1
|
Do Carmo S, Kautzmann MAI, Bhattacharjee S, Jun B, Steinberg C, Emmerson JT, Malcolm JC, Bonomo Q, Bazan NG, Cuello AC. Differential effect of an evolving amyloid and tau pathology on brain phospholipids and bioactive lipid mediators in rat models of Alzheimer-like pathology. J Neuroinflammation 2024; 21:185. [PMID: 39080670 PMCID: PMC11290283 DOI: 10.1186/s12974-024-03184-7] [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: 04/19/2024] [Accepted: 07/23/2024] [Indexed: 08/02/2024] Open
Abstract
BACKGROUND Brain inflammation contributes significantly to the pathophysiology of Alzheimer's disease, and it is manifested by glial cell activation, increased production of cytokines/chemokines, and a shift in lipid mediators from a pro-homeostatic to a pro-inflammatory profile. However, whether the production of bioactive lipid mediators is affected at earlier stages, prior to the deposition of Aβ plaques and tau hyperphosphorylation, is unknown. The differential contribution of an evolving amyloid and tau pathology on the composition and abundance of membrane phospholipids and bioactive lipid mediators also remains unresolved. METHODS In this study, we examined the cortical levels of DHA- and AA-derived bioactive lipid mediators and of membrane phospholipids by liquid chromatography with tandem mass spectrometry in transgenic rat models of the Alzheimer's-like amyloid and tau pathologies at early and advanced pathological stages. RESULTS Our findings revealed a complex balance between pro-inflammatory and pro-resolving processes in which tau pathology has a more pronounced effect compared to amyloid pathology. At stages preceding tau misfolding and aggregation, there was an increase in pro-resolving lipid mediators (RVD6 and NPD1), DHA-containing phospholipids and IFN-γ levels. However, in advanced tau pathology displaying NFT-like inclusions, neuronal death, glial activation and cognitive deficits, there was an increase in cytokine and PGD2, PGE2, and PGF2α generation accompanied by a drop in IFN-γ levels. This pathology also resulted in a marked increase in AA-containing phospholipids. In comparison, pre-plaque amyloid pathology already presented high levels of cytokines and AA-containing phospholipids together with elevated RVD6 and NPD1 levels. Finally, Aβ plaque deposition was accompanied by a modest increase in prostaglandins, increased AA-containing phospholipids and reduced DHA-containing phospholipids. CONCLUSIONS Our findings suggest a dynamic trajectory of inflammatory and lipid mediators in the evolving amyloid and tau pathologies and support their differing roles on membrane properties and, consequentially, on signal transduction.
Collapse
Affiliation(s)
- Sonia Do Carmo
- Department of Pharmacology & Therapeutics, McGill University, 3655 Promenade Sir William Osler, Room 1210, Montreal, H3G 1Y6, Canada.
| | - Marie-Audrey I Kautzmann
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, 2020 Gravier Street, Suite D, New Orleans, LA, 70112, USA
| | - Surjyadipta Bhattacharjee
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, 2020 Gravier Street, Suite D, New Orleans, LA, 70112, USA
| | - Bokkyoo Jun
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, 2020 Gravier Street, Suite D, New Orleans, LA, 70112, USA
| | - Carolyn Steinberg
- Department of Pharmacology & Therapeutics, McGill University, 3655 Promenade Sir William Osler, Room 1210, Montreal, H3G 1Y6, Canada
| | - Joshua T Emmerson
- Department of Pharmacology & Therapeutics, McGill University, 3655 Promenade Sir William Osler, Room 1210, Montreal, H3G 1Y6, Canada
| | - Janice C Malcolm
- Department of Cell Anatomy and Cell Biology, McGill University, Montreal, H3A 0C7, Canada
| | - Quentin Bonomo
- Department of Neurology and Neurosurgery, McGill University, Montreal, H3G 1Y6, Canada
| | - Nicolas G Bazan
- Department of Pharmacology & Therapeutics, McGill University, 3655 Promenade Sir William Osler, Room 1210, Montreal, H3G 1Y6, Canada.
