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Masson EAY, Serrano J, Leger-Charnay E, Acar N. Cholesterol and oxysterols in retinal neuron-glia interactions: relevance for glaucoma. FRONTIERS IN OPHTHALMOLOGY 2024; 3:1303649. [PMID: 38983043 PMCID: PMC11182186 DOI: 10.3389/fopht.2023.1303649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/04/2023] [Indexed: 07/11/2024]
Abstract
Cholesterol is an essential component of cellular membranes, crucial for maintaining their structural and functional integrity. It is especially important for nervous tissues, including the retina, which rely on high amounts of plasma membranes for the transmission of the nervous signal. While cholesterol is by far the most abundant sterol, the retina also contains cholesterol precursors and metabolites, especially oxysterols, which are bioactive molecules. Cholesterol lack or excess is deleterious and some oxysterols are known for their effect on neuron survival. Cholesterol homeostasis must therefore be maintained. Retinal glial cells, especially Müller cells, the principal glial cells of the vertebrate retina, provide mechanical, nutritional, and metabolic support for the neighboring neurons. Several pieces of evidence indicate that Müller cells are major actors of cholesterol homeostasis in the retina, as it is known for other glial cells in the brain. This process is based on a close cooperation with neurons, and sterols can be signaling molecules participating in glia-neuron interactions. While some implication of cholesterol in age-related macular degeneration is now recognized, based on epidemiological and laboratory data, evidence for its role in glaucoma is still scarce. The association between cholesterolemia and glaucoma is controversial, but experimental data suggest that sterols could take part in the pathological processes. It has been demonstrated that Müller glial cells are implicated in the development of glaucoma through an ambivalent reactive retinal gliosis process. The early steps contribute to maintaining retinal homeostasis and favor the survival of ganglion cells, which are targeted during glaucoma. If gliosis persists, dysregulation of the neuroprotective functions, cytotoxic effects of gliotic Müller cells and disruption of glia-neuron interactions lead to an acceleration of ganglion cell death. Sterols could play a role in the glial cell response to glaucomatous injury. This represents an understudied but attractive topic to better understand glaucoma and conceive novel preventive or curative strategies. The present review describes the current knowledge on i) sterol metabolism in retinal glial cells, ii) the potential role of cholesterol in glaucoma, and iii) the possible relationships between cholesterol and oxysterols, glial cells and glaucoma. Focus is put on glia-neuron interactions.
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Affiliation(s)
- Elodie A Y Masson
- Eye and Nutrition Research Group, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, Dijon, France
| | - Jeanne Serrano
- Eye and Nutrition Research Group, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, Dijon, France
- Sensory Perception, Glia/Neuron Interaction Research Group, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, Dijon, France
| | - Elise Leger-Charnay
- Eye and Nutrition Research Group, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, Dijon, France
| | - Niyazi Acar
- Eye and Nutrition Research Group, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, Dijon, France
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Dias IHK, Shokr H. Oxysterols as Biomarkers of Aging and Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1440:307-336. [PMID: 38036887 DOI: 10.1007/978-3-031-43883-7_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Oxysterols derive from either enzymatic or non-enzymatic oxidation of cholesterol. Even though they are produced as intermediates of bile acid synthesis pathway, they are recognised as bioactive compounds in cellular processes. Therefore, their absence or accumulation have been shown to be associated with disease phenotypes. This chapter discusses the contribution of oxysterol to ageing, age-related diseases such as neurodegeneration and various disorders such as cancer, cardiovascular disease, diabetes, metabolic and ocular disorders. It is clear that oxysterols play a significant role in development and progression of these diseases. As a result, oxysterols are being investigated as suitable markers for disease diagnosis purposes and some drug targets are in development targeting oxysterol pathways. However, further research will be needed to confirm the suitability of these potentials.
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Affiliation(s)
- Irundika H K Dias
- Aston Medical School, College of Health and Life Sciences, Aston University, Birmingham, UK.
| | - Hala Shokr
- Manchester Pharmacy School, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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Olivier E, Rat P. Role of Oxysterols in Ocular Degeneration Mechanisms and Involvement of P2X7 Receptor. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1440:277-292. [PMID: 38036885 DOI: 10.1007/978-3-031-43883-7_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Ocular degeneration, including cataracts, glaucoma, macular degeneration, and diabetic retinopathy, is a major public health challenge, as it affects the quality of life of millions of people worldwide and, in its advanced stages, leads to blindness. Ocular degeneration, although it can affect different parts of the eye, shares common characteristics such as oxysterols and the P2X7 receptor. Indeed, oxysterols, which are cholesterol derivatives, are associated with ocular degeneration pathogenesis and trigger inflammation and cell death pathways. Activation of the P2X7 receptor is also linked to ocular degeneration and triggers the same pathways. In age-related macular degeneration, these two key players have been associated, but further studies are needed to extrapolate this interrelationship to other ocular degenerations.
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Affiliation(s)
| | - Patrice Rat
- Université Paris Cité, CNRS, CiTCoM, Paris, France
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Rojas D, Benachenhou S, Laroui A, Aden AA, Abolghasemi A, Galarneau L, Irakoze TJ, Plantefeve R, Bouhour S, Toupin A, Corbin F, Fink G, Mallet PL, Çaku A. Development and validation of a liquid chromatography-tandem mass spectrometry assay to quantify plasma 24(S)-hydroxycholesterol and 27-hydroxycholesterol: A new approach integrating the concept of ion ratio. J Steroid Biochem Mol Biol 2023; 235:106408. [PMID: 37806531 DOI: 10.1016/j.jsbmb.2023.106408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Accurate quantification of 24(S)-hydroxycholesterol and 27-hydroxycholesterol holds substantial biological significance due to their involvement in pivotal cellular processes, encompassing cholesterol homeostasis, inflammatory responses, neuronal signaling, and their potential as disease biomarkers. The plasma determination of these oxysterols is challenging considering their low concentrations and similarities in terms of empirical formulae, molecular structure, and physicochemical properties across all human endogenous plasma oxysterols. To overcome these sensitivity and specificity issues, we developed and validated a quantification method using liquid chromatography coupled to a tandem mass spectrometry instrument. Validation studies were designed inspired by Clinical and Laboratory Standards Institute (CLSI) C62-A Guidelines. The linearity ranged between 20 and 300 nM for both oxysterols with limits of quantification at 20 nM and 30 nM for 24(S)-OHC and 27-OHC, respectively. Inter-day precision coefficient variations (CV) were lower than 10% for both oxysterols. An optimal separation of 25-OHC was obtained from 24(S)-OHC and 27-OHC with a resolution (Rs) > 1.25. The determination and validation of ion ratios for 24(S)-OHC and 27-OHC enabled another quality check in identifying interferents that could impact the quantification. Our developed and validated LC-MS/MS method allows consistent and reliable quantification of human plasmatic 24(S)-OHC and 27-OHC that is warranted in fundamental and clinical research projects.
