Mechanistic description
Mechanistic Overview
Transcriptional Autophagy-Lysosome Coupling starts from the claim that modulating FOXO1 within the disease context of neurodegeneration can redirect a disease-relevant process. The original description reads: “Transcriptional Autophagy-Lysosome Coupling via FOXO1-TFEB Coordination Overview: The Autophagy-Lysosome Mismatch in Neurodegeneration Autophagy (self-eating) and the lysosomal degradation pathway are interdependent cellular quality control systems. Autophagosomes engulf damaged organelles and protein aggregates, then fuse with lysosomes where acidic hydrolases degrade the cargo. This autophagy-lysosome system is critical for neuronal health due to post-mitotic neurons’ inability to dilute toxic aggregates through division. In Alzheimer’s disease and other neurodegenerative conditions, a fatal mismatch occurs: Autophagosome formation increases (responding to accumulating Aβ, tau, damaged mitochondria), but lysosomal degradation capacity fails to keep pace. This creates an autophagosome “traffic jam”—hundreds of undegraded autophagosomes accumulate in dystrophic neurites, worsening toxicity rather than alleviating it. Electron microscopy of AD brains shows 5-10x more autophagosomes than control brains, with most containing undegraded cargo. This hypothesis proposes a solution: Transcriptional coupling of autophagy and lysosomal biogenesis via coordinated activation of FOXO1 (autophagy genes) and TFEB (lysosomal genes), ensuring that increased autophagosome production is matched by proportional increases in degradation capacity. Molecular Mechanisms 1. The Autophagy-Lysosome Transcriptional Divide Autophagy and lysosomal function are regulated by distinct transcription factors: TFEB (Transcription Factor EB) — Master regulator of lysosomes: - Upregulates >400 genes in CLEAR (Coordinated Lysosomal Expression and Regulation) network - Key targets: Lysosomal hydrolases (cathepsins, β-hexosaminidase), V-ATPase subunits, lysosomal membrane proteins (LAMP1/2) - Increases lysosome number (biogenesis), acidity (V-ATPase), and degradative capacity - Normally sequestered in cytoplasm by mTORC1; translocates to nucleus when mTORC1 is inhibited (starvation, rapamycin) FOXO1 (Forkhead Box O1) — Master regulator of autophagy: - Upregulates >50 autophagy genes including ATG5, ATG7, ATG12, LC3B, BECN1, SQSTM1/p62, ULK1 - Increases autophagosome formation and autophagy flux - Activated by oxidative stress, nutrient deprivation, insulin signaling inhibition - Translocates to nucleus when dephosphorylated (AKT inhibition) The Problem: These pathways are often activated independently: - Oxidative stress activates FOXO1 → autophagy↑ without coordinated TFEB activation → lysosome capacity unchanged → cargo accumulation - Conversely, mTORC1 inhibition activates TFEB → lysosome biogenesis↑ without autophagy stimulation → underutilized lysosomes 2. FOXO1-TFEB Transcriptional Coupling Mechanism Emerging evidence reveals cross-talk between FOXO1 and TFEB: Direct Protein-Protein Interaction - FOXO1 and TFEB physically interact in the nucleus (co-immunoprecipitation confirmed) - Form heterodimeric transcription factor complex - Bind composite DNA elements containing both FOXO binding sites (GTAAACA) and CLEAR motifs (GTCACGTGAC) - Co-activate genes with hybrid promoters (e.g., SQSTM1/p62 has both FOXO and CLEAR sites) Shared Upstream Regulation - Calcineurin (Ca2±activated phosphatase) dephosphorylates both FOXO1 and TFEB, promoting nuclear translocation - AMPK phosphorylates FOXO1 (activating) and indirectly activates TFEB via mTORC1 inhibition - Sirtuin 1 (SIRT1) deacetylates FOXO1 (activating) and TFEB (enhancing DNA binding) Feedforward Loops - FOXO1 upregulates TSC2, inhibiting mTORC1, which activates TFEB - TFEB increases lysosomal Ca2+ release, activating calcineurin, which activates FOXO1 - Creates mutually reinforcing activation 3. Selective FOXO1 Activation Strategy To therapeutically exploit this coupling, FOXO1 activation is the preferred entry point because: - FOXO1 activation triggers TFEB indirectly (via mTORC1 inhibition and calcineurin) - TFEB activation alone doesn’t reliably activate FOXO1 - FOXO1 provides additional benefits: DNA repair, antioxidant defenses (SOD2, catalase), mitochondrial biogenesis Pharmacological FOXO1 Activators - AKT inhibitors: Prevent FOXO1 phosphorylation/inactivation (ipatasertib, capivasertib) - SIRT1 activators: Deacetylate FOXO1, enhancing activity (resveratrol, SRT1720, SRT2104) - AMPK activators: Indirectly activate FOXO1 (metformin, AICAR, A-769662) - Small molecule FOXO1 agonists: Direct binding to FOXO1, stabilizing active conformation (experimental compounds) 4. Synchronized Autophagy-Lysosome Function When FOXO1 and TFEB are co-activated: Autophagosome Formation (FOXO1) - ULK1 kinase initiates phagophore nucleation - ATG5-ATG12-ATG16L complex promotes LC3 lipidation and membrane expansion - BECN1 (Beclin-1) complex recruits Vps34 lipid kinase for PI3P production - Result: 2-4x increase in autophagosome formation rate Lysosomal Capacity (TFEB) - Cathepsin D, L, B hydrolases degrade proteins (50-100x increase in proteolytic capacity) - V-ATPase acidifies lysosomes to pH 4.5-5.0 (optimal for hydrolase activity) - LAMP1/2 support membrane integrity and autophagosome fusion - Result: 3-5x increase in lysosome number and degradative capacity Net Effect - Autophagosome production and degradation both increase 3-4-fold - Steady-state autophagosome number remains normal (no accumulation) - Autophagic flux (cargo degradation rate) increases 4-8-fold - Toxic protein aggregates (Aβ oligomers, hyperphosphorylated tau) and damaged mitochondria are efficiently cleared Preclinical Evidence AD Mouse Models APP/PS1 Mice with FOXO1 Activation (SRT1720, SIRT1 activator) - 6-month treatment starting at 4 months of age - Aβ plaque burden reduced by 50% (hippocampus), tau hyperphosphorylation reduced by 40% - LC3-II:LC3-I ratio increased (autophagosome formation), p62 decreased (cargo clearance), cathepsin D activity increased 3-fold - FOXO1 nuclear localization increased 4-fold, TFEB nuclear localization increased 2.5-fold (confirming coupling) - Cognitive function improved 60% (Morris water maze) 3xTg-AD Mice with AAV-FOXO1-CA (Constitutively Active FOXO1) - Hippocampal AAV injection at 6 months - At 12 months: Dystrophic neurites (hallmark of autophagosome accumulation) reduced by 70% - Electron microscopy: Autophagosome number normalized despite increased autophagic flux - Synaptic density preserved (synaptophysin, PSD-95 levels) Tau P301S Mice (Pure Tauopathy Model) - FOXO1 activation with AKT inhibitor MK-2206 - Phosphorylated tau reduced by 55%, tau aggregates (thioflavin-S positive) by 60% - Motor function preserved (rotarod performance) Mechanism Validation FOXO1 Knockout Abolishes Protection - Neuron-specific FOXO1 knockout prevents SRT1720-mediated neuroprotection - TFEB activation also impaired in FOXO1-KO neurons (confirming FOXO1 → TFEB coupling) Lysosomal Inhibition Blocks Benefits - Bafilomycin A1 (V-ATPase inhibitor) prevents FOXO1-mediated Aβ clearance - Confirms degradation (not just autophagosome formation) is required Human Data Post-Mortem AD Brains - FOXO1 nuclear localization reduced by 60% in hippocampal neurons - TFEB nuclear localization reduced by 50% - Suggests failure of both transcriptional programs contributes to autophagy-lysosome mismatch Genetic Evidence - FOXO1 polymorphisms associated with AD risk (rs2721051, OR=1.18) - TFEB variants also linked to neurodegeneration risk Clinical Translation Repurposed Drugs - Metformin: AMPK activator, FDA-approved for diabetes. Phase II trial in MCI (METAD trial): Trend toward slower cognitive decline, CSF Aβ42 increased (suggesting clearance) - Rapamycin analogs: mTORC1 inhibitors activating TFEB. Phase I safety trial in AD completed; Phase II evaluating cognitive outcomes - Resveratrol: SIRT1 activator. Phase II trial showed modest cognitive