Microgravity has a profound effect on cardiovascular function, however, little is known about the impact of microgravity on progenitors that reside within the heart. We investigated the effect of simulated microgravity exposure on progenitors isolated from the neonatal and adult human heart by quantifying changes in functional parameters, gene expression and protein levels after 6-7 days of 2D clinorotation. Utilization of neonatal and adult cardiovascular progenitors in ground-based studies has provided novel insight into how microgravity may affect cells differently depending on age. Simulated microgravity exposure did not impact AKT or ERK phosphorylation levels and did not influence cell migration, but elevated transcripts for paracrine factors were identified in neonatal and adult cardiovascular progenitors. Age-dependent responses surfaced when comparing the impact of microgravity on differentiation. Endothelial cell tube formation was unchanged or increased in progenitors from adults whereas neonatal cardiovascular progenitors showed a decline in tube formation (p<0.05). Von Willebrand Factor, an endothelial differentiation marker, and MLC2v and Troponin T, markers for cardiomyogenic differentiation, were elevated in expression in adult progenitors after simulated microgravity. DNA repair genes and telomerase reverse transcriptase which are highly expressed in early stem cells were increased in expression in neonatal but not adult cardiac progenitors after growth under simulated microgravity conditions. Neonatal cardiac progenitors demonstrated higher levels of MESP1, OCT4, and brachyury, markers for early stem cells. MicroRNA profiling was used to further investigate the impact of simulated microgravity on cardiovascular progenitors. Fifteen microRNAs were significantly altered in expression, including microRNAs-99a and 100 (which play a critical role in cell dedifferentiation). These microRNAs were unchanged in adult cardiac progenitors. The effect of exposure to simulated microgravity in cardiovascular progenitors is age-dependent. Adult cardiac progenitors showed elevated expression of markers for endothelial and cardiomyogenic differentiation whereas neonatal progenitors acquired characteristics of dedifferentiating cells.
Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26161778
Research Containing: Gene Expression Profiling
Enhanced cardiac differentiation of mouse embryonic stem cells by use of the slow-turning, lateral vessel (STLV) bioreactor
Embryoid body (EB) formation is a common intermediate during in vitro differentiation of pluripotent stem cells into specialized cell types. We have optimized the slow-turning, lateral vessel (STLV) for large scale and homogenous EB production from mouse embryonic stem cells. The effects of inoculating different cell numbers, time of EB adherence to gelatin-coated dishes, and rotation speed for optimal EB formation and cardiac differentiation were investigated. Using 3 x 10(5) cells/ml, 10 rpm rotary speed and plating of EBs onto gelatin-coated surfaces three days after culture, were the best parameters for optimal size and EB quality on consequent cardiac differentiation. These optimized parameters enrich cardiac differentiation in ES cells when using the STLV method.
Related URLs:
<Go to ISI>://WOS:000293752000009
Microarray profile of gene expression during osteoclast differentiation in modelled microgravity
Microgravity (microXg) leads to a 10-15% loss of bone mass in astronauts during space flight. Osteoclast (OCL) is the multinucleated bone-resorbing cell. In this study, we used the NASA developed ground-based rotating wall vessel bioreactor (RWV), rotary cell culture system (RCCS) to simulate microXg conditions and demonstrated a significant increase (2-fold) in osteoclastogenesis compared to normal gravity control (Xg). Gene expression profiling of RAW 264.7 OCL progenitor cells in modelled microXg by Agilent microarray analysis revealed significantly increased expression of critical molecules such as cytokines/growth factors, proteases and signalling proteins, which play an important role in enhanced OCL differentiation/function. Transcription factors such as c-Jun, MITF and CREB implicated in OCL differentiation are upregulated; however no significant change in the levels of NFATc1 expression in preosteoclast cells subjected to modelled microXg. We also identified high-level expression of calcium-binding protein, S100A8 (calcium-binding protein molecule A8/calgranulin A) in preosteoclast cells under microXg. Furthermore, modelled microXg stimulated RAW 264.7 cells showed elevated cytosolic calcium (Ca(2+)) levels/oscillations compared to Xg cells. siRNA knock-down of S100A8 expression in RAW 264.7 cells resulted in a significant decrease in modelled microXg stimulated OCL differentiation. We also identified elevated levels of phospho-CREB in preosteoclast cells subjected to modelled microXg compared to Xg. Thus, modelled microXg regulated gene expression profiling in preosteoclast cells provide new insights into molecular mechanisms and therapeutic targets of enhanced OCL differentiation/activation to prevent bone loss and fracture risk in astronauts during space flight missions.
