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1.
J Lipid Res ; : 100596, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39019344

ABSTRACT

Membrane lipids extensively modulate the activation gating of voltage-gated potassium channels (KV), however, much less is known about mechanisms of ceramide and glucosylceramide actions including which structural element is the main intramolecular target and whether there is any contribution of indirect, membrane biophysics-related mechanisms to their actions. We used two-electrode voltage-clamp fluorometry capable of recording currents and fluorescence signals to simultaneously monitor movements of the pore domain (PD) and the voltage sensor domain (VSD) of the KV1.3 ion channel after attaching an MTS-TAMRA fluorophore to a cysteine introduced into the extracellular S3-S4 loop of the VSD. We observed rightward shifts in the conductance-voltage (G-V) relationship, slower current activation kinetics and reduced current amplitudes in response to loading the membrane with C16-ceramide (Cer) or C16-glucosylceramide (GlcCer). When analyzing VSD movements, only Cer induced a rightward shift in the fluorescence signal-voltage (F-V) relationship and slowed fluorescence activation kinetics, whereas GlcCer exerted no such effects. These results point at a distinctive mechanism of action with Cer primarily targeting the VSD, while GlcCer only the PD of KV1.3. Using environment-sensitive probes and fluorescence-based approaches, we show that Cer and GlcCer similarly increase molecular order in the inner, hydrophobic regions of bilayers, however, Cer induces a robust molecular reorganization at the membrane-water interface. We propose that this unique ordering effect in the outermost membrane layer in which the main VSD rearrangement involving an outward sliding of the top of S4 occurs, can explain the VSD targeting mechanism of Cer, which is unavailable for GlcCer.

2.
Bio Protoc ; 14(13): e5028, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-39007159

ABSTRACT

Mitochondria are vital organelles essential for cellular functions, but their lipid composition and response to stressors are not fully understood. Recent advancements in lipidomics reveal insights into lipid functions, especially their roles in metabolic perturbations and diseases. Previous methods have focused on the protein composition of mitochondria and mitochondrial-associated membranes. The advantage of our technique is that it combines organelle isolation with targeted lipidomics, offering new insights into the composition and dynamics of these organelles in pathological conditions. We developed a mitochondria isolation protocol for L6 myotubes, enabling lipidomics analysis of specific organelles without interference from other cellular compartments. This approach offers a unique opportunity to dissect lipid dynamics within mitochondria and their associated ER compartments under cellular stress. Key features • Analysis and quantification of lipids in mitochondria-ER fraction through liquid chromatography-tandem mass spectrometry-based lipidomics (LC-MS/MS lipidomics). • LC-MS/MS lipidomics provide precise and unbiased information on the lipid composition in in vitro systems. • LC-MS/MS lipidomics facilitates the identification of lipid signatures in mammalian cells.

3.
J Lipid Res ; : 100591, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38992724

ABSTRACT

INTRODUCTION: The epidermal inflammation associated with psoriasis drives skin barrier perturbations. The skin barrier is primarily located in stratum corneum (SC). Its function depends on the SC lipid matrix of which ceramides constitute important components. Changes in the ceramide profile directly correlate to barrier function. In this study, we characterized the dynamics of the barrier function and ceramide profile of psoriatic skin during anti-Interleukin-23 therapy with guselkumab. METHODS: We conducted a double-blind, randomized controlled trial in which 26 mild-to-severe plaque psoriasis patients were randomization 3:1 to 100mg guselkumab or placebo for 16 weeks and barrier dynamics monitored throughout. Barrier function was measured by trans-epidermal Water loss measurements. Untargeted ceramide profiling was performed using liquid chromatography-mass spectrometry after SC was harvested using tape-stripping. RESULTS: The barrier function and ceramide profile of lesional skin normalized to that of controls during treatment with guselkumab, but not placebo. This resulted in significant differences compared to placebo at the end of treatment. Changes in the lesional ceramide profile during treatment correlated with barrier function and target lesion severity. Non-lesional skin remained similar throughout treatment. CONCLUSION: Guselkumab therapy restored the skin barrier in psoriasis. Concomitant correlations between skin barrier function, the ceramide profile and disease severity demonstrate their interdependency.

