Fatty Acid Metabolism Research Articles

Identifying fatty acid metabolism (FAM)-related molecular signatures to construct a prognostic model for multiple myeloma (MM) patients. Transcriptomic profiles and clinical data from MM patients were retrieved from GEO and MMRF databases. FAM-related genes were screened by WGCNA, and one-way cox analysis was performed to identify genes associated with survival. LASSO regression analysis was then performed to construct FAM-related gene characteristics and risk scores. A clinical nomogram incorporating risk scores was developed. Immune microenvironment analysis (CIBERSORT) and functional enrichment (GO/KEGG/GSVA) were performed to characterize risk groups. Quantitative PCR validated hub gene expression in bone marrow mononuclear cells (BMMCs) from 10 newly diagnosed MM patients and 10 healthy donors. In vitro functional assays (CCK-8 proliferation, flow cytometry cell cycle analysis) assessed the impact of CCNA2/KIF11/NUSAP1 knockdown in MM cell lines. We identified 37 prognostic FAM-related genes (FMGs). Among them, 16 genes were used to construct LASSO regression models. KM analysis showed that high-risk patients had poorer prognosis (training set: P < 0.001; test set: P < 0.05). The area under the ROC curve was 0.787. Immunoscape analysis showed that high-risk patients had an immunosuppressive microenvironment. Functional enrichment studies confirmed that high-risk patients had increased abnormalities in cell cycle, aging and metabolic processes. The qRT-PCR analysis revealed CCNA2, KIF11, and NUSAP1 up-regulated in MM patients. CCNA2, KIF11, and NUSAP1 knockdown significantly caused cell cycle arrest and decreased proliferation ability of MM cells. We identified 37 survival-associated FMGs in MM patients, and verified the effects of CCNA2, KIF11, and NUSAP1 on the cell cycle and proliferation of MM cells. Our results also suggest that survival-associated traits based on these genes are potentially robust prognostic biomarkers for MM patients.

Coronary microvascular disease (CMD) is an early complication of type 2 diabetes (T2D) involving adverse endothelial and smooth muscle function, vascular remodeling, and alterations in mechanics. These culminate in impaired coronary blood flow. To interrogate transcriptional differences potentially contributing to CMD, we tested the hypothesis that comprehensive single-cell and spatial transcriptomic profiling of the coronary microcirculation and surrounding myocardium will identify new pathways to target in CMD. We utilized an innovative combination of single-cell RNA profiling and spatial transcriptomics to examine transcriptional differences and molecular signatures of CMD in T2D mice. Single-cell RNA profiling and spatial transcriptomics revealed an upregulation of genes linked to adipogenesis, fatty acid metabolism, and oxidative phosphorylation in T2D cell clusters and coronary microvascular-enriched regions. In ECs, VSMCs, cardiomyocyte clusters, fibroblasts, and macrophages, the upregulation of adipogenesis was directed by Angplt4 and Ephx2, whereas Hmgcs2 and Acot2 were the key players in the upregulation of fatty acid metabolism, and Pdk4 and Ech1 were the drivers of oxidative phosphorylation upregulation. These intriguing data support the well-documented concept that cardiac metabolic inflexibility in T2D heart failure-characterized by reduced mitochondrial function, increased reliance on fatty acid oxidation, and impaired glucose utilization-contributes to oxidative stress and lipotoxicity. Our data unveiled novel and unique gene expression signatures of coronary microvessels in the presence and absence of diabetes.

Major depressive disorder (MDD), a leading global public health concern, exhibits high comorbidity with overweight/obesity. While emerging evidence implicates shared gut microbial dysregulation in both conditions, the identification of specific microbial biomarkers and their interaction with metabolic pathways in comorbid MDD-obesity remains poorly characterized. Our study investigated gut microbiota signatures in patients with MDD, and evaluated their modulation by overweight/obesity comorbidity. A total of 53 patients with MDD and 92 healthy controls (HCs) underwent 16S rRNA gene sequencing. The KEGG function analysis was performed with potential differential microbiota. Correlation analysis related to bacterial taxa, biochemical parameters, and clinical indexes was aimed to indicate the specific metabolic dysregulation and gut microbiota imbalance in MDD, and whether these biomarkers were affected by the comorbidity of overweight/obesity. Sixty-three bacterial genera showed differential abundance between MDD and HCs. Notably, Succinivibrio, Megamonas, and Bifidobacterium demonstrate significant distinctions between overweight-MDD and normal weight-MDD. The significantly altered metabolic pathways between MDD and HC primarily involve the biosynthesis and metabolism of long-chain unsaturated fatty acids. Within the MDD group, BMI demonstrated pairwise negative correlations with Bifidobacterium and total bilirubin (TBIL), while positively associating with Fusobacterium and alanine transaminase (ALT). This study provides novel insights into the interplay between gut microbiota dysbiosis and metabolic perturbations in MDD. Despite intriguing associations between BMI and specific microbial taxa within the MDD group, the preliminary nature of these associations necessitates validation through larger cohorts, multi-omics approaches, and longitudinal designs.