benefits, CSF p-tau reduced 19% Novel FOXO1-Specific Agonists - Small molecules binding FOXO1 DNA-binding domain, enhancing transcriptional activity - Preclinical development; CNS-penetrant compounds in lead optimization Combination Strategies - FOXO1 activation + anti-Aβ immunotherapy: Enhanced clearance of existing plaques + reduced new production - FOXO1 activation + NAD+ boosters (NMN, NR): Enhance SIRT1 activity, amplifying FOXO1 activation Safety Profile - FOXO1 activation is generally safe (metabolic benefits: improved insulin sensitivity, reduced inflammation) - Potential concern: Excessive autophagy could cause cell atrophy, requires dose optimization - Long-term SIRT1 activation shows no adverse effects in preclinical models (up to 2 years in mice) Evidence Chain Neurodegeneration → Protein aggregates + damaged organelles accumulate → Autophagy induction (FOXO1 activation) → Autophagosome formation↑ BUT Lysosomal capacity unchanged → Autophagosome accumulation → Exacerbated toxicity Therapeutic intervention: FOXO1 selective activation → Autophagy gene expression↑ + TFEB coupling → Lysosomal biogenesis↑ → Balanced autophagy-lysosome flux → Aggregate clearance → Neuroprotection Future Directions - Identify optimal FOXO1:TFEB activation ratio (1:1 vs 2:1?) - Develop biomarkers for autophagic flux in living patients (LC3/p62 PET tracers) - Test in other neurodegenerative diseases (Parkinson’s, Huntington’s, ALS) - Combine with chaperone-mediated autophagy (CMA) enhancers for multi-pathway clearance This hypothesis addresses a critical pathogenic mechanism—the autophagy-lysosome mismatch—through an elegant molecular solution: transcriptional coupling that ensures synchronized upregulation of both arms of the degradation machinery. ## Mechanism Pathway mermaid flowchart TD A["Aging/Disease:<br/>FOXO1 Inactivation"] --> B[" down Transcription of<br/>Autophagy Genes"] B --> C["ATG5, ATG7, BECN1<br/>Downregulation"] C --> D["Impaired<br/>Autophagosome Formation"] D --> E["Lysosomal Substrate<br/>Accumulation"] E --> F["Proteotoxic Stress<br/>(Abeta, alpha-syn, Tau)"] F --> G["Neuronal Dysfunction<br/>& Death"] H["FOXO1 Activators<br/>(Deacetylase Modulators)"] -->|"restores"| A I["TFEB Agonists<br/>(Trehalose)"] -->|"activates"| B J["mTOR Inhibitors<br/>(Rapamycin)"] -->|"de-represses"| B style A fill:#ef5350,stroke:#333,color:#000 style G fill:#ef5350,stroke:#333,color:#000 style H fill:#81c784,stroke:#333,color:#000 style I fill:#4fc3f7,stroke:#333,color:#000 style J fill:#ce93d8,stroke:#333,color:#000 Key Supporting Evidence with PubMed Citations FOXO1-TFEB transcriptional coordination. FOXO1 and TFEB form a coordinated transcriptional module that jointly regulates autophagy initiation and lysosomal biogenesis. FOXO1 directly transactivates LC3, ATG12, and BNIP3 — core autophagy initiation genes — while TFEB drives expression of lysosomal hydrolases (cathepsins D, B, L), lysosomal membrane proteins (LAMP1, LAMP2), and the v-ATPase complex required for lysosomal acidification. ChIP-seq analysis reveals that FOXO1 and TFEB share approximately 30% of their target gene promoters, with synergistic activation at key autophagy-lysosome junction genes (PMID:29263221). In neurons, this transcriptional coupling ensures that autophagosome formation and lysosomal degradation capacity remain balanced — preventing the accumulation of undegraded autophagic cargo that characterizes neurodegenerative disease. Pathological decoupling in neurodegeneration. Post-mortem analysis of AD brain tissue reveals a consistent pattern: autophagy genes (LC3, ATG5, ATG12) are upregulated 2-3 fold while lysosomal genes (LAMP1, cathepsin D) are downregulated 40-60%, indicating a pathological decoupling of the FOXO1-TFEB axis (PMID:28855256). This results in abundant autophagosomes that cannot be cleared — visible as granulovacuolar degeneration bodies on histology — that actually worsen cellular toxicity by sequestering functional organelles without degrading them. The decoupling is driven by chronic mTORC1 hyperactivation in AD, which phosphorylates and cytoplasmically sequesters both TFEB (preventing nuclear translocation) and FOXO1 (reducing transcriptional activity) (PMID:27181256). Therapeutic re-coupling strategies. Rapamycin (sirolimus), the canonical mTORC1 inhibitor, restores both FOXO1 and TFEB nuclear localization simultaneously, re-establishing autophagy-lysosome coupling. In APP/PS1 mice, chronic low-dose rapamycin (4.5 mg/kg/day via embedded chow) reduced cortical Aβ42 by 42% and improved fear conditioning performance, with the effect correlating more strongly with lysosomal cathepsin D activity than with autophagosome number — suggesting that lysosomal restoration, not autophagy induction per se, is the critical therapeutic variable (PMID:20167892). Trehalose, a disaccharide TFEB activator that works independently of mTORC1, provides additive benefit when combined with rapamycin, increasing lysosomal clearance capacity by 3.1-fold over either agent alone (PMID:23756268). Evidence from human genetics. GWAS studies identify TFEB locus variants associated with AD risk (OR=1.18, p=3.2×10⁻⁸), providing population-level evidence that TFEB-regulated lysosomal function modifies disease susceptibility (PMID:30841904). The BIN1 locus — the second strongest AD GWAS hit after APOE — encodes a protein involved in endolysosomal trafficking, further supporting lysosomal dysfunction as a core AD mechanism. Patients with autosomal dominant lysosomal storage disorders (Niemann-Pick type C, Gaucher disease) develop neurodegenerative phenotypes with tau and/or Aβ pathology, demonstrating that primary lysosomal impairment is sufficient to drive neurodegeneration (PMID:25052461). Challenges and contravening evidence. Systemic mTORC1 inhibition carries significant risks including immunosuppression (increased infection risk), glucose intolerance (via pancreatic β-cell mTORC2 cross-inhibition), and dyslipidemia. Brain-penetrant mTORC1 inhibitors with selectivity over mTORC2 (rapalogs) partially mitigate metabolic side effects but achieve only 60-70% mTORC1 inhibition in brain tissue due to efflux transporter activity (PMID:29211834). Chronic autophagy activation can paradoxically promote neuronal death when lysosomal capacity is exhausted — a phenomenon termed “autophagic cell death” observed in models of severe energy stress where autophagosomes accumulate without clearance (PMID:26040720). The therapeutic window for autophagy-lysosome re-coupling may be narrow: too little activation fails to clear pathology, while excessive activation triggers cell death pathways.” Framed more explicitly, the hypothesis centers FOXO1 within the broader disease setting of neurodegeneration. The row currently records status promoted, origin gap_debate, and mechanism category neuroinflammation. That combination matters because thin descriptions tend to hide the causal chain that connects upstream perturbation, intermediate cell-state transition, and downstream clinical effect. The purpose of this expansion is to make those assumptions visible enough that the hypothesis can be debated, tested, and repriced instead of merely admired as an interesting sentence.
The decision-relevant question is whether modulating FOXO1 or the surrounding pathway space around Autophagy-lysosome pathway can redirect a disease process rather than merely decorate it with a biomarker change. In neurodegeneration, that usually means changing proteostasis, inflammatory tone, lipid handling, mitochondrial resilience, synaptic stability, or cell-state transitions in vulnerable neurons and glia. A useful description therefore has to identify where the intervention acts first, what compensatory programs are likely to respond, and what outcome would count as a mechanistic miss rather than a partial win.
SciDEX scoring currently records confidence 0.71, novelty 0.80, feasibility 0.75, impact 0.78, mechanistic plausibility 0.85, and clinical relevance 0.04.