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Affiliation(s)
- Daniela Rojas
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Sérine Benachenhou
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Asma Laroui
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Amira Abdourahim Aden
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Armita Abolghasemi
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Luc Galarneau
- The Medical Physics Unit, McGill University Health Center, Montreal, QC, Canada
| | - Taratibu Janvière Irakoze
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Rosalie Plantefeve
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Sophie Bouhour
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Amanda Toupin
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - François Corbin
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Guy Fink
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Pierre-Luc Mallet
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Artuela Çaku
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, Canada.
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El-Darzi N, Mast N, Li Y, Dailey B, Kang M, Rhee DJ, Pikuleva IA. The normalizing effects of the CYP46A1 activator efavirenz on retinal sterol levels and risk factors for glaucoma in Apoj -/- mice. Cell Mol Life Sci 2023; 80:194. [PMID: 37392222 PMCID: PMC10314885 DOI: 10.1007/s00018-023-04848-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/03/2023]
Abstract
Apolipoprotein J (APOJ) is a multifunctional protein with genetic evidence suggesting an association between APOJ polymorphisms and Alzheimer's disease as well as exfoliation glaucoma. Herein we conducted ocular characterizations of Apoj-/- mice and found that their retinal cholesterol levels were decreased and that this genotype had several risk factors for glaucoma: increased intraocular pressure and cup-to-disk ratio and impaired retinal ganglion cell (RGC) function. The latter was not due to RGC degeneration or activation of retinal Muller cells and microglia/macrophages. There was also a decrease in retinal levels of 24-hydroxycholesterol, a suggested neuroprotectant under glaucomatous conditions and a positive allosteric modulator of N-methyl-D-aspartate receptors mediating the light-evoked response of the RGC. Therefore, Apoj-/- mice were treated with low-dose efavirenz, an allosteric activator of CYP46A1 which converts cholesterol into 24-hydroxycholesterol. Efavirenz treatment increased retinal cholesterol and 24-hydroxycholesterol levels, normalized intraocular pressure and cup-to-disk ratio, and rescued in part RGC function. Retinal expression of Abcg1 (a cholesterol efflux transporter), Apoa1 (a constituent of lipoprotein particles), and Scarb1 (a lipoprotein particle receptor) was increased in EVF-treated Apoj-/- mice, indicating increased retinal cholesterol transport on lipoprotein particles. Ocular characterizations of Cyp46a1-/- mice supported the beneficial efavirenz treatment effects via CYP46A1 activation. The data obtained demonstrate an important APOJ role in retinal cholesterol homeostasis and link this apolipoprotein to the glaucoma risk factors and retinal 24-hydroxycholesterol production by CYP46A1. As the CYP46A1 activator efavirenz is an FDA-approved anti-HIV drug, our studies suggest a new therapeutic approach for treatment of glaucomatous conditions.
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Affiliation(s)
- Nicole El-Darzi
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Natalia Mast
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Yong Li
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Brian Dailey
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Min Kang
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Douglas J Rhee
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA.
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Gabrielle PH. Lipid metabolism and retinal diseases. Acta Ophthalmol 2022; 100 Suppl 269:3-43. [PMID: 36117363 DOI: 10.1111/aos.15226] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 07/24/2022] [Indexed: 11/27/2022]
Abstract
PURPOSE The retina has enormous lipids demands and must meet those needs. Retinal lipid homeostasis appears to be based on the symbiosis between neurons, Müller glial cells (MGC), and retinal pigment epithelium (RPE) cells, which can be impacted in several retinal diseases. The current research challenge is to better understand lipid-related mechanisms involved in retinal diseases, such as age-related macular degeneration (AMD) and glaucoma. RESULTS In a first axis, in vitro and focus on Müller glial cell, we aimed to characterize whether the 24S-hydroxycholesterol (24S-OHC), an overexpressed end-product of cholesterol elimination pathway in neural tissue and likely produced by suffering retinal ganglion cells in glaucoma, may modulate MGC membrane organization, such as lipid rafts, to trigger cellular signalling pathways related to retinal gliosis. We have found that lipid composition appears to be a key factor of membrane architecture, especially for lipid raft microdomain formation, in MGC. However, 24S-OHC did not appear to trigger retinal gliosis via the modulation of lipid or protein composition within lipid rafts microdomains. This study provided a better understanding of the complex mechanisms involved in the pathophysiology of glaucoma. On a second clinical ax, we focused on the lipid-related mechanisms involved in the dysfunction of aging RPE and the appearance of drusenoid deposits in AMD. Using the Montrachet population-based study, we intend to report the frequency of reticular pseudodrusen (RPD) and its ocular and systemic risk factors, particularly related to lipid metabolisms, such as plasma lipoprotein levels, carotenoids levels, and lipid-lowering drug intake. Our study showed that RPD was less common in subjects taking lipid-lowering drugs. Lipid-lowering drugs, such as statins, may reduce the risk of RPD through their effect on the production and function of lipoproteins. This observation highlights the potential role of retinal lipid trafficking via lipoproteins between photoreceptors and retinal pigment epithelium cells in RPD formation. Those findings have been complemented with preliminary results on the analysis of plasma fatty acid (FA) profile, a surrogate marker of short-term dietary lipid intake, according to the type of predominant drusenoid deposit, soft drusen or RPD, in age-related maculopathy. CONCLUSION Further research on lipid metabolism in retinal diseases is warranted to better understand the pathophysiology of retinal diseases and develop new promising diagnostic, prognostic, and therapeutic tools for our patients.
