1
|
Perocheau D, Gurung S, Touramanidou L, Duff C, Sharma G, Sebire N, Finn PF, Cavedon A, Siddiqui S, Rice L, Martini PG, Frassetto A, Baruteau J. Ex vivo precision-cut liver slices model disease phenotype and monitor therapeutic response for liver monogenic diseases. F1000Res 2024; 12:1580. [PMID: 38618017 PMCID: PMC11016166 DOI: 10.12688/f1000research.142014.2] [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] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/03/2024] [Indexed: 04/16/2024] Open
Abstract
Background In academic research and the pharmaceutical industry, in vitro cell lines and in vivo animal models are considered as gold standards in modelling diseases and assessing therapeutic efficacy. However, both models have intrinsic limitations, whilst the use of precision-cut tissue slices can bridge the gap between these mainstream models. Precision-cut tissue slices combine the advantage of high reproducibility, studying all cell sub-types whilst preserving the tissue matrix and extracellular architecture, thereby closely mimicking a mini-organ. This approach can be used to replicate the biological phenotype of liver monogenic diseases using mouse models. Methods Here, we describe an optimised and easy-to-implement protocol for the culture of sections from mouse livers, enabling its use as a reliable ex-vivo model to assess the therapeutic screening of inherited metabolic diseases. Results We show that precision-cut liver sections can be a reliable model for recapitulating the biological phenotype of inherited metabolic diseases, exemplified by common urea cycle defects such as citrullinemia type 1 and argininosuccinic aciduria, caused by argininosuccinic synthase (ASS1) and argininosuccinic lyase (ASL) deficiencies respectively. Conclusions Therapeutic response to gene therapy such as messenger RNA replacement delivered via lipid nanoparticles can be monitored, demonstrating that precision-cut liver sections can be used as a preclinical screening tool to assess therapeutic response and toxicity in monogenic liver diseases.
Collapse
Affiliation(s)
- Dany Perocheau
- Great Ormond Street Institute of Child Health, University College London, London, England, WC1N 1EH, UK
| | - Sonam Gurung
- Great Ormond Street Institute of Child Health, University College London, London, England, WC1N 1EH, UK
| | - Loukia Touramanidou
- Great Ormond Street Institute of Child Health, University College London, London, England, WC1N 1EH, UK
| | - Claire Duff
- Great Ormond Street Institute of Child Health, University College London, London, England, WC1N 1EH, UK
| | - Garima Sharma
- Great Ormond Street Institute of Child Health, University College London, London, England, WC1N 1EH, UK
| | - Neil Sebire
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, England, WC1N 3JH, UK
| | | | | | | | - Lisa Rice
- Moderna Inc., Cambridge, MA 02139, USA
| | | | | | - Julien Baruteau
- Great Ormond Street Institute of Child Health, University College London, London, England, WC1N 1EH, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, England, WC1N 3JH, UK
- National Institute of Health Research, Great Ormond Street Biomedical Research Centre, London, WC1N 1EH, UK
| |
Collapse
|
2
|
Balakrishnan B, Yan X, McCue MD, Bellagamba O, Guo A, Winkler F, Thall J, Crawford L, Dimen R, Chen S, McEnaney S, Wu Y, Zimmer M, Sarkis J, Martini PG, Finn PF, Lai K. Whole-body galactose oxidation as a robust functional assay to assess the efficacy of gene-based therapies in a mouse model of Galactosemia. Mol Ther Methods Clin Dev 2024; 32:101191. [PMID: 38352271 PMCID: PMC10863324 DOI: 10.1016/j.omtm.2024.101191] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024]
Abstract
Despite the implementation of lifesaving newborn screening programs and a galactose-restricted diet, many patients with classic galactosemia develop long-term debilitating neurological deficits and primary ovarian insufficiency. Previously, we showed that the administration of human GALT mRNA predominantly expressed in the GalT gene-trapped mouse liver augmented the expression of hepatic GALT activity, which decreased not only galactose-1 phosphate (gal-1P) in the liver but also peripheral tissues. Since each peripheral tissue requires distinct methods to examine the biomarker and/or GALT effect, this highlights the necessity for alternative strategies to evaluate the overall impact of therapies. In this study, we established that whole-body galactose oxidation (WBGO) as a robust, noninvasive, and specific method to assess the in vivo pharmacokinetic and pharmacodynamic parameters of two experimental gene-based therapies that aimed to restore GALT activity in a mouse model of galactosemia. Although our results illustrated the long-lasting efficacy of AAVrh10-mediated GALT gene transfer, we found that GALT mRNA therapy that targets the liver predominantly is sufficient to sustain WBGO. The latter could have important implications in the design of novel targeted therapy to ensure optimal efficacy and safety.
