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Dias Araújo AR, Bello AA, Bigay J, Franckhauser C, Gautier R, Cazareth J, Kovács D, Brau F, Fuggetta N, Čopič A, Antonny B. Surface tension-driven sorting of human perilipins on lipid droplets. J Cell Biol 2024; 223:e202403064. [PMID: 39297796 PMCID: PMC11413419 DOI: 10.1083/jcb.202403064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 08/13/2024] [Accepted: 08/21/2024] [Indexed: 09/26/2024] Open
Abstract
Perilipins (PLINs), the most abundant proteins on lipid droplets (LDs), display similar domain organization including amphipathic helices (AH). However, the five human PLINs bind different LDs, suggesting different modes of interaction. We established a minimal system whereby artificial LDs covered with defined polar lipids were transiently deformed to promote surface tension. Binding of purified PLIN3 and PLIN4 AH was strongly facilitated by tension but was poorly sensitive to phospholipid composition and to the presence of diacylglycerol. Accordingly, LD coverage by PLIN3 increased as phospholipid coverage decreased. In contrast, PLIN1 bound readily to LDs fully covered by phospholipids; PLIN2 showed an intermediate behavior between PLIN1 and PLIN3. In human adipocytes, PLIN3/4 were found in a soluble pool and relocated to LDs upon stimulation of fast triglyceride synthesis, whereas PLIN1 and PLIN2 localized to pre-existing LDs, consistent with the large difference in LD avidity observed in vitro. We conclude that the PLIN repertoire is adapted to handling LDs with different surface properties.
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Affiliation(s)
- Ana Rita Dias Araújo
- Université Côte d’Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Sophia Antipolis, France
| | - Abdoul Akim Bello
- Université Côte d’Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Sophia Antipolis, France
| | - Joëlle Bigay
- Université Côte d’Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Sophia Antipolis, France
| | - Céline Franckhauser
- Centre de Recherche en Biologie Cellulaire de Montpellier-CRBM, Université de Montpellier, CNRS, UMR 5237, Montpellier, France
| | - Romain Gautier
- Université Côte d’Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Sophia Antipolis, France
| | - Julie Cazareth
- Université Côte d’Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Sophia Antipolis, France
| | - Dávid Kovács
- Université Côte d’Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Sophia Antipolis, France
| | - Frédéric Brau
- Université Côte d’Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Sophia Antipolis, France
| | - Nicolas Fuggetta
- Centre de Recherche en Biologie Cellulaire de Montpellier-CRBM, Université de Montpellier, CNRS, UMR 5237, Montpellier, France
| | - Alenka Čopič
- Centre de Recherche en Biologie Cellulaire de Montpellier-CRBM, Université de Montpellier, CNRS, UMR 5237, Montpellier, France
| | - Bruno Antonny
- Université Côte d’Azur, CNRS and Inserm, Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275, Sophia Antipolis, France
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Aytekin A, Yazir Y, Duruksu G, Öztürk A. Comparison of aquaporin profile of advanced passage mesenchymal stem cells with early passage mesenchymal stem cells and determination of its effect on adipogenic differentiation efficiency. Tissue Cell 2024; 89:102448. [PMID: 38917601 DOI: 10.1016/j.tice.2024.102448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/11/2024] [Accepted: 06/14/2024] [Indexed: 06/27/2024]
Abstract
OBJECTIVE Our study aimed to compare aquaporin profiles in advanced and early passage bone marrow-derived mesenchymal stem cells (BM-MSCs) and assess the impact of aquaporin changes after adipogenic differentiation. Aquaporins are crucial for stem cell survival and differentiation during their life cycle. We focused on the role of aquaporins in the cell structures of advanced and early passage stem cells. METHODS In our study, BM-MSCs were used for our objectives. Characterization of the cells was evaluated via flow cytometry using stem cell surface markers. The characterized BM-MSCs were divided into control and differentiation groups at passages 3 (P3) and 8 (P8). AQP1, AQP3, AQP7, AQP9, and AQP10 expression levels on days 0, 1, 3, 7, 14, and 21 were evaluated using Real Time-PCR, ELISA, and immunofluorescence studies. RESULTS The cells were characterized by flow cytometry and confirmed to exhibit BM-MSC characteristics. At P3 and P8, differentiation was initiated, and AQP protein expression was observed to initially increase and then decrease on subsequent days. The increase in AQP protein expression at P3 occurred earlier than that at P8. Gene expression analysis demonstrated a statistically significant increase in AQP gene expression on days when AQP protein expression decreased. Moreover, statistical differences were observed between late and early passage AQP profiles. CONCLUSION Our study examined the composition of AQPs in BM-MSCs in association with cell passage, and found that AQPs play a role in the differentiation process. The connection between the AQP profile and aging might be related to differentiation capacity, which could have implications for slowing down cellular aging and developing new therapeutic approaches.
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Affiliation(s)
- Ayşegül Aytekin
- Department of Histology and Embryology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey
| | - Yusufhan Yazir
- Department of Stem Cell, Institute of Health Sciences, Kocaeli University, Kocaeli, Turkey; Center for Stem Cell and Gene Therapies Research and Practice, Kocaeli University, Kocaeli, Turkey; Department of Histology and Embryology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey.
| | - Gökhan Duruksu
- Department of Stem Cell, Institute of Health Sciences, Kocaeli University, Kocaeli, Turkey; Center for Stem Cell and Gene Therapies Research and Practice, Kocaeli University, Kocaeli, Turkey
| | - Ahmet Öztürk
- Department of Stem Cell, Institute of Health Sciences, Kocaeli University, Kocaeli, Turkey; Center for Stem Cell and Gene Therapies Research and Practice, Kocaeli University, Kocaeli, Turkey; Department of Histology and Embryology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey
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Oh KI, Lim E, Uprety LP, Jeong J, Jeong H, Park E, Jeong SY. Anti-adipogenic and anti-obesity effects of morroniside in vitro and in vivo. Biomed Pharmacother 2024; 176:116762. [PMID: 38788597 DOI: 10.1016/j.biopha.2024.116762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/13/2024] [Accepted: 05/17/2024] [Indexed: 05/26/2024] Open
Abstract
Obesity is a multifaceted medical condition characterized by the pathological accumulation of excessive lipids in the body. We investigated the effects of morroniside, a bioactive compound derived from Cornus officinalis, on adipogenesis. We used a preadipocyte 3T3-L1 stable cell line and primary cultured adipose-derived stem cells (ADSCs) in vitro and ovariectomized (OVX) and a high-fat diet (HFD)-fed obese mouse model in vivo. Preadipocyte 3T3-L1 cells and ADSCs incubated with morroniside during adipocyte differentiation and obese mice subjected to OVX and HFD received oral morroniside treatment for 12 weeks. Morroniside treatment significantly reduced adipocyte differentiation and fatty acid accumulation and downregulated adipogenesis-related gene expression, concomitant with a decrease in triglyceride content and an increase in glycerol release in cells. The results of the in vivo study showed that morroniside ameliorated obesity-related phenotypes by reducing body weight gain, hepatic steatosis, and adipose tissue in obese mice. These findings suggest that morroniside is a promising compound for preventing and treating obesity.
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Affiliation(s)
- Kang-Il Oh
- Department of Medical Genetics, Ajou University School of Medicine, Suwon 16499, the Republic of Korea; Department of Biomedical Sciences, Ajou University School of Medicine, Suwon 16499, the Republic of Korea
| | - Eunguk Lim
- Department of Medical Genetics, Ajou University School of Medicine, Suwon 16499, the Republic of Korea; Department of Biomedical Sciences, Ajou University School of Medicine, Suwon 16499, the Republic of Korea
| | - Laxmi Prasad Uprety
- Department of Medical Genetics, Ajou University School of Medicine, Suwon 16499, the Republic of Korea; Department of Biomedical Sciences, Ajou University School of Medicine, Suwon 16499, the Republic of Korea
| | - Junhwan Jeong
- Department of Medical Genetics, Ajou University School of Medicine, Suwon 16499, the Republic of Korea; Department of Biomedical Sciences, Ajou University School of Medicine, Suwon 16499, the Republic of Korea
| | - Hyesoo Jeong
- Nine B Co., Ltd., Daejeon 34121, the Republic of Korea
| | - Eunkuk Park
- Department of Medical Genetics, Ajou University School of Medicine, Suwon 16499, the Republic of Korea; Department of Biomedical Sciences, Ajou University School of Medicine, Suwon 16499, the Republic of Korea.
| | - Seon-Yong Jeong
- Department of Medical Genetics, Ajou University School of Medicine, Suwon 16499, the Republic of Korea; Department of Biomedical Sciences, Ajou University School of Medicine, Suwon 16499, the Republic of Korea.
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Griseti E, Bello AA, Bieth E, Sabbagh B, Iacovoni JS, Bigay J, Laurell H, Čopič A. Molecular mechanisms of perilipin protein function in lipid droplet metabolism. FEBS Lett 2024; 598:1170-1198. [PMID: 38140813 DOI: 10.1002/1873-3468.14792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 11/27/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023]
Abstract
Perilipins are abundant lipid droplet (LD) proteins present in all metazoans and also in Amoebozoa and fungi. Humans express five perilipins, which share a similar domain organization: an amino-terminal PAT domain and an 11-mer repeat region, which can fold into amphipathic helices that interact with LDs, followed by a structured carboxy-terminal domain. Variations of this organization that arose during vertebrate evolution allow for functional specialization between perilipins in relation to the metabolic needs of different tissues. We discuss how different features of perilipins influence their interaction with LDs and their cellular targeting. PLIN1 and PLIN5 play a direct role in lipolysis by regulating the recruitment of lipases to LDs and LD interaction with mitochondria. Other perilipins, particularly PLIN2, appear to protect LDs from lipolysis, but the molecular mechanism is not clear. PLIN4 stands out with its long repetitive region, whereas PLIN3 is most widely expressed and is used as a nascent LD marker. Finally, we discuss the genetic variability in perilipins in connection with metabolic disease, prominent for PLIN1 and PLIN4, underlying the importance of understanding the molecular function of perilipins.
