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Item ApoA5 lowers triglyceride levels via suppression of ANGPTL3/8-mediated LPL inhibition(Elsevier, 2021) Chen, Yan Q.; Pottanat, Thomas G.; Zhen, Eugene Y.; Siegel, Robert W.; Ehsani, Mariam; Qian, Yue-Wei; Konrad, Robert J.; Biology, School of ScienceTriglyceride (TG) molecules represent the major storage form of fatty acids, and TG metabolism is essential to human health. However, the mechanistic details surrounding TG metabolism are complex and incompletely elucidated. Although it is known that angiopoietin-like protein 8 (ANGPTL8) increases TGs through an ANGPTL3/8 complex that inhibits LPL, the mechanism governing ApoA5, which lowers TGs, has remained elusive. Current hypotheses for how ApoA5 acts include direct stimulation of LPL, facilitation of TG-containing particle uptake, and regulation of hepatic TG secretion. Using immunoprecipitation-MS and Western blotting, biolayer interferometry, functional LPL enzymatic assays, and kinetic analyses of LPL activity, we show that ApoA5 associates with ANGPTL3/8 in human serum and most likely decreases TG by suppressing ANGPTL3/8-mediated LPL inhibition. We also demonstrate that ApoA5 has no direct effect on LPL, nor does it suppress the LPL-inhibitory activities of ANGPTL3, ANGPTL4, or ANGPTL4/8. Importantly, ApoA5 suppression of ANGPTL3/8-mediated LPL inhibition occurred at a molar ratio consistent with the circulating concentrations of ApoA5 and ANGPTL3/8. Because liver X receptor (LXR) agonists decrease ApoA5 expression and cause hypertriglyceridemia, we investigated the effect of the prototypical LXR agonist T0901317 on human primary hepatocytes. We observed that T0901317 modestly stimulated hepatocyte ApoA5 release, but markedly stimulated ANGPTL3/8 secretion. Interestingly, the addition of insulin to T0901317 attenuated ApoA5 secretion, but further increased ANGPTL3/8 secretion. Together, these results reveal a novel intersection of ApoA5 and ANGPTL3/8 in the regulation of TG metabolism and provide a possible explanation for LXR agonist-induced hypertriglyceridemia.Item Association of erythrocyte n-3 polyunsaturated fatty acids with incident type 2 diabetes in a Chinese population(Elsevier, 2018-09-26) Zheng, Ju-Sheng; Lin, Jie-sheng; Dong, Hong-li; Zeng, Fang-fang; Li, Duo; Song, Yiqing; Chen, Yu-ming; Epidemiology, School of Public HealthSummary Background & aims The association between circulating n-3 polyunsaturated fatty acid (PUFA) biomarkers and incident type 2 diabetes in Asian populations remains unclear. We aimed to examine the association of erythrocyte n-3 PUFA with incident type 2 diabetes in a Chinese population. Methods A total of 2671 participants, aged 40–75 y, free of type 2 diabetes at baseline, were included in the present analysis. Incident type 2 diabetes cases (n = 213) were ascertained during median follow-up of 5.6 years. Baseline erythrocyte fatty acids were measured by gas chromatography. We used multivariable Cox regression models to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of type 2 diabetes across quartiles of erythrocyte n-3 PUFA. Results After adjustment for potential confounders, HRs (95% CIs) of type 2 diabetes were 0.68 (0.47, 1.00), 0.77 (0.52, 1.15), and 0.63 (0.41, 0.95) in quartiles 2–4 of docosapentaenoic acid (C22:5n-3) (P-trend = 0.07), compared with quartile 1; and 1.08 (0.74, 1.60), 1.03 (0.70, 1.51), and 0.57 (0.38, 0.86) for eicosapentaenoic acid (C20:5n-3) (P-trend = 0.007). No association was found for docosahexaenoic acid (C22:6n-3) or alpha-linolenic acid (C18:3n-3). Conclusions Erythrocyte n-3 PUFA from marine sources (C22:5n-3 and C20:5n-3), as biomarkers of dietary marine n-3 PUFA, were inversely associated with incident type 2 diabetes in this Chinese population. Future prospective investigations in other Asian populations are necessary to confirm our findings.Item Benefits of Icosapent Ethyl Across the Range of Kidney Function in Patients With Established Cardiovascular Disease or Diabetes: REDUCE-IT RENAL(Wolters Kluwer, 2021-11-30) Majithia, Arjun; Bhatt, Deepak L.; Friedman, Allon N.; Miller, Michael; Steg, Ph. Gabriel; Brinton, Eliot A.; Jacobson, Terry A.; Ketchum, Steven B.; Juliano, Rebecca A.; Jiao, Lixia; Doyle, Ralph T., Jr.; Granowitz, Craig; Budoff, Matthew; Mason, R. Preston; Tardif, Jean-Claude; Boden, William E.; Ballantyne, Christie M.; Medicine, School of MedicineBackground: Chronic kidney disease is associated with adverse outcomes among patients with established cardiovascular disease (CVD) or diabetes. Commonly used medications to treat CVD are less effective among patients with reduced kidney function. Methods: REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial) was a multicenter, double-blind, placebo-controlled trial that randomly assigned statin-treated patients with elevated triglycerides (135-499 mg/dL) who had CVD or diabetes and 1 additional risk factor to treatment with icosapent ethyl (4 g daily) or placebo. Patients from REDUCE-IT were categorized by prespecified estimated glomerular filtration rate (eGFR) categories to analyze the effect of icosapent ethyl on the primary end point (composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or unstable angina) and key secondary end point (a composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke). Results: Among the 8179 REDUCE-IT patients, median baseline eGFR was 75 mL·min-1·1.73 m-2 (range, 17-123 mL·min-1·1.73 m-2). There were no meaningful changes in median eGFR for icosapent ethyl versus placebo across study visits. Treatment with icosapent ethyl led to consistent reduction in both the primary and key secondary composite end points across baseline eGFR categories. Patients with eGFR <60 mL·min-1·1.73 m-2 treated with icosapent ethyl had the largest absolute and similar relative risk reduction for the primary composite end point (icosapent ethyl versus placebo, 21.8% versus 28.9%; hazard ratio [HR], 0.71 [95% CI, 0.59-0.85]; P=0.0002) and key secondary composite end point (16.8% versus 22.5%; HR 0.71 [95% CI, 0.57-0.88]; P=0.001). The numeric reduction in cardiovascular death was greatest in the eGFR <60 mL·min-1·1.73 m-2 group (icosapent ethyl: 7.6%; placebo: 10.6%; HR, 0.70 [95% CI, 0.51-0.95]; P=0.02). Although patients with eGFR <60 mL·min-1·1.73 m-2 treated with icosapent ethyl had the highest numeric rates of atrial fibrillation/flutter (icosapent ethyl: 4.2%; placebo 3.0%; HR 1.42 [95% CI, 0.86-2.32]; P=0.17) and serious bleeding (icosapent ethyl: 5.4%; placebo 3.6%; HR, 1.40 [95% CI, 0.90-2.18]; P=0.13), HRs for atrial fibrillation/flutter and serious bleeding were similar across eGFR categories (P-interaction for atrial fibrillation/flutter=0.92; P-interaction for serious bleeding=0.76). Conclusions: In REDUCE-IT, icosapent ethyl reduced fatal and nonfatal ischemic events across the broad range of baseline eGFR categories.Item Comparative study of the modulation of fructose/sucrose-induced hepatic steatosis by mixed lipid formulations varying in unsaturated fatty acid content(Springer (Biomed Central Ltd.), 2015) Siddiqui, Rafat A.; Xu, Zhidong; Harvey, Kevin A.; Pavlina, Thomas M.; Becker, Michael J.; Zaloga, Gary P.; Department of Medicine, IU School of MedicineBACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in developed countries. NAFLD encompasses a spectrum of diseases, ranging from hepatic steatosis to non-alcoholic steatohepatitis (NASH), cirrhosis, and liver failure. The etiology of NAFLD remains unclear but is thought to relate to increased fatty acid flux within the liver that results in toxic fatty acid metabolite production. One source of increased fatty acid flux is fructose/sucrose-induced hepatic lipogenesis. Current treatment for NAFLD encompasses dietary modifications. However, little scientific evidence exists on which to base many dietary recommendations, especially the intake of different types of carbohydrates and fats. We hypothesized that lipid mixtures of unsaturated fatty acids would inhibit lipogenesis and subsequent hepatic steatosis induced by high carbohydrate diets. The aim of this study was to examine the effects of different complex mixtures of fatty acids upon the development of fructose/sucrose-induced hepatic steatosis. METHODS: C57BL/6 mice were randomized to normocaloric chow-based diets that varied in the type of carbohydrate (starch, sucrose, fructose). Animals in each carbohydrate group were further randomized to diets that varied in lipid type (no additional lipid, soybean oil, fish oil, olive/soybean oil, macadamia nut oil). These oils were chosen based upon their content of omega-6 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, omega-9 monounsaturated fatty acids, or omega-7 monounsaturated fatty acids. Fatty acid flux in the liver was determine by assessing hepatic lipid content (steatosis). We also assessed fatty acid levels in the plasma and liver of the animals, hepatic lipogenesis activity, hepatic stearoyl-CoA-1 desaturase activity, and hepatic elongase activity. RESULTS: Animals consumed similar amounts of the diets and maintained normal body weights throughout the study. Both sucrose and fructose induced hepatic lipogenesis and steatosis, with fructose being more potent. All mixed lipids similarly inhibited steatosis, limiting lipid content to levels found in the control (starch) animals. Lipogenesis and stearoyl-CoA-1 desaturase activity were increased in the sucrose and fructose groups. Levels of these enzymatic processes remained at baseline in all of the lipid groups. CONCLUSION: This is the first study to compare various complex lipid mixtures, based upon dietary oils with different types of long-chain fatty acids, upon development of sucrose/fructose-induced steatosis. Both carbohydrate source and lipid content appear important for the modulation of steatosis. Moderate intake of complex lipids with high unsaturated to saturated fatty acid ratios inhibited both lipogenesis and steatosis.Item Fatty Acid Synthase, a Novel Target for the Treatment of Drug Resistant Breast Cancers(2009-03-18T18:46:22Z) Liu, Hailan; Zhang, Jian-TingMany cancers, including breast cancer, often develop resistance to chemotherapeutic drugs over a course of treatment. Many factors, including ABC transporter-mediated drug efflux, have been shown to play a role in acquired drug resistance. Fatty acid synthase (FASN), the key enzyme of lipid synthesis pathway, was found to be over-produced in an Adiamycin resistant breast cancer cell line MCF7/AdrVp3000, compared to its parental drug sensitive MCF7 cell line. Inhibition of FASN expression increased the drug sensitivity in breast cancer cells (MCF7/AdrVp3000 and MDA-MB-468), but not in the normal breast epithelia cell line MCF10A1. Enforced overexpression of FASN in MCF7 breast cancer cells decreased its drug sensitivity. These results indicated that FASN overexpression can induce drug resistance in breast cancers. Ectopic overexpression of FASN in MCF7 cells did not affect cell membrane permeability, transporter activity, nor did it affect cell proliferation rate. However, FASN overexpression protects cancer cells from drug-induced apoptosis by decreasing caspase-8 activation. In FASN over-expressing MCF7 cells, I discovered the positive feedback relationship between FASN and activation of Akt as previously reported. However, activation of Akt did not mediate FASN-induced drug resistance. Together with the findings that FASN expression associates with poor prognosis in several types of cancers, my investigations suggest that FASN overexpression is a novel mechanism of drug resistance in breast cancer chemotherapy. Inhibitors of FASN can be used as sensitizing agents in breast cancer chemotherapy.Item Fatty acid synthesis in the perfused rat lung(1978) Buechler, Kenneth FrancisItem Identification of Tobacco-Related Compounds in Tobacco Products and Human Hair(2014-09-04) Rainey, Christina; Goodpaster, John V. (John Vincent); Minto, Robert; Shepson, Paul; Kissinger, Peter T., 1944-; Long, Eric C. (Eric Charles)Analyses of tobacco products and their usage are well-researched and have implications in analytical chemistry, forensic science, toxicology, and medicine. As such, analytical methods must be developed to extract compounds of interest from tobacco products and biological specimens in order to determine tobacco exposure. In 2009, R.J. Reynolds Tobacco Co. released a line of dissolvable tobacco products that are marketed as a smoking alternative. The dissolvables were extracted and prepared by ultrasonic extractions, derivatization, and headspace solid phase microextraction (SPME) with analysis by gas chromatography-mass spectrometry (GC-MS). The results show that the compounds present are nicotine, flavoring compounds, humectants and binders. Humectant concentrations vary among different tobacco types depending on the intended use. Humectants were quantified in various tobacco types by GC and “splitting” the column flow between a flame ionization detector (FID) and an MS using a microfluidic splitter in order to gain advantage from the MS’s selectivity. The results demonstrated excellent correlation between FID and MS and show that MS provides a higher level of selectivity and ensures peak purity. Chemometrics was also used to distinguish products by tobacco type. Hair is a common type of evidence in forensic investigations, and it is often subjected to mitochondrial DNA (mtDNA) analysis. Preliminary data was gathered on potential “lifestyle” markers for smoking status as well as any indications of subject age, gender, or race by investigating the organic “waste” produced during a mtDNA extraction procedure. The normally discarded organic fractions were analyzed by GC-MS and various lipids and fatty acids were detected. At this point, a total vaporization-SPME (TV-SPME) method was theorized, developed, and optimized for the specific determination of nicotine and its metabolite, cotinine. The theory of TV-SPME is to completely vaporize an organic extract which will eliminate