Since 1961, 559 humans have been flown into space, providing insights into the effects of environmental factors, like microgravity and radiation on human health and performance. Despite the plethora of available information on the effects of the aforementioned factors on a systems physiology level – with bone density loss being the most widely known among them – our understanding of those effects on a cellular and molecular level remains quite lackluster. A recently published study performed by NASA, provided a uniquely integrated framework for comprehensively examining astronaut biology in space but was not without its limitations, including the alteration of samples because of their preservation and transportation from the International Space Station to Earth, the limitations of studying a single subject and of course its considerable cost.
Motivated by the above, we set out to probe in a high-throughput fashion the dynamic regulation of gene expression of eukaryotic cells, under the effect of microgravity and radiation of a Low-Earth Orbit. Due to technical difficulties associated with maintaining a human cell culture, we are employing Saccharomyces cerevisiae, a yeast model so widely used for studying human cells that 5 Nobel Prizes have been awarded since 2000 for work on it. In addition to its profound usefulness as a model for human cells, yeast cells are also indispensable cellular factories, producing a wide array of pharmaceuticals, biomaterials and biofuels on Earth and possibly beyond. We are mapping in real time a significant percentage of the yeast proteome, hoping to elucidate the molecular mechanisms underlying the effect of microgravity and radiation on proteins regulating the cell cycle, the DNA damage response, cytoskeletal organization as well as numerous biochemical and metabolic pathways necessary for survival.
To achieve the desired high-throughput nature of the experiment in the limited space and power capacity of a CubeSat, we are utilizing developments in the fields of synthetic biology and Bio-MEMS (Biological-MicroElectroMechanical Systems), particularly microfluidic chips. We are hoping that the tools and technologies we are developing will define a novel modus operandi for space biology explorations on the molecular level and promote the employment of CubeSats equipped with Lab on a chip technologies for scientific investigations.