FCRL4 is an immunoregulatory receptor that belongs to the Fc receptor-like (FCRL) family. In healthy individuals, this protein is specifically expressed by memory B cells (MBCs) and is preferentially localized in subephitelial regions of lymphoid tissues. An expansion of FCRL4+ B cells has been shown in blood or other tissues in various infectious or autoimmune pathologies. In the present work, we generated and characterized in vitro FCRL4+ B cells from purified MBCs using T-dependent and/or T-independent stimulation. FCRL4+ B cells account for 17% of cells generated at day-4 of culture. Transcriptomic and phenotypic analysis of FCRL4+ cells show that they are closely related to FCRL4+ tonsillar MBCs. Interestingly, these cells highly express inhibitory receptors genes as described for exhausted FCRL4+ MBCs in the blood of HIV-viremic individuals. In agreement, in vitro generated FCRL4+ B cells show a significant underexpression of cell cycle genes with a two fold weaker number of cell division compared to FCRL4- cells. Finally, resulting from their reduced proliferation and differentiation potential, we show that FCRL4+ cells are not prone to generate plasma cells, contrary to FCRL4- cells. Given the difficulty to access to in vivo FCRL4+ cells, our in vitro model could be of major interest to study the biology of normal and pathological FCRL4+ cells.
Characterization of human FCRL4-positive B cells.
Specimen part
View SamplesDifferentiation of human skeletal stem cells (hMSC) into osteoblasts is regulated by a few well described transcription factors. Our study used clustering and gene expression data to identify a novel transcription factor. ZNF25, which we showed is involved in osteoblast differentiation.
Transcription factor ZNF25 is associated with osteoblast differentiation of human skeletal stem cells.
Cell line
View SamplesDirecting differentiation of human embryonic stem cells (hESC) into specific cell types using an easy and reproducible protocol is a perquisite for the clinical use of hESC in regenerative medicine protocols. Here, we report the generation of mesodermal cells with differentiation potential to myocytes, osteoblasts, chondrocytes and adipocytes. We demonstrate that during hESC differentiation as embryoid bodies (EB), inhibition of TGF-b/Activin/Nodal signaling using SB-431542 (SB) markedly up-regulated paraxial mesodermal markers (TBX6, TBX5), early myogenic transcriptional factors (Myf5, Pax7) as well as myocyte committed markers (NCAM, CD34, Desmin, MHC (fast), alpha-smooth muscle actin, Nkx2.5, cTNT). Establishing EB outgrowth cultures (SB-OG) in the presence of SB (1 uM) led to further enrichment of cells expressing markers for myocyte progenitor cell: CD34+ (33%), NCAM+ (CD56) (73%), PAX7 (25%) and mature myocyte proteins (MYOD1, tropomyocin, fast MHC an
Enhanced differentiation of human embryonic stem cells to mesenchymal progenitors by inhibition of TGF-beta/activin/nodal signaling using SB-431542.
Cell line
View SamplesBackground: The ability of an organism to repair damages to DNA is inextricably linked to aging and cancer. We have characterized and compared the transcriptome of C. elegans mutants deficient in DNA base excision repair, nucleotide excision repair or both to elucidate the transcriptional changes incurred by the reduction of these repair pathways.
A two-tiered compensatory response to loss of DNA repair modulates aging and stress response pathways.
No sample metadata fields
View SamplesPurpose: Diffuse large B cell lymphomas (DLBCL) frequently harbor mutations in the histone acetyltransferase CREBBP, however their functional contribution to lymphomagenesis remains largely unknown. This study aims at elucidating and characterizing the molecular pathways affected by mutations in CREBBP. Methods: U2932, a DLBCL cell line that has wild type expression of CREBBP was manipulated by CRISPR-Cas9 strategy to mutate one allele of CREBBP and examine the pathways affected. RNA was isolated using the NucleoSping RNA Kit (Macherey-Nagel) from five wild type (CREBBP+/+) and five heterozygous clones (CREBBP+/-). RNA quality was assessed by Bioanalyzer 2100 followed by library preparation using the TruSeq RNA Sample Prep Kit v4 (Illumina). Sequencing was subsequently performed on the Illumina HiSeq 2500 instrument. RNA-seq reads were quality-checked with fastqc, which computes various quality metrics for the raw reads. RNA-seq reads were mapped to the GRCh38 reference human genome using STAR and reads were counted according to Ensembl gene annotation using the featureCounts function in the Rsubread Bioconductor package. Statistical analysis of differential expression was conducted with the DESeq2 package. Overall design: Trascriptomic profiles of CREBBP+/+ and CREBBP+/- clones were generated by deep sequencing.
Inactivation of CREBBP expands the germinal center B cell compartment, down-regulates MHCII expression and promotes DLBCL growth.
