotechnologies: mRNA-based partial reprogramming (ERA platform). Demonstrated epigenetic age reversal in human cells but not yet in neurons. - Shift Bioscience: Working on partial reprogramming with machine learning-guided optimization. - Retro Biosciences: Focused on autophagy and partial reprogramming for longevity. Key differentiation: This hypothesis is uniquely positioned by its neuronal-specific modifications — ASCL1 and BRN2 as identity safeguards, c-MYC exclusion for safety, and pulsed dosing optimized for post-mitotic cells. While competitors pursue broad tissue rejuvenation, this specifically solves reprogramming of non-dividing neurons without losing identity. Regulatory Pathway The regulatory pathway would follow the gene therapy framework (CBER). Key considerations include long-term follow-up requirements (15 years recommended), tumorigenic risk assessment, and potential for RMAT designation. The combination of unmet need and novel mechanism suggests eligibility for Fast Track and Breakthrough Therapy designations that could compress the development timeline. Initial targeting of rare tauopathies (PSP, CBD) could enable Orphan Drug Designation.

Mechanistic Pathway Diagram

graph TD
 A["Complement<br/>Activation"] --> B["C1q/C3b<br/>Opsonization"]
 B --> C["Synaptic<br/>Tagging"]
 C --> D["Microglial<br/>Phagocytosis"]
 D --> E["Synapse<br/>Loss"]
 F["OCT4 Modulation"] --> G["Complement<br/>Cascade Block"]
 G --> H["Reduced Synaptic<br/>Tagging"]
 H --> I["Synapse<br/>Preservation"]
 I --> J["Cognitive<br/>Protection"]
 style A fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a
 style F fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7
 style J fill:#1b5e20,stroke:#81c784,color:#81c784

" Framed more explicitly, the hypothesis centers OCT4 within the broader disease setting of neurodegeneration. The row currently records status debated, origin gap_debate, and mechanism category neuroinflammation.

SciDEX scoring currently records confidence 0.50, novelty 0.95, feasibility 0.20, impact 0.80, mechanistic plausibility 0.40, and clinical relevance 0.42.

Molecular and Cellular Rationale

The nominated target genes are OCT4 and the pathway label is Epigenetic regulation. Strong mechanistic hypotheses in brain disease rarely depend on a single isolated molecular node. Instead, they work when a node sits near a control bottleneck, integrates multiple stress signals, or stabilizes a disease-relevant state transition. That is the standard this hypothesis should be held to. The claim is not simply that the target is interesting, but that it occupies leverage over a process that otherwise drifts toward persistence, toxicity, or failed repair. Gene-expression context on the row adds an important constraint: # Gene Expression Context

OCT4

  • Primary Function: OCT4 (Octamer-binding transcription factor 4, encoded by POU5F1) is a POU-domain pioneer transcription factor that serves as a master regulator of pluripotency and cellular reprogramming. Functions as a sequence-specific DNA-binding protein capable of binding nucleosomal DNA and recruiting chromatin remodeling complexes (SWI/SNF family members, BAF complexes) to facilitate chromatin accessibility and transcriptional activation of developmental and reprogramming genes. • Baseline Brain Expression Patterns: OCT4 expression in adult mammalian brain is markedly restricted compared to embryonic stages. Allen Human Brain Atlas data shows minimal to undetectable OCT4 mRNA expression in most mature cortical and subcortical regions, with highest relative expression in: - Subventricular zone (SVZ) neurogenic niche—focal expression in neural progenitor cells - Dentate gyrus of hippocampus—low-level expression in neural stem cells - Expression typically <5% of embryonic levels in differentiated neurons • Cell Type Specificity: In adult brain, OCT4 expression is largely restricted to: - Neural stem/progenitor cells (NSPCs) in neurogenic niches - Rare quiescent neural stem cells - Essentially absent in mature neurons under physiological conditions - Not detected in mature astrocytes, oligodendrocytes, or microglia in normal adult brain • Disease State Expression Changes in Neurodegeneration: - Alzheimer’s disease: Dysregulated OCT4 expression detected in vulnerable neuronal populations; some evidence suggests aberrant OCT4 reactivation in senescent neurons as failed reprogramming attempt - Parkinson’s disease: Limited direct evidence; however, age-related loss of NSC function correlates with reduced OCT4 in remaining progenitor populations - General neurodegeneration: OCT4 downregulation in NSPCs contributes to age-related decline in neurogenic capacity; progressive epigenetic silencing of OCT4 locus occurs during aging - Neuroinflammatory conditions: Microglial activation can suppress OCT4 expression in adjacent neural progenitors through TNF-α signaling • Relevance to Partial Reprogramming Hypothesis: OCT4’s role as a pioneer transcription factor makes it central to epigenetic rejuvenation while maintaining neuronal identity. Key mechanisms include: - Chromatin remodeling capacity: OCT4 recruitment of BAF complexes facilitates opening of aged chromatin without complete pluripotency commitment - Transient partial expression: Modified Yamanaka cocktail approach likely requires temporally-controlled, sub-maximal OCT4 activation to reverse epigenetic aging marks while suppressing full reprogramming to pluripotency - Direct reversal of senescence markers: OCT4-driven reactivation of aging-suppressed developmental genes may restore mitochondrial function, proteostasis pathways, and DNA repair capacity - Pioneer factor activity: OCT4 can establish permissive chromatin states at promoters of neuroprotective genes (e.g., BDNF, neurotrophic factors) that become epigenetically silenced during neurodegeneration • Quantitative Considerations: - Reprogramming studies indicate OCT4 requires 5-10 fold transient elevation above basal neuronal levels to initiate chromatin remodeling without triggering pluripotency - Complete silencing of OCT4 via epigenetic modification increases 2-3 fold during normal aging - Partial reprogramming protocols typically target 20-30% of the full Yamanaka factor expression intensity achieved in iPSC generation If the intervention succeeds, downstream consequences should include cleaner biomarker separation, improved cellular resilience, reduced inflammatory spillover, or better maintenance of synaptic and metabolic programs. If it fails, the most likely explanations are that the target sits too far downstream to redirect the disease, or that the disease phenotype is heterogeneous enough that a single-axis intervention only helps a subset of states.

