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. 2024 Dec 16;13(12):1186-1197.
doi: 10.1093/stcltm/szae070.

Effects of microgravity on human iPSC-derived neural organoids on the International Space Station

Davide Marotta  1 , Laraib Ijaz  1 , Lilianne Barbar  1 , Madhura Nijsure  1 , Jason Stein  2 , Nicolette Pirjanian  1 , Ilya Kruglikov  1 , Twyman Clements  3 , Jana Stoudemire  3 , Paula Grisanti  4 , Scott A Noggle  1 , Jeanne F Loring  2   4 , Valentina Fossati  1
Affiliations

Effects of microgravity on human iPSC-derived neural organoids on the International Space Station

Davide Marotta et al. Stem Cells Transl Med. .

Abstract

Research conducted on the International Space Station (ISS) in low-Earth orbit (LEO) has shown the effects of microgravity on multiple organs. To investigate the effects of microgravity on the central nervous system, we developed a unique organoid strategy for modeling specific regions of the brain that are affected by neurodegenerative diseases. We generated 3-dimensional human neural organoids from induced pluripotent stem cells (iPSCs) derived from individuals affected by primary progressive multiple sclerosis (PPMS) or Parkinson's disease (PD) and non-symptomatic controls, by differentiating them toward cortical and dopaminergic fates, respectively, and combined them with isogenic microglia. The organoids were cultured for a month using a novel sealed cryovial culture method on the International Space Station (ISS) and a parallel set that remained on Earth. Live samples were returned to Earth for analysis by RNA expression and histology and were attached to culture dishes to enable neurite outgrowth. Our results show that both cortical and dopaminergic organoids cultured in LEO had lower levels of genes associated with cell proliferation and higher levels of maturation-associated genes, suggesting that the cells matured more quickly in LEO. This study is continuing with several more missions in order to understand the mechanisms underlying accelerated maturation and to investigate other neurological diseases. Our goal is to make use of the opportunity to study neural cells in LEO to better understand and treat neurodegenerative disease on Earth and to help ameliorate potentially adverse neurological effects of space travel.

Keywords: Parkinson’s disease; induced pluripotent stem cells; microglia; microgravity; multiple sclerosis; neurons; organoids.

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Conflict of interest statement

The authors declared no potential conflicts of interests.

