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Vallée M. Advances in steroid research from the pioneering neurosteroid concept to metabolomics: New insights into pregnenolone function. Front Neuroendocrinol 2024; 72:101113. [PMID: 37993022 DOI: 10.1016/j.yfrne.2023.101113] [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: 09/22/2023] [Revised: 11/13/2023] [Accepted: 11/19/2023] [Indexed: 11/24/2023]
Abstract
Advances in neuroendocrinology have led to major discoveries since the 19th century, identifying adaptive loops for maintaining homeostasis. One of the most remarkable discoveries was the concept of neurosteroids, according to which the brain is not only a target but also a source of steroid production. The identification of new membrane steroid targets now underpins the neuromodulatory effects of neurosteroids such as pregnenolone, which is involved in functions mediated by the GPCR CB1 receptor. Structural analysis of steroids is a key feature of their interactions with the phospholipid membrane, receptors and resulting activity. Therefore, mass spectrometry-based methods have been developed to elucidate the metabolic pathways of steroids, the ultimate approach being metabolomics, which allows the identification of a large number of metabolites in a single sample. This approach should enable us to make progress in understanding the role of neurosteroids in the functioning of physiological and pathological processes.
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Affiliation(s)
- Monique Vallée
- University Bordeaux, INSERM, Neurocentre Magendie, U1215, F-33000 Bordeaux, France.
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2
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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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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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Raux PL, Drutel G, Revest JM, Vallée M. New perspectives on the role of the neurosteroid pregnenolone as an endogenous regulator of type-1 cannabinoid receptor (CB1R) activity and function. J Neuroendocrinol 2022; 34:e13034. [PMID: 34486765 DOI: 10.1111/jne.13034] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/06/2021] [Accepted: 08/06/2021] [Indexed: 12/14/2022]
Abstract
Pregnenolone is a steroid with specific characteristics, being the first steroid to be synthesised from cholesterol at all sites of steroidogenesis, including the brain. For many years, pregnenolone was defined as an inactive precursor of all steroids because no specific target had been discovered. However, over the last decade, it has become a steroid of interest because it has been recognised as being a biomarker for brain-related disorders through the development of metabolomic approaches and advanced analytical methods. In addition, physiological roles for pregnenolone emerged when specific targets were discovered. In this review, we highlight the discovery of the selective interaction of pregnenolone with the type-1 cannabinoid receptor (CB1R). After describing the specific characteristic of CB1Rs, we discuss the newly discovered mechanisms of their regulation by pregnenolone. In particular, we describe the action of pregnenolone as a negative allosteric modulator and a specific signalling inhibitor of the CB1R. These particular characteristics of pregnenolone provide a great strategic opportunity for therapeutic development in CB1-related disorders. Finally, we outline new perspectives using innovative genetic tools for the discovery of original regulatory mechanisms of pregnenolone on CB1-related functions.
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Affiliation(s)
- Pierre-Louis Raux
- INSERM U1215, Neurocentre Magendie, Group "Physiopathology and Therapeutic Approaches of Stress-Related Disease", Bordeaux, France
- University of Bordeaux, Bordeaux, France
| | - Guillaume Drutel
- INSERM U1215, Neurocentre Magendie, Group "Physiopathology and Therapeutic Approaches of Stress-Related Disease", Bordeaux, France
- University of Bordeaux, Bordeaux, France
| | - Jean-Michel Revest
- INSERM U1215, Neurocentre Magendie, Group "Physiopathology and Therapeutic Approaches of Stress-Related Disease", Bordeaux, France
- University of Bordeaux, Bordeaux, France
| | - Monique Vallée
- INSERM U1215, Neurocentre Magendie, Group "Physiopathology and Therapeutic Approaches of Stress-Related Disease", Bordeaux, France
- University of Bordeaux, Bordeaux, France
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Rudzinskas S, Hoffman JF, Martinez P, Rubinow DR, Schmidt PJ, Goldman D. In vitro model of perimenopausal depression implicates steroid metabolic and proinflammatory genes. Mol Psychiatry 2021; 26:3266-3276. [PMID: 32788687 PMCID: PMC7878574 DOI: 10.1038/s41380-020-00860-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 11/09/2022]
Abstract
The estimated 20-30% of women who develop perimenopausal depression (PMD) are at an increased risk of cardiovascular and all-cause mortality. The therapeutic benefits of estradiol (E2) and symptom-provoking effects of E2-withdrawal (E2-WD) suggest that a greater sensitivity to changes in E2 at the cellular level contribute to PMD. We developed an in vitro model of PMD with lymphoblastoid cell lines (LCLs) derived from participants of a prior E2-WD clinical study. LCLs from women with past PMD (n = 8) or control women (n = 9) were cultured in three experimental conditions: at vehicle baseline, during E2 treatment, and following E2-WD. Transcriptome analysis revealed significant differences in transcript expression in PMD in all experimental conditions, and significant overlap in genes that were changed in PMD regardless of experimental condition. Of these, chemokine CXCL10, previously linked to cardiovascular disease, was upregulated in women with PMD, but most so after E2-WD (p < 1.55 × 10-5). CYP7B1, an enzyme intrinsic to DHEA metabolism, was upregulated in PMD across experimental conditions (F(1,45) = 19.93, p < 0.0001). These transcripts were further validated via qRT-PCR. Gene networks dysregulated in PMD included inflammatory response, early/late E2-response, and cholesterol homeostasis. Our results provide evidence that differential behavioral responsivity to E2-WD in PMD reflects intrinsic differences in cellular gene expression. Genes such as CXCL10, CYP7B1, and corresponding proinflammatory and steroid biosynthetic gene networks, may represent biomarkers and molecular targets for intervention in PMD. Finally, this in vitro model allows for future investigations into the mechanisms of genes and gene networks involved in the vulnerability to, and consequences of, PMD.
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Affiliation(s)
- Sarah Rudzinskas
- Behavioral Endocrinology Branch, NIMH, Bethesda, MD, USA,Laboratory of Neurogenetics, NIAAA, Rockville, MD, USA
| | - Jessica F. Hoffman
- Behavioral Endocrinology Branch, NIMH, Bethesda, MD, USA,Laboratory of Neurogenetics, NIAAA, Rockville, MD, USA
| | - Pedro Martinez
- Behavioral Endocrinology Branch, NIMH, Bethesda, MD, USA
| | - David R. Rubinow
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | | | - David Goldman
- Laboratory of Neurogenetics, NIAAA, Rockville, MD, USA
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Concentrations of estradiol, progesterone and testosterone in sefrum and cerebrospinal fluid of patients with aneurysmal subarachnoid hemorrhage correlate weakly with transcranial Doppler flow velocities. BMC Neurosci 2021; 22:29. [PMID: 33892632 PMCID: PMC8067654 DOI: 10.1186/s12868-021-00634-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 04/13/2021] [Indexed: 12/14/2022] Open
Abstract
Background The implication of the steroids estradiol, progesterone and testosterone in cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH) has not been comprehensively assessed. In rodents, studies suggested beneficial effects of steroids on cerebral vasospasm after experimental SAH. Studies in humans are warranted, however, a general dilemma of human studies on neuroactive substances is that the brain is not directly accessible and that concentrations in the periphery may not adequately parallel concentrations in the central compartments. In the present study, concentrations of estradiol, progesterone and testosterone in serum and cerebrospinal fluid (CSF) of patients with aSAH were determined. Blood flow velocities in cerebral arteries were measured by transcranial Doppler sonography (TCD). The aim of this study was to evaluate the correlations between the cerebral blood flow velocities and levels of estradiol, progesterone and testosterone in CSF and serum. Results Samples of serum and CSF of 42 patients with aSAH were collected concomitantly daily or every other day via the arterial line and the external ventricular drainage for two weeks after the hemorrhage. Blood flow velocities in the cerebral arteries were determined by TCD. Total estradiol, progesterone and testosterone concentrations were measured by electro-chemiluminescence immunoassay. The strength of correlation was assessed by Spearman’s rank correlation coefficient. The correlation analysis revealed very weak correlations between cerebral blood flow velocities and concentrations of estradiol, progesterone and testosterone levels in both compartments with correlation coefficients below 0.2. Conclusions In humans with aSAH, merely very weak correlations between flow velocities in cerebral arteries and concentrations of estradiol, progesterone and testosterone in serum and CSF were demonstrated. These results suggest a limited influence of the respective steroids on cerebral vascular tone although vasodilatory effects were described in rodent studies. Thus, the implication of steroids in processes of neurological deterioration warrants further clarification.
