Aging changes the lipidome and mitochondrial function in a sex-dependent manner, yet their associations remain poorly understood. Twenty-four younger (7M/17F) and forty-three older (21M/22F) adults underwent blood draws and skeletal muscle biopsies for this cross-sectional investigation. Plasma lipidomic profiling was performed via liquid chromatography-tandem mass spectrometry, while peak mitochondrial O2 utilization (OXPHOS) and hydrogen peroxide (H2O2) emission were assessed using high-resolution respirometry. Plasma lipidomic analysis annotated 535 lipid species across 28 different lipid classes. Lipid-age associations were identified in four lipid classes for both sexes with twelve lipid classes demonstrating sex-specific associations, including triglycerides (TG), carnitines (CAR), and fatty acids (FA). For lipid-OXPHOS interactions, the primary lipid class and species associated with higher OXPHOS exclusively in males were ceramides (CER) and dimethyl cholesterol esters (dimethyl-CE), while TG were the primary lipid species associated with impaired OXPHOS in females. For lipid-H2O2 interactions, the primary lipid class and species associated with higher H2O2 were methyl desmosteryl esters (methyl-DE), methyl cholesterol esters (methyl-CE), FA and TG in males whereas females exhibited 10 (CE, SM, LPC, dihexosylceramides (Hex2Cer), LPE, PI, HexCer, LPI, CAR, and hexosyl-N-acetylneuraminyl-ceramides (Hex2NeuAcCer)) lipid classes associated exclusively with H2O2 emission. These findings establish novel age- and sex-specific relationships between age-related changes in plasma lipids and skeletal muscle mitochondrial function, revealing distinct lipid signatures for respiration and H2O2 emission in males and females.

Capecitabine (CAP) side effect, a prodrug of 5-fluorouracil (5-FU), is hand-foot syndrome (HFS), a localized skin disorder of the hands and feet that is believed to induce a decrease in skin barrier function. Stratum corneum (SC) lipids play an important role in skin barrier function; therefore, this study compared the SC lipid structure and composition of healthy participants with those of patients with CAP-induced HFS. Forty patients receiving a combination regimen of CAP and oxaliplatin as adjuvant chemotherapy for colorectal cancer were enrolled. All patients received 1,000 mg/m2 twice daily on days 1-14. SC samples were obtained from 11 patients with CAP-induced HFS (CSC). The SC lipid structure was analyzed using synchrotron X-ray diffraction. SC lipid components, ceramides (CERs), free fatty acids (FFAs), CAP, and its metabolites in CSC samples were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). In healthy SC (HSC), lipids formed two lamellar phases. Hexagonal and orthorhombic hydrocarbon chain packing was observed in lateral lipid organization. However, in CSC, these structures have almost disappeared. UPLC-MS/MS analysis revealed that the composition of CER and FFA differed between CSC and HSC, and that the carbon chain length of SC lipid components in CSCs was reduced compared to that in HSCs. 5-FU was detected in CSCs at 3.4 ± 1.4 ng/mg. CAP induces changes in SC lipid structure due to changes in SC lipid composition and a decrease in carbon chain length in CSCs. CAP-induced HFS is associated with 5-FU accumulation in SC.

Multiscale simulation of stratum corneum lipid mixtures: effects of ceramide headgroups on structural organization and hydrogen bonding networks.

ToF-SIMS revealing sphingolipids composition in extracellular vesicles and paternal β-cells after persistent hyperglycemia.

