Lipid metabolic alterations in cancer: Common pathophysiology with cardiovascular disease.

Non-coding RNAs in lipid metabolism

Although evidences show the role of Mg 2+ in lipid metabolism and atherosclerosis, the molecular mechanism by which loss of Mg 2+ homeostasis promotes cardiovascular disease (CVD) is not known. Mg 2+ homeostasis is regulated by mitochondria and Mrs2 is the only known molecular machinery associated with mitochondrial Mg 2+ influx. To begin elucidating the importance of Mg 2+ homeostasis in lipid metabolism and CVD we made liver-specific Mrs2 KO mouse (Mrs2 Δhep ). Liver being the central hub of lipid metabolism, we asked whether loss of Mrs2 alters lipid metabolism and lipoprotein profile. Our results show increased accumulation of hepatic triacylglycerol (TG) and cholesterol in Mrs2 Δhep . Consistent with increased TG/cholesterol, plasma cholesterol and oxidized low density lipoprotein (ox-LDL) levels significantly differed between control and KO. Because ox-LDL contribute to atherosclerosis, we hypothesized altered hepatic lipid metabolism to induce inflammation, immune imbalance and accelerate lesions through modified atherogenic lipoprotein and cytokine profile. Quantification of plasma cytokines and chemokines were performed using the proteome profiler. Because T cells are critical drivers and modifiers of atherosclerosis, we quantified the lymphocyte and monocyte subsets by flow cytometry. Because T regulatory cells have anti-antherogenic roles, we studied the effect of ox-LDL on Tregs. Our results show increased and decreased levels of inflammatory and anti-inflammatory cytokines respectively in Mrs2 Δhep . In Mrs2 Δhep stimulation with ox-LDL showed an increased antigen specific proliferation of T-cells. We also observed increased and decreased population of Th17 and Tregs respectively. The decrease in Tregs population was attributed to increased apoptosis. In conclusion our observation suggests that high levels of ox-LDL in Mrs2 Δhep to induce inflammation and inflammatory cell expansion accompanied by apoptosis in Tregs. Our results conclude dysregulated Mg 2+ homeostasis to alter lipid metabolism and atherogenesis by inducing inflammation and compromised Tregs population. Our study will be the first of its kind to establish a triangular molecular link between Mg 2+ homeostasis, lipid metabolism, and atherogenesis.

Stable isotope tracers and indirect calorimetry were used to evaluate the progressive alterations in lipid and glucose metabolism after 12, 18, 24, 30, 42, 54, and 72 h of fasting in six healthy male volunteers. The rates of appearance (Ra) of glycerol and palmitic acid in plasma doubled from 2.08 +/- 0.22 and 1.63 +/- 0.20 mumol.kg-1 x min-1, respectively, after 12 h to 4.36 +/- 0.36 and 3.26 +/- 0.40 mumol.kg-1 x min-1, respectively, after 72 h of fasting (P < 0.01). Of the total increase in lipid kinetics, 60% occurred between 12 and 24 h of fasting; the greatest interval change occurred between 18 and 24 h of fasting. Glucose Ra and plasma concentration decreased by approximately 25% between 12 h (11.0 +/- 0.4 mumol.kg-1 x min-1 and 5.58 +/- 0.08 mmol/l, respectively) and 72 h (8.3 +/- 0.3 mumol.kg-1 x min-1 and 4.14 +/- 0.10 mmol/l, respectively) of fasting (P < 0.01), but no statistically significant changes occurred between 18 and 24 h of fasting. Plasma insulin decreased by approximately 50% between 12 h (64.6 +/- 12.9 pmol/l) and 72 h (30.1 +/- 7.9 pmol/l) of fasting (P < 0.001). Of the total decline in plasma insulin, 70% occurred within the first 24 h of fasting. These results demonstrate that the mobilization of adipose tissue triglycerides increases markedly between 18 and 24 h of fasting in young adult men. The early alterations in lipid metabolism are associated with a decline in circulating insulin but do not seem to be regulated by changes in glucose kinetics or plasma glucose concentrations.