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Hippocampal 7α-Hydroxylated Neurosteroids Are Raised by Training and Bolster Remote Spatial Memory with Increase of the Spine Densities. iScience 2020; 23:101559. [PMID: 33083728 PMCID: PMC7522809 DOI: 10.1016/j.isci.2020.101559] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/01/2020] [Accepted: 09/10/2020] [Indexed: 01/01/2023] Open
Abstract
Neuroactive steroids, termed neurosteroids, are synthesized locally in the brain and influence biological functions including cognition and behavior. These neurosteroids are synthesized from cholesterol by a series of cytochrome P450 enzymes, among which a member of P450 hydroxylase, cytochrome P450-7b1 (CYP7B1), catalyzes the formation of 7α-hydroxylated neurosteroids, 7α-hydroxypregnenolone (7α-OH-Preg) and 7α-hydroxydehydroepiandrosterone (7α-OH-DHEA). Here we demonstrated the occurrence of these neurosteroids in the mouse hippocampus after spatial-learning tasks. Cyp7b1 deficiency impaired remote spatial memory with recent memory mostly unaffected. The hippocampal dendritic spine densities were reduced in Cyp7b1-deficient mice, and they were no more increased by the training. Furthermore, chronic intracerebroventricular administration of a mixture of 7α-OH-Preg and 7α-OH-DHEA rescued the deteriorated remote memory performance in Cyp7b1-deficient mice. It is concluded that the 7α-hydroxylated neurosteroids are required for long-term maintenance of spatial memory, and we suggest that these neurosteroids may induce synaptic remodeling to maintain the hippocampal function. LC-MS/MS analysis identified 7α-hydroxylated neurosteroids in the mouse hippocampus The hippocampal neurosteroids were induced by spatial water maze training KO of 7α-hydroxylating enzyme impaired remote memory and hippocampal spine density Infusion of the 7α-hydroxylated steroids to the KO rescued impaired remote memory
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Leff-Gelman P, Flores-Ramos M, Carrasco AEÁ, Martínez ML, Takashima MFS, Coronel FMC, Labonne BF, Dosal JAZ, Chávez-Peón PB, Morales SG, Camacho-Arroyo I. Cortisol and DHEA-S levels in pregnant women with severe anxiety. BMC Psychiatry 2020; 20:393. [PMID: 32758184 PMCID: PMC7409431 DOI: 10.1186/s12888-020-02788-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/17/2020] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND A complex interaction between cortisol and dehydroepiandrosterone-sulphate (DHEA-S) is crucial in the stress system balance; several studies have reported increased cortisol levels during chronic stress and a weak counter-regulation by DHEA-S. During pregnancy, scarce information about this system is available, although cortisol and DHEA-S play an important role in the initiation and acceleration of labor. We conducted the present study in order to determine both cortisol and DHEA-S levels during the last trimester of pregnancy in patients exhibiting severe anxiety. METHODS Pregnant women during the 3rd trimester of pregnancy were evaluated by using the self-reported version of the Hamilton Anxiety Rating Scale (HARS). According to the scores obtained from the psychometric scale, participants were divided into two groups: 1) patients exhibiting a cutoff score > 15 were considered with severe anxiety (ANX) (n = 101), and control pregnant subjects (CTRL) (n = 44) with a cutoff score < 5. Morning cortisol, DHEA-S and Cortisol/DHEA-S index were measured in all participants. Comparisons between groups were performed; additionally, correlations between clinical variables, biochemical data and HARS were calculated. RESULTS Cortisol levels were significantly higher in the ANX group (p < 0.001), whereas those of DHEA-S were significantly lower in the same group (p < 0.01) when compared to healthy pregnant subjects. An increased cortisol/DHEA-S index was observed in the ANX group (p < 0.05). A significant association between cortisol and HARS scores (p = 0.03), was observed even after adjusting by gestational weeks (p = 0.004). CONCLUSIONS Our data support that the cortisol/DHEA-S index is higher in pregnant women with high anxiety levels as compared with healthy pregnant women.
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Affiliation(s)
| | - Mónica Flores-Ramos
- grid.419154.c0000 0004 1776 9908Instituto Nacional de Psiquiatría, 14370 CDMX Mexico City, Mexico ,grid.418270.80000 0004 0428 7635Consejo Nacional de Ciencia y Tecnología/CONACyT, 03940 CDMX Mexico City, Mexico
| | | | - Margarita López Martínez
- grid.419218.70000 0004 1773 5302Instituto Nacional de Perinatología, 11000 CDMX Mexico City, Mexico
| | | | - Fausto Manuel Cruz Coronel
- grid.414716.10000 0001 2221 3638Hospital General de México, Dr. Eduardo Liceaga, 06720 CDMX Mexico City, Mexico
| | - Blanca Farfán Labonne
- grid.419218.70000 0004 1773 5302Instituto Nacional de Perinatología, 11000 CDMX Mexico City, Mexico
| | | | | | - Saul Garza Morales
- grid.419218.70000 0004 1773 5302Instituto Nacional de Perinatología, 11000 CDMX Mexico City, Mexico
| | - Ignacio Camacho-Arroyo
- grid.9486.30000 0001 2159 0001Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México, 04510 CDMX Mexico City, Mexico
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Hajeyah AA, Griffiths WJ, Wang Y, Finch AJ, O’Donnell VB. The Biosynthesis of Enzymatically Oxidized Lipids. Front Endocrinol (Lausanne) 2020; 11:591819. [PMID: 33329396 PMCID: PMC7711093 DOI: 10.3389/fendo.2020.591819] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022] Open
Abstract
Enzymatically oxidized lipids are a specific group of biomolecules that function as key signaling mediators and hormones, regulating various cellular and physiological processes from metabolism and cell death to inflammation and the immune response. They are broadly categorized as either polyunsaturated fatty acid (PUFA) containing (free acid oxygenated PUFA "oxylipins", endocannabinoids, oxidized phospholipids) or cholesterol derivatives (oxysterols, steroid hormones, and bile acids). Their biosynthesis is accomplished by families of enzymes that include lipoxygenases (LOX), cyclooxygenases (COX), cytochrome P450s (CYP), and aldo-keto reductases (AKR). In contrast, non-enzymatically oxidized lipids are produced by uncontrolled oxidation and are broadly considered to be harmful. Here, we provide an overview of the biochemistry and enzymology of LOXs, COXs, CYPs, and AKRs in humans. Next, we present biosynthetic pathways for oxylipins, oxidized phospholipids, oxysterols, bile acids and steroid hormones. Last, we address gaps in knowledge and suggest directions for future work.
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Affiliation(s)
- Ali A. Hajeyah
- Systems Immunity Research Institute and Division of Infection and Immunity, Cardiff University, Cardiff, United Kingdom
- *Correspondence: Ali A. Hajeyah,
| | - William J. Griffiths
- Institute of Life Science, Swansea University Medical School, Swansea, United Kingdom
| | - Yuqin Wang
- Institute of Life Science, Swansea University Medical School, Swansea, United Kingdom
| | - Andrew J. Finch
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Valerie B. O’Donnell
- Systems Immunity Research Institute and Division of Infection and Immunity, Cardiff University, Cardiff, United Kingdom
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Martin J, Plank E, Jungwirth B, Hapfelmeier A, Podtschaske A, Kagerbauer SM. Weak correlations between serum and cerebrospinal fluid levels of estradiol, progesterone and testosterone in males. BMC Neurosci 2019; 20:53. [PMID: 31619164 PMCID: PMC6794746 DOI: 10.1186/s12868-019-0535-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 10/05/2019] [Indexed: 01/16/2023] Open
Abstract
Background Neuroactive steroids seem to be implicated in a variety of neurophysiological and behavioral processes, such as sleep, learning, memory, stress, feeding and aging. Numerous studies have also addressed this implication in various cerebral disorders and diseases. Yet, the correlation and association between steroids in the periphery, e.g. blood, and the central compartments, e.g. cerebrospinal fluid (CSF), have not yet been comprehensively assessed. As the brain is not directly accessible, and the collection of human CSF usually requires invasive procedures, easier accessible compartments, such as blood, have always attracted attention. However, studies in humans are scarce. In the present study we determined estradiol, progesterone and testosterone levels in CSF and serum of 22 males without cerebral disorders or diseases. Results Samples were taken under conditions corresponding closest to basal conditions with patients expecting only spinal anesthesia and minor surgery. All samples per patient were collected concomitantly. Total estradiol, progesterone and testosterone concentrations were measured by electro-chemiluminescence immunoassay. The strength of correlation was assessed by Spearman’s rank correlation coefficient. Correlation analysis revealed merely weak to very weak correlations for estradiol, progesterone and testosterone respectively between the CSF and serum compartments. Conclusions Total steroid levels of estradiol, progesterone and testosterone in CSF and serum of males without neurological disorders were determined. Weak to very weak correlations between CSF and serum were found thus suggesting that concentrations in the periphery do not parallel concentrations in the central compartments. Further research is needed to clarify to what extent and under which conditions serum levels of estradiol, progesterone and testosterone may possibly serve as a biomarker reflecting the respective concentrations in the CSF or in the brain.
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Affiliation(s)
- Jan Martin
- Department of Anesthesiology and Intensive Care Medicine, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Ismaninger Strasse 22, 81675, Munich, Germany.
| | - Eva Plank
- Department of Anesthesiology and Intensive Care Medicine, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Ismaninger Strasse 22, 81675, Munich, Germany
| | - Bettina Jungwirth
- Department of Anesthesiology and Intensive Care Medicine, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Ismaninger Strasse 22, 81675, Munich, Germany
| | - Alexander Hapfelmeier
- Institute of Medical Informatics, Statistics und Epidemiology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Ismaninger Str. 22, 81675, Munich, Germany
| | - Armin Podtschaske
- Department of Anesthesiology and Intensive Care Medicine, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Ismaninger Strasse 22, 81675, Munich, Germany
| | - Simone M Kagerbauer
- Department of Anesthesiology and Intensive Care Medicine, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Ismaninger Strasse 22, 81675, Munich, Germany
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Rendic SP, Peter Guengerich F. Human cytochrome P450 enzymes 5-51 as targets of drugs and natural and environmental compounds: mechanisms, induction, and inhibition - toxic effects and benefits. Drug Metab Rev 2019; 50:256-342. [PMID: 30717606 DOI: 10.1080/03602532.2018.1483401] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cytochrome P450 (P450, CYP) enzymes have long been of interest due to their roles in the metabolism of drugs, pesticides, pro-carcinogens, and other xenobiotic chemicals. They have also been of interest due to their very critical roles in the biosynthesis and metabolism of steroids, vitamins, and certain eicosanoids. This review covers the 22 (of the total of 57) human P450s in Families 5-51 and their substrate selectivity. Furthermore, included is information and references regarding inducibility, inhibition, and (in some cases) stimulation by chemicals. We update and discuss important aspects of each of these 22 P450s and questions that remain open.
