251
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Ekman P, Maula T, Yamaguchi S, Yamamoto T, Nyholm TK, Katsumura S, Slotte J. Formation of an ordered phase by ceramides and diacylglycerols in a fluid phosphatidylcholine bilayer — Correlation with structure and hydrogen bonding capacity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2111-7. [DOI: 10.1016/j.bbamem.2015.06.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Revised: 06/18/2015] [Accepted: 06/19/2015] [Indexed: 12/21/2022]
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252
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Ojeda P, Bobe A, Dolan K, Leone V, Martinez K. Nutritional modulation of gut microbiota - the impact on metabolic disease pathophysiology. J Nutr Biochem 2015; 28:191-200. [PMID: 26372091 DOI: 10.1016/j.jnutbio.2015.08.013] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 07/31/2015] [Accepted: 08/12/2015] [Indexed: 02/07/2023]
Abstract
The obesity epidemic afflicts over one third of the United States population. With few therapies available to combat obesity, a greater understanding of the systemic causes of this and other metabolic disorders is needed to develop new, effective treatments. The mammalian intestinal microbiota contributes to metabolic processes in the host. This review summarizes the research demonstrating the interplay of diet, intestinal microbiota and host metabolism. We detail the effects of diet-induced modifications in microbial activity and resultant impact on (1) sensory perception of macronutrients and total energy intake; (2) nutrient absorption, transport and storage; (3) liver and biliary function; (4) immune-mediated signaling related to adipose inflammation; and (5) circadian rhythm. We also discuss therapeutic strategies aimed to modify host-microbe interactions, including prebiotics, probiotics and postbiotics, as well as fecal microbiota transplantation. Elucidating the role of gut microbes in shaping metabolic homeostasis or dysregulation provides greater insight into disease development and a promising avenue for improved treatment of metabolic dysfunction.
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Affiliation(s)
- Patricia Ojeda
- Department of Medicine, Section of Gastroenterology, University of Chicago, Chicago, IL, USA
| | - Alexandria Bobe
- Department of Medicine, Section of Gastroenterology, University of Chicago, Chicago, IL, USA
| | - Kyle Dolan
- Department of Medicine, Section of Gastroenterology, University of Chicago, Chicago, IL, USA
| | - Vanessa Leone
- Department of Medicine, Section of Gastroenterology, University of Chicago, Chicago, IL, USA
| | - Kristina Martinez
- Department of Medicine, Section of Gastroenterology, University of Chicago, Chicago, IL, USA.
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253
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Ong WY, Herr DR, Farooqui T, Ling EA, Farooqui AA. Role of sphingomyelinases in neurological disorders. Expert Opin Ther Targets 2015; 19:1725-42. [DOI: 10.1517/14728222.2015.1071794] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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254
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Aktepe TE, Pham H, Mackenzie JM. Differential utilisation of ceramide during replication of the flaviviruses West Nile and dengue virus. Virology 2015; 484:241-250. [PMID: 26122470 DOI: 10.1016/j.virol.2015.06.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 04/05/2015] [Accepted: 06/12/2015] [Indexed: 01/22/2023]
Abstract
It is well established that +ssRNA viruses manipulate cellular lipid homoeostasis and distribution to facilitate efficient replication. Here, we show that the cellular lipid ceramide is redistributed to the West Nile virus strain Kunjin virus (WNVKUN) replication complex (RC) but not to the dengue virus serotype 2 strain New Guinea C (DENVNGC) RC. We show that prolonged chemical inhibition of serine palmitoyltransferase with myriocin had a significant deleterious effect on WNVKUN replication but enhanced DENVNGC replication. Additionally, inhibition of ceramide synthase with Fumonisin B1 had a detrimental effect on WNVKUN replication and release of infectious virus particles but contrastingly an enhancing effect on DENVNGC replication and virus production. These observations suggest that ceramide production via the de novo and salvage pathway is a requirement for WNVKUN replication but inhibitory for DENVNGC replication. Thus, although these two viruses are from the same genus, they have a differential ceramide requirement for replication.