Metabolic-associated fatty liver disease (MAFLD), characterized by excessive hepatic lipid deposition, poses a global health threat, increasing the risk of severe liver complications. Here, we optimized a fast in-tube microscale ubiquitylomics strategy (abbreviated as FIT-MUbi, requiring less than 10 mg of liver tissue samples) and identified over 7384 ubiquitinated peptides, constructing a dysregulated ubiquitination network in the MAFLD model. Through bioinformatics analyses, ubiquitinated proteins were significantly enriched in lipid metabolism, particularly in the fatty acid metabolism pathway. Compared with global proteomics analysis alone, this ubiquitylomics approach better captures the typical features of lipid-metabolic dysregulation in the MAFLD model. Protein-protein interaction analysis revealed the fatty acid synthase (FASN) as a key regulator in fatty acid metabolism, showing an elevated protein level and ubiquitination with MS data, which was further confirmed by Western blot analysis. Notably, the PKS/mFAS DH domain of the FASN protein exhibits a substantially higher ubiquitination density (55.6%). By comparison, the overall ubiquitination density of the entire FASN protein is 28%, while that of its ketosynthase family 3 (KS3) domain is even lower, at only 25%. Precisely, we identified K967 as a potential function site regulating FASN stabilization and activity, suggesting that the impaired ubiquitination signal might drive its paradoxical accumulation. Our study explored the application of microscale ubiquitylomics in MAFLD research, unveiling ubiquitination-dependent protein stabilization as a novel regulatory axis. These findings provide mechanistic insights for developing targeted diagnostic and therapeutic strategies to combat MAFLD progression.

One of the most common and extensively disseminated endocrine disrupting chemicals (EDCs) is perfluorotridecanoic acid (PFTrDA), which is used extensively in food packaging and has been linked to the development of metabolic disorders. Human health and food safety are intimately intertwined. Thus, as exemplary hepatic metabolic diseases, we selected liver cancer and nonalcoholic fatty liver disease (NAFLD). By employing advanced network toxicology and molecular docking techniques, we have discovered potential molecular pathways underlying these two diseases. We pinpointed the potential targets associated with the disease by leveraging databases including PubChem, ADEMTlab3.0, Swiss Target Prediction, OMIM, and GeneCards. To identify the primary targets that were most closely connected to these metabolic disorders, we also used Cytoscape software and STRING analysis. Furthermore, the David database's Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were used to perform enrichment analysis of these key targets. Lastly, we used AutoDock Vina molecular docking to confirm PFTrDA's binding affinity to these target proteins. Our results imply that PFTrDA may regulate fatty acid metabolism and impact signal transduction pathways, which may lead to the onset of metabolic disorders. It's interesting that we also discovered links between liver cancer and NAFLD. In summary, this study offers a theoretical foundation for comprehending the molecular mechanisms behind PFTrDA toxicity and lays forth a basic theoretical framework for the creation of therapeutic and preventative approaches for hepatic metabolic disorders linked to PFTrDA.

Iron accumulation and ferroptosis occur in the brain following ischemic stroke. However, the relationship between iron overload and cell type-specific fates remains largely unclear. Here, iron deposition and neuronal loss are reported within the perilesional cortex of three patients with ischemic stroke at both acute and subacute stages. It is identified that ischemia/reperfusion-induced iron overload triggers ferroptosis predominantly in neurons and to a lesser extent in astrocytes, whereas most astrocytes undergo reactive proliferation. Mechanistically, the reduced or elevated Nrf2/GPX4 and SLC7A11 levels in neurons or astrocytes, respectively, account for these distinct iron overload-induced cellular fates. Moreover, iron overload promotes astrogliosis by enhancing the transcriptional activities of several proliferation-related genes. Using mice with partial knockout of the transferrin receptor 1 (TfR1) gene Tfrc, astrocyte-specific Tfrc knockdown, and conditional astrocytic Cpt1a partial knockout (to induce fatty acid metabolism disorders), it is revealed that increased TfR1 palmitoylation and clathrin-mediated endocytosis drive astrocytic iron overload. Notably, ischemia/reperfusion-induced elevation of palmitic acid is associated with enhanced TfR1 palmitoylation. Treatment with antioxidants or iron chelators mitigates ischemic brain injury. Together, these findings provide a comprehensive framework linking ischemia/reperfusion-induced iron overload to cell type-specific fates. TfR1 palmitoylation emerges as a potential target for ischemic stroke therapy.

