Multiple sclerosis involves an aberrant autoimmune response and progressive failure of remyelination in the central nervous system. Prevention of neural degeneration and subsequent disability requires remyelination through the generation of new oligodendrocytes, but current treatments exclusively target the immune system. Oligodendrocyte progenitor cells are stem cells in the central nervous system and the principal source of myelinating oligodendrocytes. These cells are abundant in demyelinated regions of patients with multiple sclerosis, yet fail to differentiate, thereby representing a cellular target for pharmacological intervention. To discover therapeutic compounds for enhancing myelination from endogenous oligodendrocyte progenitor cells, we screened a library of bioactive small molecules on mouse pluripotent epiblast stem-cell-derived oligodendrocyte progenitor cells. Here we show seven drugs function at nanomolar doses selectively to enhance the generation of mature oligodendrocytes from progenitor cells in vitro. Two drugs, miconazole and clobetasol, are effective in promoting precocious myelination in organotypic cerebellar slice cultures, and in vivo in early postnatal mouse pups. Systemic delivery of each of the two drugs significantly increases the number of new oligodendrocytes and enhances remyelination in a lysolecithin-induced mouse model of focal demyelination. Administering each of the two drugs at the peak of disease in an experimental autoimmune encephalomyelitis mouse model of chronic progressive multiple sclerosis results in striking reversal of disease severity. Immune response assays show that miconazole functions directly as a remyelinating drug with no effect on the immune system, whereas clobetasol is a potent immunosuppressant as well as a remyelinating agent. Mechanistic studies show that miconazole and clobetasol function in oligodendrocyte progenitor cells through mitogen-activated protein kinase and glucocorticoid receptor signalling, respectively. Furthermore, both drugs enhance the generation of human oligodendrocytes from human oligodendrocyte progenitor cells in vitro. Collectively, our results provide a rationale for testing miconazole and clobetasol, or structurally modified derivatives, to enhance remyelination in patients. Overall design: RNA sequencing of oligodendrocyte progenitor cells treated with vehicle, miconazole or clobetasol for 0, 2, 6, or 12 hours. Cells were plated 1.5 hours prior to addition of drug.
Drug-based modulation of endogenous stem cells promotes functional remyelination in vivo.
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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 SamplesPurpose: Seek for differential gene expression in vemurafenib-resistant A375 tumors vs. untreated controls to provide a rationale for resistance mechanism Methods: mRNA profiles of vemurafenib-resistant A375 tumors and untreated control tumors were generated by transcriptome sequencing of A375 melanoma bearing mice. Since our xenograft samples contain a mixture of human and mouse RNAs we mapped RNASeq reads against a hybrid human/mouse genome. We than removed reads of potential mouse origin by taking only reads that map uniquely to human chromosomes. On average 23% of reads were removed as potential mouse reads. We than took the remaining reads (on average 77% per sample) to determine the gene expression levels for each sample. Normalized expression levels of 5 resistant samples were compared to 4 untreated control samples to detect differnetially regulated genes which may contribute to vemurfenib resistance Results: Expression levels of several genes were consistently altered in all resistant samples. Expression of e.g. genes encoding SPRY2, SPRY4, DUSP6, CCND1, PIK3R3, FGFR1, EPHA4, MCL1, and IGF1R was down-regulated, whereas expression of PDGFC, VEGFC, ABCB9 and KITLG was increased. Conclusions: Our study reports several differentially expressed genes which may contribute to vemurafenib resistance in A375 tumor bearing mice Overall design: RNA sequencing of genes expressed in A375 tumors bearing mice treated with vemurafenib until in vivo resistance appeared vs. untreated A375 tumors
A Novel RAF Kinase Inhibitor with DFG-Out-Binding Mode: High Efficacy in BRAF-Mutant Tumor Xenograft Models in the Absence of Normal Tissue Hyperproliferation.
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View SamplesMurine healthy tissue samples, DCIS and invasive mammary tumors were analyzed in order to identify marker genes which show enhanced expresssion in DCIS and invasive ductal carcinomas.
Identification of early molecular markers for breast cancer.
Specimen part
View SamplesHuman healthy tissue samples, DCIS and invasive mammary tumors were analyzed in order to identify marker genes which show enhanced expresssion in DCIS and invasive ductal carcinomas.
Identification of early molecular markers for breast cancer.
