Mutations in the mitochondrial DNA (mtDNA) have been proposed to be essential for metabolic adaptation, and because metabolism is intrinsically associated with multiple disease states, including obesity, we hypothesized that changes in the mtDNA would significantly influence adiposity and gene expression in response to diet. To test these predictions we used Mitochondrial-Nuclear eXchange mice, which have nuclear and mitochondrial genomes that have been exchanged from different M. musculus strains. Overall design: Purpose: Mutations in the mitochondrial DNA (mtDNA) have been proposed to be essential for metabolic adaptation, and because metabolism is intrinsically associated with multiple disease states, including obesity, we hypothesized that changes in the mtDNA would significantly influence adiposity and gene expression in response to diet. To test these predictions we used Mitochondrial-Nuclear eXchange mice, which have nuclear and mitochondrial genomes that have been exchanged from different M. musculus strains. Methods: Wild type (C57BL6/J – C57n:C57mt and C3H/HeN - C3Hn:C3Hmt) and MNX (C57n:C3Hmt and C3Hn:C57mt) mouse were weaned with Chor diet and continued with Chow or changed to high-fat diet from 6 to 12-13 weeks of age. RNA samples were isolated from white adipose tissues collected from epididymal (eWAT) and inguinal (iWAT) fat, representing visceral and subcutaneous fat depots, respectively with RNeasy kit (Qiagen). Reverse transcribed cDNA libraries were sequenced with an Illumina HiSeq 2000. Read mapping was conducted with a proprietary algorithm by Expression Analysis (www.q2labsolutions.com), and read counts were used as input for differential expression analysis in DESeq2 version 1.10.1, using default settings. Results: Using an optimized data analysis workflow, we mapped about 20 million sequence reads per sample to the mouse genome (build mm9). Transcriptional changes were interrogated for 961 genes previously reported to be associated with fat metabolism and 29,209 genes representing the entire mouse transcriptome. These results show that the C57 mtDNA increased the number of DE genes in response to high fat diet in mice harboring the C3H nuclear genome (209% increase; C3Hn:C57mt versus C3Hn:C3Hmt, 165/79) and the C3H mtDNA decreased response in animals carrying the C57 nucleus (46% decrease; C57n:C3Hmt versus C57n:C57mt, 112/206) in eWAT (Figure 2B). Similarly, the high fat diet resulted in 25 and 231 DE genes in the C3Hn:C3Hmt and C3Hn:C57mt iWAT, respectively, and 344 and 143 DE genes in C57n:C57mt and C57n:C3Hmt iWAT. This corresponded to a 924% increase in the number of DE genes responding to high fat diet C3Hn:C57mt versus C3Hn:C3Hmt, and a decreased response (58% decrease) in C57n:C3Hmt relative to C57n:C57mt iWAT. Further analysis showed that each MNX and corresponding wild-type shared and had distinct DE genes in eWAT and iWAT. Conclusions: Results also show that the degree of transcriptional response influenced by the mtDNA can vary based upon the type of adipose tissue, suggesting that mtDNA background can have varying effects on the number of nuclear genes differentially responding to stimuli, depending upon tissue and location.
Mitochondrial - nuclear genetic interaction modulates whole body metabolism, adiposity and gene expression in vivo.
Specimen part, Subject
View SamplesWine produced at low temperature is often considered to improve sensory qualities. However, there are certain drawbacks to low temperature fermentations: e.g. low growth rate, long lag phase, and sluggish or stuck fermentations. Selection and development of new Saccharomyces cerevisiae strains well adapted at low temperature is interesting for future biotechnological applications. This study aimed to select and develop wine yeast strains that well adapt to ferment at low temperature through evolutionary engineering, and to decipher the process underlying the obtained phenotypes. To this end, we used a pool of 27 commercial yeast strains and set up batch serial dilution experiments to mimic wine fermentation conditions at 12 C. Evolutionary engineering was accomplished by using the natural yeast mutation rate and mutagenesis procedures. One strain (P5) outcompeted the others under both experimental conditions and was able to impose after 200 generations. The evolved strains showed improved growth and low-temperature fermentation performance compared to the ancestral strain. This improvement was acquired only under inositol limitation. The transcriptomic comparison between the evolved and parental strains showed the greatest up-regulation in four mannoprotein coding genes, which belong to the DAN/TIR family (DAN1, TIR1, TIR4 and TIR3). Genome sequencing of the evolved strain revealed the presence of a SNP in the GAA1 gene and the construction of a site-directed mutant (GAA1Thr108) in a derivative haploid of the ancestral strain resulted in improved fermentation performance. GAA1 encodes a GPI transamidase complex subunit that adds GPI, which is required for inositol synthesis, to newly synthesized proteins, including mannoproteins. Thus we demonstrate the importance of inositol and mannoproteins in yeast adaptation at low temperature and the central role of the GAA1 gene by linking both metabolisms.
