Non-esterified Free Fatty Acids Research Articles

The Alcohol-High-Density Lipoprotein Athero-Protective Axis.

Ingestion of alcohol is associated with numerous changes in human energy metabolism, especially that of plasma lipids and lipoproteins. Regular moderate alcohol consumption is associated with reduced atherosclerotic cardiovascular disease (ASCVD), an effect that has been attributed to the concurrent elevations of plasma high-density lipoprotein-cholesterol (HDL-C) concentrations. More recent evidence has accrued against the hypothesis that raising plasma HDL concentrations prevents ASCVD so that other metabolic processes associated with alcohol consumption have been considered. This review explored the roles of other metabolites induced by alcohol consumption—triglyceride-rich lipoproteins, non-esterified free fatty acids, and acetate, the terminal alcohol metabolite in athero-protection: Current evidence suggests that acetate has a key role in athero-protection but additional studies are needed.

Circulating Irisin Level as an Early Biomarker of Decline of Metabolic Health

A decline in metabolic health may take place before observing an alteration in the levels of the traditional metabolic markers. New indicators of metabolic derangement are therefore compelling. Irisin is a myokine which exerts important metabolic functions: it increases energy expenditure, improves insulin resistance, reduces glucose level and advanced glycation end products (AGE)‐induced inflammation. The optimal level for irisin in human and its potential role as a metabolic biomarker have not been fully established yet.To this aim, we quantified plasma irisin level in 106 healthy subjects (age 43 ± 11.72 years, 58 males/48 females) and we performed a cluster analysis to evaluate the association between irisin and subject characteristics [age, total cholesterol, LDL, HDL, tryglicerides, NEFA (non‐esterified free fatty acids), glucose, HbA1c (glycated hemoglobin), insulin, GA (glycated albumin), uric acid, creatinine, irisin, sRAGE (total soluble receptor for AGE), esRAGE (endogenously secreted receptor for AGE), cRAGE (membrane‐cleaved receptor for AGE) and cRAGE/esRAGE ratio]. ELISA tests were used for the quantification of parameters different from routine biochemical markers. Glycated albumin (GA) was meausured by the enzymatic method Lucica®GA‐L. The study was conducted in accordance with the Declaration of Helsinki.Irisin median level was 7.89 ng/ml. Although the mean levels of the traditional metabolic blood markers were within the ranges of normality, subjects in cluster 1 displayed a metabolic profile shifted toward the highest reference values. In fact, we observed higher concentrations of total cholesterol, LDL, triglycerides, NEFA, glucose, HbA1c, insulin, uric acid and creatinine. The reduced levels of the anti‐AGE molecules sRAGE and esRAGE, the increased levels of cRAGE/esRAGE (a surrogate marker of inflammation) and GA (an AGE product), and a greater percentage of subjects with visceral obesity in cluster 1 confirmed an increased metabolic stress and a pro‐inflammatory profile in this group. Irisin concentration was higher in this group too.The traditional metabolic blood tests seem to be not enough to early identify a metabolic decline. The increase of irisin level may reflect a metabolic derangement at the beginning of its development. The role of irisin as an early biomarker of decline in metabolic health seems an interest topic to be further explored.Support or Funding InformationThe study was supported by funding from Fondazione E. A. Fiera Internazionale di Milano to Università degli Studi di Milano and Ricerca Corrente funding from Italian Ministry of Health to IRCCS Policlinico San Donato.

Radix Polygoni Multiflori and Its Main Component Emodin Attenuate Non-Alcoholic Fatty Liver Disease in Zebrafish by Regulation of AMPK Signaling Pathway.

PurposeNonalcoholic fatty liver disease (NAFLD) has become a predictor of death in many diseases. This study was carried out to investigate the therapeutic effect of Radix Polygoni Multiflori Preparata (RPMP) and its main component emodin on egg yolk powder-induced NAFLD in zebrafish. Further investigation was performed to explore whether emodin was the main component of RPMP for the treatment of NAFLD as well as the underlying therapeutic mechanism of RPMP and emodin.MethodsZebrafish were divided into control group, egg yolk powder group, RPMP group and emodin group. The obesity of zebrafish was evaluated by body weight, body length and BMI. The content of lipid was detected by triglyceride (TG), total cholesterol (TC) reagent kit and the fatty acid was detected by nonesterified free fatty acids (NEFA) reagent kit. HE staining was used to detect the histological structure of liver. Whole-mount Oil red O staining and Frozen oil red O staining were carried out to investigate the lipid accumulation in liver. KEGG and STRING databases were performed to analyze the potential role of AMPK between insulin resistance (IR) and fatty acid oxidation. Western blot and RT-qPCR were carried out for mechanism research.ResultsRPMP and emodin significantly reduced zebrafish weight, body length and BMI. Both RPMP and emodin treatment could reduce the lipid deposition in zebrafish liver. RPMP significantly reduced the content of TG. However, emodin significantly reduced the contents of TG, TC and NEFA in zebrafish with NAFLD. The protein interaction network indicated that AMPK participated in both IR and fatty acid oxidation. Further investigation indicated that RPMP and emodin reduced hepatic lipogenesis via up-regulating the expressions of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT2), amp-activated protein kinase alpha (AMPKα), proliferator-activated receptor alpha (PPARα), carnitine palmitoyl transferase 1a (CPT-1a) and acyl-coenzyme A oxidase 1 (ACOX1).ConclusionThese findings suggest that emodin is the main component of RPMP for the treatment of NAFLD, which is closely related to the regulation of AMPK signaling pathway which increases IR and fatty acid oxidation.

