Methods of reprogramming somatic cells to an induced pluripotent state (iPSC) have enabled the direct modeling of human disease and ultimately promise to revolutionize regenerative medicine. iPSCs offer an invaluable source of patient-specific pluripotent stem cells for disease modeling, drug screening, toxicology tests and importantly for regenerative medicine, and already have been employed to unmask novel insights into human diseases. While iPSCs can be consistently generated through overexpression of the four Yamanaka Factors OCT4, SOX2, KLF4 and c-MYC (OSKM), reprogrammed cells present worrisome differences with embryonic stem cells in transcriptional and epigenetic profiles, as well as developmental potential and difficulties in cell culturing. A thorough mechanistic understanding of the reprogramming process is critical to overcoming these barriers to the clinical use of iPSC. We have recently published a novel factor combination based on molecules specifically enriched in the metaphase II human oocyte. We have shown that just the overexpression of histone-remodeling chaperone ASF1A and OCT4 in hADFs previously exposed to the oocyte-specific paracrine growth factor GDF9 can reprogram hADFs into pluripotent cells (AO9-iPSCs). Our study contributes to the understanding of the molecular pathways governing somatic cell reprogramming. Here we want to go deeper in the reprogramming mechanisms by understanding the importance of somatic cell origin, and analyzing (and establishing comparison with) the transcriptional and epigenetic characteristics of AO9-iPSCs. As the intrinsic histone chaperone activity of ASF1A and our data indicate, these cells could be closer to the embryonic pluripotent state, with less epigenetic memory, better culture properties and differentiation potential.
Analysis of Menstrual Blood Stromal Cells Reveals SOX15 Triggers Oocyte-Based Human Cell Reprogramming.
Sex, Specimen part, Subject
View SamplesLactoferrin is a highly multifunctional protein. Indeed, it is involved in many physiological functions, including regulation of iron absorption and immune responses.
A nutritional supplement containing lactoferrin stimulates the immune system, extends lifespan, and reduces amyloid <i>β</i> peptide toxicity in <i>Caenorhabditis elegans</i>.
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View SamplesCocoa protein content is a very interesting source for isolation of antioxidant bio-peptides, which can be used for the prevention of age-related diseases. We use microarrays to study the global genome expression of C. elegans fed with a peptide (13L) isolated from cocoa.
A cocoa peptide protects Caenorhabditis elegans from oxidative stress and β-amyloid peptide toxicity.
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View SamplesNumerous studies have shown that resistance to oxidative stress is crucial to stay healthy and to reduce the adverse effects of aging. Accordingly, nutritional interventions using antioxidant food-grade compounds or food products are currently an interesting option to help improve health and quality of life in the elderly. Live lactic acid bacteria (LAB) administered in food, such as probiotics, may be good antioxidant candidates. Nevertheless, information about LAB-induced oxidative stress protection is scarce. To identify and characterize new potential antioxidant probiotic strains, we have developed a new functional screening method using the nematode Caenorhabditis elegans as host. C. elegans were fed on different LAB strains (78 in total) and nematode viability was assessed after oxidative stress (3mM and 5mM H2O2). One strain, identified as Lactobacillus rhamnosus CNCM I-3690, protected worms by increasing their viability by 30% and, also, increased average worm lifespan by 20%. We performed a transcriptomic analysis of C. elegans fed with this strain and showed that increased lifespan is correlated with differential expression of the DAF-16/insulin-like pathway, which is highly conserved in humans.
Anti-inflammatory Lactobacillus rhamnosus CNCM I-3690 strain protects against oxidative stress and increases lifespan in Caenorhabditis elegans.
Time
View SamplesGamma oscillations (20-50Hz) are a common local field potential signature in many brain regions that are generated by a resonant circuit between fast-spiking parvalbumin (PV)-positive interneurons and pyramidal cells. Changes in the magnitude and frequency of gamma have been observed in several neuropsychiatric disorders. However, it is unclear how disruptions in gamma oscillations affect cellular pathologies seen in these disorders. Here, we investigate this using the 5XFAD mouse model of Alzheimer’s disease (AD) and find reduced power and magnitude of behaviorally driven gamma oscillatory activity — even before the onset of plaque formation or measurable cognitive decline. Because of the early onset, we aimed to determine if exogenous manipulations of gamma could influence the progression of disease pathology. We find that driving PV-positive neurons at gamma frequency (40Hz) using channelrhodopsin-2 reduced total levels of amyloid-ß (Aß) 40 and 42 isoforms in the hippocampus of 5XFAD mouse. Driving PV-positive neurons at other frequencies, or driving excitatory neurons, did not reduce Aß levels. Furthermore, driving PV-positive neurons reduced enlarged endosomes in hippocampal neurons and cleavage intermediates of APP in 5XFAD mouse. Gene expression profiling revealed a neuroprotective response with morphological transformation of microglia and markedly increased phagocytosis of Aß by microglia. Inspired by these observations, we designed a non-invasive light-flickering paradigm that drives 40Hz gamma activity in mouse visual cortex. The light-flickering paradigm profoundly reduced Aß40 and Aß42 levels in the visual cortex of pre-symptomatic mice and greatly mitigated plaque load in the visual cortex of aged, symptomatic mice. This reduction was completely blocked by a GABA-A antagonist, providing further support for an essential role of GABAergic signaling in mediating neuroprotective gamma activity. Overall, our findings uncover a dramatic and previously unappreciated function of the brain’s endogenous gamma rhythms in reducing the production and increasing the clearance of Aß peptides, whose accumulation is believed to drive the pathogenesis of AD. Overall design: Two to four weeks following virus injection and implant placement, hippocampal CA1 neurons were optigenetically manipulated. During the experiment, 1mW of optical stimulation was delivered for 1h using a 40Hz stimulation protocol.
Gamma frequency entrainment attenuates amyloid load and modifies microglia.
Age, Specimen part, Cell line, Subject
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Mutant human embryonic stem cells reveal neurite and synapse formation defects in type 1 myotonic dystrophy.
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View SamplesAnalysis of genes that were differentially expressed in mutant VUB03_DM1 as compared to controls VUB01 and SA01 Neural Precursor cells
Mutant human embryonic stem cells reveal neurite and synapse formation defects in type 1 myotonic dystrophy.
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View SamplesAnalysis of genes that were differentially expressed in mutant VUB03_DM1 as compared to controls VUB01 and SA01 undifferentiated hES cells
Mutant human embryonic stem cells reveal neurite and synapse formation defects in type 1 myotonic dystrophy.
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View SamplesAnalysis of genes that were differentially expressed in mutant VUB03_DM1 as compared to controls VUB01 and SA01 Mesodermal Precursors Cells.
Mutant human embryonic stem cells reveal neurite and synapse formation defects in type 1 myotonic dystrophy.
No sample metadata fields
View SamplesHere we propose the direct conversion of human somatic cells into naive induced pluripotent cells (niPSC). Dataset: 7 expanded niPSC lines (4 from BJ cells, 1 from HFF-1, 1 from WI38, 1from IMR90), 1 freshly-isolated primary colonies of niPSC from BJ, 1 established naive embryonic line H9, 1 primed induced pluripotent cell line (from BJ), 1 sample of BJ fibroblasts, 1 sample of WI38 fibroblasts, 1 sample IMR90 fibroblasts.
Direct generation of human naive induced pluripotent stem cells from somatic cells in microfluidics.
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