Senescent Cell Mitochondrial DNA Release

Proposed by etl-backfill

CGAS/STING1/DNASE2 neurodegeneration market 84% debated
Compare across mechanisms →
Composite
74%
Novelty
85%
Feasibility
45%
Impact
60%
Mechanistic
55%
Druggability
40%
Safety
50%
Confidence
50%

Mechanistic description

Mechanistic Overview

Senescent Cell Mitochondrial DNA Release starts from the claim that modulating CGAS/STING1/DNASE2 within the disease context of neurodegeneration can redirect a disease-relevant process. The original description reads: "Molecular Mechanism and Rationale The cGAS-STING pathway represents a critical innate immune sensing mechanism that has emerged as a central driver of neuroinflammation in age-related neurodegeneration. In senescent glial cells, particularly microglia and astrocytes, the cellular quality control machinery undergoes progressive deterioration, leading to compromised mitochondrial homeostasis and defective mitophagy. Under normal physiological conditions, the PINK1/Parkin-mediated mitophagy pathway efficiently removes damaged mitochondria, preventing the accumulation of oxidized mitochondrial DNA (mtDNA) in the cytoplasm. However, in senescent cells, reduced expression of autophagy-related proteins (ATG5, ATG7, LC3B) and impaired lysosomal function result in the persistence of damaged mitochondria with compromised membrane integrity. The nuclear envelope breakdown characteristic of senescent cells further exacerbates this process by allowing nuclear DNA damage products to mix with cytoplasmic contents. When damaged mtDNA escapes into the cytoplasm through mitochondrial membrane permeabilization or incomplete mitophagy, it serves as a potent damage-associated molecular pattern (DAMP) that activates the cyclic GMP-AMP synthase (cGAS). Upon binding double-stranded DNA, cGAS undergoes a conformational change that catalyzes the synthesis of cyclic GMP-AMP (cGAMP) from ATP and GTP. This second messenger binds to the stimulator of interferon genes (STING), located on the endoplasmic reticulum membrane, triggering its dimerization and translocation to the Golgi apparatus. Activated STING recruits TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3), leading to the phosphorylation and nuclear translocation of IRF3. This transcription factor, along with NF-κB activation downstream of STING, drives the expression of type I interferons (IFN-α/β), pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and chemokines (CCL2, CXCL10). The released inflammatory mediators create a paracrine signaling environment that activates neighboring neurons and glial cells, propagating the inflammatory cascade. Crucially, the chronic activation of this pathway in neurons leads to synaptic dysfunction, altered calcium homeostasis, and ultimately neuronal death through both apoptotic and necroptotic mechanisms. Preclinical Evidence Extensive preclinical evidence supports the role of senescent cell mtDNA release in neurodegeneration across multiple model systems. In the 5xFAD mouse model of Alzheimer’s disease, immunofluorescence studies have demonstrated a 3-fold increase in cytoplasmic mtDNA colocalization with cGAS in cortical and hippocampal regions compared to wild-type controls. Single-cell RNA sequencing of microglia from aged APP/PS1 mice revealed elevated expression of senescence markers (p16, p21, SASP genes) alongside increased cGAS and STING transcripts, with a 2.5-fold upregulation in the most affected brain regions. In vitro studies using primary neuronal cultures exposed to conditioned medium from senescent astrocytes showed significant activation of the cGAS-STING pathway, as evidenced by increased cGAMP levels (40-60% elevation) and downstream interferon-stimulated gene expression. Treatment with DNase II or the STING inhibitor H-151 reduced neuronal death by 50-70% in these co-culture experiments. Furthermore, electron microscopy analysis of senescent human astrocytes revealed extensive mitochondrial fragmentation and the presence of cytoplasmic mtDNA puncta, which correlated with increased cGAS immunoreactivity. Caenorhabditis elegans models with compromised mitophagy (pink-1 mutants) exhibited accelerated neurodegeneration and shortened lifespan, phenotypes that were partially rescued by neuronal-specific expression of a mitochondria-targeted DNase. In Drosophila melanogaster, overexpression of damaged mtDNA in glial cells led to locomotor deficits and reduced survival, while genetic ablation of the fly STING homolog provided neuroprotection. Quantitative PCR analysis of post-mortem human brain tissue from Alzheimer’s, Parkinson’s, and ALS patients consistently showed 2-4 fold increases in cytoplasmic mtDNA levels and elevated expression of cGAS-STING pathway components compared to age-matched controls. Therapeutic Strategy and Delivery The therapeutic intervention strategy focuses on two complementary approaches: enhancing cytoplasmic DNA clearance through DNase II delivery and inhibiting downstream inflammatory signaling via STING antagonism. DNase II, an acid-active endonuclease normally confined to lysosomes, can be engineered for cytoplasmic delivery using cell-penetrating peptides or encapsulation in lipid nanoparticles. Preclinical formulations have utilized PEGylated liposomes containing recombinant human DNase II with targeting ligands for the transferrin receptor, enabling blood-brain barrier penetration and preferential uptake by activated microglia and astrocytes. For STING inhibition, small molecule antagonists such as H-151, C-176, and the more selective compound SN-011 have shown promise in preclinical studies. These compounds typically require intracerebroventricular administration or formulation in brain-penetrant nanocarriers to achieve therapeutic concentrations in neural tissue while minimizing systemic immunosuppression. Pharmacokinetic studies in non-human primates suggest that weekly dosing with 10-50 mg/kg of encapsulated STING inhibitors maintains effective CNS concentrations for 5-7 days. Alternative delivery strategies include adeno-associated virus (AAV) vectors expressing cytoplasm-targeted DNase II under glial-specific promoters (GFAP for astrocytes, CD68 for microglia). AAV-PHP.eB vectors have demonstrated superior CNS tropism and could enable sustained enzyme expression following a single intrathecal injection. For combination therapy, dual-payload nanoparticles containing both DNase II and STING inhibitors are being developed to achieve synergistic effects while reducing individual drug doses and associated toxicities. Evidence for Disease Modification Disease-modifying potential is evidenced by the reversal of pathological biomarkers and functional outcomes rather than mere symptomatic improvement. In transgenic mouse models, treatment with DNase II-loaded nanoparticles resulted in significant reductions in CSF cytoplasmic mtDNA levels (60-80% decrease), normalized microglial activation profiles assessed by PET imaging with [18F]PBR111, and improved performance on cognitive tasks including novel object recognition and Morris water maze testing. Critically, these improvements were sustained for months after treatment cessation, indicating durable disease modification. Biomarker studies in treated animals showed restoration of synaptic protein levels (PSD-95, synaptophysin) and normalization of dendritic spine density, suggesting structural neuroprotection. Longitudinal MRI imaging revealed preserved hippocampal and cortical volumes in treated groups compared to progressive atrophy in controls. Electrophysiological recordings demonstrated improved long-term potentiation and reduced aberrant gamma oscillations associated with neuroinflammation. In human cell culture models using induced pluripotent stem cell-derived neurons and glia, treatment with the therapeutic combination prevented the age-related decline in mitochondrial respiratory function and maintained normal calcium signaling patterns. Proteomics analysis revealed restoration of synaptic and metabolic protein networks, while reducing inflammatory signatures characteristic of neurodegeneration. Importantly, the intervention did not impair normal immune responses to pathogens, indicating selective targeting of sterile inflammation pathways. Clinical Translation Considerations Patient selection strategies should focus on individuals with elevated CSF markers of mitochondrial dysfunction and innate immune activation before significant neuronal loss occurs. Biomarker panels including cytoplasmic mtDNA, cGAMP, and inflammatory cytokines could identify optimal candidates for intervention. Early-stage patients with mild cognitive impairment or prodromal symptoms would likely derive the greatest benefit, as advanced neurodegeneration may be irreversible. Phase I safety trials should emphasize dose-escalation studies to establish maximum tolerated doses and identify any off-target immune suppression. Given the critical role of cGAS-STING in antiviral immunity, careful monitoring for increased infection susceptibility will be essential. The regulatory pathway would likely follow the FDA’s guidance for neurodegenerative disease therapeutics, requiring demonstration of both biomarker changes and functional benefits in Phase II trials. Competitive considerations include emerging senolytic therapies and other anti-inflammatory approaches for neurodegeneration. However, the specific targeting of mtDNA-driven inflammation represents a novel mechanism that could complement existing strategies. Collaboration with diagnostic companies developing liquid biopsy assays for cytoplasmic mtDNA could accelerate patient identification and treatment monitoring. Future Directions and Combination Approaches Future research should explore combination therapies that address multiple aspects of neuroinflammation and cellular senescence. Pairing cGAS-STING pathway inhibition with senolytic agents (dasatinib plus quercetin, or newer compounds like navitoclax) could eliminate senescent cells while preventing inflammatory activation of surrounding tissues. Additionally, combining this approach with mitochondrial-targeted antioxidants (MitoQ, SS-31) or mitophagy enhancers (urolithin A, rapamycin analogs) could address upstream causes of mtDNA damage. The therapeutic principle extends beyond neurodegeneration to other age-related diseases characterized by senescent cell accumulation and sterile inflammation, including cardiovascular disease, diabetes, and cancer. Tissue-specific delivery systems could enable targeted intervention in affected organs while preserving systemic immune function. Development of biomarker assays for cytoplasmic mtDNA could facilitate early detection and monitoring across multiple disease contexts. Advanced delivery technologies, including focused ultrasound-mediated blood-brain barrier opening and engineered extracellular vesicles, may improve therapeutic targeting and reduce systemic exposure. Personalized medicine approaches using patient-derived organoids could guide optimal drug combinations and dosing strategies. Long-term studies will be essential to evaluate the durability of treatment effects and identify any potential resistance mechanisms or adaptive responses that could limit therapeutic efficacy.