4.
Nutrients ; 16(13)2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38999848

ABSTRACT

BACKGROUND: Our search for plant-derived ceramides from sustainable sources led to the discovery of ceramides and glucosylceramides in wine lees. OBJECTIVE: This study evaluated the efficacy and safety of wine lees extract (WLE)-derived ceramides and glucosylceramides in enhancing skin barrier function. METHODS: A randomized, double-blind, placebo-controlled study was conducted with 30 healthy Japanese subjects aged 20-64. Subjects were allocated to receive either the WLE-derived ceramides and glucosylceramides (test group) or placebo for 12 weeks. The primary outcome was transepidermal water loss (TEWL), and secondary outcomes included skin hydration, visual analog scale (VAS) of itching sensation, and the Japanese Skindex-29. RESULTS: One participant withdrew for personal reasons, resulting in 29 subjects for data analysis (placebo n = 15; test n = 14). The test group showed a tendency of lower TEWL compared to the placebo after 8 weeks (p = 0.07). Furthermore, after 12 weeks of administration, the test group had significantly lower TEWL than the placebo (p = 0.04). On the other hand, no significant differences were observed in the secondary outcome parameters. No adverse events related to the supplements were reported. CONCLUSIONS: Oral supplementation of WLE-derived ceramides and glucosylceramides is a prominent and safe approach to enhancing skin barrier function and health. TRIAL REGISTRATION: (UMIN000050422).


Subject(s)
Ceramides , Glucosylceramides , Plant Extracts , Skin , Humans , Double-Blind Method , Adult , Male , Female , Middle Aged , Administration, Oral , Plant Extracts/pharmacology , Plant Extracts/administration & dosage , Young Adult , Skin/drug effects , Glucosylceramides/administration & dosage , Glucosylceramides/pharmacology , Wine/analysis , Water Loss, Insensible/drug effects
5.
Sci Rep ; 14(1): 15256, 2024 07 02.
Article in English | MEDLINE | ID: mdl-38956202

ABSTRACT

Posttraumatic stress disorder (PTSD) can develop after trauma exposure. Some studies report that women develop PTSD at twice the rate of men, despite greater trauma exposure in men. Lipids and their metabolites (lipidome) regulate a myriad of key biological processes and pathways such as membrane integrity, oxidative stress, and neuroinflammation in the brain by maintaining neuronal connectivity and homeostasis. In this study, we analyzed the lipidome of 40 adults with PTSD and 40 trauma-exposed non-PTSD individuals (n = 20/sex/condition; 19-39 years old). Plasma samples were analyzed for lipidomics using Quadrupole Time-of-Flight (QToF) mass spectrometry. Additionally, ~ 90 measures were collected, on sleep, and mental and physical health indices. Poorer sleep quality was associated with greater PTSD severity in both sexes. The lipidomics analysis identified a total of 348 quantifiable known lipid metabolites and 1951 lipid metabolites that are yet unknown; known metabolites were part of 13 lipid subclasses. After adjusting for BMI and sleep quality, in women with PTSD, only one lipid subclass, phosphatidylethanolamine (PE) was altered, whereas, in men with PTSD, 9 out of 13 subclasses were altered compared to non-PTSD women and men, respectively. Severe PTSD was associated with 22% and 5% of altered lipid metabolites in men and women, respectively. Of the changed metabolites, only 0.5% measures (2 PEs and cholesterol) were common between women and men with PTSD. Several sphingomyelins, PEs, ceramides, and triglycerides were increased in men with severe PTSD. The correlations between triglycerides and ceramide metabolites with cholesterol metabolites and systolic blood pressure were dependent upon sex and PTSD status. Alterations in triglycerides and ceramides are linked with cardiac health and metabolic function in humans. Thus, disturbed sleep and higher body mass may have contributed to changes in the lipidome found in PTSD.


Subject(s)
Lipidomics , Stress Disorders, Post-Traumatic , Humans , Stress Disorders, Post-Traumatic/metabolism , Stress Disorders, Post-Traumatic/blood , Male , Female , Adult , Lipidomics/methods , Young Adult , Lipids/blood , Cohort Studies , Lipid Metabolism
6.
J Transl Med ; 22(1): 620, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38961383

