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Mastoridou EM, Goussia AC, Kanavaros P, Charchanti AV. Involvement of Lipophagy and Chaperone-Mediated Autophagy in the Pathogenesis of Non-Alcoholic Fatty Liver Disease by Regulation of Lipid Droplets. Int J Mol Sci 2023; 24:15891. [PMID: 37958873 PMCID: PMC10649352 DOI: 10.3390/ijms242115891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is defined as the accumulation of lipids in the form of lipid droplets in more than 5% of hepatocytes. It is regarded as a range of diverse pathologies, including simple steatosis and steatohepatitis. The structural characteristics of lipid droplets, along with their protein composition, mainly including perilipins, have been implicated in the etiology of the disease. These proteins have garnered increasing attention as a pivotal regulator since their levels and distinct expression appear to be associated with the progression from simple steatosis to steatohepatitis. Perilipins are target proteins of chaperone-mediated autophagy, and their degradation is a prerequisite for lipolysis and lipophagy to access the lipid core. Both lipophagy and chaperone-mediated autophagy have significant implications on the development of the disease, as evidenced by their upregulation during the initial phases of simple steatosis and their subsequent downregulation once steatosis is established. On the contrary, during steatohepatitis, the process of chaperone-mediated autophagy is enhanced, although lipophagy remains suppressed. Evidently, the reduced levels of autophagic pathways observed in simple steatosis serve as a defensive mechanism against lipotoxicity. Conversely, in steatohepatitis, chaperone-mediated autophagy fails to compensate for the continuous generation of small lipid droplets and thus cannot protect hepatocytes from lipotoxicity.
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Affiliation(s)
- Eleftheria M. Mastoridou
- Department of Anatomy-Histology-Embryology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece; (E.M.M.); (P.K.)
| | - Anna C. Goussia
- Department of Pathology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
| | - Panagiotis Kanavaros
- Department of Anatomy-Histology-Embryology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece; (E.M.M.); (P.K.)
| | - Antonia V. Charchanti
- Department of Anatomy-Histology-Embryology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece; (E.M.M.); (P.K.)
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2
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Bombarda-Rocha V, Silva D, Badr-Eddine A, Nogueira P, Gonçalves J, Fresco P. Challenges in Pharmacological Intervention in Perilipins (PLINs) to Modulate Lipid Droplet Dynamics in Obesity and Cancer. Cancers (Basel) 2023; 15:4013. [PMID: 37568828 PMCID: PMC10417315 DOI: 10.3390/cancers15154013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023] Open
Abstract
Perilipins (PLINs) are the most abundant proteins in lipid droplets (LD). These LD-associated proteins are responsible for upgrading LD from inert lipid storage structures to fully functional organelles, fundamentally integrated in the lipid metabolism. There are five distinct perilipins (PLIN1-5), each with specific expression patterns and metabolic activation, but all capable of regulating the activity of lipases on LD. This plurality creates a complex orchestrated mechanism that is directly related to the healthy balance between lipogenesis and lipolysis. Given the essential role of PLINs in the modulation of the lipid metabolism, these proteins can become interesting targets for the treatment of lipid-associated diseases. Since reprogrammed lipid metabolism is a recognized cancer hallmark, and obesity is a known risk factor for cancer and other comorbidities, the modulation of PLINs could either improve existing treatments or create new opportunities for the treatment of these diseases. Even though PLINs have not been, so far, directly considered for pharmacological interventions, there are many established drugs that can modulate PLINs activity. Therefore, the aim of this study is to assess the involvement of PLINs in diseases related to lipid metabolism dysregulation and whether PLINs can be viewed as potential therapeutic targets for cancer and obesity.
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Affiliation(s)
- Victória Bombarda-Rocha
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal; (V.B.-R.); (D.S.); (A.B.-E.); (P.N.); (P.F.)
- UCIBIO–Applied Molecular Biosciences Unit, Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
| | - Dany Silva
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal; (V.B.-R.); (D.S.); (A.B.-E.); (P.N.); (P.F.)
- UCIBIO–Applied Molecular Biosciences Unit, Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
| | - Allal Badr-Eddine
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal; (V.B.-R.); (D.S.); (A.B.-E.); (P.N.); (P.F.)
| | - Patrícia Nogueira
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal; (V.B.-R.); (D.S.); (A.B.-E.); (P.N.); (P.F.)
- UCIBIO–Applied Molecular Biosciences Unit, Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
| | - Jorge Gonçalves
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal; (V.B.-R.); (D.S.); (A.B.-E.); (P.N.); (P.F.)
- UCIBIO–Applied Molecular Biosciences Unit, Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
| | - Paula Fresco
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal; (V.B.-R.); (D.S.); (A.B.-E.); (P.N.); (P.F.)
- UCIBIO–Applied Molecular Biosciences Unit, Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
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3
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Khaddaj R, Stribny J, Cottier S, Schneiter R. Perilipin 3 promotes the formation of membrane domains enriched in diacylglycerol and lipid droplet biogenesis proteins. Front Cell Dev Biol 2023; 11:1116491. [PMID: 37465010 PMCID: PMC10350540 DOI: 10.3389/fcell.2023.1116491] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 06/14/2023] [Indexed: 07/20/2023] Open
Abstract
Lipid droplets (LDs) serve as intracellular stores of energy-rich neutral lipids. LDs form at discrete sites in the endoplasmic reticulum (ER) and they remain closely associated with the ER during lipogenic growth and lipolytic consumption. Their hydrophobic neutral lipid core is covered by a monolayer of phospholipids, which harbors a specific set of proteins. This LD surface is coated and stabilized by perilipins, a family of soluble proteins that specifically target LDs from the cytosol. We have previously used chimeric fusion proteins between perilipins and integral ER membrane proteins to test whether proteins that are anchored to the ER bilayer could be dragged onto the LD monolayer. Expression of these chimeric proteins induces repositioning of the ER membrane around LDs. Here, we test the properties of membrane-anchored perilipins in cells that lack LDs. Unexpectedly, membrane-anchored perilipins induce expansion and vesiculation of the perinuclear membrane resulting in the formation of crescent-shaped membrane domains that harbor LD-like properties. These domains are stained by LD-specific lipophilic dyes, harbor LD marker proteins, and they transform into nascent LDs upon induction of neutral lipid synthesis. These ER domains are enriched in diacylglycerol (DAG) and in ER proteins that are important for early steps of LD biogenesis, including seipin and Pex30. Formation of the domains in vivo depends on DAG levels, and we show that perilipin 3 (PLIN3) binds to liposomes containing DAG in vitro. Taken together, these observations indicate that perilipin not only serve to stabilize the surface of mature LDs but that they are likely to exert a more active role in early steps of LD biogenesis at ER subdomains enriched in DAG, seipin, and neutral lipid biosynthetic enzymes.
