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Nejabati HR, Samadi N, Shahnazi V, Mihanfar A, Fattahi A, Latifi Z, Bahrami-asl Z, Roshangar L, Nouri M. Nicotinamide and its metabolite N1-Methylnicotinamide alleviate endocrine and metabolic abnormalities in adipose and ovarian tissues in rat model of Polycystic Ovary Syndrome. Chem Biol Interact 2020; 324:109093. [DOI: 10.1016/j.cbi.2020.109093] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/18/2020] [Accepted: 04/05/2020] [Indexed: 02/06/2023]
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2
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De Silva MSI, Dayton AW, Rhoten LR, Mallett JW, Reese JC, Squires MD, Dalley AP, Porter JP, Judd AM. Involvement of adenosine monophosphate activated kinase in interleukin-6 regulation of steroidogenic acute regulatory protein and cholesterol side chain cleavage enzyme in the bovine zona fasciculata and zona reticularis. Steroids 2018; 134:53-66. [PMID: 29501754 DOI: 10.1016/j.steroids.2018.02.009] [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: 10/24/2017] [Revised: 02/01/2018] [Accepted: 02/22/2018] [Indexed: 10/17/2022]
Abstract
In bovine adrenal zona fasciculata (ZF) and NCI-H295R cells, interleukin-6 (IL-6) increases cortisol release, increases expression of steroidogenic acute regulatory protein (StAR), cholesterol side chain cleavage enzyme (P450scc), and steroidogenic factor 1 (SF-1) (increases steroidogenic proteins), and decreases the expression of adrenal hypoplasia congenita-like protein (DAX-1) (inhibits steroidogenic proteins). In contrast, IL-6 decreases bovine adrenal zona reticularis (ZR) androgen release, StAR, P450scc, and SF-1 expression, and increases DAX-1 expression. Adenosine monophosphate (AMP) activated kinase (AMPK) regulates steroidogenesis, but its role in IL-6 regulation of adrenal steroidogenesis is unknown. In the present study, an AMPK activator (AICAR) increased (P < 0.01) NCI-H295R StAR promoter activity, StAR and P450scc expression, and the phosphorylation of AMPK (PAMPK) and acetyl-CoA carboxylase (PACC) (indexes of AMPK activity). In ZR (decreased StAR, P450scc, SF-1, increased DAX-1) (P < 0.01) and ZF tissues (increased StAR, P450scc, SF-1, decreased DAX-1) (P < 0.01), AICAR modified StAR, P450scc, SF-1 and DAX-1 mRNAs/proteins similar to the effects of IL-6. The activity (increased PAMPK and PACC) (P < 0.01) of AMPK in the ZF and ZR was increased by AICAR and IL-6. In support of an AMPK role in IL-6 ZF and ZR effects, the AMPK inhibitor compound C blocked (P < 0.01) the effects of IL-6 on the expression of StAR, P450scc, SF-1, and DAX-1. Therefore, IL-6 modification of the expression of StAR and P450scc in the ZF and ZR may involve activation of AMPK and these changes may be related to changes in the expression of SF-1 and DAX-1.
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Affiliation(s)
- Matharage S I De Silva
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States
| | - Adam W Dayton
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States
| | - Lance R Rhoten
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States
| | - John W Mallett
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States
| | - Jared C Reese
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States
| | - Mathieu D Squires
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States
| | - Andrew P Dalley
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States
| | - James P Porter
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States
| | - Allan M Judd
- Department of Physiology and Developmental Biology and Neuroscience Center, Brigham Young University, 4005 LSB, Provo, Utah 84602, United States.