Evidence Supporting the Hypothesis

  1. Cyclic expression of Yamanaka factors ameliorates age-associated phenotypes in progeria mice without tumor formation. 1CitationPMID 27984723Open reference.

  2. Brief OSK treatment restores vision in aged mice by rejuvenating retinal ganglion cells. 2CitationPMID 33268894Open reference.

  3. Partial reprogramming restores cognitive function and reverses age-associated DNA methylation in aged mice. 3CitationPMID 33398039Open reference.

  4. Oct4 acts as a pioneer transcription factor capable of binding nucleosomal DNA and initiating reprogramming. 4CitationPMID 23260147Open reference.

  5. Transient reprogramming factor expression can rejuvenate cells without complete dedifferentiation. 5CitationPMID 32747729Open reference.

  6. DNA methylation changes during aging are reversible through epigenetic reprogramming interventions. 6CitationPMID 28877458Open reference.

Contradictory Evidence, Caveats, and Failure Modes

  1. Neuronal cells show resistance to reprogramming due to stable epigenetic landscapes and post-mitotic state. 7CitationPMID 22445517Open reference.

  2. Oct4 expression in neurons can lead to apoptosis and cell death rather than rejuvenation. 8CitationPMID 21885018Open reference.

  3. Aged neurons accumulate irreversible protein aggregates that cannot be cleared by epigenetic reprogramming. 9CitationPMID 24055329Open reference.

  4. Complete exclusion of c-Myc reduces reprogramming efficiency below therapeutic thresholds. 10CitationPMID 18035408Open reference.

  5. Viral vector delivery to neurons carries significant safety risks including inflammatory responses. 2CitationPMID 33268894Open reference0.

Clinical and Translational Relevance

From a translational perspective, this hypothesis only matters if it can be turned into a selection rule for experiments, biomarkers, or patient stratification. The row currently records market price 0.7043, debate count 3, citations 37, predictions 9, and falsifiability flag 1. Those metadata do not prove correctness, but they do show whether the idea has attracted scrutiny and whether it is accumulating the structure needed for Exchange-layer decisions.

  1. Trial context: Recruiting.

  2. Trial context: Recruiting.

  3. Trial context: Active, not recruiting. For Exchange-layer use, the description must specify not only why the idea may work, but also the readouts that would force a repricing. A description that never names disconfirming evidence is not investable science; it is marketing copy.

Experimental Predictions and Validation Strategy

First, the hypothesis should be decomposed into a perturbation experiment that directly manipulates OCT4 in a model matched to neurodegeneration. The key readout should include pathway markers, cell-state markers, and at least one phenotype that maps onto “Partial Neuronal Reprogramming via Modified Yamanaka Cocktail”. Second, the study design should include a rescue arm. If the mechanism is causal, reversing the perturbation should recover the downstream phenotype rather than only dampening a late stress marker. Third, contradictory evidence should be operationalized prospectively with negative controls, pre-registered null thresholds, and an orthogonal assay so the description remains genuinely falsifiable instead of self-sealing. Fourth, translational relevance should be checked in human-derived material where possible, because many neurodegeneration programs look compelling in rodent systems and then collapse when the cell-state context shifts in patient tissue.

