Chronic administration of myristic acid improves hyperglycaemia in the Nagoya-Shibata-Yasuda mouse model of congenital type 2 diabetes

Association of maternal blood metabolomics and gestational diabetes mellitus risk: a systematic review and meta-analysis

Gestational diabetes mellitus (GDM) is a common complication of pregnancy that has short- and long-term adverse effects. Therefore, further exploration of the pathophysiology of GDM and related biomarkers is important. In this study, we performed a systematic review and meta-analysis to investigate the associations between metabolites in blood detected via metabolomics techniques and the risk of GDM and to identify possible biomarkers for predicting the occurrence of GDM. We retrieved case‒control and cohort studies of metabolomics and GDM published in PubMed, Embase, and Web of Science through March 29, 2024; extracted metabolite concentrations, odds ratios (ORs), or relative risks (RRs); and evaluated the integrated results with metabolites per-SD risk estimates and 95% CIs for GDM. We estimated the results via the random effects model and the inverse variance method. Our study is registered in PROSPERO (CRD42024539435). We included a total of 28 case‒control and cohort studies, including 17,370 subjects (4,372 GDM patients and 12,998 non-GDM subjects), and meta-analyzed 67 metabolites. Twenty-five of these metabolites were associated with GDM risk. Some amino acids (isoleucine, leucine, valine, alanine, aspartate, etc.), lipids (C16:0, C18:1n-9, C18:1n-7, lysophosphatidylcholine (LPC) (16:0), LPC (18:0), and palmitoylcarnitine), and carbohydrates and energy metabolites (glucose, pyruvate, lactate, 2-hydroxybutyrate, 3-hydroxybutyrate) were discovered to be associated with increased GDM risk (hazard ratio 1.06-2.77). Glutamine, histidine, C14:0, and sphingomyelin (SM) (34:1) were associated with lower GDM risk (hazard ratio 0.75-0.84). These findings suggest that these metabolites may play essential roles in GDM progression, and serve as biomarkers, contributing to the early diagnosis and prediction of GDM.

Dietary and plasma atherogenic and thrombogenic indices and cardiometabolic risk factors among overweight and individuals with obesity

BACKGROUND

Obesity and hyperlipidemia are the two central metabolic disorders linked to non-communicable diseases (NCDs) that increase the risk of cardiovascular disease (CVD). Apart from dyslipidemia, the Atherogenic Index of Plasma (AIP), which is associated with dietary consumption, is another marker for predicting the risk of CVD. Healthy fat quality indicators may impact AIP. The purpose of this study is to ascertain whether there is any connection between Iranian obese people's plasma and dietary indices and cardiometabolic risk factors.

METHODS

This cross-sectional study, consisted of 645 overweight and obese participants. The study included assessments of body composition and anthropometric measurements. Dietary fatty acid consumption was evaluated using a validated Food Frequency Questionnaire (FFQ) containing 168 items. Additionally, biochemical parameters, including serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), fasting serum glucose (FSG), and insulin levels, were measured using enzymatic methods. The lipid profile was quantified.

RESULTS

For participants in higher tertiles of the AIP, the percentage of men was significantly higher than women (men: 48.1%, women: 51.7%, p < 0.001). Additionally, individuals in higher tertiles of AIP had a higher waist-to-hip ratio (WHR) (mean WHR: 0.92 ± 0.05 vs. 0.86 ± 0.04 in lower tertile, p < 0.001). Participants in the highest tertile of AIP had higher systolic blood pressure (SBP: 132 ± 8 mmHg vs. 118 ± 6 mmHg in lower tertile, p < 0.001), total cholesterol (TC: 210 ± 15 mg/dL vs. 185 ± 12 mg/dL, p < 0.001), triglycerides (TG: 180 ± 20 mg/dL vs. 120 ± 15 mg/dL, p < 0.001), and glucose concentrations (fasting glucose: 105 ± 10 mg/dL vs. 90 ± 8 mg/dL, p < 0.001). Participants in the lower tertile of AIP had higher HDL cholesterol levels (HDL: 60 ± 5 mg/dL vs. 45 ± 4 mg/dL in higher tertile, p < 0.001). In the model for Thrombogenicity Index (TI), participants in the higher tertile had higher glucose concentrations (glucose: 110 ± 12 mg/dL vs. 95 ± 9 mg/dL in lower tertile, p = 0.04).

CONCLUSION

This research introduces a novel field of investigation and emphasizes the possible importance of TI, AI, and AIP indices in regulating cardiometabolic risk factors.

Ubiquitin-specific peptidase 11 selectively interacts with and deubiquitination-dependently stabilizes diacylglycerol kinase δ to maintain cellular glucose uptake

Diacylglycerol kinase δ (DGKδ) phosphorylates diacylglycerol and converts it into phosphatidic acid. DGKδ contributes to glucose uptake as one of its cellular functions. However, detail mechanisms underlying the regulation of DGKδ protein stability remain unelucidated. Herein, we identified ubiquitin-specific peptidase 11 (USP11) in the DGKδ protein complex by DGKδ-interactome analysis. By mapping analysis, we clarified that a wider region of USP11, including the catalytic domain 1 region, and both the C1 domains and catalytic subdomain-a of DGKδ mainly contributed to their association. Cellular dysfunction of USP11 by mitoxiantrone (a USP11-specific inhibitor) or siRNA knockdown markedly decreased DGKδ protein levels. Additionally, we found that DGKδ ubiquitination was increased by USP11 dysfunction, and cumulative ubiquitination was reduced by rescue manipulation. Functionally, USP11 dysfunction reduced cellular glucose uptake. Altogether, our findings provide the first evidence that USP11 deubiquitination-dependently stabilizes DGKδ to maintain cellular glucose uptake.

Diacylglycerol kinase δ is required for skeletal muscle development and regeneration

Diacylglycerol kinase δ (DGKδ) phosphorylates diacylglycerol to produce phosphatidic acid. Previously, we demonstrated that down-regulation of DGKδ suppresses the myogenic differentiation of C2C12 myoblasts. However, the myogenic roles of DGKδ in vivo remain unclear. In the present study, we generated DGKδ-conditional knockout mice under the control of the myogenic factor 5 (Myf5) gene promoter, which regulates myogenesis and brown adipogenesis. The knockout mice showed a significant body weight reduction and apparent mass decrease in skeletal muscle, including the tibialis anterior (TA) muscle. Moreover, the thickness of a portion of the myofibers was reduced in DGKδ-deficient TA muscles. However, DGKδ deficiency did not substantially affect brown adipogenesis, suggesting that Myf5-driven DGKδ deficiency mainly affects muscle development. Notably, skeletal muscle injury induced by a cardiotoxin highly up-regulated DGKδ protein expression, and the DGKδ deficiency significantly reduced the thickness of myofibers, the expression levels of myogenic differentiation markers such as embryonic myosin heavy chain and myogenin, and the number of newly formed myofibers containing multiple central nuclei during muscle regeneration. DGKδ was strongly expressed in myogenin-positive satellite cells around the injured myofibers and centronucleated myofibers. These results indicate that DGKδ has important roles in muscle regeneration in activated satellite cells. Moreover, the conditional knockout mice fed with a high-fat diet showed increased fat mass and glucose intolerance. Taken together, these results demonstrate that DGKδ plays crucial roles in skeletal muscle development, regeneration, and function.

Upstream and downstream pathways of diacylglycerol kinase : Novel phosphatidylinositol turnover-independent signal transduction pathways

Diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DG) to produce phosphatidic acid (PA). Mammalian DGK comprise ten isozymes (α-κ) that regulate a wide variety of physiological and pathological events. Recently, we revealed that DGK isozymes use saturated fatty acid (SFA)/monosaturated fatty acid (MUFA)-containing and docosahexaenoic acid (22:6)-containing DG species, but not phosphatidylinositol (PI) turnover-derived 18:0/20:4-DG. For example, DGKδ, which is involved in the pathogenesis of type 2 diabetes, preferentially uses SFA/MUFA-containing DG species, such as 16:0/16:0- and 16:0/18:1-DG species, in high glucose-stimulated skeletal muscle cells. Moreover, DGKδ, which destabilizes the serotonin transporter (SERT) and regulates the serotonergic system in the brain, primarily generates 18:0/22:6-PA. Furthermore, 16:0/16:0-PA is produced by DGKζ in Neuro-2a cells during neuronal differentiation. We searched for SFA/MUFA-PA- and 18:0/22:6-PA-selective binding proteins (candidate downstream targets of DGKδ) and found that SFA/MUFA-PA binds to and activates the creatine kinase muscle type, an energy-metabolizing enzyme, and that 18:0/22:6-PA interacts with and activates Praja-1, an E3 ubiquitin ligase acting on SERT, and synaptojanin-1, a key player in the synaptic vesicle cycle. Next, we searched for SFA/MUFA-DG-generating enzymes upstream of DGKδ. We found that sphingomyelin synthase (SMS)1, SMS2, and SMS-related protein (SMSr) commonly act as phosphatidylcholine (PC)-phospholipase C (PLC) and phosphatidylethanolamine (PE)-PLC, generating SFA/MUFA-DG species, in addition to SMS and ceramide phosphoethanolamine synthase. Moreover, the orphan phosphatase PHOSPHO1 showed PC- and PE-PLC activities that produced SFA/MUFA-DG. Although PC- and PE-PLC activities were first described 70-35 years ago, their proteins and genes were not identified for a long time. We found that DGKδ interacts with SMSr and PHOSPHO1, and that DGKζ binds to SMS1 and SMSr. Taken together, these results strongly suggest that there are previously unrecognized signal transduction pathways that include DGK isozymes and generate and utilize SFA/MUFA-DG/PA or 18:0/22:6-DG/PA but not PI-turnover-derived 18:0/20:4-DG/PA.

