Integrity of the cornea, the most anterior part of the eye is indispensable for vision. 45 million individuals are bilaterally blind and another 135 millions have severely impaired vision in both eyes because of loss of corneal transparency; treatments range from local medications to corneal transplants and more recently to stem cell therapy. The corneal epithelium is a squamous epithelium that is constantly renewing with a vertical turnover of seven to fourteen days in many mammals3. Identification of slow cycling cells (label-retaining cells or LRCs) in the limbus of the mouse has led to the notion that the limbus is the niche for the stem cells responsible for the long-term renewal of the cornea4; hence, the corneal epithelium is supposedly renewed by cells generated at and migrating from the limbus, in striking opposition to other squamous epithelia in which each resident stem cell has in charge a limited area of epithelium. Here, we show that the corneal epithelium of the mouse can be serially transplanted, is self-maintained and contains oligopotent stem cells with the capacity to generate goblet cells if provided with a conjunctival environment. In addition, the entire ocular surface of the pig, including the cornea, contains oligopotent stem cells (holoclones) with the capacity to generate individual colonies of corneal and conjunctival cells; hence, the limbus is not the only niche for corneal stem cells and corneal renewal is not different from other squamous epithelia.
Oligopotent stem cells are distributed throughout the mammalian ocular surface.
No sample metadata fields
View SamplesThymic epithelial cells (TECs) are essential for thymopoiesis and form a complex three-dimensional network, the organization of which is strikingly different from other epithelia. Interestingly, TECs express simple epithelia keratins in the cortex, stratified epithelia keratins in the medulla and epidermal differentiation markers in Hassall's bodies. Here we investigate the relationship between thymic epithelium and epidermal differentiation and show that the thymus of the rat contains a population of clonogenic TECs that can be extensively cultured and cloned using conditions developed for epidermal cell therapy in human. Clonogenic TECs conserve a thymic identity and the capacity to integrate in a thymic epithelial network, but they acquire new functionalities when exposed to an inductive skin microenvironment, permanently adopting the fate of hair follicle multipotent stem cells. This change in fate, maintained over time in serial transplantation, correlates with a down-regulation of transcription factors important for thymic identity, and an up-regulation of epidermal markers. Consequently, the TECs capacity to integrate in a thymic epithelial network is altered or even lost. Our results demonstrate that the thymus contains a population of holoclone-like epithelial cells that can function as bona fide multipotent keratinocyte stem cells, and that microenvironmental cues are sufficient to re-direct epithelial-cell fate, allowing crossing of primitive germ layer boundaries from endoderm to ectoderm.
Microenvironmental reprogramming of thymic epithelial cells to skin multipotent stem cells.
No sample metadata fields
View SamplesThe development of CRISPR-Cas systems for targeting DNA and RNA in diverse organisms has transformed biotechnology and biological research. Moreover, the CRISPR revolution has highlighted bacterial adaptive immune systems as a rich and largely unexplored frontier for discovery of new genome engineering technologies. In particular, the class 2 CRISPR-Cas systems, which use single RNA-guided DNA-targeting nucleases such as Cas9, have been widely applied for targeting DNA sequences in eukaryotic genomes. Here, we report DNA-targeting and transcriptional control with class I CRISPR-Cas systems. Specifically, we repurpose the effector complex from type I variants of class 1 CRISPR-Cas systems, the most prevalent CRISPR loci in nature, that target DNA via a multi-component RNA-guided complex termed Cascade. We validate Cascade expression, complex formation, and nuclear localization in human cells and demonstrate programmable CRISPR RNA (crRNA)-mediated targeting of specific loci in the human genome. By tethering transactivation domains to Cascade, we modulate the expression of targeted chromosomal genes in both human cells and plants. This study expands the toolbox for engineering eukaryotic genomes and establishes Cascade as a novel CRISPR-based technology for targeted eukaryotic gene regulation. Overall design: Examination of transcriptome-wide changes in gene expression with Cascade-mediated activation of endogenous genes.
Targeted transcriptional modulation with type I CRISPR-Cas systems in human cells.