Decision-Oriented Summary

In summary, the operational claim is that targeting OCT4 within the disease frame of neurodegeneration can produce a measurable change in mechanism rather than only a cosmetic change in a terminal biomarker. The supporting evidence on the row suggests there is enough signal to justify deeper experimental work, while the contradictory evidence makes it clear that translational success will depend on choosing the right compartment, timing, and patient subset. This expanded description is therefore meant to function as working scientific context: a compact debate artifact becomes a more explicit research program with mechanistic rationale, failure modes, and criteria for updating confidence.

References

  1. PMID:27984723 PMID 27984723
  2. PMID:33268894 PMID 33268894
  3. PMID:33398039 PMID 33398039
  4. PMID:23260147 PMID 23260147
  5. PMID:32747729 PMID 32747729
  6. PMID:28877458 PMID 28877458
  7. PMID:22445517 PMID 22445517
  8. PMID:21885018 PMID 21885018
  9. PMID:24055329 PMID 24055329
  10. PMID:18035408 PMID 18035408
  11. PMID:21149730 PMID 21149730

Mechanism / pathway

  1. OCT4
  2. Epigenetic regulation
  3. neurodegeneration

Evidence for (17)

  • Cyclic expression of Yamanaka factors ameliorates age-associated phenotypes in progeria mice without tumor formation

    PMID:27984723 2016 Cell

    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.

  • Brief OSK treatment restores vision in aged mice by rejuvenating retinal ganglion cells

    PMID:33268894 2020 Nature

    Animal behaviours that are superficially similar can express different intents in different contexts, but how this flexibility is achieved at the level of neural circuits is not understood. For example, males of many species can exhibit mounting behaviour towards same- or opposite-sex conspecifics1, but it is unclear whether the intent and neural encoding of these behaviours are similar or different. Here we show that female- and male-directed mounting in male laboratory mice are distinguishable by the presence or absence of ultrasonic vocalizations (USVs)2-4, respectively. These and additional behavioural data suggest that most male-directed mounting is aggressive, although in rare cases it can be sexual. We investigated whether USV+ and USV- mounting use the same or distinct hypothalamic neural substrates. Micro-endoscopic imaging of neurons positive for oestrogen receptor 1 (ESR1) in either the medial preoptic area (MPOA) or the ventromedial hypothalamus, ventrolateral subdivision (

  • Partial reprogramming restores cognitive function and reverses age-associated DNA methylation in aged mice

    PMID:33398039 2020 Nature Aging

  • Oct4 acts as a pioneer transcription factor capable of binding nucleosomal DNA and initiating reprogramming

    PMID:23260147 2013 Cell

    Factor-induced reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is inefficient, complicating mechanistic studies. Here, we examined defined intermediate cell populations poised to becoming iPSCs by genome-wide analyses. We show that induced pluripotency elicits two transcriptional waves, which are driven by c-Myc/Klf4 (first wave) and Oct4/Sox2/Klf4 (second wave). Cells that become refractory to reprogramming activate the first but fail to initiate the second transcriptional wave and can be rescued by elevated expression of all four factors. The establishment of bivalent domains occurs gradually after the first wave, whereas changes in DNA methylation take place after the second wave when cells acquire stable pluripotency. This integrative analysis allowed us to identify genes that act as roadblocks during reprogramming and surface markers that further enrich for cells prone to forming iPSCs. Collectively, our data offer new mechanistic insights into the natur

  • Transient reprogramming factor expression can rejuvenate cells without complete dedifferentiation

    PMID:32747729 2020 Cell Metabolism

    BACKGROUND: Accurately assessing individual ambient air pollution exposure is a crucial part of epidemiological studies looking at the adverse health effect of poor air quality. This is particularly challenging in developing countries with high levels of air pollution, mostly due to sparse monitoring networks with a lack of consistent data. METHODS: We evaluated the performance of six different machine learning algorithms in predicting fine particulate matter (PM2.5) concentrations in Ulaanbaatar, Mongolia using data between 2010 and 2018. We found that the algorithms produce robust results based on performance metrics. RESULTS: Random forest (RF) and gradient boosting models performed the best with leave-one-location-out cross-validated R2 of 0.82 for when using data from the entire study period. After applying tuned models on the hold-out test set, R2 increased to 0.96 for the RF and 0.90 for the gradient boosting model. We also predicted PM2.5 concentrations for each administrative

  • DNA methylation changes during aging are reversible through epigenetic reprogramming interventions

