1
|
Rossetti MF, Varayoud J, Ramos JG. Steroidogenic enzymes in the hippocampus: Transcriptional regulation aspects. VITAMINS AND HORMONES 2022; 118:171-198. [PMID: 35180926 DOI: 10.1016/bs.vh.2021.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Neurosteroids are steroids synthesized de novo from cholesterol in brain regions, and regulate processes associated with the development and functioning of the nervous system. Enzymes and proteins involved in the synthesis of these steroids have been detected in several brain regions, including hippocampus, hypothalamus, and cerebral cortex. Hippocampus has long been associated with learning and memory functions, while the loss of its functionality has been linked to neurodegenerative pathologies. In this sense, neurosteroids are critical for the maintenance of hippocampal functions and neuroprotective effects. Moreover, several factors have been shown to deregulate expression of steroidogenic enzymes in the rodent brain, including aging, enrichment experiences, diet habits, drug/alcohol consumption, hormone fluctuations, neurodegenerative processes and other diseases. These transcriptional deregulations are mediated mainly by transcription factors and epigenetic mechanisms. An epigenetic modification of chromatin involves changes in bases and associated proteins in the absence of changes in the DNA sequence. One of the most well-studied mechanisms related to gene silencing is DNA methylation, which involves a reversible addition of methyl groups in a cytosine base. Importantly, these epigenetic marks could be maintained over time and could be transmitted transgenerationally. The aim of this chapter is to present the most relevant steroidogenic enzymes described in rodent hippocampus; to discuss about their transcriptional regulation under different conditions; to show the main gene control regions and to propose DNA methylation as an epigenetic mechanism through which the expression of these enzymes could be controlled.
Collapse
Affiliation(s)
- María Florencia Rossetti
- Departamento de Bioquímica Clínica y Cuantitativa, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, Santa Fe, Argentina
| | - Jorgelina Varayoud
- Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, Santa Fe, Argentina; Cátedra de Fisiología Humana, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Jorge Guillermo Ramos
- Departamento de Bioquímica Clínica y Cuantitativa, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, Santa Fe, Argentina.
| |
Collapse
|
2
|
Wang Z, Zhou S, Zhang S, Zhang S, Zhu F, Jin X, Chen Z, Xu X. Semi-rational engineering of a thermostable aldo-keto reductase from Thermotoga maritima for synthesis of enantiopure ethyl-2-hydroxy-4-phenylbutyrate (EHPB). Sci Rep 2017; 7:4007. [PMID: 28638047 PMCID: PMC5479831 DOI: 10.1038/s41598-017-03947-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 05/05/2017] [Indexed: 11/29/2022] Open
Abstract
A novel aldo-keto reductase Tm1743 characterized from Thermotoga maritima was explored as an effective biocatalyst in chiral alcohol production. Natural Tm1743 catalyzes asymmetric reduction of ethyl 2-oxo-4-phenylbutyrate (EOPB) at high efficiency, but the production of, ethyl (S)-2-hydroxy-4-phenylbutyrate ((S)-EHPB), which is less desirable, is preferred with an enantiomeric excess (ee) value of 76.5%. Thus, altering the enantioselectivity of Tm1743 to obtain the more valuable product (R)-EHPB for angiotensin drug synthesis is highly desired. In this work, we determined the crystal structure of Tm1743 in complex with its cofactor NADP+ at 2.0 Å resolution, and investigated the enantioselectivity of Tm1743 through semi-rational enzyme design. Molecular simulations based on the crystal structure obtained two binding models representing the pro-S and pro-R conformations of EOPB. Saturation mutagenesis studies revealed that Trp21 and Trp86 play important roles in determining the enantioselectivity of Tm1743. The best (R)- and (S)-EHPB preferring Tm1743 mutants, denoted as W21S/W86E and W21L/W118H, were identified; their ee values are 99.4% and 99.6% and the catalytic efficiencies are 0.81 and 0.12 mM-1s-1, respectively. Our work presents an efficient strategy to improve the enantioselectivity of a natural biocatalyst, which will serve as a guide for further exploration of new green catalysts for asymmetric reactions.