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Affiliation(s)
- Pierre-Henry Gabrielle
- Eye and Nutrition Research Group, Center for Taste and Feeding Behaviour, AgroSup Dijon, CNRS, INRAe, The University Bourgogne Franche-Comté, Dijon, France.,Department of Ophthalmology, Dijon University Hospital, Dijon, France.,The Save Sight Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
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7
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Léger-Charnay E, Gambert S, Martine L, Dubus E, Maire MA, Buteau B, Morala T, Gigot V, Bron AM, Bretillon L, Masson EAY. Retinal cholesterol metabolism is perturbated in response to experimental glaucoma in the rat. PLoS One 2022; 17:e0264787. [PMID: 35275950 PMCID: PMC8916636 DOI: 10.1371/journal.pone.0264787] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/16/2022] [Indexed: 01/26/2023] Open
Abstract
Alterations of cholesterol metabolism have been described for many neurodegenerative pathologies, such as Alzheimer's disease in the brain and age-related macular degeneration in the retina. Recent evidence suggests that glaucoma, which is characterized by the progressive death of retinal ganglion cells, could also be associated with disruption of cholesterol homeostasis. In the present study we characterized cholesterol metabolism in a rat model of laser-induced intraocular hypertension, the main risk factor for glaucoma. Sterol levels were measured using gas-chromatography and cholesterol-related gene expression using quantitative RT-PCR at various time-points. As early as 18 hours after the laser procedure, genes implicated in cholesterol biosynthesis and uptake were upregulated (+49% and +100% for HMG-CoA reductase and LDLR genes respectively, vs. naive eyes) while genes involved in efflux were downregulated (-26% and -37% for ApoE and CYP27A1 genes, respectively). Cholesterol and precursor levels were consecutively elevated 3 days post-laser (+14%, +40% and +194% for cholesterol, desmosterol and lathosterol, respectively). Interestingly, counter-regulatory mechanisms were transcriptionally activated following these initial dysregulations, which were associated with the restoration of retinal cholesterol homeostasis, favorable to ganglion cell viability, one month after the laser-induced ocular hypertension. In conclusion, we report here for the first time that ocular hypertension is associated with transient major dynamic changes in retinal cholesterol metabolism.
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Affiliation(s)
- Elise Léger-Charnay
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Ségolène Gambert
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
- Laboratoire de Biochimie Médicale, Plateforme de Biologie Hospitalo-Universitaire, Dijon, France
| | - Lucy Martine
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Elisabeth Dubus
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Marie-Annick Maire
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Bénédicte Buteau
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Tristan Morala
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Vincent Gigot
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Alain M. Bron
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
- Département d’Ophtalmologie, Centre Hospitalo-Universitaire de Dijon, Dijon, France
| | - Lionel Bretillon
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Elodie A. Y. Masson
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
- * E-mail:
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Abstract
Cholesterol is a quantitatively and biologically significant constituent of all mammalian cell membrane, including those that comprise the retina. Retinal cholesterol homeostasis entails the interplay between de novo synthesis, uptake, intraretinal sterol transport, metabolism, and efflux. Defects in these complex processes are associated with several congenital and age-related disorders of the visual system. Herein, we provide an overview of the following topics: (a) cholesterol synthesis in the neural retina; (b) lipoprotein uptake and intraretinal sterol transport in the neural retina and the retinal pigment epithelium (RPE); (c) cholesterol efflux from the neural retina and the RPE; and (d) biology and pathobiology of defects in sterol synthesis and sterol oxidation in the neural retina and the RPE. We focus, in particular, on studies involving animal models of monogenic disorders pertinent to the above topics, as well as in vitro models using biochemical, metabolic, and omic approaches. We also identify current knowledge gaps and opportunities in the field that beg further research in this topic area.
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Affiliation(s)
- Sriganesh Ramachandra Rao
- Departments of Ophthalmology and Biochemistry and Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY, USA
| | - Steven J Fliesler
- Departments of Ophthalmology and Biochemistry and Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY, USA.
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9
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Zhang X, Alhasani RH, Zhou X, Reilly J, Zeng Z, Strang N, Shu X. Oxysterols and retinal degeneration. Br J Pharmacol 2021; 178:3205-3219. [PMID: 33501641 DOI: 10.1111/bph.15391] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 01/13/2021] [Accepted: 01/19/2021] [Indexed: 12/11/2022] Open
Abstract
Retinal degeneration, characterised by the progressive death of retinal neurons, is the most common cause of visual impairment. Oxysterols are the cholesterol derivatives produced via enzymatic and/or free radical oxidation that regulate cholesterol homeostasis in the retina. Preclinical and clinical studies have suggested a connection between oxysterols and retinal degeneration. Here, we summarise early and recent work related to retina oxysterol-producing enzymes and the distribution of oxysterols in the retina. We examine the impact of loss of oxysterol-producing enzymes on retinal pathology and explore the molecular mechanisms associated with the toxic or protective roles of individual oxysterols in different types of retinal degeneration. We conclude that increased efforts to better understand the oxysterol-associated pathophysiology will help in the development of effective retinal degeneration therapies. LINKED ARTICLES: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc.