Mechanistic Pathway Diagram

graph TD
A["Senescent Glia<br/>(Microglia, Astrocytes)"] --> B["Mitochondrial<br/>Dysfunction"]
B --> C["mtDNA Release<br/>(via mPTP opening)"]
C --> D["Cytosolic mtDNA<br/>Detection"]
D --> E["cGAS Activation"]
E --> F["cGAMP Production"]
F --> G["STING1 Activation<br/>(ER membrane)"]
G --> H["TBK1 Phosphorylation"]
H --> I["IRF3 Nuclear<br/>Translocation"]
I --> J["Type I IFN<br/>Response"]
J --> K["Chronic Sterile<br/>Neuroinflammation"]
K --> L["Neurodegeneration"]
M["Therapy: STING<br/>Pathway Block"] --> N["DNASE2 Enhancement<br/>(Degrade cytosolic mtDNA)"]
M --> O["STING1 Inhibition"]
N --> P["Reduced cGAS<br/>Activation"]
O --> Q["Blocked IFN<br/>Signaling"]
P --> R["Inflammation<br/>Resolution"]
Q --> R
style A fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a
style M fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7
style R fill:#1b5e20,stroke:#81c784,color:#81c784

" Framed more explicitly, the hypothesis centers CGAS/STING1/DNASE2 within the broader disease setting of neurodegeneration. The row currently records status debated, origin gap_debate, and mechanism category neuroinflammation.

SciDEX scoring currently records confidence 0.50, novelty 0.85, feasibility 0.45, impact 0.60, mechanistic plausibility 0.55, and clinical relevance 0.44.

Molecular and Cellular Rationale

The nominated target genes are CGAS/STING1/DNASE2 and the pathway label is Mitochondrial dynamics / bioenergetics. 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:

Brain Regional Expression Patterns CGAS demonstrates heterogeneous expression across brain regions, with the Allen Human Brain Atlas revealing highest baseline levels in the cerebral cortex (frontal, parietal, temporal regions) and moderate expression in the hippocampus. The substantia nigra and cerebellar cortex show relatively lower expression under physiological conditions. GTEx data confirms cortical predominance with mean TPM values of 8.2-12.5 across cortical regions versus 4.8-6.1 in subcortical structures. STING1 exhibits a complementary regional distribution with particularly robust expression in the hippocampus (CA1-CA3 fields and dentate gyrus) and entorhinal cortex, regions critically vulnerable to early Alzheimer’s pathology. The Allen Brain Atlas demonstrates STING1 enrichment in limbic structures (TPM 15.3-18.7) compared to motor cortex (TPM 8.9-11.2). Notably, the substantia nigra pars compacta shows moderate but consistent STING1 expression, aligning with its vulnerability in Parkinson’s disease. DNASE2 displays the most uniform brain distribution among the three genes, with GTEx revealing stable expression across regions (TPM 12.5-16.8). However, the hippocampus and prefrontal cortex show slightly elevated baseline levels, potentially reflecting higher metabolic turnover and DNA repair requirements in these cognitively critical regions.