Collapse
Affiliation(s)
- Bijina Balakrishnan
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | | | | | - Olivia Bellagamba
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | - Aaron Guo
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | | | | | | | | | | | | | - Yiman Wu
- Moderna, Cambridge, MA 02139, USA
| | | | | | | | | | - Kent Lai
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| |
Collapse
|
3
|
Chen CY, Vander Kooi A, Cavedon A, Cai X, Hoggatt J, Martini PG, Miao CH. Induction of long-term tolerance to a specific antigen using anti-CD3 lipid nanoparticles following gene therapy. Mol Ther Nucleic Acids 2023; 34:102043. [PMID: 37920545 PMCID: PMC10618827 DOI: 10.1016/j.omtn.2023.102043] [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] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/28/2023] [Indexed: 11/04/2023]
Abstract
Development of factor VIII (FVIII) inhibitors is a serious complication in the treatment of hemophilia A (HemA) patients. In clinical trials, anti-CD3 antibody therapy effectively modulates the immune response of allograft rejection or autoimmune diseases without eliciting major adverse effects. In this study, we delivered mRNA-encapsulated lipid nanoparticles (LNPs) encoding therapeutic anti-CD3 antibody (αCD3 LNPs) to overcome the anti-FVIII immune responses in HemA mice. It was found that αCD3 LNPs encoding the single-chain antibodies (Fc-scFv) can efficiently deplete CD3+ and CD4+ effector T cells, whereas αCD3 LNPs encoding double-chain antibodies cannot. Concomitantly, mice treated with αCD3 (Fc-scFv) LNPs showed an increase in the CD4+CD25+Foxp3+ regulatory T cell percentages, which modulated the anti-FVIII immune responses. All T cells returned to normal levels within 2 months. HemA mice treated with αCD3 LNPs prior to hydrodynamic injection of liver-specific FVIII plasmids achieved persistent FVIII gene expression without formation of FVIII inhibitors. Furthermore, transgene expression was increased and persistent following secondary plasmid challenge, indicating induction of long-term tolerance to FVIII. Moreover, the treated mice maintained their immune competence against other antigens. In conclusion, our study established a potential new strategy to induce long-term antigen-specific tolerance using an αCD3 LNP formulation.
Collapse
Affiliation(s)
- Chun-Yu Chen
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | | | | | - Xiaohe Cai
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | | | | | - Carol H. Miao
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| |
Collapse
|
4
|
Greig JA, Chorazeczewski JK, Chowdhary V, Smith MK, Jennis M, Tarrant JC, Buza EL, Coughlan K, Martini PG, Wilson JM. Lipid nanoparticle-encapsulated mRNA therapy corrects serum total bilirubin level in Crigler-Najjar syndrome mouse model. Mol Ther Methods Clin Dev 2023; 29:32-39. [PMID: 36936447 PMCID: PMC10017950 DOI: 10.1016/j.omtm.2023.02.007] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 02/10/2023] [Indexed: 02/17/2023]
Abstract
Crigler-Najjar syndrome is a rare disorder of bilirubin metabolism caused by uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1) mutations characterized by hyperbilirubinemia and jaundice. No cure currently exists; treatment options are limited to phototherapy, whose effectiveness diminishes over time, and liver transplantation. Here, we evaluated the therapeutic potential of systemically administered, lipid nanoparticle-encapsulated human UGT1A1 (hUGT1A1) mRNA therapy in a Crigler-Najjar mouse model. Ugt1 knockout mice were rescued from lethal post-natal hyperbilirubinemia by phototherapy. These adult Ugt1 knockout mice were then administered a single lipid nanoparticle-encapsulated hUGT1A1 mRNA dose. Within 24 h, serum total bilirubin levels decreased from 15 mg/dL (256 μmol/L) to <0.5 mg/dL (9 μmol/L), i.e., slightly above wild-type levels. This reduction was sustained for 2 weeks before bilirubin levels rose and returned to pre-treatment levels by day 42 post-administration. Sustained reductions in total bilirubin levels were achieved by repeated administration of the mRNA product in a frequency-dependent manner. We were also able to rescue the neonatal lethality phenotype seen in Ugt1 knockout mice with a single lipid nanoparticle dose, which suggests that this may be a treatment modality appropriate for metabolic crisis situations. Therefore, lipid nanoparticle-encapsulated hUGT1A1 mRNA may represent a potential treatment for Crigler-Najjar syndrome.