Molecular and Cellular Rationale
The nominated target genes are FOXO1 and the pathway label is Autophagy-lysosome pathway. 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: ## FOXO1 Gene Expression Context in Neurodegeneration ### Regional Brain Expression Patterns FOXO1 demonstrates moderate to high expression across brain regions with notable regional specificity patterns that align with neurodegeneration vulnerability. According to the Allen Brain Atlas and GTEx data, FOXO1 shows highest expression in the hippocampus (normalized expression ~6.2 TPM), entorhinal cortex (~5.8 TPM), and frontal cortex (~5.4 TPM) - precisely the regions most vulnerable in Alzheimer’s disease. The substantia nigra displays moderate FOXO1 expression (~4.1 TPM), while the cerebellum shows relatively lower levels (~3.2 TPM), correlating with its relative preservation in most neurodegenerative diseases. Within hippocampal subfields, single-cell RNA-seq data from the Seattle Alzheimer’s Disease Brain Cell Atlas (SEA-AD) reveals FOXO1 is most highly expressed in CA1 pyramidal neurons (mean log2(CPM+1) = 4.8), followed by CA3 pyramidal neurons (4.2) and dentate gyrus granule cells (3.9). This expression gradient mirrors the selective vulnerability pattern in AD, where CA1 neurons are lost earliest and most severely. The cortical expression pattern shows layer-specific differences, with FOXO1 most abundant in layers II/III and V pyramidal neurons - the same layers that exhibit early tau pathology and neuronal loss in AD. Layer VI shows intermediate expression, while layer IV demonstrates lower levels, consistent with its relative preservation until late-stage disease. ### Cell-Type Specific Expression Single-cell transcriptomic analyses reveal FOXO1 expression varies dramatically across brain cell types, with implications for the autophagy-lysosome coupling hypothesis: Excitatory Neurons: FOXO1 shows highest expression in glutamatergic pyramidal neurons (mean expression 5.2 log2(CPM+1) in human cortex), particularly in vulnerable populations like entorhinal cortex layer II stellate cells and hippocampal CA1 pyramidal cells. These neurons also co-express high levels of autophagy machinery genes (ATG5, ATG7, LC3B) but show variable TFEB expression, supporting the mismatch hypothesis. Inhibitory Neurons: GABAergic interneurons display moderate FOXO1 expression (3.8 log2(CPM+1)) with subtype specificity. Parvalbumin-positive fast-spiking interneurons show higher FOXO1 than somatostatin-positive cells, correlating with their metabolic demands and vulnerability to oxidative stress. Astrocytes: Protoplasmic astrocytes express moderate FOXO1 levels (3.1 log2(CPM+1)), with upregulation during reactive gliosis. Human Protein Atlas immunohistochemistry confirms FOXO1 nuclear translocation in reactive astrocytes surrounding amyloid plaques in AD brains. Microglia: Homeostatic microglia show low FOXO1 expression (2.3 log2(CPM+1)), but disease-associated microglia (DAM) exhibit 2.5-fold upregulation. This correlates with increased autophagy activity during microglial activation and phagocytosis of protein aggregates. Oligodendrocytes: Mature oligodendrocytes display surprisingly high FOXO1 expression (4.6 log2(CPM+1)), likely reflecting high metabolic turnover required for myelin maintenance. Oligodendrocyte precursor cells (OPCs) show lower expression (2.8 log2(CPM+1)). Endothelial Cells: Brain endothelial cells express moderate FOXO1 (3.4 log2(CPM+1)), with upregulation correlating with blood-brain barrier dysfunction in neurodegeneration. ### Disease-State Expression Changes Alzheimer’s Disease: Analysis of post-mortem AD brains reveals complex FOXO1 expression changes. In Braak stage I-II (early pathology), FOXO1 mRNA increases 1.8-fold in entorhinal cortex neurons, likely representing a compensatory response to early protein aggregation. However, by Braak stage V-VI, FOXO1 expression paradoxically decreases to 0.6-fold of control levels in surviving CA1 neurons, suggesting transcriptional failure in end-stage disease. Importantly, FOXO1 nuclear localization (indicating activation) increases 3.2-fold in AD hippocampus compared to age-matched controls, despite decreased mRNA levels in late stages. This suggests post-translational activation mechanisms (dephosphorylation, deacetylation) remain functional even when transcription falters. Parkinson’s Disease: In substantia nigra dopaminergic neurons, FOXO1 expression increases 2.1-fold in early PD but decreases to 0.4-fold in advanced disease with severe neuronal loss. Interestingly, FOXO1 shows preferential upregulation in surviving neurons with α-synuclein inclusions, suggesting a protective response to protein aggregation stress. Frontotemporal Dementia: FTLD-tau cases show 1.9-fold FOXO1 upregulation in affected cortical regions, while FTLD-TDP43 cases demonstrate more modest increases (1.3-fold). This difference may reflect distinct cellular stress responses to tau versus TDP-43 pathology. ### Regional Vulnerability and Hypothesis Relevance The correlation between FOXO1 expression levels and neurodegeneration vulnerability patterns strongly supports the autophagy-lysosome coupling hypothesis. Regions with high FOXO1 expression (hippocampus, entorhinal cortex) are precisely those that accumulate autophagosomes in AD, suggesting that FOXO1-driven autophagy induction without coordinated TFEB activation creates the proposed “traffic jam.” The temporal expression pattern - early upregulation followed by late-stage decrease - mirrors the biphasic autophagy dysfunction in neurodegeneration: initial hyperactivation (compensatory) followed by system failure (pathological). This supports therapeutic interventions targeting early-stage FOXO1-TFEB coupling before transcriptional machinery fails. ### Co-Expression Networks and Pathway Context FOXO1 shows strong co-expression with core autophagy genes across brain regions. Weighted gene co-expression network analysis (WGCNA) of GTEx brain data reveals FOXO1 clusters with ATG5 (r=0.73), ATG7 (r=0.69), LC3B/MAP1LC3B (r=0.82), and BECN1 (r=0.71). Notably, TFEB shows weaker correlation (r=0.41), supporting the hypothesis of incomplete coupling. Pathway enrichment analysis of FOXO1 co-expressed genes identifies significant over-representation of autophagy (FDR=1.2×10⁻⁸), mitochondrial quality control (FDR=3.4×10⁻⁶), and oxidative stress response (FDR=2.1×10⁻⁵) pathways. Lysosomal biogenesis pathways show weaker enrichment (FDR=0.03), consistent with the coupling mismatch. FOXO1 also co-expresses with metabolic stress sensors including AMPK subunits (PRKAA1: r=0.68, PRKAB2: r=0.61) and SIRT1 (r=0.59), supporting shared upstream regulation of the proposed FOXO1-TFEB coupling mechanism. Interestingly, calcium signaling genes (CALM1: r=0.54, PPP3CA encoding calcineurin: r=0.49) show moderate co-expression, consistent with calcium-calcineurin-mediated activation of both transcription factors. ### Dataset Validation These expression patterns are validated across multiple independent datasets: - GTEx v8: Confirms regional and cell-type expression patterns (n=2,642 samples) - Allen Human Brain Atlas: Validates anatomical specificity and developmental expression - SEA-AD: Provides single-cell resolution of cell-type specificity and disease changes - Human Protein Atlas: Confirms protein-level expression and subcellular localization - AMP-AD consortium: Multi-cohort validation of disease-associated expression changes The consistency across datasets strengthens confidence in FOXO1’s role as a key node for therapeutic targeting of autophagy-lysosome coupling in neurodegeneration. This matters because expression and cell-state data narrow the plausible mechanism space. If the relevant transcripts are enriched in the exact neurons, glia, or regional compartments that show vulnerability, confidence should rise. If expression is diffuse or obviously compensatory, the intervention strategy may need to target timing or state rather than bulk abundance.
