Dr. Michael A. Schmidt and Caleb M. Schmidt of Sovaris Aerospace have partnered with Dr. Chris Mason and his team at Weill Cornell Medicine to publish a paper entitled, The NASA Twins Study: The Effect of One Year in Space on Long-Chain Fatty Acid Desaturases and Elongases.
Presently, little is known about how the enzymes that govern the metabolism of long-chain polyunsaturated fatty acids respond to extended duration spaceflight. This is important, since fatty acids affect all cell membranes and vast signaling processes throughout the human body, having downstream affects on the nervous system, cardiovascular system, bone, muscle, skin, digestive tract, and others (essentially all human systems). For context, mathematical estimates have shown that the total surface area of all the cell membranes of the human body is equivalent to roughly 10 football fields. The principal structural element of these membranes is fatty acids, including a high dependency upon polyunsaturated fatty acids. By specific example, the dry weight of the human brain is roughly 60% fat.
The response of the enzymes that govern these processes in space is of great importance to the human habitation of space. The paper by Schmidt et al. is the first to explore the impact of one year in space on these enzymes that govern the metabolism of long-chain fatty acids, during extended spaceflight. The work was based on the multi-scale omics data generated from the NASA Twins Study of One Year in Space. The abstract can be seen below, which is followed by a link to the full text paper.
Background: At present, there is no clear understanding of the effect of long-duration spaceflight on the major enzymes that govern the metabolism of omega-6 and omega-3 fatty acids. To address this gap in knowledge, we used data from the NASA Twins Study, which includes a multi-scale omics investigation of the changes that occurred during a year-long (340 days) human spaceflight. Embedded within the NASA Twins data are specific analytes associated with fatty acid metabolism.
Objectives: To examine the long-chain fatty acid desaturases and elongases in a single human during one year in space.
Method: One male twin was on board the International Space Station (ISS) for one year, while his monozygotic twin served as a genetically matched ground control. Longitudinal assessments included the genome, epigenome, transcriptome, proteome, metabolome, microbiome, and immunome during the mission, as well as six months before and after. The gene-specific fatty acid desaturase and elongase transcriptome data (FADS1, FADS2, ELOVL2, and ELOVL5) were extracted from untargeted RNA-seq measurements derived from white blood cell fractions.
Results: Most data from the elongases and desaturases exhibited relatively similar expression profiles (R2 > 0.6) over time for the CD8, CD19, and lymphocyte-depleted (LD) cell fractions, indicating overall conservation of function within and between the subjects. Both cell-type and temporal specificity was ob-served in some cases, and some differences were also apparent between the polyadenylated (polyA) fraction of processed RNAs versus the ribodepleted (ribo–) fraction. The flight subject showed a stronger enrichment of the fatty acid metabolic process pathway across almost all cell types (columns, CD4, CD8, CPT, and LD), most especially in the ribodepleted fraction of RNA, but also with the polyA+ fraction of RNA. Gene set enrichment analysis (GSEA) measures across three related fatty acid metabolism pathways showed a differential between the ground and the flight subject.
Conclusions: There appears to be no persistent alteration of desaturase and elongase gene expression associated with one year in space. However, these data provide evidence that cellular lipid metabolism can be responsive and dynamic to space-flight, even though it appears cell-type and context specific, most notably in terms of the fraction of RNA measured and the collection protocols. These results also provide new evidence of mid-flight spikes in expression of selected genes, which may indicate transient responses to specific insults during spaceflight.
Schmidt, MA, Meyden, C, Afshinnekoo, E, Schmidt, CM, Mason, CE, (2020) The NASA Twins Study: The Effect of One Year in Space on Long-Chain Fatty Acid Desaturases and Elongases. Lifestyle Genomics DOI: 10.1159/000506
The authors would like to thank Dr. Michael Snyder and Tejas Mishra of Stanford University for untargeted metabolome and fatty acid analysis. We thank Julian C. Schmidt, M.S. (Sovaris Aerospace) for manuscript support. Finally, we thank Robert Hubbard, EdD, MA (Sovaris Aerospace) for manuscript review and illustrations.