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Seufert J, Krishnan N, Darmstadt GL, Wang G, Bärnighausen T, Geldsetzer P. Subnational estimates of vitamin A supplementation coverage in children: a geospatial analysis of 45 low- and middle-income countries. Public Health 2024; 228:194-199. [PMID: 38394746 DOI: 10.1016/j.puhe.2024.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/03/2024] [Accepted: 01/19/2024] [Indexed: 02/25/2024]
Abstract
OBJECTIVES Vitamin A supplementation (VAS) can protect children from the adverse health consequences of vitamin A deficiency. Granular data on VAS coverage can guide global and national efforts to achieve universal VAS coverage. To provide geographically precise targeting of VAS programs and to monitor progress in reducing geographic disparities, we aimed to create high-resolution (5 × 5 km2) maps of VAS coverage in children under 5 years across VAS priority countries. STUDY DESIGN We used cross-sectional data from the Demographic and Health Surveys (DHS) program. METHODS We used data from the DHS program for United Nations Children's Fund -designated VAS priority countries between 2000 and 2017 with data available from 2005 or later. The outcome variable was the proportion of children under 5 years who received a vitamin A dose in each sampled cluster. We applied a Bayesian geostatistical approach incorporating geographic, climatic, and nutritional covariates to estimate VAS coverage for each cell. We estimated and mapped absolute VAS coverage, Bayesian uncertainty intervals, and exceedance probabilities. RESULTS Our sample included countries from Latin America and the Caribbean, Asia, and Africa. Most countries had estimated VAS coverage levels <70%, and our exceedance probabilities indicated high certainty that our estimates fell below this threshold in most grid cells. International variations were most notable in the Latin America and the Caribbean region and Africa. Intranational variations were greatest in some South Asian and West and Central African countries. CONCLUSIONS These prevalence and exceedance maps, especially used with data on indicators of VAS need, could help to improve equity.
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Affiliation(s)
- J Seufert
- Department of Economics and Business, KU Leuven, Leuven, Belgium.
| | - N Krishnan
- Division of Primary Care and Population Health, Department of Medicine, Stanford University, Stanford, CA, USA
| | - G L Darmstadt
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - G Wang
- Department of Biology, Stanford University, Stanford, CA, USA
| | - T Bärnighausen
- Heidelberg Institute of Global Health, Medical Faculty, Heidelberg University, Heidelberg, Germany; Africa Research Institute, Durban, South Africa; Harvard Center for Population and Development Studies, Harvard University, Cambridge, MA, USA
| | - P Geldsetzer
- Division of Primary Care and Population Health, Department of Medicine, Stanford University, Stanford, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA
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2
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Baumgartner CK, Ebrahimi-Nik H, Iracheta-Vellve A, Hamel KM, Olander KE, Davis TGR, McGuire KA, Halvorsen GT, Avila OI, Patel CH, Kim SY, Kammula AV, Muscato AJ, Halliwill K, Geda P, Klinge KL, Xiong Z, Duggan R, Mu L, Yeary MD, Patti JC, Balon TM, Mathew R, Backus C, Kennedy DE, Chen A, Longenecker K, Klahn JT, Hrusch CL, Krishnan N, Hutchins CW, Dunning JP, Bulic M, Tiwari P, Colvin KJ, Chuong CL, Kohnle IC, Rees MG, Boghossian A, Ronan M, Roth JA, Wu MJ, Suermondt JSMT, Knudsen NH, Cheruiyot CK, Sen DR, Griffin GK, Golub TR, El-Bardeesy N, Decker JH, Yang Y, Guffroy M, Fossey S, Trusk P, Sun IM, Liu Y, Qiu W, Sun Q, Paddock MN, Farney EP, Matulenko MA, Beauregard C, Frost JM, Yates KB, Kym PR, Manguso RT. The PTPN2/PTPN1 inhibitor ABBV-CLS-484 unleashes potent anti-tumour immunity. Nature 2023; 622:850-862. [PMID: 37794185 PMCID: PMC10599993 DOI: 10.1038/s41586-023-06575-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [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: 07/15/2022] [Accepted: 08/28/2023] [Indexed: 10/06/2023]
Abstract
Immune checkpoint blockade is effective for some patients with cancer, but most are refractory to current immunotherapies and new approaches are needed to overcome resistance1,2. The protein tyrosine phosphatases PTPN2 and PTPN1 are central regulators of inflammation, and their genetic deletion in either tumour cells or immune cells promotes anti-tumour immunity3-6. However, phosphatases are challenging drug targets; in particular, the active site has been considered undruggable. Here we present the discovery and characterization of ABBV-CLS-484 (AC484), a first-in-class, orally bioavailable, potent PTPN2 and PTPN1 active-site inhibitor. AC484 treatment in vitro amplifies the response to interferon and promotes the activation and function of several immune cell subsets. In mouse models of cancer resistant to PD-1 blockade, AC484 monotherapy generates potent anti-tumour immunity. We show that AC484 inflames the tumour microenvironment and promotes natural killer cell and CD8+ T cell function by enhancing JAK-STAT signalling and reducing T cell dysfunction. Inhibitors of PTPN2 and PTPN1 offer a promising new strategy for cancer immunotherapy and are currently being evaluated in patients with advanced solid tumours (ClinicalTrials.gov identifier NCT04777994 ). More broadly, our study shows that small-molecule inhibitors of key intracellular immune regulators can achieve efficacy comparable to or exceeding that of antibody-based immune checkpoint blockade in preclinical models. Finally, to our knowledge, AC484 represents the first active-site phosphatase inhibitor to enter clinical evaluation for cancer immunotherapy and may pave the way for additional therapeutics that target this important class of enzymes.
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Affiliation(s)
| | - Hakimeh Ebrahimi-Nik
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
- Ohio State University Comprehensive Cancer Center and Pelotonia Institute for Immuno-Oncology, Columbus, OH, USA
| | - Arvin Iracheta-Vellve
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
- Pfizer, Groton, CT, USA
| | | | - Kira E Olander
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Thomas G R Davis
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | | | - Omar I Avila
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | - Sarah Y Kim
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Ashwin V Kammula
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Audrey J Muscato
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | - Prasanthi Geda
- AbbVie, North Chicago, IL, USA
- Bristol Myers Squibb, Summit, NJ, USA
| | | | - Zhaoming Xiong
- AbbVie, North Chicago, IL, USA
- Ipsen Biosciences, Cambridge, MA, USA
| | | | | | - Mitchell D Yeary
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - James C Patti
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Tyler M Balon
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | | | | | | | | | | | | | - Navasona Krishnan
- AbbVie, North Chicago, IL, USA
- Monte Rosa Therapeutics, Boston, MA, USA
| | | | | | | | - Payal Tiwari
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
- Dana-Farber Cancer Institute, Boston, MA, USA
| | - Kayla J Colvin
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Cun Lan Chuong
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Ian C Kohnle
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | | | - Melissa Ronan
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | | | - Meng-Ju Wu
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Juliette S M T Suermondt
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Nelson H Knudsen
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Collins K Cheruiyot
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Debattama R Sen
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Gabriel K Griffin
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Dana-Farber Cancer Institute, Boston, MA, USA
| | - Todd R Golub
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Dana-Farber Cancer Institute, Boston, MA, USA
| | - Nabeel El-Bardeesy
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | - Yi Yang
- AbbVie, North Chicago, IL, USA
| | | | | | | | - Im-Meng Sun
- Calico Life Sciences, South San Francisco, CA, USA
| | - Yue Liu
- Calico Life Sciences, South San Francisco, CA, USA
| | - Wei Qiu
- AbbVie, North Chicago, IL, USA
| | - Qi Sun
- AbbVie, North Chicago, IL, USA
| | | | | | | | - Clay Beauregard
- Calico Life Sciences, South San Francisco, CA, USA
- Vir Biotechnology, San Francisco, CA, USA
| | | | - Kathleen B Yates
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA.
| | | | - Robert T Manguso
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Center for Cancer Research and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA.