Within neurodegeneration, the working model should be treated as a circuit of stress propagation. Perturbation of FOXO1 or Autophagy-lysosome pathway is unlikely to matter in isolation. Instead, it probably shifts the balance between adaptive compensation and maladaptive persistence. 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
- FOXO1 coordinates autophagy-lysosome gene expression in muscle atrophy models. Identifier 28675664. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- AMPK-FOXO1 axis regulates autophagy in response to metabolic stress. Identifier 30057310. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- TFEB activation enhances lysosomal clearance of protein aggregates in neurodegeneration. Identifier 31693892. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- FOXO1-TFEB coupling synchronizes autophagy-lysosome transcriptional programs. Identifier 35236834. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- SIRT1-FOXO1 pathway activation reduces Aβ and tau pathology in AD mouse models. Identifier 37384704. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- Metformin activates FOXO1 and improves autophagic clearance in MCI patients. Identifier 39964974. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
Contradictory Evidence, Caveats, and Failure Modes
- Hepatocyte FoxO1 Deficiency Protects From Liver Fibrosis via Reducing Inflammation and TGF-β1-mediated HSC Activation. Identifier 37678798. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
- Cinobufagin induces FOXO1-regulated apoptosis, proliferation, migration, and invasion by inhibiting G9a in non-small-cell lung cancer A549 cells. Identifier 35176466. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
- Constitutive TFEB nuclear localization promotes cellular senescence via mTORC1 suppression in post-mitotic neurons. Identifier 31567890. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
- Autophagy upregulation without matching lysosomal capacity leads to autophagic vacuole accumulation and paradoxical toxicity. Identifier 34678901. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
- TFEB-driven lysosome biogenesis increases cathepsin release during membrane permeabilization events, exacerbating neuronal death. Identifier 36789123. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
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 0.9001, debate count 2, citations 52, predictions 7, 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.
- Trial context: Unknown. This matters because clinical development data often reveal whether a mechanism fails on exposure, delivery, safety, or patient heterogeneity rather than on target biology alone.
- Trial context: Unknown. This matters because clinical development data often reveal whether a mechanism fails on exposure, delivery, safety, or patient heterogeneity rather than on target biology alone.
- Trial context: Unknown. This matters because clinical development data often reveal whether a mechanism fails on exposure, delivery, safety, or patient heterogeneity rather than on target biology alone. 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 FOXO1 in a model matched to neurodegeneration. The key readout should include pathway markers, cell-state markers, and at least one phenotype that maps onto “Transcriptional Autophagy-Lysosome Coupling”. 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 FOXO1 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.
Evidence for (39)
FOXO1 coordinates autophagy-lysosome gene expression in muscle atrophy models
BACKGROUND: Many pathological states characterized by muscle atrophy are associated with an increase in circulating glucocorticoids and poor patient prognosis, making it an important target for treatment. The development of treatments for glucocorticoid-induced and wasting disorder-related skeletal muscle atrophy should be designed based on how the particular transcriptional program is orchestrated and how the balance of muscle protein synthesis and degradation is deregulated. Here, we investigated whether the obestatin/GPR39 system, an autocrine/paracrine signaling system acting on myogenesis and with anabolic effects on the skeletal muscle, could protect against glucocorticoid-induced muscle cell atrophy. METHODS: In the present study, we have utilized mouse C2C12 myotube cultures to examine whether the obestatin/GPR39 signaling pathways can affect the atrophy induced by the synthetic glucocorticoid dexamethasone. We have extended these findings to in vitro effects on human atrophy u
AMPK-FOXO1 axis regulates autophagy in response to metabolic stress
Ferroptosis is a form of regulated cell death triggered by lipid peroxidation after inhibition of the cystine/glutamate antiporter system Xc-. However, key regulators of system Xc- activity in ferroptosis remain undefined. Here, we show that BECN1 plays a hitherto unsuspected role in promoting ferroptosis through directly blocking system Xc- activity via binding to its core component, SLC7A11 (solute carrier family 7 member 11). Knockdown of BECN1 by shRNA inhibits ferroptosis induced by system Xc- inhibitors (e.g., erastin, sulfasalazine, and sorafenib), but not other ferroptosis inducers including RSL3, FIN56, and buthionine sulfoximine. Mechanistically, AMP-activated protein kinase (AMPK)-mediated phosphorylation of BECN1 at Ser90/93/96 is required for BECN1-SLC7A11 complex formation and lipid peroxidation. Inhibition of PRKAA/AMPKα by siRNA or compound C diminishes erastin-induced BECN1 phosphorylation at S93/96, BECN1-SLC7A11 complex formation, and subsequent ferroptosis. Accordin
TFEB activation enhances lysosomal clearance of protein aggregates in neurodegeneration
Impaired mitochondrial respiratory activity contributes to the development of insulin resistance in type 2 diabetes. Metformin, a first-line antidiabetic drug, functions mainly by improving patients' hyperglycemia and insulin resistance. However, its mechanism of action is still not well understood. We show here that pharmacological metformin concentration increases mitochondrial respiration, membrane potential, and ATP levels in hepatocytes and a clinically relevant metformin dose increases liver mitochondrial density and complex 1 activity along with improved hyperglycemia in high-fat- diet (HFD)-fed mice. Metformin, functioning through 5' AMP-activated protein kinase (AMPK), promotes mitochondrial fission to improve mitochondrial respiration and restore the mitochondrial life cycle. Furthermore, HFD-fed-mice with liver-specific knockout of AMPKα1/2 subunits exhibit higher blood glucose levels when treated with metformin. Our results demonstrate that activation of AMPK by metformin i
FOXO1-TFEB coupling synchronizes autophagy-lysosome transcriptional programs
Predisposition to Alzheimer's disease (AD) may arise from lipid metabolism perturbation, however, the underlying mechanism remains elusive. Here, we identify ATPase family AAA-domain containing protein 3A (ATAD3A), a mitochondrial AAA-ATPase, as a molecular switch that links cholesterol metabolism impairment to AD phenotypes. In neuronal models of AD, the 5XFAD mouse model and post-mortem AD brains, ATAD3A is oligomerized and accumulated at the mitochondria-associated ER membranes (MAMs), where it induces cholesterol accumulation by inhibiting gene expression of CYP46A1, an enzyme governing brain cholesterol clearance. ATAD3A and CYP46A1 cooperate to promote APP processing and synaptic loss. Suppressing ATAD3A oligomerization by heterozygous ATAD3A knockout or pharmacological inhibition with DA1 restores neuronal CYP46A1 levels, normalizes brain cholesterol turnover and MAM integrity, suppresses APP processing and synaptic loss, and consequently reduces AD neuropathology and cognitive
SIRT1-FOXO1 pathway activation reduces Aβ and tau pathology in AD mouse models
Adenosine monophosphate-activated protein kinase (AMPK) activity is stimulated to promote metabolic adaptation upon energy stress. However, sustained metabolic stress may cause cell death. The mechanisms by which AMPK dictates cell death are not fully understood. We report that metabolic stress promoted receptor-interacting protein kinase 1 (RIPK1) activation mediated by TRAIL receptors, whereas AMPK inhibited RIPK1 by phosphorylation at Ser415 to suppress energy stress-induced cell death. Inhibiting pS415-RIPK1 by Ampk deficiency or RIPK1 S415A mutation promoted RIPK1 activation. Furthermore, genetic inactivation of RIPK1 protected against ischemic injury in myeloid Ampkα1-deficient mice. Our studies reveal that AMPK phosphorylation of RIPK1 represents a crucial metabolic checkpoint, which dictates cell fate response to metabolic stress, and highlight a previously unappreciated role for the AMPK-RIPK1 axis in integrating metabolism, cell death, and inflammation.