Collapse
Affiliation(s)
- Zhiguo Wang
- Hangzhou Normal University, Hangzhou, Zhejiang, 311121, China
| | - Shuo Zhou
- Hangzhou Normal University, Hangzhou, Zhejiang, 311121, China
| | | | - Sa Zhang
- Hangzhou Normal University, Hangzhou, Zhejiang, 311121, China
| | - Fangmeng Zhu
- Apeloa Pharmaceutical Co., Ltd., Dongyang, Zhejiang, 322118, China
| | - Xiaolu Jin
- Yosemade Pharmaceutical Co., Ltd., Jinhua, Zhejiang, 321025, China
| | - Zhenming Chen
- Hangzhou Normal University, Hangzhou, Zhejiang, 311121, China.
| | - Xiaoling Xu
- Hangzhou Normal University, Hangzhou, Zhejiang, 311121, China.
| |
Collapse
|
3
|
Hou H, Li R, Wang X, Yuan Z, Liu X, Chen Z, Xu X. Crystallographic analysis of a novel aldo-keto reductase from Thermotoga maritima in complex with NADP⁺. Acta Crystallogr F Struct Biol Commun 2015; 71:847-55. [PMID: 26144229 PMCID: PMC4498705 DOI: 10.1107/s2053230x15009735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/20/2015] [Indexed: 11/10/2022] Open
Abstract
Aldo-keto reductases (AKRs) are a superfamily of NAD(P)H-dependent oxidoreductases that catalyse the asymmetric reduction of aldehydes and ketones to chiral alcohols in various organisms. The novel aldo-keto reductase Tm1743 from Thermotoga maritima was identified to have a broad substrate specificity and high thermostability, serving as an important enzyme in biocatalysis and fine-chemical synthesis. In this study, Tm1743 was overexpressed in Escherichia coli BL21(DE3) cells with an N-terminal His6 tag and was purified by Ni(2+)-chelating affinity and size-exclusion chromatography. Purified recombinant enzyme was incubated with its cofactor NADP(+) and its substrate ethyl 2-oxo-4-phenylbutyrate (EOPB) for crystallization. Two X-ray diffraction data sets were collected at 2.0 and 1.7 Å resolution from dodecahedral crystals grown from samples containing Tm1743-NADP(+)-EOPB and Tm1743-NADP(+), respectively. Both crystals belonged to space group P3121, with similar unit-cell parameters. However, in the refined structure model only NADP(+) was observed in the active site of the full-length Tm1743 enzyme. Degradation of the N-terminal vector-derived amino acids during crystallization was confirmed by Western blot and mass-spectrometric analyses.
Collapse
Affiliation(s)
- Hai Hou
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China
- Key Laboratory for Space Bioscience and Space Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi’an, Shaanxi 710072, People’s Republic of China
| | - Ruiying Li
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China
| | - Xiaoyan Wang
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China
| | - Zhen Yuan
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China
| | - Xuemeng Liu
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China
| | - Zhenmin Chen
- Laboratory of Biocatalysis, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China
| | - Xiaoling Xu
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China
| |
Collapse
|
4
|
Liedtke AJ, Adeniji A, Chen M, Byrns MC, Jin Y, Christianson DW, Marnett LJ, Penning TM. Development of potent and selective indomethacin analogues for the inhibition of AKR1C3 (Type 5 17β-hydroxysteroid dehydrogenase/prostaglandin F synthase) in castrate-resistant prostate cancer. J Med Chem 2013; 56:2429-46. [PMID: 23432095 PMCID: PMC3638264 DOI: 10.1021/jm3017656] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Indexed: 12/02/2022]
Abstract
Castrate-resistant prostate cancer (CRPC) is a fatal, metastatic form of prostate cancer. CRPC is characterized by reactivation of the androgen axis due to changes in androgen receptor signaling and/or adaptive intratumoral androgen biosynthesis. AKR1C3 is upregulated in CRPC where it catalyzes the formation of potent androgens. This makes AKR1C3 a target for the treatment of CRPC. AKR1C3 inhibitors should not inhibit AKR1C1/AKR1C2, which inactivate 5α-dihydrotestosterone. Indomethacin, used to inhibit cyclooxygenase, also inhibits AKR1C3 and displays selectivity over AKR1C1/AKR1C2. Parallel synthetic strategies were used to generate libraries of indomethacin analogues, which exhibit reduced cyclooxygenase inhibitory activity but retain AKR1C3 inhibitory potency and selectivity. The lead compounds inhibited AKR1C3 with nanomolar potency, displayed >100-fold selectivity over AKR1C1/AKR1C2, and blocked testosterone formation in LNCaP-AKR1C3 cells. The AKR1C3·NADP(+)·2'-des-methyl-indomethacin crystal structure was determined, and it revealed a unique inhibitor binding mode. The compounds reported are promising agents for the development of therapeutics for CRPC.