Related URLs:
http://ovidsp.ovid.com/ovidweb.cgi?T=JS&CSC=Y&NEWS=N&PAGE=fulltext&D=emed9&AN=2010668708
http://sfxhosted.exlibrisgroup.com/mayo?sid=OVID:embase&id=pmid:&id=doi:10.1002%2Fjcb.22840&issn=0730-2312&isbn=&volume=111&issue=5&spage=1179&pages=1179-1187&date=2010&title=Journal+of+Cellular+Biochemistry&atitle=Microarray+profile+of+gene+expression+during+osteoclast+differentiation+in+modelled+microgravity&aulast=Sambandam&pid=%3Cauthor%3ESambandam+Y.%3C%2Fauthor%3E&%3CAN%3E2010668708%3C%2FAN%3E
Hydrodynamic Modulation of Embryonic Stem Cell Differentiation by Rotary Orbital Suspension Culture
Embryonic stern cells (ESCs) can differentiate into all somatic cell types, but the development of effective strategies to direct ESC fate is dependent upon defining environmental parameters capable of influencing cell phenotype. ESCs are commonly differentiated via cell aggregates referred to as embryoid bodies (EBs), but Current culture methods, Such as hinging drop and static Suspension, yield relatively few or heterogeneous populations of EBs. Alternatively, rotary orbital suspension culture enhances EB formation efficiency, cell yield, and homogeneity without adversely affecting differentiation. Thus, the objective of this study was to systematically examine the effects of hydrodynamic conditions created by rotary orbital shaking on EB firmation, structure, and differentiation. Mouse ESCs introduced to suspension culture at a range of rotary orbital speeds (20-60 rpm) exhibited variable EB formation sizes and yields due to differences in the kinetics of cell aggregation. Computational fluid dynamic analyses indicated that rotary orbital shaking generated relatively uniform and mild shear stresses (<= 2.5 dyn/cm(2)) within the regions EBs occupied in culture dishes, at each of the orbital speeds examined. The hydrodynamic conditions modulated EB Structure, indicated by differences in the cellular organization and morphology of the spheroids. Compared to static Culture, exposure to hydrodynamic conditions significantly altered the gene expression profile of EBs. Moreover, varying rotary orbital speeds differentially modulated the kinetic profile of gene expression and relative percentages of differentiated cell types. Over-all, this Study demonstrates that manipulation of hydrodynamic environments modulates ESC differentiation, thus providing a novel, scalable approach to integrate into the development of directed stem cell differentiation strategies. Biotechnol. Bioeng. 2010;105: 611-626. (C) 2009 Wiley Periodicals
Related URLs:
<Go to ISI>://WOS:000273799100017
Simulated microgravity using the Random Positioning Machine inhibits differentiation and alters gene expression profiles of 2T3 preosteoblasts
Exposure to microgravity causes bone loss in humans, and the underlying mechanism is thought to be at least partially due to a decrease in bone formation by osteoblasts. In the present study, we examined the hypothesis that microgravity changes osteoblast gene expression profiles, resulting in bone loss. For this study, we developed an in vitro system that simulates microgravity using the Random Positioning Machine (RPM) to study the effects of microgravity on 2T3 preosteoblast cells grown in gas-permeable culture disks. Exposure of 2T3 cells to simulated microgravity using the RPM for up to 9 days significantly inhibited alkaline phosphatase activity, recapitulating a bone loss response that occurs in real microgravity conditions without altering cell proliferation and shape. Next, we performed DNA microarray analysis to determine the gene expression profile of 2T3 cells exposed to 3 days of simulated microgravity. Among 10,000 genes examined using the microarray, 88 were downregulated and 52 were upregulated significantly more than twofold using simulated microgravity compared with the static 1-g condition. We then verified the microarray data for some of the genes relevant in bone biology using real-time PCR assays and immunoblotting. We confirmed that microgravity downregulated levels of alkaline phosphatase, runt-related transcription factor 2, osteomodulin, and parathyroid hormone receptor 1 mRNA; upregulated cathepsin K mRNA; and did not significantly affect bone morphogenic protein 4 and cystatin C protein levels. The identification of gravisensitive genes provides useful insight that may lead to further hypotheses regarding their roles in not only microgravity-induced bone loss but also the general patient population with similar pathological conditions, such as osteoporosis.