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Affiliation(s)
- Rasha Khaddaj
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Jiri Stribny
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Stéphanie Cottier
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Roger Schneiter
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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Mak KM, Wu C, Cheng CP. Lipid droplets, the Holy Grail of hepatic stellate cells: In health and hepatic fibrosis. Anat Rec (Hoboken) 2022; 306:983-1010. [PMID: 36516055 DOI: 10.1002/ar.25138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/07/2022] [Accepted: 11/29/2022] [Indexed: 12/15/2022]
Abstract
Lipid droplets (LDs) are distinct morphological markers of hepatic stellate cells (HSCs). They are composed of a core of predominantly retinyl esters and triacylglycerols surrounded by a phospholipid layer; the latter harbors perilipins 2, 3, and 5, which help control LD lipolysis. Electron microscopy distinguishes between Types I and II LDs. Type I LDs are surrounded by acid phosphatase-positive lysosomes, which likely digest LDs. LD count and retinoid concentration are modulated by vitamin A intake. Alcohol consumption depletes hepatic retinoids and HSC LDs, with concomitant transformation of HSCs to fibrogenic myofibroblast-like cells. LD loss and accompanying HSC activation occur in HSC cell culture models. Loss of LDs is a consequence of and not a prerequisite for HSC activation. LDs are endowed with enzymes for synthesizing retinyl esters and triacylglycerols as well as neutral lipases and lysosomal acid lipase for breaking down LDs. HSCs have two distinct metabolic LD pools: an "original" pool in quiescent HSCs and a "new" pool emerging in HSC activation; this two-pool model provides a platform for analyzing LD dynamics in HSC activation. Besides lipolysis, LDs are degraded by lipophagy; however, the coordination between and relative contributions of these two pathways to LD removal are unclear. While induction of autophagy accelerates LD loss in quiescent HSCs and promotes HSC activation, blocking autophagy impairs LD degradation and inhibits HSC activation and fibrosis. This article is a critique of five decades of investigations into the morphology, molecular structure, synthesis, and degradation of LDs associated with HSC activation and fibrosis.
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Affiliation(s)
- Ki M Mak
- Department of Medical Education and Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Catherine Wu
- Department of Medical Education and Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Christopher P Cheng
- Department of Medical Education and Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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5
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Sirago G, Vaccari F, Lazzer S, D'Amuri A, Sanz JM, Narici MV, Reggiani C, Passaro A, Toniolo L. Skeletal Muscle Mitochondrial and Perilipin Content in a Cohort of Obese Subjects Undergoing Moderate and High Intensity Training. Metabolites 2022; 12:855. [PMID: 36144258 DOI: 10.3390/metabo12090855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
Obesity is a complex condition characterized by abnormal and excessive fat accumulation, resulting in an increased risk for severe health problems. Skeletal muscles play a major role in movement and fat catabolism, but the insulin resistance that comes with obesity makes it difficult to fulfill these tasks. In this study, we analyse two types of training protocols, moderate intensity continuous training (MICT) versus high intensity interval training (HIIT), in a cohort of obese subjects to establish which muscle adaptations favour fat consumption in response to exercise. Mitochondria play a role in fat oxidation. We found protein upregulation of mitochondrial biomarkers, TOMM20 and Cox-4, in HIIT but not in MICT, without detecting any shifts in fibre composition phenotype of the vastus lateralis in both training groups. Interestingly, both MICT and HIIT protocols showed increased protein levels of perilipin PLIN2, which is involved in the delivery and consumption of fats. HIIT also augmented perilipin PLIN5. Perilipins are involved in fat storage in skeletal muscles and their upregulation, along with the analysis of circulatory lipid profiles reported in the present study, suggest important adaptations induced by the two types of training protocols that favour fat consumption and weight loss in obese subjects.
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Barrett JS, Whytock KL, Strauss JA, Wagenmakers AJM, Shepherd SO. High intramuscular triglyceride turnover rates and the link to insulin sensitivity: influence of obesity, type 2 diabetes and physical activity. Appl Physiol Nutr Metab 2022; 47:343-356. [PMID: 35061523 DOI: 10.1139/apnm-2021-0631] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Large intramuscular triglyceride (IMTG) stores in sedentary, obese individuals have been linked to insulin resistance, yet well-trained athletes exhibit high IMTG levels whilst maintaining insulin sensitivity. Contrary to previous assumptions, it is now known that IMTG content per se does not result in insulin resistance. Rather, insulin resistance is caused, at least in part, by the presence of high concentrations of harmful lipid metabolites, such as diacylglycerols and ceramides in muscle. Several mechanistic differences between obese sedentary individuals and their highly trained counterparts have been identified, which determine the differential capacity for IMTG synthesis and breakdown in these populations. In this review, we first describe the most up-to-date mechanisms by which a low IMTG turnover rate (both breakdown and synthesis) leads to the accumulation of lipid metabolites and results in skeletal muscle insulin resistance. We then explore current and potential exercise and nutritional strategies that target IMTG turnover in sedentary obese individuals, to improve insulin sensitivity. Overall, improving IMTG turnover should be an important component of successful interventions that aim to prevent the development of insulin resistance in the ever-expanding sedentary, overweight and obese populations. Novelty: A description of the most up-to-date mechanisms regulating turnover of the IMTG pool. An exploration of current and potential exercise/nutritional strategies to target and enhance IMTG turnover in obese individuals. Overall, highlights the importance of improving IMTG turnover to prevent the development of insulin resistance.
