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Beck TC, Wilson EM, Wilkes E, Lee LW, Norris R, Valdebran M. Kappa opioid agonists in the treatment of itch: just scratching the surface? Itch (Phila) 2023; 8:e0072. [PMID: 38099236 PMCID: PMC10720604 DOI: 10.1097/itx.0000000000000072] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Chronic pruritus is a debilitating condition affecting 23-44 million Americans. Recently, kappa opioid agonists (KOAs) have emerged as a novel class of potent antipruritic agents. In 2021, the Food and Drug Administration approved difelikefalin (Korsuva) for the treatment of moderate-to-severe pruritus associated with chronic kidney disease in adults undergoing hemodialysis. Difelikefalin is a potent, peripherally restricted KOA that is intravenously available. Although promising, difelikefalin is currently available as an intravenous composition only, limiting the scope of use. Oral formulations of difelikefalin did not meet the primary endpoint criteria in recent phase 2 clinical trials; however, additional clinical studies are ongoing. The future for KOAs in the treatment of pruritus is encouraging. Orally active pathway-biased KOAs, such as triazole 1.1, may serve as viable alternatives with broader applications. Extended-release compositions, such as the TP-2021 ProNeura subdermal implant, may circumvent the pharmacokinetic issues associated with peptide-based KOAs. Lastly, dual-acting kappa opioid receptor agonist/mu opioid receptor antagonists are orally bioavailable and may be useful in the treatment of various forms of chronic itch. In this review, we summarize the results of KOAs in clinical and preclinical trials and discuss future directions of drug development.
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Affiliation(s)
- Tyler C. Beck
- Department of Dermatology and Dermatological Surgery, Medical University of South Carolina, Charleston, SC
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC
| | - Elena M. Wilson
- Department of Dermatology and Dermatological Surgery, Medical University of South Carolina, Charleston, SC
| | - Erik Wilkes
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC
| | - Lara Wine Lee
- Department of Dermatology and Dermatological Surgery, Medical University of South Carolina, Charleston, SC
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC
| | - Russell Norris
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC
| | - Manuel Valdebran
- Department of Dermatology and Dermatological Surgery, Medical University of South Carolina, Charleston, SC
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC
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2
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Dejban P, Wilson EM, Jayachandran M, Herrera Hernandez LP, Haskic Z, Wellik LE, Sinha S, Rule AD, Denic A, Koo K, Potretzke AM, Lieske JC. Inflammatory Cells in Nephrectomy Tissue from Patients without and with a History of Urinary Stone Disease. Clin J Am Soc Nephrol 2022; 17:414-422. [PMID: 35078782 PMCID: PMC8975022 DOI: 10.2215/cjn.11730921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 09/02/2021] [Accepted: 01/03/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND OBJECTIVES Urinary stone disease has been associated with inflammation, but the specific cell interactions that mediate events remain poorly defined. This study compared calcification and inflammatory cell patterns in kidney tissue from radical nephrectomy specimens of patients without and with a history of urinary stone disease. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Nontumor parenchyma of biobanked radical nephrectomy specimens from age- and sex-matched stone formers (n=44) and nonstone formers (n=82) were compared. Calcification was detected by Yasue staining and inflammatory cell populations by immunohistochemistry for CD68 (proinflammatory M1 macrophages), CD163 and CD206 (anti-inflammatory M2 macrophages), CD3 (T lymphocytes), and tryptase (mast cells). Calcifications and inflammatory cells were quantified in cortex and medulla using Image-Pro analysis software. RESULTS Calcification in the medulla of stone formers was higher than in nonstone formers (P<0.001). M1 macrophages in the cortex and medulla of stone formers were greater than in nonstone formers (P<0.001), and greater in stone former medulla than stone former cortex (P=0.02). There were no differences in age, sex, body mass index, tumor characteristics (size, stage, or thrombus), vascular disease status, or eGFR between the groups. M2 macrophages, T lymphocytes, and mast cells did not differ by stone former status. There was a correlation between M1 macrophages and calcification in the medulla of stone formers (rho=0.48; P=0.001) and between M2 macrophages and calcification in the medulla of nonstone formers (rho=0.35; P=0.001). T lymphocytes were correlated with calcification in the cortex of both nonstone formers (rho=0.27; P=0.01) and stone formers (rho=0.42; P=0.004), whereas mast cells and calcification were correlated only in the cortex of stone formers (rho=0.35; P=0.02). CONCLUSIONS Higher medullary calcification stimulated accumulation of proinflammatory rather than anti-inflammatory macrophages in stone formers.
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Affiliation(s)
- Pegah Dejban
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Elena M. Wilson
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Muthuvel Jayachandran
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota,Division of Hematology, Mayo Clinic, Rochester, Minnesota,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | | | - Zejfa Haskic
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | | | - Sutapa Sinha
- Division of Hematology, Mayo Clinic, Rochester, Minnesota
| | - Andrew D. Rule
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Aleksandar Denic
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Kevin Koo
- Department of Urology, Mayo Clinic, Rochester, Minnesota
| | | | - John C. Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
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3
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Wilson EM, Lipp SN, Brady CT, Ishibe S, Romero MF. Feeding the Kidney Researcher Pipeline through R25-NIDDK Funded Summer Undergraduate Research Fellowships: A Student Perspective. Kidney360 2021; 3:546-549. [PMID: 35582187 PMCID: PMC9034802 DOI: 10.34067/kid.0001272021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/19/2021] [Indexed: 01/10/2023]
Affiliation(s)
- Elena M. Wilson
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois,Nephrology and Hypertension, Mayo Clinic College of Medicine & Science, Rochester, Minnesota,Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut
| | - Sarah N. Lipp
- Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut,Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana,The Indiana University Medical Scientist/Engineer Training Program, Indianapolis, Indiana
| | - Clayton T. Brady
- Nephrology and Hypertension, Mayo Clinic College of Medicine & Science, Rochester, Minnesota,University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York
| | - Shuta Ishibe
- Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut
| | - Michael F. Romero
- Nephrology and Hypertension, Mayo Clinic College of Medicine & Science, Rochester, Minnesota,Physiology and Biomedical Engineering, Mayo Clinic College of Medicine & Science, Rochester, Minnesota
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Wilson EM, Chen A, Johnson M, Perkins JA, Purnell TS. Elucidating measures of systemic racism to mitigate racial disparities in kidney transplantation. Curr Opin Organ Transplant 2021; 26:554-559. [PMID: 34456271 DOI: 10.1097/mot.0000000000000913] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Given recent national attention to the role of racism in perpetuating racial inequities in society and health, this review provides a timely and relevant summary of key measures of systemic racism in kidney transplantation. More specifically, the review identifies current and promising interventions, whereas highlighting the need for more sustainable and impactful interventions. RECENT FINDINGS Racial disparities persist in kidney transplantation. Black and Hispanic individuals are less likely to receive a kidney transplant than non-Hispanic Whites despite disproportionately higher rates of kidney failure. Studies demonstrate that socioeconomic factors do not fully explain existing racial disparities in transplantation. Systemic racism at all levels, individual, interpersonal, institutional, and structural, is at the core of racial disparities, and current interventions are insufficient in mitigating their effects. Thus, targeted and sustainable interventions must be implemented to mitigate systemic racism in kidney transplantation. SUMMARY Systemic racism in all its forms continues to influence disparities at all stages of kidney transplantation. This paper highlights recent findings that shed light on how racism contributes to racial disparities in kidney transplantation. Using these findings to identify targets and strategies for mitigation, relevant interventions and policies that show promise are detailed.
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Affiliation(s)
- Elena M Wilson
- Epidemiology Research Group in Organ Transplantation, Division of Transplantation, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Andy Chen
- Epidemiology Research Group in Organ Transplantation, Division of Transplantation, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Morgan Johnson
- Epidemiology Research Group in Organ Transplantation, Division of Transplantation, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Columbia University Mailman School of Public Health, New York City, New York
| | - Jamilah A Perkins
- Epidemiology Research Group in Organ Transplantation, Division of Transplantation, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Tanjala S Purnell
- Epidemiology Research Group in Organ Transplantation, Division of Transplantation, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Sivaguru M, Saw JJ, Wilson EM, Lieske JC, Krambeck AE, Williams JC, Romero MF, Fouke KW, Curtis MW, Kear-Scott JL, Chia N, Fouke BW. Human kidney stones: a natural record of universal biomineralization. Nat Rev Urol 2021; 18:404-432. [PMID: 34031587 DOI: 10.1038/s41585-021-00469-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 02/04/2023]
Abstract
GeoBioMed - a new transdisciplinary approach that integrates the fields of geology, biology and medicine - reveals that kidney stones composed of calcium-rich minerals precipitate from a continuum of repeated events of crystallization, dissolution and recrystallization that result from the same fundamental natural processes that have governed billions of years of biomineralization on Earth. This contextual change in our understanding of renal stone formation opens fundamentally new avenues of human kidney stone investigation that include analyses of crystalline structure and stratigraphy, diagenetic phase transitions, and paragenetic sequences across broad length scales from hundreds of nanometres to centimetres (five Powers of 10). This paradigm shift has also enabled the development of a new kidney stone classification scheme according to thermodynamic energetics and crystalline architecture. Evidence suggests that ≥50% of the total volume of individual stones have undergone repeated in vivo dissolution and recrystallization. Amorphous calcium phosphate and hydroxyapatite spherules coalesce to form planar concentric zoning and sector zones that indicate disequilibrium precipitation. In addition, calcium oxalate dihydrate and calcium oxalate monohydrate crystal aggregates exhibit high-frequency organic-matter-rich and mineral-rich nanolayering that is orders of magnitude higher than layering observed in analogous coral reef, Roman aqueduct, cave, deep subsurface and hot-spring deposits. This higher frequency nanolayering represents the unique microenvironment of the kidney in which potent crystallization promoters and inhibitors are working in opposition. These GeoBioMed insights identify previously unexplored strategies for development and testing of new clinical therapies for the prevention and treatment of kidney stones.