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Li C, Gao S, Chen S, Chen L, Zhao Y, Jiang Y, Zheng X, Zhou X. Differential expression of microRNAs in luteinising hormone-treated mouse TM3 Leydig cells. Andrologia 2017; 50. [PMID: 28762514 DOI: 10.1111/and.12824] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2017] [Indexed: 12/30/2022] Open
Abstract
Testosterone is primarily produced by Leydig cells of the mammalian male gonads. The cellular functions of Leydig cells are regulated by the hypothalamus-pituitary-gonad axis, whereas the microRNA (miRNA) changes of LH-treated Leydig cells are unknown. Mouse TM3 Leydig cells were treated with LH, and deep sequencing showed that 29 miRNAs were significantly different between two groups (fold change of >1.5 or <0.5, p < .05), of which 27 were upregulated and two were downregulated. The differential expression of miR-29b-3p, miR-378b, miR-193b and miR-3695 was confirmed by quantitative real-time polymerase chain reaction. Bioinformatic analysis revealed that miRNAs regulated a large number of genes with different functions. Pathway analysis indicated that miRNAs were involved in the Wingless and INT-1, adenosine 5'-monophosphate-activated protein kinase, NF-kappa B and Toll-like receptor signalling pathways. Results showed that miRNAs might be involved in the regulation of LH to Leydig cells.
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Affiliation(s)
- C Li
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China
| | - S Gao
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China
| | - S Chen
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China
| | - L Chen
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China
| | - Y Zhao
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China
| | - Y Jiang
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China
| | - X Zheng
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China
| | - X Zhou
- College of Animal Sciences, Jilin University, Changchun, Jilin Province, China
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Abdel-Khalik J, Björklund E, Nielsen FK, Hansen M. Incorporation of 14C-cholesterol in human adrenal corticocarcinoma H295R cell line and online-radiodetection of produced 14C-steroid hormone metabolites. J Pharm Biomed Anal 2017; 145:569-575. [PMID: 28777968 DOI: 10.1016/j.jpba.2017.06.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 06/26/2017] [Indexed: 12/28/2022]
Abstract
This study demonstrates the addition of 14C-cholesterol to the human cell line H295R will in-situ form radiolabeled steroid hormones allowing for new mechanistic and metabolic insights. The aim of the present study was to in-situ radiolabel steroid hormones from cell line-incorporated 14C-cholesterol using the OECD guideline 456, H295R steroidogenesis in-vitro assay. Radiodetection of the steroid metabolites of the steroidogenic pathway allows for an improved understanding of the various enzymatic mechanisms involved without necessarily being dependent on quantification. Generated radiolabeled steroids were analyzed using HPLC hyphenated with a Flow Scintillation Analyzer (FSA). H295R cells were incubated with radiolabeled cholesterol and cell media were collected and prepared by solid phase extraction and analyzed with HPLC-FSA. For successful radiolabeling of the steroids in the steroidogenesis of H295R cells, radioactive cholesterol may potentially only need to be added just before the cells are incubated for 72h in well plates. Based on the obtained HPLC-FSA chromatograms, and confirmation of the observations by studies in the literature, a qualitative time profile for the production of steroid hormones was estimated. Multiple radiolabeled steroid hormones were identified by means of analytical standards and UV (ultraviolet) co-chromatography, though the elucidation of multiple metabolites remains unresolved. Although online radiodetection proved to suffer from suboptimal sensitivity, the concept of radiolabeling the steroidogenesis in H295R cells with 14C-cholesterol and detecting the radiolabeled steroid hormones online was proved and may assist in further toxicological studies.