Lipid metabolites are indispensable regulators of physiological and pathological processes, including atherosclerosis and coronary artery disease (CAD). However, the complex changes in lipid metabolites and metabolism that occur in patients with these conditions are incompletely understood. We performed lipid profiling to identify alterations in lipid metabolism in patients with angina and myocardial infarction (MI). Global lipid profiling was applied to serum samples from patients with CAD (angina and MI) and age-, sex-, and body mass index-matched healthy subjects using ultra-performance liquid chromatography/quadruple time-of-flight mass spectrometry and multivariate statistical analysis. A multivariate analysis showed a clear separation between the patients with CAD and normal controls. Lysophosphatidylcholine (lysoPC) and lysophosphatidylethanolamine (lysoPE) species containing unsaturated fatty acids and free fatty acids were associated with an increased risk of CAD, whereas species of lysoPC and lyso-alkyl PC containing saturated fatty acids were associated with a decreased risk. Additionally, PC species containing palmitic acid, diacylglycerol, sphingomyelin, and ceramide were associated with an increased risk of MI, whereas PE-plasmalogen and phosphatidylinositol species were associated with a decreased risk. In MI patients, we found strong positive correlation between lipid metabolites related to the sphingolipid pathway, sphingomyelin, and ceramide and acute inflammatory markers (high-sensitivity C-reactive protein). The results of this study demonstrate altered signatures in lipid metabolism in patients with angina or MI. Lipidomic profiling could provide the information to identity the specific lipid metabolites under the presence of disturbed metabolic pathways in patients with CAD.

Lipids fulfill multiple pleiotropic roles in cellular function. Alterations in cellular lipid metabolism, trafficking and/or compartmentation contribute to the majority of mortality and morbidity in industrialized nations. Historically, lipid analysis was a time‐consuming process that required multiple sequential steps to identify and quantify a limited number of high abundance lipid molecular species. During the last 25 years, the use of mass spectrometry for global lipid analysis has revolutionized our ability to understand the role of lipids in multiple disease processes. Our laboratory has developed shotgun lipidomics procedures that can directly examine with high sensitivity the lipid composition of biologic tissues or fluids directly from their organic extracts. Through exploiting the intrinsic chemical properties of lipid classes in conjunction with intrasource separation, multidimensional mass spectrometry and array analysis, it is now possible to accurately identify and quantitate hundreds to thousands of both high and low abundance lipid molecular species directly from their biologic extracts. Through the development of multidimensional mass spectrometry, much progress has already been made in understanding the roles of alterations in lipid metabolism in many disease states including diabetic cardiomyopathy, obesity and neurodegenerative disorders. This talk will summarize progress in the lipidomics field with emphasis on the advantages and difficulties of the current approaches being employed. This research was funded by NIH Grant PO1HL57278.

Lipid disorders increase the risk for the development of cardiometabolic disorders, including type 2 diabetes, atherosclerosis, and cardiovascular disease. Lipids levels, apart from diet, smoking, obesity, alcohol consumption, and lack of exercise, are also influenced by genetic factors. Recent studies suggested the role of long noncoding RNAs (lncRNAs) in the regulation of lipid formation and metabolism. Despite their lack of protein-coding capacity, lncRNAs are crucial regulators of various physiological and pathological processes since they affect the transcription and epigenetic chromatin remodelling. LncRNAs act as molecular signal, scaffold, decoy, enhancer, and guide molecules. This review summarises available data concerning the impact of lncRNAs on lipid levels and metabolism, as well as impact on cardiovascular disease risk. This relationship is significant because altered lipid metabolism is a well-known risk factor for cardiovascular diseases, and lncRNAs may play a crucial regulatory role. Understanding these mechanisms could pave the way for new therapeutic strategies to mitigate cardiovascular disease risk through targeted modulation of lncRNAs. The identification of dysregulated lncRNAs may pose promising candidates for therapeutic interventions, since strategies enabling the restoration of their levels could offer an effective means to impede disease progression without disrupting normal biological functions. LncRNAs may also serve as valuable biomarker candidates for various pathological states, including cardiovascular disease. However, still much remains unknown about the functions of most lncRNAs, thus extensive studies are necessary elucidate their roles in physiology, development, and disease.