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Affiliation(s)
- Mayandi Sivaguru
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Carl Zeiss Labs@Location Partner, Carl R. Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Jessica J Saw
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Mayo Clinic School of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Elena M Wilson
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Amy E Krambeck
- Department of Urology, Mayo Clinic, Rochester, MN, USA.,Department of Urology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - James C Williams
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michael F Romero
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Kyle W Fouke
- Jackson School of Geosciences, University of Texas at Austin, Austin, TX, USA
| | - Matthew W Curtis
- Carl Zeiss Microscopy LLC, One North Broadway, White Plains, NY, USA
| | | | - Nicholas Chia
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Bruce W Fouke
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Carl Zeiss Labs@Location Partner, Carl R. Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Department of Geology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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6
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Zhang J, Kumar S, Jayachandran M, Herrera Hernandez LP, Wang S, Wilson EM, Lieske JC. Excretion of urine extracellular vesicles bearing markers of activated immune cells and calcium/phosphorus physiology differ between calcium kidney stone formers and non-stone formers. BMC Nephrol 2021; 22:204. [PMID: 34074247 PMCID: PMC8170929 DOI: 10.1186/s12882-021-02417-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 05/24/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUNDS Previous studies have demonstrated that excretion of urinary extracellular vesicles (EVs) from different nephron segments differs between kidney stone formers and non-stone formers (NSFs), and could reflect pathogenic mechanisms of urinary stone disease. In this study we quantified selected populations of specific urinary EVs carrying protein markers of immune cells and calcium/phosphorus physiology in calcium oxalate stone formers (CSFs) compared to non-stone formers (NSFs). METHODS Biobanked urine samples from CSFs (n = 24) undergoing stone removal surgery and age- and sex- matched NSFs (n = 21) were studied. Urinary EVs carrying proteins related to renal calcium/phosphorus physiology (phosphorus transporters (PiT1 and PiT2), Klotho, and fibroblast growth factor 23 (FGF23); markers associated with EV generation (anoctamin-4 (ANO4) and Huntington interacting protein 1 (HIP1)), and markers shed from activated immune cells were quantified by standardized and published method of digital flow cytometry. RESULTS Urine excretion of calcium, oxalate, phosphorus, and calcium oxalate supersaturation (SS) were significantly higher in CSFs compared to NSFs (P < 0.05). Urinary excretion of EVs with markers of total leukocytes (CD45), neutrophils (CD15), macrophages (CD68), Klotho, FGF23, PiT1, PiT2, and ANO4 were each markedly lower in CSFs than NSFs (P < 0.05) whereas excretion of those with markers of monocytes (CD14), T-Lymphocytes (CD3), B-Lymphocytes (CD19), plasma cells (CD138 plus CD319 positive) were not different between the groups. Urinary excretion of EVs expressing PiT1 and PiT2 negatively (P < 0.05) correlated with urinary phosphorus excretion, whereas excretion of EVs expressing FGF23 negatively (P < 0.05) correlated with both urinary calcium and phosphorus excretion. Urinary EVs with markers of HIP1 and ANO4 correlated negatively (P < 0.05) with clinical stone events and basement membrane calcifications on papillary tip biopsies. CONCLUSIONS Urinary excretion of EVs derived from specific types of activated immune cells and EVs with proteins related to calcium/phosphorus regulation differed between CSFs and NSFs. Further validation of these and other populations of urinary EVs in larger cohort could identify biomarkers that elucidate novel pathogenic mechanisms of calcium stone formation in specific subsets of patients.
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Affiliation(s)
- Jiqing Zhang
- Department of Urology, Beijing Chaoyang Hospital, Capital Medical University, No.8 Gongti Nanlu,Chaoyang District, 100020, Beijing, China
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, MN, 55905, Rochester, USA
| | - Sanjay Kumar
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, MN, 55905, Rochester, USA
- Department of Life Science, School of Basic Science and Research, Sharda University, Knowledge Park III, 201310, UP, Greater Noida, India
| | - Muthuvel Jayachandran
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, MN, 55905, Rochester, USA
- Department of Internal Medicine, Division of Hematology Research, Mayo Clinic, 55905, Rochester, MN, USA
- Department of Physiology & Biomedical Engineering, Mayo Clinic, 55905, Rochester, MN, USA
| | | | - Stanley Wang
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, MN, 55905, Rochester, USA
| | - Elena M Wilson
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, MN, 55905, Rochester, USA
| | - John C Lieske
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, MN, 55905, Rochester, USA.
- Department of Laboratory Medicine and Pathology, Mayo Clinic, 55905, Rochester, MN, USA.
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Saw JJ, Sivaguru M, Wilson EM, Dong Y, Sanford RA, Fields CJ, Cregger MA, Merkel AC, Bruce WJ, Weber JR, Lieske JC, Krambeck AE, Rivera ME, Large T, Lange D, Bhattacharjee AS, Romero MF, Chia N, Fouke BW. In Vivo Entombment of Bacteria and Fungi during Calcium Oxalate, Brushite, and Struvite Urolithiasis. Kidney360 2021; 2:298-311. [PMID: 35373025 PMCID: PMC8740987 DOI: 10.34067/kid.0006942020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 12/23/2020] [Indexed: 02/04/2023]
Abstract
Background Human kidney stones form via repeated events of mineral precipitation, partial dissolution, and reprecipitation, which are directly analogous to similar processes in other natural and manmade environments, where resident microbiomes strongly influence biomineralization. High-resolution microscopy and high-fidelity metagenomic (microscopy-to-omics) analyses, applicable to all forms of biomineralization, have been applied to assemble definitive evidence of in vivo microbiome entombment during urolithiasis. Methods Stone fragments were collected from a randomly chosen cohort of 20 patients using standard percutaneous nephrolithotomy (PCNL). Fourier transform infrared (FTIR) spectroscopy indicated that 18 of these patients were calcium oxalate (CaOx) stone formers, whereas one patient formed each formed brushite and struvite stones. This apportionment is consistent with global stone mineralogy distributions. Stone fragments from seven of these 20 patients (five CaOx, one brushite, and one struvite) were thin sectioned and analyzed using brightfield (BF), polarization (POL), confocal, super-resolution autofluorescence (SRAF), and Raman techniques. DNA from remaining fragments, grouped according to each of the 20 patients, were analyzed with amplicon sequencing of 16S rRNA gene sequences (V1-V3, V3-V5) and internal transcribed spacer (ITS1, ITS2) regions. Results Bulk-entombed DNA was sequenced from stone fragments in 11 of the 18 patients who formed CaOx stones, and the patients who formed brushite and struvite stones. These analyses confirmed the presence of an entombed low-diversity community of bacteria and fungi, including Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, and Aspergillus niger. Bacterial cells approximately 1 μm in diameter were also optically observed to be entombed and well preserved in amorphous hydroxyapatite spherules and fans of needle-like crystals of brushite and struvite. Conclusions These results indicate a microbiome is entombed during in vivo CaOx stone formation. Similar processes are implied for brushite and struvite stones. This evidence lays the groundwork for future in vitro and in vivo experimentation to determine how the microbiome may actively and/or passively influence kidney stone biomineralization.
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Affiliation(s)
- Jessica J. Saw
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Mayo Clinic Alix School of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Mayandi Sivaguru
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Elena M. Wilson
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Yiran Dong
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Robert A. Sanford
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Department of Geology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Chris J. Fields
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Melissa A. Cregger
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Annette C. Merkel
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - William J. Bruce
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Joseph R. Weber
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - John C. Lieske
- Department of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Amy E. Krambeck
- Department of Urology, Mayo Clinic, Rochester, Minnesota
- Department of Urology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Marcelino E. Rivera
- Department of Urology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Timothy Large
- Department of Urology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Dirk Lange
- The Stone Centre at Vancouver General Hospital, Department of Urologic Sciences, University of British Columbia, Jack Bell Research Centre, Vancouver, British Columbia, Canada
| | - Ananda S. Bhattacharjee
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Michael F. Romero
- Department of Individualized Medicine, Mayo Clinic, Rochester, Minnesota
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Nicholas Chia
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
- Department of Urology, Mayo Clinic, Rochester, Minnesota
| | - Bruce W. Fouke
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Department of Geology, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Department of Evolution, Ecology and Behavior, University of Illinois at Urbana-Champaign, Urbana, Illinois
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Wilson EM, Choi J, Torres VE, Somlo S, Besse W. Large Deletions in GANAB and SEC63 Explain 2 Cases of Polycystic Kidney and Liver Disease. Kidney Int Rep 2020; 5:727-731. [PMID: 32405593 PMCID: PMC7210741 DOI: 10.1016/j.ekir.2020.01.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/09/2020] [Accepted: 01/20/2020] [Indexed: 11/29/2022] Open
Affiliation(s)
- Elena M Wilson
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jungmin Choi
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Biomedical Sciences, Korea University College of Medicine, Seoul, Republic of Korea
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Stefan Somlo
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Whitney Besse
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut, USA
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9
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Wilson CE, Dickie AP, Schreiter K, Wehr R, Wilson EM, Bial J, Scheer N, Wilson ID, Riley RJ. The pharmacokinetics and metabolism of diclofenac in chimeric humanized and murinized FRG mice. Arch Toxicol 2018; 92:1953-1967. [PMID: 29721588 DOI: 10.1007/s00204-018-2212-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/25/2018] [Indexed: 11/30/2022]
Abstract
The pharmacokinetics of diclofenac were investigated following single oral doses of 10 mg/kg to chimeric liver humanized and murinized FRG and C57BL/6 mice. In addition, the metabolism and excretion were investigated in chimeric liver humanized and murinized FRG mice. Diclofenac reached maximum blood concentrations of 2.43 ± 0.9 µg/mL (n = 3) at 0.25 h post-dose with an AUCinf of 3.67 µg h/mL and an effective half-life of 0.86 h (n = 2). In the murinized animals, maximum blood concentrations were determined as 3.86 ± 2.31 µg/mL at 0.25 h post-dose with an AUCinf of 4.94 ± 2.93 µg h/mL and a half-life of 0.52 ± 0.03 h (n = 3). In C57BL/6J mice, mean peak blood concentrations of 2.31 ± 0.53 µg/mL were seen 0.25 h post-dose with a mean AUCinf of 2.10 ± 0.49 µg h/mL and a half-life of 0.51 ± 0.49 h (n = 3). Analysis of blood indicated only trace quantities of drug-related material in chimeric humanized and murinized FRG mice. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles in humanized mice were different to those of both murinized and wild-type animals, e.g., a higher proportion of the dose was detected in the form of acyl glucuronide metabolites and much reduced amounts as taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57BL/6J mice and humans revealed a greater, though not complete, match between chimeric humanized mice and humans, such that the liver humanized FRG model may represent a model for assessing the biotransformation of such compounds in humans.