Collapse
Affiliation(s)
- Jenny A. Greig
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Vivek Chowdhary
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Melanie K. Smith
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew Jennis
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - James C. Tarrant
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elizabeth L. Buza
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - James M. Wilson
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corresponding author. James M. Wilson, MD, PhD, Gene Therapy Program, Perelman School of Medicine, University of Pennsylvania, 125 South 31st Street, Suite 1200, Philadelphia, PA 19104, USA.
| |
Collapse
|
5
|
Khoja S, Liu XB, Truong B, Nitzahn M, Lambert J, Eliav A, Nasser E, Randolph E, Burke KE, White R, Zhu X, Martini PG, Nissim I, Cederbaum SD, Lipshutz GS. Intermittent lipid nanoparticle mRNA administration prevents cortical dysmyelination associated with arginase deficiency. Mol Ther Nucleic Acids 2022; 28:859-874. [PMID: 35694211 PMCID: PMC9156989 DOI: 10.1016/j.omtn.2022.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 04/22/2022] [Indexed: 11/28/2022]
Abstract
Arginase deficiency is associated with prominent neuromotor features, including spastic diplegia, clonus, and hyperreflexia; intellectual disability and progressive neurological decline are other signs. In a constitutive murine model, we recently described leukodystrophy as a significant component of the central nervous system features of arginase deficiency. In the present studies, we sought to examine if the administration of a lipid nanoparticle carrying human ARG1 mRNA to constitutive knockout mice could prevent abnormalities in myelination associated with arginase deficiency. Imaging of the cingulum, striatum, and cervical segments of the corticospinal tract revealed a drastic reduction of myelinated axons; signs of degenerating axons were also present with thin myelin layers. Lipid nanoparticle/ARG1 mRNA administration resulted in both light and electron microscopic evidence of a dramatic recovery of myelin density compared with age-matched controls; oligodendrocytes were seen to be extending processes to wrap many axons. Abnormally thin myelin layers, when myelination was present, were resolved with intermittent mRNA administration, indicative of not only a greater density of myelinated axons but also an increase in the thickness of the myelin sheath. In conclusion, lipid nanoparticle/ARG1 mRNA administration in arginase deficiency prevents the associated leukodystrophy and restores normal oligodendrocyte function.
Collapse
Affiliation(s)
- Suhail Khoja
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Xiao-Bo Liu
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Brian Truong
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Matthew Nitzahn
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Jenna Lambert
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Adam Eliav
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Eram Nasser
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Emma Randolph
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | | | - Rebecca White
- Moderna Inc., 200 Technology Square, Cambridge, MA 02139, USA
| | - Xuling Zhu
- Moderna Inc., 200 Technology Square, Cambridge, MA 02139, USA
| | | | - Itzhak Nissim
- Division of Metabolism and Human Genetics, The Children Hospital of Philadelphia and The Department of Biochemistry and Biophysics, Perlman School of Medicine, Philadelphia, PA 19104, USA
| | - Stephen D. Cederbaum
- Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Intellectual and Developmental Disabilities Research Center at UCLA, Los Angeles, CA 90095, USA
- Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Gerald S. Lipshutz
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Intellectual and Developmental Disabilities Research Center at UCLA, Los Angeles, CA 90095, USA
- Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| |
Collapse
|
6
|
Zhu X, Yin L, Theisen M, Zhuo J, Siddiqui S, Levy B, Presnyak V, Frassetto A, Milton J, Salerno T, Benenato KE, Milano J, Lynn A, Sabnis S, Burke K, Besin G, Lukacs CM, Guey LT, Finn PF, Martini PG. Systemic mRNA Therapy for the Treatment of Fabry Disease: Preclinical Studies in Wild-Type Mice, Fabry Mouse Model, and Wild-Type Non-human Primates. Am J Hum Genet 2019; 104:625-637. [PMID: 30879639 DOI: 10.1016/j.ajhg.2019.02.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 02/01/2019] [Indexed: 11/27/2022] Open
Abstract
Fabry disease is an X-linked lysosomal storage disease caused by loss of alpha galactosidase A (α-Gal A) activity and is characterized by progressive accumulation of globotriaosylceramide and its analogs in all cells and tissues. Although enzyme replacement therapy (ERT) is considered standard of care, the long-term effects of ERT on renal and cardiac manifestations remain uncertain and thus novel therapies are desirable. We herein report preclinical studies evaluating systemic messenger RNA (mRNA) encoding human α-Gal A in wild-type (WT) mice, α-Gal A-deficient mice, and WT non-human primates (NHPs). The pharmacokinetics and distribution of h-α-Gal A mRNA encoded protein in WT mice demonstrated prolonged half-lives of α-Gal A in tissues and plasma. Single intravenous administration of h-α-Gal A mRNA to Gla-deficient mice showed dose-dependent protein activity and substrate reduction. Moreover, long duration (up to 6 weeks) of substrate reductions in tissues and plasma were observed after a single injection. Furthermore, repeat i.v. administration of h-α-Gal A mRNA showed a sustained pharmacodynamic response and efficacy in Fabry mice model. Lastly, multiple administrations to non-human primates confirmed safety and translatability. Taken together, these studies across species demonstrate preclinical proof-of-concept of systemic mRNA therapy for the treatment of Fabry disease and this approach may be useful for other lysosomal storage disorders.
