The mitochondrial respiratory chain is composed of lipoprotein complexes imbedded in the inner mitochondrial membrane. This chain of enzymes transfers electrons from NADH and FADH2, provided from divers metabolic pathways, to oxygen. It couples the transfer of electrons to the translocation of protons across the membrane. Several clinical syndromes have been associated with respiratory dysfunction caused by mitochondrial or nuclear mutations. A number of mutations in the mitochondrial genes encoding for cytochrome b (CYTB) and cytochrome oxidase (COX 1, 2 and 3) have been linked with diseases. We are using yeast mutants to characterize the deleterious effect of mutations reported in patients on the assembly and catalytic properties of the affected enzymes, and to study the impact of mutations in nuclear genes, such as OXA1, encoding for factors required for the assembly of the respiratory complexes. In this work, we monitored the effects of the mutations causing respiratory defect on the whole genome expression. We compared the change in gene expression in rho0 cells (with a complete deletion of the mitochondrial genome, and by consequence without respiratory chain), in cells with either a single defective enzyme or several, and in cells after prolonged treatment with the bc1 inhibitors myxothiazol or antimycin. The impact of the mutations on the respiratory function ranged from mild to severe. The expression of approx. 350 genes was changed in at least one mutant. Cluster analysis was performed using the Cluster program (Eisen, 1998, PNAS 95:14863). Four groups of genes were studied in more details: Group A, the most repressed genes; Group B, the most over-expressed genes; Group C, genes more repressed in rho0 and Doxa1 cells; and Group D, genes more over-expressed in Doxa1.
Multiple defects in the respiratory chain lead to the repression of genes encoding components of the respiratory chain and TCA cycle enzymes.
Compound
View SamplesContinuous contact with self-major histocompatibility complex ligands is essential for the survival of naive CD4 T cells. We have previously shown that the resulting tonic TCR signaling also influences their fate upon activation by increasing their ability to differentiate into induced regulatory T cells. To decipher the molecular mechanisms governing this process, microarray data comparing highly (Ly-6C-) and lowly (Ly-6C+) Self-reactive naive CD4 T cells were obtained.
Calcium-mediated shaping of naive CD4 T-cell phenotype and function.
Specimen part
View SamplesSince bone metastatic breast cancer is an incurable disease, causing significant morbidity and mortality, understanding of the underlying molecular mechanisms would be highly valuable. Here, we describe in vitro and in vivo evidence for the importance of serine biosynthesis in the metastasis of breast cancer to bone. We first characterized the bone metastatic propensity of the MDA-MB-231(SA) cell line variant as compared to the parental MDA-MB-231 cells by radiographic and histological observations in the inoculated mice. Genome-wide gene expression profiling of this isogenic cell line pair revealed that all the three genes involved in the L-serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1), and phosphoserine phosphatase (PSPH) were upregulated in the highly metastatic variant. This pathway is the primary endogenous source for L-serine in mammalian tissues. Consistently, we observed that the proliferation of MDA-MB-231(SA) cells in serine-free conditions was dependent on PSAT1 expression. In addition, we observed that L-serine is essential for the formation of bone resorbing human osteoclasts and may thus contribute to the vicious cycle of osteolytic bone metastasis. High expression of PHGDH and PSAT1 in primary breast cancer was significantly associated with decreased relapse-free and overall survival of patients and malignant phenotypic features of breast cancer. In conclusion, high expression of serine biosynthesis genes in metastatic breast cancer cells and the stimulating effect of L-serine on osteoclastogenesis and cancer cell proliferation indicate a functionally critical role for serine biosynthesis in bone metastatic breast cancer and thereby an opportunity for targeted therapeutic interventions.
Enhanced serine production by bone metastatic breast cancer cells stimulates osteoclastogenesis.
Specimen part, Cell line
View SamplesTo find BMAL1-regulated genes in mice pituitary gland we performed a differential microarray from wild-type vs Bmal1-/- knock-out mice
Chromatin remodeling as a mechanism for circadian prolactin transcription: rhythmic NONO and SFPQ recruitment to HLTF.
Sex, Specimen part
View SamplesThis study supports an active role for PLZF and RAR-PLZF in leukemogenesis, identifies upregulation of CRABPI as a novel mechanism contributing to retinoid resistance and reveals the ability of the reciprocal fusion gene products to mediate distinct
RARalpha-PLZF overcomes PLZF-mediated repression of CRABPI, contributing to retinoid resistance in t(11;17) acute promyelocytic leukemia.
