Our understanding of how mesodermal tissue is formed, has been limited by the absence of specific and reliable markers of early mesoderm commitment. We report that mesoderm commitment from human embryonic stem cells (hESC) is initiated by Epithelial to Mesenchymal transition (EMT) as shown by gene expression profiling and by reciprocal changes in expression of the cell surface proteins, EpCAM/CD326 and NCAM/CD56. Molecular and functional assays reveal that CD326negCD56+ cells, generated from hESC in the presence of activin A, BMP4, VEGF and FGF2, represent a novel, multi-potent mesoderm-committed progenitor population. CD326negCD56+ progenitors are unique in their ability to generate all mesodermal lineages including hematopoietic, endothelial, mesenchymal (bone, cartilage, fat, fibroblast), smooth muscle and cardiomyocytes, while lacking the pluripotency of hESC. CD326negCD56+ cells are the precursors of previously reported, more lineage-restricted mesodermal progenitors. These findings present a novel approach to study how germ layer specification is regulated, and offer a unique target for tissue engineering.
Mapping the first stages of mesoderm commitment during differentiation of human embryonic stem cells.
Cell line
View SamplesThe production of definitive haematopoietic stem/progenitor cells from human pluripotent stem cells (hPSCs) remains a significant challenge. Using reporter lines to track the endothelial (SOX17) to haematopoietic (RUNX1C) transition, we found that hPSC differentiated in growth factor supplemented serum free medium generated RUNX1C+CD34+ clonogenic cells that homed to the bone marrow, but did not engraft. Compared to repopulation-competent cord blood CD34+ cells, RUNX1C+CD34+ progenitors lacked HOXA gene expression, indicating incorrect mesoderm patterning. This deficiency was ameliorated by a timed pulse of WNT activation combined with ACTIVIN antagonism. Significantly, these HOXA+ cultures now formed complex SOX17+ vessels that produced fetal liver-like haematopoietic cells, similar to the human aorta-gonad-mesonephros (AGM). Comparison of transcriptional profiles of these nascent haematopoietic stem/progenitors with cells isolated from human AGM confirmed significant similarities, consistent with the assignment of our in vitro generated cells to the definitive human haematopoietic lineage. Our findings argue that HOXA codes established early in differentiation predict cellular potential and provide correct cell patterning for the specification of definitive haematopoietic lineages from hPSCs. Overall design: mRNA profiles of 26 samples were obtained for 5 different cell populations and 2 different treatments.
Differentiation of human embryonic stem cells to HOXA<sup>+</sup> hemogenic vasculature that resembles the aorta-gonad-mesonephros.
Treatment, Subject
View SamplesThis study examines the extent to which memory CD4+ T cells share immunosurveillance strategies with CD8+ resident memory T cells (TRM). After acute viral infection, memory CD4+ T cells predominantly utilized residence to survey nonlymphoid tissues, albeit not as stringently as observed for CD8+ T cells. In contrast, memory CD4+ T cells were more likely to be resident within lymphoid organs than CD8+ T cells. Migration properties of memory-phenotype CD4+ T cells in non-SPF parabionts were similar, generalizing these results to diverse infections and conditions. CD4+ and CD8+ TRM shared overlapping transcriptional signatures and location-specific features, such as granzyme B expression in the small intestine, revealing tissue-specific and migration property-specific, in addition to lineage-specific, differentiation programs. Functionally, mucosal CD4+ TRM reactivation locally triggered both chemokine expression and broad immune cell activation. Thus, residence provides a dominant mechanism for regionalizing CD4+ T cell immunity, and location enforces shared transcriptional, phenotypic, and functional properties with CD8+ T cells. Overall design: 17 samples were analyzed by RNA-Sequencing: 3 replicates of resident memory SMARTA CD4 cells (CD62L- CD69+) from the female reproductive tract (FRT) , 2 replicates of resident memory SMARTA CD4 cells (CD62L- CD69+) from the small intestine epithelium (IEL), 3 replicates of resident memory SMARTA CD4 cells (CD62L- CD69+) small intestine lamina propria (LP), 3 replicates of resident memory SMARTA CD4 cells (CD62L- CD69+) from the spleen (SLO), 3 replicates of SMARTA CD4 cells (CD62L+ CD69- or TCM) from the spleen of mice, and 3 replicates of SMARTA CD4 cells (CD62L- CD69- or TEM) from the spleen of mice infected with LCMV-Armstrong 54 days prior.
CD4<sup>+</sup> resident memory T cells dominate immunosurveillance and orchestrate local recall responses.