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Affiliation(s)
- Elena Griseti
- Institut des Maladies Métaboliques et Cardiovasculaires - I2MC, Université de Toulouse, Inserm, Université Toulouse III - Paul Sabatier (UPS), France
| | - Abdoul Akim Bello
- Institut de Pharmacologie Moléculaire et Cellulaire - IPMC, Université Côte d'Azur, CNRS, Valbonne, France
| | - Eric Bieth
- Institut des Maladies Métaboliques et Cardiovasculaires - I2MC, Université de Toulouse, Inserm, Université Toulouse III - Paul Sabatier (UPS), France
- Departement de Génétique Médicale, Centre Hospitalier Universitaire de Toulouse, France
| | - Bayane Sabbagh
- Centre de Recherche en Biologie Cellulaire de Montpellier - CRBM, Université de Montpellier, CNRS, France
| | - Jason S Iacovoni
- Institut des Maladies Métaboliques et Cardiovasculaires - I2MC, Université de Toulouse, Inserm, Université Toulouse III - Paul Sabatier (UPS), France
| | - Joëlle Bigay
- Institut de Pharmacologie Moléculaire et Cellulaire - IPMC, Université Côte d'Azur, CNRS, Valbonne, France
| | - Henrik Laurell
- Institut des Maladies Métaboliques et Cardiovasculaires - I2MC, Université de Toulouse, Inserm, Université Toulouse III - Paul Sabatier (UPS), France
| | - Alenka Čopič
- Centre de Recherche en Biologie Cellulaire de Montpellier - CRBM, Université de Montpellier, CNRS, France
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Stribny J, Schneiter R. Binding of perilipin 3 to membranes containing diacylglycerol is mediated by conserved residues within its PAT domain. J Biol Chem 2023; 299:105384. [PMID: 37898398 PMCID: PMC10694602 DOI: 10.1016/j.jbc.2023.105384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 10/30/2023] Open
Abstract
Perilipins (PLINs) constitute an evolutionarily conserved family of proteins that specifically associate with the surface of lipid droplets (LDs). These proteins function in LD biogenesis and lipolysis and help to stabilize the surface of LDs. PLINs are typically composed of three different protein domains. They share an N-terminal PAT domain of unknown structure and function, a central region containing 11-mer repeats that form amphipathic helices, and a C-terminal domain that adopts a 4-helix bundle structure. How exactly these three distinct domains contribute to PLIN function remains to be determined. Here, we show that the N-terminal PAT domain of PLIN3 binds diacylglycerol (DAG), the precursor to triacylglycerol, a major storage lipid of LDs. PLIN3 and its PAT domain alone bind liposomes with micromolar affinity and PLIN3 binds artificial LDs containing low concentrations of DAG with nanomolar affinity. The PAT domain of PLIN3 is predicted to adopt an amphipathic triangular shaped structure. In silico ligand docking indicates that DAG binds to one of the highly curved regions within this domain. A conserved aspartic acid residue in the PAT domain, E86, is predicted to interact with DAG, and we found that its substitution abrogates high affinity binding of DAG as well as DAG-stimulated association with liposome and artificial LDs. These results indicate that the PAT domain of PLINs harbor specific lipid-binding properties that are important for targeting these proteins to the surface of LDs and to ER membrane domains enriched in DAG to promote LD formation.
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Affiliation(s)
- Jiri Stribny
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Roger Schneiter
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
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Trempus CS, Papas BN, Sifre MI, Bortner CD, Scappini E, Tucker CJ, Xu X, Johnson KL, Deterding LJ, Williams JG, Johnson DJ, Li JL, Sutton D, Ganta C, Mahapatra D, Arif M, Basu A, Pommerolle L, Cinar R, Perl AK, Garantziotis S. Functional Pdgfra fibroblast heterogeneity in normal and fibrotic mouse lung. JCI Insight 2023; 8:e164380. [PMID: 37824216 PMCID: PMC10721331 DOI: 10.1172/jci.insight.164380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/06/2023] [Indexed: 10/14/2023] Open
Abstract
Aberrant fibroblast function plays a key role in the pathogenesis of idiopathic pulmonary fibrosis, a devastating disease of unrelenting extracellular matrix deposition in response to lung injury. Platelet-derived growth factor α-positive (Pdgfra+) lipofibroblasts (LipoFBs) are essential for lung injury response and maintenance of a functional alveolar stem cell niche. Little is known about the effects of lung injury on LipoFB function. Here, we used single-cell RNA-Seq (scRNA-Seq) technology and PdgfraGFP lineage tracing to generate a transcriptomic profile of Pdgfra+ fibroblasts in normal and injured mouse lungs 14 days after bleomycin exposure, generating 11 unique transcriptomic clusters that segregated according to treatment. While normal and injured LipoFBs shared a common gene signature, injured LipoFBs acquired fibrogenic pathway activity with an attenuation of lipogenic pathways. In a 3D organoid model, injured Pdgfra+ fibroblast-supported organoids were morphologically distinct from those cultured with normal fibroblasts, and scRNA-Seq analysis suggested distinct transcriptomic changes in alveolar epithelia supported by injured Pdgfra+ fibroblasts. In summary, while LipoFBs in injured lung have not migrated from their niche and retain their lipogenic identity, they acquire a potentially reversible fibrogenic profile, which may alter the kinetics of epithelial regeneration and potentially contribute to dysregulated repair, leading to fibrosis.
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Affiliation(s)
| | | | | | | | | | | | - Xin Xu
- Epigenetics & Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Katina L. Johnson
- Epigenetics & Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Leesa J. Deterding
- Epigenetics & Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Jason G. Williams
- Epigenetics & Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | | | | | - Deloris Sutton
- Comparative & Molecular Pathogenesis Branch, National Institute of Environmental Health Sciences, Division of Translational Toxicology, Research Triangle Park, North Carolina, USA
| | - Charan Ganta
- Comparative & Molecular Pathogenesis Branch, National Institute of Environmental Health Sciences, Division of Translational Toxicology, Research Triangle Park, North Carolina, USA
- Inotiv, Research Triangle Park, North Carolina, USA
| | | | - Muhammad Arif
- Section on Fibrotic Disorders, and
- Laboratory of Cardiovascular Physiology and Tissue Injury, National Institute on Alcohol Abuse and Alcoholism, NIH, Rockville, Maryland, USA
| | | | | | | | - Anne K. Perl
- Division of Pulmonary Biology, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
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Dalen KT, Li Y. Regulation of lipid droplets and cholesterol metabolism in adrenal cortical cells. VITAMINS AND HORMONES 2023; 124:79-136. [PMID: 38408810 DOI: 10.1016/bs.vh.2023.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
The adrenal gland is composed of two distinctly different endocrine moieties. The interior medulla consists of neuroendocrine chromaffin cells that secrete catecholamines like adrenaline and noradrenaline, while the exterior cortex consists of steroidogenic cortical cells that produce steroid hormones, such as mineralocorticoids (aldosterone), glucocorticoids (cortisone and cortisol) and androgens. Synthesis of steroid hormones in cortical cells requires substantial amounts of cholesterol, which is the common precursor for steroidogenesis. Cortical cells may acquire cholesterol from de novo synthesis and uptake from circulating low- and high-density lipoprotein particles (LDL and HDL). As cholesterol is part of the plasma membrane in all mammalian cells and an important regulator of membrane fluidity, cellular levels of free cholesterol are tightly regulated. To ensure a robust supply of cholesterol for steroidogenesis and to avoid cholesterol toxicity, cortical cells store large amounts of cholesterol as cholesteryl esters in intracellular lipid droplets. Cortical steroidogenesis relies on both mobilization of cholesterol from lipid droplets and constant uptake of circulating cholesterol to replenish lipid droplet stores. This chapter will describe mechanisms involved in cholesterol uptake, cholesteryl ester synthesis, lipid droplet formation, hydrolysis of stored cholesteryl esters, as well as their impact on steroidogenesis. Additionally, animal models and human diseases characterized by altered cortical cholesteryl ester storage, with or without abnormal steroidogenesis, will be discussed.
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Affiliation(s)
- Knut Tomas Dalen
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Norway; The Norwegian Transgenic Center, Institute of Basic Medical Sciences, University of Oslo, Norway.
| | - Yuchuan Li
- Department of Hepato-Pancreato-Biliary Surgery, Institute of Clinical Medicine, University of Oslo, Norway
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Choi YM, Ajjaji D, Fleming KD, Borbat PP, Jenkins ML, Moeller BE, Fernando S, Bhatia SR, Freed JH, Burke JE, Thiam AR, Airola MV. Structural insights into perilipin 3 membrane association in response to diacylglycerol accumulation. Nat Commun 2023; 14:3204. [PMID: 37268630 PMCID: PMC10238389 DOI: 10.1038/s41467-023-38725-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 05/12/2023] [Indexed: 06/04/2023] Open
Abstract
Lipid droplets (LDs) are dynamic organelles that contain an oil core mainly composed of triglycerides (TAG) that is surrounded by a phospholipid monolayer and LD-associated proteins called perilipins (PLINs). During LD biogenesis, perilipin 3 (PLIN3) is recruited to nascent LDs as they emerge from the endoplasmic reticulum. Here, we analyze how lipid composition affects PLIN3 recruitment to membrane bilayers and LDs, and the structural changes that occur upon membrane binding. We find that the TAG precursors phosphatidic acid and diacylglycerol (DAG) recruit PLIN3 to membrane bilayers and define an expanded Perilipin-ADRP-Tip47 (PAT) domain that preferentially binds DAG-enriched membranes. Membrane binding induces a disorder to order transition of alpha helices within the PAT domain and 11-mer repeats, with intramolecular distance measurements consistent with the expanded PAT domain adopting a folded but dynamic structure upon membrane binding. In cells, PLIN3 is recruited to DAG-enriched ER membranes, and this requires both the PAT domain and 11-mer repeats. This provides molecular details of PLIN3 recruitment to nascent LDs and identifies a function of the PAT domain of PLIN3 in DAG binding.