Evogliptin, an anti-diabetic drug had positive impact on various cardiovascular events including inflammation and vascular calcification (VC), an active process driven by vascular smooth muscle cell (VSMC) phenotypic transition. Sphingolipids such as ceramide (CER) mediates inflammation and VC in the vascular tissue. We investigated whether evogliptin ameliorate phenotypic transition and pyroptosis in VSMCs as underlying cause of VC. In cultured VSMCs, isolated from the aorta of (C57/BL6) mouse, we observed more severe calcification with prior treatment of CER in Pi-treated VSMCs as detected by Alizarin Red Staining. Prior CER- stimulation led to a marked upregulation of osteogenic markers such as RUNX2, OPN, BMP2 and decreased contractile markers SM22-α and α- SMA in Pi-treated VSMCs as compared to control cells. In addition, increased expression of pyroptotic markers such as NLRP3, GSDM-D, IL-1β, IL-18, and LDH release was observed with prior treatment of CER in Pi-treated VSMCs as compared to control cells. Furthermore, MCC950 (NLRP3 inhibitor), disulfiram (GSDM-D inhibitor) and evogliptin significantly downregulated osteogenic and pyroptotic markers including LDH release in both Pi‐induced only and CER + Pi-treated VSMCs. Moreover, GW4869 (SMase inhibitor) and evogliptin significantly reduced SMase activity in sphingomyelin (SM)-induced VSMCs as compared to both Pi and SM only-treated groups. Also, the cleavage efficiency of GSDM-D was high in Pi and CER + Pi groups which was reduced with prior treatment of evogliptin. Hence, our data demonstrate that evogliptin alleviates VC by blocking phenotypic transition and associated pyroptosis via modulation of NLRP3/GSDM-D mediated pathway in CER-induced VSMCs.

Sphingolipids are bioactive lipids that regulate cell proliferation, differentiation, apoptosis, angiogenesis, and inflammation. In recent years, their role in maintaining the ovarian reserve and developing of female reproductive disorders has gained increasing attention. Ceramides (CERs) and sphingosine-1-phosphate (S1P) form a dynamic balance between pro-apoptotic and pro-survival signals, determining the fate of follicles and oocytes. Dysregulation of sphingolipid metabolism has been identified in ovarian cancer, polycystic ovary syndrome, endometriosis, obesity, diminished ovarian reserve, and premature ovarian insufficiency. These conditions are accompanied by a shift in the CERs/S1P ratio, which affects oocyte quality and their susceptibility to oxidative stress, chemotherapy, and inflammation. Emerging evidence indicates that targeted modulation of the sphingolipid pathway — including enzymes such as sphingosine kinases, ceramide synthases, sphingomyelinases, and ceramide transfer protein, as well as S1P receptors may represent a promising approach for preserving ovarian reserve, preventing infertility, and overcoming chemoresistance in ovarian cancer. S1P exhibits protective properties toward oocytes, whereas ceramide analogues and inhibitors of sphingolipid-metabolizing enzymes offer new opportunities for personalized therapy. Summarizing current data on sphingolipid metabolism in reproductive tissues highlights these molecules not only as biomarkers of pathology but also as potential therapeutic targets, which is particularly relevant for developing fertility-preserving strategies and improving the outcomes of gynecological disease treatment.

The stratum corneum (SC), the outermost layer of humanskin, owesits barrier function to highly ordered lipid lamellae composed primarilyof ceramides (CERs), cholesterol (CHOL), and free fatty acids (FFAs).Molecular dynamics simulations offer the opportunity to gain valuableinsights into the structural organization of lipids, complementingexperimental approaches. However, simulations using atomistic modelsare computationally expensive when studying the large, multilamellarstructures characteristic of the SC. Coarse-grained (CG) models ofSC lipids provide an efficient alternative but have largely been limitedto CER NS. In this work, a previously developed Multistate IterativeBoltzmann Inversion (MS-IBI) CG model for CER NS has been extendedto three additional CER subclassesCERs NP, AP, and ASwhichdiffer from CER NS in headgroup hydroxylation. By leveraging structuralsimilarity and transferring nonbonded interaction parameters for CERNS hydroxyl groups, we have developed new models with minimal reparameterization.The models have been validated against atomistic simulations of bothpure and mixed bilayers containing CHOL and FFA. To capture the multilamellarorganization, six-leaflet multilayers were self-assembled. The resultingCG systems exhibited lamellar organization, chain order, and repeatdistances consistent with the available experimental data. Comparisonsacross CER subclasses revealed that headgroup hydroxylation influenceslipid packing, chain tilt, and whether the CER tails exhibit a hairpinor extended conformation. This work demonstrates the flexibility andtransferability of the MS-IBI approach and provides CG models forkey CER subclasses in human SC, enabling large-scale simulations ofrealistic SC lipid compositions beyond the reach of atomistic models.