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Affiliation(s)
| | - F Peter Guengerich
- b Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , TN , USA
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Kakiyama G, Marques D, Takei H, Nittono H, Erickson S, Fuchs M, Rodriguez-Agudo D, Gil G, Hylemon PB, Zhou H, Bajaj JS, Pandak WM. Mitochondrial oxysterol biosynthetic pathway gives evidence for CYP7B1 as controller of regulatory oxysterols. J Steroid Biochem Mol Biol 2019; 189:36-47. [PMID: 30710743 DOI: 10.1016/j.jsbmb.2019.01.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 01/17/2019] [Accepted: 01/22/2019] [Indexed: 12/13/2022]
Abstract
The aim of this paper was to more completely study the mitochondrial CYP27A1 initiated acidic pathway of cholesterol metabolism. The mitochondrial CYP27A1 initiated pathway of cholesterol metabolism (acidic pathway) is known to synthesize two well-described vital regulators of cholesterol/lipid homeostasis, (25R)-26-hydroxycholesterol (26HC) and 25-hydroxycholesterol (25HC). Both 26HC and 25HC have been shown to be subsequently 7α-hydroxylated by Cyp7b1; reducing their regulatory abilities and furthering their metabolism to chenodeoxycholic acid (CDCA). Cholesterol delivery into the inner mitochondria membrane, where CYP27A1 is located, is considered the pathway's only rate-limiting step. To further explore the pathway, we increased cholesterol transport into mitochondrial CYP27A1 by selectively increased expression of the gene encoding the steroidogenic acute transport protein (StarD1). StarD1 overexpression led to an unanticipated marked down-regulation of oxysterol 7α-hydroxylase (Cyp7b1), a marked increase in 26HC, and the formation of a third vital regulatory oxysterol, 24(S)-hydroxycholesterol (24HC), in B6/129 mice livers. To explore the further metabolism of 24HC, as well as, 25HC and 26HC, characterizations of oxysterols and bile acids using three murine models (StarD1 overexpression, Cyp7b1-/-, Cyp27a1-/-) and human Hep G2 cells were conducted. This report describes the discovery of a new mitochondrial-initiated pathway of oxysterol/bile acid biosynthesis. Just as importantly, it provides evidence for CYP7B1 as a key regulator of three vital intracellular regulatory oxysterol levels.
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Affiliation(s)
- Genta Kakiyama
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States.
| | - Dalila Marques
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Hajime Takei
- Junshin Clinic Bile Acid Institute, Tokyo, Japan
| | | | - Sandra Erickson
- School of Medicine, University of California, San Francisco, United States
| | - Michael Fuchs
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Daniel Rodriguez-Agudo
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Gregorio Gil
- Department of Biochemistry & Molecular Biology, Virginia Commonwealth University, United States
| | - Phillip B Hylemon
- Department of Microbiology and Immunology, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Huiping Zhou
- Department of Microbiology and Immunology, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Jasmohan S Bajaj
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - William M Pandak
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
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13
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Meljon A, Crick PJ, Yutuc E, Yau JL, Seckl JR, Theofilopoulos S, Arenas E, Wang Y, Griffiths WJ. Mining for Oxysterols in Cyp7b1-/- Mouse Brain and Plasma: Relevance to Spastic Paraplegia Type 5. Biomolecules 2019; 9:biom9040149. [PMID: 31013940 PMCID: PMC6523844 DOI: 10.3390/biom9040149] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/28/2019] [Accepted: 04/02/2019] [Indexed: 01/19/2023] Open
Abstract
Deficiency in cytochrome P450 (CYP) 7B1, also known as oxysterol 7α-hydroxylase, in humans leads to hereditary spastic paraplegia type 5 (SPG5) and in some cases in infants to liver disease. SPG5 is medically characterized by loss of motor neurons in the corticospinal tract. In an effort to gain a better understanding of the fundamental biochemistry of this disorder, we have extended our previous profiling of the oxysterol content of brain and plasma of Cyp7b1 knockout (-/-) mice to include, amongst other sterols, 25-hydroxylated cholesterol metabolites. Although brain cholesterol levels do not differ between wild-type (wt) and knockout mice, we find, using a charge-tagging methodology in combination with liquid chromatography-mass spectrometry (LC-MS) and multistage fragmentation (MSn), that there is a build-up of the CYP7B1 substrate 25-hydroxycholesterol (25-HC) in Cyp7b1-/- mouse brain and plasma. As reported earlier, levels of (25R)26-hydroxycholesterol (26-HC), 3β-hydroxycholest-5-en-(25R)26-oic acid and 24S,25-epoxycholesterol (24S,25-EC) are similarly elevated in brain and plasma. Side-chain oxysterols including 25-HC, 26-HC and 24S,25-EC are known to bind to INSIG (insulin-induced gene) and inhibit the processing of SREBP-2 (sterol regulatory element-binding protein-2) to its active form as a master regulator of cholesterol biosynthesis. We suggest the concentration of cholesterol in brain of the Cyp7b1-/- mouse is maintained by balancing reduced metabolism, as a consequence of a loss in CYP7B1, with reduced biosynthesis. The Cyp7b1-/- mouse does not show a motor defect; whether the defect in humans is a consequence of less efficient homeostasis of cholesterol in brain has yet to be uncovered.
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Affiliation(s)
- Anna Meljon
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK.
- Institute for Global Food Security, Queens University Belfast, Stranmillis Road, Belfast BT9 5AG, UK.
| | - Peter J Crick
- 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.
| | - 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.
| | - 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, SE-17177 Stockholm, Sweden.
| | - Ernest Arenas
- Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden.
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK.
| | - William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK.
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14
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Spady ES, Wyche TP, Rollins NJ, Clardy J, Way JC, Silver PA. Mammalian Cells Engineered To Produce New Steroids. Chembiochem 2018; 19:1827-1833. [PMID: 29931794 PMCID: PMC6156985 DOI: 10.1002/cbic.201800214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Indexed: 11/12/2022]
Abstract
Steroids can be difficult to modify through traditional organic synthesis methods, but many enzymes regio- and stereoselectively process a wide variety of steroid substrates. We tested whether steroid-modifying enzymes could make novel steroids from non-native substrates. Numerous genes encoding steroid-modifying enzymes, including some bacterial enzymes, were expressed in mammalian cells by transient transfection and found to be active. We made three unusual steroids by stable expression, in HEK293 cells, of the 7α-hydroxylase CYP7B1, which was selected because of its high native product yield. These cells made 7α,17α-dihydroxypregnenolone and 7β,17α-dihydroxypregnenolone from 17α-hydroxypregnenolone and produced 11α,16α-dihydroxyprogesterone from 16α-hydroxyprogesterone. The last two products were the result of CYP7B1-catalyzed hydroxylation at previously unobserved sites. A Rosetta docking model of CYP7B1 suggested that these substrates' D-ring hydroxy groups might prevent them from binding in the same way as the native substrates, bringing different carbon atoms close to the active ferryl oxygen atom. This new approach could potentially use other enzymes and substrates to produce many novel steroids for drug candidate testing.
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Affiliation(s)
- Emma S. Spady
- Department of Systems Biology, Harvard Medical School – Boston, MA 02115, United States
- Laboratory of Systems Pharmacology, Harvard University – Boston, MA 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University – Boston, MA 02115, United States
| | - Thomas P. Wyche
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School – Boston, MA 02115, United States
| | - Nathanael J. Rollins
- Department of Systems Biology, Harvard Medical School – Boston, MA 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University – Boston, MA 02115, United States
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School – Boston, MA 02115, United States
| | - Jeffrey C. Way
- Department of Systems Biology, Harvard Medical School – Boston, MA 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University – Boston, MA 02115, United States
| | - Pamela A. Silver
- Department of Systems Biology, Harvard Medical School – Boston, MA 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University – Boston, MA 02115, United States
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15
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Tsutsui K, Haraguchi S, Vaudry H. 7α-Hydroxypregnenolone regulating locomotor behavior identified in the brain and pineal gland across vertebrates. Gen Comp Endocrinol 2018; 265:97-105. [PMID: 28919448 DOI: 10.1016/j.ygcen.2017.09.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 08/30/2017] [Accepted: 09/13/2017] [Indexed: 01/29/2023]
Abstract
The brain synthesizes steroids de novo from cholesterol, which are called neurosteroids. Based on extensive studies on neurosteroids over the past thirty years, it is now accepted that neurosteroidogenesis in the brain is a conserved property across vertebrates. However, the formation of bioactive neurosteroids in the brain is still incompletely elucidated in vertebrates. In fact, we recently identified 7α-hydroxypregnenolone (7α-OH PREG) as a novel bioactive neurosteroid stimulating locomotor behavior in the brain of several vertebrates. The follow-up studies have demonstrated that the stimulatory action of brain 7α-OH PREG on locomotor behavior is mediated by the dopaminergic system across vertebrates. More recently, we have further demonstrated that the pineal gland, an endocrine organ located close to the brain, is a major site of the formation of bioactive neurosteroids. In addition to the brain, the pineal gland actively produces 7α-OH PREG de novo from cholesterol as a major pineal neurosteroid that acts on the brain to control locomotor rhythms. This review summarizes the identification, biosynthesis and mode of action of brain and pineal 7α-OH PREG, a new bioactive neurosteroid regulating locomotor behavior, across vertebrates.
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Affiliation(s)
- Kazuyoshi Tsutsui
- Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo 162-8480, Japan.
| | - Shogo Haraguchi
- Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo 162-8480, Japan; Department of Biochemistry, Showa University School of Medicine, Tokyo 142-8555, Japan
| | - Hubert Vaudry
- INSERM U1239, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Normandy University, 76000 Rouen, France
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16
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Twyman H, Andersson S, Mundy NI. Evolution of CYP2J19, a gene involved in colour vision and red coloration in birds: positive selection in the face of conservation and pleiotropy. BMC Evol Biol 2018; 18:22. [PMID: 29439676 PMCID: PMC5812113 DOI: 10.1186/s12862-018-1136-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 01/31/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Exaggerated signals, such as brilliant colours, are usually assumed to evolve through antagonistic coevolution between senders and receivers, but the underlying genetic mechanisms are rarely known. Here we explore a recently identified "redness gene", CYP2J19, that is highly interesting in this context since it encodes a carotenoid-modifying enzyme (a C4 ketolase involved in both colour signalling and colour discrimination in the red (long wavelength) spectral region.) RESULTS: A single full-length CYP2J19 was retrieved from 43 species out of 70 avian genomes examined, representing all major avian clades. In addition, CYP2J19 sequences from 13 species of weaverbirds (Ploceidae), seven of which have red C4-ketocarotenoid coloration were analysed. Despite the conserved retinal function and pleiotropy of CYP2J19, analyses indicate that the gene has been positively selected throughout the radiation of birds, including sites within functional domains described in related CYP (cytochrome P450) loci. Analyses of eight further CYP loci across 25 species show that positive selection is common in this gene family in birds. There was no evidence for a change in selection pressure on CYP2J19 following co-option for red coloration in the weaverbirds. CONCLUSIONS The results presented here are consistent with an ancestral conserved function of CYP2J19 in the pigmentation of red retinal oil droplets used for colour vision, and its subsequent co-option for red integumentary coloration. The cause of positive selection on CYP2J19 is unclear, but may be partly related to compensatory mutations related to selection at the adjacent gene CYP2J40.
