Changes In Fatty Acid Oxidation Research Articles

Preconception and developmental DEHP exposure alter liver metabolism in a sex-dependent manner in adult mouse offspring

Environmental exposure to endocrine disrupting chemicals (EDCs) during critical periods of development is associated with an increased risk of metabolic diseases, including hepatic steatosis and obesity. Di-2-ethylhexyl-phthalate (DEHP) is an EDC strongly associated with these metabolic abnormalities. DEHP developmental windows of susceptibility are unknown yet have important public health implications. The purpose of this study was to identify these windows of susceptibility and determine whether developmental DEHP exposure alters hepatic metabolism later in life. Dams were exposed to control or feed containing human exposure relevant doses of DEHP (50 μg/kg BW/d) and high dose DEHP (10 mg/kg BW/d) from preconception until weaning or only exposed to DEHP during preconception. Post-weaning, all offspring were fed a control diet throughout adulthood. Using the Metabolon Untargeted Metabolomics platform, we identified 148 significant metabolites in female adult livers that were altered by preconception-gestation-lactation DEHP exposure. We found a significant increase in the levels of acylcarnitines, diacylglycerols, sphingolipids, glutathione, purines, and pyrimidines in DEHP-exposed female livers compared to controls. These changes in fatty acid oxidation and oxidative stress-related metabolites were correlated with hepatic changes including microvesicular steatosis, hepatocyte swelling, inflammation. In contrast to females, we observed fewer metabolic alterations in male offspring, which were uniquely found in preconception-only low dose DEHP exposure group. Although we found that preconception-gestational-lactation exposure causes the most liver pathology, we surprisingly found preconception exposure linked to an abnormal liver metabolome. We also found that two doses exhibited non-monotonic DEHP-induced changes in the liver. Collectively, these findings suggest that metabolic changes in the adult liver of offspring exposed periconceptionally to DHEP depends on the timing of exposure, dose, and sex.

Metabolic Reprogramming of Ovarian Cancer Spheroids during Adhesion.

Simple SummaryDuring metastasis, ovarian cancer spheroids move from the original tumor and travel through the abdominal cavity to other sites. During the movement of spheroids, cells are exposed to an environment with little oxygen or glucose, unlike how cells are traditionally cultured. In this study, we used culture conditions relevant to the abdominal cavity to investigate how energy production and fuel sources change as spheroids adhere to a secondary location. Using early time points of adhesion, we show that over time, spheroids change their metabolism as well as fuel sources as they grow out. This suggests that adhesion to another site initiates a metabolic switch that supports outgrowth and successful metastasis. This is important because if we understand how these cancer cells shift from a dormant into a growing state we can identify drug targets that may suppress these signaling pathways leading to the metabolic switch and preventing the ovarian metastases from growing and invading other tissues. This may prolong the life of women with ovarian cancer.Ovarian cancer remains a deadly disease and its recurrence disease is due in part to the presence of disseminating ovarian cancer aggregates not removed by debulking surgery. During dissemination in a dynamic ascitic environment, the spheroid cells’ metabolism is characterized by low respiration and fragmented mitochondria, a metabolic phenotype that may not support secondary outgrowth after adhesion. Here, we investigated how adhesion affects cellular respiration and substrate utilization of spheroids mimicking early stages of secondary metastasis. Using different glucose and oxygen levels, we investigated cellular metabolism at early time points of adherence (24 h and less) comparing slow and fast-developing disease models. We found that adhesion over time showed changes in cellular energy metabolism and substrate utilization, with a switch in the utilization of mostly glutamine to glucose but no changes in fatty acid oxidation. Interestingly, low glucose levels had less of an impact on cellular metabolism than hypoxia. A resilience to culture conditions and the capacity to utilize a broader spectrum of substrates more efficiently distinguished the highly aggressive cells from the cells representing slow-developing disease, suggesting a flexible metabolism contributes to the stem-like properties. These results indicate that adhesion to secondary sites initiates a metabolic switch in the oxidation of substrates that could support outgrowth and successful metastasis.

Cancer-A Major Cardiac Comorbidity With Implications on Cardiovascular Metabolism.