ABSTRACT

BACKGROUND: COVID-19 is primarily considered a respiratory tract infection, but it can also affect the central nervous system (CNS), which can result in long-term sequelae. In contrast to CNS infections by classic neurotropic viruses, SARS-CoV-2 is usually not detected in cerebrospinal fluid (CSF) from patients with COVID-19 with neurological involvement (neuro-COVID), suggesting fundamental differences in pathogenesis. METHODS: To assess differences in CNS metabolism in neuro-COVID compared to CNS infections with classic neurotropic viruses, we applied a targeted metabolomic analysis of 630 metabolites to CSF from patients with (i) COVID-19 with neurological involvement [n = 16, comprising acute (n = 13) and post-COVID-19 (n = 3)], (ii) viral meningitis, encephalitis, or myelitis (n = 10) due to herpes simplex virus (n = 2), varicella zoster virus (n = 6), enterovirus (n = 1) and tick-borne encephalitis virus (n = 1), and (iii) aseptic neuroinflammation (meningitis, encephalitis, or myelitis) of unknown etiology (n = 21) as additional disease controls. RESULTS: Standard CSF parameters indicated absent or low neuroinflammation in neuro-COVID. Indeed, CSF cell count was low in neuro-COVID (median 1 cell/µL, range 0-12) and discriminated it accurately from viral CNS infections (AUC = 0.99) and aseptic neuroinflammation (AUC = 0.98). 32 CSF metabolites passed quality assessment and were included in the analysis. Concentrations of differentially abundant (fold change ≥|1.5|, FDR ≤ 0.05) metabolites were both higher (9 and 5 metabolites) and lower (2 metabolites) in neuro-COVID than in the other two groups. Concentrations of citrulline, ceramide (d18:1/18:0), and methionine were most significantly elevated in neuro-COVID. Remarkably, triglyceride TG(20:1_32:3) was much lower (mean fold change = 0.09 and 0.11) in neuro-COVID than in all viral CNS infections and most aseptic neuroinflammation samples, identifying it as highly accurate biomarker with AUC = 1 and 0.93, respectively. Across all samples, TG(20:1_32:3) concentration correlated only moderately with CSF cell count (ρ = 0.65), protein concentration (ρ = 0.64), and Q-albumin (ρ = 0.48), suggesting that its low levels in neuro-COVID CSF are only partially explained by less pronounced neuroinflammation. CONCLUSIONS: The results suggest that CNS metabolite responses in neuro-COVID differ fundamentally from viral CNS infections and aseptic neuroinflammation and may be used to discover accurate diagnostic biomarkers in CSF and to gain insights into differences in pathophysiology between neuro-COVID, viral CNS infections and aseptic neuroinflammation.


Subject(s)
Biomarkers , COVID-19 , Metabolomics , SARS-CoV-2 , Humans , COVID-19/cerebrospinal fluid , COVID-19/virology , Biomarkers/cerebrospinal fluid , Metabolomics/methods , Male , Female , Middle Aged , Aged , Adult , Central Nervous System Infections/cerebrospinal fluid , Central Nervous System Infections/virology , Diagnosis, Differential
7.
Article in English | MEDLINE | ID: mdl-38972782

ABSTRACT

Central ceramides regulate energy metabolism by impacting hypothalamic neurons. This allows ceramides to integrate endocrine signals - such as leptin, ghrelin, thyroid hormones, or estradiol - and to modulate the central control of puberty. In this forum article we discuss recent evidence suggesting that specific ceramide species and neuronal populations are involved in these effects.

8.
Anal Chim Acta ; 1317: 342913, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-39030025

ABSTRACT

BACKGROUND: Lipidomics studies require rapid separations with accurate and reliable quantification results to further elucidate the role of lipids in biological processes and their biological functions. Supercritical fluid chromatography (SFC), in particular, can provide this rapid and high-resolution separation. The combination with trapped ion mobility spectrometry (TIMS) has not yet been applied, although the post-ionization separation method in combination with liquid chromatography or imaging techniques has already proven itself in resolving isomeric and isobaric lipids and preventing false identifications. However, a multidimensional separation method should not only allow confident identification but also provide quantitative results to substantiate studies with absolute concentrations. RESULTS: A SFC method was developed and the hyphenation of SFC and TIMS was further explored towards the separation of different isobaric overlaps. Furthermore, lipid identification was performed using mass spectrometry (MS) and parallel accumulation serial fragmentation (PASEF) MS/MS experiments in addition to retention time and collision cross section (CCS). Quantification was further investigated with short TIMS ramps and performed based on the ion mobility signal of lipids, since TIMS increases the sensitivity by noise filtering. The final method was, as an exemplary study, applied to investigate the function of different ceramide synthases (CerS) in the nematode and model organism Caenorhabditis elegans (C. elegans). Loss of three known CerS hyl-1, hyl-2 and lagr-1 demonstrated different influences on and alterations in the sphingolipidome. SIGNIFICANCE: This method describes for the first time the combination of SFC and TIMS-MS/MS, which enables a fast and sensitive quantification of lipids. The results of the application to C. elegans samples prove the functionality of the method and support research on the metabolism of sphingolipids in nematodes.