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Affiliation(s)
- J S Barrett
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - K L Whytock
- Translational Research Institute, AdventHealth, Orlando, FL 32804, USA
| | - J A Strauss
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - A J M Wagenmakers
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - S O Shepherd
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK
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7
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Conte M, Medici V, Malagoli D, Chiariello A, Cirrincione A, Davin A, Chikhladze M, Vasuri F, Legname G, Ferrer I, Vanni S, Marcon G, Poloni TE, Guaita A, Franceschi C, Salvioli S. Expression pattern of perilipins in human brain during aging and in Alzheimer's disease. Neuropathol Appl Neurobiol 2021; 48:e12756. [PMID: 34312912 PMCID: PMC9291275 DOI: 10.1111/nan.12756] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 12/16/2022]
Abstract
AIMS Perilipins are conserved proteins that decorate intracellular lipid droplets and are essential for lipid metabolism. To date, there is limited knowledge on their expression in human brain or their involvement in brain aging and neurodegeneration. The aim of this study was to characterise the expression levels of perilipins (Plin1-Plin5) in different cerebral areas from subjects of different age, with or without signs of neurodegeneration. METHODS We performed real-time RT-PCR, western blotting, immunohistochemistry and confocal microscopy analyses in autoptic brain samples of frontal and temporal cortex, cerebellum and hippocampus from subjects ranging from 33 to 104 years of age, with or without histological signs of neurodegeneration. To test the possible relationship between Plins and inflammation, correlation analysis with IL-6 expression was also performed. RESULTS Plin2, Plin3 and Plin5, but not Plin1 and Plin4, are expressed in the considered brain areas with different intensities. Plin2 appears to be expressed more in grey matter, particularly in neurons in all the areas analysed, whereas Plin3 and Plin5 appear to be expressed more in white matter. Plin3 seems to be expressed more in astrocytes. Only Plin2 expression is higher in old subjects and patients with early tauopathy or Alzheimer's disease and is associated with IL-6 expression. CONCLUSIONS Perilipins are expressed in human brain but only Plin2 appears to be modulated with age and neurodegeneration and linked to an inflammatory state. We propose that the accumulation of lipid droplets decorated with Plin2 occurs during brain aging and that this accumulation may be an early marker and initial step of inflammation and neurodegeneration.
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Affiliation(s)
- Maria Conte
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy.,Interdepartmental Centre "Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate)", University of Bologna, Bologna, Italy
| | - Valentina Medici
- Department of Neurology and Neuropathology, Golgi-Cenci Foundation, Milan, Italy
| | - Davide Malagoli
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Antonio Chiariello
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Alice Cirrincione
- Department of Neurology and Neuropathology, Golgi-Cenci Foundation, Milan, Italy
| | - Annalisa Davin
- Department of Neurology and Neuropathology, Golgi-Cenci Foundation, Milan, Italy
| | - Maia Chikhladze
- Department of Neurology and Neuropathology, Golgi-Cenci Foundation, Milan, Italy.,Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Francesco Vasuri
- Pathology Unit, S. Orsola-Malpighi Bologna Authority Hospital, Bologna, Italy
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Isidre Ferrer
- Department of Pathology and Experimental Therapeutics, Institute of Neurosciences, University of Barcelona, Barcelona, Spain.,Bellvitge Biomedical Research Institute-IDIBELL, Department of Pathologic Anatomy, Bellvitge University Hospital, Barcelona, Spain.,Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Institute Carlos III, Ministry of Health, L'Hospilatet del Llobregat, Barcelona, Spain
| | - Silvia Vanni
- Osteoncology and Rare Tumors Center, IRCCS Istituto Romagnolo Per Lo Studio Dei Tumori (IRST) "Dino Amadori", Meldola, Italy
| | - Gabriella Marcon
- DAME, University of Udine, Udine, Italy.,Department of Medical Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Tino Emanuele Poloni
- Department of Neurology and Neuropathology, Golgi-Cenci Foundation, Milan, Italy
| | - Antonio Guaita
- Department of Neurology and Neuropathology, Golgi-Cenci Foundation, Milan, Italy
| | - Claudio Franceschi
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University, Nizhniy Novgorod, Russia
| | - Stefano Salvioli
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy.,Interdepartmental Centre "Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate)", University of Bologna, Bologna, Italy
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8
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Zhao Y, Albrecht E, Li Z, Schregel J, Sciascia QL, Metges CC, Maak S. Distinct Roles of Perilipins in the Intramuscular Deposition of Lipids in Glutamine-Supplemented, Low-, and Normal-Birth-Weight Piglets. Front Vet Sci 2021; 8:633898. [PMID: 34235195 PMCID: PMC8257002 DOI: 10.3389/fvets.2021.633898] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Piglets with low birth weight (LBW) usually have reduced muscle mass and increased lipid deposition compared with their normal-birth-weight (NBW) littermates. Supplementation of piglets with amino acids during the first days of life may improve muscle growth and simultaneously alter the intramuscular lipid deposition. The aim of the current study was to investigate the influence of glutamine (Gln) supplementation during the early suckling period on lipid deposition in the longissimus muscle (MLD) and the role of different perilipin (PLIN) family members in this process. Four groups were generated consisting of 72 male LBW piglets and 72 NBW littermates. Piglets were supplemented with either 1 g Gln/kg body weight or an isonitrogenous amount of alanine (Ala) between days post natum (dpn) 1 and 12. Twelve piglets per group were slaughtered at 5, 12, and 26 dpn, and muscle tissue was collected. Perilipins were localized by immunohistochemistry in muscle sections. The mRNA and protein abundances of PLIN family members and related lipases were quantified by quantitative RT-PCR (qPCR) and western blots, respectively. While PLIN1 was localized around lipid droplets in mature and developing adipocytes, PLIN2 was localized at intramyocellular lipid droplets, PLIN3 and 4 at cell membranes of muscle fibers and adipocytes, and PLIN5 in the cytoplasm of undefined cells. The western blot results indicated higher protein abundances of PLIN2, 3, 4, and 5 in LBW piglets (p < 0.05) at 5 dpn compared with their NBW littermates independent of supplementation, while not directly reflecting the mRNA expression levels. The mRNA abundance of PLIN2 was lower while PLIN4 was higher in piglets at 26 dpn in comparison with piglets at 5 dpn (p < 0.01). Relative mRNA expression of LPL and CGI-58 was lowest in piglets at 5 dpn (p < 0.001). However, ATGL mRNA was not influenced by birth weight or supplementation, but the Spearman correlation coefficient analysis revealed close correlations with PLIN2, 4, and 5 mRNA at 5 and 26 dpn (r > 0.5, p < 0.001). The results indicated the importance of birth weight and age for intramuscular lipid deposition and different roles of PLIN family members in this process, but no clear modulating effect of Gln supplementation.