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Affiliation(s)
- Turgut E Aktepe
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Helen Pham
- Department of Microbiology, La Trobe University, Melbourne, VIC, Australia
| | - Jason M Mackenzie
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
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255
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Carreira AC, Ventura AE, Varela AR, Silva LC. Tackling the biophysical properties of sphingolipids to decipher their biological roles. Biol Chem 2015; 396:597-609. [DOI: 10.1515/hsz-2014-0283] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 01/01/2015] [Indexed: 11/15/2022]
Abstract
Abstract
From the most simple sphingoid bases to their complex glycosylated derivatives, several sphingolipid species were shown to have a role in fundamental cellular events and/or disease. Increasing evidence places lipid-lipid interactions and membrane structural alterations as central mechanisms underlying the action of these lipids. Understanding how these molecules exert their biological roles by studying their impact in the physical properties and organization of membranes is currently one of the main challenges in sphingolipid research. Herein, we review the progress in the state-of-the-art on the biophysical properties of sphingolipid-containing membranes, focusing on sphingosine, ceramides, and glycosphingolipids.
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256
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Beyersdorf N, Müller N. Sphingomyelin breakdown in T cells: role in activation, effector functions and immunoregulation. Biol Chem 2015; 396:749-58. [DOI: 10.1515/hsz-2014-0282] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/03/2015] [Indexed: 11/15/2022]
Abstract
Abstract
Host T cell activation, a key step in obtaining adaptive immunity against pathogens, is initiated by the binding of the T cell receptor to a foreign antigenic peptide presented by the major histocompatibility complex on the surface of an antigen-presenting cell and, consequently, formation of an immunological synapse. Within the immunological synapse, the engagement of the T cell receptor in cooperation with simultaneous ligation of co-stimulatory molecules induces a precisely organized cascade of signaling events and pathways that regulate clonal expansion and differentiation of naïve T cells into effector T cells contributing to pathogen clearance. The biochemical changes that underlie T cell activation and differentiation, however, not only involve proteins but also lipids. In particular, catabolic cleavage of sphingomyelin generating ceramide can substantially influence functional responses in cells of the immune system. Changes in sphingomyelin and ceramide content have been reported to directly impact on membrane physiology, thus modifying signal transmission and interfering with diverse aspects of T cell activity. In this review we will focus on sphingomyelin breakdown/ceramide generation in T cells with regard to their function and development of T cell-mediated immunity.
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257
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Karlsson I, Zhou X, Thomas R, Smith AT, Bonner MY, Bakshi P, Banga AK, Bowen JP, Qabaja G, Ford SL, Ballard MD, Petersen KS, Li X, Chen G, Ogretmen B, Zhang J, Watkins EB, Arnold RS, Arbiser JL. Solenopsin A and analogs exhibit ceramide-like biological activity. Vasc Cell 2015; 7:5. [PMID: 26015865 PMCID: PMC4443652 DOI: 10.1186/s13221-015-0030-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 04/21/2015] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND (-)-Solenopsin A is a piperidine alkaloid that is a component of the venom of the fire ant Solenopsis invicta. Previously, we have demonstrated that solenopsin exhibit anti-angiogenic activity and downregulate phosphoinositol-3 kinase (PI3K) in the p53 deficient renal cell carcinoma cell line 786-O. Solenopsin has structural similarities to ceramide, a major endogenous regulator of cell signaling and cancer therapy induced apoptosis. METHODS Different analogs of solenopsin were synthesized in order to explore structure-activity relationships. The anti-proliferative effect of solenopsin and analogs was tested on six different cell lines, including three tumor cell lines, two normal cutaneous cell lines, and one immortalized hyperproliferative cell line. FRET-based reporters were used to study the affect of solenopsin and analogs on Akt activity and PDK1 activation and sucrose density gradient fractionation was performed to examine recruitment of PTEN to membrane rafts. Western-blotting was used to evaluate the affect of solenopsin and analogs on the Akt and the MAPK 44/42 pathways in three different tumor cell lines. Measurement of cellular oxygen consumption rate together with autophagy staining was performed to study mitochondrial function. Finally, the affect of solenopsin and analogs on ROS production was investigated. RESULTS In this paper we demonstrate that solenopsin analogs with potent anti-proliferative effects can be synthesized from inexpensive dimethylpyridines. To determine whether solenopsin and analogs act as ceramide analogs, we examined the effect of solenopsin and analogs on two stereotypic sites of ceramide activity, namely at lipid rafts and mitochondria. We found that native solenopsin, (-)-solenopsin A, inhibits functional Akt activity and PDK1 activation in lipid rafts in a similar fashion as ceramide. Both cis and trans analogs of solenopsin reduce mitochondrial oxygen consumption, increase reactive oxygen, and kill tumor cells with elevated levels of Akt phosphorylation. However, only solenopsin induces mitophagy, like ceramide. CONCLUSIONS The requirements for ceramide induced mitophagy and inhibition of Akt activity and PDK1 activation in lipid rafts are under strict stereochemical control. The naturally occurring (-)-solenopsin A mimic some of the functions of ceramide and may be therapeutically useful in the treatment of hyperproliferative and malignant disorders of the skin, even in the presence of elevated levels of Akt.