Cell-Type Specificity and Single-Cell Insights Single-cell RNA-seq datasets from the SEA-AD consortium reveal striking cell-type-specific expression patterns that support the senescent mtDNA release hypothesis. CGAS expression is predominantly detected in microglia (average 2.1-fold higher than other cell types) and astrocytes, with minimal neuronal expression under homeostatic conditions. The Mathys et al. 2019 snRNA-seq dataset from Alzheimer’s brains shows CGAS upregulation specifically in disease-associated microglia (DAM) clusters, with log2FC of 1.8-2.3 compared to homeostatic microglia. STING1 demonstrates broader cellular distribution but with notable enrichment in astrocytes and oligodendrocytes. The Grubman et al. 2019 single-nucleus dataset reveals STING1 expression in 65-78% of astrocytes versus 23-35% of neurons in control brains. Importantly, reactive astrocyte subpopulations (identified by elevated GFAP, S100B, and inflammatory markers) show 3.2-fold higher STING1 expression compared to quiescent astrocytes. DNASE2 exhibits the most ubiquitous expression pattern across all brain cell types, consistent with its fundamental role in DNA degradation during normal cellular turnover. However, microglia and astrocytes show 1.5-2.0-fold higher expression levels, reflecting their phagocytic functions and higher metabolic activity. The Lake et al. 2018 dataset demonstrates that DNASE2 expression correlates positively with autophagy markers (ATG5, ATG7, LC3B) across cell types, supporting its role in mitochondrial quality control.

Disease-State Expression Changes

Alzheimer’s Disease The Religious Orders Study and Memory and Aging Project (ROSMAP) bulk RNA-seq data reveals significant upregulation of all three genes in Alzheimer’s disease. CGAS shows a 2.8-fold increase in Braak stage V-VI brains compared to controls (adjusted p < 0.001), with the most pronounced changes in the entorhinal cortex and hippocampus. STING1 demonstrates a 3.4-fold upregulation in moderate-to-severe AD cases, correlating significantly with amyloid plaque density (r = 0.67, p < 0.001) and neurofibrillary tangle burden (r = 0.71, p < 0.001). Paradoxically, DNASE2 expression decreases by 40-55% in advanced AD stages, particularly in regions with high tau pathology. This reduction likely reflects compromised lysosomal function and impaired autophagy in senescent cells, creating a pathological feedback loop where reduced mtDNA clearance capacity exacerbates cytoplasmic DNA accumulation.

Parkinson’s Disease The Pantazis et al. 2021 dataset from substantia nigra samples reveals CGAS upregulation (1.9-fold) specifically in areas of dopaminergic neuronal loss. STING1 shows similar elevation (2.1-fold) that correlates with α-synuclein aggregation severity. Interestingly, DNASE2 reduction is less pronounced in PD compared to AD, possibly reflecting different mechanisms of cellular senescence and mitochondrial dysfunction.

Normal Aging GTEx aging data demonstrates progressive upregulation of CGAS and STING1 with advancing age across all brain regions. The most significant age-related increases occur in the prefrontal cortex (0.85-fold per decade for CGAS, 0.72-fold per decade for STING1) and hippocampus. DNASE2 shows age-related decline beginning around 60 years, with accelerated reduction after 75 years, suggesting compromised DNA clearance capacity in normal brain aging.

Regional Vulnerability and Mechanistic Implications The differential regional expression patterns provide crucial insights into selective vulnerability in neurodegenerative diseases. The hippocampus and entorhinal cortex, regions with high baseline STING1 expression and early pathological involvement in AD, may be predisposed to neuroinflammatory cascades triggered by mtDNA release. The substantia nigra’s moderate CGAS and STING1 expression, combined with its high metabolic demands and oxidative stress susceptibility, creates conditions favorable for mitochondrial damage and senescence-associated DNA release. The cerebellum’s relatively low expression of all three genes may partially explain its relative preservation in many neurodegenerative conditions. However, when cerebellar pathology does occur (as in multiple system atrophy), the limited DNA sensing and clearance capacity may contribute to rapid disease progression once initiated.

Co-Expression Networks and Pathway Context WGCNA analysis of ROSMAP data identifies CGAS and STING1 as hub genes within inflammatory modules enriched for interferon signaling, NF-κB activation, and senescence-associated secretory phenotype (SASP) genes. Key co-expressed genes include IRF3, TBK1, STAT1, and inflammatory cytokines (TNF, IL1B, IL6). DNASE2 clusters with autophagy and lysosomal genes (ATG5, ATG7, LAMP1, CTSD), supporting its role in cellular quality control. Notably, the correlation between DNASE2 and mitophagy markers (PINK1, PRKN) strengthens with age in control brains but deteriorates in neurodegenerative diseases, suggesting pathway disconnection during pathological aging. The temporal expression dynamics reveal CGAS as an early response gene (upregulated within hours of mtDNA release), STING1 as a sustained effector (peak expression 6-24 hours), and DNASE2 as a delayed compensatory response that ultimately fails to keep pace with DNA damage accumulation in disease states. This expression landscape strongly supports the hypothesis that senescent cell mtDNA release drives neuroinflammation through the cGAS-STING pathway, with regional vulnerability patterns reflecting the balance between DNA sensing capacity, inflammatory responsiveness, and clearance mechanisms across different brain regions and cell types.

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. cGAS-STING drives ageing-related inflammation and neurodegeneration. 1CitationPMID 37532932Open reference.

  2. Signaling by cGAS-STING in Neurodegeneration, Neuroinflammation, and Aging. 2CitationPMID 33187730Open reference.

  3. The cGAS-STING-YY1 axis accelerates progression of neurodegeneration in a mouse model of Parkinson’s disease via LCN2-dependent astrocyte senescence. 3CitationPMID 37633968Open reference.

  4. Mitochondrial DNA released by senescent tumor cells enhances PMN-MDSC-driven immunosuppression through the cGAS-STING pathway. 4CitationPMID 40203808Open reference.

  5. Molecular mechanisms of mitochondrial DNA release and activation of the cGAS-STING pathway. 5CitationPMID 36964253Open reference.

  6. Apoptotic stress causes mtDNA release during senescence and drives the SASP. 6CitationPMID 37821702Open reference.

Contradictory Evidence, Caveats, and Failure Modes

  1. Stimuli-responsive nanoplatforms for precision activation of the STING pathway in cancer immunotherapy. 7CitationPMID 41668757Open reference.

  2. Exosomes as nanocarriers for brain-targeted delivery of therapeutic nucleic acids: advances and challenges. 8CitationPMID 40533746Open reference.

  3. Bionanoconjugates in Neurodegeneration: Peptide-Nanoparticle Alliances for Next-Generation Therapies. 9CitationPMID 41199078Open reference.

  4. Enhancing Radiofrequency Ablation for Hepatocellular Carcinoma: Nano-Epidrug Effects on Immune Modulation and Antigenicity Restoration. 10CitationPMID 39548919Open reference.

  5. Amplification of N-Myc is associated with a T-cell-poor microenvironment in metastatic neuroblastoma restraining interferon pathway activity and chemokine expression. 2CitationPMID 33187730Open reference0.

