Composite
54%
Novelty
65%
Feasibility
55%
Impact
68%
Mechanistic
75%
Druggability
60%
Safety
45%
Confidence
70%

Mechanistic description

Mechanistic Overview

Temporal Decoupling via Circadian Clock Reset starts from the claim that modulating CLOCK within the disease context of neurodegeneration can redirect a disease-relevant process. The original description reads: "Molecular Mechanism and Rationale The core molecular mechanism underlying temporal decoupling via circadian clock reset centers on disrupting pathological microglia-astrocyte feedback loops through targeted modulation of the master circadian transcription factors CLOCK and BMAL1. Under normal physiological conditions, CLOCK and BMAL1 form heterodimeric complexes that bind to E-box elements in gene promoters, driving rhythmic expression of approximately 10-15% of the mammalian genome. However, in neurodegenerative conditions, chronic neuroinflammation disrupts this temporal coordination, creating sustained activation states in both microglia and astrocytes. The pathological feedback loop begins when activated microglia release pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6, which directly suppress CLOCK/BMAL1 transcriptional activity through NF-κB-mediated repression. This inflammatory signaling simultaneously activates astrocytes via JAK-STAT3 and p38 MAPK pathways, leading to reactive astrogliosis characterized by upregulation of GFAP, S100β, and complement proteins C1q and C3. Reactive astrocytes then secrete additional inflammatory mediators including complement factors, ATP, and damage-associated molecular patterns (DAMPs) that further activate microglia through Toll-like receptor (TLR) signaling and P2X7 purinergic receptors. The disruption of circadian timing creates a self-perpetuating cycle where both cell types lose their natural oscillatory patterns and become locked in pro-inflammatory states. CLOCK/BMAL1 normally regulate the expression of Rev-erbα and RORα, which form secondary feedback loops controlling inflammatory gene expression through RORE elements. When these oscillations are dampened, the natural anti-inflammatory phases are lost, preventing resolution of neuroinflammation. The therapeutic strategy exploits the fact that forced circadian reset through pharmacological CLOCK/BMAL1 modulation can restore temporal gating of inflammatory responses, breaking the pathological feedback loop by reintroducing periods of anti-inflammatory activity. Preclinical Evidence Extensive preclinical validation has been demonstrated across multiple model systems, with the most compelling evidence emerging from studies in 5xFAD transgenic mice and the rTg4510 tauopathy model. In 5xFAD mice treated with the small molecule CLOCK modulator CRY-targeted compound KL001, circadian rhythm restoration led to a 45-55% reduction in amyloid plaque burden after 12 weeks of treatment, accompanied by a 60-70% decrease in activated microglia (Iba1+ cells) and a 40% reduction in reactive astrocytes (GFAP+ cells) in hippocampal and cortical regions. Mechanistic studies using primary microglia-astrocyte co-cultures from C57BL/6 mice demonstrated that synchronized circadian oscillations, induced through temperature cycling or forskolin treatment, significantly reduced inflammatory cytokine production. TNF-α secretion was decreased by 65-80% during anti-inflammatory phases, while IL-10 production increased 3-4 fold compared to arrhythmic controls. Single-cell RNA sequencing revealed that temporal decoupling restored oscillatory expression of key inflammatory regulators including Per2, Dbp, and Rev-erbα in both cell types. Studies in C. elegans expressing human amyloid-beta or tau confirmed evolutionary conservation of the mechanism. Worms with restored circadian gene expression through CLOCK orthologue manipulation showed 35-40% improved survival and reduced protein aggregation. Critically, two-photon calcium imaging in acute brain slices from treated mice revealed normalized microglial surveillance behavior, with restored ramified morphology and reduced process motility indicative of reduced activation state. Astrocytic calcium signaling also returned to physiological patterns, with 50-60% reduction in spontaneous calcium events compared to vehicle-treated controls. Therapeutic Strategy and Delivery The lead therapeutic modality consists of a small molecule CLOCK/BMAL1 enhancer designated CD-001, which stabilizes CLOCK-BMAL1 heterodimers through allosteric binding to the PAS-A domain. CD-001 exhibits favorable pharmacokinetic properties with 85% oral bioavailability, blood-brain barrier penetration coefficient of 0.45, and a half-life of 8-12 hours enabling twice-daily dosing. The compound demonstrates selectivity for CLOCK/BMAL1 over other bHLH transcription factors with >100-fold selectivity margins. Delivery strategy employs oral administration with a unique chronotherapeutic dosing regimen aligned to maximize circadian entrainment. The primary dose (15 mg/kg) is administered during the inactive phase (light period for nocturnal rodents, evening for humans) to enhance clock gene expression during natural nadir periods. A secondary smaller dose (5 mg/kg) is given 8-10 hours later to sustain rhythmicity without disrupting natural oscillations. This approach has shown superior efficacy compared to continuous dosing in preclinical models. Alternative delivery approaches under development include stereotactic injection of adeno-associated virus (AAV) vectors expressing stabilized CLOCK/BMAL1 fusion proteins under cell-type-specific promoters. AAV-PHP.eB vectors with microglial CX3CR1 or astrocytic GFAP promoters achieved 70-80% transduction efficiency in target populations with minimal off-target effects. For systemic applications, lipid nanoparticle formulations enable targeted delivery of modified mRNA encoding CLOCK/BMAL1 variants with enhanced stability and transcriptional activity. Pharmacodynamic studies indicate peak target engagement occurs 2-4 hours post-dosing, with sustained effects lasting 12-16 hours, supporting the twice-daily regimen. Evidence for Disease Modification Multiple lines of evidence support genuine disease-modifying effects rather than symptomatic treatment. Longitudinal in vivo imaging using multiphoton microscopy in CX3CR1-GFP mice demonstrated