Diacylglycerol kinase delta overexpression improves glucose clearance and protects against the development of obesity

BACKGROUND AND AIM

Diacylglycerol kinase (DGK) isoforms catalyze an enzymatic reaction that removes diacylglycerol (DAG) and thereby terminates protein kinase C signaling by converting DAG to phosphatidic acid. DGKδ (type II isozyme) downregulation causes insulin resistance, metabolic inflexibility, and obesity. Here we determined whether DGKδ overexpression prevents these metabolic impairments.

METHODS

We generated a transgenic mouse model overexpressing human DGKδ2 under the myosin light chain promoter (DGKδ TG). We performed deep metabolic phenotyping of DGKδ TG mice and wild-type littermates fed chow or high-fat diet (HFD). Mice were also provided free access to running wheels to examine the effects of DGKδ overexpression on exercise-induced metabolic outcomes.

RESULTS

DGKδ TG mice were leaner than wild-type littermates, with improved glucose tolerance and increased skeletal muscle glycogen content. DGKδ TG mice were protected against HFD-induced glucose intolerance and obesity. DGKδ TG mice had reduced epididymal fat and enhanced lipolysis. Strikingly, DGKδ overexpression recapitulated the beneficial effects of exercise on metabolic outcomes. DGKδ overexpression and exercise had a synergistic effect on body weight reduction. Microarray analysis of skeletal muscle revealed common gene ontology signatures of exercise and DGKδ overexpression that were related to lipid storage, extracellular matrix, and glycerophospholipids biosynthesis pathways.

CONCLUSION

Overexpression of DGKδ induces adaptive changes in both skeletal muscle and adipose tissue, resulting in protection against HFD-induced obesity. DGKδ overexpression recapitulates exercise-induced adaptations on energy homeostasis and skeletal muscle gene expression profiles.

Association of circulating long-chain free fatty acids and incident diabetes risk among normoglycemic Chinese adults: a prospective nested case-control study

BACKGROUND

Long-chain free fatty acids (FFAs) are associated with risk of incident diabetes. However, a comprehensive assessment of the associations in normoglycemic populations is lacking.

OBJECTIVES

Our study aimed to comprehensively investigate the prospective associations and patterns of FFA profiles with diabetes risk among normoglycemic Chinese adults.

METHODS

This is a prospective nested case-control study from the China Cardiometabolic Disease and Cancer Cohort (4C) study. We quantitatively measured 53 serum FFAs using a targeted metabolomics approach in 1707 incident diabetes subjects and 1707 propensity score-matched normoglycemic controls. Conditional logistic regression models were employed to estimate odds ratios (ORs) for associations. Least Absolute Shrinkage and Selection Operator (LASSO) penalty regression and quantile g-computation (qg-comp) analyses were implemented to estimate the association between multi-FFA exposures and incident diabetes.

RESULTS

The majority of odd-chain FFAs exhibited an inverse association with incident diabetes, wherein the ORs per SD increment of all 7 saturated fatty acids (SFAs), monounsaturated fatty acid (MUFA) 15:1, and polyunsaturated fatty acid (PUFA) 25:2 were ranging from 0.79 to 0.88 (95% CIs ranging between 0.71 and 0.97). Even-chain FFAs comprised 99.3% of total FFAs and displayed heterogeneity with incident diabetes. SFAs with 18-26 carbon atoms are inversely linked to incident diabetes, with ORs ranging from 0.81 to 0.86 (95% CIs ranging between 0.73 and 0.94). MUFAs 26:1 (OR: 0.85; 95% CI: 0.76, 0.94), PUFAs 20:4 (OR: 0.84; 95% CI: 0.75, 0.94), and 24:2 (OR: 0.87; 95% CI: 0.78, 0.97) demonstrated significant associations. In multi-FFA exposure model, 24 FFAs were significantly associated with incident diabetes, most of which were consistent with univariate results. The mixture OR was 0.78 (95% CI: 0.61, 0.99; P = 0.04159). Differential correlation network analysis revealed pre-existing perturbations in intraclass and interclass FFA coregulation before diabetes onset.

CONCLUSIONS

These findings underscore the variations in diabetes risk associated with FFAs across chain length and unsaturation degree, highlighting the importance of recognizing FFA subtypes in the pathogenesis of diabetes.

A network pharmacological approach for the identification of potential therapeutic targets of Brahmi Nei - a complex traditional Siddha formulation

Brahmi Nei (BN), a traditional Indian polyherbal formulation has been described in classical texts for the treatment of anxiety and depression, as well as to fortify the immune system. The individual herbs of BN have been used for treatment of wide range of disorders including cognition, inflammation, skin ailments and cancer etc., This diverse basket of therapeutic activity suggests that BN may possess therapeutic benefits to other disorders. So, the present study aims to identify the potential therapeutic targets of BN using a network pharmacological approach to comprehend the multi target action of its multiple phytoconstituents. We have employed Randić Index for the first time to calculate the contribution score of module segregated targets towards diseases. Our results suggests that BN targets could also be effective in other diseases such as lysosomal storage disorders, respiratory disorders etc., apart from neurological disorders. The key targets with highest topological measures of Targets-(Pathway)-Targets network were identified as potential therapeutic targets of BN. And the top hit target PTGS2, a gene encoding for cyclooxygenase-2 was further evaluated using molecular docking, molecular dynamic simulation and in vitro studies. Our findings open up new therapeutic facets for BN that can be explored systematically in future.

Metabolic effects of milk fatty acids: A literature review

Milk and dairy products are known to have a significant role in human development and tissue maintenance due to their high nutritional value. With the higher incidence of obesity and metabolic diseases, nutrition and public health authorities have recommended the intake of fat-free or low-fat dairy due to the saturated fatty acid content of whole-fat products and their effect on serum cholesterol levels. However, recent studies have questioned the association between milk fat consumption and cardiometabolic risk. This literature review aims to compile the scientific evidence of the metabolic effects of milk fatty acids in clinical and basic research studies, as well as their relationship with metabolic disorders and gut microbiota composition. Research shows that various milk fatty acids exert effects on metabolic alterations (obesity, type 2 diabetes and cardiovascular diseases) by modifying glucose homeostasis, inflammation and lipid profile-related factors. Additionally, recent studies have associated the consumption of milk fatty acids with the production of metabolites and the promotion of healthy gut microbiota. From mainly observational studies, evidence suggests that milk and dairy fatty acids are not directly linked to cardiometabolic risk, but further controlled research is necessary to clarify such findings and to assess whether dietary recommendations to choose low-fat dairy foods are necessary for the population for the prevention of obesity and cardiometabolic disease.

Evaluation of the Differential Postbiotic Potential of Shewanella putrefaciens Pdp11 Cultured in Several Growing Conditions

The increased knowledge of functional foods has led to the development of a new generation of health products, including those containing probiotics and products derived from them. Shewanella putrefaciens Pdp11 (SpPdp11) is a strain described as a probiotic that exerts important beneficial effects on several farmed fish. However, the use of live probiotic cells in aquaculture has limitations such as uncertain survival and shelf life, which can limit their efficacy. In addition, its efficacy can vary across species and hosts. When probiotics are administered orally, their activity can be affected by the environment present in the host and by interactions with the intestinal microbiota. Furthermore, live cells can also produce undesired substances that may negatively impact the host as well as the risk of potential virulence reversion acquired such as antibiotic resistance. Therefore, new alternatives emerged such as postbiotics. Currently, there is no knowledge about the postbiotic potential of SpPdp11 in the aquaculture industry. Postbiotic refers to the use of bacterial metabolites, including extracellular products (ECPs), to improve host physiology. However, the production of postbiotic metabolites can be affected by various factors such as cultivation conditions, which can affect bacterial metabolism. Thus, the objective of this study was to evaluate the postbiotic potential of ECPs from SpPdp11 under different cultivation conditions, including culture media, temperature, growth phase, and salinity. We analyzed their hydrolytic, antibacterial, antiviral, and cytotoxic capacity on several fish cell lines. The results obtained have demonstrated how each ECP condition can exert a different hydrolytic profile, reduce the biofilm formation by bacterial pathogens relevant to fish, lower the titer of nervous necrosis virus (NNV), and exert a cytotoxic effect on different fish cell lines. In conclusion, the ECPs obtained from SpPdp11 have different capacities depending on the cultivation conditions used. These conditions must be considered in order to recover the maximum number of beneficial capacities or to choose the appropriate conditions for specific activities.

