Disease relevance of Weightlessness

• Microarray analysis identifies Salmonella genes belonging to the low-shear modeled microgravity regulon [1].
• Hind-limb unloading by tail suspension of rats, an established model of simulated microgravity, was used to examine the efficacy of aminohydroxybutane bisphosphonate (AHBuBP) and clenbuterol in preventing bone loss and muscle atrophy, respectively [2].
• These properties have made promethazine a candidate for use in environments such as microgravity, which provoke emesis and motion sickness [3].
• Vernikos et al established that the combination of fludrocortisone, dextroamphetamine, and atropine exhibited a beneficial effect on orthostatic hypotension induced by 7-day 6 degrees head-down bed rest (a model used to simulate the weightlessness of space flight) [4].
• The dimeric multidomain enzyme aspartyl-tRNA synthetase from Thermus thermophilus has been crystallized within dialysis reactors of the Advanced Protein Crystallization Facility in the laboratory on earth and under microgravity aboard the US Space Shuttle [5].

High impact information on Weightlessness

• We have previously demonstrated that low-shear modeled microgravity (LSMMG) under optimized rotation suspension culture is a novel environmental signal that regulates the virulence, stress resistance, and protein expression levels of Salmonella enterica serovar Typhimurium [1].
• In conclusion, microgravity substantially affected osteoblastic integrin-mediated cell adhesion [6].
• When T cells were stimulated with Bead-Leu4 in microgravity culture, they were able to partially express CD69, a receptor that is constitutively stored in intracellular pools and can be expressed in the absence of new gene expression [7].
• EGF-induced c-fos and c-jun expression decreased in microgravity [8].
• These results demonstrate that FN is made by sera-activated osteoblasts even during exposure to microgravity [9].

Chemical compound and disease context of Weightlessness

• Ocular torsion (OT) was measured in human subjects during horizontal linear acceleration on a sled in the laboratory and when emerging from weightlessness during parabolic flights in NASA's KC-135 aircraft [10].
• Glucose interference in production of microcin B17 by Escherichia coli ZK650 was decreased sevenfold by growth in a ground-based rotating-wall bioreactor operated in the simulated microgravity mode as compared with growth in flasks [11].
• The scarcity of trinucleate pollen, abrupt cessation of floret development prior to anthesis, and excess tillering in wheat plants on Mir and in ethylene-containing atmospheres on earth build a strong case for the ethylene on Mir as the agent for the induced male sterility and other symptoms, rather than microgravity [12].
• The present research aimed to elucidate the effects of microgravity environments on bone turnover, with a specific focus on changes in bone resorption markers such as type I collagen cross-linked N-telopeptides (NTx) and deoxypyridinoline (Dpyr), for which scant data are available regarding detailed time course [13].
• Effect of simulated microgravity on PGE2-induced edema and hyperalgesia in rat paws: pharmacological data and biochemical correlates [14].

Biological context of Weightlessness

• RhoA and cytoskeletal disruption mediate reduced osteoblastogenesis and enhanced adipogenesis of human mesenchymal stem cells in modeled microgravity [15].
• This study shows that overexpression of constitutively active RhoA restores actin cytoskeletal arrangement, enhances the osteoblastic phenotype, and suppresses the adipocytic phenotype of human mesenchymal stem cells cultured in modeled microgravity [15].
• The manuscripts present the fundamental findings from the first direct recordings of sympathetic vasoconstrictor nerves and noradrenaline kinetics in humans during microgravity [16].
• Similar membrane potential and cytochrome c release were observed in isolated mitochondria treated with physiological amounts of 5-LOX and were enhanced by creating conditions similar to those that occur during exposure of cells to microgravity [17].
• The purpose of our study was to examine the effects of simulated weightlessness on the pharmacokinetics of antipyrine [18].

Anatomical context of Weightlessness

• Osteoblast fibronectin mRNA, protein synthesis, and matrix are unchanged after exposure to microgravity [9].
• Nothing is known about the effects of weightlessness on the resting membrane chloride conductance (gCl), which controls sarcolemma excitability and influences fibre type transition during development and adult life [19].
• An immortalized promyelocytic cell line was studied to detect how doxorubicin uptake is affected by microgravity [20].
• The purpose of this experiment was to identify the effect that microgravity may have on multidrug resistance in leukocytes [20].
• In fact, although the ultrastructure of resuspended monocytes is not altered in microgravity, the secretion of IL-1 is strongly inhibited [21].

Associations of Weightlessness with chemical compounds

• A proteolytic NH2-terminal truncation of cardiac troponin I that is up-regulated in simulated microgravity [22].
• Glucose utilization and mineralization were decreased under microgravity [23].
• These results were consistent with increased relative occupancy rates of telopeptidyl hydroxylysine-derived cross-links and helical hydroxylysine-derived forms observed under hypergravity and microgravity, respectively [24].
• In a second microgravity experiment on the formation of dust agglomerates by Brownian motion-induced collisions we find that the agglomerates have fractal dimensions as low as 1 [25].
• Cells were transferred to the rotary cell culture system to model microgravity or to be maintained at normal gravity for 7 days in DMEM, 10% FBS, 10 nM dexamethasone, 10 mM beta-glycerol phosphate, and 50 muM ascorbic acid 2-phosphate [15].

Gene context of Weightlessness

• Here, we provide evidence that the mechanical forces altered by simulated microgravity localize and maintain VEGFR-2 in the membrane, and also block VEGF-A expression [26].
• Exposure of human A431 cells to microgravity strongly suppresses EGF- and PMA-induced c-fos and c-jun expression [27].
• Using our microarray, we identified changes in the level of expression of 10 genes, belonging to either the tumor necrosis factor- (TNF) or interleukin- (IL) related gene families in fibroblasts when WI38 cells exposed to microgravity during the STS-93 Space Shuttle mission were compared with ground controls [28].
• Simulated microgravity inhibited the epidermal growth factor (EGF)-induced c-fos gene expression in the MC3T3-El cells [29].
• The decrease in c-fos and c-jun expression in microgravity may result in the decreased formation of the FOS and JUN proteins [27].

Analytical, diagnostic and therapeutic context of Weightlessness

• Using immunofluorescence, we found no significant differences in the amount or in the orientation of the FN matrix after 27.5 h in microgravity [9].
• Metabolic studies during simulated microgravity (bed rest) and true microgravity in flight have shown changes in blood glucose, fatty acids and insulin concentrations, suggesting that energy metabolism may be altered during space flight [30].
• These new data are comprised of both the NASA Protein Crystal Growth Archive, which includes information on all NASA-sponsored protein crystal growth experiments, and data describing other internationally sponsored microgravity macromolecule crystallization studies [31].
• Human PDLF-seeded mineralized PLGA scaffold in microgravity bioreactor may be used to support osteogenic differentiation in vitro [32].
• Recently, we have shown that exposure of fetal thymus organ cultures (FTOC) to modeled microgravity (MMG) using a clinostat with a microgravity organ culture dish system (MOCDS) blocks T cell development in a manner independent of steroid stress hormones present in vivo [33].

References