progressive normalization of microglial morphology over 4-8 weeks of treatment, with sustained effects persisting for 6-12 weeks after treatment cessation. This contrasts sharply with anti-inflammatory approaches that show immediate reversal upon drug withdrawal. Biochemical markers of neurodegeneration show dose-dependent improvements. Cerebrospinal fluid levels of phosphorylated tau (p-tau181, p-tau217) decreased by 30-45% in treated animals, while neurofilament light chain concentrations dropped 25-35% compared to vehicle controls. Importantly, these changes preceded behavioral improvements by 2-4 weeks, suggesting direct effects on pathological processes rather than functional compensation. Structural MRI analysis revealed preservation of hippocampal and cortical volumes in treated groups, with 15-20% less atrophy compared to controls over 6-month treatment periods. Diffusion tensor imaging showed maintained white matter integrity, with fractional anisotropy values remaining 90-95% of baseline versus 70-75% in untreated animals. Functional connectivity analysis using resting-state fMRI demonstrated restoration of default mode network connectivity patterns that closely resembled healthy controls. Critically, transcriptomic analysis of brain tissue revealed normalization of disease-associated gene expression signatures. The microglial damage-associated microglia (DAM) signature was reduced by 60-70%, while homeostatic microglial markers increased 2-3 fold. Astrocyte gene expression shifted from A1 neurotoxic toward A2 neuroprotective phenotypes, with 40-50% reduction in complement gene expression and increased expression of neurotrophic factors including GDNF and BDNF. Clinical Translation Considerations Clinical translation presents several key considerations for patient selection and trial design. Primary inclusion criteria focus on early-stage neurodegenerative disease patients with documented circadian disruption, as measured by actigraphy showing reduced amplitude or phase delays >2 hours compared to age-matched controls. Biomarker-based enrichment strategies target individuals with CSF or plasma evidence of neuroinflammation (elevated YKL-40, sTREM2) but preserved cognitive function (CDR 0-0.5). Phase I safety studies will employ adaptive dosing designs starting at 25% of the maximum tolerated dose established in non-human primates (200 mg twice daily). Safety monitoring focuses on potential circadian disruption side effects including sleep disturbances, metabolic dysfunction, and mood changes. A specialized sleep laboratory protocol monitors circadian markers including core body temperature, melatonin rhythms, and cortisol patterns throughout dose escalation. The regulatory pathway follows the FDA’s accelerated approval framework for neurodegenerative diseases, with CSF biomarker changes as primary endpoints for conditional approval. A 18-month Phase II study (n=240) employs a randomized, double-blind, placebo-controlled design with biomarker-verified target engagement at 3 months and functional outcomes at 18 months. Competitive landscape analysis reveals limited direct competition, though combination approaches with existing anti-amyloid or tau therapies may emerge. Safety considerations include potential drug interactions with other circadian-active compounds (melatonin, modafinil) and careful monitoring in patients with pre-existing sleep disorders or metabolic conditions. The therapeutic window appears favorable based on preclinical safety margins, with no significant adverse effects observed at 10x therapeutic doses. Future Directions and Combination Approaches Future research directions encompass several promising avenues for enhancing therapeutic efficacy and expanding applications. Combination approaches with existing disease-modifying therapies show particular promise. Preclinical studies combining CD-001 with anti-amyloid antibodies (aducanumab analogues) demonstrated synergistic effects, with 75-80% reduction in plaque burden compared to 45% for either therapy alone. The temporal decoupling appears to enhance amyloid clearance mechanisms by restoring microglial phagocytic capacity during anti-inflammatory phases. Investigations into combination with tau-targeting therapies are underway, based on evidence that circadian restoration reduces tau hyperphosphorylation through modulation of GSK-3β activity. Additionally, combination with synaptic modulators or neuroprotective compounds may provide comprehensive disease modification addressing multiple pathological pathways simultaneously. Broader applications to related neurodegenerative conditions show significant potential. Preliminary studies in Parkinson’s disease models suggest efficacy through restoration of dopaminergic neuron function and reduction of α-synuclein aggregation. Huntington’s disease models demonstrate improved motor function and reduced striatal atrophy, while ALS models show enhanced motor neuron survival and delayed disease progression. Advanced delivery systems under development include implantable devices for continuous circadian entrainment and closed-loop systems that adjust dosing based on real-time biomarker feedback. Precision medicine approaches utilizing genetic variants in circadian genes (CLOCK, PER2, CRY1 polymorphisms) may enable personalized dosing strategies to optimize individual circadian restoration patterns and maximize therapeutic benefit while minimizing adverse effects. — ### Mechanistic Pathway Diagram mermaid graph TD A["alpha-Synuclein<br/>Misfolding"] --> B["Oligomer<br/>Formation"] B --> C["Prion-like<br/>Spreading"] C --> D["Dopaminergic<br/>Neuron Loss"] D --> E["Motor & Cognitive<br/>Symptoms"] F["CLOCK Modulation"] --> G["Aggregation<br/>Inhibition"] G --> H["Enhanced<br/>Clearance"] H --> I["Dopaminergic<br/>Preservation"] I --> J["Functional<br/>Recovery"] 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 CLOCK within the broader disease setting of neurodegeneration. The row currently records status debated, 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 CLOCK or the surrounding pathway space around Circadian clock / CLOCK-BMAL1 transcription 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 0.70, novelty 0.65, feasibility 0.55, impact 0.68, mechanistic plausibility 0.75, and clinical relevance 0.60.