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Affiliation(s)
- Hanlu Twyman
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ UK
| | - Staffan Andersson
- Department of Biological and Environmental Sciences, University of Gothenburg, 40530 Göteborg, Sweden
| | - Nicholas I. Mundy
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ UK
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17
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STÁRKA L. The Origin of 7α-Hydroxy-Dehydroepiandrosterone and Its Physiological Role: a History of Discoveries. Physiol Res 2017; 66:S285-S294. [DOI: 10.33549/physiolres.933717] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Nearly 60 years has elapsed since the first isolation and identification of 7α-hydroxy-dehydroepiandrosterone, and in that time much information has been gained on its occurrence, metabolism, ontogeny, immunomodulatory activity, cell proliferation, cortisol control in local tissues and neuroactivity. Additional knowledge about this steroid may elucidate its role in obesity, neurodegenerative disturbances such as Alzheimer’s disease, or psychiatric disorders such as schizophrenia or depression. This review aims to provide a comprehensive summary of the available literature on 7α-hydroxy-dehydroepiandrosterone.
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Affiliation(s)
- L. STÁRKA
- Institute of Endocrinology, Prague, Czech Republic
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18
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Tuem KB, Atey TM. Neuroactive Steroids: Receptor Interactions and Responses. Front Neurol 2017; 8:442. [PMID: 28894435 PMCID: PMC5581316 DOI: 10.3389/fneur.2017.00442] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/11/2017] [Indexed: 12/21/2022] Open
Abstract
Neuroactive steroids (NASs) are naturally occurring steroids, which are synthesized centrally as de novo from cholesterol and are classified as pregnane, androstane, and sulfated neurosteroids (NSs). NASs modulate many processes via interacting with gamma-aminobutyric acid (GABA), N-methyl-d-aspartate, serotonin, voltage-gated calcium channels, voltage-dependent anion channels, α-adrenoreceptors, X-receptors of the liver, transient receptor potential channels, microtubule-associated protein 2, neurotrophin nerve growth factor, and σ1 receptors. Among these, NSs (especially allopregnanolone) have high potency and extensive GABA-A receptors and hence demonstrate anticonvulsant, anesthetic, central cytoprotectant, and baroreflex inhibitory effects. NSs are also involved in mood and learning via serotonin and anti-nociceptive activity via T-type voltage-gated Ca2+ channels. Moreover, they are modulators of mitochondrial function, synaptic plasticity, or regulators of apoptosis, which have a role in neuroprotective via voltage-dependent anion channels receptors. For proper functioning, NASs need to be in their normal level, whereas excess and deficiency may lead to abnormalities. When they are below the normal, NSs could have a part in development of depression, neuro-inflammation, multiple sclerosis, experimental autoimmune encephalitis, epilepsy, and schizophrenia. On the other hand, stress and attention deficit disorder could occur during excessive level. Overall, NASs are very important molecules with major neuropsychiatric activity.
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Affiliation(s)
- Kald Beshir Tuem
- Department of Pharmacology, School of Pharmacy, College of Health Sciences, Mekelle University, Mekelle, Ethiopia
| | - Tesfay Mehari Atey
- Clinical Pharmacy Unit, School of Pharmacy, College of Health Sciences, Mekelle University, Mekelle, Ethiopia
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19
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Vaz FM, Ferdinandusse S. Bile acid analysis in human disorders of bile acid biosynthesis. Mol Aspects Med 2017; 56:10-24. [PMID: 28322867 DOI: 10.1016/j.mam.2017.03.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/11/2017] [Accepted: 03/16/2017] [Indexed: 01/17/2023]
Abstract
Bile acids facilitate the absorption of lipids in the gut, but are also needed to maintain cholesterol homeostasis, induce bile flow, excrete toxic substances and regulate energy metabolism by acting as signaling molecules. Bile acid biosynthesis is a complex process distributed across many cellular organelles and requires at least 17 enzymes in addition to different metabolite transport proteins to synthesize the two primary bile acids, cholic acid and chenodeoxycholic acid. Disorders of bile acid synthesis can present from the neonatal period to adulthood and have very diverse clinical symptoms ranging from cholestatic liver disease to neuropsychiatric symptoms and spastic paraplegias. This review describes the different bile acid synthesis pathways followed by a summary of the current knowledge on hereditary disorders of human bile acid biosynthesis with a special focus on diagnostic bile acid profiling using mass spectrometry.
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Affiliation(s)
- Frédéric M Vaz
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, The Netherlands.
| | - Sacha Ferdinandusse
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, The Netherlands
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20
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Cheung TT, Weston MK, Wilson MJ. Selection and evaluation of reference genes for analysis of mouse (Mus musculus) sex-dimorphic brain development. PeerJ 2017; 5:e2909. [PMID: 28133578 PMCID: PMC5251938 DOI: 10.7717/peerj.2909] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 12/08/2016] [Indexed: 11/24/2022] Open
Abstract
The development of the brain is sex-dimorphic, and as a result so are many neurological disorders. One approach for studying sex-dimorphic brain development is to measure gene expression in biological samples using RT-qPCR. However, the accuracy and consistency of this technique relies on the reference gene(s) selected. We analyzed the expression of ten reference genes in male and female samples over three stages of brain development, using popular algorithms NormFinder, GeNorm and Bestkeeper. The top ranked reference genes at each time point were further used to quantify gene expression of three sex-dimorphic genes (Wnt10b, Xist and CYP7B1). When comparing gene expression between the sexes expression at specific time points the best reference gene combinations are: Sdha/Pgk1 at E11.5, RpL38/Sdha E12.5, and Actb/RpL37 at E15.5. When studying expression across time, the ideal reference gene(s) differs with sex. For XY samples a combination of Actb/Sdha. In contrast, when studying gene expression across developmental stage with XX samples, Sdha/Gapdh were the top reference genes. Our results identify the best combination of two reference genes when studying male and female brain development, and emphasize the importance of selecting the correct reference genes for comparisons between developmental stages.
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Affiliation(s)
- Tanya T Cheung
- Department of Anatomy, University of Otago , Dunedin , New Zealand
| | | | - Megan J Wilson
- Department of Anatomy, University of Otago , Dunedin , New Zealand
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21
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Walls J, Sinclair L, Finlay D. Nutrient sensing, signal transduction and immune responses. Semin Immunol 2016; 28:396-407. [DOI: 10.1016/j.smim.2016.09.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 09/13/2016] [Indexed: 12/11/2022]
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22
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Weng JH, Chung BC. Nongenomic actions of neurosteroid pregnenolone and its metabolites. Steroids 2016; 111:54-59. [PMID: 26844377 DOI: 10.1016/j.steroids.2016.01.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 01/25/2016] [Accepted: 01/25/2016] [Indexed: 02/07/2023]
Abstract
Steroids have been widely used in the clinical setting. They bind and activate nuclear receptors to regulate gene expression. In addition to activating genomic transcription, steroids also exert nongenomic actions. The current article focuses on the nongenomic actions of neurosteroids, including pregnenolone (P5), 7α-hydroxypregnenolone, pregnenolone sulfate and allopregnanolone. Pregnenolone and its derivatives promote neuronal activity by enhancing learning and memory, relieving depression, enhancing locomotor activity, and promoting neuronal cell survival. They exert these effects by activating various target proteins located in the cytoplasm or cell membrane. Pregnenolone and its metabolites bind to receptors such as microtubule-associated proteins and neurotransmitter receptors to elicit a series of reactions including stabilization of microtubules, increase of ion flux into cells, and dopamine release. The wide actions of neurosteroids indicate that pregnenolone derivatives have great potential in future treatment of neurological diseases.
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Affiliation(s)
- Jui-Hsia Weng
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan; Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Bon-Chu Chung
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan.
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23
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Xi XP, Zhuang J, Teng MJ, Xia LJ, Yang MY, Liu QG, Chen JB. MicroRNA-17 induces epithelial-mesenchymal transition consistent with the cancer stem cell phenotype by regulating CYP7B1 expression in colon cancer. Int J Mol Med 2016; 38:499-506. [PMID: 27278684 DOI: 10.3892/ijmm.2016.2624] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 04/26/2016] [Indexed: 11/05/2022] Open
Abstract
MicroRNA-17 (miRNA-17/miR‑17) expression has been confirmed to be significantly higher in colorectal cancer tissues than in normal tissues. However, its exact role in colorectal cancer has not yet been fully elucidated. In this study, we found that miR-17 not only promoted epithelial-mesenchymal transition (EMT), but also promoted the formation of a stem cell-like population in colon cancer DLD1 cells. We also wished to determine the role of cytochrome P450, family 7, subfamily B, polypeptide 1 (CYP7B1) in CRC. miR-17 was overexpressed using a recombinant plasmid and CYP7B1 was silenced by transfection with shRNA. Western blot analysis was used to determine protein expression in the DLD1 cells and in tumor tissues obtained from patients with colon cancer. Our results revealed that miR‑17 overexpression led to the degradation of CYP7B1 mRNA expression in DLD1 cells. In addition, we found that the silencing of CYB7B1 promoted EMT and the formation of a stem cell-like population in the cells. Thus, our findings demonstrate that miR‑17 induces EMT consistent with the cancer stem cell phenotype by regulating CYP7B1 expression in colon cancer.
