Skeletal muscle adapts to exercise training of various modes, intensities and durations with a programmed gene expression response. This study dissects the independent and combined effects of exercise mode, intensity and duration to identify which exercise has the most positive effects on skeletal muscle health. Full details on exercise groups can be found in: Kraus et al Med Sci Sports Exerc. 2001 Oct;33(10):1774-84 and Bateman et al Am J Cardiol. 2011 Sep 15;108(6):838-44.
Metabolite signatures of exercise training in human skeletal muscle relate to mitochondrial remodelling and cardiometabolic fitness.
Sex, Age, Specimen part, Race, Subject
View SamplesLow energy states delay aging in multiple species, yet mechanisms coordinating energetics and longevity across tissues remain poorly defined. The conserved energy sensor AMP-activated protein kinase (AMPK) and its corresponding phosphatase calcineurin modulate longevity via the ‘CREB regulated transcriptional coactivator (CRTC)-1 in C. elegans. We show that CRTC-1 specifically uncouples AMPK/calcineurin mediated effects on lifespan from pleiotropic side effects by reprogramming mitochondrial and metabolic function. Strikingly, this pro-longevity metabolic state is regulated cell-nonautonomously by CRTC-1 in the nervous system. CRTC-1/CREB act antagonistically with the functional PPARa ortholog, NHR-49 to promote distinct peripheral metabolic programs. Neuronal CRTC-1 drives mitochondrial fragmentation in distal tissues and suppresses the effect of AMPK on systemic mitochondrial metabolism and longevity via a cell-nonautonomous catecholamine signal. These results demonstrate that transcriptional control of neuronal signals can override enzymatic regulation of metabolism in peripheral tissues. Central perception of energetic state therefore represents a target to promote healthy aging. Overall design: Experiment was performed with three biological replicates. Gravid adults grown at 20¡C on 100 mm NG plates seeded with OP50-1 E. coli were collected and treated with hypochlorite to release eggs. Eggs were incubated overnight in M9 media to obtain L1 synchronized populations. One thousand L1 larvae were grown on a 100 mm NG plate seeded with OP50-1 E. coli. Worms were harvested for RNA extraction when L4 larval stage was reached. Animals were collected and washed extensively with M9 media to remove bacteria. Worms were then snap frozen in liquid nitrogen. RNA was extracted by five freeze/thaw cycles in Qiazol then purified by RNeasy mini kit (Qiagen). RNA quality was checked using an Agilent Technologies 2100 Bioanalyzer. All samples had an RNA integrity number of 10. cDNA libraries were prepared from 4 ugs of total RNA using the TruSeq RNA Sample Preparation v2 kit (Illumina). 50-cycle paired-end sequencing was performed on an Illumina HiSeq 2000 by the Harvard Biopolymer Core. Read quality was evaluated with FASTQC. Adapter sequences and poor quality bases (<20) were trimmed and filtered with CUTADAPT, resulting in a median of 44 million reads per replicate. These were aligned to the C. elegans genome (ce6, WS238) using TopHat version 2.0.8 (Kim et al., 2013), with a median 35 million reads mapped in proper pairs. The number of reads mapping to each gene was counted with htseq-count. Genes with less than 1 Count Per Million Reads (CPM) were discarded from further analysis. Counts were normalized for sequencing depth and RNA composition across all samples with edgeR (Robinson et al., 2010). Genes were tested for differential expression between each mutant strain and wild-type using edgeR’s glm method. For each comparison, genes with less than 5 CPM were filtered and those with at least 50% change and False Discovery Rate (FDR) of 1% or less were considered differentially expressed.
Neuronal CRTC-1 governs systemic mitochondrial metabolism and lifespan via a catecholamine signal.