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Affiliation(s)
- Yong Mi Choi
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Dalila Ajjaji
- Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8N 1A1, Canada
| | - Peter P Borbat
- National Biomedical Resource for Advanced Electron Spin Resonance Technology (ACERT), Cornell University, Ithaca, NY, 14853, USA
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Meredith L Jenkins
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8N 1A1, Canada
| | - Brandon E Moeller
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8N 1A1, Canada
| | - Shaveen Fernando
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Surita R Bhatia
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Jack H Freed
- National Biomedical Resource for Advanced Electron Spin Resonance Technology (ACERT), Cornell University, Ithaca, NY, 14853, USA
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8N 1A1, Canada.
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Abdou Rachid Thiam
- Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France.
| | - Michael V Airola
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA.
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Inhibitory Effects of Loganin on Adipogenesis In Vitro and In Vivo. Int J Mol Sci 2023; 24:ijms24054752. [PMID: 36902181 PMCID: PMC10003152 DOI: 10.3390/ijms24054752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/18/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
Obesity is characterized by the excessive accumulation of mature adipocytes that store surplus energy in the form of lipids. In this study, we investigated the inhibitory effects of loganin on adipogenesis in mouse preadipocyte 3T3-L1 cells and primary cultured adipose-derived stem cells (ADSCs) in vitro and in mice with ovariectomy (OVX)- and high-fat diet (HFD)-induced obesity in vivo. For an in vitro study, loganin was co-incubated during adipogenesis in both 3T3-L1 cells and ADSCs, lipid droplets were evaluated by oil red O staining, and adipogenesis-related factors were assessed by qRT-PCR. For in vivo studies, mouse models of OVX- and HFD-induced obesity were orally administered with loganin, body weight was measured, and hepatic steatosis and development of excessive fat were evaluated by histological analysis. Loganin treatment reduced adipocyte differentiation by accumulating lipid droplets through the downregulation of adipogenesis-related factors, including peroxisome proliferator-activated receptor γ (Pparg), CCAAT/enhancer-binding protein α (Cebpa), perilipin 2 (Plin2), fatty acid synthase (Fasn), and sterol regulatory element binding transcription protein 1 (Srebp1). Loganin administration prevented weight gain in mouse models of obesity induced by OVX and HFD. Further, loganin inhibited metabolic abnormalities, such as hepatic steatosis and adipocyte enlargement, and increased the serum levels of leptin and insulin in both OVX- and HFD-induced obesity models. These results suggest that loganin is a potential candidate for preventing and treating obesity.
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Jin B, Li H, Zhang H, Yang J, Ma W, Lv M, Zheng X, Li X, Liu L, Wang K. Effects of carnosic acid on arsenic-induced liver injury in mice: A comparative transcriptomics analysis. J Trace Elem Med Biol 2022; 71:126953. [PMID: 35202923 DOI: 10.1016/j.jtemb.2022.126953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 02/06/2022] [Accepted: 02/14/2022] [Indexed: 01/29/2023]
Abstract
BACKGROUND Long-term chronic exposure to arsenic can cause different degrees of liver injury. Till date, its molecular mechanism has not meant fully elucidated. Evidence indicates that Carnosic acid (CA) has a protective role in arsenic-induced liver injury. This study aimed to reveal the potential targets and evaluate the potential effect of CA intervention at transcriptional level, and provide reference for the intervention of arsenic-induced liver injury. METHODS Arsenic-induced liver injury and CA intervention models were established in C57BL/6 mice. RNA sequencing technique was carried out to obtain the differentially expressed gene (DEG) profiles. The common covariant DEGs between arsenic induction and CA intervention was screened by comparative transcriptomic analysis methods. QRT-PCR was used to verify the covariant DEGs. RESULTS Transcriptome results showed that 220 DEGs were identified after arsenic induction. 267 DEGs were identified after CA intervention (|fold change| > 2.0 and adjusted P < 0.05). 42 covariant DEGs were discovered between the comparison of "AS vs Control" and "AS & CA vs AS". In addition, hub gene analysis revealed a total of 8 covariant DEGs (Ehhadh, Fgf21, Cyp2b10, Plin2, Aacs, Cyp7a1, Per2 and Mylip). The mRNA expressions of Fgf21 and Plin2 were significantly increased (P < 0.05) and the mRNA expressions of Cyp2b10, Cyp7a1, Per2 and Mylip were significantly decreased (P < 0.05) after arsenic induction. On the contrary, the changes of these DEGs were reversed after CA intervention. CONCLUSION The present study would be helpful to understand the potential health effects of arsenic-induced liver injury and identify new potential targets, and provide a reference for the intervention of CA.
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Affiliation(s)
- Baiming Jin
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China; Department of Preventive Medicine, Qiqihar Medical University, Qiqihar 161006, PR China.
| | - Haonan Li
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China.
| | - Hua Zhang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China.
| | - Jie Yang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China.
| | - Wenjing Ma
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China.
| | - Man Lv
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China.
| | - Xiujuan Zheng
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China; Harbin Municipal Center for Disease Control and Prevention, Harbin 150056, PR China.
| | - Xuying Li
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China.
| | - Lele Liu
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China.
| | - Kewei Wang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, PR China; National Health Commission & Education Bureau of Heilongjiang Province, Key Laboratory of Etiology and Epidemiology, Harbin Medical University (23618504), Harbin 150081, PR China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health,Harbin Medical University, Harbin 150081, PR China; Institute of Cell Biotechnology, China and Russia Medical Research Center, Harbin Medical University, Harbin 150081, PR China.
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11
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Boeckmans J, Gatzios A, Heymans A, Rombaut M, Rogiers V, De Kock J, Vanhaecke T, Rodrigues RM. Transcriptomics Reveals Discordant Lipid Metabolism Effects between In Vitro Models Exposed to Elafibranor and Liver Samples of NAFLD Patients after Bariatric Surgery. Cells 2022; 11:893. [PMID: 35269515 PMCID: PMC8909190 DOI: 10.3390/cells11050893] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND AIMS Non-alcoholic steatohepatitis (NASH) is a life-threatening stage of non-alcoholic fatty liver disease (NAFLD) for which no drugs have been approved. We have previously shown that human-derived hepatic in vitro models can be used to mimic key cellular mechanisms involved in the progression of NASH. In the present study, we first characterize the transcriptome of multiple in vitro NASH models. Subsequently, we investigate how elafibranor, which is a peroxisome proliferator-activated receptor (PPAR)-α/δ agonist that has recently failed a phase 3 clinical trial as a potential anti-NASH compound, modulates the transcriptome of these models. Finally, we compare the elafibranor-induced gene expression modulation to transcriptome data of patients with improved/resolved NAFLD/NASH upon bariatric surgery, which is the only proven clinical NASH therapy. METHODS Human whole genome microarrays were used for the transcriptomics evaluation of hepatic in vitro models. Comparison to publicly available clinical datasets was conducted using multiple bioinformatic application tools. RESULTS Primary human hepatocytes (PHH), HepaRG, and human skin stem cell-derived hepatic progenitors (hSKP-HPC) exposed to NASH-inducing triggers exhibit up to 35% overlap with datasets of liver samples from NASH patients. Exposure of the in vitro NASH models to elafibranor partially reversed the transcriptional modulations, predicting an inhibition of toll-like receptor (TLR)-2/4/9-mediated inflammatory responses, NFκB-signaling, hepatic fibrosis, and leukocyte migration. These transcriptomic changes were also observed in the datasets of liver samples of patients with resolved NASH. Peroxisome Proliferator Activated Receptor Alpha (PPARA), PPARG Coactivator 1 Alpha (PPARGC1A), and Sirtuin 1 (SIRT1) were identified as the major common upstream regulators upon exposure to elafibranor. Analysis of the downstream mechanistic networks further revealed that angiopoietin Like 4 (ANGPTL4), pyruvate dehydrogenase kinase 4 (PDK4), and perilipin 2 (PLIN2), which are involved in the promotion of hepatic lipid accumulation, were also commonly upregulated by elafibranor in all in vitro NASH models. Contrarily, these genes were not upregulated in liver samples of patients with resolved NASH. CONCLUSION Transcriptomics comparison between in vitro NASH models exposed to elafibranor and clinical datasets of NAFLD patients after bariatric surgery reveals commonly modulated anti-inflammatory responses, but discordant modulations of key factors in lipid metabolism. This discordant adverse effect of elafibranor deserves further investigation when assessing PPAR-α/δ agonism as a potential anti-NASH therapy.
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Affiliation(s)
- Joost Boeckmans
- Correspondence: (J.B.); (R.M.R.); Tel.: +32-(0)-2-477-45-19 (R.M.R.)
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12
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Abstract
Lipid droplets (LDs) are ubiquitous organelles that store and supply lipids for energy metabolism, membrane synthesis and production of lipid-derived signaling molecules. While compositional differences in the phospholipid monolayer or neutral lipid core of LDs impact their metabolism and function, the proteome of LDs has emerged as a major influencer in all aspects of LD biology. The perilipins (PLINs) are the most studied and abundant proteins residing on the LD surface. This Cell Science at a Glance and the accompanying poster summarize our current knowledge of the common and unique features of the mammalian PLIN family of proteins, the mechanisms through which they affect cell metabolism and signaling, and their links to disease.
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Affiliation(s)
- Charles P. Najt
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mahima Devarajan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Douglas G. Mashek
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis, MN 55455, USA
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13
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Kiron V, Kathiresan P, Fernandes JM, Sørensen M, Vasanth GK, Qingsong L, Lin Q, Kwang LT, Dahle D, Dias J, Trichet VV. Clues from the intestinal mucus proteome of Atlantic salmon to counter inflammation. J Proteomics 2022; 255:104487. [DOI: 10.1016/j.jprot.2022.104487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 10/19/2022]
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14
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Ma X, Zhi Z, Zhang S, Zhou C, Mechler A, Liu P. Validating an artificial organelle: Studies of lipid droplet-specific proteins on adiposome platform. iScience 2021; 24:102834. [PMID: 34368652 PMCID: PMC8326204 DOI: 10.1016/j.isci.2021.102834] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/28/2021] [Accepted: 07/08/2021] [Indexed: 10/25/2022] Open
Abstract
New strategies are urgently needed to characterize the functions of the lipid droplet (LD). Here, adiposome, an artificial LD mimetic platform, was validated by comparative in vitro bioassays. Scatchard analysis found that the binding of perilipin 2 (PLIN2) to the adiposome surface was saturable. Phosphatidylinositol (PtdIns) was found to inhibit PLIN2 binding while it did not impede perilipin 3 (PLIN3). Structural analysis combined with mutagenesis revealed that the 73rd glutamic acid of PLIN2 is significant for the effect of PtdIns on the PLIN2 binding. Furthermore, adiposome was also found to be an ideal platform for in situ enzymatic activity measurement of adipose triglyceride lipase (ATGL). The significant serine mutants of ATGL were found to cause the loss of lipase activity. Our study demonstrates the adiposome as a powerful, manipulatable model system that mimics the function of LD for binding and enzymatic activity studies of LD proteins in vitro.
