1
|
Hawes EM, Boortz KA, Oeser JK, O’Rourke ML, O’Brien RM. G6PC1 and G6PC2 influence G6P flux but not HSD11B1 activity. J Mol Endocrinol 2023; 71:e230070. [PMID: 37855366 PMCID: PMC10616506 DOI: 10.1530/jme-23-0070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 09/19/2023] [Indexed: 09/21/2023]
Abstract
In the endoplasmic reticulum (ER) lumen, glucose-6-phosphatase catalytic subunit 1 and 2 (G6PC1; G6PC2) hydrolyze glucose-6-phosphate (G6P) to glucose and inorganic phosphate whereas hexose-6-phosphate dehydrogenase (H6PD) hydrolyzes G6P to 6-phosphogluconate (6PG) in a reaction that generates NADPH. 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1) utilizes this NADPH to convert inactive cortisone to cortisol. HSD11B1 inhibitors improve insulin sensitivity whereas G6PC inhibitors are predicted to lower fasting blood glucose (FBG). This study investigated whether G6PC1 and G6PC2 influence G6P flux through H6PD and vice versa. Using a novel transcriptional assay that utilizes separate fusion genes to quantitate glucocorticoid and glucose signaling, we show that overexpression of H6PD and HSD11B1 in the islet-derived 832/13 cell line activated glucocorticoid-stimulated fusion gene expression. Overexpression of HSD11B1 blunted glucose-stimulated fusion gene expression independently of altered G6P flux. While overexpression of G6PC1 and G6PC2 blunted glucose-stimulated fusion gene expression, it had minimal effect on glucocorticoid-stimulated fusion gene expression. In the liver-derived HepG2 cell line, overexpression of H6PD and HSD11B1 activated glucocorticoid-stimulated fusion gene expression but overexpression of G6PC1 and G6PC2 had no effect. In rodents, HSD11B1 converts 11-dehydrocorticosterone (11-DHC) to corticosterone. Studies in wild-type and G6pc2 knockout mice treated with 11-DHC for 5 weeks reveal metabolic changes unaffected by the absence of G6PC2. These data suggest that HSD11B1 activity is not significantly affected by the presence or absence of G6PC1 or G6PC2. As such, G6PC1 and G6PC2 inhibitors are predicted to have beneficial effects by reducing FBG without causing a deleterious increase in glucocorticoid signaling.
Collapse
Affiliation(s)
- Emily M. Hawes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Kayla A. Boortz
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - James K. Oeser
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Margaret L. O’Rourke
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Richard M. O’Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232
| |
Collapse
|
2
|
Khan S, Livingstone DEW, Zielinska A, Doig CL, Cobice DF, Esteves CL, Man JTY, Homer NZM, Seckl JR, MacKay CL, Webster SP, Lavery GG, Chapman KE, Walker BR, Andrew R. Contribution of local regeneration of glucocorticoids to tissue steroid pools. J Endocrinol 2023; 258:e230034. [PMID: 37343234 PMCID: PMC10448579 DOI: 10.1530/joe-23-0034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 06/20/2022] [Indexed: 06/23/2023]
Abstract
11β-Hydroxysteroid dehydrogenase 1 (11βHSD1) is a drug target to attenuate adverse effects of chronic glucocorticoid excess. It catalyses intracellular regeneration of active glucocorticoids in tissues including brain, liver and adipose tissue (coupled to hexose-6-phosphate dehydrogenase, H6PDH). 11βHSD1 activity in individual tissues is thought to contribute significantly to glucocorticoid levels at those sites, but its local contribution vs glucocorticoid delivery via the circulation is unknown. Here, we hypothesised that hepatic 11βHSD1 would contribute significantly to the circulating pool. This was studied in mice with Cre-mediated disruption of Hsd11b1 in liver (Alac-Cre) vs adipose tissue (aP2-Cre) or whole-body disruption of H6pdh. Regeneration of [9,12,12-2H3]-cortisol (d3F) from [9,12,12-2H3]-cortisone (d3E), measuring 11βHSD1 reductase activity was assessed at steady state following infusion of [9,11,12,12-2H4]-cortisol (d4F) in male mice. Concentrations of steroids in plasma and amounts in liver, adipose tissue and brain were measured using mass spectrometry interfaced with matrix-assisted laser desorption ionisation or liquid chromatography. Amounts of d3F were higher in liver, compared with brain and adipose tissue. Rates of appearance of d3F were ~6-fold slower in H6pdh-/- mice, showing the importance for whole-body 11βHSD1 reductase activity. Disruption of liver 11βHSD1 reduced the amounts of d3F in liver (by ~36%), without changes elsewhere. In contrast disruption of 11βHSD1 in adipose tissue reduced rates of appearance of circulating d3F (by ~67%) and also reduced regenerated of d3F in liver and brain (both by ~30%). Thus, the contribution of hepatic 11βHSD1 to circulating glucocorticoid levels and amounts in other tissues is less than that of adipose tissue.