Collapse
|
7
|
Patton C, Farr GH, An D, Martini PG, Maves L. Lipid Nanoparticle Packaging Is an Effective and Nontoxic mRNA Delivery Platform in Embryonic Zebrafish. Zebrafish 2018; 15:217-227. [DOI: 10.1089/zeb.2017.1511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Clay Patton
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington
| | - Gist H. Farr
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington
| | - Ding An
- Moderna Therapeutics, Cambridge, Massachusetts
| | | | - Lisa Maves
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington
- Department of Pediatrics, University of Washington, Seattle, Washington
| |
Collapse
|
8
|
Martini PG, Katzenellenbogen BS. Regulation of prothymosin alpha gene expression by estrogen in estrogen receptor-containing breast cancer cells via upstream half-palindromic estrogen response element motifs. Endocrinology 2001; 142:3493-501. [PMID: 11459795 DOI: 10.1210/endo.142.8.8314] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prothymosin alpha (PTalpha), a protein associated with cell proliferation and chromatin remodeling, and found to selectively enhance ER transcriptional activity by interacting with a repressor of ER activity, is shown to be a primary response gene to estrogen. Prothymosin alpha mRNA was rapidly increased by estrogen, followed by a 6-fold increase in prothymosin alpha protein content in ER-containing breast cancer cells. Analysis of the prothymosin alpha promoter and 5'-flanking region, and electrophoretic gel mobility shift studies showed the strong inducibility by the estradiol-ER complex to be mediated by two consensus half-palindromic estrogen response elements at -750 and -1051, which directly bind the ER. Estrogenic stimulation of prothymosin alpha required a DNA binding form of ER with a functional activation function-2 domain. The prothymosin alpha 5'-regulatory region also contains multiple Sp1 sites. Although addition of Sp1 did not further enhance estradiol-ER stimulated prothymosin alpha transcriptional activity in breast cancer cells, transfection and response element mutagenesis studies using Drosophila cells, which are deficient in Sp1, revealed that Sp1 and the estradiol occupied-ER can each activate the prothymosin alpha gene independently of the other and act in an additive manner. These observations, documenting robust prothymosin alpha up-regulation by the estradiol-ER complex via widely spaced half-palindromic estrogen response element motifs, are reminiscent of those shown previously for the ovalbumin gene and suggest that the use of multiple half response elements may be a more common mode for regulation of gene expression by the ER than previously appreciated. In addition, these observations suggest interrelationships between cell proliferation and gene transcriptional activities and indicate a positive mechanism by which PTalpha, which increases ER transcriptional effectiveness, is itself up-regulated by the estrogen-ER complex.
