Search Results (209)

Caveolin-1 is a scaffolding protein of caveolae, flask-shaped membrane microdomains involved in diverse cellular processes. Caveolae are primarily localized to the plasma membrane, the trans-Golgi network, and mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs). Most enzymes involved in cholesterol biosynthesis reside in the ER, and although caveolin-1 avidly binds cholesterol, its role in cholesterol trafficking remains unclear. Acyl-coenzyme A:cholesterol acyltransferases (ACAT1 and ACAT2) convert free cholesterol into cholesteryl esters for storage, with ACAT1 serving as the predominant isoenzyme in most cell types. ACAT1 is an ER-resident protein, with a fraction associated with specialized ER subdomains, including the MAM. Here, we report that a subset of caveolin-1 molecules appears to be associated with a fraction of ACAT1 in ER subdomains. Using immunoprecipitation under detergent conditions, immunoadsorption of MAM-enriched membranes under detergent-free conditions, and electron microscopy, we provide evidence consistent with an association between a subset of caveolin-1 molecules and ACAT1. Functionally, in mouse embryonic fibroblasts, we show that genetic ablation of caveolin-1 significantly increases the esterification of low-density lipoprotein-derived cholesterol, suggesting that caveolin-1 may attenuate ACAT1 activity. Collectively, these findings indicate that caveolin-1 may modulate cholesterol esterification and contribute to the regulation of cholesterol distribution among cellular membranes. Full article

Cancer remains a major global health challenge, with persistent limitations in early diagnosis, metastatic disease control, and the achievement of durable therapeutic responses with acceptable toxicity. These challenges highlight the need for more precise biomarkers and more effective therapeutic strategies. Increasing evidence implicates dysregulated lipid metabolism as a central contributor to tumor development and progression. In recent years, proprotein convertase subtilisin/kexin type 9 (PCSK9), angiopoietin-like protein 3 (ANGPTL3), and cholesteryl ester transfer protein (CETP) have gained particular attention due to their roles in cholesterol homeostasis, oncogenic signaling, and immune modulation within the tumor microenvironment (TME). This narrative review evaluates the potential of these lipid-regulatory mediators as diagnostic biomarkers and therapeutic targets in oncology. The majority of available evidence derives from preclinical and epidemiological studies, with PCSK9 representing the most extensively investigated target. Findings are sometimes contradictory and strongly influenced by tumor type, disease stage, and biological context, which currently precludes the clinical applicability of these molecules as reliable biomarkers. Similar limitations apply to their translational potential as actionable therapeutic targets. Nevertheless, emerging preclinical evidence suggests that modulation of these glycoproteins may enhance the efficacy of chemotherapy, targeted therapies, and immunotherapy, including nanomedicine-based approaches. Of note, clinical research investigating the role of PCSK9 inhibition in oncology is currently ongoing, whereas comparable studies focusing on ANGPTL3 and CETP remain scarce. Overall, further mechanistic, translational, and prospective clinical investigations are warranted to elucidate the involvement of these lipid-regulatory proteins in cancer biology and to define their potential integration into future oncologic diagnostic and therapeutic strategies. Full article

Major depressive disorder (MDD) is associated with altered membrane lipids, but the causal species remain uncertain. Using two-sample Mendelian randomization (MR) on lipidomic GWAS data and the latest MDD meta-analysis (~400,000 cases; 1.5 million controls), we identified 49 lipid species linked to MDD risk, notably enriched for phosphatidylcholines. Protective lipids were enriched for long-chain polyunsaturated fatty acids (20:3–20:5), whereas shorter-chain or less unsaturated species, particularly 18:2-containing lipids, increased risk. These associations were also observed in a subset of clinically assessed MDD cases. Colocalization supported shared causal variants between many lipid traits and MDD, prominently at the FADS1/2 locus and additional loci, suggesting multiple entry points into lipid metabolism that differ partly from bipolar disorder. MR-implicated lipid shifts overlapped with cortisol-induced changes in a human cell stress model and were often reversed by co-treatment with St. John’s wort extract (Ze 117). Cholesteryl ester 20:3 emerged as a robust candidate marker, showing protective MR effects in two cohorts, colocalizing genetic support, normalization by Ze 117, and an inverse correlation with depressive symptom severity in a non-clinical sample. Together, these results define a depression-associated lipidomic signature centered on polyunsaturated fatty acid metabolism with biomarker and therapeutic potential. Full article

