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Fioretti T, Martora F, De Maggio I, Ambrosio A, Piscopo C, Vallone S, Amato F, Passaro D, Acquaviva F, Gaudiello F, Di Girolamo D, Maiolo V, Zarrilli F, Esposito S, Vitiello G, Auricchio L, Sammarco E, Brasi DD, Petillo R, Gambale A, Cattaneo F, Ammendola R, Nappa P, Esposito G. Comprehensive Molecular Analysis of Disease-Related Genes as First-Tier Test for Early Diagnosis, Classification, and Management of Patients Affected by Nonsyndromic Ichthyosis. Biomedicines 2024; 12:1112. [PMID: 38791074 PMCID: PMC11117922 DOI: 10.3390/biomedicines12051112] [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: 04/03/2024] [Revised: 05/07/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024] Open
Abstract
Inherited ichthyoses are a group of clinically and genetically heterogeneous rare disorders of skin keratinization with overlapping phenotypes. The clinical picture and family history are crucial to formulating the diagnostic hypothesis, but only the identification of the genetic defect allows the correct classification. In the attempt to molecularly classify 17 unrelated Italian patients referred with congenital nonsyndromic ichthyosis, we performed massively parallel sequencing of over 50 ichthyosis-related genes. Genetic data of 300 Italian unaffected subjects were also analyzed to evaluate frequencies of putative disease-causing alleles in our population. For all patients, we identified the molecular cause of the disease. Eight patients were affected by autosomal recessive congenital ichthyosis associated with ALOX12B, NIPAL4, and TGM1 mutations. Three patients had biallelic loss-of-function variants in FLG, whereas 6/11 males were affected by X-linked ichthyosis. Among the 24 different disease-causing alleles we identified, 8 carried novel variants, including a synonymous TGM1 variant that resulted in a splicing defect. Moreover, we generated a priority list of the ichthyosis-related genes that showed a significant number of rare and novel variants in our population. In conclusion, our comprehensive molecular analysis resulted in an effective first-tier test for the early classification of ichthyosis patients. It also expands the genetic, mutational, and phenotypic spectra of inherited ichthyosis and provides new insight into the current understanding of etiologies and epidemiology of this group of rare disorders.
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Affiliation(s)
- Tiziana Fioretti
- CEINGE Advanced Biotechnologies Franco Salvatore, 80145 Naples, Italy; (T.F.); (A.A.); (S.V.); (F.A.); (F.Z.); (S.E.)
| | - Fabrizio Martora
- Section of Dermatology, Department of Clinical Medicine and Surgery, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (F.M.); (F.G.); (L.A.); (P.N.)
| | - Ilaria De Maggio
- Medical and Laboratory Genetics Unit, AORN A. Cardarelli, 80131 Naples, Italy; (I.D.M.); (C.P.); (R.P.)
| | - Adelaide Ambrosio
- CEINGE Advanced Biotechnologies Franco Salvatore, 80145 Naples, Italy; (T.F.); (A.A.); (S.V.); (F.A.); (F.Z.); (S.E.)
| | - Carmelo Piscopo
- Medical and Laboratory Genetics Unit, AORN A. Cardarelli, 80131 Naples, Italy; (I.D.M.); (C.P.); (R.P.)
| | - Sabrina Vallone
- CEINGE Advanced Biotechnologies Franco Salvatore, 80145 Naples, Italy; (T.F.); (A.A.); (S.V.); (F.A.); (F.Z.); (S.E.)
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
| | - Felice Amato
- CEINGE Advanced Biotechnologies Franco Salvatore, 80145 Naples, Italy; (T.F.); (A.A.); (S.V.); (F.A.); (F.Z.); (S.E.)
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
| | - Diego Passaro
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
| | - Fabio Acquaviva
- Medical Genetics Unit, Department of General and Emergency Paediatrics, AORN Santobono-Pausilipon, 80122 Naples, Italy; (F.A.); (D.D.B.)
| | - Francesca Gaudiello
- Section of Dermatology, Department of Clinical Medicine and Surgery, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (F.M.); (F.G.); (L.A.); (P.N.)
| | - Daniela Di Girolamo
- Department of Biology, University of Naples “Federico II”, 80126 Naples, Italy;
| | - Valeria Maiolo
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
| | - Federica Zarrilli
- CEINGE Advanced Biotechnologies Franco Salvatore, 80145 Naples, Italy; (T.F.); (A.A.); (S.V.); (F.A.); (F.Z.); (S.E.)
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
| | - Speranza Esposito
- CEINGE Advanced Biotechnologies Franco Salvatore, 80145 Naples, Italy; (T.F.); (A.A.); (S.V.); (F.A.); (F.Z.); (S.E.)
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
| | - Giuseppina Vitiello
- Medical Genetics Unit, Integrated Care Department of Laboratory and Transfusion Medicine, Federico II Hospital, 80131 Naples, Italy; (G.V.); (A.G.)
| | - Luigi Auricchio
- Section of Dermatology, Department of Clinical Medicine and Surgery, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (F.M.); (F.G.); (L.A.); (P.N.)
| | - Elena Sammarco
- Pediatric Dermatology Unit, Department of Dermo-Immuno-Rheumatology Paediatrics, AORN Santobono-Pausilipon, 80122 Naples, Italy;
| | - Daniele De Brasi
- Medical Genetics Unit, Department of General and Emergency Paediatrics, AORN Santobono-Pausilipon, 80122 Naples, Italy; (F.A.); (D.D.B.)
| | - Roberta Petillo
- Medical and Laboratory Genetics Unit, AORN A. Cardarelli, 80131 Naples, Italy; (I.D.M.); (C.P.); (R.P.)
| | - Antonella Gambale
- Medical Genetics Unit, Integrated Care Department of Laboratory and Transfusion Medicine, Federico II Hospital, 80131 Naples, Italy; (G.V.); (A.G.)
| | - Fabio Cattaneo
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
| | - Rosario Ammendola
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
| | - Paola Nappa
- Section of Dermatology, Department of Clinical Medicine and Surgery, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (F.M.); (F.G.); (L.A.); (P.N.)
| | - Gabriella Esposito
- CEINGE Advanced Biotechnologies Franco Salvatore, 80145 Naples, Italy; (T.F.); (A.A.); (S.V.); (F.A.); (F.Z.); (S.E.)
- Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, 80131 Naples, Italy; (D.P.); (V.M.); (F.C.); (R.A.)
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2
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Leahy C, Osborne N, Shirota L, Rote P, Lee YK, Song BJ, Yin L, Zhang Y, Garcia V, Hardwick JP. The fatty acid omega hydroxylase genes (CYP4 family) in the progression of metabolic dysfunction-associated steatotic liver disease (MASLD): An RNA sequence database analysis and review. Biochem Pharmacol 2024:116241. [PMID: 38697309 DOI: 10.1016/j.bcp.2024.116241] [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: 02/14/2024] [Revised: 04/21/2024] [Accepted: 04/25/2024] [Indexed: 05/04/2024]
Abstract
Fatty acid omega hydroxylase P450s consist of enzymes that hydroxylate various chain-length saturated and unsaturated fatty acids (FAs) and bioactive eicosanoid lipids. The human cytochrome P450 gene 4 family (CYP4) consists of 12 members that are associated with several human diseases. However, their role in the progression of metabolic dysfunction-associated fatty liver disease (MASLD) remains largely unknown. It has long been thought that the induction of CYP4 family P450 during fasting and starvation prevents FA-related lipotoxicity through FA metabolism to dicarboxylic acids that are chain-shortened in peroxisomes and then transported to the mitochondria for complete oxidation. Several studies have revealed that peroxisome succinate transported to the mitochondria is used for gluconeogenesis during fasting and starvation, and recent evidence suggests that peroxisome acetate can be utilized for lipogenesis and lipid droplet formation as well as epigenetic modification of gene transcription. In addition, omega hydroxylation of the bioactive eicosanoid arachidonic acid to 20-Hydroxyeicosatetraenoic acid (20-HETE) is essential for activating the GPR75 receptor, leading to vasoconstriction and cell proliferation. Several mouse models of diet-induced MASLD have revealed the induction of selective CYP4A members and the suppression of CYP4F during steatosis and steatohepatitis, suggesting a critical metabolic role in the progression of fatty liver disease. Thus, to further investigate the functional roles of CYP4 genes, we analyzed the differential gene expression of 12 members of CYP4 gene family in datasets from the Gene Expression Omnibus (GEO) from patients with steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. We also observed the differential expression of various CYP4 genes in the progression of MASLD, indicating that different CYP4 members may have unique functional roles in the metabolism of specific FAs and eicosanoids at various stages of fatty liver disease. These results suggest that targeting selective members of the CYP4A family is a viable therapeutic approach for treating and managing MASLD.
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Affiliation(s)
- Charles Leahy
- Department of Integrative Medical Sciences Liver focus group, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA
| | - Nicholas Osborne
- Department of Integrative Medical Sciences Liver focus group, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA
| | - Leticia Shirota
- Department of Integrative Medical Sciences Liver focus group, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA
| | - Paula Rote
- Department of Integrative Medical Sciences Liver focus group, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA
| | - Yoon-Kwang Lee
- Department of Integrative Medical Sciences Liver focus group, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA
| | - Byoung-Joon Song
- Section of Molecular Pharmacology and Toxicology, National Institute on Alcohol Abuse and Alcoholism, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Liya Yin
- Department of Integrative Medical Sciences Liver focus group, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA
| | - Yanqiao Zhang
- Department of Integrative Medical Sciences Liver focus group, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA
| | - Victor Garcia
- Department of Pharmacology, New York Medical College, 15 Dana Road Science Building, Rm. 530, Valhalla, NY 10595, USA
| | - James P Hardwick
- Department of Integrative Medical Sciences Liver focus group, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA.