Western Diet‐Induced Hypertension involves HMGB1/TLR4 Signaling in Perivascular Adipose Tissue of Female Rats

BackgroundOverconsumption of a Western Diet (WD), a high‐fat and high‐sugar diet, is a major factor implicated in rising obesity rates in the US. Perivascular adipose tissue (PVAT) possesses a vasculo‐protective role. In obesity, PVAT expands and becomes inflamed, contributing to vascular complications. High motility group box 1 (HMGB1), a cytokine, has been demonstrated to mediate vascular inflammation. Recent studies also suggest that PVAT plays a role in obesity‐related hypertension; however, the underlying mechanisms are still not well understood. We hypothesize that WD increases HMGB1 production in PVAT which in turn activates Toll‐like receptor 4 (TLR4) signaling in an autocrine/paracrine manner, resulting in hypertension.MethodsWe have established a model of WD‐induced hypertension in female rats. Adult female Wistar rats (n= 9) were randomized into two groups. Control Group (n= 4) received a regular chow diet (5% fat, 48.7% carbohydrates [3.2% sucrose], and 24.1% protein) and WD group (n= 5) received WD (40% fat, 43% carbohydrates [34% sucrose], and 17% protein) for 28 weeks. Metabolic parameters (body weight, body mass index (BMI), triglycerides, and non‐esterified free fatty acids [NEFA]) were assessed. Arterial blood pressure was measured via carotid catherization at the end of the experimental protocol. Thoracic aortas with PVAT were obtained for vascular studies and molecular assays. Vascular studies were performed using a wire myograph to assess vasodilatory responses.ResultsBody weight (358.9 ± 10.2 vs 270.1 ± 12.3g controls, p<0.005) and BMI (0.68 ± 0.02 vs. 0.06 ± 0.03 g/cm2controls, p<0.005) were increased in the WD group, confirming obesity. The WD group also demonstrated increased serum triglycerides (49.8 ± 4.7 vs. 14.3 ± 1.8mg/dL controls, p<0.05) and NEFA (0.57 ± 0.02 vs. 0.79 ± 0.04 mM controls, p<0.05). WD increased systolic blood pressure (144.04 ± 2.8 vs. 115.1 ± 3.9 mmHg controls, p<0.001), diastolic blood pressure (108.3 ± 3.1 vs. 89.5 ± 4.3 mmHg controls, p<0.01), and heart rate (386.1 ± 8.8 vs. 307.7 ± 40.3 bpm controls, p<0.05). Impaired vasodilation in the WD group in comparison to controls was worsened in the presence of PVAT, suggesting dysfunctional PVAT. Histological analysis of PVAT revealed a switch from brown‐like adipose tissue to white‐like adipose tissue, along with a significant decrease in uncoupling protein 1 (UCP‐1) expression (1.5‐fold decreased, p<0.05), a marker of thermogenesis. An oxidative/inflammatory state in the PVAT was confirmed by a 50% increase in reactive oxygen species levels (p<0.01). Strikingly, the novelty of this study revealed increased HMGB1 expression (2.0‐fold increased, p<0.05) along with increased TLR4 expression (2.5‐fold increased, p<0.05) in the PVAT of the WD group.ConclusionOur findings suggest that upregulated HMGB1/TLR4 signaling in the PVAT may induce a local inflammatory response through an autocrine/paracrine manner in the vasculature, contributing to dysregulation of blood pressure in the context of obesity.Support or Funding InformationNIH

FXR-mediated inhibition of autophagy contributes to FA-induced TG accumulation and accordingly reduces FA-induced lipotoxicity