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Affiliation(s)
- Jonas Abdel-Khalik
- Toxicology Laboratory, Analytical Biosciences, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
| | - Erland Björklund
- Toxicology Laboratory, Analytical Biosciences, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Frederik Knud Nielsen
- Toxicology Laboratory, Analytical Biosciences, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Martin Hansen
- Toxicology Laboratory, Analytical Biosciences, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
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Haas J, Bentov Y. Should metformin be included in fertility treatment of PCOS patients? Med Hypotheses 2017; 100:54-58. [PMID: 28236849 DOI: 10.1016/j.mehy.2017.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 10/11/2016] [Accepted: 01/21/2017] [Indexed: 10/20/2022]
Abstract
Metformin, a drug developed for the treatment of patients with type II diabetes, has become commonly prescribed medication for PCOS patients. Initially, metformin was prescribed for patients with impaired glucose tolerance at the pre conception period, however more recently its use was expanded to many of the PCOS patients and for the whole duration of pregnancy. Several studies examining the effects of Metformin during pregnancy reported a lower pregnancy loss, reduced gestational diabetes and no increased risk for birth defects, however, several more recent studies also raised concerns about its safe use. The therapeutic effect of metformin stems from its ability to inhibit the action of the first complex of the electron transport resulting in reduced ATP production. At the initial stages of embryo development, the only source of ATP is the mitochondrial electron transport chain. Lowering ATP production at the critical stage of early embryo development may impair oocyte maturation and embryo development as well as reprogram the metabolic characteristics of the offspring.
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Affiliation(s)
- Jigal Haas
- TRIO Fertility, Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada; Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada; Lunenfeld -Tenenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.
| | - Yaakov Bentov
- TRIO Fertility, Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada; Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada; Lunenfeld -Tenenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.
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Dean A, Nilsen M, Loughlin L, Salt IP, MacLean MR. Metformin Reverses Development of Pulmonary Hypertension via Aromatase Inhibition. Hypertension 2016; 68:446-54. [DOI: 10.1161/hypertensionaha.116.07353] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/13/2016] [Indexed: 11/16/2022]
Abstract
Females are more susceptible to pulmonary arterial hypertension than males, although the reasons remain unclear. The hypoglycemic drug, metformin, is reported to have multiple actions, including the inhibition of aromatase and stimulation of AMP-activated protein kinase. Inhibition of aromatase using anastrazole is protective in experimental pulmonary hypertension but whether metformin attenuates pulmonary hypertension through this mechanism remains unknown. We investigated whether metformin affected aromatase activity and if it could reduce the development of pulmonary hypertension in the sugen 5416/hypoxic rat model. We also investigated its influence on proliferation in human pulmonary arterial smooth muscle cells. Metformin reversed right ventricular systolic pressure, right ventricular hypertrophy, and decreased pulmonary vascular remodeling in the rat. Furthermore, metformin increased rat lung AMP-activated protein kinase signaling, decreased lung and circulating estrogen levels, levels of aromatase, the estrogen metabolizing enzyme; cytochrome P450 1B1 and its transcription factor; the aryl hydrocarbon receptor. In human pulmonary arterial smooth muscle cells, metformin decreased proliferation and decreased estrogen synthesis by decreasing aromatase activity through the PII promoter site of
Cyp19a1
. Thus, we report for the first time that metformin can reverse pulmonary hypertension through inhibition of aromatase and estrogen synthesis in a manner likely to be mediated by AMP-activated protein kinase.
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Affiliation(s)
- Afshan Dean
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Margaret Nilsen
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Lynn Loughlin
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Ian P. Salt
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Margaret R. MacLean
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Dinh Cat AN, Friederich-Persson M, White A, Touyz RM. Adipocytes, aldosterone and obesity-related hypertension. J Mol Endocrinol 2016; 57:F7-F21. [PMID: 27357931 DOI: 10.1530/jme-16-0025] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 05/09/2016] [Indexed: 12/15/2022]
Abstract
Understanding the mechanisms linking obesity with hypertension is important in the current obesity epidemic as it may improve therapeutic interventions. Plasma aldosterone levels are positively correlated with body mass index and weight loss in obese patients is reported to be accompanied by decreased aldosterone levels. This suggests a relationship between adipose tissue and the production/secretion of aldosterone. Aldosterone is synthesized principally by the adrenal glands, but its production may be regulated by many factors, including factors secreted by adipocytes. In addition, studies have reported local synthesis of aldosterone in extra-adrenal tissues, including adipose tissue. Experimental studies have highlighted a role for adipocyte-secreted aldosterone in the pathogenesis of obesity-related cardiovascular complications via the mineralocorticoid receptor. This review focuses on how aldosterone secretion may be influenced by adipose tissue and the importance of these mechanisms in the context of obesity-related hypertension.