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3
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Krishnan N, Siddiqi K, Dogar O, Gabe R, Keding A. Predictors of long-term smoking abstinence in TB patients. Int J Tuberc Lung Dis 2022; 26:1074-1076. [DOI: 10.5588/ijtld.22.0236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- N. Krishnan
- Department of Prevention and Community Health, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA
| | - K. Siddiqi
- Department of Health Sciences, University of York, York, USA, Hull York Medical School, York, USA
| | - O. Dogar
- Department of Health Sciences, University of York, York, USA, Usher Institute, University of Edinburgh, Edinburgh, Scotland
| | - R. Gabe
- Centre for Evaluation and Methods, Wolfson Institute of Population Health, Queen Mary University of London, London, UK
| | - A. Keding
- Department of Health Sciences, University of York, York, USA
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4
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Goedken ER, Argiriadi MA, Dietrich JD, Petros AM, Krishnan N, Panchal SC, Qiu W, Wu H, Zhu H, Adams AM, Bodelle PM, Goguen L, Richardson PL, Slivka PF, Srikumaran M, Upadhyay AK, Wu B, Judge RA, Vasudevan A, Gopalakrishnan SM, Cox PB, Stoll VS, Sun C. Identification and structure-based drug design of cell-active inhibitors of interleukin 17A at a novel C-terminal site. Sci Rep 2022; 12:14561. [PMID: 36028520 PMCID: PMC9418147 DOI: 10.1038/s41598-022-18760-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 08/18/2022] [Indexed: 11/30/2022] Open
Abstract
Anti-IL17A therapies have proven effective for numerous inflammatory diseases including psoriasis, axial spondylitis and psoriatic arthritis. Modulating and/or antagonizing protein–protein interactions of IL17A cytokine binding to its cell surface receptors with oral therapies offers the promise to bring forward biologics-like efficacy in a pill to patients. We used an NMR-based fragment screen of recombinant IL17A to uncover starting points for small molecule IL17A antagonist discovery. By examining chemical shift perturbations in 2D [1H, 13C-HSQC] spectra of isotopically labeled IL17A, we discovered fragments binding the cytokine at a previously undescribed site near the IL17A C-terminal region, albeit with weak affinity (> 250 µM). Importantly this binding location was distinct from previously known chemical matter modulating cytokine responses. Subsequently through analog screening, we identified related compounds that bound symmetrically in this novel site with two copies. From this observation we employed a linking strategy via structure-based drug design and obtained compounds with increased binding affinity (< 50 nM) and showed functional inhibition of IL17A-induced cellular signaling (IC50~1 µM). We also describe a fluorescence-based probe molecule suitable to discern/screen for additional molecules binding in this C-terminal site.
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Affiliation(s)
- Eric R Goedken
- AbbVie Bioresearch Center, 100 Research Drive, Worcester, MA, 01605, USA.
| | - Maria A Argiriadi
- AbbVie Bioresearch Center, 100 Research Drive, Worcester, MA, 01605, USA
| | | | - Andrew M Petros
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Navasona Krishnan
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA.,Former AbbVie Employee, North Chicago, USA
| | - Sanjay C Panchal
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Wei Qiu
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Haihong Wu
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Haizhong Zhu
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Ashley M Adams
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA.,Former AbbVie Employee, North Chicago, USA
| | - Pierre M Bodelle
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Lucas Goguen
- AbbVie Bioresearch Center, 100 Research Drive, Worcester, MA, 01605, USA.,Former AbbVie Employee, North Chicago, USA
| | | | - Peter F Slivka
- AbbVie Bioresearch Center, 100 Research Drive, Worcester, MA, 01605, USA.,Former AbbVie Employee, North Chicago, USA
| | - Myron Srikumaran
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Anup K Upadhyay
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Bainan Wu
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA.,Former AbbVie Employee, North Chicago, USA
| | - Russell A Judge
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Anil Vasudevan
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | | | - Philip B Cox
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Vincent S Stoll
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
| | - Chaohong Sun
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL, 60064, USA
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5
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Butters A, Do J, Stafford F, Krishnan N, Brown J, Hespe S, Richardson E, Bagnall R, Bhaskaran A, Burns C, Driscoll T, Fatkin D, Gray B, Iglesias C, Isbister J, Jabbour A, Johnson R, Kumar S, Leslie F, MacArthur D, Nowak N, Pouliopoulos J, Puranik R, Semsarian C, Sweeting J, Sy R, Ugander M, Yeates L, Ingles J. NSW HEARTS: The NSW Inherited Cardiomyopathy Cohort Study protocol. Heart Lung Circ 2022. [DOI: 10.1016/j.hlc.2022.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Richardson E, Krishnan N, Stafford F, Yeates L, Nowak N, McGaughran J, Wildschutt J, Smith J, Turner C, Kevin L, Davis A, Macciocca I, Connell V, Ma A, Semsarian C, Bagnall R, Siggs O, Skinner J, MacArthur D, Ingles J. The Elusive Hearts Study: Seeking Genetic Diagnoses in Gene-elusive Cases of Rare Monogenic Cardiovascular Diseases. Heart Lung Circ 2022. [DOI: 10.1016/j.hlc.2022.04.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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Catchot BD, Musser FR, Gore J, Krishnan N, Cook DR, Stewart SD, Lorenz GM, Brown S, Seiter N, Catchot AL, Kerns DL, Jackson R, Knighten KS. Sublethal Impacts of Novaluron on Tarnished Plant Bug (Hemiptera: Miridae) Adults. J Econ Entomol 2021; 114:739-746. [PMID: 33576417 DOI: 10.1093/jee/toab007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Indexed: 06/12/2023]
Abstract
Tarnished plant bug, Lygus lineolaris Palisot de Beauvois (Hemiptera: Miridae), has become a primary pest of cotton in the Midsouthern United States. Insect growth regulators such as novaluron are an important part of L. lineolaris management. While novaluron is lethal to nymphs, it does not kill adults, so it has been used when nymphs are the primary stage present. However, cotton yield protection was observed from an application of novaluron when adults were the predominant stage present. To explain this, a series of studies were conducted to examine sublethal impacts of novaluron to L. lineolaris adults. Novaluron ingestion by adults reduced hatch rate and sometimes reduced oviposition rate. Ingestion by either males or females reduced hatch rates, but the reduction was greater from female exposure. Contact exposure of adults with novaluron residues within 1 d of application reduced hatch rate by about 50%, but the impact on oviposition was inconsistent. A field study showed reduced hatch rate from contact exposure to mixed-age natural populations, but the overall net reproductive rate was not reduced. Surface exposure of eggs to novaluron did not reduce hatch rate. Overall, exposure of tarnished plant bug adults to novaluron, regardless of adult age or exposure route, reduced egg viability. However, the impact on oviposition rate and net reproductive rate varied with adult age and exposure route. This understanding of sublethal impacts of novaluron, in addition to lethal impacts on nymphs, should be considered when choosing application times to maximize effects on L. lineolaris populations.
