scholarly journals Investigation of osteogenesis changes in medaka larvae reared in normal gravity, simulated-microgravity and hypergravity environments

2021 ◽  
Vol 35 (0) ◽  
pp. 24-31
Author(s):  
Natsuhiro Takahashi ◽  
Masamichi Takami ◽  
Masahiro Chatani
Keyword(s):  
Simulated Microgravity ◽  
Normal Gravity

scholarly journals Effects of Simulated Microgravity on the Physiology of Stenotrophomonas maltophilia and Multiomic Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaolei Su ◽  
Yinghua Guo ◽  
Tingzheng Fang ◽  
Xuege Jiang ◽  
Dapeng Wang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Differentially Expressed Genes ◽  
Biofilm Formation ◽  
Stenotrophomonas Maltophilia ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Differentially Expressed ◽  
Space Environment ◽  
Biological Adhesion ◽  
Proteomic Analyses

Many studies have shown that the space environment plays a pivotal role in changing the characteristics of conditional pathogens, especially their pathogenicity and virulence. However, Stenotrophomonas maltophilia, a type of conditional pathogen that has shown to a gradual increase in clinical morbidity in recent years, has rarely been reported for its impact in space. In this study, S. maltophilia was exposed to a simulated microgravity (SMG) environment in high-aspect ratio rotating-wall vessel bioreactors for 14days, while the control group was exposed to the same bioreactors in a normal gravity (NG) environment. Then, combined phenotypic, genomic, transcriptomic, and proteomic analyses were conducted to compare the influence of the SMG and NG on S. maltophilia. The results showed that S. maltophilia in simulated microgravity displayed an increased growth rate, enhanced biofilm formation ability, increased swimming motility, and metabolic alterations compared with those of S. maltophilia in normal gravity and the original strain of S. maltophilia. Clusters of Orthologous Groups (COG) annotation analysis indicated that the increased growth rate might be related to the upregulation of differentially expressed genes (DEGs) involved in energy metabolism and conversion, secondary metabolite biosynthesis, transport and catabolism, intracellular trafficking, secretion, and vesicular transport. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the increased motility might be associated the upregulation of differentially expressed proteins (DEPs) involved in locomotion, localization, biological adhesion, and binding, in accordance with the upregulated DEGs in cell motility according to COG classification, including pilP, pilM, flgE, flgG, and ronN. Additionally, the increased biofilm formation ability might be associated with the upregulation of DEPs involved in biofilm formation, the bacterial secretion system, biological adhesion, and cell adhesion, which were shown to be regulated by the differentially expressed genes (chpB, chpC, rpoN, pilA, pilG, pilH, and pilJ) through the integration of transcriptomic and proteomic analyses. These results suggested that simulated microgravity might increase the level of corresponding functional proteins by upregulating related genes to alter physiological characteristics and modulate growth rate, motility, biofilm formation, and metabolism. In conclusion, this study is the first general analysis of the phenotypic, genomic, transcriptomic, and proteomic changes in S. maltophilia under simulated microgravity and provides some suggestions for future studies of space microbiology.

scholarly journals Transcriptomic analysis of DNA damage response in zebrafish embryos under simulated microgravity

2021 ◽  
Author(s):  
Subhrajit Barua ◽  
Elia Brodsky ◽  
Harpreet Kaur ◽  
Aleksei Komissarov
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Enrichment Analysis ◽  
Differentially Expressed ◽  
Pathway Enrichment Analysis ◽  
Zebrafish Embryos ◽  
Damage Response ◽  
Microgravity Conditions

Objective: The objective of this study is to study the transcriptome of zebrafish embryos subjected to simulated microgravity and explore affected biological pathways, especially DNA damage response (DDR). The research question is whether simulated microgravity can have an impact on the basic biology of cell division, DNA repair, inflammation, and other vital cellular mechanisms. To validate that such experiments can yield relevant insights into human health and microgravity, we will correlate the found effects of simulated microgravity on zebrafish embryos with the reported effects of spaceflight on astronauts. Methods: 12 wild-type zebrafish embryos of both sexes, and of 3 to 12 months of age were microinjected with 2 nL (1 μg/μL) poly I:C or mock PBS buffer (0.5% phenol red, 240 mM KCl, and 40 mM HEPES at pH 7.4) using a microinjector followed by subjecting them immediately to the simulated microgravity conditions generated by RCCS or the normal gravity conditions in a cell culture dish. RNA-SEQ was performed on the samples according to the standard protocol. Raw gene counts data were obtained from the public domain (NASA Gene Labs) and subjected to further downstream analyses. Differential gene expression was performed using DESeq2. The results were annotated using pathway enrichment analysis (GSEA) on the KEGG pathway database and compared with the result of the NASA twin study. Result: Similar to previously published analysis, we found that a significant number of genes were differentially expressed under simulated microgravity conditions. We identified a total of 7542 genes out of 16532 when comparing expression between the groups: simulated microgravity and normal gravity (padj. value <0.05, log2 fold change in between -2 and 2). Out of these genes, 4504 were found to be up-regulated while 3038 were down-regulated compared to controls. Pathway enrichment analysis revealed that simulated microgravity has an effect on vital basic biological processes like DNA repair, peptide transport, and metabolism. Various other well-known signalling pathways like Notch signalling, wnt signalling, and p53 signalling were also significantly altered. These pathways are known to play an important role in DDR. To explore if the same pathways were also altered in humans, we explored the NASA twin study data and found that DDR was also significantly affected in the astronaut but due to ionizing radiation. Upon further investigation, we found that 62 genes belonging to the DDR pathway were mutually differentially expressed in Scott Kelly and the zebrafish embryos. However, there were 29 significantly differentially expressed genes belonging to the DDR pathway in zebrafish embryos that were not found to be differentially expressed in Scott Kelly. Out of these 29 genes, 14 were specific to zebrafish. Upon further investigation, we found that the DDR pathway is affected differently in simulated microgravity as compared to ionizing radiation. Conclusion: Simulated microgravity alters numerous biological pathways in zebrafish embryos, including DDR. But the nature of it is different from that of real spaceflight induced DDR. These observations should be investigated further to actually understand the nature of DNA damage response during spaceflights.