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Affiliation(s)
- Aurelie Nguyen Dinh Cat
- Institute of Cardiovascular and Medical SciencesBHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
| | - Malou Friederich-Persson
- Institute of Cardiovascular and Medical SciencesBHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
| | - Anna White
- Institute of Cardiovascular and Medical SciencesBHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
| | - Rhian M Touyz
- Institute of Cardiovascular and Medical SciencesBHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
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8
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Cellular and Animal Studies: Insights into Pathophysiology and Therapy of PCOS. Best Pract Res Clin Obstet Gynaecol 2016; 37:12-24. [PMID: 27118251 DOI: 10.1016/j.bpobgyn.2016.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/04/2016] [Accepted: 03/07/2016] [Indexed: 01/12/2023]
Abstract
Basic science studies have advanced our understanding of the role of key enzymes in the steroidogenesis pathway and those that affect the pathophysiology of PCOS. Studies with ovarian theca cells taken from women with PCOS have demonstrated increased androgen production due to increased CYP17A1 and HSD3B2 enzyme activities. Furthermore, overexpression of DENND1A variant 2 in normal theca cells resulted in a PCOS phenotype with increased androgen production. Notably, cellular steroidogenesis models have facilitated the understanding of the mechanistic effects of pharmacotherapies, including insulin sensitizers (e.g., pioglitazone and metformin) used for the treatment of insulin resistance in PCOS, on androgen production. In addition, animal models of PCOS have provided a critical platform to study the effects of therapeutic agents in a manner closer to the physiological state. Indeed, recent breakthroughs have demonstrated that natural derivatives such as the dietary medium-chain fatty acid decanoic acid (DA) can restore estrous cyclicity and lower androgen levels in an animal model of PCOS, thus laying the platform for novel therapeutic developments in PCOS. This chapter reviews the current understanding on the pathways modulating androgen biosynthesis, and the cellular and animal models that form the basis for preclinical research in PCOS, and sets the stage for clinical research.
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Bertoldo MJ, Faure M, Dupont J, Froment P. AMPK: a master energy regulator for gonadal function. Front Neurosci 2015; 9:235. [PMID: 26236179 PMCID: PMC4500899 DOI: 10.3389/fnins.2015.00235] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 06/19/2015] [Indexed: 12/11/2022] Open
Abstract
From C. elegans to mammals (including humans), nutrition and energy metabolism significantly influence reproduction. At the cellular level, some detectors of energy status indicate whether energy reserves are abundant (obesity), or poor (diet restriction). One of these detectors is AMPK (5′ AMP-activated protein kinase), a protein kinase activated by ATP deficiency but also by several natural substances such as polyphenols or synthetic molecules like metformin, used in the treatment of insulin resistance. AMPK is expressed in muscle and liver, but also in the ovary and testis. This review focuses on the main effects of AMPK identified in gonadal cells. We describe the role of AMPK in gonadal steroidogenesis, in proliferation and survival of somatic gonadal cells and in the maturation of oocytes or spermatozoa. We discuss also the role of AMPK in germ and somatic cell interactions within the cumulus-oocyte complex and in the blood testis barrier. Finally, the interface in the gonad between AMPK and modification of metabolism is reported and discussion about the role of AMPK on fertility, in regards to the treatment of infertility associated with insulin resistance (male obesity, polycystic ovary syndrome).