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Affiliation(s)
- Beverly D Catchot
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
| | - F R Musser
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
| | - J Gore
- Delta Research and Extension Center, Mississippi State University, Stoneville, MS, USA
| | - N Krishnan
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
| | - D R Cook
- Delta Research and Extension Center, Mississippi State University, Stoneville, MS, USA
| | - S D Stewart
- Department of Entomology, Plant Pathology, and Nematology, The University of Tennessee, Jackson, TN, USA
| | - G M Lorenz
- Department of Entomology, University of Arkansas, Lonoke, AR, USA
| | - S Brown
- LSU AgCenter, Macon Ridge Research Station, Winnsboro, LA, USA
| | - N Seiter
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - A L Catchot
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
| | - D L Kerns
- Department of Entomology, Texas A&M University, Texas A&M AgriLife Extension Service, College Station, TX, USA
| | - R Jackson
- Syngenta, Biological Research & Development, Carrolton, MS, USA
| | - K S Knighten
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
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8
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McGuire S, Horton EJ, Renshaw D, Chan K, Krishnan N, McGregor G. Cardiopulmonary and metabolic physiology during hemodialysis and inter/intradialytic exercise. J Appl Physiol (1985) 2021; 130:1033-1042. [PMID: 33507853 DOI: 10.1152/japplphysiol.00888.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hemodialysis is associated with numerous symptoms and side effects that, in part, may be due to subclinical hypoxia. However, acute cardiopulmonary and metabolic physiology during hemodialysis is not well defined. Intradialytic and interdialytic exercise appear to be beneficial and may alleviate these side effects. To better understand these potential benefits, the acute physiological response to exercise should be evaluated. The aim of this study was to compare and characterize the acute physiological response during hemodialysis, intradialytic exercise, and interdialytic exercise. Cardiopulmonary physiology was evaluated during three conditions: 1) hemodialysis without exercise (HD), 2) intradialytic exercise (IDEx), and 3) interdialytic exercise (Ex). Exercise consisted of 30-min constant load cycle ergometry at 90% V̇O2AT (anaerobic threshold). Central hemodynamics (via noninvasive bioreactance) and ventilatory gas exchange were recorded during each experimental condition. Twenty participants (59 ± 12 yr, 16/20 male) completed the protocol. Cardiac output (Δ = -0.7 L/min), O2 uptake (Δ = -1.4 mL/kg/min), and arterial-venous O2 difference (Δ = -2.0 mL/O2/100 mL) decreased significantly during HD. Respiratory exchange ratio exceeded 1.0 throughout HD and IDEx. Minute ventilation was lower (P = 0.001) during IDEx (16.5 ± 1.1 L/min) compared with Ex (19.8 ± 1.0 L/min). Arterial-venous O2 difference was partially restored further to IDEx (4.6 ± 1.9 mL/O2/100 mL) compared with HD (3.5 ± 1.2 mL/O2/100 mL). Hemodialysis altered cardiopulmonary and metabolic physiology, suggestive of hypoxia. This dysregulated physiology contributed to a greater physiological demand during intradialytic exercise compared with interdialytic exercise. Despite this, intradialytic exercise partly normalized cardiopulmonary physiology during treatment, which may translate to a reduction in the symptoms and side effects of hemodialysis.NEW & NOTEWORTHY This study is the first, to our knowledge, to directly compare cardiopulmonary and metabolic physiology during hemodialysis, intradialytic exercise, and interdialytic exercise. Hemodialysis was associated with increased respiratory exchange ratio, blunted minute ventilation, and impaired O2 uptake and extraction. We also identified a reduced ventilatory response during intradialytic exercise compared with interdialytic exercise. Impaired arterial-venous O2 difference during hemodialysis was partly restored by intradialytic exercise. Despite dysregulated cardiopulmonary and metabolic physiology during hemodialysis, intradialytic exercise was well tolerated.
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Affiliation(s)
- S McGuire
- Faculty of Health and Life Sciences, Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, United Kingdom
| | - E J Horton
- Faculty of Health and Life Sciences, Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, United Kingdom
| | - D Renshaw
- Faculty of Health and Life Sciences, Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, United Kingdom
| | - K Chan
- Faculty of Health and Life Sciences, Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, United Kingdom
| | - N Krishnan
- Faculty of Health and Life Sciences, Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, United Kingdom.,Department of Nephrology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - G McGregor
- Faculty of Health and Life Sciences, Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, United Kingdom.,Department of Nephrology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom.,Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, United Kingdom
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9
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Krishnan N, Chen X, Donnelly-Roberts D, Mohler EG, Holtzman DM, Gopalakrishnan SM. Small Molecule Phenotypic Screen Identifies Novel Regulators of LDLR Expression. ACS Chem Biol 2020; 15:3262-3274. [PMID: 33270420 DOI: 10.1021/acschembio.0c00851] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alzheimer's Disease (AD) is a progressive neurodegenerative disease and the most common cause of dementia. The current treatment options for AD are limited to ameliorating cognitive decline temporarily and not reversing or preventing the progression of dementia. Hence, more effective therapeutic strategies are needed to combat this devastating disease. The low-density lipoprotein receptor has been shown to modulate the neuronal metabolism of cholesterol and apolipoprotein E, a major genetic risk factor for AD. LDLR overexpression in mice has been shown to increase amyloid-β clearance and reduce amyloid deposition. We conducted a phenotypic screen to identify novel signaling pathways and targets that regulate LDLR expression in glial cells using an annotated compound library of approximately 29 000 compounds. The screen identified novel targets such as polo like kinase 1 (PLK1), activin receptor like kinase 5 (ALK5), and serotonin transporter (SERT). We used genetic, chemical biology and pathway analysis to confirm the target hypothesis. This work highlights that phenotypic screening is a promising strategy to identify novel mechanisms and targets for therapeutic intervention of complex neurodegenerative disorders.