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Yamaji M, Ohno Y, Shimada M, Kihara A. Alteration of epidermal lipid composition as a result of deficiency in the magnesium transporter Nipal4. J Lipid Res 2024; 65:100550. [PMID: 38692573 DOI: 10.1016/j.jlr.2024.100550] [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: 02/02/2024] [Revised: 04/23/2024] [Accepted: 04/25/2024] [Indexed: 05/03/2024] Open
Abstract
Lipids in the stratum corneum play an important role in the formation of the skin permeability barrier. The causative gene for congenital ichthyosis, NIPAL4, encodes a Mg2+ transporter and is involved in increases in intracellular Mg2+ concentrations that depend on keratinocyte differentiation. However, the role of this increased Mg2+ concentration in skin barrier formation and its effect on the lipid composition of the stratum corneum has remained largely unknown. Therefore, in the present study, we performed a detailed analysis of epidermal lipids in Nipal4 KO mice via TLC and MS. Compared with WT mice, the Nipal4 KO mice showed compositional changes in many ceramide classes (including decreases in ω-O-acylceramides and increases in ω-hydroxy ceramides), together with increases in ω-hydroxy glucosylceramides, triglycerides, and free fatty acids and decreases in ω-O-acyl hydroxy fatty acids containing a linoleic acid. We also found increases in unusual ω-O-acylceramides containing oleic acid or palmitic acid in the KO mice. However, there was little change in levels of cholesterol or protein-bound ceramides. The TLC analysis showed that some unidentified lipids were increased, and the MS analysis showed that these were special ceramides called 1-O-acylceramides. These results suggest that elevated Mg2+ concentrations in differentiated keratinocytes affect the production of various lipids, resulting in the lipid composition necessary for skin barrier formation.
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Affiliation(s)
- Marino Yamaji
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Yusuke Ohno
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
| | - Madoka Shimada
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Akio Kihara
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
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Zoullas S, Morel D, Zafeer F, Borjas-Mendoza P, Angeli S, Zhou Y, Bademci G, Tekin M. Two novel heterozygous exonic deletions lead to Chanarin-Dorfman syndrome in a patient with congenital ichthyosis, sensorineural hearing loss, and liver dysfunction. Am J Med Genet A 2024; 194:e63481. [PMID: 37984424 DOI: 10.1002/ajmg.a.63481] [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: 08/18/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 11/22/2023]
Abstract
Chanarin-Dorfman syndrome is an autosomal recessively inherited disorder characterized by ichthyosis, sensorineural hearing loss, and hepatic dysfunction. We report on a 60-year-old female of Venezuelan descent who presented with congenital ichthyosis, progressive sensorineural hearing loss, and liver cirrhosis. We identify a heterozygous copy number deletion involving exon 1 and another heterozygous deletion involving exon 3 of the ABHD5 gene. Exon 2 is preserved. Both deletions were confirmed with RT-PCR. RNAseq from peripheral blood shows a reduction of ABHD5 expression overall and an absence of exon 3 expression, confirming the deleterious effects of the identified deletions. We present exonic deletions as a potentially common type of ABHD5 variation.
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Affiliation(s)
- Sofia Zoullas
- Dr. John T. Macdonald Foundation, Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Dayna Morel
- Dr. John T. Macdonald Foundation, Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Faraz Zafeer
- Dr. John T. Macdonald Foundation, Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Paulo Borjas-Mendoza
- Dr. John T. Macdonald Foundation, Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Simon Angeli
- Department of Otolaryngology, University of Miami, Miami, Florida, USA
| | - Yi Zhou
- Department of Pathology, University of Miami, Miami, Florida, USA
| | - Guney Bademci
- Dr. John T. Macdonald Foundation, Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Mustafa Tekin
- Dr. John T. Macdonald Foundation, Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, Florida, USA
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Lulić AM, Katalinić M. The PNPLA family of enzymes: characterisation and biological role. Arh Hig Rada Toksikol 2023; 74:75-89. [PMID: 37357879 PMCID: PMC10291501 DOI: 10.2478/aiht-2023-74-3723] [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: 02/01/2023] [Revised: 02/01/2023] [Accepted: 05/01/2023] [Indexed: 06/27/2023] Open
Abstract
This paper brings a brief review of the human patatin-like phospholipase domain-containing protein (PNPLA) family. Even though it consists of only nine members, their physiological roles and mechanisms of their catalytic activity are not fully understood. However, the results of a number of knock-out and gain- or loss-of-function research models suggest that these enzymes have an important role in maintaining the homeostasis and integrity of organelle membranes, in cell growth, signalling, cell death, and the metabolism of lipids such as triacylglycerol, phospholipids, ceramides, and retinyl esters. Research has also revealed a connection between PNPLA family member mutations or irregular catalytic activity and the development of various diseases. Here we summarise important findings published so far and discuss their structure, localisation in the cell, distribution in the tissues, specificity for substrates, and their potential physiological role, especially in view of their potential as drug targets.
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Affiliation(s)
- Ana-Marija Lulić
- Institute for Medical Research and Occupational Health, Biochemistry and Organic Analytical Chemistry Unit, Zagreb, Croatia
| | - Maja Katalinić
- Institute for Medical Research and Occupational Health, Biochemistry and Organic Analytical Chemistry Unit, Zagreb, Croatia
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Meyer JM, Boeglin WE, Brash AR. Recombinant PNPLA1 catalyzes the synthesis of acylceramides and acyl acids with selective incorporation of linoleic acid. J Lipid Res 2023; 64:100379. [PMID: 37087101 PMCID: PMC10209018 DOI: 10.1016/j.jlr.2023.100379] [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: 03/09/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 04/24/2023] Open
Abstract
Loss-of-function mutations in patatin-like phospholipase domain-containing protein 1 (PNPLA1) cause autosomal recessive congenital ichthyosis, and altered PNPLA1 activity is implicated in the pathogenesis of atopic dermatitis and other common skin diseases. To examine the hypothesis that PNPLA1 catalyzes the synthesis of acylceramides and acyl acids, we expressed and partially purified a soluble, truncated form of PNPLA1 in Escherichia coli, (PNPLA1trun) along with the related protein PNPLA2 (ATGL, adipose triglyceride lipase) and coactivator CGI-58. Liposomal substrates were incubated with recombinant enzymes for 0.5-24 h and products analyzed by HPLC-UV and LC-MS. Using trilinolein or dilinolein substrates, PNPLA1trun, like ATGLtrun, catalyzed lipolysis and acyltransferase reactions with 2-30% conversion into linoleic acid, monolinolein, and trilinolein. CGI-58 enhanced ATGL-catalyzed lipolysis as previously reported, but transacylase activity was not enhanced with ATGL or PNPLA1. In matching the proposed activity in vivo, PNPLA1 catalyzed acyl transfer from trilinolein and dilinolein donors to omega-hydroxy ceramide, omega-hydroxy glucosylceramide, and omega-hydroxy acid acceptors to form acylceramide, glucosyl-acylceramide, and acyl acid, respectively, albeit with only ∼0.05% conversion of the substrates. Notably, in experiments comparing dilinolein vs. diolein acyl donors, PNPLA1 transferred linoleate with 3:1 selectivity over oleate into acylceramide. These results support the role for PNPLA1 in the synthesis of acylceramides and acyl acids in epidermis and suggest that the enrichment of these lipids with linoleic acid could result from the substrate selectivity of PNPLA1.
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Affiliation(s)
- Jason M Meyer
- Department of Dermatology, Vanderbilt University Medical Center, Nashville, TN, USA; Dermatology Service, Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA.
| | - William E Boeglin
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Alan R Brash
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.
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The phospholipase A 2 superfamily as a central hub of bioactive lipids and beyond. Pharmacol Ther 2023; 244:108382. [PMID: 36918102 DOI: 10.1016/j.pharmthera.2023.108382] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/13/2023]
Abstract
In essence, "phospholipase A2" (PLA2) means a group of enzymes that release fatty acids and lysophospholipids by hydrolyzing the sn-2 position of glycerophospholipids. To date, more than 50 enzymes possessing PLA2 or related lipid-metabolizing activities have been identified in mammals, and these are subdivided into several families in terms of their structures, catalytic mechanisms, tissue/cellular localizations, and evolutionary relationships. From a general viewpoint, the PLA2 superfamily has mainly been implicated in signal transduction, driving the production of a wide variety of bioactive lipid mediators. However, a growing body of evidence indicates that PLA2s also contribute to phospholipid remodeling or recycling for membrane homeostasis, fatty acid β-oxidation for energy production, and barrier lipid formation on the body surface. Accordingly, PLA2 enzymes are considered one of the key regulators of a broad range of lipid metabolism, and perturbation of specific PLA2-driven lipid pathways often disrupts tissue and cellular homeostasis and may be associated with a variety of diseases. This review covers current understanding of the physiological functions of the PLA2 superfamily, focusing particularly on the two major intracellular PLA2 families (Ca2+-dependent cytosolic PLA2s and Ca2+-independent patatin-like PLA2s) as well as other PLA2 families, based on studies using gene-manipulated mice and human diseases in combination with comprehensive lipidomics.
