Lipid Ingestion Research Articles

Nonalcoholic Fatty Liver Disease Induced by High-Fat Diet in C57bl/6 Models

Researchers have a range of animal models in which to study Nonalcoholic fatty liver disease (NAFLD). Induction of NAFLD by a high-fat diet in the C57BL/6 strain is the most widely used among mice. In this study, we review works that performed NAFLD induction by a high-fat diet using the C57BL/6 strain, focusing on experiments on the effects of lipid ingestion. Studies are initially distinguished into researches in which mice received lipids by oral gavage and studies in which lipid was added to the diet, and each of these designs has peculiarities that must be considered. Oral gavage can be stressful for animals and needs trained handlers but allows accurate control of the dose administered. The addition of oils to the diet can prevent stress caused to mice by gavage, but possible changes in the consistency, taste, and smell of the diet should be considered. Regarding the experimental design, some variables, such as animal sex, treatment time, and diet-related variables, appear to have a definite pattern. However, no pattern was found regarding the number of animals per group, age at the beginning of the experiment, time of adaptation, the substance used as a vehicle, and substance used as a control.

Nutritional assessment and phytoestrogen exposure in a diet of students of the University of Costa Rica

Introduction: this study presents the results regarding diet and an analysis of natural estrogens (phytoestrogens) intake and how they affect other important aspects, which can modulate biological health functions among university students. Objectives: assessing nutritional habits and estimating the intake of phytoestrogens in the population under study. Materials and methods: Costa Rican female (n: 211, 18.83 ± 2.06 years) and male (n: 199, 19.64 ± 3.05 years) university population of the University of Costa Rica applied anthropometric tests using DEXA, the Food Frequency Questionnaire (FFQ) and the 24-hour Reminder (R-24). Results: the most serious nutritional bad habits were high ingestion of sodium, lipids and animal origin proteins in men and women and a deficit of fiber and folic acid in women. The total intake of phytoestrogens referred to: daidzein 0.23 ± 0.40 mg/day and 7.01 ± 11.94 mg/month in women and 0.17 ± 0.13 mg/day and 5.14 ± 3.96 mg/month in men; mainly consumed in the form of lignans 0.24 ± 0.12 mg/day (women) and 0.23 ± 0.14 mg/day (men). The intake of isoflavones was 0.09 ± 0.38 mg/day (women) and 0.04 ± 0.08 mg/day (men). Conclusions: The study population presented high fat percentage although the consumption of vegetables, cereals, whole grains and fruits tends slightly to be a Mediterranean diet; their food pattern was much closer to the Western diet.

Jean-Pierre Flatt, PhD (1933-2018)

Jean-Pierre Flatt, PhD (1933-2018)

Metabolic Changes Induced by High-Fat Meal Evoke Different Microvascular Responses in Accordance with Adiposity Status.

Background Frequently, ingestion of lipids exceeds our daily requirements and constantly exposes humans to circulating lipid overload which may lead to endothelial dysfunction (ED), the earliest marker of atherosclerosis. Nailfold videocapillaroscopy (NVC) technique can detect ED on microcirculation. Using NVC, we aimed to demonstrate if metabolic alterations evoked by high-fat meals can act differently on microvascular endothelial reactivity in lean and women with obesity. Methods Women, aged between 19 and 40 years, were allocated to control group (CG) and with obesity group (OBG) and were subjected to blood analysis for determination of glucose, total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c) and NVC evaluation at fasting and 30, 60, 120, and 180-min after high-fat meal ingestion. NVC technique evaluated microvascular reactivity through the following variables: red blood cell velocity (RBCV) at rest and after 1-min ischemia (maximal red blood cell velocity, RBCVmax) and time taken to reach it (TRBCVmax). A P value ≤0.05 was considered significant. Results High-fat meal promoted a two-phase response in both groups: one until 60-min, associated with glucose and insulin levels, and the other after 120-min, associated with TG levels. Significant differences between groups were observed concerning insulin and HDL-c concentrations only at fasting and TC, TG, and LDL-c levels in all-time points. Regarding microvascular reactivity, RBCV, RBCVmax, and TRBCVmax were significantly different in OBG at 30-min compared to baseline. RBCVmax and TRBCVmax were significantly different in CG at 30-min and 60-min comparing to fasting. In all-time points, OBG presented RBCV, RBCVmax , and TRBCVmax significantly different in comparison to CG. ConclusionHigh-fat meal worsened ED on microcirculation in women with obesity and induced impairment of endothelial function in lean ones, reinforcing the association between high-fat meal and atherosclerosis.

