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22 pages, 1987 KiB

Open AccessArticle

Analysis of the Phospholipid Profile of the Collection Strain PAO1 and Clinical Isolates of Pseudomonas aeruginosa in Relation to Their Attachment Capacity

by Caroline Le Sénéchal, Mathilde Puges, Christophe Barthe, Patricia Costaglioli, Caroline Tokarski, Corinne Buré and Sébastien Vilain

Int. J. Mol. Sci. 2021, 22(8), 4003; https://doi.org/10.3390/ijms22084003 - 13 Apr 2021

Cited by 1 | Viewed by 1695

Abstract

Bacteria form multicellular and resistant structures named biofilms. Biofilm formation starts with the attachment phase, and the molecular actors involved in this phase, except adhesins, are poorly characterized. There is growing evidence that phospholipids are more than simple structural bricks. They are involved [...] Read more.

Bacteria form multicellular and resistant structures named biofilms. Biofilm formation starts with the attachment phase, and the molecular actors involved in this phase, except adhesins, are poorly characterized. There is growing evidence that phospholipids are more than simple structural bricks. They are involved in bacterial adaptive physiology, but little is known about their role in biofilm formation. Here, we report a mass spectrometry analysis of the phospholipid (PL) profile of several strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients. The aim of our study was to evaluate a possible link between the PL profile of a strain and its attachment phenotype. Our results showed that PL profile is strongly strain-dependent. The PL profile of P. aeruginosa PAO1, a collection strain, was different from those of 10 clinical isolates characterized either by a very low or a very high attachment capacity. We observed also that the clinical strain’s PL profiles varied even more importantly between isolates. By comparing groups of strains having similar attachment capacities, we identified one PL, PE 18:1-18:1, as a potential molecular actor involved in attachment, the first step in biofilm formation. This PL represents a possible target in the fight against biofilms. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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20 pages, 2304 KiB

Open AccessArticle

Phosphatidic Acid Stimulates Myoblast Proliferation through Interaction with LPA1 and LPA2 Receptors

by Ana Gomez-Larrauri, Patricia Gangoiti, Natalia Presa, Asier Dominguez-Herrera, Chiara Donati, Paola Bruni, Miguel Trueba, Antonio Gomez-Muñoz and Alberto Ouro

Int. J. Mol. Sci. 2021, 22(3), 1452; https://doi.org/10.3390/ijms22031452 - 01 Feb 2021

Cited by 7 | Viewed by 3198

Abstract

Phosphatidic acid (PA) is a bioactive phospholipid capable of regulating key biological functions, including neutrophil respiratory burst, chemotaxis, or cell growth and differentiation. However, the mechanisms whereby PA exerts these actions are not completely understood. In this work, we show that PA stimulates [...] Read more.

Phosphatidic acid (PA) is a bioactive phospholipid capable of regulating key biological functions, including neutrophil respiratory burst, chemotaxis, or cell growth and differentiation. However, the mechanisms whereby PA exerts these actions are not completely understood. In this work, we show that PA stimulates myoblast proliferation, as determined by measuring the incorporation of [³H]thymidine into DNA and by staining the cells with crystal violet. PA induced the rapid phosphorylation of Akt and ERK1/2, and pretreatment of the cells with specific small interferin RNA (siRNA) to silence the genes encoding these kinases, or with selective pharmacologic inhibitors, blocked PA-stimulated myoblast proliferation. The mitogenic effects of PA were abolished by the preincubation of the myoblasts with pertussis toxin, a Gi protein inhibitor, suggesting the implication of Gi protein-coupled receptors in this action. Although some of the effects of PA have been associated with its possible conversion to lysoPA (LPA), treatment of the myoblasts with PA for up to 60 min did not produce any significant amount of LPA in these cells. Of interest, pharmacological blockade of the LPA receptors 1 and 2, or specific siRNA to silence the genes encoding these receptors, abolished PA-stimulated myoblast proliferation. Moreover, PA was able to compete with LPA for binding to LPA receptors, suggesting that PA can act as a ligand of LPA receptors. It can be concluded that PA stimulates myoblast proliferation through interaction with LPA1 and LPA2 receptors and the subsequent activation of the PI3K/Akt and MEK/ERK1-2 pathways, independently of LPA formation. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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21 pages, 2868 KiB