Subject(s)
Caenorhabditis elegans , Chromatography, Supercritical Fluid , Ion Mobility Spectrometry , Lipidomics , Lipids , Chromatography, Supercritical Fluid/methods , Caenorhabditis elegans/metabolism , Caenorhabditis elegans/chemistry , Animals , Ion Mobility Spectrometry/methods , Lipidomics/methods , Lipids/analysis , Lipids/chemistry , Mass Spectrometry/methods
9.
Pharmacol Ther ; 260: 108681, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38897295

ABSTRACT

Our skin protects us from external threats including ultraviolet radiation, pathogens and chemicals, and prevents excessive trans-epidermal water loss. These varied activities are reliant on a vast array of lipids, many of which are unique to skin, and that support physical, microbiological and immunological barriers. The cutaneous physical barrier is dependent on a specific lipid matrix that surrounds terminally-differentiated keratinocytes in the stratum corneum. Sebum- and keratinocyte-derived lipids cover the skin's surface and support and regulate the skin microbiota. Meanwhile, lipids signal between resident and infiltrating cutaneous immune cells, driving inflammation and its resolution in response to pathogens and other threats. Lipids of particular importance include ceramides, which are crucial for stratum corneum lipid matrix formation and therefore physical barrier functionality, fatty acids, which contribute to the acidic pH of the skin surface and regulate the microbiota, as well as the stratum corneum lipid matrix, and bioactive metabolites of these fatty acids, involved in cell signalling, inflammation, and numerous other cutaneous processes. These diverse and complex lipids maintain homeostasis in healthy skin, and are implicated in many cutaneous diseases, as well as unrelated systemic conditions with skin manifestations, and processes such as ageing. Lipids also contribute to the gut-skin axis, signalling between the two barrier sites. Therefore, skin lipids provide a valuable resource for exploration of healthy cutaneous processes, local and systemic disease development and progression, and accessible biomarker discovery for systemic disease, as well as an opportunity to fully understand the relationship between the host and the skin microbiota. Investigation of skin lipids could provide diagnostic and prognostic biomarkers, and help identify new targets for interventions. Development and improvement of existing in vitro and in silico approaches to explore the cutaneous lipidome, as well as advances in skin lipidomics technologies, will facilitate ongoing progress in skin lipid research.


Subject(s)
Lipids , Skin Diseases , Skin , Humans , Animals , Skin Diseases/metabolism , Skin/metabolism , Skin/microbiology , Lipid Metabolism , Keratinocytes/metabolism , Microbiota/physiology
10.
Front Neurosci ; 18: 1375299, 2024.
Article in English | MEDLINE | ID: mdl-38911600

ABSTRACT

Introduction: Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare incurable neurodegenerative disease caused by mutations in the SACS gene, which codes for sacsin, a large protein involved in protein homeostasis, mitochondrial function, cytoskeletal dynamics, autophagy, cell adhesion and vesicle trafficking. However, the pathogenic mechanisms underlying sacsin dysfunction are still largely uncharacterized, and so attempts to develop therapies are still in the early stages. Methods: To achieve further understanding of how processes are altered by loss of sacsin, we used untargeted proteomics to compare protein profiles in ARSACS fibroblasts versus controls. Results: Our analyses confirmed the involvement of known biological pathways and also implicated calcium and lipid homeostasis in ARSACS skin fibroblasts, a finding further verified in SH-SY5Y SACS -/- cells. Validation through mass spectrometry-based analysis and comparative quantification of lipids by LC-MS in fibroblasts revealed increased levels of ceramides coupled with a reduction of diacylglycerols. Discussion: In addition to confirming aberrant Ca2+ homeostasis in ARSACS, this study described abnormal lipid levels associated with loss of sacsin.