the partitioning between the sample and the headspace, thereby simplifying the thermodynamic equilibrium. Parameters such as sample volume, incubation temperature, and extraction time were optimized to achieve the maximum analyte signal. Response surface methodology (RSM) is a statistical model that is very useful in predicting and determining optimum values for variables to ensure the ideal response. RSM was used to optimize the technique of TV-SPME for the analysis of nicotine and cotinine. Lastly, quantitation of nicotine and cotinine in human hair typically requires large sample sizes and extensive extraction procedures. Hence, a method using small sample sizes and a simple alkaline digestion followed by TV-SPME-GC-MS has been developed. Hair samples were collected from anonymous volunteers and nicotine and cotinine were identified and quantitated in the hair of tobacco users.Item Impact of omega-3 fatty acid oral therapy on healing of chronic venous leg ulcers in older adults: Study protocol for a randomized controlled single-center trial(BioMed Central, 2020-01-16) McDaniel, Jodi C.; Rausch, Jamie; Tan, Alai; School of Nursing, IU Fort WayneThis trial addresses the global problem of chronic venous leg ulcers (CVLUs), wounds that cause significant infirmity for an estimated 9.7 million people annually, mainly older adults with comorbidities. Advanced therapies are needed because standard topical therapies are often ineffective or yield only short-term wound healing. Thus, we are testing a new oral therapy containing the bioactive elements of fish oil, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), for targeting and reducing the high numbers of activated polymorphonuclear leukocytes (PMN) in wound microenvironments that keep CVLUs “trapped” in a chronic inflammatory state.Item LIPIDOMIC PROFILING OF DICTYOSTELIUM DISCOIDEUM(2012-08-27) Birch, Garrison L.; Minto, Robert; Blacklock, Brenda J.; McLeish, Michael J.The lipid profile of Dictyostelium discoideum, a cellular slime mold found evolutionarily between plants and animals, has never been clearly defined. To address this, the fatty acid content of vegetative cells was analyzed by gas chromatography-mass spectrometry of fatty acid methyl esters and their identities verified with synthesized authentic standards. The synthetic scheme developed to produce the unusual fatty acids found in D. discoideum was engineered to afford the labeling of compounds (2H) for use in feeding studies to elucidate the fatty acid elongation and desaturation pathways present in D. discoideum. After establishing the fatty acid profile and acyl metabolic pathway, an initial understanding the complex lipids present in D. discoideum, chiefly sphingolipids, was sought. Triple quadrupole and quadrupole time-of flight mass spectrometers equipped with electrospray ionization sources were used to identify these complex lipids.Item Longitudinal Plasma Metabolomics Profile in Pregnancy—A Study in an Ethnically Diverse U.S. Pregnancy Cohort(MDPI, 2021-09-01) Mitro, Susanna D.; Wu, Jing; Rahman, Mohammad L.; Cao, Yaqi; Zhu, Yeyi; Chen, Zhen; Chen, Liwei; Li, Mengying; Hinkle, Stefanie N.; Bremer, Andrew A.; Weir, Natalie L.; Tsai, Michael Y.; Song, Yiqing; Grantz, Katherine L.; Gelaye, Bizu; Zhang, Cuilin; Epidemiology, School of Public HealthAmino acids, fatty acids, and acylcarnitine metabolites play a pivotal role in maternal and fetal health, but profiles of these metabolites over pregnancy are not completely established. We described longitudinal trajectories of targeted amino acids, fatty acids, and acylcarnitines in pregnancy. We quantified 102 metabolites and combinations (37 fatty acids, 37 amino acids, and 28 acylcarnitines) in plasma samples from pregnant women in the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons cohort (n = 214 women at 10-14 and 15-26 weeks, 107 at 26-31 weeks, and 103 at 33-39 weeks). We used linear mixed models to estimate metabolite trajectories and examined variation by body mass index (BMI), race/ethnicity, and fetal sex. After excluding largely undetected metabolites, we analyzed 77 metabolites and combinations. Levels of 13 of 15 acylcarnitines, 7 of 25 amino acids, and 18 of 37 fatty acids significantly declined over gestation, while 8 of 25 amino acids and 10 of 37 fatty acids significantly increased. Several trajectories appeared to differ by BMI, race/ethnicity, and fetal sex although no tests for interactions remained significant after multiple testing correction. Future studies merit longitudinal measurements to capture metabolite changes in pregnancy, and larger samples to examine modifying effects of maternal and fetal characteristics.