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Mottillo EP, Mladenovic-Lucas L, Zhang H, Zhou L, Kelly CV, Ortiz PA, Granneman JG. A FRET sensor for the real-time detection of long chain acyl-CoAs and synthetic ABHD5 ligands. CELL REPORTS METHODS 2023; 3:100394. [PMID: 36936069 PMCID: PMC10014278 DOI: 10.1016/j.crmeth.2023.100394] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 12/19/2022] [Accepted: 01/05/2023] [Indexed: 01/26/2023]
Abstract
Intracellular long-chain acyl-coenzyme As (LC-acyl-CoAs) are thought to be under tight spatial and temporal controls, yet the ability to image LC-acyl-CoAs in live cells is lacking. Here, we developed a fluorescence resonance energy transfer (FRET) sensor for LC-acyl-CoAs based on the allosterically regulated interaction between α/β hydrolase domain-containing 5 (ABHD5) and Perilipin 5. The genetically encoded sensor rapidly detects intracellular LC-acyl-CoAs generated from exogenous and endogenous fatty acids (FAs), as well as synthetic ABHD5 ligands. Stimulation of lipolysis in brown adipocytes elevated intracellular LC-acyl-CoAs in a cyclic fashion, which was eliminated by inhibiting PNPLA2 (ATGL), the major triglyceride lipase. Interestingly, inhibition of LC-acyl-CoA transport into mitochondria elevated intracellular LC-acyl-CoAs and dampened their cycling. Together, these observations reveal an intimate feedback control between LC-acyl-CoA generation from lipolysis and utilization in mitochondria. We anticipate that this sensor will be an important tool to dissect intracellular LC-acyl-CoA dynamics as well to discover novel synthetic ABHD5 ligands.
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Affiliation(s)
- Emilio P. Mottillo
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, 6135 Woodward Avenue, Detroit, MI 48202, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ljiljana Mladenovic-Lucas
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Huamei Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Li Zhou
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Christopher V. Kelly
- Department of Physics and Astronomy, Wayne State University, Detroit, MI 48202, USA
| | - Pablo A. Ortiz
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, 6135 Woodward Avenue, Detroit, MI 48202, USA
| | - James G. Granneman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48202, USA
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Schratter M, Lass A, Radner FPW. ABHD5-A Regulator of Lipid Metabolism Essential for Diverse Cellular Functions. Metabolites 2022; 12:1015. [PMID: 36355098 PMCID: PMC9694394 DOI: 10.3390/metabo12111015] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/19/2022] [Accepted: 10/23/2022] [Indexed: 11/12/2023] Open
Abstract
The α/β-Hydrolase domain-containing protein 5 (ABHD5; also known as comparative gene identification-58, or CGI-58) is the causative gene of the Chanarin-Dorfman syndrome (CDS), a disorder mainly characterized by systemic triacylglycerol accumulation and a severe defect in skin barrier function. The clinical phenotype of CDS patients and the characterization of global and tissue-specific ABHD5-deficient mouse strains have demonstrated that ABHD5 is a crucial regulator of lipid and energy homeostasis in various tissues. Although ABHD5 lacks intrinsic hydrolase activity, it functions as a co-activating enzyme of the patatin-like phospholipase domain-containing (PNPLA) protein family that is involved in triacylglycerol and glycerophospholipid, as well as sphingolipid and retinyl ester metabolism. Moreover, ABHD5 interacts with perilipins (PLINs) and fatty acid-binding proteins (FABPs), which are important regulators of lipid homeostasis in adipose and non-adipose tissues. This review focuses on the multifaceted role of ABHD5 in modulating the function of key enzymes in lipid metabolism.
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Affiliation(s)
- Margarita Schratter
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Field of Excellence BioHealth, 8010 Graz, Austria
| | - Franz P. W. Radner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
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Arai A, Takeichi T, Wakamoto H, Sassa T, Ito Y, Murase Y, Ogi T, Akiyama M, Kihara A. Ceramide profiling of stratum corneum in Sjögren-Larsson syndrome. J Dermatol Sci 2022; 107:114-122. [PMID: 35973883 DOI: 10.1016/j.jdermsci.2022.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/20/2022] [Accepted: 08/07/2022] [Indexed: 12/22/2022]
Abstract
BACKGROUND Sjögren-Larsson syndrome (SLS) is a neurocutaneous disorder whose causative gene is the fatty aldehyde dehydrogenase ALDH3A2 and of which ichthyosis is the major skin symptom. The stratum corneum contains a variety of ceramides, among which ω-O-acylceramides (acylceramides) and protein-bound ceramides are essential for skin permeability barrier formation. OBJECTIVES To determine the ceramide classes/species responsible for SLS pathogenesis and the enzymes that are impaired in SLS. METHODS Genomic DNA was collected from peripheral blood samples from an SLS patient and her parents, and whole-genome sequencing and Sanger sequencing were performed. Lipids were extracted from stratum corneum samples from the SLS patient and healthy volunteers and subjected to ceramide profiling via liquid chromatography coupled with tandem mass spectrometry. RESULTS A duplication (c.55_130dup) and a missense mutation (p.Lys447Glu) were found in the patient's ALDH3A2 gene. The patient had reduced levels of all acylceramide classes, with total acylceramide levels at 25 % of healthy controls. Reductions were also observed for several nonacylated ceramides: ceramides with phytosphingosine or 6-hydroxysphingosine in the long-chain base moiety were reduced to 24 % and 41 % of control levels, respectively, and ceramides with an α-hydroxy fatty acid as the fatty acid moiety were reduced to 29 %. The fatty acid moiety was shortened in many nonacylated ceramide classes. CONCLUSION These results suggest that reduced acylceramide levels are a primary cause of the ichthyosis symptoms of SLS, but reductions in other ceramide classes may also be involved.
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Affiliation(s)
- Ayami Arai
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Takuya Takeichi
- Department of Dermatology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroyuki Wakamoto
- Department of Pediatrics, Ehime Rehabilitation Center for Children, Ehime, Japan
| | - Takayuki Sassa
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Yasutoshi Ito
- Department of Dermatology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yuya Murase
- Department of Pediatrics, Ehime Rehabilitation Center for Children, Ehime, Japan
| | - Tomoo Ogi
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Nagoya, Japan; Department of Human Genetics and Molecular Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masashi Akiyama
- Department of Dermatology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akio Kihara
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
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11
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Nohara T, Ohno Y, Kihara A. Impaired production of skin barrier lipid acylceramides and abnormal localization of PNPLA1 due to ichthyosis-causing mutations in PNPLA1. J Dermatol Sci 2022; 107:89-94. [DOI: 10.1016/j.jdermsci.2022.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/14/2022] [Accepted: 07/31/2022] [Indexed: 10/16/2022]
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12
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A novel ABHD5 mutation in two Chanarin Dorfman siblings with severe and heterogeneous clinical phenotype. Genes Dis 2022. [DOI: 10.1016/j.gendis.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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13
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Merleev AA, Le ST, Alexanian C, Toussi A, Xie Y, Marusina AI, Watkins SM, Patel F, Billi AC, Wiedemann J, Izumiya Y, Kumar A, Uppala R, Kahlenberg JM, Liu FT, Adamopoulos IE, Wang EA, Ma C, Cheng MY, Xiong H, Kirane A, Luxardi G, Andersen B, Tsoi LC, Lebrilla CB, Gudjonsson JE, Maverakis E. Biogeographic and disease-specific alterations in epidermal lipid composition and single cell analysis of acral keratinocytes. JCI Insight 2022; 7:159762. [PMID: 35900871 PMCID: PMC9462509 DOI: 10.1172/jci.insight.159762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The epidermis is the outermost layer of skin. Here, we used targeted lipid profiling to characterize the biogeographic alterations of human epidermal lipids across 12 anatomically distinct body sites, and we used single-cell RNA-Seq to compare keratinocyte gene expression at acral and nonacral sites. We demonstrate that acral skin has low expression of EOS acyl-ceramides and the genes involved in their synthesis, as well as low expression of genes involved in filaggrin and keratin citrullination (PADI1 and PADI3) and corneodesmosome degradation, changes that are consistent with increased corneocyte retention. Several overarching principles governing epidermal lipid expression were also noted. For example, there was a strong negative correlation between the expression of 18-carbon and 22-carbon sphingoid base ceramides. Disease-specific alterations in epidermal lipid gene expression and their corresponding alterations to the epidermal lipidome were characterized. Lipid biomarkers with diagnostic utility for inflammatory and precancerous conditions were identified, and a 2-analyte diagnostic model of psoriasis was constructed using a step-forward algorithm. Finally, gene coexpression analysis revealed a strong connection between lipid and immune gene expression. This work highlights (a) mechanisms by which the epidermis is uniquely adapted for the specific environmental insults encountered at different body surfaces and (b) how inflammation-associated alterations in gene expression affect the epidermal lipidome.