Specimen part, Subject
View SamplesDesmin is a cytoskeletal protein in muscle involved in integrating cellular space and transmitting forces. In this study we sought to determine the combinatory effects of desmin deletion, aging and eccentric exercise on skeletal muscle at the transcriptional level across many pathways of muscle physiology.
Role of the cytoskeleton in muscle transcriptional responses to altered use.
Specimen part, Treatment
View SamplesWe identified two isoforms of human MKL1 that differ in their N-terminal domains. Since MKL1 is a transcriptional coactivator of SRF and regulates many SRF target genes, we wanted to analyze if transcription is differentially regulated by the two isoforms upon stimulation of the Rho-actin-MKL1-SRF pathway.
TGF-β-induced differentiation into myofibroblasts involves specific regulation of two MKL1 isoforms.
Cell line
View SamplesImmunosurveillance of secondary lymphoid organs (SLO) is performed by central memory T cells that recirculate through blood. Resident memory T cells (TRM) remain parked in nonlymphoid tissues and often stably express CD69. We recently identified TRM within SLO, and this study addresses knowledge gaps in their origin and phenotype. Parabiosis of dirty mice revealed that CD69 expression is insufficient to infer stable residence. Using selective depletion strategies, parabiosis, imaging, tissue grafting, and photoactivatable T cells, we report that restimulation of TRM within the skin or mucosa results in a substantial increase in TRM that patrol all regions of draining lymph nodes. SLO TRM were derived from nonlymphoid tissue residents. Transcriptional profiling and flow cytometry revealed a refined phenotype shared between both nonlymphoid and SLO TRM. These data demonstrate the nonlymphoid origin of SLO TRM and suggest vaccination strategies by which memory CD8 T cell immunosurveillance can be regionalized to specific lymph nodes.
T Cells in Nonlymphoid Tissues Give Rise to Lymph-Node-Resident Memory T Cells.
Specimen part
View SamplesCyclosporin A induces expression of proapoptotic factors when cells are challenged by increased tonicity
Cyclosporin-A induced toxicity in rat renal collecting duct cells: interference with enhanced hypertonicity induced apoptosis.
Specimen part, Treatment
View SamplesThe Mediator complex is an evolutionary conserved multiprotein complex that plays an essential role in initiating and regulating transcription. Its function is to act as a universal adaptor between RNA Polymerase II and DNA-bound transcription factors to translate regulatory information from activators and repressors to the transcriptional machinery. We have found that the PFT1 gene (which encodes the MED25 subunit of the Mediator complex) is required for the uncompromised expression of both salicylic acid- and jasmonate-dependent defense genes as well as resistance to the leaf-infecting fungal pathogens, Alternaria brassicicola and Botrytis cinerea in Arabidopsis. Surprisingly, we found that the pft1/med25 mutant showed increased resistance to the root infecting pathogen Fusarium oxysporum and that this resistance was independent of classical defense genes. In addition, the over-expression of PFT1 led to increased susceptibility to F. oxysporum. Therefore, to explore this phenomenon further, we wished to use whole genome transcript profiling to identify which genes may be playing a role in pft1/med25-mediated resistance to F. oxysporum.
The mediator complex subunit PFT1 is a key regulator of jasmonate-dependent defense in Arabidopsis.
Specimen part, Treatment
View SamplesIntegration of multiple signals shapes cell adaptation to their microenvironment through synergistic and antagonistic interactions. The combinatorial complexity governing signal integration for multiple cellular output responses has not been resolved. For outputs measured in the conditions 0 (control), signals X, Y, X+Y, combinatorial analysis revealed 82 possible interaction profiles, which we biologically assimilated to 5 positive, and 5 negative interaction modes. To experimentally validate their use in living cells, we designed an original computational workflow, and applied it to transcriptomics data of innate immune cells integrating physiopathological signal combinations. Up to 9 of the 10 defined modes coexisted in context-dependent proportions. Each integration mode was enriched in specific molecular pathways, suggesting a coupling between genes involved in particular functions, and the corresponding mode of integration. We propose that multimodality and functional coupling are general principles underlying the systems level integration of physiopathological and pharmacological stimuli by mammalian cells.
Combinatorial code governing cellular responses to complex stimuli.
Time
View SamplesTranscriptome profiles for innate and adaptive immune stimuli important for host response against mycobacteria. Human monocyte-derived macrophages were stimulated with TLR2/1 ligand and interferon-g, stimuli present during innate and adaptive immune responses, respectively. Overall design: Human monocyte-dervided macrophages from five healthy donors were stimulated with TLR2/1L, IFN-g, or media control for 2, 6, and 24 hours. RNA-sequencing was performed on a total of 45 samples.
S100A12 Is Part of the Antimicrobial Network against Mycobacterium leprae in Human Macrophages.
Specimen part, Subject
View Samples