Open AccessArticle

Untargeted Lipidomics Analysis of the Cyanobacterium Synechocystis sp. PCC 6803: Lipid Composition Variation in Response to Alternative Cultivation Setups and to Gene Deletion

by Weronika Hewelt-Belka, Ágata Kot-Wasik, Paula Tamagnini and Paulo Oliveira

Int. J. Mol. Sci. 2020, 21(23), 8883; https://doi.org/10.3390/ijms21238883 - 24 Nov 2020

Cited by 13 | Viewed by 3340

Abstract

Cyanobacteria play an important role in several ecological environments, and they are widely accepted to be the ancestors of chloroplasts in modern plants and green algae. Cyanobacteria have become attractive models for metabolic engineering, with the goal of exploring them as microbial cell [...] Read more.

Cyanobacteria play an important role in several ecological environments, and they are widely accepted to be the ancestors of chloroplasts in modern plants and green algae. Cyanobacteria have become attractive models for metabolic engineering, with the goal of exploring them as microbial cell factories. However, the study of cyanobacterial lipids’ composition and variation, and the assessment of the lipids’ functional and structural roles have been largely overlooked. Here, we aimed at expanding the cyanobacterial lipidomic analytical pipeline by using an untargeted lipidomics approach. Thus, the lipid composition variation of the model cyanobacterium Synechocystis sp. PCC 6803 was investigated in response to both alternative cultivation setups and gene deletion. This approach allowed for detecting differences in total lipid content, alterations in fatty-acid unsaturation level, and adjustments of specific lipid species among the identified lipid classes. The employed method also revealed that the cultivation setup tested in this work induced a deeper alteration of the cyanobacterial cell lipidome than the deletion of a gene that results in a dramatic increase in the release of lipid-rich outer membrane vesicles. This study further highlights how growth conditions must be carefully selected when cyanobacteria are to be engineered and/or scaled-up for lipid or fatty acids production. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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14 pages, 3924 KiB

Open AccessArticle

Pro-Resolving Lipid Mediator Resolvin E1 Mitigates the Progress of Diethylnitrosamine-Induced Liver Fibrosis in Sprague-Dawley Rats by Attenuating Fibrogenesis and Restricting Proliferation

by Maria José Rodríguez, Francisca Herrera, Wendy Donoso, Iván Castillo, Roxana Orrego, Daniel R. González and Jessica Zúñiga-Hernández

Int. J. Mol. Sci. 2020, 21(22), 8827; https://doi.org/10.3390/ijms21228827 - 22 Nov 2020

Cited by 8 | Viewed by 2260

Abstract

Liver fibrosis is a complex process associated to most types of chronic liver disease, which is characterized by a disturbance of hepatic tissue architecture and the excessive accumulation of extracellular matrix. Resolvin E1 (RvE1) is a representative member of the eicosapentaenoic omega-3 lipid [...] Read more.

Liver fibrosis is a complex process associated to most types of chronic liver disease, which is characterized by a disturbance of hepatic tissue architecture and the excessive accumulation of extracellular matrix. Resolvin E1 (RvE1) is a representative member of the eicosapentaenoic omega-3 lipid derivatives, and is a drug candidate of the growing family of endogenous resolvins. Considering the aforementioned, the main objective of this study was to analyze the hepatoprotective effect of RvE1 in a rat model of liver fibrosis. Male Sprague-Dawley rats received diethylnitrosamine (DEN, 70 mg/mg body weight intraperitoneally (i.p)) as an inductor of liver fibrosis once weekly and RvE1(100 ng/body weight i.p) twice weekly for four weeks. RvE1 suppressed the alterations induced by DEN, normalizing the levels of alanine aminotransferase (ALT), albumin, and lactate dehydrogenase (LDH), and ameliorated DEN injury by decreasing the architecture distortion, inflammatory infiltration, necrotic areas, and microsteatosis. RvE1 also limited DEN-induced proliferation through a decrease in Ki67-positive cells and cyclin D1 protein expression, which is related to an increase of the levels of cleaved caspase-3. Interestingly, we found that RvE1 promotes higher nuclear translocation of nuclear factor κB (NF-κB)p65 than DEN. RvE1 also increased the levels of nuclear the nuclear factor erythroid 2–related factor 2 (Nrf2), but with no antioxidant effect, measured as an increase in glutathione disulfide (GSSG) and a decrease in the ratio of glutathione (GSH)/GSSG. Taken together, these results suggest that RvE1 modulates the fibrogenesis, steatosis, and cell proliferation in a model of DEN induced fibrosis. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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25 pages, 5588 KiB

