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Shibuya T, Sato A, Nishimoto-Kusunose S, Yoshizawa K, Higashi T. Further evidence for blood-to-brain influx of unconjugated bile acids by passive diffusion: Determination of their brain-to-serum concentration ratios in rats by LC/MS/MS. Steroids 2024; 204:109397. [PMID: 38508483 DOI: 10.1016/j.steroids.2024.109397] [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: 01/28/2024] [Revised: 02/28/2024] [Accepted: 03/17/2024] [Indexed: 03/22/2024]
Abstract
Bile acids (BAs) reside in the brain and are probably involved in some neurological disorders. The view that most of unconjugated BAs in the brain are derived across the blood-brain barrier from the periphery by passive diffusion depending on their hydrophobicity is currently dominant, but some studies have made conflicting claims. In this study, the correlation analysis between the rat brain and serum levels of unconjugated BAs with a wider range of hydrophobicity was conducted to obtain further evidence about the blood-to-brain influx of unconjugated BAs by passive diffusion. We first developed the precise, accurate and matrix effect-free LC/ESI-MS/MS methods for quantifying eight major unconjugated BAs in the rat brain and serum. Derivatization was employed for increasing the assay sensitivity and specificity. The analysis using these methods reproduced the strong positive correlations between the brain and serum levels, and significant higher concentrations in the serum than in the brain for all the unconjugated BAs. The BA with the higher logPow (hydrophobicity) had the higher brain-to-serum concentration ratio (mono- > di- > trihydroxy BAs). Furthermore, the hydrophobicity was considered as the stronger factor for the blood-to-brain influx of the BAs than the serum protein binding ratio. Thus, this study provided further evidence supporting that passive diffusion is the major mechanism for the blood-to-brain influx of the unconjugated BAs.
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Affiliation(s)
- Toma Shibuya
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Anri Sato
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Shoich Nishimoto-Kusunose
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Kazumi Yoshizawa
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Tatsuya Higashi
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
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2
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Spinedi M, Clark C, Zullo L, Kerksiek A, Pistis G, Castelao E, von Gunten A, Preisig M, Lütjohann D, Popp J. Cholesterol-metabolism, plant sterols, and long-term cognitive decline in older people - Effects of sex and APOEe4. iScience 2024; 27:109013. [PMID: 38327787 PMCID: PMC10847741 DOI: 10.1016/j.isci.2024.109013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/07/2023] [Accepted: 01/22/2024] [Indexed: 02/09/2024] Open
Abstract
Neurodegenerative, vascular, and dementia diseases are linked to dysregulations in cholesterol metabolism. Dietary plant sterols, or phytosterols, may interfere to neurodegeneration and cognitive decline, and have cholesterol-lowering, anti-inflammatory, and antioxidant qualities. Here, we investigated the potential associations between circulating cholesterol precursors and metabolites, triglycerides, and phytosterols with cognitive decline in older people by performing multivariate analysis on 246 participants engaged in a population-based prospective study. In our analysis we considered the potential effect of sex and APOEe4. We reveal particular dysregulations of diet-derived phytosterols and endogenous cholesterol synthesis and metabolism, and their variations over time linked to cognitive decline in the general population. These results are significant to the development of interventions to avoid cognitive decline in older adults and suggest that levels of circulating sterols should be taken into account when evaluating risk.
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Affiliation(s)
- Matteo Spinedi
- University Hospital of Psychiatry and University of Zürich, Zürich, Switzerland
| | - Christopher Clark
- University Hospital of Psychiatry and University of Zürich, Zürich, Switzerland
| | - Leonardo Zullo
- Service of Old Age Psychiatry, Department of Psychiatry, University Hospital of Lausanne, Lausanne, Switzerland
| | - Anja Kerksiek
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Giorgio Pistis
- Psychiatric Epidemiology and Psychopathology Research Center, Department of Psychiatry, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Enrique Castelao
- Psychiatric Epidemiology and Psychopathology Research Center, Department of Psychiatry, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Armin von Gunten
- Service of Old Age Psychiatry, Department of Psychiatry, University Hospital of Lausanne, Lausanne, Switzerland
| | - Martin Preisig
- Psychiatric Epidemiology and Psychopathology Research Center, Department of Psychiatry, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Julius Popp
- University Hospital of Psychiatry and University of Zürich, Zürich, Switzerland
- Service of Old Age Psychiatry, Department of Psychiatry, University Hospital of Lausanne, Lausanne, Switzerland
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3
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Goikolea J, Latorre-Leal M, Tsagkogianni C, Pikkupeura S, Gulyas B, Cedazo-Minguez A, Loera-Valencia R, Björkhem I, Rodriguez Rodriguez P, Maioli S. Different effects of CYP27A1 and CYP7B1 on cognitive function: Two mouse models in comparison. J Steroid Biochem Mol Biol 2023; 234:106387. [PMID: 37648096 DOI: 10.1016/j.jsbmb.2023.106387] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/27/2023] [Indexed: 09/01/2023]
Abstract
The oxysterol 27-hydroxycholesterol (27OHC) is produced by the enzyme sterol 27-hydroxylase (Cyp27A1) and is mainly catabolized to 7α-Hydroxy-3-oxo-4-cholestenoic acid (7-HOCA) by the enzyme cytochrome P-450 oxysterol 7α-hydroxylase (Cyp7B1). 27OHC is mostly produced in the liver and can reach the brain by crossing the blood-brain barrier. A large body of evidence shows that CYP27A1 overexpression and high levels of 27OHC have a detrimental effect on the brain, causing cognitive and synaptic dysfunction together with a decrease in glucose uptake in mice. In this work, we analyzed two mouse models with high levels of 27OHC: Cyp7B1 knock-out mice and CYP27A1 overexpressing mice. Despite the accumulation of 27OHC in both models, Cyp7B1 knock-out mice maintained intact learning and memory capacities, neuronal morphology, and brain glucose uptake over time. Neurons treated with the Cyp7B1 metabolite 7-HOCA did not show changes in synaptic genes and 27OHC-treated Cyp7B1 knock-out neurons could not counteract 27OHC detrimental effects. This suggests that 7-HOCA and Cyp7B1 deletion in neurons do not mediate the neuroprotective effects observed in Cyp7B1 knock-out animals. RNA-seq of neuronal nuclei sorted from Cyp7B1 knock-out brains revealed upregulation of genes likely to confer neuroprotection to these animals. Differently from Cyp7B1 knock-out mice, transcriptomic data from CYP27A1 overexpressing neurons showed significant downregulation of genes associated with synaptic function and several metabolic processes. Our results suggest that the differences observed in the two models may be mediated by the higher levels of Cyp7B1 substrates such as 25-hydroxycholesterol and 3β-Adiol in the knock-out mice and that CYP27A1 overexpressing mice may be a more suitable model for studying 27-OHC-specific signaling. We believe that future studies on Cyp7B1 and Cyp27A1 will contribute to a better understanding of the pathogenic mechanisms of neurodegenerative diseases like Alzheimer's disease and may lead to potential new therapeutic approaches.
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Affiliation(s)
- Julen Goikolea
- Karolinska Institutet, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Stockholm, Sweden
| | - Maria Latorre-Leal
- Karolinska Institutet, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Stockholm, Sweden
| | - Christina Tsagkogianni
- Karolinska Institutet, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Stockholm, Sweden
| | - Sonja Pikkupeura
- Karolinska Institutet, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Stockholm, Sweden
| | - Balazs Gulyas
- Karolinska Institutet, Department of Clinical Neuroscience, Stockholm, Sweden
| | - Angel Cedazo-Minguez
- Karolinska Institutet, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Stockholm, Sweden
| | - Raul Loera-Valencia
- Karolinska Institutet, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Stockholm, Sweden; Tecnologico de Monterrey, School of Medicine and Health Sciences, Chihuahua, Mexico
| | - Ingemar Björkhem
- Karolinska Institutet, Department of Laboratory Medicine, Huddinge, Sweden
| | - Patricia Rodriguez Rodriguez
- Karolinska Institutet, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Stockholm, Sweden
| | - Silvia Maioli
- Karolinska Institutet, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Stockholm, Sweden.
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Mehramiz M, Porter T, O’Brien EK, Rainey-Smith SR, Laws SM. A Potential Role for Sirtuin-1 in Alzheimer's Disease: Reviewing the Biological and Environmental Evidence. J Alzheimers Dis Rep 2023; 7:823-843. [PMID: 37662612 PMCID: PMC10473168 DOI: 10.3233/adr-220088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 07/08/2023] [Indexed: 09/05/2023] Open
Abstract
Sirtuin-1 (Sirt1), encoded by the SIRT1 gene, is a conserved Nicotinamide adenine dinucleotide (NAD+) dependent deacetylase enzyme, considered as the master regulator of metabolism in humans. Sirt1 contributes to a wide range of biological pathways via several mechanisms influenced by lifestyle, such as diet and exercise. The importance of a healthy lifestyle is of relevance to highly prevalent modern chronic diseases, such as Alzheimer's disease (AD). There is growing evidence at multiple levels for a role of Sirt1/SIRT1 in AD pathological mechanisms. As such, this review will explore the relevance of Sirt1 to AD pathological mechanisms, by describing the involvement of Sirt1/SIRT1 in the development of AD pathological hallmarks, through its impact on the metabolism of amyloid-β and degradation of phosphorylated tau. We then explore the involvement of Sirt1/SIRT1 across different AD-relevant biological processes, including cholesterol metabolism, inflammation, circadian rhythm, and gut microbiome, before discussing the interplay between Sirt1 and AD-related lifestyle factors, such as diet, physical activity, and smoking, as well as depression, a common comorbidity. Genome-wide association studies have explored potential associations between SIRT1 and AD, as well as AD risk factors and co-morbidities. We summarize this evidence at the genetic level to highlight links between SIRT1 and AD, particularly associations with AD-related risk factors, such as heart disease. Finally, we review the current literature of potential interactions between SIRT1 genetic variants and lifestyle factors and how this evidence supports the need for further research to determine the relevance of these interactions with respect to AD and dementia.
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Affiliation(s)
- Mehrane Mehramiz
- Centre for Precision Health, Edith Cowan University, Joondalup, Western Australia, Australia
- Collaborative Genomics and Translation Group, Edith Cowan University, Joondalup, Western Australia, Australia
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Tenielle Porter
- Centre for Precision Health, Edith Cowan University, Joondalup, Western Australia, Australia
- Collaborative Genomics and Translation Group, Edith Cowan University, Joondalup, Western Australia, Australia
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
- Curtin Medical School, Curtin University, Bentley, Western Australia, Australia
| | - Eleanor K. O’Brien
- Centre for Precision Health, Edith Cowan University, Joondalup, Western Australia, Australia
- Collaborative Genomics and Translation Group, Edith Cowan University, Joondalup, Western Australia, Australia
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Stephanie R. Rainey-Smith
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
- Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- School of Psychological Science, University of Western Australia, Crawley, Western Australia, Australia
| | - Simon M. Laws
- Centre for Precision Health, Edith Cowan University, Joondalup, Western Australia, Australia
- Collaborative Genomics and Translation Group, Edith Cowan University, Joondalup, Western Australia, Australia
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
- Curtin Medical School, Curtin University, Bentley, Western Australia, Australia
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5
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Nazeri Z, Mohammadzadeh G, Rashidi M, Azizdoost S, Cheraghzadeh M, Kheirollah A. 24-Hydroxycholesterol Moderates the Effects of Amyloid-β on Expression of HMG-CoA Reductase and ABCA1 Proteins in Mouse Astrocytes. Adv Biomed Res 2023; 12:167. [PMID: 37564436 PMCID: PMC10410428 DOI: 10.4103/abr.abr_245_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 10/21/2022] [Accepted: 11/13/2022] [Indexed: 08/12/2023] Open
Abstract
Background Elevated brain cholesterol increases the risk of Alzheimer's disease. Production of 24-hydroxycholesterol (24s-OHC) by neurons prevents cholesterol accumulation in the brain. In this study, we investigated the effect of 24s-OHC on the HMG-COA reductase and ABCA1 which are involved in the brain cholesterol homeostasis with or without β-amyloid in astrocytes. Methods and Materials Astrocytes were treated with 24s-OHC with or without Aβ. Western blot and real-time polymerase chain reaction were done to detect protein and gene expression of β-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) and ABCA1, respectively. Cholesterol release was determined using a quantitation kit. Results Protein levels of HMGCR and ABCA1 were significantly increased by Aβ; however, the 24s-OHC was able to restore their levels and diminish the effect of amyloid-β. Aβ did not have a significant effect on HMGCR expression, while 24s-OHC reduced it by 68%. Aβ-induced ABCA1 expression did not increase cholesterol efflux as the lower levels of cholesterol in conditioned medium of Aβ-treated cells were found. Conclusion Our novel findings show that Aβ affects two key elements in the brain cholesterol homeostasis, HMGCR and ABCA1, which are crucial in cholesterol synthesis and efflux. Since 24s-OHC could suppress the Aβ effects on enhancement of HMGCR and ABCA1, therefore the cytochrome P450 46A1 (Cyp46A1), which is exclusively expressed in the central nervous system and responsible for producing of 24s-OHC, could consider as a therapeutic target in the cholesterol-related neurodegenerative diseases such as Alzheimer's disease.
