Overview
Following subcutaneous or intraperitoneal administration, FOXO4-DRI distributes systemically. Its D-amino acid composition renders it resistant to serine/cysteine proteases, providing superior bioavailability compared to native peptides. The peptide crosses cell membranes via endocytic and direct membrane-transduction mechanisms. Its selectivity for senescent cells is attributable to the differential expression of FOXO4 — markedly upregulated in senescent vs. quiescent cells — and the reliance of senescent cells on the FOXO4-p53 survival axis, which normal proliferating or post-mitotic cells do not predominantly utilize for survival. Clearance is likely renal and hepatic with metabolites being peptide fragments of varying bioactivity.
Proposed mechanism
Senescent cells overexpress FOXO4, which binds to and sequesters p53 in the nucleus, preventing p53-mediated apoptosis and allowing senescent cells to persist and secrete pro-inflammatory cytokines (the senescence-associated secretory phenotype, or SASP). FOXO4-DRI is a competitive peptidomimetic that binds FOXO4 with high affinity, displacing p53 from the FOXO4 complex and restoring p53's ability to translocate to mitochondria where it triggers intrinsic apoptosis. Because normal, non-senescent cells do not rely on this FOXO4-p53 survival axis, the apoptotic effect is preferentially targeted to senescent cells.
What the evidence supports
Most data comes from preclinical animal studies. Human clinical trial evidence is limited or absent.
Graded Animal
Evidence drawn from in vivo animal models or in vitro systems. Mechanistically informative; translation to humans is unproven.
Key citations
Representative primary sources, including results that did not favour the compound.
- [1]
Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging
· Cell. 169(1):132-147.e13. Baar MP et al. doi:10.1016/j.cell.2017.02.031 · 2017
- [2]
Senolytics in idiopathic pulmonary fibrosis: Results from a first-in-human, open-label, pilot study
· EBioMedicine. 40:554-563. Kirkland JL et al. doi:10.1016/j.ebiom.2018.12.052 (Dasatinib+Quercetin, not FOXO4-DRI, cited for senolytic human context) · 2019
- [3]
The role of senescent cells in ageing
· Nature. 509:439-446. van Deursen JM. doi:10.1038/nature13193 · 2014
Citation records in this build are illustrative placeholders for the design.
Reference information for research purposes. Not medical advice, and not a recommendation to use any compound. Many entries describe substances that are not approved for human use.