Modeling of Phosphate Ion Transfer to the Surface of Osteoblasts under Normal Gravity and Simulated Microgravity Conditions

2004 ◽  
Vol 1027 (1) ◽  
pp. 85-98 ◽  
Author(s):  
KARTHIK MUKUNDAKRISHNAN ◽  
PORTONOVO S. AYYASWAMY ◽  
MAKARAND RISBUD ◽  
HOWARD H. HU ◽  
IRVING M. SHAPIRO
Keyword(s):  
Simulated Microgravity ◽  
Normal Gravity ◽  
Ion Transfer ◽  
Phosphate Ion ◽  
Microgravity Conditions

scholarly journals Mechanism for enhancing the growth of mung bean seedlings under simulated microgravity

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Shusaku Nakajima ◽  
Masayasu Nagata ◽  
Akifumi Ikehata
Keyword(s):  
Mung Bean ◽  
Gravitational Force ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Near Infrared ◽  
Amylase Activity ◽  
Infrared Image ◽  
Water Evaporation ◽  
Fresh Weight ◽  
Microgravity Conditions

AbstractTo elucidate a mechanism for enhancing mung bean seedlings’ growth under microgravity conditions, we measured growth, gene expression, and enzyme activity under clinorotation (20 rpm), and compared data obtained to those grown under normal gravity conditions (control). An increase in fresh weight, water content, and lengths were observed in the clinostat seedlings, compared to those of the control seedlings. Real-time PCR showed that aquaporin expression and the amylase gene were upregulated under clinorotation. Additionally, seedlings under clinorotation exhibited a significantly higher amylase activity. Near-infrared image showed that there was no restriction of water evaporation from the seedlings under clinorotation. Therefore, these results indicate that simulated microgravity could induce water uptake, resulting in enhanced amylase activity and seedling growth. Upregulated aquaporin expression could be the first trigger for enhanced growth under clinorotation. We speculated that the seedlings under clinorotation do not use energy against gravitational force and consumed surplus energy for enhanced growth.

scholarly journals Synthesis and Characteristics of CdS Nanoparticles in Normal (1 g) and Simulated Microgravity (SMG)

2020 ◽  
Vol 22 (1) ◽  
pp. 7
Author(s):  
P. S. Shinde ◽  
L. D. Adhav ◽  
R. M. Pise ◽  
S. S. Jagtap
Keyword(s):  
Simulated Microgravity ◽  
Normal Gravity ◽  
Control Sample ◽  
Cadmium Sulphide ◽  
Cds Nanoparticles ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Random Positioning Machine ◽  
Cds Nanoparticle ◽  
Microgravity Conditions

In the present investigation, the cadmium sulphide (CdS) nanoparticles are synthesized in the normal gravity i.e. 1 g (called as control) and in simulated microgravity (called as SMG). The SMG was created by using an instrument called Random Positioning Machine (RPM). Cadmium sulfide nanoparticles were synthesized by using standard chemical method under normal gravity (1 g) and simulated microgravity conditions. The synthesized CdS nanoparticles were characterized by Ultraviolet Visible spectroscopy, Fourier Transform Infrared Ray spectroscopy (FTIR), X-ray diffraction (XRD). The UV-visible absorption spectrum of CdS nanoparticle solution showed a distinct absorption peak at 472.19 nm in control and 458.26 nm in SMG. The band gap calculated from the absorption edge for microgravity sample was 2.71 eV and for control sample was 2.63 eV.  The crystalline size of CdS nanoparticles synthesised in control and Micro-g was determined by XRD. Obtained results showed smaller the particle size in microgravity sample (10.78 nm) as compared to control sample (13.89 nm).

scholarly journals Evaluation of pathogenesis and biofilm formation ability of Yersinia pestis after 40-day exposure to simulated microgravity