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Affiliation(s)
- C E Wilson
- Nestlé Skin Health R&D, Les Templiers, Route des Colles, BP 87, 06902, Sophia-Antipolis, France.
| | - A P Dickie
- Evotec (UK) Ltd, 114 Innovation Drive, Abingdon, Oxfordshire, OX14 4RZ, UK
| | - K Schreiter
- Evotec International GmbH, Manfred Eigen Campus, Essener Bogen 7, Hamburg, Germany
| | - R Wehr
- Evotec International GmbH, Manfred Eigen Campus, Essener Bogen 7, Hamburg, Germany
| | - E M Wilson
- Yecuris Corporation, PO Box 4645, Tualatin, OR, 97062, USA
| | - J Bial
- Yecuris Corporation, PO Box 4645, Tualatin, OR, 97062, USA
| | - N Scheer
- CEVEC Pharmaceuticals GmbH, Gottfried-Hagen-Str. 60-62, 51105, Cologne, Germany
| | - I D Wilson
- Department of Surgery and Cancer, Imperial College, Exhibition Rd, South Kensington, London, SW7 2AZ, UK
| | - R J Riley
- Evotec (UK) Ltd, Alderley Park, Nether Alderley, Cheshire, SK10 4TG, UK
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10
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Rojas AM, Lyn BE, Wilson EM, Williams FJ, Shah N, Dickson J, Saunders MI. Toxicity and outcome of a phase II trial of taxane-based neoadjuvant chemotherapy and 3-dimensional, conformal, accelerated radiotherapy in locally advanced nonsmall cell lung cancer. Cancer 2006; 107:1321-30. [PMID: 16902985 DOI: 10.1002/cncr.22123] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The objective of this study was to evaluate prospectively the acute and late adverse effects of taxane/carboplatin neoadjuvant chemotherapy and 3-dimensional, conformal radiotherapy in patients with locally advanced nonsmall cell lung cancer (NSCLC). METHODS Forty-two patients were entered into a nonrandomized Phase II study of continuous, hyperfractionated, accelerated radiotherapy (CHART) week-end less (CHARTWEL) to a dose of 60 grays (Gy). Three cycles of chemotherapy were given over 9 weeks before radiotherapy. Dose escalation with paclitaxel was from 150 mg/m2 to 225 mg/m2. Systemic toxicity to chemotherapy was monitored throughout. Radiation-induced, early, adverse effects were assessed during the first 9 weeks from the start of radiotherapy, and late effects were assessed from 3 months onward. Overall survival, disease-free survival, and locoregional tumor control also were monitored. RESULTS Twenty percent of patients failed to receive chemotherapy as planned, primarily because of neutropenia. The incidence of Dische Dictionary Grade >or=2 and Grade >or=3 dysphagia was 57.5% and 10%, respectively, with an average duration of 1.2 weeks and 1.5 days, respectively. By 9 weeks, <3% of patients were symptomatic; and, eventually, all acute reactions were healed, and there has been no evidence of consequential damage. At 6 months, the actuarial incidence of moderate-to-severe pneumonitis was 10%. During this time, all patients were free of severe pulmonary complications. Actuarial estimates of Grade >or=2 late lung dysfunction were 3% at 1 year, 10% at 2 years, and remained at this level thereafter. The actuarial 3-year locoregional control and overall survival rates were 54% and 45%, respectively. CONCLUSIONS Neoadjuvant chemotherapy followed by 3-dimensional, conformal CHARTWEL 60-Gy radiotherapy in patients with advanced NSCLC was feasible and was tolerated well. Historic comparisons indicated that locoregional tumor control is not compromised by the use of conformal techniques.
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Affiliation(s)
- Ana M Rojas
- Marie Curie Research Wing, Mount Vernon Hospital, Northwood, Middlesex, United Kingdom.
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11
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Wilson EM, Joy Williams F, Lyn BE, Aird EGA. Comparison of two dimensional and three dimensional radiotherapy treatment planning in locally advanced non-small cell lung cancer treated with continuous hyperfractionated accelerated radiotherapy weekend less. Radiother Oncol 2005; 74:307-14. [PMID: 15763312 DOI: 10.1016/j.radonc.2004.12.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2003] [Revised: 08/29/2004] [Accepted: 12/10/2004] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Patients with inoperable non-small cell lung cancer being treated with continuous hyperfractionated accelerated radiotherapy weekend less (CHARTWEL) were planned and treated with a three dimensional (3D) conformal protocol and comparison made with two dimensional (2D) planning, as used previously, to compare past practice and methods. PATIENTS AND METHODS Twenty-four patients were planned initially using 3D and then replanned using a 2D system. The 2D plans were transferred onto the 3D system and recalculated. Dose volume histograms could then be constructed of planning target volumes for phases 1 and 2 (PTV 1 and 2, respectively), lung and spinal cord for the 2D plans and compared with the 3D plans. RESULTS There was a significantly lower absolute dose to the isocentre with 2D compared to 3D planning with dose reductions of 3.9% for phase 1, 4.4% for phase 2 and 4.7% for those treated with a single phase. Maximum dose to spinal cord was greater in 17 of the 24 2D plans with a median dose reduction of 0.82 Gy for 3D (P=0.04). The percentage volume of whole lung receiving > or =20 Gy (V20) was greater in 16 of the 24 2D plans with a median reduction in V20 of 2.4% for 3D (P=0.03). CONCLUSIONS A lower dose to tumour was obtained using 2D planning due to the method of dose calculation and spinal cord and lung doses were significantly higher.
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Affiliation(s)
- Elena M Wilson
- Department of Clinical Oncology, Mount Vernon Cancer Centre, Northwood, Middlesex, HA6 2RN, England, UK
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12
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Burd CJ, Petre CE, Moghadam H, Wilson EM, Knudsen KE. Cyclin D1 binding to the androgen receptor (AR) NH2-terminal domain inhibits activation function 2 association and reveals dual roles for AR corepression. Mol Endocrinol 2004; 19:607-20. [PMID: 15539430 DOI: 10.1210/me.2004-0266] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [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: 01/26/2023] Open
Abstract
The androgen receptor (AR) is a member of the nuclear receptor superfamily, the activity of which is critical for the development and progression of prostate cancer. We and others have previously demonstrated that cyclin D1 is a potent corepressor of the AR. Although cyclin D1 is suspected to recruit histone deacetylases to the AR complex, previous studies have demonstrated that this activity alone is insufficient for cyclin D1 function. Here, we uncover a novel, secondary means of cyclin D1-mediated repression, through modulation of AR amino-carboxy terminal interactions. We show that cyclin D1 predominantly binds the N-terminal domain of the AR, dependent on the AR 23FxxLF27 motif. Through this motif, cyclin D1 abrogates the ability of the AR N-terminal domain to interact with the C terminus. Secondary amino-terminal domain sites capable of fostering interaction with the C terminus were refractory to cyclin D1 action, indicating that the ability of cyclin D1 to modulate AR amino-carboxy terminal interactions is specific to 23FxxLF27. Deletion of the N-terminal cyclin D1 binding site severely compromised AR activity (due to loss of FxxLF) but unmasked a repressor action through interaction with the AR C terminus. In summary, these data reveal novel, unexpected mechanisms of cyclin D1 activity and demonstrate that this function of cyclin D1 is critical for AR modulation.
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Affiliation(s)
- C J Burd
- Department of Cell Biology, University of Cincinnati College of Medicine, P.O. Box 670521, 3125 Eden Avenue, Cincinnati, Ohio 45267-0521, USA
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13
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Munro JF, MacCuish AC, Wilson EM, Duncan LJ. Comparison of continuous and intermittent anorectic therapy in obesity. Br Med J 2004; 1:352-4. [PMID: 15508204 PMCID: PMC1984840 DOI: 10.1136/bmj.1.5588.352] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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14
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Wilson EM, Williams FJ, Lyn BE, Wong JW, Aird EGA. Validation of active breathing control in patients with non–small-cell lung cancer to be treated with CHARTWEL. Int J Radiat Oncol Biol Phys 2003; 57:864-74. [PMID: 14529794 DOI: 10.1016/s0360-3016(03)00712-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [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: 11/26/2022]
Abstract
PURPOSE Active breathing control (ABC) was validated using patients with non-small-cell lung cancer (NSCLC) to be treated with continuous hyperfractionated accelerated radiotherapy weekend-less (CHARTWEL). Effects of breath hold (BH) on accuracy and normal tissue doses were evaluated. METHODS AND MATERIALS Eleven patients were studied. Immediately after a free breathing (FB) planning scan, two ABC scans (ABC 1 and 2) were performed to assess intrafraction variation. A third ABC scan (ABC 3) was performed some weeks later to assess interfraction variation. Assisted BH was set at 75% of vital capacity and reproducibility assessed using computed tomography (CT) lung volumes. Planning target volumes (PTVs), doses to lung and spinal cord for FB and ABC 1 scans were compared. RESULTS Results were available for 10 patients. Disease and elective nodal regions were easier to define on ABC scans making PTVs smaller. ABC lung volumes showed no significant variation over several weeks, percentage volume of whole lung receiving > or =20 Gy (V(20)) was reduced in all (median 6.4%, p = 0.005), and spinal cord dose in 80% (median 1.03 Gy, p = 0.02), of the plans. CONCLUSION ABC allowed reproducible BH, and enabled better delineation of tumor and normal structures, as well as reduction in PTV, V(20), and spinal cord dose.