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Affiliation(s)
- Xun Zhang
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Reem Hasaballah Alhasani
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK.,Department of Biology, Faculty of Applied Science, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Xinzhi Zhou
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK
| | - James Reilly
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Zhihong Zeng
- College of Biological and Environmental Engineering, Changsha University, Changsha, Hunan, China
| | - Niall Strang
- Department of Vision Science, Glasgow Caledonian University, Glasgow, UK
| | - Xinhua Shu
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK.,Department of Vision Science, Glasgow Caledonian University, Glasgow, UK.,School of Basic Medical Sciences, Shaoyang University, Shaoyang, Hunan, China
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10
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Sodero AO. 24S-hydroxycholesterol: Cellular effects and variations in brain diseases. J Neurochem 2020; 157:899-918. [PMID: 33118626 DOI: 10.1111/jnc.15228] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/13/2020] [Accepted: 10/17/2020] [Indexed: 12/12/2022]
Abstract
The adult brain exhibits a characteristic cholesterol homeostasis, with low synthesis rate and active catabolism. Brain cholesterol turnover is possible thanks to the action of the enzyme cytochrome P450 46A1 (CYP46A1) or 24-cholesterol hydroxylase, that transforms cholesterol into 24S-hydroxycholesterol (24S-HC). But before crossing the blood-brain barrier (BBB), this oxysterol, that is the most abundant in the brain, can act locally, affecting the functioning of neurons, astrocytes, oligodendrocytes, and vascular cells. The first part of this review addresses different aspects of 24S-HC production and elimination from the brain. The second part concentrates in the effects of 24S-HC at the cellular level, describing how this oxysterol affects cell viability, amyloid β production, neurotransmission, and transcriptional activity. Finally, the role of 24S-HC in Alzheimer, Huntington and Parkinson diseases, multiple sclerosis and amyotrophic lateral sclerosis, as well as the possibility of using this oxysterol as predictive and/or evolution biomarker in different brain disorders is discussed.
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Affiliation(s)
- Alejandro O Sodero
- Institute of Biomedical Research (BIOMED), Pontifical Catholic University of Argentina (UCA) and National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
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11
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Eye lymphatic defects induced by bone morphogenetic protein 9 deficiency have no functional consequences on intraocular pressure. Sci Rep 2020; 10:16040. [PMID: 32994463 PMCID: PMC7524742 DOI: 10.1038/s41598-020-71877-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 08/18/2020] [Indexed: 11/08/2022] Open
Abstract
Aqueous humor drainage is essential for the regulation of intraocular pressure (IOP), a major risk factor for glaucoma. The Schlemm's canal and the non-conventional uveoscleral pathway are known to drain aqueous humor from the eye anterior chamber. It has recently been reported that lymphatic vessels are involved in this process, and that the Schlemm's canal responds to some lymphatic regulators. We have previously shown a critical role for bone morphogenetic protein 9 (BMP9) in lymphatic vessel maturation and valve formation, with repercussions in drainage efficiency. Here, we imaged eye lymphatic vessels and analyzed the consequences of Bmp9 (Gdf2) gene invalidation. A network of lymphatic vessel hyaluronan receptor 1 (LYVE-1)-positive lymphatic vessels was observed in the corneolimbus and the conjunctiva. In contrast, LYVE-1-positive cells present in the ciliary bodies were belonging to the macrophage lineage. Although enlarged conjunctival lymphatic trunks and a reduced valve number were observed in Bmp9-KO mice, there were no morphological differences in the Schlemm's canal compared to wild type animals. Moreover, there were no functional consequences on IOP in both basal control conditions and after laser-induced ocular hypertonia. Thus, the BMP9-activated signaling pathway does not constitute a wise target for new glaucoma therapeutic strategies.
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12
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Léger-Charnay E, Masson EAY, Morala T, Martine L, Buteau B, Leclere L, Bretillon L, Gambert S. Is 24(S)-hydroxycholesterol a potent modulator of cholesterol metabolism in Müller cells? An in vitro study about neuron to glia communication in the retina. Exp Eye Res 2019; 189:107857. [PMID: 31654618 DOI: 10.1016/j.exer.2019.107857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/12/2019] [Accepted: 10/21/2019] [Indexed: 11/19/2022]
Abstract
Communication between neurons and glia plays a major role in nervous tissue homeostasis. It is thought to participate in tuning cholesterol metabolism to cellular demand, which is a critical issue for neuronal health. Cholesterol is a membrane lipid crucial for nervous tissue functioning, and perturbed regulation of its metabolism has been linked to several neurodegenerative disorders. In the brain, 24(S)-hydroxycholesterol (24S-OHC) is an oxysterol synthesized by neurons to eliminate cholesterol, and 24S-OHC has been shown to regulate cholesterol metabolism in astrocytes, glial cells which provide cholesterol to neurons. In the retina, 24S-OHC is also an elimination product of cholesterol produced by neurons, especially the retinal ganglion cells. However, it is not known whether Müller cells, the major macroglial cells of the retina, play the role of cholesterol provider for retinal neurons and whether they respond to 24S-OHC signaling, similarly to brain glial cells. In the present study, primary cultures of rat Müller cells were treated with 0, 0.5 or 1.5 μM 24S-OHC for 48 hours. The levels of cholesterol, precursors and oxysterols were quantified using gas chromatography coupled to flame-ionization detection or mass spectrometry. In addition, the expression of key genes related to cholesterol metabolism was analyzed using RTq-PCR. Müller cells were shown to express many genes linked to cholesterol metabolism, including genes coding for proteins implicated in cholesterol biosynthesis (HMGCR), cholesterol uptake and export via lipoproteins (LDL-R, SR-BI, ApoE and ABACA1) and regulation of cholesterol metabolism (SREBP2 and LXRβ). Cholesterol and several of its precursors and oxidative products were present. CYP27A1, the main retinal enzyme implicated in cholesterol elimination via oxysterol production, was quantified at low transcript levels but neither of its two typical products were detected in Müller cells. Furthermore, our results demonstrate that 24S-OHC has a strong hypocholesterolemic effect in Müller cells, leading to cholesterol depletion (-37 % at 1.5 μM). This was mediated by a decrease in cholesterol synthesis, as illustrated by reduced levels of cholesterol precursors: desmosterol (-38 % at 1.5 μM) and lathosterol (-84 % at 1.5 μM), and strong downregulation of HMGCR gene expression (2.4 fold decrease at 1.5μM). In addition, LDL-R and SR-BI gene expression were reduced in response to 24S-OHC treatment (2 fold and 1.6 fold at 1.5 μM, respectively), suggesting diminished lipoprotein uptake by the cells. On the contrary, there was a dramatic overexpression of ABCA1 transporter (10 fold increase at 1.5 μM), probably mediating an increase in cholesterol efflux. Finally, 24S-OHC induced a small but significant upregulation of the CYP27A1 gene. These data indicate that Müller cells possess the necessary cholesterol metabolism machinery and that they are able to sharply adjust their cholesterol metabolism in response to 24S-OHC, a signal molecule of neuronal cholesterol status. This suggests that Müller cells could be major players of cholesterol homeostasis in the retina via neuron-glia crosstalk.