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Affiliation(s)
- Yaolu Zhao
- Institute of Muscle Biology and Growth, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Elke Albrecht
- Institute of Muscle Biology and Growth, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Zeyang Li
- Institute of Nutritional Physiology "Oskar Kellner", Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Johannes Schregel
- Institute of Nutritional Physiology "Oskar Kellner", Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Quentin L Sciascia
- Institute of Nutritional Physiology "Oskar Kellner", Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Cornelia C Metges
- Institute of Nutritional Physiology "Oskar Kellner", Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Steffen Maak
- Institute of Muscle Biology and Growth, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
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9
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Titus AR, Ridgway EN, Douglas R, Brenes ES, Mann EK, Kooijman EE. The C-Terminus of Perilipin 3 Shows Distinct Lipid Binding at Phospholipid-Oil-Aqueous Interfaces. Membranes (Basel) 2021; 11:265. [PMID: 33917451 DOI: 10.3390/membranes11040265] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/25/2021] [Accepted: 04/01/2021] [Indexed: 12/13/2022]
Abstract
Lipid droplets (LDs) are ubiquitously expressed organelles; the only intracellular organelles that contain a lipid monolayer rather than a bilayer. Proteins localize and bind to this monolayer as they do to intracellular lipid bilayers. The mechanism by which cytosolic LD binding proteins recognize, and bind, to this lipid interface remains poorly understood. Amphipathic α-helix bundles form a common motif that is shared between cytosolic LD binding proteins (e.g., perilipins 2, 3, and 5) and apolipoproteins, such as apoE and apoLp-III, found on lipoprotein particles. Here, we use pendant drop tensiometry to expand our previous work on the C-terminal α-helix bundle of perilipin 3 and the full-length protein. We measure the recruitment and insertion of perilipin 3 at mixed lipid monolayers at an aqueous-phospholipid-oil interface. We find that, compared to its C-terminus alone, the full-length perilipin 3 has a higher affinity for both a neat oil/aqueous interface and a phosphatidylcholine (PC) coated oil/aqueous interface. Both the full-length protein and the C-terminus show significantly more insertion into a fully unsaturated PC monolayer, contrary to our previous results at the air-aqueous interface. Additionally, the C-terminus shows a preference for lipid monolayers containing phosphatidylethanolamine (PE), whereas the full-length protein does not. These results strongly support a model whereby both the N-terminal 11-mer repeat region and C-terminal amphipathic α-helix bundle domains of perilipin 3 have distinct lipid binding, and potentially biological roles.
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10
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Casey CA, Donohue TM, Kubik JL, Kumar V, Naldrett MJ, Woods NT, Frisbie CP, McNiven MA, Thomes PG. Lipid droplet membrane proteome remodeling parallels ethanol-induced hepatic steatosis and its resolution. J Lipid Res 2021; 62:100049. [PMID: 33617872 PMCID: PMC8010705 DOI: 10.1016/j.jlr.2021.100049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/29/2021] [Accepted: 02/10/2021] [Indexed: 10/25/2022] Open
Abstract
Lipid droplets (LDs) are composed of neutral lipids enclosed in a phospholipid monolayer, which harbors membrane-associated proteins that regulate LD functions. Despite the crucial role of LDs in lipid metabolism, remodeling of LD protein composition in disease contexts, such as steatosis, remains poorly understood. We hypothesized that chronic ethanol consumption, subsequent abstinence from ethanol, or fasting differentially affects the LD membrane proteome content and that these changes influence how LDs interact with other intracellular organelles. Here, male Wistar rats were pair-fed liquid control or ethanol diets for 6 weeks, and then, randomly chosen animals from both groups were either refed a control diet for 7 days or fasted for 48 h before euthanizing. From all groups, LD membrane proteins from purified liver LDs were analyzed immunochemically and by MS proteomics. Liver LD numbers and sizes were greater in ethanol-fed rats than in pair-fed control, 7-day refed, or fasted rats. Compared with control rats, ethanol feeding markedly altered the LD membrane proteome, enriching LD structural perilipins and proteins involved in lipid biosynthesis, while lowering LD lipase levels. Ethanol feeding also lowered LD-associated mitochondrial and lysosomal proteins. In 7-day refed (i.e., ethanol-abstained) or fasted-ethanol-fed rats, we detected distinct remodeling of the LD proteome, as judged by lower levels of lipid biosynthetic proteins, and enhanced LD interaction with mitochondria and lysosomes. Our study reveals evidence of significant remodeling of the LD membrane proteome that regulates ethanol-induced steatosis, its resolution after withdrawal and abstinence, and changes in LD interactions with other intracellular organelles.
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Affiliation(s)
- Carol A Casey
- VA-Nebraska-Western Iowa Health Care System, Department of Veterans' Affairs, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Terrence M Donohue
- VA-Nebraska-Western Iowa Health Care System, Department of Veterans' Affairs, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Jacy L Kubik
- VA-Nebraska-Western Iowa Health Care System, Department of Veterans' Affairs, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Vikas Kumar
- Department of Genetics Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA; Mass Spectrometry and Proteomics Core Facility, University of Nebraska Medical Center, Omaha, NE, USA
| | - Michael J Naldrett
- Nebraska Center for Biotechnology, University of Nebraska-Lincoln, NE, USA
| | - Nicholas T Woods
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | - Cole P Frisbie
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Mark A McNiven
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Paul G Thomes
- VA-Nebraska-Western Iowa Health Care System, Department of Veterans' Affairs, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
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11
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Keenan SN, De Nardo W, Lou J, Schittenhelm RB, Montgomery MK, Granneman JG, Hinde E, Watt MJ. Perilipin 5 S155 phosphorylation by PKA is required for the control of hepatic lipid metabolism and glycemic control. J Lipid Res 2021; 62:100016. [PMID: 33334871 PMCID: PMC7900760 DOI: 10.1194/jlr.ra120001126] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/09/2020] [Accepted: 12/17/2020] [Indexed: 12/22/2022] Open
Abstract
Perilipin 5 (PLIN5) is a lipid-droplet-associated protein that coordinates intracellular lipolysis in highly oxidative tissues and is thought to regulate lipid metabolism in response to phosphorylation by protein kinase A (PKA). We sought to identify PKA phosphorylation sites in PLIN5 and assess their functional relevance in cultured cells and the livers of mice. We detected phosphorylation on S155 and identified S155 as a functionally important site for lipid metabolism. Expression of phosphorylation-defective PLIN5 S155A in Plin5 null cells resulted in decreased rates of lipolysis and triglyceride-derived fatty acid oxidation. FLIM-FRET analysis of protein-protein interactions showed that PLIN5 S155 phosphorylation regulates PLIN5 interaction with adipose triglyceride lipase at the lipid droplet, but not with α-β hydrolase domain-containing 5. Re-expression of PLIN5 S155A in the liver of Plin5 liver-specific null mice reduced lipolysis compared with wild-type PLIN5 re-expression, but was not associated with other changes in hepatic lipid metabolism. Furthermore, glycemic control was impaired in mice with expression of PLIN5 S155A compared with mice expressing PLIN5. Together, these studies demonstrate that PLIN5 S155 is required for PKA-mediated lipolysis and builds on the body of evidence demonstrating a critical role for PLIN5 in coordinating lipid and glucose metabolism.