Collapse
Affiliation(s)
- P G Martini
- Department of Molecular and Integrative Physiology, University of Illinois and College of Medicine, Urbana, Illinois 61801, USA
| | | |
Collapse
|
9
|
Katzenellenbogen BS, Montano MM, Ediger TR, Sun J, Ekena K, Lazennec G, Martini PG, McInerney EM, Delage-Mourroux R, Weis K, Katzenellenbogen JA. Estrogen receptors: selective ligands, partners, and distinctive pharmacology. Recent Prog Horm Res 2001; 55:163-93; discussion 194-5. [PMID: 11036937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The action of nuclear hormone receptors is tripartite, involving the receptor, its ligands, and its co-regulator proteins. The estrogen receptor (ER), a member of this superfamily, is a hormone-regulated transcription factor that mediates the effects of estrogens and anti-estrogens (e.g., tamoxifen) in breast cancer and other estrogen target cells. This chapter presents our recent work on several aspects of estrogen action and the function of the ER: 1) elucidation of ER structure-function relationships and development of ligands that are selective for one of the two ER subtypes, ERalpha or ERbeta; 2) identification of ER-selective co-regulators that potentiate the inhibitory effectiveness of anti-estrogens and dominant-negative ERs and modulate the activity of estrogens; 3) characterization of genes that are regulated by the anti-estrogen-ER versus the estrogen-ER complex; and 4) elucidation of the intriguing pharmacology of these ER complexes at different gene regulatory sites. These findings indicate that different residues of the ER hormone-binding domain are involved in the recognition of structurally distinct estrogens and anti-estrogens and highlight the exquisite precision of the regulation of ER activities by ligands, with small changes in ligand structure resulting in major changes in receptor character. Studies also explore the biology and distinct pharmacology mediated by ERalpha and ERbeta complexed with different ligands through different target genes. The upregulation of the anti-oxidant detoxifying phase II enzyme, quinone reductase, by the anti-estrogen-occupied ER, mediated via the electrophile response element in the QR gene, may contribute to the beneficial antioxidant effects of anti-estrogens in breast cancer and illustrates the activation of some genes by ER via non-estrogen response element sequences. The intriguing biology of estrogen in its diverse target cells is thus determined by the structure of the ligand, the ER subtype involved, the nature of the hormone-responsive gene promoter, and the character and balance of co-activators and co-repressors that modulate the cellular response to the ER-ligand complex. The continuing development of novel ligands and the study of how they function as selective agonists or antagonists through ERalpha or ERbeta should allow optimized tissue selectivity of these agents for hormone replacement therapy and treatment and prevention of breast cancer.
Collapse
Affiliation(s)
- B S Katzenellenbogen
- Department of Molecular and Integrative Physiology, University of Illinois and College of Medicine, Urbana 6180, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Katzenellenbogen BS, Choi I, Delage-Mourroux R, Ediger TR, Martini PG, Montano M, Sun J, Weis K, Katzenellenbogen JA. Molecular mechanisms of estrogen action: selective ligands and receptor pharmacology. J Steroid Biochem Mol Biol 2000; 74:279-85. [PMID: 11162936 DOI: 10.1016/s0960-0760(00)00104-7] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Estrogens exert profound effects on the physiology of diverse target cells and these effects appear to be mediated by two estrogen receptor (ER) subtypes, ERalpha and ERbeta. We have investigated how ER ligands, ranging from pure agonists to antagonists, interact with ERalpha and ERbeta, and regulate their transcriptional activity on different genes. Mutational mapping-structure activity studies indicate that different residues of the ER ligand binding domain are involved in the recognition of structurally distinct estrogens and antiestrogens. We have identified from ligands of diverse structure, several particularly interesting ones that are high potency selective agonists via ERalpha and others that are full agonists through ERalpha while being full antagonists through ERbeta. Antiestrogens such as hydroxytamoxifen, which are mixed agonist/antagonists through ERalpha, are pure antagonists through ERbeta at estrogen response element-containing gene sites. Studies with ERalpha/beta chimeric proteins reveal that tamoxifen agonism requires the activation function 1 region of ERalpha. Through two-hybrid assays, we have isolated an ER-specific coregulator that potentiates antiestrogen antagonist effectiveness and represses ER transcriptional activity. We have also focused on understanding the distinct pharmacologies of antiestrogen- and estrogen-regulated genes. Although antiestrogens are thought to largely act by antagonizing the actions of estrogens, we have found among several new ER-regulated genes, quinone reductase (QR), a detoxifying phase II antioxidant enzyme, that has its activity up-regulated by antiestrogens in an ER-dependent manner in breast cancer cells. This response is antagonized by estrogens, thus showing 'reversed pharmacology'. Increased QR activity by antiestrogens requires a functional ER (ERalpha or ERbeta) and is, interestingly, mediated via the electrophile response element in the QR gene 5' regulatory region. The up-regulation of QR may contribute to the beneficial effects of tamoxifen, raloxifene, and other antiestrogens in breast cancer prevention and treatment. Estrogens rapidly up-regulate expression of several genes associated with cell cytoarchitectural changes including NHE-RF, the sodium hydrogen exchanger regulatory factor, also known as EBP50. NHE-RF/EBP50 is enriched in microvilli, and may serve as a scaffold adaptor protein in regulating early changes in cell architecture and signal transduction events induced by estrogen. Analyses of the regulatory regions of these primary response genes, and the antioxidant and other signaling pathways involved, are providing considerable insight into the mechanisms by which ligands, that function as selective estrogen receptor modulators or SERMs, exert their marked effects on the activities and properties of target cells. The intriguing biology of estrogens in its diverse target cells is thus determined by the structure of the ligand, the ER subtype involved, the nature of the hormone-responsive gene promoter, and the character and balance of coactivators and corepressors that modulate the cellular response to the ER-ligand complex. The continuing development of ligands that function as selective estrogens or antiestrogens for ERalpha or ERbeta should allow optimized tissue selectivity of these agents for menopausal hormone replacement therapy and the treatment and prevention of breast cancer.