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Affiliation(s)
- Elise Léger-Charnay
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Elodie A Y Masson
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Tristan Morala
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Lucy Martine
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Bénédicte Buteau
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Laurent Leclere
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Lionel Bretillon
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Ségolène Gambert
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France; Laboratoire de Biochimie Médicale, Plateforme de Biologie Hospitalo-Universitaire, F-21000, Dijon, France.
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13
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Species Differences in the Nutrition of Retinal Ganglion Cells among Mammals Frequently Used as Animal Models. Cells 2019; 8:cells8101254. [PMID: 31615137 PMCID: PMC6829614 DOI: 10.3390/cells8101254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 09/26/2019] [Accepted: 10/13/2019] [Indexed: 12/23/2022] Open
Abstract
The diffusion rate for proper nutrition of the inner retina depends mainly on four factors which are discussed in this review: 1. The diffusion distance between blood and retinal ganglion cells shows morphological variants in different mammalian species, namely a choroidal nutrition type, a retinal nutrition type, and a mixture of both types. 2. Low oxygen concentration levels in the inner retina force the diffusion of oxygen especially in the choroidal nutrition type. Other nutrients might be supplied by surrounding cells, mainly Müller cells. 3. Diffusion in the eye is influenced by the intraocular pressure, which is vital for the retinal ganglion cells but might also influence their proper function. Again, the nutrition types established might explain the differences in normal intraocular pressure levels among different species. 4. Temperature is a critical feature in the eye which has to be buffered to avoid neuronal damage. The most effective buffer system is the increased blood turnover in the choroid which has to be established in all species.
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14
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Ishikawa M, Yoshitomi T, Covey DF, Zorumski CF, Izumi Y. Neurosteroids and oxysterols as potential therapeutic agents for glaucoma and Alzheimer's disease. ACTA ACUST UNITED AC 2018; 8:344-359. [PMID: 30774720 DOI: 10.4172/neuropsychiatry.1000356] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glaucoma is one of the most frequent causes of visual impairment worldwide and involves selective damage to retinal ganglion cells (RGCs) resulting in degeneration of neural pathways connecting retina to visual cortex. It is of interest that similarities in pathological changes have been described in Alzheimer's disease (AD), the most common cause of progressive memory loss and dementia in older people. Accumulation of amyloid-beta (Abeta) and hyperphosphorylated tau is thought to contribute to apoptotic neuronal death in Alzheimer's disease, and similar changes have been linked to apoptotic RGC death in glaucoma. Both glaucoma and Alzheimer's disease also suffer from a lack of effective treatments prompting a search for novel therapeutic interventions. Neurosteroids (NSs) (including oxysterols) are endogenous molecules synthesized in the nervous system from cholesterol that can modulate glutamate and GABA receptors, the primary mediators of fast excitatory and inhibitory neurotransmission in the brain, respectively. Because changes in the glutamate and GABA neurotransmitter systems contribute to the pathogenesis of AD and glaucoma, NSs are possible therapeutic targets for these disorders. In this review, we present recent evidence supporting pathological links between Alzheimer's disease and glaucoma, and focus on the possible role of NSs in these diseases and how NSs might be developed for therapeutic purposes.
