Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Andjelic, A.
EFFECTS OF ARTIFICIAL GRAVITY ON MOLECULAR MECHANISMS
Humanmedizin; [ Diplomarbeit ] Medical University of Graz; 2014. pp. 103
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Goswami Nandu
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- Abstract:
- Background: Weightlessness (or microgravity) is known to have multiple effects on human physiology. In absence of gravity, the body has to adapt to the new environment. This adaptation causes changes of cardiovascular, renal, endocrine and neurovestibular function. Furthermore, the disuse of bones and muscles in space leads to structural alterations of these tissues. An important principle to prevent negative effects of microgravity represents artificial gravity training with human centrifuges. The effects of application of artificial gravity have been investigated in numerous studies. Until now, however, no studies have focused on effects of artificial gravity on molecular mechanisms. With this study, we have examined molecular changes caused by application of artificial gravity with regard to the entirety of mRNA (transcriptome) present in the peripheral blood and using the DNA microarray technique. Methodology: 12 test subjects underwent a mutual ‘continuous’ centrifugation protocol on a short-arm human centrifuge. A second ‘intermittent’ protocol was used for 6 of the 12 subjects, additionally. Blood was taken from test subjects before and after each experiment. RNA from each blood sample was isolated and used to generate labeled cRNA, which was competitively hybridized to microarrays. Signals were analyzed using different thresholds of p-value and fold change (FC) and multiple testing corrections were performed. Analysis of differential gene expression was performed with Gene Ontology, gene cluster analysis was performed with PANTHER. Results: 661 genes were significantly affected by AG in continuous protocol, 234 genes in intermittent protocol (p = 0.05 and FC = 1.5). More significantly, 42 genes were affected in constant protocol and 8 genes in intermittent protocol (p = 0.01, FC = 2). PANTHER analysis revealed genes organized in 3 significant pathway clusters, 5 clusters of biological process and 2 of protein classes for continuous protocol and no clusters in intermittent protocol. Discussion: We have observed that application of centrifugation as the method of generating artificial gravity has effects on molecular mechanisms, using the transcriptomic technique of DNA microarray. Since investigations of the transcriptome allow to draw inferences on the level of gene expression, we have concluded that centrifugation leads to altered gene expression. Furthermore we have observed that application of two different centrifugation protocols has differences on the molecular level. We think that this study is the first to examine effects of application of artificial gravity in terms of molecular mechanisms in humans.