Gut microbiota-palmitoleic acid-interleukin-5 axis orchestrates benzene-induced hematopoietic toxicity

Due to the annual increase in its production and consumption in occupational environments, the adverse blood outcomes caused by benzene are of concern. However, the mechanism of benzene-induced hematopoietic damage remains elusive. Here, we report that benzene exposure causes hematopoietic damage in a dose-dependent manner and is associated with disturbances in gut microbiota-long chain fatty acids (LCFAs)-inflammation axis. C57BL/6J mice exposed to benzene for 45 days were found to have a significant reduction in whole blood cells and the suppression of hematopoiesis, an increase in Bacteroides acidifaciens and a decrease in Lactobacillus murinus. Recipient mice transplanted with fecal microbiota from benzene-exposed mice showed potential for hematopoietic disruption, LCFAs, and interleukin-5 (IL-5) elevation. Abnormally elevated plasma LCFAs, especially palmitoleic acid (POA) exacerbated benzene-induced immune-inflammation and hematopoietic damage via carnitine palmitoyltransferase 2 (CPT2)-mediated disorder of fatty acid oxidation. Notably, oral administration of probiotics protects the mice against benzene-induced hematopoietic toxicity. In summary, our data reveal that the gut microbiota-POA-IL-5 axis is engaged in benzene-induced hematopoietic damage. Probiotics might be a promising candidate to prevent hematopoietic abnormalities from benzene exposure.

Effects of Supplementing Growing-Finishing Crossbred Pigs with Glycerin, Vitamin C and Niacinamide on Carcass Characteristics and Meat Quality

The objective of this study was to determine the influence of supplementing the diet of growing-finishing pigs with glycerin and/or a mixture of vitamin C and niacinamide on carcass traits and pork quality. Eighty-four weaned piglets with an initial average body weight of 20.35 ± 2.14 kg were assigned, at random, to four groups for a 103-day feeding experiment: control; glycerin-supplemented group; vitamin C and niacinamide-supplemented group; and glycerin, vitamin C and niacinamide-supplemented group. At the end of the experiment, three pigs/group were randomly selected and slaughtered, and samples were collected for analysis. The results indicated that supplementing crossbred pigs with glycerin, vitamin C and niacinamide simultaneously increased the redness (a*) value (p < 0.05), glycerol content (p < 0.01) and myristoleic acid content (p < 0.01) in the longissimus dorsi and tended to increase the level of flavor amino acids, linoleic acid, linolenic acid and erucic acid, as well as the percentage and density of type I myofibers in the longissimus dorsi and the semimembranosus muscle. Glycerin had an influence (p < 0.01) on the erucic acid content in the longissimus dorsi and the semimembranosus muscle, and vitamin C and niacinamide had an interaction effect (p < 0.05) on the redness (a*) value of the longissimus dorsi. Glycerin, vitamin C and niacinamide supplementation in the diet of crossbred pigs improved the color, flavor and nutritional value of pork, which contributed to an increased intent to purchase this product.

Human sphingomyelin synthase 1 generates diacylglycerol in the presence and absence of ceramide via multiple enzymatic activities

Sphingomyelin (SM) synthase 1 (SMS1), which is involved in lipodystrophy, deafness, and thrombasthenia, generates diacylglycerol (DG) and SM using phosphatidylcholine (PC) and ceramide as substrates. Here, we found that SMS1 possesses DG-generating activities via hydrolysis of PC and phosphatidylethanolamine (PE) in the absence of ceramide and ceramide phosphoethanolamine synthase (CPES) activity. In the presence of the same concentration (4.7 mol%) of PC and ceramide, the amounts of DG produced by SMS and PC-phospholipase C (PLC) activities of SMS1 were approximately 65% and 35% of total DG production, respectively. PC-PLC activity showed substrate selectivity for saturated and/or monounsaturated fatty acid-containing PC species. A PC-PLC/SMS inhibitor, D609, inhibited only SMS activity. Mn2+ inhibited only PC-PLC activity. Intriguingly, DG attenuated SMS/CPES activities. Our study indicates that SMS1 is a unique enzyme with PC-PLC/PE-PLC/SMS/CPES activities.

Exploring the potential mechanisms of Tongmai Jiangtang capsules in treating diabetic nephropathy through multi-dimensional data

Background

Diabetic nephropathy (DN) is a prevalent and debilitating disease that represents the leading cause of chronic kidney disease which imposes public health challenges Tongmai Jiangtang capsule (TMJT) is commonly used for the treatment of DN, albeit its underlying mechanisms of action are still elusive.

Methods

This study retrieved databases to identify the components and collect the targets of TMJT and DN. Target networks were constructed to screen the core components and targets. Samples from the GEO database were utilized to perform analyses of targets and immune cells and obtain significantly differentially expressed core genes (SDECGs). We also selected a machine learning model to screen the feature genes and construct a nomogram. Furthermore, molecular docking, another GEO dataset, and Mendelian randomization (MR) were utilized for preliminary validation. We subsequently clustered the samples based on SDECG expression and consensus clustering and performed analyses between the clusters. Finally, we scored the SDECG score and analyzed the differences between clusters.

Results

This study identified 13 SDECGs between DN and normal groups which positively regulated immune cells. We also identified five feature genes (CD40LG, EP300, IL1B, GAPDH, and EGF) which were used to construct a nomogram. MR analysis indicated a causal link between elevated IL1B levels and an increased risk of DN. Clustering analysis divided DN samples into four groups, among which, C1 and CI were mainly highly expressed and most immune cells were up-regulated. C2 and CII were the opposite. Finally, we found significant differences in SDECG scores between C1 and C2, CI and CII, respectively.

Conclusion

TMJT may alleviate DN via core components (e.g. Denudatin B, hancinol, hirudinoidine A) targeting SDECGs (e.g. SRC, EGF, GAPDH), with the involvement of feature genes and modulation of immune and inflammation-related pathways. These findings have potential implications for clinical practice and future investigations.

The heavy suckling lamb of Sarda dairy sheep and its crossbreed with Dorper rams: Performance, meat quality and consumer perceptions

The increase of meat production in dairy sheep farms, has been evaluated by the extension of the suckling period from the traditional 28 days to 75 days to obtain a new product, the heavy suckling lamb. Nineteen single-born Sarda (S) lambs (10 male, 9 female) and 20 single-born Dorper x Sarda (DS) lambs (9 male, 11 female), randomly selected from autumn lambing season, were fed exclusively with maternal milk until slaughtering at 20 ± 0.28 kg of body weight (BW, mean ± standard deviation, SD) and approximately 11 weeks of age. Body weight were recorded at birth and every 15 days until slaughter to estimate average daily gain (ADG). At slaughter, carcass measurements, pH and colour traits were recorded from the left side of the carcass. Proximate composition, fatty acid (FA) profile, cooking and drip losses were evaluated using the Longissimus thoracis et lumborum (LTL) muscle. In addition, Visual Panel Test (VPT) and Taste Panel Test (TPT) were performed. Experimental results evidenced that ADG did not differ between pure and crossbreed lambs and between sexes. The S lamb carcasses showed a higher fat content and rib fat thickness compared to that of crossbreed. No significant differences were found between genetic types and sex for colour and pH determinations, cooking and drip losses, whereas LTL fat of DS displayed a higher nutritional FA profile with higher content of 22:5n-3, 22:6n-3, branched-chain FA, and odd- and branched chain FA. No differences emerged during VPT and TPT, demonstrating that both DS and S lamb meats present no distinguishable visual and eating quality characteristics. The production of heavy suckling lambs from Sarda and Dorper crossbreed by the extension of suckling period appeared a promising strategy for producing meat of high quality, well appreciated by the consumers.

Exercise in cold: Friend than foe to cardiovascular health

Exercise has been proven to benefit human health comprehensively regardless of the intensity, time, or environment. Recent studies have found that combined exercise with a cold environment displays a synergistical beneficial effect on cardiovascular system compared to exercise in thermoneutral environment. Cold environment leads to an increase in body heat loss, and has been considered a notorious factor for cardiovascular system. Exercise in cold increases the stress of cardiovascular system and risks of cardiovascular diseases, but increases the body tolerance to detrimental insults and benefits cardiovascular health. The biological effects and its underlying mechanisms of exercise in cold are complex and not well studied. Evidence has shown that exercise in cold exerts more noticeable effects on sympathetic nervous activation, bioenergetics, anti-oxidative capacity, and immune response compared to exercise in thermoneutral environment. It also increases the secretion of a series of exerkines, including irisin and fibroblast growth factor 21, which may contribute to the cardiovascular benefits induced by exercise in cold. Further well-designed studies are needed to advance the biological effects of exercise in cold. Understanding the mechanisms underlying the benefits of exercise in cold will help prescribe cold exercise to those who can benefit from it.