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Affiliation(s)
- Elena M Wilson
- Department of Clinical OncologyMount Vernon Cancer Centre, Northwood, Middlesex, UK.
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15
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Wilson EM. Three-dimensional conformal radiotherapy in the radical treatment of non-small cell lung cancer. Clin Oncol (R Coll Radiol) 2003; 15:412-9. [PMID: 14570090 DOI: 10.1016/s0936-6555(03)00116-x] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Patients with locally advanced, inoperable, non-small cell lung cancer (NSCLC) have a poor prognosis mainly due to failure of local control after treatment with radical radiotherapy. This overview addresses the role of three-dimensional conformal radiotherapy (3D CRT) in trying to improve survival and reduce toxicity for patients with NSCLC. Current techniques of 3D CRT are analysed and discussed. They include imaging, target volume definition, optimisation of the delivery of radiotherapy through improvement of set-up inaccuracy and reduction of organ motion, dosimetry and implementation and verification issues; the overview concludes with the clinical results of 3D CRT.
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Affiliation(s)
- E M Wilson
- Specialist Registrar in Clinical Oncology, Mount Vernon Cancer Centre, Rickmansworth Road, Northwood, Middlesex, UK.
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16
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Abstract
AIMS AND METHODS Urgent referral guidelines for patients with suspected colorectal cancer were introduced in 2000. In a district general hospital, we prospectively assessed the effect of these guidelines on the number of urgent referrals received and the number found to have cancer. RESULTS Over the first year, 180 urgent referrals were received of whom 95 (55%) fitted the guidelines. Of these 95 patients, 24 (25%) had colorectal cancer. Conversely, only 2 of the 85 patients (2%) who did not fit the guidelines had colorectal cancer. During the same time period, a total of 145 new cancers were identified within the district of which 119 (82%) were in patients who had not been urgently referred to out-patients as suspected colorectal cancer. DISCUSSION The guidelines are effective in that patients who fit them have a significant chance of having colorectal cancer. However, the majority of cancers are identified outside the new system. Efforts to reduce delays in diagnosis need to recognise that many patients do not have features which fit published referral criteria. Improved support for general practitioners and better access to specialist services are required to reduce delays in diagnosis.
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17
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Affiliation(s)
- M Liao
- Loeb Health Research Institute, University of Ottawa, Ottawa, Ontario, Canada
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18
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Abstract
The progression of left ventricular (LV) dysfunction is often accompanied by changes in LV geometry and myocardial architecture that can be defined as LV myocardial remodelling. An important event in LV myocardial remodelling is alterations in the extracellular matrix (ECM). A family of zinc-dependent proteases implicated in facilitating myocardial tissue remodelling by degrading components of the ECM are the matrix metalloproteinases (MMPs). The temporal expression of MMPs and the local tissue inhibitors of MMPs (TIMPs) appear to be differentially regulated in several cardiovascular disease states such as myocardial infarction, LV hypertrophy, and dilated cardiomyopathy. Both pharmacological and genetic modulation of myocardial MMP expression has been demonstrated to alter the course of LV myocardial remodelling and LV dysfunction. The induction of MMPs within the myocardium during the heart failure process probably results in liberation of bioactive molecules, proteolytic degradation of ECM structural proteins, and alterations in cell-cell contact and adhesion. Modifying MMP expression and activation may reduce this turmoil within the myocardial interstitium and, in turn, prove to be a useful therapeutic paradigm for heart failure treatment.
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Affiliation(s)
- E M Wilson
- Medical University of South Carolina, Charleston, USA
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19
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Abstract
Activation domains in the 114 kDa androgen receptor (AR) NH(2)- and carboxyl-terminal regions are thought to contribute to different extents to AR-mediated transactivation. We investigated using anti-peptide antibodies whether smaller AR forms that migrate like the previously described 87 kDa AR-A occur in vivo resulting in constitutive or increased gene activation. Immunoblots of prostate cancer and fibroblast cell culture extracts revealed 114 and 84 kDa AR forms. Antibody mapping indicated the 84 kDa AR lacked the ligand-binding domain and comigrated with the constitutively active AR fragment AR1-660. AR expressed in COS cells was 114 and 92 kDa. Migration of the 92 kDa AR was slightly slower than that of a 90 kDa expressed fragment that was designed to initiate at the second methionine (residue 189) and lacked the NH(2)-terminal FxxLF interaction sequence. The 92 kDa AR did not result from alternative initiation since it was observed when the second methionine was changed to alanine. Optimization of extraction conditions indicated that both 84 and 92 kDa forms resulted from in vitro proteolytic cleavage and that cleavage by caspase-3 could account for the 92 kDa form. The results suggest that AR forms with gel mobility similar to that of the previously described 87 kDa AR-A result from in vitro proteolytic cleavage of NH(2)- or carboxyl-terminal regions during cell extraction and storage and that smaller forms with increased transcriptional activity do not occur in vivo.
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Affiliation(s)
- C W Gregory
- Laboratories for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
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20
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He B, Bowen NT, Minges JT, Wilson EM. Androgen-induced NH2- and COOH-terminal Interaction Inhibits p160 coactivator recruitment by activation function 2. J Biol Chem 2001; 276:42293-301. [PMID: 11551963 DOI: 10.1074/jbc.m107492200] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [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: 02/03/2023] Open
Abstract
The androgen receptor undergoes an androgen-specific NH(2)- and COOH-terminal interaction between NH(2)-terminal motif FXXLF and activation function 2 in the ligand binding domain. We demonstrated previously that activation function 2 forms overlapping binding sites for the androgen receptor FXXLF motif and the LXXLL motifs of p160 coactivators. Here we investigate the influence of the NH(2)- and COOH-terminal interaction on androgen receptor function. Specificity and relative potency of the motif interactions were evaluated by ligand dissociation rate and the stability of chimeras of transcriptional intermediary factor 2 with full-length and truncated androgen or glucocorticoid receptor. The results indicate that the androgen receptor activation function 2 interacts specifically and with greater avidity with the single FXXLF motif than with the LXXLL motif region of p160 coactivators, whereas this region of the glucocorticoid receptor interacts preferentially with the LXXLL motifs. Expression of the LXXLL motifs as a fusion protein with the glucocorticoid receptor resulted in loss of agonist-induced receptor destabilization and increased half-time of ligand dissociation. The NH(2)- and COOH-terminal interaction inhibited binding and activation by transcriptional intermediary factor 2. We conclude that the androgen receptor NH(2)- and COOH-terminal interaction reduces the dissociation rate of bound androgen, stabilizes the receptor, and inhibits p160 coactivator recruitment by activation function 2.
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Affiliation(s)
- B He
- Department of Biochemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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21
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Curtin D, Jenkins S, Farmer N, Anderson AC, Haisenleder DJ, Rissman E, Wilson EM, Shupnik MA. Androgen suppression of GnRH-stimulated rat LHbeta gene transcription occurs through Sp1 sites in the distal GnRH-responsive promoter region. Mol Endocrinol 2001; 15:1906-17. [PMID: 11682622 DOI: 10.1210/mend.15.11.0723] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [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
Steroids may regulate LH subunit gene transcription by modulating hypothalamic GnRH pulse patterns or by acting at the pituitary gonadotrope to alter promoter activity. We tested direct pituitary effects of the androgen dihydrotestosterone (DHT) to modulate the rat LHbeta promoter in transfected LbetaT2 clonal gonadotrope cells and in pituitaries of transgenic mice expressing LHbeta-luciferase. The LHbeta promoter (-617 to +44 bp)-luciferase construct was stimulated in LbetaT2 cells 7- to 10-fold by GnRH. Androgen treatment had little effect on basal promoter activity but suppressed GnRH stimulation by approximately 75%. GnRH stimulation of LHbeta was also suppressed by DHT in isolated pituitary cells from male or female mice with functional nuclear ARs, but not in male littermates with mutant AR. GnRH stimulation of the LHbeta promoter requires interactions between a complex distal response element containing two specificity protein-1 (Sp1) binding sites and a CArG box, and a proximal element with two bipartite binding sites for steroidogenic factor-1 and early growth response protein-1 (Egr-1). DHT effectively suppressed promoter constructs with an intact distal response element. The distal response element does not bind AR, but AR reduces Sp1 binding to this region. Glutathione-S-transferase pull-down studies demonstrated direct interactions of AR with Sp1, which requires the DNA-binding domain of AR, and weaker interactions with Egr-1. We conclude that androgen suppression of the rat LHbeta promoter occurs primarily through direct interaction of AR with Sp1, with some possible role through binding to Egr-1. These interactions result in interference with GnRH-stimulated gene transcription by reducing cooperation between the distal and proximal GnRH response elements.