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Affiliation(s)
- Xuejing Ma
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zelun Zhi
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia
| | - Shuyan Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chang Zhou
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Adam Mechler
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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15
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Deng Y, Zhou C, Mirza AH, Bamigbade AT, Zhang S, Xu S, Liu P. Rab18 binds PLIN2 and ACSL3 to mediate lipid droplet dynamics. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158923. [PMID: 33713834 DOI: 10.1016/j.bbalip.2021.158923] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/26/2021] [Accepted: 03/05/2021] [Indexed: 01/16/2023]
Abstract
Lipid droplet (LD) is a vital organelle governing lipid homeostasis and Rab18 has been linked to lipid metabolism. However, the mechanisms of Rab18-mediated LD dynamics in myoblast cells remain elusive. Here, we report that Rab18 plays an important role in oleic acid (OA)-induced LD accumulation in mouse myoblast C2C12 cells. Rab18 was translocated from the endoplasmic reticulum (ER) to LDs during LD accumulation, which was regulated by perilipin 2 (PLIN2), a major LD protein. LD-associated Rab18 bound with the C terminus of PLIN2 and the LD localization of Rab18 was diminished when PLIN2 was depleted. Moreover, loss of function of Rab18 led to reduced triacylglycerol (TAG) level and fewer but larger LDs. In contrast, overexpression of Rab18 resulted in elevated TAG content and LD number. Furthermore, LD-associated Rab18 interacted with acyl-CoA synthetase long-chain family member 3 (ACSL3), which in turn promoted the LD localization of this protein. These data show that Rab18 interacts with PLIN2 and forms a complex with PLIN2 and ACSL3, which plays a critical role in LD accumulation and dynamics of myoblast cells.
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Affiliation(s)
- Yaqin Deng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chang Zhou
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Ahmed Hammad Mirza
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Adekunle T Bamigbade
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuyan Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Shimeng Xu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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16
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Liu R, Lee JH, Li J, Yu R, Tan L, Xia Y, Zheng Y, Bian XL, Lorenzi PL, Chen Q, Lu Z. Choline kinase alpha 2 acts as a protein kinase to promote lipolysis of lipid droplets. Mol Cell 2021; 81:2722-2735.e9. [PMID: 34077757 DOI: 10.1016/j.molcel.2021.05.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/02/2021] [Accepted: 05/07/2021] [Indexed: 02/08/2023]
Abstract
Lipid droplets are important for cancer cell growth and survival. However, the mechanism underlying the initiation of lipid droplet lipolysis is not well understood. We demonstrate here that glucose deprivation induces the binding of choline kinase (CHK) α2 to lipid droplets, which is sequentially mediated by AMPK-dependent CHKα2 S279 phosphorylation and KAT5-dependent CHKα2 K247 acetylation. Importantly, CHKα2 with altered catalytic domain conformation functions as a protein kinase and phosphorylates PLIN2 at Y232 and PLIN3 at Y251. The phosphorylated PLIN2/3 dissociate from lipid droplets and are degraded by Hsc70-mediated autophagy, thereby promoting lipid droplet lipolysis, fatty acid oxidation, and brain tumor growth. In addition, levels of CHKα2 S279 phosphorylation, CHKα2 K247 acetylation, and PLIN2/3 phosphorylation are positively correlated with one another in human glioblastoma specimens and are associated with poor prognosis in glioblastoma patients. These findings underscore the role of CHKα2 as a protein kinase in lipolysis and glioblastoma development.
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Affiliation(s)
- Rui Liu
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China; State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China.
| | - Jong-Ho Lee
- Department of Health Sciences, The Graduate School of Dong-A University, Busan, 49315, Republic of Korea; Department of Biological Sciences, Dong-A University, Busan 49315, Republic of Korea
| | - Jingyi Li
- The Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, Chengdu, Sichuan, 610051, China
| | - Rilei Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
| | - Lin Tan
- The Proteomics and Metabolomics Core Facility, Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Yan Xia
- Department of Neuro-Oncology and Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Yanhua Zheng
- Department of Neuro-Oncology and Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xue-Li Bian
- The Affiliated Hospital of Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China
| | - Philip L Lorenzi
- The Proteomics and Metabolomics Core Facility, Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Qianming Chen
- Stomatology Hospital, School of Stomatology, Cancer Center, Zhejiang University School of Medicine, and Key Laboratory of Oral Biomedical Research of Zhejiang Province, Clinical Research Center of Oral Diseases of Zhejiang Province, Hangzhou, 310006, Zhejiang, China.
| | - Zhimin Lu
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China; Zhejiang University Cancer Center, Hangzhou, 310029, China.
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17
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Rare Variants in Autophagy and Non-Autophagy Genes in Late-Onset Pompe Disease: Suggestions of Their Disease-Modifying Role in Two Italian Families. Int J Mol Sci 2021; 22:ijms22073625. [PMID: 33807278 PMCID: PMC8036926 DOI: 10.3390/ijms22073625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 12/30/2022] Open
Abstract
Pompe disease is an autosomal recessive disorder caused by a deficiency in the enzyme acid alpha-glucosidase. The late-onset form of Pompe disease (LOPD) is characterized by a slowly progressing proximal muscle weakness, often involving respiratory muscles. In LOPD, the levels of GAA enzyme activity and the severity of the clinical pictures may be highly variable among individuals, even in those who harbour the same combination of GAA mutations. The result is an unpredictable genotype–phenotype correlation. The purpose of this study was to identify the genetic factors responsible for the progression, severity and drug response in LOPD. We report here on a detailed clinical, morphological and genetic study, including a whole exome sequencing (WES) analysis of 11 adult LOPD siblings belonging to two Italian families carrying compound heterozygous GAA mutations. We disclosed a heterogeneous pattern of myopathic impairment, associated, among others, with cardiac defects, intracranial vessels abnormality, osteoporosis, vitamin D deficiency, obesity and adverse response to enzyme replacement therapy (ERT). We identified deleterious variants in the genes involved in autophagy, immunity and bone metabolism, which contributed to the severity of the clinical symptoms observed in the LOPD patients. This study emphasizes the multisystem nature of LOPD and highlights the polygenic nature of the complex phenotype disclosed in these patients.
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18
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Moreto F, Ferron AJT, Francisqueti-Ferron FV, D'Amato A, Garcia JL, Costa MR, Silva CCVA, Altomare A, Correa CR, Aldini G, Ferreira ALA. Differentially expressed proteins obtained by label-free quantitative proteomic analysis reveal affected biological processes and functions in Western diet-induced steatohepatitis. J Biochem Mol Toxicol 2021; 35:1-11. [PMID: 33729641 DOI: 10.1002/jbt.22751] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/26/2020] [Accepted: 02/24/2021] [Indexed: 12/12/2022]
Abstract
Nonalcoholic steatohepatitis (NASH) is a pathological manifestation with a progressive incidence in response to the epidemic of hepatic steatosis caused primarily by excessive energy intake. The present study unravels affected biological processes and functions by the presence of NASH in rats using a label-free quantitative proteomic strategy. NASH was induced by a Western high-sugar and high-fat diet for 20 weeks. The liver tissue was collected for histology and for a mass spectrometry-based proteomic protocol. The NASH group showed severe lipidosis, hepatocyte ballooning, and the presence of collagen deposition. Among upregulated proteins in NASH perilipin-2 (Plin-2; F6QBA3; difference [diff]: 2.29), ferritin heavy (Fth1; Q66HI5; diff: 2.19) and light (Ftl1; P02793; diff: 1.75) chains, macrophage migration inhibitory factor 1 (Mif; P30904; diff: 1.69), and fibronectin (Fn1; F1LST1; diff: 0.35) were observed, whereas among downregulated proteins, plectin (Q6S399; diff: -3.34), some Cyp2 family proteins of the cytochrome P450 complex, glutathione S-transferases, flavin-containing monooxygenase 1 (Fmo1; P36365; diff: -2.08), acetyl-CoA acetyltransferase 2 (Acat2; Q5XI22; diff: -2.25), acyl-CoA oxidase 2 (Acox2; F1LNW3; diff: -1.59), and acyl-CoA oxidase 3 (Acox3; F1M9A7; diff: -2.41) were observed. Also, biological processes and functions such as LPS/IL-1 inhibition of RXR, fatty acid metabolism, Nrf2-mediated oxidative stress response, xenobiotic metabolism, and PXR/RXR and CAR/RXR activations were predicted to be affected. In conclusion, the liver of rats with NASH induced by Western diet shows a decreased capacity of metabolizing lipids, fatty acids, and xenobiotic compounds that predispose fibrosis development.