Maternal PBDE exposure disrupts gut microbiome and promotes hepatic proinflammatory signaling in humanized PXR-transgenic mouse offspring over time

Developmental exposure to the persistent environmental pollutant, polybrominated diphenyl ethers (PBDEs), is associated with increased diabetes prevalence. The microbial tryptophan metabolite, indole-3-propionic acid (IPA), is associated with reduced risk of type 2 diabetes and lower-grade inflammation and is a pregnane X receptor (PXR) activator. To explore the role of IPA in modifying the PBDE developmental toxicity, we orally exposed humanized PXR-transgenic (hPXR-TG) mouse dams to vehicle, 0.1 mg/kg/day DE-71 (an industrial PBDE mixture), DE-71+IPA (20 mg/kg/day), or IPA, from 4 weeks preconception to the end of lactation. Pups were weaned at 21 days of age and IPA supplementation continued in the corresponding treatment groups. Tissues were collected at various ages until 6 months of age (n = 5 per group). In general, the effect of maternal DE-71 exposure on the gut microbiome of pups was amplified over time. The regulation of hepatic cytokines and prototypical xenobiotic-sensing transcription factor target genes by DE-71 and IPA was age- and sex-dependent, where DE-71-mediated mRNA increased selected cytokines (Il10, Il12p40, Il1β [both sexes], and [males]). The hepatic mRNA of the aryl hydrocarbon receptor (AhR) target gene Cyp1a2 was increased by maternal DE-71 and DE-71+IPA exposure at postnatal day 21 but intestinal Cyp1a1 was not altered by any of the exposures and ages. Maternal DE-71 exposure persistently increased serum indole, a known AhR ligand, in age- and sex-dependent manner. In conclusion, maternal DE-71 exposure produced a proinflammatory signature along the gut-liver axis, including gut dysbiosis, dysregulated tryptophan microbial metabolism, attenuated PXR signaling, and elevated AhR signaling in postweaned hPXR-TG pups over time, which was partially corrected by IPA supplementation.

The impact of high-glucose or high-fat diets on the metabolomic profiling of mice

Objective

Diets high in glucose or fat contribute to an increased prevalence of the diseases. Therefore, the objective of the current research was to observe and evaluate the impact of dietary components on different metabolomic profiles in primary tissues of mice.

Methods

For 8 weeks, diet with high-glucose or-fat was given to C57BL/6 J mice. The levels of metabolites in the primary tissues of mice were studied using gas chromatography-mass spectrometry (GC-MS) and analyzed using multivariate statistics.

Results

By comparing the metabolic profiles between the two diet groups and control group in mice main tissues, our study revealed 32 metabolites in the high-glucose diet (HGD) group and 28 metabolites in the high-fat diet (HFD) group. The most significantly altered metabolites were amino acids (AAs; L-alanine, L-valine, glycine, L-aspartic acid, L-isoleucine, L-leucine, L-threonine, L-glutamic acid, phenylalanine, tyrosine, serine, proline, and lysine), fatty acids (FAs; propanoic acid, 9,12-octadecadienoic acid, pentadecanoic acid, hexanoic acid, and myristic acid), and organic compounds (succinic acid, malic acid, citric acid, L-(+)-lactic acid, myo-inositol, and urea). These metabolites are implicated in many metabolic pathways related to energy, AAs, and lipids metabolism.

Conclusion

We systematically analyzed the metabolic changes underlying high-glucose or high-fat diet. The two divergent diets induced patent changes in AA and lipid metabolism in the main tissues, and helped identify metabolic pathways in a mouse model.

Nobiletin Ameliorates Nonalcoholic Fatty Liver Disease by Regulating Gut Microbiota and Myristoleic Acid Metabolism

Disturbance of the gut microbiota plays a critical role in the development of nonalcoholic fatty liver disease (NAFLD). Increasing evidence supports that natural products may serve as prebiotics to regulate the gut microbiota in the treatment of NAFLD. In the present study, the effect of nobiletin, a naturally occurring polymethoxyflavone, on NAFLD was evaluated, and metabolomics, 16S rRNA gene sequencing, and transcriptomics analysis were performed to determine the underlying mechanism of nobiletin, and the key bacteria and metabolites screened were confirmed by in vivo experiment. Nobiletin treatment could significantly reduce lipid accumulation in high-fat/high-sucrose diet-fed mice. 16S rRNA analysis demonstrated that nobiletin could reverse the dysbiosis of gut microbiota in NAFLD mice and nobiletin could regulate myristoleic acid metabolism, as revealed by untargeted metabolomics analysis. Treatment with the bacteria Allobaculum stercoricanis, Lactobacillus casei, or the metabolite myristoleic acid displayed a protective effect on liver lipid accumulation under metabolic stress. These results indicated that nobiletin might target gut microbiota and myristoleic acid metabolism to ameliorate NAFLD.

Temperature-dependent metabolite orchestration to acute submaximal exercise indicates cardiorespiratory fitness in humans

AIMS

Cardiorespiratory fitness (CRF), an important biomarker of human health, is impaired in cold environment compared to thermoneutral condition. The study aimed to investigate the role of metabolome response to acute exercise in regulation of CRF at different ambient temperatures.

MAIN METHODS

A total of 27 young adults were recruited, and each subject underwent a cardiopulmonary exercise test (CPET) and a constant load submaximal exercise at both room temperature (25 °C) and cold temperature (0 °C). The serum samples were collected before and immediately after constant load exercise.

KEY FINDINGS

Acute cold exposure decreased CRF by 41 %, accompanied by a metabolic shift to anaerobic respiration. It also decreased VO₂ and increased respiratory quotient during constant load exercise. Metabolome profiling revealed that acute exercise reprogrammed serum metabolome in an ambient temperature-dependent manner. Specifically, exercise increased a cluster of fatty acids during cold exposure, possibly due to impaired fatty acid oxidation. The correlations between metabolite responses to acute exercise and exercise parameters were analyzed using partial least squares regression and machine learning, revealing that metabolite responses to acute exercise were highly correlated with exercise parameters and predictive of CRF. Among the contributors, tryptophan and its metabolites stood out as important ones.

SIGNIFICANCE

These results suggested that the metabolite responses to acute submaximal exercise unmasks the exercise performance at different ambient temperatures, highlighting the role of metabolite orchestration in the physiological regulation of CRF.

Targeted and untargeted metabolomic approach for GDM diagnosis

Gestational diabetes mellitus (GDM) is a disorder which manifests itself for the first time during pregnancy and is mainly connected with glucose metabolism. It is also known that fatty acid profile changes in erythrocyte membranes and plasma could be associated with obesity and insulin resistance. These factors can lead to the development of diabetes. In the reported study, we applied the untargeted analysis of plasma in GDM against standard glucose-tolerant (NGT) women to identify the differences in metabolomic profiles between those groups. We found higher levels of 2-hydroxybutyric and 3-hydroxybutyric acids. Both secondary metabolites are associated with impaired glucose metabolism. However, they are products of different metabolic pathways. Additionally, we applied lipidomic profiling using gas chromatography to examine the fatty acid composition of cholesteryl esters in the plasma of GDM patients. Among the 14 measured fatty acids characterizing the representative plasma lipidomic cluster, myristic, oleic, arachidonic, and α-linoleic acids revealed statistically significant changes. Concentrations of both myristic acid, one of the saturated fatty acids (SFAs), and oleic acid, which belong to monounsaturated fatty acids (MUFAs), tend to decrease in GDM patients. In the case of polyunsaturated fatty acids (PUFAs), some of them tend to increase (e.g., arachidonic), and some of them tend to decrease (e.g., α-linolenic). Based on our results, we postulate the importance of hydroxybutyric acid derivatives, cholesteryl ester composition, and the oleic acid diminution in the pathophysiology of GDM. There are some evidence suggests that the oleic acid can have the protective role in diabetes onset. However, metabolic alterations that lead to the onset of GDM are complex; therefore, further studies are needed to confirm our observations.