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Affiliation(s)
- Stacey N Keenan
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - William De Nardo
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Jieqiong Lou
- School of Physics, University of Melbourne, Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Ralf B Schittenhelm
- Monash Proteomics & Metabolomics Facility and Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia
| | | | - James G Granneman
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, USA
| | - Elizabeth Hinde
- School of Physics, University of Melbourne, Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Matthew J Watt
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia.
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12
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Depommier C, Van Hul M, Everard A, Delzenne NM, De Vos WM, Cani PD. Pasteurized Akkermansia muciniphila increases whole-body energy expenditure and fecal energy excretion in diet-induced obese mice. Gut Microbes 2020; 11:1231-1245. [PMID: 32167023 PMCID: PMC7524283 DOI: 10.1080/19490976.2020.1737307] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Accumulating evidence points to Akkermansia muciniphila as a novel candidate to prevent or treat obesity-related metabolic disorders. We recently observed, in mice and in humans, that pasteurization of A. muciniphila increases its beneficial effects on metabolism. However, it is currently unknown if the observed beneficial effects on body weight and fat mass gain are due to specific changes in energy expenditure. Therefore, we investigated the effects of pasteurized A. muciniphila on whole-body energy metabolism during high-fat diet feeding by using metabolic chambers. We confirmed that daily oral administration of pasteurized A. muciniphila alleviated diet-induced obesity and decreased food energy efficiency. We found that this effect was associated with an increase in energy expenditure and spontaneous physical activity. Strikingly, we discovered that energy expenditure was enhanced independently from changes in markers of thermogenesis or beiging of the white adipose tissue. However, we found in brown and white adipose tissues that perilipin2, a factor associated with lipid droplet and known to be altered in obesity, was decreased in expression by pasteurized A. muciniphila. Finally, we observed that treatment with pasteurized A. muciniphila increased energy excretion in the feces. Interestingly, we demonstrated that this effect was not due to the modulation of intestinal lipid absorption or chylomicron synthesis but likely involved a reduction of carbohydrates absorption and enhanced intestinal epithelial turnover. In conclusion, this study further dissects the mechanisms by which pasteurized A. muciniphila reduces body weight and fat mass gain. These data also further support the impact of targeting the gut microbiota by using specific bacteria to control whole-body energy metabolism.
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Affiliation(s)
- Clara Depommier
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Walloon Excellence in Life Sciences and BIOtechnology (WELBIO), UCLouvain, Université Catholique De Louvain, Brussels, Belgium
| | - Matthias Van Hul
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Walloon Excellence in Life Sciences and BIOtechnology (WELBIO), UCLouvain, Université Catholique De Louvain, Brussels, Belgium
| | - Amandine Everard
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Walloon Excellence in Life Sciences and BIOtechnology (WELBIO), UCLouvain, Université Catholique De Louvain, Brussels, Belgium
| | - Nathalie M. Delzenne
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Walloon Excellence in Life Sciences and BIOtechnology (WELBIO), UCLouvain, Université Catholique De Louvain, Brussels, Belgium
| | - Willem M. De Vos
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands,Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Patrice D. Cani
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Walloon Excellence in Life Sciences and BIOtechnology (WELBIO), UCLouvain, Université Catholique De Louvain, Brussels, Belgium,CONTACT Patrice D. Cani UCLouvain, Université Catholique De Louvain, LDRI, Metabolism and Nutrition Research Group, Av. E. Mounier, 73 Box B1.73.11, B-1200Brussels, Belgium
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13
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Espinosa A, Ross A, Dovale-Rosabal G, Pino-de la Fuente F, Uribe-Oporto E, Sacristán C, Ruiz P, Valenzuela R, Romero N, Aubourg SP, Rodríguez A. EPA/DHA Concentrate by Urea Complexation Decreases Hyperinsulinemia and Increases Plin5 in the Liver of Mice Fed a High-Fat Diet. Molecules 2020; 25:E3289. [PMID: 32698439 DOI: 10.3390/molecules25143289] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 06/27/2020] [Accepted: 07/15/2020] [Indexed: 12/14/2022] Open
Abstract
Dietary intake of eicosapentaenoic/docosahexaenoic acid (EPA/DHA) reduces insulin resistance and hepatic manifestations through the regulation of metabolism in the liver. Obese mice present insulin resistance and lipid accumulation in intracellular lipid droplets (LDs). LD-associated proteins perilipin (Plin) have an essential role in both adipogenesis and lipolysis; Plin5 regulates lipolysis and thus contributes to fat oxidation. The purpose of this study was to compare the effects of deodorized refined salmon oil (DSO) and its polyunsaturated fatty acids concentrate (CPUFA) containing EPA and DHA, obtained by complexing with urea, on obesity-induced metabolic alteration. CPUFA maximum content was determined using the Box-Behnken experimental design based on Surface Response Methodology. The optimized CPUFA was administered to high-fat diet (HFD)-fed mice (200 mg/kg/day of EPA + DHA) for 8 weeks. No significant differences (p > 0.05) in cholesterol, glycemia, LDs or transaminase content were found. Fasting insulin and hepatic Plin5 protein level increased in the group supplemented with the EPA + DHA optimized product (38.35 g/100 g total fatty acids) compared to obese mice without fish oil supplementation. The results suggest that processing salmon oil by urea concentration can generate an EPA+DHA dose useful to prevent the increase of fasting insulin and the decrease of Plin5 in the liver of insulin-resistant mice.