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Affiliation(s)
- Fernando Moreto
- Medical School, Sao Paulo State University, Botucatu, Brazil
| | | | | | - Alfonsina D'Amato
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy
| | | | - Mariane R Costa
- Medical School, Sao Paulo State University, Botucatu, Brazil
| | | | | | | | - Giancarlo Aldini
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy
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19
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Conn CS, Yang H, Tom HJ, Ikeda K, Oses-Prieto JA, Vu H, Oguri Y, Nair S, Gill RM, Kajimura S, DeBerardinis RJ, Burlingame AL, Ruggero D. The major cap-binding protein eIF4E regulates lipid homeostasis and diet-induced obesity. Nat Metab 2021; 3:244-257. [PMID: 33619378 DOI: 10.1038/s42255-021-00349-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 01/19/2021] [Indexed: 12/18/2022]
Abstract
Obesity is a global epidemic leading to increased mortality and susceptibility to comorbidities, with few viable therapeutic interventions. A hallmark of disease progression is the ectopic deposition of lipids in the form of lipid droplets in vital organs such as the liver. However, the mechanisms underlying the dynamic storage and processing of lipids in peripheral organs remain an outstanding question. Here, we show an unexpected function for the major cap-binding protein, eIF4E, in high-fat-diet-induced obesity. In response to lipid overload, select networks of proteins involved in fat deposition are altered in eIF4E-deficient mice. Specifically, distinct messenger RNAs involved in lipid metabolic processing and storage pathways are enhanced at the translation level by eIF4E. Failure to translationally upregulate these mRNAs results in increased fatty acid oxidation, which enhances energy expenditure. We further show that inhibition of eIF4E phosphorylation genetically-and by a potent clinical compound-restrains weight gain following intake of a high-fat diet. Together, our study uncovers translational control of lipid processing as a driver of high-fat-diet-induced weight gain and provides a pharmacological target to treat obesity.
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Affiliation(s)
- Crystal S Conn
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
- School of Medicine and Department of Urology, University of California, San Francisco, CA, USA
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Haojun Yang
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.
- School of Medicine and Department of Urology, University of California, San Francisco, CA, USA.
| | - Harrison J Tom
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
- School of Medicine and Department of Urology, University of California, San Francisco, CA, USA
| | - Kenji Ikeda
- Diabetes Center, University of California, San Francisco, CA, USA
- Department of Cell and Tissue Biology, University of California, San Francisco, CA, USA
| | - Juan A Oses-Prieto
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Hieu Vu
- Children's Research Institute and Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yasuo Oguri
- Diabetes Center, University of California, San Francisco, CA, USA
- Department of Cell and Tissue Biology, University of California, San Francisco, CA, USA
| | - Supna Nair
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Ryan M Gill
- Department of Pathology, University of California, San Francisco, CA, USA
| | - Shingo Kajimura
- Diabetes Center, University of California, San Francisco, CA, USA
- Department of Cell and Tissue Biology, University of California, San Francisco, CA, USA
| | - Ralph J DeBerardinis
- Children's Research Institute and Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA
| | - Alma L Burlingame
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Davide Ruggero
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.
- School of Medicine and Department of Urology, University of California, San Francisco, CA, USA.
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.
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20
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Mashek DG. Hepatic lipid droplets: A balancing act between energy storage and metabolic dysfunction in NAFLD. Mol Metab 2020; 50:101115. [PMID: 33186758 PMCID: PMC8324678 DOI: 10.1016/j.molmet.2020.101115] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/21/2020] [Accepted: 11/06/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Non-alcoholic fatty liver disease (NAFLD) is defined by the abundance of lipid droplets (LDs) in hepatocytes. While historically considered simply depots for energy storage, LDs are increasingly recognized to impact a wide range of biological processes that influence cellular metabolism, signaling, and function. While progress has been made toward understanding the factors leading to LD accumulation (i.e. steatosis) and its progression to advanced stages of NAFLD and/or systemic metabolic dysfunction, much remains to be resolved. SCOPE OF REVIEW This review covers many facets of LD biology. We provide a brief overview of the major pathways of lipid accretion and degradation that contribute to steatosis and how they are altered in NAFLD. The major focus is on the relationship between LDs and cell function and the detailed mechanisms that couple or uncouple steatosis from the severity and progression of NAFLD and systemic comorbidities. The importance of specific lipids and proteins within or on LDs as key components that determine whether LD accumulation is linked to cellular and metabolic dysfunction is presented. We discuss emerging areas of LD biology and future research directions that are needed to advance our understanding of the role of LDs in NAFLD etiology. MAJOR CONCLUSIONS Impairments in LD breakdown appear to contribute to disease progression, but inefficient incorporation of fatty acids (FAs) into LD-containing triacylglycerol (TAG) and the consequential changes in FA partitioning also affect NAFLD etiology. Increased LD abundance in hepatocytes does not necessarily equate to cellular dysfunction. While LD accumulation is the prerequisite step for most NAFLD cases, the protein and lipid composition of LDs are critical factors in determining the progression from simple steatosis. Further defining the detailed molecular mechanisms linking LDs to metabolic dysfunction is important for designing effective therapeutic approaches targeting NAFLD and its comorbidities.
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Affiliation(s)
- Douglas G Mashek
- Department of Biochemistry, Molecular Biology, and Biophysics, Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Minnesota, Suite 6-155, 321 Church St. SE, Minneapolis, MN, 55455, USA.
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21
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Brekk OR, Honey JR, Lee S, Hallett PJ, Isacson O. Cell type-specific lipid storage changes in Parkinson's disease patient brains are recapitulated by experimental glycolipid disturbance. Proc Natl Acad Sci U S A 2020; 117:27646-27654. [PMID: 33060302 PMCID: PMC7959493 DOI: 10.1073/pnas.2003021117] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Neurons are dependent on proper trafficking of lipids to neighboring glia for lipid exchange and disposal of potentially lipotoxic metabolites, producing distinct lipid distribution profiles among various cell types of the central nervous system. Little is known of the cellular distribution of neutral lipids in the substantia nigra (SN) of Parkinson's disease (PD) patients and its relationship to inflammatory signaling. This study aimed to determine human PD SN neutral lipid content and distribution in dopaminergic neurons, astrocytes, and microglia relative to age-matched healthy subject controls. The results show that while total neutral lipid content was unchanged relative to age-matched controls, the levels of whole SN triglycerides were correlated with inflammation-attenuating glycoprotein non-metastatic melanoma protein B (GPNMB) signaling in human PD SN. Histological localization of neutral lipids using a fluorescent probe (BODIPY) revealed that dopaminergic neurons and midbrain microglia significantly accumulated intracellular lipids in PD SN, while adjacent astrocytes had a reduced lipid load overall. This pattern was recapitulated by experimental in vivo inhibition of glucocerebrosidase activity in mice. Agents or therapies that restore lipid homeostasis among neurons, astrocytes, and microglia could potentially correct PD pathogenesis and disease progression.
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Affiliation(s)
- Oeystein Roed Brekk
- Neuroregeneration Institute, McLean Hospital/Departments of Neurology and Psychiatry, Harvard Medical School, Belmont, MA 02478
| | - Jonathan R Honey
- Neuroregeneration Institute, McLean Hospital/Harvard Medical School, Belmont, MA 02478
| | - Seungil Lee
- Neuroregeneration Institute, McLean Hospital/Harvard Medical School, Belmont, MA 02478
| | - Penelope J Hallett
- Neuroregeneration Institute, McLean Hospital/Departments of Neurology and Psychiatry, Harvard Medical School, Belmont, MA 02478
| | - Ole Isacson
- Neuroregeneration Institute, McLean Hospital/Departments of Neurology and Psychiatry, Harvard Medical School, Belmont, MA 02478
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22
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The Puzzling Conservation and Diversification of Lipid Droplets from Bacteria to Eukaryotes. Results Probl Cell Differ 2020; 69:281-334. [PMID: 33263877 DOI: 10.1007/978-3-030-51849-3_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Membrane compartments are amongst the most fascinating markers of cell evolution from prokaryotes to eukaryotes, some being conserved and the others having emerged via a series of primary and secondary endosymbiosis events. Membrane compartments comprise the system limiting cells (one or two membranes in bacteria, a unique plasma membrane in eukaryotes) and a variety of internal vesicular, subspherical, tubular, or reticulated organelles. In eukaryotes, the internal membranes comprise on the one hand the general endomembrane system, a dynamic network including organelles like the endoplasmic reticulum, the Golgi apparatus, the nuclear envelope, etc. and also the plasma membrane, which are linked via direct lateral connectivity (e.g. between the endoplasmic reticulum and the nuclear outer envelope membrane) or indirectly via vesicular trafficking. On the other hand, semi-autonomous organelles, i.e. mitochondria and chloroplasts, are disconnected from the endomembrane system and request vertical transmission following cell division. Membranes are organized as lipid bilayers in which proteins are embedded. The budding of some of these membranes, leading to the formation of the so-called lipid droplets (LDs) loaded with hydrophobic molecules, most notably triacylglycerol, is conserved in all clades. The evolution of eukaryotes is marked by the acquisition of mitochondria and simple plastids from Gram-positive bacteria by primary endosymbiosis events and the emergence of extremely complex plastids, collectively called secondary plastids, bounded by three to four membranes, following multiple and independent secondary endosymbiosis events. There is currently no consensus view of the evolution of LDs in the Tree of Life. Some features are conserved; others show a striking level of diversification. Here, we summarize the current knowledge on the architecture, dynamics, and multitude of functions of the lipid droplets in prokaryotes and in eukaryotes deriving from primary and secondary endosymbiosis events.
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23
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Najt CP, Khan SA, Heden TD, Witthuhn BA, Perez M, Heier JL, Mead LE, Franklin MP, Karanja KK, Graham MJ, Mashek MT, Bernlohr DA, Parker L, Chow LS, Mashek DG. Lipid Droplet-Derived Monounsaturated Fatty Acids Traffic via PLIN5 to Allosterically Activate SIRT1. Mol Cell 2019; 77:810-824.e8. [PMID: 31901447 DOI: 10.1016/j.molcel.2019.12.003] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/17/2019] [Accepted: 12/03/2019] [Indexed: 12/20/2022]
Abstract
Lipid droplets (LDs) provide a reservoir for triacylglycerol storage and are a central hub for fatty acid trafficking and signaling in cells. Lipolysis promotes mitochondrial biogenesis and oxidative metabolism via a SIRT1/PGC-1α/PPARα-dependent pathway through an unknown mechanism. Herein, we identify that monounsaturated fatty acids (MUFAs) allosterically activate SIRT1 toward select peptide-substrates such as PGC-1α. MUFAs enhance PGC-1α/PPARα signaling and promote oxidative metabolism in cells and animal models in a SIRT1-dependent manner. Moreover, we characterize the LD protein perilipin 5 (PLIN5), which is known to enhance mitochondrial biogenesis and function, to be a fatty-acid-binding protein that preferentially binds LD-derived monounsaturated fatty acids and traffics them to the nucleus following cAMP/PKA-mediated lipolytic stimulation. Thus, these studies identify the first-known endogenous allosteric modulators of SIRT1 and characterize a LD-nuclear signaling axis that underlies the known metabolic benefits of MUFAs and PLIN5.
