During space travel, astronauts will experience a unique environment that includes continuous exposure to microgravity and stressful living conditions. Physiological adaptation to this is a…

The National Aeronautics and Space Administration (NASA) awarded a $299,141.27 grant to the Board of Regents of the Nevada System of Higher Education, doing business as the University of Nevada, Las Vegas (UNLV). The grant supports research on how simulated microgravity affects mammary gland development and stem cell function, with a focus on understanding underlying genetic factors and potential cancer risks. This fundamental research aims to address key questions about the physiological effects of spaceflight on organ growth and function. The grant does not have a set-aside designation. As a premier public research university, UNLV has extensive experience collaborating with federal agencies like NASA on studies related to space exploration and health impacts.

During space travel, astronauts will experience a unique environment that includes continuous exposure to microgravity and stressful living conditions. Physiological adaptation to this is a challenge and the effect of microgravity on organ development, architecture, and function is not well understood. How microgravity may impact the growth and development of an organ is an important issue, especially as space flight becomes more commonplace. These fundamental questions can be addressed by studying simulated microgravity exposed cells in vitro. 3D tissue culture models mimicking mammary gland structures have been optimized and can be used to define if exposed cells can correctly assemble into these structures to address some of NASA􀁇s key questions regarding microgravity effects on cells and organs. Additionally, as proper activation of stem cells is key to organ formation IT is important to define how microgravity may affect these specialized cells. In the proposed work we will expose a mammary epithelial cell line (comma 1D) known to contain a high proportion of stem cells and quantify the changes in mammary stem cell populations before and after microgravity exposure. Further, we will identify how exposure to simulated microgravity affects the cells ability to form normal 3D structures important in mammary organ development following this exposure. In addition, we will test role of genetics by isolating mouse mammary epithelial cells from mice showing increased and reduced sensitivities to cancer to define if simulated microgravity shows differential effects dependent on underlying genetics. Next, we will identify mirna changes in stem cells isolated pre and post simulated microgravity exposure to define the underlying molecular reasons for defects in correct 3D structure formation. A final aim will be to define whether microgravity in combination with certain genetic backgrounds causes cellular changes indicative of an increased cancer risk. We hypothesize that cells exposed to simulated microgravity and assayed in 3D will allow US to define how this exposure would impact the growth and development of the mammary gland in vivo. We furthermore hypothesize that the magnitude of this response depends upon genetic susceptibility and thus will utilize cells from different mouse strains to investigate this (cancer prone and resistant). Lastly, we hypothesize that the simulated microgravity exposure in an at risk genetic background may cause changes in cells that increase the propensity to develop cancer. These studies will help identify the cellular and molecular changes and underlying genetic mechanisms of simulated microgravity and how IT impacts overall tissue function.