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MESH Headings
- Animals
- Binding Sites
- Cells, Cultured
- Dihydrotestosterone/pharmacology
- Female
- Glycoprotein Hormones, alpha Subunit/genetics
- Glycoprotein Hormones, alpha Subunit/metabolism
- Gonadotropin-Releasing Hormone/metabolism
- Gonadotropin-Releasing Hormone/pharmacology
- Luteinizing Hormone/drug effects
- Luteinizing Hormone/genetics
- Luteinizing Hormone/metabolism
- Male
- Mice
- Mice, Transgenic
- Pituitary Gland/cytology
- Pituitary Gland/physiology
- Promoter Regions, Genetic
- Rats
- Receptors, Androgen/drug effects
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Receptors, LHRH/drug effects
- Receptors, LHRH/genetics
- Response Elements/drug effects
- Response Elements/genetics
- Sp1 Transcription Factor/metabolism
- Steroidogenic Factor 1
- Suppression, Genetic
- Transcription, Genetic
- Transfection
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Affiliation(s)
- D Curtin
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
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22
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Tureckova J, Wilson EM, Cappalonga JL, Rotwein P. Insulin-like growth factor-mediated muscle differentiation: collaboration between phosphatidylinositol 3-kinase-Akt-signaling pathways and myogenin. J Biol Chem 2001; 276:39264-70. [PMID: 11500504 DOI: 10.1074/jbc.m104991200] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [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 differentiation and maturation of skeletal muscle require interactions between signaling pathways activated by hormones and growth factors and an intrinsic regulatory network controlled by myogenic transcription factors. Insulin-like growth factors (IGFs) play key roles in muscle development in the embryo and in regeneration in the adult. To study mechanisms of IGF action in muscle, we developed a myogenic cell line that overexpresses IGF-binding protein-5. C2BP5 cells remain quiescent in low serum differentiation medium until the addition of IGF-I. Here we use this cell line to identify signaling pathways controlling IGF-mediated differentiation. Induction of myogenin by IGF-I and myotube formation were prevented by the phosphatidylinositol (PI) 3-kinase inhibitor, LY294002, even when included 2 days after growth factor addition, whereas expression of active PI 3-kinase could promote differentiation in the absence of IGF-I. Differentiation also was induced by myogenin but was blocked by LY294002. The differentiation-promoting effects of IGF-I were mimicked by a modified membrane-targeted inducible Akt-1 (iAkt), and iAkt was able to stimulate differentiation of C2 myoblasts and primary mouse myoblasts incubated with otherwise inhibitory concentrations of LY294002. These results show that an IGF-regulated PI 3-kinase-Akt pathway controls muscle differentiation by mechanisms acting both upstream and downstream of myogenin.
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Affiliation(s)
- J Tureckova
- Oregon Health and Science University, Molecular Medicine Division, Department of Medicine, Portland, Oregon 97201-3098, USA
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23
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Buckway CK, Wilson EM, Ahlsén M, Bang P, Oh Y, Rosenfeld RG. Mutation of three critical amino acids of the N-terminal domain of IGF-binding protein-3 essential for high affinity IGF binding. J Clin Endocrinol Metab 2001; 86:4943-50. [PMID: 11600567 DOI: 10.1210/jcem.86.10.7936] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [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
The N-terminal domain is conserved in all members of the IGF-binding protein superfamily. Most recently, studies have demonstrated the importance of an IGF-binding protein N-terminal hydrophobic pocket for IGF binding. To examine more critically the amino acids important for IGF binding within the full-length IGF-binding protein-3 protein while minimizing changes in the tertiary structure, we targeted residues I56, L80, and L81 within the proposed hydrophobic pocket for mutation. With a single change at these sites to the nonconserved glycine there was a notable decrease in binding. A greater reduction was seen when both L80 and L81 were substituted with glycine, and complete loss of affinity for IGF-I and IGF-II occurred when all three targeted amino acids were changed to glycine. Furthermore, the ability of the IGF-binding protein-3 mutants to inhibit IGF-I-stimulated phosphorylation of its receptor was a reflection of their affinity for IGF, with the lowest affinity mutants having the least inhibitory effect. These studies, thus, support the hypothesis that an N-terminal hydrophobic pocket is the primary site of high affinity binding of IGF to IGF-binding protein-3. The mutants provide a tool for future studies directed at IGF-dependent and IGF-independent actions of IGF-binding protein-3.
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Affiliation(s)
- C K Buckway
- Department of Pediatrics, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97201, USA.
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24
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Wilson EM, Oh Y, Hwa V, Rosenfeld RG. Interaction of IGF-binding protein-related protein 1 with a novel protein, neuroendocrine differentiation factor, results in neuroendocrine differentiation of prostate cancer cells. J Clin Endocrinol Metab 2001; 86:4504-11. [PMID: 11549700 DOI: 10.1210/jcem.86.9.7845] [Citation(s) in RCA: 24] [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: 02/12/2023]
Abstract
Neuroendocrine cells have been implicated in many cancers, including small cell lung, cervical, breast, and prostate carcinomas. The increase in neuroendocrine cell number in prostate cancer has been reported to correlate with poor prognosis, progressive tumors, and androgen insensitivity. The mechanisms involved in this differentiation remain unknown. IGF-binding protein-related protein 1 is a member of the IGF-binding protein superfamily and has recently been shown to exhibit differentiation and tumor suppression activity in prostate cancer cell lines stably overexpressing IGF-binding protein-related protein 1. From a yeast two-hybrid screen, a novel IGF-binding protein-related protein 1-interacting protein was identified. Immunocytochemical techniques indicate that this protein, 25.1, and intracellular IGF-binding protein-related protein 1 colocalize in the nucleus. When 25.1 is transiently expressed in a stable prostate cancer cell line overexpressing IGF-binding protein-related protein 1, cells assume a neuritic-like morphology with long dendritic-like processes and express the neuroendocrine markers chromogranin A and neuron-specific enolase. We propose that 25.1 (neuroendocrine differentiation factor) together with IGF-binding protein-related protein 1 can induce neuroendocrine cell differentiation in prostate cancer cells.
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Affiliation(s)
- E M Wilson
- Department of Pediatrics, Oregon Health Sciences University, Portland, Oregon 97201, USA
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25
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Walker GE, Wilson EM, Powell D, Oh Y. Butyrate, a histone deacetylase inhibitor, activates the human IGF binding protein-3 promoter in breast cancer cells: molecular mechanism involves an Sp1/Sp3 multiprotein complex. Endocrinology 2001; 142:3817-27. [PMID: 11517158 DOI: 10.1210/endo.142.9.8380] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Specific cell growth stimulators and inhibitors regulate IGF binding protein-3 (IGFBP-3), where in turn IGFBP-3 mediates their biological effects. The molecular mechanism(s) by which these factors regulate IGFBP-3 are unknown. Sodium butyrate, a histone deacetylase inhibitor causing growth arrest and differentiation, increases IGFBP-3 expression. We investigated the molecular mechanism of this induction using an IGFBP-3 promoter reporter system in MCF-7 and Hs578T breast cancer cells. IGFBP-3 promoter activity was induced up to 40-fold following a 24-h treatment with sodium butyrate and 46-fold in cells treated with trichostatin A, a pure histone deacetylase inhibitor. Deletion analysis of the IGFBP-3 promoter identified key sodium butyrate-responsive element(s) to a 45-bp region containing consensus binding sites for Sp1 and activating protein-2. Sp1 binding to the Sp1 site and Sp3 to the activating protein-2/GA-box played a functional role in sodium butyrate's activation of the IGFBP-3 promoter, however, with no change in binding direct sodium butyrate regulation was attributed to cofactors. The histone acetyltransferase p300 and histone deacetylase-1 were identified in multiprotein complexes containing DNA bound Sp1 and Sp3, with p300 accumulating following sodium butyrate treatment. Taken together, these data suggest that sodium butyrate increases IGFBP-3 expression by activating the IGFBP-3 promoter via an Sp1/Sp3 multiprotein complex, a mechanism that may be important for other key regulators of IGFBP-3.
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Affiliation(s)
- G E Walker
- Department of Pediatrics, Oregon Health Sciences University, Portland, Oregon 97201, USA
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Jenkins R, Angus RA, McNatt H, Howell WM, Kemppainen JA, Kirk M, Wilson EM. Identification of androstenedione in a river containing paper mill effluent. Environ Toxicol Chem 2001; 20:1325-1331. [PMID: 11392143 DOI: 10.1897/1551-5028(2001)020<1325:ioaiar>2.0.co;2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Effluent from a paper mill discharging into the Fenholloway River, Taylor County, Florida, USA, contains chemicals that masculinize females of the resident population of eastern mosquitofish (Gambusia holbrooki), as evidenced in females by elongated anal fins, which is normally a male-specific trait. To identify androgenic components in the effluent, water collected from the Fenholloway River and a control tributary was fractionated using solid-phase extraction and reverse-phase high-performance-liquid chromatography. Two Fenholloway River fractions induced androgen receptor-dependent transcriptional activity in transient transfection cell culture assays. Of these, androstenedione was confirmed by liquid chromatography-mass spectrometry with multiple reaction monitoring.
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Affiliation(s)
- R Jenkins
- Biology Department, Samford University, Birmingham, Alabama 35229, USA
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27
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Gregory CW, He B, Johnson RT, Ford OH, Mohler JL, French FS, Wilson EM. A mechanism for androgen receptor-mediated prostate cancer recurrence after androgen deprivation therapy. Cancer Res 2001; 61:4315-9. [PMID: 11389051] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The development and growth of prostate cancer depends on the androgen receptor and its high-affinity binding of dihydrotestosterone, which derives from testosterone. Most prostate tumors regress after therapy to prevent testosterone production by the testes, but the tumors eventually recur and cause death. A critical question is whether the androgen receptor mediates recurrent tumor growth after androgen deprivation therapy. Here we report that a majority of recurrent prostate cancers express high levels of the androgen receptor and two nuclear receptor coactivators, transcriptional intermediary factor 2 and steroid receptor coactivator 1. Overexpression of these coactivators increases androgen receptor transactivation at physiological concentrations of adrenal androgen. Furthermore, we provide a molecular basis for this activation and suggest a general mechanism for recurrent prostate cancer growth.
