SASHA

The SASHA-3 (Space Hematopoeitic Stem Cell Aging) study, led by the University of California-San Diego (UCSD), investigates the effects of spaceflight on hematopoietic stem cells (HSCs) by examining the activation of DNA and RNA-editing enzymes, APOBEC and ADAR1, which are linked to inflammatory diseases and cancer. The research aims to evaluate how these enzymes impact HSCs and their mutations during space travel. HSCs will be isolated from blood samples collected at various time points before, during, and after flight. Understanding how spaceflight influences HSC function and mutations could provide insights into the mechanisms of stem cell aging, cancer, and inflammation, with potential benefits for improving treatments for blood disorders and understanding disease processes on Earth.

Research Overview

• SASHA (Space Hematopoietic Stem Cell Aging) evaluates whether immune dysregulation of stem cells occurs in human subjects due to spaceflight. Specifically, changes in editing activity of APOBEC and ADAR1 in human hematopoietic stem cells due to spaceflight.
• This investigation assesses ADAR1 and APOBEC activity in hematopoietic stem cells isolated from whole blood samples from human spaceflight subjects returned at ambient temperature.
• Dysregulation of adenosine deaminase acting on ribonucleic acid (ADAR; RNA editing enzyme) and the apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC; DNA editing enzyme), has been linked to cancer.
• Whole peripheral blood samples are collected from crew members several times on the Axiom Mission 2 (Ax-2): preflight launch-30 ± 10 days, preflight launch-1 ± 10 day on the International Space Station (ISS) (immediately before egress from the ISS), postflight return+1 ± 10 day, postflight return +30 ± 10 days, postflight return+1 year, with annual sample collection desired up to return+5 years postflight.
• This longitudinal collection of samples allows investigators to study short- and long-term human stem cell immune dysregulation in spaceflight.

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