Collapse
Affiliation(s)
- Andy J. Liedtke
- Departments of Biochemistry,
Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology,
Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville,
Tennessee 37232-0146, United States
| | - Adegoke
O. Adeniji
- Department of Pharmacology and
Center of Excellence in Environmental Toxicology, Perelman School
of Medicine, University of Pennsylvania, 1315 BRB II/III, 420 Curie Boulevard, Philadelphia, Pennsylvania
19104-6061, United States
| | - Mo Chen
- Department of Pharmacology and
Center of Excellence in Environmental Toxicology, Perelman School
of Medicine, University of Pennsylvania, 1315 BRB II/III, 420 Curie Boulevard, Philadelphia, Pennsylvania
19104-6061, United States
| | - Michael C. Byrns
- Department of Pharmacology and
Center of Excellence in Environmental Toxicology, Perelman School
of Medicine, University of Pennsylvania, 1315 BRB II/III, 420 Curie Boulevard, Philadelphia, Pennsylvania
19104-6061, United States
| | - Yi Jin
- Department of Pharmacology and
Center of Excellence in Environmental Toxicology, Perelman School
of Medicine, University of Pennsylvania, 1315 BRB II/III, 420 Curie Boulevard, Philadelphia, Pennsylvania
19104-6061, United States
| | - David W. Christianson
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street,
Philadelphia, Pennsylvania 19104-6323, United States
| | - Lawrence J. Marnett
- Departments of Biochemistry,
Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology,
Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville,
Tennessee 37232-0146, United States
| | - Trevor M. Penning
- Department of Pharmacology and
Center of Excellence in Environmental Toxicology, Perelman School
of Medicine, University of Pennsylvania, 1315 BRB II/III, 420 Curie Boulevard, Philadelphia, Pennsylvania
19104-6061, United States
| |
Collapse
|
5
|
Adeniji AO, Twenter BM, Byrns MC, Jin Y, Chen M, Winkler JD, Penning TM. Development of potent and selective inhibitors of aldo-keto reductase 1C3 (type 5 17β-hydroxysteroid dehydrogenase) based on N-phenyl-aminobenzoates and their structure-activity relationships. J Med Chem 2012; 55:2311-23. [PMID: 22263837 DOI: 10.1021/jm201547v] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Aldo-keto reductase 1C3 (AKR1C3; type 5 17β-hydroxysteroid dehydrogenase) is overexpressed in castration resistant prostate cancer (CRPC) and is implicated in the intratumoral biosynthesis of testosterone and 5α-dihydrotestosterone. Selective AKR1C3 inhibitors are required because compounds should not inhibit the highly related AKR1C1 and AKR1C2 isoforms which are involved in the inactivation of 5α-dihydrotestosterone. NSAIDs, N-phenylanthranilates in particular, are potent but nonselective AKR1C3 inhibitors. Using flufenamic acid, 2-{[3-(trifluoromethyl)phenyl]amino}benzoic acid, as lead compound, five classes of structural analogues were synthesized and evaluated for AKR1C3 inhibitory potency and selectivity. Structure-activity relationship (SAR) studies revealed that a meta-carboxylic acid group relative to the amine conferred pronounced AKR1C3 selectivity without loss of potency, while electron withdrawing groups on the phenylamino B-ring were optimal for AKR1C3 inhibition. Lead compounds did not inhibit COX-1 or COX-2 but blocked the AKR1C3 mediated production of testosterone in LNCaP-AKR1C3 cells. These compounds offer promising leads toward new therapeutics for CRPC.
