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Kwon YB, Kim CD, Youm JK, Gwak HS, Park BD, Lee SH, Jeon S, Kim BJ, Seo YJ, Park JK, Lee JH. Novel synthetic ceramide derivatives increase intracellular calcium levels and promote epidermal keratinocyte differentiation. J Lipid Res 2007; 48:1936-43. [PMID: 17554144 DOI: 10.1194/jlr.m700185-jlr200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ceramide is an important constituent of stratum corneum lipids, which act as both physical barriers and signal modulators. We synthesized several ceramide derivatives and investigated their effects on keratinocyte differentiation. RT-PCR and Western blotting showed that the novel synthetic ceramide derivatives K6PC-4 [N-(2,3-dihydroxypropyl)-2-hexyl-3-oxo-decanamide], K6PC-5, [N-(1,3-dihydroxypropyl-2-hexyl-3-oxo-decanamide] and K6PC-9 (N-ethanol-2-hexyl-3-oxo-decanamide) [corrected] These ceramide derivatives elicited a rapid transient increase in intracellular calcium levels, which were measured using laser scanning confocal microscopy. In addition, K6PC-4, K6PC-5, and K6PC-9 stimulated the phosphorylation of p42/44 extracellular signal-regulated kinase and c-Jun N-terminal kinase. In a reconstituted epidermis model, K6PC-4, K6PC-5, and K6PC-9 significantly increased keratin 1 expression in the suprabasal layer. These results indicate that these novel synthetic ceramide derivatives have the potential to promote keratinocyte differentiation, suggesting that the lipid molecules are applicable for treating skin diseases involving abnormal keratinocyte differentiation.
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Affiliation(s)
- Yoo Bin Kwon
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
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Bandhuvula P, Saba JD. Sphingosine-1-phosphate lyase in immunity and cancer: silencing the siren. Trends Mol Med 2007; 13:210-7. [PMID: 17416206 DOI: 10.1016/j.molmed.2007.03.005] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Revised: 03/07/2007] [Accepted: 03/26/2007] [Indexed: 12/20/2022]
Abstract
Sphingosine-1-phosphate (S1P) is a bioactive lipid that promotes cell survival, proliferation and migration, platelet aggregation, mediates ischemic preconditioning, and is essential for angiogenesis and lymphocyte trafficking. Sphingosine-1-phosphate lyase (SPL) is the enzyme responsible for the irreversible degradation of S1P and is, thus, in a strategic position to regulate these same processes by removing available S1P signaling pools, that is, silencing the siren. In fact, recent studies have implicated SPL in the regulation of immunity, cancer surveillance and other physiological processes. Here, we summarize the current understanding of SPL function and regulation, and discuss how SPL might facilitate cancer chemoprevention and serve as a target for modulation of immune responses in transplantation settings and in the treatment of autoimmune disease.