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, 2020 Gravier Street, Suite D, New Orleans, LA, 70112, USA.
| | - A Claudio Cuello
- Department of Pharmacology & Therapeutics, McGill University, 3655 Promenade Sir William Osler, Room 1210, Montreal, H3G 1Y6, Canada.
- Department of Cell Anatomy and Cell Biology, McGill University, Montreal, H3A 0C7, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montreal, H3G 1Y6, Canada.
- Department of Pharmacology, Oxford University, Oxford, OX1 3QT, UK.
| |
Collapse
|
2
|
Gyening YK, Chauhan NK, Tytanic M, Ea V, Brush RS, Agbaga MP. ELOVL4 Mutations That Cause Spinocerebellar Ataxia-34 Differentially Alter Very Long Chain Fatty Acid Biosynthesis. J Lipid Res 2023; 64:100317. [PMID: 36464075 PMCID: PMC9823237 DOI: 10.1016/j.jlr.2022.100317] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/28/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
The FA Elongase-4 (ELOVL4) enzyme mediates biosynthesis of both very long chain (VLC)-PUFAs and VLC-saturated FA (VLC-SFAs). VLC-PUFAs play critical roles in retina and sperm function, whereas VLC-SFAs are predominantly associated with brain function and maintenance of the skin permeability barrier. While some ELOVL4 mutations cause Autosomal Dominant Stargardt-like Macular Dystrophy (STGD3), other ELOVL4 point mutations, such as L168F and W246G, affect the brain and/or skin, leading to Spinocerebellar Ataxia-34 (SCA34) and Erythrokeratodermia variabilis. The mechanisms by which these ELOVL4 mutations alter VLC-PUFA and VLC-SFA biosynthesis to cause the different tissue-specific pathologies are not well understood. To understand how these mutations alter VLC-PUFA and VLC-SFA biosynthesis, we expressed WT-ELOVL4, L168F, and W246G ELOVL4 variants in cell culture and supplemented the cultures with VLC-PUFA or VLC-SFA precursors. Total lipids were extracted, converted to FA methyl esters, and quantified by gas chromatography. We showed that L168F and W246G mutants were capable of VLC-PUFA biosynthesis. W246G synthesized and accumulated 32:6n3, while L168F exhibited gain of function in VLC-PUFA biosynthesis as it made 38:5n3, which we did not detect in WT-ELOVL4 or W246G-expressing cells. However, compared with WT-ELOVL4, both L168F and W246G mutants were deficient in VLC-SFA biosynthesis, especially the W246G protein, which showed negligible VLC-SFA biosynthesis. These results suggest VLC-PUFA biosynthetic capabilities of L168F and W246G in the retina, which may explain the lack of retinal phenotype in SCA34. Defects in VLC-SFA biosynthesis by these variants may be a contributing factor to the pathogenic mechanism of SCA34 and Erythrokeratodermia variabilis.