Cardiovascular diseases have multifactorial causes. Classical cardiovascular risk factors, such as arterial hypertension, smoking, hyperlipidemia, and diabetes associate with the development of vascular stenoses and coronary heart disease. Further comorbidities and its impact on cardiovascular metabolism have gotten more attention recently. Thus, also cancer biology may affect the heart, apart from cardiotoxic side effects of chemotherapies. Cancer is a systemic disease which primarily leads to metabolic alterations within the tumor. An emerging number of preclinical and clinical studies focuses on the interaction between cancer and a maladaptive crosstalk to the heart. Cachexia and sarcopenia can have dramatic consequences for many organ functions, including cardiac wasting and heart failure. These complications significantly increase mortality and morbidity of heart failure and cancer patients. There are concurrent metabolic changes in fatty acid oxidation (FAO) and glucose utilization in heart failure as well as in cancer, involving central molecular regulators, such as PGC-1α. Further, specific inflammatory cytokines (IL-1β, IL-6, TNF-α, INF-β), non-inflammatory cytokines (myostatin, SerpinA3, Ataxin-10) and circulating metabolites (D2-HG) may mediate a direct and maladaptive crosstalk of both diseases. Additionally, cancer therapies, such as anthracyclines and angiogenesis inhibitors target common metabolic mechanisms in cardiomyocytes and malignant cells. This review focuses on cardiovascular, cancerous, and cancer therapy-associated alterations on the systemic and cardiac metabolic state.

Metabolomics of Multiorgan Radiation Injury in Non-human Primate Model Reveals System-wide Metabolic Perturbations.

Exposure to ionizing radiation following a nuclear or radiological incident results in potential acute radiation syndromes causing sequelae of multi-organ injury in a dose- and time-dependent manner. Currently, medical countermeasures against radiation injury are limited, and no biomarkers have been approved by regulatory authorities. Identification of circulating plasma biomarkers indicative of radiation injury can be useful for early triage and injury assessment and in the development of novel therapies (medical countermeasures). Aims of this study are to (1) identify metabolites and lipids with consensus signatures that can inform on mechanism of injury in radiation-induced multi-organ injury and (2) identify plasma biomarkers in non-human primate (NHP) that correlate with tissues (kidney, liver, lung, left and right heart, jejunum) indicative of radiation injury, assessing samples collected over 3 wk post-exposure to 12 Gy partial body irradiation with 2.5% bone marrow sparing. About 180 plasma and tissue metabolites and lipids were quantified through Biocrates AbsoluteIDQ p180 kit using liquid chromatography and mass spectrometry. System-wide perturbations of specific metabolites and lipid levels and pathway alterations were identified. Citrulline, Serotonin, PC ae 38:2, PC ae 36:2, and sum of branched chain amino acids were identified as potential biomarkers of radiation injury. Pathway analysis revealed consistent changes in fatty acid oxidation and metabolism and perturbations in multiple other pathways.

Targeting Bone Marrow Adipose Tissue and the FABP Family Increases Efficacy of Dexamethasone in Multiple Myeloma

