Human pluripotent stem cells are a promising source of diverse cells for developmental studies, cell transplantation, disease modeling, and drug testing. However, their widespread use even for intensely studied cell types like spinal motor neurons, is hindered by the long duration and low yields of existing protocols for in vitro differentiation and by the molecular heterogeneity of the populations generated. We report a combination of small molecules that induce up to 50% motor neurons within 3 weeks from human pluripotent stem cells with defined subtype identities that are relevant to neurodegenerative diseases. Despite their accelerated differentiation, motor neurons expressed combinations of HB9, ISL1 and column-specific markers that mirror those observed in vivo in human fetal spinal cord. They also exhibited spontaneous and induced activity, and projected axons towards muscles when grafted into developing chick spinal cord. Strikingly, this novel protocol preferentially generates motor neurons expressing markers of limb-innervating lateral motor column motor neurons (FOXP1+/LHX3-). Access to high-yield cultures of human limb-innervating motor neuron subtypes will facilitate in-depth study of motor neuron subtype-specific properties, disease modeling, and development of large-scale cell-based screening assays. Overall design: We analyzed 3 samples including 2 positive samples and 1 negative sample. Descriptions are as follows: a) Positive Sample 1: SHH-derived, day 21 GFP-high FACS-purified motor neurons. b) Positive Sample 2: S+P-derived, day 21 GFP-high FACS-purified motor neurons. c) Negative: S+P condition, day 21 GFP-off FACS-purified non-motor neurons. Initial analysis of data was performed on ~40% of fastq reads (Amoroso et al., J Neurosci 2013 Jan 9;33(2):574-86. PMID: 23303937). Further processing of the full dataset has since been carried out and the updated rpkm file and expression analysis reflecting all aligned reads can be accessed at: http://scholar.harvard.edu/amorosornaseq/
Accelerated high-yield generation of limb-innervating motor neurons from human stem cells.
Specimen part, Cell line, Treatment, Subject
View SamplesThe microbial population that live within the gut of animals influences their physiology. We used axenic and recolonized flies to identify genes whose expression is modulated by the presence of a bacterial flora in the gut.
Drosophila microbiota modulates host metabolic gene expression via IMD/NF-κB signaling.
Specimen part, Treatment
View SamplesDentatorubral-pallidoluysian Atrophy (DRPLA) is a human polyQ disease caused by the expansion of a CAG strech in the atrophin-1 (at-1) gene. In all vertebrates, a second atrophin gene (at-2) is present and it encodes a related protein void of polyQ tracks. In D.melanogaster there is one conserved Atrophin (Atro) gene, ubiquitously expressed, which contains all functional domains of vertebrate Atrophins, including two polyQ stretches. To understand to what extent transcriptional alterations cause neurodegeneration and are linked to the normal functions of Atrophin, we performed a genome wide transcriptional profiling in our Drosophila models, focusing on primary events that precede neurodegeneration.
Polyglutamine Atrophin provokes neurodegeneration in Drosophila by repressing fat.
No sample metadata fields
View SamplesInvasion of lymphatic vessels is a key step in the metastasis of primary tumour cells to draining lymph nodes. Recent evidence indicates that such metastasis can be facilitated by tumour lymphangiogenesis, although it remains unclear whether this is a consequence of increased lymphatic vessel numbers or alteration in the properties of the vessels themselves. Here we have addressed this important question by comparing the RNA profile of normal dermal lymphatic endothelial cells (LEC) with those isolated from tumours of murine T-241/VEGF-C metastatic fibrosarcoma. Our findings reveal significant changes in the expression of some 792 genes in tumour lymphatics ( 2 fold up/downregulation, p 0.05), involving particularly transcripts associated with junctional adhesion, immunomodulation, extracellular matrix and vessel growth/patterning, several of which we have confirmed by RT-PCR and/or immunohistochemistry. Interestingly, this altered phenotype could not be attributed solely to VEGF-C induced lymphoproliferation, as no similar change in gene expression was reported when human LEC were cultured with VEGF-C in vitro. Moreover, we show that a key protein upregulated in the mouse model, namely the tight junction protein Endothelial Cell Specific Adhesion Molecule (ESAM), is similarly upregulated in tumour lymphatic vessels from 2/2 patients with head and neck squamous cell carcinoma and 4/4 patients with aggressive bladder carcinoma. These findings demonstrate a previously unrecognized influence of tumour environment on lymphatic gene expression and identify candidate tumour specific vessel markers that may prove valuable for either prognosis or therapy.
A novel gene expression profile in lymphatics associated with tumor growth and nodal metastasis.
No sample metadata fields
View SamplesTo elucidate the mechanisms by which the mir-200 and the miR-183~96~182 cluster could regulate EMT and thus cellular migration, invasion and metastasis in NSCLC, we searched for common predicted targets of these microRNA families that might have a potential role in these biological processes. First we performed a cross comparison of multiple gene expression datasets from our mouse models of metastasis. We overlapped 224 genes that were elevated greater than four-folds upon Zeb1 induction in 393P cells with 210 genes that showed greater than two-fold increase in expression in the metastatic 344SQ cells compared to the non-metastatic 393P cells and 143 genes that were repressed to less than 0.5-fold in cells with exogenous expression of miR-200. This resulted in an enriched list of 45 genes that are potential miR-200 targets having a role in the process of EMT and metastasis. Next we performed an overlap of genes that were predicted targets of the miR-200 family members and the miR-183~96~182 cluster using the microRNA prediction algorithms miRanda (www.microRNA.org) and identified a list of 17 highly conserved common targets with a mirSVR score less than -6.0. The only 2 genes common in both the overlapping subsets were Zeb1 and Foxf2.