Collapse
Affiliation(s)
- S Khan
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - D E W Livingstone
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
- Centre for Discovery Brain Science, University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - A Zielinska
- College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - C L Doig
- Department of Biosciences, School of Science & Technology, Nottingham Trent University, Nottingham, UK
| | - D F Cobice
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - C L Esteves
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - J T Y Man
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - N Z M Homer
- Mass Spectrometry Core Laboratory, Edinburgh Clinical Research Facility, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - J R Seckl
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - C L MacKay
- SIRCAMS, School of Chemistry, University of Edinburgh, Joseph Black Building, King's Buildings, Edinburgh, UK
| | - S P Webster
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - G G Lavery
- Department of Biosciences, School of Science & Technology, Nottingham Trent University, Nottingham, UK
| | - K E Chapman
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - B R Walker
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
- Clinical & Translational Research Institute, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, UK
| | - R Andrew
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
- Mass Spectrometry Core Laboratory, Edinburgh Clinical Research Facility, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
3
|
Su CC, Lyu M, Zhang Z, Miyagi M, Huang W, Taylor DJ, Yu EW. High-resolution structural-omics of human liver enzymes. Cell Rep 2023; 42:112609. [PMID: 37289586 PMCID: PMC10592444 DOI: 10.1016/j.celrep.2023.112609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/28/2023] [Accepted: 05/20/2023] [Indexed: 06/10/2023] Open
Abstract
We applied raw human liver microsome lysate to a holey carbon grid and used cryo-electron microscopy (cryo-EM) to define its composition. From this sample we identified and simultaneously determined high-resolution structural information for ten unique human liver enzymes involved in diverse cellular processes. Notably, we determined the structure of the endoplasmic bifunctional protein H6PD, where the N- and C-terminal domains independently possess glucose-6-phosphate dehydrogenase and 6-phosphogluconolactonase enzymatic activity, respectively. We also obtained the structure of heterodimeric human GANAB, an ER glycoprotein quality-control machinery that contains a catalytic α subunit and a noncatalytic β subunit. In addition, we observed a decameric peroxidase, PRDX4, which directly contacts a disulfide isomerase-related protein, ERp46. Structural data suggest that several glycosylations, bound endogenous compounds, and ions associate with these human liver enzymes. These results highlight the importance of cryo-EM in facilitating the elucidation of human organ proteomics at the atomic level.