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Affiliation(s)
- Isabella Karlsson
- />Department of Dermatology, Emory University School of Medicine, Atlanta, GA USA
| | - Xin Zhou
- />Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Raquela Thomas
- />Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC USA
| | - Allorie T Smith
- />Department of Pharmaceutical Sciences, School of Pharmacy, Union University, Jackson, TN USA
| | - Michael Y Bonner
- />Department of Dermatology, Emory University School of Medicine, Atlanta, GA USA
| | - Pooja Bakshi
- />Center for Drug Design, Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA USA
| | - Ajay K Banga
- />Center for Drug Design, Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA USA
| | - J Phillip Bowen
- />Center for Drug Design, Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA USA
| | - Ghassan Qabaja
- />Department of Chemistry & Biochemistry, University of North Carolina Greensboro, Greensboro, NC USA
| | - Shavon L Ford
- />Department of Chemistry & Biochemistry, University of North Carolina Greensboro, Greensboro, NC USA
| | - Matthew D Ballard
- />Department of Chemistry & Biochemistry, University of North Carolina Greensboro, Greensboro, NC USA
| | - Kimberly S Petersen
- />Department of Chemistry & Biochemistry, University of North Carolina Greensboro, Greensboro, NC USA
| | - Xuechen Li
- />Department of Physiology and Renal Division, Emory University School of Medicine, Atlanta, GA USA
| | - Guangping Chen
- />Department of Physiology and Renal Division, Emory University School of Medicine, Atlanta, GA USA
| | - Besim Ogretmen
- />Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC USA
| | - Jin Zhang
- />Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - E Blake Watkins
- />Department of Pharmaceutical Sciences, School of Pharmacy, Union University, Jackson, TN USA
| | - Rebecca S Arnold
- />Department of Urology, Emory University School of Medicine, Atlanta, GA USA
| | - Jack L Arbiser
- />Department of Dermatology, Emory University School of Medicine, Atlanta, GA USA
- />Atlanta Veterans Administration Hospital, and Winship Cancer Institute, Emory University, Atlanta, GA USA
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258
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Wang W, Fromm M. Sphingolipids are required for efficient triacylglycerol loss in conjugated linoleic Acid treated adipocytes. PLoS One 2015; 10:e0119005. [PMID: 25906159 PMCID: PMC4407960 DOI: 10.1371/journal.pone.0119005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 01/13/2015] [Indexed: 11/19/2022] Open
Abstract
Conjugated linoleic acid (CLA) reduces adiposity in human and mouse adipocytes. This outcome is achieved through a variety of biological responses including increased energy expenditure and fatty acid oxidation, increased inflammation, repression of fatty acid biosynthesis, attenuated glucose transport, and apoptosis. In the current study, profiling of 261 metabolites was conducted to gain new insights into the biological pathways responding to CLA in 3T3-L1 adipocytes. Sphinganine and sphingosine levels were observed to be highly elevated in CLA treated adipocytes. Exogenous chemicals that increased endogenous ceramide levels decreased lipid levels in adipocytes, and activated AMP-activated protein kinase (AMPK) as well as NF-κB, both of which are typically activated in CLA treated adipocytes. Concurrent inhibition of ceramide de novo biosynthesis and recycling from existing sphingolipid pools attenuated the lipid lowering effect normally associated with responses to CLA, implicating ceramides as an important component of the lipid lowering response in CLA treated adipocytes.
