NASA Postdoctoral Program Opportunities

• U.S. Citizens Accepted
• Lawful Permanent Residents Accepted

Spaceflight factors, including microgravity and space radiation, are known to affect somatic stem cell-based tissue regeneration and cause significant degenerative conditions in multiple mammalian tissues, posing a significant risk for long-term human space exploration. Our lab’s previous spaceflight research has shown an inability of both embryonic and somatic stem cells to proliferate, differentiate, and regenerate damaged cells in microgravity conditions, which may be the cause of the widespread tissue degeneration observed in space. However, the molecular mechanisms activated by spaceflight conditions in stem cell populations are not completely understood. Our studies using genome-wide microarrays and RT-qPCR studies of gene expression on post-flight mouse bone marrow tissues flown in microgravity on STS-131, and Bion M1 have shown significant down-regulation and loss of terminal differentiation markers with a corresponding increase in markers associated with stem cell maintenance, which may indicate activation of a stress response that appears to promote cell survival under quiescence conditions. However, due to the complex and heterogenous nature of most tissue compartments, whole tissue genomic analysis are impossible to assign to specific sub-populations. Therefore, in this postdoctoral research opportunity we seek to support a fellow’s effort to understand and characterize more broadly the growth and proliferative molecular changes that occur at the single cell level either in animal or plant model systems enabling the identification and characterization of individual cell and molecular responses to the spaceflight microgravity and analog unloaded environments, to obtain a greater insight into the molecular basis for the observed shifts in cellular phenotypes. We specifically hypothesize that mechanical unloading in microgravity modifies single cell transcriptome expression profiles resulting in alterations to stem cell proliferation and differentiation capabilities. Furthermore, this opportunity seeks to support work to understand the effects of different loading environments on progenitor and differentiated cell populations using different tissues, and to analyze the effects of reloading on the ability of these cells to recover from spaceflight or unloading conditions.