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Affiliation(s)
- Alexander A Merleev
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Stephanie T Le
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Claire Alexanian
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Atrin Toussi
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Yixuan Xie
- Department of Chemistry, University of California, Davis, Sacramento, United States of America
| | - Alina I Marusina
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | | | - Forum Patel
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Allison C Billi
- Department of Dermatology, University of Michigan, Ann Arbor, United States of America
| | - Julie Wiedemann
- Department of Dermatology, University of California, Irvine, Irvine, United States of America
| | - Yoshihiro Izumiya
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Ashish Kumar
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Ranjitha Uppala
- Department of Dermatology, University of Michigan, Ann Arbor, United States of America
| | - J Michelle Kahlenberg
- Department of Internal Medicine, Division of Rheumatology, University of Michigan, Ann Arbor, United States of America
| | - Fu-Tong Liu
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Iannis E Adamopoulos
- Department of Rheumatology, University of California, Davis, Sacramento, United States of America
| | - Elizabeth A Wang
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Chelsea Ma
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Michelle Y Cheng
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Halani Xiong
- Verso Biosciences, Davis, United States of America
| | - Amanda Kirane
- Department of Surgery, University of California, Davis, Sacramento, United States of America
| | - Guillaume Luxardi
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
| | - Bogi Andersen
- Department of Dermatology, University of California, Irvine, Irvine, United States of America
| | - Lam C Tsoi
- Department of Dermatology, University of Michigan, Ann Arbor, United States of America
| | - Carlito B Lebrilla
- Department of Chemistry, University of California, Davis, Sacramento, United States of America
| | - Johann E Gudjonsson
- Department of Dermatology, University of Michigan, Ann Arbor, United States of America
| | - Emanual Maverakis
- Department of Dermatology, University of California, Davis, Sacramento, United States of America
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14
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PNPLA1-Mediated Acylceramide Biosynthesis and Autosomal Recessive Congenital Ichthyosis. Metabolites 2022; 12:metabo12080685. [PMID: 35893253 PMCID: PMC9332298 DOI: 10.3390/metabo12080685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/14/2022] [Accepted: 07/21/2022] [Indexed: 02/01/2023] Open
Abstract
The stratum corneum of the epidermis acts as a life-sustaining permeability barrier. Unique heterogeneous ceramides, especially ω-O-acylceramides, are key components for the formation of stable lamellar membrane structures in the stratum corneum and are essential for a vital epidermal permeability barrier. Several enzymes involved in acylceramide synthesis have been demonstrated to be associated with ichthyosis. The function of patatin-like phospholipase domain-containing protein 1 (PNPLA1) was a mystery until the finding that PNPLA1 gene mutations were involved in autosomal-recessive congenital ichthyosis (ARCI) patients, both humans and dogs. PNPLA1 plays an essential role in the biosynthesis of acylceramide as a CoA-independent transacylase. PNPLA1 gene mutations cause decreased acylceramide levels and impaired skin barrier function. More and more mutations in PNPLA1 genes have been identified in recent years. Herein, we describe the structural and functional specificity of PNPLA1, highlight its critical roles in acylceramide synthesis and skin barrier maintenance, and summarize the PNPLA1 mutations currently identified in ARCI patients.
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15
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Shima K, Inoue T, Uehara Y, Iwamura M, Fukagawa S, Kuwano T, Tanida K, Takada N, Saito‐Abe M, Yamamoto‐Hanada K, Ohya Y, Murase T. Non‐invasive transcriptomic analysis using
mRNAs
in skin surface lipids obtained from children with mild‐to‐moderate atopic dermatitis. J Eur Acad Dermatol Venereol 2022; 36:1477-1485. [PMID: 35462437 PMCID: PMC9545805 DOI: 10.1111/jdv.18173] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 03/23/2022] [Indexed: 11/29/2022]
Abstract
Background Specimens for analysing the molecular pathology of skin disease are generally obtained through invasive methods, such as biopsy. However, less burdensome methods are desirable for paediatric patients. We recently established a method that comprehensively analyses RNA present in sebum (skin surface lipid–RNAs: SSL‐RNAs) using a next‐generation sequencer. Using this method, biological information can be obtained from the skin in a completely non‐invasive manner. Objectives To verify the applicability of the SSL‐RNA method for analysis of paediatric skin and analyse the molecular pathology of mild‐to‐moderate atopic dermatitis (AD) in children. Methods We collected sebum specimens from the whole faces of 23 healthy children and 16 children with mild‐to‐moderate AD (eczema area and severity index (EASI) score: 5.9 ± 2.6) ranging in age from 6 months to 5 years, using an oil‐blotting film. We then extracted SSL‐RNAs from the samples and performed an AmpliSeq transcriptomic analysis. Results The expressions of genes related to keratinization (LCE, PSORS1C2, IVL and KRT17), triglyceride synthesis and storage (PLIN2, DGAT2 and CIDEA), wax synthesis (FAR2), ceramide synthesis (GBA2, SMPD3 and SPTLC3), antimicrobial peptides (DEFB1) and intercellular adhesion (CDSN), all of which are related to the skin barrier, are lower in children with AD than in healthy children. The children with AD also have higher expression of CCL17, a Th2‐cytokine and an increased Th2‐immune response as demonstrated by a gene set variation analysis. Moreover, KRT17 and CCL17 expression levels are significantly correlated with the EASI score. Conclusions Molecular changes associated with abnormal immune responses and the epidermal barrier in children with mild‐to‐moderate AD can be determined using the SSL‐RNA method. This non‐invasive method could therefore be a useful means for understanding the molecular pathology of paediatric AD.
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Affiliation(s)
- K. Shima
- Biological Science Research, Kao Corporation Tochigi Japan
| | - T. Inoue
- Biological Science Research, Kao Corporation Tochigi Japan
| | - Y. Uehara
- Biological Science Research, Kao Corporation Tochigi Japan
| | - M. Iwamura
- Biological Science Research, Kao Corporation Tochigi Japan
| | - S. Fukagawa
- Biological Science Research, Kao Corporation Tochigi Japan
| | - T. Kuwano
- Biological Science Research, Kao Corporation Tochigi Japan
| | - K. Tanida
- Biological Science Research, Kao Corporation Tochigi Japan
| | - N. Takada
- Biological Science Research, Kao Corporation Tochigi Japan
| | - M. Saito‐Abe
- Allergy Center, National Center for Child Health and Development Tokyo Japan
| | - K. Yamamoto‐Hanada
- Allergy Center, National Center for Child Health and Development Tokyo Japan
| | - Y. Ohya
- Allergy Center, National Center for Child Health and Development Tokyo Japan
| | - T. Murase
- Biological Science Research, Kao Corporation Tochigi Japan
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16
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Tseng YY, Sanders MA, Zhang H, Zhou L, Chou CY, Granneman JG. Structural and functional insights into ABHD5, a ligand-regulated lipase co-activator. Sci Rep 2022; 12:2565. [PMID: 35173175 PMCID: PMC8850477 DOI: 10.1038/s41598-021-04179-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/09/2021] [Indexed: 02/06/2023] Open
Abstract
Alpha/beta hydrolase domain-containing protein 5 (ABHD5) is a highly conserved protein that regulates various lipid metabolic pathways via interactions with members of the perilipin (PLIN) and Patatin-like phospholipase domain-containing protein (PNPLA) protein families. Loss of function mutations in ABHD5 result in Chanarin-Dorfman Syndrome (CDS), characterized by ectopic lipid accumulation in numerous cell types and severe ichthyosis. Recent data demonstrates that ABHD5 is the target of synthetic and endogenous ligands that might be therapeutic beneficial for treating metabolic diseases and cancers. However, the structural basis of ABHD5 functional activities, such as protein-protein interactions and ligand binding is presently unknown. To address this gap, we constructed theoretical structural models of ABHD5 by comparative modeling and topological shape analysis to assess the spatial patterns of ABHD5 conformations computed in protein dynamics. We identified functionally important residues on ABHD5 surface for lipolysis activation by PNPLA2, lipid droplet targeting and PLIN-binding. We validated the computational model by examining the effects of mutating key residues in ABHD5 on an array of functional assays. Our integrated computational and experimental findings provide new insights into the structural basis of the diverse functions of ABHD5 as well as pathological mutations that result in CDS.
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Affiliation(s)
- Yan Yuan Tseng
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
- Karmanos Cancer Institute, Wayne State University School of Medicine, 4100 John R, Detroit, MI, 48201, USA.
| | - Matthew A Sanders
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA
- Center for Integrative Metabolic and Endocrine Research, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Huamei Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA
- Center for Integrative Metabolic and Endocrine Research, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Li Zhou
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA
- Center for Integrative Metabolic and Endocrine Research, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Chia-Yi Chou
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - James G Granneman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
- Center for Integrative Metabolic and Endocrine Research, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
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17
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Kiener S, Wiener DJ, Hopke K, Diesel AB, Jagannathan V, Mauldin EA, Casal ML, Leeb T. ABHD5 frameshift deletion in Golden Retrievers with ichthyosis. G3 (BETHESDA, MD.) 2022; 12:6428539. [PMID: 34791225 PMCID: PMC9210301 DOI: 10.1093/g3journal/jkab397] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/05/2021] [Indexed: 11/16/2022]
Abstract
Ichthyoses are hereditary skin disorders characterized by the formation of scales and defects in the outermost layer of the epidermis. In dogs, at least six different breed-specific ichthyoses including a relatively common PNPLA1-related autosomal recessive ichthyosis in Golden Retrievers are known. In this study, we investigated 14 Golden Retrievers with scales that were not homozygous for the mutant PNPLA1 allele suggesting a genetically distinct new form of ichthyosis. Histopathological examinations showed lamellar, orthokeratotic hyperkeratosis, and mildly hyperplastic epidermis that led to the diagnosis of a nonepidermolytic ichthyosis. Combined linkage and homozygosity mapping in 14 cases and 30 nonaffected family members delimited a critical interval of ∼12.7 Mb on chromosome 23. Whole-genome sequencing of an affected dog revealed a single protein-changing variant within this region that was not present in 795 control genomes. The identified variant is a 14 bp deletion in the ABHD5 gene (c.1006_1019del), leading to a frameshift and altering the last 14 codons p.(Asp336Serfs*6). The genotypes at this variant showed perfect cosegregation with the ichthyosis phenotype in a large family comprising 14 cases and 72 controls. ABHD5 encodes an acyltransferase required for lipid metabolism. In humans, variants in ABHD5 cause Chanarin-Dorfman syndrome, a neutral lipid storage disease with ichthyosis. Our data in dogs together with the knowledge on the effects of ABHD5 variants in humans strongly suggest ABHD5:c.1006_1019del as candidate causative genetic variant for a new canine form of ichthyosis, which we propose to designate as Golden Retriever ichthyosis type 2 (ICH2).
