Basal cells represent a specific cell type in the epididymis, with specific functions. We performed gene expression analysis to detect differentially regulated genes in basal cells versus other, non-basal, cells in rat epididymis, in order to understand basal cell functions.
Isolated Rat Epididymal Basal Cells Share Common Properties with Adult Stem Cells.
Age, Specimen part
View SamplesBackground. Primary cilia (PC) are solitary antennae present at the cell surface. These non-motile cilia play an important role in organ development and tissue homeostasis through the transduction of the Hedgehog (Hh) signaling pathway. We recently revealed the presence of PC in the epithelium of the developing epididymis, an organ of the male reproductive system whose dysfunction triggers male infertility. Acknowledging that systemic blockade of the Hh pathway trigger epididymal dysfunctions in vivo, our main goals were 1) to portray the epididymal Hh environment, 2) to determine the direct responsiveness of epididymal epithelial cells to Hh, and 3) to define the contribution of PC to the transduction of this pathway. Results. The Hh ligands Indian and Sonic hedgehog (Ihh and Shh) were respectively located in principal and clear cells of the mouse epididymis by immunofluorescent staining. The propensity of epididymal principal cells to respond to Hh signaling was assessed on immortalized epididymal DC2 cells by western-blot, confocal imaging and 3D-reconstruction. Our results indicate that epididymal principal cells secrete Ihh and expose PC that co-localize with the conventional acetylated tubulin/Arl13b ciliary markers, as well as with GLI3 Hh signaling factor. Gene expression microarray profiling indicated that the expression of 43 and 248 genes was respectively and significantly modified following pharmacological treatment of DC2 cells with the Hh agonist SAG (250 nM) or the Hh antagonist cyclopamine (20 µM) compared with the control. Among Hh target genes identified, 6.7 % presented perfect matches for GLI-transcription factor consensus sequences, and the majority belonged to interferon-dependent immune response and lipocalin 2 pathways. Finally, the contribution of epididymal PC to the transduction of canonical Hh pathway was validated by ciliobrevinD treatment, which induced a significant decrease of PC length and the expressional reduction of Hh signalling targets. Conclusions. All together our data indicate that PC from epithelial principal cells regulate gene expression profile through a possible autocrine Hh signaling. This provides new hypotheses regarding the potential contribution of PC and Hh signaling in intercellular cross-talk and immunological regulation of the epididymis.
Hedgehog signaling pathway regulates gene expression profile of epididymal principal cells through the primary cilium.
Cell line, Treatment
View SamplesIn order to propagate a solid tumor, cancer cells must adapt to and survive under various tumor microenvironment (TME) stresses, such as hypoxia or lactic acidosis. To systematically identify genes that modulate cancer cell survival under stresses, we performed genome-wide shRNA screens under hypoxia or lactic acidosis. We discovered that genetic depletion of acetyl-CoA carboxylase (ACACA or ACC1) or ATP citrate lyase (ACLY) protected cancer cells from hypoxia-induced apoptosis. Additionally, loss of ACLY or ACC1 reduced levels and activities of the oncogenic transcription factor ETV4. Silencing ETV4 also protected cells from hypoxia-induced apoptosis and led to remarkably similar transcriptional responses as with silenced ACLY or ACC1, including an anti-apoptotic program. Metabolomic analysis found that while -ketoglutarate levels decrease under hypoxia in control cells, -ketoglutarate is paradoxically increased by hypoxia when ACC1 or ACLY are depleted. Supplementation with -ketoglutarate rescued the hypoxia-induced apoptosis and recapitulated the decreased expression and activity of ETV4 via an epigenetic mechanism. Therefore, ACC1 and ACLY regulate the levels of ETV4 under hypoxia via increased -ketoglutarate. These results reveal that ACC1/ACLY- -ketoglutarate-ETV4 is a novel means by which metabolic states regulate transcriptional output for life vs. death decisions under hypoxia. Since many lipogenic inhibitors are under investigation as cancer therapeutics, our findings suggest that the use of these inhibitors will need to be carefully considered with respect to oncogenic drivers, tumor hypoxia, progression and dormancy. More broadly, our screen provides a framework for studying additional tumor cell stress-adaption mechanisms in the future.
ACLY and ACC1 Regulate Hypoxia-Induced Apoptosis by Modulating ETV4 via α-ketoglutarate.
