201
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Abstract
Vertebrate reproduction requires a myriad of precisely orchestrated events-in particular, the maternal production of oocytes, the paternal production of sperm, successful fertilization, and initiation of early embryonic cell divisions. These processes are governed by a host of signaling pathways. Protein kinase and phosphatase signaling pathways involving Mos, CDK1, RSK, and PP2A regulate meiosis during maturation of the oocyte. Steroid signals-specifically testosterone-regulate spermatogenesis, as does signaling by G-protein-coupled hormone receptors. Finally, calcium signaling is essential for both sperm motility and fertilization. Altogether, this signaling symphony ensures the production of viable offspring, offering a chance of genetic immortality.
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Affiliation(s)
- Sally Kornbluth
- Duke University School of Medicine, Durham, North Carolina 27710
| | - Rafael Fissore
- University of Massachusetts, Amherst, Veterinary and Animal Sciences, Amherst, Massachusetts 01003
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202
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Yen PM. Classical nuclear hormone receptor activity as a mediator of complex biological responses: a look at health and disease. Best Pract Res Clin Endocrinol Metab 2015; 29:517-28. [PMID: 26303080 DOI: 10.1016/j.beem.2015.07.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Nuclear hormone receptors are a large family of receptors that bind a wide range of lipolic hormones and intracellular ligands. They act as ligand-inducible transcription factors to regulate the expression of target genes and play important roles in normal development, reproduction, and metabolism. NRs bind to hormones steroids, thyroid hormone, and vitamin D as well as metabolites of fatty acids, cholesterol, and bild acids. Orphan receptors are another group of NRs for which no known ligands have been identified yet but appear to have major roles in regulating intracellular metabolism. Targeting NRs has been a major source for the development of new drugs, particularly selective agonists and antagonists for cancer and metabolic diseases. Additionally, hormone resistance syndromes in man have enlarged our understanding of the functions of specific NRs and their isoforms as well as genetic mechanisms for phenotype expression.
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Affiliation(s)
- Paul Michael Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, Singapore.
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203
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Abstract
Cancer is driven by genetic and epigenetic alterations that allow cells to overproliferate and escape mechanisms that normally control their survival and migration. Many of these alterations map to signaling pathways that control cell growth and division, cell death, cell fate, and cell motility, and can be placed in the context of distortions of wider signaling networks that fuel cancer progression, such as changes in the tumor microenvironment, angiogenesis, and inflammation. Mutations that convert cellular proto-oncogenes to oncogenes can cause hyperactivation of these signaling pathways, whereas inactivation of tumor suppressors eliminates critical negative regulators of signaling. An examination of the PI3K-Akt and Ras-ERK pathways illustrates how such alterations dysregulate signaling in cancer and produce many of the characteristic features of tumor cells.
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Affiliation(s)
- Richard Sever
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Joan S Brugge
- Harvard Medical School, Department of Cell Biology, Boston, Massachusetts 02115
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204
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Prakash C, Zuniga B, Song CS, Jiang S, Cropper J, Park S, Chatterjee B. Nuclear Receptors in Drug Metabolism, Drug Response and Drug Interactions. NUCLEAR RECEPTOR RESEARCH 2015; 2:101178. [PMID: 27478824 PMCID: PMC4963026 DOI: 10.11131/2015/101178] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Orally delivered small-molecule therapeutics are metabolized in the liver and intestine by phase I and phase II drug-metabolizing enzymes (DMEs), and transport proteins coordinate drug influx (phase 0) and drug/drug-metabolite efflux (phase III). Genes involved in drug metabolism and disposition are induced by xenobiotic-activated nuclear receptors (NRs), i.e. PXR (pregnane X receptor) and CAR (constitutive androstane receptor), and by the 1α, 25-dihydroxy vitamin D3-activated vitamin D receptor (VDR), due to transactivation of xenobiotic-response elements (XREs) present in phase 0-III genes. Additional NRs, like HNF4-α, FXR, LXR-α play important roles in drug metabolism in certain settings, such as in relation to cholesterol and bile acid metabolism. The phase I enzymes CYP3A4/A5, CYP2D6, CYP2B6, CYP2C9, CYP2C19, CYP1A2, CYP2C8, CYP2A6, CYP2J2, and CYP2E1 metabolize >90% of all prescription drugs, and phase II conjugation of hydrophilic functional groups (with/without phase I modification) facilitates drug clearance. The conjugation step is mediated by broad-specificity transferases like UGTs, SULTs, GSTs. This review delves into our current understanding of PXR/CAR/VDR-mediated regulation of DME and transporter expression, as well as effects of single nucleotide polymorphism (SNP) and epigenome (specified by promoter methylation, histone modification, microRNAs, long non coding RNAs) on the expression of PXR/CAR/VDR and phase 0-III mediators, and their impacts on variable drug response. Therapeutic agents that target epigenetic regulation and the molecular basis and consequences (overdosing, underdosing, or beneficial outcome) of drug-drug/drug-food/drug-herb interactions are also discussed. Precision medicine requires understanding of a drug's impact on DME and transporter activity and their NR-regulated expression in order to achieve optimal drug efficacy without adverse drug reactions. In future drug screening, new tools such as humanized mouse models and microfluidic organs-on-chips, which mimic the physiology of a multicellular environment, will likely replace the current cell-based workflow.