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Affiliation(s)
- Makoto Ishikawa
- Department of Ophthalmology, Akita University Graduate School of Medicine, Akita, Japan
| | - Takeshi Yoshitomi
- Department of Ophthalmology, Akita University Graduate School of Medicine, Akita, Japan
| | - Douglas F Covey
- Department of Developmental Biology, Akita University Graduate School of Medicine, Akita, Japan.,Taylor Family Institute for Innovative Psychiatric Research, Akita University Graduate School of Medicine, Akita, Japan
| | - Charles F Zorumski
- Taylor Family Institute for Innovative Psychiatric Research, Akita University Graduate School of Medicine, Akita, Japan.,Center for Brain Research in Mood Disorders, Akita University Graduate School of Medicine, Akita, Japan.,Department of Psychiatry, Washington University School of Medicine, St. Louis, M.O, USA
| | - Yukitoshi Izumi
- Taylor Family Institute for Innovative Psychiatric Research, Akita University Graduate School of Medicine, Akita, Japan.,Center for Brain Research in Mood Disorders, Akita University Graduate School of Medicine, Akita, Japan.,Department of Psychiatry, Washington University School of Medicine, St. Louis, M.O, USA
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15
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Whitfield M, Guiton R, Rispal J, Acar N, Kocer A, Drevet JR, Saez F. Dyslipidemia alters sperm maturation and capacitation in LXR-null mice. Reproduction 2017; 154:827-842. [DOI: 10.1530/rep-17-0467] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/26/2017] [Accepted: 10/02/2017] [Indexed: 12/20/2022]
Abstract
Lipid metabolism disorders (dyslipidemia) are causes of male infertility, but little is known about their impact on male gametes when considering post-testicular maturation events, given that studies concentrate most often on endocrine dysfunctions and testicular consequences. In this study, three-month-old wild-type (wt) and Liver-X-Receptors knock out (Lxrα;β−/−) males were fed four weeks with a control or a lipid-enriched diet containing 1.25% cholesterol (high cholesterol diet (HCD)). The HCD triggered a dyslipidemia leading to sperm post-testicular alterations and infertility. Sperm lipids were analyzed by LC–MS and those fromLxrα;β−/−males fed the HCD showed higher chol/PL and PC/PE ratios compared towt-HCD (P < 0.05) and lower oxysterol contents compared to wt (P < 0.05) orLxrα;β−/−(P < 0.05). These modifications impaired membrane-associated events triggering the tyrosine phosphorylation normally occurring during the capacitation process, as shown by phosphotyrosine Western blots. Using flow cytometry, we showed that a smaller subpopulation of spermatozoa fromLxrα;β−/−-HCD males could raise their membrane fluidity during capacitation (P < 0.05 vswtorwt-HCD) as well as their intracellular calcium concentration (P < 0.05 vsLxrα;β−/−andP < 0.001 vswt). The accumulation of the major sperm calcium efflux pump (PMCA4) was decreased inLxrα;β−/−males fed the HCD (P < 0.05 vsLxrα;β−/−andP < 0.001 vswt). This study is the first showing an impact of dyslipidemia on post-testicular sperm maturation with consequences on the capacitation signaling cascade. It may lead to the identification of fertility prognostic markers in this pathophysiological situation, which could help clinicians to better understand male infertilities which are thus far classified as idiopathic.
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16
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Cholesterol metabolism and glaucoma: Modulation of Muller cell membrane organization by 24S-hydroxycholesterol. Chem Phys Lipids 2017; 207:179-191. [DOI: 10.1016/j.chemphyslip.2017.05.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/19/2017] [Accepted: 05/23/2017] [Indexed: 02/04/2023]
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17
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24(S)-Hydroxycholesterol protects the ex vivo rat retina from injury by elevated hydrostatic pressure. Sci Rep 2016; 6:33886. [PMID: 27653972 PMCID: PMC5032171 DOI: 10.1038/srep33886] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 09/05/2016] [Indexed: 01/01/2023] Open
Abstract
In the central nervous system, 24(S)-hydroxycholesterol (24(S)-HC) is an oxysterol synthesized from cholesterol by cholesterol 24-hydroxylase (CYP46A1) encoded by the cyp46a1 gene. In the present study using a rat ex vivo glaucoma model, we found that retinal 24(S)-HC synthesis is facilitated by pressure elevation. Moreover, we found that 24(S)-HC is neuroprotective against pressure mediated retinal degeneration. Quantitative real-time RT-PCR, ELISA, and immunohistochemistry revealed that elevated pressure facilitated the expression of cyp46a1 and CYP46A1. Immunohistochemically, the enhanced expression of CYP46A1 was mainly observed in retinal ganglion cells (RGC). LC-MS/MS revealed that 24(S)-HC levels increased in a pressure-dependent manner. Axonal injury and apoptotic RGC death induced by 75 mmHg high pressure was ameliorated by exogenously administered 1 μM 24(S)-HC. In contrast, voriconazole, a CYP46A1 inhibitor, was severely toxic even at normobaric pressure. Under normobaric conditions, 30 μM 24(S)-HC was required to prevent the voriconazole-mediated retinal damage. Taken together, our findings indicate that 24(S)-HC is facilitated by elevated pressure and plays a neuroprotective role under glaucomatous conditions, while voriconazole, an antifungal drug, is retinotoxic. 24(S)-HC and related compounds may serve as potential therapeutic targets for protecting glaucomatous eyes from pressure-induced injuries.
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18
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Moutinho M, Nunes MJ, Rodrigues E. Cholesterol 24-hydroxylase: Brain cholesterol metabolism and beyond. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1911-1920. [PMID: 27663182 DOI: 10.1016/j.bbalip.2016.09.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/05/2016] [Accepted: 09/16/2016] [Indexed: 01/19/2023]
Abstract
Dysfunctions in brain cholesterol homeostasis have been extensively related to brain disorders. The major elimination pathway of brain cholesterol is its hydroxylation into 24 (S)-hydroxycholesterol by the cholesterol 24-hydroxylase (CYP46A1). Interestingly, there seems to be an association between CYP46A1 and high-order brain functions, in a sense that increased expression of this hydroxylase improves cognition, while a reduction leads to a poor cognitive performance. Moreover, increasing amount of epidemiological, biochemical and molecular evidence, suggests that CYP46A1 has a role in the pathogenesis or progression of neurodegenerative disorders, in which up-regulation of this enzyme is clearly beneficial. However, the mechanisms underlying these effects are poorly understood, which highlights the importance of studies that further explore the role of CYP46A1 in the central nervous system. In this review we summarize the major findings regarding CYP46A1, and highlight the several recently described pathways modulated by this enzyme from a physiological and pathological perspective, which might account for novel therapeutic strategies for neurodegenerative disorders.
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Affiliation(s)
- Miguel Moutinho
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Portugal, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Maria João Nunes
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Portugal, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Elsa Rodrigues
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Portugal, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.