The fatty acid binding protein (FABP) family is instrumental in adipocyte biology and contributes to metabolic disorders such as obesity. Recent evidence suggests these proteins may also play a role in cancer through affecting fatty acid metabolism, PPARG signaling, or other pathways. We analyzed several microarray patient datasets and found that increases in FABP5 expression in multiple myeloma (MM) cells correlates with poor overall survival and shorter relapse free survival (Zhan et al. Blood, 2006., Mulligan et al. Blood, 2006., Carrasco et al. Cancer Cell, 2006). Interestingly, when MM patients are classified into molecular subtypes, MM cells from "proliferative" (most aggressive) patient subgroups have the highest expression of FABP5 (Zhan et al. 2006). Additionally, MM cells from relapsed patients have increased expression of FABP5 versus newly-diagnosed patients (Chng et al. Cancer Research, 2007). Since FABPs have been shown to compensate for each other, and the Zhen dataset revealed that FABP4 and FABP5 expression are significantly correlated in MM cells, we next investigated targeting both FABP4 and FABP5 in myeloma preclinically. We tested two well-known FABP inhibitors, BMS309403 and SBFI-26 (which are mainly inhibitors of FABP4 and FABP5 respectively, termed iFABP4 and iFABP5). We assessed their effects on MM cell apoptosis, cell cycle, cell number, gene expression and fatty acid metabolism. iFABP4 or iFABP5 demonstrated a dose-dependent decrease (using 0-150μM) in MM.1S, RPMI-8226 and OPM2 cell number over 72 hours of treatment via bioluminescence. Additionally, 50 μM iFABP4 or iFABP5 inhibit MM.1S cell growth in a time-dependent manner, and combination treatment of both inhibitors led to the greatest reduction in cell number. A flow-based analysis of MM.1S cell cycle revealed that co-treatment of iFABP4 and iFABP5 (iFABP4/5) led to a significant increase in G1 and a reduction in S phase, suggesting cell cycle arrest. Single treatment with either inhibitor led to a ~5% increase in apoptosis at 72 hours, and co-treatment resulted in ~10% increase via flow cytometry, suggesting that both increased apoptosis and cell cycle arrest contributed to decreased MM cell numbers. Results from RNAseq and Seahorse platform analysis of fatty acid oxidation changes are in progress and will be presented at the conference. We next tested if iFABPs could enhance the efficacy of dexamethasone (dex), a common anti-myeloma treatment. Treatment of MM.1S cells with 80 μM dex led to a 3-fold increase in apoptosis, and combination with iFABP4 or iFABP5 led to significantly more apoptosis. The greatest increase in apoptosis occurred with the combination of iFABP4, iFABP5 and dex, which resulted in a 9-fold increase in apoptosis versus the vehicle. Similar trends were observed combining dex with iFABP4/5 on MM cell number, suggesting that combination treatments hold promise for MM patients. Finally, in vivo we tested the potential of targeting FABPs in a MM xenograft mouse model. Eight week old SCID-beige female mice (n=12) were inoculated with 5x10^6 human GFP+luc+MM.1S cells i.v, followed by iFABP treatments, initiated the next day. Treatments continued three times/week at 5mg/kg BMS309403, 1 mg/kg SBFI-26, or both, and mice were analyzed biweekly with live bioluminescent imaging of whole mice starting ten days post inoculation. As early as 21 days after MM cell injection, there was significantly lower tumor burden in all treatment groups compared to the vehicle, and this trend continued for the duration of the study (Fig 1A). The BMS309403 (iFABP4) treatment group had the least amount of tumor burden, and all 3 treatment regimens caused the mice to live significantly longer than the vehicle mice (Fig 1B). Our future studies will interrogate if effects on the tumor cells directly, and/or effects on the tumor microenvironment (eg. bone marrow adipocytes), caused these observed outcomes using FABP4/5-knockout or knockdown MM.1S cells and FABP4/5-/- genetic mouse models. We will also interrogate addition of dex and other MM drugs to the FABPi's. Collectively, this work suggests that FABPs are newly-identified targets pivotal for MM cell growth in vitro and in vivo and that inhibition of FABPs in vivo significantly improves mouse survival and decreases tumor burden. Thus, our research demonstrates a new, untapped therapeutic avenue for the treatment of MM patients. Figure 1 Disclosures No relevant conflicts of interest to declare.

Comparative metabolome analysis of serum changes in sheep under overgrazing or light grazing conditions

BackgroundOvergrazing is a primary contributor to severe reduction in forage quality and production in Inner Mongolia, leading to extensive ecosystem degradation, sheep health impairment and growth performance reduction. Further studies to identify serum biomarkers that reflect changes in sheep health and nutritional status following overgrazing would be beneficial. We hereby hypothesize that reduced sheep growth performance under overgrazing conditions would be associated with metabolic and immune response alterations. This study used an untargeted metabolomics analysis by conducting ultra-high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) of sheep serum under overgrazing and light grazing conditions to identify metabolic disruptions in response to overgrazing.ResultsThe sheep body weight gains as well as serum biochemical variables associated with immune responses and nutritional metabolism (immunoglobulin G, albumin, glucose, and nonesterified fatty acids) were significantly decreased with overgrazing compared with light grazing condition. In contrast, other serum parameters such as alanine and aspartate aminotransferase, alkaline phosphatase, total bilirubin, blood urea nitrogen, and interleukin-8 were markedly higher in the overgrazing group. Principal component analysis discriminated the metabolomes of the light grazing from the overgrazing group. Multivariate and univariate analyses revealed changes in the serum concentrations of 15 metabolites (9 metabolites exhibited a marked increase, whereas 6 metabolites showed a significant decrease) in the overgrazing group. Major changes of fatty acid oxidation, bile acid biosynthesis, and purine and protein metabolism were observed.ConclusionsThese findings offer metabolic evidence for putative biomarkers for overgrazing-induced changes in serum metabolism. Target-identification of these particular metabolites may potentially increase our knowledge of the molecular mechanisms of altered immune responses, nutritional metabolism, and reduced sheep growth performance under overgrazing conditions.