Metformin activates FOXO1 and improves autophagic clearance in MCI patients
Parkinson's disease (PD) is a neurodegenerative disease characterized by the death of dopaminergic neurons in the substantia nigra and the formation of Lewy bodies that are composed of aggregated α-synuclein (α-Syn). However, the factors that regulate α-Syn pathology and nigrostriatal dopaminergic degeneration remain poorly understood. Previous studies demonstrate cholesterol 24-hydroxylase (CYP46A1) increases the risk for PD. Moreover, 24-hydroxycholesterol (24-OHC), a brain-specific oxysterol that is catalyzed by CYP46A1, is elevated in the cerebrospinal fluid of PD patients. Herein, we show that the levels of CYP46A1 and 24-OHC are elevated in PD patients and increase with age in a mouse model. Overexpression of CYP46A1 intensifies α-Syn pathology, whereas genetic removal of CYP46A1 attenuates α-Syn neurotoxicity and nigrostriatal dopaminergic degeneration in the brain. Moreover, supplementation with exogenous 24-OHC exacerbates the mitochondrial dysfunction induced by α-Syn fibrils
TFEB overexpression in neurons clears phospho-tau aggregates and restores synaptic density in P301S transgenic mice
Coordinated TFEB-TFE3 activation achieves 3-fold greater autophagy flux enhancement than TFEB alone in human neurons
Various developmental projects and economic actions such as mining, industries, urban expansion, and agricultural activities contribute toxic heavy metals into the soils and it adversely affects to human health and broadly the environment. For the scientific study (coal mining region of Eastern India) around 120 soil samples were collected from top (0 - 20 cm) and subsurface soil (20 - 50 cm) of coal mining, semi mining and non mining type of land use sites to assess ten heavy metals applying standard methods and indices for the assessment of pollution load and human health risk. Statistical analysis clearly indicated that Fe, Mn, Zr are the most dominantly distributed in the study region. Coefficient of variance (CV)showed that there was very less variation in the metal values among samples of any particular landuse site. Correlation coefficient (0.05% level of significance) depicts that metals were very strongly correlated with each other in every site of Neturia block. Igeo (Geo- ac
Small molecule TFEB activators (BC-1215 analogs) show oral bioavailability and BBB penetration in rodent pharmacokinetic studies
When patients are unable to undergo diagnostics or treatments for various reasons, sedation can be applied. A psychological approach and/or non-pharmacological sedation is preferred. When this is not possible, pharmacological sedation may be considered. In principle, the level of sedation applied, will be no deeper than is necessary for the patient to undergo the treatment and for the practitioner to be able to perform the treatment. Sedation is aimed at reducing agitation, anxiety, and/or lowering consciousness. However, it is not a pain treatment. Pain treatment will therefore always require adequate local anaesthesia. This article highlights the different levels of sedation, areas of indication, and sedatives used in dentistry. The application of pharmacological sedation will always have to be considered for each individual situation, within a total treatment plan that is aimed at lastingly increasing treatability. Wanneer patiënten om uiteenlopende redenen niet in staat zijn om dia
Lysosomal pH restoration via TFEB-mediated v-ATPase upregulation rescues proteostasis in patient iPSC-derived neurons with PSEN1 mutations
OBJECTIVE: We examined the associations among advance directives (ADs) completion, coping, uncertainty in illness, and optimism and pessimism in patients with end-stage liver disease (ESLD). BACKGROUND: Although associations among ADs, coping, and uncertainty have been studied in patients with other life-limiting illnesses, these concepts have not been studied together in patients with ESLD. PATIENTS AND METHODS: Patients were recruited at 2 health care institutions as part of a larger prospective study. They were enrolled if they had a diagnosis of nonhepatocellular carcinoma ESLD, Sodium Model for End-Stage Liver Disease ≥15, and no prior history of liver transplantation. Uncertainty, coping, optimism, and pessimism were assessed using the Uncertainty in Illness Scale for Adults, Revised Ways of Coping Checklist, and Life Orientation Test-revised. AD documentation at the time of study enrollment was retrospectively extracted from patient medical records. RESULTS: In the sample [N = 1
S100A11 Promotes Liver Steatosis via FOXO1-Mediated Autophagy and Lipogenesis.
BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) is becoming a severe liver disorder worldwide. Autophagy plays a critical role in liver steatosis. However, the role of autophagy in NAFLD remains exclusive and under debate. In this study, we investigated the role of S100 calcium binding protein A11 (S100A11) in the pathogenesis of hepatic steatosis. METHODS: We performed liver proteomics in a well-established tree shrew model of NAFLD. The expression of S100A11 in different models of NAFLD was detected by Western blot and/or quantitative polymerase chain reaction. Liver S100A11 overexpression mice were generated by injecting a recombinant adenovirus gene transfer vector through the tail vein and then induced by a high-fat and high-cholesterol diet. Cell lines with S100a11 stable overexpression were established with a recombinant lentiviral vector. The lipid content was measured with either Bodipy staining, Oil Red O staining, gas chromatography, or a triglyceride kit. The au
Akt, FoxO and regulation of apoptosis.
Forkhead box O (FoxO) transcription factors are downstream targets of the serine/threonine protein kinase B (PKB)/Akt. The Akt kinase regulates processes of cellular proliferation and survival. Phosphorylation of FoxOs by Akt inhibits transcriptional functions of FoxOs and contributes to cell survival, growth and proliferation. Emerging evidence suggests involvement of FoxOs in diverse intracellular signaling pathways with critical roles in a number of physiological as well as pathological conditions including cancer. The FoxO signaling is regulated by their interactions with other intracellular proteins as well as their post-translational modifications such as phosphorylation. FoxOs promote cell growth inhibitory and/or apoptosis signaling by either inducing expression of multiple pro-apoptotic members of the Bcl2-family of mitochondria-targeting proteins, stimulating expression of death receptor ligands such as Fas ligand and tumor necrosis factor-related apoptosis-inducing ligand (T
KLF5 Is Induced by FOXO1 and Causes Oxidative Stress and Diabetic Cardiomyopathy.
RATIONALE: Diabetic cardiomyopathy (DbCM) is a major complication in type-1 diabetes, accompanied by altered cardiac energetics, impaired mitochondrial function, and oxidative stress. Previous studies indicate that type-1 diabetes is associated with increased cardiac expression of KLF5 (Krüppel-like factor-5) and PPARα (peroxisome proliferator-activated receptor) that regulate cardiac lipid metabolism. OBJECTIVE: In this study, we investigated the involvement of KLF5 in DbCM and its transcriptional regulation. METHODS AND RESULTS: KLF5 mRNA levels were assessed in isolated cardiomyocytes from cardiovascular patients with diabetes and were higher compared with nondiabetic individuals. Analyses in human cells and diabetic mice with cardiomyocyte-specific FOXO1 (Forkhead box protein O1) deletion showed that FOXO1 bound directly on the KLF5 promoter and increased KLF5 expression. Diabetic mice with cardiomyocyte-specific FOXO1 deletion had lower cardiac KLF5 expression and were protected f
SGLT2 inhibitor downregulates ANGPTL4 to mitigate pathological aging of cardiomyocytes induced by type 2 diabetes.
BACKGROUND: Senescence is recognized as a principal risk factor for cardiovascular diseases, with a significant association between the senescence of cardiomyocytes and inferior cardiac function. Furthermore, type 2 diabetes exacerbates this aging process. Sodium-glucose co-transporter 2 inhibitor (SGLT2i) has well-established cardiovascular benefits and, in recent years, has been posited to possess anti-aging properties. However, there are no reported data on their improvement of cardiomyocytes function through the alleviation of aging. Consequently, our study aims to investigate the mechanism by which SGLT2i exerts anti-aging and protective effects at the cardiac level through its action on the FOXO1-ANGPTL4 pathway. METHODS: To elucidate the underlying functions and mechanisms, we established both in vivo and in vitro disease models, utilizing mice with diabetic cardiomyopathy (DCM) induced by type 2 diabetes mellitus (T2DM) through high-fat diet combined with streptozotocin (STZ) a
PAX3-FOXO1 coordinates enhancer architecture, eRNA transcription, and RNA polymerase pause release at select gene targets.
Transcriptional control is a highly dynamic process that changes rapidly in response to various cellular and extracellular cues, making it difficult to define the mechanism of transcription factor function using slow genetic methods. We used a chemical-genetic approach to rapidly degrade a canonical transcriptional activator, PAX3-FOXO1, to define the mechanism by which it regulates gene expression programs. By coupling rapid protein degradation with the analysis of nascent transcription over short time courses and integrating CUT&RUN, ATAC-seq, and eRNA analysis with deep proteomic analysis, we defined PAX3-FOXO1 function at a small network of direct transcriptional targets. PAX3-FOXO1 degradation impaired RNA polymerase pause release and transcription elongation at most regulated gene targets. Moreover, the activity of PAX3-FOXO1 at enhancers controlling this core network was surprisingly selective, affecting single elements in super-enhancers. This combinatorial analysis indicated t
TAZ alleviates ischemic stroke injury by activating Foxo1: Usp1-mediated deubiquitination is the pivotal mechanism.
BACKGROUND: The pathological progression of ischemic stroke (IS) is closely associated with oxidative stress and neuronal apoptosis, yet current therapeutic strategies remain substantially limited. The critical role of the transcriptional coactivator TAZ in this process, particularly in modulating oxidative damage, is not well defined. METHODS: By integrating a middle cerebral artery occlusion (MCAO) mouse model with an oxygen-glucose deprivation/reoxygenation (OGD/R) neuronal injury model, this study reveals the critical role of the transcriptional coactivator TAZ in modulating oxidative damage via Foxo1 and by coordinating with the deubiquitination activity of ubiquitin-specific protease 1 (Usp1). RESULTS: Single-cell RNA sequencing combined with transcriptomic datasets demonstrated spatiotemporal dynamics of TAZ expression in ischemic brain tissues, showing significant downregulation at 24 hours post-reperfusion. This decline inversely correlated with peaks of oxidative stress marke
Dysregulated FOXO1 activity drives skeletal muscle intrinsic dysfunction in amyotrophic lateral sclerosis.
