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Single nucleus multiomics reveals an early inflammatory response to high-fat diet in mouse islets.

In periods of sustained hyper-nutrition, pancreatic β-cells undergo functional compensation through transcriptional upregulation of gene programs driving insulin secretion. This adaptation is essential for maintaining systemic glucose homeostasis and metabolic health. Using single nuclei multiomics, we have mapped the early transcriptional adaptive mechanisms in murine islets of Langerhans exposed to high-fat diet (HFD) for 1 and 3 wk. We show that β-cells exhibit the largest transcriptional response to HFD, characterized by early activation of pro-inflammatory eRegulons and down-regulation of β-cell identity genes, particularly in a distinct subset of β-cells. These observations extend to humans, where the prevalence of an β-cells with a high inflammatory signature is increased in diabetes. Collectively, these observations point to cellular crosstalk through pro-inflammatory signaling as a central and early driver of β-cell dysfunction that limits the compensatory capacity of β-cells, which is closely linked to the development of diabetes.

Animals

Maternal high-fat diet modulates lupus nephritis through fetal Wnt-steroid hormone and epigenetic reprogramming in MRL/lpr mouse offspring.

We previously investigated whether maternal high-fat diet (HFD) exposure alters lupus nephritis (LN) progression in MRL/lpr offspring. Contrary to expectation, maternally HFD-exposed offspring showed delayed and attenuated nephritic progression compared with control diet offspring. The maternal HFD developmental impact on LN remains unclear. Here, integrated amniotic fluid metabolomics and fetal liver transcriptomics revealed that maternal HFD reshaped the intrauterine molecular environment, particularly involving steroid hormone biosynthesis and Wnt/β-catenin-associated regulatory networks. Methylome profiling further demonstrated broad CpG hypomethylation, immune-related differentially methylated region enrichment, and an inverse association between global CpG methylation and oxidative genomic DNA damage. Among candidate regulatory nodes, Axin2, a canonical Wnt/β-catenin target and feedback regulator, emerged as a potential link between fetal nutritional exposure, epigenetic remodeling, and persistent pathway modulation. Although whole-locus and gene body methylation of Axin2 were not markedly altered, promoter-region methylation showed an increasing tendency under maternal HFD exposure. In adult offspring, maternal HFD was associated with reduced Axin2 protein expression, decreased Wnt-responsive transcripts, increased peripheral corticosterone levels, and attenuation of LN progression. The inverse association between Axin2 expression and corticosterone further suggested coupling between suppressed Wnt pathway output and steroid hormone remodeling. Together, these findings support a developmental model in which maternal HFD reshapes the fetal intrauterine environment and establishes a persistent Wnt-steroid hormone-epigenetic regulatory axis that unexpectedly attenuates LN progression in genetically susceptible offspring.

Axin2

Integrated miRNA-mRNA profiling reveals candidate regulatory relationships associated with high-fat diet-induced muscle lipid deposition in black seabream (Acanthopagrus schlegelii).

High-fat diets are increasingly used in aquaculture due to their protein-sparing effects; however, the post-transcriptional regulatory mechanisms of fish muscle in response to high-fat diets (HFD) remain unclear. In this study, juvenile black seabream were fed either a normal-fat diet (NFD) or a HFD to investigate the miRNA-mRNA regulatory network associated with diet-induced muscle lipid deposition. Oil Red O staining and biochemical analysis showed that high-fat diet feeding markedly increased lipid droplet accumulation and crude lipid content in muscle, indicating significant induction of muscle lipid deposition. Integrated mRNA and miRNA expression profiling revealed substantial transcriptomic and post-transcriptional responses to high-fat diet challenge. A total of 271 differentially expressed genes were identified, including 120 upregulated and 151 downregulated genes. Through combined target prediction and expression correlation analysis, thirteen candidate inverse miRNA-mRNA relationships were subsequently identified, and RT-qPCR supported the expression patterns of selected miRNAs and mRNAs. These pairs included miR-499-x-dmgdh, miR-499-y-gatm, miR-727-y-ass1, miR-4649-x-foxo4, miR-9129-z-myl7, and several novel miRNA-mediated interactions involving adk, chst11, lypla2, frem2, kcnc4, wars1, bag2, and capn2. Functional analysis suggested that these regulatory pairs were mainly associated with metabolic adaptation, structural remodeling, and cellular stress responses. In particular, gatm, dmgdh, ass1, and adk were associated with energy metabolism-related processes, including pathways previously linked to Ampk regulation, whereas myl7, frem2, and kcnc4 may contribute to muscle structural maintenance and excitability regulation. Overall, this study provides candidate miRNA-mRNA regulatory relationships potentially involved in high-fat diet-induced muscle lipid deposition and adaptive remodeling in black seabream, offering a basis for future functional studies on muscle metabolism and quality regulation in marine fish.