A Fatty Acid Oxidation-dependent Metabolic Shift Regulates the Adaptation of BRAF-mutated Melanoma to MAPK Inhibitors.

Treatment of BRAFV600E -mutant melanomas with MAPK inhibitors (MAPKi) results in significant tumor regression, but acquired resistance is pervasive. To understand nonmutational mechanisms underlying the adaptation to MAPKi and to identify novel vulnerabilities of melanomas treated with MAPKi, we focused on the initial response phase during treatment with MAPKi. By screening proteins expressed on the cell surface of melanoma cells, we identified the fatty acid transporter CD36 as the most consistently upregulated protein upon short-term treatment with MAPKi. We further investigated the effects of MAPKi on fatty acid metabolism using in vitro and in vivo models and analyzing patients' pre- and on-treatment tumor specimens. Melanoma cells treated with MAPKi displayed increased levels of CD36 and of PPARα-mediated and carnitine palmitoyltransferase 1A (CPT1A)-dependent fatty acid oxidation (FAO). While CD36 is a useful marker of melanoma cells during adaptation and drug-tolerant phases, the upregulation of CD36 is not functionally involved in FAO changes that characterize MAPKi-treated cells. Increased FAO is required for BRAFV600E -mutant melanoma cells to survive under the MAPKi-induced metabolic stress prior to acquiring drug resistance. The upfront and concomitant inhibition of FAO, glycolysis, and MAPK synergistically inhibits tumor cell growth in vitro and in vivo. Thus, we identified a clinically relevant therapeutic approach that has the potential to improve initial responses and to delay acquired drug resistance of BRAFV600E -mutant melanoma.

Platycodon grandiflorus Root Extract Attenuates Body Fat Mass, Hepatic Steatosis and Insulin Resistance through the Interplay between the Liver and Adipose Tissue.

The Platycodon grandiflorus root, a Korean medicinal food, is well known to have beneficial effects on obesity and diabetes. In this study, we demonstrated the metabolic effects of P. grandiflorus root ethanol extract (PGE), which is rich in platycodins, on diet-induced obesity. C57BL/6J mice (four-week-old males) were fed a normal diet (16.58% of kilocalories from fat), high-fat diet (HFD, 60% of kilocalories from fat), and HFD supplemented with 5% (w/w) PGE. In the HFD-fed mice, PGE markedly suppressed the body weight gain and white fat mass to normal control level, with simultaneous increase in the expression of thermogenic genes (such as SIRT1, PPARα, PGC1α, and UCP1), that accompanied changes in fatty acid oxidation (FAO) and energy expenditure. In addition, PGE improved insulin sensitivity through activation of the PPARγ expression, which upregulates adiponectin while decreasing leptin gene expression in adipocytes. Furthermore, PGE improved hepatic steatosis by suppressing hepatic lipogenesis while increasing expression of FAO-associated genes such as PGC1α. PGE normalized body fat and body weight, which is likely associated with the increased energy expenditure and thermogenic gene expression. PGE can protect from HFD-induced insulin resistance, and hepatic steatosis by controlling lipid and glucose metabolism.

Variation of long-chain 3-hydroxyacyl CoA dehydrogenase DNA methylated modification and correlation with gene mRNA expression of early-onset preeclampsia, HELLP syndrome and antiphospholipid syndrome in trophoblast cells of placenta

