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Vincent BM, Tardiff DF, Piotrowski JS, Aron R, Lucas MC, Chung CY, Bacherman H, Chen Y, Pires M, Subramaniam R, Doshi DB, Sadlish H, Raja WK, Solís EJ, Khurana V, Le Bourdonnec B, Scannevin RH, Rhodes KJ. Inhibiting Stearoyl-CoA Desaturase Ameliorates α-Synuclein Cytotoxicity. Cell Rep 2019; 25:2742-2754.e31. [PMID: 30517862 DOI: 10.1016/j.celrep.2018.11.028] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/19/2018] [Accepted: 11/05/2018] [Indexed: 12/18/2022] Open
Abstract
The lack of disease-modifying treatments for neurodegenerative disease stems in part from our rudimentary understanding of disease mechanisms and the paucity of targets for therapeutic intervention. Here we used an integrated discovery paradigm to identify a new therapeutic target for diseases caused by α-synuclein (α-syn), a small lipid-binding protein that misfolds and aggregates in Parkinson's disease and other disorders. Using unbiased phenotypic screening, we identified a series of compounds that were cytoprotective against α-syn-mediated toxicity by inhibiting the highly conserved enzyme stearoyl-CoA desaturase (SCD). Critically, reducing the levels of unsaturated membrane lipids by inhibiting SCD reduced α-syn toxicity in human induced pluripotent stem cell (iPSC) neuronal models. Taken together, these findings suggest that inhibition of fatty acid desaturation has potential as a therapeutic approach for the treatment of Parkinson's disease and other synucleinopathies.
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Affiliation(s)
- Benjamin M Vincent
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Daniel F Tardiff
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA.
| | - Jeff S Piotrowski
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Rebecca Aron
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Matthew C Lucas
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Chee Yeun Chung
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Helene Bacherman
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - YiQun Chen
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Michelle Pires
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Radha Subramaniam
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Dimple B Doshi
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Heather Sadlish
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Waseem K Raja
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Eric J Solís
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Vikram Khurana
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA; Ann Romney Center for Neurologic Disease, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Robert H Scannevin
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Kenneth J Rhodes
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
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DeStefano GM, Kurban M, Anyane-Yeboa K, Dall'Armi C, Di Paolo G, Feenstra H, Silverberg N, Rohena L, López-Cepeda LD, Jobanputra V, Fantauzzo KA, Kiuru M, Tadin-Strapps M, Sobrino A, Vitebsky A, Warburton D, Levy B, Salas-Alanis JC, Christiano AM. Mutations in the cholesterol transporter gene ABCA5 are associated with excessive hair overgrowth. PLoS Genet 2014; 10:e1004333. [PMID: 24831815 PMCID: PMC4022463 DOI: 10.1371/journal.pgen.1004333] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 03/07/2014] [Indexed: 01/09/2023] Open
Abstract
Inherited hypertrichoses are rare syndromes characterized by excessive hair growth that does not result from androgen stimulation, and are often associated with additional congenital abnormalities. In this study, we investigated the genetic defect in a case of autosomal recessive congenital generalized hypertrichosis terminalis (CGHT) (OMIM135400) using whole-exome sequencing. We identified a single base pair substitution in the 5' donor splice site of intron 32 in the ABC lipid transporter gene ABCA5 that leads to aberrant splicing of the transcript and a decrease in protein levels throughout patient hair follicles. The homozygous recessive disruption of ABCA5 leads to reduced lysosome function, which results in an accumulation of autophagosomes, autophagosomal cargos as well as increased endolysosomal cholesterol in CGHT keratinocytes. In an unrelated sporadic case of CGHT, we identified a 1.3 Mb cryptic deletion of chr17q24.2-q24.3 encompassing ABCA5 and found that ABCA5 levels are dramatically reduced throughout patient hair follicles. Collectively, our findings support ABCA5 as a gene underlying the CGHT phenotype and suggest a novel, previously unrecognized role for this gene in regulating hair growth.