Specimen part, Cell line, Subject
View SamplesBovine papillomavirus (BPV) is the causative agent of papillomatosis in cattle. The disease causes cutaneous and mucosal lesions that can be minimized or lead to the appearance of malignant tumors. This study aims to identify possible molecular mechanisms that are behind the pathological processes associated with bovine papillomatosis through the identification of genes related to the development of the lesions. For this, next-generation RNA sequencing was used to assess differentially expressed genes in infected by BPV and non-infected bovines. Three animals with papillomatosis lesion and three without papillomatosis lesion were studied. The Galaxy platform was used to analyze the data generated by the sequencing. The Illumina output files were converted to FASTQ format. Quality evaluation was performed using FastQC and the sequence quality cut was performed using Trimmomatic. TopHat and Bowtie were used to map and align the reads with the reference genome. The abundance of the expressed genes was verified using Cuffilinks. Cuffdiff was used for differential expression analysis. Functional annotation of the differentially expressed genes was performed using Gene Ontology (GO) databases. RNA-sequencing generated a total of 121,722,238 of reads. In the gene expression analysis, a total of 13,421 genes expressed were identified and of these 1343 were differentially expressed. The functional annotation of differentially significant genes showed that many genes presented functions or they were related to metabolic pathways associated with the progression of papillomatosis lesions and cancer development in cattle. Although more studies are needed, this is the first study that focused on a large-scale evaluation of gene expression associated with the BPV infection, which is important to identify possible mechanisms regulated by the host genes that are necessary the development of the lesion Overall design: Analysis of three BPV infected and three BPV non-infected samples
Comparative transcriptomic analysis of bovine papillomatosis.
Age, Specimen part, Treatment, Subject
View SamplesWe have shown that Sox10 plays a crucial role in the initiation and maintenance of giant congenital nevi and melanoma in a mouse model of melanoma.To dissect the molecular mechanisms and analyze the role of SOX10 in the maintenance of human melanoma, we have performed microarray study.
Sox10 promotes the formation and maintenance of giant congenital naevi and melanoma.
Cell line, Treatment, Time
View SamplesThe global prevalence of obesity is increasing across age and gender. The rising burden of obesity in young people contributes to the early emergence of type 2 diabetes. Having one parent obese is an independent risk factor for childhood obesity. While the detrimental impact of diet-induced maternal obesity on offspring is well established, the extent of the contribution of obese fathers is unclear, as is the role of non-genetic factors in the casual pathway. Here we show that paternal high fat diet exposure programmed -cell dysfunction in their F1 female offspring. Chronic high fat diet consumption in Sprague Dawley fathers led to increased body weight, adiposity, impaired glucose tolerance and insulin sensitivity. Relative to controls, their female offspring had lower body weight at day-1, increased pubertal growth rate, impaired insulin secretion and glucose tolerance, in the absence of obesity or increased adiposity. Paternal high fat diet was observed to alter gene expression of pancreatic islet genes in adult female offspring (P < 0.001); affected functional clusters includes calcium ion binding, insulin, apoptosis, Wnt and cell cycle organ/system development. This is the first reported study in mammals describing non-genetic, intergenerational transmission of metabolic sequelae of high fat diet from father to offspring. These findings support a role of fathers in metabolic programming of offspring and form a framework for further studies.
Chronic high-fat diet in fathers programs β-cell dysfunction in female rat offspring.
Sex
View SamplesReactive astrogliosis is characterized by a profound change in astrocyte phenotype in response to all CNS injuries and diseases. To better understand the reactive astrocyte state, we used Affymetrix GeneChip arrays to profile gene expression in populations of reactive astrocytes isolated at various time points after induction using two different mouse injury models, ischemic stroke and neuroinflammation.
Genomic analysis of reactive astrogliosis.
Sex, Specimen part, Treatment
View SamplesAnalyses of gene expression by RNA-Seq in mouse E14.5 fetal liver burst-forming unit erythroid (BFU-E) cells untreated or treated by dexamethasone (DEX) with or without PPARa agonist GW7647. Overall design: RNA-Seq was performed on enriched populations of mouse BFU-E isolated from E14.5 fetal liver, as well as BFU-E enriched cells treated with Dex ± GW7647.
PPAR-α and glucocorticoid receptor synergize to promote erythroid progenitor self-renewal.
No sample metadata fields
View Samplessingle cell RNA sequencing of freshly isolated mouse BFU-E (burst forming unit-erythroid ) cells cultured for 1, 2, or 3 days with and without 100nM dexamethasone Overall design: six 96 well plates
Rate of Progression through a Continuum of Transit-Amplifying Progenitor Cell States Regulates Blood Cell Production.
Specimen part, Cell line, Treatment, Subject
View SamplesSingle cell RNA sequencing of freshly isolated mouse burst forming unit-erythroid (BFU-E) , colony forming unit-erythroid (CFU-E), and intermediate stages of erythroid development cells. Overall design: One 96 well plate with 24 BFU-E, 24 CFU-E, 24 cells with 25-35% expression of CD71/CD24, and 24 cells with 50-60% expression of CD71/CD24.
Rate of Progression through a Continuum of Transit-Amplifying Progenitor Cell States Regulates Blood Cell Production.
Specimen part, Cell line, Subject
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