Collapse
Affiliation(s)
- Adegoke O Adeniji
- Department of Pharmacology and Center of Excellence in Environmental Toxicology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6084, USA
| | | | | | | | | | | | | |
Collapse
|
6
|
Mindnich RD, Penning TM. Aldo-keto reductase (AKR) superfamily: genomics and annotation. Hum Genomics 2009; 3:362-70. [PMID: 19706366 PMCID: PMC3206293 DOI: 10.1186/1479-7364-3-4-362] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Aldo-keto reductases (AKRs) are phase I metabolising enzymes that catalyse the reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H)-dependent reduction of carbonyl groups to yield primary and secondary alcohols on a wide range of substrates, including aliphatic and aromatic aldehydes and ketones, ketoprostaglan-dins, ketosteroids and xenobiotics. In so doing they functionalise the carbonyl group for conjugation (phase II enzyme reactions). Although functionally diverse, AKRs form a protein superfamily based on their high sequence identity and common protein fold, the (α/(β)8-barrel structure. Well over 150 AKR enzymes, from diverse organisms, have been annotated so far and given systematic names according to a nomenclature that is based on multiple protein sequence alignment and degree of identity. Annotation of non-vertebrate AKRs at the National Center for Biotechnology Information or Vertebrate Genome Annotation (vega) database does not often include the systematic nomenclature name, so the most comprehensive overview of all annotated AKRs is found on the AKR website (http://www.med.upenn.edu/akr/). This site also hosts links to more detailed and specialised information (eg on crystal structures, gene expression and single nucleotide polymorphisms [SNPs]). The protein-based AKR nomenclature allows unambiguous identification of a given enzyme but does not reflect the wealth of genomic and transcriptomic variation that exists in the various databases. In this context, identification of putative new AKRs and their distinction from pseudogenes are challenging. This review provides a short summary of the characteristic features of AKR biochemistry and structure that have been reviewed in great detail elsewhere, and focuses mainly on nomenclature and database entries of human AKRs that so far have not been subject to systematic annotation. Recent developments in the annotation of SNP and transcript variance in AKRs are also summarised.
Collapse
Affiliation(s)
- Rebekka D Mindnich
- Department of Pharmacology, Center for Excellence in Environmental Toxicology, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104-6084, USA
| | | |
Collapse
|
7
|
Do Rego JL, Seong JY, Burel D, Leprince J, Luu-The V, Tsutsui K, Tonon MC, Pelletier G, Vaudry H. Neurosteroid biosynthesis: enzymatic pathways and neuroendocrine regulation by neurotransmitters and neuropeptides. Front Neuroendocrinol 2009; 30:259-301. [PMID: 19505496 DOI: 10.1016/j.yfrne.2009.05.006] [Citation(s) in RCA: 283] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 05/12/2009] [Accepted: 05/21/2009] [Indexed: 01/09/2023]
Abstract
Neuroactive steroids synthesized in neuronal tissue, referred to as neurosteroids, are implicated in proliferation, differentiation, activity and survival of nerve cells. Neurosteroids are also involved in the control of a number of behavioral, neuroendocrine and metabolic processes such as regulation of food intake, locomotor activity, sexual activity, aggressiveness, anxiety, depression, body temperature and blood pressure. In this article, we summarize the current knowledge regarding the existence, neuroanatomical distribution and biological activity of the enzymes responsible for the biosynthesis of neurosteroids in the brain of vertebrates, and we review the neuronal mechanisms that control the activity of these enzymes. The observation that the activity of key steroidogenic enzymes is finely tuned by various neurotransmitters and neuropeptides strongly suggests that some of the central effects of these neuromodulators may be mediated via the regulation of neurosteroid production.
