Contribution of mono- and co-culture of Pseudomonas paralactis, Acinetobacter MN21 and Stenotrophomonas maltophilia to the spoilage of chill-stored lamb.

Exploring the contribution of common microorganisms to spoilage is of great significance in inhibiting spoilage in lamb. This work investigated the extent of protein degradation and profile changes of free amino acids (FAAs), free fatty acids (FFAs) and volatile organic compounds (VOCs) in lamb caused by single- and co-culture of the common aerobic spoilage bacteria, P. paralactis, Ac. MN21 and S. maltophilia. Meanwhile, some key VOCs produced by the three bacteria during lamb spoilage were also screened by orthogonal partial least square discriminant analysis and difference value in VOCs content between inoculated groups and sterile group. Lamb inoculated with P. paralactis had the higher total viable counts, pH, total volatile base nitrogen and TCA-soluble peptides than those with the other two bacteria. Some FAAs and FFAs could be uniquely degraded by P. paralactis but not Ac. MN21 and S. maltophilia, such as Arg, Glu, C15:0, C18:0 and C18:1n9t. Co-culture of the three bacteria significantly promoted the overall spoilage, including bacterial growth, proteolysis and lipolysis. Key VOCs produced by P. paralactis were 2, 3-octanedione, those by Ac. MN21 were 1-octanol, octanal, hexanoic acid, 1-pentanol and hexanoic acid methyl ester, and that by S. maltophilia were hexanoic acid. The production of extensive key-VOCs was significantly and negatively correlated with C20:0, C23:0 and C18:ln9t degradation. This study can provide a basis for inhibiting common spoilage bacteria and promoting high-quality processing of fresh lamb.

Exploring lipid digestion discrepancies between preterm formula and human milk: Insights from in vitro gastrointestinal digestion and the impact of added milk fat.

Lipids play a pivotal role in the nutrition of preterm infants, acting as a primary energy source. Due to their underdeveloped gastrointestinal systems, lipid malabsorption is common, leading to insufficient energy intake and slowed growth. Therefore, it is critical to explore the reasons behind the low lipid absorption rate in formulas for preterm infants. This study utilized a simulated in intro gastrointestinal digestion model to assess the differences in lipid digestion between preterm human milk and various infant formulas. Results showed that the fatty acid release rates for formulas IF3, IF5, and IF7 were 58.90 %, 56.58 %, and 66.71 %, respectively, lower than human milk's 72.31 %. The primary free fatty acids (FFA) and 2-monoacylglycerol (2-MAG) released during digestion were C14:0, C16:0, C18:0, C18:1n-9, and C18:2n-6, in both human milk and formulas. Notably, the higher release of C16:0 in formulas may disrupt fatty acid balance, impacting lipid absorption. Further investigations are necessary to elucidate lipid absorption differences, which will inform the optimization of lipid content in preterm infant formulas.

Revealing the intrinsic relationship between microbial communities and physicochemical properties during ripening of Xuanwei ham.

To clarify the relationship between microorganisms and physicochemical indicators of Xuanwei ham. Six ham samples for the first, second and third year were selected, respectively. The changes of physicochemical properties, the free fatty acids and microbial communities of Xuanwei ham were investigated by GC-MS and high-throughput sequencing technology. Results showed that scores of colour, overall acceptability, texture, taste and aroma were the highest in the third year sample. With increasing ripening time, moisture content, water activity (Aw), lightness (L*), springiness, and resilience decreased continuously, and yellowness (b*) was the highest in the second year sample. 31 free fatty acids were detected, and unsaturated fatty acids such as palmitoleic acid, oleic acid, and linoleic acid were the major fatty acids. The content of palmitoleic acid, oleic acid and eicosenoic acid increased significantly during processing. At the phylum level, the dominant bacteria were Proteobacteria and Firmicutes, and fungi were Ascomycota. At the genus level, the dominant bacteria were Staphylococcus and Psychrobacter, and fungi were Aspergillus. Correlation analysis showed that water content and Aw were closely related to microorganisms, and most unsaturated fatty acids were significantly correlated with microorganisms. These findings showed that microorganisms played an important role in the quality of Xuanwei ham, and provided a scientific basis for the quality control of Xuanwei ham.