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Affiliation(s)
- Zahra Nazeri
- Department of Biochemistry, Faculty of Medicine, Cellular and Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ghorban Mohammadzadeh
- Department of Biochemistry, Faculty of Medicine, Cellular and Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mojtaba Rashidi
- Department of Biochemistry, Faculty of Medicine, Cellular and Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shirin Azizdoost
- Atherosclerosis Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Maryam Cheraghzadeh
- Department of Biochemistry, Faculty of Medicine, Cellular and Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Alireza Kheirollah
- Department of Biochemistry, Faculty of Medicine, Cellular and Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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6
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Clark C, Gholam M, Zullo L, Kerksiek A, Castelao E, von Gunten A, Preisig M, Lütjohann D, Popp J. Plant sterols and cholesterol metabolism are associated with five-year cognitive decline in the elderly population. iScience 2023; 26:106740. [PMID: 37250771 PMCID: PMC10209479 DOI: 10.1016/j.isci.2023.106740] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 02/13/2023] [Accepted: 04/20/2023] [Indexed: 05/31/2023] Open
Abstract
Dysregulations in cholesterol metabolism are associated with neurodegenerative and vascular pathologies, and dementia. Diet-derived plant sterols (phytosterols) have cholesterol-lowering, anti-inflammatory, and antioxidant properties and may interfere with neurodegeneration and cognitive decline. Here we performed multivariate analysis in 720 individuals enrolled in a population-based prospective study to determine whether circulating cholesterol precursors and metabolites, triglycerides, and phytosterols, are associated with cognitive impairment and decline in the older population. We report specific dysregulations of endogenous cholesterol synthesis and metabolism, and diet-derived phytosterols, and their changes over time associated with cognitive impairment, and decline in the general population. These findings suggest circulating sterols levels could be considered in risk evaluation and are relevant for the development of strategies to prevent cognitive decline in older people.
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Affiliation(s)
- Christopher Clark
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Lenggstrasse 31, PO Box 363, 8032 Zürich, Switzerland
- Department of Mathematics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Mehdi Gholam
- Department of Mathematics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Leonardo Zullo
- Old Age Psychiatry, Department of Psychiatry, Lausanne University Hospital, Route de Cery 60, 1008 Prilly, Switzerland
| | - Anja Kerksiek
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Enrique Castelao
- Department of Psychiatry, Center for Research in Psychiatric Epidemiology and Psychopathology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Armin von Gunten
- Old Age Psychiatry, Department of Psychiatry, Lausanne University Hospital, Route de Cery 60, 1008 Prilly, Switzerland
| | - Martin Preisig
- Department of Psychiatry, Center for Research in Psychiatric Epidemiology and Psychopathology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Julius Popp
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Lenggstrasse 31, PO Box 363, 8032 Zürich, Switzerland
- Old Age Psychiatry, Department of Psychiatry, Lausanne University Hospital, Route de Cery 60, 1008 Prilly, Switzerland
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7
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Mast N, El-Darzi N, Li Y, Pikuleva IA. Quantitative characterizations of the cholesterol-related pathways in the retina and brain of hamsters. J Lipid Res 2023:100401. [PMID: 37330011 PMCID: PMC10394389 DOI: 10.1016/j.jlr.2023.100401] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/08/2023] [Accepted: 06/13/2023] [Indexed: 06/19/2023] Open
Abstract
The retina and brain are separated from the systemic circulation by the anatomical barriers, which are permeable (the outer blood-retinal barrier) and impermeable (the blood-brain and inner blood-retina barriers) to cholesterol. Herein we investigated whether the whole-body cholesterol maintenance affects cholesterol homeostasis in the retina and brain. We used hamsters, whose whole-body cholesterol handling is more similar to those in humans than in mice and conducted separate administrations of deuterated water and deuterated cholesterol. We assessed the quantitative significance of the retinal and brain pathways of cholesterol input and compared the results with those from our previous studies in mice. The utility of the measurements in the plasma of deuterated 24-hydroxycholesterol, the major cholesterol elimination product from the brain, was investigated as well. We established that despite a 7-fold higher serum LDL to HDL ratio and other cholesterol-related differences, in situ biosynthesis remained the major source of cholesterol for hamster retina, although its quantitative significance was reduced to 53% as compared to 72-78% in mouse retina. In the brain, the principal pathway of cholesterol input was also the same, in situ biosynthesis, accounting for 94% of the total brain cholesterol input (96% in mice); the interspecies differences pertained to the absolute rates of the total cholesterol input and turnover. We documented the correlations between deuterium enrichments of the brain 24-hydroxycholesterol, brain cholesterol, and plasma 24-hydroxycholesterol, which suggested that deuterium enrichment of plasma 24-hydroxycholesteol could be an in vivo marker of cholesterol elimination and turnover in the brain.
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Affiliation(s)
- Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH USA
| | - Nicole El-Darzi
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH USA
| | - Yong Li
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH USA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH USA.
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8
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Xing C, Huang X, Wang D, Yu D, Hou S, Cui H, Song L. Roles of bile acids signaling in neuromodulation under physiological and pathological conditions. Cell Biosci 2023; 13:106. [PMID: 37308953 PMCID: PMC10258966 DOI: 10.1186/s13578-023-01053-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 05/13/2023] [Indexed: 06/14/2023] Open
Abstract
Bile acids (BA) are important physiological molecules not only mediating nutrients absorption and metabolism in peripheral tissues, but exerting neuromodulation effect in the central nerve system (CNS). The catabolism of cholesterol to BA occurs predominantly in the liver by the classical and alternative pathways, or in the brain initiated by the neuronal-specific enzyme CYP46A1 mediated pathway. Circulating BA could cross the blood brain barrier (BBB) and reach the CNS through passive diffusion or BA transporters. Brain BA might trigger direct signal through activating membrane and nucleus receptors or affecting activation of neurotransmitter receptors. Peripheral BA may also provide the indirect signal to the CNS via farnesoid X receptor (FXR) dependent fibroblast growth factor 15/19 (FGF15/19) pathway or takeda G protein coupled receptor 5 (TGR5) dependent glucagon-like peptide-1 (GLP-1) pathway. Under pathological conditions, alterations in BA metabolites have been discovered as potential pathogenic contributors in multiple neurological disorders. Attractively, hydrophilic ursodeoxycholic acid (UDCA), especially tauroursodeoxycholic acid (TUDCA) can exert neuroprotective roles by attenuating neuroinflammation, apoptosis, oxidative or endoplasmic reticulum stress, which provides promising therapeutic effects for treatment of neurological diseases. This review summarizes recent findings highlighting the metabolism, crosstalk between brain and periphery, and neurological functions of BA to elucidate the important role of BA signaling in the brain under both physiological and pathological conditions.
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Affiliation(s)
- Chen Xing
- Beijing Institute of Basic Medical Sciences, Taiping Road #27, Beijing, 100850, China.
| | - Xin Huang
- Beijing Institute of Basic Medical Sciences, Taiping Road #27, Beijing, 100850, China
| | - Dongxue Wang
- Beijing Institute of Basic Medical Sciences, Taiping Road #27, Beijing, 100850, China
- College of Pharmacy, Jiamusi University, Jiamusi, 154007, China
| | - Dengjun Yu
- Beijing Institute of Basic Medical Sciences, Taiping Road #27, Beijing, 100850, China
- College of Pharmacy, Jiamusi University, Jiamusi, 154007, China
| | - Shaojun Hou
- Beijing Institute of Basic Medical Sciences, Taiping Road #27, Beijing, 100850, China
- Anhui Medical University, Heifei, 230032, China
| | - Haoran Cui
- Beijing Institute of Basic Medical Sciences, Taiping Road #27, Beijing, 100850, China
| | - Lung Song
- Beijing Institute of Basic Medical Sciences, Taiping Road #27, Beijing, 100850, China.
- Anhui Medical University, Heifei, 230032, China.
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9
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Alanko V, Gaminde-Blasco A, Quintela-López T, Loera-Valencia R, Solomon A, Björkhem I, Cedazo-Minguez A, Maioli S, Tabacaru G, Latorre-Leal M, Matute C, Kivipelto M, Alberdi E, Sandebring-Matton A. 27-hydroxycholesterol promotes oligodendrocyte maturation: Implications for hypercholesterolemia-associated brain white matter changes. Glia 2023; 71:1414-1428. [PMID: 36779429 DOI: 10.1002/glia.24348] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 02/14/2023]
Abstract
Oxidized cholesterol metabolite 27-hydroxycholesterol (27-OH) is a potential link between hypercholesterolemia and neurodegenerative diseases since unlike peripheral cholesterol, 27-OH is transported across the blood-brain barrier. However, the effects of high 27-OH levels on oligodendrocyte function remain unexplored. We hypothesize that during hypercholesterolemia 27-OH may impact oligodendrocytes and myelin and thus contribute to the disconnection of neural networks in neurodegenerative diseases. To test this idea, we first investigated the effects of 27-OH in cultured oligodendrocytes and found that it induces cell death of immature O4+ /GalC+ oligodendrocytes along with stimulating differentiation of PDGFR+ oligodendrocyte progenitors (OPCs). Next, transgenic mice with increased systemic 27-OH levels (Cyp27Tg) underwent behavioral testing and their brains were immunohistochemically stained and lysed for immunoblotting. Chronic exposure to 27-OH in mice resulted in increased myelin basic protein (MBP) but not 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) or myelin oligodendrocyte glycoprotein (MOG) levels in the corpus callosum and cerebral cortex. Intriguingly, we also found impairment of spatial learning suggesting that subtle changes in myelinated axons of vulnerable areas like the hippocampus caused by 27-OH may contribute to impaired cognition. Finally, we found that 27-OH levels in cerebrospinal fluid from memory clinic patients were associated with levels of the myelination regulating CNPase, independently of Alzheimer's disease markers. Thus, 27-OH promotes OPC differentiation and is toxic to immature oligodendrocytes as well as it subtly alters myelin by targeting oligodendroglia. Taken together, these data indicate that hypercholesterolemia-derived higher 27-OH levels change the oligodendrocytic capacity for appropriate myelin remodeling which is a crucial factor in neurodegeneration and aging.