Collapse
Affiliation(s)
- Yeboah Kofi Gyening
- Departments of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; Department of Ophthalmology, Dean McGee Eye Institute, Oklahoma City, Oklahoma, USA
| | - Neeraj Kumar Chauhan
- Departments of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; Department of Ophthalmology, Dean McGee Eye Institute, Oklahoma City, Oklahoma, USA
| | - Madison Tytanic
- Departments of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; Department of Ophthalmology, Dean McGee Eye Institute, Oklahoma City, Oklahoma, USA
| | - Vicki Ea
- Department of Ophthalmology, Dean McGee Eye Institute, Oklahoma City, Oklahoma, USA
| | - Richard S Brush
- Department of Ophthalmology, Dean McGee Eye Institute, Oklahoma City, Oklahoma, USA; Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Martin-Paul Agbaga
- Departments of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; Department of Ophthalmology, Dean McGee Eye Institute, Oklahoma City, Oklahoma, USA; Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
| |
Collapse
|
3
|
He Y, Phan K, Bhatia S, Pickford R, Fu Y, Yang Y, Hodges JR, Piguet O, Halliday GM, Kim WS. Increased VLCFA-lipids and ELOVL4 underlie neurodegeneration in frontotemporal dementia. Sci Rep 2021; 11:21348. [PMID: 34725421 PMCID: PMC8560873 DOI: 10.1038/s41598-021-00870-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 10/18/2021] [Indexed: 12/22/2022] Open
Abstract
Rare, yet biologically critical, lipids that contain very long chain fatty acids (VLCFA-lipids) are synthesized in the brain by the enzyme ELOVL4. High levels of VLCFA-lipids are toxic to cells and excess VLCFA-lipids are actively removed by ABCD1 in an ATP-dependent manner. Virtually nothing is known about the impact of VLCFA-lipids in neurodegenerative diseases. Here, we investigated the possible role of VLCFA-lipids in frontotemporal dementia (FTD), which is a leading cause of younger-onset dementia. Using quantitative discovery lipidomics, we identified three VLCFA-lipid species that were significantly increased in FTD brain compared to controls, with strong correlations with ELOVL4. Increases in ELOVL4 expression correlated with significant decreases in the membrane-bound synaptophysin in FTD brain. Furthermore, increases in ABCD1 expression correlated with increases in VLCFA-lipids. We uncovered a new pathomechanism that is pertinent to understanding the pathogenesis of FTD.
Collapse
Affiliation(s)
- Ying He
- Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2050, Australia
| | - Katherine Phan
- Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2050, Australia
| | - Surabhi Bhatia
- Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2050, Australia
| | - Russell Pickford
- Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, NSW, Australia
| | - YuHong Fu
- Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2050, Australia
| | - Yue Yang
- Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2050, Australia
| | - John R Hodges
- Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2050, Australia
| | - Olivier Piguet
- Brain and Mind Centre and School of Psychology, The University of Sydney, Sydney, NSW, Australia
- Neuroscience Research Australia, Sydney, NSW, Australia
| | - Glenda M Halliday
- Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2050, Australia
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Woojin Scott Kim
- Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2050, Australia.
- Neuroscience Research Australia, Sydney, NSW, Australia.
- School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.
| |
Collapse
|
4
|
Yeboah GK, Lobanova ES, Brush RS, Agbaga MP. Very long chain fatty acid-containing lipids: a decade of novel insights from the study of ELOVL4. J Lipid Res 2021; 62:100030. [PMID: 33556440 PMCID: PMC8042400 DOI: 10.1016/j.jlr.2021.100030] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 01/12/2021] [Accepted: 01/27/2021] [Indexed: 11/18/2022] Open
Abstract
Lipids play essential roles in maintaining cell structure and function by modulating membrane fluidity and cell signaling. The fatty acid elongase-4 (ELOVL4) protein, expressed in retina, brain, Meibomian glands, skin, testes and sperm, is an essential enzyme that mediates tissue-specific biosynthesis of both VLC-PUFA and VLC-saturated fatty acids (VLC-SFA). These fatty acids play critical roles in maintaining retina and brain function, neuroprotection, skin permeability barrier maintenance, and sperm function, among other important cellular processes. Mutations in ELOVL4 that affect biosynthesis of these fatty acids cause several distinct tissue-specific human disorders that include blindness, age-related cerebellar atrophy and ataxia, skin disorders, early-childhood seizures, mental retardation, and mortality, which underscores the essential roles of ELOVL4 products for life. However, the mechanisms by which one tissue makes VLC-PUFA and another makes VLC-SFA, and how these fatty acids exert their important functional roles in each tissue, remain unknown. This review summarizes research over that last decade that has contributed to our current understanding of the role of ELOVL4 and its products in cellular function. In the retina, VLC-PUFA and their bioactive "Elovanoids" are essential for retinal function. In the brain, VLC-SFA are enriched in synaptic vesicles and mediate neuronal signaling by determining the rate of neurotransmitter release essential for normal neuronal function. These findings point to ELOVL4 and its products as being essential for life. Therefore, mutations and/or age-related epigenetic modifications of fatty acid biosynthetic gene activity that affect VLC-SFA and VLC-PUFA biosynthesis contribute to age-related dysfunction of ELOVL4-expressing tissues.