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Affiliation(s)
- Chandra Prakash
- Department of Molecular Medicine/Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, Texas Research Park, 15355 Lambda Drive, San Antonio, Texas 78245
- William Carey University College of Osteopathic Medicine, 498 Tucsan Ave, Hattiesburg, Mississipi 39401
| | - Baltazar Zuniga
- Department of Molecular Medicine/Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, Texas Research Park, 15355 Lambda Drive, San Antonio, Texas 78245
- University of Texas at Austin, 2100 Comal Street, Austin, Texas 78712
| | - Chung Seog Song
- Department of Molecular Medicine/Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, Texas Research Park, 15355 Lambda Drive, San Antonio, Texas 78245
| | - Shoulei Jiang
- Department of Molecular Medicine/Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, Texas Research Park, 15355 Lambda Drive, San Antonio, Texas 78245
| | - Jodie Cropper
- Department of Molecular Medicine/Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, Texas Research Park, 15355 Lambda Drive, San Antonio, Texas 78245
| | - Sulgi Park
- Department of Molecular Medicine/Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, Texas Research Park, 15355 Lambda Drive, San Antonio, Texas 78245
| | - Bandana Chatterjee
- Department of Molecular Medicine/Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, Texas Research Park, 15355 Lambda Drive, San Antonio, Texas 78245
- South Texas Veterans Health Care System, Audie L Murphy VA Hospital, 7400 Merton Minter Boulevard, San Antonio, Texas 78229
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205
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Feed-forward transcriptional programming by nuclear receptors: regulatory principles and therapeutic implications. Pharmacol Ther 2014; 145:85-91. [PMID: 25168919 DOI: 10.1016/j.pharmthera.2014.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 08/19/2014] [Indexed: 01/22/2023]
Abstract
Nuclear receptors (NRs) are widely targeted to treat a range of human diseases. Feed-forward loops are an ancient mechanism through which single cell organisms organize transcriptional programming and modulate gene expression dynamics, but they have not been systematically studied as a regulatory paradigm for NR-mediated transcriptional responses. Here, we provide an overview of the basic properties of feed-forward loops as predicted by mathematical models and validated experimentally in single cell organisms. We review existing evidence implicating feed-forward loops as important in controlling clinically relevant transcriptional responses to estrogens, progestins, and glucocorticoids, among other NR ligands. We propose that feed-forward transcriptional circuits are a major mechanism through which NRs integrate signals, exert temporal control over gene regulation, and compartmentalize client transcriptomes into discrete subunits. Implications for the design and function of novel selective NR ligands are discussed.
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206
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Thorpy MJ, Roth T. Toward a classification of medications for sleep and circadian rhythm disorders. Nat Sci Sleep 2013; 5:143-5. [PMID: 24363563 PMCID: PMC3862774 DOI: 10.2147/nss.s55679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
While some systems classify medications according to therapeutic class, others are based on the mechanism of action of the drugs. The two main classifications of medications used to treat patients in the United States are those of the United States Pharmacopeia and US Food and Drug Administration, and they vary in their organization of the medication categories. Here we propose a taxonomy for medications used to treat sleep and circadian rhythm disorders based on symptoms and disorders.
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Affiliation(s)
- Michael J Thorpy
- Sleep-Wake Disorders Center, Montefiore Medical Center, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, NY, USA
| | - Thomas Roth
- University of Michigan School of Medicine, Ann Arbor, Michigan, USA ; Sleep Disorders and Research Center, Henry Ford Hospital, Detroit, Michigan, USA
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