148 research outputs found
Metabolomics dataset of PPAR-pan treated rat liver
This article contains mass spectrometry (MS) data investigating small molecule changes as an effect of a triple peroxisome proliferator-activated receptor (PPAR-pan) agonist GW625019 in the liver as described in the manuscript (Ament et al., 2016) [1]. Samples were measured using gas chromatography-mass spectrometry (GC–MS) for total fatty acid content, and liquid chromatography-mass spectrometry (LC–MS) to measure intact lipids, carnitines and selected aqueous metabolites and eicosanoids. Data files comprise of Excel (Microsoft, WA, USA) spreadsheets of identified metabolites and their area ratio values for total fatty acids, carnitines, aqueous metabolites, and eicosanoids where the intensity of the analytes were normalised to the intensity of the internal standard. In the case of open profiling intact lipid data, the Excel file contains area ratio values of retention time and mass to charge ratio pairs; again, the area ratio values were calculated by normalising to the intensity of the internal standard. It should be noted that several metabolic changes are potentially indirect (secondary, tertiary and ensuing changes)
Myc Expression Drives Aberrant Lipid Metabolism in Lung Cancer
MYC-mediated pathogenesis in lung cancer continues to attract interest for new therapeutic strategies. In this study, we describe a transgenic mouse model of KRAS-driven lung adenocarcinoma that affords reversible activation of MYC, used here as a tool for lipidomic profiling of MYC-dependent lung tumors formed in this model. Advanced mass spectrometric imaging and surface analysis techniques were used to characterize the spatial and temporal changes in lipid composition in lung tissue. We found that normal lung tissue was characterized predominantly by saturated phosphatidylcholines and phosphatidylglycerols, which are major lipid components of pulmonary surfactant. In contrast, tumor tissues displayed an increase in phosphatidylinositols and arachidonate-containing phospholipids that can serve as signaling precursors. Deactivating MYC resulted in a rapid and dramatic decrease in arachidonic acid and its eicosanoid metabolites. In tumors with high levels of MYC, we found an increase in cytosolic phospholipase A2 (cPLA2) activity with a preferential release of membrane-bound arachidonic acid, stimulating the lipoxygenase (LOX) and COX pathways also amplified by MYC at the level of gene expression. Deactivating MYC lowered cPLA2 activity along with COX2 and 5-LOX mRNA levels. Notably, inhibiting the COX/5-LOX pathways in vivo reduced tumor burden in a manner associated with reduced cell proliferation. Taken together, our results show how MYC drives the production of specific eicosanoids critical for lung cancer cell survival and proliferation, with possible implications for the use of COX and LOX pathway inhibitors for lung cancer therapy.This research was funded by the Medical Research Council (Lipid Profiling and Signaling, MC UP A90 1006 & Lipid Dynamics and Regulation, MC PC 13030) and Cancer Research UK (program grant A12077)
Lipid zonation and phospholipid remodeling in nonalcoholic fatty liver disease
Nonalcoholic fatty liver disease (NAFLD) can progress from simple steatosis (i.e., nonalcoholic fatty liver [NAFL]) to nonalcoholic steatohepatitis (NASH), cirrhosis, and cancer. Currently, the driver for this progression is not fully understood; in particular, it is not known how NAFLD and its early progression affects the distribution of lipids in the liver, producing lipotoxicity and inflammation. In this study, we used dietary and genetic mouse models of NAFL and NASH and translated the results to humans by correlating the spatial distribution of lipids in liver tissue with disease progression using advanced mass spectrometry imaging technology. We identified several lipids with distinct zonal distributions in control and NAFL samples and observed partial to complete loss of lipid zonation in NASH. In addition, we found increased hepatic expression of genes associated with remodeling the phospholipid membrane, release of arachidonic acid (AA) from the membrane, and production of eicosanoid species that promote inflammation and cell injury. The results of our immunohistochemistry analyses suggest that the zonal location of remodeling enzyme LPCAT2 plays a role in the change in spatial distribution for AA-containing lipids. This results in a cycle of AA-enrichment in pericentral hepatocytes, membrane release of AA, and generation of proinflammatory eicosanoids and may account for increased oxidative damage in pericentral regions in NASH. Conclusion: NAFLD is associated not only with lipid enrichment, but also with zonal changes of specific lipids and their associated metabolic pathways. This may play a role in the heterogeneous development of NAFLD. (Hepatology 2017;65:1165-1180)
Dispersive charge density wave excitations and temperature dependent commensuration in Bi2Sr2CaCu2O8+{\delta}
Experimental evidence on high-Tc cuprates reveals ubiquitous charge density
wave (CDW) modulations, which coexist with superconductivity. Although the CDW
had been predicted by theory, important questions remain about the extent to
which the CDW influences lattice and charge degrees of freedom and its
characteristics as functions of doping and temperature. These questions are
intimately connected to the origin of the CDW and its relation to the
mysterious cuprate pseudogap. Here, we use ultrahigh resolution resonant
inelastic x-ray scattering (RIXS) to reveal new CDW character in underdoped
Bi2Sr2CaCu2O8+{\delta} (Bi2212). At low temperature, we observe dispersive