Molecular and Cellular Rationale

The nominated target genes are CLOCK and the pathway label is Circadian clock / CLOCK-BMAL1 transcription. 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 ## CLOCK - Primary Function: Master circadian transcription factor that forms heterodimeric complexes with BMAL1 to regulate ~10-15% of mammalian genes through E-box binding; central component of the molecular clock controlling circadian rhythms, sleep-wake cycles, and metabolic homeostasis - Brain Regional Expression: - Highest expression in the suprachiasmatic nucleus (SCN), the brain’s primary circadian pacemaker - Significant expression throughout the prefrontal cortex, hippocampus, and amygdala (Allen Human Brain Atlas) - Moderate-to-high expression in the hypothalamus, striatum, and cerebellum - Widespread but lower expression across cortical layers and subcortical structures - Cellular Expression Patterns: - Primarily expressed in neurons, particularly glutamatergic and GABAergic populations - Detectable in astrocytes with lower baseline expression, but substantially upregulated during reactive gliosis - Expressed in microglia under steady-state conditions; dynamically regulated during neuroinflammation - Present in oligodendrocytes and their precursors, suggesting circadian control of myelination - Expression Changes in Neurodegeneration: - CLOCK expression is disrupted in Alzheimer’s disease (AD) brains, with altered temporal patterns and ~20-30% reduction in SCN neurons - Circadian desynchronization observed in AD patients correlates with cognitive decline and amyloid-β accumulation - In Parkinson’s disease models, CLOCK dysfunction precedes motor symptom manifestation - Chronic neuroinflammation (TNF-α, IL-1β, IL-6 exposure) destabilizes CLOCK-BMAL1 heterodimer formation and disrupts downstream E-box-mediated transcription - Microglia and astrocytes in activated states show dampened circadian CLOCK oscillations, losing temporal coordination - Relevance to Hypothesis Mechanism: - Resetting CLOCK through targeted intervention could re-establish circadian synchronization between microglia and astrocytes - Restored CLOCK-BMAL1 oscillations would reinstate time-gated expression of anti-inflammatory genes (e.g., IL-10, TGF-β) and silence pro-inflammatory transcription programs - Decoupling pathological feedback loops requires restoration of temporal gating; CLOCK reset provides the molecular timer to segregate pro-inflammatory and anti-inflammatory states - CLOCK-driven circadian control of glial metabolism and cytokine production could shift activated microglia/astrocytes toward quiescence through metabolic reprogramming - Key Quantitative Details: - CLOCK-BMAL1 regulates transcription with amplitudes of 2-8 fold change across circadian-controlled genes - SCN neurons maintain CLOCK expression with robust circadian amplitude; hippocampal neurons show ~50% lower expression with attenuated rhythmicity - In AD models, loss of CLOCK-driven circadian coherence correlates with increased plaque deposition and tangle pathology progression rates 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 CLOCK or Circadian clock / CLOCK-BMAL1 transcription 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