Open AccessArticle

Influence of Lipoxygenase Inhibition on Glioblastoma Cell Biology

by Felipe da Costa Souza, Matthew Thomas Ferreira and Alison Colquhoun

Int. J. Mol. Sci. 2020, 21(21), 8395; https://doi.org/10.3390/ijms21218395 - 09 Nov 2020

Cited by 14 | Viewed by 6390

Abstract

Background: The relationship between glioblastoma (GBM) and fatty acid metabolism could be the key to elucidate more effective therapeutic targets. 15-lipoxygenase-1 (15-LOX), a linolenic acid and arachidonic acid metabolizing enzyme, induces both pro- and antitumorigenic effects in different cancer types. Its role in [...] Read more.

Background: The relationship between glioblastoma (GBM) and fatty acid metabolism could be the key to elucidate more effective therapeutic targets. 15-lipoxygenase-1 (15-LOX), a linolenic acid and arachidonic acid metabolizing enzyme, induces both pro- and antitumorigenic effects in different cancer types. Its role in glioma activity has not yet been clearly described. The objective of this study was to identify the influence of 15-LOX and its metabolites on glioblastoma cell activity. Methods: GBM cell lines were examined using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to identify 15-LOX metabolites. GBM cells treated with 15-LOX metabolites, 13-hydroxyoctadecadeinoic acid (HODE) and 9-HODE, and two 15-LOX inhibitors (luteolin and nordihydroguaiaretic acid) were also examined. Dose response/viability curves, RT-PCRs, flow cytometry, migration assays, and zymograms were performed to analyze GBM growth, migration, and invasion. Results: Higher quantities of 13-HODE were observed in five GBM cell lines compared to other lipids analyzed. Both 13-HODE and 9-HODE increased cell count in U87MG. 15-LOX inhibition decreased migration and increased cell cycle arrest in the G2/M phase. Conclusion: 15-LOX and its linoleic acid (LA)-derived metabolites exercise a protumorigenic influence on GBM cells in vitro. Elevated endogenous levels of 13-HODE called attention to the relationship between linoleic acid metabolism and GBM cell activity. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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27 pages, 4070 KiB

Open AccessArticle

Moderate High Caloric Maternal Diet Impacts Dam Breast Milk Metabotype and Offspring Lipidome in a Sex-Specific Manner

by Marie-Cécile Alexandre-Gouabau, Agnès David-Sochard, Anne-Lise Royer, Patricia Parnet and Vincent Paillé

Int. J. Mol. Sci. 2020, 21(15), 5428; https://doi.org/10.3390/ijms21155428 - 30 Jul 2020

Cited by 8 | Viewed by 2859

Abstract

Lactation is a critical period during which maternal sub- or over-nutrition affect milk composition and offspring development that can have lasting health effects. The consequences of moderate high-fat, high-simple carbohydrate diet (WD) consumption by rat dams, during gestation and lactation, on milk composition [...] Read more.

Lactation is a critical period during which maternal sub- or over-nutrition affect milk composition and offspring development that can have lasting health effects. The consequences of moderate high-fat, high-simple carbohydrate diet (WD) consumption by rat dams, during gestation and lactation, on milk composition and offspring blood lipidome and its growth, at weaning, were investigated by using a comprehensive lipidomic study on mass-spectrometric platform combined to targeted fatty- and free amino-acids analysis. This holistic approach allowed clear-cut differences in mature milk-lipidomic signature according to maternal diet with a similar content of protein, lactose and leptin. The lower WD-milk content in total fat and triglycerides (TGs), particularly in TGs-with saturated medium-chain, and higher levels in both sphingolipid (SL) and TG species with unsaturated long-chain were associated to a specific offspring blood-lipidome with decreased levels in TGs-containing saturated fatty acid (FA). The sexual-dimorphism in the FA-distribution in TG (higher TGs-rich in oleic and linoleic acids, specifically in males) and SL species (increased levels in very long-chain ceramides, specifically in females) could be associated with some differences that we observed between males and females like a higher total body weight gain in females and an increased preference for fatty taste in males upon weaning. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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14 pages, 2191 KiB