Preferential deposition of dairy derived fatty acids in muscle tissue is partially due to the upregulation of CD36 in a low-birth-weight swine model

Metabolic syndrome is a worldwide health issue. Previous research has revealed that low-birth weight (LBW) swine fed a high-fat (HF) diet were susceptible to insulin resistance (IR) and developed a preferential intestinal lipid absorption, hypertriglyceridemia, and muscle steatosis. We hypothesized that fatty acid transporters such as CD36, FATP4, and FABP2 could potentially explain the development of these conditions. In addition, dairy-derived fatty acids have been shown to be valid biomarkers to assess dairy intake, which can be utilized to investigate muscle lipid deposition in LBW swine. The overall aim of this study was to delineate molecular transport candidates responsible for intestinal lipid absorption and muscle lipid deposition in LBW swine; and secondly to determine what dietary fatty acids might accumulate preferentially in pork muscle when consuming dairy products. At 5 weeks of age, normal birth weight (NBW) and LBW piglets were randomly assigned to three experimental diets: 1-chow diet, 2-HF diet, or 3-isocaloric HF diet supplemented with full fat dairy products. At 12 weeks of age, piglets were euthanized, and carcass, fasting plasma, biceps femoris and jejunum mucosal scrapings were collected. Results showed that HF-fed LBW swine exhibited early signs of IR (fasting glucose, P < 0.05; fasting insulin, P = 0.091; HOMA-IR, P = 0.086) compared with NBW-Chow, which were attenuated with increased dairy intake. Muscle samples from HF-fed LBW swine contained significantly more triglyceride compared to Chow-fed NBW swine (P < 0.05). Increased dairy intake significantly increased myristic acid (C14:0) and DPA (C22:5n3) relative to HF feeding alone (P < 0.05). All HF-fed LBW swine (regardless of dairy intake) exhibited an upregulation of CD36 expression (but not FABP2) compared with NBW littermates in both the small intestine and muscle (P < 0.05). Interestingly, increased dairy intake significantly increased the Canadian Lean Yield percentage in LBW swine fed an HF diet (P < 0.05). Findings from this study provide evidence on the mechanistic pathway of intestinal and muscle lipid metabolism in an innovative LBW swine model. We have also revealed that increasing dairy intake can enhance the incorporation of dietary long-chain polyunsaturated fatty acids into pork, as well as increasing the predicted lean yield of the carcass.

Regulation of semen quality by fatty acids in diets, extender, and semen

Fatty acids (FAs) are classified into different types according to the degree of hydrocarbon chain saturation, including saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), omega-3 polyunsaturated fatty acids (omega-3 PUFAs) and omega-6 polyunsaturated fatty acids (omega-6 PUFAs), which play an important role in maintaining semen quality. This review focuses on the regulation of FAs in semen, diet and extender on semen quality, and expounds its effects on sperm motility, plasma membrane integrity, DNA integrity, hormone content, and antioxidant capacity. It can be concluded that there are species differences in the FAs profile and requirements in sperm, and their ability to regulate semen quality is also affected by the addition methods or dosages. Future research directions should focus on analyzing the FAs profiles of different species or different periods of the same species and exploring suitable addition methods, doses and mechanism of regulating semen quality.

Saturated Fatty Acid Intake and Risk of Type 2 Diabetes: An Updated Systematic Review and Dose-Response Meta-Analysis of Cohort Studies

This systematic review and meta-analysis was conducted to pool findings of cohort studies that investigated hazards of type 2 diabetes mellitus (T2DM) in relation to intakes of SFAs. A systematic search was conducted in the PubMed, Scopus, and Embase databases up to June 2021 to find eligible studies. Review articles or commentaries, clinical trials, cross-sectional studies, studies on gestational or type 1 diabetes patients, animal studies, articles with no access to full-texts, articles published in non-English languages, and articles with missing critical data needed for the systematic review were excluded from the meta-analysis. A random-effects model was used to combine study-specific results. Thirteen cohort studies with 361,686 participants and 11,865 T2DM events were included. Dietary total SFA intake, as well as dietary palmitic acid (PA) or stearic acid (SA) were not associated with risk of T2DM when the highest was compared with the lowest intake category (HR = 0.99; 95% CI: 0.91, 1.09; n = 13 for total SFAs; HR = 0.96; 95% CI: 0.79, 1.15; n = 4 for PA; and HR = 1.08; 95% CI: 0.79, 1.49; n = 4 for SA). However, the risk of T2DM decreased by 11% in the highest compared with the lowest category of dietary lauric acid (HR = 0.89; 95% CI: 0.82, 0.97; n = 2), and by 17% in the highest compared with lowest category of dietary myristic acid (MA) (HR = 0.83; 95% CI: 0.74, 0.92; n = 3). There was evidence of publication bias among studies on dietary total SFAs and T2DM. Our results indicated no significant association between dietary total SFA and risk of T2DM. However, dietary intake of MA was negatively associated with developing T2DM.

Change in fatty acid composition of plasma triglyceride caused by a 2 week comprehensive risk management for diabetes: A prospective observational study of type 2 diabetes patients with supercritical fluid chromatography/mass spectrometry-based semi-target lipidomic analysis

AIMS/INTRODUCTION

Hypertriglyceridemia is common in patients with diabetes. Although the fatty acid (FA) composition of triglycerides (TGs) is suggested to be related to the pathology of diabetes and its complications, changes in the fatty acid composition caused by diabetes treatment remain unclear. This study aimed to identify short-term changes in the fatty acid composition of plasma triglycerides after diabetes treatment.

MATERIALS AND METHODS

This study was a sub-analysis of a prospective observational study of patients with type 2 diabetes aged between 20 and 75 years who were hospitalized to improve glycemic control (n = 31). A lipidomic analysis of plasma samples on the 2nd and 16th hospital days was conducted by supercritical fluid chromatography coupled with mass spectrometry.

RESULTS

In total, 104 types of triglycerides with different compositions were identified. Most of them tended to decrease after treatment. In particular, triglycerides with a lower carbon number and fewer double bonds showed a relatively larger reduction. The inclusion of FA 14:0 (myristic acid), as a constituent of triglyceride, was significantly associated with a more than 50%, and statistically significant, reduction (odds ratio 39.0; P < 0.001). The total amount of FA 14:0 as a constituent of triglycerides also decreased significantly, and its rate of decrease was the greatest of all the fatty acid constituents.

CONCLUSIONS

A 2 week comprehensive risk management for diabetes resulted in decreased levels of plasma triglycerides and a change in the fatty acid composition of triglycerides, characterized by a relatively large reduction in FA 14:0 as a constituent of triglycerides.

Integrated analysis of plasma and urine reveals unique metabolomic profiles in idiopathic inflammatory myopathies subtypes

OBJECTIVES

Idiopathic inflammatory myopathies (IIM) are a class of autoimmune diseases with high heterogeneity that can be divided into different subtypes based on clinical manifestations and myositis-specific autoantibodies (MSAs). However, even in each IIM subtype, the clinical symptoms and prognoses of patients are very different. Thus, the identification of more potential biomarkers associated with IIM classification, clinical symptoms, and prognosis is urgently needed.

METHODS

Plasma and urine samples from 79 newly diagnosed IIM patients (mean disease duration 4 months) and 52 normal control (NC) samples were analysed by high-performance liquid chromatography of quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS)/MS-based untargeted metabolomics. Orthogonal partial least-squares discriminate analysis (OPLS-DA) were performed to measure the significance of metabolites. Pathway enrichment analysis was conducted based on the KEGG human metabolic pathways. Ten machine learning (ML) algorithms [linear support vector machine (SVM), radial basis function SVM, random forest, nearest neighbour, Gaussian processes, decision trees, neural networks, adaptive boosting (AdaBoost), Gaussian naive Bayes and quadratic discriminant analysis] were used to classify each IIM subtype and select the most important metabolites as potential biomarkers.

RESULTS

OPLS-DA showed a clear separation between NC and IIM subtypes in plasma and urine metabolic profiles. KEGG pathway enrichment analysis revealed multiple unique and shared disturbed metabolic pathways in IIM main [dermatomyositis (DM), anti-synthetase syndrome (ASS), and immune-mediated necrotizing myopathy (IMNM)] and MSA-defined subtypes (anti-Mi2+, anti-MDA5+, anti-TIF1γ+, anti-Jo1+, anti-PL7+, anti-PL12+, anti-EJ+, and anti-SRP+), such that fatty acid biosynthesis was significantly altered in both plasma and urine in all main IIM subtypes (enrichment ratio > 1). Random forest and AdaBoost performed best in classifying each IIM subtype among the 10 ML models. Using the feature selection methods in ML models, we identified 9 plasma and 10 urine metabolites that contributed most to separate IIM main subtypes and MSA-defined subtypes, such as plasma creatine (fold change = 3.344, P = 0.024) in IMNM subtype and urine tiglylcarnitine (fold change = 0.351, P = 0.037) in anti-EJ+ ASS subtype. Sixteen common metabolites were found in both the plasma and urine samples of IIM subtypes. Among them, some were correlated with clinical features, such as plasma hypogeic acid (r = -0.416, P = 0.005) and urine malonyl carnitine (r = -0.374, P = 0.042), which were negatively correlated with the prevalence of interstitial lung disease.

CONCLUSIONS

In both plasma and urine samples, IIM main and MSA-defined subtypes have specific metabolic signatures and pathways. This study provides useful clues for understanding the molecular mechanisms, searching potential diagnosis biomarkers and therapeutic targets for IIM.