Demyelination associated microglia (DMAM) orchestrate the regenerative response to demyelination by clearing myelin debris and promoting oligodendrocyte maturation. Peroxisomal metabolism has emerged as a candidate regulator of DMAMs, though the cell-intrinsic contribution in microglia remains undefined. Here we elucidate the role of peroxisome integrity in DMAMs using cuprizone mediated demyelination coupled with conditional knockout of peroxisome biogenesis factor 5 (PEX5) in microglia. Absent demyelination, PEX5 conditional knockout (PEX5cKO) had minimal impact on homeostatic microglia. However, during cuprizone-induced demyelination, the emergence of DMAMs unmasked a critical requirement for peroxisome integrity. At peak demyelination, PEX5cKO DMAMs exhibited increased lipid droplet burden and reduced lipophagy suggestive of impaired lipid catabolism. Although lipid droplet burden declined during the remyelination phase, PEX5cKO DMAMs accumulated intralysosomal crystals and curvilinear profiles, which features were largely absent in controls. Aberrant lipid processing was accompanied by elevated lysosomal damage markers and downregulation of the lipid exporter gene Apoe, consistent with defective lipid clearance. Furthermore, the disruptions in PEX5cKO DMAMs were associated with defective myelin debris clearance and impaired remyelination. Together, these findings delineate a stage-specific role for peroxisomes in coordinating lipid processing pathways essential to DMAM function and necessary for enabling a pro-remyelinating environment.

Non-alcoholic fatty liver disease (NAFLD), recently reclassified as metabolic dysfunction-associated fatty liver disease (MAFLD), is closely linked to mitochondrial dysfunction and impaired lipid metabolism. Bifidobacterium bifidum has emerged as a promising probiotic candidate for restoring metabolic balance, yet its mitochondrial-targeted mechanisms remain underexplored. This study investigates the role of B. bifidum in modulating hepatic mitochondrial β-oxidation pathways and key transcriptional regulators involved in fatty acid metabolism. MAFLD was induced in male Sprague-Dawley rats using a high-fat diet and streptozotocin (STZ). Following disease induction, B. bifidum was administered over two treatment durations (6 and 14 weeks). Liver function tests, lipid profiles, and stereological analyses were performed, and hepatic gene expression of UCP2, CPT1A, PGC-1α, PPAR-α, and PPAR-γ was evaluated using quantitative RT-PCR. B. bifidum treatment significantly reduced serum triglycerides, total cholesterol, and LDL-C levels, while showing a non-significant upward trend in HDL-C levels. Gene expression analysis revealed that B. bifidum restored downregulated PGC-1α, CPT1A, and PPAR-α expression and normalized elevated UCP2 and PPAR-γ levels, suggesting enhanced mitochondrial fatty acid oxidation. Histological and stereological assessments confirmed structural improvements in liver tissue, including reduced steatosis and improved hepatocyte morphology. These findings provide new mechanistic evidence that B. bifidum exerts hepatoprotective effects by reprogramming mitochondrial lipid metabolism through the PPAR-α/PGC-1α/CPT1A axis. This probiotic may offer a novel, mitochondria-targeted therapeutic strategy for managing MAFLD and related metabolic disorders. Further studies are warranted to evaluate strain-specific effects and long-term outcomes in clinical settings.

Tumor cells reprogram their fatty acid metabolism to meet the demands for their rapid proliferation. However, the interplay between fatty acid metabolism and the tumor microenvironment (TME) in lung cancer remains poorly defined. This study aims to elucidate how arachidonic acid (AA) metabolism, specifically via the enzyme 5-lipoxygenase (ALOX5), modulates anti-tumor immunity in non-small cell lung cancer (NSCLC). Data from public transcriptomic datasets were analyzed to identify differentially expressed and immune regulatory fatty acid metabolism-related genes in NSCLC. Spatial correlation between ALOX5 expression and CD8⁺ T cell infiltration was assessed via immunofluorescence. Functional impacts of ALOX5 on tumor growth, immune recruitment, and immunotherapy response were characterized using knockdown and overexpression models. Clinical relevance was evaluated by profiling plasma fatty acids via mass spectrometry in immunotherapy-treated cohorts. Bioinformatic analysis nominated ALOX5-mediatedAA metabolic pathway as a key regulator of immune infiltration. Genetic knockdown of ALOX5 accelerated tumor progression, attenuated CD8⁺ T cell recruitment, and reduced leukotriene B4 (LTB4) production alongside downregulation of cytotoxic (granzymes) and chemotactic genes. Conversely, ALOX5 overexpression suppressed tumor growth and synergized with anti-PD-1 therapy. Exogenous AA supplementation similarly potentiated the efficacy of PD-1 blockade in vivo. Clinically, elevated plasma levels of AA and linoleic acid correlated with improved immunotherapy response and survival outcomes. Tumor-intrinsic ALOX5 is a novel tumor suppressor that orchestrates CD8⁺ T infiltration via the AA-LTB4 axis in NSCLC. Our findings establish ALOX5-mediated AA metabolism as a therapeutically targetable pathway to overcome immunotherapy resistance, positioning dietary AA supplementation as a promising adjunctive strategy. Not applicable.