Open AccessArticle

Oxylipin Profiles as Functional Characteristics of Acute Inflammatory Responses in Astrocytes Pre-Treated with IL-4, IL-10, or LPS

by Dmitry V. Chistyakov, Gleb E. Gavrish, Sergei V. Goriainov, Viktor V. Chistyakov, Alina A. Astakhova, Nadezda V. Azbukina and Marina G. Sergeeva

Int. J. Mol. Sci. 2020, 21(5), 1780; https://doi.org/10.3390/ijms21051780 - 05 Mar 2020

Cited by 19 | Viewed by 3651

Abstract

Functional phenotypes, which cells can acquire depending on the microenvironment, are currently the focus of investigations into new anti-inflammatory therapeutic approaches. Glial cells, microglia, and astrocytes are major participants in neuroinflammation, but their roles differ, as microglia are cells of mesodermal origin, while [...] Read more.

Functional phenotypes, which cells can acquire depending on the microenvironment, are currently the focus of investigations into new anti-inflammatory therapeutic approaches. Glial cells, microglia, and astrocytes are major participants in neuroinflammation, but their roles differ, as microglia are cells of mesodermal origin, while astrocytes are cells of ectodermal origin. The inflammatory phenotype of cells can be modulated by ω-6- and ω-3-polyunsaturated fatty acid-derived oxylipins, although data on changes in oxylipin profiles in different cell adaptations to pro- and anti-inflammatory stimuli are scarce. Our study aimed to compare UPLC-MS/MS-measured oxylipin profiles in various rat astrocyte adaptation states. We used cells treated for 24 h with lipopolysaccharide (LPS) for classical pro-inflammatory adaptation and with interleukin 4 (IL-4) or 10 (IL-10) for alternative anti-inflammatory adaptation, with the resulting phenotypes characterized by quantitative real-time PCR (RT-PCR). We also tested long-term, low-concentration LPS treatment (endotoxin treatment) as a model of astrocyte adaptations. The functional response of astrocytes was estimated by acute (4 h) LPS-induced cell reactivity, measured by gene expression markers and oxylipin synthesis. We discovered that, as well as gene markers, oxylipin profiles can serve as markers of pro- (A1-like) or anti-inflammatory (A2-like) adaptations. We observed predominant involvement of ω-6 polyunsaturated fatty acid (PUFA) and the cyclooxygenase branch for classical (LPS) pro-inflammatory adaptations and ω-3 PUFA and the lipoxygenase branch for alternative (IL-4) anti-inflammatory adaptations. Treatment with IL-4, but not IL-10, primes the ability of astrocytes to activate the innate immunity signaling pathways in response to LPS. Endotoxin-treated astrocytes provide an alternative anti-inflammatory adaptation, which makes cells less sensitive to acute LPS stimulation than the IL-4 induced adaptation. Taken together, the data reveal that oxylipin profiles associate with different states of polarization to generate a pro-inflammatory or anti-inflammatory phenotype. This association manifests itself both in native cells and in their responses to a pro-inflammatory stimulus. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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18 pages, 6629 KiB

Open AccessArticle

Maresin 1, a Proresolving Lipid Mediator, Ameliorates Liver Ischemia-Reperfusion Injury and Stimulates Hepatocyte Proliferation in Sprague-Dawley Rats

by Gonzalo Soto, María José Rodríguez, Roberto Fuentealba, Adriana V. Treuer, Iván Castillo, Daniel R. González and Jessica Zúñiga-Hernández

Int. J. Mol. Sci. 2020, 21(2), 540; https://doi.org/10.3390/ijms21020540 - 15 Jan 2020

Cited by 30 | Viewed by 3568

Abstract

Maresin-1 (MaR1) is a specialized pro-resolving mediator, derived from omega-3 fatty acids, whose functions are to decrease the pro-inflammatory and oxidative mediators, and also to stimulate cell division. We investigated the hepatoprotective actions of MaR1 in a rat model of liver ischemia-reperfusion (IR) [...] Read more.