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Affiliation(s)
- Michael J Bertoldo
- Discipline of Obstetrics and Gynaecology, School of Women's and Children's Health, University of New South Wales Sydney, NSW, Australia
| | - Melanie Faure
- Unité de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, UMR85 Nouzilly, France
| | - Joëlle Dupont
- Unité de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, UMR85 Nouzilly, France
| | - Pascal Froment
- Unité de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, UMR85 Nouzilly, France
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Kelly PS, Breen L, Gallagher C, Kelly S, Henry M, Lao NT, Meleady P, O'Gorman D, Clynes M, Barron N. Re-programming CHO cell metabolism using miR-23 tips the balance towards a highly productive phenotype. Biotechnol J 2015; 10:1029-40. [DOI: 10.1002/biot.201500101] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/24/2015] [Accepted: 06/03/2015] [Indexed: 12/21/2022]
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11
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Udhane SS, Pandey AV, Hofer G, Mullis PE, Flück CE. Retinoic acid receptor beta and angiopoietin-like protein 1 are involved in the regulation of human androgen biosynthesis. Sci Rep 2015; 5:10132. [PMID: 25970467 PMCID: PMC4429542 DOI: 10.1038/srep10132] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 03/31/2015] [Indexed: 12/17/2022] Open
Abstract
Androgens are essential for sexual development and reproduction. However, androgen regulation in health and disease is poorly understood. We showed that human adrenocortical H295R cells grown under starvation conditions acquire a hyperandrogenic steroid profile with changes in steroid metabolizing enzymes HSD3B2 and CYP17A1 essential for androgen production. Here we studied the regulatory mechanisms underlying androgen production in starved H295R cells. Microarray expression profiling of normal versus starved H295R cells revealed fourteen differentially expressed genes; HSD3B2, HSD3B1, CYP21A2, RARB, ASS1, CFI, ASCL1 and ENC1 play a role in steroid and energy metabolism and ANGPTL1, PLK2, DUSP6, DUSP10 and FREM2 are involved in signal transduction. We discovered two new gene networks around RARB and ANGPTL1, and show how they regulate androgen biosynthesis. Transcription factor RARB stimulated the promoters of genes involved in androgen production (StAR, CYP17A1 and HSD3B2) and enhanced androstenedione production. For HSD3B2 regulation RARB worked in cooperation with Nur77. Secretory protein ANGPTL1 modulated CYP17A1 and DUSP6 expression by inducing ERK1/2 phosphorylation. By contrast, our studies revealed no evidence for hormones or cell cycle involvement in regulating androgen biosynthesis. In summary, these studies establish a firm role for RARB and ANGPTL1 in the regulation of androgen production in H295R cells.
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Affiliation(s)
- Sameer S Udhane
- Pediatric Endocrinology and Diabetology, Department of Pediatrics, University Children's Hospital, Inselspital.,The Department of Clinical Research, University of Bern, 3010 Bern, Switzerland
| | - Amit V Pandey
- Pediatric Endocrinology and Diabetology, Department of Pediatrics, University Children's Hospital, Inselspital.,The Department of Clinical Research, University of Bern, 3010 Bern, Switzerland
| | - Gaby Hofer
- Pediatric Endocrinology and Diabetology, Department of Pediatrics, University Children's Hospital, Inselspital.,The Department of Clinical Research, University of Bern, 3010 Bern, Switzerland
| | - Primus E Mullis
- Pediatric Endocrinology and Diabetology, Department of Pediatrics, University Children's Hospital, Inselspital.,The Department of Clinical Research, University of Bern, 3010 Bern, Switzerland
| | - Christa E Flück
- Pediatric Endocrinology and Diabetology, Department of Pediatrics, University Children's Hospital, Inselspital.,The Department of Clinical Research, University of Bern, 3010 Bern, Switzerland