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Affiliation(s)
- Vilma Alanko
- Division of Clinical Geriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden.,Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - Adhara Gaminde-Blasco
- Department of Neuroscience, University of Basque Country (UPV/EHU) and CIBERNED, Leioa, Spain.,Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Tania Quintela-López
- Department of Neuroscience, University of Basque Country (UPV/EHU) and CIBERNED, Leioa, Spain.,Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Raúl Loera-Valencia
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - Alina Solomon
- Division of Clinical Geriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden.,Institute of Clinical Medicine/Neurology, University of Eastern Finland, Kuopio, Finland.,Ageing Epidemiology (AGE) Research Unit, School of Public Health, Imperial College London, London, UK
| | - Ingemar Björkhem
- Department of Laboratory Medicine, Karolinska University Hospital, Huddinge, Sweden
| | - Angel Cedazo-Minguez
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - Silvia Maioli
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - Graziella Tabacaru
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - María Latorre-Leal
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - Carlos Matute
- Department of Neuroscience, University of Basque Country (UPV/EHU) and CIBERNED, Leioa, Spain.,Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Miia Kivipelto
- Division of Clinical Geriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden.,Institute of Clinical Medicine/Neurology, University of Eastern Finland, Kuopio, Finland.,Ageing Epidemiology (AGE) Research Unit, School of Public Health, Imperial College London, London, UK.,Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | - Elena Alberdi
- Department of Neuroscience, University of Basque Country (UPV/EHU) and CIBERNED, Leioa, Spain.,Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Anna Sandebring-Matton
- Division of Clinical Geriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden.,Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden.,Ageing Epidemiology (AGE) Research Unit, School of Public Health, Imperial College London, London, UK
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10
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Hartz P, Fehlmann T, Wagenpfeil G, Unger MM, Bernhardt R. A CYPome-wide study reveals new potential players in the pathogenesis of Parkinson's disease. Front Pharmacol 2023; 13:1094265. [PMID: 36744208 PMCID: PMC9892771 DOI: 10.3389/fphar.2022.1094265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/22/2022] [Indexed: 01/20/2023] Open
Abstract
Genetic and environmental factors lead to the manifestation of Parkinson's disease (PD) but related mechanisms are only rudimentarily understood. Cytochromes P450 (P450s) are involved in the biotransformation of toxic compounds and in many physiological processes and thus predestinated to be involved in PD. However, so far only SNPs (single nucleotide polymorphisms) in CYP2D6 and CYP2E1 have been associated with the susceptibility of PD. Our aim was to evaluate the role of all 57 human P450s and their redox partners for the etiology and pathophysiology of PD and to identify novel potential players which may lead to the identification of new biomarkers and to a causative treatment of PD. The PPMI (Parkinson's Progression Markers Initiative) database was used to extract the gene sequences of all 57 P450s and their three redox partners to analyze the association of SNPs with the occurrence of PD. Applying statistical analyses of the data, corresponding odds ratios (OR) and confidence intervals (CI) were calculated. We identified SNPs significantly over-represented in patients with a genetic predisposition for PD (GPD patients) or in idiopathic PD (IPD patients) compared to HC (healthy controls). Xenobiotic-metabolizing P450s show a significant accumulation of SNPs in PD patients compared with HC supporting the role of toxic compounds in the pathogenesis of PD. Moreover, SNPs with high OR values (>5) in P450s catalyzing the degradation of cholesterol (CYP46A1, CY7B1, CYP39A1) indicate a prominent role of cholesterol metabolism in the brain for PD risk. Finally, P450s participating in the metabolism of eicosanoids show a strong over-representation of SNPs in PD patients underlining the effect of inflammation on the pathogenesis of PD. Also, the redox partners of P450 show SNPs with OR > 5 in PD patients. Taken together, we demonstrate that SNPs in 26 out of 57 P450s are at least 5-fold over-represented in PD patients suggesting these P450s as new potential players in the pathogenesis of PD. For the first time exceptionally high OR values (up to 12.9) were found. This will lead to deeper insight into the origin and development of PD and may be applied to develop novel strategies for a causative treatment of this disease.
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Affiliation(s)
- Philip Hartz
- Institut für Biochemie, Fachbereich Biologie, Universität des Saarlandes, Naturwissenschaftlich-Technische Fakultät, Saarbrücken, Germany
| | - Tobias Fehlmann
- Institut für Klinische Bioinformatik, Universität des Saarlandes, Saarbrücken, Germany
| | - Gudrun Wagenpfeil
- Institut für Medizinische Biometrie, Epidemiologie und Medizinische Informatik, Universität des Saarlandes, Homburg, Germany
| | - Marcus Michael Unger
- KLinik für Neurologie, Fachbereich Klinische Medizin, Universität des Saarlandes, Homburg, Germany,Klinik für Neurologie, SHG Kliniken Sonnenberg, Saarbrücken, Germany,*Correspondence: Marcus Michael Unger, ; Rita Bernhardt,
| | - Rita Bernhardt
- Institut für Biochemie, Fachbereich Biologie, Universität des Saarlandes, Naturwissenschaftlich-Technische Fakultät, Saarbrücken, Germany,*Correspondence: Marcus Michael Unger, ; Rita Bernhardt,
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11
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Molecular Basis of Bile Acid-FXR-FGF15/19 Signaling Axis. Int J Mol Sci 2022; 23:ijms23116046. [PMID: 35682726 PMCID: PMC9181207 DOI: 10.3390/ijms23116046] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 02/04/2023] Open
Abstract
Bile acids (BAs) are a group of amphiphilic molecules consisting of a rigid steroid core attached to a hydroxyl group with a varying number, position, and orientation, and a hydrophilic side chain. While BAs act as detergents to solubilize lipophilic nutrients in the small intestine during digestion and absorption, they also act as hormones. Farnesoid X receptor (FXR) is a nuclear receptor that forms a heterodimer with retinoid X receptor α (RXRα), is activated by BAs in the enterohepatic circulation reabsorbed via transporters in the ileum and the colon, and plays a critical role in regulating gene expression involved in cholesterol, BA, and lipid metabolism in the liver. The FXR/RXRα heterodimer also exists in the distal ileum and regulates production of fibroblast growth factor (FGF) 15/FGF19, a hormone traveling via the enterohepatic circulation that activates hepatic FGF receptor 4 (FGFR4)-β-klotho receptor complex and regulates gene expression involved in cholesterol, BA, and lipid metabolism, as well as those regulating cell proliferation. Agonists for FXR and analogs for FGF15/19 are currently recognized as a promising therapeutic target for metabolic syndrome and cholestatic diseases.
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12
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Ondaro J, Hernandez-Eguiazu H, Garciandia-Arcelus M, Loera-Valencia R, Rodriguez-Gómez L, Jiménez-Zúñiga A, Goikolea J, Rodriguez-Rodriguez P, Ruiz-Martinez J, Moreno F, Lopez de Munain A, Holt IJ, Gil-Bea FJ, Gereñu G. Defects of Nutrient Signaling and Autophagy in Neurodegeneration. Front Cell Dev Biol 2022; 10:836196. [PMID: 35419363 PMCID: PMC8996160 DOI: 10.3389/fcell.2022.836196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/21/2022] [Indexed: 12/27/2022] Open
Abstract
Neurons are post-mitotic cells that allocate huge amounts of energy to the synthesis of new organelles and molecules, neurotransmission and to the maintenance of redox homeostasis. In neurons, autophagy is not only crucial to ensure organelle renewal but it is also essential to balance nutritional needs through the mobilization of internal energy stores. A delicate crosstalk between the pathways that sense nutritional status of the cell and the autophagic processes to recycle organelles and macronutrients is fundamental to guarantee the proper functioning of the neuron in times of energy scarcity. This review provides a detailed overview of the pathways and processes involved in the balance of cellular energy mediated by autophagy, which when defective, precipitate the neurodegenerative cascade of Parkinson’s disease, frontotemporal dementia, amyotrophic lateral sclerosis or Alzheimer’s disease.
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Affiliation(s)
- Jon Ondaro
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Haizea Hernandez-Eguiazu
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Maddi Garciandia-Arcelus
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Raúl Loera-Valencia
- Department of Neurology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet (KI), Stockholm, Sweden
| | - Laura Rodriguez-Gómez
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Andrés Jiménez-Zúñiga
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Julen Goikolea
- Department of Neurology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet (KI), Stockholm, Sweden
| | - Patricia Rodriguez-Rodriguez
- Department of Neurology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet (KI), Stockholm, Sweden
| | - Javier Ruiz-Martinez
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Donostia University Hospital, San Sebastian, Spain
| | - Fermín Moreno
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Donostia University Hospital, San Sebastian, Spain
| | - Adolfo Lopez de Munain
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Donostia University Hospital, San Sebastian, Spain
| | - Ian James Holt
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, United Kingdom.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain
| | - Francisco Javier Gil-Bea
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Gorka Gereñu
- Department of Neuroscience, Biodonostia Health Research Institute (IIS Biodonostia), San Sebastian, Spain.,Center for Biomedical Research of Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Department of Physiology, Faculty of Medicine and Nursing, University of Basque Country (UPV-EHU), Leioa, Spain
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13
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Wang T, Zhang X, Wang Y, Liu W, Wang L, Hao L, Ju M, Xiao R. High cholesterol and 27-hydroxycholesterol contribute to phosphorylation of tau protein by impairing autophagy causing learning and memory impairment in C57BL/6J mice. J Nutr Biochem 2022; 106:109016. [DOI: 10.1016/j.jnutbio.2022.109016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 01/05/2022] [Accepted: 03/03/2022] [Indexed: 12/15/2022]
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14
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Sandebring-Matton A, Goikolea J, Björkhem I, Paternain L, Kemppainen N, Laatikainen T, Ngandu T, Rinne J, Soininen H, Cedazo-Minguez A, Solomon A, Kivipelto M. 27-Hydroxycholesterol, cognition, and brain imaging markers in the FINGER randomized controlled trial. Alzheimers Res Ther 2021; 13:56. [PMID: 33676572 PMCID: PMC7937194 DOI: 10.1186/s13195-021-00790-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/15/2021] [Indexed: 12/18/2022]
Abstract
BACKGROUND 27-Hydroxycholesterol (27-OH), the main circulating oxysterol in humans and the potential missing link between peripheral hypercholesterolemia and Alzheimer's disease (AD), has not been investigated previously in relation to cognition and neuroimaging markers in the context of preventive interventions. METHODS The 2-year Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) included older individuals (60-77 years) at increased risk for dementia but without dementia or substantial cognitive impairment from the general population. Participants were randomized to a multidomain intervention (diet, exercise, cognitive training, and vascular risk management) or control group (general health advice) in a 1:1 ratio. Outcome assessors were masked to group allocation. This FINGER exploratory sub-study included 47 participants with measures of 27-OH, cognition, brain MRI, brain FDG-PET, and PiB-PET. Linear regression models were used to assess the cross-sectional and longitudinal associations between 27-OH, cognition, and neuroimaging markers, considering several potential confounders/intervention effect modifiers. RESULTS 27-OH reduction during the intervention was associated with improvement in cognition (especially memory). This was not observed in the control group. The intervention reduced 27-OH particularly in individuals with the highest 27-OH levels and younger age. No associations were found between changes in 27-OH levels and neuroimaging markers. However, at baseline, a higher 27-OH was associated with lower total gray matter and hippocampal volume, and lower cognitive scores. These associations were unaffected by total cholesterol levels. While sex seemed to influence associations at baseline, it did not affect longitudinal associations. CONCLUSION 27-OH appears to be a marker not only for dementia/AD risk, but also for monitoring the effects of preventive interventions on cholesterol metabolism. TRIAL REGISTRATION ClinicalTrials.gov , NCT01041989 . Registered on 4 January 2010.
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Affiliation(s)
- Anna Sandebring-Matton
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden.