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14
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Nocetti D, Espinosa A, Pino-De la Fuente F, Sacristán C, Bucarey JL, Ruiz P, Valenzuela R, Chouinard-Watkins R, Pepper I, Troncoso R, Puente L. Lipid droplets are both highly oxidized and Plin2-covered in hepatocytes of diet-induced obese mice. Appl Physiol Nutr Metab 2020; 45:1368-1376. [PMID: 32585124 DOI: 10.1139/apnm-2019-0966] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Chronic high-fat diet feeding is associated with obesity and accumulation of fat in the liver, leading to the development of insulin resistance and nonalcoholic fatty liver disease. This condition is characterized by the presence of a high number of intrahepatic lipid droplets (LDs), with changes in the perilipin pattern covering them. This work aimed to describe the distribution of perilipin (Plin) 2, an LD-associated protein involved in neutral lipid storage, and Plin5, which favors lipid oxidation in LD, and to evaluate lipid peroxidation through live-cell visualization using the lipophilic fluorescent probe C11-BODIPY581/591 in fresh hepatocytes isolated from mice fed a high-fat diet (HFD). Male C57BL/6J adult mice were divided into control and HFD groups and fed with a control diet (10% fat, 20% protein, and 70% carbohydrates) or an HFD (60% fat, 20% protein, and 20% carbohydrates) for 8 weeks. The animals fed the HFD showed a significant increase of Plin2 in LD of hepatocytes. LD from HFD-fed mice have a stronger lipid peroxidation level than control hepatocytes. These data provide evidence that obesity status is accompanied by a higher degree of lipid peroxidation in hepatocytes, both in the cytoplasm and in the fats stored inside the LD. Novelty Our study shows that lipid droplets from isolated hepatocytes in HFD-fed mice have a stronger lipid peroxidation level than control hepatocytes. C11-BODIPY581/591 is a useful tool to measure the initial level of intracellular lipid peroxidation in single isolated hepatocytes. Perilipins pattern changes with HFD feeding, showing an increase of Plin2 covering lipid droplets.
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Affiliation(s)
- Diego Nocetti
- Departamento de Tecnología Médica, Universidad de Tarapacá, Arica 1010069, Chile.,Programa de Doctorado en Ciencias Médicas, Universidad de La Frontera, Temuco 4811230, Chile
| | - Alejandra Espinosa
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago 8380463, Chile.,Escuela de Medicina, Campus San Felipe, Universidad de Valparaíso, San Felipe 2340000, Chile.,Center for Studies of Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Universidad de Chile, Santiago 8380463, Chile
| | | | - Camila Sacristán
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - José Luis Bucarey
- Escuela de Medicina, Campus San Felipe, Universidad de Valparaíso, San Felipe 2340000, Chile
| | - Paulina Ruiz
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Rodrigo Valenzuela
- Nutrition Department, Faculty of Medicine, University of Chile, Santiago 8380453, Chile.,Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Raphaël Chouinard-Watkins
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Inés Pepper
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Rodrigo Troncoso
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago 7830490, Chile
| | - Luis Puente
- Departamento de Ciencia de los Alimentos, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago 8380494, Chile
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15
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Arumugam MK, Talawar S, Listenberger L, Donohue TM, Osna NA, Kharbanda KK. Role of Elevated Intracellular S-Adenosylhomocysteine in the Pathogenesis of Alcohol-Related Liver Disease. Cells 2020; 9:cells9061526. [PMID: 32585865 PMCID: PMC7349643 DOI: 10.3390/cells9061526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/19/2020] [Accepted: 06/21/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The earliest manifestation of alcohol-related liver disease (ALD) is steatosis, characterized by the accumulation of lipid droplets (LDs) in hepatocytes. Findings from our laboratory have indicated that many pathological changes, including steatosis, correlate with the alcohol-induced hepatocellular increases in S-adenosylhomocysteine (SAH). Based on these considerations, we hypothesized that an experimental increase in intracellular SAH alone will result in similar steatotic changes to those seen after alcohol exposure. METHODS Freshly isolated rat hepatocytes grown on collagen-coated plates were exposed to serum-free medium containing 50 µmol/L oleic acid and varying concentrations of 3-deazaadenosine (DZA) to experimentally elevate intracellular SAH levels. RESULTS Overnight exposure to DZA treatment dose-dependently increased hepatocellular triglyceride accumulation, which was also evident by morphological visualization of larger-sized LDs. The rise in triglycerides and LDs accompanied increases in mRNA and protein levels of several LD-associated proteins known to regulate LD number and size. Furthermore, DZA treatment caused a decline in the levels of lipases that prevent fat accumulation as well as increased the expression of factors involved in lipogenesis and fatty acid mobilization. Collectively, our results indicate that the elevation of intracellular SAH is sufficient to promote fat accumulation in hepatocytes, which is similar to that seen after alcohol exposure.
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Affiliation(s)
- Madan Kumar Arumugam
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Sharanappa Talawar
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Laura Listenberger
- Departments of Biology and Chemistry, St. Olaf College, Northfield, MN 55057, USA;
| | - Terrence M. Donohue
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Natalia A. Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kusum K. Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Correspondence: ; Tel.: +1-402-995-3752; Fax: +1-402-995-4600
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16
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Kirpich IA, Warner DR, Feng W, Joshi-Barve S, McClain CJ, Seth D, Zhong W, Zhou Z, Osna NA, Kharbanda KK. Mechanisms, biomarkers and targets for therapy in alcohol-associated liver injury: From Genetics to nutrition: Summary of the ISBRA 2018 symposium. Alcohol 2020; 83:105-114. [PMID: 31129175 PMCID: PMC7043088 DOI: 10.1016/j.alcohol.2019.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 02/06/2023]
Abstract
The symposium "Mechanisms, Biomarkers and Targets for Therapy in Alcohol-associated Liver Injury: From Genetics to Nutrition" was held at the 19th Congress of International Society for Biomedical Research on Alcoholism on September 13th, 2018 in Kyoto, Japan. The goal of the symposium was to discuss the importance of genetics and nutrition in alcoholic liver disease (ALD) development from mechanistic and therapeutic perspectives. The following is a summary of this session addressing the gene polymorphisms in ALD, the role of zinc in gut-liver axis perturbations associated with ALD, highlighting the importance of dietary fat in ALD pathogenesis, the hepatic n6 and n3 PUFA oxylipin pattern associated with ethanol-induced liver injury, and finally deliberating on new biomarkers for alcoholic hepatitis and their implications for diagnosis and therapy. This summary of the symposium will benefit junior and senior faculty currently investigating alcohol-induced organ pathology as well as undergraduate, graduate, and post-graduate students and fellows.