BackgroundExcessive dietary fat intake induces lipid deposition and contributes to the progress of nonalcoholic fatty liver disease (NAFLD). However, the underlying mechanisms are still unclear.MethodsYellow catfish were given two experimental diets with dietary lipid levels of 11.3 and 15.4%, respectively, for 56 days, and the contents of triglyceride (TG), nonesterified free fatty acids (NEFA) and bile acid (BA), RNA-seq, enzymatic activities and mRNA expression were deteremined in the liver tissues. Hepatocytes from yellow catfish liver tissues were isolated and cultured. Fatty acids (FA) (palmitic acid: OA, oleic acid =1:1), pathway inhibitors (MA, autophagy inhibitor; guggulsterone, FXR inhibitor) and agonist (rapamyicn, autophagy agonist; GW4064, FXR agonist) were used to incubate the cells. TG and NEFA contents, ultrastructural observation, autophagic vesicles and intracellular LD,apoptosis,western blot and Co-IP, and Immunofluorescence analysis, enzymatic activities and Q-PCR were decided.ResultsUsing RNA sequencing, we found that high fat diets induced changes in expression of many genes associated with the pathways of lipid metabolism and autophagy. The mRNA profiles of the differentially expressed genes (DEG) indicated that high dietary fat-induced lipid deposition was predominantly influenced by the inhibition of autophagy. Using primary hepatocytes, we found that fatty acids (FA) suppressed autophagy, which in turn reduced cellular free FA level by decreasing triglyceride (TG) breakdown. Moreover, our study indicated that farnesoid X receptor (FXR)-cyclic AMP-responsive element-binding protein (CREB) axis was the pivotal physiological switch regulating FA-induced changes of autophagy and lipid metabolism, which represented cellular defenses against FA-induced lipotoxicity.ConclusionThis discovery may provide new targets for treating pathological changes involved in the dysfunction of autophagy and metabolism, including NAFLD.AmrG3KeYnpRNJADevGhfpFVideo Graphical abstract

Relation between Liver Lipid Content and Plasma Biochemical Indicators in Dairy Cows

Background: The incidence of metabolic disorders in dairy cows has increased as a result of intensive production practices and genetic selection for milk yield. Among such disorders, liver lipidosis is very frequently observed and has significant negative effects on cow health and milk yield. Severe energy supply deficit causes high fat mobilization, resulting in rapid body condition loss and liver lipid infiltration, which cannot always be detected by known blood biochemical indicators. The main objective of the study was to determine possible associations of blood biochemical parameters with liver lipid infiltration severity in high-yield multiparous Holstein cows along prepartum and postpartum periods.Materials, Methods & Results: Fifty-four high-yield Holstein cows from a herd managed in a free-stall system in the northwest region of the state of Rio Grande do Sul, Brazil were evaluated. Cows were divided in two groups according to their physiological status. Group 1 included 19 prepartum cows, with an average milk yield of 44.7 L/d in the previous lactation, and 2.8 average parity, and Group 2 included 35 postpartum cows, with an average milk yield of 46.8 L/d in the previous lactation, and 2.5 average parity. The farm produced 10,000 kg milk per year, containing 3.5% of fat, 3.2% of protein and 4.7% of lactose. Total cholesterol (CH), plasma triglycerides (TGp), beta-hydroxybutyrate (BHB), albumin (ALB), non-esterified free fatty acids (NEFA) levels, and aspartate aminotransferase (AST) and creatine kinase (CK) activities were analyzed in the plasma and liver triglycerides (TGl) levels were determined in liver tissue samples.The SPSS statistical software was used for the statistical analyses. The obtained data were analyzed for normality by the Shapiro-Wilk test and for homoscedasticity by Bartlett test. Data were submitted to analysis of variance, and means were compared by the t-test (PROC TTEST). Pearson correlation test (PROC CORR) was used to compare the results between prepartum and postpartum cows, and between those with and without lipidosis.An overall incidence of 20% severe hepatic lipidosis was determined both in prepartum and postpartum cows. Positive significant correlations were obtained between days in milk (DIM) and AST (r= 0.43; P < 0.01), CH and TGp (r= 0.44; P < 0.01), TGl and AST (r=0.32; P < 0.05), NEFA and AST (r= 0.45; P < 0.01) and CK and AST (r= 0.447; P < 0.01). Negative significant correlations were detected between TGp and DIM (r= -0.45; P < 0.01), and between TGl and TGp (r= -0.30; P < 0.05).Discussion: Prepartum cows showed moderate fat infiltration in the liver, while 25.7% of postpartum cows presented severe lipidosis. AST values increased as lactation progressed, suggesting a greater tendency of liver damage, in early postpartum. The obtained CK values were within the reference range, except for the cows with hepatic lipidosis, indicating that the measured AST activity was originated from the liver and not from the muscle tissues. TGp, NEFA and AST values indicate the degree of fat mobilization and, possibly, liver infiltration, while TGl indicates fat infiltration in the liver. Although negative energy balance (NEB) may trigger lipolysis and some degree of hepatic lipidosis, plasma BHB values did not significantly increase. The obtained results show that the evaluated plasma parameters may be useful to establish guidelines for the identification of changes in the metabolic profile of dairy cows during different production stages, as well as measures for the prevention and control of metabolic disorders.