BackgroundAccurate stratification of recurrence risk after curative resection remains a critical challenge in the management of hepatocellular carcinoma (HCC). Dysregulated ceramide (CER) metabolism has been implicated in HCC progression and relapse. This paper evaluates whether preoperative plasma CER profiling coupled with machine learning (ML) enhances the risk prediction of HCC recurrence.MethodsIn this retrospective study, 257 HCC patients undergoing curative resection participated. Preoperative plasma CERs were quantified by targeted Lipidomics. Independent predictors were identified via multivariate Cox regression and incorporated into ten ML models. Using an internal 20% validation cohort, model performance was assessed by the area under the curve (AUC), concordance index (C-index), calibration, and decision curve analysis. Model interpretability employed Shapley additive explanations (SHAP), correlation analysis, and Bayesian network-based causal inference. The model’s risk stratification capability was evaluated. This study was registered on clinicaltrials.gov (NCT06623474).ResultsPreoperative plasma CERs exhibited significant prognostic value in patients with HCC after curative resections. Multivariate analyses revealed that serum α-fetoprotein (AFP), tumor size, CER(d18:1/20:1), and CER(d18:1/22:1) independently predicted recurrence, and these variables were incorporated into ten ML models. Among them, the gradient boosting machine (GBM) algorithm demonstrated the best predictive performance (AUC: 0.959 at 1 year, 0.954 at 2 years, 0.931 at 3 years; C-index ≈ 0.93), outperforming all the other approaches. Model interpretability analysis (SHAP) highlighted tumor burden as the major determinant, with CER (d18:1/20:1) acting as a recurrence-promoting factor, and CER (d18:1/22:1) exerting a protective effect. Correlation analyses further revealed that CER(d18:1/20:1) was positively related to tumor multiplicity, systemic inflammation, and shorter recurrence-free survival (RFS), whereas CER(d18:1/22:1) was linked to better liver function and longer RFS. Bayesian causal inference indicated that elevated CER(d18:1/20:1) directly accounted for approximately 26% of the recurrence risk through effects on AFP and tumor size, whereas reduced CER(d18:1/22:1) conferred approximately 30% causal protection by modulating RFS, AFP, Liver function, and inflammation. Notably, the GBM model successfully identified 54 of 56 recurrent cases as high risk, enabling clear stratification of patients for precision surveillance.ConclusionsPreoperative plasma CER profiling, integrated with clinical parameters in a GBM framework, provides a highly accurate and interpretable strategy for predicting postoperative HCC recurrence, which paves the way for precise risk stratification and targeted management. This study provides insights that may enhance liver health and reduce disease burden in patients with HCC.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12944-025-02749-6.

Lipid rafts are known as dynamic microcompartments in cell membranes implicated with cellular penetration and molecular recruitment. Its compact structure reduces membrane fluidity, thereby affecting drug permeability and distribution and represents an underlying mechanism for cancer cells to resist chemotherapy. Lipid exchange within lipid rafts has attracted increasing attention, and ceramide (CER) is a potential candidate for dismantling lipid rafts; however, the molecular details and dynamic mechanism remain unclear. This study employs high-throughput coarse-grained molecular dynamic simulations to elucidate the mechanisms of lipid raft disintegrated by CER in atom-nearly resolution. Our results reveal that CER-induced lipid raft disruption is associated with its acyl chain length, specifically favoring chains of 8 carbons (CER-C8), which interferes with the association between cholesterol and saturated phospholipids within the lipid raft. This interference leads to structural disorganization of the lipid raft and membrane homogeneity. Furthermore, lipid raft dissociation is concentration-dependent: compared to a CER/lipid ratio of 34/287, higher CER amounts (80 or 120) exert a more pronounced disruptive effect. It is noteworthy that ganglioside GM1 plays a critical role in the efficient adsorption of CER clusters to lipid raft, other than a membrane nonbound state. The findings of this study provide a theoretical basis for understanding the role of CERs in disease and elucidate the molecular mechanisms by which CER disrupts the lipid raft.

