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Updated: Aug 15, 2025
Culturing Lymphocytes in Simulated Microgravity Using a Rotary Cell Culture System
Published on: August 25, 2022
Detrimental effects of simulated microgravity on mast cell homeostasis and function
Minjin Kim1,2, Gyeongin Jang1,2, Kyu-Sung Kim1,3
1Inha Research Institute for Aerospace Medicine, Inha University College of Medicine, Incheon, Republic of Korea.
Abstract:
Exposure to microgravity causes significant alterations in astronauts' immune systems during spaceflight; however, it is unknown whether microgravity affects mast cell homeostasis and activation. Here we show that microgravity negatively regulates the survival and effector function of mast cells. Murine bone marrow-derived mast cells (BMMCs) were cultured with IL-3 in a rotary cell culture system (RCCS) that generates a simulated microgravity (SMG) environment. BMMCs exposed to SMG showed enhanced apoptosis along with the downregulation of Bcl-2, and reduced proliferation compared to Earth's gravity (1G) controls. The reduction in survival and proliferation caused by SMG exposure was recovered by stem cell factor. In addition, SMG impaired mast cell degranulation and cytokine secretion. BMMCs pre-exposed to SMG showed decreased release of β-hexosaminidase, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) upon stimulation with phorbol 12-myristate-13-acetate (PMA) plus calcium ionophore ionomycin, which correlated with decreased calcium influx. These findings provide new insights into microgravity-mediated alterations of mast cell phenotypes, contributing to the understanding of immune system dysfunction for further space medicine research.
Insights
Microgravity impairs mast cell survival, proliferation, and function, impacting immune responses during spaceflight. Stem cell factor can partially restore these effects, offering insights for space medicine.
Area of Science:
- Immunology
- Space Biology
- Cell Biology
Background:
- Spaceflight, particularly microgravity, significantly alters astronaut immune systems.
- The specific effects of microgravity on mast cell homeostasis and activation remain largely unknown.
- Mast cells play crucial roles in immune responses and allergic reactions.
Purpose of the Study:
- To investigate the impact of microgravity on mast cell survival, proliferation, and effector functions.
- To elucidate the mechanisms underlying microgravity-induced changes in mast cells.
- To explore potential countermeasures for microgravity-related mast cell dysfunction.
Main Methods:
- Murine bone marrow-derived mast cells (BMMCs) were cultured in a simulated microgravity (SMG) environment using a rotary cell culture system (RCCS).
- Effects of SMG on BMMC apoptosis, proliferation, degranulation, and cytokine secretion were assessed.
- The role of stem cell factor (SCF) as a potential recovery agent was evaluated.
- Calcium influx and expression of apoptosis-related proteins (Bcl-2) were measured.
Main Results:
- SMG exposure led to increased BMMC apoptosis and decreased proliferation, associated with Bcl-2 downregulation.
- Stem cell factor (SCF) treatment rescued BMMCs from SMG-induced reductions in survival and proliferation.
- SMG impaired mast cell degranulation, evidenced by reduced β-hexosaminidase release.
- Cytokine secretion (IL-6, TNF-α) and calcium influx were diminished in SMG-exposed BMMCs.
Conclusions:
- Microgravity negatively regulates mast cell survival and effector functions, contributing to immune system dysfunction in space.
- These findings highlight the vulnerability of mast cells to microgravity and suggest SCF as a potential therapeutic target.
- Understanding these microgravity-mediated alterations is vital for advancing space medicine and ensuring astronaut health.