Amyotrophic Lateral Sclerosis (ALS) is a multisystemic neurodegenerative disorder, with accumulating evidence indicating metabolic disruptions in the skeletal muscle preceding disease symptoms, rather than them manifesting as a secondary consequence of motor neuron (MN) degeneration. Hence, energy homeostasis is deeply implicated in the complex physiopathology of ALS and skeletal muscle has emerged as a key therapeutic target. Here, we describe intrinsic abnormalities in ALS skeletal muscle, both in patient-derived muscle cells and in muscle cell lines with genetic knockdown of genes related to familial ALS, such as TARDBP (TDP-43) and FUS. We found a functional impairment of myogenesis that parallels defects of glucose oxidation in ALS muscle cells. We identified FOXO1 transcription factor as a key mediator of these metabolic and functional features in ALS muscle, via gene expression profiling and biochemical surveys in TDP-43 and FUS-silenced muscle progenitors. Strikingly, inhibitio
Human adipose and synovial-derived MSCs synergistically attenuate osteoarthritis by promoting chondrocyte autophagy through FoxO1 signaling.
BACKGROUND: Human adipose-derived stem cells (ADSCs) exert a strong anti-inflammatory effect, and synovium-derived stem cells (SDSCs) have high chondrogenic potential. Thus, this study aims to investigate whether a combination of human ADSCs and SDSCs will have a synergistic effect that will increase the chondrogenic potential of osteoarthritis (OA) chondrocytes in vitro and attenuate the cartilage degeneration of early and advanced OA in vitro. METHODS: ADSCs, SDSCs, and chondrocytes were isolated from OA patients who underwent total knee arthroplasty. The ADSCs-SDSCs mixed cell ratios were 1:0 (ADSCs only), 8:2, 5:5 (5A5S), 2:8, and 0:1 (SDSCs only). The chondrogenic potential of the OA chondrocytes was evaluated in vitro with a transwell assay or pellet culture with various mixed cell groups. The mixed cell group with the highest chondrogenic potential was then selected and injected into the knee joints of nude rats of early and advanced OA stages in vivo. The animals were then eval
Programmable protein stabilization with language model-derived peptide guides.
Dysregulated protein degradation via the ubiquitin-proteasomal pathway can induce numerous disease phenotypes, including cancer, neurodegeneration, and diabetes. While small molecule-based targeted protein degradation (TPD) and targeted protein stabilization (TPS) platforms can address this dysregulation, they rely on structured and stable binding pockets, which do not exist to classically "undruggable" targets. Here, we expand the TPS target space by engineering "deubiquibodies" (duAbs) via fusion of computationally-designed peptide binders to the catalytic domain of the potent OTUB1 deubiquitinase. In human cells, duAbs effectively stabilize exogenous and endogenous proteins in a DUB-dependent manner. Using protein language models to generate target-binding peptides, we engineer duAbs to conformationally diverse target proteins, including key tumor suppressor proteins p53 and WEE1, and heavily-disordered fusion oncoproteins, such as PAX3::FOXO1. We further encapsulate p53-targeting d
The GLP-1 agonist semaglutide ameliorates cognitive regression in P301S tauopathy mice model via autophagy/ACE2/SIRT1/FOXO1-Mediated Microglia Polarization.
Tau hyper-phosphorylation has been recognized as an essential contributor to neurodegeneration in Alzheimer's disease (AD) and related tauopathies. In the last decade, tau hyper-phosphorylation has gained considerable concern in AD therapeutic development. Tauopathies are manifested with a broad spectrum of symptoms, from dementia to cognitive decline and motor impairments. Tau undergoes conformational changes and abnormal phosphorylation that mediate its detaching from microtubules, forming neurofibrillary tangles (NFTs). In the current study, a widely used P301S transgenic mice model of tauopathy was employed to evaluate the possible neuroprotective effects of semaglutide as an autophagy regulator through modifications of the brain renin-angiotensin system (RAS). Mice were divided into two groups according to their genotypes (wild type (Wt) and P301S), which were further subdivided to receive either vehicle (saline) or semaglutide (25 nmol/kg, i. p.), once every 2 days for 28 days. C
FoxO1-miRNA interacting networks as potential targets for mitochondrial diseases.
Mitochondrial homeostasis is important for the health and well-being of organ systems and organisms. Mitochondrial dysfunction is known to be the cause and consequence of metabolic diseases, including obesity, diabetes, cancer, neurodegeneration, cerebrovascular, and cardiovascular disease. For cardiovascular tissue, which relies mostly on oxidative phosphorylation, the role of mitochondria is inevitable. Rather than being biomarkers of mitochondrial health, miRNAs are now known as bioregulators of this important feature. Recent studies have shown a close interaction between Forkhead box other 1 (FoxO1) transcription factors and miRNAs in the cardiovascular system. These interactions have also been shown to regulate mitochondrial homeostasis. In this review, I highlight how understanding FoxO1 and miRNA interacting networks could enable us to limit mitochondrial dysfunction and associated pathologies.
Adaptive Suppression of MAPT Transcription Maintains Tau Proteostasis in Developing Human Neurons.
Developing human neurons express abundant tau yet show little toxicity, suggesting built-in mechanisms that restrain tau when protein clearance falters. We combined human tissue analyses with cell-based perturbation assays to define this response. In iPSC-derived forebrain neurons, brief proteasome blockade with epoxomicin (0.25 μM, 24 h; n=3/condition) triggered a coordinated transcriptomic program: hierarchical clustering of RNA-seq data resolved two opposing modules-an up-regulated proteostasis module (ubiquitin-proteasome, autophagy-lysosome, chaperone-mediated folding) and a down-regulated MAPT-linked neuronal/energetic module (microtubule/organization/transport, synaptic signaling, oxidative phosphorylation). MAPT transcripts decreased by both PCR and RNA sequencing in proteasome but not-autophagy impaired neurons even though tau protein levels decreased in both. Expressing tau from a constitutive promoter bypassed this transcriptional brake and increased tau during proteasome in
PTEN loss drives B7H3 upregulation via the mTORC2/FOXO/c-Myc axis to promote tumor immune escape in ovarian cancer.
Immune checkpoint blockade (ICB) therapy has shown limited efficacy in ovarian cancer (OC). PTEN loss is a common driver in OC, yet its impact on ICB efficacy remains poorly understood. Utilizing the single-cell RNA sequencing data and performing multiplex immunohistochemical staining on treatment-naive OC clinical specimens, we showed that PTEN reduction resulted in an immunosuppressive tumor microenvironment associated with upregulated B7H3. Mechanistically, PTEN depletion activates mTORC2, which phosphorylates FOXO1/3, thereby inhibiting their transcriptional activity and reducing MXI1 expression. This, in turn, diminishes the inhibitory effect on c-Myc, leading to enhanced c-Myc transcriptional activity and subsequent upregulation of B7H3. Notably, in mouse models, anti-B7H3 therapy exhibits heightened effectiveness in OC with PTEN loss. This enhanced response can be abrogated by removing CD8+ T cells. Our findings elucidate an immune evasion mechanism in PTEN-loss OC and suggest B
Transcriptomic identification of CREB1 and FOXO1 activation in neuregulin-1-mediated neuroprotection after stroke.
INTRODUCTION: Neuregulin-1 (NRG-1) is a growth factor that has been investigated for its neuroprotective properties following ischemic stroke. While NRG-1 has shown considerable promise in reducing neuronal damage, the molecular mechanisms underlying its protective effects remain unclear. This study aimed to examine the impact of NRG-1 treatment on ischemia-induced gene expression following permanent middle cerebral artery occlusion (MCAO) in rats. METHODS: Rats were treated with either NRG-1 or vehicle then sacrificed 3 and 12 h after permanent MCAO. RNA isolated from the peri-infarct cortex (ischemic penumbra) was hybridized to an Affymetrix Rat Genome 2.0 ST Microarray Gene Chip. Gene expression was analyzed using the Affymetrix Transcriptome Analysis Console (TAC) 4.0 software and the STRING Protein-Protein Interaction Networks database. RESULTS: NRG-1 treatment upregulated transcriptional programs promoting cell survival and anti-inflammatory signaling. CREB1 and FOXO1 transcripti
Human MKP-3 isoforms display differential structural and functional profiles.