excitations from an incommensurate CDW that induces anomalously enhanced phonon
intensity, unseen using other techniques. Near the pseudogap temperature T*,
the CDW persists, but the associated excitations significantly weaken and the
CDW wavevector shifts, becoming nearly commensurate with a periodicity of four
lattice constants. The dispersive CDW excitations, phonon anomaly, and
temperature dependent commensuration provide a comprehensive momentum space
picture of complex CDW behavior and point to a closer relationship with the
pseudogap state
Cost of diabetes care in out-patient clinics of Karachi, Pakistan
<p>Abstract</p> <p>Background</p> <p>Diabetes Mellitus (DM) is a growing epidemic and the cost of treating diabetes is largely increasing. The objective of this study was to estimate the cost-of-illness of DM among attendees of out-patient clinics in Karachi, Pakistan. This is the first study conducted from a societal perspective to estimate the cost of managing diabetes in Pakistan.</p> <p>Methods</p> <p>A prevalence-based 'Cost-of-Illness' study for diabetes care was conducted in six different out-patient clinics of Karachi, Pakistan from July to September 2006. A pre-tested questionnaire was administered to collect the data from 345 randomly selected persons with diabetes.</p> <p>Results</p> <p>The annual mean direct cost for each person with diabetes was estimated to be Pakistani rupees 11,580 (US$ 197). Medicines accounted for the largest share of direct cost (46%), followed by laboratory investigations (32%). We found that increased age, the number of complications and longer duration of the disease significantly increase the burden of cost on society (p < 0.001). Comparing cost with family income it was found that the poorest segment of society is spending 18% of total family income on diabetes care.</p> <p>Conclusion</p> <p>This study concluded that substantial expenditure is incurred by people with diabetes; with the implication that resources could be saved by prevention, earlier detection and a reduction in diabetes co-morbidities and complications through improved diabetes care. Large scale and cost-effective prevention programs need to be initiated to maximise health gains and to reverse the advance of this epidemic.</p
Analysis of Resonant Inelastic X-Ray Scattering in Stripe-Ordered Nickelate
We analyze theoretically the resonant inelastic x-ray scattering (RIXS) at
the Ni K edge in the stripe-ordered state of La_{2-x}Sr_xNiO_4 at x=1/3. In the
calculation of RIXS spectra, the stripe-ordered ground state is described
within the Hartree-Fock approximation by using a realistic tight-binding model
for Ni3d\gamma and O2p_{x, y} orbitals, and the electron correlations in the
electronic excitation processes are taken into account within the random-phase
approximation. The calculated RIXS spectrum shows a tail toward the low-energy
region when the momentum transfer of photons equals the stripe vector Q, being
consistent with a recent experimental result. The origin of this anomalous
momentum dependence of RIXS spectra is discussed microscopically.Comment: 23 pages, 9 figures. Published version in J. Phys. Soc. Jp
The Transcription Factor Ultraspiracle Influences Honey Bee Social Behavior and Behavior-Related Gene Expression
Behavior is among the most dynamic animal phenotypes, modulated by a variety of internal and external stimuli. Behavioral differences are associated with large-scale changes in gene expression, but little is known about how these changes are regulated. Here we show how a transcription factor (TF), ultraspiracle (usp; the insect homolog of the Retinoid X Receptor), working in complex transcriptional networks, can regulate behavioral plasticity and associated changes in gene expression. We first show that RNAi knockdown of USP in honey bee abdominal fat bodies delayed the transition from working in the hive (primarily “nursing” brood) to foraging outside. We then demonstrate through transcriptomics experiments that USP induced many maturation-related transcriptional changes in the fat bodies by mediating transcriptional responses to juvenile hormone. These maturation-related transcriptional responses to USP occurred without changes in USP's genomic binding sites, as revealed by ChIP–chip. Instead, behaviorally related gene expression is likely determined by combinatorial interactions between USP and other TFs whose cis-regulatory motifs were enriched at USP's binding sites. Many modules of JH– and maturation-related genes were co-regulated in both the fat body and brain, predicting that usp and cofactors influence shared transcriptional networks in both of these maturation-related tissues. Our findings demonstrate how “single gene effects” on behavioral plasticity can involve complex transcriptional networks, in both brain and peripheral tissues
Multi-Target Drugs: The Trend of Drug Research and Development
Summarizing the status of drugs in the market and examining the trend of drug research and development is important in drug discovery. In this study, we compared the drug targets and the market sales of the new molecular entities approved by the U.S. Food and Drug Administration from January 2000 to December 2009. Two networks, namely, the target–target and drug–drug networks, have been set up using the network analysis tools. The multi-target drugs have much more potential, as shown by the network visualization and the market trends. We discussed the possible reasons and proposed the rational strategies for drug research and development in the future
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