Collapse
Affiliation(s)
- Chih-Chia Su
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Meinan Lyu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Zhemin Zhang
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Masaru Miyagi
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Wei Huang
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Derek J Taylor
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Edward W Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| |
Collapse
|
4
|
Marbet P, Klusonova P, Birk J, Kratschmar DV, Odermatt A. Absence of hexose-6-phosphate dehydrogenase results in reduced overall glucose consumption but does not prevent 11β-hydroxysteroid dehydrogenase-1-dependent glucocorticoid activation. FEBS J 2018; 285:3993-4004. [PMID: 30153376 DOI: 10.1111/febs.14642] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 08/09/2018] [Accepted: 08/21/2018] [Indexed: 01/15/2023]
Abstract
Hexose-6-phosphate dehydrogenase (H6PD) is thought to be the major source of NADPH within the endoplasmic reticulum (ER), determining 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) reaction direction to convert inert 11-oxo- to potent 11β-hydroxyglucocorticoids. Here, we tested the hypothesis whether H6pd knock-out (KO) in primary murine bone marrow-derived macrophages results in a switch from 11β-HSD1 oxoreduction to dehydrogenation, thereby inactivating glucocorticoids (GC) and affecting macrophage phenotypic activation as well as causing a more aggressive M1 macrophage phenotype. H6pdKO did not lead to major disturbances of macrophage activation state, although a slightly more pronounced M1 phenotype was observed with enhanced proinflammatory cytokine release, an effect explained by the decreased 11β-HSD1-dependent GC activation. Unexpectedly, ablation of H6pd did not switch 11β-HSD1 reaction direction. A moderately decreased 11β-HSD1 oxoreduction activity by 40-50% was observed in H6pdKO M1 macrophages but dehydrogenation activity was undetectable, providing strong evidence for the existence of an alternative source of NADPH in the ER. H6pdKO M1 activated macrophages showed decreased phagocytic activity, most likely a result of the reduced 11β-HSD1-dependent GC activation. Other general macrophage functions reported to be influenced by GC, such as nitrite production and cholesterol efflux, were altered negligibly or not at all. Importantly, assessment of energy metabolism using an extracellular flux analyzer and lactate measurements revealed reduced overall glucose consumption in H6pdKO M1 activated macrophages, an effect that was GC independent. The GC-independent influence of H6PD on energy metabolism and the characterization of the alternative source of NADPH in the ER warrant further investigations. ENZYMES: 11β-HSD1, EC 1.1.1.146; H6PD, EC 1.1.1.47.
Collapse
Affiliation(s)
- Philippe Marbet
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Switzerland
| | - Petra Klusonova
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Switzerland
| | - Julia Birk
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Switzerland
| | - Denise V Kratschmar
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Switzerland
| | - Alex Odermatt
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Switzerland
| |
Collapse
|
5
|
Wang Y, Yan C, Liu L, Wang W, Du H, Fan W, Lutfy K, Jiang M, Friedman TC, Liu Y. 11β-Hydroxysteroid dehydrogenase type 1 shRNA ameliorates glucocorticoid-induced insulin resistance and lipolysis in mouse abdominal adipose tissue. Am J Physiol Endocrinol Metab 2015; 308:E84-95. [PMID: 25389364 PMCID: PMC4281684 DOI: 10.1152/ajpendo.00205.2014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Long-term glucocorticoid exposure increases the risk for developing type 2 diabetes. Prereceptor activation of glucocorticoid availability in target tissue by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) coupled with hexose-6-phosphate dehydrogenase (H6PDH) is an important mediator of the metabolic syndrome. We explored whether the tissue-specific modulation of 11β-HSD1 and H6PDH in adipose tissue mediates glucocorticoid-induced insulin resistance and lipolysis and analyzed the effects of 11β-HSD1 inhibition on the key lipid metabolism genes and insulin-signaling cascade. We observed that corticosterone (CORT) treatment increased expression of 11β-HSD1 and H6PDH and induced lipase HSL and ATGL with suppression of p-Thr(172) AMPK in adipose tissue of C57BL/6J mice. In contrast, CORT induced adipose insulin resistance, as reflected by a marked decrease in IR and IRS-1 gene expression with a reduction in p-Thr(308) Akt/PKB. Furthermore, 11β-HSD1 shRNA attenuated CORT-induced 11β-HSD1 and lipase expression and improved insulin sensitivity with a concomitant stimulation of pThr(308) Akt/PKB and p-Thr(172) AMPK within adipose tissue. Addition of CORT to 3T3-L1 adipocytes enhanced 11β-HSD1 and H6PDH and impaired p-Thr(308) Akt/PKB, leading to lipolysis. Knockdown of 11β-HSD1 by shRNA attenuated CORT-induced lipolysis and reversed CORT-mediated inhibition of pThr(172) AMPK, which was accompanied by a parallel improvement of insulin signaling response in these cells. These findings suggest that elevated adipose 11β-HSD1 expression may contribute to glucocorticoid-induced insulin resistance and adipolysis.