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Affiliation(s)
- Gina M. DeStefano
- Department of Genetics and Development, Columbia University, New York, New York, United States of America
| | - Mazen Kurban
- Department of Dermatology, Columbia University, New York, New York, United States of America
| | - Kwame Anyane-Yeboa
- Department of Pediatrics, Columbia University Medical Center, New York, New York, United States of America
| | - Claudia Dall'Armi
- Department of Pathology and Cell Biology, Columbia University, New York, New York, United States of America
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, New York, United States of America
| | - Gilbert Di Paolo
- Department of Pathology and Cell Biology, Columbia University, New York, New York, United States of America
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, New York, United States of America
| | - Heather Feenstra
- St. Luke's-Roosevelt Hospital Center, New York, New York, United States of America
| | - Nanette Silverberg
- St. Luke's-Roosevelt Hospital Center, New York, New York, United States of America
| | - Luis Rohena
- Department of Pediatrics, Columbia University Medical Center, New York, New York, United States of America
| | | | - Vaidehi Jobanputra
- Department of Pathology and Cell Biology, Columbia University, New York, New York, United States of America
| | - Katherine A. Fantauzzo
- Department of Dermatology, Columbia University, New York, New York, United States of America
| | - Maija Kiuru
- Department of Dermatology, Columbia University, New York, New York, United States of America
| | - Marija Tadin-Strapps
- Department of Genetics and Development, Columbia University, New York, New York, United States of America
| | - Antonio Sobrino
- New York Presbyterian Hospital, New York, New York, United States of America
| | - Anna Vitebsky
- Department of Genetics and Development, Columbia University, New York, New York, United States of America
| | - Dorothy Warburton
- Department of Genetics and Development, Columbia University, New York, New York, United States of America
- Department of Pediatrics, Columbia University Medical Center, New York, New York, United States of America
| | - Brynn Levy
- Department of Pathology and Cell Biology, Columbia University, New York, New York, United States of America
| | | | - Angela M. Christiano
- Department of Genetics and Development, Columbia University, New York, New York, United States of America
- Department of Dermatology, Columbia University, New York, New York, United States of America
- * E-mail:
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Bloksgaard M, Neess D, Færgeman NJ, Mandrup S. Acyl-CoA binding protein and epidermal barrier function. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:369-76. [DOI: 10.1016/j.bbalip.2013.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/20/2013] [Accepted: 09/23/2013] [Indexed: 11/29/2022]
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Sampath H, Ntambi JM. Role of stearoyl-CoA desaturase-1 in skin integrity and whole body energy balance. J Biol Chem 2013; 289:2482-8. [PMID: 24356954 DOI: 10.1074/jbc.r113.516716] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The skin is the single largest organ in humans, serving as a major barrier to infection, water loss, and abrasion. The functional diversity of skin requires the synthesis of large amounts of lipids, such as triglycerides, wax esters, squalene, ceramides, free cholesterol, free fatty acids, and cholesterol and retinyl esters. Some of these lipids are used as cell membrane components, signaling molecules, and a source of energy. An important class of lipid metabolism enzymes expressed in skin is the Δ(9)-desaturases, which catalyze the synthesis in Δ(9)-monounsaturated lipids, primarily oleoyl-CoA (18:1n-9) and palmitoyl-CoA (16:1n-7), the major monounsaturated fatty acids in cutaneous lipids. Mice with a deletion of the Δ(9)-desaturase-1 isoform (SCD1) either globally (Scd1(-/-)) or specifically in the skin (skin-specific Scd1-knockout; SKO) present with marked changes in cutaneous lipids and skin integrity. Interestingly, these mice also exhibit increased whole body energy expenditure, protection against diet-induced adiposity, hepatic steatosis, and glucose intolerance. The increased energy expenditure in skin-specific Scd1-knockout (SKO) mice is a surprising phenotype, as it links cutaneous lipid homeostasis with whole body energy balance. This minireview summarizes the role of skin SCD1 in regulating skin integrity and whole body energy homeostasis and offers a discussion of potential pathways that may connect these seemingly disparate phenotypes.