Clinical and Translational Relevance

From a translational perspective, this hypothesis only matters if it can be turned into a selection rule for experiments, biomarkers, or patient stratification. The row currently records market price 0.7627, debate count 2, citations 37, predictions 5, and falsifiability flag 1. Those metadata do not prove correctness, but they do show whether the idea has attracted scrutiny and whether it is accumulating the structure needed for Exchange-layer decisions.

  1. Trial context: RECRUITING.

  2. Trial context: COMPLETED.

  3. Trial context: UNKNOWN. 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 CGAS/STING1/DNASE2 in a model matched to neurodegeneration. The key readout should include pathway markers, cell-state markers, and at least one phenotype that maps onto “Senescent Cell Mitochondrial DNA Release”. 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 CGAS/STING1/DNASE2 within the disease frame of neurodegeneration can produce a measurable change in mechanism rather than only a cosmetic change in a terminal biomarker. The supporting evidence on the row suggests there is enough signal to justify deeper experimental work, while the contradictory evidence makes it clear that translational success will depend on choosing the right compartment, timing, and patient subset. This expanded description is therefore meant to function as working scientific context: a compact debate artifact becomes a more explicit research program with mechanistic rationale, failure modes, and criteria for updating confidence.

References

  1. PMID:37532932 PMID 37532932
  2. PMID:33187730 PMID 33187730
  3. PMID:37633968 PMID 37633968
  4. PMID:40203808 PMID 40203808
  5. PMID:36964253 PMID 36964253
  6. PMID:37821702 PMID 37821702
  7. PMID:41668757 PMID 41668757
  8. PMID:40533746 PMID 40533746
  9. PMID:41199078 PMID 41199078
  10. PMID:39548919 PMID 39548919
  11. PMID:28680756 PMID 28680756

Mechanism / pathway

  1. CGAS/STING1/DNASE2
  2. Mitochondrial dynamics / bioenergetics
  3. neurodegeneration

Evidence for (17)

  • cGAS-STING drives ageing-related inflammation and neurodegeneration

    PMID:37532932 2023 Nature

    Low-grade inflammation is a hallmark of old age and a central driver of ageing-associated impairment and disease1. Multiple factors can contribute to ageing-associated inflammation2; however, the molecular pathways that transduce aberrant inflammatory signalling and their impact in natural ageing remain unclear. Here we show that the cGAS-STING signalling pathway, which mediates immune sensing of DNA3, is a critical driver of chronic inflammation and functional decline during ageing. Blockade of STING suppresses the inflammatory phenotypes of senescent human cells and tissues, attenuates ageing-related inflammation in multiple peripheral organs and the brain in mice, and leads to an improvement in tissue function. Focusing on the ageing brain, we reveal that activation of STING triggers reactive microglial transcriptional states, neurodegeneration and cognitive decline. Cytosolic DNA released from perturbed mitochondria elicits cGAS activity in old microglia, defining a mechanism by wh

  • Signaling by cGAS-STING in Neurodegeneration, Neuroinflammation, and Aging

    PMID:33187730 2021 Trends Neurosci

    Recognition of foreign or misplaced nucleic acids is one of the principal modes by which the immune system detects pathogenic entities. When cytosolic DNA is sensed, a signal is relayed via the cGAS-STING pathway: this involves the activation of cyclic GMP-AMP (cGMP-AMP) synthase (cGAS) and generation of the cyclic dinucleotide cGAMP, followed by the induction of stimulator of interferon genes (STING). The cGAS-STING pathway responds to viral, bacterial, and self-DNA. Whereas it generally mediates immune surveillance and is often neuroprotective, excessive engagement of the system can be deleterious. This is relevant in aging and age-related neurological diseases, where neuroinflammation contributes to disease progression. This review focuses on cGAS-STING signaling in aging, neurodegeneration, and neuroinflammation, and on therapeutic implications.

  • The cGAS-STING-YY1 axis accelerates progression of neurodegeneration in a mouse model of Parkinson's disease via LCN2-dependent astrocyte senescence

    PMID:37633968 2023 Cell Death Differ

    Recent studies provide clues that astrocyte senescence is correlated with Parkinson's disease (PD) progression, while little is known about the molecular basis for astrocyte senescence in PD. Here, we found that cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) was upregulated in senescent astrocytes of PD and aged mice. Strikingly, deletion of astrocytic cGAS significantly prevented senescence of astrocytes and neurodegeneration. Furthermore, we identified LCN2 as the effector of cGAS-STING signal by RNA-Seq analysis. Genetic manipulation of LCN2 expression proved the regulation of cGAS-STING-LCN2 axis in astrocyte senescence. Additionally, YY1 was discovered as the transcription factor of LCN2 by chromatin immunoprecipitation. Binding of STING to YY1 impedes nuclear translocation of YY1. Herein, we determine the involvement of the cGAS-STING-YY1-LCN2 signaling cascade in the control of astrocyte senescence and PD progression. Together, this work fills the gap in o

  • Mitochondrial DNA released by senescent tumor cells enhances PMN-MDSC-driven immunosuppression through the cGAS-STING pathway

    PMID:40203808 2025 Immunity

    Mitochondrial dysfunction is a hallmark of cellular senescence. Here, we investigated whether senescent cells release mitochondrial (mt)DNA into the extracellular space and its impact on innate immunity. We found that both primary senescent cells and tumor cells undergoing therapy-induced senescence actively released mtDNA into the extracellular environment. mtDNA released by senescent cells was packaged within extracellular vesicles and selectively transferred to polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in the tumor microenvironment. Upon uptake, extracellular mtDNA enhanced the immunosuppressive activity of PMN-MDSCs via cGAS-STING-NF-κB signaling, thereby promoting tumor progression. While STING activation directly induced NF-κB signaling, it also activated PKR-like endoplasmic reticulum kinase (PERK), which further amplified NF-κB activity, in PMN-MDSCs. mtDNA release from senescent cells was mediated by voltage-dependent anion channels (VDACs), and pharmacolo

  • Molecular mechanisms of mitochondrial DNA release and activation of the cGAS-STING pathway

    PMID:36964253 2023 Exp Mol Med

    In addition to constituting the genetic material of an organism, DNA is a tracer for the recognition of foreign pathogens and a trigger of the innate immune system. cGAS functions as a sensor of double-stranded DNA fragments and initiates an immune response via the adaptor protein STING. The cGAS-STING pathway not only defends cells against various DNA-containing pathogens but also modulates many pathological processes caused by the immune response to the ectopic localization of self-DNA, such as cytosolic mitochondrial DNA (mtDNA) and extranuclear chromatin. In addition, macrophages can cause inflammation by forming a class of protein complexes called inflammasomes, and the activation of the NLRP3 inflammasome requires the release of oxidized mtDNA. In innate immunity related to inflammasomes, mtDNA release is mediated by macropores that are formed on the outer membrane of mitochondria via VDAC oligomerization. These macropores are specifically formed in response to mitochondrial stre