Animals

Murine metabolic HFpEF is associated with altered mitochondrial substrate handling and S-nitrosylation remodeling.

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous condition with incompletely defined myocardial mechanisms. Here, using a two-hit murine model of cardiometabolic HFpEF induced by high-fat diet and endothelial nitric oxide synthase inhibition, we define a mitochondrial metabolic phenotype characterized by altered substrate handling, redox stress, and S-nitrosylation remodeling. While global proteomic changes were modest, metabolomic profiling revealed selective remodeling of tricarboxylic acid cycle intermediates, increased dicarboxylic acids, and altered redox-associated metabolites, consistent with mitochondrial metabolic and redox imbalance in this experimental setting. S-nitrosylation proteomics demonstrated a highly organized and bidirectional remodeling pattern affecting proteins involved in fatty acid/lipid metabolism, carbohydrate metabolism, mitochondrial energy metabolism, amino acid and organic acid metabolism, nucleotide/co-factor metabolism, and redox defense. Stable isotope tracing showed reduced glucose-derived and increased palmitate-derived acetyl-CoA in HFpEF, whereas Na-βHB reduced palmitate contribution and increased βHB-derived acetyl-CoA without restoring glucose contribution, indicating substrate redistribution and preserved ketone oxidation. Na-βHB supplementation increased oligomycin-sensitive respiration in freshly prepared left ventricular tissue, partially normalized selected TCA-cycle intermediates, reduced mitochondrial ROS and the NADH/NAD+ ratio, restored the GSH/GSSG ratio, and improved diastolic function without altering ejection fraction. Together, these findings define a redox-sensitive mitochondrial metabolic state in the HFD/l-NAME model and identify ketone supplementation as a partial metabolic rescue strategy in this context. At the same time, these findings highlight an important limitation of the murine HFD/l-NAME model, which should be interpreted as an experimental system for studying high-fat-induced cardiometabolic stress rather than as a metabolic equivalent of human HFpEF.

Animals

Dietary effects on cytosolic and mitochondrial tRNA abundance and modification patterns across mouse tissues.

Transfer RNAs (tRNAs) are central to protein synthesis and are increasingly recognized as dynamic regulators of gene expression whose abundance and chemical modifications are subject to precise biological control. Here, we systematically investigate how two distinct dietary interventions, low-protein and high-fat diets, reshape the tRNA landscape across multiple mouse tissues, using RNA mass spectrometry and ordered two-template relay sequencing (OTTR-seq) to comprehensively profile cytosolic and mitochondrial tRNAs at single-nucleotide resolution. We reveal pronounced tissue-specific biases in tRNA isodecoder expression, including the unexpected presence of full-length cytosolic tRNAs in mature sperm with a distinct isotype composition. In somatic tissues such as liver and heart, dietary conditions alter both tRNA abundance and key modifications known to regulate decoding efficiency, whereas in reproductive tissues diet primarily affects the abundance of select tRNAs with comparatively limited changes in modification profiles. We further demonstrate that mitochondrial tRNAs are subject to diet-responsive changes in both abundance and modification status and that even subtle differences in dietary fat composition are sufficient to alter tRNA modification signatures. Together, these findings establish the tRNA epitranscriptome as a sensitive and tissue-specific sensor of nutritional state and provide a resource for understanding how dietary cues interface with translational regulation in somatic and reproductive tissues.

Male

Transcriptome Analysis and Experimental Validation of Palmitoylation- Related Biomarkers in Atherosclerosis.

