Is spaceflight-induced immune dysfunction linked to systemic changes in metabolism?

PLoS One. 2017 May 24;12(5):e0174174. doi: 10.1371/journal.pone.0174174. eCollection 2017.

Abstract

The Space Shuttle Atlantis launched on its final mission (STS-135) on July 8, 2011. After just under 13 days, the shuttle landed safely at Kennedy Space Center (KSC) for the last time. Female C57BL/6J mice flew as part of the Commercial Biomedical Testing Module-3 (CBTM-3) payload. Ground controls were maintained at the KSC facility. Subsets of these mice were made available to investigators as part of NASA's Bio-specimen Sharing Program (BSP). Our group characterized cell phenotype distributions and phagocytic function in the spleen, catecholamine and corticosterone levels in the adrenal glands, and transcriptomics/metabolomics in the liver. Despite decreases in most splenic leukocyte subsets, there were increases in reactive oxygen species (ROS)-related activity. Although there were increases noted in corticosterone levels in both the adrenals and liver, there were no significant changes in catecholamine levels. Furthermore, functional analysis of gene expression and metabolomic profiles suggest that the functional changes are not due to oxidative or psychological stress. Despite changes in gene expression patterns indicative of increases in phagocytic activity (e.g. endocytosis and formation of peroxisomes), there was no corresponding increase in genes related to ROS metabolism. In contrast, there were increases in expression profiles related to fatty acid oxidation with decreases in glycolysis-related profiles. Given the clear link between immune function and metabolism in many ground-based diseases, we propose a similar link may be involved in spaceflight-induced decrements in immune and metabolic function.

MeSH terms

  • Adrenal Glands / metabolism*
  • Adrenal Glands / pathology
  • Animals
  • Catecholamines / metabolism
  • Cell Survival
  • Corticosterone / metabolism
  • Female
  • Gene Expression Profiling
  • Immune System Diseases / etiology
  • Immune System Diseases / metabolism
  • Immune System Diseases / pathology
  • Leukocytes / immunology
  • Leukocytes / metabolism
  • Leukocytes / pathology
  • Liver / metabolism*
  • Metabolic Diseases / etiology
  • Metabolic Diseases / metabolism
  • Metabolic Diseases / pathology
  • Metabolome
  • Metabolomics
  • Mice, Inbred C57BL
  • Models, Animal
  • Phagocytosis
  • Reactive Oxygen Species / metabolism
  • Receptors, Corticotropin / metabolism
  • Space Flight*
  • Spleen / immunology*
  • Spleen / metabolism*
  • Spleen / pathology
  • Transcriptome

Substances

  • Catecholamines
  • Reactive Oxygen Species
  • Receptors, Corticotropin
  • Corticosterone

Grants and funding

This study was supported by NASA managed cooperative agreement NNX10AJ31G and the LLUMC Department of Radiation Medicine. Metabolon provided support in the form of salaries for RM, but did not have any additional role in the study design, decision to publish, or preparation of the manuscript. RM played a role in the study design, data collection, analysis, and preparation of the manuscript.