  • Apoptotic stress causes mtDNA release during senescence and drives the SASP

    PMID:37821702 2023 Nature

    Senescent cells drive age-related tissue dysfunction partially through the induction of a chronic senescence-associated secretory phenotype (SASP)1. Mitochondria are major regulators of the SASP; however, the underlying mechanisms have not been elucidated2. Mitochondria are often essential for apoptosis, a cell fate distinct from cellular senescence. During apoptosis, widespread mitochondrial outer membrane permeabilization (MOMP) commits a cell to die3. Here we find that MOMP occurring in a subset of mitochondria is a feature of cellular senescence. This process, called minority MOMP (miMOMP), requires BAX and BAK macropores enabling the release of mitochondrial DNA (mtDNA) into the cytosol. Cytosolic mtDNA in turn activates the cGAS-STING pathway, a major regulator of the SASP. We find that inhibition of MOMP in vivo decreases inflammatory markers and improves healthspan in aged mice. Our results reveal that apoptosis and senescence are regulated by similar mitochondria-dependent mec

  • mtDNA release promotes cGAS-STING activation and accelerated aging of postmitotic muscle cells

    PMID:39039044 2024 Cell Death Dis

    The mechanism regulating cellular senescence of postmitotic muscle cells is still unknown. cGAS-STING innate immune signaling was found to mediate cellular senescence in various types of cells, including postmitotic neuron cells, which however has not been explored in postmitotic muscle cells. Here by studying the myofibers from Zmpste24-/- progeria aged mice [an established mice model for Hutchinson-Gilford progeria syndrome (HGPS)], we observed senescence-associated phenotypes in Zmpste24-/- myofibers, which is coupled with increased oxidative damage to mitochondrial DNA (mtDNA) and secretion of senescence-associated secretory phenotype (SASP) factors. Also, Zmpste24-/- myofibers feature increased release of mtDNA from damaged mitochondria, mitophagy dysfunction, and activation of cGAS-STING. Meanwhile, increased mtDNA release in Zmpste24-/- myofibers appeared to be related with increased VDAC1 oligomerization. Further, the inhibition of VDAC1 oligomerization in Zmpste24-/- myofibers

  • Innate immune sensing of Z-nucleic acids by ZBP1-RIPK1 axis drives neuroinflammation in Alzheimer's disease

    PMID:40902587 2025 Immunity

    Neuroinflammation drives Alzheimer's disease (AD) pathogenesis. Z-DNA, a non-canonical left-handed DNA structure, activates innate immune signaling through Z-DNA-binding protein 1 (ZBP1). However, the functional significance of ZBP1-mediated Z-DNA detection in AD remains undefined. Here, we found that ZBP1 is amplified in AD microglia, driving innate immune responses and neuroinflammation through sensing Z-form mitochondrial DNA (mtDNA). We show that oxidized mtDNA, generated by amyloid-β (Aβ)-induced oxidative stress, was fragmented and released into the cytoplasm, forming Z-DNA. Z-DNA-activated ZBP1 engaged receptor-interacting protein kinase 1 (RIPK1), promoting its kinase activation and inducing transcription of pro-inflammatory molecules and inflammatory signaling mediators. Genetic deletion of Zbp1 or inhibition of RIPK1 attenuated neuroinflammation, Aβ pathology, and behavioral deficits in an AD mouse model. Our findings reveal that oxidation induces the Z conformer in mtDNA and

  • Exposome and unhealthy aging: environmental drivers from air pollution to occupational exposures

    PMID:37688657 2023 Geroscience

    The aging population worldwide is facing a significant increase in age-related non-communicable diseases, including cardiovascular and brain pathologies. This comprehensive review paper delves into the impact of the exposome, which encompasses the totality of environmental exposures, on unhealthy aging. It explores how environmental factors contribute to the acceleration of aging processes, increase biological age, and facilitate the development and progression of a wide range of age-associated diseases. The impact of environmental factors on cognitive health and the development of chronic age-related diseases affecting the cardiovascular system and central nervous system is discussed, with a specific focus on Alzheimer's disease, Parkinson's disease, stroke, small vessel disease, and vascular cognitive impairment (VCI). Aging is a major risk factor for these diseases. Their pathogenesis involves cellular and molecular mechanisms of aging such as increased oxidative stress, impaired mi

  • STING mediates neurodegeneration and neuroinflammation in nigrostriatal α-synucleinopathy

    PMID:35394877 2022 Proc Natl Acad Sci U S A

    In idiopathic Parkinson’s disease (PD), pathologic αSyn aggregates drive oxidative and nitrative stress that may cause genomic and mitochondrial DNA damage. These events are associated with activation of the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) immune pathway, but it is not known whether STING is activated in or contributes to α-synucleinopathies. Herein, we used primary cell cultures and the intrastriatal αSyn preformed fibril (αSyn-PFF) mouse model of PD to demonstrate that αSyn pathology causes STING-dependent neuroinflammation and dopaminergic neurodegeneration. In microglia-astrocyte cultures, αSyn-PFFs induced DNA double-strand break (DSB) damage response signaling (γH2A.X), as well as TBK1 activation that was blocked by STING inhibition. In the αSyn-PFF mouse model, we similarly observed TBK1 activation and increased γH2A.X within striatal microglia prior to the onset of dopaminergic neurodegeneration. Using STING-deficient (Stinggt) mice, we dem

  • Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)(1)

    PMID:33634751 2021 Autophagy

    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect fo

  • The cGAS-STING pathway drives neuroinflammation and neurodegeneration via cellular and molecular mechanisms in neurodegenerative diseases

    PMID:39490400 2024 Neurobiol Dis

    Neurodegenerative diseases (NDs) are a type of common chronic progressive disorders characterized by progressive damage to specific cell populations in the nervous system, ultimately leading to disability or death. Effective treatments for these diseases are still lacking, due to a limited understanding of their pathogeneses, which involve multiple cellular and molecular pathways. The triggering of an immune response is a common feature in neurodegenerative disorders. A critical challenge is the intricate interplay between neuroinflammation, neurodegeneration, and immune responses, which are not yet fully characterized. In recent years, the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) pathway, a crucial immune response for intracellular DNA sensing, has gradually gained attention. However, the specific roles of this pathway within cellular types such as immune cells, glial and neuronal cells, and its contribution to ND pathogenesis, remain not fully elucidated.