INTRODUCTION: Protein palmitoylation contributes to membrane localisation, signal transduction, and cell-fate regulation. It is closely associated with lipid metabolic dysfunction, immune inflammation, and vascular remodelling in atherosclerosis (AS). However, key palmitoylation-related transcriptomic markers and their potential causal associations with AS remain incompletely defined. METHODS: The Gene Expression Omnibus (GEO) dataset GSE100927 was used as the training cohort, and GSE43292 was used as an external validation cohort. Differentially expressed genes were identified using limma and intersected with palmitoylation-related genes to obtain palmitoylation-related differentially expressed genes (PRDEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were then performed using clusterProfiler. Two-sample Mendelian randomisation was used to evaluate potential causal relationships between characteristic genes and AS. Feature selection was conducted using random forest and support vector machine recursive feature elimination (SVM-RFE), and the overlapping genes selected by both methods were retained. Receiver operating characteristic (ROC) curves were used to assess diagnostic performance. A five-gene nomogram was constructed, and its clinical utility was evaluated using calibration curves and decision curve analysis (DCA). Gene set variation analysis (GSVA) was applied to compare pathway activity between high- and low-expression groups for each core gene. Single-cell analysis using Seurat and expression-based cell-cell communication analysis using CellChat were conducted with GSE159677, and upstream transcription factors were predicted using NetworkAnalyst. For in vivo validation, an AS model was established in ApoE⁸/⁸ mice fed a high-fat diet, and aortic gene and protein expression were assessed by RT-qPCR and western blotting. RESULTS: In GSE100927, 51 PRDEGs were identified. GO and KEGG enrichment analyses highlighted pathways associated with regulation of monoatomic ion transport, sarcomere and myofibril organisation, and immune inflammation. Mendelian randomisation suggested a potential protective causal association between SLC7A7 and AS. By integrating MR with random forest and SVM-RFE feature selection, we prioritised five core genes: PLCB2, GMIP, NEXN, PLN, and SLC7A7. These genes showed good diagnostic performance in GSE43292. The resulting nomogram was well calibrated and demonstrated stable net benefit in decision curve and clinical impact curve analyses. Single-gene GSVA identified consistently activated pathways across multiple genes, including innate and adaptive immune recognition, calcium signalling and myocardial contraction/cardiomyopathy, extracellular matrix-receptor interaction, cell junction pathways, autophagy-lysosome pathways, and several metabolic programmes. At the single-cell level, PLCB2 and GMIP were predominantly expressed in T cells and macrophages, NEXN and PLN were enriched in vascular smooth muscle cells, and SLC7A7 was mainly expressed in macrophages. CellChat analysis indicated increased signals for immune-related ligand-receptor interactions. In ApoE⁸/⁸ mice fed a high-fat diet, PLCB2, GMIP, and SLC7A7 were upregulated, whereas NEXN and PLN were downregulated; protein-level changes were concordant with the transcriptomic trends. DISCUSSION: These findings indicate that palmitoylation-related dysregulation in AS converges on immune inflammation, calcium signalling/contractile programmes, ECM remodelling, and autophagy-linked metabolism. The five-gene panel is supported by external validation, single-cell localisation to immune and vascular compartments, and concordant results in ApoE⁸/⁸ mice. CONCLUSION: This study identified and validated five palmitoylation-related genes associated with AS. SLC7A7 showed a potential protective causal signal in MR analysis. The enriched pathway patterns linked these genes to immune inflammation, calcium signalling-contraction coupling, ECM remodelling, cell adhesion, and autophagy- associated metabolic reprogramming. The five-gene nomogram showed potential utility for diagnostic classification and decision support, nominating candidate biomarkers and pathway targets for AS molecular subtyping, diagnosis, and mechanistic investigation.

Atherosclerosis (AS)

Diet-dependent effects of an environmentally relevant dose of polyethylene and polyethylene terephthalate on white adipose tissue and systemic insulin resistance in mice.

As human exposure to micro- and nanoplastics (NPs) is unavoidable, it remains unclear whether dietary composition can modulate their health impacts. To address this, we investigated the metabolic effects of two common yet understudied polymers, polyethylene (PE) and polyethylene terephthalate (PET), in mice with either healthy or energy-dense diet. C57BL/6 J male mice were exposed to an environmentally relevant dose of PE or PET (100 nm, 25 mg/kg BW/day) for 29 weeks under either a normal diet (ND) or a high-fat diet (HFD). The metabolic consequence of NP exposure was highly diet-dependent. In ND-fed mice, PE and PET reduced white adipose tissue (WAT) mass, with PET inducing metabolic changes that toward a lipodystrophy-like state. Conversely, in HFD-fed mice, both polymers impaired systemic insulin sensitivity. Regardless of diet, PE and PET promoted immunoglobin G (IgG) accumulation in epididymal WAT, with PE-exposed lean mice exhibited the most robust IgG elevation, WAT fibrosis and impaired adipogenesis. These findings demonstrate that chronic, environmentally relevant PE or PET exposure disrupts metabolic health in male mice under both dietary contexts. While dietary composition dictates the specific metabolic phenotype, it does not prevent adverse outcomes. This complicates lifestyle-based mitigation strategies and underscores the urgent need for environmental source controls.