Background/Objectives: Colorectal cancer (CRC) is a leading cause of cancer-related mortality, with colorectal liver metastasis (CRLM) being the major determinant of poor prognosis. Tumor metabolic reprogramming and spatial heterogeneity complicate biomarker discovery and clinical management. This study aimed to characterize the spatial metabolomic landscape of CRC and identify progression-associated metabolic alterations and potential metabolic signatures for liver metastasis. Methods: A total of 23 tissue samples were collected from patients with CRC, with and without liver metastasis. Air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) was used to map the spatial metabolite distributions. Region-of-interest analysis guided by histopathology enabled comparative metabolomic profiling across different tissue types. Multivariate statistical analysis, pathway enrichment, and receiver operating characteristic (ROC) curve analyses were performed to identify key metabolic alterations and evaluate potential biomarker performance. Results: Distinct spatial metabolomic profiles were observed across normal mucosa, primary tumors, liver metastases, and normal liver tissues. In primary colorectal tumors, amino acid, purine, and choline metabolism were significantly upregulated, whereas liver metastases were characterized by elevated levels of triglycerides, diglycerides, cholesteryl esters, and acylcarnitines, indicating enhanced lipid synthesis, incomplete fatty acid oxidation, and/or mitochondrial dysfunction. Progression-associated analyses across tissue types revealed consistently increasing trends in glycerides and acylcarnitines, along with heterogeneous alterations in amino acids and phospholipids. Furthermore, 122 differential metabolites were identified between metastatic and non-metastatic CRC, and a four-lipid panel demonstrated strong discriminatory performance. Conclusions: This study provides a spatially resolved characterization of metabolic reprogramming during CRC progression and liver metastasis, highlighting lipid and amino acid metabolism as key features and revealing the metabolic signatures of CRLM. Full article

Older age is a well-established risk factor for many chronic diseases, yet the biological mechanisms underlying this increased risk are not fully understood. Both gut microbiome composition and the plasma metabolome change with age and may help explain how aging influences disease susceptibility. In this study, we examined the associations between age-related gut microbiota and metabolomic biomarkers in participants of the Baltimore Longitudinal Study of Aging (BLSA), covering a broad age range (27–98 years; 55% female). At the phylum level, we identified four age-associated phyla: Firmicutes, which was negatively associated with age, and Proteobacteria, Euryarchaeota, and Verrucomicrobia, which were positively associated with age. At the genus level, six genera—Akkermansia, Escherichia, Klebsiella, Methanobrevibacter, Oscillibacter, and Ruthenibacterium—were positively associated with age, whereas Faecalibacterium and Longibaculum were negatively associated with age. Many of these microbial taxa were found to influence one or more aging-related metabolites, mediating their effects across various metabolite classes, including bile acids, amino acids, triglycerides, cholesteryl esters, and phosphatidylcholines. Notably, three metabolites, Asparagine, Sphingomyelin C26:0, and Dihydroceramide (d18:0/24:1), were associated with a decreased risk of mortality, whereas six metabolites—Glycoursodeoxycholic acid, Triacylglyceride (16:1_34:3), Triacylglyceride (18:0_34:3), Phosphatidylcholine aa C32:1, Phosphatidylcholine aa C32:2, and Cholesteryl ester 16:1—were linked to an increased risk of mortality. This study highlights connections between age-associated gut microbial taxa at both the phylum and genus levels as potential mediators of circulating metabolites that are linked to mortality risk. Full article