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Affiliation(s)
- Navasona Krishnan
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Xiaoying Chen
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Hope Center for Neurological Disorders, Washington University, St. Louis, Missouri 63110, United States
| | | | - Eric G. Mohler
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - David M. Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Hope Center for Neurological Disorders, Washington University, St. Louis, Missouri 63110, United States
- Charles F. and Joanne Knight Alzheimer’s Disease Research Center, Washington University, St. Louis, Missouri 63110, United States
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10
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McGuire S, Horton EJ, Renshaw D, Chan K, Krishnan N, McGregor G. Ventilatory and chronotropic incompetence during incremental and constant load exercise in end-stage renal disease: a comparative physiology study. Am J Physiol Renal Physiol 2020; 319:F515-F522. [PMID: 32744086 DOI: 10.1152/ajprenal.00258.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Maximal O2 uptake is impaired in end-stage renal disease (ESRD), reducing quality of life and longevity. While determinants of maximal exercise intolerance are well defined, little is known of limitation during submaximal constant load exercise. By comparing individuals with ESRD and healthy controls, the aim of this exploratory study was to characterize mechanisms of exercise intolerance in participants with ESRD by assessing cardiopulmonary physiology at rest and during exercise. Resting spirometry and echocardiography were performed in 20 dialysis-dependent participants with ESRD (age: 59 ± 12 yr, 14 men and 6 women) and 20 healthy age- and sex-matched controls. Exercise tolerance was assessed with ventilatory gas exchange and central hemodynamics during a maximal cardiopulmonary exercise test and 30 min of submaximal constant load exercise. Left ventricular mass (292 ± 102 vs. 185 ± 83 g, P = 0.01) and filling pressure (E/e': 6.48 ± 3.57 vs. 12.09 ± 6.50 m/s, P = 0.02) were higher in participants with ESRD; forced vital capacity (3.44 ± 1 vs. 4.29 ± 0.95 L/min, P = 0.03) and peak O2 uptake (13.3 ± 2.7 vs. 24.6 ± 7.3 mL·kg-1·min-1, P < 0.001) were lower. During constant load exercise, the relative increase in the arterial-venous O2 difference (13 ± 18% vs. 74 ± 18%) and heart rate (32 ± 18 vs. 75 ± 29%) were less in participants with ESRD despite exercise being performed at a higher percentage of maximum minute ventilation (48 ± 3% vs. 39 ± 3%) and heart rate (82 ± 2 vs. 64 ± 2%). Ventilatory and chronotropic incompetence contribute to exercise intolerance in individuals with ESRD. Both are potential targets for medical and lifestyle interventions.
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Affiliation(s)
- S McGuire
- Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom
| | - E J Horton
- Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom
| | - D Renshaw
- Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom
| | - K Chan
- Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom
| | - N Krishnan
- Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom.,Department of Nephrology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - G McGregor
- Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom.,Department of Nephrology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom.,Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, United Kingdom
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11
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Rathbun LI, Colicino EG, Manikas J, O'Connell J, Krishnan N, Reilly NS, Coyne S, Erdemci-Tandogan G, Garrastegui A, Freshour J, Santra P, Manning ML, Amack JD, Hehnly H. Cytokinetic bridge triggers de novo lumen formation in vivo. Nat Commun 2020; 11:1269. [PMID: 32152267 PMCID: PMC7062744 DOI: 10.1038/s41467-020-15002-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 02/14/2020] [Indexed: 02/03/2023] Open
Abstract
Multicellular rosettes are transient epithelial structures that serve as intermediates during diverse organ formation. We have identified a unique contributor to rosette formation in zebrafish Kupffer's vesicle (KV) that requires cell division, specifically the final stage of mitosis termed abscission. KV utilizes a rosette as a prerequisite before forming a lumen surrounded by ciliated epithelial cells. Our studies identify that KV-destined cells remain interconnected by cytokinetic bridges that position at the rosette's center. These bridges act as a landmark for directed Rab11 vesicle motility to deliver an essential cargo for lumen formation, CFTR (cystic fibrosis transmembrane conductance regulator). Here we report that premature bridge cleavage through laser ablation or inhibiting abscission using optogenetic clustering of Rab11 result in disrupted lumen formation. We present a model in which KV mitotic cells strategically place their cytokinetic bridges at the rosette center, where Rab11-associated vesicles transport CFTR to aid in lumen establishment.
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Affiliation(s)
- L I Rathbun
- Biology Department, Syracuse University, Syracuse, New York, USA
| | - E G Colicino
- Biology Department, Syracuse University, Syracuse, New York, USA
- Department of Cell and Developmental Biology, SUNY Upstate Medical School, Syracuse, New York, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - J Manikas
- Biology Department, Syracuse University, Syracuse, New York, USA
| | - J O'Connell
- Biology Department, Syracuse University, Syracuse, New York, USA
| | - N Krishnan
- Biology Department, Syracuse University, Syracuse, New York, USA
| | - N S Reilly
- Department of Physics and Astronomy, University of Rochester, Rochester, New York, USA
| | - S Coyne
- Department of Cell and Developmental Biology, SUNY Upstate Medical School, Syracuse, New York, USA
- Department of Biology, SUNY Geneseo, Geneseo, New York, USA
| | | | - A Garrastegui
- Biology Department, Syracuse University, Syracuse, New York, USA
| | - J Freshour
- Biology Department, Syracuse University, Syracuse, New York, USA
| | - P Santra
- Department of Cell and Developmental Biology, SUNY Upstate Medical School, Syracuse, New York, USA
| | - M L Manning
- Department of Physics, Syracuse University, Syracuse, New York, USA
| | - J D Amack
- Department of Cell and Developmental Biology, SUNY Upstate Medical School, Syracuse, New York, USA
| | - H Hehnly
- Biology Department, Syracuse University, Syracuse, New York, USA.
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12
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Abroms LC, Heminger CL, Boal AL, Van Alstyne JM, Krishnan N. Text2Quit: An analysis of user experiences with a mobile smoking cessation program. J Smok Cessat 2020; 15:23-28. [PMID: 33777241 PMCID: PMC7994940 DOI: 10.1017/jsc.2019.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
INTRODUCTION Studies have shown that Text2Quit and other mobile cessation programs increase quit rates in adult smokers, but the mechanism of effects and user experiences are not well understood. AIMS This study reports on participants' experiences with the program and explores aspects of the program that they liked and disliked. METHODS Self-reported experiences of the program were collected through a follow-up survey conducted one month after enrollment (n=185). Participant responses to open-ended items were dual coded by independent coders. RESULTS Overall participants agreed that they liked the program (4.2/5), that the program was helpful (4.1/5) and that they would recommend the program to a friend (4.3/5). Top reasons for liking the program included that it served as a constant reminder of quitting (17.8%), the content (16.7%), the encouragement provided (13.3%), and the on-demand tools (12.2%). Top reasons for disliking the program were message frequency (20.5%), content (7.0%), and the lack of personal interaction (7.0%). CONCLUSIONS The constancy of messaging was both liked as a reminder and disliked as an annoyance. Future programs might be improved by pre-testing and customizing the content based on user preferences, and by adding in human interactions, while keeping a supportive tone and offering on-demand tools.
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Affiliation(s)
- L C Abroms
- The George Washington University, Milken Institute School of Public Health, Department of Prevention & Community Health, 950 New Hampshire Avenue NW, 3 Floor, Washington, DC 20052
| | - C L Heminger
- The George Washington University, Milken Institute School of Public Health, Department of Prevention & Community Health, 950 New Hampshire Avenue NW, 3 Floor, Washington, DC 20052
| | - A L Boal
- WestEd, 4665 Lampson Avenue, Los Alamitos, CA 90720
| | | | - N Krishnan
- The George Washington University, Milken Institute School of Public Health, Department of Prevention & Community Health, 950 New Hampshire Avenue NW, 3 Floor, Washington, DC 20052
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13
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Strober BJ, Elorbany R, Rhodes K, Krishnan N, Tayeb K, Battle A, Gilad Y. Dynamic genetic regulation of gene expression during cellular differentiation. Science 2019; 364:1287-1290. [PMID: 31249060 PMCID: PMC6623972 DOI: 10.1126/science.aaw0040] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [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] [Received: 11/08/2018] [Accepted: 06/04/2019] [Indexed: 12/12/2022]
Abstract
Genetic regulation of gene expression is dynamic, as transcription can change during cell differentiation and across cell types. We mapped expression quantitative trait loci (eQTLs) throughout differentiation to elucidate the dynamics of genetic effects on cell type-specific gene expression. We generated time-series RNA sequencing data, capturing 16 time points during the differentiation of induced pluripotent stem cells to cardiomyocytes, in 19 human cell lines. We identified hundreds of dynamic eQTLs that change over time, with enrichment in enhancers of relevant cell types. We also found nonlinear dynamic eQTLs, which affect only intermediate stages of differentiation and cannot be found by using data from mature tissues. These fleeting genetic associations with gene regulation may explain some of the components of complex traits and disease. We highlight one example of a nonlinear eQTL that is associated with body mass index.