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Affiliation(s)
- Sarah Kiener
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland
- Dermfocus, University of Bern, Bern 3001, Switzerland
| | - Dominique J Wiener
- Department of Veterinary Pathobiology, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences, College Station, TX 77843-4467, USA
| | - Kaitlin Hopke
- Department of Small Animal Clinical Sciences, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences, College Station, TX 77843-4474, USA
| | - Alison B Diesel
- Department of Small Animal Clinical Sciences, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences, College Station, TX 77843-4474, USA
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland
| | - Elizabeth A Mauldin
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Margret L Casal
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tosso Leeb
- Corresponding author: Institute of Genetics, University of Bern, Bremgartenstrasse 109a, 3001 Bern, Switzerland.
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18
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Grabner GF, Xie H, Schweiger M, Zechner R. Lipolysis: cellular mechanisms for lipid mobilization from fat stores. Nat Metab 2021; 3:1445-1465. [PMID: 34799702 DOI: 10.1038/s42255-021-00493-6] [Citation(s) in RCA: 185] [Impact Index Per Article: 61.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/15/2021] [Indexed: 12/13/2022]
Abstract
The perception that intracellular lipolysis is a straightforward process that releases fatty acids from fat stores in adipose tissue to generate energy has experienced major revisions over the last two decades. The discovery of new lipolytic enzymes and coregulators, the demonstration that lipophagy and lysosomal lipolysis contribute to the degradation of cellular lipid stores and the characterization of numerous factors and signalling pathways that regulate lipid hydrolysis on transcriptional and post-transcriptional levels have revolutionized our understanding of lipolysis. In this review, we focus on the mechanisms that facilitate intracellular fatty-acid mobilization, drawing on canonical and noncanonical enzymatic pathways. We summarize how intracellular lipolysis affects lipid-mediated signalling, metabolic regulation and energy homeostasis in multiple organs. Finally, we examine how these processes affect pathogenesis and how lipolysis may be targeted to potentially prevent or treat various diseases.
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Affiliation(s)
- Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Hao Xie
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
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19
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Zwara A, Wertheim-Tysarowska K, Mika A. Alterations of Ultra Long-Chain Fatty Acids in Hereditary Skin Diseases-Review Article. Front Med (Lausanne) 2021; 8:730855. [PMID: 34497816 PMCID: PMC8420999 DOI: 10.3389/fmed.2021.730855] [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: 06/25/2021] [Accepted: 07/30/2021] [Indexed: 11/27/2022] Open
Abstract
The skin is a flexible organ that forms a barrier between the environment and the body's interior; it is involved in the immune response, in protection and regulation, and is a dynamic environment in which skin lipids play an important role in maintaining homeostasis. The different layers of the skin differ in both the composition and amount of lipids. The epidermis displays the best characteristics in this respect. The main lipids in this layer are cholesterol, fatty acids (FAs) and ceramides. FAs can occur in free form and as components of complex molecules. The most poorly characterized FAs are very long-chain fatty acids (VLCFAs) and ultra long-chain fatty acids (ULCFAs). VLCFAs and ULCFAs are among the main components of ceramides and are part of the free fatty acid (FFA) fraction. They are most abundant in the brain, liver, kidneys, and skin. VLCFAs and ULCFAs are responsible for the rigidity and impermeability of membranes, forming the mechanically and chemically strong outer layer of cell membranes. Any changes in the composition and length of the carbon chains of FAs result in a change in their melting point and therefore a change in membrane permeability. One of the factors causing a decrease in the amount of VLCFAs and ULCFAs is an improper diet. Another much more important factor is mutations in the genes which code proteins involved in the metabolism of VLCFAs and ULCFAs—regarding their elongation, their attachment to ceramides and their transformation. These mutations have their clinical consequences in the form of inborn errors in metabolism and neurodegenerative disorders, among others. Some of them are accompanied by skin symptoms such as ichthyosis and ichthyosiform erythroderma. In the following review, the structure of the skin is briefly characterized and the most important lipid components of the skin are presented. The focus is also on providing an overview of selected proteins involved in the metabolism of VLCFAs and ULCFAs in the skin.
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Affiliation(s)
- Agata Zwara
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
| | | | - Adriana Mika
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
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20
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Impaired skin barrier function due to reduced ω- O-acylceramide levels in a mouse model of Sjögren-Larsson syndrome. Mol Cell Biol 2021; 41:e0035221. [PMID: 34370553 DOI: 10.1128/mcb.00352-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sjögren-Larsson syndrome (SLS) is an inherited neurocutaneous disorder whose causative gene encodes the fatty aldehyde dehydrogenase ALDH3A2. To date, the detailed molecular mechanism of the skin pathology of SLS has remained largely unclear. We generated double knockout (DKO) mice for Aldh3a2 and its homolog Aldh3b2 (a pseudogene in humans). These mice showed hyperkeratosis and reduced fatty aldehyde dehydrogenase activity and skin barrier function. The levels of ω-O-acylceramides (acylceramides), which are specialized ceramides essential for skin barrier function, in the epidermis of DKO mice were about 60% of those in wild type mice. In the DKO mice, levels of acylceramide precursors (ω-hydroxy ceramides and triglycerides) were increased, suggesting that the final step of acylceramide production was inhibited. A decrease in acylceramide levels was also observed in human immortalized keratinocytes lacking ALDH3A2. Differentiated keratinocytes prepared from the DKO mice exhibited impaired long-chain base metabolism. Based on these results, we propose that the long-chain-base-derived fatty aldehydes that accumulate in DKO mice and SLS patients attack and inhibit the enzyme involved in the final step of acylceramide. Our findings provide insight into the pathogenesis of the skin symptoms of SLS, i.e., decreased acylceramide production, and its molecular mechanism.
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21
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Cakmak E, Bagci G. Chanarin-Dorfman Syndrome: A comprehensive review. Liver Int 2021; 41:905-914. [PMID: 33455044 DOI: 10.1111/liv.14794] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 12/13/2022]
Abstract
The Chanarin-Dorfman syndrome (CDS) is a rare, autosomal recessively inherited genetic disease. This syndrome is associated with a decrease in the lipolysis activity in multiple tissue cells because of recessive mutations in the abhydrolase domain containing 5 (ABHD5) gene, which leads to the accumulation of lipid droplets in multiple types of cells. Major clinical symptoms in patients with CDS include ichthyosis and intracytoplasmic lipid droplets. The variability of clinical symptoms in patients with CDS depends on a large number of mutations involved. In this syndrome, liver involvement is an important cause of mortality and morbidity. This review aims to summarize the demographic characteristic, clinical symptoms, liver involvement and mutations in CDS patients in the literature to date.
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Affiliation(s)
- Erol Cakmak
- Department of Gastroenterology, Cumhuriyet University Faculty of Medicine, Sivas, Turkey
| | - Gokhan Bagci
- Department of Biochemistry, Cumhuriyet University Faculty of Medicine, Sivas, Turkey
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22
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Meyer JM, Crumrine D, Schneider H, Dick A, Schmuth M, Gruber R, Radner FPW, Grond S, Wakefield JS, Mauro TM, Elias PM. Unbound Corneocyte Lipid Envelopes in 12R-Lipoxygenase Deficiency Support a Specific Role in Lipid-Protein Cross-Linking. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:921-929. [PMID: 33607042 DOI: 10.1016/j.ajpath.2021.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/26/2021] [Accepted: 02/02/2021] [Indexed: 12/15/2022]
Abstract
Loss-of-function mutations in arachidonate lipoxygenase 12B (ALOX12B) are an important cause of autosomal recessive congenital ichthyosis (ARCI). 12R-lipoxygenase (12R-LOX), the protein product of ALOX12B, has been proposed to covalently bind the corneocyte lipid envelope (CLE) to the proteinaceous corneocyte envelope, thereby providing a scaffold for the assembly of barrier-providing, mature lipid lamellae. To test this hypothesis, an in-depth ultrastructural examination of CLEs was performed in ALOX12B-/- human and Alox12b-/- mouse epidermis, extracting samples with pyridine to distinguish covalently attached CLEs from unbound (ie, noncovalently bound) CLEs. ALOX12B--/- stratum corneum contained abundant pyridine-extractable (ie, unbound) CLEs, compared with normal stratum corneum. These unbound CLEs were associated with defective post-secretory lipid processing, and were specific to 12R-LOX deficiency, because they were not observed with deficiency of the related ARCI-associated proteins, patatin-like phospholipase 1 (Pnpla1) or abhydrolase domain containing 5 (Abhd5). These results suggest that 12R-LOX contributes specifically to CLE-corneocyte envelope cross-linking, which appears to be a prerequisite for post-secretory lipid processing, and provide insights into the pathogenesis of 12R-LOX deficiency in this subtype of ARCI, as well as other conditions that display a defective CLE.