Collapse
Affiliation(s)
- Jean Luc Do Rego
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 413, 76821 Mont-Saint-Aignan, France
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Faucher F, Cantin L, Luu-The V, Labrie F, Breton R. The crystal structure of human Delta4-3-ketosteroid 5beta-reductase defines the functional role of the residues of the catalytic tetrad in the steroid double bond reduction mechanism. Biochemistry 2008; 47:8261-70. [PMID: 18624455 DOI: 10.1021/bi800572s] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The 5beta-reductases (AKR1D1-3) are unique enzymes able to catalyze efficiently and in a stereospecific manner the 5beta-reduction of the C4-C5 double bond found into Delta4-3-ketosteroids, including steroid hormones and bile acids. Multiple-sequence alignments and mutagenic studies have already identified one of the residues presumably located at their active site, Glu 120, as the major molecular determinant for the unique activity displayed by 5beta-reductases. To define the exact role played by this glutamate in the catalytic activity of these enzymes, biochemical and structural studies on human 5beta-reductase (h5beta-red) have been undertaken. The crystal structure of h5beta-red in a ternary complex with NADP (+) and 5beta-dihydroprogesterone (5beta-DHP), the product of the 5beta-reduction of progesterone (Prog), revealed that Glu 120 does not interact directly with the other catalytic residues, as previously hypothesized, thus suggesting that this residue is not directly involved in catalysis but could instead be important for the proper positioning of the steroid substrate in the catalytic site. On the basis of our structural results, we thus propose a realistic scheme for the catalytic mechanism of the C4-C5 double bond reduction. We also propose that bile acid precursors such as 7alpha-hydroxy-4-cholesten-3-one and 7alpha,12alpha-dihydroxy-4-cholesten-3-one, when bound to the active site of h5beta-red, can establish supplementary contacts with Tyr 26 and Tyr 132, two residues delineating the steroid-binding cavity. These additional contacts very likely account for the higher activity of h5beta-red toward the bile acid intermediates versus steroid hormones. Finally, in light of the structural data now available, we attempt to interpret the likely consequences of mutations already identified in the gene encoding the h5beta-red enzyme which lead to a reduction of its enzymatic activity and which can progress to severe liver function failure.
Collapse
Affiliation(s)
- Frédérick Faucher
- Oncology and Molecular Endocrinology Research Center, Laval University Medical Center, Québec (QC), G1V 4G2 Canada
| | | | | | | | | |
Collapse
|
9
|
Thorn A, Egerer-Sieber C, Jäger CM, Herl V, Müller-Uri F, Kreis W, Muller YA. The Crystal Structure of Progesterone 5β-Reductase from Digitalis lanata Defines a Novel Class of Short Chain Dehydrogenases/Reductases. J Biol Chem 2008; 283:17260-9. [DOI: 10.1074/jbc.m706185200] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
10
|
Weng J, Cao Y, Moss N, Zhou M. Modulation of voltage-dependent Shaker family potassium channels by an aldo-keto reductase. J Biol Chem 2006; 281:15194-200. [PMID: 16569641 PMCID: PMC2862575 DOI: 10.1074/jbc.m513809200] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The beta subunit (Kvbeta) of the Shaker family voltage-dependent potassium channels (Kv1) is a cytosolic protein that forms a permanent complex with the channel. Sequence and structural conservation indicates that Kvbeta resembles an aldo-keto reductase (AKR), an enzyme that catalyzes a redox reaction using an NADPH cofactor. A putative AKR in complex with a Kv channel has led to the hypothesis that intracellular redox potential may dynamically influence the excitability of a cell through Kvbeta. Since the AKR function of Kvbeta has never been demonstrated, a direct functional coupling between the two has not been established. We report here the identification of Kvbeta substrates and the demonstration that Kvbeta is a functional AKR. We have also found that channel function is modulated when the Kvbeta-bound NADPH is oxidized. Further studies of the enzymatic properties of Kvbeta seem to favor the role of Kvbeta as a redox sensor. These results suggest that Kvbeta may couple the excitability of the cell to its metabolic state and present a new avenue of research that may lead to understanding of the physiological functions of Kvbeta.