Insulin Sensitivity

Opposite metabolic and gut responses to oral glutamine in male and female mice with diet-induced obesity.

Obesity is often associated with sex-dependent metabolic complications, to which altered intestinal barrier function and gut microbiota contribute. Glutamine supplementation has previously shown beneficial effects on gut barrier function and glycemic control. We thus aimed to characterize, in male and female mice, the effects of oral glutamine supplementation during high-fat-diet-induced obesity. Male and female C57BL/6 mice received a standard (SD) or high-fat diet (HFD; 60 % kcal from fat) for 14 weeks (W14). From W12 onward, mice received glutamine in drinking water (2 g/kg/day) or no supplementation. Body composition, glucose tolerance, insulin sensitivity, intestinal permeability, colonic inflammatory response, cecal microbiota and inflammatory/endocrine adipose response were assessed. In both male and female mice, glutamine supplementation failed to improve body weight and body composition. However, glutamine reduced glucose intolerance in HFD-fed males (AUC reduced by 14.57 %) that was associated with a partial restoration of plasma resistin and insulin and a trend toward limiting adipose inflammatory response. In males, glutamine did not affect gut microbiota composition and colonic response. Conversely, in HFD-fed females, glutamine supplementation led to gut microbiota changes (increase in Bacteroidota and Pseudomonadota phyla; increase in Muribaculaceae and Tannerellaceae families), increased colonic inflammatory markers (Il1b, Tlr4, Myd88, Irf3), increased inflammatory response in subcutaneous adipose tissue and increased HOMA-IR. Finally, HFD-fed mice exhibited sex-specific responses to glutamine supplementation with protective effects in males and harmful effects in females that need to be further deeply explored.

Animals

Generation and validation of a Myh11Dre-Spp1Cre intersectional mouse model for lineage tracing of disease-associated smooth muscle cell states.

BACKGROUND: Phenotypic modulation of vascular smooth muscle cells (VSMCs) is a hallmark of vascular remodeling and cardiovascular disease. Recent lineage-tracing and single-cell transcriptomic studies have identified secreted phosphoprotein 1 (SPP1) as a prominent marker associated with disease-associated VSMC states, particularly those linked to fibrotic remodeling and vascular calcification. However, the cellular origins and fate of SPP1-associated VSMC populations remain incompletely understood. METHODS AND RESULTS: We generated a novel Spp1-rSTOPr-Cre (Spp1Cre) knock-in mouse line in which Cre recombinase is expressed from the endogenous Spp1 locus following Dre-mediated excision of a rox-flanked transcriptional STOP cassette. Correct targeting of the knock-in allele was validated by internal, 5' junction, 3' junction, and long-range PCR analyses, as well as Sanger sequencing. To establish an intersectional lineage-tracing strategy, Spp1Cre mice were crossed with Myh11DreERT2 and Rosa26-RSR-LSL-tdTomato-LSL-eGFP reporter mice, enabling permanent labeling of VSMC-derived populations following activation of the endogenous Spp1 locus. Under physiological conditions, eGFP-positive cells were detected at low frequency within the vascular wall and were predominantly negative for the contractile markers ACTA2 and MYH11. As a proof-of-principle application, eGFP-positive cells markedly expanded within atherosclerotic lesions induced by AAV-PCSK9D377Y and high-fat diet feeding. These lineage-traced cells remained largely ACTA2- and MYH11-negative, consistent with a modulated phenotype. Notably, only a minority of eGFP-positive cells expressed SPP1 or fibronectin at the time of analysis, demonstrating the utility of permanent lineage tracing for tracking cells with a history of endogenous Spp1 activation during vascular remodeling. CONCLUSION: We report the generation and validation of a novel Myh11Dre-Spp1Cre intersectional mouse model for lineage tracing of VSMC-derived populations that have activated the endogenous Spp1 locus. This genetic resource provides a valuable platform for investigating the origin, fate, and phenotypic evolution of Spp1-associated VSMC populations during vascular remodeling and cardiovascular disease.

