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.
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View SamplesSatellite cells are the primary source of stem cells for skeletal muscle growth and regeneration. Since adult stem cell maintenance involves a fine balance between intrinsic and extrinsic mechanisms, we performed genome-wide chronological expression profiling to identify the transcriptomic changes involved in acquisition of muscle stem cell characteristics.
Gene Expression Profiling of Muscle Stem Cells Identifies Novel Regulators of Postnatal Myogenesis.
Age, Specimen part
View SamplesWe report gene expression data for the human cell lines HL-60 and PLB-985, which serve as models for human neutrophils. We measured gene expression using RNA-Seq for these cell lines both prior and after differentiation into a neutrophil-like state using two differentiation protocols (treatment with DMSO or treatment with DMSO and replacement of serum with Nutridoma). Overall design: HL-60 and PLB-985 cells grown in culture were processed for RNA-Seq both before and after differentiation for six days in media supplemented with 1.3% dimethyl sulfoxide (DMSO). The cell lines were also analyzed after differentiation for six days in media with 1.3% DMSO, reduced serum (0.5% FBS), and Nutridoma-CS (2%). PLB-985 cells were also analyzed at intermediate time points of 2 days and 4 days with the Nutridoma protocol.
A map of gene expression in neutrophil-like cell lines.
Cell line, Subject
View SamplesRetinoic acid (RA), the main active vitamin A metabolite, controls multiple biological processes such as cell proliferation and differentiation through genomic programs and kinase cascades activation. Several breast cancer cells respond to the antiproliferative effects of RA, but others are RA-resistant. In several cases resistance has been correlated to the amplification of the erb-b2 receptor tyrosine kinase 2 (ERBB2) gene, but the overall signaling and transcriptional pathways that are altered in such cells have not been elucidated. Here we compared two human breast cancer cell lines, the MCF7 cell line, which responds to the antiproliferative action of RA and the BT474 cell line, which is RA-resistant subsequent to ERBB2 amplification in a large-scale analysis of the phosphoproteins and in a genome-wide analysis of the RA-regulated genes. Using high-resolution nano-LC-LTQ-Orbitrap mass spectrometry associated to phosphopeptide enrichment, we found that several proteins involved in signaling and in transcription, are differentially phosphorylated after RA addition. The paradigm of these proteins is the RA receptor a (RARa), which was phosphorylated in MCF7 cells but not in BT474 cells. The panel of the RA-regulated genes was also different. Overall our results indicate that ERBB2 amplification interferes with the ability of RA to activate kinases with consequences on the phosphorylation of several proteins involved in transcription and thus on gene expression. Overall design: Two human breast cancer cell lines were compared for their repertoire of genes regulated by retinoic acid (RA): the RA sensitive MCF7 cell line and the RA resistant B7474 cell line
Phosphoproteome and Transcriptome of RA-Responsive and RA-Resistant Breast Cancer Cell Lines.
Specimen part, Cell line, Treatment, Subject
View SamplesMyelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic stem cell diseases characterized by dysplasia of one or more hematologic lineages and a high-risk of developing acute myeloid leukemia (AML). MDS patients have recurrent bacterial infections and abnormal expression of CD56 by monocytes. We investigated MDS patients’ bone marrow CD56+/CD56- monocytes and their in vitro derived dendritic cell (DCs) populations in comparison to cells obtained from disease-free subjects. We found that monocytes from MDS patients, irrespective of CD56 expression, have reduced phagocytosis activity and low expression of genes involved in triggering immune responses, regulation of immune and inflammatory response signaling pathways, and in the response to lipopolysaccharide. Dendritic cells (DCs) derived in vitro from MDS monocytes failed to develop dendritic projections and had reduced expression of HLA-DR and CD86 suggesting that antigen processing and T cell activation capabilities are impaired. In conclusion, we identified in both CD56+ and CD56- monocytes from MDS-patients several abnormalities that may be related to the increased susceptibility to infections observed in these patients.
