Skeletal muscle stem cells (MuSC), also called satellite cells, are indispensable for maintenance and regeneration of adult skeletal muscles. Yet, a comprehensive picture of the regulatory events controlling the fate of MuSC is missing. Here, we determine the proteome of MuSC to design a loss-of-function screen, and identify 120 genes important for MuSC function including the arginine methyltransferase Prmt5. MuSC-specific inactivation of Prmt5 in adult mice prevents expansion of MuSC, abolishes long-term MuSC maintenance and abrogates skeletal muscle regeneration. Interestingly, Prmt5 is dispensable for proliferation and differentiation of Pax7(+) myogenic progenitor cells during mouse embryonic development, indicating significant differences between embryonic and adult myogenesis. Mechanistic studies reveal that Prmt5 controls proliferation of adult MuSC by direct epigenetic silencing of the cell cycle inhibitor p21. We reason that Prmt5 generates a poised state that keeps MuSC in a standby mode, thus allowing rapid MuSC amplification under disease conditions. Overall design: RNA from cultured satellite cells on Ion torrent sequencer
RNA-Seq analysis of isolated satellite cells in Prmt5 deficient mice.
No sample metadata fields
View SamplesDevelopment and function of tissues and organs are powered by the activity of mitochondria. In humans, inherited genetic mutations that lead to progressive mitochondrial pathology often manifest during infancy and can lead to death, reflecting the indispensable nature of mitochondrial function and biogenesis. Here, we describe a zebrafish mutant for the gene mia40a, the life-essential homologue of the evolutionarily conserved Mia40 oxidoreductase which drives the biogenesis of cysteine-rich mitochondrial proteins. We report that mia40a mutant animals undergo progressive cellular respiration defects and develop enlarged mitochondria in skeletal muscles before their ultimate at the larval stage. We generated a rich transcriptomic and proteomic resource that allowed us to identify abnormalities in the development of endodermal organs, in particular the liver and pancreas. We identify the acinar cells of the exocrine pancreas to be severely affected by mutations in the MIA pathway. Our data contribute to a better understanding of the molecular, cellular and organismal effects of mitochondrial deficiency, important for the accurate diagnosis and future treatment strategies of these diseases. Overall design: Embryos obtained from an in-cross of heterozygous mia40awaw1/+ siblings were genotyped at 3 dpf. Pools of five mia40+/+ or mia40waw1/waw1 larvae, derived from the same clutch, were collected at indicated time-points for RNA extraction and transcriptomic profiling. Larvae used in 8 dpf experiments were subjected to external feeding from 5dpf before being collected for the analysis at 8dpf.
Loss of the Mia40a oxidoreductase leads to hepato-pancreatic insufficiency in zebrafish.
Specimen part, Subject
View SamplesThe short-lived turquoise killifish Nothobranchius furzeri (Nfu) is a valid model for aging studies. Here, we investigated its age-associated cardiac function. We observed oxidative stress accumulation and an engagement of microRNAs (miRNAs) in the aging heart. MiRNA-sequencing of 5 week (young), 12-21 week (adult) and 28-40 week (old) Nfu hearts revealed 23 up-regulated and 18 down-regulated miRNAs with age. MiR-29 family turned out as one of the most up-regulated miRNAs during aging. MiR-29 family increase induces a decrease of known targets like collagens and DNA methyl transferases (DNMTs) paralleled by 5´methyl-cytosine (5mC) level decrease. To further investigate miR-29 family role in the fish heart we generated a transgenic zebrafish model where miR-29 was knocked-down. In this model we found significant morphological and functional cardiac alterations and an impairment of oxygen dependent pathways by transcriptome analysis leading to hypoxic marker up-regulation. To get insights the possible hypoxic regulation of miR-29 family, we exposed human cardiac fibroblasts to 1% O2 levels. In hypoxic condition we found miR-29 down-modulation responsible for the accumulation of collagens and 5mC. Overall, our data suggest that miR-29 family up-regulation might represent an endogenous mechanism aimed at ameliorating the age-dependent cardiac damage leading to hypertrophy and fibrosis. Overall design: RNA was isolated from zebrafish heart samples (3 wt and 3 miR-29-sponge) and sequenced.