Weight Regain, but not Weight Loss, Is Related to Competitive Success in Real-Life Mixed Martial Arts Competition.

We aimed to describe the nutritional and behavioral strategies for rapid weight loss (RWL), investigate the effects of RWL and weight regain in winners and losers, and verify mood state and technical-tactical/time-motion parameters in mixed martial arts. The sample consisted of mixed martial arts athletes after a single real match and was separated into two groups: winners (n = 8; age: 25.4 ± 6.1 years, height: 173.9 ± 0.2cm, habitual body mass: 89.9 ± 17.3kg) and losers (n = 7; age: 24.4 ± 6.8 years, height: 178.4 ± 0.9cm, habitual body mass: 90.8 ± 19.5kg). Both groups exhibited RWL and weight regain, verified their macronutrient intake, underwent weight and height assessments, and completed two questionnaires (Profile of Mood States and RWL) at (a)24hr before weigh-in, (b)weigh-in, (c)postbout, and (d)during a validated time-motion and technical-tactical analysis during the bout. Variance analysis, repeated measures, and a logistic regression analysis were used. The main results showed significant differences between the time points in terms of total caloric intake as well as carbohydrate, protein, and lipid ingestion. Statistical differences in combat analysis were observed between the winners and losers in terms of high-intensity relative time (58 [10-98]s and 32 [1-60]s, respectively), lower limb sequences (3.5 [1.0-7.5] sequences and 1.0 [0.0-1.0] sequences, respectively), and ground and pound actions (2.5 [0.0-4.5] actions and 0.0 [0.0-0.5] actions, respectively), and logistic regression confirmed the importance of high-intensity relative time and lower limb sequences on mixed martial arts performance. RWL and weight regain strategies were related to technical-tactical and time-motion patterns as well as match outcomes. Weight management should be carefully supervised by specialized professionals to reduce health risks and raise competitive performance.

Neurotensin Is a Lipid-Induced Gastrointestinal Peptide Associated with Visceral Adipose Tissue Inflammation in Obesity.

Neurotensin (NT) is a 13-amino acid peptide localized in the neuroendocrine cells of the small intestine, which promotes fat absorption and fatty acids translocation in response to lipid ingestion. NT-knock-out mice fed with a high-fat diet are protected from obesity, fatty liver, and the development of insulin-resistance. In humans, higher plasma levels of pro-NT, which is the stable circulating precursor of NT, predict obesity, type 2 diabetes (T2D), and cardiovascular disease. In obesity, the presence of visceral adipose tissue (VAT) inflammation leads to unfavorable metabolic outcomes and is associated with the development of T2D and non-alcoholic fatty liver disease (NAFLD). In this study, we investigated the relationship between plasma pro-NT levels and the presence of VAT inflammation in biopsies from 40 morbidly obese subjects undergoing bariatric surgery. We demonstrated that higher proNT levels are significantly associated with greater macrophages infiltration, HIF-1α, WISP-1, and UNC5B expression in VAT (all p < 0.01) due to the diagnosis of T2D and NAFLD. The overall results show that, in obesity, pro-NT is a biomarker of VAT inflammation and insulin-resistance. Additionally, NT may be involved in the development of dysmetabolic conditions likely mediated by increased gut fat absorption and the presence of a proinflammatory milieu in the adipose tissue.