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Affiliation(s)
- Irina A Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, USA; Robley Rex Veterans Medical Center, Louisville, KY, USA; Hepatobiology & Toxicology Program, University of Louisville, Louisville, KY, USA
| | - Dennis R Warner
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Wenke Feng
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, USA; Hepatobiology & Toxicology Program, University of Louisville, Louisville, KY, USA
| | - Swati Joshi-Barve
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, USA; Hepatobiology & Toxicology Program, University of Louisville, Louisville, KY, USA
| | - Craig J McClain
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, USA; Robley Rex Veterans Medical Center, Louisville, KY, USA; Hepatobiology & Toxicology Program, University of Louisville, Louisville, KY, USA
| | - Devanshi Seth
- Drug Health Services, Royal Prince Alfred Hospital, Camperdown, NSW, Australia, And Centenary Institute of Cancer Medicine and Cell Biology, The University of Sydney, Sydney, NSW, Australia
| | - Wei Zhong
- Center for Translational Biomedical Research, Department of Nutrition, University of North Carolina at Greensboro, Kannapolis, NC, 28081, USA
| | - Zhanxiang Zhou
- Center for Translational Biomedical Research, Department of Nutrition, University of North Carolina at Greensboro, Kannapolis, NC, 28081, USA
| | - Natalia A Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Kusum K Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
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17
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Lee MJ, Jash S, Jones JEC, Puri V, Fried SK. Rosiglitazone remodels the lipid droplet and britens human visceral and subcutaneous adipocytes ex vivo. J Lipid Res 2019; 60:856-868. [PMID: 30782959 PMCID: PMC6446708 DOI: 10.1194/jlr.m091173] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/15/2019] [Indexed: 12/28/2022] Open
Abstract
Treatment with PPARγ agonists in vivo improves human adipocyte metabolism, but the cellular mechanisms and possible depot differences in responsiveness to their effects are poorly understood. To examine the ex vivo metabolic effects of rosiglitazone (Rosi), we cultured explants of human visceral (omental) and abdominal subcutaneous adipose tissues for 7 days. Rosi increased mRNA levels of transcriptional regulators of brite/beige adipocytes (PGC1α, PRDM16), triglyceride synthesis (GPAT3, DGAT1), and lipolysis (ATGL) similarly in adipose tissues from both depots. In parallel, Rosi increased key modulators of FA oxidation (UCP1, FABP3, PLIN5 protein), rates of FA oxidation, and protein levels of electron transport complexes, suggesting an enhanced respiratory capacity as confirmed in newly differentiated adipocytes. Rosi led to the formation of small lipid droplets (SLDs) around the adipocyte central lipid droplet; each SLD was decorated with redistributed mitochondria that colocalized with PLIN5. SLD maintenance required lipolysis and FA reesterification. Rosi thus coordinated a structural and metabolic remodeling in adipocytes from both visceral and subcutaneous depots that enhanced oxidative capacity. Selective targeting of these cellular mechanisms to improve adipocyte FA handling may provide a new approach to treat metabolic complications of obesity and diabetes.
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Affiliation(s)
- Mi-Jeong Lee
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY; Obesity Center, Boston University School of Medicine, Boston, MA.
| | - Sukanta Jash
- Obesity Center, Boston University School of Medicine, Boston, MA; Department of Biomedical Sciences and Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH
| | - Jessica E C Jones
- Department of Medicine, and Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Vishwajeet Puri
- Obesity Center, Boston University School of Medicine, Boston, MA; Department of Biomedical Sciences and Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH
| | - Susan K Fried
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY; Obesity Center, Boston University School of Medicine, Boston, MA
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18
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Listenberger L, Townsend E, Rickertsen C, Hains A, Brown E, Inwards EG, Stoeckman AK, Matis MP, Sampathkumar RS, Osna NA, Kharbanda KK. Decreasing Phosphatidylcholine on the Surface of the Lipid Droplet Correlates with Altered Protein Binding and Steatosis. Cells 2018; 7:cells7120230. [PMID: 30477200 PMCID: PMC6316228 DOI: 10.3390/cells7120230] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/19/2018] [Accepted: 11/22/2018] [Indexed: 02/05/2023] Open
Abstract
Alcoholic fatty liver disease (AFLD) is characterized by an abnormal accumulation of lipid droplets (LDs) in the liver. Here, we explore the composition of hepatic LDs in a rat model of AFLD. Five to seven weeks of alcohol consumption led to significant increases in hepatic triglyceride mass, along with increases in LD number and size. Additionally, hepatic LDs from rats with early alcoholic liver injury show a decreased ratio of surface phosphatidylcholine (PC) to phosphatidylethanolamine (PE). This occurred in parallel with an increase in the LD association of perilipin 2, a prominent LD protein. To determine if changes to the LD phospholipid composition contributed to differences in protein association with LDs, we constructed liposomes that modeled the LD PC:PE ratios in AFLD and control rats. Reducing the ratio of PC to PE increased the binding of perilipin 2 to liposomes in an in vitro experiment. Moreover, we decreased the ratio of LD PC:PE in NIH 3T3 and AML12 cells by culturing these cells in choline-deficient media. We again detected increased association of specific LD proteins, including perilipin 2. Taken together, our experiments suggest an important link between LD phospholipids, protein composition, and lipid accumulation.
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Affiliation(s)
- Laura Listenberger
- Departments of Biology and Chemistry, St. Olaf College, Northfield, MN 55057, USA.
| | - Elizabeth Townsend
- Departments of Biology and Chemistry, St. Olaf College, Northfield, MN 55057, USA.
| | - Cassandra Rickertsen
- Departments of Biology and Chemistry, St. Olaf College, Northfield, MN 55057, USA.
| | - Anastasia Hains
- Departments of Biology and Chemistry, St. Olaf College, Northfield, MN 55057, USA.
| | - Elizabeth Brown
- Departments of Biology and Chemistry, St. Olaf College, Northfield, MN 55057, USA.
| | - Emily G Inwards
- Department of Chemistry, Bethel University, St. Paul, MN 55112, USA.
| | | | - Mitchell P Matis
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE and Departments of Internal Medicine and Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68105, USA.
| | - Rebecca S Sampathkumar
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE and Departments of Internal Medicine and Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68105, USA.
| | - Natalia A Osna
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE and Departments of Internal Medicine and Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68105, USA.
| | - Kusum K Kharbanda
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE and Departments of Internal Medicine and Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68105, USA.