Quantification of Fatty Acids in Mammalian Tissues by Gas Chromatography-Hydrogen Flame Ionization Detection.

In mammalian organisms, fatty acids (FAs) exist mostly in esterified forms, as building blocks of phospholipids, triglycerides, and cholesteryl esters, while some exist as non-esterified free FAs. The absolute quantification of FA species in total lipids or in a specific lipid class is critical in lipid-metabolism studies. To quantify FAs in biological samples, gas chromatography-hydrogen flame ionization detection (GC-FID)-based methods have been used as highly robust and reliable techniques. Prior to GC-FID analysis, FAs need to be derivatized to volatile FA methyl esters (FAMEs). The derivatization of unsaturated FAs using classical derivatization methods that rely on high reaction temperature requires skill; consequently, the quantification results are often unreliable. The recently available FA-methylation procedure rapidly and reliably derivatizes a variety of FA species, including poly-unsaturated FAs (PUFAs). To analyze FAs in mammalian tissue samples, lipid extraction and fractionation are also critical for robust analysis. In this report, we describe a whole protocol for the GC-FID-based FA quantification of mammalian tissue samples, including lipid extraction, fractionation, derivatization, and quantification. The protocol is useful when various FAs, especially unsaturated FAs, need to be reliably quantified.

Pathophysiological Implication of Fetuin-A Glycoprotein in the Development of Metabolic Disorders: A Concise Review.

Alpha 2-Heremans-Schmid glycoprotein, also known as fetuin-A (Fet-A), is a multifunctional plasma glycoprotein that has been identified in both animal and human beings. The protein is a hepatokine predominantly synthesized in the liver, which is considered as an important component of diverse normal and pathological processes, including bone metabolism regulation, vascular calcification, insulin resistance, and protease activity control. Epidemiological studies have already consistently demonstrated significant elevated circulating Fet-A in the course of obesity and related complications, such as type 2 diabetes mellitus, metabolic syndrome, and nonalcoholic fatty liver disorder (NAFLD). Moreover, Fet-A has been strongly correlated with many parameters related to metabolic homeostasis dysregulation, such as insulin sensitivity, glucose tolerance, circulating lipid levels (non-esterified free fatty acids and triglycerides), and circulating levels of both pro- and anti-inflammatory factors (C-reactive protein, tumor necrosis factor-α (TNF-α), and interleukin (IL)-6). Metabolic-interfering effects of Fet-A have thus been shown to highly exacerbate insulin resistance (IR) through blocking insulin-stimulated glucose transporter 4 (GLUT-4) translocation and protein kinase B (Akt) activation. Furthermore, the protein appeared to interfere with downstream phosphorylation events in insulin receptor and insulin receptor substrate signaling. The emerging importance of Fet-A for both diagnosis and therapeutics has therefore come to the attention of researchers and the pharmaceutical industry, in the prospect of developing new therapeutic strategies and diagnosis methods for metabolic disorders.

Mitochondrial Proton Leak Regulated by Cyclophilin D Elevates Insulin Secretion in Islets at Nonstimulatory Glucose Levels.

Fasting hyperinsulinemia precedes the development of type 2 diabetes. However, it is unclear whether fasting insulin hypersecretion is a primary driver of insulin resistance or a consequence of the progressive increase in fasting glycemia induced by insulin resistance in the prediabetic state. Herein, we have discovered a mechanism that specifically regulates non-glucose-stimulated insulin secretion (NGSIS) in pancreatic islets that is activated by nonesterified free fatty acids, the major fuel used by β-cells during fasting. We show that the mitochondrial permeability transition pore regulator cyclophilin D (CypD) promotes NGSIS, but not glucose-stimulated insulin secretion, by increasing mitochondrial proton leak. Islets from prediabetic obese mice show significantly higher CypD-dependent proton leak and NGSIS compared with lean mice. Proton leak-mediated NGSIS is conserved in human islets and is stimulated by exposure to nonesterified free fatty acids at concentrations observed in obese subjects. Mechanistically, proton leak activates islet NGSIS independently of mitochondrial ATP synthesis but ultimately requires closure of the KATP channel. In summary, we have described a novel nonesterified free fatty acid-stimulated pathway that selectively drives pancreatic islet NGSIS, which may be therapeutically exploited as an alternative way to halt fasting hyperinsulinemia and the progression of type 2 diabetes.