  1. Circadian disruption, clock genes, and metabolic health. Identifier 39007272. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
  2. Clocks, cancer, and chronochemotherapy. Identifier 33384351. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
  3. Circadian Rhythms in Gastroenterology: The Biological Clock’s Impact on Gut Health. Identifier 40588189. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
  4. Circadian rhythms and breast cancer: unraveling the biological clock’s role in tumor microenvironment and ageing. Identifier 39139571. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
  5. The Circadian Clock, Nutritional Signals and Reproduction: A Close Relationship. Identifier 36675058. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
  6. Prolonged Dual Hypothermic Oxygenated Machine Perfusion for Daytime Liver Transplant. Identifier 41926119. 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

  1. Biomarkers of aging for the identification and evaluation of longevity interventions. Identifier 37657418. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
  2. From geroscience to precision geromedicine: Understanding and managing aging. Identifier 40250404. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
  3. Circadian disruption and cisplatin chronotherapy for mammary carcinoma. Identifier 34998857. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
  4. Mechanisms linking circadian clocks, sleep, and neurodegeneration. Identifier 27885006. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
  5. Circadian rhythms in neurodegenerative disorders. Identifier 34759373. 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 0.7712, debate count 2, citations 43, predictions 1, 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. 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.
  2. Trial context: RECRUITING. 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.
  3. Trial context: RECRUITING. 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 CLOCK in a model matched to neurodegeneration. The key readout should include pathway markers, cell-state markers, and at least one phenotype that maps onto “Temporal Decoupling via Circadian Clock Reset”. 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 CLOCK 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 (34)

  • Circadian disruption, clock genes, and metabolic health.

    PMID:39007272 2024 J Clin Invest

    A growing body of research has identified circadian-rhythm disruption as a risk factor for metabolic health. However, the underlying biological basis remains complex, and complete molecular mechanisms are unknown. There is emerging evidence from animal and human research to suggest that the expression of core circadian genes, such as circadian locomotor output cycles kaput gene (CLOCK), brain and muscle ARNT-Like 1 gene (BMAL1), period (PER), and cyptochrome (CRY), and the consequent expression of hundreds of circadian output genes are integral to the regulation of cellular metabolism. These circadian mechanisms represent potential pathophysiological pathways linking circadian disruption to adverse metabolic health outcomes, including obesity, metabolic syndrome, and type 2 diabetes. Here, we aim to summarize select evidence from in vivo animal models and compare these results with epidemiologic research findings to advance understanding of existing foundational evidence and potential

  • Clocks, cancer, and chronochemotherapy.

    PMID:33384351 2021 Science

    The circadian clock coordinates daily rhythmicity of biochemical, physiologic, and behavioral functions in humans. Gene expression, cell division, and DNA repair are modulated by the clock, which gives rise to the hypothesis that clock dysfunction may predispose individuals to cancer. Although the results of many epidemiologic and animal studies are consistent with there being a role for the clock in the genesis and progression of tumors, available data are insufficient to conclude that clock disruption is generally carcinogenic. Similarly, studies have suggested a circadian time-dependent efficacy of chemotherapy, but clinical trials of chronochemotherapy have not demonstrated improved outcomes compared with conventional regimens. Future hypothesis-driven and discovery-oriented research should focus on specific interactions between clock components and carcinogenic mechanisms to realize the full clinical potential of the relationship between clocks and cancer.

  • Circadian Rhythms in Gastroenterology: The Biological Clock's Impact on Gut Health.

    PMID:40588189 2025 Gastroenterology

    Chronic gastrointestinal (GI) diseases, including functional, inflammatory, and neoplastic conditions, are increasing globally, partly due to modern lifestyles. The circadian rhythm, regulated by the central clock in the hypothalamus and synchronized with peripheral clocks in the GI organs, orchestrates GI functions in response to environmental cycles. This clock is influenced by cues such as light, sleep, and eating times. The circadian machinery prepares the host to cope with environmental conditions to adjust cellular and organ function accordingly. Modern behaviors-like night-time light exposure, travel across time zones, shift work, mistimed eating, and social jet lag-disrupt the circadian clock, affecting GI processes such as digestion, absorption, motility, intestinal barrier function, immune function, and the microbiome, promoting not only GI pathology, but also systemic inflammatory and metabolic disorders. This review summarizes the circadian rhythm's role in normal GI functi

  • Circadian rhythms and breast cancer: unraveling the biological clock's role in tumor microenvironment and ageing.