Sargassum fusiforme fucoidan ameliorates diet-induced obesity through enhancing thermogenesis of adipose tissues and modulating gut microbiota

Obesity has become a global epidemic. Sargassum fusiforme fucoidan (Fuc) is a group of water-soluble heteropolysaccharides that exhibits a wide range of medicinal functions. It consists of l-fucose and sulfate groups, with l-fucose as the main monosaccharide. This study investigated the therapeutic effects of Fuc on diet-induced obesity (DIO) in C57BL/6J female mice. Fuc significantly alleviated obesity in mice induced by high-fat high-fructose (HFHF) feeding, inhibiting body weight gain, reducing fat accumulation, and improving hepatic steatosis. In addition, Fuc significantly improved glucose tolerance and insulin sensitivity by enhancing the phosphorylation level of AKT (at Ser473) in the adipose tissues. Mechanistically, although Fuc did not decrease the energy intake in DIO mice, it significantly increased the energy expenditure by up-regulating the expression of uncoupling protein 1 (UCP1) in the adipose tissues. Notably, Fuc also improved the obesity-driven dysbiosis of gut microbiota and decreased the relative abundance of the obesity-related intestinal bacteria. However, Fuc was unable to alleviate DIO-induced metabolic disorders in pseudo-sterile mice. Our findings suggested that Fuc might remodel gut microbiota and exert its weight loss and hypolipidemic effects by increasing the energy expenditure, thus providing a novel perspective for treating obesity and related complications.

Myristic acid selectively augments β-tubulin levels in C2C12 myotubes via diacylglycerol kinase δ

Effective amelioration of type II diabetes requires therapies that increase both glucose uptake activity per cell and skeletal muscle mass. Myristic acid (14:0) increases diacylglycerol kinase (DGK) δ protein levels and enhances glucose uptake in myotubes in a DGKδ-dependent manner. However, it is still unclear whether myristic acid treatment affects skeletal muscle mass. In this study, we found that myristic acid treatment increased the protein level of β-tubulin, which constitutes microtubules and is closely related to muscle mass, in C2C12 myotubes but not in the proliferation stage in C2C12 myoblasts. However, lauric (12:0), palmitic (16:0) and oleic (18:1) acids failed to affect DGKδ and β-tubulin protein levels in C2C12 myotubes. Moreover, knockdown of DGKδ by siRNA significantly inhibited the increased protein level of β-tubulin in the presence of myristic acid, suggesting that the increase in β-tubulin protein by myristic acid depends on DGKδ. These results indicate that myristic acid selectively affects β-tubulin protein levels in C2C12 myotubes via DGKδ, suggesting that this fatty acid improves skeletal muscle mass in addition to increasing glucose uptake activity per cell.

Deep-Sea Natural Products from Extreme Environments: Cold Seeps and Hydrothermal Vents

The deep sea has been proven to be a great treasure for structurally unique and biologically active natural products in the last two decades. Cold seeps and hydrothermal vents, as typical representatives of deep-sea extreme environments, have attracted more and more attention. This review mainly summarizes the natural products of marine animals, marine fungi, and marine bacteria derived from deep-sea cold seeps and hydrothermal vents as well as their biological activities. In general, there were 182 compounds reported, citing 132 references and covering the literature from the first report in 1984 up to March 2022. The sources of the compounds are represented by the genera Aspergillus sp., Penicillium sp., Streptomyces sp., and so on. It is worth mentioning that 90 of the 182 compounds are new and that almost 60% of the reported structures exhibited diverse bioactivities, which became attractive targets for relevant organic synthetic and biosynthetic studies.

Fermented Rosa Roxburghii Tratt Juice Alleviates High-Fat Diet-Induced Hyperlipidemia in Rats by Modulating Gut Microbiota and Metabolites

Hyperlipidemia endangers human health and has become a significant public health problem. This study aimed to investigate the mechanism of the hypolipidemic effects of Fermented Rosa roxburghii Tratt juice (FRRT) on hyperlipidemic rats and a new hypolipidemic intervention strategy was disclosed. The study revealed 12 weeks FRRT treatment significantly decreased the body weight, total cholesterol (TC), triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-c), while high-density lipoprotein cholesterol (HDL-c) increased. We integrated the 16S rDNA sequencing and metabolomic profiling to evaluate the changes in the gut microbiota and metabolites. Significant changes in microbial composition accompanied marked changes in 56 feces metabolites. The results showed that FRRT could decrease the ratio of Firmicutes to Bacteroidetes, while increase the abundance of some bacterial genera (Prevotella, Paraprevotellaceae_Prevotella, Ruminococcus, Oscillospira). Metabolomics analysis displayed that the metabolisms of bile acid, amino acid and lipid were significantly affected by FRRT. Correlation analysis suggest that the reductions in serum lipids by FRRT are associated with the gut microbial community and their associated metabolites (amino acid metabolites, bile acid metabolites, and lipid metabolites). This study confirmed FRRT could be used as a new dietary and therapeutic strategy to dyslipidemia by improving the gut microbiota dysbiosis, metabolomic disorders and regulating the dyslipidemia. Our study also extended the understanding of the relationship between gut microbiota, metabolites, and lipid-lowering functions.

Myristic Acid Supplementation Aggravates High Fat Diet-Induced Adipose Inflammation and Systemic Insulin Resistance in Mice

Saturated fatty acids (SFAs) are considered to be detrimental to human health. One of the SFAs, myristic acid (MA), is known to exert a hypercholesterolemic effect in mice as well as humans. However, its effects on altering adipose tissue (AT) inflammation and systemic insulin resistance (IR) in obesity are still unclear. Here, we sought to determine the effects of a high fat (HF) diet supplemented with MA on obesity-associated metabolic disorders in mice. Wild-type C57BL/6 mice were fed a HF diet in the presence or absence of 3% MA for 12 weeks. Plasma lipids, plasma adipokines, AT inflammation, systemic IR, glucose homeostasis, and hepatic steatosis were assessed. The body weight and visceral adipose tissue (VAT) mass were significantly higher in mice receiving the HF+MA diet compared to HF diet-fed controls. Plasma total cholesterol levels were marginally increased in HF+MA-fed mice compared to controls. Fasting blood glucose was comparable between HF and HF+MA-fed mice. Interestingly, the plasma insulin and HOMA-IR index, a measure of insulin resistance, were significantly higher in HF+MA-fed mice compared to HF controls. Macrophage and inflammatory markers were significantly elevated in the AT and AT-derived stromal vascular cells upon MA feeding. Moreover, the level of circulating resistin, an adipokine promoting insulin resistance, was significantly higher in HF+MA-fed mice compared with HF controls. The insulin tolerance test revealed that the IR was higher in mice receiving the MA supplementation compared to HF controls. Moreover, the glucose tolerance test showed impairment in systemic glucose homeostasis in MA-fed mice. Analyses of liver samples showed a trend towards an increase in liver TG upon MA feeding. However, markers of oxidative stress and inflammation were reduced in the liver of mice fed an MA diet compared to controls. Taken together, our data suggest that chronic administration of MA in diet exacerbates obesity-associated insulin resistance and this effect is mediated in part, via increased AT inflammation and increased secretion of resistin.

Effects of In Vitro Digestion on Anti-α-Amylase and Cytotoxic Potentials of Sargassum spp

This is the first study to examine the effects of in vitro digestion on biological activities of Sargassum spp., a broadly known brown seaweed for therapeutic potential. Three fractions (F1-F3) were obtained from hexane extract by column chromatography. Under in vitro simulated digestion, the anti-α-amylase capacity of F1 in oral and intestinal phases increases, while it significantly decreases in the gastric phase. The α-amylase inhibition of F2 promotes throughout all digestive stages while the activity of F3 significantly reduces. The cytotoxic activity of F1 against U266 cell-line accelerates over the oral, gastric, and intestinal stages. The fractions F2 and F3 exhibited the declined cytotoxic potentialities in oral and gastric phases, but they were strengthened under intestinal condition. Palmitic acid and fucosterol may play an active role in antidiabetic and cytotoxic activity against multiple myeloma U266 cell line of Sargassum spp. However, the involvement of other phytochemicals in the seaweed should be further investigated.

Sauropus androgynus (L.) Merr.: a multipurpose plant with multiple uses in traditional ethnic culinary and ethnomedicinal preparations

Various plants form the basis of multiple traditional ethnic cuisines and ethnomedicinal practices across the globe. The ethnic cuisines cater to the nutritional, dietary and medicinal requirements of the tribal and rural communities even today. Using literature from various scholarly databases, this study was conducted to consolidate a comprehensive review on the use of Sauropus androgynus (L.) Merr. in various traditional ethnic cuisines and ethnomedicinal preparations across the globe. The survey shows that it is used in multiple ethnic cuisines and is variously known in different countries and among the communities. Further, it possesses multiple nutritional and ethnomedicinal properties. Considering its importance in ethnic foods and ethnomedicinal preparations, it is important to investigate the nutritional composition, phytochemical constitution and pharmacological basis of ethnomedicinal uses. Therefore, we further compiled this information and found that it is a rich source of both micro- and macronutrients and packed with several bioactive compounds. Survey of pharmacological studies on its traditional medicinal uses supports its ethnomedicinal properties. Despite its importance in traditional food and ethnomedicinal systems, it remains underexplored. Limited information on the toxicity of its various extracts shows that further studies should be conducted to understand its safety aspects. Further clinical studies to prospect possible drug candidates from it should be attempted.