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Affiliation(s)
- Xiang-Peng Xi
- Department of General Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Jing Zhuang
- Department of Gastrointestinal Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Mu-Jian Teng
- Department of General Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Li-Jian Xia
- Department of Gastrointestinal Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Ming-Yu Yang
- Department of Gastrointestinal Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Qing-Gen Liu
- Department of Gastrointestinal Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Jing-Bo Chen
- Department of Gastrointestinal Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
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24
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Coignion C, Banneau G, Goizet C. Paraplegie spastiche ereditarie. Neurologia 2016. [DOI: 10.1016/s1634-7072(16)77572-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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25
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do Rego JL, Vaudry H. Comparative aspects of neurosteroidogenesis: From fish to mammals. Gen Comp Endocrinol 2016; 227:120-9. [PMID: 26079790 DOI: 10.1016/j.ygcen.2015.05.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 11/24/2022]
Abstract
It is now clearly established that the central and peripheral nervous systems have the ability to synthesize de novo steroids referred to as neurosteroids. The major evidence for biosynthesis of neuroactive steroids by nervous tissues is based on the expression of enzymes implicated in the formation of steroids in neural cells. The aim of the present review is to summarize the current knowledge regarding the presence of steroidogenic enzymes in the brain of vertebrates and to highlight the very considerable contribution of Professor Kazuyoshi Tsutsui in this domain. The data indicate that expression of steroid-producing enzymes in the brain appeared early during vertebrate evolution and has been preserved from fish to mammals.
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Affiliation(s)
- Jean Luc do Rego
- Institute for Research and Innovation in Biomedicine (IRIB), Institut National de la Santé et de la Recherche Médicale (INSERM), University of Rouen, 76821 Mont-Saint-Aignan, France
| | - Hubert Vaudry
- Institute for Research and Innovation in Biomedicine (IRIB), Institut National de la Santé et de la Recherche Médicale (INSERM), University of Rouen, 76821 Mont-Saint-Aignan, France; Neurotrophic Factors and Neuronal Differentiation Team, Inserm U982, University of Rouen, 76821 Mont-Saint-Aignan, France.
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26
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Sedláčková B, Dušátková L, Zamrazilová H, Matucha P, Bičíková M, Stárka L. 7-oxygenated Derivatives of Dehydroepiandrosterone and Obesity. Prague Med Rep 2015; 113:147-55. [DOI: 10.14712/23362936.2015.29] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
7-hydroxy/oxo derivatives of dehydroepiandrosterone are potential regulators of the local cortisol activity due to their competition in the cortisolcortisone balance mediated by 11β-hydroxysteroid dehydrogenase. 7-hydroxydehydroepiandrosterone is marketed as anti-obesity medication, though no clinical study aimed at the benefit of administering 7-oxygenated derivatives of dehydroepiandrosterone has appeared until now. We tried to show whether there exist differences in levels of circulating 7-hydroxy/oxo-dehydroepiandrosterone derivatives between lean and obese boys and girls. From a cohort of adolescents investigated within the frame of anti-obesity programme 10 obese boys and 10 obese girls were compared with age-matched lean boys and girls in their anthropometric data, and concentrations of both epimers of 7-hydroxydehydroepiandrosterone and 7-oxo-dehydroepiandrosterone were determined by the RIA method. The basal levels of 7α-hydroxy-dehydroepiandrosterone were significantly higher in obese boys than in lean boys but not in girls. The association was found for anthropometric parameters and 7α-hydroxy-dehydroepiandrosterone, however again only in boys and not in girls. Higher levels of 7α-hydroxydehydroepiandrosterone its positive association with anthropometric data in obese boys may serve as a sign that, at least in boys, 7-oxygenated 5-ene-steroids may take part in regulating the hormonal signal for fat formation or distribution.
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G protein-coupled receptor 183 facilitates endothelial-to-hematopoietic transition via Notch1 inhibition. Cell Res 2015; 25:1093-107. [PMID: 26358189 PMCID: PMC4650626 DOI: 10.1038/cr.2015.109] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 07/28/2015] [Accepted: 07/31/2015] [Indexed: 12/15/2022] Open
Abstract
In vertebrates, embryonic hematopoietic stem and progenitor cells (HSPCs) are derived from a subset of endothelial cells, the hemogenic endothelium (HE), through the endothelial-to-hematopoietic transition (EHT). Notch signaling is essential for HSPC development during embryogenesis across vertebrates. However, whether and how it regulates EHT remains unclear. Here, we show that G protein-coupled receptor 183 (Gpr183) signaling serves as an indispensable switch for HSPC emergence by repressing Notch signaling before the onset of EHT. Inhibition of Gpr183 significantly upregulates Notch signaling and abolishes HSPC emergence. Upon activation by its ligand 7α-25-OHC, Gpr183 recruits β-arrestin1 and the E3 ligase Nedd4 to degrade Notch1 in specified HE cells and then facilitates the subsequent EHT. Importantly, 7α-25-OHC stimulation promotes HSPC emergence in vivo and in vitro, providing an attractive strategy for enhancing the in vitro generation of functional HSPCs.
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Giatti S, Garcia-Segura LM, Melcangi RC. New steps forward in the neuroactive steroid field. J Steroid Biochem Mol Biol 2015; 153:127-34. [PMID: 25797031 DOI: 10.1016/j.jsbmb.2015.03.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/07/2015] [Accepted: 03/17/2015] [Indexed: 12/12/2022]
Abstract
Evidence accumulated in recent years suggests that the systemic treatment with neuroactive steroids, or the pharmacological modulation of its production by brain cells, represent therapeutic options to promote neuroprotection. However, new findings, which are reviewed in this paper, suggest that the factors to be considered for the design of possible therapies based on neuroactive steroids are more complex than previously thought. Thus, although as recently reported, the nervous system regulates neuroactive steroid synthesis and metabolism in adaptation to modifications in peripheral steroidogenesis, the neuroactive steroid levels in the brain do not fully reflect its levels in plasma. Even, in some cases, neuroactive steroid level modifications occurring in the nervous tissues, under physiological and pathological conditions, are in the opposite direction than in the periphery. This suggests that the systemic treatment with these molecules may have unexpected outcomes on neural steroid levels. In addition, the multiple metabolic pathways and signaling mechanisms of neuroactive steroids, which may change from one brain region to another, together with the existence of regional and sex differences in its neural levels are additional sources of complexity that should be clarified. This complexity in the levels and actions of these molecules may explain why in some cases these molecules have detrimental rather than beneficial actions for the nervous system. This article is part of a Special Issue entitled 'Steroid Perspectives'.
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Affiliation(s)
- Silvia Giatti
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | | | - Roberto Cosimo Melcangi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy.
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Haraguchi S, Yamamoto Y, Suzuki Y, Hyung Chang J, Koyama T, Sato M, Mita M, Ueda H, Tsutsui K. 7α-Hydroxypregnenolone, a key neuronal modulator of locomotion, stimulates upstream migration by means of the dopaminergic system in salmon. Sci Rep 2015. [PMID: 26220247 PMCID: PMC4518220 DOI: 10.1038/srep12546] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Salmon migrate upstream against an opposing current in their natal river. However, the molecular mechanisms that stimulate upstream migratory behavior are poorly understood. Here, we show that 7α-hydroxypregnenolone (7α-OH PREG), a newly identified neuronal modulator of locomotion, acts as a key factor for upstream migration in salmon. We first identified 7α-OH PREG and cytochrome P450 7α-hydroxylase (P4507α), a steroidogenic enzyme producing 7α-OH PREG, in the salmon brain and then found that 7α-OH PREG synthesis in the brain increases during upstream migration. Subsequently, we demonstrated that 7α-OH PREG increases upstream migratory behavior of salmon. We further found that 7α-OH PREG acts on dopamine neurons in the magnocellular preoptic nucleus during upstream migration. Thus, 7α-OH PREG stimulates upstream migratory behavior through the dopaminergic system in salmon. These findings provide new insights into the molecular mechanisms of fish upstream migration.
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Affiliation(s)
- Shogo Haraguchi
- 1] Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan [2] Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Yuzo Yamamoto
- 1] Field Science Center for Northern Biosphere, Hokkaido University, Hokkaido, Japan [2] Current address: Demonstration Laboratory, Marine Ecology Research Institute, Niigata, Japan
| | - Yuko Suzuki
- Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan
| | - Joon Hyung Chang
- Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan
| | - Teppei Koyama
- Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan
| | - Miku Sato
- Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan
| | - Masatoshi Mita
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Hiroshi Ueda
- Field Science Center for Northern Biosphere, Hokkaido University, Hokkaido, Japan
| | - Kazuyoshi Tsutsui
- Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan
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Niro S, Hennebert O, Morfin R. A native steroid hormone derivative triggers the resolution of inflammation. Horm Mol Biol Clin Investig 2015; 1:11-9. [PMID: 25961967 DOI: 10.1515/hmbci.2010.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Accepted: 04/27/2009] [Indexed: 12/12/2022]
Abstract
Inflamed tissues produce both prostaglandins (PGs) and 7α-hydroxylated derivatives of native circulating 3β-hydroxysteroids. These 7α-hydroxysteroids are in turn transformed into 7β-hydroxylated epimers by 11β-hydroxysteroid dehydrogenase type 1 in the tissue. 7β-Hydroxy-epiandrosterone (7β-hydroxy-EpiA) affects PG production in two models of inflammation, dextran sodium sulfate-induced colitis in the rat and TNF-α-induced activation of PG production and PG synthase expression in cultured human peripheral blood monocytes (hPBMC). Treatment with 7β-hydroxy-EpiA led to a shift from high to low colonic PGE2 levels and from low to high 15-deoxy-Δ12-14-PGJ2 (15d-PGJ2) levels, together with changes in the expression of the respective PG synthases and resolution of colonic inflammation. Addition of 7β-hydroxy-EpiA to hPBMC also changed the expression of PG synthases and decreased PGE2 while increasing 15d-PGJ2 production. These effects were only observed with 7β-hydroxy-EpiA and not with 7α-hydroxy- or 7β-hydroxy-dehydroepiandrosterone (7α-hydroxy-DHEA and 7β-hydroxy-DHEA). 15d-PGJ2, which is the native ligand for peroxisome proliferator-activated receptor subtype γ, contributes to cell protection and to the resolution of inflammation. Our results therefore suggest that 7β-hydroxy-EpiA may facilitate inflammatory resolution by shifting PG production from PGE2 to PGD2 and 15d-PGJ2. The finding that 7β-hydroxy-EpiA was effective at nM concentrations, whereas the two structurally closely related hydroxysteroids 7α-hydroxy-DHEA and 7β-hydroxy-DHEA were inactive suggests that the effects of 7β-hydroxy-EpiA are specific to this steroid and may be mediated by a specific receptor.