Effects of acute and chronic stair-climbing exercise on metabolic health: A systematic review.

Stair climbing exercise (SE) provides a feasible approach to elevate physical activity, but the effects on metabolic health are unclear. We systematically reviewed the currently available evidence on the effects of SE on fasting and postprandial glycaemia and lipidaemia. Studies were included if they investigated the effects of acute or chronic (at least 2 weeks) SE on fasting and/or postprandial glycaemic (insulin and glucose) and lipidaemic (triacylglycerols and non-esterified fatty acids) responses in healthy, prediabetic or type 2 diabetic adult populations. PubMed, Web of Science and Scopus were searched for eligible studies until July 2022. A total of 25 studies (14 acute and 11 chronic) were eligible for review. Acute bout(s) of SE can reduce postprandial glycaemia in individuals with prediabetes and type 2 diabetes (8 of 9 studies), but not in normoglycemic individuals. The effects of acute SE on postprandial lipidaemic responses and SE training on both fasting and postprandial glycaemia/lipidaemia were unclear. Acute SE may reduce postprandial glucose concentrations in people with impaired glycaemic control, but high-quality studies are needed. More studies are needed to determine the effect of chronic SE training on postprandial glucose and lipid responses, and the acute effects of SE on lipid responses.

Effects of Dietary Carbohydrate Concentration and Glycemic Index on Blood Glucose Variability and Free Fatty Acids in Individuals with Type 1 Diabetes.

Monitoring glycemic control status is the cornerstone of diabetes management. This study aimed to reveal whether moderate-carbohydrate (CHO) diets increase the risk of free fatty acid (FFA) levels, and it presents the short-term effects of four different diet models on blood sugar, glycemic variability (GV), and FFA levels. This crossover study included 17 patients with type 1 diabetes mellitus to identify the effects of four diets with different CHO contents and glycemic index (GI) on GV and plasma FFA levels. Diet 1 (D1) contained 40% CHO with a low GI, diet 2 (D2) contained 40% CHO with a high GI, diet 3 (D3) contained 60% CHO with a low GI, and diet 4 (D4) contained 60% CHO with a high GI. Interventions were performed with sensor monitoring in four-day periods and completed in four weeks. No statistical difference was observed among the groups in terms of blood glucose area under the curve (p = 0.78), mean blood glucose levels (p = 0.28), GV (p = 0.59), and time in range (p = 0.567). FFA and total triglyceride levels were higher in the D1 group (p < 0.014 and p = 0.002, respectively). Different diets may increase the risk of cardiovascular diseases by affecting GI, FFA, and blood glucose levels.

Insulin regulation of regional lipolysis in upper-body obese and lean humans.

BACKGROUND: Upper-body obesity (UBO) results in insulin resistance with regards to free fatty acid (FFA) release; how this differs by fat depot and sex between adults with UBO and lean adults is unknown. We tested the hypothesis that insulin suppression of FFA release from the splanchnic bed, leg fat, and upper-body nonsplanchnic (UBNS) adipose tissue would be impaired in UBO. METHODS: Fourteen volunteers with UBO (7 men and 7 women) and 14 healthy volunteers with normal weight (7 men and 7 women) participated in studies that included femoral artery, femoral vein, and hepatic vein catheterization. We then measured leg and splanchnic plasma flow as well as FFA kinetics (using isotopic tracers) under overnight fasting as well as low- and high-dose insulin infusion using the insulin clamp technique. RESULTS: We found the expected insulin resistance in UBO; the most quantitatively important difference between adults with UBO and lean adults was greater FFA release from UBNS adipose tissue when plasma insulin concentrations were in the postprandial, physiological range. There were obesity, but not sex, differences in the regulation of splanchnic FFA release and sex differences in the regulation of leg FFA release. CONCLUSION: Reversing the defects in insulin-regulated UBNS adipose tissue FFA release would have the greatest effect on systemic FFA abnormalities in UBO. FUNDING: These studies were supported by the US Public Health Service (grants DK45343 and DK40484), the Novo Nordic Foundation (grant NNF18OC0031804 and NNF16OC0021406), and the Independent Research Fund Denmark (grant 8020-00420B).