Traditional anticoagulants used in atrial fibrillation (AF) are being increasingly replaced by novel oral anticoagulants such as rivaroxaban, improving patient outcomes. Although rivaroxaban 20 mg/1× daily is approved to reduce stroke and systemic embolism risk in AF, some patients still develop thrombus in the left atrial appendage (LAA). A previous study demonstrated thrombus lysis with a modified regimen of rivaroxaban 15 mg/2× daily, yet over 50% of patients remained unresponsive despite therapeutic plasma levels. This study compared metabolic profiles of responders and non-responders to identify predictive markers of treatment efficacy. From the RIVA-TWICE study cohort (n = 249), 15 AF patients with LAA thrombus despite standard dosing were switched to 2 × 15 mg rivaroxaban. Plasma samples collected prior to dose modification underwent untargeted and targeted LC-MS analysis, focusing on acylcarnitines (ACs), carnitine, and its precursors. Thrombus resolution occurred in 7 (46.7%) patients, who showed differential abundance of metabolites related to alpha-linolenic acid and fatty acid metabolism, carnitine synthesis, and arginine/proline pathways. Targeted analysis confirmed elevated levels of ACs, carnitine, and precursors. Findings suggest that a patient phenotype, including carnitine, its precursors, and ACs, may predict rivaroxaban efficacy in thrombus lysis. While these metabolites may not directly mediate lysis, their elevated levels represent potential biomarkers of treatment response.

New Zealand abalone (Haliotis iris) holds ecological, economic, and cultural value, with wild stocks supporting fisheries and an emerging aquaculture industry. Wild-caught adult abalone are often used as broodstock, but captivity can affect spawning and offspring quality. This study is the first to profile wild and farmed H. iris broodstock using histology, proximate composition, microbiome, and metabolomics analyses. Histology showed higher gonadal abnormalities in farmed abalone, while wild abalone exhibited increased ciliates in their gills, indicating richer marine–microorganism interactions. Microbiome analyses revealed a higher microbial richness and diversity in the buccal cavity of wild abalone. The core microbiota phyla across both groups included Proteobacteria, Bacteroidota, Campylobacterota, Fusobacteria, and Firmicutes. Proximate analyses showed higher muscle protein in farmed abalone, while gonadal tissue partitioned by sex showed higher fat in females and higher protein in males. Metabolomics revealed altered amino acid metabolism in the adductor muscle, carboxylic acid metabolism in the gonad, and fatty acid metabolism in the foot. This investigation expands our understanding of the physiological and microbial differences between wild and farmed abalone, showing altered gonad and muscle conditions from prolonged captivity and highlighting the need for greater microbial diversity in cultured stocks.

BackgroundSporisorium scitamineum is the causal agent of sugarcane smut, affecting global sugarcane production. Despite advances in smut genomics, the relationships between fungal genetic diversity, host adaptation, and virulence remain elusive.MethodsWe applied chromosome-level genome sequencing (Oxford Nanopore and Illumina technologies) of two haploid strains (MAT-1 x MAT-2) per isolate and high-depth transcriptomic profiling (Illumina) during early infection (48 hpi) of a more virulent isolate (SSC04) in resistant (SP80-3280) and susceptible (IAC66-6) sugarcane genotypes.ResultsDespite the overall genomic similarity (99.9%), we identified nine highly polymorphic genomic islands (HPIs). The most variant HPI harbors the mating-type loci, where dense sequence variation, intrachromosomal rearrangements, and inversions, potentially linked to transposable element remnants, were observed. Additionally, the genome-wide analysis revealed non-synonymous single-nucleotide variants (SNVs) in 160 genes, including those involved in vesicular trafficking and candidate-secreted effectors. Transcriptomic profiling of the more virulent isolated revealed host-dependent transcriptional reprogramming in response to immune and metabolic cues, driving distinct infection strategies: in resistant plants, the fungus upregulated genes associated with detoxification, nitrogen starvation responses, and cell wall-degrading enzymes, while in susceptible hosts, it induced genes related to hyphal growth, lipid catabolism, and the unfolded protein response. The repertoire of expressed candidate effector genes also varied according to host and isolate genotypes.ConclusionsThese findings uncover genomic signatures and context-dependent transcriptional regulation shaping the adaptive landscape of S. scitamineum virulence, identifying targets for pathogen monitoring and breeding for resistance.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12864-025-12160-1.

Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid essential for human health, is primarily produced at scale using Schizochytrium sp. Mutagenesis-based strain improvement has increased DHA yields, but the genetic and metabolic mechanisms underlying high productivity remain poorly understood. Here, we conducted the comparative whole-genome sequencing and transcriptomic profiling of a high-DHA-yielding mutant strain (HS01) and its parental strain (GS00). The GS00 genome assembly spans 62.4 Mb and encodes 14,886 predicted genes. Functional annotation highlighted pathways involved in central metabolism, saturated fatty acid (SFA) synthesis, and polyunsaturated fatty acid (PUFA)/DHA biosynthesis. Comparative genomics identified 40 insertions/deletions and 396 single-nucleotide polymorphisms between HS01 and GS00, including mutations in the coding and regulatory regions of key metabolic genes. Transcriptomic analysis revealed extensive metabolic reprogramming in HS01, including the upregulation of glycolysis and tricarboxylic acid (TCA) cycle genes, along with a distinct fatty acid profile and the altered expression of fatty acid metabolism genes compared with GS00. Collectively, the integrated genomic and transcriptomic analyses not only pinpointed specific mutations potentially associated with the HS01 high-DHA phenotype but also revealed substantial transcriptional and metabolic remodeling, providing valuable insights into the mechanisms that drive enhanced DHA biosynthesis.

Background: Lipid metabolism plays a crucial role in in cardiovascular disease pathophysiology. Lipin1 is a key regulator of lipid metabolism. In the nucleus, lipin1 acts as a transcriptional coactivator, interacting with PGC1α and PPARα. In the cytoplasm, it functions as a phosphatidate phosphatase, converting phosphatidic acid to diacylglycerol. Low expression of Lipin1 has been implicated in the severity of cardiac dysfunction in mice. Hypothesis: We hypothesized that Lipin1 protects against myocardial ischemic injury by regulating lipid homeostasis in cardiomyocytes, thereby attenuating adverse remodeling, inflammation, and oxidative stress following infarction. Aims: To investigate the role of Lipin1 in cardiac remodeling after myocardial infarction (MI), revealing its impact on lipid metabolism and molecular pathway associated with cardiac dysfunction. Methods: Cardiomyocyte-specific Lipin1 knockout (cKO) and overexpression (cOE) mice were used. Eight to ten-week-old male mice were subjected to MI by coronary artery ligation. One week after MI, cardiac lipid droplet (LD) density, levels of triacylglycerol and free fatty acids were quantified. Four weeks after MI, echocardiographic assessments, heart weight (HW)/ body weight (BW) ratio were recorded. Histological and gene expression analyses were performed to evaluate cardiac fibrosis, inflammation, oxidative stress, and fatty acid metabolism. Results: Before MI surgery, there were no differences in HW/BW ratio, left ventricular end-diastolic diameter (LVDd) or LV fractional area change (LVFAC) among cKO/ cOE mice and their littermate controls. After MI, cKO mice exhibited significant cardiac dysfunction with enlarged LVDd, reduced LVFAC and increased HW/BW ratio. These changes were accompanied by increased cardiac fibrosis, inflammation, and reactive oxygen species compared with their controls. Conversely, cOE mice showed improved LVFAC, reduced cardiac fibrosis, inflammation, and oxidative stress. Notably, after MI surgery, cKO mice showed a reduction in cardiac LDs with decreased levels of triacylglycerol and free fatty acids compared to the littermate controls. In contrast, cOE mice displayed increased cardiac LDs and upregulated expression of fatty acid metabolism–related genes after MI. Conclusion: These findings demonstrate that Lipin1 protects ischemic cardiomyocytes by regulating lipid metabolism, highlighting its potential as a therapeutic target for MI.

