Exposure to aristolochic acid (AA) is linked to kidney disease and urothelial cancer in humans. The major carcinogenic component of the AA plant extract is aristolochic acid I (AAI). The transcription factor p53 acts as a tumour suppressor and is frequently mutated in AA-induced tumours. Using a mouse model, we previously showed that Trp53 genotype impacts on AAI-induced nephrotoxicity in vivo (i.e. p53 protects from AAI-induced renal proximal tubular injury), but the underlying mechanism(s) involved remain to be further explored. In the present study, we investigated the impact of p53 on AAI-induced gene expression in vivo by treating Trp53(+/+), Trp53(+/-) and Trp53(-/-) mice with 3.5 mg/kg body weight (bw) AAI daily for 6 days. The Clariom™ S Assay microarray was used to elucidate gene expression profiles in mouse kidneys after AAI treatment in order to identify potential mechanisms by which AAI drives renal injury in Trp53(-/-) kidneys. Principle component analysis and hierarchical clustering in Qlucore Omics Explorer showed that gene expression in AAI-exposed Trp53(+/+), Trp53(+/-) and Trp53(-/-) kidneys is treatment-dependent. However, gene expression profiles did not segregate in a clear-cut manner according to Trp53 genotype, hence further investigations were performed by pathway analysis with MetaCore™. Several pathways, such as those related to epithelial-to-mesenchymal transition, transcription of hypoxia-inducible factor 1 targets, renal injury and secretion of xenobiotics were significantly altered to varying degrees for AAI-exposed kidneys. The top ten up-regulated genes included cyclin-dependent kinase inhibitor 1a (Cdkn1a), a mediator of cell cycle arrest; and neutrophil gelatinase-associated lipocalin (Ngal), which has been shown to play a role in nephritis by promoting inflammation and apoptosis. Members of the solute carrier (Slc) family (i.e. Slc22a2, Slc22a6, Slc22a7, Slc22a8) were amongst the top ten down-regulated genes. Pathway analysis also identified genes that are uniquely affected by AAI treatment in Trp53(+/+), Trp53(+/-) and Trp53(-/-) kidneys. Apoptotic pathways were modulated in Trp53(+/+) kidneys; whereas oncogenic and pro-survival pathways were significantly altered for Trp53(+/-) and Trp53(-/-) kidneys, respectively. Microarray gene expression analysis identified significant toxicogenomic responses to AAI that give novel insights into its mechanism of nephrotoxicity. Alterations of biological processes by AAI in Trp53(+/+), Trp53(+/-) and Trp53(-/-) kidneys could explain the mechanisms by which p53 protects from or p53 loss drives AAI-induced renal injury in vivo.
The impact of p53 on aristolochic acid I-induced nephrotoxicity and DNA damage in vivo and in vitro.
Sex, Specimen part, Treatment
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 SamplesThis SuperSeries is composed of the SubSeries listed below.
TTCA: an R package for the identification of differentially expressed genes in time course microarray data.
Cell line, Treatment
View SamplesThe analysis of microarray time series promises a deeper insight into the dynamics of the cellular response following stimulation. A common observation in this type of data is that some genes respond with quick, transient dynamics, while other genes change their expression slowly over time. The existing methods for the detection of significant expression dynamics often fail when the expression dynamics show a large heterogeneity, and often cannot cope with irregular and sparse measurements.
TTCA: an R package for the identification of differentially expressed genes in time course microarray data.
Cell line, Treatment
View SamplesThe analysis of microarray time series promises a deeper insight into the dynamics of the cellular response following stimulation. A common observation in this type of data is that some genes respond with quick, transient dynamics, while other genes change their expression slowly over time. The existing methods for the detection of significant expression dynamics often fail when the expression dynamics show a large heterogeneity, and often cannot cope with irregular and sparse measurements.
TTCA: an R package for the identification of differentially expressed genes in time course microarray data.
Cell line, Treatment
View SamplesDiabetes and obesity are widespread diseases with signifciant socioeconomic implications. We used three different types of human adipose tissue (epigastric, visceral, and subcutaneous) in order to determine differences in global gene expression between these adipose depots in severely obese patients.
Gene expression profiling in subcutaneous, visceral and epigastric adipose tissues of patients with extreme obesity.