- Division of Clinical Geriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden.
| | - Julen Goikolea
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Laura Paternain
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - Nina Kemppainen
- Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Tiina Laatikainen
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
- Joint Municipal Authority for North Karelia Social and Health Services, Joensuu, Finland
- Public Health Promotion Unit, Department of Public Health Solutions, Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Tiia Ngandu
- Division of Clinical Geriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
- Public Health Promotion Unit, Department of Public Health Solutions, Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Juha Rinne
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Hilkka Soininen
- Institute of Clinical Medicine/Neurology, University of Eastern Finland, Kuopio, Finland
- Neurocenter, Neurology Kuopio University Hospital, Kuopio, Finland
| | - Angel Cedazo-Minguez
- Division of Neurogeriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
| | - Alina Solomon
- Division of Clinical Geriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
- Institute of Clinical Medicine/Neurology, University of Eastern Finland, Kuopio, Finland
- Ageing Epidemiology (AGE) Research Unit, School of Public Health, Imperial College London, London, UK
| | - Miia Kivipelto
- Division of Clinical Geriatrics, Center for Alzheimer Research, NVS, Karolinska Institutet, Stockholm, Sweden
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
- Ageing Epidemiology (AGE) Research Unit, School of Public Health, Imperial College London, London, UK
- Theme Aging, Karolinska University Hospital, Stockholm, Sweden
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15
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High levels of 27-hydroxycholesterol results in synaptic plasticity alterations in the hippocampus. Sci Rep 2021; 11:3736. [PMID: 33580102 PMCID: PMC7881004 DOI: 10.1038/s41598-021-83008-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 01/25/2021] [Indexed: 12/16/2022] Open
Abstract
Alterations in brain cholesterol homeostasis in midlife are correlated with a higher risk of developing Alzheimer’s disease (AD). However, global cholesterol-lowering therapies have yielded mixed results when it comes to slowing down or preventing cognitive decline in AD. We used the transgenic mouse model Cyp27Tg, with systemically high levels of 27-hydroxycholesterol (27-OH) to examine long-term potentiation (LTP) in the hippocampal CA1 region, combined with dendritic spine reconstruction of CA1 pyramidal neurons to detect morphological and functional synaptic alterations induced by 27-OH high levels. Our results show that elevated 27-OH levels lead to enhanced LTP in the Schaffer collateral-CA1 synapses. This increase is correlated with abnormally large dendritic spines in the stratum radiatum. Using immunohistochemistry for synaptopodin (actin-binding protein involved in the recruitment of the spine apparatus), we found a significantly higher density of synaptopodin-positive puncta in CA1 in Cyp27Tg mice. We hypothesize that high 27-OH levels alter synaptic potentiation and could lead to dysfunction of fine-tuned processing of information in hippocampal circuits resulting in cognitive impairment. We suggest that these alterations could be detrimental for synaptic function and cognition later in life, representing a potential mechanism by which hypercholesterolemia could lead to alterations in memory function in neurodegenerative diseases.
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16
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Dai L, Zou L, Meng L, Qiang G, Yan M, Zhang Z. Cholesterol Metabolism in Neurodegenerative Diseases: Molecular Mechanisms and Therapeutic Targets. Mol Neurobiol 2021; 58:2183-2201. [PMID: 33411241 DOI: 10.1007/s12035-020-02232-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/24/2020] [Indexed: 12/24/2022]
Abstract
Cholesterol is an indispensable component of the cell membrane and plays vital roles in critical physiological processes. Brain cholesterol accounts for a large portion of total cholesterol in the human body, and its content must be tightly regulated to ensure normal brain function. Disorders of cholesterol metabolism in the brain are linked to neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and other atypical cognitive deficits that arise at old age. However, the specific role of cholesterol metabolism disorder in the pathogenesis of neurodegenerative diseases has not been fully elucidated. Statins that are a class of lipid-lowering drugs have been reported to have a positive effect on neurodegenerative diseases. Herein, we reviewed the physiological and pathological conditions of cholesterol metabolism and discussed the possible mechanisms of cholesterol metabolism and statin therapy in neurodegenerative diseases.
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Affiliation(s)
- Lijun Dai
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Li Zou
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Guifen Qiang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing, China
| | - Mingmin Yan
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
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17
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Rickman OJ, Baple EL, Crosby AH. Lipid metabolic pathways converge in motor neuron degenerative diseases. Brain 2020; 143:1073-1087. [PMID: 31848577 PMCID: PMC7174042 DOI: 10.1093/brain/awz382] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/11/2019] [Accepted: 10/01/2019] [Indexed: 12/11/2022] Open
Abstract
Motor neuron diseases (MNDs) encompass an extensive and heterogeneous group of upper and/or lower motor neuron degenerative disorders, in which the particular clinical outcomes stem from the specific neuronal component involved in each condition. While mutations in a large number of molecules associated with lipid metabolism are known to be implicated in MNDs, there remains a lack of clarity regarding the key functional pathways involved, and their inter-relationships. This review highlights evidence that defines defects within two specific lipid (cholesterol/oxysterol and phosphatidylethanolamine) biosynthetic cascades as being centrally involved in MND, particularly hereditary spastic paraplegia. We also identify how other MND-associated molecules may impact these cascades, in particular through impaired organellar interfacing, to propose ‘subcellular lipidome imbalance’ as a likely common pathomolecular theme in MND. Further exploration of this mechanism has the potential to identify new therapeutic targets and management strategies for modulation of disease progression in hereditary spastic paraplegias and other MNDs.
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Affiliation(s)
- Olivia J Rickman
- Medical Research (Level 4), RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Emma L Baple
- Medical Research (Level 4), RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Andrew H Crosby
- Medical Research (Level 4), RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
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18
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Merino-Serrais P, Loera-Valencia R, Rodriguez-Rodriguez P, Parrado-Fernandez C, Ismail MA, Maioli S, Matute E, Jimenez-Mateos EM, Björkhem I, DeFelipe J, Cedazo-Minguez A. 27-Hydroxycholesterol Induces Aberrant Morphology and Synaptic Dysfunction in Hippocampal Neurons. Cereb Cortex 2020; 29:429-446. [PMID: 30395175 PMCID: PMC6294414 DOI: 10.1093/cercor/bhy274] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 10/04/2018] [Indexed: 12/11/2022] Open
Abstract
Hypercholesterolemia is a risk factor for neurodegenerative diseases, but how high blood cholesterol levels are linked to neurodegeneration is still unknown. Here, we show that an excess of the blood-brain barrier permeable cholesterol metabolite 27-hydroxycholesterol (27-OH) impairs neuronal morphology and reduces hippocampal spine density and the levels of the postsynaptic protein PSD95. Dendritic spines are the main postsynaptic elements of excitatory synapses and are crucial structures for memory and cognition. Furthermore, PSD95 has an essential function for synaptic maintenance and plasticity. PSD95 synthesis is controlled by the REST-miR124a-PTBP1 axis. Here, we report that high levels of 27-OH induce REST-miR124a-PTBP1 axis dysregulation in a possible RxRγ-dependent manner, suggesting that 27-OH reduces PSD95 levels through this mechanism. Our results reveal a possible molecular link between hypercholesterolemia and neurodegeneration. We discuss the possibility that reduction of 27-OH levels could be a useful strategy for preventing memory and cognitive decline in neurodegenerative disorders.
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Affiliation(s)
- Paula Merino-Serrais
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Raul Loera-Valencia
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Patricia Rodriguez-Rodriguez
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Cristina Parrado-Fernandez
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Muhammad A Ismail
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Neurology, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Silvia Maioli
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Eduardo Matute
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Eva Maria Jimenez-Mateos
- Department of Physiology and Medical Physics Royal, College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Madrid, Spain.,Instituto Cajal, CSIC, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Angel Cedazo-Minguez
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
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19
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Loera-Valencia R, Goikolea J, Parrado-Fernandez C, Merino-Serrais P, Maioli S. Alterations in cholesterol metabolism as a risk factor for developing Alzheimer's disease: Potential novel targets for treatment. J Steroid Biochem Mol Biol 2019; 190:104-114. [PMID: 30878503 DOI: 10.1016/j.jsbmb.2019.03.003] [Citation(s) in RCA: 140] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 01/01/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia and it is characterized by the deposition of amyloid-β (Aβ) plaques and neurofibrillary tangles in the brain. However, the complete pathogenesis of the disease is still unknown. High level of serum cholesterol has been found to positively correlate with an increased risk of dementia and some studies have reported a decreased prevalence of AD in patients taking cholesterol-lowering drugs. Years of research have shown a strong correlation between blood hypercholesterolemia and AD, however cholesterol is not able to cross the Blood Brain Barrier (BBB) into the brain. Cholesterol lowering therapies have shown mixed results in cognitive performance in AD patients, raising questions of whether brain cholesterol metabolism in the brain should be studied separately from peripheral cholesterol metabolism and what their relationship is. Unlike cholesterol, oxidized cholesterol metabolites known as oxysterols are able to cross the BBB from the circulation into the brain and vice-versa. The main oxysterols present in the circulation are 24S-hydroxycholesterol and 27-hydroxycholesterol. These oxysterols and their catalysing enzymes have been found to be altered in AD brains and there is evidence indicating their influence in the progression of the disease. This review gives a broad perspective on the relationship between hypercholesterolemia and AD, cholesterol lowering therapies for AD patients and the role of oxysterols in pathological and non-pathological conditions. Also, we propose cholesterol metabolites as valuable targets for prevention and alternative AD treatments.
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Affiliation(s)
- Raúl Loera-Valencia
- Karolinska Institutet, Center for Alzheimer Research, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Stockholm, Sweden.
| | - Julen Goikolea
- Karolinska Institutet, Center for Alzheimer Research, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Stockholm, Sweden
| | - Cristina Parrado-Fernandez
- Karolinska Institutet, Center for Alzheimer Research, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Stockholm, Sweden; Institute of Molecular Biology and Genetics-IBGM, (University of Valladolid-CSIC), Valladolid, Spain
| | - Paula Merino-Serrais
- Karolinska Institutet, Center for Alzheimer Research, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Stockholm, Sweden; Instituto Cajal (CSIC), Laboratorio Cajal de Circuitos Corticales, Madrid, Spain
| | - Silvia Maioli
- Karolinska Institutet, Center for Alzheimer Research, Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Stockholm, Sweden.
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20
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Ma W, Li C, Zhao L, Wang Y, Xiao R. NF-κB-mediated inflammatory damage is differentially affected in SH-SY5Y and C6 cells treated with 27-hydroxycholesterol. Food Sci Nutr 2019; 7:1685-1694. [PMID: 31139381 PMCID: PMC6526694 DOI: 10.1002/fsn3.1005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 03/03/2019] [Accepted: 03/07/2019] [Indexed: 12/12/2022] Open
Abstract
Previous studies have demonstrated that 27-hydroxycholesterol (27-OHC), a cholesterol metabolite, was involved in the inflammatory process of Alzheimer's disease (AD). The present study aimed to investigate the 27-OHC-induced inflammatory damage to neurons and astrocytes and the underlying mechanism(s) accounting for this damage. Human neuroblastoma cells (SH-SY5Y cells) and rat glioma cells (C6 cells) were treated with vehicle or 27-OHC (5, 10, or 20 μM) for 24 hr. The levels of secreted interleukin-1β (IL-1β), interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-α), and inducible nitric oxide synthase (iNOS) were determined by using an enzyme-linked immunosorbent assay (ELISA). Immunofluorescence staining was used to determine the cellular expression of toll-like receptor 4 (TLR4) and transforming growth factor-β (TGF-β). The mRNA and protein expression levels of nuclear factor-κB p65 (NF-κB p65), nuclear factor-κB p50 (NF-κB p50) and cyclooxygenase-2 (COX-2) in both SH-SY5Y and C6 cells were also detected by real-time PCR and Western blot, respectively. The results of this study showed that 27-OHC treatment increased secretion of TNF-α and iNOS and decreased secretion of IL-10, upregulated expression of TGF-β, NF-κB p65 and p50, and downregulated expression of COX-2 in SH-SY5Y cells. In C6 cells, treatment with 27-OHC resulted in decreased secretion of IL-1β, IL-10, TNF-α, and iNOS, and increased expression of TLR4 and TGF-β. These results suggest that 27-OHC may cause inflammatory damage to neurons by activating the TGF-β/NF-κB signaling pathway and to astrocytes by activating the TLR4/TGF-β signaling, which results in the subsequent release of inflammatory cytokines.