Sedentary lifestyle and overweight are major public health, clinical, and economical problems in modern societies. The worldwide epidemic of excess weight is due to imbalance between physical activity and dietary energy intake. Sedentary lifestyle, unhealthy diet, and consequent overweight and obesity markedly increase the risk of cardiovascular diseases. Regular physical activity 45-60 min per day prevents unhealthy weight gain and obesity, whereas sedentary behaviors such as watching television promote them. Regular exercise can markedly reduce body weight and fat mass without dietary caloric restriction in overweight individuals. An increase in total energy expenditure appears to be the most important determinant of successful exercise-induced weight loss. The best long-term results may be achieved when physical activity produces an energy expenditure of at least 2,500 kcal/week. Yet, the optimal approach in weight reduction programs appears to be a combination of regular physical activity and caloric restriction. A minimum of 60 min, but most likely 80-90 min of moderate-intensity physical activity per day may be needed to avoid or limit weight regain in formerly overweight or obese individuals. Regular moderate intensity physical activity, a healthy diet, and avoiding unhealthy weight gain are effective and safe ways to prevent and treat cardiovascular diseases and to reduce premature mortality in all population groups. Although the efforts to promote cardiovascular health concern the whole population, particular attention should be paid to individuals who are physically inactive, have unhealthy diets or are prone to weight gain. They have the highest risk for worsening of the cardiovascular risk factor profile and for cardiovascular disease. To combat the epidemic of overweight and to improve cardiovascular health at a population level, it is important to develop strategies to increase habitual physical activity and to prevent overweight and obesity in collaboration with communities, families, schools, work sites, health care professionals, media and policymakers.

Consensus development conference on antipsychotic drugs and obesity and diabetes.

Patients with diabetes suffer disproportionately from impaired lipid metabolism and cardiovascular disease, but the relevant roles of insulin resistance and hyperglycemia in these processes are unclear. Transcription factor FoxO1 is regulated dually by insulin and nutrients. In this study, we addressed the hypothesis that, in addition to its established role to regulate hepatic glucose production, FoxO1 controls aspects of lipid metabolism in the diabetic liver. Mice with a liver-specific deletion of FoxO1 (L-FoxO1) and their control littermates were rendered hyperglycemic by streptozotocin administration. Subsequently, we monitored serum lipids, liver VLDL secretion, and hepatic expression of genes related to lipid metabolism. Hepatic FoxO1 ablation resulted in increased VLDL secretion, increased cholesterol, and increased plasma free fatty acids, three hallmarks of the diabetic state. l-FoxO1 mice expressed increased levels of SREBP-2 and FGF21 without affecting lipogenic genes. We propose that FoxO1 fine tunes lipolysis through its actions on FGF21 and that hepatic FoxO1 ablation increases availability of substrates for hepatic triglyceride and cholesterol synthesis and VLDL secretion. The implications of these findings are that FoxO1 protects against excessive hepatic lipid production during hyperglycemia and that its inhibition by intensive insulin treatment may exacerbate paradoxically the lipid abnormalities of diabetes.

To investigate the metabolic impact of currently used therapies in polycystic ovary syndrome (PCOS). This is an observational, retrospective and transversal protocol. A small cohort of 133 patients, aged 14-48years, diagnosed with PCOS was divided into four experimental groups: 1) untreated PCOS patients (n = 51); 2) PCOS patients treated with one of the following therapies (n = 82): a) combined oral contraceptives (COC, n = 35); b) metformin (n = 11); and c) inositols (n = 36). Although only < 10% of patients included in this cohort can be strictly encompassed in the development of metabolic syndrome, approximately 20% had insulin resistance. In PCOS patients, COC treatment modified the hormonal profile and worsened lipid parameters (increasing cholesterol and triglyceride levels) and insulin resistance, whereas inositol therapies improved significantly insulin resistance and glycosylated hemoglobin, reducing cholesterol and triglyceride levels. In these women, obesity was associated with greater alterations in lipid and glycemic metabolism and with higher blood pressure levels. PCOS patients with phenotype A presented vaster alterations in lipid metabolism and higher values of glycosylated hemoglobin as well as blood pressure compared to other PCOS phenotypes. Results in this paper suggest that inositol therapies (alone or combined with COC) are the most useful therapies with the best benefits against PCOS symptoms. Thus, integrative treatment may become a more efficient long-term choice to control PCOS symptoms. Furthermore, obesity can be considered as an adverse symptom and calorie restriction a key element of combined treatment in PCOS, not only for fertility management but also in long-term metabolic sequelae.

the nobel prize in physiology or medicine was awarded to Brown and Goldstein in 1985 for their discovery of the low-density lipoprotein (LDL) receptor and its importance in the regulation of cholesterol metabolism ([2][1]). Cholesterol, an essential component of the mammalian cell membrane, is

