MicroRNA Expression Profiles in Cultured Human Fibroblasts in Space (Micro-7) - 07.29.14
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The majority of cells in the human body are non-dividing cells that provide critical functions, from blood cells, to cells in different organs. Micro-7 studies how microgravity affects the genetic expression and physical shape of these types of cells for the first time. Understanding how these cells function in microgravity is a step toward understanding how organs, tissues, and the entire body change during spaceflight.
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University of Colorado at Boulder, BioServe Space Technologies, Boulder, CO, United States
NASA Ames Research Center, Moffett Field, CA, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
March 2014 - September 2014
Previous ISS Missions
It is not known how the space flight environment affects non-dividing cells, which are the majority of cells that make up the human body. Changes are observed to organs, tissues and whole body systems, yet the root causes are not understood or known. In order to gain insight, it is important to study the fundamental functional unit of tissues and organs, which is the cell. By studying a single cell type in culture instead of whole tissues or organs, the scientist will be able to clearly investigate the root molecular and cellular biological effects of the space flight environment on the cell and eliminate potential complicating factors due to different cell types that may make up a specific tissue type or organ. The bleomycin study will examine the induction of, as well as cellular responses to, DNA double strand breaks (DSB) in the microgravity environment. Living organisms in space are constantly exposed to space radiation and other environmental toxins. Differences in the capability to repair or misrepair DNA damages between the microG and 1G conditions will impact the accuracy of the risk assessment of astronauts, and the accuracy in predicting the mutation rate in microorganisms.
The data from this study will provide deeper insight into how gene expression regulates cellular adaptation to the space flight environment. Specifically, it will provide further understanding of the roles microRNA (miRNA) play in gene expression regulation that will be of benefit to both space flight exploration and Earth scientific research.
The identification of the role of miRNA in gene regulation will help to elucidate the fundamental process that are affect by or regulate adaptation to the space flight environment. Since this experiment compares space flight samples with ground samples, differences between the the specimens will elucidate unknown functions of miRNA and identification of cellular/biochemical pathways that are regulated by miRNAs. Also, since the experiment uses normal human fibroblast in their non-dividing condition, it will provide new information on how normal cellular function and adaptation are affected by the space environment. Collectively, the data may be used for Earth-based fundamental and biomedical research to examine if the changes observed in space flight are seen in disease states of tissues and organs. Furthermore, the data may point out important targets for further study in ground-based and space-based research. Ultimately, the data may be applied to understanding tissue and organ structural maintenance and disease.
1) Determine miRNA expression profiles in confluent AG1522 human fibroblast cells in space and on the ground with PCR array.
2) Determine gene expression profiles in confluent AG1522 human fibroblast cells in space and on the ground with Illumina gene array.
3) Determine changes in miRNA and gene expression profiles in and pathways affected by the microgravity environment using statistical and bioinformatics methodologies. Determine correlation between miRNA and RNA expression patterns.
4) Measure the number of DSB in the cultures used for the Bleomycin study plus 1-3 above.
Human tissues and organs are made of non-dividing but functional cells. According to Earth-based experiments, non-dividing cells’ genetic expression and micro-RNA profiles change in response to simulated microgravity. Micro-7 is the first space experiment to directly investigate how microgravity affects the gene expression and physical shape of fibroblasts, which are common tissue cells. Fibroblasts are critical for wound healing and tissue structure, so understanding how they function in space could provide crucial insight for future space missions.
Understanding the differences between cells’ genetic expression on the ground and in microgravity can provide new insights into genetic regulation and signaling pathways. Micro-7 aims to explain the role of micro-RNA, a type of molecule involved in how genetic information is processed in a cell. Micro-RNA might be important in regulating how cells respond to the space environment, and data from Micro-7 could be compared with ground-based data to provide insight into miRNA’s role in gene regulation. Understanding fundamental molecular processes in cells could provide new pathways for disease treatment, including potential new pharmaceutical products.
See previous sections listing requirements.
The crew will inject a preservative or fixative into the biochamber at specific time points. After the specimens are processed, the biochambers will be transferred to either +4 oC or -80 oC stowage. If the CGBA will be powered for return, the +4 oC stowed specimens may be returned to the CGBA for return, otherwise the specimens will be transferred to a +4 oC cold stowage bag. The cryo (if needed) specimens will be transferred to either GLACIER or a cryo-cold stowage bag for return.
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