Background/Objectives: Human milk (HM) is recognized as the optimal source of infant nutrition, particularly during the first six months of life. While its nutritional aspects and bioactive components are well studied, the HM metabolome remains less understood, particularly in low- and middle-income countries. This study utilized targeted metabolomics for HM profiling and investigated associations of the HM metabolome with maternal and infant characteristics. Methods: In total, 267 HM samples and demographic data from mothers participating in the Maternal and environmental Impact assessment on Neurodevelopment in Early childhood years (MINE) study were collected during enrolment (up to 6-months postpartum) and analyzed using the MxP^® Quant 500 targeted metabolomics kit from Biocrates. Results: A total of 440 metabolites were quantified, mostly lipids such as triglycerides (59.73%), phosphatidylcholines (14.25%), and diglycerides (8.49%), and small molecules including amino acids (26.67%), amino acid-related compounds (21.33%), hexosylceramides (17.33%), and fatty acids (14.67%). Maternal age was positively correlated with a wide range of metabolites, mainly cholesteryl esters, sphingomyelins, triglycerides, and acylcarnitines, while child age was associated with metabolites belonging to acylcarnitine, phosphatidyl-choline, ceramide, diacylglycerol, sphingomyelin, and triglyceride classes. Child’s gender was associated with metabolites, including ceramides, phosphatidylcholines, and sphingomyelins. Pathway enrichment analysis revealed that the metabolites were significantly enriched in valine, leucine, and isoleucine biosynthesis; arginine biosynthesis; phenylalanine, tyrosine, and tryptophan biosynthesis; and glutathione metabolism; however, these reflect annotation-based clustering rather than evidence of active metabolic processes in HM. Conclusions: The HM metabolome varies with maternal and infant characteristics, particularly infant age, reflecting cross-sectional differences in milk composition among mother–infant dyads. Enrichment of metabolites annotated to amino acid and antioxidant-related pathways highlights coordinated representation of nutritionally relevant compounds. These findings provide new insight into the factors shaping HM composition in a low- and middle-income populations. Full article

Background/Objectives: Oxidized lipid droplet formation and cardiolipin (CL) profile abnormality in mitochondrial membranes are associated with metabolic dysfunction-associated steatotic liver disease (MASLD). However, studies on cell models to easily and simultaneously assess the preventive effects on oxidized lipid droplet formation and CL abnormality by indirect antioxidants are limited. Here, we aimed to develop a lipidomics-based cell screening platform to simultaneously evaluate the preventive effects of indirect antioxidants on oxidized lipid droplet formation and mitochondrial membrane lipid abnormalities. Methods: We created a novel lipidomics-based cell screening platform using oxidized low-density lipoprotein (oxLDL) and a human liver-derived cell line (C3A), and screened indirect antioxidants to promote the expression of cellular antioxidant enzymes, preventing oxidized lipid droplet formation. Results: Mass spectrometry revealed that oxLDL increased the levels of cholesteryl ester hydroperoxides. Thus, oxidized lipid droplet formation was confirmed. Three indirect antioxidants (kaempferol, quercetin, and hesperetin) were examined in the lipidomics-based platform. Consequently, quercetin significantly decreased major lipids and lipid hydroperoxide species, particularly triglycerides and triglyceride hydroperoxides with five or more double bonds. Furthermore, fluorescence microscopy revealed that quercetin reduced the size of small oxidized lipid droplets; it also decreased monolysocardiolipin, which could be associated with mitochondrial dysfunction. Conclusions: Overall, we demonstrated that this method could be useful for screening indirect antioxidants with excellent preventive effects against oxidized lipid droplet formation and CL abnormality by simultaneously analyzing various lipids. Full article