Exercise training increases skeletal muscle sphingomyelinases and affects mitochondrial quality control in men with type 2 diabetes.

The osteoarthritis associated sphingolipid sphingomyelin 34:1 causes inflammatory pain in mice.

Skin lipids, such as ceramides (CERs), play an important role in maintaining the skin barrier. Although the benefits of CERs are well known, few studies have investigated the effects of other skin lipid components on the skin barrier. Therefore, this study compared the efficacy of several skin lipid components and their structural derivatives, including CERs, on the skin barrier. The water-holding capacity and occlusion factor were determined to evaluate the moisture barrier and sealing effects, respectively, of creams containing various skin lipid components. A human study using sodium dodecyl sulfate (SDS) to induce skin damage was also conducted to explore skin barrier recovery. Epidermal thickness and density were measured using an ultrasonic instrument. The cream containing behenic acid (BA) had the best water-holding capacity, and the creams with CER and BA significantly increased the occlusion factor. The BA-containing cream had a cubic structural pattern in the small-angle X-ray scattering analysis, which may explain the high occlusion factor. In SDS-damaged skin, transepidermal water loss recovered significantly faster in skin areas treated with cream containing BA and CER compared with non-treated skin. This study compares the skin barrier recovery effects of skin lipid components, demonstrating that BA elicits a high skin barrier recovery effect similar to that of CER, which has known efficacy. BA also had an excellent sealing effect through lipid packaging, whereas CER had a combined sealing effect and increased the epidermal thickness and density. These results provide foundational evidence for formulating products that help restore the skin barrier by supplying lipids to the skin surface.

Emerging role of the cardiac lipidome in the progression of heart failure.

Women have a higher white matter hyperintensity (WMH) burden compared to men of a similar age, but the causes of this remain unclear. Ceramide (CER) levels differ between men and women and were previously linked to WMH, suggesting they could underlie these sex differences. Therefore, we associated twelve CERs, CER totals, six CER ratios, and a CER score reflecting the CERs most strongly associated with cardiovascular disease, with WMH load in 3,283 participants (30–95 years) of the community-based Rhineland Study. We assessed sex-specific relations between CERs and WMH by including an interaction term and performing sex-stratified analyses. We further investigated the influence of menopause by comparing relations in pre- and postmenopausal women of the same age. Multiple CERs, CER ratios, and the CER score were associated with increased WMH load, with most associations being significantly stronger in women than in men. We found no influence of menopausal status on the associations between CERs and WMH. Thus, we showed novel and strong associations of CERs, CER ratios and the CER score with WMH burden, especially in women. This study suggests that CERs may play an important role in the observed sex differences in WMH burden.