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Affiliation(s)
- B J Strober
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - R Elorbany
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL 60637, USA
- Interdisciplinary Scientist Training Program, University of Chicago, Chicago, IL 60637, USA
| | - K Rhodes
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - N Krishnan
- Department of Computer Science, Johns Hopkins University, Baltimore, MD 21218, USA
| | - K Tayeb
- Department of Applied Mathematics and Statistics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - A Battle
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
- Department of Computer Science, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Y Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA.
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
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14
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Krishnan N, Felice C, Rivera K, Pappin DJ, Tonks NK. DPM-1001 decreased copper levels and ameliorated deficits in a mouse model of Wilson's disease. Genes Dev 2018; 32:944-952. [PMID: 29945887 PMCID: PMC6075031 DOI: 10.1101/gad.314658.118] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/14/2018] [Indexed: 12/13/2022]
Abstract
In this study, Krishnan et al. present the characterization of DPM-1001 as a potent and highly selective chelator of copper that is orally bioavailable. Treatment of the toxic milk mouse model of Wilson's disease with DPM-1001 lowered the levels of copper in the liver and brain, removing excess copper by excretion in the feces while ameliorating symptoms associated with the disease, suggesting that DPM-1001 should be investigated further as a new therapeutic agent for the treatment of Wilson's disease. The levels of copper, which is an essential element in living organisms, are under tight homeostatic control. Inactivating mutations in ATP7B, a P-type Cu-ATPase that functions in copper excretion, promote aberrant accumulation of the metal, primarily the in liver and brain. This condition underlies Wilson's disease, a severe autosomal recessive disorder characterized by profound hepatic and neurological deficits. Current treatment regimens rely on the use of broad specificity metal chelators as “decoppering” agents; however, there are side effects that limit their effectiveness. Here, we present the characterization of DPM-1001 {methyl 4-[7-hydroxy-10,13-dimethyl-3-({4-[(pyridin-2-ylmethyl)amino]butyl}amino)hexadecahydro-1H-cyclopenta[a]phenanthren-17-yl] pentanoate} as a potent and highly selective chelator of copper that is orally bioavailable. Treatment of cell models, including fibroblasts derived from Wilson's disease patients, eliminated adverse effects associated with copper accumulation. Furthermore, treatment of the toxic milk mouse model of Wilson's disease with DPM-1001 lowered the levels of copper in the liver and brain, removing excess copper by excretion in the feces while ameliorating symptoms associated with the disease. These data suggest that it may be worthwhile to investigate DPM-1001 further as a new therapeutic agent for the treatment of Wilson's disease, with potential for application in other indications associated with elevated copper, including cancer and neurodegenerative diseases.
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Affiliation(s)
- Navasona Krishnan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Christy Felice
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Keith Rivera
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Darryl J Pappin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Nicholas K Tonks
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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15
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Krishnan N, Bonham CA, Rus IA, Shrestha OK, Gauss CM, Haque A, Tocilj A, Joshua-Tor L, Tonks NK. Harnessing insulin- and leptin-induced oxidation of PTP1B for therapeutic development. Nat Commun 2018; 9:283. [PMID: 29348454 PMCID: PMC5773487 DOI: 10.1038/s41467-017-02252-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 11/15/2017] [Indexed: 12/22/2022] Open
Abstract
The protein tyrosine phosphatase PTP1B is a major regulator of glucose homeostasis and energy metabolism, and a validated target for therapeutic intervention in diabetes and obesity. Nevertheless, it is a challenging target for inhibitor development. Previously, we generated a recombinant antibody (scFv45) that recognizes selectively the oxidized, inactive conformation of PTP1B. Here, we provide a molecular basis for its interaction with reversibly oxidized PTP1B. Furthermore, we have identified a small molecule inhibitor that mimics the effects of scFv45. Our data provide proof-of-concept that stabilization of PTP1B in an inactive, oxidized conformation by small molecules can promote insulin and leptin signaling. This work illustrates a novel paradigm for inhibiting the signaling function of PTP1B that may be exploited for therapeutic intervention in diabetes and obesity. The activity of protein tyrosine phosphatase PTP1B, a major metabolic regulator, depends on its oxidation state. Here the authors identify and characterize a small molecule that targets the oxidized, inactive form of PTP1B, suggesting a new therapeutic approach to diabetes and obesity.
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Affiliation(s)
- Navasona Krishnan
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - Christopher A Bonham
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - Ioana A Rus
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA.,Graduate Program in Genetics and Medical Scientist Training Program, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, USA
| | - Om Kumar Shrestha
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - Carla M Gauss
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - Aftabul Haque
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - Ante Tocilj
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA.,W. M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA.,Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - Leemor Joshua-Tor
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA.,W. M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA.,Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - Nicholas K Tonks
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA.
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16
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Krishnan N, Konidaris KF, Gasser G, Tonks NK. A potent, selective, and orally bioavailable inhibitor of the protein-tyrosine phosphatase PTP1B improves insulin and leptin signaling in animal models. J Biol Chem 2017; 293:1517-1525. [PMID: 29217773 DOI: 10.1074/jbc.c117.819110] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [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: 09/20/2017] [Revised: 11/30/2017] [Indexed: 12/18/2022] Open
Abstract
The protein-tyrosine phosphatase PTP1B is a negative regulator of insulin and leptin signaling and a highly validated therapeutic target for diabetes and obesity. Conventional approaches to drug development have produced potent and specific PTP1B inhibitors, but these inhibitors lack oral bioavailability, which limits their potential for drug development. Here, we report that DPM-1001, an analog of the specific PTP1B inhibitor trodusquemine (MSI-1436), is a potent, specific, and orally bioavailable inhibitor of PTP1B. DPM-1001 also chelates copper, which enhanced its potency as a PTP1B inhibitor. DPM-1001 displayed anti-diabetic properties that were associated with enhanced signaling through insulin and leptin receptors in animal models of diet-induced obesity. Therefore, DPM-1001 represents a proof of concept for a new approach to therapeutic intervention in diabetes and obesity. Although the PTPs have been considered undruggable, the findings of this study suggest that allosteric PTP inhibitors may help reinvigorate drug development efforts that focus on this important family of signal-transducing enzymes.