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Affiliation(s)
- Harini Sampath
- From the Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon 97239 and
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Zouboulis CC, Angres S, Seltmann H. Regulation of stearoyl-coenzyme A desaturase and fatty acid delta-6 desaturase-2 expression by linoleic acid and arachidonic acid in human sebocytes leads to enhancement of proinflammatory activity but does not affect lipogenesis. Br J Dermatol 2011; 165:269-76. [PMID: 21457203 DOI: 10.1111/j.1365-2133.2011.10340.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Treatment of SZ95 sebocytes with the essential fatty acid linoleic acid (LA) and the polyunsaturated fatty acid arachidonic acid (AA) leads to sebaceous lipogenesis. Animal data indicate that stearoyl-coenzyme A desaturase (SCD), a key enzyme in fatty acid biosynthesis, is involved in sebaceous lipogenesis and proinflammatory signalling in the sebaceous gland. On the other hand, fatty acid delta-6 desaturase-2 (FADS2) catalyses the conversion of LA to AA. OBJECTIVES To identify the effects of LA and AA on the expression of SCD and FADS2 and to detect its biological relevance. METHODS SZ95 sebocytes were treated with LA (10(-5) and 10(-4) mol L(-1) ), AA (10(-6) and 10(-5) mol L(-1) ) and the combination of LA (10(-4) mol L(-1) ) and testosterone (2 × 10(-8) mol L(-1) ), with or without addition of the SCD inhibitor FPCA (10(-8) and 10(-6) mol L(-1) ). Cytotoxicity was determined by the lactate dehydrogenase assay. SCD and FACS2 mRNA levels were assessed by semiquantitative reverse transcription-polymerase chain reaction and protein expression by Western blot analysis. SZ95 sebocyte lipid content and cell number were measured by the Nile red and the fluorescein diacetate microassays, respectively. Determination of interleukin (IL)-6 and IL-8 release was evaluated by enzyme-linked immunosorbent assay. RESULTS LA treatment induced an increase of SCD and FADS2 at mRNA and protein levels in SZ95 sebocytes after 1·5 h. Treatment with AA led to an increase of SCD but to a decrease of FADS2 mRNA levels. LA/testosterone cotreatment stimulated lipogenesis in SZ95 sebocytes. A distinct proinflammatory pattern was registered: whereas LA strongly upregulated IL-6 secretion only, AA induced a mild level of IL-6 and IL-8 release from SZ95 sebocytes. Treatment with the SCD inhibitor FPCA reduced the LA/testosterone-upregulated SCD and FADS2 mRNA levels and resulted in an anti-inflammatory effect, but did not affect sebaceous lipogenesis. CONCLUSIONS LA-induced sebaceous lipogenesis is likely to be an SCD-independent effect. Regulation of SCD and FADS2 expression by LA and AA leads to enhancement of proinflammatory activity but does not affect lipogenesis in human sebocytes.
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Affiliation(s)
- C C Zouboulis
- Department of Dermatology, Dessau Medical Center, Auenweg 38, 06847 Dessau, Germany.
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Guillou H, Zadravec D, Martin PGP, Jacobsson A. The key roles of elongases and desaturases in mammalian fatty acid metabolism: Insights from transgenic mice. Prog Lipid Res 2009; 49:186-99. [PMID: 20018209 DOI: 10.1016/j.plipres.2009.12.002] [Citation(s) in RCA: 569] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 12/09/2009] [Accepted: 12/10/2009] [Indexed: 12/31/2022]
Abstract
In mammalian cells, elongases and desaturases play critical roles in regulating the length and degree of unsaturation of fatty acids and thereby their functions and metabolic fates. In the past decade, a great deal has been learnt about these enzymes and the first part of this review summarizes our current knowledge concerning these enzymes. More recently, several transgenic mouse models lacking either an elongase (Elovl3(-/-), Elovl4(-/-), Elovl5(-/-), Elovl6(-/-)) or a desaturase (Scd-1(-/-), Scd-2(-/-), Fads2(-/-)) have been developed and the second part of this review focuses on the insights gained from studies with these mice, as well as from investigations on cell cultures.