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19
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Griffiths WJ, Abdel-Khalik J, Crick PJ, Yutuc E, Wang Y. New methods for analysis of oxysterols and related compounds by LC-MS. J Steroid Biochem Mol Biol 2016; 162:4-26. [PMID: 26639636 DOI: 10.1016/j.jsbmb.2015.11.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 12/21/2022]
Abstract
Oxysterols are oxygenated forms of cholesterol or its precursors. They are formed enzymatically and via reactive oxygen species. Oxysterols are intermediates in bile acid and steroid hormone biosynthetic pathways and are also bioactive molecules in their own right, being ligands to nuclear receptors and also regulators of the processing of steroid regulatory element-binding proteins (SREBPs) to their active forms as transcription factors regulating cholesterol and fatty acid biosynthesis. Oxysterols are implicated in the pathogenesis of multiple disease states ranging from atherosclerosis and cancer to multiple sclerosis and other neurodegenerative diseases including Alzheimer's and Parkinson's disease. Analysis of oxysterols is challenging on account of their low abundance in biological systems in comparison to cholesterol, and due to the propensity of cholesterol to undergo oxidation in air to generate oxysterols with the same structures as those present endogenously. In this article we review the mass spectrometry-based methods for oxysterol analysis paying particular attention to analysis by liquid chromatography-mass spectrometry (LC-MS).
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Affiliation(s)
- William J Griffiths
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
| | - Jonas Abdel-Khalik
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Peter J Crick
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Eylan Yutuc
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Yuqin Wang
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
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20
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Gu R, Zhou M, Jiang C, Yu J, Xu G. Elevated concentration of cytokines in aqueous in post-vitrectomy eyes. Clin Exp Ophthalmol 2015; 44:128-34. [PMID: 26317489 DOI: 10.1111/ceo.12638] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 08/16/2015] [Indexed: 11/29/2022]
Affiliation(s)
- RuiPing Gu
- Department of Ophthalmology and Shanghai Key Laboratory of Visual Impairment and Restoration, Eye and ENT Hospital, Shanghai Medical College; Fudan University; Shanghai China
| | - Min Zhou
- Department of Ophthalmology and Shanghai Key Laboratory of Visual Impairment and Restoration, Eye and ENT Hospital, Shanghai Medical College; Fudan University; Shanghai China
| | - ChunHui Jiang
- Department of Ophthalmology and Shanghai Key Laboratory of Visual Impairment and Restoration, Eye and ENT Hospital, Shanghai Medical College; Fudan University; Shanghai China
- Department of Ophthalmology; No. 5 People's Hospital of Shanghai; Shanghai China
| | - Jian Yu
- Department of Ophthalmology and Shanghai Key Laboratory of Visual Impairment and Restoration, Eye and ENT Hospital, Shanghai Medical College; Fudan University; Shanghai China
| | - GeZhi Xu
- Department of Ophthalmology and Shanghai Key Laboratory of Visual Impairment and Restoration, Eye and ENT Hospital, Shanghai Medical College; Fudan University; Shanghai China
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21
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van Gijsel-Bonnello M, Acar N, Molino Y, Bretillon L, Khrestchatisky M, de Reggi M, Gharib B. Pantethine Alters Lipid Composition and Cholesterol Content of Membrane Rafts, With Down-Regulation of CXCL12-Induced T Cell Migration. J Cell Physiol 2015; 230:2415-25. [PMID: 25728249 DOI: 10.1002/jcp.24971] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 02/20/2015] [Indexed: 11/08/2022]
Abstract
Pantethine, a natural low-molecular-weight thiol, shows a broad activity in a large range of essential cellular pathways. It has been long known as a hypolipidemic and hypocholesterolemic agent. We have recently shown that it exerts a neuroprotective action in mouse models of cerebral malaria and Parkinson's disease through multiple mechanisms. In the present study, we looked at its effects on membrane lipid rafts that serve as platforms for molecules engaged in cell activity, therefore providing a target against inappropriate cell response leading to a chronic inflammation. We found that pantethine-treated cells showed a significant change in raft fatty acid composition and cholesterol content, with ultimate downregulation of cell adhesion, CXCL12-driven chemotaxis, and transendothelial migration of various T cell types, including human Jurkat cell line and circulating effector T cells. The mechanisms involved include the alteration of the following: (i) CXCL12 binding to its target cells; (ii) membrane dynamics of CXCR4 and CXCR7, the two CXCL12 receptors; and (iii) cell redox status, a crucial determinant in the regulation of the chemokine system. In addition, we considered the linker for activation of T cells molecule to show that pantethine effects were associated with the displacement from the rafts of the acylated signaling molecules which had their palmitoylation level reduced.. In conclusion, the results presented here, together with previously published findings, indicate that due to its pleiotropic action, pantethine can downregulate the multifaceted process leading to pathogenic T cell activation and migration.
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Affiliation(s)
| | - Niyazi Acar
- INRA UMR 6265, University of Burgundy, Dijon, France
| | - Yves Molino
- Vect-Horus, 51 Boulevard Pierre Dramard, Marseille, France
| | | | | | - Max de Reggi
- Aix Marseille University, CNRS, NICN UMR 7259, Marseille, France
| | - Bouchra Gharib
- Aix Marseille University, CNRS, NICN UMR 7259, Marseille, France
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22
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Thierry M, Pasquis B, Buteau B, Fourgeux C, Dembele D, Leclere L, Gambert-Nicot S, Acar N, Bron AM, Creuzot-Garcher CP, Bretillon L. Early adaptive response of the retina to a pro-diabetogenic diet: Impairment of cone response and gene expression changes in high-fructose fed rats. Exp Eye Res 2015; 135:37-46. [PMID: 25912194 DOI: 10.1016/j.exer.2015.04.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 04/17/2015] [Accepted: 04/21/2015] [Indexed: 11/17/2022]
Abstract
The lack of plasticity of neurons to respond to dietary changes, such as high fat and high fructose diets, by modulating gene and protein expression has been associated with functional and behavioral impairments that can have detrimental consequences. The inhibition of high fat-induced rewiring of hypothalamic neurons induced obesity. Feeding rodents with high fructose is a recognized and widely used model to trigger obesity and metabolic syndrome. However the adaptive response of the retina to short term feeding with high fructose is poorly documented. We therefore aimed to characterize both the functional and gene expression changes in the neurosensory retina of Brown Norway rats fed during 3 and 8 days with a 60%-rich fructose diet (n = 16 per diet and per time point). Glucose, insulin, leptin, triacylglycerols, total cholesterol, HDL-cholesterol, LDL-cholesterol and fructosamine were quantified in plasma (n = 8 in each group). Functionality of the inner retina was studied using scotopic single flash electroretinography (n = 8 in each group) and the individual response of rod and cone photoreceptors was determined using 8.02 Hz Flicker electroretinography (n = 8 in each group). Analysis of gene expression in the neurosensory retina was performed by Affymetrix genechips, and confirmed by RT-qPCR (n = 6 in each group). Elevated glycemia (+13%), insulinemia (+83%), and leptinemia (+172%) was observed after 8 days of fructose feeding. The cone photoreceptor response was altered at day 8 in high fructose fed rats (Δ = 0.5 log unit of light stimulus intensity). Affymetrix analysis of gene expression highlighted significant modulation of the pathways of eIF2 signaling and endoplasmic reticulum stress, regulation of eIF4 and p70S6K signaling, as well as mTOR signaling and mitochondrial dysfunction. RT-qPCR analysis confirmed the down regulation of Crystallins, Npy, Nid1 and Optc genes after 3 days of fructose feeding, and up regulation of End2. Meanwhile, a trend towards an increased expression of αA- and αB-crystallin proteins was observed at day 8. Our results are consistent with early alterations of the functioning and gene expression in the retina in a pro diabetogenic environment.