Animals

Conditional eIF2A Deletion Suggests Extra-Adipose Mechanisms Underlying Metabolic Syndrome in Total-Body eIF2A Knockout Mice.

Dynamic regulation of protein synthesis is essential for metabolic homeostasis, with translation initiation playing a key role in this process. Emerging evidence strongly indicates that in addition to canonical eukaryotic initiation factors (e.g., eIF2, eIF4E) non-canonical factors, such as eukaryotic initiation factor 2A can modulate metabolic homeostasis. eIF2A is a highly conserved eukaryotic protein originally proposed to function analogously to bacterial IF2, promoting initiator Met-tRNAi recruitment to the 40S ribosomal subunit, though its precise mechanism remains debated. To investigate its organismal role, we have previously generated the total-body eIF2A knockout mouse, which revealed eIF2A functions in lipid homeostasis, glucose tolerance, insulin sensitivity, and susceptibility to metabolic syndrome. To further determine whether adipose tissue drives these phenotypes, we presently generated adipose-specific eIF2A knockout mice. Despite dysregulation of some key adipokines, including for example, adiponectin, these mice did not develop metabolic syndrome, even under high-fat diet conditions, indicating that adipose tissue specific deficiency of eIF2A is insufficient to reproduce the metabolic defects observed in total-body knockout. However, we found that eIF2A deficiency in the liver of the total body eIF2A-KO mice can independently drive metabolic syndrome components via translational control of Lpin1 (a phosphatidate phosphatase and a transcriptional coactivator) that controls hepatic lipid storage and metabolism. eIF2A deficiency in the liver leads to disruption of fatty acid oxidation and the production of ketone bodies, not observed in adipose-specific eIF2A knockout mice. Our findings suggest that systemic metabolic effects observed in the total body eIF2A-KO mice may arise from coordinated functions across multiple organs.

adipose tissue

Low Carbohydrate Availability in Energy Balance Alters Bone Turnover and Muscle Proteomic Response With Limited Endocrine Disruption.

Training with low carbohydrate availability (LCA) has been proposed as an independent determinant of physiological perturbations commonly attributed to low energy availability (LEA) and to increase skeletal muscle oxidative machinery, yet the effects of LCA in isolation from LEA remain unclear. We examined whether short-term carbohydrate restriction under energy balance alters endocrine and metabolic markers associated with LEA and skeletal muscle proteomic response. In a randomized crossover design, eight trained males completed 4 days of either a low-carbohydrate high-fat diet (LOW; 12% carbohydrate, 69% fat, 19% protein) or a normal-carbohydrate diet (NORM; 62% carbohydrate, 19% fat, 19% protein), while undertaking daily cycloergometer exercise (15 kcal kg FFM-1 day-1) and maintaining energy availability at 45 kcal kg FFM-1 day-1. LOW induced a clear metabolic shift consistent with LCA, evidenced by elevated circulating free fatty acids, glycerol and β-hydroxybutyrate, in fasting conditions and fat oxidation at rest and during exercise, alongside reduced exercise glucose concentrations. Despite these responses, LOW did not alter insulin, testosterone, triiodothyronine, leptin, hepcidin, or P1NP. In contrast, β-CTX increased and IGF-1 decreased relative to NORM. Muscle glycogen concentration decreased only in LOW (40% ± 14%). Proteomic analysis identified 671 proteins; 57 differentially expressed in LOW relative to NORM were limited to fatty acid metabolism pathways and suppression of ribosomal, sarcomeric, and extracellular matrix proteins. These findings indicate that isolated LCA exerts limited endocrine disruption but may selectively compromise bone turnover and muscle anabolic response, suggesting that without acute LEA, LCA has limited influence on muscle oxidative phenotype.

Male

[Study on mechanism of Wendan Decoction in intervening in nonalcoholic fatty liver disease based on proteomics and network pharmacology].