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Affiliation(s)
- Wei Wang
- Department of Animal Science, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Michael Fromm
- Center for Biotechnology, University of Nebraska, Lincoln, Nebraska, United States of America
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259
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Engberg O, Nurmi H, Nyholm TKM, Slotte JP. Effects of cholesterol and saturated sphingolipids on acyl chain order in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayers--a comparative study with phase-selective fluorophores. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:4255-4263. [PMID: 25806833 DOI: 10.1021/acs.langmuir.5b00403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Saturated sphingolipids have high acyl chain order. Our aim was to study how palmitoylated sphingomyelin (PSM), ceramide (PCer), glucosyl (GlcPCer)-, and galactosylceramide (GalPCer) were able to order the bulk acyl chains of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), in comparison with cholesterol. For this reason, we used lipid probes which had preferred phases that were either the disordered phase (1-oleoyl-2-propionyl[DPH-sn-glycero-3-phosphcholine (18:1-DPH-PC) or the ordered phase (trans parinaric acid (tPA). DPH was also used, although it has no clear phase preference. We measured steady-state anisotropy (all probes) and performed fluorescence lifetime analysis (tPA) as a function of composition and temperature. At concentrations where the saturated sphingolipids were not aggregated into ordered domains (and 23 °C), they did not increase POPC acyl chain order as determined from 18:1-DPH-PC anisotropy. As expected, cholesterol increased the POPC acyl chain order linearly as a function of concentration (0-28 mol %). Since PCer already forms ordered domains below 5 mol % (at 23 °C), we measured the acyl chain ordering effect of PCer at 50 °C (0-13 mol %) and observed that PCer ordered POPC acyl chains as efficiently as cholesterol. We conclude that the bulk acyl chain order of POPC was not markedly affected in bilayers where disordered and ordered domains coexist.
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Affiliation(s)
- Oskar Engberg
- Biochemistry - Department of Biosciences, Åbo Akademi University, Turku, Finland
| | - Henrik Nurmi
- Biochemistry - Department of Biosciences, Åbo Akademi University, Turku, Finland
| | - Thomas K M Nyholm
- Biochemistry - Department of Biosciences, Åbo Akademi University, Turku, Finland
| | - J Peter Slotte
- Biochemistry - Department of Biosciences, Åbo Akademi University, Turku, Finland
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260
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Barriga HMG, Parsons ES, McCarthy NLC, Ces O, Seddon JM, Law RV, Brooks NJ. Pressure-temperature phase behavior of mixtures of natural sphingomyelin and ceramide extracts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3678-3686. [PMID: 25742392 DOI: 10.1021/la504935c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ceramides are a group of sphingolipids that act as highly important signaling molecules in a variety of cellular processes including differentiation and apoptosis. The predominant in vivo synthetic pathway for ceramide formation is via sphingomyelinase catalyzed hydrolysis of sphingomyelin. The biochemistry of this essential pathway has been studied in detail; however, there is currently a lack of information on the structural behavior of sphingomyelin- and ceramide-rich model membrane systems, which is essential for developing a bottom-up understanding of ceramide signaling and platform formation. We have studied the lyotropic phase behavior of sphingomyelin-ceramide mixtures in excess water as a function of temperature (30-70 °C) and pressure (1-200 MPa) by small- and wide-angle X-ray scattering. At low ceramide concentrations the mixtures form the ripple gel phase (P(β)') below the gel transition temperature for sphingomyelin, and this observation has been confirmed by atomic force microscopy. Formation of the ripple gel phase can also be induced at higher temperatures via the application of hydrostatic pressure. At high ceramide concentration an inverse hexagonal phase (HII) is formed coexisting with a cubic phase.