Collapse
Affiliation(s)
- Gyening Kofi Yeboah
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Ekaterina S Lobanova
- Department of Ophthalmology Research, University of Florida, Gainesville, FL, USA
| | - Richard S Brush
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Dean A. McGee Eye Institute, Oklahoma City, OK, USA
| | - Martin-Paul Agbaga
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Dean A. McGee Eye Institute, Oklahoma City, OK, USA.
| |
Collapse
|
5
|
Homozygous Expression of Mutant ELOVL4 Leads to Seizures and Death in a Novel Animal Model of Very Long-Chain Fatty Acid Deficiency. Mol Neurobiol 2017; 55:1795-1813. [PMID: 29168048 PMCID: PMC5820379 DOI: 10.1007/s12035-017-0824-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 11/07/2017] [Indexed: 10/24/2022]
Abstract
Lipids are essential components of the nervous system. However, the functions of very long-chain fatty acids (VLC-FA; ≥ 28 carbons) in the brain are unknown. The enzyme ELOngation of Very Long-chain fatty acids-4 (ELOVL4) catalyzes the rate-limiting step in the biosynthesis of VLC-FA (Agbaga et al., Proc Natl Acad Sci USA 105(35): 12843-12848, 2008; Logan et al., J Lipid Res 55(4): 698-708, 2014), which we identified in the brain as saturated fatty acids (VLC-SFA). Homozygous mutations in ELOVL4 cause severe neuropathology in humans (Ozaki et al., JAMA Neurol 72(7): 797-805, 2015; Mir et al., BMC Med Genet 15: 25, 2014; Cadieux-Dion et al., JAMA Neurol 71(4): 470-475, 2014; Bourassa et al., JAMA Neurol 72(8): 942-943, 2015; Aldahmesh et al., Am J Hum Genet 89(6): 745-750, 2011) and are post-natal lethal in mice (Cameron et al., Int J Biol Sci 3(2): 111-119, 2007; Li et al., Int J Biol Sci 3(2): 120-128, 2007; McMahon et al., Molecular Vision 13: 258-272, 2007; Vasireddy et al., Hum Mol Genet 16(5): 471-482, 2007) from dehydration due to loss of VLC-SFA that comprise the skin permeability barrier. Double transgenic mice with homozygous knock-in of the Stargardt-like macular dystrophy (STDG3; 797-801_AACTT) mutation of Elovl4 with skin-specific rescue of wild-type Elovl4 expression (S + Elovl4 mut/mut mice) develop seizures by P19 and die by P21. Electrophysiological analyses of hippocampal slices showed aberrant epileptogenic activity in S + Elovl4 mut/mut mice. FM1-43 dye release studies showed that synapses made by cultured hippocampal neurons from S + Elovl4 mut/mut mice exhibited accelerated synaptic release kinetics. Supplementation of VLC-SFA to cultured hippocampal neurons from mutant mice rescued defective synaptic release to wild-type rates. Together, these studies establish a critical, novel role for ELOVL4 and its VLC-SFA products in regulating synaptic release kinetics and epileptogenesis. Future studies aimed at understanding the molecular mechanisms by which VLC-SFA regulate synaptic function may provide new targets for improved seizure therapies.