Importance of Food Selection for Celiac Sprue Disease

Abstract A questionnaire survey was conducted among people with celiac disease. Questions were focused on dietary foods available and the preference of suitable grain food species. A one-week diet menu was prepared for the participants of the survey. Daily intake of major nutrients and energy was determined. Supermarkets have the largest selection of dietary foods, although in a narrow range. Celiac patients often rely on themselves to make and prepare food. The majority of respondents (57%) considered dietary restrictions as burdening; 43% have adapted to this situation. Food made of rice was the most popular among cereal foods for 50% of respondents, corn for 39%, and buckwheat and millet for only 7% of respondents. Nobody classified amaranth as the most popular food. The model diet for people with celiac disease exceeded the recommended daily intake of protein and undervalued lipid ingestion. This problem was mainly caused by the food composition of the evening meal. Total daily energy intake of 9900 kJ met the women’s needs. There were still 2100 kJ missing for men. The terms ‘gluten-free food or diet’ and ‘gliadin content’, which generally relate to the products of wheat, rye, oats, and triticale, are not accurate.

Long-chain acyl-CoA synthetase 6 regulates lipid synthesis and mitochondrial oxidative capacity in human and rat skeletal muscle.

Long-chain acyl-CoA synthetase 6 (ACSL6) mRNA is present in human and rat skeletal muscle, and is modulated by nutritional status: exercise and fasting decrease ACSL6 mRNA, whereas acute lipid ingestion increase its expression. ACSL6 genic inhibition in rat primary myotubes decreased lipid accumulation, as well as activated the higher mitochondrial oxidative capacity programme and fatty acid oxidation through the AMPK/PGC1-α pathway. ACSL6 overexpression in human primary myotubes increased phospholipid species and decreased oxidative metabolism. Long-chain acyl-CoA synthetases (ACSL 1 to 6) are key enzymes regulating the partitioning of acyl-CoA species toward different metabolic fates such as lipid synthesis or β-oxidation. Despite our understanding of ecotopic lipid accumulation in skeletal muscle being associated with metabolic diseases such as obesity and type II diabetes, the role of specific ACSL isoforms in lipid synthesis remains unclear. In the present study, we describe for the first time the presence of ACSL6 mRNA in human skeletal muscle and the role that ACSL6 plays in lipid synthesis in both rodent and human skeletal muscle. ACSL6 mRNA was observed to be up-regulated by acute high-fat meal ingestion in both rodents and humans. In rats, we also demonstrated that fasting and chronic aerobic training negatively modulated the ACSL6 mRNA and other genes of lipid synthesis. Similar results were obtained following ACSL6 knockdown in rat myotubes, which was associated with a decreased accumulation of TAGs and lipid droplets. Under the same knockdown condition, we further demonstrate an increase in fatty acid content, p-AMPK, mitochondrial content, mitochondrial respiratory rates and palmitate oxidation. These results were associated with increased PGC-1α, UCP2 and UCP3 mRNA and decreased reactive oxygen species production. In human myotubes, ACSL6 overexpression reduced palmitate oxidation and PGC-1α mRNA. In conclusion, ACSL6 drives acyl-CoA toward lipid synthesis and its downregulation improves mitochondrial biogenesis, respiratory capacity and lipid oxidation. These outcomes are associated with the activation of the AMPK/PGC1-α pathway.

Differential Effects of Oral and Intravenous Lipid Administration on Key Molecules Related to Energy Homeostasis.