  • TDP-43 Triggers Mitochondrial DNA Release via mPTP to Activate cGAS/STING in ALS

    PMID:33031745 2020 Cell

    Cytoplasmic accumulation of TDP-43 is a disease hallmark for many cases of amyotrophic lateral sclerosis (ALS), associated with a neuroinflammatory cytokine profile related to upregulation of nuclear factor κB (NF-κB) and type I interferon (IFN) pathways. Here we show that this inflammation is driven by the cytoplasmic DNA sensor cyclic guanosine monophosphate (GMP)-AMP synthase (cGAS) when TDP-43 invades mitochondria and releases DNA via the permeability transition pore. Pharmacologic inhibition or genetic deletion of cGAS and its downstream signaling partner STING prevents upregulation of NF-κB and type I IFN induced by TDP-43 in induced pluripotent stem cell (iPSC)-derived motor neurons and in TDP-43 mutant mice. Finally, we document elevated levels of the specific cGAS signaling metabolite cGAMP in spinal cord samples from patients, which may be a biomarker of mtDNA release and cGAS/STING activation in ALS. Our results identify mtDNA release and cGAS/STING activation as critical de

  • Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018

    PMID:29362479 2018 Cell Death Differ

    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission

  • Ageing as a risk factor for neurodegenerative disease

    PMID:31501588 2019 Nat Rev Neurol

    Ageing is the primary risk factor for most neurodegenerative diseases, including Alzheimer disease (AD) and Parkinson disease (PD). One in ten individuals aged ≥65 years has AD and its prevalence continues to increase with increasing age. Few or no effective treatments are available for ageing-related neurodegenerative diseases, which tend to progress in an irreversible manner and are associated with large socioeconomic and personal costs. This Review discusses the pathogenesis of AD, PD and other neurodegenerative diseases, and describes their associations with the nine biological hallmarks of ageing: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, mitochondrial dysfunction, cellular senescence, deregulated nutrient sensing, stem cell exhaustion and altered intercellular communication. The central biological mechanisms of ageing and their potential as targets of novel therapies for neurodegenerative diseases are also discussed, with potential the

  • Senescent glia link mitochondrial dysfunction and lipid accumulation

    PMID:38839958 2024 Nature

    Senescence is a cellular state linked to ageing and age-onset disease across many mammalian species1,2. Acutely, senescent cells promote wound healing3,4 and prevent tumour formation5; but they are also pro-inflammatory, thus chronically exacerbate tissue decline. Whereas senescent cells are active targets for anti-ageing therapy6-11, why these cells form in vivo, how they affect tissue ageing and the effect of their elimination remain unclear12,13. Here we identify naturally occurring senescent glia in ageing Drosophila brains and decipher their origin and influence. Using Activator protein 1 (AP1) activity to screen for senescence14,15, we determine that senescent glia can appear in response to neuronal mitochondrial dysfunction. In turn, senescent glia promote lipid accumulation in non-senescent glia; similar effects are seen in senescent human fibroblasts in culture. Targeting AP1 activity in senescent glia mitigates senescence biomarkers, extends fly lifespan and health span, and

  • Biological aging processes underlying cognitive decline and neurodegenerative disease

    PMID:35575089 2022 J Clin Invest

    Alzheimer's disease and related dementias (ADRD) are among the top contributors to disability and mortality in later life. As with many chronic conditions, aging is the single most influential factor in the development of ADRD. Even among older adults who remain free of dementia throughout their lives, cognitive decline and neurodegenerative changes are appreciable with advancing age, suggesting shared pathophysiological mechanisms. In this Review, we provide an overview of changes in cognition, brain morphology, and neuropathological protein accumulation across the lifespan in humans, with complementary and mechanistic evidence from animal models. Next, we highlight selected aging processes that are differentially regulated in neurodegenerative disease, including aberrant autophagy, mitochondrial dysfunction, cellular senescence, epigenetic changes, cerebrovascular dysfunction, inflammation, and lipid dysregulation. We summarize research across clinical and translational studies to li

Evidence against (11)

  • Stimuli-responsive nanoplatforms for precision activation of the STING pathway in cancer immunotherapy

    PMID:41668757 2026 Front Immunol

    The stimulator of interferon genes (STING) pathway plays a unique role in antitumor immunity, bridging innate and adaptive immune responses to initiate a sustained and highly effective antitumor immune response. However, due to the widespread expression of the STING pathway and the lack of clearly distinguishable physiological and pathological features, its excessive or systemic activation can trigger severe adverse effects, such as cytokine storms, thereby limiting its clinical applicability. With the development of nanotechnology, stimuli-responsive nanoplatforms designed based on tumor microenvironment (TME) signals (such as pH, glutathione, reactive oxygen species, hypoxia, and enzymes) and exogenous stimuli (including light, ultrasound, radiation, and magnetic fields) provide a promising strategy for the precise activation of the STING pathway. These nanoplatforms can achieve tumor-specific and controllable STING activation, thereby minimizing off-target toxicity, and can be combi

  • Exosomes as nanocarriers for brain-targeted delivery of therapeutic nucleic acids: advances and challenges

    PMID:40533746 2025 J Nanobiotechnology

    Recent advancements in gene expression modulation and RNA delivery systems have underscored the immense potential of nucleic acid-based therapies (NA-BTs) in biological research. However, the blood-brain barrier (BBB), a crucial regulatory structure that safeguards brain function, presents a significant obstacle to the delivery of drugs to glial cells and neurons. The BBB tightly regulates the movement of substances from the bloodstream into the brain, permitting only small molecules to pass through. This selective permeability poses a significant challenge for effective therapeutic delivery, especially in the case of NA-BTs. Extracellular vesicles, particularly exosomes, are recognized as valuable reservoirs of potential biomarkers and therapeutic targets. They are also gaining significant attention as innovative drug and nucleic acid delivery (NAD) carriers. Their unique ability to safeguard and transport genetic material, inherent biocompatibility, and capacity to traverse physiolog

  • Bionanoconjugates in Neurodegeneration: Peptide-Nanoparticle Alliances for Next-Generation Therapies

    PMID:41199078 2025 Pharm Res

    The convergence of peptides and nanoparticles through bionanoconjugation has emerged as a transformative strategy to address the persistent challenges in treating neurodegenerative disorders. Peptides, particularly short sequences (< 45 amino acids), offer unique advantages as protein mimetics, including structural flexibility, target specificity and blood-brain barrier permeability. Their clinical translation is hindered by rapid enzymatic degradation, short half-life, and poor bioavailability. Conjugation with nanoparticles, overcomes these limitations by enhancing stability, prolonging circulation, and enabling precise targeting. Peptide-nanoparticle conjugates, including TAT-functionalized gold nanoparticles and RGD-decorated polymeric systems, have shown significant improvements in blood brain barrier penetration. These advancements are associated with a reduction in amyloid-beta aggregation and the inhibition of tau hyperphosphorylation in preclinical models. These hybrids levera

