Space Associated Stem Cell Hallmarks of Aging in Astronauts

This study examined the effects of the stress of space, specifically low earth orbit, on hematopoietic stem and progenitor cells (HSPCs) that maintain lifelong hematopoiesis and immune responses. Enriched CD34+ HSPCs were derived from 7 astronauts before, during and after 10 and 21-day ISS missions on the International Space Station. The samples were used as input to whole transcriptome sequencing by bulk RNA-Seq performed at The Scripps Research Institute Next Generation Sequencing Core on Illumina NextSeq 2000 sequencer and single cell RNA-Seq performed at The Salk Institute for Biological Studies on Illumina NovaSeq X Plus sequencer. Subsequent expression, RNA editing, and retrotransposon analyses were performed to assess HSPC and immune subpopulation survival dynamics. Overall, these analyses revealed space-associated stem cell hallmarks of aging (SASHA), including spaceflight dependent alterations in HSPC survival and self-renewal, ADAR1, telomere maintenance, mobilization and cell cycle gene expression, combined with space-induced clonal hematopoietic mutations, APOBEC3C activation and retrotransposon deregulation to warrant countermeasure development to enable long-duration spaceflight. Post-spaceflight analysis revealed increased C-to-T and clonal hematopoiesis-associated mutations, repetitive element and base deaminase deregulation, decreased telomere maintenance gene expression, and decreased self-renewal capacity compared to ground controls. These results demonstrate the space-associated aging effects in HSPCs after month-long exposure to LEO, providing insights into utilizing the LEO environment to model space-accelerated aging and other age-related malignancies.]]>
Inclusion criteria:Individuals traveling to the International Space Station who provided informed consentExclusion Criteria:None]]>
This study was conducted under IRB-approved protocol (NASA #0547) and includes biospecimens collected from individuals at various timepoints before, during, and after traveling to the International Space Station aboard Axiom-2 and Axiom-3 missions in 2023 and 2024.]]>