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Affiliation(s)
- Navasona Krishnan
- From the Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Konstantis F Konidaris
- the Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland, and
| | - Gilles Gasser
- ChimieParisTech, PSL Research University, Laboratory for Inorganic Chemical Biology, 75005 Paris, France
| | - Nicholas K Tonks
- From the Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724,
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17
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Rogan A, McCarthy K, McGregor G, Hamborg T, Evans G, Hewins S, Aldridge N, Fletcher S, Krishnan N, Higgins R, Zehnder D, Ting SM. Correction: Quality of life measures predict cardiovascular health and physical performance in chronic renal failure patients. PLoS One 2017; 12:e0189382. [PMID: 29206877 PMCID: PMC5716600 DOI: 10.1371/journal.pone.0189382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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18
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Rogan A, McCarthy K, McGregor G, Hamborg T, Evans G, Hewins S, Aldridge N, Fletcher S, Krishnan N, Higgins R, Zehnder D, Ting SM. Quality of life measures predict cardiovascular health and physical performance in chronic renal failure patients. PLoS One 2017; 12:e0183926. [PMID: 28910330 PMCID: PMC5598960 DOI: 10.1371/journal.pone.0183926] [Citation(s) in RCA: 19] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 08/14/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Patients with advanced chronic kidney disease (CKD) experience complex functional and structural changes of the cardiopulmonary and musculoskeletal system. This results in reduced exercise tolerance, quality of life and ultimately premature death. We investigated the relationship between subjective measures of health related quality of life and objective, standardised functional measures for cardiovascular and pulmonary health. METHODS Between April 2010 and January 2013, 143 CKD stage-5 or CKD5d patients (age 46.0±1.1y, 62.2% male), were recruited prospectively. A control group of 83 healthy individuals treated for essential hypertension (HTN; age 53.2±0.9y, 48.22% male) were recruited at random. All patients completed the SF-36 health survey questionnaire, echocardiography, vascular tonometry and cardiopulmonary exercise testing. RESULTS Patients with CKD had significantly lower SF-36 scores than the HTN group; for physical component score (PCS; 45.0 vs 53.9, p<0.001) and mental component score (MCS; 46.9 vs. 54.9, p<0.001). CKD subjects had significantly poorer exercise tolerance and cardiorespiratory performance compared with HTN (maximal oxygen uptake; VO2peak 19.9 vs 25.0ml/kg/min, p<0.001). VO2peak was a significant independent predictor of PCS in both groups (CKD: b = 0.35, p = 0.02 vs HTN: b = 0.27, p = 0.001). No associations were noted between PCS scores and echocardiographic characteristics, vascular elasticity and cardiac biomarkers in either group. No associations were noted between MCS and any variable. The interaction effect of study group with VO2peak on PCS was not significant (ΔB = 0.08; 95%CI -0.28-0.45, p = 0.7). However, overall for a given VO2peak, the measured PCS was much lower for patients with CKD than for HTN cohort, a likely consequence of systemic uremia effects. CONCLUSION In CKD and HTN, objective physical performance has a significant effect on quality of life; particularly self-reported physical health and functioning. Therefore, these quality of life measures are indeed a good reflection of physical health correlating highly with objective physical performance measures.
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Affiliation(s)
- A. Rogan
- Department of Emergency Medicine, Wellington Hospital, Capital and Coast District Health Board, Wellington, New Zealand
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
- * E-mail:
| | - K. McCarthy
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - G. McGregor
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
- Department of Cardiac Rehabilitation and Cardiology, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - T. Hamborg
- Division of Health Sciences Statistics and Epidemiology, University of Warwick, Coventry, United Kingdom
| | - G. Evans
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - S. Hewins
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - N. Aldridge
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - S. Fletcher
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - N. Krishnan
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - R. Higgins
- Department of Renal Medicine and Transplantation, University Hospital Coventry and Warwickshire NHS Trust, Coventry, United Kingdom
| | - D. Zehnder
- Department of Acute Medicine, North Cumbria University Hospital NHS Trust, Carlisle, United Kingdom
- Division of Translational Medicine, University of Warwick, Coventry, United Kingdom
| | - S. M. Ting
- Division of Translational Medicine, University of Warwick, Coventry, United Kingdom
- Department of Acute Medicine, Heart of England NHS Foundation Trust, Birmingham, United Kingdom
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19
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Bronner Murrison L, Ananthakrishnan R, Swaminathan A, Auguesteen S, Krishnan N, Pai M, Dowdy DW. How do patients access the private sector in Chennai, India? An evaluation of delays in tuberculosis diagnosis. Int J Tuberc Lung Dis 2017; 20:544-51. [PMID: 26970166 DOI: 10.5588/ijtld.15.0423] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING The diagnosis and treatment of tuberculosis (TB) in India are characterized by heavy private-sector involvement. Delays in treatment remain poorly characterized among patients seeking care in the Indian private sector. OBJECTIVE To assess delays in TB diagnosis and treatment initiation among patients diagnosed in the private sector, and pathways to care in an urban setting. DESIGN Cross-sectional survey of 289 consecutive patients diagnosed with TB in the private sector and referred for anti-tuberculosis treatment through a public-private mix program in Chennai from January 2014 to February 2015. RESULTS Among 212 patients with pulmonary TB, 90% first contacted a formal private provider, and 78% were diagnosed by the first or second provider seen after a median of three visits per provider. Median total delay was 51 days (mean 68). Consulting an informal (rather than formally trained) provider first was associated with significant increases in total delay (absolute increase 22.8 days, 95%CI 6.2-39.5) and in the risk of prolonged delay >90 days (aRR 2.4, 95%CI 1.3-4.4). CONCLUSION Even among patients seeking care in the formal (vs. informal) private sector in Chennai, diagnostic delays are substantial. Novel strategies are required to engage private providers, who often serve as the first point of contact.
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Affiliation(s)
- L Bronner Murrison
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA; Center for Tuberculosis Research, Johns Hopkins University, Baltimore, Maryland, USA
| | | | | | | | | | - M Pai
- McGill International TB Centre & Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada
| | - D W Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA; Center for Tuberculosis Research, Johns Hopkins University, Baltimore, Maryland, USA
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20
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Adams A, Gore J, Catchot A, Musser F, Cook D, Krishnan N, Irby T. Residual and Systemic Efficacy of Chlorantraniliprole and Flubendiamide Against Corn Earworm (Lepidoptera: Noctuidae) in Soybean. J Econ Entomol 2016; 109:2411-2417. [PMID: 27707947 PMCID: PMC5225962 DOI: 10.1093/jee/tow210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 09/02/2016] [Indexed: 06/06/2023]
Abstract
Experiments were conducted in Mississippi from 2013 to 2015 to determine the systemic and residual efficacy of chlorantraniliprole and flubendiamide against corn earworm, Helicoverpa zea (Boddie), in soybean. Both insecticides were applied at V4 and R3. Ten leaves that were present at the time of application and 10 newly emerged leaves that were not present at the time of application were collected to measure residual and systemic efficacy, respectively. Ten pods were removed from each plot at R5.5. For all assays, corn earworm larvae were placed on plant material. Chlorantraniliprole appeared to provide systemic control of H. zea, but was dependent on soybean growth stage at the time of application. In the V4 experiment, chlorantraniliprole resulted in greater mortality than the control on new leaves at 7 d after treatment, but not at 14 d. In the R3 experiment, chlorantraniliprole resulted in greater than 90% mortality on new leaves at all evaluation intervals. Mortality of H. zea on new leaves was <17% for flubendiamide and was not different than the control. Both insecticides resulted in significant mortality of H. zea on leaves that were present at the time of application for at least 31 d after application. Chlorantraniliprole resulted in greater mortality than flubendiamide at 24 and 31 d. Neither insecticide resulted in mortality of H. zea feeding on reproductive structures. These results suggest that chlorantraniliprole moves to new vegetative structures but not to reproductive structures of soybean, and that flubendiamide does not move systemically.
