Rejuvenation of neutrophils and their extracellular vesicles is associated with enhanced aged fracture healing.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35657721.
- Also identified by DOI 10.1111/acel.13651 and PMC identifier 9282841.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Tissue repair is negatively affected by advanced age. Recent evidence indicates that hematopoietic cell-derived extracellular vesicles (EVs) are modulators of regenerative capacity. Here, we report that plasma EVs carrying specific surface markers indicate the degree of age-associated immunosenescence; moreover, this immunosenescence phenotype was accentuated by fracture injury. The number of CD11b<sup>+</sup> Ly6C<sup>intermediate</sup> Ly6G<sup>high</sup> neutrophils significantly decreased with age in association with defective tissue regeneration. In response to fracture injury, the frequencies of neutrophils and associated plasma EVs were significantly higher in fracture calluses than in peripheral blood. Exposure of aged mice to youthful circulation through heterochronic parabiosis increased the number of neutrophils and their correlated Ly6G<sup>+</sup> plasma EVs, which were associated with improved fracture healing in aged mice of heterochronic parabiosis pairs. Our findings create a foundation for utilizing specific immune cells and EV subsets as potential biomarkers and therapeutic strategies to promote resilience to stressors during aging.
Medical subject headings
- Extracellular Vesicles
- Fractures, Bone
- Immunosenescence