Background: Metabolic dysfunction–associated steatotic liver disease (MASLD) is strongly associated with obesity. Sex and age affect MASLD prevalence and pathophysiology. The use of animal models fed Western-style diets is vital for investigating the molecular mechanisms contributing to metabolic dysregulation and for facilitating novel drug target identification. However, the sex-associated and age-associated mechanisms underlying the pathophysiology remain poorly understood. This knowledge gap limits the development of personalized sex-specific and age-specific drug treatments. Methods: Young (7 wk) and aged (52 wk) male and female mice were fed a high-fat diet (HFD) or low-fat diet. Liver metabolome (>600 molecules) and transcriptome profiles were analyzed. Results: Male and female mice fed an HFD developed obesity, glucose intolerance, and hepatic steatosis. However, fasting blood glucose, insulin, and serum alanine aminotransferase levels were higher in males fed an HFD, indicating a more severe metabolic disease. In addition, males showed significant increases in liver diacylglycerides and glycosylceramides (known mediators of insulin resistance and fibrosis), and more changes in the transcriptome: extracellular matrix organization and proinflammatory genes were elevated only in males. In contrast, no major increase in damaging lipid classes was observed in females fed an HFD. However, aging affected the liver to a greater extent in females. Acylcarnitine levels were significantly reduced, suggestive of changes in fatty acid oxidation, and broad changes in the transcriptome were observed, including reduced oxidative stress response gene expression and alterations in lipid partitioning genes. Conclusions: Here, we show distinct responses to an HFD between males and females. Our study underscores the need for using both sexes in drug target identification studies, and characterizing the molecular mechanisms contributing to the MASLD pathophysiology in aging animals. Export

Background: This study aimed to identify distinct metabolic signatures associated with disease progression by integrating high-resolution computed tomography (HRCT) visual scoring with comprehensive metabolomic profiling. Materials and Methods: This single-center, cross-sectional study enrolled 60 idiopathic pulmonary fibrosis/interstitial lung disease (IPF/ILD) patients with usual interstitial pneumonia pattern. Participants underwent standardized pulmonary function testing, HRCT imaging, and peripheral blood collection for metabolomic analysis using one-dimensional hydrogen nuclear magnetic resonance spectroscopy and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. Linear regression analysis integrated radiographic scores with metabolomic profiles, adjusted for multiple covariates. Results: Stable IPF/ILD exhibited moderate negative correlations between the six most significant metabolites and HRCT scores (r = −0.27 to −0.51), along with a high abundance of specific phospholipids (triacylglycerol, monoacylglycerol, phosphatidylglycerol, phosphatidylethanolamine, diacylglycerol), sphingomyelin, ceramide, and acylcarnitine. In contrast, progressive disease showed weak positive correlations between the six most significant metabolites and HRCT scores (r = 0.19–0.26), and moderate negative correlation between specific triacylglycerol species and HRCT scores (r = −0.37–0.4). Furthermore, metabolomic analysis in individuals with progressive disease revealed both high and low abundances of specific phospholipid species (including high and low triacylglycerol species, as well as low levels of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, and phosphatidylinositol), along with high levels of certain sphingomyelin, ceramide, taurine, and purine bases, and low levels of xanthine and lactic acid observed. Conclusions: Integration of systematic HRCT semi-quantitative scoring with metabolomic profiling successfully differentiated stable from progressive IPF/ILD through distinct molecular-radiographic signatures.

Background/Objectives: Metabolomics has emerged as a tool to gain insight into the body’s biological responses to therapeutic interventions. Bariatric surgery remains the most effective treatment for severe obesity and associated comorbidities, leading to significant weight and metabolic improvements. Using a multi-platform, multi-compartment metabolomics approach, this study systematically characterizes longitudinal changes in fecal and serum metabolomes of 45 patients following sleeve gastrectomy (SG). Participants were stratified by weight loss outcomes to identify metabolic signatures associated with differential responses, which may serve as predictors of weight loss and provide mechanistic insights in developing targeted therapeutic strategies. Methods: Metabolomic and lipidomic responses to SG were analyzed using multivariable linear mixed-effects models based on data collected pre-operatively and at 3 and 12 months post-operatively. Results: The percentage total weight loss for the highest versus lowest weight loss tertiles (T₃ vs. T₁) at twelve months was 35.81 + 5.4% and 19.49 + 2.62%, p < 0.001, respectively. Substantial alterations in fecal metabolites and lipid species were observed among T3 after twelve months, including aspartate, tyrosine, carnitine, glycine, PC.ae.C36.4, PC.aa.C38.0, PC.ae.C44.4, PC.ae.C40.2, and PC.aa.C40:5. Specifically, changes in serum lipid species including SM.OH.C22:1, PC.ae.C32:1, PC.aa.C34:4, PC.aa.C36:6, PC.ae.C34:3, PC.ae.C34:1, and PC.ae.C32:2, support serum lipidomics as a minimally invasive marker of gut remodeling and adaptation following SG. Sex-stratified analysis revealed unique fecal and serum metabolic changes, highlighting the significance of personalized metabolic monitoring and obesity treatment. Conclusions: Our findings identify metabolic alterations associated with response variability following SG and highlight the potential utility of machine learning to predict weight-loss trajectories and inform personalized interventions.

Background: In cattle, the second week after estrus encompasses critical changes in uterine function. The endometrium will either prepare for the release of luteolytic pulses of prostaglandin-F2 alpha or for the support of an eventual pregnancy. We hypothesized that concentrations of amino acids and lipids in the uterine luminal fluid (ULF), and the gene expression in luminal epithelial cells (LE), change across the second week of the estrous cycle. The objective was to compare amino acid and lipid concentrations in ULF and target gene expression in LE 7 (D7), 10 and 14 d after estrus. The ULF and LE samples were collected from the uterine body of five primiparous, non-lactating, cyclic Bos indicus -influenced crossbred cows using a cytological brush on each day after synchronized estrus. Targeted metabolomics of ULF was performed using mass spectrometry, and gene expression in LE was assessed using RNA sequencing. Data were analyzed by uni- and multivariate statistics. Results: Multivariate analyses separated D7, D10, and D14, with amino acid metabolism and lipid biosynthesis as enriched pathways. Luminal concentrations of amino acids (e.g., arginine, histidine) and lipids (e.g., CE(17:1), PC aa C34:1) increased from D7 to D10, but from D10 to D14 concentrations of amino acids (e.g., glutamine, glutamic acid) decreased while that of lipids (e.g., CE(18:2), SM C16:0) continued to increase. Transcriptomic profiling revealed temporal regulation of 186 amino acid-related and 133 lipid-related genes. Between D7 and D10, there was increased expression of genes for oxidative phosphorylation and extracellular secretion pathways supporting secretory capacity, while decreased expression of genes in arginine-proline metabolism and solute carrier-mediated transport pathways promoted luminal metabolite accumulation. From D10 to D14, there was increased expression of genes in fatty acid elongation and sphingolipid metabolism pathways likely driving lipid synthesis and amino acid catabolism, while decreased expression of genes in protein digestion/absorption and PI3K/AKT signaling pathways reduced nutrient export to the lumen. Conclusions: ULF composition and LE gene expression changed markedly during the second week of the estrous cycle. It is plausible that the dynamic shifts in amino acid and lipid metabolites in the uterine lumen reflect changing responses to sex steroids. The influence of such changes on embryo development and pregnancy success in cattle warrants investigation.