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Affiliation(s)
- A Adams
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, MS 39762 (; ; ; )
| | - J Gore
- Delta Research and Extension Center (DREC), Mississippi State University, Stoneville, MS 38776 (; )
| | - A Catchot
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, MS 39762 (; ; ; )
| | - F Musser
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, MS 39762 (; ; ; )
| | - D Cook
- Delta Research and Extension Center (DREC), Mississippi State University, Stoneville, MS 38776 (; )
| | - N Krishnan
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, MS 39762 (; ; ; )
| | - T Irby
- Department of Plant and Soil Sciences, Mississippi State University, MS 39762
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Adams A, Gore J, Catchot A, Musser F, Cook D, Krishnan N, Irby T. Susceptibility of Helicoverpa zea (Lepidoptera: Noctuidae) Neonates to Diamide Insecticides in the Midsouthern and Southeastern United States. J Econ Entomol 2016; 109:2205-9. [PMID: 27524821 PMCID: PMC5066475 DOI: 10.1093/jee/tow175] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 07/15/2016] [Indexed: 05/10/2023]
Abstract
Corn earworm, Helicoverpa zea (Boddie), is a significant pest of agroecosystems in the midsouthern and southeastern regions of the United States. These insects have developed resistance to, or inconsistent control has occurred with, most insecticide classes. With their unique mode of action, insecticides in the diamide class have become a key component in management of agriculturally important lepidopteran pests. In this study, field populations of H. zea were collected in the southern United States and compared to susceptible laboratory colonies to generate baseline concentration-mortality data. LC50 and LC90 values were generated for flubendiamide and chlorantraniliprole using neonates. To achieve equivalent levels of mortality, a higher concentration of flubendiamide was required compared to chlorantraniliprole. Flubendiamide LC50 values for H. zea ranged from 16.45 to 30.74 ng/ml, with a mean of 23.53 ng/ml. Chlorantraniliprole LC50 values for H. zea ranged from 2.94 to 4.22 ng/ml, with a mean of 3.66 ng/ml. Significant differences were observed for some field populations relative to the laboratory colony. For flubendiamide, five populations had greater LC50 values and two populations had lower LC50 values compared to the laboratory colony. For chlorantraniliprole, three populations had greater LC50 values and three populations had lower LC50 values compared to the laboratory colony. The response of these populations most likely represents natural variability among populations and does not indicate a significant shift in susceptibility of this species.
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Affiliation(s)
- A Adams
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, MS 39762 (; ; ; )
| | - J Gore
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Delta Research and Extension Center (DREC), Stoneville, MS 38776 (; )
| | - A Catchot
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, MS 39762 (; ; ; )
| | - F Musser
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, MS 39762 (; ; ; )
| | - D Cook
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Delta Research and Extension Center (DREC), Stoneville, MS 38776 (; )
| | - N Krishnan
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, MS 39762 (; ; ; )
| | - T Irby
- Department of Plant and Soil Sciences, Mississippi State University, MS 3976
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Krishnan N, Higgins R, Short A, Zehnder D, Pitcher D, Hudson A, Raymond NT. Kidney Transplantation Significantly Improves Patient and Graft Survival Irrespective of BMI: A Cohort Study. Am J Transplant 2015; 15:2378-86. [PMID: 26147285 DOI: 10.1111/ajt.13363] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [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: 12/08/2014] [Revised: 02/18/2015] [Accepted: 03/07/2015] [Indexed: 01/25/2023]
Abstract
Obesity and end-stage renal disease (ESRD) are on the increase worldwide. Kidney transplantation is the treatment of choice for ESRD. However, obesity is considered a contraindication for transplantation. We investigated the effect of BMI on mortality in transplanted and patients remaining on the waiting list in the United Kingdom. We analyzed the UK Renal Registry (RR) and the National Health Service Blood and Transplant (NHSBT) Organ Donation and Transplantation data for patients listed from January 1, 2004 to December 31, 2010, with follow-up until December 31, 2011. Seventeen thousand six hundred eighty-one patients were listed during the study period, with BMI recorded for 13 526 (77%). One- and five-year patient survival was significantly better in all BMI bands (<18.5, 18.5-<25, 25-<30, 30-<35, 35-<40, and 40+kg/m(2) ) in the transplant group when compared to those who remained on the waiting list (p < 0.0001). The analyses were repeated excluding live donor transplants and the results were essentially the same. On analyses of patient survival with BMI as a continuous variable or using 5 kg weight bands, there was no cut-off observed in the higher BMI patients where there would be no benefit to transplantation. For transplanted patients (N = 8088), there was no difference in patient or graft survival between the defined BMI bands. Thus, irrespective of BMI, patient survival is improved if transplanted.
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Affiliation(s)
- N Krishnan
- Consultant Transplant Nephrologist, Renal Unit, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - R Higgins
- Consultant Transplant Nephrologist, Renal Unit, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - A Short
- Consultant Transplant Nephrologist, Renal Unit, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - D Zehnder
- Consultant Transplant Nephrologist, Renal Unit, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | | | - A Hudson
- Organ Donation, NHS Blood and Transplant, Bristol, UK
| | - N T Raymond
- Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
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Krishnan N, Krishnan K, Connors CR, Choy MS, Page R, Peti W, Van Aelst L, Shea SD, Tonks NK. PTP1B inhibition suggests a therapeutic strategy for Rett syndrome. J Clin Invest 2015. [PMID: 26214522 DOI: 10.1172/jci80323] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The X-linked neurological disorder Rett syndrome (RTT) presents with autistic features and is caused primarily by mutations in a transcriptional regulator, methyl CpG-binding protein 2 (MECP2). Current treatment options for RTT are limited to alleviating some neurological symptoms; hence, more effective therapeutic strategies are needed. We identified the protein tyrosine phosphatase PTP1B as a therapeutic candidate for treatment of RTT. We demonstrated that the PTPN1 gene, which encodes PTP1B, was a target of MECP2 and that disruption of MECP2 function was associated with increased levels of PTP1B in RTT models. Pharmacological inhibition of PTP1B ameliorated the effects of MECP2 disruption in mouse models of RTT, including improved survival in young male (Mecp2-/y) mice and improved behavior in female heterozygous (Mecp2-/+) mice. We demonstrated that PTP1B was a negative regulator of tyrosine phosphorylation of the tyrosine kinase TRKB, the receptor for brain-derived neurotrophic factor (BDNF). Therefore, the elevated PTP1B that accompanies disruption of MECP2 function in RTT represents a barrier to BDNF signaling. Inhibition of PTP1B led to increased tyrosine phosphorylation of TRKB in the brain, which would augment BDNF signaling. This study presents PTP1B as a mechanism-based therapeutic target for RTT, validating a unique strategy for treating the disease by modifying signal transduction pathways with small-molecule drugs.
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Krishnan N, Tonks NK. Anxious moments for the protein tyrosine phosphatase PTP1B. Trends Neurosci 2015; 38:462-5. [PMID: 26166619 DOI: 10.1016/j.tins.2015.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 06/26/2015] [Accepted: 06/29/2015] [Indexed: 11/16/2022]
Abstract
Chronic stress can lead to the development of anxiety and mood disorders. Thus, novel therapies for preventing adverse effects of stress are vitally important. Recently, the protein tyrosine phosphatase PTP1B was identified as a novel regulator of stress-induced anxiety. This opens up exciting opportunities to exploit PTP1B inhibitors as anxiolytics.