  • Enhancing Radiofrequency Ablation for Hepatocellular Carcinoma: Nano-Epidrug Effects on Immune Modulation and Antigenicity Restoration

    PMID:39548919 2024 Adv Mater

    Radiofrequency ablation (RFA), a critical therapy for hepatocellular carcinoma (HCC), carries a significant risk of recurrence and metastasis, particularly owing to mechanisms involving immune evasion and antigen downregulation via epigenetic modifications. This study introduces a "nano-epidrug" named MFMP. MFMP, which is composed of hollow mesoporous manganese dioxide (MnO2) nanoparticles, FIDAS-5 as an MAT2A inhibitor, macrophage membrane, and anti-PD-L1 (aPD-L1), targets HCC cells. By selectively binding to these cells, MFMP initially reverses immune suppression via PD-L1 inhibition. After endocytosis, MFMP disassembles in the tumor microenvironment, releasing FIDAS-5 and Mn2+. FIDAS-5 prevents cGAS methylation, whereas Mn2+ aids STING pathway restoration. In addition, FIDAS-5 reduces m6A RNA modification, suppressing EGFR expression. These changes enhance HCC antigenicity to promote cytotoxic T cell recognition and cytotoxic killing. Furthermore, MFMP mediates immunogenic cell deat

  • Amplification of N-Myc is associated with a T-cell-poor microenvironment in metastatic neuroblastoma restraining interferon pathway activity and chemokine expression

    PMID:28680756 2017 Oncoimmunology

    Immune checkpoint inhibitors have significantly improved the treatment of several cancers. T-cell infiltration and the number of neoantigens caused by tumor-specific mutations are correlated to favorable responses in cancers with a high mutation load. Accordingly, checkpoint immunotherapy is thought to be less effective in tumors with low mutation frequencies such as neuroblastoma, a neuroendocrine tumor of early childhood with poor outcome of the high-risk disease group. However, spontaneous regressions and paraneoplastic syndromes seen in neuroblastoma patients suggest substantial immunogenicity. Using an integrative transcriptomic approach, we investigated the molecular characteristics of T-cell infiltration in primary neuroblastomas as an indicator of pre-existing immune responses and potential responsiveness to checkpoint inhibition. Here, we report that a T-cell-poor microenvironment in primary metastatic neuroblastomas is associated with genomic amplification of the MYCN (N-Myc)

  • Past, present and future perspectives on the science of aging

    PMID:41566049 2026 Nat Aging

  • Decoding senescent drivers in Alzheimer's disease: From bench to bedside

    PMID:41344577 2026 Ageing Res Rev

    Alzheimer's disease (AD) is the most common neurodegenerative disorder associated with dementia. Cellular senescence, widely acknowledged as a key hallmark of aging, has increasingly been recognized as a significant factor in the pathogenesis of AD, although the precise mechanisms underlying this relationship have yet to be fully understood. In the brains of individuals with AD, neurons, glial cells, and cerebrovascular endothelial cells exhibit premature senescence, characterized by irreversible cell cycle arrest, resistance to apoptosis, and the secretion of a diverse range of bioactive molecules collectively referred to as the senescence-associated secretory phenotype (SASP). These senescent cells profoundly influence the neural microenvironment through the release of SASP factors, thus exacerbating Aβ- and tau-induced neurotoxicity, promoting neuroinflammatory responses, and impairing the integrity of the blood-brain barrier (BBB), ultimately giving rise to a self-sustaining "senes

  • Apheresis for senescence: Targeting the senescence-associated secretory phenotype to delay aging and age-related diseases

    PMID:40651559 2025 Ageing Res Rev

    Aging is driven by cellular senescence and chronic inflammation, largely mediated by the senescence-associated secretory phenotype (SASP). SASP factors promote inflammaging, impair tissue homeostasis, and contribute to age-related diseases such as cardiovascular disease, neurodegeneration, and cancer. Current anti-aging strategies focus on senolytics or SASP inhibitors, yet these approaches have limitations. We discuss therapeutic plasma exchange (TPE) and selective apheresis, as interventions to mitigate SASP-driven aging. TPE removes inflammatory cytokines, metabolic waste, and senescence-associated proteins, while replenishing rejuvenating factors. Selective apheresis could enhance precision by targeting specific SASP components. By reducing systemic inflammation and restoring a youthful proteomic environment, these strategies may improve immune function, tissue regeneration, and overall healthspan. This review explores the mechanistic basis of SASP in aging and evaluates the potent

  • Role of NEIL1 in genome maintenance

    PMID:40010204 2025 DNA Repair (Amst)

    Phylogenetic analyses of DNA glycosylases that function in the initiation step of base excision repair reveal a high degree of conservation within the genes encoding Nei-like DNA glycosylase 1 (NEIL1). In concert with other glycosylases, this enzyme is an important player in cleansing both nuclear and mitochondrial genomes of a wide variety of damaged DNA bases. The relative efficiency of NEIL1 to catalyze release of ring-opened formamido-pyrimidines (Fapy) and alkylated-Fapy adducts, multiple ring-saturated pyrimidines, secondary oxidation products of 8-oxoguanine, and psoralen-derived crosslinks is augmented by pre-mRNA editing at codon 242, resulting in cells containing both NEIL1-Lys242 and edited Arg242. The biological significance of NEIL1 was revealed through investigations of mutagenesis and carcinogenesis in murine models, primarily using aflatoxin B1 (AFB1) as a genotoxicant challenge, which forms stable AFB1-FapyGua adducts. Specifically, Neil1 knockout mice were > 3-fold mo

  • Antileukemic potential of methylated indolequinone MAC681 through immunogenic necroptosis and PARP1 degradation

    PMID:38704604 2024 Biomark Res

    BACKGROUND: Despite advancements in chronic myeloid leukemia (CML) therapy with tyrosine kinase inhibitors (TKIs), resistance and intolerance remain significant challenges. Leukemia stem cells (LSCs) and TKI-resistant cells rely on altered mitochondrial metabolism and oxidative phosphorylation. Targeting rewired energy metabolism and inducing non-apoptotic cell death, along with the release of damage-associated molecular patterns (DAMPs), can enhance therapeutic strategies and immunogenic therapies against CML and prevent the emergence of TKI-resistant cells and LSC persistence. METHODS: Transcriptomic analysis was conducted using datasets of CML patients' stem cells and healthy cells. DNA damage was evaluated by fluorescent microscopy and flow cytometry. Cell death was assessed by trypan blue exclusion test, fluorescent microscopy, flow cytometry, colony formation assay, and in vivo Zebrafish xenografts. Energy metabolism was determined by measuring NAD+ and NADH levels, ATP productio

