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Frontiers in Nutrition 2024Studies have shown that sphingomyelin (SM) and its metabolites play signaling roles in the regulation of human health. Endogenous SM is involved in metabolic syndrome...
BACKGROUND
Studies have shown that sphingomyelin (SM) and its metabolites play signaling roles in the regulation of human health. Endogenous SM is involved in metabolic syndrome (MetS), while dietary SM supplementation may maintain lipid metabolism and prevent or alleviate MetS. Therefore, we hypothesized that dietary SM supplementation is beneficial for human health.
AIMS
In order to examine the impacts of dietary SM on metabolic indexes in adults without MetS, we performed a meta-analysis to test our hypothesis.
METHODS
A comprehensive search was performed to retrieve randomized controlled trials that were conducted between 2003 and 2023 to examine the effects of dietary SM supplementation on metabolic parameters in the Cochrane Library, PubMed, Web of Science, Embase, and ClinicalTrials.gov databases. RevMan 5.4 and Stata 14.0 software were used for meta-analysis, a sensitivity analysis, the risk of bias, and the overall quality of the resulted evidence.
RESULTS
Eventually, 10 articles were included in this meta-analysis. Dietary SM supplementation did not affect the endline blood SM level. When compared to the control, SM supplementation reduced the blood total cholesterol level [MD: -12.97, 95% CI: (-14.57, -11.38), < 0.00001], low-density lipoprotein cholesterol level [MD: -6.62, 95% CI: (-10.74, -2.49), = 0.002], and diastolic blood pressure [MD: -3.31; 95% CI (-4.03, -2.58), < 0.00001] in adults without MetS. The supplementation also increased high-density lipoprotein level [MD:1.41, 95% CI: (0.94, 1.88), < 0.00001] and muscle fiber conduction velocity [MD: 95% 1.21 CI (0.53, 1.88), = 0.0005]. The intake of SM had no effect on the blood phospholipids and lyso-phosphatidylcholine, but slightly decreased phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol concentrations. Dietary SM supplementation reduced insulin level [MD: -0.63; 95% CI (-0.96, -0.31), = 0.0001] and HOMA-IR [MD: -0.23; 95% CI (-0.31, -0.16), < 0.00001] without affecting blood levels of glucose and inflammatory cytokines.
CONCLUSION
Overall, dietary SM supplementation had a protective effect on blood lipid profiles and insulin level, but had limited impacts on other metabolic parameters in adults without MetS. More clinical trials and basic research are required.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO, identifier CRD42023438460.
PubMed: 38463938
DOI: 10.3389/fnut.2024.1363077 -
Ecotoxicology and Environmental Safety Apr 2024Arsenic, a ubiquitous environmental toxicant with various forms and complex food matrix interactions, can reportedly exert differential effects on the liver compared to...
Arsenic, a ubiquitous environmental toxicant with various forms and complex food matrix interactions, can reportedly exert differential effects on the liver compared to drinking water exposure. To examine its specific liver-related harms, we targeted the liver in C57BL/6 J mice (n=48, 8-week-old) fed with arsenic-contaminated food (30 mg/kg) for 60 days, mimicking the rice arsenic composition observed in real-world scenarios (iAs: 7.3%, iAs: 72.7%, MMA: 1.0%, DMA: 19.0%). We then comprehensively evaluated liver histopathology, metabolic changes, and the potential role of the gut-liver axis using human hepatocellular carcinoma cells (HepG2) and microbiota/metabolite analyses. Rice arsenic exposure significantly altered hepatic lipid (fatty acids, glycerol lipids, phospholipids, sphingolipids) and metabolite (glutathione, thioneine, spermidine, inosine, indole-derivatives, etc.) profiles, disrupting 33 metabolic pathways (bile secretion, unsaturated fatty acid biosynthesis, glutathione metabolism, ferroptosis, etc.). Pathological examination revealed liver cell necrosis/apoptosis, further confirmed by ferroptosis induction in HepG2 cells. Gut microbiome analysis showed enrichment of pathogenic bacteria linked to liver diseases and depletion of beneficial strains. Fecal primary and secondary bile acids, short-chain fatty acids, and branched-chain amino acids were also elevated. Importantly, mediation analysis revealed significant correlations between gut microbiota, fecal metabolites, and liver metabolic alterations, suggesting fecal metabolites may mediate the impact of gut microbiota and liver metabolic disorders. Gut microbiota and its metabolites may play significant roles in arsenic-induced gut-liver injuries. Overall, our findings demonstrate that rice arsenic exposure triggers oxidative stress, disrupts liver metabolism, and induces ferroptosis.
Topics: Mice; Humans; Animals; Arsenic; Mice, Inbred C57BL; Microbiota; Liver; Glutathione; Lipid Metabolism
PubMed: 38460405
DOI: 10.1016/j.ecoenv.2024.116147 -
Molecular Metabolism Apr 2024Adipose tissue mass is maintained by a balance between lipolysis and lipid storage. The contribution of adipose tissue lipogenesis to fat mass, especially in the setting...
OBJECTIVE
Adipose tissue mass is maintained by a balance between lipolysis and lipid storage. The contribution of adipose tissue lipogenesis to fat mass, especially in the setting of high-fat feeding, is considered minor. Here we investigated the effect of adipose-specific inactivation of the peroxisomal lipid synthetic protein PexRAP on fatty acid synthase (FASN)-mediated lipogenesis and its impact on adiposity and metabolic homeostasis.
METHODS
To explore the role of PexRAP in adipose tissue, we metabolically phenotyped mice with adipose-specific knockout of PexRAP. Bulk RNA sequencing was used to determine transcriptomic responses to PexRAP deletion and C-malonyl CoA allowed us to measure de novo lipogenic activity in adipose tissue of these mice. In vitro cell culture models were used to elucidate the mechanism of cellular responses to PexRAP deletion.
RESULTS
Adipose-specific PexRAP deletion promoted diet-induced obesity and insulin resistance through activation of de novo lipogenesis. Mechanistically, PexRAP inactivation inhibited the flux of carbons to ethanolamine plasmalogens. This increased the nuclear PC/PE ratio and promoted cholesterol mislocalization, resulting in activation of liver X receptor (LXR), a nuclear receptor known to be activated by increased intracellular cholesterol. LXR activation led to increased expression of the phospholipid remodeling enzyme LPCAT3 and induced FASN-mediated lipogenesis, which promoted diet-induced obesity and insulin resistance.
CONCLUSIONS
These studies reveal an unexpected role for peroxisome-derived lipids in regulating LXR-dependent lipogenesis and suggest that activation of lipogenesis, combined with dietary lipid overload, exacerbates obesity and metabolic dysregulation.
Topics: Animals; Mice; 1-Acylglycerophosphocholine O-Acyltransferase; Adipose Tissue; Cholesterol; Dietary Fats; Insulin Resistance; Lipogenesis; Liver X Receptors; Mice, Knockout; Obesity
PubMed: 38458567
DOI: 10.1016/j.molmet.2024.101913 -
International Journal of Health Sciences 2024Hyperglycemia, hyperlipidemia, and systemic resistance to insulin are typical manifestations of type 2 diabetes mellitus. One of the main pathophysiological alterations...
OBJECTIVE
Hyperglycemia, hyperlipidemia, and systemic resistance to insulin are typical manifestations of type 2 diabetes mellitus. One of the main pathophysiological alterations in insulin-sensitive organs is mitochondrial malfunction associated with oxidative stress and diminished fuel utilization. β-Caryophyllene (BCP) has qualities that are anti-inflammatory, anti-tumor, antioxidant, hypolipidemic, and hypoglycemic. In this work, rats suffering from type 2 diabetes were given a diet high in fat and sugar with the aim of examining the ameliorative effects of BCP on oxidative stress-mediated hepatic mitochondrial dysfunction.
METHODS
The diabetic condition was experimentally induced by feeding rats a high-calorie diet. The rats were then administered the recommended doses of BCP and metformin (MET) once every day for 30 days at 200 mg and 50 mg concentrations per kg of body weight, respectively, to prove the hypothesis of the study that BCP ameliorates mitochondrial dysfunction induced by oxidative stress in diabetic rats. Mitochondrial dysfunction can be identified by indicators such as oxidative stress, cardiolipin dienes, membrane phospholipid concentration, and mitochondrial enzymes.
RESULTS
The mitochondria in the liver of rats with diabetes exhibit elevated redox imbalance-related parameters and malfunctioning mitochondria with peroxided cardiolipin, while their amounts of glutathione and phospholipids are lowered. Oxidative stress indices, ameliorated mitochondrial activities, and peroxided cardiolipin were drastically decreased in rats with diabetes treated with BCP or MET.
CONCLUSIONS
The present research demonstrated that BCP improved the vital role of mitochondria by reducing free radical dominance in type 2 diabetic experimental rats fed high-fat and high-sugar diets.
PubMed: 38455602
DOI: No ID Found -
Food & Function Apr 2024Endothelial dysfunction (ED) is an initiating trigger and key factor in vascular complications, leading to disability and mortality in individuals with diabetes. The...
Endothelial dysfunction (ED) is an initiating trigger and key factor in vascular complications, leading to disability and mortality in individuals with diabetes. The research concerning therapeutic interventions for ED has gained considerable interest. Fenugreek, a commonly used edible plant in dietary consumption, has attracted significant attention due to its management of diabetes and its associated complications. The research presented in this study examines the potential therapeutic benefits of fenugreek in treating ED and investigates the underlying mechanism associated with its effects. The analysis on fenugreek was performed using 70% ethanol extract, and its chemical composition was analyzed using ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). In total, we identified 49 compounds present in the fenugreek extract. These compounds encompass flavonoids, saponins, and phospholipids. Then, the models of ED in streptozotocin-induced diabetic mice and high glucose-induced isolated rat aortas were established for research. Through vascular function testing, it was observed that fenugreek extract effectively improved ED induced by diabetes or high glucose. By analyzing the protein expression of arginase 1 (Arg1), Arg activity, Arg1 immunohistochemistry, nitric oxide (NO) level, and the protein expression of endothelial nitric oxide synthase (eNOS), p38 mitogen-activated protein kinase (p38 MAPK), and p-p38 MAPK in aortas, this study revealed that the potential mechanism of fenugreek extract in anti-ED involves the downregulation of Arg1, leading to enhanced NO production. Furthermore, analysis of serum exosomes carrying Arg activity indicates that fenugreek may decrease the activity of Arg transported by serum exosomes, potentially preventing the increase in Arg levels triggered by the uptake of serum exosomes by vascular endothelial cells. In general, this investigation offers valuable observations regarding the curative impact of fenugreek extract on anti-ED in diabetes, revealing the involvement of the Arg1 pathway in its mechanism.
Topics: Rats; Mice; Animals; Endothelial Cells; Diabetes Mellitus, Experimental; Arginase; p38 Mitogen-Activated Protein Kinases; Glucose; Nitric Oxide Synthase Type III; Plant Extracts; Trigonella
PubMed: 38450419
DOI: 10.1039/d3fo04283a -
Frontiers in Microbiology 2024It is well-known that different populations and animals, even experimental animals with the same rearing conditions, differ in their susceptibility to obesity. The...
INTRODUCTION
It is well-known that different populations and animals, even experimental animals with the same rearing conditions, differ in their susceptibility to obesity. The disparity in gut microbiota could potentially account for the variation in susceptibility to obesity. However, the precise impact of gut microbiota on gut metabolites and its subsequent influence on susceptibility to obesity remains uncertain.
METHODS
In this study, we established obesity-prone (OP) and obesity-resistant (OR) mouse models by High Fat Diet (HFD). Fecal contents of cecum were examined using 16S rDNA sequencing and untargeted metabolomics. Correlation analysis and MIMOSA2 analysis were used to explore the association between gut microbiota and intestinal metabolites.
RESULTS
After a HFD, gut microbiota and gut metabolic profiles were significantly different between OP and OR mice. Gut microbiota after a HFD may lead to changes in eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), a variety of branched fatty acid esters of hydroxy fatty acids (FAHFAs) and a variety of phospholipids to promote obesity. The bacteria (Greengene ID: 175696) may contribute to the difference in obesity susceptibility through the synthesis of glycerophosphoryl diester phosphodiesterase (glpQ) to promote choline production and the synthesis of valyl-tRNA synthetase (VARS) which promotes L-Valine degradation. In addition, gut microbiota may affect obesity and obesity susceptibility through histidine metabolism, linoleic acid metabolism and protein digestion and absorption pathways.
PubMed: 38450171
DOI: 10.3389/fmicb.2024.1343511 -
Maturitas Jun 2024Middle-aged women with obesity are at increased risk of iron overload and iron disorder is known to disrupt n-3 polyunsaturated fatty acid homeostasis. We evaluated... (Randomized Controlled Trial)
Randomized Controlled Trial
Weight loss induced by a hypocaloric diet with or without fish oil supplementation re-established iron and omega-3 fatty acid homeostasis in middle-aged women with obesity: A post-hoc analysis of a randomized controlled trial.
OBJECTIVE
Middle-aged women with obesity are at increased risk of iron overload and iron disorder is known to disrupt n-3 polyunsaturated fatty acid homeostasis. We evaluated relationships between pretreatment hemoglobin and n-3 polyunsaturated fatty acid levels, and tested whether pretreatment hemoglobin contributed to inter-individual variability in weight loss with special focus on changes in body weight, iron and n-3 polyunsaturated fatty acid profiles.
STUDY DESIGN
117 middle and older aged women with obesity and more than two metabolic abnormalities were randomized to a 12-week hypocaloric diet without or with fish oil supplementation. Blood iron biomarker and erythrocyte membrane phospholipid profiles were evaluated.
MAIN OUTCOME
The absolute change from baseline to week 12 in serum iron and erythrocyte n-3 polyunsaturated fatty acid levels according to pretreatment hemoglobin tertiles and fish oil supplementation.
RESULTS
A Pearson correlation analysis showed that pretreatment hemoglobin levels were negatively correlated with linoleic acid (r = -0.231), α-linoleic acid (r = -0.279), and n-3 polyunsaturated fatty acid (r = -0.217) (all p < 0.05). Dietary weight loss markedly enhanced erythrocyte membrane lipids of linoleic acid, α-linoleic acid, and n-6 and n-3 polyunsaturated fatty acid only in those women with the highest pretreatment hemoglobin levels (tertile 3) (all p < 0.05). Fish oil supplementation increased bioavailable iron in women with moderate pretreatment hemoglobin levels (tertile 2) (p < 0.05) and, to a lesser extent, prevented a reduction in circulating iron in those with the lowest hemoglobin levels (tertile 1).
CONCLUSION
Dietary weight loss is an effective treatment program to manage obesity-related iron and n-3 polyunsaturated fatty acid disorders, particularly for middle-aged women with obesity and iron overload.
Topics: Humans; Female; Middle Aged; Fatty Acids, Omega-3; Obesity; Dietary Supplements; Fish Oils; Iron; Weight Loss; Homeostasis; Erythrocyte Membrane; Hemoglobins; Diet, Reducing; Adult; Caloric Restriction; Phospholipids
PubMed: 38447232
DOI: 10.1016/j.maturitas.2024.107948 -
Cell Biology International Jun 2024Oxidized low-density lipoprotein (oxLDL), a key component in atherosclerosis and hyperlipidemia, is a risk factor for atherothrombosis in dyslipidemia, yet its...
Oxidized low-density lipoprotein (oxLDL), a key component in atherosclerosis and hyperlipidemia, is a risk factor for atherothrombosis in dyslipidemia, yet its mechanism is poorly understood. In this study, we used oxLDL-induced human aortic endothelial cells (HAECs) and high-fat diet (HFD)-fed mice as a hyperlipidemia model. Phosphatidylserine (PS) exposure, cytosolic Ca, reactive oxygen species (ROS), and lipid peroxidation were measured by flow cytometer. TMEM16F expression was detected by immunofluorescence, western blot, and reverse transcription polymerase chain reaction. Procoagulant activity (PCA) was measured by coagulation time, intrinsic/extrinsic factor Xase, and thrombin generation. We found that oxLDL-induced PS exposure and the corresponding PCA of HAECs were increased significantly compared with control, which could be inhibited over 90% by lactadherin. Importantly, TMEM16F expression in oxLDL-induced HAECs was upregulated by enhanced intracellular Ca concentration, ROS, and lipid peroxidation, which led to PS exposure. Meanwhile, the knockdown of TMEM16F by short hairpin RNA significantly inhibited PS exposure in oxLDL-induced HAECs. Moreover, we observed that HFD-fed mice dramatically increased the progress of thrombus formation and accompanied upregulated TMEM16F expression by thromboelastography analysis, FeCl-induced carotid artery thrombosis model, and western blot. Collectively, these results demonstrate that TMEM16F-mediated PS exposure may contribute to prothrombotic status under hyperlipidemic conditions, which may serve as a novel therapeutic target for the prevention of thrombosis in hyperlipidemia.
Topics: Lipoproteins, LDL; Animals; Humans; Phosphatidylserines; Endothelial Cells; Mice; Anoctamins; Reactive Oxygen Species; Mice, Inbred C57BL; Male; Hyperlipidemias; Calcium; Diet, High-Fat; Thrombosis; Lipid Peroxidation; Cells, Cultured; Blood Coagulation
PubMed: 38444077
DOI: 10.1002/cbin.12150 -
Communications Medicine Mar 2024Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent chronic liver disease worldwide, and can rapidly progress to metabolic...
BACKGROUND
Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent chronic liver disease worldwide, and can rapidly progress to metabolic dysfunction-associated steatohepatitis (MASH). Accurate preclinical models and methodologies are needed to understand underlying metabolic mechanisms and develop treatment strategies. Through meta-analysis of currently proposed mouse models, we hypothesized that a diet- and chemical-induced MASH model closely resembles the observed lipid metabolism alterations in humans.
METHODS
We developed transcriptomics-driven metabolic pathway analysis (TDMPA), a method to aid in the evaluation of metabolic resemblance. TDMPA uses genome-scale metabolic models to calculate enzymatic reaction perturbations from gene expression data. We performed TDMPA to score and compare metabolic pathway alterations in MASH mouse models to human MASH signatures. We used an already-established WD+CCl4-induced MASH model and performed functional assays and lipidomics to confirm TDMPA findings.
RESULTS
Both human MASH and mouse models exhibit numerous altered metabolic pathways, including triglyceride biosynthesis, fatty acid beta-oxidation, bile acid biosynthesis, cholesterol metabolism, and oxidative phosphorylation. We confirm a significant reduction in mitochondrial functions and bioenergetics, as well as in acylcarnitines for the mouse model. We identify a wide range of lipid species within the most perturbed pathways predicted by TDMPA. Triglycerides, phospholipids, and bile acids are increased significantly in mouse MASH liver, confirming our initial observations.
CONCLUSIONS
We introduce TDMPA, a methodology for evaluating metabolic pathway alterations in metabolic disorders. By comparing metabolic signatures that typify human MASH, we show a good metabolic resemblance of the WD+CCl4 mouse model. Our presented approach provides a valuable tool for defining metabolic space to aid experimental design for assessing metabolism.
PubMed: 38443644
DOI: 10.1038/s43856-024-00465-3 -
Metabolomics : Official Journal of the... Mar 2024Accumulating data on the associations between food consumption and lipid composition in the body is essential for understanding the effects of dietary habits on health.
INTRODUCTION
Accumulating data on the associations between food consumption and lipid composition in the body is essential for understanding the effects of dietary habits on health.
OBJECTIVES
As part of omics research in the Tohoku Medical Megabank Community-Based Cohort Study, this study sought to reveal the dietary impact on plasma lipid concentration in a Japanese population.
METHODS
We conducted a correlation analysis of food consumption and plasma lipid concentrations measured using mass spectrometry, for 4032 participants in Miyagi Prefecture, Japan.
RESULTS
Our analysis revealed 83 marked correlations between six food categories and the concentrations of plasma lipids in nine subclasses. Previously reported associations, including those between seafood consumption and omega-3 fatty acids, were validated, while those between dairy product consumption and odd-carbon-number fatty acids (odd-FAs) were validated for the first time in an Asian population. Further analysis suggested that dairy product consumption is associated with odd-FAs via sphingomyelin (SM), which suggests that SM is a carrier of odd-FAs. These results are important for understanding odd-FA metabolism with regards to dairy product consumption.
CONCLUSION
This study provides insight into the dietary impact on plasma lipid concentration in a Japanese population.
Topics: Humans; Japan; Cohort Studies; Metabolomics; Feeding Behavior; Fatty Acids; Sphingomyelins
PubMed: 38441752
DOI: 10.1007/s11306-024-02087-1