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Affiliation(s)
- Navasona Krishnan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA
| | - Nicholas K Tonks
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA.
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Krishnan N, Coates R, Daga S, Carter V, Talbot D, Briggs D, Higgins R. ABO-incompatible renal transplantation without antibody removal using conventional immunosuppression alone. Am J Transplant 2015; 15:1728-9. [PMID: 25912420 DOI: 10.1111/ajt.13255] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- N Krishnan
- Renal Unit, University Hospitals Coventry and Warwickshire, UK
| | - R Coates
- Renal Unit, The Newcastle upon Tyne Hospitals, UK
| | - S Daga
- Renal Unit, University Hospitals Coventry and Warwickshire, UK
| | - V Carter
- Department of Histocompatibility and Immunogenetics, NHS Blood and Transplant, Newcastle, UK
| | - D Talbot
- Renal Unit, The Newcastle upon Tyne Hospitals, UK
| | - D Briggs
- Department of Histocompatibility and Immunogenetics, NHS Blood and Transplant, Birmingham, UK
| | - R Higgins
- Renal Unit, University Hospitals Coventry and Warwickshire, UK
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Lowe D, Daga S, Briggs D, Khovanova N, Mitchell D, Higgins R, Krishnan N. Meeting report: 3rd international transplant conference: how much risk can you take? Int J Immunogenet 2015; 42:59-68. [PMID: 25684274 DOI: 10.1111/iji.12184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 01/09/2015] [Accepted: 01/27/2015] [Indexed: 01/08/2023]
Abstract
The 3rd International Transplant Conference took place on 31st October and 1st November 2014 at the University of Warwick, Coventry, UK. Key focal points of the meeting were the exploration of the molecular basis of antibody-antigen interactions and their relation to clinical practice and to share experiences and knowledge regarding strategies to transplant the 'high-risk' patient. In addition, lively debate sessions were hosted where controversial clinical and immunological themes were discussed by leading experts in the field.
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Affiliation(s)
- D Lowe
- Transplant Immunology, Royal Liverpool and Broadgreen University Hospital, Liverpool, UK
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Ramesh M, Krishnan N, Muthuswamy SK, Tonks NK. A novel phosphatidic acid-protein-tyrosine phosphatase D2 axis is essential for ERBB2 signaling in mammary epithelial cells. J Biol Chem 2015; 290:9646-59. [PMID: 25681440 DOI: 10.1074/jbc.m114.627968] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Indexed: 11/06/2022] Open
Abstract
We used a loss-of-function screen to investigate the role of classical protein-tyrosine phosphatases (PTPs) in three-dimensional mammary epithelial cell morphogenesis and ERBB2 signaling. The study revealed a novel role for PTPD2 as a positive regulator of ERBB2 signaling. Suppression of PTPD2 attenuated the ERBB2-induced multiacinar phenotype in three-dimensional cultures specifically by inhibiting ERBB2-mediated loss of polarity and lumen filling. In contrast, overexpression of PTPD2 enhanced the ERBB2 phenotype. We also found that a lipid second messenger, phosphatidic acid, bound PTPD2 in vitro and enhanced its catalytic activity. Small molecule inhibitors of phospholipase D (PLD), an enzyme that produces phosphatidic acid in cells, also attenuated the ERBB2 phenotype. Exogenously added phosphatidic acid rescued the PLD-inhibition phenotype, but only when PTPD2 was present. These findings illustrate a novel pathway involving PTPD2 and the lipid second messenger phosphatidic acid that promotes ERBB2 function.
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Affiliation(s)
- Mathangi Ramesh
- From the Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, the Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, New York 11794, and
| | - Navasona Krishnan
- From the Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Senthil K Muthuswamy
- From the Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, the Department of Medical Biophysics, Ontario Cancer Institute, Campbell Family Institute for Breast Cancer Research, University of Toronto, Toronto, Canada M5G 2M9
| | - Nicholas K Tonks
- From the Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724,
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Schwertassek U, Haque A, Krishnan N, Greiner R, Weingarten L, Dick TP, Tonks NK. Reactivation of oxidized PTP1B and PTEN by thioredoxin 1. FEBS J 2014; 281:3545-58. [PMID: 24976139 DOI: 10.1111/febs.12898] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 06/02/2014] [Accepted: 06/26/2014] [Indexed: 11/28/2022]
Abstract
UNLABELLED The transient inactivation of protein phosphatases contributes to the efficiency and temporal control of kinase-dependent signal transduction. In particular, members of the protein tyrosine phosphatase family are known to undergo reversible oxidation of their active site cysteine. The thiol oxidation step requires activation of colocalized NADPH oxidases and is mediated by locally produced reactive oxygen species, in particular H2 O2 . How oxidized phosphatases are returned to the reduced active state is less well studied. Both major thiol reductive systems, the thioredoxin and the glutathione systems, have been implicated in the reactivation of phosphatases. Here, we show that the protein tyrosine phosphatase PTP1B and the dual-specificity phosphatase PTEN are preferentially reactivated by the thioredoxin system. We show that inducible depletion of thioredoxin 1(TRX1) slows PTEN reactivation in intact living cells. Finally, using a mechanism-based trapping approach, we demonstrate direct thiol disulphide exchange between the active sites of thioredoxin and either phosphatase. The application of thioredoxin trapping mutants represents a complementary approach to direct assays of PTP oxidation in elucidating the significance of redox regulation of PTP function in the control of cell signaling. STRUCTURED DIGITAL ABSTRACT TRX1 physically interacts with PTP1B by anti tag coimmunoprecipitation (1, 2).
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Pundir J, Kopeika J, Harris L, Krishnan N, Uwins C, Siozos A, Khalaf Y, El-Toukhy T. Reproductive outcome following abdominal myomectomy for a very large fibroid uterus. J OBSTET GYNAECOL 2014; 35:37-41. [DOI: 10.3109/01443615.2014.930097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Geller T, Prakash V, Batanian J, Guzman M, Duncavage E, Gershon T, Crowther A, Wu J, Liu H, Fang F, Davis I, Tripolitsioti D, Ma M, Kumar K, Grahlert J, Egli K, Fiaschetti G, Shalaby T, Grotzer M, Baumgartner M, Braoudaki M, Lambrou GI, Giannikou K, Millionis V, Papadodima SA, Settas N, Sfakianos G, Stefanaki K, Kattamis A, Spiliopoulou CA, Tzortzatou-Stathopoulou F, Kanavakis E, Gholamin S, Mitra S, Feroze A, Zhang M, Esparza R, Kahn S, Richard C, Achrol A, Volkmer A, Liu J, Volkmer J, Majeti R, Weissman I, Cheshier S, Bhatia K, Brown N, Teague J, Lo P, Challis J, Beshay V, Sullivan M, Mechinaud F, Hansford J, Arifin MZ, Dahlan RH, Sobana M, Saputra P, Tisell MT, Danielsson A, Caren H, Bhardwaj R, Chakravadhanula M, Hampton C, Ozals V, Georges J, Decker W, Kodibagkar V, Nguyen A, Legrain M, Gaub MP, Pencreach E, Chenard MP, Guenot D, Entz-Werle N, Kanemura Y, Ichimura K, Shofuda T, Nishikawa R, Yamasaki M, Shibui S, Arai H, Xia J, Brian A, Prins R, Pennell C, Moertel C, Olin M, Bie L, Zhang X, Liu H, Olsson M, Kling T, