Cytoskeleton changes and impaired motility of monocytes at modelled low gravity

Abstract

Summary. Investigations performed in space have shown that gravity changes affect important cellular mechanisms like proliferation, differentiation, genetic expression, cytoskeletal architecture, and motility in lymphocytes, monocytes, and other mammalian cells. In particular, a dramatic depression of the mitogenic in vitro activation of human peripheral blood lymphocytes was observed at low gravity. The hypothesis of the present work is that a reduced interaction between T lymphocytes and monocytes, essential for the second signalling pathway, might be one of the reasons for the observed depression of the in vitro activation of human lymphocytes. Cell motility and with it a continuous rearrangement of the cytoskeletal network within the cell is essential for cell-tocell contacts. Whereas nonactivated lymphocytes in suspension are highly motile at low gravity, no data are available so far on the motility of adherent monocytes. It thus can be argued that impaired monocyte locomotion and cytoskeletal changes could be responsible for a reduced interaction of monocytes with T lymphocytes. In this study, the locomotion ability of J-111 cells, an adherent monocyte cell line, attached to colloidal gold particles on coverslips and exposed to modelled low gravity in the random positioning machine was found to be severely reduced compared with that of controls and the structures of actin, tubulin, and vinculin were affected.

Modelled microgravity cultivation modulates N-acylhomoserine lactone production in Rhodospirillum rubrum S1H independently of cell density

“…The RPM has been extensively used to study cytoskeleton structure and motility of human cells (Meloni et al, 2006;Walther et al, 1998) and plant gravitropism (Barjaktarović et al, 2009;Hoson et al, 1997) and more recently the RPM has been used to study bacterial cultivation (Beuls et al, 2009;Crabbé et al, 2010;Leroy et al, 2010;Mastroleo et al, 2009b;Mauclaire & Egli, 2010). In the present study, at the proteomic level, only a few common proteins were found in the response of R. rubrum S1H to LSMMG and RPM cultivation, and the LSMMG appeared to induce a higher number of significantly regulated proteins than the RPM compared to the control conditions.…”

Simulation of Microgravity by Magnetic Levitation and Random Positioning: Effect on Human A431 Cell Morphology

“…Recently, the RPM is used as a simulator for microgravity in various studies investigating responses in animal cells (for example Grimm et al 2002;Uva et al 2002;Infanger et al 2006;Pardo et al 2005;Patel et al 2009;Meloni et al 2006). However, the mode of operation of the RPM that was used in these studies varies.…”

Chronic exposure to simulated space conditions predominantly affects cytoskeleton remodeling and oxidative stress response in mouse fetal fibroblasts

“…SRF was shown to be mediated by the Rho signaling pathway (25)(26)(27), which may have been triggered by the RPM. Rho signaling is believed to be an important pathway for focal adhesion assembly and cytoskeleton remodeling in response to cellular tension stress (28) and has been suggested to play a role in the microgravity response (21,(29)(30)(31). Furthermore, Rho GTPase activities were shown to be increased in dermal fibroblasts subjected to simulated microgravity for 30 and 120 min, thereafter decreasing to reach similar values to those of the CTRL at 48 h of treatment (32).…”

“…While it has been shown in various cell types that cytoskeleton remodeling starts immediately after exposure to simulated or real microgravity (21,(29)(30)(31), few studies investigated the effects of IR on the cytoskeleton. However, therapeutic doses of irradiation were shown to affect cell permeability of microvascular endothelial cells through Rho-mediated cytoskeleton remodeling (37).…”