Specimen part, Cell line
View SamplesIn Huntingtons disease (HD), an expanded CAG repeat produces characteristic striatal neurodegeneration. Interestingly, the HD CAG repeat, whose length determines age at onset, undergoes tissue-specific somatic instability, predominant in the striatum, suggesting that tissue-specific CAG length changes could modify the disease process. Therefore, understanding the mechanisms underlying the tissue specificity of somatic instability may provide novel routes to therapies. However progress in this area has been hampered by the lack of sensitive high-throughput instability quantification methods and global approaches to identify the underlying factors.
A novel approach to investigate tissue-specific trinucleotide repeat instability.
Specimen part
View SamplesIn Huntingtons disease (HD), an expanded CAG repeat produces characteristic striatal neurodegeneration. Interestingly, the HD CAG repeat, whose length determines age at onset, undergoes tissue-specific somatic instability, predominant in the striatum, suggesting that tissue-specific CAG length changes could modify the disease process. Therefore, understanding the mechanisms underlying the tissue specificity of somatic instability may provide novel routes to therapies. However progress in this area has been hampered by the lack of sensitive high-throughput instability quantification methods and global approaches to identify the underlying factors.
A novel approach to investigate tissue-specific trinucleotide repeat instability.
Age, Specimen part
View SamplesStaphylococcus aureus causes a spectrum of human infection. Diagnostic delays and uncertainty lead to treatment delays and inappropriate antibiotic use. A growing literature suggests the hosts inflammatory response to the pathogen represents a potential tool to improve upon current diagnostics. The hypothesis of this study is that the host responds differently to S. aureus than to E. coli infection in a quantifiable way, providing a new diagnostic avenue. This study uses Bayesian sparse factor modeling and penalized binary regression to define peripheral blood gene-expression classifiers of murine and human S. aureus infection. The murine-derived classifier distinguished S. aureus infection from healthy controls and Escherichia coli-infected mice across a range of conditions (mouse and bacterial strain, time post infection) and was validated in outbred mice (AUC>0.97). A S. aureus classifier derived from a cohort of 95 human subjects distinguished S. aureus blood stream infection (BSI) from healthy subjects (AUC 0.99) and E. coli BSI (AUC 0.82). Murine and human responses to S. aureus infection share common biological pathways, allowing the murine model to classify S. aureus BSI in humans (AUC 0.84). Both murine and human S. aureus classifiers were validated in an independent human cohort (AUC 0.95 and 0.94, respectively). The approach described here lends insight into the conserved and disparate pathways utilized by mice and humans in response to these infections. Furthermore, this study advances our understanding of S. aureus infection; the host response to it; and identifies new diagnostic and therapeutic avenues.
Gene expression-based classifiers identify Staphylococcus aureus infection in mice and humans.
Race
View SamplesTo determine genes regulated by HNF1A in 22Rv1, we performed siRNA mediated knockdown of HNF1A using pooled siHNF1A (L-008215-00-0005 5 nmol) and pooled siSCR purchased from Dharmacon. RNA was harvested 3 days after transfection and gene expression profiling was performed. Similarly to determine genes regulated by HNF1A in LNCaP, we performed retroviral transduction of LNCaP cells in duplicate for HNF1A and empty vector control expression. cDNA for HNF1A in RC211201 vector (origene) was subcloned into a murine stem cell virus (MSCV)-based retroviral vector with hygromycin selection marker (Addgene). After 3 days of transduction, cells were selected for four days in hygromycin and later on RNA was harvested for gene expression profiling. Overall design: RNA profiles were generated by deep sequencing using Illumina HiSeq.
Aberrant Activation of a Gastrointestinal Transcriptional Circuit in Prostate Cancer Mediates Castration Resistance.
Cell line, Subject
View SamplesTo study the underlying mechanism of androgen independent growth we performed transcriptome analysis of LNCaP/AR-Vec and LNCaP/AR-HNF4G at day 9 of growth in CSS and LNCaP/AR-HNF4G at 32 days of growth in CSS to identify the HNF4G transcriptome, as well as determinants of castration-resistant growth Overall design: RNA-seq
Aberrant Activation of a Gastrointestinal Transcriptional Circuit in Prostate Cancer Mediates Castration Resistance.
Cell line, Subject
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