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Affiliation(s)
- Hanna M G Barriga
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom
| | - Edward S Parsons
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom
| | - Nicola L C McCarthy
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom
| | - Oscar Ces
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom
| | - John M Seddon
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom
| | - Robert V Law
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom
| | - Nicholas J Brooks
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom
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261
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Abstract
Two distinct metabolic abnormalities are encompassed under the eponym Niemann-Pick disease (NPD). The first is due to the deficient activity of the enzyme acid sphingomyelinase (ASM). Patients with ASM deficiency are classified as having types A and B Niemann-Pick disease (NPD). Type A NPD patients exhibit hepatosplenomegaly in infancy and profound central nervous system involvement. They rarely survive beyond two years of age. Type B patients also have hepatosplenomegaly and pathologic alterations of their lungs, but there are usually no central nervous system signs. The age of onset and rate of disease progression varies greatly among type B patients, and they frequently live into adulthood. Recently, patients with phenotypes intermediate between types A and B NPD also have been identified. These individuals represent the expected continuum caused by inheriting different mutations in the ASM gene (SMPD1). Patients in the second NPD category are designated as having types C and D NPD. These patients may have mild hepatosplenomegaly, but the central nervous system is profoundly affected. Impaired intracellular trafficking of cholesterol causes types C and D NPD, and two distinct gene defects have been found. In this chapter only types A and B NPD will be discussed.
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Affiliation(s)
- Edward H Schuchman
- Department of Genetics & Genomic Sciences, Ichan School of Medicine at Mount Sinai, 1425 Madison Avenue, Room 14-20A, New York, NY 10029, United States.
| | - Melissa P Wasserstein
- Department of Genetics & Genomic Sciences, Ichan School of Medicine at Mount Sinai, 1428 Madison Avenue, 1st Floor, Room AB1-12, New York, NY 10029, United States.
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262
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Gillams RJ, Busto JV, Busch S, Goñi FM, Lorenz CD, McLain SE. Solvation and Hydration of the Ceramide Headgroup in a Non-Polar Solution. J Phys Chem B 2014; 119:128-39. [DOI: 10.1021/jp5107789] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
| | - Jon V. Busto
- Unidad
de Biofísica (CSIC, UPV-EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | - Sebastian Busch
- Department
of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K
| | - Félix M. Goñi
- Unidad
de Biofísica (CSIC, UPV-EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | | | - Sylvia E. McLain
- Department
of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K
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263
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Increased glucocerebrosidase expression and activity in preeclamptic placenta. Placenta 2014; 36:160-9. [PMID: 25552189 DOI: 10.1016/j.placenta.2014.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Lysosomal glucosidase beta acid (GBA) deficiency is inherent to Gaucher disease, Parkinsonism and Lewy-body dementia. Increased GBA expression has never been associated with human disease. We describe increased GBA expression and activity in placenta from preeclamptic pregnancies. METHODS 112 placenta biopsies were available for qPCR, analysis of GBA gene expression and activity. Microanalysis was performed on 20 placenta samples. Alternatively spliced placental GBA transcripts were cloned, expressed in HEK293 cells and analyzed by Western blot and activity assay. RESULTS GBA is expressed in the syncytiotrophoblast layer of human placenta already at 5 weeks of gestation. We identified five novel GBA transcripts in placenta that enzymatically inactive when expressed in HEK293 cells. Both GBA RNA expression and enzymatic activity are upregulated in preeclamptic placenta. Microarray analysis of 20 placenta tissues identified 158 genes co-regulating with GBA expression and gene enrichment analysis highlights lysosomal function. In our micro-array data GBA expression does not correlate with FLT1 expression, currently the most powerful marker for preeclampsia. There are 89 transcripts that are negatively correlated with GBA expression of which BMP4 and TFEB are interesting as they are essential to early placenta function. DISCUSSION Although very speculative, we hypothesize that increased GBA expression might relate to placentation through decreased BMP4 signaling or vascularization through downregulation of TFEB. Ceramide, the product of hydrolysis of glucosylceramide by GBA and involved in the regulation of cell differentiation, survival and apoptosis, is another putative candidate linking increased GBA activity to preeclampsia. Both pathways merit further investigation.