    PMID:28877458 2017 Nature Communications

    Ketogenic diets recapitulate certain metabolic aspects of dietary restriction such as reliance on fatty acid metabolism and production of ketone bodies. We investigated whether an isoprotein ketogenic diet (KD) might, like dietary restriction, affect longevity and healthspan in C57BL/6 male mice. We find that Cyclic KD, KD alternated weekly with the Control diet to prevent obesity, reduces midlife mortality but does not affect maximum lifespan. A non-ketogenic high-fat diet (HF) fed similarly may have an intermediate effect on mortality. Cyclic KD improves memory performance in old age, while modestly improving composite healthspan measures. Gene expression analysis identifies downregulation of insulin, protein synthesis, and fatty acid synthesis pathways as mechanisms common to KD and HF. However, upregulation of PPARα target genes is unique to KD, consistent across tissues, and preserved in old age. In all, we show that a non-obesogenic ketogenic diet improves survival, memory, and h

  • Ascl1 functions as neuronal pioneer transcription factor maintaining chromatin accessibility at neural loci

    PMID:23417675 2013 Nature Neuroscience

    PD-1, a receptor expressed by T cells, B cells, and monocytes, is a potent regulator of immune responses and a promising therapeutic target. The structure and interactions of human PD-1 are, however, incompletely characterized. We present the solution nuclear magnetic resonance (NMR)-based structure of the human PD-1 extracellular region and detailed analyses of its interactions with its ligands, PD-L1 and PD-L2. PD-1 has typical immunoglobulin superfamily topology but differs at the edge of the GFCC' sheet, which is flexible and completely lacks a C" strand. Changes in PD-1 backbone NMR signals induced by ligand binding suggest that, whereas binding is centered on the GFCC' sheet, PD-1 is engaged by its two ligands differently and in ways incompletely explained by crystal structures of mouse PD-1 · ligand complexes. The affinities of these interactions and that of PD-L1 with the costimulatory protein B7-1, measured using surface plasmon resonance, are significantly weaker than expecte

  • TET enzymes are recruited by pluripotency factors to promote active DNA demethylation during reprogramming

    PMID:21451524 2011 Cell Stem Cell

    Epigenetic modification of the mammalian genome by DNA methylation (5-methylcytosine) has a profound impact on chromatin structure, gene expression and maintenance of cellular identity. The recent demonstration that members of the Ten-eleven translocation (Tet) family of proteins can convert 5-methylcytosine to 5-hydroxymethylcytosine raised the possibility that Tet proteins are capable of establishing a distinct epigenetic state. We have recently demonstrated that Tet1 is specifically expressed in murine embryonic stem (ES) cells and is required for ES cell maintenance. Using chromatin immunoprecipitation coupled with high-throughput DNA sequencing, here we show in mouse ES cells that Tet1 is preferentially bound to CpG-rich sequences at promoters of both transcriptionally active and Polycomb-repressed genes. Despite an increase in levels of DNA methylation at many Tet1-binding sites, Tet1 depletion does not lead to downregulation of all the Tet1 targets. Interestingly, although Tet1-

  • Partial reprogramming improves mitochondrial function and cellular energetics in aged tissues

    PMID:35437332 2022 Nature Aging

    Implementation of polygenic risk scores (PRS) may improve disease prevention and management but poses several challenges: the construction of clinically valid assays, interpretation for individual patients, and the development of clinical workflows and resources to support their use in patient care. For the ongoing Veterans Affairs Genomic Medicine at Veterans Affairs (GenoVA) Study we developed a clinical genotype array-based assay for six published PRS. We used data from 36,423 Mass General Brigham Biobank participants and adjustment for population structure to replicate known PRS-disease associations and published PRS thresholds for a disease odds ratio (OR) of 2 (ranging from 1.75 (95% CI: 1.57-1.95) for type 2 diabetes to 2.38 (95% CI: 2.07-2.73) for breast cancer). After confirming the high performance and robustness of the pipeline for use as a clinical assay for individual patients, we analyzed the first 227 prospective samples from the GenoVA Study and found that the frequency

  • Gene Therapy-Mediated Partial Reprogramming Extends Lifespan and Reverses Age-Related Changes in Aged Mice.

    PMID:38381405 2024 Cell Reprogram

    Aging is a complex progression of changes best characterized as the chronic dysregulation of cellular processes leading to deteriorated tissue and organ function. Although aging cannot currently be prevented, its impact on life- and healthspan in the elderly can potentially be minimized by interventions that aim to return these cellular processes to optimal function. Recent studies have demonstrated that partial reprogramming using the Yamanaka factors (or a subset; OCT4, SOX2, and KLF4; OSK) can reverse age-related changes in vitro and in vivo. However, it is still unknown whether the Yamanaka factors (or a subset) are capable of extending the lifespan of aged wild-type (WT) mice. In this study, we show that systemically delivered adeno-associated viruses, encoding an inducible OSK system, in 124-week-old male mice extend the median remaining lifespan by 109% over WT controls and enhance several health parameters. Importantly, we observed a significant improvement in frailty scores in

  • Mechanisms of OCT4-SOX2 motif readout on nucleosomes.