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Uchida Y, Hama H, Alderson NL, Douangpanya S, Wang Y, Crumrine DA, Elias PM, Holleran WM. Fatty acid 2-hydroxylase, encoded by FA2H, accounts for differentiation-associated increase in 2-OH ceramides during keratinocyte differentiation. J Biol Chem 2007; 282:13211-9. [PMID: 17355976 DOI: 10.1074/jbc.m611562200] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ceramides in mammalian stratum corneum comprise a heterogeneous mixture of molecular species that subserve the epidermal permeability barrier, an essential function for survival in a terrestrial environment. In addition to a variation of sphingol species, hydroxylation of the amide-linked fatty acids contributes to the diversity of epidermal ceramides. Fatty acid 2-hydroxylase, encoded by the gene FA2H, the mammalian homologue of FAH1 in yeast, catalyzes the synthesis of 2-hydroxy fatty acid-containing sphingolipids. We assessed here whether FA2H accounts for 2-hydroxyceramide/2-hydroxyglucosylceramide synthesis in epidermis. Reverse transcription-PCR and Western immunoblots demonstrated that FA2H is expressed in cultured human keratinocytes and human epidermis, with FA2H expression and fatty acid 2-hydroxylase activity increased with differentiation. FA2H-siRNA suppressed 2-hydroxylase activity and decreased 2-hydroxyceramide/2-hydroxyglucosylceramide levels, demonstrating that FA2H accounts for synthesis of these sphingolipids in keratinocytes. Whereas FA2H expression and 2-hydroxy free fatty acid production increased early in keratinocyte differentiation, production of 2-hydroxyceramides/2-hydroxyglucosylceramides with longer chain amide-linked fatty acids (> or =C24) increased later. Keratinocytes transduced with FA2H-siRNA contained abnormal epidermal lamellar bodies and did not form the normal extracellular lamellar membranes required for the epidermal permeability barrier. These results reveal that 1) differentiation-dependent up-regulation of ceramide synthesis and fatty acid elongation is accompanied by up-regulation of FA2H; 2) 2-hydroxylation of fatty acid by FA2H occurs prior to generation of ceramides/glucosylceramides; and 3) 2-hydroxyceramides/2-hydroxyglucosylceramides are required for epidermal lamellar membrane formation. Thus, late differentiation-linked increases in FA2H expression are essential for epidermal permeability barrier homeostasis.
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Affiliation(s)
- Yoshikazu Uchida
- Department of Dermatology, School of Medicine, University of California, San Francisco, CA, USA.
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205
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Li W, Sandhoff R, Kono M, Zerfas P, Hoffmann V, Ding BCH, Proia RL, Deng CX. Depletion of ceramides with very long chain fatty acids causes defective skin permeability barrier function, and neonatal lethality in ELOVL4 deficient mice. Int J Biol Sci 2007; 3:120-8. [PMID: 17311087 PMCID: PMC1796950 DOI: 10.7150/ijbs.3.120] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Accepted: 02/06/2007] [Indexed: 11/12/2022] Open
Abstract
Very long chain fatty acids (VLCFA), either free or as components of glycerolipids and sphingolipids, are present in many organs. Elongation of very long chain fatty acids-4 (ELOVL4) belongs to a family of 6 members of putative fatty acid elongases that are involved in the formation of VLCFA. Mutations in ELOVL4 were found to be responsible for an autosomal dominant form of Stargardt's-like macular dystrophy (STGD3) in human. We have previously disrupted the mouse Elovl4 gene, and found that Elovl4+/- mice were developmentally normal, suggesting that haploinsufficiency of ELOVL4 is not a cause for the juvenile retinal degeneration in STGD3 patients. However, Elovl4-/- mice died within several hours of birth for unknown reason(s). To study functions of ELOVL4 further, we have explored the causes for the postnatal lethality in Elovl4-/- mice. Our data indicated that the mutant mice exhibited reduced thickness of the dermis, delayed differentiation of keratinocytes, and abnormal structure of the stratum corneum. We showed that all Elovl4-/- mice exhibited defective skin water permeability barrier function, leading to the early postnatal death. We further showed that the absence of ELOVL4 results in depletion in the epidermis of ceramides with ω-hydroxy very long chain fatty acids (≥C28) and accumulation of ceramides with non ω-hydroxy fatty acids of C26, implicating C26 fatty acids as possible substrates of ELOVL4. These data demonstrate that ELOVL4 is required for VLCFA synthesis that is essential for water permeability barrier function of skin.