By detecting the DNA methylation and gene expression of long-chain 3-hydroxyacyl CoA dehydrogenase(LCHAD)in trophoblast cells, analyze the correlation of DNA methylation and gene expression in early-onset preeclampsia(EPE), hemolysis, elevated liver enzymes, and low platelets(HELLP)syndrome and antiphospholipid syndrome(APS), to investigate the molecular basis of long-chain fatty acid oxidation changes in different preeclampsia and pathological pregnancy. Primary human cytotrophoblast cells and HTR8/Svneo cells were treated with serum from patients with EPE(14 cases), HELLP(12 cases), APS(14 cases), and normal pregnant women(NP, 14 cases). The methylation level of LCHAD gene promoter region through the MassARRAY platform and mRNA expression level by real-time fluorescent quantitative PCR technique were conducted. (1)Cytosine-phosphate-guanine(CpG)sites in human LCHAD DNA promoter region: CpG sites were detected in the range of 558 bp before LCHAD gene transcription start site, the detected CpG sites were 11 sites including 8 single sites and 3 complex sites. The position of these sites were at-984,-960,-899,-853,-811,-796,-774,-727,-615,-595,-579 respectively.(2)The sites of-899,-853,-615 and-595 showed increased methylation level in EPE and HELLP groups. The methylation level at-899,-853 and-615 sites in EPE and HELLP groups were significantly higher than those in NP group(P<0.01). The methylation level at-853 site was higher in EPE group than that in HELLP group(P<0.05). The-595 site showed the unmethylated in EPE, HELLP and APS groups. There were significantly difference between the 3 groups and EPE group(P<0.01).(3)The gene expression of LCHAD mRNA in EPE(0.048±0.005), HELLP(0.045±0.006)and APS(0.044±0.004)groups were significantly lower than NP group(0.076±0.009; P<0.01).(4)The correlation of methylation level and gene expression in all groups: the methylation level at-899,-853,-727,-615 and-579 sites were negatively correlated with gene mRNA expression in EPE group(P<0.05). The methylation level at-899,-853 and-615 sites were negatively correlated with gene mRNA expression in HELLP group(P< 0.05). The variation of LCHAD DNA methylation of trophoblast cells are found among EPE, HELLP syndrome and APS. The different correlation of LCHAD DNA methylation and gene expression are different in pathological groups. LCHAD DNA methylation of EPE and HELLP syndrome were significantly increased and negatively correlated with LCHAD gene mRNA expression. These results further revealed the molecular basis of long-chain fatty acid oxidation in different preeclampsia and pathological pregnancy.

P1082 : Fatty acid oxidation changes in early-onset pre-eclampsia, HELLP syndrome and antiphospholipid syndrome and its correlation with oxidative stress and endothelial injury in human trophoblasts

P1082 : Fatty acid oxidation changes in early-onset pre-eclampsia, HELLP syndrome and antiphospholipid syndrome and its correlation with oxidative stress and endothelial injury in human trophoblasts

Decreased liver triglyceride content in adult rats exposed to protein restriction during gestation and lactation: role of hepatic triglyceride utilization.

We have previously demonstrated that protein restriction throughout gestation and lactation reduces liver triglyceride content in adult rat offspring. However, the mechanisms mediating the decrease in liver triglyceride content are not understood. The aim of the current study was to use a new group of pregnant animals and their offspring and determine the contribution of increased triglyceride utilization via the hepatic fatty-acid oxidation and triglyceride secretory pathways to the reduction in liver triglyceride content. Pregnant Sprague-Dawley rats received either a control or a low protein diet throughout pregnancy and lactation. Pups were weaned onto laboratory chow on day 28 and killed on day 65. Liver triglyceride content was reduced in male, but not female, low-protein offspring, both in the fed and fasted states. The reduction was accompanied by a trend towards higher liver carnitine palmitoyltransferase-1a activity, suggesting increased fatty-acid transport into the mitochondrial matrix. However, medium-chain acyl coenzyme A dehydrogenase activity within the mitochondrial matrix, expression of nuclear peroxisome proliferator activated receptor-α, and plasma levels of β-hydroxybutyrate were similar between low protein and control offspring, indicating a lack of change in fatty-acid oxidation. Hepatic triglyceride secretion, assessed by blocking peripheral triglyceride utilization and measuring serum triglyceride accumulation rate, and the activity of microsomal transfer protein, were similar between low protein and control offspring. Because enhanced triglyceride utilization is not a significant contributor, the decrease in liver triglyceride content in male low-protein offspring is likely due to alterations in liver fatty-acid transport or triglyceride biosynthesis.

Fatty acid oxidation changes and the correlation with oxidative stress in different preeclampsia-like mouse models.