ß-Cell Insulin Resistance Plays a Causal Role in Fat-Induced ß-Cell Dysfunction In Vitro and In Vivo.

In the classical insulin target tissues of liver, muscle, and adipose tissue, chronically elevated levels of free fatty acids (FFA) impair insulin signaling. Insulin signaling molecules are also present in ß-cells where they play a role in ß-cell function. Therefore, inhibition of the insulin/insulin-like growth factor 1 pathway may be involved in fat-induced ß-cell dysfunction. To address the role of ß-cell insulin resistance in FFA-induced ß-cell dysfunction we co-infused bisperoxovanadate (BPV) with oleate or olive oil for 48 hours in rats. BPV, a tyrosine phosphatase inhibitor, acts as an insulin mimetic and is devoid of any antioxidant effect that could prevent ß-cell dysfunction, unlike most insulin sensitizers. Following fat infusion, rats either underwent hyperglycemic clamps for assessment of ß-cell function in vivo or islets were isolated for ex vivo assessment of glucose-stimulated insulin secretion (GSIS). We also incubated islets with oleate or palmitate and BPV for in vitro assessment of GSIS and Akt (protein kinase B) phosphorylation. Next, mice with ß-cell specific deletion of PTEN (phosphatase and tensin homolog; negative regulator of insulin signaling) and littermate controls were infused with oleate for 48 hours, followed by hyperglycemic clamps or ex vivo evaluation of GSIS. In rat experiments, BPV protected against fat-induced impairment of ß-cell function in vivo, ex vivo, and in vitro. In mice, ß-cell specific deletion of PTEN protected against oleate-induced ß-cell dysfunction in vivo and ex vivo. These data support the hypothesis that ß-cell insulin resistance plays a causal role in FFA-induced ß-cell dysfunction.

A novel ABCD1 gene mutation causes adrenomyeloneuropathy presenting with spastic paraplegia: A case report.

RATIONALE: X-linked adrenoleukodystrophy (X-ALD) is caused by mutations in the ABCD1 gene leading to very long chain fatty acid (VLCFA) accumulation. The disease demonstrates a spectrum of phenotypes including adrenomyeloneuropathy (AMN). We aimed to identify the genetic basis of disease in a patient presenting with AMN features in order to confirm the diagnosis, expand genetic knowledge of ABCD1 mutations, and elucidate potential genotype-phenotype associations to inform management. PATIENT CONCERNS: A 29-year-old male presented with a 4-year history of progressive spastic paraplegia, weakness of lower limbs, fecal incontinence, sexual dysfunction, hyperreflexia, and positive Babinski and Chaddock signs. DIAGNOSES: Neuroimaging revealed brain white matter changes and spinal cord thinning. Significantly elevated levels of hexacosanoic acid (C26:0) and tetracosanoic acid (C24:0) suggested very long chain fatty acids (VLCFA) metabolism disruption. Genetic testing identified a novel hemizygous ABCD1 mutation c.249dupC (p.F83fs). These findings confirmed a diagnosis of X-linked ALD with an AMN phenotype. INTERVENTIONS: The patient received dietary counseling to limit VLCFA intake. Monitoring for adrenal insufficiency and consideration of Lorenzo's oil were advised. Genetic counseling and testing were offered to at-risk relatives. OUTCOMES: At present, the patient continues to experience progressive paraplegia. Adrenal function remains normal thus far without steroid replacement. Family members have undergone predictive testing. LESSONS: This case expands the known mutation spectrum of ABCD1-linked X-ALD, providing insight into potential genotype-phenotype correlations. A thoughtful diagnostic approach integrating clinical, biochemical and genetic data facilitated diagnosis. Findings enabled genetic counseling for at-risk relatives regarding this X-linked disorder.