Collapse
|
6
|
Current Progress in Deciphering Importance of VLC-PUFA in the Retina. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 854:145-51. [DOI: 10.1007/978-3-319-17121-0_20] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
|
7
|
Astarita G, Kendall AC, Dennis EA, Nicolaou A. Targeted lipidomic strategies for oxygenated metabolites of polyunsaturated fatty acids. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1851:456-68. [PMID: 25486530 PMCID: PMC4323855 DOI: 10.1016/j.bbalip.2014.11.012] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/19/2014] [Accepted: 11/26/2014] [Indexed: 12/13/2022]
Abstract
Oxidation of polyunsaturated fatty acids (PUFA) through enzymatic or non-enzymatic free radical-mediated reactions can yield an array of lipid metabolites including eicosanoids, octadecanoids, docosanoids and related species. In mammals, these oxygenated PUFA mediators play prominent roles in the physiological and pathological regulation of many key biological processes in the cardiovascular, renal, reproductive and other systems including their pivotal contribution to inflammation. Mass spectrometry-based technology platforms have revolutionized our ability to analyze the complex mixture of lipid mediators found in biological samples, with increased numbers of metabolites that can be simultaneously quantified from a single sample in few analytical steps. The recent development of high-sensitivity and high-throughput analytical tools for lipid mediators affords a broader view of these oxygenated PUFA species, and facilitates research into their role in health and disease. In this review, we illustrate current analytical approaches for a high-throughput lipidomic analysis of eicosanoids and related mediators in biological samples. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance."
Collapse
Affiliation(s)
- Giuseppe Astarita
- Waters Corporation, Milford, MA, USA; Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC, USA.
| | - Alexandra C Kendall
- Manchester Pharmacy School, Faculty of Medical and Human Sciences, The University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, UK
| | - Edward A Dennis
- Department of Chemistry/Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0601, USA; Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0601, USA
| | - Anna Nicolaou
- Manchester Pharmacy School, Faculty of Medical and Human Sciences, The University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, UK.
| |
Collapse
|
8
|
Yu M, Benham A, Logan S, Brush RS, Mandal MNA, Anderson RE, Agbaga MP. ELOVL4 protein preferentially elongates 20:5n3 to very long chain PUFAs over 20:4n6 and 22:6n3. J Lipid Res 2012; 53:494-504. [PMID: 22158834 PMCID: PMC3276472 DOI: 10.1194/jlr.m021386] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We hypothesized that reduction/loss of very long chain PUFAs (VLC-PUFAs) due to mutations in the ELOngase of very long chain fatty acid-4 (ELOVL4) protein contributes to retinal degeneration in autosomal dominant Stargardt-like macular dystrophy (STGD3) and age-related macular degeneration; hence, increasing VLC-PUFA in the retina of these patients could provide some therapeutic benefits. Thus, we tested the efficiency of elongation of C20-C22 PUFA by the ELOVL4 protein to determine which substrates are the best precursors for biosynthesis of VLC-PUFA. The ELOVL4 protein was expressed in pheochromocytoma cells, while green fluorescent protein-expressing and nontransduced cells served as controls. The cells were treated with 20:5n3, 22:6n3, and 20:4n6, either individually or in equal combinations. Both transduced and control cells internalized and elongated the supplemented FAs to C22-C26 precursors. Only ELOVL4-expressing cells synthesized C28-C38 VLC-PUFA from these precursors. In general, 20:5n3 was more efficiently elongated to VLC-PUFA in the ELOVL4-expressing cells, regardless of whether it was in combination with 22:6n3 or with 20:4n6. In each FA treatment group, C34 and C36 VLC-PUFAs were the predominant VLC-PUFAs in the ELOVL4-expressing cells. In summary, 20:5n3, followed by 20:4n6, seems to be the best precursor for boosting the synthesis of VLC-PUFA by ELOVL4 protein.