The spectrum of lipid-induced changes in the secretion of hormones important in energy homeostasis has not yet been fully elucidated. To identify potential incretin-like effects in response to lipid administration, we examined the short-term effect of iv vs oral lipids on key molecules regulating energy homeostasis. Design, Intervention, and Participants: After a 10-hour overnight fast, 26 subjects were randomized to receive an oral lipid load, a 10% iv lipid emulsion, a 20% iv lipid emulsion, or an iv saline infusion. We obtained blood samples at 30-minute intervals for the first 2 hours and hourly thereafter for a total of 6 hours. Circulating levels of insulin, glucose, c-peptide, free fatty acids, incretins (glucagon-like peptide-1, gastric inhibitory polypeptide), glucagon, peptide YY, ghrelin, fibroblast growth factor 21, fetuin A, irisin, omentin, and adiponectin were measured. Oral lipid ingestion resulted in higher glucagon-like peptide-1, gastric inhibitory polypeptide, glucagon, and peptide YY levels, compared with the other three groups (incremental area under the curve P = .003, P < .001, P < .001, P < .001, respectively). The 20% lipid emulsion, leading to higher free fatty acid levels, resulted in greater insulin, c-peptide, and fibroblast growth factor 21 responses compared with placebo and the other two groups (incremental area under the curve P = .002, P = .005, P < .001, P < .001, respectively). Omentin, adiponectin, fetuin A, and irisin levels were not affected by either mode of lipid administration. Metabolic responses to lipids depend on the route of administration. Only iv lipids trigger a dose-dependent fibroblast growth factor 21 secretion, which is nonglucagon mediated. Intravenous lipids also induce hyperinsulinemia without concurrent decreases in glucose, a phenomenon observed in insulin-resistant states. Orally administered lipids mostly affect gastrointestinal tract-secreted molecules important in glucose and energy homeostasis such as glucagon, incretins, and peptide YY.

Pro-inflammatory chemokines CCL2, chemerin, IP-10 and RANTES in human serum during an oral lipid tolerance test

BackgroundThere is a strong coincidence of obesity and a chronic state of modest inflammation. Secretion of pro-inflammatory cytokines from adipocytes and immune cells represents a key mechanism in this process and is affected by fatty acids. Material and methodsA study cohort of 100 overnight fasted healthy volunteers underwent an oral lipid tolerance test (OLTT) by ingestion of 160ml of a protein- and sugar-free lipid emulsion of defined composition. Venal blood was drawn at 0h (fasting) and at 2, 4, and 6h after lipid ingestion. Subjects were characterized by anthropometric and standard laboratory parameters. Serum concentrations of CCL2, IP-10, chemerin, and RANTES were measured by enzyme-linked immunosorbent assay (ELISA). Murine 3T3-L1 adipocytes were stimulated with free fatty acids (FA) and with sex steroids and concentrations of CCL2 and chemerin in cell culture supernatants were measured by ELISA. ResultsA significant reduction of circulating CCL2, IP-10, and chemerin concentrations was observed as a consequence of triglyceride ingestion whereas RANTES levels were increased. CCL2 serum concentrations were positively correlated with resistin and visfatin levels and with LDL/HDL ratio and negatively with adiponectin. There were significant differences in chemerin and RANTES serum concentrations in female and male subjects. CCL2 secretion from 3T3-L1 adipocytes was inhibited by treatment with linoleic (LA) and oleic acid (OA) whereas chemerin secretion was induced. Chemerin release from 3T3-L1 adipocytes was inhibited by testosterone. ConclusionsOral lipid loading is linked to reduced circulating pro-inflammatory chemokines CCL2, IP-10, and chemerin and to increased RANTES levels, suggesting that dietary lipids affect immune function.

How relevant are assembled equilibrium samples in understanding structure formation during lipid digestion?

Lipid-based formulations are gaining interest for use as drug delivery systems for poorly water-soluble drug compounds. During digestion, the lipolysis products self-assemble with endogenous surfactants in the gastrointestinal tract to form colloidal structures, enabling enhanced drug solubilisation. Although earlier studies in the literature focus on assembled equilibrium systems, little is known about structure formation under dynamic lipolysis conditions. The purpose of this study was to investigate the likely colloidal structure formation in the small intestine after the ingestion of lipids, under equilibrium and dynamic conditions. The structural aspects were studied using small angle X-ray scattering and dynamic light scattering, and were found to depend on lipid composition, lipid chain length, prandial state and emulsification. Incorporation of phospholipids and lipolysis products into bile salt micelles resulted in swelling of the structure. At insufficient bile salt concentrations, a co-existing lamellar phase was observed, due to a reduction in the solubilisation capacity for lipolysis products. Emulsification accelerated the rate of lipolysis and structure formation.

