Physical performance relies on the concerted action of myriad responses, many of which are under circadian clock control. Little is known, however, regarding the time-dependent effect on exercise performance at the molecular level. We found that both mice and humans exhibit day-time variance in exercise capacity between the early and late part of their active phase. The day-time variance in mice was dependent on exercise intensity and relied on the circadian clock proteins PER1/2. High throughput gene expression and metabolic profiling of skeletal muscle revealed metabolic pathways that are differently activated upon exercise in a day-time dependent manner. Remarkably, we discovered that ZMP, an endogenous AMPK activator, is induced by exercise in a time-dependent manner to regulate key steps in glycolytic and fatty acid oxidation pathways and potentially enhance exercise capacity. Overall, we propose that time of the day is a major modifier of exercise capacity and associated metabolic pathways. Overall design: basal, high intensity and moderate intensity runnig protocol at ZT14 and ZT22 in gastrocnemius muscle in C57B6 mice
Physiological and Molecular Dissection of Daily Variance in Exercise Capacity.
Sex, Cell line, Subject, Time
View SamplesWe have derived induced porcine pluripotent stem cells (iPPSCs) from porcine fetal fibroblasts by lentiviral transduction of four human (h) reprogramming genes, hOCT4, hSOX2, hKLF4 and hc-MYC , the same combination of factors used for deriving induced pluripotent stem cell (iPSC) lines in both mouse and human. The obtained iPPSC lines resemble human embryonic stem cells (ESC) in their gross morphology and dependence on FGF2, on the other hand, the iPPSCs share characteristics like growth rate and cell surface markers with mESC . Additionally, the iPPSCs express pluripotency- associated genes similar to mouse and human iPSCs as well as ESC, along with the pig epiblast cells. Some of the iPPSC lines retained a stable karyotype and phenotype even in culture for a prolonged period of time (passage 39). The iPPSCs can be induced to differentiate along lineages representative of the three embryonic germ layers both in vitro and in vivo demonstrating the pluripotency of these cells.
Derivation of induced pluripotent stem cells from pig somatic cells.
Specimen part
View SamplesTo realize the full potential of human embryonic stem cells (hESC), it is important to develop culture conditions that maintain hESC in a pluripotent, undifferentiated state. A low O2 atmosphere (~4% O2), for example, prevents spontaneous differentiation and supports self-renewal of hESC. To identify genes whose expression is sensitive to O2 conditions, microarray analysis was performed on RNA from hESC that had been maintained under either 4% or 20% O2. Of 149 genes differentially expressed, 42 were up-regulated and 107 down-regulated under 20% O2. Several of the down-regulated genes are most likely under the control of hypoxia-inducing factors and include genes encoding enzymes involved in carbohydrate catabolism and cellular redox state. Although genes associated with pluripotency, including OCT4, SOX2 and NANOG were generally unaffected, some genes controlled by these transcription factors, including LEFTY2, showed lowered expression under 20% O2, while a few genes implicated in lineage specification were up-regulated. Although the differences between O2 conditions were generally subtle, they were observed in two different hESC lines and at different passage numbers. The data are consistent with the hypothesis that 4% O2 favors the molecular mechanisms required for the maintenance of pluripotency.
Identification of oxygen-sensitive transcriptional programs in human embryonic stem cells.
No sample metadata fields
View SamplesThe pig is important for agriculture and as an animal model in human and veterinary medicine, yet, despite over 20 years of effort, it has proved a difficult species from which to generate pluripotent stem cells analogous to those derived from mouse embryos. Here we report the production of LIF-dependent, so called nave type, pluripotent stem cells from the inner cell mass of porcine blastocysts by up-regulating expression of KLF4 and POU5F1. These cells resemble mouse ES cells and are distinct from the FGF2-dependent, induced pluripotent cell type derived from porcine somatic cells.
Leukemia inhibitory factor (LIF)-dependent, pluripotent stem cells established from inner cell mass of porcine embryos.