Collapse
Affiliation(s)
- Man Yu
- Departments of Ophthalmology and Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Ophthalmic Laboratories and Department of Ophthalmology, West China Hospital, Sichuan University, P. R. China
| | - Aaron Benham
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Dean McGee Eye Institute, Oklahoma City, OK; and
| | - Sreemathi Logan
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Departments of Ophthalmology and Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Dean McGee Eye Institute, Oklahoma City, OK; and
| | - R Steven Brush
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Dean McGee Eye Institute, Oklahoma City, OK; and
| | - Md Nawajes A Mandal
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Dean McGee Eye Institute, Oklahoma City, OK; and
| | - Robert E Anderson
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Departments of Ophthalmology and Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Dean McGee Eye Institute, Oklahoma City, OK; and
| | - Martin-Paul Agbaga
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Dean McGee Eye Institute, Oklahoma City, OK; and.
| |
Collapse
|
9
|
Liu A, Lin Y, Terry R, Nelson K, Bernstein PS. Role of long-chain and very-long-chain polyunsaturated fatty acids in macular degenerations and dystrophies. ACTA ACUST UNITED AC 2011; 6:593-613. [PMID: 25324899 DOI: 10.2217/clp.11.41] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Macular degeneration is a progressive, bilateral eye disorder that damages the macula of the human eye. The most common form of macular degeneration is age-related macular degeneration (AMD), which is the leading cause of irreversible blindness in people older than 50 years in developed countries. Autosomal dominant Stargardt disease-3 (STGD3) is an inherited macular dystrophy that has clinical features similar to dry AMD, but occurs at a much earlier age. It is caused by a mutation in the elongation of very-long-chain fatty acids-like 4 (ELOVL4) gene, which is responsible for encoding the elongase enzyme that converts shorter chain fatty acids into C28-C38 very long-chain polyunsaturated fatty acids (VLCPUFAs, total number of carbons ≥24). Diets rich in long-chain polyunsaturated fatty acids (LCPUFAs) have inverse associations with the progression of AMD and STGD3, and a deficiency in retinal LCPUFAs and VLCPUFAs has been detected in AMD retinas and STGD3 animal models. This article systematically summarizes the roles of LCPUFAs and VLCPUFAs in AMD and STGD3, and discusses future research directions.
Collapse
Affiliation(s)
- Aihua Liu
- Department of Ophthalmology and Visual Sciences, 65 Mario Capecchi Drive, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Yanhua Lin
- Department of Ophthalmology and Visual Sciences, 65 Mario Capecchi Drive, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Ryan Terry
- Department of Ophthalmology and Visual Sciences, 65 Mario Capecchi Drive, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Kelly Nelson
- Department of Ophthalmology and Visual Sciences, 65 Mario Capecchi Drive, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Paul S Bernstein
- Department of Ophthalmology and Visual Sciences, 65 Mario Capecchi Drive, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| |
Collapse
|
10
|
Molday RS, Zhang K. Defective lipid transport and biosynthesis in recessive and dominant Stargardt macular degeneration. Prog Lipid Res 2010; 49:476-92. [PMID: 20633576 DOI: 10.1016/j.plipres.2010.07.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Stargardt disease is a common inherited macular degeneration characterized by a significant loss in central vision in the first or second decade of life, bilateral atrophic changes in the central retina associated with degeneration of photoreceptors and underlying retinal pigment epithelial cells, and the presence of yellow flecks extending from the macula. Autosomal recessive Stargardt disease, the most common macular dystrophy, is caused by mutations in the gene encoding ABCA4, a photoreceptor ATP binding cassette (ABC) transporter. Biochemical studies together with analysis of abca4 knockout mice and Stargardt patients have implicated ABCA4 as a lipid transporter that facilitates the removal of potentially toxic retinal compounds from photoreceptors following photoexcitation. An autosomal dominant form of Stargardt disease also known as Stargardt-like dystrophy is caused by mutations in a gene encoding ELOVL4, an enzyme that catalyzes the elongation of very long-chain fatty acids in photoreceptors and other tissues. This review focuses on the molecular characterization of ABCA4 and ELOVL4 and their role in photoreceptor cell biology and the pathogenesis of Stargardt disease.