Visceral Adipose Tissue: The Hidden Culprit for Type 2 Diabetes.

Type 2 diabetes (T2D) is a chronic metabolic disorder characterized by insulin resistance in various tissues. Though conventionally associated with obesity, current research indicates that visceral adipose tissue (VAT) is the leading determining factor, wielding more influence regardless of individual body mass. The heightened metabolic activity of VAT encourages the circulation of free fatty acid (FFA) molecules, which induce insulin resistance in surrounding tissues. Individuals most vulnerable to this preferential fat deposition are older males with ancestral ties to Asian countries because genetics and sex hormones are pivotal factors for VAT accumulation. However, interventions in one's diet and lifestyle have the potential to strategically discourage the growth of VAT. This illuminates the possibility that the expansion of VAT and, subsequently, the risk of T2D development are preventable. Therefore, by reducing the amount of VAT accumulated in an individual and preventing it from building up, one can effectively control and prevent the development of T2D.

Influences of oxidative stress and energy balance on pregnancy rates after the transfer of embryos to repeat-breeder Japanese Black cattle.

The purpose of this study is to reassess our previously reported findings on the diminished pregnancy rate of embryo transfer (ET) in summer for repeat-breeder (RB) cows compared with other seasons, with a focus on oxidative stress and energy balance. The study involved Japanese Black cattle, including 224 heifers (aged <3 years) and 278 (aged <9 years) cows with one or more deliveries, defined as RB animals. Evaluation of the effects of season on pregnancy rates revealed significantly lower rates in RB cows during summer compared with spring and autumn. Moreover, serum malondialdehyde (MDA) concentration in RB cows during summer was significantly higher than in winter, with no difference in RB heifers. Seasonal effects on serum nonesterified fatty acid (NEFA) concentration in both RB heifers and RB cows showed no significant differences. However, median MDA and NEFA concentrations in RB cows were significantly elevated compared with RB heifers, suggesting that factors contributing to low fertility should consider parity. Furthermore, our study indicated that RB cows were under oxidative stress, as demonstrated by significantly elevated MDA concentrations compared with normally reproducing cows in summer. Further investigation is necessary to gain a better understanding of these observations in the future.

Models of the Three-Component Bilayer of Stratum Corneum: A Molecular Simulation Study.

The construction of the stratum corneum (SC) is crucial to the problems of transdermal drug delivery. SC consists of the keratinocyte layers and the lipid matrix surrounding it. Among them, the lipid matrix is the barrier for many exogenous molecules, mainly composed of ceramides (CERs), free fatty acids (FFA), and cholesterol (CHOL). In this work, we developed single-component (CERs, CER-NS, and CER-EOS) and six three-component models, and each model was simulated by using the GROMOS-54A7 force field. Short-period phase (SPP) and long-period phase (LPP) systems were established separately, and area per lipid (APL), thickness, order of carbon chain (SCD), and density distribution were analyzed. The transition of CER-NS and CER-EOS in LPP was observed. The results of hydrogen bonds in the lipid systems indicated that a strong hydrogen-bond network was formed between the skin-lipid bilayers. Umbrella sampling method simulations were performed to calculate the free energy change of ethanol moving into the skin-lipid bilayer. The results revealed that ethanol molecules pulled some water molecules into the membrane when they passed through SPP-1. Our findings provided some insights and models of the stratum corneum that could be used for the subsequent mechanism of macromolecule permeation through membranes in drugs, cosmetics, and so on.

Clusters of adipose tissue dysfunction in adults with type 2 diabetes identify those with worse lipidomic profile despite similar glycaemic control.