This study systematically explored the molecular mechanism of Wendan Decoction(WDD) in treating nonalcoholic fatty liver disease(NAFLD) by integrating network pharmacology, proteomics, and experimental validation. A mouse NAFLD model was established using a high-fat diet, and the mice were randomly divided into a blank control group, a model group, a positive drug group(simvastatin, 3.03 mg·kg~(-1)), and low-(3.035 g·kg~(-1)), medium-(6.07 g·kg~(-1)), and high-dose(12.14 g·kg~(-1)) WDD groups, with intervention lasting for 6 weeks. After the intervention, the serum levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), triglycerides(TG), total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C), and high-density lipoprotein cholesterol(HDL-C) were measured using an automatic biochemical analyzer. The serum levels of interleukin-1β(IL-1β), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α) were detected by ELISA. Liver histopathology was observed via hematoxylin-eosin(HE) staining and oil red O staining. Network pharmacology was used to predict potential targets and pathways, and proteomics was applied to identify differentially expressed proteins and related pathways. RT-qPCR and Western blot were performed to detect mRNA and protein expression of relevant genes. Animal experiments demonstrated that WDD dose-dependently ameliorated hepatic steatosis, inflammation, and lipid deposition, significantly reducing serum levels of ALT, AST, TG, TC, LDL-C, and pro-inflammatory cytokines(IL-1β, IL-6, and TNF-α), while significantly increasing serum HDL-C levels. Network pharmacology screening identified naringenin, baicalein, and other key active components, which were involved in pathways such as the peroxisome proliferator-activated receptor(PPAR), lipid, and atherosclerosis pathways. Proteomics further revealed differentially expressed pathways including the PPAR and advanced glycation end product-receptor(AGE-RAGE) signaling pathways. Integrated analysis highlighted the PPAR signaling pathway as the core mechanism. Molecular biology validation showed that WDD significantly regulated the mRNA expression of sterol regulatory element-binding protein-1c(SREBP-1c), fatty acid synthase(FASN), carnitine palmitoyl transferase 1A(CPT1A), acyl-CoA oxidase 1(ACOX1), and PPARα, as well as protein expression of PPARα, CPT1A, and PPARγ in mouse liver tissue. These results suggested that WDD might exert a multi-component, multi-target, and multi-pathway synergistic effect to improve lipid metabolism disorders and inflammatory responses with the PPAR signaling pathway as the central hub, thereby alleviating NAFLD progression.

Animals

Reduced R-loop abundance at proinflammatory loci: a shared epigenetic mechanism in inflammatory and metabolic diseases.

INTRODUCTION: R-loops, RNA-DNA hybrid structures with a displaced single-stranded DNA loop, are key regulators of transcriptional control, chromatin architecture, and genome stability and have emerging roles in inflammatory signaling. However, the relationship between R-loop abundance and strongly modulated inflammatory effector genes in metabolic inflammation and influenza virus infection remains underexplored. METHODS: We performed a locus-centric integrative analysis combining robust differentially expressed genes (DEGs) from multiple inflammatory and infection-related murine and human transcriptomic disease models with experimentally validated multi-cell R-loop annotations from the reference atlas RLoopBase. Our correlation framework evaluated the directional relationship between R-loop abundance and inflammatory gene expression rather than assuming disease-sample-matched R-loop measurements. We further analyzed R-loop regulatory proteins, NRF2-associated R-loop regulators, and overlaps between R-loop regulators and CRISPRi-identified mitochondrial and cellular reactive oxygen species (ROS) regulators. RESULTS: In angiotensin II-infused apolipoprotein E-deficient (ApoE-/-) mice, a model of abdominal aortic aneurysm (AAA), genomic regions encoding the top significantly upregulated genes exhibited significantly fewer R-loops than those encoding downregulated genes at days 14 and 28. Similarly, in atherosclerotic ApoE-/- mice fed a high-fat diet for 32 and 78 weeks, upregulated genes were associated with fewer R-loops than downregulated genes. Reduced R-loop abundance was also observed in genomic regions encoding the top significantly upregulated genes in liver tissues from patients with non-alcoholic steatohepatitis (NASH), as well as in monosodium urate (MSU)-stimulated lymphatic endothelial cells (LECs) and influenza virus-infected human umbilical vein endothelial cells (HUVECs). R-loop regulatory proteins upregulated during metabolic inflammation were enriched in immune and inflammatory pathways. NRF2 was identified as a regulator of 27 R-loop regulatory proteins, including 10 positively and 17 negatively regulated proteins. Furthermore, 54 R-loop regulatory proteins overlapped with CRISPRi-identified mitochondrial and cellular ROS regulators, suggesting potential reciprocal regulation between R-loop homeostasis and ROS signaling. Disease-associated changes in pro-ROS and anti-ROS R-loop regulatory proteins further linked R-loop regulation to inflammatory and oxidative stress pathways. DISCUSSION: These findings identify reduced R-loop abundance at genomic regions encoding strongly upregulated inflammatory genes as a shared feature across multiple models of metabolic inflammation and influenza virus infection. The results further suggest that immune-associated R-loop regulatory proteins and the NRF2-ROS axis may contribute to R-loop remodeling during inflammatory disease. This integrative framework provides new insight into the potential role of R-loops and ROS-sensitive R-loop regulators in inflammatory and metabolic diseases and identifies candidate pathways for future mechanistic investigation and therapeutic targeting.