Collapse
Affiliation(s)
- Robert S Molday
- Department of Biochemistry and Molecular Biology, Centre of Macular Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada.
| | | |
Collapse
|
11
|
Brush RS, Tran JTA, Henry KR, McClellan ME, Elliott MH, Mandal MNA. Retinal sphingolipids and their very-long-chain fatty acid-containing species. Invest Ophthalmol Vis Sci 2010; 51:4422-31. [PMID: 20393115 DOI: 10.1167/iovs.09-5134] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Recent evidence suggests that ceramide metabolism plays an important role in retinal photoreceptor cell survival and apoptosis. The purpose of this study was to characterize sphingolipids in the retina with special emphasis on the very-long-chain-containing saturated (VLC-FA) and polyunsaturated (VLC-PUFA) fatty acid-containing species. The VLC-FAs and VLC-PUFAs are synthesized by the ELOVL4 protein, which is involved in human Stargardt's macular dystrophy type 3 (STGD3). METHODS Total lipids were extracted from retina and other tissues, and different sphingolipid classes were isolated and purified using various combinations of liquid- and solid-phase separation. Purified sphingolipids were analyzed by high-performance thin layer chromatography (HPTLC), gas chromatography (GC), and GC-MS (GC-mass spectrometry). RESULTS Nonsialylated sphingolipids (NSLs) comprised approximately 3.5% of total retinal lipids of which 70% was sphingomyelin. Ceramide and glycosylceramides (GCs) constituted<or=1% of total retinal lipids. Gangliosides (GGs), on the other hand, comprised approximately 3.0% of total retinal lipids. Fatty acid analysis of retinal NSLs indicated an abundance of saturated fatty acids, with the presence of VLC-FAs but not of VLC-PUFAs beyond 24 carbons. However, GG had significant levels of unsaturated, polyunsaturated, and VLC-PUFAs. Retinal rod outer segments (ROS) contained approximately 1% each of NSL and GG, and their fatty acid profile was not very different from whole retinal NSL and GG, respectively. CONCLUSIONS Retina has a total of 6% to 7% fatty acids that are N-linked to a sphingosine, which would be 11 to 13 mole % in comparison to phospholipids. The presence of VLC-FAs and VLC-PUFAs in retinal sphingolipids indicates that they may play role in ELOVL4-mediated Stargardt 3.
Collapse
Affiliation(s)
- Richard S Brush
- Department of Ophthalmology, Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | | | | | | | | | | |
Collapse
|
12
|
Role of Stargardt-3 macular dystrophy protein (ELOVL4) in the biosynthesis of very long chain fatty acids. Proc Natl Acad Sci U S A 2008; 105:12843-8. [PMID: 18728184 DOI: 10.1073/pnas.0802607105] [Citation(s) in RCA: 196] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stargardt-like macular dystrophy (STGD3) is a dominantly inherited juvenile macular degeneration that eventually leads to loss of vision. Three independent mutations causing STGD3 have been identified in exon six of a gene named Elongation of very long chain fatty acids 4 (ELOVL4). The ELOVL4 protein was predicted to be involved in fatty acid elongation, although evidence for this and the specific step(s) it may catalyze have remained elusive. Here, using a gain-of-function approach, we provide direct and compelling evidence that ELOVL4 is required for the synthesis of C28 and C30 saturated fatty acids (VLC-FA) and of C28-C38 very long chain polyunsaturated fatty acids (VLC-PUFA), the latter being uniquely expressed in retina, sperm, and brain. Rat neonatal cardiomyocytes and a human retinal epithelium cell line (ARPE-19) were transduced with recombinant adenovirus type 5 carrying mouse Elovl4 and supplemented with 24:0, 20:5n3, or 22:5n3. The 24:0 was elongated to 28:0 and 30:0; 20:5n3 and 22:5n3 were elongated to a series of C28-C38 PUFA. Because retinal degeneration is the only known phenotype in STGD3 disease, we propose that reduced VLC-PUFA in the retinas of these patients may be the cause of photoreceptor cell death.
Collapse
|