Maresin-1 (MaR1) is a specialized pro-resolving mediator, derived from omega-3 fatty acids, whose functions are to decrease the pro-inflammatory and oxidative mediators, and also to stimulate cell division. We investigated the hepatoprotective actions of MaR1 in a rat model of liver ischemia-reperfusion (IR) injury. MaR1 (4 ng/gr body weight) was administered prior to ischemia (1 h) and reperfusion (3 h), and controls received isovolumetric vehicle solution. To analyze liver function, transaminases levels and tissue architecture were assayed, and serum cytokines TNF-α, IL-6, and IL-10, mitotic activity index, and differential levels of NF-κB and Nrf-2 transcription factors, were analyzed. Transaminase, TNF-α levels, and cytoarchitecture were normalized with the administration of MaR1 and associated with changes in NF-κB. IL-6, mitotic activity index, and nuclear translocation of Nrf-2 increased in the MaR1-IR group, which would be associated with hepatoprotection and cell proliferation. Taken together, these results suggest that MaR1 alleviated IR liver injury, facilitated by the activation of hepatocyte cell division, increased IL-6 cytokine levels, and the nuclear localization of Nrf-2, with a decrease of NF-κB activity. All of them were related to an improvement of liver injury parameters. These results open the possibility of MaR1 as a potential therapeutic tool in IR and other hepatic pathologies. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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18 pages, 3767 KiB

Open AccessArticle

25-Hydroxycholesterol Inhibits Adipogenic Differentiation of C3H10T1/2 Pluripotent Stromal Cells

by Dorothy Moseti, Alemu Regassa, Chongxiao Chen, Karmin O and Woo Kyun Kim

Int. J. Mol. Sci. 2020, 21(2), 412; https://doi.org/10.3390/ijms21020412 - 09 Jan 2020

Cited by 8 | Viewed by 2681

Abstract

Understanding of adipogenesis is important to find remedies for obesity and related disorders. In addition, it is also critical in bone disorders because there is a reciprocal relationship between adipogenesis and osteogenesis in bone micro-environment. Oxysterols are pro-osteogenic and anti-adipogenic molecules via hedgehog [...] Read more.

Understanding of adipogenesis is important to find remedies for obesity and related disorders. In addition, it is also critical in bone disorders because there is a reciprocal relationship between adipogenesis and osteogenesis in bone micro-environment. Oxysterols are pro-osteogenic and anti-adipogenic molecules via hedgehog activation in pluripotent bone marrow stomal cells. However, no study has evaluated the role of specific oxysterols in C3H10T1/2 cells, which are a good cell model for studying osteogenesis and adipogenesis in bone-marrows. Thus, we investigated the effects of specific oxysterols on adipogenesis and expression of adipogenic transcripts in C3H10T1/2 cells. Treatment of cells with DMITro significantly induced mRNA expression of Pparγ. This induction was significantly inhibited by 25-HC. The expression of C/cepα, Fabp4 and Lpl was also inhibited by 25-HC. To determine the mechanism by which 25-HC inhibits adipogenesis, the effects of the hedgehog signalling pathway inhibitor, cyclopamine and CUR61414, were evaluated. Treatment of C3H10T1/2 cells with DMITro + cyclopamine or DMITro + CUR61414 for 96h did not modulate adipocyte differentiation; cyclopamine and CUR61414 did not reverse the inhibitory effects of 25-HC, suggesting that the canonical hedgehog signalling may not play a role in the anti-adipogenic effects of 25-HC in C3H10T1/2 cells. In addition, LXR agonist did not inhibit adipogenesis, but 25-HC strongly inhibits adipogenesis of C3H10T1/2 cells. Our observations showed that 25-HC was the most potent oxysterol in inhibiting adipogenesis and the expression of key adipogenic transcripts in C3H10T1/2 cells among the tested oxysterols, suggesting its potential application in providing an intervention in osteoporosis and obesity. We also report that the inhibitory effects of 25-HC on adipogenic differentiation in C3H10T1/2 cells are not mediated by hedgehog signaling and LXR. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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18 pages, 11059 KiB