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Affiliation(s)
- Charles P Najt
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Salmaan A Khan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Timothy D Heden
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Bruce A Witthuhn
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Minervo Perez
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Jason L Heier
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Linnea E Mead
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Mallory P Franklin
- Department of Food Science and Nutrition, University of Minnesota, Minneapolis, MN, USA
| | - Kenneth K Karanja
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | | | - Mara T Mashek
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - David A Bernlohr
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Laurie Parker
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Lisa S Chow
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis, Minnesota, USA
| | - Douglas G Mashek
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA; Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis, Minnesota, USA.
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24
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Chen X, Firdaus SJ, Fu Z, Wu Z, Soulages JL, Arrese EL. Manduca sexta Perilipin 1B: A new PLIN1 isoform linked to fat storage prior to pupation. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 110:69-79. [PMID: 31055048 DOI: 10.1016/j.ibmb.2019.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/01/2019] [Accepted: 05/01/2019] [Indexed: 06/09/2023]
Abstract
Perilipins (PLINs) are proteins that associate with lipid droplets (LDs) and play roles in the control of triglycerides (TG) metabolism. Two types of PLINs - 1 and 2- occur in insects. Following previous work on MsPLIN1A (a 42 kDa protein formerly called MsLsd1), here we report a new PLIN1 isoform, MsPLIN1B. MsPLIN1B cDNA was cloned and the 1835bp cDNA contains an ORF encoding a 47.9 kDa protein whose expression was confirmed by mass spectrometry. Alternative transcripts A and B, which differ in the alternative use of exon 1, were the most abundant PLIN1 transcripts in the fat body. These transcripts encode nearly identical proteins except that the B isoform contains 59 additional residues in its amino terminus. No conserved domain was identified in the extra region of MsPLIN1B. The novel PLIN1 isoform is found in lepidopteran species. In Manduca, PLIN1B was expressed only in the 5th instar larva and its levels correlated with fat storage. Furthermore, PLIN1B levels increased with the fat content of the diet in insects of the same age confirming a direct relationship between PLIN1B and TG storage irrespective of development. The nutritional status impacted PLIN1B levels, which decreased in starvation and increased with subsequent re-feeding. Altogether data support a link between PLIN1B and TG storage in caterpillars prior to pupation. The combined findings suggest distinct roles for PLIN1A, PLIN1B and PLIN2. MsPLIN1A abundance correlates with mobilization of TG stores, MsPLIN2 with the synthesis of new LDs and MsPLIN1B abundance correlates with high levels of TG storage and large LD sizes at the end of the last feeding period.
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Affiliation(s)
- Xiao Chen
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Sarah J Firdaus
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Zhiyan Fu
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Zengying Wu
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jose L Soulages
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Estela L Arrese
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
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25
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Wu H, Ploeger JM, Kamarajugadda S, Mashek DG, Mashek MT, Manivel JC, Shekels LL, Lapiro JL, Albrecht JH. Evidence for a Novel Regulatory Interaction Involving Cyclin D1, Lipid Droplets, Lipolysis, and Cell Cycle Progression in Hepatocytes. Hepatol Commun 2019; 3:406-422. [PMID: 30859152 PMCID: PMC6396375 DOI: 10.1002/hep4.1316] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/22/2018] [Indexed: 12/12/2022] Open
Abstract
During normal proliferation, hepatocytes accumulate triglycerides (TGs) in lipid droplets (LDs), but the underlying mechanisms and functional significance of this steatosis are unknown. In the current study, we examined the coordinated regulation of cell cycle progression and LD accumulation. As previously shown, hepatocytes develop increased LD content after mitogen stimulation. Cyclin D1, in addition to regulating proliferation, was both necessary and sufficient to promote LD accumulation in response to mitogens. Interestingly, cyclin D1 promotes LD accumulation by inhibiting the breakdown of TGs by lipolysis through a mechanism involving decreased lipophagy, the autophagic degradation of LDs. To examine whether inhibition of lipolysis is important for cell cycle progression, we overexpressed adipose TG lipase (ATGL), a key enzyme involved in TG breakdown. As expected, ATGL reduced LD content but also markedly inhibited hepatocyte proliferation, suggesting that lipolysis regulates a previously uncharacterized cell cycle checkpoint. Consistent with this, in mitogen-stimulated cells with small interfering RNA-mediated depletion of cyclin D1 (which inhibits proliferation and stimulates lipolysis), concurrent ATGL knockdown restored progression into S phase. Following partial hepatectomy, a model of robust hepatocyte proliferation in vivo, ATGL overexpression led to decreased LD content, cell cycle inhibition, and marked liver injury, further indicating that down-regulation of lipolysis is important for normal hepatocyte proliferation. Conclusion: We suggest a new relationship between steatosis and proliferation in hepatocytes: cyclin D1 inhibits lipolysis, resulting in LD accumulation, and suppression of lipolysis is necessary for cell cycle progression.
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Affiliation(s)
- Heng Wu
- Gastroenterology DivisionMinneapolis VA Health Care SystemMinneapolisMN
- Division of Gastroenterology, Hepatology, and NutritionUniversity of MinnesotaMinneapolisMN
| | - Jonathan M. Ploeger
- Department of Biochemistry, Molecular Biology, and BiophysicsUniversity of MinnesotaMinneapolisMN
| | | | - Douglas G. Mashek
- Department of Biochemistry, Molecular Biology, and BiophysicsUniversity of MinnesotaMinneapolisMN
| | - Mara T. Mashek
- Department of Biochemistry, Molecular Biology, and BiophysicsUniversity of MinnesotaMinneapolisMN
| | - Juan C. Manivel
- Department of PathologyMinneapolis VA Health Care SystemMinneapolisMN
| | - Laurie L. Shekels
- Gastroenterology DivisionMinneapolis VA Health Care SystemMinneapolisMN
| | - Jessica L. Lapiro
- Gastroenterology DivisionMinneapolis VA Health Care SystemMinneapolisMN
- Division of Gastroenterology, Hepatology, and NutritionUniversity of MinnesotaMinneapolisMN
| | - Jeffrey H. Albrecht
- Gastroenterology DivisionMinneapolis VA Health Care SystemMinneapolisMN
- Division of Gastroenterology, Hepatology, and NutritionUniversity of MinnesotaMinneapolisMN
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26
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Zhang C, Liu P. The New Face of the Lipid Droplet: Lipid Droplet Proteins. Proteomics 2018; 19:e1700223. [DOI: 10.1002/pmic.201700223] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 08/13/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Congyan Zhang
- National Laboratory of BiomacromoleculesCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of Sciences Beijing 100101 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Pingsheng Liu
- National Laboratory of BiomacromoleculesCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of Sciences Beijing 100101 China
- University of Chinese Academy of Sciences Beijing 100049 China
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27
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Schmölz L, Schubert M, Kirschner J, Kluge S, Galli F, Birringer M, Wallert M, Lorkowski S. Long-chain metabolites of vitamin E: Interference with lipotoxicity via lipid droplet associated protein PLIN2. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:919-927. [DOI: 10.1016/j.bbalip.2018.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 04/17/2018] [Accepted: 05/03/2018] [Indexed: 01/25/2023]
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28
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Visualization of lipid directed dynamics of perilipin 1 in human primary adipocytes. Sci Rep 2017; 7:15011. [PMID: 29118433 PMCID: PMC5678101 DOI: 10.1038/s41598-017-15059-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/19/2017] [Indexed: 12/20/2022] Open
Abstract
Perilipin 1 is a lipid droplet coating protein known to regulate lipid metabolism in adipocytes by serving as a physical barrier as well as a recruitment site for lipases to the lipid droplet. Phosphorylation of perilipin 1 by protein kinase A rapidly initiates lipolysis, but the detailed mechanism on how perilipin 1 controls lipolysis is unknown. Here, we identify specific lipid binding properties of perilipin 1 that regulate the dynamics of lipolysis in human primary adipocytes. Cellular imaging combined with biochemical and biophysical analyses demonstrate that perilipin 1 specifically binds to cholesteryl esters, and that their dynamic properties direct segregation of perilipin 1 into topologically distinct micro domains on the lipid droplet. Together, our data points to a simple unifying mechanism that lipid assembly and segregation control lipolysis in human primary adipocytes.
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29
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Kimmel AR, Sztalryd C. The Perilipins: Major Cytosolic Lipid Droplet-Associated Proteins and Their Roles in Cellular Lipid Storage, Mobilization, and Systemic Homeostasis. Annu Rev Nutr 2017; 36:471-509. [PMID: 27431369 DOI: 10.1146/annurev-nutr-071813-105410] [Citation(s) in RCA: 176] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The discovery by Dr. Constantine Londos of perilipin 1, the major scaffold protein at the surface of cytosolic lipid droplets in adipocytes, marked a fundamental conceptual change in the understanding of lipolytic regulation. Focus then shifted from the enzymatic activation of lipases to substrate accessibility, mediated by perilipin-dependent protein sequestration and recruitment. Consequently, the lipid droplet became recognized as a unique, metabolically active cellular organelle and its surface as the active site for novel protein-protein interactions. A new area of investigation emerged, centered on lipid droplets' biology and their role in energy homeostasis. The perilipin family is of ancient origin and has expanded to include five mammalian genes and a growing list of evolutionarily conserved members. Universally, the perilipins modulate cellular lipid storage. This review provides a summary that connects the perilipins to both cellular and whole-body homeostasis.
