AAV9 delivery of a soil metagenomics-derived glucosepane-degrading enzyme to aged C57BL/6J mice will reduce aortic an...
IF a single intravenous dose (1×10¹² vg/mouse) of AAV9-CAG-glucosepane-degrading-enzyme (Revel Pharmaceuticals / Spiegel Lab class I-like metagenomics-derived enzyme) is administered to 22-month-old male and female C57BL/6J mice,
THEN at 12 weeks post-injection:
- Aortic and dermal glucosepane concentration (LC-MS/MS) will decrease by ≥30% versus AAV9-GFP vehicle controls,
- Plasma and tissue citrulline levels will increase proportionally as the stoichiometric enzymatic degradation product of glucosepane cleavage,
- Carotid-femoral pulse wave velocity (cfPWV) will decrease by ≥10% versus vehicle (indicating reduced aortic stiffness),
- Cutometer-derived skin elasticity ratio (Ur/Uf) will improve by ≥15% versus vehicle,
- The magnitude of these functional gains will exceed what could be predicted from crosslink reduction alone, because glucosepane-crosslinked ECM independently sustains a pro-senescent mechanotransductive microenvironment; its degradation will secondarily reduce vascular and dermal tissue burden of p16^INK4A^-expressing senescent cells,
BECAUSE the following causal chain connects the intervention to the outcomes:
-
Glucosepane is the dominant irreversible arginine-lysine crosslink accumulating in aged murine collagen. Age-dependent accumulation in C57BL/6J tendons follows a progressive trajectory detectable by HPLC-MS, and lysine glycation in diabetic db/db mice at 16 weeks reaches levels comparable to 96-week wild-type animals, confirming that glucosepane accumulation is the principal biochemical signature of ECM aging in this strain. (Age-related crosslink profiling in C57BL/6J mouse tail tendon)[https://doi.org/10.1074/jbc.ra119.011031]
-
The Revel/Spiegel soil metagenomics-derived enzyme selectively cleaves glucosepane via a class I-like catalytic mechanism, releasing citrulline as the stoichiometric arginine-side product. This makes plasma and tissue citrulline a uniquely specific, non-invasive pharmacodynamic biomarker for on-target enzymatic activity — an approach orthogonal to all prior small-molecule AGE-breaker programs, which lacked this product-linked readout. [SPECULATIVE — no published in vivo citrulline PD data exist for this enzyme; mechanistic basis is derived from the enzyme's documented catalytic chemistry and supported by glucosepane detection methods] (Anti-glucosepane antibody development enabling in-tissue detection)[https://doi.org/10.1021/acschembio.0c00093]
-
AAV9 administered systemically at 1×10¹² vg/mouse achieves robust biodistribution in vascular and dermal tissues of aged mice with peak transgene expression at 4–6 weeks. Use of a CAG or EF1α promoter is critical to avoid age-associated CpG methylation-driven silencing of viral promoters. Expression is stable and persistent for months in post-mitotic vascular cells, encompassing both the 6-week and 12-week measurement timepoints. [SPECULATIVE link — specific CAG durability in 22-month aortic VSMCs has not been directly publishe...
SENS category: GlycoSENS
Key references: • doi.org/10.1074/jbc.ra119.011031] • doi.org/10.1021/acschembio.0c00093] • doi.org/10.1016/j.matbio.2013.11.005] • doi.org/10.1101/2025.05.13.653823] • doi.org/10.1007/s11357-020-00180-6]