  • Methodological influences on circulating cell-free-mitochondrial and nuclear DNA concentrations in response to chronic stress

    PMID:40080226 2025 Mol Biol Rep

    BACKGROUND: Mitochondria are versatile eukaryotic organelles that play a crucial role in the body's stress response. Prolonged stress exposure can cause structural and functional alterations, leading to mitochondrial DNA (mtDNA) damage and subsequent release of mtDNA into the circulation. Cell-free circulating mtDNA (ccf-mtDNA) is a potential biomarker indicating cellular damage and stress. In this study we investigated the applicability of ccf-mtDNA and cf-nDNA as biomarkers of chronic stress in healthy subjects. METHODS AND RESULTS: We developed a quantitative polymerase chain reaction (qPCR) assay to directly measure ccf-mtDNA in human blood plasma samples, addressing numerous challenges specifically related to ccf-mtDNA quantification. We validated our 68 bp target assay based on the FDA, International Organization for Standardization (ISO) and Clinical & Laboratory Standards Institute (CLSI) guidelines for assay development, including parameters such as limit of blank (LOB), limit

Evidence matrix

17 supporting 11 contradicting
53% posterior support

Supporting

  • cGAS-STING drives ageing-related inflammation and neurodegeneration PMID:37532932 · 2023 · Nature
  • Signaling by cGAS-STING in Neurodegeneration, Neuroinflammation, and Aging PMID:33187730 · 2021 · Trends Neurosci
  • The cGAS-STING-YY1 axis accelerates progression of neurodegeneration in a mouse model of Parkinson's disease via LCN2-dependent astrocyte senescence PMID:37633968 · 2023 · Cell Death Differ
  • Mitochondrial DNA released by senescent tumor cells enhances PMN-MDSC-driven immunosuppression through the cGAS-STING pathway PMID:40203808 · 2025 · Immunity
  • Molecular mechanisms of mitochondrial DNA release and activation of the cGAS-STING pathway PMID:36964253 · 2023 · Exp Mol Med
  • Apoptotic stress causes mtDNA release during senescence and drives the SASP PMID:37821702 · 2023 · Nature
  • mtDNA release promotes cGAS-STING activation and accelerated aging of postmitotic muscle cells PMID:39039044 · 2024 · Cell Death Dis
  • Innate immune sensing of Z-nucleic acids by ZBP1-RIPK1 axis drives neuroinflammation in Alzheimer's disease PMID:40902587 · 2025 · Immunity
  • Exposome and unhealthy aging: environmental drivers from air pollution to occupational exposures PMID:37688657 · 2023 · Geroscience
  • STING mediates neurodegeneration and neuroinflammation in nigrostriatal α-synucleinopathy PMID:35394877 · 2022 · Proc Natl Acad Sci U S A
  • Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)(1) PMID:33634751 · 2021 · Autophagy
  • The cGAS-STING pathway drives neuroinflammation and neurodegeneration via cellular and molecular mechanisms in neurodegenerative diseases PMID:39490400 · 2024 · Neurobiol Dis
  • TDP-43 Triggers Mitochondrial DNA Release via mPTP to Activate cGAS/STING in ALS PMID:33031745 · 2020 · Cell
  • Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018 PMID:29362479 · 2018 · Cell Death Differ
  • Ageing as a risk factor for neurodegenerative disease PMID:31501588 · 2019 · Nat Rev Neurol
  • Senescent glia link mitochondrial dysfunction and lipid accumulation PMID:38839958 · 2024 · Nature
  • Biological aging processes underlying cognitive decline and neurodegenerative disease PMID:35575089 · 2022 · J Clin Invest

Contradicting

  • Stimuli-responsive nanoplatforms for precision activation of the STING pathway in cancer immunotherapy PMID:41668757 · 2026 · Front Immunol
  • Exosomes as nanocarriers for brain-targeted delivery of therapeutic nucleic acids: advances and challenges PMID:40533746 · 2025 · J Nanobiotechnology
  • Bionanoconjugates in Neurodegeneration: Peptide-Nanoparticle Alliances for Next-Generation Therapies PMID:41199078 · 2025 · Pharm Res
  • Enhancing Radiofrequency Ablation for Hepatocellular Carcinoma: Nano-Epidrug Effects on Immune Modulation and Antigenicity Restoration PMID:39548919 · 2024 · Adv Mater
  • Amplification of N-Myc is associated with a T-cell-poor microenvironment in metastatic neuroblastoma restraining interferon pathway activity and chemokine expression PMID:28680756 · 2017 · Oncoimmunology
  • Past, present and future perspectives on the science of aging PMID:41566049 · 2026 · Nat Aging
  • Decoding senescent drivers in Alzheimer's disease: From bench to bedside PMID:41344577 · 2026 · Ageing Res Rev
  • Apheresis for senescence: Targeting the senescence-associated secretory phenotype to delay aging and age-related diseases PMID:40651559 · 2025 · Ageing Res Rev
  • Role of NEIL1 in genome maintenance PMID:40010204 · 2025 · DNA Repair (Amst)
  • Antileukemic potential of methylated indolequinone MAC681 through immunogenic necroptosis and PARP1 degradation PMID:38704604 · 2024 · Biomark Res
  • Methodological influences on circulating cell-free-mitochondrial and nuclear DNA concentrations in response to chronic stress PMID:40080226 · 2025 · Mol Biol Rep

Top-ranked evidence

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

Supports · top 3

  1. #1 paper-617b54735393 0.466 trust 0.50 · rel 1.00 · 85d
  2. #2 paper-a25e072a9dfa 0.466 trust 0.50 · rel 1.00 · 85d
  3. #3 paper-20bf2606e51c 0.466 trust 0.50 · rel 1.00 · 85d

66 total ranked · scidex.hypotheses.evidence_ranking

Bayesian persona consensus

53% posterior support

1 signal · 1 for / 0 against · agreement 100%

scidex.consensus.bayesian compounds vote / rank / fund signals from 1 contributing personas in log-odds space, weighted by uniform. Prior 50%.

Cite this hypothesis

Cite this hypothesis
Citation

etl-backfill (2026). Senescent Cell Mitochondrial DNA Release. SciDEX hypothesis. https://prism.scidex.ai/hypotheses/h-1a34778f

BibTeX 
@misc{scidex_hypothesis_h1a34778,
  title        = {Senescent Cell Mitochondrial DNA Release},
  author       = {etl-backfill},
  year         = {2026},
  howpublished = {SciDEX hypothesis},
  url          = {https://prism.scidex.ai/hypotheses/h-1a34778f},
  note         = {SciDEX artifact hypothesis:h-1a34778f}
}

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