AIMS: To investigate clusters of adipose tissue dysfunction, that is, with adipose tissue insulin resistance (ADIPO-IR) and large waist circumference (WC), identify a worse lipidomic profile characterised by a high proportion of lipids rich in saturated fatty acids (SFA). MATERIALS AND METHODS: Hierarchical clustering based on WC and ADIPO-IR (calculated as fasting plasma non-esterified fatty acids times fasting plasma insulin, FFA×INS), was performed in 192 adults with overweight/obesity and type 2 diabetes (T2D) treated with metformin (HbA1c = 7.8%). Free fatty acid composition and lipidomic profile were measured by mass spectrometry (GC-MS and LC-MSQTOF). Indexes of fatty acid desaturation (stearoyl-coA desaturase-1 activity, SCD116 = palmitoleic acid/palmitic acid and SCD118 = oleic acid/stearic acid) and of insulin resistance (HOMA-IR) were also calculated. RESULTS: Three clusters were identified: CL1 (ADIPO-IR = 4.9 ± 2.4 and WC = 96±7 cm, mean ± SD), CL2 (ADIPO-IR = 6.5 ± 2.5 and WC = 114 ± 7 cm), and CL3 (ADIPO-IR = 15.0 ± 4.7 and WC = 107 ± 8 cm). Insulin concentrations, ADIPO-IR, and HOMA-IR significantly increased from CL1 to CL3 (all p < 0.001), while fasting glucose concentrations, HbA1c, dietary lipids and caloric intake were similar. Moreover, CL3 showed significantly higher concentrations of monounsaturated free fatty acids, oleic and palmitoleic acids, triglycerides (TAG) rich in saturated FA and associated with de novo lipogenesis (i.e., TAG 46-50), higher SCD116, SCD118, ceramide (d18:0/18:0), and phosphatidylcholine aa(36:5) compared with CL1/CL2 (all p < 0.005). CONCLUSIONS: High ADIPO-IR and large WC identify a worse lipid profile in T2D characterised by complex lipids rich in SFA, likely due to de novo synthesis given higher plasma monounsaturated FFA and increased desaturase activity indexes. REGISTRATION NUMBER TRIAL: ID NCT00700856 https://clinicaltrials.gov.

GLUT4 localisation with the plasma membrane is unaffected by an increase in plasma free fatty acid availability.

BACKGROUND: Insulin-stimulated glucose uptake into skeletal muscle occurs via translocation of GLUT4 from intracellular storage vesicles to the plasma membrane. Elevated free fatty acid (FFA) availability via a lipid infusion reduces glucose disposal, but this occurs in the absence of impaired proximal insulin signalling. Whether GLUT4 localisation to the plasma membrane is subsequently affected by elevated FFA availability is not known. METHODS: Trained (n = 11) and sedentary (n = 10) individuals, matched for age, sex and body mass index, received either a 6 h lipid or glycerol infusion in the setting of a concurrent hyperinsulinaemic-euglycaemic clamp. Sequential muscle biopsies (0, 2 and 6 h) were analysed for GLUT4 membrane localisation and microvesicle size and distribution using immunofluorescence microscopy. RESULTS: At baseline, trained individuals had more small GLUT4 spots at the plasma membrane, whereas sedentary individuals had larger GLUT4 spots. GLUT4 localisation with the plasma membrane increased at 2 h (P = 0.04) of the hyperinsulinemic-euglycemic clamp, and remained elevated until 6 h, with no differences between groups or infusion type. The number of GLUT4 spots was unchanged at 2 h of infusion. However, from 2 to 6 h there was a decrease in the number of small GLUT4 spots at the plasma membrane (P = 0.047), with no differences between groups or infusion type. CONCLUSION: GLUT4 localisation with the plasma membrane increases during a hyperinsulinemic-euglycemic clamp, but this is not altered by elevated FFA availability. GLUT4 appears to disperse from small GLUT4 clusters located at the plasma membrane to support glucose uptake during a hyperinsulinaemic-euglycaemic clamp.

Levels of lipid-derived gut microbial metabolites differ among plant matrices in an in vitro model of colon fermentation.