Collapse
Affiliation(s)
- Jun Weng
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA
| | | | | | | |
Collapse
|
11
|
Larkin P, Sabo-Attwood T, Kelso J, Denslow ND. Gene expression analysis of largemouth bass exposed to estradiol, nonylphenol, and p,p'-DDE. Comp Biochem Physiol B Biochem Mol Biol 2002; 133:543-57. [PMID: 12470818 DOI: 10.1016/s1096-4959(02)00155-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of this study was to determine the specific expression profile of 132 genes, some of which are estrogen responsive, in largemouth bass (LMB) following exposure to estradiol (E(2)), or to two hormonally active agents, 4-nonylphenol (4-NP) and 1,1-dichloro-2, 2-bis (p-chlorophenyl) ethylene (p,p'-DDE), using gene array technology. The results of these experiments show that LMB exposed to E(2) and 4-NP had similar, but not identical genetic signatures for the genes examined, some of which are known to be estrogen-responsive genes. The differences suggest that 4-NP may have additional modes of action that are independent of the estrogen receptor (ER). We have also shown that exposure of male LMB to p,p'-DDE results in an increase in some estrogen-responsive genes. But in female LMB, the observed changes were a down-regulation of the normally up-regulated estrogen responsive genes. Other genes were also down-regulated. These results suggest that p,p'-DDE may affect regulation of genes differently in male and female LMB. This study further suggests that gene arrays have the potential to map out the gene activation pathways of hormonally active compounds.
Collapse
Affiliation(s)
- P Larkin
- Department of Biochemistry, PO Box 100156 HC, 1600 Archer Road, MSB Building, Room MG-42, Gainesville, FL 32610, USA
| | | | | | | |
Collapse
|
12
|
Gavidia I, Pérez-Bermúdez P, Seitz HU. Cloning and expression of two novel aldo-keto reductases from Digitalis purpurea leaves. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:2842-50. [PMID: 12071946 DOI: 10.1046/j.1432-1033.2002.02931.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aldo-keto reductase (AKR) superfamily comprises proteins that catalyse mainly the reduction of carbonyl groups or carbon-carbon double bonds of a wide variety of substrates including steroids. Such types of reactions have been proposed to occur in the biosynthetic pathway of the cardiac glycosides produced by Digitalis plants. Two cDNAs encoding leaf-specific AKR proteins (DpAR1 and DpAR2) were isolated from a D. purpurea cDNA library using the rat Delta4-3-ketosteroid 5beta-reductase clone. Both cDNAs encode 315 amino acid proteins showing 98.4% identity. DpAR proteins present high identities (68-80%) with four Arabidopsis clones and a 67% identity with the aldose/aldehyde reductase from Medicago sativa. A molecular phylogenetic tree suggests that these seven proteins belong to a new subfamily of the AKR superfamily. Southern analysis indicated that DpARs are encoded by a family of at most five genes. RNA-blot analyses demonstrated that the expression of DpAR genes is developmentally regulated and is restricted to leaves. The expression of DpAR genes has also been induced by wounding, elevated salt concentrations, drought stress and heat-shock treatment. The isolated cDNAs were expressed in Escherichia coli and the recombinant proteins purified. The expressed enzymes present reductase activity not only for various sugars but also for steroids, preferring NADH as a cofactor. These studies indicate the presence of plant AKR proteins with ketosteroid reductase activity. The function of the enzymes in cardenolide biosynthesis is discussed.
Collapse
Affiliation(s)
- Isabel Gavidia
- Center of Plant Molecular Biology (ZMBP), University of Tübingen, Germany.
| | | | | |
Collapse
|