The relationship between hair metabolites, air pollution exposure and gestational diabetes mellitus: A longitudinal study from pre-conception to third trimester

BACKGROUND

Gestational diabetes mellitus (GDM) is a metabolic condition defined as glucose intolerance with first presentation during pregnancy. Many studies suggest that environmental exposures, including air pollution, contribute to the pathogenesis of GDM. Although hair metabolite profiles have been shown to reflect pollution exposure, few studies have examined the link between environmental exposures, the maternal hair metabolome and GDM. The aim of this study was to investigate the longitudinal relationship (from pre-conception through to the third trimester) between air pollution exposure, the hair metabolome and GDM in a Chinese cohort.

METHODS

A total of 1020 women enrolled in the Complex Lipids in Mothers and Babies (CLIMB) birth cohort were included in our study. Metabolites from maternal hair segments collected pre-conception, and in the first, second, and third trimesters were analysed using gas chromatography-mass spectrometry (GC-MS). Maternal exposure to air pollution was estimated by two methods, namely proximal and land use regression (LUR) models, using air quality data from the air quality monitoring station nearest to the participant's home. Logistic regression and mixed models were applied to investigate associations between the air pollution exposure data and the GDM associated metabolites.

RESULTS

Of the 276 hair metabolites identified, the concentrations of fourteen were significantly different between GDM cases and non-GDM controls, including some amino acids and their derivatives, fatty acids, organic acids, and exogenous compounds. Three of the metabolites found in significantly lower concentrations in the hair of women with GDM (2-hydroxybutyric acid, citramalic acid, and myristic acid) were also negatively associated with daily average concentrations of PM_2.5, PM₁₀, SO₂, NO₂, CO and the exposure estimates of PM_2.5 and NO_2, and positively associated with O₃.

CONCLUSIONS

This study demonstrated that the maternal hair metabolome reflects the longitudinal metabolic changes that occur in response to environmental exposures and the development of GDM.

Aegle marmelos Leaf Extract Phytochemical Analysis, Cytotoxicity, In Vitro Antioxidant and Antidiabetic Activities

For many years, Aegle marmelos (A. marmelos) has been used medicinally and as a dietary supplement. Despite this, there are minimal research data on A. marmelos phytochemical properties and pharmacological effects. This study aimed to explore the phytoconstituents, cytotoxicity, glucose uptake, and antioxidant and antidiabetic potential of an alcoholic extract of A. marmelos leaf. The cytotoxicity of A. marmelos in HepG2 cells was tested in vitro, and the results revealed that it has strong cytocompatibility and cytoprotective properties. The extract's antioxidant activities were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. Antioxidant potential was shown to be quite impressive. The enzymes α-amylase and α-glycosidase were found to be substantially inhibited by A. marmelos, with IC₅₀ values of 46.21 and 42.07 mg/mL, respectively. In HepG2 cells, A. marmelos significantly reduced ROS levels that were elevated due to high glucose and enhanced glucose consumption (p < 0.05). These activities might be due to the enrichment of bioactive phytoconstituents analyzed chromatographically using GC/MS and HPLC. The findings of this study show that A. marmelos could be an effective restorative therapy for diabetes and related diseases.

Myristic acid reduces skin inflammation and nociception

This study evaluated the inhibitory effect of myristic acid (MA) on models of inflammation and nociception. The in vitro anti-inflammatory activities of MA were assessed on LPS-stimulated macrophages, membrane stabilization assay, and inhibition of protein denaturation, whereas the inhibitory activity of MA on in vivo inflammation was assessed on TPA-induced ear edema using acute and chronic assays in mice. The inhibitory effect of MA on nociception was assessed using three in vivo models. MA exerted in vitro anti-inflammatory activity by the increase (58%) in the production of IL-10 in LPS-stimulated macrophages. In the in vivo assay, MA showed good anti-inflammatory effects on the acute (ED₅₀ = 62 mg/kg) and chronic (ED₅₀ = 77 mg/kg) TPA-induced ear edema. The antinociceptive activity of MA was related to the participation of the nitrergic system in the formalin-induced paw licking test. PRACTICAL APPLICATIONS: Previous studies with different plant extracts containing MA, as one of their major components, have demonstrated anti-inflammatory and antinociceptive actions. However, the anti-inflammatory and antinociceptive actions of myristic acid have not been previously reported. The results suggest that MA induced anti-inflammatory effects in LPS-stimulated macrophages through the participation of IL-10. The antinociceptive effects of MA are attributed to the participation of the nitrergic system.

Myristic acid defends against testicular oxidative stress, inflammation, apoptosis: Restoration of spermatogenesis, steroidogenesis in diabetic rats

Diabetes mellitus (DM) may lead to testicular-related infertility while Myristic acid (MA) is beneficial to lower hyperglycaemia. Thus, we hypothesized that MA could protect testes against hyperglycaemia-induced damage in DM. DM was induced in adult male rats by high-fat diet consumption for 12 weeks, accompanied by a single dose streptozotocin injection. Following DM confirmation, the rats were fed orally with 10 and 20 mg/kg body weight MA for 28 consecutive days. After completion of treatment, rats were sacrificed and blood, cauda epididymis and testes were harvested. Serum was separated, epididymal sperm was collected for analysis. Molecular studies of the testes were performed by qPCR, Western blotting and immunostaining. MA was found to protect the testes against oxidative stress via preventing the upregulation of RAGE, Keap1, and the downregulation of Nrf2, NQO1, HO1, SOD, CAT and GPx. MA also prevented increase in testicular inflammation and apoptosis, as indicated by low inflammatory (NF-κB p65, IKKβ, TNF-α, IL-1β and iNOS) and apoptosis (Bax and caspase-9), but high anti-apoptosis (Bcl-2) markers' levels. Besides, MA prevented the downregulation of testicular steroidogenic markers (3βHSD, 17βHSD, StAR, ARA-54 and CYP11A1). Sperm analysis revealed near normal sperm count, motility, viability, lower abnormal sperm morphology in diabetic rats received MA. MA also prevented the loss of germ cells via preventing the decreased in cell proliferative marker (PCNA) while maintaining near normal epithelial height, tubular and Leydig cell diameters in the testes in DM. MA protects the testes against damage in DM, thus maintaining spermatogenesis and steroidogenesis, consequently preserving male fertility in diabetes.

Adipose-specific C-C motif chemokine ligand (CCL) 19 overexpression drives the mice to both insulin resistance and weight gain

INTRODUCTION

Enlarged adipose tissue is characterized by infiltration of activated immune cells and increased expression of chemokines recruiting these cells including C-C motif ligand 19 (CCL19), although the role of adipose CCL19 is still inconclusive.

RESEARCH DESIGN AND METHODS

Adipocyte-specific Ccl19 knock-in (KI) mice were generated, and the mice were fed either a normal diet or 40% or 60% fat diet (FD) to investigate the effects of CCL19 on the induction of inflammation and lipid metabolism.

RESULTS

Ccl19KI mice exhibited increased inflammatory signs in adipose tissue and enlarged subcutaneous white and brown adipose tissue than those of wild-type (WT) mice. The adipose tissue of Ccl19KI mice was characterized by increased extracellular signal-regulated kinase 1/2 and decreased AMP-activated protein kinase α phosphorylation. The protein expression of peroxisome proliferator-activated receptor γ coactivator 1α and uncoupling protein 1 was significantly reduced in brown adipose tissue of Ccl19KI mice compared with that in WT mice. The most remarkable changes between genotypes were observed in mice fed a 40% FD.

CONCLUSION

A 40% FD enhanced the effects of CCL19 overexpression, and these mice could be a suitable model to study metabolic disorders in overweight Asians.

New Era of Diacylglycerol Kinase, Phosphatidic Acid and Phosphatidic Acid-Binding Protein

Diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DG) to generate phosphatidic acid (PA). Mammalian DGK consists of ten isozymes (α–κ) and governs a wide range of physiological and pathological events, including immune responses, neuronal networking, bipolar disorder, obsessive-compulsive disorder, fragile X syndrome, cancer, and type 2 diabetes. DG and PA comprise diverse molecular species that have different acyl chains at the sn-1 and sn-2 positions. Because the DGK activity is essential for phosphatidylinositol turnover, which exclusively produces 1-stearoyl-2-arachidonoyl-DG, it has been generally thought that all DGK isozymes utilize the DG species derived from the turnover. However, it was recently revealed that DGK isozymes, except for DGKε, phosphorylate diverse DG species, which are not derived from phosphatidylinositol turnover. In addition, various PA-binding proteins (PABPs), which have different selectivities for PA species, were recently found. These results suggest that DGK–PA–PABP axes can potentially construct a large and complex signaling network and play physiologically and pathologically important roles in addition to DGK-dependent attenuation of DG–DG-binding protein axes. For example, 1-stearoyl-2-docosahexaenoyl-PA produced by DGKδ interacts with and activates Praja-1, the E3 ubiquitin ligase acting on the serotonin transporter, which is a target of drugs for obsessive-compulsive and major depressive disorders, in the brain. This article reviews recent research progress on PA species produced by DGK isozymes, the selective binding of PABPs to PA species and a phosphatidylinositol turnover-independent DG supply pathway.