R-loop regulatory proteins

Exercise elicits mitonuclear protein imbalance and UPRmt in the liver of mice with obesity.

Mitochondrial dysfunction plays a critical role in the development of metabolic dysfunction-associated steatotic liver disease (MASLD). It has been proposed that mitochondrial unfolded-protein response (UPRmt) activation improves mitochondrial function in the liver. Growing evidence demonstrates that physical exercise effectively prevents and treats MASLD. However, the effects of exercise on UPRmt activation in the liver are unknown. Thus, we investigated the impact of aerobic training on the mechanisms involved in mitochondrial quality control in the liver in a mouse model of obesity. Liver transcript data from a genetic reference panel of BXD isogenic mice revealed a negative correlation between UPRmt-related genes and hepatic triacylglycerol content. In addition, the liver UPRmt markers were strongly associated with several mitochondrial-related genes in the hepatic tissue of BXD mice and humans. Notably, 4 weeks of aerobic exercise strongly impacted the liver metabolism, preventing intrahepatic lipid accumulation in HFD-fed mice. Physical exercise boosted the NAD-biosynthesis pathway, elicited the mitonuclear protein imbalance, stimulated the protein content of UPRmt-markers, including CLpP, Lonp1, and Yme1L1, and improved the mitochondrial proteostasis and function in the liver in HFD-fed mice. Thus, our findings link the mitonuclear protein imbalance and UPRmt activation in the liver to mitochondrial proteostasis and MASLD prevention in response to physical exercise.

Animals

Maternal vitamin B12 deprivation exacerbates offspring obesity by reducing early-life colonization with Bifidobacterium pseudolongum.

Vitamin B12 deficiency during pregnancy and lactation is common, yet its mechanistic impact on reproductive outcomes and offspring health remains poorly understood. Here, we show that maternal dietary vitamin B12 deprivation not only impairs maternal glucose metabolism and reproductive outcomes but also exacerbates high-fat-diet-induced obesity in offspring. These effects are mediated by gut microbiota and associated with a marked reduction of Bifidobacterium pseudolongum (B. pseudolongum) in both dams and their offspring. Maternal vitamin B12 deprivation limits early-life acquisition of B. pseudolongum in offspring during lactation, subsequently intensifying obesity and metabolic dysregulation. Early-life restoration of B. pseudolongum or its key metabolite, acetate, effectively ameliorates this aggravated obesity. Mechanistically, acetate acts through the Ffar2 receptor to upregulate Ehhadh expression. Together, these data establish that perinatal nutrition imprints long-term metabolic phenotypes in offspring via early-life acquisition of the gut microbiota, with a critical window during lactation.

Animals

Effects of phytosterols supplementation on hepatic lipid metabolism and metabolic outcomes in obese rodent models: a systematic review and meta-analysis.

This study aimed to synthesize and quantitatively assess the available evidence on the effects of phytosterol supplementation on hepatic lipid metabolism and obesity-related metabolic outcomes in obese rodent models, integrating biochemical, histological, and molecular evidence. A systematic search was conducted in electronic databases (PubMed, EMBASE, and Web of Science). Data on study design, population, intervention, outcomes, and risk of bias were extracted and analyzed. A quantitative meta-analysis was performed. Meta-analysis showed reductions in body weight, serum triglycerides, total cholesterol, LDL-C, VLDL-C, glucose, liver weight, hepatic cholesterol, hepatic triglycerides, and nonalcoholic fatty liver disease activity score. No significant changes were observed for adiposity index, HDL-C, insulin, or hepatic expression of PPARα, FAS, and SREBP1c. Conversely, CPT1A expression was significantly increased following PS supplementation. Subgroup analyses indicated that the beneficial effects on lipid and hepatic outcomes were generally consistent across rodent species (mice, rats, and hamsters), obesity induction models, and routes of administration, although the magnitude of responses varied between strains, with C57BL/6 mice showing more pronounced metabolic improvements. Additional analyses suggested that treatment duration and phytosterol composition may modulate specific outcomes, whereas dose-response meta-regression identified dose-dependent associations for serum and hepatic cholesterol, and PPARα expression in dietary supplementation studies. Overall, the available preclinical evidence suggests that phytosterol supplementation may improve several metabolic and hepatic outcomes in rodent models of obesity. However, the substantial heterogeneity across studies highlights the need for standardized experimental protocols and future clinical studies before these findings can be translated to human health.