ObjectiveThis study aimed to characterize the plasma lipidomic profile of patients with pulmonary tuberculosis (PTB), identify lipid species with potential diagnostic utility, and explore their associations with clinical parameters to inform future biomarker development and mechanistic understanding.MethodsIn a case–control study, 50 newly diagnosed PTB patients and 50 age- and sex-matched healthy controls (HC) were enrolled between April and June 2021. Plasma samples were analyzed using LC–MS/MS-based lipidomics. Multivariate modeling and univariate statistical analyses were performed to identify differential lipid species. Receiver-operating characteristic (ROC) curves evaluated diagnostic performance, and correlation analyses assessed associations with clinical indicators.ResultsA total of 633 lipid species were profiled, with 61 showing significant differential expression between PTB and HC groups. When compared with controls, PTB patients exhibited significantly lower plasma levels of total cholesterol, triglycerides, HDL, and LDL (all P < 0.05), as well as reduced triacylglycerol (TAG), ceramide (CER), and hexosylceramide (HCER). In contrast, phosphatidylethanolamine (PE) and phosphatidylcholine (PC) levels were elevated in PTB. ROC analysis identified several lipid species—particularly CER(24:0) H, HCER(d18:0/22:0) H, and PE(18:1/18:1)—with strong discriminative power (AUC > 0.75). Correlation analysis revealed weak-to-moderate associations of select lipids with age and glucose, but minimal or no correlation with BMI, sex, or smoking, indicating that lipidomic alterations are primarily disease-driven.ConclusionPTB patients display a distinct plasma lipidomic signature, marked by disrupted glycerolipid and sphingolipid metabolism. These findings support the diagnostic value of lipidomic profiling and provide insights into PTB-associated metabolic disturbances, laying a foundation for future biomarker validation and therapeutic exploration.

Fentanyl is a potent and short-acting opioid that is often given to pediatric patients during surgery to relieve pain and as an adjunct to anesthesia. Its effects on the developing brain are yet to be determined. In the present study, commercially available human neural stem cells (NSCs) were used to model the effects of fentanyl on the developing human brain. We determined the dose dependent effects and temporal relationships between fentanyl exposures and NSC health, viability, and differentiation. Markers of mitochondrial health [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetra-zolium bromide (MTT)] and cell death/damage [lactate dehydrogenase (LDH)] were monitored to determine the dose response effects of fentanyl on NSC viability. In addition, lipidomics analysis was conducted to investigate lipid profile changes in differentiated neural cells treated with fentanyl. Fentanyl did not cause a significant increase in LDH release, nor MTT reduction after 24-h exposure at concentrations of 0.5, 1.0, 3.0, 10, or 100μM, for both NSCs and differentiated neural cells. Lipidomics data showed the top 15 most variable important in projection (VIP) lipid species (the higher the VIP scores, the bigger changes in treated groups vs. controls), including lysophosphatidylcholines (LPCs), lysophosphatidylethanolamines (LPEs), ceramides (CER), cholesterol esters (ChEs) and sphingosine (SPH). The lipidomic data indicate that LPC (16:0), LPC (16:1), LPC (18:1), CER (d18:0_22:0), CER (d18:2_18:0), CER(d18:2_24:1) were significantly increased, and only ChE (24:5) and SPH (d18:1) were significantly decreased in the highest dose group versus control. These data indicated that fentanyl exposure (24-h) did not induce detectable cell death. However, a lipidomic analysis indicated that fentanyl may affect immature neural cell functions through modifying lipid composition and lipid metabolism. These data indicated that despite the absence of clear neurodegeneration, fentanyl may still have a negative impact on the developing brain.

The lipid composition of membranesystems plays a critical role in regulating their structural dynamicsand curvature, particularly in the biological context of matrix vesicles(MVs) formation during bone mineralization. Recent evidence suggeststhat the lipid composition of MVs, particularly the balance betweensphingomyelin (SM) and ceramide (CER), influences their curvatureand stability. We report on the impact of SM and CER ratios on membranecurvature through surface pressure–area isotherm measurementsand molecular dynamics (MD) simulations at atomistic and coarse-grainedlevels. Our findings reveal that increasing the CER content up to25% significantly enhances membrane curvature, as demonstrated bychanges in experimental compressibility moduli and lateral pressureprofiles. The lateral pressure profiles and spontaneous bending momentscalculated from MD simulations of osteoblast-mimetic membrane modelssuggest a strong propensity for curvature, particularly in asymmetricalbilayers. It also reveals the role of CER-rich domains in the stabilizationof membrane curvature, potentially facilitating the budding processescritical for MVs formation in osteoblasts. These findings underscorethe critical role of lipid composition in the mechanisms driving MVsbiogenesis.