The miR-200 family and the miR-183~96~182 cluster target Foxf2 to inhibit invasion and metastasis in lung cancers.
Cell line, Treatment
View SamplesEpithelial-neuronal signaling is essential for sensory encoding in touch, itch and nociception; however, little is known about the release mechanisms and neurotransmitter receptors through which skin cells govern neuronal excitability. Merkel cells are mechanosensory epidermal cells that have long been proposed to activate neuronal afferents through chemical synaptic transmission. We employed a set of classical criteria for chemical neurotransmission as framework to directly test this hypothesis. RNA sequencing of adult Merkel cells demonstrated that they express presynaptic molecules and biosynthetic machinery for adrenergic transmission. Moreover, live-cell imaging directly demonstrated that Merkel cells mediate activity- and VMAT-dependent release of fluorescent catecholamine neurotransmitter analogues. Touch-evoked firing in Merkel-cell afferents was inhibited either by pre-synaptic silencing of SNARE-mediated vesicle release from Merkel cells or by neuronal deletion of b2-adrenergic receptors. Together, these results identify both pre- and postsynaptic mechanisms through which Merkel cells excite mechanosensory afferents to encode gentle touch. Overall design: RNA-seq of basal keratinocytes and Merkel cells purified with FACS
Merkel Cells Activate Sensory Neural Pathways through Adrenergic Synapses.
Sex, Specimen part, Cell line, Subject
View SamplesIdentification of genes and pathways relevant to Cervical cancer pathogenesis. The study also aimed at identifying probable mechanistic differences in the low and high HOTAIR expressing cervical cancers patients .
Bridging Links between Long Noncoding RNA HOTAIR and HPV Oncoprotein E7 in Cervical Cancer Pathogenesis.
Age, Specimen part
View SamplesThe nuclear receptor PPARalpha is recognized as the primary target of the fibrate class of hypolipidemic drugs and mediates lipid lowering in part by activating a transcriptional cascade that induces genes involved in the catabolism of lipids. We report here the characterization of three novel PPARalpha agonists with therapeutic potential for treating dyslipidemia. These structurally related compounds display potent and selective binding to human PPARalpha and support robust recruitment of coactivator peptides in vitro. These compounds markedly potentiate chimeric transcription systems in cell-based assays and strikingly lower serum triglycerides in vivo. The transcription networks induced by these selective PPARalpha agonists were assessed by transcriptional profiling of mouse liver after acute and chronic treatment. The induction of several known PPARalpha target genes involved with fatty acid metabolism were observed, reflecting the expected pharmacology associated with PPARalpha activation. We also noted the downregulation of a number of genes related to immune cell function, the acute phase response, and glucose metabolism; suggesting that these compounds may have anti-inflammatory action in the mammalian liver. Taken together, these studies articulate the therapeutic promise of a selective PPARalpha agonist.
Molecular characterization of novel and selective peroxisome proliferator-activated receptor alpha agonists with robust hypolipidemic activity in vivo.
No sample metadata fields
View SamplesMitogen-activated protein kinase kinase 4 (MKK4) is a dual-specificity kinase activated by environmental stress, cytokines, and peptide growth factors that reportedly can promote or inhibit tumor cell growth and metastasis. Somatic mutations in the gene encoding MKK4 (MAP2K4) have been identified in various human cancers, but the consequences of these mutations on MKK4 function and the biology of tumor cells that have them have not been elucidated. Here we report that, of the eleven mutations within the MAP2K kinase domain described thus far, one had gain-of-function (Q142L) and six had loss-of-function. Three of the loss-of-function mutations are nonsense mutations that produced C-terminally-truncated proteins (I295fs*23, R304*, and W310*) that were highly ubiqitinated and rapidly degraded when introduced into cells, and three are missense mutations in the ATP-binding pocket (N234I), activation loop (S251N), or C-lobe (P326L). We modeled the consequences of MAP2K4 loss-of-function mutations on cells by introducing MKK4 short-hairpin RNA constructs and found that MKK4 depletion enhanced the ability of a weakly tumorigenic murine cancer cell to metastasize when injected into syngeneic mice but had no effect on primary tumor formation. MKK4-depleted cells exhibited an increased capacity to migrate across PET filters and to invade through matrigel but no change in anchorage-dependent or -independent proliferation. Transcriptional profiling of these cells revealed gene expression changes that promote epithelial-to-mesenchymal transition and angiogenesis. We conclude that MKK4 inactivation promoted metastasis but not primary tumor formation. Collectively, these findings implicate loss-of-function MAP2K4 somatic mutations in tumor metastasis and provide one of the few examples of a somatic mutation in cancer cells that exerts a metastasis-specific effect.
Map2k4 functions as a tumor suppressor in lung adenocarcinoma and inhibits tumor cell invasion by decreasing peroxisome proliferator-activated receptor γ2 expression.
Specimen part, Cell line
View SamplesHIV-1 and HIV-2 can both infect humans, but HIV-2 causes a slow progressing disease and is well controlled by the immune system for prolonged period of times.
HIV-1 and HIV-2 differentially mature plasmacytoid dendritic cells into IFN-producing cells or APCs.
Treatment, Subject, Time
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