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Affiliation(s)
- Hervé Guillou
- Integrative Toxicology and Metabolism, Pôle de Toxicologie Alimentaire, Laboratoire de Pharmacologie et Toxicologie, Institut National de la Recherche Agronomique INRA UR66, Toulouse Cedex 3, France
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7
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Harrison WJ, Bull JJ, Seltmann H, Zouboulis CC, Philpott MP. Expression of lipogenic factors galectin-12, resistin, SREBP-1, and SCD in human sebaceous glands and cultured sebocytes. J Invest Dermatol 2007; 127:1309-17. [PMID: 17363919 DOI: 10.1038/sj.jid.5700743] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The transcription factors CCAAT enhancer-binding protein alpha, beta, and delta, and peroxisome proliferator-activated receptor gamma are known to be crucial to the differentiation of adipocytes and are expressed in sebaceous gland cells. As lipogenesis is key to both adipocyte and sebocyte differentiation we hypothesize that sebocytes follow a similar program of differentiation to adipocytes. We have investigated the expression of known adipogenic factors resistin, galectin-12, sterol response-element-binding protein-1 (SREBP-1) and stearoyl-CoA desaturase in the immortalized sebaceous gland cell line SZ95 and whole skin. Reverse transcriptase-PCR analysis showed the expression of galectin-12, resistin, SREBP-1, and stearoyl-CoA desaturase mRNAs in SZ95 sebocytes. Immunoreactivity was observed for galectin-12 and SREBP-1 in the nuclei and resistin in the cytoplasm of basal sebocytes, and stearoyl CoA desaturase in the cytoplasm of basal and luminal sebocytes of human scalp skin. Expression of galectin-12, resistin, and SREBP-1 in SZ95 sebocytes was confirmed by Western blot analysis. These data provide further evidence that pathways of differentiation in adipocytes and sebocytes could be similar and therefore further understanding of sebaceous gland differentiation and lipogenesis and potential therapies for sebaceous gland disorders may be obtained from our knowledge of adipocyte differentiation.
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Affiliation(s)
- Wesley J Harrison
- Centre for Cutaneous Research, Barts and The London, Queen Mary's School of Medicine and Dentistry, London, UK
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8
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Heinemann FS, Ozols J. Stearoyl-CoA desaturase, a short-lived protein of endoplasmic reticulum with multiple control mechanisms. Prostaglandins Leukot Essent Fatty Acids 2003; 68:123-33. [PMID: 12538076 DOI: 10.1016/s0952-3278(02)00262-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Stearoyl-CoA desaturase (SCD) is a short-lived, polytopic membrane-bound non-heme iron enzyme localized primarily in the endoplasmic reticulum. SCD is required for the biosynthesis of monounsaturated fatty acids, and plays a key role in hepatic synthesis of triglycerides and very-low-density lipoproteins. The intracellular concentration of SCD fluctuates in a wide range in response to complex and often competing hormonal and dietary factors. A combination of transcriptional regulation and rapid protein degradation produces transient elevations of SCD enzyme activity in response to physiologic demands. Dysregulation of SCD has been implicated in non-alcoholic fatty liver disease, hyperlipidemia, and obesity.