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Affiliation(s)
- Jason M Meyer
- San Francisco Veterans Affairs Medical Center, Dermatology Service and UC San Francisco Department of Dermatology, San Francisco, California.
| | - Debra Crumrine
- San Francisco Veterans Affairs Medical Center, Dermatology Service, San Francisco, California
| | - Holm Schneider
- Department of Pediatrics, University of Erlangen-Nürnberg, Nürnberg, Germany
| | - Angela Dick
- Department of Pediatrics, University of Erlangen-Nürnberg, Nürnberg, Germany
| | - Matthias Schmuth
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Innsbruck, Austria
| | - Robert Gruber
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Innsbruck, Austria
| | - Franz P W Radner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Susanne Grond
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Joan S Wakefield
- San Francisco Veterans Affairs Medical Center, Dermatology Service and UC San Francisco Department of Dermatology, San Francisco, California
| | - Theodora M Mauro
- San Francisco Veterans Affairs Medical Center, Dermatology Service and UC San Francisco Department of Dermatology, San Francisco, California
| | - Peter M Elias
- San Francisco Veterans Affairs Medical Center, Dermatology Service and UC San Francisco Department of Dermatology, San Francisco, California
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Brejchova K, Radner FPW, Balas L, Paluchova V, Cajka T, Chodounska H, Kudova E, Schratter M, Schreiber R, Durand T, Zechner R, Kuda O. Distinct roles of adipose triglyceride lipase and hormone-sensitive lipase in the catabolism of triacylglycerol estolides. Proc Natl Acad Sci U S A 2021; 118:e2020999118. [PMID: 33372146 PMCID: PMC7812821 DOI: 10.1073/pnas.2020999118] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Branched esters of palmitic acid and hydroxy stearic acid are antiinflammatory and antidiabetic lipokines that belong to a family of fatty acid (FA) esters of hydroxy fatty acids (HFAs) called FAHFAs. FAHFAs themselves belong to oligomeric FA esters, known as estolides. Glycerol-bound FAHFAs in triacylglycerols (TAGs), named TAG estolides, serve as metabolite reservoir of FAHFAs mobilized by lipases upon demand. Here, we characterized the involvement of two major metabolic lipases, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), in TAG estolide and FAHFA degradation. We synthesized a library of 20 TAG estolide isomers with FAHFAs varying in branching position, chain length, saturation grade, and position on the glycerol backbone and developed an in silico mass spectra library of all predicted catabolic intermediates. We found that ATGL alone or coactivated by comparative gene identification-58 efficiently liberated FAHFAs from TAG estolides with a preference for more compact substrates where the estolide branching point is located near the glycerol ester bond. ATGL was further involved in transesterification and remodeling reactions leading to the formation of TAG estolides with alternative acyl compositions. HSL represented a much more potent estolide bond hydrolase for both TAG estolides and free FAHFAs. FAHFA and TAG estolide accumulation in white adipose tissue of mice lacking HSL argued for a functional role of HSL in estolide catabolism in vivo. Our data show that ATGL and HSL participate in the metabolism of estolides and TAG estolides in distinct manners and are likely to affect the lipokine function of FAHFAs.
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Affiliation(s)
- Kristyna Brejchova
- Institute of Physiology, Czech Academy of Sciences, 142 20 Prague 4, Czech Republic
| | | | - Laurence Balas
- Institut des Biomolécules Max Mousseron, UMR 5247, CNRS, École Nationale Supérieure de Chimie de Montpellier, Faculté de Pharmacie, Université de Montpellier, 34093 Montpellier, France
| | - Veronika Paluchova
- Institute of Physiology, Czech Academy of Sciences, 142 20 Prague 4, Czech Republic
| | - Tomas Cajka
- Institute of Physiology, Czech Academy of Sciences, 142 20 Prague 4, Czech Republic
| | - Hana Chodounska
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Eva Kudova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | | | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron, UMR 5247, CNRS, École Nationale Supérieure de Chimie de Montpellier, Faculté de Pharmacie, Université de Montpellier, 34093 Montpellier, France
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria;
- BioTechMed-Graz, 8010 Graz, Austria
| | - Ondrej Kuda
- Institute of Physiology, Czech Academy of Sciences, 142 20 Prague 4, Czech Republic;
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24
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Adipocyte lipolysis: from molecular mechanisms of regulation to disease and therapeutics. Biochem J 2020; 477:985-1008. [PMID: 32168372 DOI: 10.1042/bcj20190468] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/19/2020] [Accepted: 02/26/2020] [Indexed: 12/20/2022]
Abstract
Fatty acids (FAs) are stored safely in the form of triacylglycerol (TAG) in lipid droplet (LD) organelles by professional storage cells called adipocytes. These lipids are mobilized during adipocyte lipolysis, the fundamental process of hydrolyzing TAG to FAs for internal or systemic energy use. Our understanding of adipocyte lipolysis has greatly increased over the past 50 years from a basic enzymatic process to a dynamic regulatory one, involving the assembly and disassembly of protein complexes on the surface of LDs. These dynamic interactions are regulated by hormonal signals such as catecholamines and insulin which have opposing effects on lipolysis. Upon stimulation, patatin-like phospholipase domain containing 2 (PNPLA2)/adipocyte triglyceride lipase (ATGL), the rate limiting enzyme for TAG hydrolysis, is activated by the interaction with its co-activator, alpha/beta hydrolase domain-containing protein 5 (ABHD5), which is normally bound to perilipin 1 (PLIN1). Recently identified negative regulators of lipolysis include G0/G1 switch gene 2 (G0S2) and PNPLA3 which interact with PNPLA2 and ABHD5, respectively. This review focuses on the dynamic protein-protein interactions involved in lipolysis and discusses some of the emerging concepts in the control of lipolysis that include allosteric regulation and protein turnover. Furthermore, recent research demonstrates that many of the proteins involved in adipocyte lipolysis are multifunctional enzymes and that lipolysis can mediate homeostatic metabolic signals at both the cellular and whole-body level to promote inter-organ communication. Finally, adipocyte lipolysis is involved in various diseases such as cancer, type 2 diabetes and fatty liver disease, and targeting adipocyte lipolysis is of therapeutic interest.
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25
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Updating Phospholipase A 2 Biology. Biomolecules 2020; 10:biom10101457. [PMID: 33086624 PMCID: PMC7603386 DOI: 10.3390/biom10101457] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/09/2020] [Accepted: 10/15/2020] [Indexed: 12/30/2022] Open
Abstract
The phospholipase A2 (PLA2) superfamily contains more than 50 enzymes in mammals that are subdivided into several distinct families on a structural and biochemical basis. In principle, PLA2 has the capacity to hydrolyze the sn-2 position of glycerophospholipids to release fatty acids and lysophospholipids, yet several enzymes in this superfamily catalyze other reactions rather than or in addition to the PLA2 reaction. PLA2 enzymes play crucial roles in not only the production of lipid mediators, but also membrane remodeling, bioenergetics, and body surface barrier, thereby participating in a number of biological events. Accordingly, disturbance of PLA2-regulated lipid metabolism is often associated with various diseases. This review updates the current state of understanding of the classification, enzymatic properties, and biological functions of various enzymes belonging to the PLA2 superfamily, focusing particularly on the novel roles of PLA2s in vivo.
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Akiyama M. Acylceramide is a key player in skin barrier function: insight into the molecular mechanisms of skin barrier formation and ichthyosis pathogenesis. FEBS J 2020. [DOI: 10.1111/febs.15497] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Masashi Akiyama
- Department of Dermatology Nagoya University Graduate School of Medicine Nagoya Japan
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27
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Hofer P, Taschler U, Schreiber R, Kotzbeck P, Schoiswohl G. The Lipolysome-A Highly Complex and Dynamic Protein Network Orchestrating Cytoplasmic Triacylglycerol Degradation. Metabolites 2020; 10:E147. [PMID: 32290093 PMCID: PMC7240967 DOI: 10.3390/metabo10040147] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/03/2020] [Accepted: 04/08/2020] [Indexed: 12/25/2022] Open
Abstract
The catabolism of intracellular triacylglycerols (TAGs) involves the activity of cytoplasmic and lysosomal enzymes. Cytoplasmic TAG hydrolysis, commonly termed lipolysis, is catalyzed by the sequential action of three major hydrolases, namely adipose triglyceride lipase, hormone-sensitive lipase, and monoacylglycerol lipase. All three enzymes interact with numerous protein binding partners that modulate their activity, cellular localization, or stability. Deficiencies of these auxiliary proteins can lead to derangements in neutral lipid metabolism and energy homeostasis. In this review, we summarize the composition and the dynamics of the complex lipolytic machinery we like to call "lipolysome".
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Affiliation(s)
- Peter Hofer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (P.H.); (U.T.); (R.S.)
| | - Ulrike Taschler
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (P.H.); (U.T.); (R.S.)
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (P.H.); (U.T.); (R.S.)
| | - Petra Kotzbeck
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria;
| | - Gabriele Schoiswohl
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; (P.H.); (U.T.); (R.S.)