Bone Marrow Monocytes and Derived Dendritic Cells from Myelodysplastic Patients Have Functional Abnormalities Associated with Defective Response to Bacterial Infection.
Specimen part, Disease
View SamplesFusarium head blight (FHB) is a major disease of cereal crops caused by the fungus Fusarium graminearum (Fg). FHB affects the flowering heads (or spikes) and developing seeds. This study compare the gene expression profile in wheat spikelets (spk 2) inoculated with either water (mock treatment) or a pathogenic strain of Fusarium graminearum (WT); spikelets 2 were inoculated 24 hrs after a neighbour spikelet (spk 0) was treated with either water or F. graminerum mutant strain Tri6 or NoxAB. Spikelets 2 were sampled 8 and 24 hrs after the second treatment.
Components of priming-induced resistance to Fusarium head blight in wheat revealed by two distinct mutants of Fusarium graminearum.
Specimen part
View SamplesIn this experiment, we sought to analyze how the transcriptome of WT, ?5|6, and ?5|6:7|9 cells vary during differentiation of ESCs into cervical motor neurons Overall design: 3 lines (WT, ?5|6, ?5|6:7|9)
CTCF establishes discrete functional chromatin domains at the Hox clusters during differentiation.
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View SamplesSweat glands are abundant glands of our body and essential for thermoregulation. Like mammary glands, they originate from epidermal progenitors. However, they display few signs of cellular turnover, and whether they have stem cells and tissue regenerative capacity remain largely unexplored. Here we address these issues. Using lineage-tracing, we identify multipotent progenitors in sweat duct that transition to unipotency after developing the sweat gland. In characterizing four adult stem cell populations of glandular skin, we show that they display distinct regenerative capabilities and remain unipotent when healing epidermal, myoepithelial-specific and luminal-specific injuries. We devise purification schemes, isolate and transcriptionally profile progenitors. Exploiting molecular differences between sweat and mammary glands, we show that only some progenitors regain multipotency to produce de novo ductal and glandular structures, but that these can retain their identity even within certain foreign microenvironments. Our findings provide new concepts about glandular stem cells and sweat gland biology.
Identification of stem cell populations in sweat glands and ducts reveals roles in homeostasis and wound repair.
Sex, Specimen part
View SamplesCre recombinase-mediated conditional knockout of floxed Dicer1 alleles causes depletion of small RNAs including microRNAs, which function to repress target mRNA expression by inhibiting translation and/or stimulating mRNA degradation.
MicroRNA-183 family expression in hair cell development and requirement of microRNAs for hair cell maintenance and survival.
Specimen part
View SamplesMYC is a major oncogenic driver of Multiple Myeloma (MM) and yet almost no therapeutic agents exist that target MYC in MM. Here we report that the let-7 biogenesis inhibitor LIN28B correlates with MYC expression in MM and is associated with adverse outcome. We also demonstrate that the LIN28B/let-7 axis modulates the expression of MYC, itself a let-7 target. Further, perturbation of the axis regulates the proliferation of MM cells in vivo in a xenograft tumor model. RNA sequencing and gene set enrichment analyses of CRISPR-engineered cells further suggest that the LIN28/let-7 axis regulates MYC and cell cycle pathways in MM. We provide proof-of-principle for therapeutic regulation of MYC through let-7 with an LNA-GapmeR containing a let-7b mimic in vivo, demonstrating that high levels of let-7 expression repress tumor growth by regulating MYC expression. These findings reveal a novel mechanism of therapeutic targeting of MYC through the LIN28B/let-7 axis in MM that may impact other MYC dependent cancers as well. Overall design: RNA sequencing of MOLP-8 cells transduced with lentiCRISPRv2 scrambled control or containing a sgRNA against LIN28B. Both control and LIN28B KO cells were sequenced in triplicate.
The LIN28B/let-7 axis is a novel therapeutic pathway in multiple myeloma.
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