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Affiliation(s)
- F Scott Heinemann
- Department of Pathology, Hoag Memorial Hospital Presbyterian, Newport Beach, CA 92663, USA
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9
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Bull JJ, Müller-Röver S, Chronnell CMT, Paus R, Philpott MP, McKay IA. Contrasting expression patterns of CCAAT/enhancer-binding protein transcription factors in the hair follicle and at different stages of the hair growth cycle. J Invest Dermatol 2002; 118:17-24. [PMID: 11851871 DOI: 10.1046/j.0022-202x.2001.01629.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hair follicles undergo repeated cycles of growth and regression, throughout the entire life of the organism. These dynamic changes require closely co-ordinated regulation of gene expression. The CCAAT/enhancer-binding proteins are a family of basic region/leucine zipper transcription factors that regulate gene transcription in various tissues. They have been implicated in epidermal differentiation and may therefore play an important role in the hair follicle. We have investigated the localization of four members of this family--CCAAT/enhancer-binding protein-alpha, -beta, and -delta, and Gadd153--in both human and murine hair follicles by immunohistochemistry. Furthermore, we examined CCAAT/enhancer-binding protein-alpha, -beta, and -delta immunoreactivity at different stages of the depilation-induced murine hair growth cycle. Distinct immunoreactivity patterns for CCAAT/enhancer-binding protein-alpha, -beta, and -delta, and Gadd153 were observed in the outer root sheath, sebaceous gland, dermal papilla, and connective tissue sheath of human anagen hair follicles. In murine follicles, CCAAT/enhancer-binding protein-alpha was expressed in the outer root sheath, sebaceous gland, and dermal papilla, whereas CCAAT/enhancer-binding protein-beta expression was confined to the matrix, sebaceous gland, and inner and outer root sheaths. Both CCAAT/enhancer-binding protein-alpha and -beta were upregulated during anagen, then downregulated in catagen follicles. In contrast, CCAAT/enhancer-binding protein-delta showed no hair cycle-dependent variation in immunoreactivity. These data suggests that the expression of CCAAT/enhancer-binding protein-alpha and -beta may, in turn, play a part in regulating hair cycle-dependent gene expression. Moreover, as CCAAT/enhancer-binding protein-alpha, -beta, and -delta are crucial in the regulation of adipocyte differentiation and lipid metabolism, their expression in sebocytes suggests they may also play a similar role in differentiation and lipid metabolism of the sebaceous gland.
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Affiliation(s)
- Jonathan J Bull
- Centre for Cutaneous Research, St Bartholomew's and the Royal London School of Medicine and Dentistry, London, UK
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10
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Miyazaki M, Man WC, Ntambi JM. Targeted disruption of stearoyl-CoA desaturase1 gene in mice causes atrophy of sebaceous and meibomian glands and depletion of wax esters in the eyelid. J Nutr 2001; 131:2260-8. [PMID: 11533264 DOI: 10.1093/jn/131.9.2260] [Citation(s) in RCA: 213] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Stearoyl-CoA desaturase (SCD) is a microsomal rate-limiting enzyme in the cellular synthesis of monounsaturated fatty acids (MUFA), mainly oleate (18:1) and palmitoleate (16:1), which are the major MUFA of membrane phospholipids, cholesterol esters and triglycerides. Three well-characterized isoforms of SCD, SCD1, SCD2 and SCD3, exist in mice. To investigate the physiologic functions of SCD1, we generated SCD1 null (SCD1-/-) mice. The skin and eyelid of SCD1-/- mice are deficient in triglycerides and cholesterol esters, and the eyelid also is deficient in wax esters. Furthermore, the eyelid and skin of SCD1-/- mice have higher levels of free cholesterol. SCD1-/- mice develop cutaneous abnormalities and narrow eye fissure with atrophic sebaceous and meibomian glands. Consumption of diets containing high levels of oleate, failed to restore the levels of triglycerides, cholesterol esters and wax esters in SCD1-/- mice to the levels found in the eyelid of wild-type mice. These results reveal a physiologic role of SCD in cholesterol homeostasis as well as in the de novo biosynthesis of cholesterol esters, triglycerides and wax esters required for normal skin and eyelid function.