Background: Exercise improves cardiac health and lowers cardiovascular disease (CVD) risk, yet its protective molecular mechanisms remain incompletely understood. The Molecular Transducers of Physical Activity Consortium (MoTrPAC) provides a multi-omic atlas of endurance exercise responses in rat tissues. We performed a sex- and time-resolved integration of heart data to identify key adaptations and their relevance to CVD prevention. Methods: We applied MEFISTO, a time-aware extension of Multi-Omics Factor Analysis (MOFA2), to integrate longitudinal MoTrPAC multi-omics data—including transcriptomics, epigenomics, proteomics, post-translational modifications, and metabolomics—collected across 1 to 8 weeks of endurance training in male and female rats. Latent factors, which summarize multi-omics features covariation, were used to identify sex-specific molecular responses to endurance exercise. These factors were compared to public CVD datasets to assess shared and divergent molecular signatures. Results: We identified six latent factors spanning at least three omics layers, including four associated with endurance training. Factors 3, 4, and 5 reflected early, sex-specific adaptations involving energy and fatty acid metabolism. Particularly, Factor 1 captured a progressive, sex-shared signature, strongly correlated with VO2max (r &gt; 0.8, p &lt; 1e–6; Figure 1). This factor reflected a shift from acute metabolic responses to long-term remodeling, with upregulation of ATP metabolism, cardiac morphogenesis, and contractility pathways, supported by epigenetic and post-translational regulation (Figure 2). These findings suggest that endurance exercise enhances mitochondrial efficiency and promotes cardiac tissue maturation. Comparison with human CVD signatures revealed significant inverse enrichment in ischemic heart disease (p &lt; 2e–10), heart failure (p &lt; 2e–3), and cardiac hypertrophy (p &lt; 6e–4). Genes associated with Factor 1 and inversely linked to CVD signatures were enriched for reduced T cell immunity and increased extracellular matrix organization, highlighting a coordinated immunomodulatory and structural adaptation. Conclusion: Endurance exercise drives sustained molecular remodeling, shifting from early metabolic activation to enhanced mitochondrial efficiency, epigenetic regulation, and cardiac development. Its inverse association with CVD signatures highlights exercise’s protective role through immune modulation and structural remodeling of the heart.

Background: Selexipag is an established oral therapy for pulmonary arterial hypertension (PAH). In some patients, it enables withdrawal from continuous prostacyclin infusion. However, the mechanisms underlying inter-individual differences in treatment response remain unclear. Objective: To identify clinical and molecular determinants associated with selexipag responsiveness in patients with PAH. Methods: We evaluated 21 patients aged ≥16 years with PAH who received selexipag at Hokkaido University Hospital between 2021 and 2024. Patients who had undergone lung transplantation, were on hemodialysis, or initiated selexipag concurrently with other vasodilators were excluded; 15 patients remained eligible. Clinical data—including NYHA class, right heart catheterization, 6-minute walk distance, cardiac MRI, and echocardiography—were collected before and after treatment. Based on composite improvement in these measures, patients were classified into responder (n = 8) and non-responder (n = 7) groups. Whole-exome sequencing and plasma metabolomics profiling (CE-TOFMS and LC-TOFMS) were conducted, targeting 281 ionic and 189 lipid metabolites. Statistical analyses included t-tests, chi-square tests, and Fisher’s exact tests (p &lt; 0.05). For metabolite comparisons, Wilcoxon rank sum tests were performed, and p-values were adjusted using the Benjamini–Hochberg method to control the false discovery rate (adjusted p &lt; 0.1). This study was approved by the institutional ethics committee (No. 023-0073). Results: A pathogenic ACVRL1 variant was identified in one non-responder. Rare variants in PTGIS (n = 1) and RNF213 (n = 2) were found in non-responders, and one RNF213 variant was found in a responder. Acylcarnitine levels were significantly higher in responders than in non-responders (adjusted p = 0.088). The rs1799821 AA genotype in CPT2 was significantly more frequent in responders (p = 0.003). Upstream metabolic pathway analysis revealed downregulation of ATP citrate lyase (p = 0.004) and fatty acid synthase (p = 0.026), and upregulation of CPT1C (p = 0.005) in responders. Conclusion: The rs1799821 AA genotype in CPT2 may contribute to impaired mitochondrial fatty acid oxidation and suppressed endogenous prostacyclin production, potentially leading to increased responsiveness to selexipag. Altered expression of ATP citrate lyase, fatty acid synthase, and CPT1C may further affect lipid metabolism and contribute to inter-individual variability in treatment response.