Postprandial Responses to Lipid and Carbohydrate Ingestion in Repeated Subcutaneous Adipose Tissue Biopsies in Healthy Adults.

Adipose tissue is a primary site of meta-inflammation. Diet composition influences adipose tissue metabolism and a single meal can drive an inflammatory response in postprandial period. This study aimed to examine the effect lipid and carbohydrate ingestion compared with a non-caloric placebo on adipose tissue response. Thirty-three healthy adults (age 24.5 ± 3.3 year (mean ± standard deviation (SD)); body mass index (BMI) 24.1 ± 3.2 kg/m2, were randomised into one of three parallel beverage groups; placebo (water), carbohydrate (maltodextrin) or lipid (dairy-cream). Subcutaneous, abdominal adipose tissue biopsies and serum samples were collected prior to (0 h), as well as 2 h and 4 h after consumption of the beverage. Adipose tissue gene expression levels of monocyte chemoattractant protein-1 (MCP-1), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) increased in all three groups, without an increase in circulating TNF-α. Serum leptin (0.6-fold, p = 0.03) and adipose tissue leptin gene expression levels (0.6-fold, p = 0.001) decreased in the hours following the placebo beverage, but not the nutrient beverages. Despite increased inflammatory cytokine gene expression in adipose tissue with all beverages, suggesting a confounding effect of the repeated biopsy method, differences in metabolic responses of adipose tissue and circulating adipokines to ingestion of lipid and carbohydrate beverages were observed.

Lipid is absorbed in the stomach by epithelial neoplasms (adenomas and early cancers): a novel functional endoscopy technique.

Background and study aims: The authors have successfully demonstrated that the white opaque substance (WOS) identified in gastric epithelial neoplasms is an accumulation of minute lipid droplets on the epithelial neoplasm. It is not known whether the lipid droplets originate from externally ingested lipids (typically foods). The purpose of this study was to investigate whether the oral ingestion of foods containing emulsified fats increases the density of the WOS in epithelial neoplasms. Patients and methods: We examined 92 gastric epithelial neoplastic lesions in 89 patients. The patients were given emulsified fatty foods before the procedure, and magnifying endoscopy with narrow-band imaging (M-NBI) was used to image the lesions. An increase in WOS density after the ingestion of emulsified fatty foods was defined as a positive fat-loading test result.The patients were divided into the following groups: control group, no emulsified fat administered; group 1, fatty food administered 16 hours prior; group 3, fatty food administered both 16 and 4 hours prior. The proportion of positive fat-loading test results was determined in all groups. Results: The rates of positive fat-loading test results were as follows: control group, 9 %; group 1, 26 %; group 2, 52 %; group 3, 78 %. The increase in the rates of positive fat-loading test results in groups 2 and 3 relative to the rate in the control group was statistically significant (chi-squared test). Conclusions: This study demonstrated for the first time that the ingestion of external lipids causes lipid droplets to aggregate in situ on the gastric epithelial neoplasm. These results can be used to develop a novel functional endoscopy technique that harnesses the lipid absorption capacity of neoplasms.

Regulation of pro-inflammatory adipokines CCL2, chemerin and resistin by oral lipid ingestion in healthy probands

Dysbalance of pro- and anti-inflammatory adipokines is a hallmark of metabolic syndrome but their nutrition-dependent regulation in healthy individuals is poorly characterized. We investigated the regulation of pro-inflammatory CCL2 (chemokine (C-C motif) ligand 2), chemerin, resistin and of anti-inflammatory adiponectin after oral lipid ingestion (OLI) in healthy adults. Response of CCL2, chemerin and resistin upon free fatty acid (FFA) stimulation was investigated in 3T3-L1 adipocytes.