Mutations in leucine-rich repeat kinase 2 (LRRK2) are among the most common genetic causes of Parkinson’s disease (PD), yet substantial heterogeneity exists among pathogenic variants. How mutations in distinct functional domains of LRRK2 differentially perturb cellular homeostasis remains incompletely understood. Here, we compared two pathogenic LRRK2 mutations—G2019S in the kinase domain and I1371V in the GTPase domain—across multiple cellular models, including SH-SY5Y and U87 cells, and healthy human iPSC-derived floor plate cells. We demonstrate that the I1371V mutation induces markedly more severe cellular dysfunction than G2019S. I1371V-expressing cells exhibited elevated LRRK2 autophosphorylation at S1292 and robust hyperphosphorylation of Rab8A and Rab10, indicating enhanced downstream signaling. These alterations impaired sterol trafficking, leading to selective depletion of membrane cholesterol without changes in total cellular cholesterol. Consequently, I1371V cells displayed increased membrane fluidity, disrupted microdomain organization, altered membrane topology, reduced caveolin-1 expression, and impaired dopamine transporter surface expression and dopamine uptake. Lipidomic profiling further revealed a broad disruption of lipid homeostasis, including reductions in cholesteryl esters, sterols, sphingolipids, and glycerophospholipids, whereas G2019S cells showed comparatively modest changes. Pharmacological intervention revealed mutation-specific responses, with the non-selective LRRK2 modulator GW5074 outperforming the kinase-selective inhibitor MLi-2 in restoring Rab8A phosphorylation, membrane integrity, and dopaminergic function. Collectively, these findings identify membrane lipid dysregulation as a central cell biological mechanism in LRRK2-associated PD and underscore the importance of variant-specific therapeutic strategies. Full article

Cholesterol plays a fundamental role in the human body—it stabilizes cell membranes, modulates gene expression, and is a precursor to steroid hormones, vitamin D, and bile salts. Its correct level is crucial for homeostasis, while both excess and deficiency are associated with serious metabolic and health consequences. Excessive accumulation of cholesterol leads to the development of atherosclerosis, while its deficiency disrupts the transport of fat-soluble vitamins. Magnetic resonance spectroscopy (MRS) enables the detection of cholesterol esters and the differentiation between their liquid and crystalline phases, but the technical limitations of clinical MRI systems require the use of dedicated coils and sequence modifications. This study demonstrates the feasibility of using MRS to identify cholesterol-specific spectral signatures in atherosclerotic plaque through ex vivo analysis. Using a custom-designed experimental coil adapted for small-volume samples, we successfully detected characteristic cholesterol peaks from plaque material dissolved in chloroform, with spectral signatures corresponding to established NMR databases. To further enhance spectral quality, a deep-learning denoising framework based on a 1D U-Net architecture was implemented, enabling the recovery of low-intensity cholesterol peaks that would otherwise be obscured by noise. The trained U-Net was applied to experimental MRS data from atherosclerotic plaques, where it significantly outperformed traditional denoising methods (Gaussian, Savitzky–Golay, wavelet, median) across six quantitative metrics (SNR, PSNR, SSIM, RMSE, MAE, correlation), enhancing low-amplitude cholesteryl ester detection. This approach substantially improved signal clarity and the interpretability of cholesterol-related resonances, supporting more accurate downstream spectral assessment. The integration of MRS with NMR-based lipidomic analysis, which allows the identification of lipid signatures associated with plaque progression and destabilization, is becoming increasingly important. At the same time, the development of high-resolution techniques such as μOCT provides evidence for the presence of cholesterol crystals and their potential involvement in the destabilization of atherosclerotic lesions. In summary, nanotechnology-assisted MRI has the potential to become an advanced tool in the proof-of-concept of atherosclerosis, enabling not only the identification of cholesterol and its derivatives, but also the monitoring of treatment efficacy. However, further clinical studies are necessary to confirm the practical usefulness of these solutions and their prognostic value in assessing cardiovascular risk. Full article

Background: Early molecular changes on the facial skin surface during early adulthood remain insufficiently characterized. We integrated biophysical readouts with untargeted skin surface lipid (SSL) profiling to identify region-dependent, age-associated features in women with combination skin. Methods: Eighty healthy Chinese women were stratified into 22–28 years (n = 40) and 29–35 years (n = 40). Sebum was measured on the cheek and forehead; cheek elasticity, hydration (CM), transepidermal water loss (TEWL), pH, and tone indices were assessed under standardized conditions. SSLs from both regions were profiled by UPLC–QTOF–MS. Differential features were prioritized using OPLS-DA (VIP > 1) with univariate screening (p < 0.05; fold change > 2 or <0.5). Results: TEWL, CM, and pH were comparable between age groups, whereas the older group showed lower cheek elasticity and reduced sebum. Lipidomics revealed clearer remodeling on the cheek than the forehead: 30 and 59 differential SSL features were identified in the cheek and forehead, respectively. Cheek changes in the older group were characterized by lower ceramides (including acylceramides), TG/DG and long-chain fatty acids, alongside relatively higher cholesteryl esters. Conclusions: Conventional barrier indices remained largely stable across this age window, while cheek SSL profiles captured earlier molecular shifts, providing candidates for targeted validation and longitudinal follow-up. Full article