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Affiliation(s)
- Wei‐Wei Ma
- Beijing Key Laboratory of Environmental Toxicology, School of Public HealthCapital Medical UniversityBeijingChina
| | - Chao‐Qun Li
- Beijing Key Laboratory of Environmental Toxicology, School of Public HealthCapital Medical UniversityBeijingChina
| | - Lei Zhao
- Department of Molecular Physiology and Biophysics, Holden Comprehensive Cancer CenterUniversity of Iowa Carver College of MedicineIowa CityIowa
| | - Yu‐Shan Wang
- Beijing Key Laboratory of Environmental Toxicology, School of Public HealthCapital Medical UniversityBeijingChina
| | - Rong Xiao
- Beijing Key Laboratory of Environmental Toxicology, School of Public HealthCapital Medical UniversityBeijingChina
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21
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Petek B, Villa-Lopez M, Loera-Valencia R, Gerenu G, Winblad B, Kramberger MG, Ismail MAM, Eriksdotter M, Garcia-Ptacek S. Connecting the brain cholesterol and renin-angiotensin systems: potential role of statins and RAS-modifying medications in dementia. J Intern Med 2018; 284:620-642. [PMID: 30264910 DOI: 10.1111/joim.12838] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Millions of people worldwide receive agents targeting the renin-angiotensin system (RAS) to treat hypertension or statins to lower cholesterol. The RAS and cholesterol metabolic pathways in the brain are autonomous from their systemic counterparts and are interrelated through the cholesterol metabolite 27-hydroxycholesterol (27-OHC). These systems contribute to memory and dementia pathogenesis through interference in the amyloid-beta cascade, vascular mechanisms, glucose metabolism, apoptosis, neuroinflammation and oxidative stress. Previous studies examining the relationship between these treatments and cognition and dementia risk have produced inconsistent results. Defining the blood-brain barrier penetration of these medications has been challenging, and the mechanisms of action on cognition are not clearly established. Potential biases are apparent in epidemiological and clinical studies, such as reverse epidemiology, indication bias, problems defining medication exposure, uncertain and changing doses, and inappropriate grouping of outcomes and medications. This review summarizes current knowledge of the brain cholesterol and RAS metabolism and the mechanisms by which these pathways affect neurodegeneration. The putative mechanisms of action of statins and medications inhibiting the RAS will be examined, together with prior clinical and animal studies on their effects on cognition. We review prior epidemiological studies, analysing their strengths and biases, and identify areas for future research. Understanding the pathophysiology of the brain cholesterol system and RAS and their links to neurodegeneration has enormous potential. In future, well-designed epidemiological studies could identify potential treatments for Alzheimer's disease (AD) amongst medications that are already in use for other indications.
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Affiliation(s)
- B Petek
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Neurology, University Medical Centre, Ljubljana, Slovenia.,University of Ljubljana, Ljubljana, Slovenia
| | - M Villa-Lopez
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - R Loera-Valencia
- Center for Alzheimer Research, Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - G Gerenu
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Neurosciences, Biodonostia Health Research Institute, San Sebastian, Spain.,Center for Networked Biomedical Research in Neurodegenerative Diseases, CIBERNED, Health Institute Carlos III, Ministry of Economy and Competitiveness, Madrid, Spain
| | - B Winblad
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Geriatric Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - M G Kramberger
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Neurology, University Medical Centre, Ljubljana, Slovenia.,University of Ljubljana, Ljubljana, Slovenia
| | - M-A-M Ismail
- Center for Alzheimer Research, Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Theme Neuro, Diseases of the Nervous System patient flow, Karolinska University Hospital, Huddinge, Sweden
| | - M Eriksdotter
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Geriatric Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - S Garcia-Ptacek
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Department of Internal Medicine, Neurology Section, Södersjukhuset, Stockholm, Sweden
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22
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Griffiths WJ, Crick PJ, Meljon A, Theofilopoulos S, Abdel-Khalik J, Yutuc E, Parker JE, Kelly DE, Kelly SL, Arenas E, Wang Y. Additional pathways of sterol metabolism: Evidence from analysis of Cyp27a1-/- mouse brain and plasma. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:191-211. [PMID: 30471425 PMCID: PMC6327153 DOI: 10.1016/j.bbalip.2018.11.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 10/29/2018] [Accepted: 11/18/2018] [Indexed: 12/21/2022]
Abstract
Cytochrome P450 (CYP) 27A1 is a key enzyme in both the acidic and neutral pathways of bile acid biosynthesis accepting cholesterol and ring-hydroxylated sterols as substrates introducing a (25R)26-hydroxy and ultimately a (25R)26-acid group to the sterol side-chain. In human, mutations in the CYP27A1 gene are the cause of the autosomal recessive disease cerebrotendinous xanthomatosis (CTX). Surprisingly, Cyp27a1 knockout mice (Cyp27a1−/−) do not present a CTX phenotype despite generating a similar global pattern of sterols. Using liquid chromatography – mass spectrometry and exploiting a charge-tagging approach for oxysterol analysis we identified over 50 cholesterol metabolites and precursors in the brain and circulation of Cyp27a1−/− mice. Notably, we identified (25R)26,7α- and (25S)26,7α-dihydroxy epimers of oxysterols and cholestenoic acids, indicating the presence of an additional sterol 26-hydroxylase in mouse. Importantly, our analysis also revealed elevated levels of 7α-hydroxycholest-4-en-3-one, which we found increased the number of oculomotor neurons in primary mouse brain cultures. 7α-Hydroxycholest-4-en-3-one is a ligand for the pregnane X receptor (PXR), activation of which is known to up-regulate the expression of CYP3A11, which we confirm has sterol 26-hydroxylase activity. This can explain the formation of (25R)26,7α- and (25S)26,7α-dihydroxy epimers of oxysterols and cholestenoic acids; the acid with the former stereochemistry is a liver X receptor (LXR) ligand that increases the number of oculomotor neurons in primary brain cultures. We hereby suggest that a lack of a motor neuron phenotype in some CTX patients and Cyp27a1−/− mice may involve increased levels of 7α-hydroxycholest-4-en-3-one and activation PXR, as well as increased levels of sterol 26-hydroxylase and the production of neuroprotective sterols capable of activating LXR. Besides CYP27A1 an additional sterol 26-hydroxylase is present in mouse. Sterol-acids are observed as 7α-hydroxy-(25R/S)26-acid epimers. The (25S)26-acid is found in mouse brain of the CYP27A1−/− mouse. The (25R)26-acid is found in brain of the wild type animal. Both epimers are found in plasma of both genotypes.
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Affiliation(s)
- William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK.
| | - Peter J Crick
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Anna Meljon
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Spyridon Theofilopoulos
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK; Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm SE-17177, Sweden
| | - Jonas Abdel-Khalik
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Eylan Yutuc
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Josie E Parker
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Diane E Kelly
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Steven L Kelly
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Ernest Arenas
- Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm SE-17177, Sweden
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK.
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23
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Lütjohann D, Lopez AM, Chuang JC, Kerksiek A, Turley SD. Identification of Correlative Shifts in Indices of Brain Cholesterol Metabolism in the C57BL6/Mecp2 tm1.1Bird Mouse, a Model for Rett Syndrome. Lipids 2018; 53:363-373. [PMID: 29770459 DOI: 10.1002/lipd.12041] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/26/2018] [Accepted: 04/03/2018] [Indexed: 01/14/2023]
Abstract
Rett syndrome (RS) is a pervasive neurodevelopmental disorder resulting from loss-of-function mutations in the X-linked gene methyl-Cpg-binding protein 2 (MECP2). Using a well-defined model for RS, the C57BL6/Mecp2tm1.1Bird mouse, we have previously found a moderate but persistently lower rate of cholesterol synthesis, measured in vivo, in the brains of Mecp2-/y mice, starting from about the third week after birth. There was no genotypic difference in the total cholesterol concentration throughout the brain at any age. This raised the question of whether the lower rate of cholesterol synthesis in the mutants was balanced by a fall in the rate at which cholesterol was converted via cholesterol 24-hydroxylase (Cyp46A1) to 24S-hydroxycholesterol (24S-OHC), the principal route through which cholesterol is ordinarily removed from the brain. Here, we show that while there were no genotypic differences in the concentrations in plasma and liver of three cholesterol precursors (lanosterol, lathosterol, and desmosterol), two plant sterols (sitosterol and campesterol), and two oxysterols (27-hydroxycholesterol [27-OHC] and 24S-OHC), the brains of the Mecp2 -/y mice had significantly lower concentrations of all three cholesterol precursors, campesterol, and both oxysterols, with the level of 24S-OHC being ~20% less than in their Mecp2 +/y controls. Together, these data suggest that coordinated regulation of cholesterol synthesis and catabolism in the central nervous system is maintained in this model for RS. Furthermore, we speculate that the adaptive changes in these two pathways conceivably resulted from a shift in the permeability of the blood-brain barrier as implied by the significantly lower campesterol and 27-OHC concentrations in the brains of the Mecp2-/y mice.
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Affiliation(s)
- Dieter Lütjohann
- Institute for Clinical Chemistry and Clinical Pharmacology, University Clinics of Bonn, Sigmund-Freud-Str. 25, 53127 Bonn, Germany
| | - Adam M Lopez
- Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9151, USA
| | - Jen-Chieh Chuang
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9060, USA
| | - Anja Kerksiek
- Institute for Clinical Chemistry and Clinical Pharmacology, University Clinics of Bonn, Sigmund-Freud-Str. 25, 53127 Bonn, Germany
| | - Stephen D Turley
- Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9151, USA
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24
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Mast N, Lin JB, Anderson KW, Bjorkhem I, Pikuleva IA. Transcriptional and post-translational changes in the brain of mice deficient in cholesterol removal mediated by cytochrome P450 46A1 (CYP46A1). PLoS One 2017; 12:e0187168. [PMID: 29073233 PMCID: PMC5658173 DOI: 10.1371/journal.pone.0187168] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 10/13/2017] [Indexed: 01/12/2023] Open
Abstract
Cytochrome P450 46A1 (CYP46A1) converts cholesterol to 24-hydroxycholesterol and thereby controls the major pathways of cholesterol removal from the brain. Cyp46a1-/- mice have a reduction in the rate of cholesterol biosynthesis in the brain and significant impairments to memory and learning. To gain insights into the mechanisms underlying Cyp46a1-/- phenotype, we used Cyp46a1-/- mice and quantified their brain sterol levels and the expression of the genes pertinent to cholesterol homeostasis. We also compared the Cyp46a1-/- and wild type brains for protein phosphorylation and ubiquitination. The data obtained enable the following inferences. First, there seems to be a compensatory upregulation in the Cyp46a1-/- brain of the pathways of cholesterol storage and CYP46A1-independent removal. Second, transcriptional regulation of the brain cholesterol biosynthesis via sterol regulatory element binding transcription factors is not significantly activated in the Cyp46a1-/- brain to explain a compensatory decrease in cholesterol biosynthesis. Third, some of the liver X receptor target genes (Abca1) are paradoxically upregulated in the Cyp46a1-/- brain, possibly due to a reduced activation of the small GTPases RAB8, CDC42, and RAC as a result of a reduced phosphorylation of RAB3IP and PAK1. Fourth, the phosphorylation of many other proteins (a total of 146) is altered in the Cyp46a1-/- brain, including microtubule associated and neurofilament proteins (the MAP and NEF families) along with proteins related to synaptic vesicles and synaptic neurotransmission (e.g., SLCs, SHANKs, and BSN). Fifth, the extent of protein ubiquitination is increased in the Cyp46a1-/- brain, and the affected proteins pertain to ubiquitination (UBE2N), cognition (STX1B and ATP1A2), cytoskeleton function (TUBA1A and YWHAZ), and energy production (ATP1A2 and ALDOA). The present study demonstrates the diverse potential effects of CYP46A1 deficiency on brain functions and identifies important proteins that could be affected by this deficiency.
