Effects of 14 days of confinement on blood gene expression profiles in men

The effects of short-term confinement on gene expression profiles in blood were evaluated. Fourteen days confinement study was conducted 2 times. In each experiment, 8 male subjects were stayed in an isolation and confinement facility at Japan Aerospace Exploration Agency. DNA microarray of extracted RNA from whole blood samples revealed that the expression levels of 3,659 genes were significantly altered by the 14-day confinement. The changes in gene expression profiles were not exactly the same as those in response to the other stress conditions, such as chronic psychological stress and spaceflight. In particular, 7 genes, LIN9, AK125040.1, MGC45922, C9orf173-AS1, OR1P1P, KRTAP10-12, and ARFRP1, responded to the confinement prominently. Therefore, the analysis of expression levels of these genes might be useful to assess the stress responses of human body to the confinement. In addition, biological interpretation of the alteration of gene expression profiles with Ingenuity Pathway Analysis indicated that 14-day confinement stimulated various signaling related to pro inflammation and leukocyte extravasation but suppressed apoptosis signaling. In agreement with the interpretation, the decrease of white blood cells in blood was confirmed during the confinement. On the other hand, red blood cells and platelets did not decrease. These results suggest that 14-day confinement is likely to induce shift of white blood cells from “the circulating pool” to “the marginated pool”.