This study explored differences in microbial lipid metabolites among sunflower seeds, soybeans, and walnuts. The matrices were subjected to in vitro digestion and colonic fermentation. Defatted digested materials and fiber/phenolics extracted therefrom were added to sunflower oil (SO) and also fermented. Targeted and untargeted lipidomics were employed to monitor and tentatively identify linoleic acid (LA) metabolites. Walnut fermentation produced the highest free fatty acids (FFAs), LA, and conjugated LAs (CLAs). Defatted digested walnuts added to SO boosted FFAs and CLAs production; the addition of fibre boosted CLAs, whereas the addition of phenolics only increased 9e,11z-CLA and 10e,12z-CLA. Several di-/tri-hydroxy-C18-FAs, reported as microbial LA metabolites for the first time, were annotated. Permutational multivariate analysis of variance indicated significant impacts of food matrix presence and type on lipidomics and C18-FAs. Our findings highlight how the food matrices affect CLA production from dietary lipids, emphasizing the role of food context in microbial lipid metabolism.

Lipidomics analysis unveils the dynamic alterations of lipid degradation in rice bran during storage.

Recent explorations into rice bran oil (RBO) have highlighted its potential, owing to an advantageous fatty acid profile in the context of health and nutrition. Despite this, the susceptibility of rice bran lipids to oxidative degradation during storage remains a critical concern. This study focuses on the evolution of lipid degradation in RBO during storage, examining the increase in free fatty acids (FFAs), the formation of oxylipids, and the generation of volatile secondary oxidation products. Our findings reveal a substantial rise in FFA levels, from 109.55 to 354.06 mg/g, after 14 days of storage, highlighting significant lipid deterioration. Notably, key oxylipids, including 9,10-EpOME, 12,13(9,10)-DiHOME, and 13-oxoODE, were identified, with a demonstrated positive correlation between total oxylipids and free polyunsaturated fatty acids (PUFAs), specifically linoleic acid (LA) and α-linolenic acid (ALA). Furthermore, the study provides a detailed analysis of primary volatile secondary oxidation products. The insights gained from this study not only sheds light on the underlying mechanisms of lipid rancidity in rice bran but also offers significant implications for extending the shelf life and preserving the nutritional quality of RBO, aligning with the increasing global interest in this high-quality oil.

Gene expression of free fatty acids-sensing G protein-coupled receptors in beef cattle.

Many physiological functions are regulated by free fatty acids (FFA). Recently, the discovery of FFA-specific G protein-coupled receptors (FFARs) has added to the complexity of their actions at the cellular level. The study of FFAR in cattle is still in its earliest stages focusing mainly on dairy cows. In this study, we set out to map the expression of genes encoding FFARs in 6 tissues of beef cattle. We also investigated the potential effect of dietary forage nature on FFAR gene expression. To this end, 16 purebred Charolais bulls were fed a grass silage ration or a maize silage ration (n = 8/group) with a forage/concentrate ratio close to 60:40 for 196 d. The animals were then slaughtered at 485 ±â€…42 d and liver, spleen, ileum, rectum, perirenal adipose tissue (PRAT), and Longissimus Thoracis muscle were collected. FFAR gene expression was determined by real-time quantitative PCR. Our results showed that of the five FFARs investigated, FFAR1, FFAR2, FFAR3, and GPR84 are expressed (Ct < 30) in all six tissues, whereas FFAR4 was only expressed (Ct < 30) in PRAT, ileum, and rectum. In addition, our results showed that the nature of the forage, i.e., grass silage or maize silage, had no effect on the relative abundance of FFAR in any of the tissues studied (P value > 0.05). Taken together, these results open new perspectives for studying the physiological role of these receptors in beef cattle, particularly in nutrient partitioning during growth.