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Affiliation(s)
- C W Gregory
- Laboratory for Reproductive Biology, Department of Pediatrics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
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Gregory CW, Johnson RT, Mohler JL, French FS, Wilson EM. Androgen receptor stabilization in recurrent prostate cancer is associated with hypersensitivity to low androgen. Cancer Res 2001; 61:2892-8. [PMID: 11306464] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The androgen receptor (AR) is highly expressed in androgen-dependent and recurrent prostate cancer (CaP) suggesting it has a role in the growth and progression of CaP. Previously proposed mechanisms for AR reactivation in recurrent CaP include altered growth factor signaling leading to protein phosphorylation and AR mutations that broaden ligand specificity. To further establish a role for AR in recurrent CaP, we compared several properties of AR in relation to the growth response to low levels of androgens in model systems of androgen-dependent and recurrent CaP. AR from all of the tumors and cell lines bound [3H]R1881 with similar high affinity (mean Kd, 0.12 nM). In the absence of androgen, AR in androgen-dependent LNCaP cells was unstable with a degradation half-time (t(1/2)) of 3 h at 37 degrees C. In contrast, AR was 2-4 times more stable in recurrent CWR22 tumors (t(1/2), >12 h) and CWR-R1 or LNCaP-C4-2 cell lines (t(1/2), 6-7 h) derived from recurrent prostate tumors. In the recurrent CWR22 tumor and its CWR-R1 cell line grown in the absence of androgen, AR immunostaining was entirely nuclear, whereas under the same conditions AR in LNCaP-C4-2 and LNCaP cells was predominantly nuclear but was also detected in the cytoplasm. High level expression, increased stability, and nuclear localization of AR in recurrent tumor cells were associated with an increased sensitivity to the growth-promoting effects of dihydrotestosterone in the femtomolar range. The concentration of dihydrotestosterone required for growth stimulation in CWR-R1 and LNCaP-C4-2 cells was four orders of magnitude lower than that required for androgen-dependent LNCaP cells. The results suggest that AR is transcriptionally active in recurrent CaP and can increase cell proliferation at the low circulating levels of androgen reported in castrated men.
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Affiliation(s)
- C W Gregory
- Department of Pediatrics, and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill 27599, USA.
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29
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Massaad C, Garlatti M, Wilson EM, Cadepond F, Barouki R. A natural sequence consisting of overlapping glucocorticoid-responsive elements mediates glucocorticoid, but not androgen, regulation of gene expression. Biochem J 2000; 350 Pt 1:123-9. [PMID: 10926835 PMCID: PMC1221233] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Cytosolic aspartate aminotransferase (cAspAT) is regulated by glucocorticoids in rat liver and kidney. Part of this regulation is mediated by an unusual glucocorticoid-responsive element (GRE)-like sequence called GRE A. GRE A is composed of two overlapping imperfect GREs, each comprising a conserved half-site (half-sites 1 and 4 respectively) and a poorly conserved half-site (half-sites 2 and 3 respectively). The sequence binds co-operatively two dimers of the glucocorticoid receptor (GR) and mediates efficient glucocorticoid regulation of gene expression. Analysis of deletions of the cAspAT gene promoter and subcloning of GRE A upstream of the thymidine kinase promoter indicate that this sequence is responsive to glucocorticoids, but not to androgens. Electrophoretic mobility shift assays indicate that the GRE A unit does not bind the androgen receptor (AR). The modification of three nucleotides in the poorly conserved half-sites 2 and 3, converting GRE A into two overlapping high-affinity GREs (ov-cGRE), resulted in co-operative binding of the AR. Furthermore, ov-cGRE efficiently mediated androgen regulation of the thymidine kinase promoter. A single base modification in half-site 2 or 3 in GRE A allowed the binding of the AR as one or two dimers respectively, and restored transcriptional activation by androgens only in the latter case. Thus the poor affinity of the AR for half-sites 2 and 3 prevented its binding to GRE A, indicating that the overlapping GRE A sequence of the cAspAT gene promoter discriminates a glucocorticoid-mediated from an androgen-mediated response.
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Affiliation(s)
- C Massaad
- INSERM Unité 490, Université René Descartes, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France
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30
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He B, Kemppainen JA, Wilson EM. FXXLF and WXXLF sequences mediate the NH2-terminal interaction with the ligand binding domain of the androgen receptor. J Biol Chem 2000; 275:22986-94. [PMID: 10816582 DOI: 10.1074/jbc.m002807200] [Citation(s) in RCA: 308] [Impact Index Per Article: 12.8] [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 nuclear receptor superfamily members of eukaryotic transcriptional regulators contain a highly conserved activation function 2 (AF2) in the hormone binding carboxyl-terminal domain and, for some, an additional activation function 1 in the NH(2)-terminal region which is not conserved. Recent biochemical and crystallographic studies revealed the molecular basis of AF2 is hormone-dependent recruitment of LXXLL motif-containing coactivators, including the p160 family, to a hydrophobic cleft in the ligand binding domain. Our previous studies demonstrated that AF2 in the androgen receptor (AR) binds only weakly to LXXLL motif-containing coactivators and instead mediates an androgen-dependent interaction with the AR NH(2)-terminal domain required for its physiological function. Here we demonstrate in a mammalian two-hybrid assay, glutathione S-transferase fusion protein binding studies, and functional assays that two predicted alpha-helical regions that are similar, but functionally distinct from the p160 coactivator interaction sequence, mediate the androgen-dependent, NH(2)- and carboxyl-terminal interaction. FXXLF in the AR NH(2)-terminal domain with the sequence (23)FQNLF(27) mediates interaction with AF2 and is the predominant androgen-dependent interaction site. This FXXLF sequence and a second NH(2)-terminal WXXLF sequence (433)WHTLF(437) interact with different regions of the ligand binding domain to stabilize the hormone-receptor complex and may compete with AF2 recruitment of LXXLL motif-containing coactivators. The results suggest a unique mechanism for AR-mediated transcriptional activation.
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Affiliation(s)
- B He
- Laboratories for Reproductive Biology, Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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31
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Johnson BA, Wilson EM, Li Y, Moller DE, Smith RG, Zhou G. Ligand-induced stabilization of PPARgamma monitored by NMR spectroscopy: implications for nuclear receptor activation. J Mol Biol 2000; 298:187-94. [PMID: 10764590 DOI: 10.1006/jmbi.2000.3636] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Nuclear receptors are ligand-dependent transcription factors that are mediators of the action of lipophilic hormones and other endogenous ligands and are the targets of drugs useful in a variety of therapeutic areas. Peroxisome proliferator-activated receptor (PPAR)gamma is a nuclear receptor that, acting as a heterodimer with RXR, mediates a variety of cellular effects including adipocyte-differentiation. Due to its role in modulating insulin sensitivity, it is the target of therapeutically active anti-diabetic agents such as rosiglitazone. We have assigned the chemical shifts of the backbone atoms of the 32 kDa ligand-binding domain of PPARgamma in the presence of bound rosiglitazone. Three-dimensional HNCO spectra of the apo ligand-binding domain (LBD) have less than half the expected number of cross-peaks. The missing cross-peaks are restored upon binding strong agonists such as rosiglitazone. The NMR results indicate that the apo-LBD of PPARgamma is in a conformationally mobile state, and that agonist binding is associated with a marked stabilization of the conformation. Mapping the missing peaks to the 3D X-ray crystallographic structure indicates the region of mobility is extensive and includes the ligand-binding region and the cofactor-binding site. This leads to the conclusion that activation of this nuclear receptor is a result of a population shift of a dynamic ensemble of conformations, rather than a two-state switch from an inactive to an active conformation. Our results have important implications for the mechanisms by which antagonists, partial agonists, and agonists of nuclear receptor function operate.
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Affiliation(s)
- B A Johnson
- Department of Endocrinology and Chemical Biology, Merck Research Laboratories, Rahway, NJ 07065, USA.
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32
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Wilson EM. A model for prehospital personnel continuing education. J Emerg Nurs 2000; 26:48-50. [PMID: 10657799 DOI: 10.1016/s0099-1767(00)90016-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- E M Wilson
- Department of Clinical Research, Connecticut Asthma and Allergy Center, West Hartford, Conn., USA
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He B, Kemppainen JA, Voegel JJ, Gronemeyer H, Wilson EM. Activation function 2 in the human androgen receptor ligand binding domain mediates interdomain communication with the NH(2)-terminal domain. J Biol Chem 1999; 274:37219-25. [PMID: 10601285 DOI: 10.1074/jbc.274.52.37219] [Citation(s) in RCA: 267] [Impact Index Per Article: 10.7] [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
Activation function 2 in the ligand binding domain of nuclear receptors forms a hydrophobic cleft that binds the LXXLL motif of p160 transcriptional coactivators. Here we provide evidence that activation function 2 in the androgen receptor serves as the contact site for the androgen dependent NH(2)- and carboxyl-terminal interaction of the androgen receptor and only weakly interacts with p160 coactivators in an LXXLL-dependent manner. Mutagenesis studies indicate that it is the NH(2)-/carboxyl-terminal interaction that is required by activation function 2 to stabilize helix 12 and slow androgen dissociation critical for androgen receptor activity in vivo. The androgen receptor recruits p160 coactivators through its NH(2)-terminal and DNA binding domains in an LXXLL motif-independent manner. The results suggest a novel function for activation function 2 and a unique mechanism of nuclear receptor transactivation.
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Affiliation(s)
- B He
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina 27599-7500, USA
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34
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Wilson EM. The forgotten copper 7 - a circus tale. Br J Fam Plann 1999; 25:122-3. [PMID: 10567065] [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] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
A forgotten Gravigard intra-uterine contraceptive device, in a woman with an itinerant lifestyle, caused pelvic actinomycosis, mimicking ovarian malignancy. This case illustrates that although rare, this complication can still occur.
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Affiliation(s)
- E M Wilson
- Gateshead Health NHS Trust, Low Fell, Gateshead, UK
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35
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Leon MD, Wilson EM. Development of a statewide protocol for the prehospital identification of DNR patients in Connecticut including new DNR regulations. Ann Emerg Med 1999; 34:263-74. [PMID: 10424934 DOI: 10.1016/s0196-0644(99)70242-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This article describes the development and implementation of a standardized protocol for the prehospital identification of terminally ill "do-not-resuscitate" (DNR) patients. This pilot program was initiated by members of the Connecticut College of Emergency Physicians and instituted on a voluntary basis statewide in July 1991. Key components of the program are discussed, including developmental rationale, formation of a DNR Coalition, educational rollout, and implementation activities. The second phase of this initiative involved passage of state legislation and development of new DNR regulations, which went into effect in July 1997. The regulations successfully addressed the limitations and difficulties encountered in the pilot program. Major modifications included applicability of the bracelet program to a broader group of DNR patients, development of a uniform system for interfacility transfer of DNR patients, and mandatory compliance by health care personnel.
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Affiliation(s)
- M D Leon
- Department of Traumatology and Emergency Medicine, University of Connecticut Health Center, Farmington, CT, USA.