2021 ◽  
Author(s):  
Ye Li ◽  
Yulu Chen ◽  
Lei Wang ◽  
Yixuan Li ◽  
Ruifu Yang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Microgravity Condition ◽  
Microgravity Environment ◽  
Crystal Violet Staining ◽  
Rna Seq ◽  
Manned Space ◽  
Manned Space Missions

Abstract Background: With the increase of manned space missions and the rise of space microbiology, the research of microbes grown under microgravity environment attracts more attentions. The research scope in space microbiology has been extended beyond pathogens directly related to spaceflight Y. pestis, the causative agent of plague, is also of interest to researchers. Results: After Y. pestis strain 201 cultivated for 40 consecutive passages in either simulated microgravity and normal gravity (NG) conditions, the cultures were used to observe the main phenotypic features of Y. pestis. By using crystal violet staining assays, increased biofilm amount was detected in Y. pestis grown under SMG condition. Besides that, the damage degrees of Hela cell caused by SMG-grown Y. pestis were found diminished in relative to those NG condition. Consistent with this observation, death course was delayed in mice infected with SMG-grown Y. pestis, suggesting that microgravity condition could contribute the attenuated virulence. RNA-seq-based transcriptomics analysis showed a total of 219 genes were differentially regulated, of which 92 upregulated and 127 downregulated. We found dozens of virulence-associated genes were downregulated, which partially explained the reduced virulence of Y. pestis under SMG condition. Our study demonstrated that long-term exposure to simulated microgravity influence the pathogenesis and biofilm formation ability of Y. pestis in a different way, which provides a novel avenue to study the mechanism of physiology and virulence in this pathogen.Conclusions: Microgravity enhanced the ability of biofilm formation of Y. pestis. The virulence and cytotoxicity of Y. pestis were reduced under the microgravity environment. The expressions of many virulence-associated genes of Y. pestis were differentially regulated in response to the stimulated microgravity.

scholarly journals Microgravity as a Novel Environmental Signal Affecting Salmonella enterica Serovar Typhimurium Virulence

2000 ◽  
Vol 68 (6) ◽  
pp. 3147-3152 ◽  
Author(s):  
Cheryl A. Nickerson ◽  
C. Mark Ott ◽  
Sarah J. Mister ◽  
Brian J. Morrow ◽  
Lisa Burns-Keliher ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Salmonella Enterica ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Acid Stress ◽  
Disease Process ◽  
Murine Spleen ◽  
Serovar Typhimurium ◽  
Macrophage Killing

ABSTRACT The effects of spaceflight on the infectious disease process have only been studied at the level of the host immune response and indicate a blunting of the immune mechanism in humans and animals. Accordingly, it is necessary to assess potential changes in microbial virulence associated with spaceflight which may impact the probability of in-flight infectious disease. In this study, we investigated the effect of altered gravitational vectors on Salmonella virulence in mice. Salmonella enterica serovar Typhimurium grown under modeled microgravity (MMG) were more virulent and were recovered in higher numbers from the murine spleen and liver following oral infection compared to organisms grown under normal gravity. Furthermore, MMG-grown salmonellae were more resistant to acid stress and macrophage killing and exhibited significant differences in protein synthesis than did normal-gravity-grown cells. Our results indicate that the environment created by simulated microgravity represents a novel environmental regulatory factor of Salmonellavirulence.

scholarly journals Decreased biofilm formation in Proteus mirabilis after short-term exposure to a simulated microgravity environment

2021 ◽  
Author(s):  
Dapeng Wang ◽  
Po Bai ◽  
Bin Zhang ◽  
Xiaolei Su ◽  
Xuege Jiang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Space Station ◽  
Biological Characteristics ◽  
Microgravity Environment ◽  
Short Term ◽  
Future Space ◽  
Short Term Exposure

Background: Microbes threaten human health in space exploration. Studies have shown that P. mirabilis has been found in human space habitats. In addition, the biological characteristics of P. mirabilis in space have been studied unconditionally. The simulated microgravity environment provides a platform for understanding the changes in the biological characteristics of P. mirabilis. Objective: This study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm and its related mechanism. Methods: The strange deformable rods were cultured continuously for 14 days under the microgravity simulated by (HARVs) in a high- aspect ratio vessels. The morphology, growth rate, metabolism and biofilm formation of the strain were measured, and the phenotypic changes of P. mirabilis were evaluated. Transcriptome sequencing was used to detect differentially expressed genes under simulated microgravity and compared with phenotype. Results: The growth rate, metabolic ability and biofilm forming ability of P. mirabilis were lower than those of normal gravity culture under the condition of simulated microgravity. Further analysis showed that the decrease of growth rate, metabolic ability and biofilm forming ability may be caused by the down-regulation of related genes (pstS,sodB and fumC). Conclusion: It provides a certain reference for the prevention and treatment of P. mirabilis infection in the future space station by exploring the effect of simulated microgravity exposure on P. mirabilis.

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