18 Nov Spaceflight microgravity & epigenetic research
Epigenetics focuses on any process that alters gene expression and cellular phenotype through chromatin remodelling with histone modifications, DNA methylation and RNA interference, without changing the DNA nucleotide sequence. External stimuli detected by the body, such as differences in the environment, exposure to chemicals or radiation, trauma, or exercises, could cause epigenetic changes. It has been suggested that epigenetic changes could have a key role in several physio- and pathological processes, including the natural mechanism of ageing and some severe disorders such as cancer, cardiovascular and autoimmune diseases as well.
Regarding the space environment, it is well-known that long-term exposure to microgravity induces several physiological and biochemical modifications, like negative calcium balance resulting in bone loss, muscle atrophy, decreased plasma volume and cardiovascular deconditioning. Microgravity-related transcriptional alterations have been observed in several spaceflight experiments, thus suggesting that epigenetic changes might occur in these extreme conditions.
In this regard, the identification of epigenetics markers can allow to delineate the pathways determining the adaptations and the surveys of the cells in microgravity and a number of studies have been carried out so far, as briefly listed in the following:
• “Epigenetics in Space-flown C. elegans” is an investigation examining whether adaptations to microgravity transmit from one cell generation to another without changing the DNA sequence
• “Transcriptome Analysis and Germ-Cell Development Analysis of Mice in Space” investigates molecular alterations in organ-specific gene expression patterns and epigenetic modifications
• NASA’s human research “Differential effects of homozygous twin astronauts associated with differences in exposure to spaceflight factors”, includes investigations evaluating differential epigenetic effects via comprehensive whole genome analysis.
In this scenario, it is reasonable to expect a downstream translation since space is a real harsh environment that deeply modifies the physiological response by stressing cell functions. The epigenetic space research can therefore benefit Earth medical investigation with potential cues to understand specific phenomena aimed to develop novel strategies for personalised medicine.
References
- Garrett-Bakelman, F. E., Darshi, M., Green, S. J., Gur, R. C., Lin, L., Macias, B. R., … & Turek, F. W. (2019). The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight. Science, 364(6436), eaau8650.
- Wolfe, J. W., & Rummel, J. D. (1992). Long-term effects of microgravity and possible countermeasures. Advances in Space Research, 12(1), 281-284.
- Higashitani, A., Hashizume, T., Takiura, M., Higashitani, N., Teranishi, M., Oshima, R., … & Higashibata, A. (2021). Histone deacetylase HDA-4-mediated epigenetic regulation in space-flown C. elegans. npj Microgravity, 7(1), 1-8.
- Love, J. (2018). Epigenetics Research on the International Space Station. 42nd COSPAR Scientific Assembly, 42, F2-4.Wang, J., Yang, J., Li, D., & Li, J. (2021). Technologies for targeting DNA methylation modifications: basic mechanism and potential application in cancer.
- Biochimica et Biophysica Acta (BBA)-Reviews on Cancer, 1875(1), 188454.
- Okada, R., Fujita, S. I., Suzuki, R., Hayashi, T., Tsubouchi, H., Kato, C., … & Takahashi, S. (2021). Transcriptome analysis of gravitational effects on mouse skeletal muscles under microgravity and artificial 1 g onboard environment. Scientific reports, 11(1), 1-15.