Background: Exhaled volatile organic compounds (VOCs) can provide insight into various physiological and metabolic processes. Aim: The purpose of this study was to determine if exhaled VOCs would differ across disease severity in heart failure (HF) patients. Methods: We recruited 62 individuals who were classified as healthy control (CTL), admissions with fluid overload (DHF), NYHA class I-II or NYHA class II-III. Breath samples were collected using the ReCIVA Breath Sampler (Owlstone Medical Ltd) and analyzed using mass spectrometry and gas chromatography. Typical clinical characteristics were documented at the time of exhaled breath collection. Results: Data were obtained on 16 CTL, 21 DHF, 15 NYHA I-II and 10 NYHA II-III (characteristics shown in Table). For the HF groups, DHF, NYHA I-II and NYHA II-III, the %HPEFF were 32, 63 and 63% respectively. Regarding exhaled VOCs, we observed a stepwise increase in VOCs potentially linked to lipid peroxidation or fatty acid metabolism, such as pent-3-en-2-one, 2-pentanone, and 4-heptanone, as disease severity worsened. A similar trend was seen for sulphur containing compounds (methyl propyl sulfide, allyl methyl sulfide and 1(methyl thiol)-1 propene)), potentially providing insight into impaired hepatic or renal clearance in more advanced HF. The level of methyl pyruvate on breath also rose with increasing disease severity, which may reflect altered energy metabolism. Finally, gut microbiome-related VOCs (acetoin, 2,3-butanediol, and butyric anhydride) increased across severity groups, potentially reflecting dysbiosis in advanced disease. Conclusions: In a small pilot study aiming to identify potential exhaled breath biomarkers in HF, we observed significant differences in VOCs across disease severity. These compounds have been linked to lipid peroxidation, energy metabolism, liver and kidney function as well as microbial fermentation and short-chain fatty acid metabolism. Collectively, these data demonstrate the ability of breath omics to potentially stratify disease severity and provide additional biological insights into HF pathophysiology. Larger studies are needed to determine whether a breath biomarker panel could be established to quantify disease severity and predict decompensation risk in HF.

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing globally due to rising obesity and metabolic syndrome. MASLD can progress to MASH, cirrhosis, and liver cancer, and shares causes with cardiovascular disease. Recent studies have demonstrated that ketone bodies have diverse protective effects, including roles in energy metabolism, antioxidant function, and signal transduction. However, it remains unclear whether ketone bodies have a protective role in fatty liver disease. Aim To clarify the role of ketogenesis in MASLD and examine the therapeutic effect and mechanism of Pemafibrate (PEMA). Method/Result Wild-type mice were fed normal diet ( ND ) and Gubra Amylin NASH (GAN) diet with water containing Nω-Nitro-L-arginine Methyl Ester Hydrochloride (L-NAME)[ MASLD ] for 10 weeks. MASLD groups showed significantly elevated body weight and systolic blood pressure compared to ND group. The liver in MASLD showed increased weight and a more yellowish-brown color. Hepatocyte-specific Hmgcs2 deficient mice (Alb-cre;Hmgcs2 flox/flox ; Hmgcs2 ΔHEP ) and control mice ( Hmgcs2 flox/flox ; Ctrl) were fed ND or MASLD , accessing the effectiveness of PEMA and the impacts of ketogenesis on MASLD. Liver tissues were stained with HE and Sirius red. Hmgcs2 ΔHEP showed more fatty deposits in the liver compared to Ctrl. Serum samples were collected for biochemical tests. PEMA administration showed no notable improvement in hepatobiliary enzymes and triglycerides (TG). Furthermore, RNA-seq analysis revealed that PEMA-treated Ctrl significantly increased expression of genes involved in fatty acid metabolism and oxidative phosphorylation, such as Aldh2 , ACAA2 and Sdha . These results indicated that PEMA might have therapeutic effects on MASLD, mediating ketogenesis. In vitro experiments, using primary hepatocytes of mice, Real-time PCR analysis indicated the results similar to RNA-seq in vivo, with upregulation of gene expression related to fatty acid metabolism and oxidative phosphorylation. Conclusion: Ketone body metabolism plays a crucial role in the progression of MASLD, and its impairment may lead to worsening hepatic steatosis. Moreover, the beneficial effects of PEMA on fatty liver appear to require intact ketone metabolism, suggesting that individual differences in therapeutic response may be influenced by metabolic status. These findings highlight the potential of ketone body metabolism as a novel therapeutic target for MASLD.