Collapse
Affiliation(s)
- B S Katzenellenbogen
- Department of Molecular and Integrative Physiology, University of Illinois and College of Medicine, 524 Burrill Hall, 407 S. Goodwin Avenue, 61801-3704, Urbana, IL, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Delage-Mourroux R, Martini PG, Choi I, Kraichely DM, Hoeksema J, Katzenellenbogen BS. Analysis of estrogen receptor interaction with a repressor of estrogen receptor activity (REA) and the regulation of estrogen receptor transcriptional activity by REA. J Biol Chem 2000; 275:35848-56. [PMID: 10960470 DOI: 10.1074/jbc.m001327200] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcriptional activity of nuclear hormone receptors is known to be modulated by coregulator proteins. We found that the repressor of estrogen receptor activity (REA), a protein recruited to the hormone-occupied estrogen receptor (ER), decreased the transcriptional activity of ER, both when ER was acting directly through DNA response elements as well as when it was tethered to other transcription factors. Administration of antisense REA resulted in a 2-4-fold increase in ER transactivation, implying that endogenous REA normally dampens the stimulatory response to estradiol. To define the interaction regions between ER and REA, we used glutathione S-transferase pull-down assays. We found that REA bound to the ligand-binding domain (E domain) of ER, but not to other regions of ER, and that REA interaction with ER involved a region in the C-terminal half of REA. REA and the coactivator SRC-1 were involved in a functional competition for regulation of ER transcriptional activity, which we show results from competition between these two coregulators for interaction with ER. REA contains an LXXLL motif near its N terminus, but this motif was not involved in its binding to ER. Rather, this sequence was required for the competitive binding of REA and SRC-1 to ER and thus for optimal repression of ER activity. Our findings show that the regions of REA required for its interaction with ER and for its repression of ER activity are different.
Collapse
Affiliation(s)
- R Delage-Mourroux
- Departments of Molecular and Integrative Physiology and Cell and Structural Biology, University of Illinois and the College of Medicine, Urbana, Illinois 61801-3704, USA
| | | | | | | | | | | |
Collapse
|
12
|
Martini PG, Delage-Mourroux R, Kraichely DM, Katzenellenbogen BS. Prothymosin alpha selectively enhances estrogen receptor transcriptional activity by interacting with a repressor of estrogen receptor activity. Mol Cell Biol 2000; 20:6224-32. [PMID: 10938099 PMCID: PMC86097 DOI: 10.1128/mcb.20.17.6224-6232.2000] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We find that prothymosin alpha (PTalpha) selectively enhances transcriptional activation by the estrogen receptor (ER) but not transcriptional activity of other nuclear hormone receptors. This selectivity for ER is explained by PTalpha interaction not with ER, but with a 37-kDa protein denoted REA, for repressor of estrogen receptor activity, a protein that we have previously shown binds to ER, blocking coactivator binding to ER. We isolated PTalpha, known to be a chromatin-remodeling protein associated with cell proliferation, using REA as bait in a yeast two-hybrid screen with a cDNA library from MCF-7 human breast cancer cells. PTalpha increases the magnitude of ERalpha transcriptional activity three- to fourfold. It shows lesser enhancement of ERbeta transcriptional activity and has no influence on the transcriptional activity of other nuclear hormone receptors (progesterone receptor, glucocorticoid receptor, thyroid hormone receptor, or retinoic acid receptor) or on the basal activity of ERs. In contrast, the steroid receptor coactivator SRC-1 increases transcriptional activity of all of these receptors. Cotransfection of PTalpha or SRC-1 with increasing amounts of REA, as well as competitive glutathione S-transferase pulldown and mammalian two-hybrid studies, show that REA competes with PTalpha (or SRC-1) for regulation of ER transcriptional activity and suppresses