Infantile-onset lysosomal acid lipase deficiency (LAL-D) (Wolman disease, historically) is a rare inherited, rapidly progressive disorder caused by pathogenic variants in the LIPA gene, which encodes the enzyme LAL. LAL is essential for the metabolism of cholesteryl esters and triglycerides. LAL deficiency leads to the accumulation of cholesteryl esters and triglycerides within the lysosomes, macrophages, and parenchymal cells in most tissue types, including those in the liver, gastrointestinal tract, and lymph nodes but excluding the central nervous system. Infants with rapidly progressive LAL-D present with gastrointestinal disturbance, adrenomegaly with calcification, hepatosplenomegaly, growth failure due to malabsorption, and systemic inflammation. If untreated, rapidly progressive LAL-D typically leads to death within the first year of life. Treatment takes the two-pronged approach of sebelipase alfa, a human lysosomal acid lipase enzyme replacement therapy (ERT) that improves lipid metabolism, combined with nutritional management. Dietary substrate (lipid) reduction, known as substrate reduction therapy, is essential for optimal management in LAL-D. Following a nutritional plan and managing gastrointestinal disturbances together reduce systemic inflammation and improve growth, gut function, liver health, quality of life, and survival in patients with infantile-onset LAL-D. A multidisciplinary specialized team is necessary to manage the highly complex, multisystemic conditions in these patients. Nutritional management of LAL-D has evolved with increasing experience with the clinical management of ERT-treated infantile-onset LAL-D. A review of guidance for best practice nutritional management is needed. This narrative review aims to provide updated recommendations and guidance for the optimal nutritional management of infantile-onset LAL-D. Full article

Atherosclerosis, a leading cause of cardiovascular disease, is driven by a complex interplay of dyslipidemia, inflammation, and arterial plaque formation and progression. Animal models are indispensable to elucidate the pathogenesis and develop novel therapies. Rodent models are widely utilized due to their cost-effectiveness, reproducibility, and rapid disease progression. However, notable species differences exist in lipoprotein composition and lipid metabolism pathways. Mice and rats exhibit an HDL-dominant profile, whereas Syrian golden hamsters express cholesteryl ester transfer protein (CETP) and display a higher LDL fraction, but lower than that of humans, offering a model closer to human metabolically. Divergent CETP activity across species further complicates the translational relevance of the findings from these models for atherosclerosis and related metabolic disorders. This review systematically examines the key factors in rodent model selection and optimization, with consideration on the roles of sex and age. We focus on three commonly used and well-characterized rodent strains prone to atherosclerosis: C57BL/6J mice, Sprague-Dawley (SD) rats, Wistar rats, and golden hamsters. On Apoe^−/− or Ldlr^−/− backgrounds, male C57BL/6 mice, owing to their pronounced hypercholesterolemia and extended survival with high-fat diet, are preferentially used in late-stage plaque stability studies. In contrast, male SD or Wistar rats develop atherosclerosis slowly with limited lesion progression, while hamsters, despite their human-like lipid metabolism, exhibit substantial individual variability and lesions that typically arrest at early fatty streaks with poor reproducibility. Therefore, rats and hamsters are better suited for studies focusing on early disease mechanisms and human-mimetic lipid metabolism. Full article