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36
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Liao M, Zhou ZX, Wilson EM. Redox-dependent DNA binding of the purified androgen receptor: evidence for disulfide-linked androgen receptor dimers. Biochemistry 1999; 38:9718-27. [PMID: 10423251 DOI: 10.1021/bi990589i] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [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: 11/30/2022]
Abstract
Full-length histidine-tagged, dihydrotestosterone-bound human androgen receptor (AR) was purified to homogeneity by affinity and gel-filtration chromatography for antibody production and analysis of AR dimerization and DNA binding properties. A monoclonal antibody was raised that recognized human and rat AR epitope (360)ArgAspTyrTyrAsnPheProLeuAla(368) in the NH(2)-terminal domain and slowed migration of AR-DNA complexes in mobility shift assays. AR binding to androgen response element DNA had a K(d) of 2.0 nM and a Hill coefficient of 2.1, indicating high-affinity, cooperative binding. AR solution dimerization was detected only at >/=0.2 microM AR, and DNA binding increased dimerization up to 30-fold. Slow- and fast-migrating AR-DNA complexes were detected under different reducing conditions that differed 5-fold in their dissociation rates from DNA. Treatment with the sulfhydryl oxidizing reagent diamide formed the faster migrating, slower dissociating complex, indicating it represents disulfide-linked AR dimers bound to DNA. The results indicate that high concentrations of purified AR are required for solution dimerization and that cooperative DNA binding stabilizes two dimer forms that differ in redox state.
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Affiliation(s)
- M Liao
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill 27599, USA
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37
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Kemppainen JA, Langley E, Wong CI, Bobseine K, Kelce WR, Wilson EM. Distinguishing androgen receptor agonists and antagonists: distinct mechanisms of activation by medroxyprogesterone acetate and dihydrotestosterone. Mol Endocrinol 1999; 13:440-54. [PMID: 10077001 DOI: 10.1210/mend.13.3.0255] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.0] [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
Natural and pharmacological androgen receptor (AR) ligands were tested for their ability to induce the AR NH2-terminal and carboxyl-terminal (N/C) interaction in a two-hybrid protein assay to determine whether N/C complex formation distinguishes in vivo AR agonists from antagonists. High-affinity agonists such as dihydrotestosterone, mibolerone, testosterone, and methyltrienolone at concentrations between 0.1 and 1 nM induce the N/C interaction more than 40-fold. The lower affinity anabolic steroids, oxandrolone and fluoxymesterone, require concentrations of 10-100 nM for up to 23-fold induction of the N/C interaction. However no N/C interaction was detected in the presence of the antagonists, hydroxyflutamide, cyproterone acetate, or RU56187, at concentrations up to 1 microM, or with 1 microM estradiol, progesterone, or medroxyprogesterone acetate; each of these steroids at 1-500 nM inhibited the dihydrotestosterone-induced N/C interaction, with medroxyprogesterone acetate being the most effective. In transient and stable cotransfection assays using the mouse mammary tumor virus reporter vector, all ligands displayed concentration-dependent AR agonist activity that paralleled induction of the N/C interaction, with antagonists and weaker agonists failing to induce the N/C interaction. AR dimerization and DNA binding in mobility shift assays and AR stabilization reflected, but were not dependent on, the N/C interaction. The results indicate that the N/C interaction facilitates agonist potency at low physiological ligand concentrations as detected in transcription, dimerization/DNA binding, and stabilization assays. However the N/C interaction is not required for agonist activity at sufficiently high ligand concentrations, nor does its inhibition imply antagonist activity.
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Affiliation(s)
- J A Kemppainen
- Department of Pediatrics, University of North Carolina, Chapel Hill 27599, USA
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Burren CP, Wilson EM, Hwa V, Oh Y, Rosenfeld RG. Binding properties and distribution of insulin-like growth factor binding protein-related protein 3 (IGFBP-rP3/NovH), an additional member of the IGFBP Superfamily. J Clin Endocrinol Metab 1999; 84:1096-103. [PMID: 10084601 DOI: 10.1210/jcem.84.3.5577] [Citation(s) in RCA: 26] [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
The protein product of the novH oncogene, a member of the CCN family, is structurally related to the insulin-like growth factor (IGF) binding proteins (IGFBPs). We have characterized aspects of structure, function, and distribution of this protein, which, as IGFBP-related protein 3 (IGFBP-rP3), is a proposed member of the IGFBP Superfamily. Affinity cross-linking experiments performed with baculovirus synthesized recombinant human IGFBP-rP3 established that rhIGFBP-rP3 binds IGF-I, IGF-II, and insulin with low affinity. Specificity of binding was shown by competitive cross-linking experiments; binding to IGF-I and -II was also demonstrated by nondenaturing Western ligand blots. Northern blot analysis indicated the presence of IGFBP-rP3 messenger RNA (mRNA) in a broad range of human tissues. Western immunoblotting studies, using a polyclonal rabbit anti-rhIGFBP-rP3 antibody, demonstrated that IGFBP-rP3 protein is synthesized in vitro by several breast and prostate cancer cell lines: Hs578T, PC3, P69, and LNCaP cells. Western immunoblotting studies of human biological fluids identified that IGFBP-rP3 was present in normal serum, pregnancy serum, serum from patients with growth hormone receptor deficiency, cerebrospinal fluid, amniotic fluid, peritoneal fluid, and follicular fluid, while IGFBP-rP3 fragments were identified in cerebrospinal fluid, amniotic fluid, and prepubertal and pubertal urine samples. Our studies demonstrate that IGFBP-rP3 exhibits IGF binding, albeit at low affinity, and IGFBP-rP3 thus merits inclusion in the IGFBP Superfamily. The low affinity IGF binding suggests that IGFBP-rP3 may act primarily independently of the IGFs. The synthesis of IGFBP-rP3 by several malignant cell lines and its presence in human biological fluids suggest that this protein possesses other interesting roles, potentially in cell growth regulation.
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Affiliation(s)
- C P Burren
- Department of Pediatrics, School of Medicine, Oregon Health Sciences University, Portland 97201, USA
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39
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Yamanaka Y, Fowlkes JL, Wilson EM, Rosenfeld RG, Oh Y. Characterization of insulin-like growth factor binding protein-3 (IGFBP-3) binding to human breast cancer cells: kinetics of IGFBP-3 binding and identification of receptor binding domain on the IGFBP-3 molecule. Endocrinology 1999; 140:1319-28. [PMID: 10067859 DOI: 10.1210/endo.140.3.6566] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [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: 11/19/2022]
Abstract
Insulin-like growth factor binding protein-3 (IGFBP-3) binds to specific membrane proteins located on human breast cancer cells, which may be responsible for mediating the IGF-independent growth inhibitory effects of IGFBP-3. In this study, we evaluated IGFBP-3 binding sites on breast cancer cell membranes by competitive binding studies with IGFBP-1 through -6 and various forms of IGFBP-3, including synthetic IGFBP-3 fragments. Scatchard analysis revealed the existence of high-affinity sites for IGFBP-3 in estrogen receptor-negative Hs578T human breast cancer cells (dissociation constant (Kd) = 8.19 +/- 0.97 x 10(-9) M and 4.92 +/- 1.51 x 10(5) binding sites/cell) and 30-fold fewer receptors in estrogen receptor-positive MCF-7 cells (Kd = 8.49 +/- 0.78 x 10(-9) M and 1.72 +/- 0.31 x 10(4) binding sites/cell), using a one-site model. These data demonstrate binding characteristics of typical receptor-ligand interactions, strongly suggesting an IGFBP-3:IGFBP-3 receptor interaction. Among IGFBPs, only IGFBP-5 showed weak competition, indicating that IGFBP-3 binding to breast cancer cell surfaces is specific and cannot be attributed to nonspecific interaction with glycosaminoglycans. This was confirmed by showing that synthetic IGFBP-3 peptides containing IGFBP-3 glycosaminoglycan-binding domains competed only weakly for IGFBP-3 binding to the cell surface. Rat IGFBP-3 was 20-fold less potent in its ability to compete with human IGFBP-3(Echerichia coli), as well as 10- to 20-fold less potent for cell growth inhibition than human IGFBP-3, suggesting the existence of species specificity in the interaction between IGFBP-3 and the IGFBP-3 receptor. When various IGFBP-3 fragments were evaluated for affinity for the IGFBP-3 receptor, only those fragments that contain the midregion of the IGFBP-3 molecule were able to inhibit 125I-IGFBP-3(Escherichia coli) binding, indicating that the midregion of the IGFBP-3 molecule is responsible for binding to its receptor. These observations demonstrate that specific, high-affinity IGFBP-3 receptors are located on breast cancer cell membranes. These receptors have properties that support the notion that they may mediate the IGF-independent inhibitory actions of IGFBP-3 in breast cancer cells.
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Affiliation(s)
- Y Yamanaka
- Department of Pediatrics, School of Medicine, Oregon Health Sciences University, Portland 97201-3042, USA
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40
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Affiliation(s)
- C S Choong
- Department of Pediatric Endocrinology, Mater Misericordiae Children's Hospital, South Brisbane, Queensland 4101, Australia
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41
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Abstract
Steroid hormone receptors control fundamental events in embryonic development and sex differentiation through their function as ligand-inducible transcription factors. The consequences of disrupting these processes can be especially profound during development due to the crucial role hormones play in controlling transient and irreversible developmental processes. Several environmental chemicals, including metabolites of the fungicide vinclozolin and the pesticide DDT, disrupt male reproductive development and function by inhibiting androgen receptor mediated events. A variety of in vitro and in vivo approaches have been used to determine the molecular basis of environmental antiandrogen toxicity. These chemicals commonly bind androgen receptor with moderate affinity and act as antagonists by inhibiting transcription of androgen dependent genes.