Dynamics of Lipid Metabolism in Volunteers during Short-Term Isolation in a Hermetic Chamber

In this study we have examined the crew of the SIRIUS 17 international experiment with a 17-day isolation in a hermetic chamber. The experiment was conducted at the experimental facilities of the Institute of Biomedical Problems, Russian Academy of Sciences. The crew consisted of six people of both sexes aged 27 to 43 years. We measured the serum level of total cholesterol, high-density lipoprotein cholesterol (HDL), apolipoproteins A1 and B, phospholipids, triglycerides, nonesterified (free) fatty acids, and β-hydroxybutyrate. Then we calculated the concentrations of low-density lipoprotein cholesterol (LDL) and very-low-density lipoprotein cholesterol (VLDL) and the values of atherogenic index (IA), ApoB/ApoA1 and phospholipids/cholesterol (PL/CHO) ratios. It was found that the “basic” parameters of cholesterol metabolism (cholesterol, HDL and LDL cholesterol, IA, the ratio of FL/CHO) were almost constant during the experiment, while the parameters indicative of the changes in the lipoprotein spectrum were changing, which reflects atherogenesis. The content of VLDL cholesterol, triglycerides, and ApoB was increasing, as did the value of the ApoB/ApoA1 index. Thus, even a short-term effect of the factors of hermetic chamber leads to the initial shifts in lipid metabolism, which indicate the activation of atherogenesis processes. Our findings show that further studies are needed to investigate the changes in lipid metabolism in experiments with longer periods of isolation.

Profound weight loss induces reactive astrogliosis in the arcuate nucleus of obese mice

ObjectiveObesity has been linked to an inflammation like state in the hypothalamus, mainly characterized by reactive gliosis (RG) of astrocytes and microglia. Here, using two diet models or pharmacological treatment, we assessed the effects of mild and drastic weight loss on RG, in the context of high-fat diet (HFD) induced obesity. MethodsWe subjected HFD-induced obese (DIO) male C57BL/6J mice to a weight loss intervention with a switch to standard chow, calorie restriction (CR), or treatment with the Glp1 receptor agonist Exendin-4 (EX4). The severity of RG was estimated by an ordinal scoring system based on fluorescence intensities of glial fibrillary acidic protein, ionized calcium-binding adapter molecule 1 positive (Iba1), cell numbers, and morphological characteristics. ResultsIn contrast to previous reports, DIO mice fed chronically with HFD showed no differences in microglial or astrocytic RG, compared to chow controls. Moreover, mild or profound weight loss had no impact on microglial RG. However, astrocyte RG was increased in CR and EX4 groups compared to chow fed animals and strongly correlated to body weight loss. Profound weight loss by either CR or EX4 was further linked to increased levels of circulating non-esterified free fatty acids. ConclusionsOverall, our data demonstrate that in a chronically obese state, astrocyte and microglial RG is indifferent from that observed in age-matched chow controls. Nonetheless, profound acute weight loss can induce astrocyte RG in the hypothalamic arcuate nucleus, possibly due to increased circulating NEFAs. This suggests that astrocytes may sense acute changes to both the dietary environment and body weight.

Overexpression of Human NPY or AgRP in the Paraventricular Nucleus Increases Feeding and Bodyweight in Young Rhesus Macaques

Background: The roles of neuropeptides agouti-related peptide (AgRP) and neuropeptide Y (NPY) in feeding behavior regulation have been extensively studied in rodents. However, the biological functions of these peptides in primates are not fully addressed. Methods: Lenti-virus mediated expression of human NPY (hNPY) or human AgRP (hAgRP) in paraventricular nucleus (PVN) of the hypothalamus to establish obesity model in monkeys. Findings: The feeding behavior and bodyweight were significantly increased in transgenic Rhesus Macaques. Whereas, the blood level of glucose and insulin, as well as metabolic parameters, including blood levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c), non-esterified free fatty acids (NEFA) and leptin remained unchanged after virus injection. Interpretation: These results have recapitulated some parts of previous reports in rodents, and suggest that these non-germline genetically modified monkeys may provide new models for studying feeding behaviors and related disease, such as obesity and diabetes. Funding Statement: This study was supported by the National Natural Science Foundation of China (81671516 to X. Huang) and National Key R&D Program of China (2016YFC0905901 to X. Huang). Xingxu Huang is sponsored by Startup Foundation of ShanghaiTech University. Declaration of Interests: All authors have no competing interests to declare, financial or otherwise. Ethics Approval Statement: The use and care of animals complied with the guideline of the biomedical research ethics committee at the Shanghai University of Traditional Chinese Medicine. The experimental procedures were approved by the Sichuan Hengshu Bio-Tech Co., Ltd animal care and use committee.