Collapse
Affiliation(s)
- Ying Wang
- Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Sciences, University of California Los Angeles (UCLA) School of Medicine, Los Angeles, California
| | - Chaoying Yan
- Department of Pediatrics, First Hospital, Jilin University, ChangChun, China
| | - Limei Liu
- Department of Endocrinology and Metabolism, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - Wei Wang
- Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Sciences, University of California Los Angeles (UCLA) School of Medicine, Los Angeles, California
| | - Hanze Du
- Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Sciences, University of California Los Angeles (UCLA) School of Medicine, Los Angeles, California
| | - Winnie Fan
- Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Sciences, University of California Los Angeles (UCLA) School of Medicine, Los Angeles, California
| | - Kabirullah Lutfy
- Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Sciences, University of California Los Angeles (UCLA) School of Medicine, Los Angeles, California; Department of Pharmaceutical Sciences, Western University of Health Sciences, Pomona, California; and
| | - Meisheng Jiang
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Theodore C Friedman
- Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Sciences, University of California Los Angeles (UCLA) School of Medicine, Los Angeles, California
| | - Yanjun Liu
- Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Sciences, University of California Los Angeles (UCLA) School of Medicine, Los Angeles, California;
| |
Collapse
|
6
|
Yaw HP, Ton SH, Amanda S, Kong IGXF, Cheng HS, Fernando HA, Chin HF, Kadir KA. Irregularities in glucose metabolism induced by stress and high-calorie diet can be attenuated by glycyrrhizic acid. Int J Physiol Pathophysiol Pharmacol 2014; 6:172-184. [PMID: 25755839 PMCID: PMC4348707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 12/13/2014] [Indexed: 06/04/2023]
Abstract
Stress and high-calorie diet increase the risk of developing metabolic syndrome. Glycyrrhizic acid (GA) has been shown to improve hyperglycaemia and dyslipidaemia under various physiological conditions. This study was aimed at examining the effects of stress and GA on glucose metabolism under short- or long-term stress. Forty-eight Sprague Dawley rats were divided into two groups with constant stress induced by light (300-400 lux) for either 14 days (short-term stress) or 28 days (long-term stress). Within each group, the rats were subdivided into three treatment groups i.e. Group A (control group): high-calorie diet (HCD) only; Group B: HCD + stress (14 or 28 days) and Group C: HCD + stress (14 or 28 days) + GA (100 mg/kg). The blood glucose concentrations of the rats exposed to 14-day stress were elevated significantly and GA lowered blood glucose concentration significantly in the 14-day exposure group. The 28-day exposure group adapted to stress as shown by the lower adrenaline level and gluconeogenic enzymes activities in most of the tissues than the 14-day exposure group. With regards to adrenaline and corticosterone, GA was found to increased adrenaline significantly in the short-term exposure group while lowering corticosterone in the long-term exposure group. GA-treated short- and long-term exposure groups had significant reduction in hexose-6-phosphate dehydrogenase activities in the visceral adipose tissues and quadriceps femoris respectively. The results may indicate the role of GA in improving blood glucose concentration in individuals exposed to short-term stress who are already on a high-calorie diet via selective action on gluconeogenic enzymes in different tissues.