Evolutionary engineering of a wine yeast strain revealed a key role of inositol and mannoprotein metabolism during low-temperature fermentation.
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View SamplesThe total abundance of phosphatidylcholine (PC) is known to influence lipoprotein production. However, the role of specific phospholipid species in lipid transport has been difficult to assess due to an inability to selectively manipulate membrane composition in vivo. Here we show that the LXR-regulated phospholipid remodeling enzyme lysophosphatidylcholine acyltransferase 3 (Lpcat3) is a critical determinant of membrane phospholipid composition and lipoprotein production. Mice lacking Lpcat3 in the liver show defects in lipoprotein production.
Lpcat3-dependent production of arachidonoyl phospholipids is a key determinant of triglyceride secretion.
Sex, Specimen part
View SamplesThe total abundance of phosphatidylcholine (PC) is known to influence lipoprotein production. However, the role of specific phospholipid species in lipid transport has been difficult to assess due to an inability to selectively manipulate membrane composition in vivo. Here we show that the LXR-regulated phospholipid remodeling enzyme lysophosphatidylcholine acyltransferase 3 (Lpcat3) is a critical determinant of membrane phospholipid composition and lipoprotein production. Mice lacking Lpcat3 in the liver show defects in lipoprotein production.
Lpcat3-dependent production of arachidonoyl phospholipids is a key determinant of triglyceride secretion.
Sex, Specimen part
View SamplesRhabdoid tumors (RTs) are aggressive tumors of early childhood that occur most often in brain (AT/RTs) or kidney (KRTs). Regardless of location, they are characterized by loss of functional SMARCB1 protein, a component of the SWI/SNF chromatin remodeling complex. The aim of this study was to determine genes and biological process dysregulated in common to both AT/RTs and KRTs. Gene expression for AT/RTs was compared to that of other brain tumors and normal brain using microarray data from our lab. Similar analysis was performed for KRTs and other kidney tumors and normal kidney using data from GEO. Dysregulated genes common to both analyses were analyzed for functional significance. Unsupervised hierarchical clustering of RTs identified 3 major subsets: 2 comprised of AT/RTs, and 1 of KRTs. Compared to other tumors, 1187, 663 and 539 genes were dysregulated in each subset, respectively. Only 14 dysregulated genes were common to all 3 subsets. Compared to normal tissue, 5209, 4275 and 2841 genes were dysregulated in each subset, with an overlap of 610 dysregulated genes. Among these genes, processes associated with cell proliferation, MYC activation, and epigenetic dysregulation were common to all 3 RT subsets. The low overlap of dysregulated genes in AT/RTs and KRTs suggests that factors in addition to SMARCB1 loss play a role in determining subsequent gene expression. Drugs which target cell cycle or epigenetic genes may be useful in all RTs. Additionally, targeted therapies tailored to specific RT subset molecular profiles should be considered.
Pediatric rhabdoid tumors of kidney and brain show many differences in gene expression but share dysregulation of cell cycle and epigenetic effector genes.
Specimen part
View SamplesWhile infection of chickens with highly pathogenic avian influenza (HPAI) H5N1 subtypes often leads to complete mortality within 24 to 48 h, infection of ducks in contrast causes mild or no clinical signs. Rapid onsets of fatal disease in chickens, but with no evidence of severe clinical symptoms in ducks, suggest underlying differences in their innate immune mechanisms. To understand the molecular basis for such difference, chicken and duck primary lung cells, infected with a low-pathogenicity avian influenza (LPAI) and two HPAI H5N1 viruses, were subjected to RNA expression profiling using Affymetrix Chicken GeneChip arrays.
Highly pathogenic avian influenza virus infection in chickens but not ducks is associated with elevated host immune and pro-inflammatory responses.