Chronic alcohol exposure alters circulating insulin and ghrelin levels: role of ghrelin in hepatic steatosis.

Fatty liver is the earliest response of the liver to excessive ethanol consumption. Central in the development of alcoholic steatosis is increased mobilization of nonesterified free fatty acids (NEFAs) to the liver from the adipose tissue. In this study, we hypothesized that ethanol-induced increase in ghrelin by impairing insulin secretion, could be responsible for the altered lipid metabolism observed in adipose and liver tissue. Male Wistar rats were fed for 5-8 wk with control or ethanol Lieber-DeCarli diet, followed by biochemical analyses in serum and liver tissues. In addition, in vitro studies were conducted on pancreatic islets isolated from experimental rats. We found that ethanol increased serum ghrelin and decreased serum insulin levels in both fed and fasting conditions. These results were corroborated by our observations of a significant accumulation of insulin in pancreatic islets of ethanol-fed rats, indicating that its secretion was impaired. Furthermore, ethanol-induced reduction in circulating insulin was associated with lower adipose weight and increased NEFA levels observed in these rats. Additionally, we found that increased concentration of serum ghrelin was due to increased synthesis and maturation in the stomach of the ethanol-fed rats. We also report that in addition to its effect on the pancreas, ghrelin can also directly act on hepatocytes via the ghrelin receptors and promote fat accumulation. In conclusion, alcohol-induced elevation of circulating ghrelin levels impairs insulin secretion. Consequently, reduced circulating insulin levels likely contribute to increased free fatty acid mobilization from adipose tissue to liver, thereby contributing to hepatic steatosis. NEW & NOTEWORTHY Our studies are the first to report that ethanol-induced increases in ghrelin contribute to impaired insulin secretion, which results in the altered lipid metabolism observed in adipose and liver tissue in the setting of alcoholic fatty liver disease.

Impact of Dietary Propylene Glycol Supplementation on Some Biochemical Parameters, Productive and Reproductive Performance of Lactating Dairy Cows

The aim of this study was to determine the effect of propylene glycol on milk yield, milk composition, parameters of subclinical ketosis and reproductive performance of high producing dairy cows. Twenty Holstein cows in the close up period were distributed into two equal groups. The control group received the basal diet. The other group was supplemented with propylene glycol (PG) (300 g per cow per day). The dietary treatment lasted from 3 weeks prepartum to 8 weeks postpartum. Body condition scores (BCS) were monitored using 1 to 5 scale at the start, parturition, 4 weeks and 8 weeks postpartum. All the cows were kept in tie-stall barns. Milk yield was daily recorded for each cow. Milk samples were collected weekly and analyzed for composition and somatic cell count (SCC). Blood samples were collected from all cows on day 10 prepartum to estimate non- esterified free fatty acids (NEFA). Further blood samples were collected on day 30 postpartum to determine serum NEFA, beta hydroxyl butyric acid (BHBA), urea, triglycerides and liver enzymes. Also, on day 30 postpartum, milk samples were collected to measure BHBA. Conception rate, days open and service pre conception were recorded for all cows. Cows supplemented with PG significantly had better BCS (3.2±0.06) than the control cows (2.8±0.04) at 8 weeks post-partum. PG significantly increased milk yield by 32.26% and milk protein by 32.9% than the control, while the other milk constituents and SCC were nearly similar in the two groups. Also, PG improved the energy status of the cows through increasing blood glucose level (57.8 ±1.1 versus 30±3.1) mg/dl and decreasing prepartum NEFA (0.3±0.02 versus 0.42±0.04) mmol/l. Also, lowering post-partum BHBA (0.73±0.12 versus 1.16±0.23) mmol/l. Moreover, PG significantly improved the reproductive performance of the lactating cows through shortening of days open by 31.0%, and decreasing service per conception by 23.08%. Finally, practical dietary supplementation of PG could be used to increase milk yield, improve reproductive performance and prevent subclinical ketosis of Holstein cows.

Changes in lipid droplets morphometric features in mammary epithelial cells upon exposure to non-esterified free fatty acids compared with VLDL.