脂質性の栄養成分および原材料名の表示について

Consumer interest in foods and food safety has been increasing recently, and food-related information is easily available on demand. While nutrition and ingredient labeling of food should, in the first place, be easily intelligible to any consumer, current nutrition labeling in Japan is voluntary and does not necessarily present information helpful for consumers. Thus, providing accurate information to allow adequate and safe ingestion of lipids via ingredient labeling is one of our first priorities. We have, accordingly, decided to approach the national government with a proposal to improve the current labeling standards. The following article, “Improvements we seek in lipid nutrition and ingredient labeling and the reasons for our proposal - including problems in current lipid nutrition ingredient labeling and an explanation of the need for change -” is to be attached to the proposal. The purpose of this article is to provide adequate grounds for proposing changes in labeling, and we would invite suggestions and comments on this article from subscribers concerned with lipid nutrition and ingredient labeling of food, for our consideration.

P5 Lipid-laden Macrophages In Bronchoalveolar Lavage Fluid Are Not Diagnostic Of Airway Reflux

Aims Demonstration of lipid-laden macrophages in respiratory secretions has been suggested to be a marker of reflux and aspiration. However studies looking at the diagnostic value of quantifying macrophage ingested lipids have been inconclusive. We wanted to look evaluate the utility of this technique in diagnosing airway reflux. Methods In this prospective study bronchoalveolar lavage samples were collected from patient’s undergoing flexible bronchoscopy for various indications (lung cancer, chronic cough, ILD etc). Cells collected were stained with Oil-Red-O. Lipid-laden macrophage index (LLMI) was used to quantify lipid accumulation. This is calculated by grading the amount of intracellular Oil-Red-O positive particles per 100 alveolar macrophages. A score of 0 (no opacification) to 4 (total opacification) is assigned to each macrophage. The sum of the scores yields the LLMI. Patients were asked to complete the Hull Airways Reflux Questionnaire (HARQ), a validated tool to diagnose airways reflux. One of the investigators, blind to the analysis, independently reviewed the clinical notes to establish a diagnosis of associated airway reflux. The investigator performing cell analysis was blind to the clinical details. The groups with and without a clinical diagnosis of airway reflux were compared. Correlations between the HARQ score and LLMI were sought. Results Twenty nine patients (19 females, mean age 64 years) were included in the study. Of these in 11 a clinical diagnosis of associated airway reflux was made. The mean [SD] LLMI in the group with airway reflux (95[105]) was not significantly different from those without airway reflux (90[75]). There was a weak correlation observed between the HARQ score and the LLMI (0.09) which was not statistically significant (p = 0.69). Conclusions We fail to demonstrate significant association between LLMI and either a clinical diagnosis of airway reflux or the HARQ score. This could be due to the fact that macrophages scavenge both exogenous and endogenous material. However our study is limited by small numbers and disparate underlying clinical diagnoses. The small correlation of LLMI with HARQ scores merits further evaluation. Whether the proportion of macrophages phagocytising lipids or the degree of lipid ingestion by the macrophages is more important needs further study.

Combination of grape seed proanthocyanidin extract and docosahexaenoic acid-rich oil increases the hepatic detoxification by GST mediated GSH conjugation in a lipidic postprandial state

The ingestion of dietary lipids leads to oxidative stress. This postprandial oxidative stress may potentiate the adverse effects of postprandial hyperlipidaemia. Proanthocyanidins have been shown to alleviate oxidative stress and hypertriglyceridaemia associated with the postprandial state. Additionally, omega-3 polyunsaturated fatty acids (PUFAs) also have beneficial effects on lipoprotein metabolism and oxidative stress. The present study was designed to investigate the possible additive effects in liver of an acute dose of grape seed proanthocyanidins extract (GSPE) and oil rich in docosahexaenoic acid (DHA-OR) on lipidic postprandial oxidative stress in Wistar rats. GSPE+DHA-OR modifies the hepatic antioxidant enzymatic activities (GST and GPx), clearly showing that this combination increases the detoxification of postprandial xenobiotics via the GST action mediated hepatic GSH conjugation. In conclusion, this study provides evidence that the combination of GSPE and DHA-OR ameliorate the transient imbalance between the lipid hydroperoxide level and antioxidant status related to a lipidic postprandial state.

Short-term regulation of visfatin release in vivo by oral lipid ingestion and in vitro by fatty acid stimulation

Short-term regulation of visfatin release in vivo by oral lipid ingestion and in vitro by fatty acid stimulation

Short-term Regulation of Visfatin Release in vivo by Oral Lipid Ingestion and in vitro by Fatty Acid Stimulation

Visfatin represents a new adipokine secreted by visceral adipose tissue and possibly regulating insulin sensitivity. Data on the regulation of visfatin are sparse and contradictory. Our study investigates the regulation of serum visfatin concentrations in healthy and non-diabetic subjects in response to the ingestion of a newly developed oral lipid solution (OLI) in vivo. Furthermore, the effects of a broad spectrum of fatty acids on adipocytic visfatin release were investigated in vitro.100 (42 male and 58 female) healthy volunteers were included in the study. Anthropometric and laboratory parameters (lipoproteins, glucose, insulin, C-peptide) were measured after an overnight fast at 0 h and 2 h, 4 h, and 6 h after OLI. 3T3-L1 preadipocytes were differentiated into mature adipocytes and stimulated with increasing doses of 10 different fatty acids, and the release of visfatin into the supernatants was measured by ELISA.Serum triglycerides significantly rose after OLI. This was accompanied by a significant decrease of glucose, insulin and C-peptide. Serum visfatin levels significantly decreased after OLI. Fasting visfatin levels were negatively correlated with fasting glucose levels. Of the 5 saturated fatty acids tested, only palmitic acid exerted significant effects by strongly downregulating visfatin release by about 66%. The mono-unsaturated fatty acids palmitoleic acid and oleic acid exerted opposite effects decreasing/increasing visfatin release, respectively. Both of the poly-unsaturated fatty acids linoleic acid and arachidonic acid decreased visfatin release.Oral lipid ingestion is a physiological regulator of systemic visfatin release. Fatty acids differentially regulate visfatin release in vitro.

Lipid accumulation, lipid oxidation, and low plasma levels of acquired antibodies against oxidized lipids associate with degeneration and rupture of the intracranial aneurysm wall

BackgroundRupture of a saccular intracranial aneurysm (sIA) causes an often fatal subarachnoid hemorrhage (SAH). Why some sIAs rupture remains unknown. Since sIA walls bear some histological similarities with early atherosclerotic lesions, we hypothesized that accumulation and oxidation of lipids might occur in the sIA wall and might associate with sIA wall degeneration. Tissue samples from sIA fundi (n = 54) were studied with histochemistry and a panel of previously characterized antibodies for epitopes of oxidized LDL (OxLDL). Plasma samples from sIA carriers (n = 125) were studied with ELISA and EIA for IgG and IgM -antibodies against a panel of OxLDL epitopes.ResultsLipid accumulation, foam cells, and oxidized lipids were found both in unruptured and ruptured sIA walls. Lipid accumulation associated with wall degeneration (P < 0.001), as did the expression of adipophilin, a marker of lipid ingestion by cells. Lipid accumulation associated also with loss of mural cells (P < 0.001), as did the accumulation of OxLDL (P < 0.001). Plasma IgG antibody titers against OxLDL or malondialdehyde modified LDL were higher in patients with unruptured sIAs than in patients with aneurysmal SAH (P ≤ 0.001). A trend but not statistically significant differences were found in plasma IgM antibodies against oxidized lipids.ConclusionsAccumulation of lipids and their oxidation in the sIA wall associates with the degeneration of the sIA wall. Acquired immunity against oxidized lipid epitopes may be protective of lipid associated sIA wall degeneration, but warrants further studies.