Collapse
Affiliation(s)
- Hui Ping Yaw
- School of Science, Monash University MalaysiaJalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia
| | - So Ha Ton
- School of Science, Monash University MalaysiaJalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia
| | - Stella Amanda
- School of Science, Monash University MalaysiaJalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia
| | | | - Hong Sheng Cheng
- School of Science, Monash University MalaysiaJalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia
| | - Hamish Alexander Fernando
- School of Science, Monash University MalaysiaJalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia
| | - Hsien Fei Chin
- School of Science, Monash University MalaysiaJalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia
| | - Khalid Abdul Kadir
- School of Medicine and Health Sciences, Monash University MalaysiaJalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia
| |
Collapse
|
7
|
Gottfried-Blackmore A, Jellinck PH, Vecchiarelli HA, Masheeb Z, Kaufmann M, McEwen BS, Bulloch K. 7α-hydroxylation of dehydroepiandrosterone does not interfere with the activation of glucocorticoids by 11β-hydroxysteroid dehydrogenase in E(t)C cerebellar neurons. J Steroid Biochem Mol Biol 2013; 138:290-7. [PMID: 23851218 DOI: 10.1016/j.jsbmb.2013.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Revised: 06/14/2013] [Accepted: 07/03/2013] [Indexed: 10/26/2022]
Abstract
The neuroprotective action of dehydroepiandrosterone (DHEA) in the absence of a known specific receptor has been attributed to its metabolism by different cell types in the brain to various steroids, with a preference to its 7-hydroxylated products. The E(t)C cerebellar granule cell line converts DHEA almost exclusively to 7α-hydroxy-DHEA (7α-OH-DHEA). It has been postulated that DHEA's 7-OH and 7-oxo metabolites can decrease glucocorticoid levels by an interactive mechanism involving 11β-hydroxysteroid dehydrogenase (11β-HSD). In order to study the relationship of 7-hydroxylation of DHEA and glucocorticoid metabolism in intact brain cells, we examined whether E(t)C cerebellar neurons, which are avid producers of 7α-OH-DHEA, could also metabolize glucocorticoids. We report that E(t)C neuronal cells exhibit 11β-HSD1 reductase activity, and are able to convert 11-dehydrocorticosterone into corticosterone, whereas they do not demonstrate 11β-HSD2 dehydrogenase activity. Consequently, E(t)C cells incubated with DHEA did not yield 7-oxo- or 7β-OH-DHEA. Our findings are supported by the reductive environment of E(t)C cells through expression of hexose-6-phosphate dehydrogenase (H6PDH), which fosters 11β-HSD1 reductase activity. To further explore the role of 7α-OH-DHEA in E(t)C neuronal cells, we examined the effect of preventing its formation using the CYP450 inhibitor ketoconazole. Treatment of the cells with this drug decreased the yield of 7α-OH-DHEA by about 75% without the formation of alternate DHEA metabolites, and had minimal effects on glucocorticoid conversion. Likewise, elevated levels of corticosterone, the product of 11β-HSD1, had no effect on the metabolic profile of DHEA. This study shows that in a single population of whole-cells, with a highly reductive environment, 7α-OH-DHEA is unable to block the reducing activity of 11β-HSD1, and that 7-hydroxylation of DHEA does not interfere with the activation of glucocorticoids. Our investigation on the metabolism of DHEA in E(t)C neuronal cells suggest that other alternate mechanisms must be at play to explain the in vivo anti-glucocorticoid properties of DHEA and its 7-OH-metabolites.