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View SamplesDe novo ASXL1 mutations are found in patients with Bohring-Opitz syndrome, a disease with severe developmental defects and early childhood fatality. The underlying pathologic mechanisms remain largely unknown. Using Asxl1-targeted murine models,we found that Asxl1 global loss or conditional deletion in osteoblasts and their progenitors in mice leads to significant bone loss and markedly decreased numbers of marrow mesenchymal stem/progenitor cells (MSPCs) compared with wild-type (WT) littermates. Asxl1-/- MSPCs displayed impaired self-renewal and skewed differentiation-away from osteoblasts and favoring adipocytes. RNA-seq analysis reveals the altered expression of genes involved in cell proliferation, skeletal development and morphogenesis. Furthermore, gene set enrichment analysis showed a decreased gene expression of stem cell self-renewal signature,suggesting the role of Asxl1 in regulating the stemness of MSPCs. Importantly, introducing Asxl1 normalized NANOG and OCT4 expression and restored the self-renewal capacity of Asxl1-/- MSPCs. Our study unveils a pivotal role of ASXL1 in maintenance of MSPC functions and skeletal development. Overall design: Examination of mRNA profiles in wild type and Asxl1-/- MSPCs by deep sequencing
Loss of Asxl1 Alters Self-Renewal and Cell Fate of Bone Marrow Stromal Cell, Leading to Bohring-Opitz-like Syndrome in Mice.
Specimen part, Subject
View SamplesTransforming growth factor- (TGF-) is a key factor for the development of prostate cancer metastases in bone. In breast cancer and melanoma, studies have shown how TGF- regulates gene expression to allow cancer cells to adapt to the bone microenvironment.
The TGF-β Signaling Regulator PMEPA1 Suppresses Prostate Cancer Metastases to Bone.
Specimen part, Cell line, Treatment
View SamplesGrb14 is an endogenous inhibitor of insulin signaling
Novel Grb14-Mediated Cross Talk between Insulin and p62/Nrf2 Pathways Regulates Liver Lipogenesis and Selective Insulin Resistance.
Specimen part, Treatment
View SamplesPurpose: Nephron progenitor cells generate nephrons, the basic units of kidney. We developed methods to culture mouse and human NPCs in their self-renewal state in vitro with full nephrogenic potentials. The RNA-seq here is used to compare the global gene expression of long-term cultured mouse NPCs and their cognate freshly isolated primary NPCs Methods: mRNA profiles were generated by deep sequencing in duplicate from E11.5, E12.5, E13.5, E16.5 and P1 primary NPCs, and from long-term cultured NPCs derived from E11.5, E13.5, E16.5 and P1 (Passage 20 and Passage 80 for each cell line). To generate rpkm values from raw data, single-end 50bp reads were mapped to the UCSC mouse transcriptome (mm9) by STAR9, allowing for up to 10 mismatches (which is the default by STAR). Only the reads aligned uniquely to one genomic location were retained for subsequent analysis. And expression levels of all genes were estimated by Cufflink10 using only the reads with exact matches. Results: The gene expression levels of the "NPC-signature genes" were firstly transformed as logarithm scales. And then the program “prcomp”, a built-in program for principal component analysis in R packages, was employed with default parameters. We evaluated the variance percentage of each principal component, and found the top 3 components accounted for 84.1% of the total variance, where PC1 accounted for 46.42%, PC2 23.87% and PC3 13.81%. Those three PCs are therefore selected as candidate principal components in the further analysis. Another program “scatterplot3d” in the R packages was used to plot the 3D view of PCA, and “ggplot2” was used in 2D view of PCA. The PCA results indicate that cultured NPCs cluster together in PCA analysis while primary NPCs segregate into early (E11.5 to E13.5) and later (E16.5, P1) NPC groups. Interestingly, cultured NPCs are close to early NPCs in both PC1 and PC2 axes, suggesting that cultured NPCs are maintained in state close to early NPCs. The close cluster of P20 and P80 NPCs show the robustness of our culture condition in maintaining stable self-renewal state of NPCs. Conclusions: Our study represents the first analysis comparing the long-term cultured NPC lines we geneated with primary NPCs, with biologic replicates, generated by RNA-seq technology. The optimized data analysis workflows reported here should provide a framework for comparative investigations of expression profiles. Our results show that NGS offers a comprehensive and more accurate quantitative and qualitative evaluation of mRNA content within a cell or tissue. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic functions. Overall design: mRNA profiles were generated by deep sequencing in duplicate from E11.5, E12.5, E13.5, E16.5 and P1 primary NPCs, and from long-term cultured NPCs derived from E11.5, E13.5, E16.5 and P1 (Passage 20 and Passage 80 for each cell line)
3D Culture Supports Long-Term Expansion of Mouse and Human Nephrogenic Progenitors.
Specimen part, Cell line, Subject
View SamplesThe mechanisms that allow breast cancer cells to metabolically sustain growth are poorly understood. In breast cancer, FoxA1 transcription factor, along with estrogen receptor, regulates luminal cell specification and proliferation. Here we report that FoxA transcription factor family members FoxA1 and FoxA2 fuel cellular growth in breast cancer through the expression of a common target gene, namely the endothelial lipase (LIPG)
FoxA and LIPG endothelial lipase control the uptake of extracellular lipids for breast cancer growth.
Cell line
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