Journal Article

Effects of Low Dose Space Radiation Exposures on the Splenic Metabolome

Evagelia C. Laiakis, Brooke L. Barnette, Igor Shuryak, Yongjia Yu, Yi-Wen Wang, Mark R. Emmett, Robert L. Ullrich, Annabella Deziel, Albert J. Fornace

2021

Overview

Future space missions will include a return to the Moon and long duration deep space roundtrip missions to Mars. Leaving the protection that Low Earth Orbit provides will unavoidably expose astronauts to higher cumulative doses of space radiation, in addition to other stressors, e.g., microgravity. Immune regulation is known to be impacted by both radiation and spaceflight and it remains to be seen whether prolonged effects that will be encountered in deep space can have an adverse impact on health. In this study, we investigated the effects in the overall metabolism of three different low dose radiation exposures (γ-rays, 16O, and 56Fe) in spleens from male C57BL/6 mice at 1, 2, and 4 months after exposure. Forty metabolites were identified with significant enrichment in purine metabolism, tricarboxylic acid cycle, fatty acids, acylcarnitines, and amino acids. Early perturbations were more prominent in the γ irradiated samples, while later responses shifted towards more prominent responses in groups with high energy particle irradiations. Regression analysis showed a positive correlation of the abundance of identified fatty acids with time and a negative association with γ-rays, while the degradation pathway of purines was positively associated with time. Taken together, there is a strong suggestion of mitochondrial implication and the possibility of long-term effects on DNA repair and nucleotide pools following radiation exposure.

• Publisher: MDPI AG,MDPI
• Subject: 60 APPLIED LIFE SCIENCES / Animals / Astronauts / Biochemistry & Molecular Biology / Chemistry / Citric Acid Cycle / Citric Acid Cycle - radiation effects / Cosmic Radiation / Cosmic rays / Data analysis / Discriminant analysis / Dose-Response Relationship, Radiation / Dosimetry / immune / Immune system / INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY / Laboratories / Linear Models / Male / Mass spectrometry / Metabolism / Metabolites / Metabolome / Metabolome - radiation effects / Mice / Mice, Inbred C57BL / mitochondria / Moon / Multivariate Analysis / Physiology / Purines / Purines - metabolism / RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY / Radiation Exposure / Scientific imaging / Software / space radiation / Spleen / Spleen - metabolism / Spleen - radiation effects / Variance analysis