Animals

Supplementations of docosahexaenoic acid and blueberry suppress a high-fat breakfast-induced postprandial inflammation but only docosahexaenoic acid improves endothelial function in healthy adults: a randomized, double-blind, placebo-controlled crossover intervention study.

Blueberries and n - 3 polyunsaturated fatty acids each can provide protection against inflammation and cardiometabolic disorders. However, the underlying mechanisms are not fully understood. We hypothesized that blueberry and docosahexaenoic acid (DHA) can suppress high fat (HF) meal-induced postprandial inflammation and improve endothelial function. Sixty-two healthy participants (age: 26.8 &#xb1; 1.2 y; BMI: 22.1 &#xb1; 1.2 kg/m&#xb2;) consumed an isoenergetic breakfast (850 kcal) containing 34.7 g mostly animal fat (36% kcal), 25.3 g protein, and 111 g carbohydrate, with or without either 42.2 g blueberry powder (BBP) or 1.76 g DHA in a randomized, double-blind, placebo-controlled crossover intervention study. Blood samples were collected before and 1 h, 3 h and 6 h after breakfast. Monocyte activation, proinflammatory gene expression, cytokine production and endothelial function were assessed. Compared with the placebo control, DHA supplementation suppressed the HF breakfast-induced: expression of IL-1&#x3b2; by 21.6% (P < .01) and prostaglandin-endoperoxide synthase 2 (PTGS2, i.e., cyclooxygenase 2) by 22.8% (P < .01) at 6 h; plasma IL-1&#x3b2; production by 40.1 to 49.8% (P < .01) at 1-6 h; lipoprotein lipase (LPL)-treated blood IL-1&#x3b2; production by 40.9% (P < .0001) at 6 h; and total cholesterol/HDL cholesterol ratio by 2.2% (P < .01) at 3 h and 3.5% (P < .0001) at 6 h. BBP supplementation suppressed LPL-treated blood IL-1&#x3b2; production by 23.1% (P < .05) at 6 h. BBP and DHA also induced postprandial increases in reactive hyperemia index (RHI) scores relative to the fasting baselines, with DHA producing a 13.3% increase compared with placebo at 6 h (P < .05). In conclusion, supplementation with BBP or DHA suppressed the HF meal-induced postprandial inflammation but only DHA improved postprandial endothelial function. This study was registered at clinicaltrails.gov (NCT02472171).

Blueberry

Evaluation of metabolic, reproductive, and gut microbiota alterations in a comparative study of different preclinical models of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a multifaceted, complex metabolic and endocrine disease where gut flora is considered an important factor in causing PCOS. This study aimed to identify a suitable PCOS model that contributes to gut microbial dysbiosis and metabolic and hormonal disturbances. Prepubertal SD rats were administered with normal control (NC), dihydrotestosterone (DHT), DHT with fructose (F), DHT+ high fat diet (HFD) for 91&#x2009;days, dehydroepiandrosterone (DHEA), DHEA with fructose, DHEA with HFD for 30&#x2009;days, sodium valproate (SV), sodium valproate with fructose, and sodium valproate with HFD for 21&#x2009;days. The estrous cycles were assessed over this timeframe. At the end of the experiment, superoxide dismutase and uterine and ovarian morphology were evaluated, along with hormone levels, lipid profiles, and 16S rRNA genomic sequencing. All models exhibited PCOS characteristics, including hormonal imbalances, insulin resistance (p&#x2009;&#x2264;&#x2009;.001), multiple follicular cysts on ultrasonography, and histological alterations. Gut microbial dysbiosis was observed across all PCOS-induced groups; however, the DHT alone group showed more pronounced alterations in microbial composition than the other experimental groups. Specifically, the DHT alone group exhibited reduced abundance of Firmicutes and increased abundance of Proteobacteria. Among the evaluated models, the DHT-only model showed more pronounced metabolic, hormonal, reproductive, and gut microbial alterations and may serve as a suitable model for PCOS research.

Animals