Collapse
Affiliation(s)
- Andres Gottfried-Blackmore
- Harold and Margaret Milliken Hatch, Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | | | | | | | | | | | | |
Collapse
|
8
|
Chapman KE, Coutinho AE, Zhang Z, Kipari T, Savill JS, Seckl JR. Changing glucocorticoid action: 11β-hydroxysteroid dehydrogenase type 1 in acute and chronic inflammation. J Steroid Biochem Mol Biol 2013; 137:82-92. [PMID: 23435016 PMCID: PMC3925798 DOI: 10.1016/j.jsbmb.2013.02.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 01/22/2013] [Accepted: 02/04/2013] [Indexed: 12/18/2022]
Abstract
Since the discovery of cortisone in the 1940s and its early success in treatment of rheumatoid arthritis, glucocorticoids have remained the mainstay of anti-inflammatory therapies. However, cortisone itself is intrinsically inert. To be effective, it requires conversion to cortisol, the active glucocorticoid, by the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). Despite the identification of 11β-HSD in liver in 1953 (which we now know to be 11β-HSD1), its physiological role has been little explored until recently. Over the past decade, however, it has become apparent that 11β-HSD1 plays an important role in shaping endogenous glucocorticoid action. Acute inflammation is more severe with 11β-HSD1-deficiency or inhibition, yet in some inflammatory settings such as obesity or diabetes, 11β-HSD1-deficiency/inhibition is beneficial, reducing inflammation. Current evidence suggests both beneficial and detrimental effects may result from 11β-HSD1 inhibition in chronic inflammatory disease. Here we review recent evidence pertaining to the role of 11β-HSD1 in inflammation. This article is part of a Special Issue entitled 'CSR 2013'.
Collapse
Affiliation(s)
- Karen E Chapman
- University/BHF Centre for Cardiovascular Sciences, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
| | | | | | | | | | | |
Collapse
|
9
|
Fan Z, Du H, Zhang M, Meng Z, Chen L, Liu Y. Direct regulation of glucose and not insulin on hepatic hexose-6-phosphate dehydrogenase and 11β-hydroxysteroid dehydrogenase type 1. Mol Cell Endocrinol 2011; 333:62-9. [PMID: 21163329 PMCID: PMC3741409 DOI: 10.1016/j.mce.2010.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 12/06/2010] [Accepted: 12/07/2010] [Indexed: 12/22/2022]
Abstract
Abnormal hepatic gluconeogenesis contributes significantly to both fasting and non-fasting hyperglycemia of patients with type 2 diabetes. 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) regulates the key hepatic gluconeogenic enzymes including phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) through the amplification of glucocorticoid receptor (GR) - mediated tissue glucocorticoid action, and is crucially dependent on hexose-6-phosphate dehydrogenase (H6PDH) - generating NADPH system. Here, we observed that compared with fasting state, H6PDH and 11β-HSD1 expression in livers were all increased under non-fasting state in both normal and diabetic rats, and the non-fasting diabetic group was the highest among the four experimental groups. Moreover, incubation of primary hepatocytes with increasing glucose caused dose-dependent increases in H6PDH, 11β-HSD1, GR, PEPCK and G6Pase expression. Also, glucose-6-phosphate (G6P) had a positive regulation on H6PDH and 11β-HSD1 in hepatocytes. In addition, primary hepatocytes treated with different doses of insulin in high glucose induced alteration of H6PDH and 11β-HSD1 while in low glucose there was no significant effect. These findings suggest that glucose instead of insulin directly regulates H6PDH and 11β-HSD1 and suppression of the two enzymes could be considered as an effective target for the treatment of type 2 diabetes.
Collapse
Affiliation(s)
- Zheng Fan
- Department of Pharmacology, School of Basic Medical Sciences, Jilin University, 126 Xin Min Street, Changchun 130021, China
| | - Hongwei Du
- Department of Pediatric Endocrinology, The First Clinical Hospital Affiliated to Jilin University, China
| | - Ming Zhang
- Department of Pharmacology, School of Basic Medical Sciences, Jilin University, 126 Xin Min Street, Changchun 130021, China
| | - Zhaojie Meng
- Department of Pharmacology, School of Basic Medical Sciences, Jilin University, 126 Xin Min Street, Changchun 130021, China
| | - Li Chen
- Department of Pharmacology, School of Basic Medical Sciences, Jilin University, 126 Xin Min Street, Changchun 130021, China
- Corresponding author
| | - Yanjun Liu
- Division of Endocrinology, Metabolism and Molecular Medicine, UCLA School of Medicine, Charles Drew University of Medicine and Science, 1731 East 120th Street, Los Angeles, CA 90059, USA
- Corresponding author
| |
Collapse
|