The effects of the macrostructure of long chain fatty acids on the lipid metabolism and biosynthesis of lipid droplets (LD) was studied in mammary epithelial cells (MEC). MEC were exposed to similar compositions and concentrations of fatty acids in the form of either triglycerides (Tg), as part of the very-low-density lipids (VLDL) isolated from lactating cow plasma, or as non-esterified- free fatty acids (FFA). Exposing MEC to FFA resulted in two distinct processes; each independently could increase LD size: an elevation in Tg production and alterations in phospholipid (PL) composition. In particular, the lower PC/PE ratio in the FFA treatment indicated membrane destabilization, which was concomitant with the biosynthesis of larger LD. In addition, 6 fold increase in the cellular concentration of the exogenously added linoleic acid (C18:2) was found in MEC treated with FFA, implying that long chain fatty acids administrated as FFA have higher availability to MEC, enabling greater PL synthesis, more material for the LD envelope, thereby enhancing LD formation. Availability of long chain fatty acids administrated as VLDL-Tg, is dependent on LPL which its activity can be inhibited by the hydrolysis products. Therefore, we used increasing concentrations of albumin, to reduce the allosteric inhibition on LPL by the hydrolysis products. Indeed, a combined treatment of VLDL and albumin, increased LD size and number, similar to the phenotype found in the FFA treatment. These results reveal the role played by the macrostructure of long chain fatty acids in the regulation of LD size in MEC which determine the size of the secreted MFG.

Overexpression of Human NPY or AgRP in the Paraventricular Nucleus Increase Bodyweight in Young Rhesus Macaques

The role of neuropeptides agouti-related peptide (AgRP) and neuropeptide Y (NPY) in feeding behavior regulation have been extensively studied in rodents. However, the biological functions of these peptides in primates are not fully addressed. Here we shown that, through Lenti-virus mediated selective expression of human NPY (hNPY) or human AgRP (hAgRP) in the paraventricular nucleus (PVN), the bodyweight was significantly increased in young Rhesus Macaques. Whereas, the blood level of glucose and insulin, as well as metabolic parameters, including blood level of triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), non-esterified free fatty acids (NEFA) and leptin remain unchanged after virus injection. Although further investigations of long-term effects are needed, these results have recapitulated some parts of previous reports in rodents, and suggest that these non-germlines geneticlly modified monkeys may provide new models for studying feeding behaviors and related disease, such as obesity and diabetes.

Roux-en-Y gastric bypass surgery alters serum metabolites and fatty acids in patients with morbid obesity.

AimBariatric surgery induces significant weight loss, increases insulin sensitivity, and reduces mortality, but the underlying mechanisms are not clear. It was hypothesized that Roux‐en‐Y gastric bypass (RYGB) surgery improves metabolic profile along with weight loss. The objective of this pilot study was to evaluate changes in serum metabolites and fatty acids (FA) at 2 weeks and 6 months after RYGB.Materials and MethodsSerum samples were collected pre‐surgery, at 2 weeks and 6 months post‐surgery from 20 patients undergoing RYGB surgery. Serum non‐esterified free FA (NEFA) were measured. Serum metabolites and FA were measured using nuclear magnetic resonance spectroscopy and improved direct fatty acid methyl ester synthesis and the gas chromatography/mass spectrometry method, respectively, in subjects who completed follow‐up at 6 months (n = 8).ResultsMean (standard deviation) percent total weight loss was 6.70% (1.7) and 24.91% (6.63) at 2 weeks (n = 15) and 6 months (n = 8) post‐surgery, respectively. NEFA were significantly reduced at 6 months post‐surgery (P = 0.001, n = 8). Serum branched chain amino acids, 2‐aminobutyrate, butyrate, 2‐hydroxybutyrate, 3‐hydroxybutyrate, acetone, 2‐methylglutarate, and 2‐oxoisocaproate were significantly reduced, while serum alanine, glycine, pyruvate, and taurine were significantly elevated at 6 months post‐surgery compared with pre‐surgery (n = 8, P < 0.05). Also, serum FA C10:0, C13:0, C14:0, C15:0, and C18:0 increased significantly (n = 8, P < 0.05) by 6 months post‐surgery.ConclusionsChanges in serum metabolites and FA at 6 months post‐RYGB surgery in this pilot study with limited number of participants are suggestive of metabolic improvement; larger studies are warranted for confirmation.

Effects of feed intake restriction during late pregnancy on the function, anti-oxidation capability and acute phase protein synthesis of ovine liver.