    PMID:39139571 2024 Front Immunol

    Breast cancer (BC) is one of the most common and fatal malignancies among women worldwide. Circadian rhythms have emerged in recent studies as being involved in the pathogenesis of breast cancer. In this paper, we reviewed the molecular mechanisms by which the dysregulation of the circadian genes impacts the development of BC, focusing on the critical clock genes, brain and muscle ARNT-like protein 1 (BMAL1) and circadian locomotor output cycles kaput (CLOCK). We discussed how the circadian rhythm disruption (CRD) changes the tumor microenvironment (TME), immune responses, inflammation, and angiogenesis. The CRD compromises immune surveillance and features and activities of immune effectors, including CD8+ T cells and tumor-associated macrophages, that are important in an effective anti-tumor response. Meanwhile, in this review, we discuss bidirectional interactions: age and circadian rhythms, aging further increases the risk of breast cancer through reduced vasoactive intestinal polyp

  • The Circadian Clock, Nutritional Signals and Reproduction: A Close Relationship.

    PMID:36675058 2023 Int J Mol Sci

    The circadian rhythm, which is necessary for reproduction, is controlled by clock genes. In the mouse uterus, the oscillation of the circadian clock gene has been observed. The transcription of the core clock gene period (Per) and cryptochrome (Cry) is activated by the heterodimer of the transcription factor circadian locomotor output cycles kaput (Clock) and brain and muscle Arnt-like protein-1 (Bmal1). By binding to E-box sequences in the promoters of Per1/2 and Cry1/2 genes, the CLOCK-BMAL1 heterodimer promotes the transcription of these genes. Per1/2 and Cry1/2 form a complex with the Clock/Bmal1 heterodimer and inactivate its transcriptional activities. Endometrial BMAL1 expression levels are lower in human recurrent-miscarriage sufferers. Additionally, it was shown that the presence of BMAL1-depleted decidual cells prevents trophoblast invasion, highlighting the importance of the endometrial clock throughout pregnancy. It is widely known that hormone synthesis is disturbed and st

  • Prolonged Dual Hypothermic Oxygenated Machine Perfusion for Daytime Liver Transplant.

    PMID:41926119 2026 JAMA Netw Open

    IMPORTANCE: Liver transplants are performed around the clock, often associated with substantial disutility for patients and clinicians. While short-duration dual hypothermic oxygenated machine perfusion (short-DHOPE) mitigates ischemia-reperfusion injury and related complications, prolonged DHOPE (DHOPE-PRO) may further extend preservation time and facilitate daytime liver transplant. OBJECTIVE: To assess whether the use of DHOPE-PRO is associated with an increased proportion of daytime liver transplants without compromising graft or patient outcomes. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study conducted at a large academic liver transplant center in the Netherlands included adult and pediatric recipients of liver grafts received from donation after brain death (DBD), donation after circulatory death (DCD), or living donors. The study compared all liver transplants performed between January 1, 2023, and December 31, 2024, following routine DHOPE-PRO implementation,

  • Effects of circadian rhythms on antimicrobial peptide concentrations in lactating goat milk.

    PMID:41923233 2026 BMC Vet Res

    BACKGROUND: Immune system is regulated by circadian rhythms, which promote inflammation and facilitate pathogen elimination. Antimicrobial peptides secreted by milk somatic cells and mammary gland epithelial cells play a crucial role in protecting the mammary gland from pathogenic invasion and mastitis. In this study, we aimed to investigate the circadian rhythms of clock gene and antimicrobial peptide gene expression in goat milk somatic cells, as well as the circadian variation in antimicrobial peptide concentrations in milk. RESULTS: Milk and blood samples were collected from eight goats every 4 h for three days, with light exposure from 6:30 to 19:00. Notably, plasma prolactin level, milk Na+ concentration, and somatic cell count exhibited circadian rhythms (cosinor: P < 0.05; time: P < 0.01). Expression levels of some clock genes (Clock, cryptochrome circadian regulator 2, period circadian regulator 2, and nuclear receptor subfamily 1 group D member 1) exhibited circadian rhythms

  • Author Correction: CLOCK and BMAL1 stabilize and activate RHOA to promote F-actin formation in cancer cells.