Figures

Graphical Abstract
Graphical Abstract
Figure 1.
Figure 1.
Experimental design. A. iPSCs from 4 individuals were selected for experiments: 2 controls and 2 with the neurodegenerative diseases Parkinson’s disease or primary progressive multiple sclerosis. B. iPSCs were differentiated into cortical or dopaminergic neuron precursors, aggregated to form organoids, and matched microglia derived from each of the cell lines were added to half of the organoids. Each organoid was placed in a separate cryovial with 1 mL of culture medium and sealed for the duration of the experiment. One set of cryovials was transported to the ISS on the SpX CRS-19 mission while the other replicate set remained on ground. C. Matching sets of cryovial cultures were incubated for a month at 37 °C on ground and onboard the ISS. D. Upon return to Earth, both sets of organoid cultures were analyzed by multiple methods. E. Timeline of the mission.
Figure 2.
Figure 2.
Neural organoids cultured in the static system without medium exchange were viable after 30 days. A. Phase-contrast images of cortical and dopaminergic neural organoids, from preflight stage to the post-flight stage in low-Earth orbit (LEO) and on ground. B. Organoid cultured after 30 days in LEO shows outgrowth of neurites with growth cones. C. Immunocytochemistry of cryosectioned cortical organoid shows the neural rosettes typical of cortical organoids (red: PAX6; green: CDH2 [NCAD]) for ground and LEO samples. D. Telemetry shows the temperature maintained inside the CubeLab onboard the ISS and the images show the organoid (arrows) cultured in the static system at mission days 5.119 and 30.09 (images taken onboard the ISS).
Figure 3.
Figure 3.
Microgravity alters gene expression in neural organoids: Dopaminergic organoids. A. Volcano plot showing the differentially expressed genes (DEGs) between iPSC-derived cortical organoids in low-Earth orbit (LEO) and ground. Expression levels of genes with significant enrichment (padj < .05) are plotted as red (lower in LEO, “down”) or blue (higher in LEO, “up”), NO = no difference. B. PCA plot showing the differences between LEO (red) and ground (blue) of the dopaminergic organoids derived from the 2 iPSC lines. Labels refer to the samples from the 2 subjects listed in Supplementary Table S1. C-F. Upregulated and downregulated gene sets. C. Cell cycle markers; D. Progenitors; E. Radial glia markers; F. Pro-neural and post-mitotic differentiation markers.
Figure 3.
Figure 3.
Microgravity alters gene expression in neural organoids: Dopaminergic organoids. A. Volcano plot showing the differentially expressed genes (DEGs) between iPSC-derived cortical organoids in low-Earth orbit (LEO) and ground. Expression levels of genes with significant enrichment (padj < .05) are plotted as red (lower in LEO, “down”) or blue (higher in LEO, “up”), NO = no difference. B. PCA plot showing the differences between LEO (red) and ground (blue) of the dopaminergic organoids derived from the 2 iPSC lines. Labels refer to the samples from the 2 subjects listed in Supplementary Table S1. C-F. Upregulated and downregulated gene sets. C. Cell cycle markers; D. Progenitors; E. Radial glia markers; F. Pro-neural and post-mitotic differentiation markers.
Figure 4.
Figure 4.
Microgravity alters gene expression in neural organoids: Cortical organoids. A. Volcano plot showing the differentially expressed genes (DEGs) between iPSC-derived cortical organoids in low-Earth orbit (LEO) and ground. NO = no difference. B. PCA plot showing the differences between LEO (red) and ground (blue) of the cortical organoids derived from the 2 iPSC lines. Labels refer to the samples from the 2 subjects, listed in Supplementary Table S1. C-F. Upregulated and downregulated gene sets. C. Cell Cycle markers; D. Progenitor and positional markers; E. Ependymal, Radial glia, and Cilia markers; F. Cajal-Retzius neuron markers.
Figure 4.
Figure 4.
Microgravity alters gene expression in neural organoids: Cortical organoids. A. Volcano plot showing the differentially expressed genes (DEGs) between iPSC-derived cortical organoids in low-Earth orbit (LEO) and ground. NO = no difference. B. PCA plot showing the differences between LEO (red) and ground (blue) of the cortical organoids derived from the 2 iPSC lines. Labels refer to the samples from the 2 subjects, listed in Supplementary Table S1. C-F. Upregulated and downregulated gene sets. C. Cell Cycle markers; D. Progenitor and positional markers; E. Ependymal, Radial glia, and Cilia markers; F. Cajal-Retzius neuron markers.
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References

    1. Roy-O’Reilly M, Mulavara A, Williams T.. A review of alterations to the brain during spaceflight and the potential relevance to crew in long-duration space exploration. npj Microgravity. 2021;7(1):5. https://doi.org/10.1038/s41526-021-00133-z - DOI - PMC - PubMed
    1. Clayton BLL, Barbar L, Sapar M, et al.Patient iPSC models reveal glia-intrinsic phenotypes in multiple sclerosis. Cell Stem Cell. 2024. https://doi.org/10.1016/j.stem.2024.08.002 - DOI - PMC - PubMed
    1. Paull D, Sevilla A, Zhou H, et al.Automated, high-throughput derivation, characterization and differentiation of induced pluripotent stem cells. Nat Methods. 2015;12(9):885-892. https://doi.org/10.1038/nmeth.3507 - DOI - PubMed
    1. Hills R, Mossman JA, Bratt-Leal AM, et al.Neurite outgrowth and gene expression profile correlate with efficacy of human induced pluripotent stem cell-derived dopamine neuron grafts. Stem Cells Dev. 2023;32(13-14):387-397. https://doi.org/10.1089/scd.2023.0043 - DOI - PMC - PubMed
    1. Bhutani K, Nazor KL, Williams R, et al.Whole-genome mutational burden analysis of three pluripotency induction methods. Nat Commun. 2016;7(19):10536. https://doi.org/10.1038/ncomms10536 - DOI - PMC - PubMed