BackgroundLong-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) expression is decreased in placenta of some cases of preeclampsia (PE) which may result in free fatty acid (FFA) increased. High FFA level will induce oxidative stress, so abnormal long-chain fatty acid-oxidation may participate in the pathogenesis of PE through oxidative stress pathway.MethodsPE-like groups were ApoC3 transgenic mice with abnormal fatty acid metabolism, classical PE-like models with injection of Nw-nitro-L-arginine-methyl ester (L-NA) or lipopolysaccharide (LPS) and the antiphospholipid syndrome (APS) mouse model with β2GPI injection (ApoC3+NS, ApoC3+L-NA, L-NA, LPS and β2GPI groups). The control group was wild-type mice with normal saline injection. Except for β2GPI mice, the other mice were subdivided into pre-implantation (Pre) and mid-pregnancy (Mid) subgroups by injection time.ResultsAll PE-like groups showed hypertension and proteinuria except ApoC3+NS mice only showed hypertension. Serum FFA levels increased significantly except in LPS group compared to controls (P<0.05). LCHAD mRNA and protein expression in the liver and placenta was significantly higher for ApoC3+NS, ApoC3+L-NA and β2GPI mice and lower for L-NA mice than controls (P<0.05) but did not differ between LPS mice and controls. P47phox mRNA and protein expression in the liver significantly increased in all PE-like groups except LPS group, while P47phox expression in the placenta only significantly increased in L-NA and β2GPI groups.ConclusionsAbnormal long-chain fatty acid-oxidation may play a different role in different PE-like models and in some cases participate in the pathogenesis of PE through oxidative stress pathway.

Hepatic carboxylesterase 1 is essential for both normal and farnesoid X receptor-controlled lipid homeostasis

Nonalcoholic fatty liver disease (NAFLD) is one of the major health concerns worldwide. Farnesoid X receptor (FXR) is considered a therapeutic target for treatment of NAFLD. However, the mechanism by which activation of FXR lowers hepatic triglyceride (TG) levels remains unknown. Here we investigated the role of hepatic carboxylesterase 1 (CES1) in regulating both normal and FXR-controlled lipid homeostasis. Overexpression of hepatic CES1 lowered hepatic TG and plasma glucose levels in both wild-type and diabetic mice. In contrast, knockdown of hepatic CES1 increased hepatic TG and plasma cholesterol levels. These effects likely resulted from the TG hydrolase activity of CES1, with subsequent changes in fatty acid oxidation and/or de novo lipogenesis. Activation of FXR induced hepatic CES1, and reduced the levels of hepatic and plasma TG as well as plasma cholesterol in a CES1-dependent manner. Hepatic CES1 plays a critical role in regulating both lipid and carbohydrate metabolism and FXR-controlled lipid homeostasis.

Eicosapentaenoic acid regulation of muscle lipid metabolism in vivo and in vitro (1037.2)

Eicosapentaenoic acid (EPA), an omega 3 fatty acid exerts potent anti‐inflammatory and hypolipidemic effects. We previously reported that mice fed high fat diets supplemented with EPA (HF‐EPA) were resistant to diet‐induced obesity, inflammation and insulin resistance. Here we further investigate both in vivo and in vitro the mechanisms by which muscle tissue contributes to the metabolic benefits of EPA. We compared changes in gene and protein expression and tissue metabolites in mice fed either HF or HF‐EPA for 11 weeks and in C2C12 cells treated with or without EPA. Docosahexaenoic acid, saturated fatty acids and cholesterol precursors were increased in muscle of mice fed HF‐EPA vs. HF. Surprisingly, EPA increased fatty acid oxidation in adipose tissue but not in muscle. To determine mechanisms mediating direct effects of EPA in muscle in vitro, we used the mouse myocyte cell line C2C12 cells. Consistent with our findings in vivo, treatment of C2C12 cells with 50μM EPA increased lipoprotein lipase (Lpl) gene expression in a time‐dependent manner while fatty acid oxidation was unchanged. In conclusion, high fat diets supplemented with EPA increased saturated fatty acids and cholesterol precursors content in muscle with no significant changes in fatty acid oxidation. These findings suggest a possible unique role of EPA in mediating muscle cholesterogenesis in mice.Grant Funding Source: Suported by USDA, AHA &amp; TTU (COHS &amp;OVPR)

Long-chain fatty acid oxidation changes in a β2 glycoprotein I-induced preeclampsia-like mouse model