the ER stimulation by PTalpha or SRC-1, indicating that REA can function as an anticoactivator in cells. Our data support a model in which PTalpha, which does not interact with ER, selectively enhances the transcriptional activity of the ER but not that of other nuclear receptors by recruiting the repressive REA protein away from ER, thereby allowing effective coactivation of ER with SRC-1 or other coregulators. The ability of PTalpha to directly interact in vitro and in vivo with REA, a selective coregulator of the ER, thereby enabling the interaction of ER with coactivators, appears to explain its ability to selectively enhance ER transcriptional activity. These findings highlight a new role for PTalpha as a coregulator activity-modulating protein that confers receptor specificity. Proteins such as PTalpha represent an additional regulatory component that defines a novel paradigm enabling receptor-selective enhancement of transcriptional activity by coactivators.
Collapse
Affiliation(s)
- P G Martini
- Departments of Molecular and Integrative Physiology and Cell and Structural Biology, University of Illinois and College of Medicine, Urbana, Illinois 61801, USA
| | | | | | | |
Collapse
|
13
|
Gee AC, Carlson KE, Martini PG, Katzenellenbogen BS, Katzenellenbogen JA. Coactivator peptides have a differential stabilizing effect on the binding of estrogens and antiestrogens with the estrogen receptor. Mol Endocrinol 1999; 13:1912-23. [PMID: 10551784 DOI: 10.1210/mend.13.11.0373] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The effectiveness of estrogens in stimulating gene transcription mediated by the estrogen receptor (ER) appears to depend on ER interactions with coactivator proteins. These coactivators bind to ER when it is liganded with an estrogen agonist, but not when it is liganded with an estrogen antagonist. Because estrogen agonists are known to induce a conformation in ER that stabilizes coactivator binding, we asked whether coactivator binding to ER causes a reciprocal stabilization of agonist ligand binding. We used a fluorescent ligand for ER, tetrahydrochrysene-ketone, to monitor the rates of ligand dissociation from ERalpha and ERbeta, and to see how this process is affected by the p160-class coactivator, steroid receptor coactivator-1 (SRC-1). We used a 15-amino acid peptide corresponding to the second nuclear receptor box LXXLL motif in SRC-1 (NR-2 peptide), which is known to interact with the ER ligand-binding domain, a mutant peptide with an LXXAL sequence (NR-2A peptide), and a 203-amino acid fragment of SRC-1, termed the nuclear receptor domain (SRC1-NRD), embodying all three of the internal NR boxes of this protein. Both the NR-2 peptide and the SRC1-NRD fragment markedly slow the rate of dissociation of the agonist ligands tetrahydrochrysene-ketone, estradiol, and diethylstilbestrol, increasing the half-life of the ER-agonist complex by up to 50- to 60-fold. The SRC1-NRD has much higher potency in retarding ligand dissociation than does the NR-2 peptide; it is maximally effective at 30 nM, and it appears to bind with the stoichiometry of one SRC1-NRD per ER dimer. The peptides had little effect on the dissociation rate of antagonist ligands. Consistent with these results, we find that increasing the concentration of SRC-1 in cells by transfection of an expression plasmid encoding SRC-1 causes a 17-fold increase in the potency of estradiol in an estrogen-responsive reporter gene transcription assay. Thus, there is multifactorial control over receptor-coactivator interaction, its strength being determined by the agonist vs. antagonist nature of the ligand and the particular structure of the agonist ligand, and by the receptor subtype and the NR box sequence. The stabilizing effect of coactivator on ER-agonist ligand complexes may be important in determining the potency of estrogen agonists in a cell and may also underlie the tissue-selective pharmacology of certain synthetic estrogens.
Collapse
Affiliation(s)
- A C Gee
- Department of Chemistry, University of Illinois, Urbana 61801, USA
| | | | | | | | | |
Collapse
|