Age-dependent increase of oxidative stress regulates microRNA-29 family preserving cardiac health.
Specimen part, Subject
View SamplesPrimary bile acids are produced in the liver whereas secondary bile acids such as lithocholic acid (LCA) are generated by gut bacteria from primary bile acids that escape the ileal absorption. Besides their well-known function as detergents in lipid digestion, bile acids are important signaling molecules mediating effects on the hosts metabolism. As energy metabolism is closely linked to aging and longevity we supplemented fruit flies (Drosophila melanogaster) with 50 mol/l LCA either for 30 days or throughout their lifetime. LCA supplementation resulted in a significant induction of the mean (+12 days), median (+10 days) and maximum lifespan (+ 11 days) in comparison to untreated control flies. This lifespan extension was accompanied by an induction of spargel (srl), the fly homolog of mammalian PPARG co-activator 1a(PGC1A. In srl mutant flies, LCA failed to induce longevity emphasizing the essential role of srl in the observed lifespan extension. In addition, the administration of antibiotics to wild type flies abrogated LCA-mediated effects on both lifespan and srl expression, suggesting a substantial contribution of the intestinal microbiota to the LCA-induced longevity.
Lithocholic Acid Improves the Survival of Drosophila Melanogaster.
Sex, Age, Specimen part
View SamplesBackground: Here, the role of a-ketoglutarate (aKG) in the epi-metabolic control of DNA demethylation has been investigated in therapeutically relevant cardiac mesenchymal cells (CMSCs) isolated from controls and type 2 diabetes donors. Methods & results: Quantitative global analysis, methylated and hydroxymethylated DNA sequencing and gene specific GC methylation detection revealed an accumulation of 5mC, 5hmC and 5fC in the genomic DNA of human CMSCs isolated from diabetic (D) donors (D-CMSCs). Whole heart genomic DNA analysis revealed iterative oxidative cytosine modification accumulation in mice exposed to high fat diet (HFD), injected with streptozotocin (STZ) or both in combination (STZ-HFD). In this context, untargeted and targeted metabolomics indicated an intracellular reduction of aKG synthesis in D-CMSCs and in the whole heart of HFD mice. This observation was paralleled by a compromised thymine DNA glycosylase (TDG) and ten eleven translocation protein 1 (TET1) association and function with TET1 relocating out of the nucleus. Molecular dynamics and mutational analyses showed that aKG binds TDG on Arg275 providing an enzymatic allosteric activation. As a consequence, the enzyme significantly increased its capacity to remove G/T nucleotide mismatched or 5fC. Accordingly, an exogenous source of aKG restored the DNA demethylation cycle by promoting TDG function, TET1 nuclear localization and TET/TDG association. TDG inactivation by CRISPR/Cas9 knockout or TET/TDG siRNA knockdown induced 5fC accumulation thus partially mimicking the diabetic epigenetic landscape in cells of non- diabetic origin. The novel compound (S)-2-[(2,6-dichlorobenzoyl)amino]succinic acid (AA6), identified as an inhibitor of aKG-dehydrogenase, increased the aKG level in D- CMSCs and in the heart of HFD mice eliciting DNA demethylation, glucose uptake and insulin response. Conclusions: In this report we established that diabetes may epigenetically modify and compromise function of therapeutically relevant cardiac mesenchymal cells. Restoring the epi-metabolic control of DNA demethylation cycle promises beneficial effects on cells compromised by environmental metabolic changes. Overall design: Human primary cardiac mesenchymal cells (CMSC) from 7 diabetic (D) and 7 non-diabetic (ND) donors were analyzed after few rounds of ex vivo expansion. RNA was isolated and sequenced.