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Affiliation(s)
- Wenmei Li
- 1. Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
| | - Roger Sandhoff
- 2. Cellular and Molecular Pathology (E090), German Cancer Research Center, Heidelberg, Germany
| | - Mari Kono
- 1. Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
| | - Patricia Zerfas
- 3. Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vickie Hoffmann
- 3. Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bryan Char-Hoa Ding
- 1. Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
| | - Richard L. Proia
- 1. Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
| | - Chu-Xia Deng
- 1. Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
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Vasireddy V, Uchida Y, Salem N, Kim SY, Mandal MNA, Reddy GB, Bodepudi R, Alderson NL, Brown JC, Hama H, Dlugosz A, Elias PM, Holleran WM, Ayyagari R. Loss of functional ELOVL4 depletes very long-chain fatty acids (> or =C28) and the unique omega-O-acylceramides in skin leading to neonatal death. Hum Mol Genet 2007; 16:471-82. [PMID: 17208947 PMCID: PMC1839956 DOI: 10.1093/hmg/ddl480] [Citation(s) in RCA: 197] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mutations in elongation of very long-chain fatty acid-4 (ELOVL4) are associated with autosomal dominant Stargardt-like macular degeneration (STGD3), with a five base-pair (5 bp) deletion mutation resulting in the loss of 51 carboxy-terminal amino acids and truncation of the protein. In addition to the retina, Elovl4 is expressed in a limited number of mammalian tissues, including skin, with unknown function(s). We generated a knock-in mouse model with the 5-bp deletion in the Elovl4 gene. As anticipated, mice carrying this mutation in the heterozygous state (Elovl4(+/del)) exhibit progressive photoreceptor degeneration. Unexpectedly, homozygous mice (Elovl4(del/del)) display scaly, wrinkled skin, have severely compromised epidermal permeability barrier function, and die within a few hours after birth. Histopathological evaluation of the Elovl4(del/del) pups revealed no apparent abnormality(ies) in vital internal organs. However, skin histology showed an abnormally-compacted outer epidermis [stratum corneum (SC)], while electron microscopy revealed deficient epidermal lamellar body contents, and lack of normal SC lamellar membranes that are essential for permeability barrier function. Lipid analyses of epidermis from Elovl4(del/del) mice revealed a global decrease in very long-chain fatty acids (VLFAs) (i.e., carbon chain > or =C28) in both the ceramide/glucosylceramide and the free fatty-acid fractions. Strikingly, Elovl4(del/del) skin was devoid of the epidermal-unique omega-O-acylceramides, that are key hydrophobic components of the extracellular lamellar membranes in mammalian SC. These findings demonstrate that ELOVL4 is required for generating VLFA critical for epidermal barrier function, and that the lack of epidermal omega-O-acylceramides is incompatible with survival in a desiccating environment.
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Affiliation(s)
- Vidyullatha Vasireddy
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI- 48105
| | - Yoshikazu Uchida
- Department of Dermatology, School of Medicine, University of California San Francisco, and Veterans Administration Medical Center, San Francisco, CA-94121
| | - Norman Salem
- Laboratory of Membrane Biochemistry and Biophysics, NIAAA, National Institutes of Health, Rockville, MD-20892
| | - Soo Yeon Kim
- Laboratory of Membrane Biochemistry and Biophysics, NIAAA, National Institutes of Health, Rockville, MD-20892
| | - Md Nawajesh Ali Mandal
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI- 48105
| | | | - Ravi Bodepudi
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI- 48105
| | - Nathan L. Alderson
- Department of Medicine Medical University of South Carolina, Charleston, SC-29425
| | | | - Hiroko Hama
- Department of Medicine Medical University of South Carolina, Charleston, SC-29425
| | - Andrzej Dlugosz
- Department of Dermatology, University of Michigan, Ann Arbor, MI- 48105
| | - Peter M. Elias
- Department of Dermatology, School of Medicine, University of California San Francisco, and Veterans Administration Medical Center, San Francisco, CA-94121
| | - Walter M. Holleran
- Department of Dermatology, School of Medicine, University of California San Francisco, and Veterans Administration Medical Center, San Francisco, CA-94121
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA-94143
| | - Radha Ayyagari
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI- 48105
- Address for correspondence: *Radha Ayyagari, PhD., Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, 1000 Wall Street, Ann Arbor, MI 48105, Phone: 734-647-6345, Fax: 734-936-7231,
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