A pilot study by researchers at the Icahn School of Medicine at Mount Sinai suggests relatively short (median 12 dayslong) low-Earth orbit (LEO) spaceflight induces changesin circulating plasma small extracellular vesicle (sEV)microRNA expression. Normalization of small RNAsequencing (sRNAseq) data and quantitative polymerasechain reaction (qPCR) validation confirmed miR-4732-3pis significantly upregulated up to 3 days post-landing, andenrichment analysis suggests this miRNA is expressed invarious central nervous system tissues and hematopoieticcells and may be linked to different organ disorders.
Preparation of peripheral blood small extracellular vesicle (sEV) RNA for sequencing
(A) Schematic representation of experimental design and bioinformatics pipeline. The table shows non-attributable demographic information, binned ages, of 14 astronauts who flew space Shuttle missions between 1998–2001. Peripheral blood was isolated from astronauts at three different time points: 10 days before launch (L-10), day of return from mission (R-0), and 3 days after return (R+3). sEVs were isolated from plasma, and sEV-derived total RNA was processed for small RNA sequencing (sRNAseq). Differentially expressed microRNA (miRNAs) were identified using three computational pipelines: RUVseq+EdgeR, EdgeR+Limma, and EdgeR only. For the identified miRNA, pathway enrichment analysis was performed using Gene Ontology (GO) Term, 2021 Kyoto Encyclopedia of Genes and Genomes (KEGG), Online Mendelian Inheritance in Man (OMIM), and Jensen Tissue databases. (B, C) Characterization of exosomes by concentration and size using Nanosignt analysis. (D) Exosome isolation was further validated using an exosome-specific antibody array (exosome markers: CD63, CD81, ALIX, FLOT1, ICAM1, EpCam, ANXA5, and TSG101). Cis-Golgi marker GM130 monitors any cellular contamination in exosome isolation, and a positive control spot was derived from human serum exosomes. (E) Self-organizing maps (SOM) transcriptomic portrayal projects high dimensional transcript expression data onto a 2D grid map. Each map expresses a transcriptome profile for each astronaut at L-10, R-0, and R+3 and is characterized by red-blue spots that reflect up-and downregulated miRNAs