Myristoleic acid produced by enterococci reduces obesity through brown adipose tissue activation

OBJECTIVE

Dietary fibre has beneficial effects on energy metabolism, and the majority of studies have focused on short-chain fatty acids produced by gut microbiota. Ginseng has been reported to aid in body weight management, however, its mechanism of action is not yet clear. In this study, we focused on the potential modulating effect of ginseng on gut microbiota, aiming to identify specific strains and their metabolites, especially long-chain fatty acids (LCFA), which mediate the anti-obesity effects of ginseng.

DESIGN

Db/db mice were gavaged with ginseng extract (GE) and the effects of GE on gut microbiota were evaluated using 16S rDNA-based high throughput sequencing. To confirm the candidate fatty acids, untargeted metabolomics analyses of the serum and medium samples were performed.

RESULTS

We demonstrated that GE can induce Enterococcus faecalis, which can produce an unsaturated LCFA, myristoleic acid (MA). Our results indicate that E. faecalis and its metabolite MA can reduce adiposity by brown adipose tissue (BAT) activation and beige fat formation. In addition, the gene of E. faecalis encoding Acyl-CoA thioesterases (ACOTs) exhibited the biosynthetic potential to synthesise MA, as knockdown (KD) of the ACOT gene by CRISPR-dCas9 significantly reduced MA production. Furthermore, exogenous treatment with KD E. faecalis could not reproduce the beneficial effects of wild type E. faecalis, which work by augmenting the circulating MA levels.

CONCLUSIONS

Our results demonstrated that the gut microbiota-LCFA-BAT axis plays an important role in host metabolism, which may provide a strategic advantage for the next generation of anti-obesity drug development.

Dairy Fat Consumption and the Risk of Metabolic Syndrome: An Examination of the Saturated Fatty Acids in Dairy

Lifestyle is a key modifiable risk factor involved in the manifestation of metabolic syndrome and, in particular, diet plays a pivotal role in its prevention and development. Current dietary guidelines discourage the consumption of saturated fat and dietary sources rich in saturated fat, such as dairy products, despite data suggesting that full-fat dairy consumption is protective against metabolic syndrome. This narrative review assessed the recent epidemiological and clinical research that examined the consumption of dairy-derived saturated fatty acids (SFA) on metabolic syndrome risk. In addition, this review evaluated studies of individual SFA to gain insight into the potential mechanisms at play with intake of a diet enriched with these dairy-derived fatty acids. This work underscores that SFA are a heterogenous class of fatty acids that can differ considerably in their biological activity within the body depending on their length and specific chemical structure. In summary, previous work on the impact of dairy-derived SFA consumption on disease risk suggests that there is currently insufficient evidence to support current dietary guidelines which consolidate all dietary SFA into a single group of nutrients whose consumption should be reduced, regardless of dietary source, food matrix, and composition.

Myristic acid specifically stabilizes diacylglycerol kinase δ protein in C2C12 skeletal muscle cells

Decreased levels of the δ isozyme of diacylglycerol kinase (DGK) in skeletal muscle attenuate glucose uptake and, consequently, are critical for the pathogenesis of type 2 diabetes. We recently found that free myristic acid (14:0), but not free palmitic acid (16:0), increased the DGKδ protein levels and enhanced glucose uptake in C2C12 myotube cells. However, it has been unclear how myristic acid regulates the level of DGKδ2 protein. In the present study, we characterized the myristic acid-dependent increase of DGKδ protein. A cycloheximide chase assay demonstrated that myristic acid, but not palmitic acid, markedly stabilized DGKδ protein. Moreover, other DGK isozymes, DGKη and ζ, as well as glucose uptake-related proteins, such as protein kinase C (PKC) α, PKCζ, Akt and glycogen synthase kinase 3β, failed to be stabilized by myristic acid. Furthermore, DGKδ was not stabilized in cultured hepatocellular carcinoma cells, pancreas carcinoma cells or neuroblastoma cells, and only a moderate stabilizing effect was observed in embryonic kidney cells. A proteasome inhibitor and a lysosome inhibitor, MG132 and chloroquine, respectively, partly inhibited DGKδ degradation, suggesting that myristic acid prevents, at least in part, the degradation of DGKδ by the ubiquitin-proteasome system and the autophagy-lysosome pathway. Overall, these results strongly suggest that myristic acid attenuates DGKδ protein degradation in skeletal muscle cells and that this attenuation is fatty acid-, protein- and cell line-specific. These new findings provide novel insights into the molecular mechanisms of the pathogenesis of type 2 diabetes mellitus.

Metabolomic Salivary Signature of Pediatric Obesity Related Liver Disease and Metabolic Syndrome

Pediatric obesity-related metabolic syndrome (MetS) and nonalcoholic fatty liver disease (NAFLD) are increasingly frequent conditions with a still-elusive diagnosis and low-efficacy treatment and monitoring options. In this study, we investigated the salivary metabolomic signature, which has been uncharacterized to date. In this pilot-nested case-control study over a transversal design, 41 subjects (23 obese patients and 18 normal weight (NW) healthy controls), characterized based on medical history, clinical, anthropometric, and laboratory data, were recruited. Liver involvement, defined according to ultrasonographic liver brightness, allowed for the allocation of the patients into four groups: obese with hepatic steatosis ([St+], n = 15) and without hepatic steatosis ([St⁻], n = 8), and with (n = 10) and without (n = 13) MetS. A partial least squares discriminant analysis (PLS-DA) model was devised to classify the patients' classes based on their salivary metabolomic signature. Pediatric obesity and its related liver disease and metabolic syndrome appear to have distinct salivary metabolomic signatures. The difference is notable in metabolites involved in energy, amino and organic acid metabolism, as well as in intestinal bacteria metabolism, possibly reflecting diet, fatty acid synthase pathways, and the strict interaction between microbiota and intestinal mucins. This information expands the current understanding of NAFLD pathogenesis, potentially translating into better targeted monitoring and/or treatment strategies in the future.

Acalypha Wilkesiana 'Java White': Identification of Some Bioactive Compounds by Gc-Ms and Their Effects on Key Enzymes Linked to Type 2 Diabete

In this study, we identified bioactive compounds from the ethanolic extracts of the leaves, stem bark and root bark of Acalypha wilkesiana through GC-MS analysis and investigated the effects of these extracts on some of the enzymes linked to type 2 diabetes. Plant parts were extracted sequentially with ethyl acetate, ethanol and water. GC-MS analysis revealed the presence of long-chain alkyl acids, esters, ketones and alcohols including phytol and phytol acetate along with some secondary metabolites such as xanthone, vitamin E and various types of sterols including stigmasterol, campesterol and sitosterol. Ethanolic extracts of all the parts showed a dose- -dependent inhibition of α-glucosidase and α-amylase activity. The extracts also demonstrated anti-lipase activity. The ethanolic extract of root bark showed the highest inhibition of enzymes compared to other extracts. The EC50 values (concentrations for 50 % inhibition) of α-glucosidase, α-amylase and lipase inhibition were 35.75 ± 1.95, 6.25 ± 1.05 and 101.33 ± 5.21 μg mL-1, resp. The study suggests that A. wilkesiana ethanolic extracts have the ability to inhibit the activity of enzymes linked to type 2 diabetes. Further studies are needed to confirm the responsible bioactive compounds in this regard.

Diacylglycerol kinase δ controls down-regulation of cyclin D1 for C2C12 myogenic differentiation

Diacylglycerol kinase (DGK) is a lipid-metabolizing enzyme that phosphorylates diacylglycerol (DG) to produce phosphatidic acid (PA). DGKδ is highly expressed in the skeletal muscle, and a decrease in DGKδ expression increases the severity of type 2 diabetes. However, the role of DGKδ in myogenic differentiation is still unknown. The present study demonstrated that DGKδ expression was down-regulated in the early stage of C2C12 myogenic differentiation almost concurrently with a decrease in cyclin D1 expression. The knockdown of DGKδ by DGKδ-specific siRNAs significantly increased the levels of cyclin D1 expression at 48 h after C2C12 myogenic differentiation. In contrast, at the same time, the knockdown of DGKδ decreased the levels of myogenin expression and the number of myosin heavy chain (MHC)-positive cells. These results indicate that DGKδ regulates the early differentiation of C2C12 myoblasts via controlling the down-regulation of cyclin D1 expression. Moreover, the suppression of DGKδ expression increased the phosphorylation levels of conventional and novel protein kinase Cs (cnPKCs). Furthermore, DGKδ suppression increased the levels of cyclin D1 and phospho-cnPKCs even at the first 24 h of myogenic differentiation. These results suggest that DGKδ controls the down-regulation of cyclin D1 expression by attenuating the PKC signaling pathway for C2C12 myogenic differentiation.