IntroductionAbnormal fatty acid oxidation (FAO) and lipid metabolism have been found related to preeclampsia (PE). Antiphospholipid syndrome (APS) as a clinical risk factor for PE has also been reported with abnormal lipid metabolism. However, the role of FAO in PE accompanied with APS is unknown. We aimed to investigate long-chain FAO changes in a PE-like rodent model induced by beta 2-glycoprotein I (β2GPI). MethodsThe PE-like model was established by injection of β2GPI (β2GPI group) or normal saline (control group) into C57BL/6J mice which were sacrificed on day 14 or 18 of gestation. Serum levels of anti-cardiolipin antibodies (aCL), anti-β2GPI antibodies (aβ2GPI) and serum lipids were assayed. Lipid deposition in the placenta and maternal liver was detected by lipid staining. Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) mRNA and protein expression in the placenta and maternal liver was analyzed. ResultsThe β2GPI group showed PE-like symptoms including hypertension, proteinuria and adverse pregnancy outcomes. Serum aCL, aβ2GPI, free fatty acid (FFA) and triglyceride (TG) levels in the β2GPI group were significantly elevated compared with the corresponding control group (P < 0.05), while cholesterol showed no significant changes. Placenta and maternal liver fatty infiltration was found in the β2GPI group. LCHAD mRNA and protein expression in the placenta and maternal liver in the β2GPI group were significantly elevated compared with the corresponding control group (P < 0.05). Conclusionβ2GPI can induce PE-like symptoms, elevated serum FFA and TG, and abnormal LCHAD expression in pregnant mice. Changes in long-chain FAO could be a factor linking PE and APS.

Bezafibrate in skeletal muscle fatty acid oxidation disorders

To assess whether bezafibrate increases fatty acid oxidation (FAO) and lowers heart rate (HR) during exercise in patients with carnitine palmitoyltransferase (CPT) II and very long-chain acyl-CoA dehydrogenase (VLCAD) deficiencies. This was a 3-month, randomized, double-blind, crossover study of bezafibrate in patients with CPT II (n = 5) and VLCAD (n = 5) deficiencies. Primary outcome measures were changes in FAO, measured with stable-isotope methodology and indirect calorimetry, and changes in HR during exercise. Bezafibrate lowered low-density lipoprotein, triglyceride, and free fatty acid concentrations; however, there were no changes in palmitate oxidation, FAO, or HR during exercise. Bezafibrate does not improve clinical symptoms or FAO during exercise in patients with CPT II and VLCAD deficiencies. These findings indicate that previous in vitro studies suggesting a therapeutic potential for fibrates in disorders of FAO do not translate into clinically meaningful effects in vivo. This study provides Class I evidence that bezafibrate 200 mg 3 times daily is ineffective in improving changes in FAO and HR during exercise in adults with CPT II and VLCAD deficiencies.

Tissue-specific changes in fatty acid oxidation in hypoxic heart and skeletal muscle

Exposure to hypobaric hypoxia is sufficient to decrease cardiac PCr/ATP and alters skeletal muscle energetics in humans. Cellular mechanisms underlying the different metabolic responses of these tissues and the time-dependent nature of these changes are currently unknown, but altered substrate utilization and mitochondrial function may be a contributory factor. We therefore sought to investigate the effects of acute (1 day) and more sustained (7 days) hypoxia (13% O₂) on the transcription factor peroxisome proliferator-activated receptor α (PPARα) and its targets in mouse cardiac and skeletal muscle. In the heart, PPARα expression was 40% higher than in normoxia after 1 and 7 days of hypoxia. Activities of carnitine palmitoyltransferase (CPT) I and β-hydroxyacyl-CoA dehydrogenase (HOAD) were 75% and 35% lower, respectively, after 1 day of hypoxia, returning to normoxic levels after 7 days. Oxidative phosphorylation respiration rates using palmitoyl-carnitine followed a similar pattern, while respiration using pyruvate decreased. In skeletal muscle, PPARα expression and CPT I activity were 20% and 65% lower, respectively, after 1 day of hypoxia, remaining at this level after 7 days with no change in HOAD activity. Oxidative phosphorylation respiration rates using palmitoyl-carnitine were lower in skeletal muscle throughout hypoxia, while respiration using pyruvate remained unchanged. The rate of CO₂ production from palmitate oxidation was significantly lower in both tissues throughout hypoxia. Thus cardiac muscle may remain reliant on fatty acids during sustained hypoxia, while skeletal muscle decreases fatty acid oxidation and maintains pyruvate oxidation.