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Affiliation(s)
- Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Joseph B. Lin
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Kyle W. Anderson
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland, United States of America
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland, United States of America
| | - Ingemar Bjorkhem
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institute, Huddinge, Sweden
| | - Irina A. Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
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25
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Heverin M, Ali Z, Olin M, Tillander V, Joibari MM, Makoveichuk E, Leitersdorf E, Warner M, Olivercrona G, Gustafsson JÅ, Björkhem I. On the regulatory importance of 27-hydroxycholesterol in mouse liver. J Steroid Biochem Mol Biol 2017; 169:10-21. [PMID: 26851362 DOI: 10.1016/j.jsbmb.2016.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 01/17/2023]
Abstract
27-Hydroxycholesterol (27OH) is a strong suppressor of cholesterol synthesis and a weak activator of LXR in vitro. The regulatory importance of 27OH in vivo is controversial. Here we utilized male mice with increased levels of 27OH either due to increased production (CYP27A1 transgenic mice) or reduced metabolism (Cyp7b1-/- mice). We also used mice lacking 27OH due to a knockout of Cyp27a1. The latter mice were treated with cholic acid to compensate for reduced bile acid synthesis. The effects of the different levels of 27OH on Srebp- and other LXR-regulated genes in the liver were investigated. In the liver of CYP27tg mice we found a modest increase of the mRNA levels corresponding to the LXR target genes Cyp7b1 and Abca1. A number of other LXR-regulated genes were not affected. The effect on Abca1 mRNA was not seen in the liver of Cyp7b1-/- mice. There were little or no effects on cholesterol synthesis. In the liver of the Cyp27-/- mice treated with 0.025% cholic acid there was no significant effect of the knockout on the LXR target genes. In a previous work triple-knockout mice deficient in the biosynthesis of 24S-hydroxycholesterol, 25-hydroxycholesterol and 27OH were shown to have impaired response to dietary cholesterol, suggesting side-chain oxidized oxysterols to be mediators in cholesterol-induced effects on LXR target genes at a transcriptional level (Chen W. et al., Cell Metab. 5 (2007) 73-79). The hydroxylated oxysterol responsible for the effect was not defined. We show here that treatment of wildtype mice with dietary cholesterol under the same conditions as in the above study induced the LXR target genes Lpl, Abcg8 and Srebp1c in wild type mice but failed to activate the same genes in mice lacking 27-hydroxycholesterol due to a knockout of Cyp27. We failed to demonstrate the above effects at the protein level (Abcg8) or at the activity level (Lpl). The results suggest that 27OH is not an important regulator of Srebp- or LXR regulated genes under basal conditions in mouse liver. On the other hand 27OH appears to mediate cholesterol-induced effects on some LXR target genes at a transcriptional level under some in vivo conditions.
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Affiliation(s)
- Maura Heverin
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Zeina Ali
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Maria Olin
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Veronika Tillander
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | | | - Elena Makoveichuk
- Department of Medical Biosciences/Physiological Chemistry, Umeå University, Umeå, Sweden
| | - Eran Leitersdorf
- Department of Medicine B, Hadassah-Hebrew University Hospital, Israel
| | - Margret Warner
- Center for Nuclear Receptors and Cell Signaling, University of Houston, TX, USA
| | - Gunilla Olivercrona
- Department of Medical Biosciences/Physiological Chemistry, Umeå University, Umeå, Sweden
| | - Jan-Åke Gustafsson
- Center for Nuclear Receptors and Cell Signaling, University of Houston, TX, USA
| | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden.
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26
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Lopez AM, Chuang JC, Posey KS, Turley SD. Suppression of brain cholesterol synthesis in male Mecp2-deficient mice is age dependent and not accompanied by a concurrent change in the rate of fatty acid synthesis. Brain Res 2016; 1654:77-84. [PMID: 27789278 DOI: 10.1016/j.brainres.2016.10.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 10/13/2016] [Accepted: 10/21/2016] [Indexed: 12/29/2022]
Abstract
Mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2) are the principal cause of Rett syndrome, a progressive neurodevelopmental disorder afflicting 1 in 10,000 to 15,000 females. Studies using hemizygous Mecp2 mouse models have revealed disruptions to some aspects of their lipid metabolism including a partial suppression of cholesterol synthesis in the brains of mature Mecp2 mutants. The present studies investigated whether this suppression is evident from early neonatal life, or becomes manifest at a later stage of development. We measured the rate of cholesterol synthesis, in vivo, in the brains of male Mecp2-/y and their Mecp2+/y littermates at 7, 14, 21, 28, 42 and 56 days of age. Brain weight was consistently lower in the Mecp2-/y mice than in their Mecp2+/y controls except at 7 days of age. In the 7- and 14-day-old mice there was no genotypic difference in the rate of brain cholesterol synthesis but, from 21 days and later, it was always marginally lower in the Mecp2-/y mice than in age-matched Mecp2+/y littermates. At no age was a genotypic difference detected in either the rate of fatty acid synthesis or cholesterol concentration in the brain. Cholesterol synthesis rates in the liver and lungs of 56-day-old Mecp2-/y mice were normal. The onset of lower rates of brain cholesterol synthesis at about the time closure of the blood brain barrier purportedly occurs might signify a disruption to mechanism(s) that dictate intracellular levels of cholesterol metabolites including oxysterols known to exert a regulatory influence on the cholesterol biosynthetic pathway.
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Affiliation(s)
- Adam M Lopez
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Jen-Chieh Chuang
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Kenneth S Posey
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Stephen D Turley
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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27
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Wang H, Yuan L, Ma W, Han J, Lu Y, Feng L, Xiao R. The cytotoxicity of 27-hydroxycholesterol in co-cultured SH-SY5Y cells and C6 cells. Neurosci Lett 2016; 632:209-17. [DOI: 10.1016/j.neulet.2016.08.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 08/26/2016] [Accepted: 08/30/2016] [Indexed: 12/16/2022]
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28
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Mutemberezi V, Guillemot-Legris O, Muccioli GG. Oxysterols: From cholesterol metabolites to key mediators. Prog Lipid Res 2016; 64:152-169. [PMID: 27687912 DOI: 10.1016/j.plipres.2016.09.002] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/13/2016] [Accepted: 09/23/2016] [Indexed: 12/13/2022]
Abstract
Oxysterols are cholesterol metabolites that can be produced through enzymatic or radical processes. They constitute a large family of lipids (i.e. the oxysterome) involved in a plethora of physiological processes. They can act through GPCR (e.g. EBI2, SMO, CXCR2), nuclear receptors (LXR, ROR, ERα) and through transporters or regulatory proteins. Their physiological effects encompass cholesterol, lipid and glucose homeostasis. Additionally, they were shown to be involved in other processes such as immune regulatory functions and brain homeostasis. First studied as precursors of bile acids, they quickly emerged as interesting lipid mediators. Their levels are greatly altered in several pathologies and some oxysterols (e.g. 4β-hydroxycholesterol or 7α-hydroxycholestenone) are used as biomarkers of specific pathologies. In this review, we discuss the complex metabolism and molecular targets (including binding properties) of these bioactive lipids in human and mice. We also discuss the genetic mouse models currently available to interrogate their effects in pathophysiological settings. We also summarize the levels of oxysterols reported in two key organs in oxysterol metabolism (liver and brain), plasma and cerebrospinal fluid. Finally, we consider future opportunities and directions in the oxysterol field in order to gain a better insight and understanding of the complex oxysterol system.
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Affiliation(s)
- Valentin Mutemberezi
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium
| | - Owein Guillemot-Legris
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium
| | - Giulio G Muccioli
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium.
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29
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Koopal C, Visseren FL, Marais AD, Westerink J, Spiering W. Tendon xanthomas: Not always familial hypercholesterolemia. J Clin Lipidol 2016; 10:1262-5. [DOI: 10.1016/j.jacl.2016.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/31/2016] [Accepted: 05/06/2016] [Indexed: 02/07/2023]
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30
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Umetani M. Re-adopting classical nuclear receptors by cholesterol metabolites. J Steroid Biochem Mol Biol 2016; 157:20-6. [PMID: 26563834 PMCID: PMC4724260 DOI: 10.1016/j.jsbmb.2015.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 07/10/2015] [Accepted: 11/04/2015] [Indexed: 12/22/2022]
Abstract
Since the first cloning of the human estrogen receptor (ER) α in 1986 and the subsequent cloning of human ERβ, there has been extensive investigation of the role of estrogen/ER. Estrogens/ER play important roles not only in sexual development and reproduction but also in a variety of other functions in multiple tissues. Selective Estrogen Receptor Modulators (SERMs) are ER lignds that act as agonists or antagonists depending on the target genes and tissues, and until recently, only synthetic SERMs have been recognized. However, the discovery of the first endogenous SERM, 27-hydroxycholesterol (27HC), opened a new dimension of ER action in health and disease. In addition to the identification of 27HC as a SERM, oxysterols have been recently demonstrated as indirect modulators of ER through interaction with the nuclear receptor Liver X Receptor (LXR) β. In this review, the recent progress on these novel roles of oxysterols in ER modulation is summarized.
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Affiliation(s)
- Michihisa Umetani
- Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, 3517 Cullen Blvd, SERC 545, Houston, TX 77204-5056, USA.
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Mignarri A, Magni A, Del Puppo M, Gallus GN, Björkhem I, Federico A, Dotti MT. Evaluation of cholesterol metabolism in cerebrotendinous xanthomatosis. J Inherit Metab Dis 2016; 39:75-83. [PMID: 26153518 DOI: 10.1007/s10545-015-9873-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 06/02/2015] [Accepted: 06/05/2015] [Indexed: 02/02/2023]
Abstract
BACKGROUND Cerebrotendinous xanthomatosis (CTX) is a treatable bile acid disorder caused by mutations of CYP27A1. The pathogenesis of neurological damage has not been completely explained. Oral chenodeoxycholic acid (CDCA) can lead to clinical stabilization, but in a subgroup of patients the disease progresses despite treatment. In the present study, we aimed at clarifying cholesterol metabolism abnormalities and their response to CDCA treatment, in order to identify reliable diagnostic and prognostic markers and understand if differences exist between stable patients and those with neurological progression. METHODS We enrolled 19 untreated CTX patients and assessed serum profile of bile acids intermediates, oxysterols, cholesterol, lathosterol, and plant sterols. Then we performed a long-term follow up during CDCA therapy, and compared biochemical data with neurological outcome. RESULTS We observed increase of cholestanol, 7α-hydroxy-4-cholesten-3-one (7αC4), lathosterol, and plant sterols, whereas 27-hydroxycholesterol (27-OHC) was extremely low or absent. CDCA treatment at a daily dose of 750 mg normalized all biochemical parameters except for 7αC4 which persisted slightly higher than normal in most patients, and 27-OHC which was not modified by therapy. Biochemical evaluation did not reveal significant differences between stable and worsening patients. DISCUSSION Cholestanol and 7αC4 represent important markers for CTX diagnosis and monitoring of therapy. Treatment with CDCA should aim at normalizing serum 7αC4 as well as cholestanol, since 7αC4 better mirrors 7α-hydroxylation rate and is thought to be correlated with cholestanol accumulation in the brain. Assessment of serum 27-OHC is a very good tool for biochemical diagnosis at any stage of disease. Lathosterol and plant sterols should be considered as additional markers for diagnosis and monitoring of therapy. Further studies including long-term assessment of bile acid intermediates in cerebrospinal fluid are needed in patients who show clinical progression despite treatment.