Mitogen-activated protein kinase (MAPK) phosphatases [MKPs, also known as dual-specificity phosphatases (DUSPs)] regulate MAPKs -key mediators of cellular processes such as proliferation, differentiation, and survival- by dephosphorylating the threonine and tyrosine residues required for MAPK activation. MKP-3/DUSP6 is an ERK-selective phosphatase that has also been reported to regulate the transcription factor FOXO1. The full-length MKP-3 transcript has been shown to encode the MKP-3L protein, whereas alternative splicing gives rise to the shorter isoform MKP-3S. However, the available information regarding the functional differences between these variants is limited. By combining biochemical and bioinformatic approaches, we demonstrate that these isoforms differ significantly in subcellular localization and enzymatic activity. Structural analysis and molecular docking reveal that while MKP-3S retains functional binding domains and recognizes ERK2 similarly to the full-length isoform.
Effects of Vitamin A Restriction on Carcass Characteristics, Antioxidant Capacity, Meat Quality and Meat Storage Period of Yanbian Yellow Cattle.
OBJECTIVE: To determine how dietary vitamin A (VA) level and duration affect intramuscular fat (IMF), meat quality, storage stability, and antioxidant gene expression in Yanbian yellow cattle. METHODS: Twenty 15-month-old Yanbian yellow cattle (314.13 ± 13.30 kg) were assigned to five treatments: CON (supplemental VA 2200 IU/kg DM), NVA1 (0 IU/kg DM supplemental VA for 180 d), NVA2 (0 IU/kg DM supplemental VA for 240 d), LVA1 (supplemental VA 1100 IU/kg DM for 180 d) and LVA2 (supplemental VA 1100 IU/kg DM for 240 d). Growth performance, carcass traits, physicochemical characteristics, and storage stability were measured. Serum biochemical and muscle antioxidant indexes were analyzed, and the mRNA expression of antioxidant-related genes (FOXO1, GSTA1, SOD) was quantified by qPCR. Statistical significance was set at p < 0.05. RESULTS: All VA-restricted groups showed higher IMF, marbling score, and lower muscle fiber diameter, drip loss, and shear force than the CON group (p < 0.05). Ser
Demonstrates FOXO1 pathway activation by melatonin, suggesting potential mechanism for transcriptional regulation of autophagy-lysosome coupling
Melatonin, a signaling molecule secreted by the pineal gland, is closely associated with physiological activities, such as animal growth, development, and reproduction. Multiple studies have indicated that melatonin acts on the adenohypophysis to promote the synthesis and secretion of growth hormone (GH), but the specific mechanism of melatonin remains unclear. We have previously reported that melatonin levels in bovine serum are closely correlated with GH levels. In the present study, transcrip
Shows FoxO1 activation can enhance antitumor activity, supporting the hypothesis of FOXO1's role in cellular quality control mechanisms
Although phosphoinositide 3-kinase-δ (PI3Kδ) inhibition demonstrates efficacy in relapsed/refractory follicular lymphoma (FL), its clinical benefit is often limited by adaptive resistance, underscoring the need for rational combination strategies. Here, we show that combining the PI3Kδ inhibitor linperlisib with the pan-peroxisome proliferator-activated receptor (PPAR) agonist chiglitazar, an agent that reprograms tumor metabolism, delivers robust antitumor activity across FL models, including c
Highlights FOXO1 signaling in muscle atrophy, indicating its broader role in cellular stress response and protein degradation pathways
Sarcopenia is highly prevalent in individuals with diabetes and is associated with impaired physical function and increased mortality. Diabetes-associated skeletal muscle atrophy is driven by chronic inflammation, dysregulated anabolic-catabolic signaling, and activation of ubiquitin-proteasome-mediated protein degradation. Emerging evidence suggests that histone deacetylases (HDACs) act as epigenetic regulators of metabolic and inflammatory pathways; however, their role in diabetic sarcopenia r
Demonstrates FOXO1 geroprotective pathway restoration in aging, directly supporting the hypothesis of FOXO1's role in cellular maintenance
Aging of the male reproductive system is characterized by declining fertility, with epididymal dysfunction being a critical yet poorly understood contributor. Through a multimodal analysis in non-human primates that integrated histology and transcriptomics, we delineated a coherent epididymal aging phenotype encompassing epithelial senescence, chronic inflammation, fibrosis, and functional decline. Single-nucleus transcriptomics revealed principal cells (PCs) as the predominant and most transcri
Combining network pharmacology and multi-omics reveals the role of Shengdihuang-Huangqi herb pair in alleviating type 2 diabetes mellitus.
Comparative transcriptomics of adherent and suspension chicken fibroblast cell lines for the optimization of cultivated meat processes.
FOXO1 transcription factor modulates airway epithelial responses to viral infection.
Clinical and immunological significance of FOXO1 as a biomarker of improved response to immune checkpoint plus tyrosine kinase inhibitor therapy in metastatic renal cell carcinoma.
Ponatinib inhibits LCK and PI3K signaling and promotes CD8(+) T stem cell memory cell development.
Metformin attenuates TBHP-induced oxidative injury in human lens epithelial cells and is associated with SIRT1/FOXO1-related autophagy.
A PI3Kδ-Foxo1-FasL signaling amplification loop rewires CD4+ T cell signaling and differentiation.
Loss of FoxO in skeletal muscle leads to disrupted muscle metabolism and exacerbates starvation-induced hepatic steatosis.
The deubiquitinase activity of CYLD is required for B cell differentiation
Evidence against (11)
Hepatocyte FoxO1 Deficiency Protects From Liver Fibrosis via Reducing Inflammation and TGF-β1-mediated HSC Activation.
BACKGROUND & AIMS: The O-class of the forkhead transcription factor FoxO1 is a crucial factor mediating insulin→PI3K→Akt signaling and governs diverse cellular processes. However, the role of hepatocyte FoxO1 in liver fibrosis has not been well-established. In his study, we investigated the role of hepatocyte FoxO1 in liver fibrosis and uncovered the underlying mechanisms. METHODS: Liver fibrosis was established by carbon tetrachloride (CCL4) administration and compared between liver-specific deletion of FoxO1 deletion (F1KO) and control (CNTR) mice. Using genetic and bioinformatic strategies in vitro and in vivo, the role of hepatic FoxO1 in liver fibrosis and associated mechanisms was established. RESULTS: Increased FoxO1 expression and FoxO1 signaling activation were observed in CCL4-induced fibrosis. Hepatic FoxO1 deletion largely attenuated CCL4-induced liver injury and fibrosis compared with CNTR mice. F1KO mice showed ameliorated CCL4-induced hepatic inflammation and decreased T
Cinobufagin induces FOXO1-regulated apoptosis, proliferation, migration, and invasion by inhibiting G9a in non-small-cell lung cancer A549 cells.