Specimen part, Disease, Disease stage
View SamplesMicroarray analyses provide a powerful approach to identify gene expression alterations following kidney transplantation. However, the heterogeneity of human kidney transplant specimens and the variation in sample preparation precludes conclusions regarding the underlying mechanisms of the observed alterations. We used a well defined experimental rat kidney transplantation model with consistent transplant and sample preparation procedures to analyze genome wide changes in gene expression after syngeneic (sTX) and allogeneic transplantation (aTX) four days after transplantation. Both interventions were associated with dramatic changes in gene expression. Genes and Pathways related to immune response were extremely up regulated after aTX. Several of the up regulated genes have been described by other groups and we are able to proof this in one study. But several genes are reported for the first time to be up regulated in expression after renal aTX. The function of these genes in acute rejection process has to be evaluated. On the other hand the up regulation of regulatory or protective genes indicates that regulatory mechanism are activated after aTX trying to down regulate the immune response or protect the tissue against the immune system. The study is capable to serve as a representative study in aTX mediated gene expression by covering the known transcriptional changes reported by other groups and identification of novel markers and pathways. Further analysis of the duplicated datasets by other groups can help for a better understanding of the mechanisms mediated by acute rejection and thereby increase the therapeutic threatment.
Activation of counter-regulatory mechanisms in a rat renal acute rejection model.
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View SamplesWe used microarrays to detail transcriptional changes in the rat heart in response to doxorubicin, a chemotherapeutic drug known to induce cardiac disfunction/heart failure
Early effects of doxorubicin in perfused heart: transcriptional profiling reveals inhibition of cellular stress response genes.
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View SamplesWNT-induced secreted protein 1 (WISP1/CCN4), a member of the CCN protein family, acts as a downstream factor of the canonical WNT-signaling pathway. A dysregulated expression of WISP1 often reflects its oncogenic potential by inhibition of apoptosis, a necessary form of cell death that protect cell populations for transformation into malignant phenotypes. WISP1-signaling is also known to affect proliferation and differentiation of human mesenchymal stem cells (hMSCs), which are fundamental for the constitution and maintenance of the musculoskeletal system. Our study emphasizes the importance of WISP1-signaling for cell survival of primary human cells. Therefore, we established a successful down-regulation of endogenous WISP1 transcripts through gene silencing in hMSCs. We were able to demonstrate the consequence of cell death immediately after WISP1 down-regulation took place. Bioinformatical analyses of subsequent performed microarrays from WISP1 down-regulated vs. control samples confirmed this observation. We uncovered several clusters of differential expressed genes important for cellular apoptosis induction and immuno-regulatory processes, thereby indicating TRAIL-induced and p53-mediated apoptosis as well as IFNbeta-signaling. Since all of them act as potent inhibitors for malignant cell growth, in vitro knowledge about the connection with WISP1-signaling could help to find new therapeutic approaches concerning cancerogenesis and tumor growth in musculoskeletal tissues.
WISP 1 is an important survival factor in human mesenchymal stromal cells.
Specimen part, Treatment
View SamplesIn this study we analyzed the myeloma cell contact-mediated changes on the transcriptome of skeletal precursor cells. Therefore, human mesenchymal stem cells (MSC) and osteogenic precursor cells (OPC) were co-cultured with the representative myeloma cell line INA-6 for 24 h. Afterwards, MSC and OPC were separated from INA-6 cells by fluorescence activated cell sorting. Total RNA of MSC and OPC fractions was used for whole genome array analysis.
Contact of myeloma cells induces a characteristic transcriptome signature in skeletal precursor cells -Implications for myeloma bone disease.
Sex, Age, Specimen part, Disease stage
View SamplesGenome-wide association studies (GWAS) have identified dozens of genomic loci, whose single nucleotide polymorphisms (SNPs) predispose to prostate cancer (PCa). However, the biological functions of these common genetic variants and the mechanisms to increase disease risk are largely unknown. We integrated chromatin-IP coupled sequencing (ChIP-seq) and microarray expression profiling in the TMPRSS2-ERG gene rearrangement positive DuCaP cell model with the NHGRI GWAS PCa risk SNPs catalog, in an attempt to identify disease susceptibility SNPs localized within functional androgen receptor binding sites (ARBSs). Among the 48 GWAS index SNPs and 2,702 linked SNPs defined by the 1000G project 104 were found to be localized in the AR ChIP-seq peaks. Of these risk SNPs, rs11891426 T/G in the 7th intron of its host gene melanophilin (MLPH) was found located within a putative auxiliary ARE motif, which we found enriched in the neighborhood of canonical ARE motifs. Exchange of T to G attenuated the transcriptional activity of the MLPH-ARBS in a reporter gene assay. The expression of MLPH protein in tissue samples from prostate cancer patients was significantly lower in those with the G compared to the T allele. Moreover, a significant positive correlation of AR and MLPH protein expression levels was also confirmed in tissue samples. These results unravel a hidden link between AR and a functional PCa risk SNP rs11891426, whose allele alteration affects androgen regulation of its host gene MLPH. This study shows the power of integrative studies to pin down functional risk SNPs and justifies further investigations.
Putative Prostate Cancer Risk SNP in an Androgen Receptor-Binding Site of the Melanophilin Gene Illustrates Enrichment of Risk SNPs in Androgen Receptor Target Sites.
Cell line, Treatment, Time
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