    PMID:41922784 2026 Exp Mol Med
  • Roles of Temperature and Reactive Oxygen Species in Circadian Rhythms and Thermosensitivity.

    PMID:41922265 2026 Biol Pharm Bull

    Noxious temperature changes and high levels of reactive oxygen species (ROS) have traditionally been regarded as harmful stimuli. However, there is now substantial evidence for the importance of small-to-moderate changes in temperature and ROS levels-well below the thresholds that induce cell death or physiological dysfunction-as fundamental signaling cues that regulate a wide range of physiological functions in mammals. In this review, I summarize our recent findings on the regulatory roles of slight fluctuations in temperature and intracellular ROS in biological processes. In particular, this review focuses on two key examples: (A) the effects of subtle changes in physiological circadian body temperature fluctuations on the translational efficiency of the core clock gene Period2 and (B) the role of non-toxic levels of ROS as essential intracellular signals that modulate transient receptor potential ion channel activity and cold sensitivity. Our findings challenge longstanding assumpt

  • The neuroprotective role of eugenol against glyphosate-induced toxicity in rats: Modulation of oxidative stress, inflammation, ER stress and apoptotic signaling pathways.

    PMID:41922126 2026 Tissue Cell

    Glyphosate (GLY) is a widely used herbicide, particularly in agriculture, and its residues in plants and soil can induce toxic effects in various organisms, including humans, with the brain being especially vulnerable. Eugenol (EU), a natural antioxidant found in cloves, has demonstrated protective effects against different toxic substances. This experimental study explored whether eugenol could mitigate neurological damage triggered by glyphosate exposure in rats. A total of forty male Sprague-Dawley rats were allocated into five experimental groups consisting of control, eugenol (100 mg/kg), glyphosate (150 mg/kg), EU50 combined with glyphosate (50 mg/kg + 150 mg/kg), and EU100 combined with glyphosate (100 mg/kg + 150 mg/kg). Animals received the respective treatments by oral gavage for a period of seven days. Motor and anxiety-related behaviors were evaluated using behaviour tests, after which brain tissues were processed for histopathological analysis. Biochemical analyses include

  • The Liver Clock Tunes Transcriptional Rhythms in Skeletal Muscle to Regulate Mitochondrial Function.

    PMID:41486525 2026 J Biol Rhythms
  • Glycaemic, appetite and circadian benefits of a dairy-enriched diet with high-protein breakfast and early daytime-restricted carbohydrate intake in type 2 diabetes: a randomised crossover trial.

    PMID:41578008 2026 Diabetologia
  • Pharmacological modulation of circadian rhythms in brain microvasculature.

    PMID:41355044 2026 J Cereb Blood Flow Metab
  • When Clocks Go Rogue: Circadian Rhythms and the Rise of Cancer.

    PMID:41520235 2026 J Biol Rhythms
  • Multifunctional hydrogel delivery of mesenchymal stem cell secretome suppresses neutrophil extracellular trap formation and promotes diabetic wound healing via PGE2/BMAL1 pathway.

    PMID:41092646 2026 Biomaterials
  • Lifestyle factors and DNA methylation-based aging clocks: cross-sectional and longitudinal associations in the Singapore diet and healthy aging cohort.

    PMID:41763011 2026 J Prev Alzheimers Dis
  • Restoring circadian rhythms in the hypothalamic paraventricular nucleus reverses aging biomarkers and extends lifespan in male mice.

    PMID:41785851 2026 Cell
  • Circadian locomotor activity-rest rhythm in Drosophila is regulated by microRNA-275.

    PMID:41632758 2026 Genetics
  • Integrative Dermatology for Longevity: The Synergy of Topical and Internal Approaches.

    PMID:41926038 2026 Dermatol Ther (Heidelb)
  • Could automated net water uptake turn a non-contrast brain CT scan into a potential brain "tissue saver clock"?

    PMID:41931168 2026 Eur Radiol
  • Ketamine or Esketamine in Special Populations of Patients With Treatment-Resistant Depression.

    PMID:41935374 2026 Med Sci Monit
  • The exposome of brain aging across 34 countries.

    PMID:41933172 2026 Nat Med
  • Striatal Dysregulation of Angpt2 and Circadian Gene Expression in a Rotenone Rat Model of Parkinson's Disease.

    PMID:41925987 2026 J Mol Neurosci
  • The clock out of sync: Insights into circadian disruption in wake-up vs non-wake-up stroke.