Free fatty acids (FFA) are key modulators of bovine physiology. Recently, it has been discovered that some G protein-coupled receptors, termed free fatty acid receptors (FFARs), may help mediate the action of FFA at the cellular level. In humans and rodents, a growing body of evidence has shown that i) FFARs are expressed in a wide range of tissues and ii) FFARs are involved in the regulation of major FFA-dependent physiological processes (inflammation, feed intake, insulin release, etc.). In cattle, information on FFAR expression and function in tissues are scarce and mainly concern dairy cows. In this study, we showed that FFARs are expressed in 6 different tissues of beef cattle: adipose tissue, muscle tissue, ileum, rectum, liver, and spleen. We also showed that the nature of forage fed to the animals (i.e., grass silage vs. maize silage) has no effect on FFARs gene expression.

Albumin is an important factor in the control of serum free fatty acid flux in both male and female mice.

Albumin knockout (Alb-/-) mice exhibit a low plasma free fatty acid (FFA) concentration, but it was not known if the suppressed concentration reflects a lower rate of appearance (Ra) of FFA in the circulation (i.e., lower FFA flux) or if the absence of albumin alters the relationship between FFA flux and concentration. For understanding the role of albumin in FFA transport through the bloodstream, it is not sufficient to rely on FFA concentration data alone. Therefore, we developed a method to study FFA kinetics in Alb-/- mice. Using an albumin-free formulation of [U-13C]palmitate tracer, serum FFA kinetics were tested in Alb-/- and wild-type (WT) mice. Results indicate that the flux of FFA in serum of Alb-/- mice was significantly lower than in WT mice (P < 0.05), while albumin deficiency did not alter the relationship between FFA flux and concentration. Next, to test if suppressed lipolysis might have also been involved in the suppressed FFA kinetics, gene expression of a lipolytic enzyme (adipose triglyceride lipase, Atgl) and a marker of lipolysis (phosphorylation of hormone-sensitive lipase, p-HSL) were measured in adipose tissue. In contrast to the low FFA flux in Alb-/-, both Atgl gene expression and p-HSL protein were significantly higher in adipose tissue of Alb-/- than in WT mice (P < 0.05). Thus, the low FFA flux in Alb-/- appeared to be driven by the absence of albumin's FFA binding functions rather than through regulation of lipolysis, indicating that albumin is an important factor in determining the flux of FFA in circulation.NEW & NOTEWORTHY To improve understanding of the albumin protein's function in vivo, we tested plasma free fatty acid kinetics in albumin knockout mice compared with wild-type mice. Using a new tracer formulation strategy, it was discovered that the appearance rate of free fatty acids in serum is lower in albumin knockout mice than in wild-type mice. The results indicate that albumin is a major controller of free fatty acid kinetics.

Prepartum behaviors as early indicators for postpartum energy associated biomarkers status in Holstein dairy cows.

Our main aim was to investigate the predictive value of prepartum behaviors such as total daily rumination (TDR), total daily activity (TDA) and dry matter intake (DMI) as early indicators to detect cows at risk for hyperketonemia (HYK), hypoglycemia (HYG) or high non-esterified fatty acid (NEFA) status in the first (wk1) and second week (wk2) postpartum. In a case control study, 64 Holstein cows were enrolled 3 weeks before the expected time of calving and monitored until 15 days in milk (DIM). Postpartum blood samples were taken at D3 and D6 for wk1 and at D12 and D15 for wk2 to measure beta-hydroxybutyrate, NEFA and glucose concentration. Ear-mounted accelerometers were used to measure TDR and TDA. DMI and milk yield were obtained from farm records. Relationships between the average daily rate of change in prepartum TDR (ΔTDR), TDA (ΔTDA), and DMI (ΔDMI) with postpartum HYK, HYG and NEFA status in wk1 and wk2 post-partum were evaluated using linear regression models. Models were adjusted for potential confounding variables, and covariates retained in the final models were determined by backward selection. No evidence was found to support the premise that prepartum ΔTDR, ΔTDA or ΔDMI predicted postpartum HYK, HYG or NEFA status in wk1 or in wk2. Overall, prepartum ΔTDR, ΔTDA and ΔDMI were not effective predictors of HYK, HYG or NEFA status in the first 2 weeks postpartum.