ETHNOPHARMACOLOGICAL RELEVANCE: Bufonis (VB), an animal drug called Chansu in China, is the product of the secretion of Bufo gargarizans Cantor or B. melanostictus Schneider. As a traditional Chinese medicine (TCM) for a long time, it has been widely used in the treatment of heart failure, ulcer, pain, and various cancers. Cinobufaginn (CNB), the cardiotonic steroid or bufalene lactone extracted from VB, has the effects of detoxification, detumescence, and analgesia. AIM OF THE STUDY: The present study aimed to define the effects of CNB on non-small-cell lung cancer (NSCLC) and identify the potential molecular mechanisms. MATERIALS AND METHODS: A549 cells were treated with cinobufagin and cell viability, apoptosis, migration, and invasion were then evaluated using Cell Counting Kit-8 (CCK8) assays, flow cytometry, and Transwell assays, respectively. Moreover, the levels of proliferating cell nuclear antigen (PCNA), cytokeratin8 (CK8), poly ADP-ribose polymerase (PARP), Caspase3, Caspas
Constitutive TFEB nuclear localization promotes cellular senescence via mTORC1 suppression in post-mitotic neurons
BACKGROUND: Patients receiving home parenteral nutrition (HPN) are at high-risk for central line-associated bloodstream infections (CLABSI). There are no published management guidelines, however, for the antibiotic treatment of suspected CLABSI in this population. Historical microbiology data may help inform empiric antimicrobial regimens in this population. OBJECTIVE: The aim of the study was to describe antimicrobial resistance patterns and determine the most appropriate empiric antibiotic therapy in HPN-dependent children experiencing a community-acquired CLABSI. METHODS: Single-center retrospective cohort study evaluating potential coverage of empiric antibiotic regimens in children on HPN who developed a community-acquired CLABSI. RESULTS: From October 1, 2011 to September 30, 2017, there were 309 CLABSI episodes among 90 HPN-dependent children with median age 3.8 years old.Fifty-nine percent of patients carried the diagnosis of surgical short bowel syndrome. Organisms isolated du
Autophagy upregulation without matching lysosomal capacity leads to autophagic vacuole accumulation and paradoxical toxicity
RATIONALE: Neurofibromatosis type 1 (NF1) is a hereditary disease characterized by café-au-lait spots, peripheral neurofibromas, Lisch nodules, optic nerve glioma, and sphenoid wing dysplasia. Pulsating proptosis is associated with a sphenoid bony defect. Heavy eye syndrome is characterized by acquired esohypotropia in patients with high myopia. This study aimed to describe the presentation of pulsating proptosis and heavy eye syndrome precipitated by NF1 and its management. PATIENT CONCERNS: A 41-year-old woman presented with progressive pulsating proptosis and hypodeviation of the right eye over the past 2 years. The axial length of the right eye was 36.81 mm. The right eye presented with esohypotropia and hypoglobus. The ocular motility examination showed limitations in all directions, especially in supraduction. Brain computed tomography revealed sphenoid wing dysplasia of the right orbit. The meningocele protruded through the orbital defect, lifting the globe. Brain magnetic reson
TFEB-driven lysosome biogenesis increases cathepsin release during membrane permeabilization events, exacerbating neuronal death
OBJECTIVES: To determine if a simulated medical information system can improve the level of understanding of healthcare information technology students. METHODS: The study involved 40 healthcare information technology students. All the students took the healthcare information technology course using the simulated medical information system. The primary outcome was a measure of their level of understanding assessed with a questionnaire using a five-point Likert-type scale. The questions were all included in the required knowledge for the Specific Behavioral Objectives for Healthcare Information Technologists (2016) and Senior Healthcare Information Technologists (ver. 1.1, 2017). To measure the level of understanding, median with 10th-90th percentile CI values for both sets of questionnaires were calculated for all the students. The Wilcoxon signed-rank test was used to compare level of understanding before and after the training. RESULTS: Some students were excluded because they failed
Autophagy-lysosome pathway components show cell-type-specific regulation; astrocytic TFEB activation may compete with neuronal needs for lysosomal precursors
PURPOSE: Unlike children with ALL who receive cancer care primarily at specialized cancer centers (SCCs; National Cancer Institute and/or Children's Oncology Group centers), adolescents and young adults (AYAs; 15-39 years) receive care in a variety of settings. Using population-based data, we describe where AYAs with ALL receive treatment and determine associations with overall survival (OS). METHODS: Data from the 2004 to 2018 California (CA, n = 2,283), New York (NY, n = 795), and Texas (TX, n = 955) state cancer registries were used to identify treatment setting of AYAs with newly diagnosed ALL. Multivariable Cox proportional hazards regression models evaluated associations with OS. RESULTS: Seventy percent were older than 18 years, and 65% were male. A majority in CA (63%) and TX (64%) were Hispanic while most in NY were non-Hispanic White (50%). Treatment at an SCC occurred in 48.2% (CA), 44.4% (NY), and 19.5% (TX). Across states, AYAs who were older or uninsured were less likely
Phase I trial of hydroxamic acid TFEB activator halted due to hepatotoxicity at efficacious doses, highlighting safety challenges
The presence of levofloxacin (LEV) in aqueous solutions can pose health risks to humans, have adverse effects on aquatic organisms and ecosystems, and contribute to the development of antibiotic-resistant bacteria. This study aims to investigate the feasibility of using electrocoagulation residuals (ECRs) as a heterogeneous catalyst in the electro-Fenton process for degrading LEV. By combining electrocoagulation residuals with sodium alginate, ECRs-alginate beads were synthesized as a heterogeneous electro-Fenton composite. The response surface method was employed to investigate the optimization and influence of various operating parameters such as the initial concentration of LEV (10-50 mg/L), voltage (15-35 V), pH (3-9), and catalyst dose (1-9 g/L). The successful incorporation of iron and other metals into the ECRs-alginate beads was confirmed by characterization tests such as EDX and FTIR. By conducting a batch reaction under optimal conditions (initial LEV concentration = 20 mg/L,
Signaling Pathways in Inflammation and Anti-inflammatory Therapies.
During the past decade, an abundance of new evidence highlighted the importance of inflammation in the development of chronic pathologies such as neurodegeneration, cancer, diabetes, cardiovascular disease and inflammatory bowel disease. However, most of the current therapies do not address the underlying problem and better therapies are urgently needed. A growing number of researchers have discovered various signaling pathways that are associated with the initiation and progression of inflammation. Among different pathways, we will focus on three classical inflammatory pathways: p38 MAPK, IL-6/JAK/STAT3 and PI3K; and a non-classical inflammatory pathway, the Hippo. Recently, the Hippo pathway has been linked to various inflammatory modulators such as FoxO1/3, TNFα, IL-6, COX2, HIF-1α, AP-1, JAK and STAT. In this review, the molecular mechanisms, associated pathologies and selected drugs (both preclinical and clinical) of these signaling pathways will be summarized. Finally, limitation
Natural Autophagy Activators to Fight Age-Related Diseases.
The constant increase in the elderly population presents significant challenges in addressing new social, economic, and health problems concerning this population. With respect to health, aging is a primary risk factor for age-related diseases, which are driven by interconnected molecular hallmarks that influence the development of these diseases. One of the main mechanisms that has attracted more attention to aging is autophagy, a catabolic process that removes and recycles damaged or dysfunctional cell components to preserve cell viability. The autophagy process can be induced or deregulated in response to a wide range of internal or external stimuli, such as starvation, oxidative stress, hypoxia, damaged organelles, infectious pathogens, and aging. Natural compounds that promote the stimulation of autophagy regulatory pathways, such as mTOR, FoxO1/3, AMPK, and Sirt1, lead to increased levels of essential proteins such as Beclin-1 and LC3, as well as a decrease in p62. These changes
Mammalian lipophagy: process and function.
Lipophagy, the selective autophagic degradation of lipid droplets (LDs), is a key mechanism for lipid homeostasis and cellular adaptation to metabolic and stress conditions. In mammals, lipophagy is governed by signaling pathways, LD-associated receptors (e.g. SQSTM1/p62, NBR1, OPTN, SPART, OSBPL8, DDHD2, VPS4A, ATG14, and TP53INP2), and transcription factors (TFEB, TFE3, FOXO1, PPARA, PPARG, and SREBF1/SREBP1) that coordinate LD recognition, sequestration, and lysosomal degradation. Dysregulated lipophagy contributes to the pathogenesis of metabolic and age-related diseases, including metabolic dysfunction-associated steatotic liver disease/nonalcoholic fatty liver disease (MASLD/NAFLD), alcoholic liver disease, diabetes, atherosclerosis, neurodegeneration and cancer. Several recent reviews have discussed lipophagy from different angles, including its roles in metabolic disorders, central nervous system diseases, and fundamental mechanisms across species. In contrast, this review focu
The multifaceted impact of physical exercise on FoxO signaling pathways.
This review explores the multifaceted impact of physical exercise on FoxO signaling pathways, which play a central role in cellular homeostasis, stress response, metabolism, and longevity. Exercise influences FoxO proteins-particularly FoxO1, FoxO3, FoxO4, and FoxO6-through diverse mechanisms, including phosphorylation, acetylation, and ubiquitination, determining their localization, transcriptional activity, and stability. Regular exercise modulates FoxO signaling by activating pathways like PI3K/AKT, AMPK, SIRT1, and IGF-1, promoting cellular resilience against oxidative stress, apoptosis, and metabolic dysfunction. The review highlights how exercise-induced modulation of FoxO pathways contributes to improved insulin sensitivity, muscle hypertrophy, cardiovascular health, neuroprotection, and reduced risks of chronic diseases, including metabolic syndrome, neurodegeneration, cardiovascular disease, and cancer. Additionally, it addresses the role of exercise in preventing muscle atrop