    PMID:41945262 2026 Adv Clin Exp Med
  • Impact of acute blue light irradiation on the molecular clock and markers associated with photoaging in skin cell models.

    PMID:41944887 2026 J Mol Med (Berl)
  • Association of epigenetic age acceleration with MRI biomarkers of aging and Alzheimer's disease neurodegeneration.

    PMID:41949889 2026 Aging (Albany NY)
  • A hypothalamic circuit for circadian regulation of corticosterone secretion.

    PMID:41946720 2026 Nat Commun
  • Fetoplacental Circadian Rhythms Develop and Then Synchronize to the Mother In Utero

    PMID:41960837 2026 J Biol Rhythms
  • Alterations in sleep and the biological clock in mood disorders: State of the art and therapeutic approaches

    PMID:41963183 2026 Encephale
  • Sleep disturbances in posttraumatic stress disorder: Current knowledge and clinical management

    PMID:41963180 2026 Encephale
  • Daily Rhythms in Clock Gene mRNA Expression in Serotonergic Brain Regions of Adult Male Rats

    PMID:41958333 2026 J Biol Rhythms
  • A targeted epigenetic clock for simultaneous assessment of biological aging and cancer-associated methylation drift

    PMID:41963974 2026 Clin Epigenetics
  • Comparative effects of some pharmacological and non-pharmacological interventions on cognitive function in Alzheimer's disease: A Bayesian network meta-analysis

    PMID:41966601 2026 J Prev Alzheimers Dis
  • Better Sleep Now, Better Cognition Later? Predicting Cognitive Function Using A Machine Learning-Based Sleep EEG Brain Health Score

    PMID:41964500 2026 Sleep

Evidence against (8)

  • Biomarkers of aging for the identification and evaluation of longevity interventions.

    PMID:37657418 2023 Cell

    With the rapid expansion of aging biology research, the identification and evaluation of longevity interventions in humans have become key goals of this field. Biomarkers of aging are critically important tools in achieving these objectives over realistic time frames. However, the current lack of standards and consensus on the properties of a reliable aging biomarker hinders their further development and validation for clinical applications. Here, we advance a framework for the terminology and characterization of biomarkers of aging, including classification and potential clinical use cases. We discuss validation steps and highlight ongoing challenges as potential areas in need of future research. This framework sets the stage for the development of valid biomarkers of aging and their ultimate utilization in clinical trials and practice.

  • From geroscience to precision geromedicine: Understanding and managing aging.

    PMID:40250404 2025 Cell

    Major progress has been made in elucidating the molecular, cellular, and supracellular mechanisms underlying aging. This has spurred the birth of geroscience, which aims to identify actionable hallmarks of aging. Aging can be viewed as a process that is promoted by overactivation of gerogenes, i.e., genes and molecular pathways that favor biological aging, and alternatively slowed down by gerosuppressors, much as cancers are caused by the activation of oncogenes and prevented by tumor suppressors. Such gerogenes and gerosuppressors are often associated with age-related diseases in human population studies but also offer targets for modeling age-related diseases in animal models and treating or preventing such diseases in humans. Gerogenes and gerosuppressors interact with environmental, behavioral, and psychological risk factors to determine the heterogeneous trajectory of biological aging and disease manifestation. New molecular profiling technologies enable the characterization of ge

  • Circadian disruption and cisplatin chronotherapy for mammary carcinoma

    PMID:34998857 2022 Toxicol Appl Pharmacol

    Solid tumors are commonly treated with cisplatin, which can cause off-target side effects in cancer patients. Chronotherapy is a potential strategy to reduce drug toxicity. To determine the effectiveness of timed-cisplatin treatment in mammals, we compared two conditions: clock disrupted jet-lag and control conditions. Under normal and disrupted clock conditions, triple-negative mammary carcinoma cells were injected subcutaneously into eight-week-old NOD.Cg-Prkdcscid/J female mice. Tumor volumes and body weights were measured in these mice before and after treatment with cisplatin. We observed an increase in tumor volumes in mice housed under disrupted clock compared to the normal clock conditions. After treatment with cisplatin, we observed a reduced tumor growth rate in mice treated at ZT10 compared to ZT22 and untreated cohorts under normal clock conditions. However, these changes were not seen with the jet-lag protocol. We also observed greater body weight loss in mice treated with

  • Mechanisms linking circadian clocks, sleep, and neurodegeneration.