Abstract 435: Hepatic Carboxylesterase 1 is Essential for Maintaining Hepatic Triglyceride and Plasma Cholesterol Homeostasis and is Regulated by the Farnesoid X Receptor

Non-alcoholic fatty liver disease (NAFLD) is one of the major health concerns worldwide, and is associated with increased risk of cardiovascular disease. Farnesoid X receptor (FXR) is considered a therapeutic target for treatment of NAFLD and lipid disorders. Here we investigated the role of hepatic carboxylesterase 1 (CES1) in lipid and carbohydrate metabolism. We found that the hepatic CES1 expression is affected by the status of glucose. Over-expression of hepatic CES1 lowered the levels of hepatic TG and plasma glucose in both wild-type and diabetic mice. Knockdown of hepatic CES1 increased both hepatic TG level and plasma cholesterol level. Such effects of CES1 likely resulted from its TG hydrolase activity, and subsequent changes in fatty acid oxidation and/or de novo lipogenesis. Hepatic CES1 was also inducible by FXR and was indispensable for activated FXR to improve both hepatic and plasma lipid homeostasis. Thus, hepatic CES1 plays a critical role in regulating lipid and carbohydrate metabolism and in FXR-controlled lipid homeostasis.

1331 PHENFORMIN INDUCES METABOLIC SHIFT OF PROSTATE CANCER CELLS TOWARDS UTILIZATION OF FATTY ACID METABOLISM

You have accessJournal of UrologyProstate Cancer: Basic Research (VI)1 Apr 20131331 PHENFORMIN INDUCES METABOLIC SHIFT OF PROSTATE CANCER CELLS TOWARDS UTILIZATION OF FATTY ACID METABOLISM M. Minhaj Siddiqui, Hong Truong, Carole Sourbier, Jane B. Trepel, Peter Pinto, Len Neckers, and W. Marston Linehan M. Minhaj SiddiquiM. Minhaj Siddiqui Bethesda, MD More articles by this author , Hong TruongHong Truong Bethesda, MD More articles by this author , Carole SourbierCarole Sourbier Bethesda, MD More articles by this author , Jane B. TrepelJane B. Trepel Bethesda, MD More articles by this author , Peter PintoPeter Pinto Bethesda, MD More articles by this author , Len NeckersLen Neckers Bethesda, MD More articles by this author , and W. Marston LinehanW. Marston Linehan Bethesda, MD More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.2685AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Biguanide drugs (most notably metformin) have generated significant interest lately due to their unanticipated anticancer properties. The mechanism(s) responsible for this activity remain unclear although preliminary data point to involvement of energy production pathways, either through complex 1 in the mitochondria or AMPK. We sought to further characterize the metabolic changes incurred in prostate cancer cells upon exposure to phenformin, a more potent analogue of metformin. METHODS LNCaP cells were utilized for this study. Phenformin exposures were for 2-24 hours at concentrations ranging from 0.1 to 100 uM. Western blot analysis was used to assess for changes in protein expression. The Seahorse XF96 analyzer was used to measure oxygen consumption rate (OCR) following injection of Palmitic acid bound to BSA to measure fatty acid oxidation (FAO). Cells were also exposed to 5 uM AICAR (a direct AMPK activator) and 10 uM compound C (an AMPK inhibitor) to assess the influence of AMPK on phenformin induced changes. RESULTS LNCaP cells exposed to 100 uM phenformin demonstrated a 210 % increase in OCR in response to fatty acid injection compared to LNCaP cells not exposed to phenformin (p<0.0001, Fig 1). No changes in FAO were observed after treatment of LNCaP cells with the direct AMPK activator AICAR or with the AMPK inhibitor compound C, suggesting that phenformin effect is at least not solely due to AMPK activation. Co-treatment with AICAR and phenformin demonstrated no significant change in FAO compared to phenformin alone, however co-treatment with phenformin and compound C demonstrated a statistically significant blunting of the effect of phenformin (50%; p<0.0001). Western blot analysis and densitometry demonstrated a significant induction of fatty acid synthetase and acetyl-CoA carboxylase (ACC) in phenformin-treated cells (p<0.001). CONCLUSIONS Phenformin seems to shift the metabolic balance of LNCaP cells towards oxidation of fatty acids in mitochondria. Although not directly induced by AMPK, this phenomenon seems to be modulated by AMPK activity state. Future studies will expand this study to include additional prostate cancer cell lines, and we will investigate whether targeting fatty acid metabolism represents a novel therapeutic strategy to treat prostate cancer. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e543-e544 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information M. Minhaj Siddiqui Bethesda, MD More articles by this author Hong Truong Bethesda, MD More articles by this author Carole Sourbier Bethesda, MD More articles by this author Jane B. Trepel Bethesda, MD More articles by this author Peter Pinto Bethesda, MD More articles by this author Len Neckers Bethesda, MD More articles by this author W. Marston Linehan Bethesda, MD More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

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