Age, Specimen part, Treatment
View SamplesPurpose: The goal of this study was to identify the gene expression profile of mouse retina which carries deletions in Dnmt1, Dnmt3a and Dnmt3b genes. Method: Retinal mRNA profiles of Postnatal day 15 wild type mice and Dnmt1, Dnmt3a and Dnmt3b mutant mice were generated by deep-sequencing Overall design: Retinal mRNA profiles of post natal day 15 wild type and mutant mice with Illumina HiSeq 2500
Dnmt1, Dnmt3a and Dnmt3b cooperate in photoreceptor and outer plexiform layer development in the mammalian retina.
Specimen part, Cell line, Subject
View SamplesMolecular profiling of tumors has proven a valuable tool for identification of prognostic and diagnostic subgroups in medulloblastomas, glioblastomas and other cancers. However, the molecular landscape of atypical teratoid / rhabdoid tumors (AT/RTs) remains largely unexplored. To address this issue, we used microarrays to measure the gene expression profiles of 18 AT/RTs, and performed unsupervised hierarchical clustering to determine molecularly similar subgroups. Four major subgroups (clusters) were identified. These did not conform to gender, tumor location, or presence of monosomy 22. Clusters showed distinct gene signatures and differences in enriched biological processes, including elevated expression of choroid plexus genes in Cluster 4. In addition, survival differed significantly by cluster, with shortest survival (mean 4.7 months) in both Clusters 3 and 4 compared to Clusters 1 and 2 (mean 28.1 months). Analysis showed that multiple bone morphogenetic protein (BMP) pathway genes were up-regulated in the short survival clusters, with BMP4 showing the most significant up-regulation (270-fold). Thus, high expression of BMP pathway genes was negatively associated with survival in this dataset. Our study indicates that molecular subgroups exist within AT/RTs, and that molecular profiling of these comparatively rare tumors may be of diagnostic, prognostic and therapeutic value.
High expression of BMP pathway genes distinguishes a subset of atypical teratoid/rhabdoid tumors associated with shorter survival.
Sex, Specimen part
View SamplesWe analyzed the global transcriptome signature over the time course of the cardiac differentiation from hESC by RNA-seq. We characterized the genome-wide transcriptome profile of 5 distinct stages; undifferentiated hESC (day 0), mesodermal precursor stage (hMP, day 2), cardiac progenitor stage (hCP, day 5), immature cardiomyocyte (hCM14) and hESC-CMS differentiated for 14 additional days (hCM28). While the stem cell signature decreases over the five stages, the signatures associated with heart and smooth muscle development increase, indicating the efficient cardiac differentiation of our protocol. Overall design: Five different temporal samples, two replicates for only first four samples day 0 through day 15
Glucose inhibits cardiac muscle maturation through nucleotide biosynthesis.
Specimen part, Subject
View SamplesMutation or deletion of Neurofibromin (NF1), an inhibitor of RAS signaling, frequently occurs in epithelial ovarian cancer (EOC), supporting therapies that target downstream RAS effectors, such as the RAF-MEK-ERK pathway. However, no comprehensive studies have been carried out testing the efficacy of MEK inhibition in NF1-deficient EOC. Here, we performed a detailed characterization of MEK inhibition in NF1-deficient EOC cell lines using kinome profiling and RNA sequencing. Our studies showed MEK inhibitors were ineffective at providing durable growth inhibition in NF1-deficient cells due to kinome reprogramming. MEKi-mediated destabilization of FOSL1 resulted in induced expression of RTKs and their downstream RAF and PI3K signaling overcoming MEKi therapy. MEKi synthetic enhancement screens identified BRD2 and BRD4 as integral mediators of the MEKi-induced RTK signatures. Inhibition of BET proteins using BET bromodomain inhibitors (BETi) blocked MEKi-induced RTK reprogramming, indicating BRD2 and BRD4 represent promising therapeutic targets in combination with MEKi to block resistance due to kinome reprogramming in NF1-deficient EOC. Overall design: Examination of the global effects on transcription in response to trametinib (GSK212) in A1847 cells.
Intrinsic Resistance to MEK Inhibition through BET Protein-Mediated Kinome Reprogramming in NF1-Deficient Ovarian Cancer.
Specimen part, Cell line, Treatment, Subject
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