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Das D, Goyal A. Characterization and biocompatibility of glucan: a safe food additive from probiotic Lactobacillus plantarum DM5. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2014; 94:683-690. [PMID: 23852706 DOI: 10.1002/jsfa.6305] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 07/06/2013] [Accepted: 07/13/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND Exopolysaccharide produced by lactic acid bacteria are the subject of an increasing number of studies for their potential applications in the food industry as stabilizing, bio-thickening and immunostimulating agents. In this regard, the authors isolated an exopolysaccharide producing probiotic lactic acid bacterium from fermented beverage Marcha of north eastern Himalayas. RESULTS The isolate Lactobacillus plantarum DM5 showed extracellular glucansucrase activity of 0.48 U mg⁻¹ by synthesizing natural exopolysaccharide glucan (1.87 mg mL⁻¹) from sucrose. Zymogram analysis of purified enzyme confirms the presence of glucosyltransferase of approximately 148 kDa with optimal activity of 18.7 U mg⁻¹ at 30 °C and pH 5.4. The exopolysaccharide was purified by gel permeation chromatography and had an average molecular weight of 1.11 × 10⁶ Da. Acid hydrolysis and structural characterization of exopolysaccharide revealed that it was composed of d-glucose residues, containing 86.5% of α-(1→6) and 13.5% of α-(1→3) linkages. Rheological study exhibited a shear thinning effect of glucan appropriate for food additives. A cytotoxicity test of glucan on human embryonic kidney 293 (HEK 293) and human cervical cancer (HeLa) cell lines revealed its nontoxic biocompatible nature. CONCLUSION This is the first report on the structure and biocompatibility of homopolysaccharide α-D-glucan (dextran) from probiotic Lactobacillus plantarum strain and its unique physical and rheological properties that facilitate its application in the food industry as viscosifying and gelling agent.
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Affiliation(s)
- Deeplina Das
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, 781 039, India
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13
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Guo Y, Zhang Y, Hong K, Luo F, Gu Q, Lu N, Bai A. AMPK inhibition blocks ROS-NFκB signaling and attenuates endotoxemia-induced liver injury. PLoS One 2014; 9:e86881. [PMID: 24475189 PMCID: PMC3901729 DOI: 10.1371/journal.pone.0086881] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 12/16/2013] [Indexed: 11/28/2022] Open
Abstract
Background AMP-activated protein kinase (AMPK) is an important enzyme in regulation of cellular energy homeostasis. We have previously shown that AMPK activation by 5-aminoimidazole-4-carboxamide (AICAR) results in suppression of immune responses, indicating the pivotal role of AMPK in immune regulation. However, the cellular mechanism underpinning AMPK inhibition on immune response remains largely to be elucidated. The study aimed to investigate the effects of AMPK inhibition on reactive oxygen species (ROS)-nuclear factor κB (NFκB) signaling and endotoxemia-induced liver injury. Methodology/Principal Findings RAW 264.7 cells were pretreated with AMPK activator or inhibitor, followed by LPS challenge. In addition, LPS was injected intraperitoneally into mice to induce systemic inflammation. The parameters of liver injury and immune responses were determined, and survival of mice was monitored respectively. LPS challenge in RAW 264.7 cells resulted in AMPK activation which was then inhibited by compound C treatment. Both AMPK activation by AICAR or inhibition by compound C diminished LPS-induced ROS generation, inhibited phosphorylation of IKK, IκB, and NFκB p65, and consequently, decreased TNF production of RAW 264.7 cells. AICAR or compound C treatment decreased ALT, AST, and TNF levels in serum, reduced CD68 expression and MPO activity in liver tissue of mice with endotoxemia. Moreover, AICAR or compound C treatment improved survival of endotoxemic mice. Conclusions AICAR or compound C treatment attenuates LPS-induced ROS-NFκB signaling, immune responses and liver injury. Strategies to activate or inhibit AMPK signaling may provide alternatives to the current clinical approaches to inhibit immune responses of endotoxemia.