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Affiliation(s)
- Andrea Mignarri
- Unit of Neurology and Neurometabolic Disorders, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy.
| | - Alessandro Magni
- Department of Health Sciences, Medical School, University of Milano-Bicocca, Milano, Italy
| | - Marina Del Puppo
- Department of Health Sciences, Medical School, University of Milano-Bicocca, Milano, Italy
| | - Gian Nicola Gallus
- Unit of Neurology and Neurometabolic Disorders, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Ingemar Björkhem
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institute, Karolinska University Hospital, Huddinge, Sweden
| | - Antonio Federico
- Unit of Neurology and Neurometabolic Disorders, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Maria Teresa Dotti
- Unit of Neurology and Neurometabolic Disorders, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
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27-Hydroxycholesterol contributes to disruptive effects on learning and memory by modulating cholesterol metabolism in the rat brain. Neuroscience 2015; 300:163-73. [PMID: 25987203 DOI: 10.1016/j.neuroscience.2015.05.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/21/2015] [Accepted: 05/08/2015] [Indexed: 12/30/2022]
Abstract
Cholesterol metabolism is important for neuronal function in the central nervous system (CNS). The oxysterol 27-hydroxycholesterol (27-OHC) is a cholesterol metabolite that crosses the blood-brain barrier (BBB) and may be a useful substitutive marker for neurodegenerative diseases. However, the effects of 27-OHC on learning and memory and the underlying mechanisms are unclear. To determine this mechanism, we investigated learning and memory and cholesterol metabolism in rat brain following the injection of various doses of 27-OHC into the caudal vein. We found that 27-OHC increased cholesterol levels and upregulated the expression of liver X receptor-α (LXR-α) and adenosine triphosphate (ATP)-binding cassette transporter protein family member A1 (ABCA1). In addition, 27-OHC decreased the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CR) and low-density lipoprotein receptor (LDLR) in rat brain tissues. These findings suggest that 27-OHC may negatively modulate cognitive effects and cholesterol metabolism in the brain.
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Pedrós I, Petrov D, Artiach G, Abad S, Ramon-Duaso C, Sureda F, Pallàs M, Beas-Zarate C, Folch J, Camins A. Adipokine pathways are altered in hippocampus of an experimental mouse model of Alzheimer's disease. J Nutr Health Aging 2015; 19:403-12. [PMID: 25809804 DOI: 10.1007/s12603-014-0574-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A growing body of evidence suggests that β-amyloid peptides (Aβ) are unlikely to be the only factor involved in Alzheimer's disease (AD) aetiology. In fact, a strong correlation has been established between AD patients and patients with type 2 diabetes and/or cholesterol metabolism alterations. In addition, a link between adipose tissue metabolism, leptin signalling in particular, and AD has also been demonstrated. In the present study we analyzed the expression of molecules related to metabolism, with the main focus on leptin and prolactin signalling pathways in an APPswe/PS1dE9 (APP/PS1) transgenic mice model, at 3 and 6 months of age, compared to wild-type controls. We have chosen to study 3 months-old APP/PS1 animals at an age when neither the cognitive deficits nor significant Aβ plaques in the brain are present, and to compare them to the 6 months-old mice, which exhibit elevated levels of Aβ in the hippocampus and memory loss. A significant reduction in both mRNA and protein levels of the prolactin receptor (PRL-R) was detected in the hippocampi of 3 months old APP/PS1 mice, with a decrease in the levels of the leptin receptor (OB-R) first becoming evident at 6 months of age. We proceeded to study the expression of the intracellular signalling molecules downstream of these receptors, including stat (1-5), sos1, kras and socs (1-3). Our data suggest a downregulation in some of these molecules such as stat-5b and socs (1-3), in 3 months-old APP/PS1 brains. Likewise, at the same age, we detected a significant reduction in mRNA levels of lrp1 and cyp46a1, both of which are involved in cholesterol homeostasis. Taken together, these results demonstrate a significative impairment in adipokine receptors signalling and cholesterol regulation pathways in the hippocampus of APP/PS1 mice at an early age, prior to the Aβ plaque formation.
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MESH Headings
- Adipokines/metabolism
- Alzheimer Disease/metabolism
- Alzheimer Disease/physiopathology
- Amyloid beta-Peptides/genetics
- Amyloid beta-Peptides/metabolism
- Animals
- Cholesterol/metabolism
- Cholesterol 24-Hydroxylase
- Diabetes Mellitus, Type 2/metabolism
- Disease Models, Animal
- Eating/genetics
- Hippocampus/metabolism
- Hippocampus/physiopathology
- Low Density Lipoprotein Receptor-Related Protein-1
- Male
- Memory Disorders
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Obesity/genetics
- Plaque, Amyloid/genetics
- Plaque, Amyloid/metabolism
- Proto-Oncogene Proteins p21(ras)/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, LDL/genetics
- Receptors, Leptin/genetics
- Receptors, Leptin/metabolism
- Receptors, Prolactin/genetics
- Receptors, Prolactin/metabolism
- SOS1 Protein/metabolism
- STAT Transcription Factors/metabolism
- Signal Transduction
- Steroid Hydroxylases/genetics
- Suppressor of Cytokine Signaling Proteins/metabolism
- Tumor Suppressor Proteins/genetics
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Affiliation(s)
- I Pedrós
- Antoni Camins PhD, Unitat de Farmacologia i Farmacognosia, Facultat de Farmàcia, Universitat de Barcelona, Spain. Avda/ Diagonal 643, E-08028 Barcelona, Spain. Tel: +34 93 4024531, Fax: +34 934035982,
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Estrogen receptor β and Liver X receptor β: biology and therapeutic potential in CNS diseases. Mol Psychiatry 2015; 20:18-22. [PMID: 24662928 DOI: 10.1038/mp.2014.23] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 02/03/2014] [Indexed: 12/13/2022]
Abstract
In the last decade of the twentieth century, two nuclear receptors were discovered in our laboratory and, very surprisingly, were found to have key roles in the central nervous system. These receptors have provided some novel insights into the etiology and progression of neurodegenerative diseases and anxiety disorders. The two receptors are estrogen receptor beta (ERβ) and liver X receptor beta (LXRβ). Both ERβ and LXRβ have potent anti-inflammatory activities and, in addition, LXRβ is involved in the genesis of dopaminergic neurons during development and protection of these neurons against neurodegeneration in adult life. ERβ is involved in migration of cortical neurons and calretinin-positive GABAergic interneurons during development and maintenance of serotonergic neurons in adults. Both receptors are present in magnocellular neurons of the hypothalamic preoptic area including those expressing vasopressin and oxytocin. As both ERβ and LXRβ are ligand-activated transcription factors, their ligands hold great potential in the treatment of diseases of the CNS.
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Lee WR, Ishikawa T, Umetani M. The interaction between metabolism, cancer and cardiovascular disease, connected by 27-hydroxycholesterol. ACTA ACUST UNITED AC 2014; 9:617-624. [PMID: 25632306 DOI: 10.2217/clp.14.53] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxysterols are metabolites of cholesterol that are produced in liver and other peripheral tissues as a means to eliminate cholesterol to bile acid. Recent studies have revealed that the most abundant circulating oxysterol 27-hydroxycholesterol (27HC) is the first identified endogenous selective estrogen receptor modulator. 27HC levels correlate well with that of cholesterol, and also rise progressively with age. 27HC affects estrogen receptor function by the antagonism of estrogen action and also by the direct modulation of the receptor function, and similar to estrogen/estrogen receptors, 27HC has many actions in various tissues. This review article introduces the recent progress in the understanding of the role of 27HC in breast cancer and cardiovascular dysfunction.
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Affiliation(s)
- Wan-Ru Lee
- Division of Pulmonary & Vascular Biology, Departments of Pediatrics & Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Tomonori Ishikawa
- Division of Pulmonary & Vascular Biology, Departments of Pediatrics & Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA ; Comprehensive Reproductive Medicine, Graduate School of Medical & Dental Sciences, Tokyo Medical & Dental University, Tokyo, Japan
| | - Michihisa Umetani
- Division of Pulmonary & Vascular Biology, Departments of Pediatrics & Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
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Vurusaner B, Gamba P, Testa G, Gargiulo S, Biasi F, Zerbinati C, Iuliano L, Leonarduzzi G, Basaga H, Poli G. Survival signaling elicited by 27-hydroxycholesterol through the combined modulation of cellular redox state and ERK/Akt phosphorylation. Free Radic Biol Med 2014; 77:376-85. [PMID: 25110320 DOI: 10.1016/j.freeradbiomed.2014.07.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 07/08/2014] [Accepted: 07/21/2014] [Indexed: 01/16/2023]
Abstract
The oxysterol 27-hydroxycholesterol (27-OH) is increasingly considered to be involved in a variety of pathophysiological processes, having been shown to modulate cell proliferation and metabolism, and also to exert proinflammatory and proapoptotic effects. This study aimed to elucidate the molecular pathways whereby 27-OH may generate survival signals in cells of the macrophage lineage, and to clarify whether its known prooxidant effect is involved in that process. A net up-regulation of survival signaling, involving the extracellular signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K)/Akt phosphorylation pathways, was observed in U937 promonocytic cells cultivated over time in the presence of a low micromolar concentration of the oxysterol. Interestingly, the up-regulation of both kinases was shown to be closely dependent on an early 27-OH-induced intracellular increase of reactive oxygen species (ROS). In turn, stimulation of ERK and PI3K/Akt both significantly quenched ROS steady state and markedly phosphorylated Bad, thereby determining a marked delay of the oxysterol׳s proapoptotic action. The 27-OH-induced survival pathways thus appear to be redox modulated and, if they occur within or nearby inflammatory cells during progression of chronic diseases such as cancer and atherosclerosis, they could significantly impact the growth and evolution of such diseases.
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Affiliation(s)
- Beyza Vurusaner
- Biological Sciences and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli-Tuzla, 34956 Istanbul, Turkey.
| | - Paola Gamba
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy.
| | - Gabriella Testa
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy.
| | - Simona Gargiulo
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy.
| | - Fiorella Biasi
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy.
| | - Chiara Zerbinati
- Department of Medical-Surgical Sciences and Biotechnology, Vascular Biology and Mass Spectrometry Laboratory, Sapienza University of Rome, Latina, Italy.
| | - Luigi Iuliano
- Department of Medical-Surgical Sciences and Biotechnology, Vascular Biology and Mass Spectrometry Laboratory, Sapienza University of Rome, Latina, Italy.
| | | | - Huveyda Basaga
- Biological Sciences and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli-Tuzla, 34956 Istanbul, Turkey.
| | - Giuseppe Poli
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy.
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Kuzaj P, Kuhn J, Dabisch-Ruthe M, Faust I, Götting C, Knabbe C, Hendig D. ABCC6- a new player in cellular cholesterol and lipoprotein metabolism? Lipids Health Dis 2014; 13:118. [PMID: 25064003 PMCID: PMC4124508 DOI: 10.1186/1476-511x-13-118] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/17/2014] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Dysregulations in cholesterol and lipid metabolism have been linked to human diseases like hypercholesterolemia, atherosclerosis or the metabolic syndrome. Many ABC transporters are involved in trafficking of metabolites derived from these pathways. Pseudoxanthoma elasticum (PXE), an autosomal-recessive disease caused by ABCC6 mutations, is characterized by atherogenesis and soft tissue calcification. METHODS In this study we investigated the regulation of cholesterol biosynthesis in human dermal fibroblasts from PXE patients and healthy controls. RESULTS Gene expression analysis of 84 targets indicated dysregulations in cholesterol metabolism in PXE fibroblasts. Transcript levels of ABCC6 were strongly increased in lipoprotein-deficient serum (LPDS) and under serum starvation in healthy controls. For the first time, increased HMG CoA reductase activities were found in PXE fibroblasts. We further observed strongly elevated transcript and protein levels for the proprotein convertase subtilisin/kexin type 9 (PCSK9), as well as a significant reduction in APOE mRNA expression in PXE. CONCLUSION Increased cholesterol biosynthesis, elevated PCSK9 levels and reduced APOE mRNA expression newly found in PXE fibroblasts could enforce atherogenesis and cardiovascular risk in PXE patients. Moreover, the increase in ABCC6 expression accompanied by the induction of cholesterol biosynthesis supposes a functional role for ABCC6 in human lipoprotein and cholesterol homeostasis.
