Space Microgravity Alters Neural Stem Cell Division: Implications for Brain Cancer Research on Earth and in Space

Abstract

Considering the imminence of long-term space travel, it is necessary to investigate the impact of space microgravity (SPC-µG) in order to determine if this environment has consequences on the astronauts’ health, in particular, neural and cognitive functions. Neural stem cells (NSCs) are the basis for the regeneration of the central nervous system (CNS) cell populations and learning how weightlessness impacts NSCs in health and disease provides a critical tool for the potential mitigation of specific mechanisms leading to neurological disorders. In previous studies, we found that exposure to SPC-µG resulted in enhanced proliferation, a shortened cell cycle, and a larger cell diameter of NSCs compared to control cells. Here, we report the frequent occurrence of abnormal cell division (ACD) including incomplete cell division (ICD), where cytokinesis is not successfully completed, and multi-daughter cell division (MDCD) of NSCs following SPC-µG as well as secretome exposure compared to ground control (1G) NSCs. These findings provide new insights into the potential health implications of space travel and have far-reaching implications for understanding the mechanisms leading to the deleterious effects of long-term space travel as well as potential carcinogenic susceptibility. Knowledge of these mechanisms could help to develop preventive or corrective measures for successful long-term SPC-µG exposure.

Omics Studies of Tumor Cells under Microgravity Conditions

“…Finally, the authors asked the question whether the space-produced secretome would induce ICD and MDCD in naïve NSCs that have never been subjected to r-µg. A clear tendency towards increased ICD and MDCD was observed in naïve NSCs incubated with space-produced secretome compared to ground controls [88].…”

“…To investigate whether these observed changes occurred in the cells directly during spaceflight, the authors focused on molecules that would have been secreted by the NSCs under the influence of µg. Interestingly, the secretome produced similar rates of ICD, suggesting that secreted molecules rather than mechanistical forces are responsible for the observed effects [88]. Finally, the authors asked the question whether the space-produced secretome would induce ICD and MDCD in naïve NSCs that have never been subjected to r-µg.…”

“…In addition, the authors took a closer look at proliferation abnormalities in single cell division. Using time-lapse microscopy analysis, the study found frequent occurrence of abnormal cell division (ACD), including incomplete cell division (ICD), where cytokinesis is not successfully completed, and multidaughter cell division (MDCD) of NSCs subjected to r-µg compared to ground controls (1g) [88]. The study not only supports previous data obtained in s-µg, but also shows an increased appearance of more than two daughter cells, as would the characteristic for a single cell division after cytokinesis be.…”

3D cell culture model: From ground experiment to microgravity study

“…For example, the proliferation of murine osteoblasts was enhanced by 6-21 days of culture on RPM and the expression of osteogenic marker genes in osteogenic (Braveboy-Wagner et al, 2021). RMG resulted in enhanced proliferation and a shortened cell cycle of neural stem cells within 38 days of culture in space (Shaka et al, 2022). The amount of Ki67-positive cells and formation of canning epithelium could be observed after 10 days of culture in human epidermal stem cells (hEpSCs) on RCCS (Lei et al, 2011a).…”

More than a Feeling: Dermatological Changes Impacted by Spaceflight

“…This cluster contains around 80% of the key genes, which indicates that their inclusion in the key genes arise from the fact that cell and DNA functions can be regarded as key functions in space ight. These pathways are often considered to be important in space ight, with studies showing that space ight and altered gravity affects microtubules and mitochondria as well as altering apoptosis in several organisms in vivo and in vitro 29,30 .…”