Open AccessArticle

Contribution of Palmitic Acid to Epidermal Morphogenesis and Lipid Barrier Formation in Human Skin Equivalents

by Arnout Mieremet, Richard Helder, Andreea Nadaban, Gert Gooris, Walter Boiten, Abdoelwaheb El Ghalbzouri and Joke A. Bouwstra

Int. J. Mol. Sci. 2019, 20(23), 6069; https://doi.org/10.3390/ijms20236069 - 02 Dec 2019

Cited by 20 | Viewed by 4091

Abstract

The outermost barrier layer of the skin is the stratum corneum (SC), which consists of corneocytes embedded in a lipid matrix. Biosynthesis of barrier lipids occurs de novo in the epidermis or is performed with externally derived lipids. Hence, in vitro developed human [...] Read more.

The outermost barrier layer of the skin is the stratum corneum (SC), which consists of corneocytes embedded in a lipid matrix. Biosynthesis of barrier lipids occurs de novo in the epidermis or is performed with externally derived lipids. Hence, in vitro developed human skin equivalents (HSEs) are developed with culture medium that is supplemented with free fatty acids (FFAs). Nevertheless, the lipid barrier formation in HSEs remains altered compared to native human skin (NHS). The aim of this study is to decipher the role of medium supplemented saturated FFA palmitic acid (PA) on morphogenesis and lipid barrier formation in HSEs. Therefore, HSEs were developed with 100% (25 μM), 10%, or 1% PA. In HSEs supplemented with reduced PA level, the early differentiation was delayed and epidermal activation was increased. Nevertheless, a similar SC lipid composition in all HSEs was detected. Additionally, the lipid organization was comparable for lamellar and lateral organization, irrespective of PA concentration. As compared to NHS, the level of monounsaturated lipids was increased and the FFA to ceramide ratio was drastically reduced in HSEs. This study describes the crucial role of PA in epidermal morphogenesis and elucidates the role of PA in lipid barrier formation of HSEs. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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17 pages, 2158 KiB

Open AccessArticle

Changes in Membrane Ceramide Pools in Rat Soleus Muscle in Response to Short-Term Disuse

by Alexey M. Petrov, Maria N. Shalagina, Vladimir A. Protopopov, Valeriy G. Sergeev, Sergey V. Ovechkin, Natalia G. Ovchinina, Alexey V. Sekunov, Andrey L. Zefirov, Guzalia F. Zakirjanova and Irina G. Bryndina

Int. J. Mol. Sci. 2019, 20(19), 4860; https://doi.org/10.3390/ijms20194860 - 30 Sep 2019

Cited by 18 | Viewed by 4469

Abstract

Lipid raft disruption is an early event during skeletal muscle unloading. Ceramide (Cer) serves as a signaling lipid that can contribute to lipid raft disturbance and muscle atrophy. Using biochemical and fluorescent approaches, the distribution of Cer and related molecules in the rat [...] Read more.

Lipid raft disruption is an early event during skeletal muscle unloading. Ceramide (Cer) serves as a signaling lipid that can contribute to lipid raft disturbance and muscle atrophy. Using biochemical and fluorescent approaches, the distribution of Cer and related molecules in the rat soleus muscle subjected to 12 h of hindlimb suspension (HS) was studied. HS led to upregulation of TNFα receptor 1 (TNFR1), Cer-producing enzymes, and acid and neutral sphingomyelinase (SMase) in detergent-resistant membranes (lipid rafts), which was accompanied by an increase in Cer and a decrease in sphingomyelin in this membrane fraction. Fluorescent labeling indicated increased Cer in the sarcoplasm as well as the junctional (synaptic) and extrajunctional compartments of the suspended muscles. Also, a loss of membrane asymmetry (a hallmark of membrane disturbance) was induced by HS. Pretreatment with clomipramine, a functional inhibitor of acid SMase, counteracted HS-mediated changes in the Cer/sphingomyelin ratio and acid SMase abundance as well as suppressed Cer accumulation in the intracellular membranes of junctional and extrajunctional regions. However, the elevation of plasma membrane Cer and disturbance of the membrane asymmetry were suppressed only in the junctional compartment. We suggest that acute HS leads to TNFR1 and SMase upregulation in the lipid raft fraction and deposition of Cer throughout the sarcolemma and intracellularly. Clomipramine-mediated downregulation of acid SMase can suppress Cer accumulation in all compartments, excluding the extrajunctional plasma membrane. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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20 pages, 1832 KiB