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31
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Wicher G, Norlin M. Estrogen-mediated regulation of steroid metabolism in rat glial cells; effects on neurosteroid levels via regulation of CYP7B1-mediated catalysis. J Steroid Biochem Mol Biol 2015; 145:21-7. [PMID: 25263657 DOI: 10.1016/j.jsbmb.2014.09.022] [Citation(s) in RCA: 9] [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: 04/30/2014] [Revised: 09/22/2014] [Accepted: 09/23/2014] [Indexed: 11/28/2022]
Abstract
Many neuroactive steroids, including dehydroepiandrosterone (DHEA), pregnenolone, 27-hydroxycholesterol and 17β-estradiol, are known to affect development and function of the brain and nervous system. These and other steroids can undergo tissue and/or cell-specific enzymatic conversions into steroid metabolites. Carefully regulated production of steroids with various physiological effects is important for cells of the nervous system. Astrocytes express many steroidogenic enzymes and are considered important producers of brain steroids. The quantitative roles of different pathways for steroid metabolism in rat astrocytes are not clear. In the current study we examined effects of estrogens on steroid metabolism catalyzed by CYP7B1 and other enzymes in primary cultures of rat astrocytes. The CYP7B1 enzyme, which has been linked to neurodegenerative disease, is involved in the metabolism of several important neurosteroids. In the present study, we found that 7α-hydroxylation, performed by CYP7B1, is the quantitatively most important pathway for DHEA metabolism in rat astrocytes. In addition, our present experiments on catalytic steroid conversions revealed that estrogens significantly suppress the CYP7B1-catalyzed metabolism of not only DHEA but also of pregnenolone and 27-hydroxycholesterol in rat astrocytes. These novel findings point to a regulatory mechanism for control of the cellular levels of these neurosteroids via CYP7B1. Our hypothesis that estrogens can regulate neurosteroid levels via this enzymatic reaction was supported by experiments using ELISA to assay levels of DHEA and pregnenolone in the presence or absence of estrogen. Furthermore, the present results show that estrogen suppresses CYP7B1-catalyzed 7α-hydroxylation also in primary cultures of rat Schwann cells, indicating that regulation by estrogen via this enzyme may be of relevance in both the CNS and the PNS.
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Affiliation(s)
- Grzegorz Wicher
- Department of Pharmaceutical Biosciences, Uppsala University, Sweden
| | - Maria Norlin
- Department of Pharmaceutical Biosciences, Uppsala University, Sweden.
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Stárka L, Dušková M, Hill M. Dehydroepiandrosterone: a neuroactive steroid. J Steroid Biochem Mol Biol 2015; 145:254-60. [PMID: 24704258 DOI: 10.1016/j.jsbmb.2014.03.008] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 10/25/2022]
Abstract
Dehydroepiandrosterone (DHEA) and its sulfate bound form (DHEAS) are important steroids of mainly adrenal origin. They are produced also in gonads and in the brain. Dehydroepiandrosterone easily crosses the brain-blood barrier and in part is also produced locally in the brain tissue. In the brain, DHEA exerts its effects after conversion to either testosterone and dihydrotestosterone or estradiol via androgen and estrogen receptors present in the most parts of the human brain, through mainly non-genomic mechanisms, or eventually indirectly via the effects of its metabolites formed locally in the brain. As a neuroactive hormone, DHEA in co-operation with other hormones and transmitters significantly affects some aspects of human mood, and modifies some features of human emotions and behavior. It has been reported that its administration can increase feelings of well-being and is useful in ameliorating atypical depressive disorders. It has neuroprotective and antiglucocorticoid activity and modifies immune reactions, and some authors have also reported its role in degenerative brain diseases. Here we present a short overview of the possible actions of dehydroepiandrosterone and its sulfate in the brain, calling attention to various mechanisms of their action as neurosteroids and to prospects for the knowledge of their role in brain disorders.
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Affiliation(s)
- Luboslav Stárka
- Institute of Endocrinology, Národní 8, 11694 Prague, Czech Republic.
| | - Michaela Dušková
- Institute of Endocrinology, Národní 8, 11694 Prague, Czech Republic.
| | - Martin Hill
- Institute of Endocrinology, Národní 8, 11694 Prague, Czech Republic.
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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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34
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Lathe R, Kotelevtsev Y. Steroid signaling: ligand-binding promiscuity, molecular symmetry, and the need for gating. Steroids 2014; 82:14-22. [PMID: 24462647 DOI: 10.1016/j.steroids.2014.01.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 12/03/2013] [Accepted: 01/06/2014] [Indexed: 11/28/2022]
Abstract
Steroid/sterol-binding receptors and enzymes are remarkably promiscuous in the range of ligands they can bind to and, in the case of enzymes, modify - raising the question of how specific receptor activation is achieved in vivo. Estrogen receptors (ER) are modulated by 27-hydroxycholesterol and 5α-androstane-3β,17β-diol (Adiol), in addition to estradiol (E2), and respond to diverse small molecules such as bisphenol A. Steroid-modifying enzymes are also highly promiscuous in ligand binding and metabolism. The specificity problem is compounded by the fact that the steroid core (hydrogenated cyclopentophenanthrene ring system) has several planes of symmetry. Ligand binding can be in symmetrical East-West (rotation) and North-South (inversion) orientations. Hydroxysteroid dehydrogenases (HSDs) can modify symmetrical 7 and 11, also 3 and 17/20, positions, exemplified here by yeast 3α,20β-HSD and mammalian 11β-HSD and 17β-HSD enzymes. Faced with promiscuity and symmetry, other strategies are clearly necessary to promote signaling selectivity in vivo. Gating regulates hormone access via enzymes that preferentially inactivate (or activate) a subclass of ligands, thereby governing which ligands gain receptor access - exemplified by 11β-HSD gating cortisol access to the mineralocorticoid receptor, and P450 CYP7B1 gating Adiol access to ER. Counter-intuitively, the specificity of steroid/sterol action is achieved not by intrinsic binding selectivity but by the combination of local metabolism and binding affinity.
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Affiliation(s)
- Richard Lathe
- State University of Pushchino, Prospekt Nauki, Pushchino 142290, Moscow Region, Russia; Pushchino Branch of the Institute of Bio-Organic Chemistry, Russian Academy of Sciences, Pushchino 142290, Moscow Region, Russia; Pieta Research, PO Box 27069, Edinburgh EH10 5YW, UK.
| | - Yuri Kotelevtsev
- State University of Pushchino, Prospekt Nauki, Pushchino 142290, Moscow Region, Russia; Pushchino Branch of the Institute of Bio-Organic Chemistry, Russian Academy of Sciences, Pushchino 142290, Moscow Region, Russia; Biomedical Centre for Research Education and Innovation (CREI), Skolkovo Institute of Science and Technology, 143025 Skolkovo, Russia; Queens Medical Research Institute, University of Edinburgh, Little France, Edinburgh EH16 4TJ, UK.
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35
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Yantsevich AV, Dichenko YV, Mackenzie F, Mukha DV, Baranovsky AV, Gilep AA, Usanov SA, Strushkevich NV. Human steroid and oxysterol 7α-hydroxylase CYP7B1: substrate specificity, azole binding and misfolding of clinically relevant mutants. FEBS J 2014; 281:1700-13. [PMID: 24491228 DOI: 10.1111/febs.12733] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 12/23/2013] [Accepted: 01/28/2014] [Indexed: 11/28/2022]
Abstract
Oxysterols and neurosteroids are important signaling molecules produced by monooxygenases of the cytochrome P450 family that realize their effect through nuclear receptors. CYP7B1 catalyzes the 6- or 7-hydroxylation of both steroids and oxysterols and thus is involved in the metabolism of neurosteroids and bile acid synthesis, respectively. The dual physiological role of CYP7B1 is evidenced from different diseases, liver failure and progressive neuropathy, caused by enzyme malfunction. Here we present biochemical characterization of CYP7B1 at the molecular level to understand substrate specificity and susceptibility to azole drugs. Based on our experiments with purified enzyme, the requirements for CYP7B1 hydroxylation of steroid molecules are as follows: C5 hydrogen in the α-configuration (or double bond at C5), a polar group at C17, a hydroxyl group at C3, and the absence of the hydroxyl group at C20-C24 in the C27-sterol side chain. 21-hydroxy-pregnenolone was identified as a new substrate, and overall low activity toward pregnanes could be related to the increased potency of 7-hydroxy derivatives produced by CYP7B1. Metabolic conversion (deactivation) of oxysterols by CYP7B1 in a reconstituted system proceeds via two sequential hydroxylations. Two mutations that are found in patients with diseases, Gly57Arg and Phe216Ser, result in apo-P450 (devoid of heme) protein formation. Our CYP7B1 homology model provides a rationale for understanding clinical mutations and relatively broad substrate specificity for steroid hydroxylase.