11.
Clin Res Hepatol Gastroenterol ; 48(7): 102402, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38909684

ABSTRACT

BACKGROUND: Diabetes and obesity are associated with altered lipid metabolism and hepatic steatosis. Studies suggest that increases in lipid accumulation in these patients with metabolic dysfunction-associated steatotic liver disease (MASLD) are not uniform for all lipid components. This study evaluates this variation. METHODS: A comprehensive lipidomic analysis of different lipid groups, were performed on liver tissue and plasma samples obtained at the time of histology from a well-defined cohort of 72 MASLD participants. The lipid profiles of controls were compared to those of MASLD patients with obesity, diabetes, or a combination of both. RESULTS: MASLD patients without obesity or diabetes exhibited distinct changes in the lipid profile of their liver tissue. The presence of diabetes or obesity further modified these lipid profiles (e.g., ceramide 47:7;4O), with positive or negative correlation (p < 0.05). A step-wise increase (long-chain fatty acids, triglycerides, and ceramides) or decrease (ultra-long fatty acids, diglycerides, and phospholipids) for lipid groups was observed compared to control among patients with MASLD without obesity or diabetes to MASLD patients with obesity as a single risk factor, and MASLD patients with obesity and diabetes. Changes in lipids observed in the plasma did not align with their corresponding liver tissue findings. CONCLUSION: The changes observed in the composition of lipids are not similar in patients with obesity and diabetes among those with MASLD. This highlights the different metabolic processes at play. The presence of obesity or diabetes in patients with MASLD exacerbates these lipid derangements, underscoring the potential for targeted intervention in MASLD patients.

12.
Nutrients ; 16(11)2024 May 26.
Article in English | MEDLINE | ID: mdl-38892556

ABSTRACT

Sphingosine-1-phosphate lyase (SPL) resides at the endpoint of the sphingolipid metabolic pathway, catalyzing the irreversible breakdown of sphingosine-1-phosphate. Depletion of SPL precipitates compromised muscle morphology and function; nevertheless, the precise mechanistic underpinnings remain elusive. Here, we elucidate a model of SPL functional deficiency in Caenorhabditis elegans using spl-1 RNA interference. Within these SPL-deficient nematodes, we observed diminished motility and perturbed muscle fiber organization, correlated with the accumulation of sphingoid bases, their phosphorylated forms, and ceramides (collectively referred to as the "sphingolipid rheostat"). The disturbance in mitochondrial morphology was also notable, as SPL functional loss resulted in heightened levels of reactive oxygen species. Remarkably, the administration of the antioxidant N-acetylcysteine (NAC) ameliorates locomotor impairment and rectifies muscle fiber disarray, underscoring its therapeutic promise for ceramide-accumulation-related muscle disorders. Our findings emphasize the pivotal role of SPL in preserving muscle integrity and advocate for exploring antioxidant interventions, such as NAC supplementation, as prospective therapeutic strategies for addressing muscle function decline associated with sphingolipid/ceramide metabolism disruption.


Subject(s)
Acetylcysteine , Aldehyde-Lyases , Caenorhabditis elegans , Ceramides , Sphingolipids , Animals , Caenorhabditis elegans/drug effects , Acetylcysteine/pharmacology , Ceramides/metabolism , Aldehyde-Lyases/metabolism , Sphingolipids/metabolism , Reactive Oxygen Species/metabolism , Antioxidants/pharmacology , Antioxidants/metabolism , Muscles/drug effects , Muscles/metabolism , RNA Interference , Sphingosine/analogs & derivatives , Sphingosine/metabolism
13.
Article in English | MEDLINE | ID: mdl-38895980