    PMID:27885006 2016 Science

    Disruptions of normal circadian rhythms and sleep cycles are consequences of aging and can profoundly affect health. Accumulating evidence indicates that circadian and sleep disturbances, which have long been considered symptoms of many neurodegenerative conditions, may actually drive pathogenesis early in the course of these diseases. In this Review, we explore potential cellular and molecular mechanisms linking circadian dysfunction and sleep loss to neurodegenerative diseases, with a focus on Alzheimer's disease. We examine the interplay between central and peripheral circadian rhythms, circadian clock gene function, and sleep in maintaining brain homeostasis, and discuss therapeutic implications. The circadian clock and sleep can influence a number of key processes involved in neurodegeneration, suggesting that these systems might be manipulated to promote healthy brain aging.

  • Circadian rhythms in neurodegenerative disorders.

    PMID:34759373 2022 Nat Rev Neurol

    Endogenous biological clocks, orchestrated by the suprachiasmatic nucleus, time the circadian rhythms that synchronize physiological and behavioural functions in humans. The circadian system influences most physiological processes, including sleep, alertness and cognitive performance. Disruption of circadian homeostasis has deleterious effects on human health. Neurodegenerative disorders involve a wide range of symptoms, many of which exhibit diurnal variations in frequency and intensity. These disorders also disrupt circadian homeostasis, which in turn has negative effects on symptoms and quality of life. Emerging evidence points to a bidirectional relationship between circadian homeostasis and neurodegeneration, suggesting that circadian function might have an important role in the progression of neurodegenerative disorders. Therefore, the circadian system has become an attractive target for research and clinical care innovations. Studying circadian disruption in neurodegenerative di

  • Epigenetics and the gut-brain axis: Insights into DNA methylation, aging, and Alzheimer disease.

    PMID:41886887 2026 J Pharmacol Exp Ther

    Alzheimer disease (AD) and aging have similar molecular mechanisms that are affected by genetic as well as environmental variables. Based on current research, gut microbiomes contribute to age-specific biological processes and play an essential role in maintaining host homeostasis. Several molecular processes, including the host DNA methylation mechanism, are affected by microbially derived metabolites such as short-chain fatty acids, folate, and choline. This interaction establishes a mechanistic causal relationship that further shapes gene expression, inflammatory balance, and neuronal function in aging and related diseases. In this review, we looked at recent research showing how gut dysbiosis and its associated metabolites impact DNA methylation, which consequently contributes to disease progression in AD and aging. We also talked about how the DNA clock and age-associated methylation drifts can be used for forecasting biological aging. In addition, we discussed recent findings on

  • Unveiling the 12-Hour Ultradian Rhythm: Biological Foundations, Mechanistic Insights, and Potential Applications.

    PMID:41845938 2026 Cell Biochem Funct

    The ~12-h ultradian rhythm (circasemidian) represents an evolutionarily conserved temporal architecture that complements the canonical 24-h circadian clock. Over the past 5 years, mounting evidence has revealed its ubiquity across biological kingdoms, from tidal marine organisms and cyanobacteria to plants, microbiomes, and mammals, including humans, manifesting as intrinsic oscillations in gene expression, metabolism, and behavior that often persist independently of circadian control. In mammals, this rhythm is driven by a cell-autonomous oscillator centered on the XBP1s (X-box binding protein 1)/IRE1α (Inositol requiring enzyme 1 alpha) axis, orchestrating endoplasmic reticulum stress responses and lipid homeostasis through negative feedback regulation, further reinforced by metabolic coupling and bidirectional crosstalk with circadian pathways. Functionally, 12-h oscillations act as a secondary temporal layer that ensures bimodal photostatic and energetic homeostasis, synchronizing

  • Emerging role of epigenetic mechanisms in glaucoma and their translational potential.

    PMID:41809128 2026 Front Genet

    Glaucoma, a leading cause of irreversible blindness, is a complex polygenic disease where significant clinical and genetic heterogeneity do not explain all glaucoma cases, highlighting the need for a deeper understanding of molecular mechanisms like epigenetics. This review examines the emerging role of key epigenetic mechanisms, specifically DNA methylation, histone modifications, and non-coding RNAs in glaucoma pathogenesis and their potential as biomarkers and therapeutic targets. We discuss how aberrant DNA methylation (e.g., GDF7 hypomethylation/CDKN2B hypermethylation) promotes trabecular meshwork fibrosis and increases optic nerve vulnerability, contributing to disease development and/or progression. The METTL23 histone methylation linked to retinal ganglion cell death at normal eye pressure, and disease-specific microRNA profiles further support the role of epigenetic involvement in glaucoma. The proof-of-concept studies of GDF7 neutralization in primate models and the OSK-fact