Background: Despite the achievements of genome-wide association studies (GWAS), the genetic mechanisms that predispose individuals to type 2 diabetes (T2D) and its cardiovascular (CV) complications remain poorly understood. The prevalence of T2D is three to six times higher among South Asian Indians compared to Europeans. High-throughput metabolite profiling techniques have advanced rapidly, evolving from focusing on single-gene/single-metabolite associations to a genome-wide/metabolome-wide approach. However, data is limited on non-white populations. We conducted an integrated genome-wide lipidomic analysis and Mendelian randomization (MR) to identify gene variants associated with lipid metabolites and determine the causal relationships between circulating lipid species and T2D, as well as CV risk factors, using a discovery cohort of Asian Indian Diabetic Heart Study (AIDHS) (3871) and validation cohorts comprising over 1.14 million European and South Asian Individuals from multiple independent studies. Methods: Untargeted lipidomic analysis was performed on blood samples of AIDHS individuals using liquid chromatography and high-resolution mass spectrometry (LC-MS/MS). We analyzed the association of 269 metabolites with T2D and CVD by conducting a metabolome-GWAS using genotyped and imputed data from 20,006,524 variants in discovery and replication cohorts. Results: Our study identified 261 SNP-metabolite associations of genome-wide significance, of which 59 association signals (p ranging from 8.4×10 −8 to 1.8×10 -18 ) were from genes involved in atherosclerosis, fatty acid biosynthesis, inflammation, insulin signaling, and apoptosis pathways. Two-sample MR and sensitivity analysis using independent of 1,141,060 individuals from European and South Asian populations from the UK Biobank, DIAGRAM, DIAMANT, and Australia, identified species of fatty acids, PC, and LPCs contributing to increased or decreased risk for T2D and CVD. Conclusion: In this first metabolome-GWAS in Asian Indians, we report new mQTLs beyond FADS1/2 associated with lipid subclasses not reported previously. MR analysis in independent datasets identified new molecular signatures of circulating lipid and fatty acid metabolism that are causally associated with inflammation and vascular ischemic disease in dysregulated insulin metabolism and T2D. Funding: The AIDHS study was supported by NIH grants R01DK082766 and R01DK118427 (NIDDK) and grants from the Presbyterian Health Foundation of Oklahoma.

Introduction: Excess lipolysis and dysregulated fatty acid oxidation can exacerbate neuroglial injury and impair neurodevelopment. Neurodevelopment is also regulated by histone deacetylation and methylation, which often repress gene transcription and can alter cerebral metabolism. It is unknown if fatty acid metabolism and histone modifications are altered in the neonatal brain following cardiopulmonary bypass (CPB). Research Question: This study sought to determine if histone modifications regulating chromatin accessibility and gene transcription are altered in the brain or associated with changes in cerebral metabolism at 12-24hrs post-CPB. Methods: Fifteen neonatal swine underwent 3hrs of CPB prior to decannulation and survival for 12hrs, 18hrs, or 24hrs (N=5 per cohort). Three additional piglets underwent similar sham procedures with 4hr survival. Cortical brain tissue was then analyzed with liquid chromatography-mass spectrometry using an untargeted approach to quantify 129 metabolites and 45 histone modifications in each sample. Histone modifications with a statistically significant fold-change (FC) post-CPB ( P &lt;0.0001) were correlated with metabolites across all timepoints of analysis. Results: In total, 6/45 (13%) histone modifications were significantly altered in cortical brain tissue following CPB. The acetylation of histone H4 on lysine residue 16 (H4K16ac) was reduced at 12-24hrs post-CPB (FC=0.7-0.8, P &lt;0.0001 ), while trimethylation was enriched on histone H4 at lysine residue 20 (H4K20me3: FC=1.5-2.4; Figure ). H4K20me3 enrichment directly correlated with intermediates of fatty acid metabolism, specifically polyunsaturated long-chain acylcarnitines ( Table ). Histone H3 variants had enriched mono-methylation on lysine 36 residues at 12hrs (H33K36me1: FC=6.9, P &lt;0.0001 ) and 18hrs post-CPB (H31K36me1: FC=1.6, P &lt;0.0001 ). Histone H3 mono-methylation was also enriched on lysine residue 23 (H3K23me1) at 18hrs post-CPB (FC=5.1, P &lt;0.0001 ), and phosphorylation on serine residue 10 (H3S10ph) was enriched at 24hrs post-CPB (FC=6.2, P &lt;0.0001 ). Conclusion: Dynamic changes in histone methylation and deacetylation post-CPB may impact metabolic homeostasis in the neonatal brain during critical periods of neurodevelopment. Further investigations are warranted to elucidate how alterations in lipolysis, fatty acid oxidation, chromatin accessibility, and gene transcription may affect myelination, neuroglial injury, and neurodevelopment in neonates requiring cardiac surgery.