Specimen part, Race
View SamplesHuman naïve pluripotent stem cells (PSC) share features with pre-implantation epiblast. They thus provide an unmatched opportunity for characterising the developmental programme of pluripotency in Homo sapiens. Here we confirm that naïve PSC do not respond directly to germ layer induction, but must first acquire competence. Capacitation for multi-lineage differentiation occurs without exogenous growth factor stimulation and is facilitated by inhibition of Wnt signalling. Whole transcriptome profiling during this formative transition highlights dynamic changes in gene expression, affecting many cellular properties, including metabolism and epithelialisation. Notably, naïve pluripotency factors are exchanged for post-implantation factors, but competent cells remain devoid of lineage primed transcription. The gradual pace of transition for human naïve PSC is consistent with the timespan of primate development from blastocyst to gastrulation. Transcriptome trajectory during in vitro capacitation of human naïve cells tracks the progression of epiblast during embryogenesis in Macaca fascicularis, but shows greater divergence from mouse development. Thus the formative transition of naïve PSC in a simple culture system may recapitulate essential and specific features of pluripotency dynamics during an inaccessible period of human embryogenesis. Overall design: 2 lines of human naïve pluripotent stem cells (embryo-derived HNES1 and chemically reset cR-H9-EOS) were cultured in N2B27 and 2uM XAV939 for 10 days. After that the cells were split into two conditions: N2B27 + 2uM XAV939 + 3ng/ml Activin A + 10ng/ml FGF2 (XAF), or E8 medium, for extended maintenance. The experiment was performed in biological triplicates for each cell line. RNAseq was performed with the cells on day 0, 1, 2, 3, 7, 10, when the cells were cultured in XAV939; and one time point after transfer to maintenance conditions, at not less than 22 days of culture from the start of the experiment. Conventional hES cell line H9-EOS, which was a parental line for the chemically reset cR-H9-EOS was used as a control (in biological triplicate).
Capacitation of human naïve pluripotent stem cells for multi-lineage differentiation.
Specimen part, Cell line, Subject
View SamplesMembers of the CUG-BP, Elav-like family (CELF) regulate alternative splicing in the heart. In MHC-CELFdelta transgenic mice, CELF splicing activity is inhibited postnatally in heart muscle via expression of a nuclear dominant negative CELF protein under an a-myosin heavy chain promoter. MHC-CELFdelta mice develop dilated cardiomyopathy characterized by alternative splicing defects, enlarged hearts, and severe contractile dysfunction. In this study, gene expression profiles in the hearts of wild type, high- and low-expressing lines of MHC-CELFdelta mice were compared using microarrays. Gene ontology and pathway analyses identified contraction and calcium signaling as the most affected processes. Network analysis revealed that the serum response factor (SRF) network is highly affected. Downstream targets of SRF were up-regulated in MHC-CELFdelta mice compared to the wild type, suggesting an increase in SRF activity. Although SRF levels remained unchanged, known inhibitors of SRF activity were down-regulated. These results suggest a role for CELF-mediated alternative splicing in the regulation of contractile gene expression, achieved in part through modulating the activity of SRF, a key cardiac transcription factor.
Gene expression analyses implicate an alternative splicing program in regulating contractile gene expression and serum response factor activity in mice.
Sex, Age, Specimen part
View SamplesAsymmetric cell division results in two distinctly fated daughter cells to generate cellular diversity. A major molecular hallmark of an asymmetric division is the unequal partitioning of cell-fate determinant proteins. We have previously established that growth factor signaling promotes protein depalmitoylation to foster polarized protein localization, which in turns drives migration and metastasis. Here, we report protein palmitoylation as a key mechanism for the asymmetric partitioning of the cell-fate determinants Numb (Notch antagonist) and ß-catenin (canonical Wnt regulator) through the activity of a depalmitoylating enzyme, APT1. Using point mutants, we show specific palmitoylated residues on proteins, such as Numb, are required for asymmetric localization. Furthermore, by live-cell imaging, we show that reciprocal interactions between APT1 and CDC42 regulate the asymmetric localization of Numb and ß-catenin to the plasma membrane. This in turn restricts Notch and Wnt transcriptional activity to one daughter cell. Moreover, we show altering APT1 expression changes the transcriptional signatures to those resembling that of Notch and ß-catenin in MDA-MB-231 cells. We also show loss of APT1 depletes the population of CD44+/CD24lo/ALDH+ tumorigenic cells in colony formation assays. Together, the findings of this study demonstrate that palmitoylation, via APT1, is a major mechanism of asymmetric cell division regulating Notch and Wnt-associated protein dynamics, gene expression, and cellular functions. Overall design: Gene expression by RNAseq of MDA-MB-231 triple receptor negative breast cancer cells expressing scramble control vector, shAPT1 knockdown, and APT1wt performed in triplicate. Total of 9 samples were analyzed.
The depalmitoylase APT1 directs the asymmetric partitioning of Notch and Wnt signaling during cell division.
Specimen part, Cell line, Treatment, Subject
View SamplesMost lung adenocarcinoma deaths are related to metastases, indicating the necessity of detecting and inhibiting tumor cell dissemination. We have identified that overexpression of miRNAs located on 14q32 was associated with metastasis in lung adenocarcinoma patients. For functional analysis, we utilized CRISPR activation technology to increase levels of miRNAs clustered on 14q32 in a coordinated manner, and the results showed that 14q32 miRNA overexpression promoted tumor cell migratory and invasive properties. Whole transcriptome microarray analysis of the miRNA-overexpressing cells was performed to define the underlying molecular mechanisms.
Epigenetically Regulated Chromosome 14q32 miRNA Cluster Induces Metastasis and Predicts Poor Prognosis in Lung Adenocarcinoma Patients.
Specimen part, Cell line
View Samples