Background/Objectives: Both HIV infection and antiretroviral therapy contribute to dyslipidemia and abnormal body fat distribution in people living with HIV (PLWH). Exercise training is an effective intervention to protect against these metabolic changes. However, little is known about the mechanisms underlying the impact of exercise training on lipid metabolism in PLWH. This study aimed to comparatively evaluate the effect of high-intensity functional circuit training on the plasma lipidome of PLWH and HIV-negative subjects (control). Methods: PLWH (n = 13) and control (n = 14) were submitted to 8 weeks of exercise training. Body composition, anthropometric, and biochemical parameters were measured. Plasma was obtained in a fasting state for lipidomic analysis. Results: Anthropometric and biochemical parameters revealed lower levels of leptin, HDL-C, body fat %, and BMI combined with elevated aspartate transaminase (AST) and Homeostasis Model Assessment of β-cell function (HOMA_beta) in PLWH when compared to control subjects that persisted from baseline to post-exercise training. Nonetheless, contrasting levels of adiponectin, fasting insulin, and phosphatidylcholine-containing lipids observed at baseline were equalized after training in PLWH. In control subjects, significant reductions in concentrations of triglycerides alongside phosphatidylinositol and glycosylated ceramides were observed post-exercise training. By contrast, PWLH displayed an increase in diglycerides, acylcarnitines, and free cholesterol levels after exercise training, together with decreased concentrations of free fatty acids, cholesteryl esters, and glycosylated ceramides. Conclusions: In addition to specific lipidome alterations in each group, particularly driven by improved insulin resistance in PLWH, this study showed concomitant modulation of several glycerophospholipids and sphingolipids, suggesting health-promoting effects of short-term exercise training. Collectively, these modulated lipid species represent interesting targets for future lipidomic-based studies evaluating not only the effects of exercise training but also the molecular mechanisms resulting in a healthier plasma lipidome profile. Full article

Meibum—a lipid-rich secretion produced by holocrine Meibomian glands (MG)—plays a central role in maintaining ocular surface homeostasis in humans. Previously, changes in MG lipidomes induced by inactivation of critical genes of meibogenesis, such as Elovl3, Soat1, Awat2, Sdr16c5/Sdr16c6, and others were shown to cause MG dysfunction (MGD) and dry eye in experimental animals. Here, we describe the impact of the changes in the lipid composition of meibum on its protective properties, specifically physiologically relevant thermotropic characteristics, using various mutant and wild-type animal models, and comparing them with healthy human subjects and patients with MGD. Meibum samples were analyzed using liquid chromatography/mass spectrometry (LC/MS) and differential scanning microcalorimetry (DSC). We found that any change in the balance between major lipid classes in meibum—wax esters, cholesteryl esters, triacylglycerols, and free cholesterol—cause detrimental changes in its thermotropic properties, loss of cohesiveness, and abnormal expressibility from MG, resulting in MGD-like phenotypes of the eyes and adnexa. We conclude that tested knockout mice can be valuable models for modeling and studying MGD. A combination of LC/MS and DSC can be a powerful diagnostic tool and may help to diagnose MGD and other pathologies, as well as determine their molecular mechanisms. Full article

Parkinson’s disease, associated with mutations in the GBA1 gene (GBA1-PD), is the most common genetic form of Parkinson’s disease (PD), marked by clinical heterogeneity influenced by mutation type. Extracellular vesicles (EVs), key mediators of intercellular communication, are implicated in PD pathogenesis through the transport of pathological proteins and lipids. In this study, we analyzed blood plasma-derived EVs from GBA1-PD patients carrying p.N370S and p.L444P mutations and from healthy controls using cryo-electron microscopy, lipidomics, and proteomics. EVs from GBA1-PD patients were significantly larger than those from controls, with the largest size and most multilayered vesicles observed in p.N370S carriers. Lipidomic profiling identified 237 lipid species; of these, 186 lipids were altered in p.N370S and 24 in p.L444P versus controls. Mutation carriers showed distinct lipid signatures, with p.L444P samples enriched predominantly in sphingolipids, while p.N370S carriers exhibited more extensive lipid remodeling across multiple classes, including triglycerides, cholesteryl esters, and phospholipids. Notably, Cer 23:0 was elevated across all GBA1-PD groups. Proteomic analysis revealed enrichment in pathways related to lipid transport, immune regulation, and vesicle-mediated processes. Overall, GBA1-PD patients share a distinct lipidomic EV signature, with mutation-specific patterns reflecting differing mechanisms of lysosomal dysfunction. These findings support the potential of EV profiling to unravel disease heterogeneity and identify biomarkers. Full article