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28
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Chang P, Sun T, Heier C, Gao H, Xu H, Huang F. Interaction of the Lysophospholipase PNPLA7 with Lipid Droplets through the Catalytic Region. Mol Cells 2020; 43:286-297. [PMID: 32208367 PMCID: PMC7103881 DOI: 10.14348/molcells.2020.2283] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/28/2020] [Accepted: 02/10/2020] [Indexed: 12/25/2022] Open
Abstract
Mammalian patatin-like phospholipase domain containing proteins (PNPLAs) play critical roles in triglyceride hydrolysis, phospholipids metabolism, and lipid droplet (LD) homeostasis. PNPLA7 is a lysophosphatidylcholine hydrolase anchored on the endoplasmic reticulum which associates with LDs through its catalytic region (PNPLA7-C) in response to increased cyclic nucleotide levels. However, the interaction of PNPLA7 with LDs through its catalytic region is unknown. Herein, we demonstrate that PNPLA7-C localizes to the mature LDs ex vivo and also colocalizes with pre-existing LDs. Localization of PNPLA7-C with LDs induces LDs clustering via non-enzymatic intermolecular associations, while PNPLA7 alone does not induce LD clustering. Residues 742-1016 contains four putative transmembrane domains which act as a LD targeting motif and are required for the localization of PNPLA7-C to LDs. Furthermore, the N-terminal flanking region of the LD targeting motif, residues 681-741, contributes to the LD targeting, whereas the C-terminal flanking region (1169-1326) has an anti-LD targeting effect. Interestingly, the LD targeting motif does not exhibit lysophosphatidylcholine hydrolase activity even though it associates with LDs phospholipid membranes. These findings characterize the specific functional domains of PNPLA7 mediating subcellular positioning and interactions with LDs, as wells as providing critical insights into the structure of this evolutionarily conserved phospholipid-metabolizing enzyme family.
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Affiliation(s)
- Pingan Chang
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Tengteng Sun
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Hao Gao
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Hongmei Xu
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Feifei Huang
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
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29
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Western diet induces severe nonalcoholic steatohepatitis, ductular reaction, and hepatic fibrosis in liver CGI-58 knockout mice. Sci Rep 2020; 10:4701. [PMID: 32170127 PMCID: PMC7070035 DOI: 10.1038/s41598-020-61473-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 02/27/2020] [Indexed: 12/13/2022] Open
Abstract
Humans and rodents with Comparative Gene Identification-58 (CGI-58) mutations manifest nonalcoholic fatty liver disease (NAFLD). Here we show that liver CGI-58 knockout (LivKO) mice fed a Western diet rapidly develop advanced NAFLD, including nonalcoholic steatohepatitis (NASH) and hepatic fibrosis. After 14 weeks of diet challenge, starting at 6 weeks of age, LivKO mice showed increased inflammatory cell infiltration and proinflammatory gene expression in the liver, which was associated with elevated plasma levels of aminotransferases. Hepatic ductular reactions, pericellular fibrosis, and bridging fibrosis were observed only in the LivKO mice. Consistently, the KO mice had a significant increase in hepatic mRNAs for fibrogenic genes. In addition, LivKO mice displayed massive accumulation of lipid droplets (LDs) in hepatocytes. LDs were also observed in the cholangiocytes of the LivKO mice, but not the floxed controls. Four of the five LD coat proteins, including perilipins 2, 3, 4, and 5, were increased in the CGI-58 KO liver. CRISPR/Cas9-mediated knockout of CGI-58 in Huh7 human hepatoma cells induced LD deposition and perilipin expression, suggesting a cell autonomous effect. Our findings establish the Western diet-fed LivKO mice as an animal model of NASH and hepatic fibrosis. These animals may facilitate preclinical screening of therapeutic agents that counter against NAFLD progression.
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Skin permeability barrier formation by the ichthyosis-causative gene FATP4 through formation of the barrier lipid ω- O-acylceramide. Proc Natl Acad Sci U S A 2020; 117:2914-2922. [PMID: 31974308 DOI: 10.1073/pnas.1917525117] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The epidermis-specific lipid acylceramide plays a pivotal role in the formation of the permeability barrier in the skin; abrogation of its synthesis causes the skin disorder ichthyosis. However, the acylceramide synthetic pathway has not yet been fully elucidated: Namely, the acyl-CoA synthetase (ACS) involved in this pathway remains to be identified. Here, we hypothesized it to be encoded by FATP4/ACSVL4, the causative gene of ichthyosis prematurity syndrome (IPS). In vitro experiments revealed that FATP4 exhibits ACS activity toward an ω-hydroxy fatty acid (FA), an intermediate of the acylceramide synthetic pathway. Fatp4 knockout (KO) mice exhibited severe skin barrier dysfunction and morphological abnormalities in the epidermis. The total amount of acylceramide in Fatp4 KO mice was reduced to ∼10% of wild-type mice. Decreased levels and shortening of chain lengths were observed in the saturated, nonacylated ceramides. FA levels were not decreased in the epidermis of Fatp4 KO mice. The expression levels of the FA elongase Elovl1 were reduced in Fatp4 KO epidermis, partly accounting for the reduction and shortening of saturated, nonacylated ceramides. A decrease in acylceramide levels was also observed in human keratinocytes with FATP4 knockdown. From these results, we conclude that skin barrier dysfunction observed in IPS patients and Fatp4 KO mice is caused mainly by reduced acylceramide production. Our findings further elucidate the molecular mechanism governing acylceramide synthesis and IPS pathology.
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31
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Yu L, Li Y, Grisé A, Wang H. CGI-58: Versatile Regulator of Intracellular Lipid Droplet Homeostasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1276:197-222. [PMID: 32705602 PMCID: PMC8063591 DOI: 10.1007/978-981-15-6082-8_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Comparative gene identification-58 (CGI-58), also known as α/β-hydrolase domain-containing 5 (ABHD5), is a member of a large family of proteins containing an α/β-hydrolase-fold. CGI-58 is well-known as the co-activator of adipose triglyceride lipase (ATGL), which is a key enzyme initiating cytosolic lipid droplet lipolysis. Mutations in either the human CGI-58 or ATGL gene cause an autosomal recessive neutral lipid storage disease, characterized by the excessive accumulation of triglyceride (TAG)-rich lipid droplets in the cytoplasm of almost all cell types. CGI-58, however, has ATGL-independent functions. Distinct phenotypes associated with CGI-58 deficiency commonly include ichthyosis (scaly dry skin), nonalcoholic steatohepatitis, and hepatic fibrosis. Through regulated interactions with multiple protein families, CGI-58 controls many metabolic and signaling pathways, such as lipid and glucose metabolism, energy balance, insulin signaling, inflammatory responses, and thermogenesis. Recent studies have shown that CGI-58 regulates the pathogenesis of common metabolic diseases in a tissue-specific manner. Future studies are needed to molecularly define ATGL-independent functions of CGI-58, including the newly identified serine protease activity of CGI-58. Elucidation of these versatile functions of CGI-58 may uncover fundamental cellular processes governing lipid and energy homeostasis, which may help develop novel approaches that counter against obesity and its associated metabolic sequelae.
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Affiliation(s)
- Liqing Yu
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Yi Li
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alison Grisé
- College of Computer, Math, and Natural Sciences, College of Behavioral and Social Sciences, University of Maryland, College Park, MD, USA
| | - Huan Wang
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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32
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Eskiocak AH, Missaglia S, Moro L, Durdu M, Tavian D. A novel mutation of ABHD5 gene in a Chanarin Dorfman patient with unusual dermatological findings. Lipids Health Dis 2019; 18:232. [PMID: 31883530 PMCID: PMC6935165 DOI: 10.1186/s12944-019-1181-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/23/2019] [Indexed: 12/13/2022] Open
Abstract
Background Chanarin Dorfman Syndrome (CDS) is a rare autosomal recessive disorder characterized by the multisytemic accumulation of neutral lipids inside the cytoplasmic lipid droplets. This condition is caused by mutations in the abhydrolase domain containing 5 gene (ABHD5). In CDS the skin involvement is the prevalent and always observed clinical feature, consisting of a non-bullous congenital ichthyosiform erythroderma (NCIE). Moreover, a variable involvement of the liver and neuromuscular system can be also observed. In this report, we aimed to perform the clinical and genetic characterization of a patient affected by CDS with atypical dermatological findings, considering this rare inborn error of neutral lipid metabolism. Methods Genomic DNA samples obtained from patient and his parents were used to perform the sequencing of the ABHD5 exons and their intron/exon boundaries. Bioinformatic analyses were performed to investigate the possible effect of the identified mutation on protein structure. Results Here we present the case of a 29-year-old male patient with CDS, who, for long time, has been misdiagnosed as pityriasis rubra pilaris (PRP). He has a history of increasing hyperlipidemia; hepatomegaly associated with hepatosteatosis was also detected. ABHD5 molecular analysis revealed a novel missense mutation, the c.811G > A (p.G271R). Bioinformatic investigations showed that the variant has a deleterious effect on ABHD5 function, probably causing an incorrect folding of the mutant protein. Conclusions These results highlihts the importance of genetic testing for ABHD5 in unresolved cases of patients presenting unusual skin lesions, that resemble PRP, associated with a history of hyperlipidemia and nonalcoholic fatty liver.
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Affiliation(s)
- Ali Haydar Eskiocak
- Department of Dermatology, Baskent University Faculty of Medicine, Adana Hospital, Adana, Turkey
| | - Sara Missaglia
- Laboratory of Cellular Biochemistry and Molecular Biology, CRIBENS, Catholic University of the Sacred Heart, pz Buonarroti 30, 20145, Milan, Italy.,Department of Psychology, Catholic University of the Sacred Heart, Largo Gemelli 1, 20123, Milan, Italy
| | - Laura Moro
- Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy
| | - Murat Durdu
- Department of Dermatology, Baskent University Faculty of Medicine, Adana Hospital, Adana, Turkey
| | - Daniela Tavian
- Laboratory of Cellular Biochemistry and Molecular Biology, CRIBENS, Catholic University of the Sacred Heart, pz Buonarroti 30, 20145, Milan, Italy. .,Department of Psychology, Catholic University of the Sacred Heart, Largo Gemelli 1, 20123, Milan, Italy.