Related URLs:
http://ovidsp.ovid.com/ovidweb.cgi?T=JS&CSC=Y&NEWS=N&PAGE=fulltext&D=emed7&AN=2005320574
http://sfxhosted.exlibrisgroup.com/mayo?sid=OVID:embase&id=pmid:&id=doi:10.1152%2Fajpcell.00222.2004&issn=0363-6143&isbn=&volume=288&issue=6+57-6&spage=C1211&pages=C1211-C1221&date=2005&title=American+Journal+of+Physiology+-+Cell+Physiology&atitle=Simulated+microgravity+using+the+Random+Positioning+Machine+inhibits+differentiation+and+alters+gene+expression+profiles+of+2T3+preosteoblasts&aulast=Pardo&pid=%3Cauthor%3EPardo+S.J.%3C%2Fauthor%3E&%3CAN%3E2005320574%3C%2FAN%3E
Experimental design and environmental parameters affect Rhodospirillum rubrum S1H response to space flight
In view of long-haul space exploration missions, the European Space Agency initiated the Micro-Ecological Life Support System Alternative (MELiSSA) project targeting the total recycling of organic waste produced by the astronauts into oxygen, water and food using a loop of bacterial and higher plant bioreactors. In that purpose, the alpha-proteobacterium, Rhodospirillum rubrum S1H, was sent twice to the International Space Station and was analyzed post-flight using a newly developed R. rubrum whole genome oligonucleotide microarray and high throughput gel-free proteomics with Isotope-Coded Protein Label technology. Moreover, in an effort to identify a specific response of R. rubrum S1H to space flight, simulation of microgravity and space-ionizing radiation were performed on Earth under identical culture set-up and growth conditions as encountered during the actual space journeys. Transcriptomic and proteomic data were integrated and permitted to put forward the importance of medium composition and culture set-up on the response of the bacterium to space flight-related environmental conditions. In addition, we showed for the first time that a low dose of ionizing radiation (2 mGy) can induce a significant response at the transcriptomic level, although no change in cell viability and only a few significant differentially expressed proteins were observed. From the MELiSSA perspective, we could argue the effect of microgravity to be minimized, whereas R. rubrum S1H could be more sensitive to ionizing radiation during long-term space exploration mission.
Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/19571896
Microarray analysis of spaceflown murine thymus tissue reveals changes in gene expression regulating stress and glucocorticoid receptors
The detrimental effects of spaceflight and simulated microgravity on the immune system have been extensively documented. We report here microarray gene expression analysis, in concert with quantitative RT-PCR, in young adult C57BL/6NTac mice at 8 weeks of age after exposure to spaceflight aboard the space shuttle (STS-118) for a period of 13 days. Upon conclusion of the mission, thymus lobes were extracted from space flown mice (FLT) as well as age- and sex-matched ground control mice similarly housed in animal enclosure modules (AEM). mRNA was extracted and an automated array analysis for gene expression was performed. Examination of the microarray data revealed 970 individual probes that had a 1.5-fold or greater change. When these data were averaged (n = 4), we identified 12 genes that were significantly up- or down-regulated by at least 1.5-fold after spaceflight (P < or = 0.05). The genes that significantly differed from the AEM controls and that were also confirmed via QRT-PCR were as follows: Rbm3 (up-regulated) and Hsph110, Hsp90aa1, Cxcl10, Stip1, Fkbp4 (down-regulated). QRT-PCR confirmed the microarray results and demonstrated additional gene expression alteration in other T cell related genes, including: Ctla-4, IFN-alpha2a (up-regulated) and CD44 (down-regulated). Together, these data demonstrate that spaceflight induces significant changes in the thymic mRNA expression of genes that regulate stress, glucocorticoid receptor metabolism, and T cell signaling activity. These data explain, in part, the reported systemic compromise of the immune system after exposure to the microgravity of space.
Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/20213684
Gravity, a regulation factor in the differentiation of rat bone marrow mesenchymal stem cells
BACKGROUND: Stem cell therapy has emerged as a potential therapeutic option for tissue engineering and regenerative medicine, but many issues remain to be resolved, such as the amount of seed cells, committed differentiation and the efficiency. Several previous studies have focused on the study of chemical inducement microenvironments. In the present study, we investigated the effects of gravity on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into force-sensitive or force-insensitive cells. METHODS AND RESULTS: Rat BMSCs (rBMSCs) were cultured under hypergravity or simulated microgravity (SMG) conditions with or without inducement medium. The expression levels of the characteristic proteins were measured and analyzed using immunocytochemical, RT-PCR and Western-blot analyses. After treatment with 5-azacytidine and hypergravity, rBMSCs expressed more characteristic proteins of cardiomyocytes such as cTnT, GATA4 and beta-MHC; however, fewer such proteins were seen with SMG. After treating rBMSCs with osteogenic inducer and hypergravity, there were marked increases in the expression levels of ColIA1, Cbfa1 and ALP. Reverse results were obtained with SMG. rBMSCs treated with adipogenic inducer and SMG expressed greater levels of PPARgamma. Greater levels of Cbfa1- or cTnT-positive cells were observed under hypergravity without inducer, as shown by FACS analysis. These results indicate that hypergravity induces differentiation of rBMSCs into force-sensitive cells (cardiomyocytes and osteoblasts), whereas SMG induces force-insensitive cells (adipocytes). CONCLUSION: Taken together, we conclude that gravity is an important factor affecting the differentiation of rBMSCs; this provides a new avenue for mechanistic studies of stem cell differentiation and a new approach to obtain more committed differentiated or undifferentiated cells.
Related URLs:
http://ovidsp.ovid.com/ovidweb.cgi?T=JS&CSC=Y&NEWS=N&PAGE=fulltext&D=emed9&AN=19772591
http://sfxhosted.exlibrisgroup.com/mayo?sid=OVID:embase&id=pmid:19772591&id=doi:&issn=1423-0127&isbn=&volume=16&issue=&spage=87&pages=87&date=2009&title=Journal+of+biomedical+science&atitle=Gravity%2C+a+regulation+factor+in+the+differentiation+of+rat+bone+marrow+mesenchymal+stem+cells&aulast=Huang&pid=%3Cauthor%3EHuang+Y.%3C%2Fauthor%3E&%3CAN%3E19772591%3C%2FAN%3E
Decreased expression of myogenic transcription factors and myosin heavy chains in Caenorhabditis elegans muscles developed during spaceflight
The molecular mechanisms underlying muscle atrophy during spaceflight are not well understood. We have analyzed the effects of a 10-day spaceflight on Caenorhabditis elegans muscle development. DNA microarray, real-time quantitative PCR, and quantitative western blot analyses revealed that the amount of MHC in both body-wall and pharyngeal muscle decrease in response to spaceflight. Decreased transcription of the body-wall myogenic transcription factor HLH-1 (CeMyoD) and of the three pharyngeal myogenic transcription factors, PEB-1, CEH-22 and PHA-4 were also observed. Upon return to Earth animals displayed reduced rates of movement, indicating a functional defect. These results demonstrate that C. elegans muscle development is altered in response to spaceflight. This altered development occurs at the level of gene transcription and was observed in the presence of innervation, not simply in isolated cells. This important finding coupled with past observations of decreased levels of the same myogenic transcription factions in vertebrates after spaceflight raises the possibility that altered muscle development is a contributing factor to spaceflight-induced muscle atrophy in vertebrates.
Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/16888068
http://jeb.biologists.org/content/209/16/3209.full.pdf
Spaceflight effects on T lymphocyte distribution, function and gene expression
The immune system is highly sensitive to stressors present during spaceflight. The major emphasis of this study was on the T lymphocytes in C57BL/6NTac mice after return from a 13-day space shuttle mission (STS-118). Spleens and thymuses from flight animals (FLT) and ground controls similarly housed in animal enclosure modules (AEM) were evaluated within 3-6 h after landing. Phytohemagglutinin-induced splenocyte DNA synthesis was significantly reduced in FLT mice when based on both counts per minute and stimulation indexes (P < 0.05). Flow cytometry showed that CD3(+) T and CD19(+) B cell counts were low in spleens from the FLT group, whereas the number of NK1.1(+) natural killer (NK) cells was increased (P < 0.01 for all three populations vs. AEM). The numerical changes resulted in a low percentage of T cells and high percentage of NK cells in FLT animals (P < 0.05). After activation of spleen cells with anti-CD3 monoclonal antibody, interleukin-2 (IL-2) was decreased, but IL-10, interferon-gamma, and macrophage inflammatory protein-1alpha were increased in FLT mice (P < 0.05). Analysis of cancer-related genes in the thymus showed that the expression of 30 of 84 genes was significantly affected by flight (P < 0.05). Genes that differed from AEM controls by at least 1.5-fold were Birc5, Figf, Grb2, and Tert (upregulated) and Fos, Ifnb1, Itgb3, Mmp9, Myc, Pdgfb, S100a4, Thbs, and Tnf (downregulated). Collectively, the data show that T cell distribution, function, and gene expression are significantly modified shortly after return from the spaceflight environment.
Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/18988762