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36
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Hydroxylation of DHEA and its analogues by Absidia coerulea AM93. Can an inducible microbial hydroxylase catalyze 7α- and 7β-hydroxylation of 5-ene and 5α-dihydro C19-steroids? Bioorg Med Chem 2014; 22:883-91. [DOI: 10.1016/j.bmc.2013.11.050] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 11/03/2013] [Accepted: 11/28/2013] [Indexed: 01/16/2023]
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: enzymes. Br J Pharmacol 2013; 170:1797-867. [PMID: 24528243 PMCID: PMC3892293 DOI: 10.1111/bph.12451] [Citation(s) in RCA: 415] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. Enzymes are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, nuclear hormone receptors, catalytic receptors and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen PH Alexander
- School of Life Sciences, University of Nottingham Medical SchoolNottingham, NG7 2UH, UK
| | - Helen E Benson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Elena Faccenda
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Adam J Pawson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Joanna L Sharman
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | | | - John A Peters
- Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of DundeeDundee, DD1 9SY, UK
| | - Anthony J Harmar
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
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Chu WT, Zheng QC. Conformational changes of enzymes and DNA in molecular dynamics: influenced by pH, temperature, and ligand. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2013; 92:179-217. [PMID: 23954102 DOI: 10.1016/b978-0-12-411636-8.00005-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Protein conformation, which has been a research hotspot for human diseases, is an important factor of protein properties. Recently, a series of approaches have been utilized to investigate the conformational changes under different conditions. Some of them have gained promising achievements, but it is still deficient in the detail researches at the atomic level. In this chapter, a series of computational examples of protein conformational changes under different pH environment, temperature, and ligand binding are described. We further show some useful methods, such as constant pH molecular dynamics simulations, molecular docking, and molecular mechanics Poisson-Boltzmann surface area/generalized Born surface area calculations. In comparison with the experimental results, the methods mentioned above are reasonable to detect and predict the interaction between residue and residue, residue and DNA, and residue and ligand. Additionally, some crucial interactions that cause protein conformational changes are discovered and discussed in this chapter. In summary, our work can give penetrating information to understand the pH-, temperature-, and ligand-induced conformational change mechanisms.
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Affiliation(s)
- Wen-Ting Chu
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, PR China
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39
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Abstract
The cytochrome P450 superfamily consists of a large number of heme-containing monooxygenases. Many human P450s metabolize drugs used to treat human diseases. Others are necessary for synthesis of endogenous compounds essential for human physiology. In some instances, alterations in specific P450s affect the biological processes that they mediate and lead to a disease. In this minireview, we describe medically significant human P450s (from families 2, 4, 7, 11, 17, 19, 21, 24, 27, 46, and 51) and the diseases associated with these P450s.
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Affiliation(s)
- Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio 44106, USA.
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40
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Cui YL, Zhang JL, Zheng QC, Niu RJ, Xu Y, Zhang HX, Sun CC. Structural and Dynamic Basis of Human Cytochrome P450 7B1: A Survey of Substrate Selectivity and Major Active Site Access Channels. Chemistry 2012. [DOI: 10.1002/chem.201202627] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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41
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Yau JLW, Seckl JR. Local amplification of glucocorticoids in the aging brain and impaired spatial memory. Front Aging Neurosci 2012; 4:24. [PMID: 22952463 PMCID: PMC3430012 DOI: 10.3389/fnagi.2012.00024] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 08/02/2012] [Indexed: 12/24/2022] Open
Abstract
The hippocampus is a prime target for glucocorticoids (GCs) and a brain structure particularly vulnerable to aging. Prolonged exposure to excess GCs compromises hippocampal electrophysiology, structure, and function. Blood GC levels tend to increase with aging and correlate with impaired spatial memory in aging rodents and humans. The magnitude of GC action within tissues depends not only on levels of steroid hormone that enter the cells from the periphery and the density of intracellular receptors but also on the local metabolism of GCs by 11β-hydroxysteroid dehydrogenases (11β-HSD). The predominant isozyme in the adult brain, 11β-HSD1, locally regenerates active GCs from inert 11-keto forms thus amplifying GC levels within specific target cells including in the hippocampus and cortex. Aging associates with elevated hippocampal and neocortical 11β-HSD1 and impaired spatial learning while deficiency of 11β-HSD1 in knockout (KO) mice prevents the emergence of cognitive decline with age. Furthermore, short-term pharmacological inhibition of 11β-HSD1 in already aged mice reverses spatial memory impairments. Here, we review research findings that support a key role for GCs with special emphasis on their intracellular regulation by 11β-HSD1 in the emergence of spatial memory deficits with aging, and discuss the use of 11β-HSD1 inhibitors as a promising novel treatment in ameliorating/improving age-related memory impairments.
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Affiliation(s)
- Joyce L W Yau
- Centre for Cognitive Ageing and Cognitive Epidemiology and Endocrinology Unit, Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh Edinburgh, UK
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42
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Zhang L, Shih AY, Yang XV, Kuei C, Wu J, Deng X, Mani NS, Mirzadegan T, Sun S, Lovenberg TW, Liu C. Identification of structural motifs critical for epstein-barr virus-induced molecule 2 function and homology modeling of the ligand docking site. Mol Pharmacol 2012; 82:1094-103. [PMID: 22930711 DOI: 10.1124/mol.112.080275] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Epstein-Barr virus-induced molecule 2 (EBI2) (also known as G-protein-coupled receptor 183) is a G-protein-coupled receptor (GPCR) that is best known for its role in B cell migration and localization. Our recent deorphanization effort led to the discovery of 7α,25-dihydroxycholesterol (7α,25-OHC) as the endogenous ligand for EBI2, which provides a tool for mechanistic studies of EBI2 function. Because EBI2 is the first GPCR known to bind and to be activated by an oxysterol, the goal of this study was to understand the molecular and structural bases for its ligand-dependent activation; this was achieved by identifying structural moieties in EBI2 or in 7α,25-OHC that might affect receptor-ligand interactions. By using a series of chemically related OHC analogs, we demonstrated that all three hydroxyl groups in 7α,25-OHC contributed to ligand-induced activation of the receptor. To determine the location and composition of the ligand binding domain in EBI2, we used a site-directed mutagenesis approach and generated mutant receptors with single amino acid substitutions at selected positions of interest. Biochemical and pharmacological profiling of these mutant receptors allowed for structure-function analyses and revealed critical motifs that likely interact with 7α,25-OHC. By using a hybrid β(2)-adrenergic receptor-C-X-C chemokine receptor type 4 structure as a template, we created a homology model for EBI2 and optimized the docking of 7α,25-OHC into the putative ligand binding site, so that the hydroxyl groups interact with residues Arg87, Asn114, and Glu183. This model of ligand docking yields important structural insight into the molecular mechanisms mediating EBI2 function and may facilitate future efforts to design novel therapeutic agents that target EBI2.
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Affiliation(s)
- Li Zhang
- Janssen Pharmaceutical Research and Development, San Diego, California, USA
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Xu L, Sheflin LG, Porter NA, Fliesler SJ. 7-Dehydrocholesterol-derived oxysterols and retinal degeneration in a rat model of Smith-Lemli-Opitz syndrome. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:877-83. [PMID: 22425966 DOI: 10.1016/j.bbalip.2012.03.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 02/17/2012] [Accepted: 03/02/2012] [Indexed: 01/08/2023]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a recessive disease characterized by markedly elevated levels of 7-dehydrocholesterol (7-DHC) and reduced levels of cholesterol in tissues and fluids of affected individuals, due to defective 3β-hydroxysterol-Δ(7)-reductase (Dhcr7). Treatment of Sprague Dawley rats with AY9944 (an inhibitor of Dhcr7) leads to similar biochemical features as observed in SLOS. Eighteen oxysterols previously have been identified as oxidation products of 7-DHC (most of them distinct from cholesterol (Chol)-derived oxysterols) in solution, in cells, and in brains obtained from Dhcr7-KO mice and AY9944-treated rats, formed either via free radical oxidation (peroxidation) or P450-catalyzed enzymatic oxidation. We report here the identification of five 7-DHC-derived oxysterols, including 3β,5α-dihydroxycholest-7-en-6-one (DHCEO), 4α- and 4β-hydroxy-7-DHC, 24-hydroxy-7-DHC and 7-ketocholesterol (7-kChol, an oxysterol that is normally derived from Chol), in the retinas of AY9944-treated rats by comparing the retention times and mass spectrometric characteristics with corresponding synthetic standards in HPLC-MS analysis. Levels of 4α- and 4β-hydroxy-7-DHC, DHCEO, and 7-kChol were quantified using d(7)-DHCEO as an internal standard. Among the five oxysterols identified, only 7-kChol was observed in retinas of control rats, but the levels of 7-kChol in retinas of AY9944-rats were 30-fold higher. Intravitreal injection of 7-kChol (0.25μmol) into a normal rat eye induced panretinal degeneration within one week; by comparison, contralateral (control) eyes injected with vehicle alone exhibited normal histology. These findings are discussed in the context of the potential involvement of 7-DHC-derived oxysterols in the retinal degeneration associated with the SLOS rat model and in SLOS patients.
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Affiliation(s)
- Libin Xu
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
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El Kihel L. Oxidative metabolism of dehydroepiandrosterone (DHEA) and biologically active oxygenated metabolites of DHEA and epiandrosterone (EpiA)--recent reports. Steroids 2012; 77:10-26. [PMID: 22037250 DOI: 10.1016/j.steroids.2011.09.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 09/14/2011] [Accepted: 09/18/2011] [Indexed: 12/24/2022]
Abstract
Dehydroepiandrosterone (DHEA) is a multifunctional steroid with a broad range of biological effects in humans and animals. DHEA can be converted to multiple oxygenated metabolites in the brain and peripheral tissues. The mechanisms by which DHEA exerts its effects are not well understood. However, evidence that the effects of DHEA are mediated by its oxygenated metabolites has accumulated. This paper will review the panel of oxygenated DHEA metabolites (7, 16 and 17-hydroxylated derivatives) including a number of 5α-androstane derivatives, such as epiandrosterone (EpiA) metabolites. The most important aspects of the oxidative metabolism of DHEA in the liver, intestine and brain are described. Then, this article reviews the reported biological effects of oxygenated DHEA metabolites from recent findings with a specific focus on cancer, inflammatory and immune processes, osteoporosis, thermogenesis, adipogenesis, the cardiovascular system, the brain and the estrogen and androgen receptors.
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Affiliation(s)
- Laïla El Kihel
- Université de Caen Basse-Normandie, UFR des Sciences Pharmaceutiques, Centre d'Etudes et de Recherche sur le Médicament de Normandie, UPRES EA-4258, FR CNRS INC3M, Caen, France.