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Affiliation(s)
| | | | | | | | | | | | - Doris Hendig
- Herz- und Diabeteszentrum NRW, Institut für Laboratoriums- und Transfusionsmedizin, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32 545 Bad Oeynhausen, Germany.
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Saeed AA, Genové G, Li T, Lütjohann D, Olin M, Mast N, Pikuleva IA, Crick P, Wang Y, Griffiths W, Betsholtz C, Björkhem I. Effects of a disrupted blood-brain barrier on cholesterol homeostasis in the brain. J Biol Chem 2014; 289:23712-22. [PMID: 24973215 PMCID: PMC4156098 DOI: 10.1074/jbc.m114.556159] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The presence of the blood-brain barrier (BBB) is critical for cholesterol metabolism in the brain, preventing uptake of lipoprotein-bound cholesterol from the circulation. The metabolic consequences of a leaking BBB for cholesterol metabolism have not been studied previously. Here we used a pericyte-deficient mouse model, Pdgfbret/ret, shown to have increased permeability of the BBB to a range of low-molecular mass and high-molecular mass tracers. There was a significant accumulation of plant sterols in the brains of the Pdgfbret/ret mice. By dietary treatment with 0.3% deuterium-labeled cholesterol, we could demonstrate a significant flux of cholesterol from the circulation into the brains of the mutant mice roughly corresponding to about half of the measured turnover of cholesterol in the brain. We expected the cholesterol flux into the brain to cause a down-regulation of cholesterol synthesis. Instead, cholesterol synthesis was increased by about 60%. The levels of 24(S)-hydroxycholesterol (24S-OHC) were significantly reduced in the brains of the pericyte-deficient mice but increased in the circulation. After treatment with 1% cholesterol in diet, the difference in cholesterol synthesis between mutants and controls disappeared. The findings are consistent with increased leakage of 24S-OHC from the brain into the circulation in the pericyte-deficient mice. This oxysterol is an efficient suppressor of cholesterol synthesis, and the results are consistent with a regulatory role of 24S-OHC in the brain. To our knowledge, this is the first demonstration that a defective BBB may lead to increased flux of a lipophilic compound out from the brain. The relevance of the findings for the human situation is discussed.
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Affiliation(s)
- Ahmed A Saeed
- From the Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institute, Huddinge, Stockholm 141 86, Sweden, the Department of Biochemistry, Faculty of Medicine, University of Khartoum, 11111 Khartoum, Sudan
| | - Guillem Genové
- the Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Tian Li
- the Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Dieter Lütjohann
- the Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn, D-53127 Bonn, Germany
| | - Maria Olin
- From the Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institute, Huddinge, Stockholm 141 86, Sweden
| | - Natalia Mast
- the Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio 44106, and
| | - Irina A Pikuleva
- the Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio 44106, and
| | - Peter Crick
- the Institute of Mass Spectrometry, College of Medicine, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Yuqin Wang
- the Institute of Mass Spectrometry, College of Medicine, Swansea University, Swansea SA2 8PP, United Kingdom
| | - William Griffiths
- the Institute of Mass Spectrometry, College of Medicine, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Christer Betsholtz
- the Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Ingemar Björkhem
- From the Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institute, Huddinge, Stockholm 141 86, Sweden,
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Wang Y, Karu K, Meljon A, Turton J, Yau JL, Seckl JR, Wang Y, Griffiths WJ. 24S,25-Epoxycholesterol in mouse and rat brain. Biochem Biophys Res Commun 2014; 449:229-34. [PMID: 24832732 PMCID: PMC4053837 DOI: 10.1016/j.bbrc.2014.05.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 05/05/2014] [Indexed: 11/17/2022]
Abstract
24S,25-Epoxycholesterol identified and quantified in rodent brain. Knock out of Cyp27a1 leads to a decrease in 24S,25-epoxycholesterol. Knock out of Cyp7b1 leads to an increase in 24S,25-epoxycholesterol. 24S,25-Epoxycholesterol is metabolised by Cyp7b1 but not Cyp27a1.
24S,25-Epoxycholesterol is formed in a shunt of the mevalonate pathway that produces cholesterol. It is one of the most potent known activators of the liver X receptors and can inhibit sterol regulatory element-binding protein processing. Until recently analysis of 24S,25-epoxycholesterol at high sensitivity has been precluded by its thermal lability and lack of a strong chromophore. Here we report on the analysis of 24S,25-epoxycholesterol in rodent brain where its level was determined to be of the order of 0.4–1.4 μg/g wet weight in both adult mouse and rat. For comparison the level of 24S-hydroxycholesterol in brain of both rodents was of the order of 20 μg/g, while that of cholesterol in mouse was 10–20 mg/g. By exploiting knockout mice for the enzyme oxysterol 7α-hydroxylase (Cyp7b1) we show that this enzymes is important for the subsequent metabolism of the 24S,25-epoxide.
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Affiliation(s)
- Yuchen Wang
- Clinical Laboratory, Jinan Infectious Disease Hospital, Shandong University, Jinan, Shandong, China.
| | - Kersti Karu
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Anna Meljon
- Institute of Mass Spectrometry, College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - John Turton
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Joyce L Yau
- Endocrinology Unit, BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Jonathan R Seckl
- Endocrinology Unit, BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Yuqin Wang
- Institute of Mass Spectrometry, College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - William J Griffiths
- Institute of Mass Spectrometry, College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
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Abstract
PURPOSE OF REVIEW Cerebrotendinous xanthomatosis (CTX) is a rare neurological disease characterized by accumulation of cholesterol and cholestanol in brain and tendons caused by a mutation in the sterol 27-hydroxylase gene (CYP27A1). The mechanism behind the accumulation of cholestanol in the brain was recently clarified and a role of 27-hydroxycholesterol as a regulator of brain cholesterol homeostasis has been established. RECENT FINDINGS There is a significant flux of the bile acid precursor 7α-hydroxy-4-cholesten-3-one across the blood-brain barrier in cy27-/- mice with its subsequent conversion into cholestanol. CTX patients with white matter lesions and vacuolation are described. CYP27A1 was identified as a candidate gene for sporadic amyotrophic lateral sclerosis (ALS). SUMMARY The mechanism behind accumulation of cholestanol in brain and tendons of patients with CTX has been clarified but it is not known why this accumulation is associated with parallel accumulation of cholesterol and formation of xanthomas. Further studies are needed to understand why some patients with CTX develop white matter lesions in the brain. In view of the fact that CTX can present with upper motor neuronal signs it is interesting that CYP27 has been shown to be a candidate gene for sporadic ALS.
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Affiliation(s)
- Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden.
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Maioli S, Båvner A, Ali Z, Heverin M, Ismail MAM, Puerta E, Olin M, Saeed A, Shafaati M, Parini P, Cedazo-Minguez A, Björkhem I. Is it possible to improve memory function by upregulation of the cholesterol 24S-hydroxylase (CYP46A1) in the brain? PLoS One 2013; 8:e68534. [PMID: 23874659 PMCID: PMC3712995 DOI: 10.1371/journal.pone.0068534] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 05/30/2013] [Indexed: 01/25/2023] Open
Abstract
We previously described a heterozygous mouse model overexpressing human HA-tagged 24S-hydroxylase (CYP46A1) utilizing a ubiquitous expression vector. In this study, we generated homozygotes of these mice with circulating levels of 24OH 30–60% higher than the heterozygotes. Female homozygous CYP46A1 transgenic mice, aged 15 months, showed an improvement in spatial memory in the Morris water maze test as compared to the wild type mice. The levels of N-Methyl-D-Aspartate receptor 1, phosphorylated-N-Methyl-D-Aspartate receptor 2A, postsynaptic density 95, synapsin-1 and synapthophysin were significantly increased in the hippocampus of the CYP46A1 transgenic mice as compared to the controls. The levels of lanosterol in the brain of the CYP46A1 transgenic mice were significantly increased, consistent with a higher synthesis of cholesterol. Our results are discussed in relation to the hypothesis that the flux in the mevalonate pathway in the brain is of importance in cognitive functions.
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Affiliation(s)
- Silvia Maioli
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Alzheimer's Disease Research Center, Novum, Stockholm, Sweden.
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Ačimovič J, Rozman D. Steroidal triterpenes of cholesterol synthesis. Molecules 2013; 18:4002-17. [PMID: 23558541 PMCID: PMC6269928 DOI: 10.3390/molecules18044002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 03/19/2013] [Accepted: 03/27/2013] [Indexed: 11/21/2022] Open
Abstract
Cholesterol synthesis is a ubiquitous and housekeeping metabolic pathway that leads to cholesterol, an essential structural component of mammalian cell membranes, required for proper membrane permeability and fluidity. The last part of the pathway involves steroidal triterpenes with cholestane ring structures. It starts by conversion of acyclic squalene into lanosterol, the first sterol intermediate of the pathway, followed by production of 20 structurally very similar steroidal triterpene molecules in over 11 complex enzyme reactions. Due to the structural similarities of sterol intermediates and the broad substrate specificity of the enzymes involved (especially sterol-Δ24-reductase; DHCR24) the exact sequence of the reactions between lanosterol and cholesterol remains undefined. This article reviews all hitherto known structures of post-squalene steroidal triterpenes of cholesterol synthesis, their biological roles and the enzymes responsible for their synthesis. Furthermore, it summarises kinetic parameters of enzymes (Vmax and Km) and sterol intermediate concentrations from various tissues. Due to the complexity of the post-squalene cholesterol synthesis pathway, future studies will require a comprehensive meta-analysis of the pathway to elucidate the exact reaction sequence in different tissues, physiological or disease conditions. A major reason for the standstill of detailed late cholesterol synthesis research was the lack of several steroidal triterpene standards. We aid to this efforts by summarizing commercial and laboratory standards, referring also to chemical syntheses of meiosis-activating sterols.
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Affiliation(s)
- Jure Ačimovič
- Centre for Functional Genomics and Bio-Chips, Faculty of Medicine, Institute of Biochemistry, University of Ljubljana, Zaloška 4, Ljubljana SI-1000, Slovenia.
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Meljon A, Watson GL, Wang Y, Shackleton CHL, Griffiths WJ. Analysis by liquid chromatography-mass spectrometry of sterols and oxysterols in brain of the newborn Dhcr7(Δ3-5/T93M) mouse: a model of Smith-Lemli-Opitz syndrome. Biochem Pharmacol 2013; 86:43-55. [PMID: 23500538 DOI: 10.1016/j.bcp.2013.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Revised: 02/28/2013] [Accepted: 03/01/2013] [Indexed: 10/27/2022]
Abstract
In this study the sterol and oxysterol profile of newborn brain from the Dhcr7(Δ3-5/T93M) mouse model of Smith-Lemli-Opitz syndrome (SLOS) has been investigated. This is a viable mouse model which is compound heterozygous containing one null allele and one T93M mutation on Dhcr7. We find the SLOS mouse has reduced levels of cholesterol and desmosterol and increased levels of 7- and 8-dehydrocholesterol and of 7- and 8-dehydrodesmosterol in brain compared to the wild type. The profile of enzymatically formed oxysterols in the SLOS mouse resembles that in the wild type but the level of 24S-hydroxycholesterol, the dominating cholesterol metabolite, is reduced in a similar proportion to that of cholesterol. A number of oxysterols abundant in the SLOS mouse are probably derived from 7-dehydrocholesterol, however, the mechanism of their formation is unclear.
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Affiliation(s)
- Anna Meljon
- Institute of Mass Spectrometry, College of Medicine, Swansea University, Singleton Park, Swansea SA2 8PP, UK
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