ObjectiveAn experiment was conducted to investigate the effects of feed intake restriction during late pregnancy on the function, anti-oxidation capability and acute phase protein synthesis of ovine liver.MethodsEighteen time-mated ewes with singleton fetuses were allocated to three groups: restricted group 1 (RG1, 0.18 MJ ME/kg W0.75 d, n = 6), restricted group 2 (RG2, 0.33 MJ ME/kg W0.75 d), n = 6) and a control group (CG, ad libitum, 0.67 MJ ME/kg W0.75 d, n = 6). The feed restriction period was from 90 days to 140 days of pregnancy.ResultsThe ewe’s body weight, liver weights, water, and protein content of liver in the restricted groups were reduced compared with the CG group (p<0.05), but the liver fat contents in the RG1 group were higher than those of the CG group (p<0.05). The increased hepatic collagen fibers and reticular fibers were observed in the restricted groups with the reduction of energy intake. The concentrations of nonesterified free fatty acids in the RG1 and RG2 groups were higher than those of the CG group with the reduction of energy intake (p<0.05), but there were decreased concentrations of lipoprotein lipase and hepatic lipase in both restricted groups compared with the CG group (p<0.05). In addition, the increased concentrations of β-hydroxybutyric acid, triglycerides, malondialdehyde, total antioxidant capacity and activities of superoxide dismutase activity and catalase were found in the RG1 group, and the concentrations of cholinesterase in the RG1 group were reduced compared with the CG group (p<0.05). For the concentrations of acute phase proteins, the C-reactive protein (CRP) in the RG1 group were reduced compared with the CG group, but there were no differences in haptoglobin relative to the controls (p>0.05).ConclusionThe fat accumulation, increased hepatic fibrosis, antioxidant imbalance and modified synthesis of acute phase proteins were induced in ewe’s liver by maternal malnutrition during late pregnancy, which were detrimental for liver function to accommodate pregnancy.

Short-term effects of dapagliflozin on insulin sensitivity, postprandial glucose excursion and ketogenesis in type 1 diabetes mellitus: A randomized, placebo-controlled, double blind, cross-over pilot study.

We investigated the short-term effects of dapagliflozin as adjunct to insulin on insulin sensitivity, postprandial glucose excursions and ketone body production in type 1 diabetes mellitus (T1DM). A total of seven male patients completed the randomized, double-blind, placebo-controlled cross-over trial, receiving 10 mg of dapagliflozin daily for 3 days, followed by placebo, or the reverse. At Day 3, hyperinsulinaemic, euglycaemic clamps and oral glucose tolerance test clamps with repeated blood sampling were performed. Required glucose infusion and blood glucose excursions did not differ significantly between dapagliflozin treatment and placebo (P = 0.491; P = 0.342). Prior to oral glucose, total ketone bodies showed a higher trend following dapagliflozin treatment (P = 0.051). Following oral glucose, total ketone bodies decreased while concentrations of total GLP-1 were higher following dapagliflozin (P = 0.009). Non-esterified free fatty acids did not differ between dapagliflozin treatment and placebo and ketonuria was absent under both conditions. In T1DM, short-term addition of dapagliflozin to insulin influenced neither postprandial glucose excursions nor insulin sensitivity. Following oral glucose, total ketone bodies decreased in parallel with an increase in GLP-1 concentrations, which were higher under dapagliflozin treatment as compared with placebo.

Changes in energy metabolism, and levels of stress-related hormones and electrolytes in horses after intravenous administration of romifidine and the peripheral \u03b1-2 adrenoceptor antagonist vatinoxan

BackgroundRomifidine, an α-2 adrenoceptor agonist, is a widely-used sedative in equine medicine. Besides the desired sedative and analgesic actions, α-2 adrenoceptor agonists have side effects like alterations of plasma concentrations of glucose and certain stress-related hormones and metabolites in various species. Vatinoxan (previously known as MK-467), in turn, is an antagonist of α-2 adrenoceptors. Because vatinoxan does not cross the blood brain barrier in significant amounts, it has only minor effect on sedation induced by α-2 adrenoceptor agonists. Previously, vatinoxan is shown to prevent the hyperglycaemia, increase of plasma lactate concentration and the decrease of insulin and non-esterified free fatty acids (FFAs) caused by α-2 adrenoceptor agonists in different species. The aim of our study was to investigate the effects of intravenous romifidine and vatinoxan, alone and combined, on plasma concentrations of glucose and some stress-related hormones and metabolites in horses.ResultsPlasma glucose concentration differed between all intravenous treatments: romifidine (80 μg/kg; ROM), vatinoxan (200 μg/kg; V) and the combination of these (ROM + V). Glucose concentration was the highest after ROM and the lowest after V. Serum FFA concentration was higher after V than after ROM or ROM + V. The baseline serum concentration of insulin varied widely between the individual horses. No differences were detected in serum insulin, cortisol or plasma adrenocorticotropic hormone (ACTH) concentrations between the treatments. Plasma lactate, serum triglyceride or blood sodium and chloride concentrations did not differ from baseline or between the treatments. Compared with baseline, plasma glucose concentration increased after ROM and ROM + V, serum cortisol, FFA and base excess increased after all treatments and plasma ACTH concentration increased after V. Serum insulin concentration decreased after V and blood potassium decreased after all treatments.ConclusionsRomifidine induced hyperglycaemia, which vatinoxan partially prevented despite of the variations in baseline levels of serum insulin. The effects of romifidine and vatinoxan on the insulin concentration in horses need further investigation.