Targets of Retinoic Acid (RA) and 3,4-didehydroretinoic acid (ddRA) were identified in primary human epidermal keratinocytes grown in the presence of atRA or ddRA for 4 and 24 hours.
The effect of two endogenous retinoids on the mRNA expression profile in human primary keratinocytes, focusing on genes causing autosomal recessive congenital ichthyosis.
Treatment
View SamplesA key requisite for the success of a dendritic cell (DC)-based vaccine in treating malignancies is the capacity of the DCs to attract immune effector cells for further interaction and activation, considering crosstalk with DCs is partially regulated by cell-contact-dependent mechanisms. Although critical for therapeutic efficacy, immune cell recruitment is a largely overlooked aspect regarding optimization of DC therapy. In this paper we examine if the so-called interleukin (IL)-15 DC vaccine provides a favorable chemokine milieu for recruiting T cells, natural killer (NK) cells and gamma delta () T cells, in comparison with the IL-4 DCs used routinely for clinical studies, as well as the underlying mechanisms of immune cell attraction by IL-15 DCs. Chemokine signaling is studied both at the RNA level, using microarray data of mature DCs, and functional level, by means of a transwell chemotaxis assay. Important to note, the classic IL-4 DC vaccine falls short to attract the required immune effector lymphocytes, whereas the IL-15 DCs provide a favorable chemokine milieu for recruiting all cytolytic effector cells. The elevated secretion of the chemokine (C-C motif) ligand 4 (CCL4), also known as macrophage inflammatory protein-1 (MIP-1), by IL-15 DCs underlies the enhanced migratory responsiveness of T cells, NK cells and T cells. Namely, neutralizing its receptor CCR5 resulted in a significant drop in migration of the aforementioned effector cells towards IL-15 DCs. These findings should be kept in mind in the design of future DC-based cancer vaccines.
Desirable cytolytic immune effector cell recruitment by interleukin-15 dendritic cells.
Specimen part, Subject
View SamplesConrad et al. Nature 456, 344349 (2008) have generated human adult germline stem cells (haGSCs) from human testicular tissue, which they claim have similar pluripotent properties to human embryonic stem cells (hESCs). Here we investigate the pluripotency of haGSCs by using global gene-expression analysis based on their gene array data and comparing the expression of pluripotency marker genes in haGSCs and hESCs, and in haGSCs and human fibroblast samples derived from different laboratories, including our own. We find that haGSCs and fibroblasts have a similar gene-expression profile, but that haGSCs and hESCs do not. The pluripotency of Conrad and colleagues haGSCs is therefore called into question.
Human adult germline stem cells in question.
Specimen part
View SamplesWe analyzed small RNAs from three mammalian species, and found that in all these species piRNA-directed targeting is accompanied by the generation of short sequences that have a very precisely defined length and a specific spatial relationship with the guide piRNAs. Overall design: small RNA-seq of testes lysate (beta-eliminated)
Conserved generation of short products at piRNA loci.
No sample metadata fields
View SamplesMicroarray analysis of gene expression after transverse aortic constriction in mice: comparison of TAC vs. sham group at 48 hours, 10 days, and 3 weeks.
Microarray analysis of gene expression after transverse aortic constriction in mice.
No sample metadata fields
View SamplesThe four transcription factors Oct4, Sox2, Klf4, and c-Myc can induce pluripotency in mouse and human fibroblasts. We previously described direct reprogramming of adult mouse neural stem cells (NSCs) by Oct4 and either Klf4 or c-Myc. NSCs endogenously express Sox2, c-Myc, and Klf4 as well as several intermediate reprogramming markers. Here we report that exogenous expression of the germline-specific transcription factor Oct4 is sufficient to generate pluripotent stem cells from adult mouse NSCs. These one-factor induced pluripotent stem (1F iPS) cells are similar to embryonic stem cells in vitro and in vivo. Not only can these cells be efficiently differentiated into NSCs, cardiomyocytes and germ cells in vitro, but they are also capable of teratoma formation and germline transmission in vivo. Our results demonstrate that Oct4 is required and sufficient to directly reprogram NSCs to pluripotency.
Oct4-induced pluripotency in adult neural stem cells.
No sample metadata fields
View SamplesDespite the widespread interest in direct neuronal reprogramming, the mechanisms underpinning fate conversion remain largely unknown. Our study revealed a critical time point after which cells either successfully convert into neurons or succumb to cell death. Co-transduction with Bcl-2 greatly improved negotiation of this critical point by faster neuronal differentiation. Surprisingly, mutants with reduced or no affinity for Bax demonstrated that Bcl-2 exerts this effect by an apoptosis-independent mechanism. Consistent with a caspase-independent role, ferroptosis inhibitors potently increased neuronal reprogramming by inhibiting lipid peroxidation occurring during fate conversion. Genome-wide expression analysis confirmed that treatments promoting neuronal reprogramming elicit an anti-oxidative stress response. Importantly, coexpression of Bcl-2 and anti-oxidative treatments lead to an unprecedented improvement in glial-to-neuron conversion after traumatic brain injury in vivo, underscoring the relevance of these pathways in cellular reprograming irrespective of cell type, in vitro and in vivo.
Identification and Successful Negotiation of a Metabolic Checkpoint in Direct Neuronal Reprogramming.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Reprogramming factor expression initiates widespread targeted chromatin remodeling.
Specimen part
View SamplesDespite rapid progress in characterizing transcription factor-driven reprogramming of somatic cells to an induced pluripotent stem (iPS) cell state, many mechanistic questions still remain. To gain insight into the earliest events in the reprogramming process, we systematically analyzed the transcriptional and epigenetic changes that occur during early factor induction after discrete numbers of divisions. We observed rapid, genome-wide changes in the euchromatic histone modification, H3K4me2, at more than a thousand loci including large subsets of pluripotency or developmentally related gene promoters and enhancers. In contrast, patterns of the repressive H3K27me3 modification remained largely unchanged except for focused depletion specifically at positions where H3K4 methylation is gained. These chromatin regulatory events precede transcriptional changes within the corresponding loci. Our data provide evidence for an early, organized, and population-wide epigenetic response to ectopic reprogramming factors that clarify the temporal order through which somatic identity is reset during reprogramming.
Reprogramming factor expression initiates widespread targeted chromatin remodeling.
Specimen part
View SamplesThe recruitment of mesenchymal stem cells in order to reconstruct damaged cartilage of osteoarthritis joints is a challenging tissue engineering task. Vision towards this goal is blurred by a lack of knowledge about the underlying differences between chondrocytes and MSC during the chondrogenic cultivation process. The aim of this study was to shed light on the differences between chondrocytes and MSC occurring during chondral differentiation through tissue engineering.
Expression pattern differences between osteoarthritic chondrocytes and mesenchymal stem cells during chondrogenic differentiation.
Specimen part
View Samples