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Affiliation(s)
- Alan R Kimmel
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, The National Institutes of Health, Bethesda, Maryland 20892;
| | - Carole Sztalryd
- The Geriatric Research Education and Clinical Center, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201.,Division of Endocrinology, Department of Medicine, School of Medicine, University of Maryland, Baltimore, Maryland 21201;
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30
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Simino J, Wang Z, Bressler J, Chouraki V, Yang Q, Younkin SG, Seshadri S, Fornage M, Boerwinkle E, Mosley TH. Whole exome sequence-based association analyses of plasma amyloid-β in African and European Americans; the Atherosclerosis Risk in Communities-Neurocognitive Study. PLoS One 2017; 12:e0180046. [PMID: 28704393 PMCID: PMC5509141 DOI: 10.1371/journal.pone.0180046] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 06/08/2017] [Indexed: 12/30/2022] Open
Abstract
Objective We performed single-variant and gene-based association analyses of plasma amyloid-β (aβ) concentrations using whole exome sequence from 1,414 African and European Americans. Our goal was to identify genes that influence plasma aβ42 concentrations and aβ42:aβ40 ratios in late middle age (mean = 59 years), old age (mean = 77 years), or change over time (mean = 18 years). Methods Plasma aβ measures were linearly regressed onto age, gender, APOE ε4 carrier status, and time elapsed between visits (fold-changes only) separately by race. Following inverse normal transformation of the residuals, seqMeta was used to conduct race-specific single-variant and gene-based association tests while adjusting for population structure. Linear regression models were fit on autosomal variants with minor allele frequencies (MAF)≥1%. T5 burden and Sequence Kernel Association (SKAT) gene-based tests assessed functional variants with MAF≤5%. Cross-race fixed effects meta-analyses were Bonferroni-corrected for the number of variants or genes tested. Results Seven genes were associated with aβ in late middle age or change over time; no associations were identified in old age. Single variants in KLKB1 (rs3733402; p = 4.33x10-10) and F12 (rs1801020; p = 3.89x10-8) were significantly associated with midlife aβ42 levels through cross-race meta-analysis; the KLKB1 variant replicated internally using 1,014 additional participants with exome chip. ITPRIP, PLIN2, and TSPAN18 were associated with the midlife aβ42:aβ40 ratio via the T5 test; TSPAN18 was significant via the cross-race meta-analysis, whereas ITPRIP and PLIN2 were European American-specific. NCOA1 and NT5C3B were associated with the midlife aβ42:aβ40 ratio and the fold-change in aβ42, respectively, via SKAT in African Americans. No associations replicated externally (N = 725). Conclusion We discovered age-dependent genetic effects, established associations between vascular-related genes (KLKB1, F12, PLIN2) and midlife plasma aβ levels, and identified a plausible Alzheimer’s Disease candidate gene (ITPRIP) influencing cell death. Plasma aβ concentrations may have dynamic biological determinants across the lifespan; plasma aβ study designs or analyses must consider age.
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Affiliation(s)
- Jeannette Simino
- Gertrude C. Ford MIND Center, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
- Department of Data Science, John D. Bower School of Population Health, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
- * E-mail:
| | - Zhiying Wang
- Human Genetics Center, Department of Epidemiology, Human Genetics & Environmental Sciences, School of Public Health, University of Texas Health Science Center, Houston, Texas, United States of America
| | - Jan Bressler
- Human Genetics Center, Department of Epidemiology, Human Genetics & Environmental Sciences, School of Public Health, University of Texas Health Science Center, Houston, Texas, United States of America
| | - Vincent Chouraki
- Lille University, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk factors and molecular determinants of aging-related diseases; Lille, France
| | - Qiong Yang
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
- The National Heart, Lung, and Blood Institute’s Framingham Heart Study, Framingham, Massachusetts, United States of America
| | - Steven G. Younkin
- Department of Neuroscience, Mayo Clinic College of Medicine, Mayo Clinic Jacksonville, Jacksonville, Florida, United States of America
| | - Sudha Seshadri
- The National Heart, Lung, and Blood Institute’s Framingham Heart Study, Framingham, Massachusetts, United States of America
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Myriam Fornage
- Human Genetics Center, Department of Epidemiology, Human Genetics & Environmental Sciences, School of Public Health, University of Texas Health Science Center, Houston, Texas, United States of America
- The Brown Foundation Institute of Molecular Medicine, Research Center for Human Genetics, The University of Texas Health Science Center, Houston, Texas, United States of America
| | - Eric Boerwinkle
- Human Genetics Center, Department of Epidemiology, Human Genetics & Environmental Sciences, School of Public Health, University of Texas Health Science Center, Houston, Texas, United States of America
- The Brown Foundation Institute of Molecular Medicine, Research Center for Human Genetics, The University of Texas Health Science Center, Houston, Texas, United States of America
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, United States of America
| | - Thomas H. Mosley
- Gertrude C. Ford MIND Center, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
- Department of Medicine, University of Mississippi Medical Center, Jackson, Massachusetts, United States of America
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31
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Siegler H, Valerius O, Ischebeck T, Popko J, Tourasse NJ, Vallon O, Khozin-Goldberg I, Braus GH, Feussner I. Analysis of the lipid body proteome of the oleaginous alga Lobosphaera incisa. BMC PLANT BIOLOGY 2017; 17:98. [PMID: 28587627 PMCID: PMC5461629 DOI: 10.1186/s12870-017-1042-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 05/22/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Lobosphaera incisa (L. incisa) is an oleaginous microalga that stores triacylglycerol (TAG) rich in arachidonic acid in lipid bodies (LBs). This organelle is gaining attention in algal research, since evidence is accumulating that proteins attached to its surface fulfill important functions in TAG storage and metabolism. RESULTS Here, the composition of the LB proteome in L incisa was investigated by comparing different cell fractions in a semiquantitative proteomics approach. After applying stringent filters to the proteomics data in order to remove contaminating proteins from the list of possible LB proteins (LBPs), heterologous expression of candidate proteins in tobacco pollen tubes, allowed us to confirm 3 true LBPs: A member of the algal Major Lipid Droplet Protein family, a small protein of unknown function and a putative lipase. In addition, a TAG lipase that belongs to the SUGAR DEPENDENT 1 family of TAG lipases known from oilseed plants was identified. Its activity was verified by functional complementation of an Arabidopsis thaliana mutant lacking the major seed TAG lipases. CONCLUSIONS Here we describe 3 LBPs as well as a TAG lipase from the oleaginous microalga L. incisa and discuss their possible involvement in LB metabolism. This study highlights the importance of filtering LB proteome datasets and verifying the subcellular localization one by one, so that contaminating proteins can be recognized as such. Our dataset can serve as a valuable resource in the identification of additional LBPs, shedding more light on the intriguing roles of LBs in microalgae.
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Affiliation(s)
- Heike Siegler
- University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Department of Plant Biochemistry, Goettingen, Germany
| | - Oliver Valerius
- University of Goettingen, Institute for Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Goettingen, Germany
| | - Till Ischebeck
- University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Department of Plant Biochemistry, Goettingen, Germany
| | - Jennifer Popko
- University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Department of Plant Biochemistry, Goettingen, Germany
| | - Nicolas J. Tourasse
- UMR7141, CNRS/Université Pierre et Marie Curie, Paris, France
- Present address: Laboratoire ARNA, INSERM U1212, CNRS UMR5320, Université Bordeaux 2; Institut Européen de Chimie et Biologie (IECB), 2 rue Robert Escarpit, 33607 Pessac, France
| | - Olivier Vallon
- UMR7141, CNRS/Université Pierre et Marie Curie, Paris, France
| | - Inna Khozin-Goldberg
- Ben-Gurion University of the Negev, Microalgal Biotechnology Laboratory, Beer-Sheva, Israel
| | - Gerhard H. Braus
- University of Goettingen, Institute for Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Goettingen, Germany
- University of Goettingen, Goettingen Center for Molecular Biosciences (GZMB), Goettingen, Germany
| | - Ivo Feussner
- University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Department of Plant Biochemistry, Goettingen, Germany
- University of Goettingen, Goettingen Center for Molecular Biosciences (GZMB), Goettingen, Germany
- University of Goettingen, International Center for Advanced Studies of Energy Conversion (ICASEC), Goettingen, Germany
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32
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Itabe H, Yamaguchi T, Nimura S, Sasabe N. Perilipins: a diversity of intracellular lipid droplet proteins. Lipids Health Dis 2017; 16:83. [PMID: 28454542 PMCID: PMC5410086 DOI: 10.1186/s12944-017-0473-y] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 04/22/2017] [Indexed: 01/04/2023] Open
Abstract
Intracellular lipid droplets (LDs) are found in a wide variety of cell types and have been recognized as organelles with unique spherical structures. Although LDs are not stable lipid-depots, they are active sites of neutral lipid metabolism, and comprise neutral lipid or cholesterol cores surrounded by phospholipid monolayers containing specialized proteins. However, sizes and protein compositions vary between cell and tissue types. Proteins of the perilipin family have been associated with surfaces of LDs and all carry a conserved 11-mer repeat motif. Accumulating evidence indicates that all perilipins are involved in LD formation and that all play roles in LD function under differing conditions. In this brief review, we summarize current knowledge of the roles of perilipins and lipid metabolizing enzymes in a variety of mammalian cell types.
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Affiliation(s)
- Hiroyuki Itabe
- Division of Biological Chemistry, Department of Molecular Biology, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan.
| | - Tomohiro Yamaguchi
- Division of Biological Chemistry, Department of Molecular Biology, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan.,Present address: College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyaka-ku, Nagoya, 463-8521, Japan
| | - Satomi Nimura
- Division of Biological Chemistry, Department of Molecular Biology, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan.,Department of Hospital Pharmaceutics, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan
| | - Naoko Sasabe
- Division of Biological Chemistry, Department of Molecular Biology, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan
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Conte M, Franceschi C, Sandri M, Salvioli S. Perilipin 2 and Age-Related Metabolic Diseases: A New Perspective. Trends Endocrinol Metab 2016; 27:893-903. [PMID: 27659144 DOI: 10.1016/j.tem.2016.09.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/01/2016] [Accepted: 09/01/2016] [Indexed: 12/20/2022]
Abstract
Perilipin 2 (Plin2), a protein associated with the metabolism of intracellular lipid droplets (LDs), has long been considered only for its role in lipid storage. However, the manipulation of its expression affects the severity of a variety of metabolic and age-related diseases, such as fatty liver, insulin resistance and type 2 diabetes (T2D), cardiovascular disease, atherosclerosis, sarcopenia, and cancer, suggesting that this protein may play a role in these pathological conditions. In particular, its downregulation in mice prevents or mitigates some of the above mentioned diseases. Conversely, in humans high levels of Plin2 are present in sarcopenia, hepatic steatosis, atherosclerosis, and some types of cancer. We propose that inhibition of Plin2 might be a strategy to counteract several metabolic and age-related diseases.