ABSTRACT

Elevated skeletal muscle diacylglycerols (DAG) and ceramides can impair insulin signaling, and acylcarnitines (acylCN) reflect impaired fatty acid oxidation, thus the intramuscular lipid profile is indicative of insulin resistance. Acute (i.e., postprandial) hyperinsulinemia has been shown to elevate lipids in healthy muscle and is an independent risk factor for type 2 diabetes (T2D). It is unclear how the relationship between acute hyperinsulinemia and the muscle lipidome interacts, thus contributing to or exacerbating insulin resistance. We investigated the impact of acute hyperinsulinemia on the muscle lipidome in order to help characterize the physiological basis in which hyperinsulinemia elevates T2D risk. Endurance athletes (n=12), sedentary lean adults (n=12), and individuals with obesity (n=13) and T2D (n=7) underwent a hyperinsulinemic-euglycemic clamp with muscle biopsies. While there were no significant differences in total 1,2-DAG fluctuations, there was a 2% decrease in athletes versus a 53% increase in T2D. C18 1,2-DAGs increased during the clamp with T2D only, which negatively correlated with insulin sensitivity. Basal muscle C18:0 ceramides were elevated with T2D, but not altered by clamp. Acylcarnitines were universally lowered during hyperinsulinemia, with more robust reductions of 80% in athletes compared to only 46% with T2D. Similar fluctuations with acute hyperinsulinemia increasing 1,2 DAGs in insulin-resistant phenotypes and universally lowering acylcarnitines were observed in male mice. In conclusion, acute hyperinsulinemia elevates muscle 1,2-DAG levels with insulin-resistant phenotypes. This suggests a possible dysregulation of intramuscular lipid metabolism in the fed state in individuals with low insulin sensitivity, which may exacerbate insulin resistance.

14.
Cell Commun Signal ; 22(1): 304, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38831326

ABSTRACT

Elevated concentrations of palmitate in serum of obese individuals can impair endothelial function, contributing to development of cardiovascular disease. Although several molecular mechanisms of palmitate-induced endothelial dysfunction have been proposed, there is no consensus on what signaling event is the initial trigger of detrimental palmitate effects. Here we report that inhibitors of ER stress or ceramid synthesis can rescue palmitate-induced autophagy impairment in macro- and microvascular endothelial cells. Furthermore, palmitate-induced cholesterol synthesis was reverted using these inhibitors. Similar to cell culture data, autophagy markers were increased in serum of obese individuals. Subsequent lipidomic analysis revealed that palmitate changed the composition of membrane phospholipids in endothelial cells and that these effects were not reverted upon application of above-mentioned inhibitors. However, ER stress inhibition in palmitate-treated cells enhanced the synthesis of trilglycerides and restored ceramide levels to control condition. Our results suggest that palmitate induces ER-stress presumably by shift in membrane architecture, leading to impaired synthesis of triglycerides and enhanced production of ceramides and cholesterol, which altogether enhances lipotoxicity of palmitate in endothelial cells.


Subject(s)
Endoplasmic Reticulum Stress , Endothelial Cells , Endoplasmic Reticulum Stress/drug effects , Humans , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Autophagy/drug effects , Triglycerides/metabolism , Cholesterol/metabolism , Palmitates/pharmacology , Ceramides/metabolism
16.
Article in English | MEDLINE | ID: mdl-38899471

ABSTRACT

Ceramides, a group of biologically active sphingolipids, have been described as the new cholesterol given strong evidence linking high plasma ceramide with endothelial damage, risk for early adverse cardiovascular events, and development of cardiometabolic disease. This relationship has sparked great interest in investigating therapeutic targets with the goal of suppressing ceramide formation. However, the growing data challenge this paradigm of ceramide as solely eliciting detrimental effects to the cardiovascular system. Studies show that ceramides are necessary for maintaining proper endothelial redox states, mechanosensation, and membrane integrity. Recent work in preclinical models and isolated human microvessels highlights that the loss of ceramide formation can in fact propagate vascular endothelial dysfunction. Here, we delve into these conflicting findings to evaluate how ceramide may be capable of exerting both beneficial and damaging effects within the vascular endothelium. We propose a unifying theory that while basal levels of ceramide in response to physiological stimuli are required for the production of vasoprotective metabolites such as S1P (sphingosine-1-phosphate), the chronic accumulation of ceramide can promote activation of pro-oxidative stress pathways in endothelial cells. Clinically, the evidence discussed here highlights the potential challenges associated with therapeutic suppression of ceramide formation as a means of reducing cardiovascular disease risk.

17.
Biochimie ; 223: 159-165, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38825062

ABSTRACT

The central nervous system continuously detects circulating concentrations of lipids such as fatty acids and troglycerides. Once information has been detected, the central nervous system can in turn participate in the control of energy balance and blood sugar levels and in particular regulate the secretion and action of insulin. Neurons capable of detecting circulating lipid variations are located in the hypothalamus and in other regions such as the nucleus accumbens, the striatum or the hippocampus. An excess of lipids will have deleterious effects and may induce central lipotoxicity, in particular following local production of ceramides and the appearance of neuroinflammation which may lead to metabolic diseases such as obesity and type 2 diabetes.