    PMID:32327602 2020 Science

    Transcription factors (TFs) regulate gene expression through chromatin where nucleosomes restrict DNA access. To study how TFs bind nucleosome-occupied motifs, we focused on the reprogramming factors OCT4 and SOX2 in mouse embryonic stem cells. We determined TF engagement throughout a nucleosome at base-pair resolution in vitro, enabling structure determination by cryo-electron microscopy at two preferred positions. Depending on motif location, OCT4 and SOX2 differentially distort nucleosomal DNA. At one position, OCT4-SOX2 removes DNA from histone H2A and histone H3; however, at an inverted motif, the TFs only induce local DNA distortions. OCT4 uses one of its two DNA-binding domains to engage DNA in both structures, reading out a partial motif. These findings explain site-specific nucleosome engagement by the pluripotency factors OCT4 and SOX2, and they reveal how TFs distort nucleosomes to access chromatinized motifs.

  • Cooperative Binding of Transcription Factors Orchestrates Reprogramming.

    PMID:28111071 2017 Cell

    Oct4, Sox2, Klf4, and cMyc (OSKM) reprogram somatic cells to pluripotency. To gain a mechanistic understanding of their function, we mapped OSKM-binding, stage-specific transcription factors (TFs), and chromatin states in discrete reprogramming stages and performed loss- and gain-of-function experiments. We found that OSK predominantly bind active somatic enhancers early in reprogramming and immediately initiate their inactivation genome-wide by inducing the redistribution of somatic TFs away from somatic enhancers to sites elsewhere engaged by OSK, recruiting Hdac1, and repressing the somatic TF Fra1. Pluripotency enhancer selection is a stepwise process that also begins early in reprogramming through collaborative binding of OSK at sites with high OSK-motif density. Most pluripotency enhancers are selected later in the process and require OS and other pluripotency TFs. Somatic and pluripotency TFs modulate reprogramming efficiency when overexpressed by altering OSK targeting, somatic

  • Targeted partial reprogramming of age-associated cell states improves markers of health in mouse models of aging.

    PMID:39259812 2024 Sci Transl Med

    Aging is a complex multifactorial process associated with epigenome dysregulation, increased cellular senescence, and decreased rejuvenation capacity. Short-term cyclic expression of octamer-binding transcription factor 4 (Oct4), sex-determining region Y-box 2 (Sox2), Kruppel-like factor 4 (Klf4), and cellular myelocytomatosis oncogene (cMyc) (OSKM) in wild-type mice improves health but fails to distinguish cell states, posing risks to healthy cells. Here, we delivered a single dose of adeno-associated viruses (AAVs) harboring OSK under the control of the cyclin-dependent kinase inhibitor 2a (Cdkn2a) promoter to specifically partially reprogram aged and stressed cells in a mouse model of Hutchinson-Gilford progeria syndrome (HGPS). Mice showed reduced expression of proinflammatory cytokines and extended life spans upon aged cell-specific OSK expression. The bone marrow and spleen, in particular, showed pronounced gene expression changes, and partial reprogramming in aged HGPS mice led

  • Engineered LINC MIR503HG-loaded extracellular vesicles maintain stemness and pluripotency during long-term hiPSCs culture.

    PMID:41551196 2026 Bioact Mater

  • Development of a practical GMP-compliant manufacturing process for T cell-derived induced pluripotent stem cells.

    PMID:41691922 2026 Cytotherapy

  • Establishment of a human induced pluripotent stem cell line (BTHBIOi005-A) from a retinitis pigmentosa patient with a MERTK gene mutation.

    PMID:41713384 2026 Stem Cell Res

  • Dose-resolved control of somatic reprogramming by Rora.

    PMID:41932336 2026 Stem Cell Reports

Evidence against (10)

  • Neuronal cells show resistance to reprogramming due to stable epigenetic landscapes and post-mitotic state

    PMID:22445517 2012 Nature

    Recent studies have shown that defined sets of transcription factors can directly reprogram differentiated somatic cells to a different differentiated cell type without passing through a pluripotent state, but the restricted proliferative and lineage potential of the resulting cells limits the scope of their potential applications. Here we show that a combination of transcription factors (Brn4/Pou3f4, Sox2, Klf4, c-Myc, plus E47/Tcf3) induces mouse fibroblasts to directly acquire a neural stem cell identity-which we term as induced neural stem cells (iNSCs). Direct reprogramming of fibroblasts into iNSCs is a gradual process in which the donor transcriptional program is silenced over time. iNSCs exhibit cell morphology, gene expression, epigenetic features, differentiation potential, and self-renewing capacity, as well as in vitro and in vivo functionality similar to those of wild-type NSCs. We conclude that differentiated cells can be reprogrammed directly into specific somatic stem c