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Affiliation(s)
- W R Kelce
- Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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42
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Abstract
Androgen effects mediated by the androgen receptor (AR) are essential for male reproductive development and virilization. Comparison of AR DNA coding sequence from five primate species, Homo sapiens (human), Pan troglodytes (chimpanzee), Papio hamadryas (baboon), Macaca fascicularis (macaque), and Eulemur fulvus collaris (collared brown lemur), supports their phylogeny with complete conservation of the DNA and steroid binding domain protein sequence. A linear increase in trinucleotide repeat expansion of homologous CAG and GGC sequences occurs in the NH2-terminal transcriptional activation region and is proportional to the time of species divergence. A serine phosphate/glutamine repeat interaction is observed where increasing CAG repeat length is associated with an increased rate of serine 94 phosphorylation. Disparity in the calculated and apparent molecular weight with CAG repeat expansion of an AR NH2-terminal fragment suggests self-aggregation with increasing glutamine repeat length into the pathological range. These results suggest that a CAG/glutamine repeat expanded during divergence of the higher primate species, which may have a direct effect on AR structure and support a common pathway in CAG trigenic diseases in the pathophysiology of neurodegeneration observed in X-linked spinal bulbar and muscular atrophy.
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Affiliation(s)
- C S Choong
- Laboratories for Reproductive Biology and Department of Pediatrics, University of North Carolina, Chapel Hill, NC 27599, USA
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Yang DH, Kim HS, Wilson EM, Rosenfeld RG, Oh Y. Identification of glycosylated 38-kDa connective tissue growth factor (IGFBP-related protein 2) and proteolytic fragments in human biological fluids, and up-regulation of IGFBP-rP2 expression by TGF-beta in Hs578T human breast cancer cells. J Clin Endocrinol Metab 1998; 83:2593-6. [PMID: 9661651 DOI: 10.1210/jcem.83.7.5097] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [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: 02/08/2023]
Abstract
Connective Tissue Growth Factor (CTGF) is a cysteine-rich peptide involved in human atherosclerosis and fibrotic disorders such as scleroderma. CTGF has considerable N-terminal sequence similarity with the insulin-like growth factor binding proteins (IGFBPs), including preservation of cysteines, and has been postulated to be a member of the IGFBP superfamily. Indeed, recent studies have shown that baculovirus generated CTGF, a secreted 38-kDa protein, binds IGFs in a specific manner, leading to the provisional renaming of CTGF as IGFBP-8 (or IGFBP-rP2). With immunoprecipitation and immunoblotting, using polyclonal anti-IGFBP-rP2 antibody generated against recombinant human IGFBP-rP2bac, IGFBP-rP2 can be identified in the serum-free conditioned media of Hs578T human breast cancer cells, as well as in various human biological fluids, such as normal sera, pregnancy sera, and cerebrospinal, amniotic, follicular and peritoneal fluids. Glycosylation studies with endoglycosidase F reveal that endogenous human IGFBP-rP2 is a secreted, glycosylated, approximately 32-38-kDa protein with 2-8-kDa of N-linked sugars and a 30-kDa core. There are 18- and 24-kDa proteins that appear to be IGFBP-rP2 degradation products. In Hs578T human breast cancer cells, transforming growth factor (TGF)-beta 2, a potent growth inhibitor for these cells, upregulates IGFBP-rP2 mRNA and protein levels. Expression of Hs578T IGFBP-rP2 is significantly increased by TGF-beta 2 treatment in a dose-dependent manner, with 2.5- and 6-fold increases in mRNA and protein levels, respectively, at a TGF-beta 2 concentration of 10 ng/ml. Our studies indicate that IGFBP-rP2 appears to be an important endocrine factor, and one of the critical downstream effectors of the critical downstream effectors of TGF-beta, similar to the role of IGFBP-3 in TGF-beta-induced growth inhibition in human breast cancer cells.
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Affiliation(s)
- D H Yang
- Dept. of Pediatrics NRC5, Oregon Health Sciences University, Portland 97201, USA
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Wilson EM. Strokes, CVAs, or brain attacks: by any name they need quick attention. J Emerg Nurs 1998; 24:251-3. [PMID: 9775801 DOI: 10.1016/s0099-1767(98)90069-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Delbridge TR, Bailey B, Chew JL, Conn AK, Krakeel JJ, Manz D, Miller DR, O'Malley PJ, Ryan SD, Spaite DW, Stewart RD, Suter RE, Wilson EM. EMS agenda for the future: where we are ... where we want to be. EMS Agenda for the Future Steering Committee. Ann Emerg Med 1998; 31:251-63. [PMID: 9472190] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the "EMS Agenda for the Future." Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are Integration of Health Services, EMS Research, Legislation and Regulation, System Finance, Human Resources, Medical Direction, Education Systems, Public Education, Prevention, Public Access, Communication Systems, Clinical Care, Information Systems, and Evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care.
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Affiliation(s)
- T R Delbridge
- Department of Emergency Medicine, University of Pittsburgh, PA, USA
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Langley E, Kemppainen JA, Wilson EM. Intermolecular NH2-/carboxyl-terminal interactions in androgen receptor dimerization revealed by mutations that cause androgen insensitivity. J Biol Chem 1998; 273:92-101. [PMID: 9417052 DOI: 10.1074/jbc.273.1.92] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.0] [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: 02/05/2023] Open
Abstract
Structural alignment of the human androgen receptor dimer was investigated by introducing steroid binding domain mutations that cause partial or complete androgen insensitivity into fusion proteins containing the full-length androgen receptor or the steroid binding domain. Most of the mutants had unchanged apparent equilibrium androgen binding affinity and increased dissociation rates of [3H]methyltrienolone and required increased dihydrotestosterone concentrations for transcriptional activation. In a 2-hybrid protein interaction assay in mammalian cells, the steroid binding domain interacts with an NH2-terminal-DNA binding domain fragment and with the full-length androgen receptor at physiological androgen concentrations in a dose-dependent manner. However, mutations at Val-889 and Arg-752 disrupt the NH2-/carboxyl-terminal interaction when introduced into the steroid binding domain fragment but not when present in the full-length androgen receptor. The N-C bimolecular interaction reduces the dissociation rate of bound androgen and slows the degradation rate of the carboxyl-terminal steroid binding domain fragment. The results suggest that steroid binding domain residues Val-889 and Arg-752 are critical to the NH2-/carboxyl-terminal interaction and that an intermolecular N-C interaction occurs during receptor dimerization that results in an antiparallel arrangement of androgen receptor monomers.
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Affiliation(s)
- E Langley
- Laboratories for Reproductive Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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Delbridge TR, Bailey B, Chew JL, Conn AK, Krakeel JJ, Manz D, Miller DR, O'Malley PJ, Ryan SD, Spaite DW, Stewart RD, Suter RE, Wilson EM. EMS Agenda for the Future: where we are...where we want to be. PREHOSP EMERG CARE 1998; 2:1-12. [PMID: 9737400 DOI: 10.1080/10903129808958832] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the EMS Agenda for the Future. Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are integration of health services, EMS research, legislation and regulation, system finance, human resources, medical direction, education systems, public education, prevention, public access, communication systems, clinical care, information systems, and evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care.
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Affiliation(s)
- T R Delbridge
- Department of Emergency Medicine, University of Pittsburgh, PA 15213, USA. delbridg+@pitt.edu
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Abstract
The insulin-like growth factors (IGFs) are transported by a family of high-affinity binding proteins (IGFBPs) that protect IGFs from degradation, limit their binding to IGF receptors, and modulate IGF actions. The six classical IGFBPs have been believed to have no affinity for insulin. We now demonstrate that IGFBP-7/mac25, a newly identified member of the IGFBP superfamily that binds IGFs specifically with low affinity is a high-affinity insulin binding protein. IGFBP-7 blocks insulin binding to the insulin receptor and thereby inhibiting the earliest steps in insulin action, such as autophosphorylation of the insulin receptor beta subunit and phosphorylation of IRS-1, indicating that IGFBP-7 is a functional insulin-binding protein. The affinity of other IGFBPs for insulin can be enhanced by modifications that disrupt disulfide bonds or remove the conserved COOH terminus. Like IGFBP-7, an NH2-terminal fragment of IGFBP-3 (IGFBP-3((1-87))), also binds insulin with high affinity and blocks insulin action. IGFBPs with enhanced affinity for insulin might contribute to the insulin resistance of pregnancy, type II diabetes mellitus, and other pathological conditions.
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Affiliation(s)
- Y Yamanaka
- Department of Pediatrics, School of Medicine, Oregon Health Sciences University, Portland, Oregon 97201, USA
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Heckert LL, Wilson EM, Nilson JH. Transcriptional repression of the alpha-subunit gene by androgen receptor occurs independently of DNA binding but requires the DNA-binding and ligand-binding domains of the receptor. Mol Endocrinol 1997; 11:1497-506. [PMID: 9280065 PMCID: PMC1502414 DOI: 10.1210/mend.11.10.9996] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [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: 02/05/2023] Open
Abstract
The pituitary glycoprotein hormones LH and FSH regulate the reproductive cycle and are sensitive to feedback by gonadal steroids. The common alpha-subunit shared by these hormones is transcriptionally repressed by androgen receptor (AR) in the presence of its ligand dihydrotestosterone. This identifies at least one mechanism that contributes to AR-dependent suppression of gonadotropin synthesis. Repression of alpha-subunit transcription by AR requires only the sequences within the first 480 bp of the promoter. While this region contains a high-affinity binding site for AR, this element does not mediate the suppressive effects of androgens. Instead, two other elements within the promoter-regulatory region (alpha-basal element and cAMP-regulatory element), which are important for expression of the alpha-subunit gene in gonadotropes, mediate the effects of AR. This suggests that AR inhibits activity of the alpha-subunit promoter by interfering with the transcriptional properties of the proteins that bind to alpha-basal element and the cAMP-regulatory elements. Furthermore, transfection analysis of various mutant ARs identified both the DNA-binding and ligand-binding domains of the receptor as critical for repression. Comparisons with the MMTV promoter revealed distinct structural requirements that underlie the transactivation and transrepression properties of AR.
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Affiliation(s)
- L L Heckert
- Department of Molecular and Integrative Physiology, The University of Kansas Medical Center, Kansas City 66160, USA
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