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Quantification of Monocyte Chemotactic Activity In Vivo and Characterization of Blood Monocyte Derived Macrophages
Published on: August 12, 2019
Regulation of ICAM-1 in cells of the monocyte/macrophage system in microgravity
Katrin Paulsen1, Svantje Tauber2, Claudia Dumrese3
1Institute of Anatomy, Faculty of Medicine, University of Zurich, Winterthurerstraß 190, 8057 Zurich, Switzerland.
Abstract:
Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells.
Insights
Immune cells like monocytes and macrophages show altered function in microgravity. This study reveals Intercellular Adhesion Molecule-1 (ICAM-1) expression changes in these cells, impacting immune responses.
Area of Science:
- Space biology
- Immunology
- Cellular biology
Background:
- Immune cell function, particularly monocytes and macrophages, is sensitive to microgravity.
- Previous research indicates impaired monocyte and macrophage function under altered gravity conditions.
Purpose of the Study:
- To investigate the impact of microgravity on Intercellular Adhesion Molecule-1 (ICAM-1) expression in monocyte/macrophage systems.
- To determine if ICAM-1 modulation contributes to immune dysfunction in space.
Main Methods:
- Experiments utilized clinostats, parabolic flights, sounding rockets, and orbital missions (SIMBOX/Shenzhou-8).
- Analyzed surface protein and mRNA expression of ICAM-1 in murine BV-2 microglial cells and human U937 cells (differentiated and undifferentiated).
Main Results:
- Murine BV-2 cells showed downregulated ICAM-1 in clinorotation and parabolic flights.
- Differentiated human U937 cells exhibited increased ICAM-1 during parabolic flights and long-term microgravity.
- Undifferentiated U937 cells showed no significant ICAM-1 changes during parabolic flights.
Conclusions:
- Microgravity significantly modulates ICAM-1 expression in a cell-type-dependent manner.
- ICAM-1 changes in monocytes/macrophages may underlie altered immune responses and cell migration in microgravity.
- ICAM-1 is identified as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells.