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Affiliation(s)
- Maria Conte
- Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, 40126 Bologna, Italy; Interdepartmental Centre 'L. Galvani' (CIG), University of Bologna, 40126 Bologna, Italy.
| | - Claudio Franceschi
- IRCCS, Institute of Neurological Sciences of Bologna, 40139 Bologna, Italy
| | - Marco Sandri
- Department of Biomedical Science, University of Padova, 35121 Padova, Italy; Venetian Institute of Molecular Medicine, 35129 Padova, Italy
| | - Stefano Salvioli
- Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, 40126 Bologna, Italy; Interdepartmental Centre 'L. Galvani' (CIG), University of Bologna, 40126 Bologna, Italy
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Sentinelli F, Capoccia D, Incani M, Bertoccini L, Severino A, Pani MG, Manconi E, Cossu E, Leonetti F, Baroni MG. The perilipin 2 (PLIN2) gene Ser251Pro missense mutation is associated with reduced insulin secretion and increased insulin sensitivity in Italian obese subjects. Diabetes Metab Res Rev 2016; 32:550-6. [PMID: 26443937 DOI: 10.1002/dmrr.2751] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 09/07/2015] [Accepted: 10/05/2015] [Indexed: 01/23/2023]
Abstract
BACKGROUND Perilipin 2 (PLIN2), a member of the family of perilipin lipid droplets coating proteins, is very widely expressed. The Ser251Pro (rs35568725) missense mutation in exon 6 of PLIN2 gene was previously associated with increased lipid accumulation, decreased lipolysis and increased number of small lipid droplets per cell. Furthermore, the Pro251 mutation was associated with decreased plasma triglyceride and very low density lipoprotein concentrations in population studies. The aim of this study was to evaluate the effect of the Ser251Pro mutation of PLIN2 gene in a cohort with a higher predisposition to obesity-associated metabolic alterations, such as insulin resistance, decreased insulin-secretion, hyperglycaemia, and dyslipidaemia. METHODS A large cohort (N = 1692) of Italian obese subjects (mean body mass index = 41 kg/m(2) ) was genotyped for the Ser251Pro mutation. All participants underwent oral glucose tolerance tests (OGTT), with measurement of glucose and insulin levels. Indices of insulin resistance and of insulin secretion were also calculated. Clinical and biochemical parameters were collected for all participants. RESULTS We observed that insulin concentration was significantly reduced at 120 min after the administration of glucose in Pro251 allele carriers, whereas glucose levels were similar in Pro251 allele carriers and non-carriers throughout the OGTT. Furthermore, the CIR120 index of insulin secretion was significantly lower (P < 0.035) and the ISI index of insulin-sensitivity was significantly higher (P < 0.031) in carriers of the Pro251 allele. When we analysed men and women separately to test for gender-specific associations, we observed that in women insulin levels were significantly lower in Pro251 allele carriers compared with wild-type subjects throughout the whole OGTT. In men, we confirmed a significant reduction in insulin concentration only at 120 min after the OGTT. No significant differences between genotype groups regarding triglyceride levels and anyother clinical and metabolic parameters were observed. CONCLUSION We observed a strong significant association between the PLIN2 Pro251 mutation and lower insulin secretion associated with an increased insulin sensitivity. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Federica Sentinelli
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Danila Capoccia
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Michela Incani
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
| | - Laura Bertoccini
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Anna Severino
- Institute of Cardiology, Catholic University, Rome, Italy
| | - Maria Grazia Pani
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
| | - Ettore Manconi
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
| | - Efisio Cossu
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
| | - Frida Leonetti
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Marco G Baroni
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
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Najt CP, Senthivinayagam S, Aljazi MB, Fader KA, Olenic SD, Brock JRL, Lydic TA, Jones AD, Atshaves BP. Liver-specific loss of Perilipin 2 alleviates diet-induced hepatic steatosis, inflammation, and fibrosis. Am J Physiol Gastrointest Liver Physiol 2016; 310:G726-38. [PMID: 26968211 PMCID: PMC4867327 DOI: 10.1152/ajpgi.00436.2015] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/08/2016] [Indexed: 01/31/2023]
Abstract
Hepatic inflammation and fibrosis are key elements in the pathogenesis of nonalcoholic steatohepatitis (NASH), a progressive liver disease initiated by excess hepatic lipid accumulation. Lipid droplet protein Perilipin 2 (Plin2) alleviates dietary-induced hepatic steatosis when globally ablated; however, its role in the progression of NASH remains unknown. To investigate this further, we challenged Plin2 liver-specific knockout mice (designated L-KO) and their respective wild-type (WT) controls with a methionine-choline-deficient (MCD) diet for 15 days to induce a NASH phenotype of increased hepatic triglyceride levels through impaired phosphatidylcholine (PC) synthesis and very-low-density lipoprotein (VLDL) secretion. Results on liver weights, body weights, fat tissue mass, and histology in WT and L-KO mice fed the MCD diet revealed signs of hepatic steatosis, fibrosis, and inflammation; however, these effects were blunted in L-KO mice. In addition, levels of PC and VLDL were unchanged, and hepatic steatosis was reduced in L-KO mice fed the MCD diet, due in part to an increase in remodeling of PE to PC via the enzyme phosphatidylethanolamine N-methyltransferase (PEMT). These mice also exhibited decreased hepatic expression of proinflammatory markers cyclooxygenase 2, IL-6, TNF-α, IL-1β, and reduced expression of endoplasmic reticulum (ER) stress proteins C/EBP homologous protein and cleaved caspase-1. Taken together, these results suggest that Plin2 liver-specific ablation alleviates diet-induced hepatic steatosis and inflammation via a PEMT-mediated mechanism that involves compensatory changes in proteins involved in phospholipid remodeling, inflammation, and ER stress that work to alleviate diet-induced NASH. Overall, these findings support a role for Plin2 as a target for NASH therapy.
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Affiliation(s)
- Charles P. Najt
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | | | - Mohammad B. Aljazi
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | - Kelly A. Fader
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | - Sandra D. Olenic
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | - Julienne R. L. Brock
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | - Todd A. Lydic
- 2Department of Physiology, Michigan State University, East Lansing, Michigan; and
| | - A. Daniel Jones
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan; ,3Department of Chemistry, Michigan State University, East Lansing, Michigan
| | - Barbara P. Atshaves
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
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Rowe ER, Mimmack ML, Barbosa AD, Haider A, Isaac I, Ouberai MM, Thiam AR, Patel S, Saudek V, Siniossoglou S, Savage DB. Conserved Amphipathic Helices Mediate Lipid Droplet Targeting of Perilipins 1-3. J Biol Chem 2016; 291:6664-78. [PMID: 26742848 PMCID: PMC4807253 DOI: 10.1074/jbc.m115.691048] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 01/05/2016] [Indexed: 12/21/2022] Open
Abstract
Perilipins (PLINs) play a key role in energy storage by orchestrating the activity of lipases on the surface of lipid droplets. Failure of this activity results in severe metabolic disease in humans. Unlike all other lipid droplet-associated proteins, PLINs localize almost exclusively to the phospholipid monolayer surrounding the droplet. To understand how they sense and associate with the unique topology of the droplet surface, we studied the localization of human PLINs inSaccharomyces cerevisiae,demonstrating that the targeting mechanism is highly conserved and that 11-mer repeat regions are sufficient for droplet targeting. Mutations designed to disrupt folding of this region into amphipathic helices (AHs) significantly decreased lipid droplet targetingin vivoandin vitro Finally, we demonstrated a substantial increase in the helicity of this region in the presence of detergent micelles, which was prevented by an AH-disrupting missense mutation. We conclude that highly conserved 11-mer repeat regions of PLINs target lipid droplets by folding into AHs on the droplet surface, thus enabling PLINs to regulate the interface between the hydrophobic lipid core and its surrounding hydrophilic environment.
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Affiliation(s)
- Emily R Rowe
- From the University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, United Kingdom
| | - Michael L Mimmack
- From the University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, United Kingdom
| | - Antonio D Barbosa
- the Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Afreen Haider
- From the University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, United Kingdom
| | - Iona Isaac
- From the University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, United Kingdom
| | - Myriam M Ouberai
- the Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge CB3 0FF, United Kingdom, and
| | - Abdou Rachid Thiam
- the Laboratoire de Physique Statistique, Ecole Normale Supérieure de Paris, Université Pierre et Marie Curie, Université Paris Diderot, CNRS, 24 Rue Lhomond, 75005 Paris, France
| | - Satish Patel
- From the University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, United Kingdom
| | - Vladimir Saudek
- From the University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, United Kingdom
| | - Symeon Siniossoglou
- the Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - David B Savage
- From the University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, United Kingdom,
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Targeting Fat: Mechanisms of Protein Localization to Lipid Droplets. Trends Cell Biol 2016; 26:535-546. [PMID: 26995697 DOI: 10.1016/j.tcb.2016.02.007] [Citation(s) in RCA: 206] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/22/2016] [Accepted: 02/23/2016] [Indexed: 12/18/2022]
Abstract
How proteins specifically localize to the phospholipid monolayer surface of lipid droplets (LDs) is being unraveled. We review here the major known pathways of protein targeting to LDs and suggest a classification framework based on the localization origin for the protein. Class I proteins often have a membrane-embedded, hydrophobic 'hairpin' motif, and access LDs from the endoplasmic reticulum (ER) either during LD formation or after formation via ER-LD membrane bridges. Class II proteins access the LD surface from the cytosol and bind through amphipathic helices or other hydrophobic domains. Other proteins require lipid modifications or protein-protein interactions to bind to LDs. We summarize knowledge for targeting and removal of the different classes, and highlight areas needing investigation.
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