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Affiliation(s)
- M Miyazaki
- Departments of Biochemistry, University of Wisconsin, Madison, 53706, USA
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11
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Zhang L, Ge L, Tran T, Stenn K, Prouty SM. Isolation and characterization of the human stearoyl-CoA desaturase gene promoter: requirement of a conserved CCAAT cis-element. Biochem J 2001; 357:183-93. [PMID: 11415448 PMCID: PMC1221940 DOI: 10.1042/0264-6021:3570183] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Stearoyl-CoA desaturase is the rate-limiting enzyme in the production of mono-unsaturated fatty acids. We have recently cloned and characterized the human Scd cDNA and SCD (the stearoyl-CoA desaturase structural gene) on chromosome 10, as well as the non-transcribed pseudogene on chromosome 17. In order to further define SCD regulation and function, we have isolated and characterized the promoter of the structural gene. Screening of chromosome-10-specific libraries resulted in the isolation of 4.1 kb of SCD sequence upstream of the translation start site. Binding sites for transcription factors critical for mouse Scd1 and Scd2 promoter activity, such as sterol-regulated-element-binding protein and nuclear factor Y, were present in the human SCD promoter (Scd is the mouse stearoyl-CoA desaturase gene). Deletion analysis in HaCaT keratinocytes identified a critical region for promoter activity between nts 496-609 upstream of the translation start site. Site-directed mutagenesis of binding sites in this region identified the CCAAT box as the critical cis-element for SCD promoter activity. An electrophoretic mobility-shift assay confirmed that this element binds nuclear proteins from HaCaT keratinocytes. The polyunsaturated-fatty-acid (PUFA) response element, previously identified in the promoters of mouse Scd1 and Scd2, was found to be conserved in the human SCD promoter, and contained the critical CCAAT cis-element. A minimal promoter construct including this region was responsive to fatty acids, with oleate and linoleate decreasing transcription and stearate increasing it. These studies indicate that CCAAT-box-binding proteins activate SCD transcription in cultured keratinocytes and that fatty acids modulate transcription, most likely through the conserved PUFA response element.
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Affiliation(s)
- L Zhang
- Skin Biology Technical Resourse Center, Johnson and Johnson, Consumer Products World Wide, 199 Grandview Road, Skillman, NJ 08558, USA
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12
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A lipogenic diet in mice with a disruption of the stearoyl-CoA desaturase 1 gene reveals a stringent requirement of endogenous monounsaturated fatty acids for triglyceride synthesis. J Lipid Res 2001. [DOI: 10.1016/s0022-2275(20)31589-3] [Citation(s) in RCA: 210] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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13
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Watts JL, Browse J. A palmitoyl-CoA-specific delta9 fatty acid desaturase from Caenorhabditis elegans. Biochem Biophys Res Commun 2000; 272:263-9. [PMID: 10872837 DOI: 10.1006/bbrc.2000.2772] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Biosynthesis of polyunsaturated fatty acids in C. elegans is initiated by the introduction of a double bond at the delta9 position of a saturated fatty acid. We identified three C. elegans fatty acid desaturase genes related to the yeast delta9 desaturase OLE1 and the rat stearoyl-CoA desaturase SCD1. Heterologous expression of all three genes rescues the fatty acid auxotrophy of the yeast delta9 desaturase mutant ole1. Examination of the fatty acid composition of the transgenic yeast reveals striking differences in the substrate specificities of these desaturases. Two desaturases, FAT-6 and FAT-7, readily desaturate stearic acid (18:0) and show less activity on palmitic acid (16:0). In contrast, the other desaturase, FAT-5, readily desaturates palmitic acid (16:0), but shows nearly undetectable activity on the common delta9 substrate stearic acid. This is the first report of a palmitoyl-CoA-specific membrane fatty acid desaturase.
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Affiliation(s)
- J L Watts
- Institute of Biological Chemistry, Washington State University, Pullman 99164-6340, USA
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