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33
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Li Q, Fang H, Dang E, Wang G. The role of ceramides in skin homeostasis and inflammatory skin diseases. J Dermatol Sci 2019; 97:2-8. [PMID: 31866207 DOI: 10.1016/j.jdermsci.2019.12.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 10/25/2022]
Abstract
Ceramides, members of sphingolipid family, are not only the building blocks of epidermal barrier structure, but also bioactive metabolites involved in epidermal self-renewal and immune regulation. Hence, abnormal ceramide expression profile is recognized to defect extracellular lipid organization, disturb epidermal self-renewal, exacerbate skin immune response and actively participate in progression of several inflammatory dermatoses, exemplifying by psoriasis and atopic dermatitis. Here, we discuss recent advances in understanding skin ceramides and their regulatory roles in skin homeostasis and pathogenic roles of altered ceramide metabolism in inflammatory skin diseases. These insights provide new opportunities for therapeutic intervention in inflammatory dermatoses.
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Affiliation(s)
- Qingyang Li
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Hui Fang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Erle Dang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Gang Wang
- Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
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Severe Skin Permeability Barrier Dysfunction in Knockout Mice Deficient in a Fatty Acid ω-Hydroxylase Crucial to Acylceramide Production. J Invest Dermatol 2019; 140:319-326.e4. [PMID: 31356814 DOI: 10.1016/j.jid.2019.07.689] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/08/2019] [Accepted: 07/22/2019] [Indexed: 12/20/2022]
Abstract
The skin permeability barrier is indispensable for maintaining water inside the body and preventing the invasion of pathogens and allergens; abnormalities lead to skin disorders such as atopic dermatitis and ichthyosis. Acylceramide is an essential lipid for skin barrier formation, and CYP4F22 is a fatty acid ω-hydroxylase involved in its synthesis. Mutations in CYP4F22 cause autosomal recessive congenital ichthyosis, although the symptoms vary among mutation sites and types. Here, we generated knockout mice deficient in Cyp4f39, the mouse ortholog of human CYP4F22, to investigate the effects of completely abrogating the function of the fatty acid ω-hydroxylase involved in acylceramide production on skin barrier formation. Cyp4f39 knockout mice died within 8 hours of birth. Large increases in transepidermal water loss and penetration of a dye from outside the body were observed, indicating severe skin barrier dysfunction. Histologic analyses of the epidermis revealed impairment of lipid lamella formation, accumulation of corneodesmosomes in the stratum corneum, and persistence of periderm. In addition, lipid analyses by mass spectrometry showed almost complete loss of acylceramide and its precursor ω-hydroxy ceramide. In conclusion, our findings provide clues to the molecular mechanisms of skin barrier abnormalities and the pathogenesis of ichthyosis caused by Cyp4f39 and CYP4F22 by association.
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35
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Wang Y, Kory N, BasuRay S, Cohen JC, Hobbs HH. PNPLA3, CGI-58, and Inhibition of Hepatic Triglyceride Hydrolysis in Mice. Hepatology 2019; 69:2427-2441. [PMID: 30802989 PMCID: PMC6563103 DOI: 10.1002/hep.30583] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 02/16/2019] [Indexed: 12/12/2022]
Abstract
A variant (148M) in patatin-like phospholipase domain-containing protein 3 (PNPLA3) is a major risk factor for fatty liver disease. Despite its clinical importance, the pathogenic mechanism linking the variant to liver disease remains poorly defined. Previously, we showed that PNPLA3(148M) accumulates to high levels on hepatic lipid droplets (LDs). Here we examined the effect of that accumulation on triglyceride (TG) hydrolysis by adipose triglyceride lipase (ATGL), the major lipase in the liver. As expected, overexpression of ATGL in cultured hepatoma (HuH-7) cells depleted the cells of LDs, but unexpectedly, co-expression of PNPLA3(wild type [WT] or 148M) with ATGL inhibited that depletion. The inhibitory effect of PNPLA3 was not caused by the displacement of ATGL from LDs. We tested the hypothesis that PNPLA3 interferes with ATGL activity by interacting with its cofactor, comparative gene identification-58 (CGI-58). Evidence supporting such an interaction came from two findings. First, co-expression of PNPLA3 and CGI-58 resulted in LD depletion in cultured cells, but expression of PNPLA3 alone did not. Second, PNPLA3 failed to localize to hepatic LDs in liver-specific Cgi-58 knockout (KO) mice. Moreover, overexpression of PNPLA3(148M) increased hepatic TG levels in WT, but not in Cgi-58 KO mice. Thus, the pro-steatotic effects of PNPLA3 required the presence of CGI-58. Co-immunoprecipitation and pulldown experiments in livers of mice and in vitro using purified proteins provided evidence that PNPLA3 and CGI-58 can interact directly. Conclusion: Taken together, these findings are consistent with a model in which PNPLA3(148M) promotes steatosis by CGI-58-dependent inhibition of ATGL on LDs.
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Affiliation(s)
- Yang Wang
- Department of Molecular GeneticsUniversity of Texas Southwestern Medical CenterDallasTX
| | - Nora Kory
- Department of Molecular GeneticsUniversity of Texas Southwestern Medical CenterDallasTX
| | - Soumik BasuRay
- Department of Molecular GeneticsUniversity of Texas Southwestern Medical CenterDallasTX
| | - Jonathan C. Cohen
- Department of Internal MedicineUniversity of Texas Southwestern Medical CenterDallasTX,The Center for Human NutritionUniversity of Texas Southwestern Medical CenterDallas TX
| | - Helen H. Hobbs
- Department of Molecular GeneticsUniversity of Texas Southwestern Medical CenterDallasTX,Department of Internal MedicineUniversity of Texas Southwestern Medical CenterDallasTX,Howard Hughes Medical InstituteUniversity of Texas Southwestern Medical CenterDallasTX
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Yang A, Mottillo EP, Mladenovic-Lucas L, Zhou L, Granneman JG. Dynamic interactions of ABHD5 with PNPLA3 regulate triacylglycerol metabolism in brown adipocytes. Nat Metab 2019; 1:560-569. [PMID: 31497752 PMCID: PMC6730670 DOI: 10.1038/s42255-019-0066-3] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Patatin-Like Phospholipase Domain Containing 2 (PNPLA2)/Adipose Triglyceride Lipase (ATGL) and PNPLA3/Adiponutrin are close paralogs that appear to have opposite functions on triacylglycerol (TAG) mobilization and storage. PNPLA2/ATGL is a major triglyceride lipase in adipose tissue and liver, whereas a common human variant of PNPLA3, I148M, greatly increases risk of hepatosteatosis. Nonetheless, the function of PNPLA3 and the mechanism by which the I148M variant promotes TAG accumulation are poorly understood. Here we demonstrate that PNPLA3 strongly interacts with α/β hydrolase domain-containing 5 (ABHD5/CGI-58), an essential co-activator of PNPLA2/ATGL. Molecular imaging experiments demonstrate that PNPLA3 effectively competes with PNPLA2/ATGL for ABHD5, and that PNPLA3 I148M is more effective in this regard. Inducible overexpression of PNPLA3 I148M greatly suppressed PNPLA2/ATGL-dependent lipolysis and triggered massive TAG accumulation in brown adipocytes, and these effects were dependent on ABHD5. The interaction of PNPLA3 and ABHD5 can be regulated by fatty acid supplementation and synthetic ABHD5 ligands, raising the possibility that this interaction might be targeted for treatment of fatty liver disease.
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Affiliation(s)
- Alexander Yang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA 48201
- Co-first authors
| | - Emilio P. Mottillo
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA 48201
- Co-first authors
- Correspondence and requests for materials should be addressed to E.P.M. or J.G.G. (J.G.G.), (E.P.M.)
| | - Ljiljana Mladenovic-Lucas
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA 48201
| | - Li Zhou
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA 48201
| | - James G. Granneman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA 48201
- Correspondence and requests for materials should be addressed to E.P.M. or J.G.G. (J.G.G.), (E.P.M.)
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Neutral Lipid Storage Diseases as Cellular Model to Study Lipid Droplet Function. Cells 2019; 8:cells8020187. [PMID: 30795549 PMCID: PMC6406896 DOI: 10.3390/cells8020187] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 01/10/2023] Open
Abstract
Neutral lipid storage disease with myopathy (NLSDM) and with ichthyosis (NLSDI) are rare autosomal recessive disorders caused by mutations in the PNPLA2 and in the ABHD5/CGI58 genes, respectively. These genes encode the adipose triglyceride lipase (ATGL) and α-β hydrolase domain 5 (ABHD5) proteins, which play key roles in the function of lipid droplets (LDs). LDs, the main cellular storage sites of triacylglycerols and sterol esters, are highly dynamic organelles. Indeed, LDs are critical for both lipid metabolism and energy homeostasis. Partial or total PNPLA2 or ABHD5/CGI58 knockdown is characteristic of the cells of NLSD patients; thus, these cells are natural models with which one can unravel LD function. In this review we firstly summarize genetic and clinical data collected from NLSD patients, focusing particularly on muscle, skin, heart, and liver damage due to impaired LD function. Then, we discuss how NLSD cells were used to investigate and expand the current structural and functional knowledge of LDs.
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