With successful antiretroviral therapy, patients infected with the human immunodeficiency virus (HIV) are living longer; however, recent reports suggest increased rates of coronary heart disease (CHD) among HIV-infected patients,1 and cardiovascular disease has become an important cause of morbidity and mortality in this population.2 Increased CHD rates in the HIV population may relate to traditional risk factors, including advancing age, higher smoking rates, dyslipidemia, insulin resistance, and impaired glucose tolerance. Cardiovascular disease may also be due to nontraditional factors, including changes in body composition with loss of subcutaneous fat and/or accumulation of visceral fat in some patients, inflammation, and direct effects of the virus on the vasculature, as well as to direct effects of specific antiretroviral drugs. Important questions remain as to the pathogenesis, detection, and treatment of cardiovascular disease and related risk factors in HIV-infected patients. These questions concern, among other things, the design of adequate trials to determine CHD incidence and the utility of existing CHD guidelines for screening, prevention, treatment, and risk stratification. To ascertain the state of the science with respect to these and related questions, a multidisciplinary conference with interested HIV specialists, cardiologists, endocrinologists, primary care physicians, National Institutes of Health representatives, and patient advocates was convened June 28–30, 2007, in Chicago, Ill, and chaired by Drs Steven Grinspoon and Robert Eckel. The discussions focused on 6 areas of interest, each with its own working group, including the following: (1) the contribution of metabolic and anthropometric abnormalities to cardiovascular disease risk factors (chaired by Drs Carl Grunfeld and Donald Kotler); (2) the epidemiological evidence for cardiovascular disease and its relationship to highly active antiretroviral therapy (HAART; chaired by Drs Judy Currier and Jens Lundgren); (3) the effects of HIV infection and antiretroviral therapy on the heart and vasculature (chaired by Drs Michael Dube …

Lipids in Liver Disease: Looking Beyond Steatosis

Pathogenesis of liver steatosis in laying hen remains poorly understood. However, it has been suggested that liver steatosis could result from increased fatty acid synthesis in liver, impaired transport from liver and decreased oxidation of fatty acids. Nutritional approaches have been developed to prevent hepatic steatosis in laying hen. The efficacy of African Melon Oil Seed (AMOS) supplement with its high content of omega‐3 fatty acids in altering lipid metabolism was evaluated in laying hens. Seventy‐two white leghorn birds, placed in separate cages, were randomly assigned to two treatment diets containing: 1) standard layer diet without AMOS (control); or 2) standard layer diet plus 10% AMOS for 6 weeks. Fatty acids content in eggs were not different among treatments. Taste panel evaluation of egg yolk showed similar color, aroma, and texture. Livers from AMOS fed birds had normal color, whereas livers from control fed birds had distinctive pale yellow color that is typical for fatty liver. Histological examination revealed micro‐vesicular steatosis in all control liver tissues. Western blots performed with antibody specific to chicken microsomal triglyceride transfer protein (MTP) showed distinct bands of large subunit and small subunit, but no difference in expression between treatments. This result is important for the understanding of AMOS in the regulation of genes involve in lipid biosynthesis.

Aging is associated with an accrual of body fat, progressive development of insulin resistance and other obesity comorbidities that contribute to decrease life span. Caloric restriction (CR), which primarily affects energy stores in adipose tissue, is known to extend life span and retard the aging process in animal models. In this study, a proteomic approach combining 2-DE and MS was used to identify proteins modulated by aging and CR in rat white adipose tissue proteome. Proteomic analysis revealed 133 differentially expressed spots, 57 of which were unambiguously identified by MS. Although CR opposed part of the age-associated protein expression patterns, many effects of CR were on proteins unaltered by age, suggesting that the effects of CR on adipose tissue are only weakly related to those of aging. Particularly, CR and aging altered glucose, intermediate and lipid metabolism, with CR enhancing the expression of enzymes involved in oxalacetate and NADPH production, lipid biosynthesis and lipolysis. Consistently, insulin-β and β3-adrenergic receptors were also increased by CR, which denotes improved sensitivity to lipogenic/lipolytic stimuli. Other beneficial outcomes of CR were an improvement in oxidative stress, preventing the age-associated decrease in several antioxidant enzymes. Proteins involved in cytoskeleton, iron storage, energy metabolism and several proteins with novel or unknown functions in adipose tissue were also modulated by age and/or CR. Such orchestrated changes in expression of multiple proteins provide insights into the mechanism underlying CR effects, ultimately allowing the discovery of new markers of aging and targets for the development of CR-mimetics.