Activation of free fatty acid receptors, FFAR1 and FFAR4, ameliorates ulcerative colitis by promote fatty acid metabolism and mediate macrophage polarization.

OBJECTIVE: To investigate the mechanism of action of fatty acid receptors, FFAR1 and FFAR4, on ulcerative colitis (UC) through fatty acid metabolism and macrophage polarization. METHODS: Dextran sulfate sodium (DSS)-induced mouse model of UC mice was used to evaluate the efficacy of FFAR1 (GW9508) and FFAR4 (GSK137647) agonists by analyzing body weight, colon length, disease activity index (DAI), and histological scores. Real-time PCR and immunofluorescence analysis were performed to quantify the levels of fatty acid metabolizing enzymes and macrophage makers. FFA-induced lipid accumulation in RAW264.7 cells was visualized by Oil Red O staining analysis, and cells were collected to detect macrophage polarization by flow cytometry. RESULTS: The combination of GW9508 and GSK137647 significantly improved DSS-induced UC symptoms, caused recovery in colon length, and decreased histological injury. GW9508 + GSK137647 treatment upregulated the expressions of CD206, lipid oxidation enzyme (CPT-1α) and anti-inflammatory cytokines (IL-4, IL-10, IL-13) but downregulated those of CD86, lipogenic enzymes (ACC1, FASN, SCD1), and pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α). Combining the two agonists decreased FFA-induced lipid accumulation and increased CD206 expression in cell-based experiments. CONCLUSION: Activated FFAR1 and FFAR4 ameliorates DSS-induced UC by promoting fatty acid metabolism to reduce lipid accumulation and mediate M2 macrophage polarization.

Alterations of circulating free fatty acids in patients with pemphigus vulgaris.

Free fatty acids (FFA) have gained research interest owing to their functions in both local and systemic immune regulation. Changes in the serum levels of anti-inflammatory short chain fatty acids (SCFA), primarily derived from the gut microbiota, and pro-inflammatory medium (MCFA) and long (LCFA) chain fatty acids, derived from either the gut microbiota or the diet, have been associated with autoimmunity. Circulating FFA were retrospectively analysed by a gas chromatography-mass spectrometry method in the serum of 18 patients with pemphigus vulgaris (PV) at the baseline and 6 months (n = 10) after immunosuppressive treatments, and 18 healthy controls (HC). Circulating FFA were correlated with the Pemphigus Disease Area Index (PDAI) and serum concentrations of interferon-gamma (IFN-γ), Interleukin (IL)-17A, IL-5, IL-10 and IL-21. Principal Component analysis computed on FFA abundances revealed significant differences in the profile of SCFA (p = 0,012), MCFA (p = 0.00015) and LCFA (p = 0,035) between PV patients and HC, which were not significantly changed by immunosuppressive treatments. PV patients showed a significantly lower serum concentration of propionic (p < 0.0005) and butyric (p < 0.0005) acids, SCFA with anti-inflammatory functions, while hexanoic (p < 0.0005) and hexadecanoic (p = 0.0006) acids, pro-inflammatory MCFA and LCFA respectively, were over-represented. Treatments induced a significant decrease of hexanoic (p = 0.035) and a further increase of hexadecanoic (p = 0.046) acids. Positive correlations emerged between IFN-γ and acetic acid (Rho = 0.60), IFN-γ and hexanoic acid (Rho = 0.46), IL-5 and both hexadecanoic acid (Rho = 0.50) and octadecanoic acid (Rho = 0.53), butyric acid and PDAI (Rho = 0.53). PV was associated with a remarked imbalance of circulating FFA compared to HC. The serum alterations of SCFA, MCFA, and LCFA may contribute to promoting inflammation in PV. Deeper insights into the immunomodulatory functions of these molecules may pave the way for personalized dietary interventions in PV patients.