  • Oct4 expression in neurons can lead to apoptosis and cell death rather than rejuvenation

    PMID:21885018 2011 Cell Death and Differentiation

    Using mouse skin, where bountiful reservoirs of synchronized hair follicle stem cells (HF-SCs) fuel cycles of regeneration, we explore how adult SCs remodel chromatin in response to activating cues. By profiling global mRNA and chromatin changes in quiescent and activated HF-SCs and their committed, transit-amplifying (TA) progeny, we show that polycomb-group (PcG)-mediated H3K27-trimethylation features prominently in HF-lineage progression by mechanisms distinct from embryonic-SCs. In HF-SCs, PcG represses nonskin lineages and HF differentiation. In TA progeny, nonskin regulators remain PcG-repressed, HF-SC regulators acquire H3K27me3-marks, and HF-lineage regulators lose them. Interestingly, genes poised in embryonic stem cells, active in HF-SCs, and PcG-repressed in TA progeny encode not only key transcription factors, but also signaling regulators. We document their importance in balancing HF-SC quiescence, underscoring the power of chromatin mapping in dissecting SC behavior. Our

  • Aged neurons accumulate irreversible protein aggregates that cannot be cleared by epigenetic reprogramming

    PMID:24055329 2013 Nature Reviews Neuroscience

    The identification of distinct tissue-specific natural killer (NK) cell populations that apparently mature from local precursor populations has brought new insight into the diversity and developmental regulation of this important lymphoid subset. NK cells provide a necessary link between the early (innate) and late (adaptive) immune responses to infection. Gaining a better understanding of the processes that govern NK cell development should allow us to harness better NK cell functions in multiple clinical settings, as well as to gain further insight into how these cells undergo malignant transformation. In this review, we summarize recent advances in understanding sites and cellular stages of NK cell development in humans and mice.

  • Complete exclusion of c-Myc reduces reprogramming efficiency below therapeutic thresholds

    PMID:18035408 2007 Nature Biotechnology

    Successful reprogramming of differentiated human somatic cells into a pluripotent state would allow creation of patient- and disease-specific stem cells. We previously reported generation of induced pluripotent stem (iPS) cells, capable of germline transmission, from mouse somatic cells by transduction of four defined transcription factors. Here, we demonstrate the generation of iPS cells from adult human dermal fibroblasts with the same four factors: Oct3/4, Sox2, Klf4, and c-Myc. Human iPS cells were similar to human embryonic stem (ES) cells in morphology, proliferation, surface antigens, gene expression, epigenetic status of pluripotent cell-specific genes, and telomerase activity. Furthermore, these cells could differentiate into cell types of the three germ layers in vitro and in teratomas. These findings demonstrate that iPS cells can be generated from adult human fibroblasts.

  • Viral vector delivery to neurons carries significant safety risks including inflammatory responses

    PMID:21149730 2011 Gene Therapy

    Disruption of the nucleotide excision repair (NER) pathway by mutations can cause xeroderma pigmentosum, a syndrome predisposing affected individuals to development of skin cancer. The xeroderma pigmentosum C (XPC) protein is essential for initiating global genome NER by recognizing the DNA lesion and recruiting downstream factors. Here we show that inhibition of the deacetylase and longevity factor SIRT1 impairs global genome NER through suppressing the transcription of XPC in a SIRT1 deacetylase-dependent manner. SIRT1 enhances XPC expression by reducing AKT-dependent nuclear localization of the transcription repressor of XPC. Finally, we show that SIRT1 levels are significantly reduced in human skin tumors from Caucasian patients, a population at highest risk. These findings suggest that SIRT1 acts as a tumor suppressor through its role in DNA repair.

  • Chromatin remodeling in aged neurons may disrupt essential memory engrams and learned behaviors

    PMID:25297091 2014 Cell

    Alzheimer's disease (AD) is a devastating neurodegenerative disorder and a major medical problem. Here, we have investigated the impact of amyloid-β (Aβ) oligomers, AD-related neurotoxins, in the brains of rats and adult nonhuman primates (cynomolgus macaques). Soluble Aβ oligomers are known to accumulate in the brains of AD patients and correlate with disease-associated cognitive dysfunction. When injected into the lateral ventricle of rats and macaques, Aβ oligomers diffused into the brain and accumulated in several regions associated with memory and cognitive functions. Cardinal features of AD pathology, including synapse loss, tau hyperphosphorylation, astrocyte and microglial activation, were observed in regions of the macaque brain where Aβ oligomers were abundantly detected. Most importantly, oligomer injections induced AD-type neurofibrillary tangle formation in the macaque brain. These outcomes were specifically associated with Aβ oligomers, as fibrillar amyloid deposits were

  • Partial reprogramming approaches show limited efficacy in human cells compared to rodent models