Stable Oxidative Cytosine Modifications Accumulate in Cardiac Mesenchymal Cells From Type2 Diabetes Patients: Rescue by α-Ketoglutarate and TET-TDG Functional Reactivation.
Specimen part, Subject
View SamplesThis study provides the first comprehensive analysis of gene expression and transcriptome dynamics of bovine metaphase II oocytes and in vivo developing bovine embryos.
Genome-wide expression profiling reveals distinct clusters of transcriptional regulation during bovine preimplantation development in vivo.
No sample metadata fields
View SamplesHigh-throughput sequencing of mRNA from mouse lung infected with 1918 pandemic influenza virus revealed that reactive oxygen species scavenger EUK-207 treatment resulted in decreased expression of inflammatory response genes and increased lung metabolic and repair responses.
Treatment with the reactive oxygen species scavenger EUK-207 reduces lung damage and increases survival during 1918 influenza virus infection in mice.
No sample metadata fields
View SamplesGene expression analysis has been established as a tool for the characterization of genotoxic mechanisms of chemical mutagens. This approach has been shown to differentiate between DNA reactive genotoxins and non-DNA reactive or indirectly-acting genotoxins. In this context, it has been suggested that expression analysis is capable of distinguishing compounds that cause DNA damage from those that interfere with mitotic spindle function. Formaldehyde (FA) is known to be a DNA-reactive substance which mainly induces chromosomal damage in cultured mammalian cells. However, there has been concern that FA might also act as an aneugen (i.e., induce aneuploidy) but recent cytogenetic studies did not support this assumption. To further characterize FA's genotoxic mode of action, we now used gene expression profiling as a molecular tool to differentiate between clastogenic and aneugenic activity. TK6 cells were exposed to FA for 4 and 24 h and changes in gene expression were analyzed using a whole-genome human microarray. Results were compared to the expression profiles of two DNA-damaging clastogens (methyl methanesulfonate [MMS] and ethyl methanesulfonate [EMS]) and two aneugens (colcemid [COL] and vincristine [VCR]). The gene expression profiles indicated that clastogens and aneugens induce discriminable gene expression patterns. The expression profile of FA showed more similarities to clastogens than to aneugens. Hierarchical clustering analysis as well as several class prediction algorithms revealed a much closer relationship of FA with clastogens than with aneugens. A pathway analysis of differentially regulated genes also demonstrated an overall better agreement of FA with clastogens than with aneugens. Altogether, the results of this study revealed great similarities in gene expression in response to FA and clastogens but did not support an aneugenic activity of FA.
Characterization of formaldehyde's genotoxic mode of action by gene expression analysis in TK6 cells.
Cell line, Treatment
View SamplesSteer liver transcriptome
Differential expression of genes related to gain and intake in the liver of beef cattle.
Sex, Specimen part
View SamplesMutations involving the NFKB pathway are present in at least 17% of multiple myeloma (MM) tumors and 40% of MM cell lines (MMCL). These mutations, which are thought to be progression events, enable MM tumors to become less dependent on extrinsic bone marrow signals that activate NFKB. Studies on a panel of 50 MMCL provide some clarification of the mechanisms through which these mutations act and the significance of classical vs alternative activation of NFKB. First, only one mutation (NFKB2) selectively activates the alternative pathway, whereas several mutations (CYLD, NFKB1, TACI) selectively activate the classical pathway. However, most mutations affecting NIK level (NIK, TRAF2, TRAF3, cIAP1&2, CD40) activate the alternative but often both pathways. Second, we confirm the critical role of TRAF2 in regulating NIK degradation, whereas TRAF3 enhances but is not essential for cIAP1/2-mediated proteosomal degradation of NIK in MM.
Classical and/or alternative NF-kappaB pathway activation in multiple myeloma.
Cell line
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