Specimen part, Subject
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 SamplesCompelling evidence suggests that mitochondrial dysfunction contributes to the pathogenesis of heart failure, including defects in the substrate oxidation, and the electron transport chain (ETC) and oxidative phosphorylation (OXPHOS). However, whether such changes occur early in the development of heart failure, and are potentially involved in the pathologic events that lead to cardiac dysfunction is unknown. To address this question, we conducted transcriptomic/metabolomics profiling in hearts of mice with two progressive stages of pressure overload-induced cardiac hypetrophy: i) cardiac hypertrophy with preserved ventricular function achieved via transverse aortic constriction for 4 weeks (TAC) and ii) decompensated cardiac hypertrophy or heart failure (HF) caused by combining 4 wk TAC with a small apical myocardial infarction. Transcriptomic analyses revealed, as shown previously, downregulated expression of genes involved in mitochondrial fatty acid oxidation in both TAC and HF hearts compared to sham-operated control hearts. Surprisingly, however, there were very few changes in expression of genes involved in other mitochondrial energy transduction pathways, ETC, or OXPHOS. Metabolomic analyses demonstrated significant alterations in pathway metabolite levels in HF (but not in TAC), including elevations in acylcarnitines, a subset of amino acids, and the lactate/pyruvate ratio. In contrast, the majority of organic acids were lower than controls. This metabolite profile suggests bottlenecks in the carbon substrate input to the TCA cycle. This transcriptomic/metabolomic profile was markedly different from that of mice PGC-1a/b deficiency in which a global downregulation of genes involved in mitochondrial ETC and OXPHOS was noted. In addition, the transcriptomic/metabolomic signatures of HF differed markedly from that of the exercise-trained mouse heart. We conclude that in contrast to current dogma, alterations in mitochondrial metabolism that occur early in the development of heart failure reflect largely post-transcriptional mechanisms resulting in impedance to substrate flux into the TCA cycle, reflected by alterations in the metabolome.
Energy metabolic reprogramming in the hypertrophied and early stage failing heart: a multisystems approach.
Sex, Age, Specimen part
View SamplesERRa is an orphan nuclear receptor with an established role in cell metabolism. Our studies demonstrate that acute or chronic loss of ERRa broadly affects mitochondrial and glycolytic metabolism in CD4+ T cells and results in diminished T cell function and differentation.
Estrogen-related receptor-α is a metabolic regulator of effector T-cell activation and differentiation.
Specimen part, Treatment
View SamplesHepatocellular carcinoma (HCC) is the fifth most-common cancer worldwide causing nearly 600,000 deaths esch year. Approximately 80% of HCC develops on the background of cirrhosis.It is necessary to identify novel genes involved in HCC to implement new diagnostic and treatment options. However, the molecular pathogenesis of HCC largely remains unsolved. Only a few genetic alterations, namely those affecting p53, -catenin and p16INK4a have been implicated at moderate frequencies of these cancers. Early detection of HCC with appropriate treatment can decrease tumor-related deaths
Genome-wide transcriptional reorganization associated with senescence-to-immortality switch during human hepatocellular carcinogenesis.
Specimen part
View SamplesCellular senescence is a tumor suppressor mechanism, and immortalization facilitates neoplastic transformation. Both mechanisms may be highly relevant to hepatocellular carcinoma (HCC) development and its molecular heterogeneity. Cellular senescence appears to play a major role in liver diseases. Chronic liver diseases are associated with progressive telomere shortening leading senescence that is observed highly in cirrhosis, but also in some HCC. We previously described the generation of immortal and senescence-programmed clones from HCC-derived Huh7 cell line.
Genome-wide transcriptional reorganization associated with senescence-to-immortality switch during human hepatocellular carcinogenesis.
Sex, Specimen part
View SamplesInsulin degrading enzyme (IDE) is a major enzyme responsible for insulin degradation in the liver. The modulation of insulin degrading enzyme activity is hypothesized to be a link between T2DM and liver cancer. Results provide insight into role of IDE in proliferation and other cell functions.
Modulation of insulin degrading enzyme activity and liver cell proliferation.
Cell line
View Samples