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Lorbek G, Lewinska M, Rozman D. Cytochrome P450s in the synthesis of cholesterol and bile acids--from mouse models to human diseases. FEBS J 2011; 279:1516-33. [PMID: 22111624 DOI: 10.1111/j.1742-4658.2011.08432.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The present review describes the transgenic mouse models that have been designed to evaluate the functions of the cytochrome P450s involved in cholesterol and bile acid synthesis, as well as their link with disease. The knockout of cholesterogenic Cyp51 is embrionally lethal, with symptoms of Antley-Bixler syndrome occurring in mice, whereas the evidence for this association is conflicting in humans. Disruption of Cyp7a1 from classic bile acid synthesis in mice leads to either increased postnatal death or a milder phenotype with elevated serum cholesterol. The latter is similar to the case in humans, where CYP7A1 mutations associate with high plasma low-density lipoprotein and hepatic cholesterol content, as well as deficient bile acid excretion. Disruption of Cyp8b1 from an alternative bile acid pathway results in the absence of cholic acid and a reduced absorption of dietary lipids; however, the human CYP8B1 polymorphism fails to explain differences in bile acid composition. Unexpectedly, apparently normal Cyp27a1(-/-) mice still synthesize bile acids that originate from the compensatory pathway. In humans, CYP27A1 mutations cause cerebrotendinous xanthomatosis, suggesting that only mice can compensate for the loss of alternative bile acid synthesis. In line with this, Cyp7b1 knockouts are also apparently normal, whereas human CYP7B1 mutations lead to a congenital bile acid synthesis defect in children or spastic paraplegia in adults. Mouse knockouts of the brain-specific Cyp46a1 have reduced brain cholesterol excretion, whereas, in humans, CYP46A1 polymorphisms associate with cognitive impairment. At present, cytochrome P450 family 39 is poorly characterized. Despite important physiological differences between humans and mice, mouse models prove to be an invaluable tool for understanding the multifactorial facets of cholesterol and bile acid-related disorders.
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Affiliation(s)
- Gregor Lorbek
- Center for Functional Genomics and Bio-Chips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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Increased serum levels of dehydroepiandrosterone (DHEA) and interleukin-6 (IL-6) in women with mild to moderate Alzheimer's disease. Int Psychogeriatr 2011; 23:1386-92. [PMID: 21729423 DOI: 10.1017/s1041610211000810] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND It has been suggested that hypercortisolism contributes to the pathophysiology of Alzheimer's disease (AD), based on the fact that excess glucocorticoid exposure has potent adverse effects on the central nervous system. In contrast, dehydroepiandrosterone (DHEA) has been linked to a broad range of beneficial physiological effects including neuronal excitability and neuroprotection and even memory enhancing properties. Of note, proinflammatory cytokines are present in neuritic plaques (a hallmark of AD) and may regulate cortisol/DHEA release. In this exploratory study, we hypothesized that there is a flattened diurnal curve of cortisol and DHEA in mild to moderate AD, linked to increased cytokine levels. METHODS Diurnal profiles of cortisol, adrenocorticotropic hormone (ACTH), and DHEA were studied in 15 patients with mild to moderate AD (7 men and 8 women, 75.6 ± 5.5 years) and 15 healthy elderly controls (7 men and 8 women, 73.3 ± 5.8 years, respectively). Interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and soluble TNF receptors were analyzed. RESULTS Women with AD had significantly increased morning levels of ACTH, DHEA, and IL-6 compared to healthy elderly women. Cortisol levels were significantly increased in men with AD at 0300 h versus healthy elderly men, in spite of slightly decreased ACTH levels. CONCLUSIONS Our data suggest important sex differences in hypothalamic-pituitary-adrenal (HPA) axis regulation and steroid hormone clearance in patients with AD. Increased secretion of IL-6 may have a contributory role in this difference.
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Liu C, Yang XV, Wu J, Kuei C, Mani NS, Zhang L, Yu J, Sutton SW, Qin N, Banie H, Karlsson L, Sun S, Lovenberg TW. Oxysterols direct B-cell migration through EBI2. Nature 2011; 475:519-23. [PMID: 21796211 DOI: 10.1038/nature10226] [Citation(s) in RCA: 271] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Accepted: 05/17/2011] [Indexed: 12/31/2022]
Abstract
EBI2 (also called GPR183) is an orphan G-protein-coupled receptor that is highly expressed in spleen and upregulated upon Epstein-Barr-virus infection. Recent studies indicated that this receptor controls follicular B-cell migration and T-cell-dependent antibody production. Oxysterols elicit profound effects on immune and inflammatory responses as well as on cholesterol metabolism. The biological effects of oxysterols have largely been credited to the activation of nuclear hormone receptors. Here we isolate oxysterols from porcine spleen extracts and show that they are endogenous ligands for EBI2. The most potent ligand and activator is 7α,25-dihydroxycholesterol (OHC), with a dissociation constant of 450 pM for EBI2. In vitro, 7α,25-OHC stimulated the migration of EBI2-expressing mouse B and T cells with half-maximum effective concentration values around 500 pM, but had no effect on EBI2-deficient cells. In vivo, EBI2-deficient B cells or normal B cells desensitized by 7α,25-OHC pre-treatment showed reduced homing to follicular areas of the spleen. Blocking the synthesis of 7α,25-OHC in vivo with clotrimazole, a CYP7B1 inhibitor, reduced the content of 7α,25-OHC in the mouse spleen and promoted the migration of adoptively transferred pre-activated B cells to the T/B boundary (the boundary between the T-zone and B-zone in the spleen follicle), mimicking the phenotype of pre-activated B cells from EBI2-deficient mice. Our results show an unexpected causal link between EBI2, an orphan G-protein-coupled receptor controlling B-cell migration, and the known immunological effects of certain oxysterols, thus uncovering a previously unknown role for this class of molecules.
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Affiliation(s)
- Changlu Liu
- Johnson & Johnson Pharmaceutical Research & Development, L.L.C., 3210 Merryfield Row, San Diego, California 92121, USA.
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Neuroactive steroids in periphery and cerebrospinal fluid. Neuroscience 2011; 191:22-7. [PMID: 21641969 DOI: 10.1016/j.neuroscience.2011.05.054] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 05/20/2011] [Accepted: 05/22/2011] [Indexed: 11/24/2022]
Abstract
Some peripheral steroids penetrate the blood-brain barrier (BBB), providing at least substances for the CNS steroid metabolome. That is why the predictive value of the peripheral steroids appears to be comparable with that of the cerebrospinal fluid (CSF) steroids. The concentrations of the CSF steroids are pronouncedly lower in comparison with the ones in circulation. The available data indicate that the levels of pregnenolone sulfate substantially increase in the rat brain tissue after the administration of pregnenolone into the circulation. In the human circulation there are about two orders of magnitude higher levels of pregnenolone sulfate compared to the free pregnenolone. Our data show insignificant correlation between CSF and serum pregnenolone, but a borderline one between CSF pregnenolone and serum pregnenolone sulfate. Therefore in humans, the circulating pregnenolone sulfate might be of an importance for pregnenolone concentration in the CNS. In contrast to free pregnenolone, dehydroepiandrosterone (DHEA) in the CSF correlates with both unconjugated and conjugated DHEA in the serum. These data as well as the low C17-hydroxylase-C17,20-lyase activity in the CNS might indicate that DHEA levels in the CNS are influenced by peripheral levels of DHEA and its sulfate. According to the information, available part of the neurosteroids may be synthesized de novo in the CNS, but substantial part of the steroid metabolites may be also synthesized in the CNS from the steroid precursors or directly transported through BBB from the periphery. The processes mentioned above may be complimentary in some cases. Brain synthesis may provide minimal level of neurosteroids, which are indispensable for the CNS functions. Thus, brain steroids of peripheral origin may reflect various physiological situations or even pathologies. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain.
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Fex Svenningsen A, Wicher G, Lundqvist J, Pettersson H, Corell M, Norlin M. Effects on DHEA levels by estrogen in rat astrocytes and CNS co-cultures via the regulation of CYP7B1-mediated metabolism. Neurochem Int 2011; 58:620-4. [PMID: 21300119 DOI: 10.1016/j.neuint.2011.01.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 12/17/2010] [Accepted: 01/20/2011] [Indexed: 11/29/2022]
Abstract
The neurosteroid dehydroepiandrosterone (DHEA) is formed locally in the CNS and has been implicated in several processes essential for CNS function, including control of neuronal survival. An important metabolic pathway for DHEA in the CNS involves the steroid hydroxylase CYP7B1. In previous studies, CYP7B1 was identified as a target for estrogen regulation in cells of kidney and liver. In the current study, we examined effects of estrogens on CYP7B1-mediated metabolism of DHEA in primary cultures of rat astrocytes and co-cultures of rat CNS cells. Astrocytes, which interact with neurons in several ways, are important for brain neurosteroidogenesis. We found that estradiol significantly suppressed CYP7B1-mediated DHEA hydroxylation in primary mixed CNS cultures from fetal and newborn rats. Also, CYP7B1-mediated DHEA hydroxylation and CYP7B1 mRNA were markedly suppressed by estrogen in primary cultures of rat astrocytes. Interestingly, diarylpropionitrile, a well-known agonist of estrogen receptor β, also suppressed CYP7B1-mediated hydroxylation of DHEA. Several previous studies have reported neuroprotective effects of estrogens. The current data indicate that one of the mechanisms whereby estrogen can exert protective effects in the CNS may involve increase of the levels of DHEA by suppression of its metabolism.
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Kołek T, Milecka N, Świzdor A, Panek A, Białońska A. Hydroxylation of DHEA, androstenediol and epiandrosterone by Mortierella isabellina AM212. Evidence indicating that both constitutive and inducible hydroxylases catalyze 7α- as well as 7β-hydroxylations of 5-ene substrates. Org Biomol Chem 2011; 9:5414-22. [DOI: 10.1039/c1ob05350g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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