Cutaneous ceramide synthesis is dysregulated in pediatric eosinophilic esophagitis.

ABSTRACTAcute liver hepatotoxicity, characterised by inflammation, apoptosis and metabolic dysfunction, is often caused by drug‐induced toxic events. This study evaluated the protective effects of COG133, a synthetic peptide derived from apolipoprotein E (ApoE), against carbon tetrachloride (CCl4)‐induced liver damage, focusing on inflammation, apoptosis and sphingolipid metabolism. An acute hepatotoxicity model was established in rats utilising CCl4, with co‐administration of COG133 at varying doses. Histological analyses, immunostaining, messenger RNA (mRNA)/protein quantification, flow cytometry and mass spectrometry were employed to assess necroinflammation, apoptosis and sphingolipid levels. Cell viability assays and morphological evaluations were conducted on rat hepatocytes and hepatic stellate cells (HSC‐T6) to evaluate the protective effects of COG133. COG133 reduced liver damage, necroinflammation and apoptosis, restoring cell viability and lowering markers of inflammation, fibrosis and oxidative stress, including tumour necrosis factor‐alpha (TNF‐α), nuclear factor kappa‐B (NF‐κB), inducible nitric oxide synthase (NOS2), interleukin‐1 beta (IL‐1β), transforming growth factor‐beta (TGF‐β) and collagen type I (Col‐1). Immunostaining and molecular analyses confirmed these effects. Sphingomyelin (SM) and sphingosine‐1‐phosphate (S1P) levels were partially restored, while ceramide (CER) levels remained reduced in COG133‐treated groups. COG133 protects against CCl4‐induced liver injury by reducing inflammation, apoptosis and morphological damage, with partial restoration of sphingolipid metabolism. These findings support its potential as a novel therapeutic agent for acute liver injury.

BackgroundWhile electronic cigarettes (ECIG) may have lower toxicant delivery than cigarettes, ECIG-liquids and aerosols still contain toxicants that can potentially disrupt lung lipid homeostasis.MethodsParticipants from two studies underwent bronchoscopy and bronchoalveolar lavage (BAL). Ninety-eight participants (21-44 years old) were included in a cross-sectional study, with 17 ECIG users, 52 non-smokers, and 29 smokers. In the four-week clinical trial, 30 non-smokers were randomly assigned to use nicotine-free, flavorless ECIG or no use. A panel of 75 quantifiable lipid species and 7 lipid classes were assessed in the BAL using two tandem mass spectrometry (MS/MS) platforms. Ten cytokines and lipid-laden macrophages (LLM) were analyzed using the V-PLEX Plus Proinflam Combo 10 panel and Oil Red O staining, respectively. ResultsIn the cross-sectional study, 43 lipids were associated with smoking status at FDR<0.1, including two between ECIG and non-smokers (PC(14:0/18:1) and PC(18:0/14:0)) in pairwise follow-up analyses (Bonferroni-adjusted p<0.017). Associations between lipid species and cotinine, inflammatory markers, including IL-1β and IL-8, and LLM were also identified, as well as differences in lipid classes between smokers and the other groups. Smokers had higher saturated lipids, including ceramide (CER), sphingomyelin (SM), and diacylglycerol (DAG) than that of non-smokers and ECIG users. No significant associations were identified in the 4-week clinical trial.ConclusionsSmoking was associated with altered lipid levels, as compared to both non-smokers and ECIG users; the majority were downregulated and ECIG effects tend to be smaller in magnitude than smoking effects, although some were different than those in the smokers group. This is a novel study of healthy individuals examining lipidomic differences between smokers, ECIG users, and non-smokers, indicating potential roles of smoking and ECIG-related lipid alterations in pulmonary disease.Trial registrationThe study was approved by The OSU Institutional Review Board (OSU-2015C0088) in accordance with its ethical standards, the Helsinki declaration, and the Belmont Report, and is registered on Clinicaltrials.gov (NCT02596685; 2015-11-04).