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264
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Beyoğlu D, Krausz KW, Martin J, Maurhofer O, Dorow J, Ceglarek U, Gonzalez FJ, Dufour JF, Idle JR. Disruption of tumor suppressor gene Hint1 leads to remodeling of the lipid metabolic phenotype of mouse liver. J Lipid Res 2014; 55:2309-19. [PMID: 25193995 DOI: 10.1194/jlr.m050682] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A lipidomic and metabolomic investigation of serum and liver from mice was performed to gain insight into the tumor suppressor gene Hint1. A major reprogramming of lipid homeostasis was found in both serum and liver of Hint1-null (Hint(-/-)) mice, with significant changes in the levels of many lipid molecules, as compared with gender-, age-, and strain-matched WT mice. In the Hint1(-/-) mice, serum total and esterified cholesterol were reduced 2.5-fold, and lysophosphatidylcholines (LPCs) and lysophosphatidic acids were 10-fold elevated in serum, with a corresponding fall in phosphatidylcholines (PCs). In the liver, MUFAs and PUFAs, including arachidonic acid (AA) and its metabolic precursors, were also raised, as was mRNA encoding enzymes involved in AA de novo synthesis. There was also a significant 50% increase in hepatic macrophages in the Hint1(-/-) mice. Several hepatic ceramides and acylcarnitines were decreased in the livers of Hint1(-/-) mice. The changes in serum LPCs and PCs were neither related to hepatic phospholipase A2 activity nor to mRNAs encoding lysophosphatidylcholine acetyltransferases 1-4. The lipidomic phenotype of the Hint1(-/-) mouse revealed decreased inflammatory eicosanoids with elevated proliferative mediators that, combined with decreased ceramide apoptosis signaling molecules, may contribute to the tumor suppressor activity of Hint1.
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Affiliation(s)
- Diren Beyoğlu
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland
| | - Kristopher W Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Juliette Martin
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland
| | - Olivier Maurhofer
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland
| | - Juliane Dorow
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Uta Ceglarek
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Jean-François Dufour
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland
| | - Jeffrey R Idle
- Hepatology Research Group, Department of Clinical Research, University of Bern, Switzerland Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
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265
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Kreydiyyeh SI, Dakroub Z. Ceramide and its metabolites modulate time-dependently the activity of the Na⁺/K⁺ ATPase in HepG2 cells. Int J Biochem Cell Biol 2014; 53:102-7. [PMID: 24819540 DOI: 10.1016/j.biocel.2014.04.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 04/17/2014] [Accepted: 04/30/2014] [Indexed: 02/03/2023]
Abstract
Ceramide is involved in the regulation of many cellular processes including cell proliferation and apoptosis, which are accompanied respectively with a decrease and an increase in the activity of the Na(+)/K(+) ATPase. These antagonistic effects may be time-dependent and due to different signaling pathways requiring different time intervals to be activated. While we showed previously a ceramide-induced inhibition of the ATPase in HepG2 cells during the first hour, we study here the effect of ceramide thereafter. Ceramide stimulated the Na(+)/K(+) ATPase between 1 and 4h with a peak at 2h. This stimulation was maintained in the simultaneous presence of an inhibitor of ceramidase (CAY 10466) but disappeared when ceramide kinase was inhibited, suggesting a role of ceramide-1-phosphate (cer-1-P) in the observed effect. Exogenous cer-1-P caused a similar stimulation of the ATPase which was not affected by an inhibition of JNK but changed into a decrease in presence of PDTC, a specific inhibitor of NF-κB, and disappeared when NF-κB and JNK were inhibited simultaneously. It was concluded that cer-1-P activates both JNK and NF-κB. While JNK exerts an inhibitory effect on the ATPase, NF-κB increases its activity and abrogates the stimulatory effect of the sphingolipid on JNK leading thus to an additional increase in the ATPase activity.
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Affiliation(s)
| | - Zeina Dakroub
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
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