Circulating miRNA spaceflight signature reveals targets for countermeasure development

This research paper explores how space travel affects our bodies, specifically focusing on changes in tiny RNA molecules called miRNAs within cells of mice. These small particles can influence many aspects of health, including bone and muscle strength, immune system functioning, brain activity, vision quality, and heart health. The study found that two different types of space-related stressors-microgravity (the effect of being in low Earth orbit) and radiation from cosmic rays-can change the levels of miRNAs differently within cells. The researchers conducted experiments on mice to simulate these conditions, using a special bed called HU for microgravity studies and exposing some mice to gamma-irradiation (a type of ionizing radiation) while others were not exposed but underwent the same procedures without actual irradiation. They also studied rats that experienced prolonged periods in spaceflight conditions, known as PWB rats.

The research paper investigates microRNA (miRNA) expression profiles in response to spaceflight, focusing on both reduced gravity environments such as low Earth orbit (LEO) and exposure to deep space radiation. The study employs a comprehensive experimental approach using mouse models subjected to simulated LEO conditions through hindlimb unloading (HU), partial weight bearing (PWB), or complete immobilization, alongside gamma-irradiated mice as controls for the effects of deep space radiation. The methodology involves miRNA profiling using next-generation sequencing techniques to identify differentially expressed miRNAs between experimental groups and sham conditions (no exposure). The study analyzes a total of 16 samples, with four replicates per group: NL Sham controls, HU mice in LEO simulation, PWB rats simulating partial gravity reduction, and gamma-irradiated mice as deep space radiation analogues.