Subject
View SamplesBackground: The terminal duct lobular unit (TDLU) is the most dynamic structure in the human breast and the putative site of origin of human breast cancer. Although stromal cells contribute to a specialized microenvironment in many organs, this component remains largely understudied in the human breast. We here demonstrate the impact on epithelium of two lineages of breast stromal fibroblasts, one of which accumulates in the TDLU while the other resides outside the TDLU in the interlobular stroma. Methods: The two lineages are prospectively isolated by FACS based on different expression levels of CD105 and CD26. The characteristics of the two fibroblast lineages are assessed by immunocytochemical staining and gene expression analysis. The differentiation capacity of the two fibroblast populations is determined by exposure to specific differentiating conditions followed by analysis of adipogenic and osteogenic differentiation. To test whether the two fibroblast lineages are functionally imprinted by their site of origin, single cell sorted CD271low/MUC1high normal breast luminal epithelial cells are plated on fibroblast feeders for the observation of morphological development. Epithelial structure formation and polarization is shown by immunofluorescence and digitalized quantification of immunoperoxidase stained cultures. Results: Lobular fibroblasts are CD105high/CD26low while interlobular fibroblasts are CD105low/CD26high. Once isolated the two lineages remain phenotypically stable and functionally distinct in culture. Lobular fibroblasts have properties in common with bone marrow derived mesenchymal stem cells and they specifically convey growth and branching morphogenesis of epithelial progenitors. Conclusions: Two distinct functionally specialized fibroblast lineages exist in the normal human breast, of which the lobular fibroblasts have properties in common with mesenchymal stem cells and support epithelial growth and morphogenesis. We propose that lobular fibroblasts constitute a specialized microenvironment for human breast luminal epithelial progenitors, i.e. the putative precursors of breast cancer.
Evidence of two distinct functionally specialized fibroblast lineages in breast stroma.
Specimen part
View SamplesThe nematode Caenorhabditis elegans has been used extensively to study responses to DNA damage. In contrast, little is known about DNA repair in this organism. C. elegans is unusual in that it encodes few DNA glycosylases and the uracil-DNA glycosylase (UDG) encoded by the ung-1 gene is the only known UDG. C. elegans could therefore become a valuable model organism for studies of the genetic interaction networks involving base excision repair (BER). As a first step towards characterization of BER in C. elegans, we show that the UNG-1 protein is an active uracil-DNA glycosylase. We demonstrate that an ung-1 mutant has reduced ability to repair uracil-containing DNA but that an alternative Ugi-inhibited activity is present in ung-1 nuclear extracts. Finally, we demonstrate that ung-1 mutants show altered levels of apoptotic cell corpses formed in response to DNA damaging agents. Increased apoptosis in the ung-1 mutant in response to ionizing radiation (IR) suggests that UNG-1 contributes to repair of IR-induced DNA base damage in vivo. Following treatment with paraquat however, the apoptotic corpse-formation was reduced. Gene expression profiling suggests that this phenotype is a consequence of compensatory transcriptomic shifts that modulate oxidative stress responses in the mutant and not an effect of reduced DNA damage signaling.
Loss of Caenorhabditis elegans UNG-1 uracil-DNA glycosylase affects apoptosis in response to DNA damaging agents.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Defective mitophagy in XPA via PARP-1 hyperactivation and NAD(+)/SIRT1 reduction.
Sex, Cell line, Treatment
View SamplesMitochondrial dysfunction is a common feature in neurodegeneration and aging. We identify mitochondrial dysfunction in xeroderma pigmentosum group A (XPA), a nucleotide excision DNA repair disorder with severe neurodegeneration, in silico and in vivo. XPA deficient cells show defective mitophagy with excessive cleavage of PINK1 and increased mitochondrial membrane potential. The mitochondrial abnormalities appear to be caused by decreased activation of the NAD+-SIRT1-PGC-1 axis triggered by hyperactivation of the DNA damage sensor PARP1. This phenotype is rescued by PARP1 inhibition or by supplementation with NAD+ precursors that also rescue the lifespan defect in xpa-1 nematodes. Importantly, this pathogenesis appears common to ataxia-telangiectasia and Cockayne syndrome, two other DNA repair disorders with neurodegeneration, but absent in XPC, a DNA repair disorder without neurodegeneration. Our findings reveal a novel nuclear-mitochondrial cross-talk that is critical for the maintenance of mitochondrial health.
Defective mitophagy in XPA via PARP-1 hyperactivation and NAD(+)/SIRT1 reduction.
Sex, Treatment
View SamplesThe development of T cells has been characterized as taking place over three stages: nave (Tn), central memory (Tcm), and effector memory (Tem) cells.
Polarization diversity of human CD4+ stem cell memory T cells.
Sex, Age
View Samples