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Affiliation(s)
- Magalie Thierry
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Bruno Pasquis
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Bénédicte Buteau
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Cynthia Fourgeux
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Doulaye Dembele
- INSERM, UMR964 Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), F-67404 Illkirch, France; CNRS, UMR7104 Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), F-67404 Illkirch, France; Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), F-67404 Illkirch, France; IGBMC, Microarray and Sequencing Platform, F-67404 Illkirch, France
| | - Laurent Leclere
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Ségolène Gambert-Nicot
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; University Hospital, Department of Clinical Chemistry, F-21000 Dijon, France
| | - Niyazi Acar
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Alain M Bron
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; University Hospital, Department of Ophthalmology, F-21000 Dijon, France
| | - Catherine P Creuzot-Garcher
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; University Hospital, Department of Ophthalmology, F-21000 Dijon, France
| | - Lionel Bretillon
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Eye and Nutrition Research Group, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.
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Zarrouk A, Hammami M, Moreau T, Lizard G. Accumulation of 24S-hydroxycholesterol in neuronal SK-N-BE cells treated with hexacosanoic acid (C26:0): Argument in favor of 24S-hydroxycholesterol as a potential biomarker of neurolipotoxicity. Rev Neurol (Paris) 2015; 171:125-9. [DOI: 10.1016/j.neurol.2014.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 08/04/2014] [Accepted: 10/17/2014] [Indexed: 11/16/2022]
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Ishikawa M, Yoshitomi T, Zorumski CF, Izumi Y. Neurosteroids are endogenous neuroprotectants in an ex vivo glaucoma model. Invest Ophthalmol Vis Sci 2014; 55:8531-41. [PMID: 25406290 DOI: 10.1167/iovs.14-15624] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
PURPOSE Allopregnanolone is a neurosteroid and powerful modulator of neuronal excitability. The neuroprotective effects of allopregnanolone involve potentiation of γ-aminobutyric acid (GABA) inhibitory responses. Although glutamate excitotoxicity contributes to ganglion cell death in glaucoma, the role of GABA in glaucoma remains uncertain. The aim of this study was to determine whether allopregnanolone synthesis is induced by high pressure in the retina and whether allopregnanolone modulates pressure-mediated toxicity. METHODS Ex vivo rat retinas were exposed to hydrostatic pressure (10, 35, and 75 mm Hg) for 24 hours. Endogenous allopregnanolone production was determined by liquid chromatography and tandem mass spectrometry (LC-MS/MS) and immunochemistry. We also examined the effects of allopregnanolone, finasteride, and dutasteride (inhibitors of 5α-reductase), picrotoxin (a GABA(A) receptor antagonist), and D-2-amino-5-phosphonovalerate (APV, a broad-spectrum N-methyl-D-aspartate receptor [NMDAR] antagonist). RESULTS Pressure loading at 75 mm Hg significantly increased allopregnanolone levels as measured by LC-MS/MS. Elevated hydrostatic pressure also increased neurosteroid immunofluorescence, especially in the ganglion cell layer and inner nuclear layers. Staining was negligible at lower pressures. Enhanced allopregnanolone levels and immunostaining were substantially blocked by finasteride, but more effectively inhibited by dutasteride and APV. Administration of exogenous allopregnanolone suppressed pressure-induced axonal swelling in a concentration-dependent manner, while picrotoxin overcame these neuroprotective effects. CONCLUSIONS These results indicate that the synthesis of allopregnanolone is enhanced mainly via NMDARs in the pressure-loaded retina, and that allopregnanolone diminishes pressure-mediated retinal degeneration via GABAA receptors. Allopregnanolone and other related neurosteroids may serve as potential novel therapeutic targets for the prevention of pressure-induced retinal damage in glaucoma.
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Affiliation(s)
- Makoto Ishikawa
- Department of Ophthalmology, Akita Graduate University School of Medicine, Akita, Japan
| | - Takeshi Yoshitomi
- Department of Ophthalmology, Akita Graduate University School of Medicine, Akita, Japan
| | - Charles F Zorumski
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, United States Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Yukitoshi Izumi
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, United States Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri, United States
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Fourgeux C, Martine L, Acar N, Bron AM, Creuzot-Garcher CP, Bretillon L. In vivo consequences of cholesterol-24S-hydroxylase (CYP46A1) inhibition by voriconazole on cholesterol homeostasis and function in the rat retina. Biochem Biophys Res Commun 2014; 446:775-81. [DOI: 10.1016/j.bbrc.2014.01.118] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 01/23/2014] [Indexed: 01/06/2023]
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