Subject(s)
Energy Metabolism , Humans , Animals , Brain/metabolism , Lipid Metabolism , Obesity/metabolism , Neurons/metabolism , Diabetes Mellitus, Type 2/metabolism
18.
J Am Heart Assoc ; 13(13): e032536, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38904223

ABSTRACT

BACKGROUND: A growing body of research indicates that associations of ceramides and sphingomyelins with mortality depend on the chain length of the fatty acid acylated to the backbone sphingoid base. We examined associations of 8 ceramide and sphingomyelin species with mortality among an American Indian population. METHODS AND RESULTS: The analysis comprised 2688 participants from the SHFS (Strong Heart Family Study). Plasma ceramide and sphingomyelin species carrying long-chain (ie, 16:0) and very-long-chain (ie, 20:0, 22:0, 24:0) saturated fatty acids were measured by sequential liquid chromatography and mass spectroscopy using samples from 2001 to 2003. Participants were followed for 18.8 years (2001-2020). Associations of ceramides and sphingomyelins with mortality were assessed using Cox models. The mean age of participants was 40.8 years. There were 574 deaths during a median 17.4-year follow-up. Ceramides and sphingomyelins carrying fatty acid 16:0 were positively associated with mortality. Ceramides and sphingomyelins carrying longer fatty acids were inversely associated with mortality. Per SD difference in each ceramide and sphingomyelin species, hazard ratios for death were: 1.68 (95% CI, 1.44-1.96) for ceramide-16 (Cer-16), 0.82 (95% CI, 0.71-0.95) for Cer-20, 0.60 (95% CI, 0.51-0.70) for Cer-22, 0.67 (95% CI, 0.56-0.79) for Cer-24, 1.80 (95% CI-1.57, 2.05) for sphingomyelin-16 (SM-16), 0.54 (95% CI, 0.47-0.62) for SM-20, 0.50 (95% CI, 0.44-0.57) for SM-22, and 0.59 (95% CI, 0.52-0.67) for SM-24. CONCLUSIONS: The direction/magnitude of associations of ceramides and sphingomyelins with mortality differs according to the length of the fatty acid acylated to the backbone sphingoid base. REGISTRATION: URL: https://www.clinicatrials.gov; Unique identifier: NCT00005134.


Subject(s)
Cause of Death , Ceramides , Sphingolipids , Sphingomyelins , Humans , Male , Female , Adult , Middle Aged , Ceramides/blood , Sphingomyelins/blood , Sphingolipids/blood , United States/epidemiology , Biomarkers/blood , Risk Factors , American Indian or Alaska Native/statistics & numerical data , Fatty Acids/blood , Risk Assessment
20.
Adv Exp Med Biol ; 1447: 151-167, 2024.
Article in English | MEDLINE | ID: mdl-38724792

ABSTRACT

The pathogenesis of atopic dermatitis (AD) is complex and multifactorial. However, recent advancements in the genetics and pathophysiology of AD suggest that epidermal barrier dysfunction is paramount in the development and progression of the condition (Boguniewicz M, Leung DYM, Immunol Rev 242(1):233-246, 2011). In addition to standard therapy for AD, there are a plethora of nonprescription treatment modalities which may be employed. Over-the-counter treatments for atopic dermatitis can come in the form of topical corticosteroids, moisturizers/emollients, and oral antihistamines. Though these treatments are beneficial, prescription treatments may be quicker acting and more efficacious in patients with moderate to severe disease or during flares. OTC agents are best used for maintenance between flares and to prevent progression of mild disease. Alternative and complementary treatments lack strong efficacy evidence. However, wet wraps, bleach baths, and other treatments appear to be promising when used in conjunction with conventional treatments. With the financial burden of atopic dermatitis ranging from 364 million to 3.8 billion dollars each year in the United States, we suspect this topic will gain further research attention.


Subject(s)
Dermatitis, Atopic , Histamine Antagonists , Nonprescription Drugs , Humans , Adrenal Cortex Hormones/therapeutic use , Dermatitis, Atopic/drug therapy , Emollients/therapeutic use , Histamine Antagonists/therapeutic use , Nonprescription Drugs/therapeutic use
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