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Novel Markers of the Metabolic Impact of Exogenous Retinoic Acid with A Focus on Acylcarnitines and Amino Acids

by Joan Ribot, Andrea Arreguín, Ondrej Kuda, Jan Kopecky, Andreu Palou and Maria Luisa Bonet

Int. J. Mol. Sci. 2019, 20(15), 3640; https://doi.org/10.3390/ijms20153640 - 25 Jul 2019

Cited by 2 | Viewed by 3435

Abstract

Treatment with all-trans retinoic acid (ATRA), the carboxylic form of vitamin A, lowers body weight in rodents by promoting oxidative metabolism in multiple tissues including white and brown adipose tissues. We aimed to identify novel markers of the metabolic impact of ATRA through [...] Read more.

Treatment with all-trans retinoic acid (ATRA), the carboxylic form of vitamin A, lowers body weight in rodents by promoting oxidative metabolism in multiple tissues including white and brown adipose tissues. We aimed to identify novel markers of the metabolic impact of ATRA through targeted blood metabolomics analyses, with a focus on acylcarnitines and amino acids. Blood was obtained from mice treated with a high ATRA dose (50 mg/kg body weight/day, subcutaneous injection) or placebo (controls) during the 4 days preceding collection. LC-MS/MS analyses with a focus on acylcarnitines and amino acids were conducted on plasma and PBMC. Main results showed that, relative to controls, ATRA-treated mice had in plasma: increased levels of carnitine, acetylcarnitine, and longer acylcarnitine species; decreased levels of citrulline, and increased global arginine bioavailability ratio for nitric oxide synthesis; increased levels of creatine, taurine and docosahexaenoic acid; and a decreased n-6/n-3 polyunsaturated fatty acids ratio. While some of these features likely reflect the stimulation of lipid mobilization and oxidation promoted by ATRA treatment systemically, other may also play a causal role underlying ATRA actions. The results connect ATRA to specific nutrition-modulated biochemical pathways, and suggest novel mechanisms of action of vitamin A-derived retinoic acid on metabolic health. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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17 pages, 1150 KiB

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Gangliosides in Podocyte Biology and Disease

by Berkan Savas, Giuseppe Astarita, Massimo Aureli, Dil Sahali and Mario Ollero

Int. J. Mol. Sci. 2020, 21(24), 9645; https://doi.org/10.3390/ijms21249645 - 17 Dec 2020

Cited by 7 | Viewed by 3373

Abstract

Gangliosides constitute a subgroup of glycosphingolipids characterized by the presence of sialic acid residues in their structure. As constituents of cellular membranes, in particular of raft microdomains, they exert multiple functions, some of them capital in cell homeostasis. Their presence in cells is [...] Read more.

Gangliosides constitute a subgroup of glycosphingolipids characterized by the presence of sialic acid residues in their structure. As constituents of cellular membranes, in particular of raft microdomains, they exert multiple functions, some of them capital in cell homeostasis. Their presence in cells is tightly regulated by a balanced expression and function of the enzymes responsible for their biosynthesis, ganglioside synthases, and their degradation, glycosidases. The dysregulation of their abundance results in rare and common diseases. In this review, we make a point on the relevance of gangliosides and some of their metabolic precursors, such as ceramides, in the function of podocytes, the main cellular component of the glomerular filtration barrier, as well as their implications in podocytopathies. The results presented in this review suggest the pertinence of clinical lipidomic studies targeting these metabolites. Full article

(This article belongs to the Special Issue Bioactive Lipids and Lipidomics 2020)

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