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Affiliation(s)
- Yuan Guo
- Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang, China
- Department of Pharmacy, the First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yi Zhang
- Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Kai Hong
- Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Fengyan Luo
- Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qiuping Gu
- Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Nonghua Lu
- Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Aiping Bai
- Department of Gastroenterology, the First Affiliated Hospital of Nanchang University, Nanchang, China
- * E-mail:
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14
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Udhane S, Kempna P, Hofer G, Mullis PE, Flück CE. Differential regulation of human 3β-hydroxysteroid dehydrogenase type 2 for steroid hormone biosynthesis by starvation and cyclic AMP stimulation: studies in the human adrenal NCI-H295R cell model. PLoS One 2013; 8:e68691. [PMID: 23874725 PMCID: PMC3706324 DOI: 10.1371/journal.pone.0068691] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 05/31/2013] [Indexed: 12/14/2022] Open
Abstract
Human steroid biosynthesis depends on a specifically regulated cascade of enzymes including 3β-hydroxysteroid dehydrogenases (HSD3Bs). Type 2 HSD3B catalyzes the conversion of pregnenolone, 17α-hydroxypregnenolone and dehydroepiandrosterone to progesterone, 17α-hydroxyprogesterone and androstenedione in the human adrenal cortex and the gonads but the exact regulation of this enzyme is unknown. Therefore, specific downregulation of HSD3B2 at adrenarche around age 6–8 years and characteristic upregulation of HSD3B2 in the ovaries of women suffering from the polycystic ovary syndrome remain unexplained prompting us to study the regulation of HSD3B2 in adrenal NCI-H295R cells. Our studies confirm that the HSD3B2 promoter is regulated by transcription factors GATA, Nur77 and SF1/LRH1 in concert and that the NBRE/Nur77 site is crucial for hormonal stimulation with cAMP. In fact, these three transcription factors together were able to transactivate the HSD3B2 promoter in placental JEG3 cells which normally do not express HSD3B2. By contrast, epigenetic mechanisms such as methylation and acetylation seem not involved in controlling HSD3B2 expression. Cyclic AMP was found to exert differential effects on HSD3B2 when comparing short (acute) versus long-term (chronic) stimulation. Short cAMP stimulation inhibited HSD3B2 activity directly possibly due to regulation at co-factor or substrate level or posttranslational modification of the protein. Long cAMP stimulation attenuated HSD3B2 inhibition and increased HSD3B2 expression through transcriptional regulation. Although PKA and MAPK pathways are obvious candidates for possibly transmitting the cAMP signal to HSD3B2, our studies using PKA and MEK1/2 inhibitors revealed no such downstream signaling of cAMP. However, both signaling pathways were clearly regulating HSD3B2 expression.
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Affiliation(s)
- Sameer Udhane
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetology, University Children’s Hospital, Berne, Switzerland
- Department of Clinical Research, University of Berne, Berne, Switzerland
- Graduate School Berne for Cellular and Biomedical Sciences, University of Berne, Berne, Switzerland
| | - Petra Kempna
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetology, University Children’s Hospital, Berne, Switzerland
- Department of Clinical Research, University of Berne, Berne, Switzerland
| | - Gaby Hofer
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetology, University Children’s Hospital, Berne, Switzerland
- Department of Clinical Research, University of Berne, Berne, Switzerland
| | - Primus E. Mullis
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetology, University Children’s Hospital, Berne, Switzerland
- Department of Clinical Research, University of Berne, Berne, Switzerland
| | - Christa E. Flück
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetology, University Children’s Hospital, Berne, Switzerland
- Department of Clinical Research, University of Berne, Berne, Switzerland
- * E-mail:
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Hirsch A, Hahn D, Kempná P, Hofer G, Nuoffer JM, Mullis PE, Flück CE. Metformin inhibits human androgen production by regulating steroidogenic enzymes HSD3B2 and CYP17A1 and complex I activity of the respiratory chain. Endocrinology 2012; 153:4354-66. [PMID: 22778212 DOI: 10.1210/en.2012-1145] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Metformin is treatment of choice for the metabolic consequences seen in polycystic ovary syndrome for its insulin-sensitizing and androgen-lowering properties. Yet, the mechanism of action remains unclear. Two potential targets for metformin regulating steroid and glucose metabolism are AMP-activated protein kinase (AMPK) signaling and the complex I of the mitochondrial respiratory chain. Androgen biosynthesis requires steroid enzymes 17α-Hydroxylase/17,20 lyase (CYP17A1) and 3β-hydroxysteroid dehydrogenase type 2 (HSD3B2), which are overexpressed in ovarian cells of polycystic ovary syndrome women. Therefore, we aimed to understand how metformin modulates androgen production using NCI-H295R cells as an established model of steroidogenesis. Similar to in vivo situation, metformin inhibited androgen production in NCI cells by decreasing HSD3B2 expression and CYP17A1 and HSD3B2 activities. The effect of metformin on androgen production was dose dependent and subject to the presence of organic cation transporters, establishing an important role of organic cation transporters for metformin's action. Metformin did not affect AMPK, ERK1/2, or atypical protein kinase C signaling. By contrast, metformin inhibited complex I of the respiratory chain in mitochondria. Similar to metformin, direct inhibition of complex I by rotenone also inhibited HSD3B2 activity. In conclusion, metformin inhibits androgen production by mechanisms targeting HSD3B2 and CYP17-lyase. This regulation involves inhibition of mitochondrial complex I but appears to be independent of AMPK signaling.
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Affiliation(s)
- Andrea Hirsch
- Department of Pediatrics, Division of Pediatric Endocrinology, Diabetology and Metabolism, University Hospital Inselspital, University of Bern, 3010 Bern, Switzerland
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Komori T, Doi A, Nosaka T, Furuta H, Akamizu T, Kitamura T, Senba E, Morikawa Y. Regulation of AMP-activated protein kinase signaling by AFF4 protein, member of AF4 (ALL1-fused gene from chromosome 4) family of transcription factors, in hypothalamic neurons. J Biol Chem 2012; 287:19985-96. [PMID: 22528490 DOI: 10.1074/jbc.m112.367854] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In the hypothalamus, fasting induces a member of the AF4 family of transcription factors, AFF4, which was originally identified as a fusion partner of the mixed-lineage leukemia gene in infant acute lymphoblastic leukemia. However, the roles of AFF4 in the hypothalamus remain unclear. We show herein that expression of AFF4 increased upon addition of ghrelin and fasting in the growth hormone secretagogue receptor-expressing neurons of the hypothalamus. In the growth hormone secretagogue receptor-expressing hypothalamic neuronal cell line GT1-7, ghrelin markedly induced expression of AFF4 in a time- and dose-dependent manner. Overexpression of AFF4 in GT1-7 cells specifically induced expression of the AMP-activated protein kinase (AMPK) α2 subunit but failed to induce other AMPK subunits and AMPK upstream kinases. The promoter activity of the AMPKα2 gene increased upon addition of AFF4, suggesting that AFF4 regulates transcription of the AMPKα2 gene. Additionally, AFF4 also increased the phosphorylation of acetyl-CoA carboxylase α (ACCα), a downstream target of AMPK. In GT1-7 cells, ghrelin phosphorylated ACCα through AMPKα phosphorylation in the early phase (15 min) of the activation. However, ghrelin-induced expression of AMPKα2 and phosphorylation of ACCα in the late phase (2 h) of the activation were independent of AMPKα phosphorylation. Attenuation of expression of AFF4 by its siRNA in GT1-7 cells decreased ghrelin-induced AMPKα2 expression and ACCα phosphorylation in the late phase of the activation. AFF4 may therefore help to maintain activation of AMPK downstream signaling under conditions of prolonged stimulation with ghrelin, such as during fasting.
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Affiliation(s)
- Tadasuke Komori
- Department of Anatomy and Neurobiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-8509, Japan
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