Sex
View SamplesPurpose: Syncytiotrophoblast (STB) is a multi-nucleated, terminally differentiated syncytium that covers the surface of the villous placenta and forms the major interface with maternal blood. It releases placental hormones and plays a primary role in exchange of gases, nutrients and waste products. Alterations in STB development and turnover have been implicated in placental diseases, including preeclampsia (PE). In vitro cell models are badly needed to study STB development and physiology due to inaccessibility to placental tissues during gestation. To establish in vitro STB model system, we generate STB and its mononucleated precursors from human embryonic stem cells (hESC) and profile for RNA content by RNAseq. Methods: H1 Human ESC (WA01) were treated with BMP4, the ALK4/5/7 inhibitor (A83-01), and the FGF2 signaling inhibitor (PD173074) (BAP) to direct them to the trophoblast lineage and provided both STB and extravillous trophoblast. Syncytial areas emerged at day 8 BAP treatment ranged in diameter from ~40 µm to > 100 µm. The intact syncytial areas were isolated by sieving successively through 70 µm and 40 µm mesh cell strainers. The captured cells are recovered by inverting the strainer and rinsing with culture medium to separate large (>70 µm) and middle size cell sheets (40-70 µm). The fraction that passes through both sieves represents cells of smallest diameter (< 40 µm), presumably cytotrophoblast. Total 12 RNA samples from triplicate three size-fractioned BAP treated and three untreated hESC cultured in a FGF2 supplemented medium in parallel were analyzed. Results: The larger > 70 µm areas stained positively for STB markers while ultrastructural analysis clearly revealed multi-nuclear cells with an extensive cytoplasm containing many prominent secretion granules. The larger STB areas also had a larger DNA content that > 70 µm fraction contained 37 times more nuclear content and 40-70 µm fraction did 16 times more. Compared to the < 40 µm cell fraction, these larger cells over-expressed a full repertoire of genes characteristic of STB, e.g. CGA, CGB, PGF, ERVW1, GCM1. The smallest cell fraction had a DNA content consistent with mononuclear diploid cells, contained few secretory granules, and were only weakly positive for STB markers. Conclusion: The data are consistent with the > 70 µm cells being mature STB, while the intermediate fraction may represent a precursor population. Human ESC directed along the trophoblast lineage by BAP treatment offers a useful model for following STB formation in vitro and suggest that this protocol may have utility in studying the basis of certain placental diseases, especially preeclampsia, where placental tissue isolated at term or after pregnancy terminations can only offer limited information. Overall design: Three size fraction mRNA profiles of syncytial areas emerged at day 8 BAP treatment of hESC were generated by deep sequencing along with untreated hESC, in triplicate, using Illumina HiSeq 2500.
Comparison of syncytiotrophoblast generated from human embryonic stem cells and from term placentas.
No sample metadata fields
View SamplesHuman pluripotent stem cells (hPSC) exposed to BMP4 (B) and inhibitors of ACTIVIN signaling (A83-01; A) and FGF2 (PD173074; P) in absence of FGF2 (BAP conditions) differentiate into colonies primarily comprised of trophoblast. In an attempt to isolate trophoblast stem cells, colonies of hESC were exposed to BAP for 24 h at which time they had begun to transition into a CDX2-positive state. Cultures were then dissociated into single cells by trypsin and grown on a gelatin substratum. Under these conditions, organized CDX2+/KRT7- colonies began to emerge within a few days. The self-renewing cell lines were not TBSC, but met standard criteria for pluripotency. They were named H1BP cells. They differed from the progenitor hPSC in morphology, ability to be clonally propagated from single cells onto gelatin, requirements for FGF2, and transcriptome profile.
Heightened potency of human pluripotent stem cell lines created by transient BMP4 exposure.
Specimen part, Time
View SamplesIn pregnancies involving preeclampsia (PE), there is evidence that the fetal-placental unit is under oxidative stress. Here we examined primary cell lines generated from umbilical cords (UC) delivered by mothers who had either a normal pregnancy or experienced early onset PE to determine whether the two had distinguishable phenotypes. While all UC provided outgrowths when established in 4 % O2, success was less assured for PE cords under ambient (20 % O2) conditions (P < 0.05). Moreover, proliferation rates of established PE lines, although similar to controls in 4 % O2, were significantly lower in 20 % O2. PE lines grown in 4 % O2 were also more susceptible to the pro-oxidant diethylmaleate than control lines, and unlike controls, were not protected by glutathione.
Abnormal oxidative stress responses in fibroblasts from preeclampsia infants.
Specimen part, Disease
View SamplesRetinoid X receptor (RXR)-gamma is a nuclear receptor-type transcription factor expressed mostly in the skeletal muscle, and regulated by nutritional conditions. Previously, we established transgenic mice overexpressing RXR-gamma in the skeletal muscle (RXR-gamma mice), which showed lower blood glucose than the control mice. We used microarrays to investigate their glucose metabolism gene expression change.
Increased systemic glucose tolerance with increased muscle glucose uptake in transgenic mice overexpressing RXRγ in skeletal muscle.
Sex, Age
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