Mechanism: Oxidative lesions (8-oxoG) on telomeres activate cGAS-STING, driving mitochondrial ROS production and a pro-aging feedback loop, which dysbiotic gut microbiota exacerbate. Readout: Readout: Interventions like probiotic consortia or STING inhibition reduce telomeric 8-oxoG and mitochondrial ROS, increasing lifespan by 25% and decreasing inflammation score by 75%.
Hypothesis
Telomere length alone does not capture the informational entropy that drives aging; instead, the density of oxidative lesions such as 8‑oxoguanine (8‑oxoG) within telomeric repeats quantifies entropy loss and directly modulates mitochondrial ROS production via a retrograde NF‑κB–p53 loop.
Mechanistic Reasoning
- Oxidative lesions impair shelterin binding, increasing telomere exposure to cytoplasmic DNA sensors.
- This activates cGAS‑STING → NF‑κB, which upregulates mitochondrial NADPH oxidase (NOX4) and suppresses SIRT3, raising mitochondrial superoxide.
- Elevated ROS feeds back to telomeres, creating a stochastic entropy‑amplification cycle independent of replication count.
- Gut microbiota influence this cycle: commensal bacteria secreting antioxidants (e.g., ergothioneine) or producing short‑chain fatty acids reduce luminal ROS, lowering lesion acquisition in intestinal epithelial telomeres.
- Dysbiosis shifts the balance toward pro‑inflammatory species, diminishing antioxidant flux and accelerating telomere entropy.
Testable Predictions
- In intestinal epithelial cells, telomeric 8‑oxoG frequency will correlate positively with mitochondrial superoxide levels across individual crypts.
- Germ‑free mice colonized with a defined antioxidant‑producing consortium (e.g., Lactobacillus plantarum + Bifidobacterium longum) will show lower telomeric 8‑oxoG, higher shelterin occupancy, and extended lifespan compared with colonized controls.
- Pharmacological inhibition of cGAS‑STING will break the lesion‑ROS feedback loop, decreasing mitochondrial ROS without altering telomere length.
Experimental Approach
- Measure telomeric 8‑oxoG using lesion‑specific immunoprecipitation followed by qPCR (IP‑qPCR) in sorted intestinal epithelial cells from young and old mice.
- Simultaneously assess mitochondrial ROS with MitoSOX flow cytometry.
- Manipulate microbiota via antibiotics, fecal transplant, or defined probiotic consortia.
- Track telomere length (TRF), lesion load, mitochondrial ROS, and survival over 12‑month periods.
- Use cGAS‑STING knockout or pharmacological inhibitor (e.g., C‑176) to test pathway necessity.
Falsifiability
If telomeric 8‑oxoG shows no correlation with mitochondrial ROS, or microbiota alterations fail to change lesion density despite changes in inflammation, the hypothesis is refuted. Likewise, if blocking cGAS‑STING does not diminish the lesion‑ROS coupling, the proposed retrograde signaling is invalid.
Implications
Reframing telomeres as an informational entropy sensor links genome maintenance, mitochondrial homeostasis, and gut‑derived redox ecology into a single aging axis. Interventions that preserve telomeric sequence fidelity—through microbiota‑based antioxidants or STING inhibition—could decouple informational entropy from replicative history and extend healthspan.
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