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19
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Lin J, Zheng S, Attie AD, Keller MP, Bernlohr DA, Blaner WS, Newberry EP, Davidson NO, Chen A. Perilipin 5 and liver fatty acid binding protein function to restore quiescence in mouse hepatic stellate cells. J Lipid Res 2018; 59:416-428. [PMID: 29317465 DOI: 10.1194/jlr.m077487] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 12/07/2017] [Indexed: 12/23/2022] Open
Abstract
Hepatic stellate cell (HSC) activation occurs along with decreased Perilipin5 (Plin5) and liver fatty acid-binding protein (L-Fabp) expression and coincident lipid droplet (LD) depletion. Conversely, the activated phenotype is reversible in WT HSCs upon forced expression of Plin5. Here, we asked if L-Fabp expression is required for Plin5-mediated rescue of the quiescent phenotype. Lentiviral Plin5 transduction of passaged L-Fabp-/- HSCs failed to reverse activation markers or restore lipogenic gene expression and LD formation. However, adenoviral L-Fabp infection of lentiviral Plin5 transduced L-Fabp-/- HSCs restored both the quiescent phenotype and LD formation, an effect also mediated by adenoviral intestine-Fabp or adipocyte-Fabp. Expression of exogenous Plin5 in activated WT HSCs induced a transcriptional program of lipogenic gene expression including endogenous L-Fabp, but none of the other FABPs. We further demonstrated that selective, small molecule inhibition of endogenous L-Fabp also eliminated the ability of exogenous Plin5 to rescue LD formation and reverse activation of WT HSCs. This functional coordination of L-Fabp with Plin5 was 5'-AMP-activated protein kinase (AMPK)-dependent and was eliminated by AMPK inhibition. Taken together, our results indicate that L-Fabp is required for Plin5 to activate a transcriptional program that restores LD formation and reverses HSC activation.
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Affiliation(s)
- Jianguo Lin
- Department of Pathology, School of Medicine, Saint Louis University, St. Louis, MO.,Department of Neurology, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Shizhong Zheng
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Alan D Attie
- Department of Biochemistry, Molecular Biology and Biophysics, University of Wisconsin, Madison, WI, 53706
| | - Mark P Keller
- Department of Biochemistry, Molecular Biology and Biophysics, University of Wisconsin, Madison, WI, 53706
| | - David A Bernlohr
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | | | - Elizabeth P Newberry
- Gastroenterology Division, Washington University School of Medicine, St. Louis, MO 63110
| | - Nicholas O Davidson
- Gastroenterology Division, Washington University School of Medicine, St. Louis, MO 63110
| | - Anping Chen
- Department of Pathology, School of Medicine, Saint Louis University, St. Louis, MO
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Abstract
Lipids stored in lipid droplets are hydrolyzed via either cytosolic lipases or a selective form of macroautophagy known as lipophagy. We recently demonstrated that chaperone-mediated autophagy (CMA) is required for the initiation of lipolysis by either of these independent lipolytic pathways. CMA selectively degrades the lipid droplet proteins perilipins (PLIN) 2 and 3 from the lipid droplet surface, thus, facilitating the recruitment of cytosolic lipases and autophagy effector proteins to the lipid droplets. PLIN2 phosphorylation was observed upon induction of lipolysis, but the phosphorylating kinase and the relation of this phosphorylation with CMA of PLIN2 remained unknown. Here, we report that phosphorylation of PLIN2 is dependent on AMPK and occurs after the interaction of PLIN2 with the CMA chaperone HSPA8/Hsc70. Our results highlight a role for posttranslational modifications in priming proteins to be amenable for degradation by CMA.
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Affiliation(s)
- Susmita Kaushik
- a Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine , Bronx , NY USA
| | - Ana Maria Cuervo
- a Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine , Bronx , NY USA
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21
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Camera E, Dahlhoff M, Ludovici M, Zouboulis CC, Schneider MR. Perilipin 3 modulates specific lipogenic pathways in SZ95 sebocytes. Exp Dermatol 2016; 23:759-61. [PMID: 25039349 DOI: 10.1111/exd.12507] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2014] [Indexed: 11/27/2022]
Abstract
Lipid droplets (LD) are dynamic organelles that manage cellular lipid synthesis, storage and retrieval. Although LD-associated proteins, including the perilipin family (PLIN1-PLIN5), are essential for these functions, they have been poorly characterized in sebocytes. Here, we employed siRNAs to downregulate PLIN3 in SZ95 sebaceous gland cells and evaluated the consequences in lipid accumulation by nile red staining and mass spectrometry. Nile red staining revealed that siRNA-mediated downregulation of PLIN3 significantly impaired linoleic acid-induced lipid accumulation in SZ95 sebocytes. Mass spectrometry revealed that PLIN3 was implicated in the metabolism of linoleic acid, a lipid source used in the build-up of triglycerides, among other acyl lipids. Furthermore, the expression of key enzymes of sebaceous lipogenesis was altered in PLIN3-deficient sebocytes, consistent with the changes observed in the neutral lipid abundance, suggesting that PLIN3 functions are intertwined with the lipogenic pathways implicated in sebaceous lipogenesis, such as desaturation and triglyceride synthesis.
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Affiliation(s)
- Emanuela Camera
- Laboratory of Cutaneous Physiopathology and Integrated Center of Metabolomics Research, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy
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Mishra S, Schneiter R. Expression of perilipin 5 promotes lipid droplet formation in yeast. Commun Integr Biol 2015; 8:e1071728. [PMID: 27066172 PMCID: PMC4802777 DOI: 10.1080/19420889.2015.1071728] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 08/11/2014] [Accepted: 08/12/2014] [Indexed: 11/05/2022] Open
Abstract
Neutral lipids are packed into dedicated intracellular compartments termed lipid droplets (LDs). LDs are spherical structures delineated by an unusual lipid monolayer and they harbor a specific set of proteins, many of which function in lipid synthesis and lipid turnover. In mammals, LDs are covered by abundant scaffolding proteins, the perilipins (PLIN1–5). LDs in yeast are functionally similar to that of mammalian cells, but they lack the perilipins. We have previously shown that perilipins (PLIN1–3) are properly targeted to LDs when expressed in yeast and that they promote LD formation from the ER membrane enriched in neutral lipids. Here we address the question whether PLIN5 (OXPAT) has a similar function. Both human and murine PLIN5 were properly targeted to yeast LDs, but the protein localized to the cytosol and its steady-state level was reduced when expressed in yeast mutants lacking the capacity to synthesize storage lipids. When expressed in cells containing high levels of neutral lipids within the membrane of the endoplasmatic reticulum, PLIN5 promoted the formation of LDs. Interestingly, PLIN5 was properly targeted to LDs, irrespective of whether these LDs were filled with triacylglycerol or steryl esters, indicating that PLIN5 did not exhibit targeting specificity for a particular subtypes of LDs as was reported for mammalian cells.
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Affiliation(s)
- Shirish Mishra
- Department of Biology; Division of Biochemistry; University of Fribourg ; Fribourg, Switzerland
| | - Roger Schneiter
- Department of Biology; Division of Biochemistry; University of Fribourg ; Fribourg, Switzerland
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