    PMID:31292550 2019 Nature Communications

    Mutations in BRCA1 and BRCA2 predispose individuals to certain cancers1-3, and disease-specific screening and preventative strategies have reduced cancer mortality in affected patients4,5. These classical tumour-suppressor genes have tumorigenic effects associated with somatic biallelic inactivation, although haploinsufficiency may also promote the formation and progression of tumours6,7. Moreover, BRCA1/2-mutant tumours are often deficient in the repair of double-stranded DNA breaks by homologous recombination8-13, and consequently exhibit increased therapeutic sensitivity to platinum-containing therapy and inhibitors of poly-(ADP-ribose)-polymerase (PARP)14,15. However, the phenotypic and therapeutic relevance of mutations in BRCA1 or BRCA2 remains poorly defined in most cancer types. Here we show that in the 2.7% and 1.8% of patients with advanced-stage cancer and germline pathogenic or somatic loss-of-function alterations in BRCA1/2, respectively, selective pressure for biallelic i

  • Brain-specific factors may actively resist reprogramming to maintain neural circuit integrity

    PMID:22445518 2012 Science

    Recent advances have suggested that direct induction of neural stem cells (NSCs) could provide an alternative to derivation from somatic tissues or pluripotent cells. Here we show direct derivation of stably expandable NSCs from mouse fibroblasts through a curtailed version of reprogramming to pluripotency. By constitutively inducing Sox2, Klf4, and c-Myc while strictly limiting Oct4 activity to the initial phase of reprogramming, we generated neurosphere-like colonies that could be expanded for more than 50 passages and do not depend on sustained expression of the reprogramming factors. These induced neural stem cells (iNSCs) uniformly display morphological and molecular features of NSCs, such as the expression of Nestin, Pax6, and Olig2, and have a genome-wide transcriptional profile similar to that of brain-derived NSCs. Moreover, iNSCs can differentiate into neurons, astrocytes, and oligodendrocytes. Our results demonstrate that functional NSCs can be generated from somatic cells b

  • Cellular reprogramming: a new approach to modelling Parkinson's disease.

    PMID:22988881 2012 Biochem Soc Trans

    iPSCs (induced pluripotent stem cells) offer an unparalleled opportunity to generate and study physiologically relevant cell types in culture. iPSCs can be generated by reprogramming almost any somatic cell type using pluripotency factors such as Oct4, SOX2, Nanog and Klf4. By reprogramming cells from patients carrying disease-associated mutations, and subsequent differentiation into the cell type of interest, researchers now have the opportunity to study disease-specific cell types which were previously inaccessible. In the case of PD (Parkinson's disease), reprogramming is advancing rapidly, and cell lines have been generated from patients carrying mutations in several disease-associated genes, including SNCA (α-synuclein), PARK2 (parkin), PINK1 (phosphatase and tensin homologue deleted on chromosome 10-induced putative kinase 1), PARK7 (DJ-1) and LRRK2 (leucine-rich repeat kinase 2), as well as idiopathic cases. Functional dopaminergic neurons have been differentiated from these cel

  • The Use of Stem Cell Differentiation Stage Factors (SCDSFs) Taken from Zebrafish Embryos during Organogenesis and Their Role in Regulating the Gene Expression of Normal and Pathological (Stem) Cells.

    PMID:32664640 2020 Int J Mol Sci

    Studies conducted on Zebrafish embryos in our laboratory have allowed for the identification of precise moments of organogenesis in which a lot of genes are switched on and off, a sign that the genome is undergoing substantial changes in gene expression. Stem cell growth and differentiation stage-factors present in different moments of organogenesis have proven to have different specific functions in gene regulation. The substances present in the first stages of cell differentiation in Zebrafish embryos have demonstrated an ability to counteract the senescence of stem cells, reducing the expression of the beta-galactosidase marker, enhancing the genes Oct-4, Sox-2, c-Myc, TERT, and the transcription of Bmi-1, which act as key telomerase-independent repressors of cell aging. The molecules present in the intermediate to late stages of cell differentiation have proven to be able to reprogram pathological human cells, such as cancer cells and those of the basal layer of the epidermis in ps

Evidence matrix

17 supporting 10 contradicting
63% supporting

Supporting

  • Cyclic expression of Yamanaka factors ameliorates age-associated phenotypes in progeria mice without tumor formation PMID:27984723 · 2016 · Cell
  • Brief OSK treatment restores vision in aged mice by rejuvenating retinal ganglion cells PMID:33268894 · 2020 · Nature
  • Partial reprogramming restores cognitive function and reverses age-associated DNA methylation in aged mice PMID:33398039 · 2020 · Nature Aging
  • Oct4 acts as a pioneer transcription factor capable of binding nucleosomal DNA and initiating reprogramming PMID:23260147 · 2013 · Cell
  • Transient reprogramming factor expression can rejuvenate cells without complete dedifferentiation PMID:32747729 · 2020 · Cell Metabolism
  • DNA methylation changes during aging are reversible through epigenetic reprogramming interventions PMID:28877458 · 2017 · Nature Communications
  • Ascl1 functions as neuronal pioneer transcription factor maintaining chromatin accessibility at neural loci PMID:23417675 · 2013 · Nature Neuroscience
  • TET enzymes are recruited by pluripotency factors to promote active DNA demethylation during reprogramming PMID:21451524 · 2011 · Cell Stem Cell
  • Partial reprogramming improves mitochondrial function and cellular energetics in aged tissues PMID:35437332 · 2022 · Nature Aging
  • Gene Therapy-Mediated Partial Reprogramming Extends Lifespan and Reverses Age-Related Changes in Aged Mice. PMID:38381405 · 2024 · Cell Reprogram
  • Mechanisms of OCT4-SOX2 motif readout on nucleosomes. PMID:32327602 · 2020 · Science
  • Cooperative Binding of Transcription Factors Orchestrates Reprogramming. PMID:28111071 · 2017 · Cell
  • Targeted partial reprogramming of age-associated cell states improves markers of health in mouse models of aging. PMID:39259812 · 2024 · Sci Transl Med
  • Engineered LINC MIR503HG-loaded extracellular vesicles maintain stemness and pluripotency during long-term hiPSCs culture. PMID:41551196 · 2026 · Bioact Mater
  • Development of a practical GMP-compliant manufacturing process for T cell-derived induced pluripotent stem cells. PMID:41691922 · 2026 · Cytotherapy
  • Establishment of a human induced pluripotent stem cell line (BTHBIOi005-A) from a retinitis pigmentosa patient with a MERTK gene mutation. PMID:41713384 · 2026 · Stem Cell Res
  • Dose-resolved control of somatic reprogramming by Rora. PMID:41932336 · 2026 · Stem Cell Reports

Contradicting

  • Neuronal cells show resistance to reprogramming due to stable epigenetic landscapes and post-mitotic state PMID:22445517 · 2012 · Nature
  • Oct4 expression in neurons can lead to apoptosis and cell death rather than rejuvenation PMID:21885018 · 2011 · Cell Death and Differentiation
  • Aged neurons accumulate irreversible protein aggregates that cannot be cleared by epigenetic reprogramming PMID:24055329 · 2013 · Nature Reviews Neuroscience
  • Complete exclusion of c-Myc reduces reprogramming efficiency below therapeutic thresholds PMID:18035408 · 2007 · Nature Biotechnology
  • Viral vector delivery to neurons carries significant safety risks including inflammatory responses PMID:21149730 · 2011 · Gene Therapy
  • Chromatin remodeling in aged neurons may disrupt essential memory engrams and learned behaviors PMID:25297091 · 2014 · Cell
  • Partial reprogramming approaches show limited efficacy in human cells compared to rodent models PMID:31292550 · 2019 · Nature Communications
  • Brain-specific factors may actively resist reprogramming to maintain neural circuit integrity PMID:22445518 · 2012 · Science
  • Cellular reprogramming: a new approach to modelling Parkinson's disease. PMID:22988881 · 2012 · Biochem Soc Trans
  • The Use of Stem Cell Differentiation Stage Factors (SCDSFs) Taken from Zebrafish Embryos during Organogenesis and Their Role in Regulating the Gene Expression of Normal and Pathological (Stem) Cells. PMID:32664640 · 2020 · Int J Mol Sci

Top-ranked evidence

trust_score × relevance_score × exp(-recency_weight × recency_days / 365)

Supports · top 3

  1. #1 paper-75b2626b0cd4 0.233 trust 0.50 · rel 0.50 · 84d
  2. #2 paper-db23eeb824d4 0.233 trust 0.50 · rel 0.50 · 84d
  3. #3 paper-fca078816caf 0.233 trust 0.50 · rel 0.50 · 84d

63 total ranked · scidex.hypotheses.evidence_ranking

Cite this hypothesis

Cite this hypothesis
Citation

etl-backfill (2026). Partial Neuronal Reprogramming via Modified Yamanaka Cocktail. SciDEX hypothesis. https://prism.scidex.ai/hypotheses/h-baba5269

BibTeX 
@misc{scidex_hypothesis_hbaba526,
  title        = {Partial Neuronal Reprogramming via Modified Yamanaka Cocktail},
  author       = {etl-backfill},
  year         = {2026},
  howpublished = {SciDEX hypothesis},
  url          = {https://prism.scidex.ai/hypotheses/h-baba5269},
  note         = {SciDEX artifact hypothesis:h-baba5269}
}

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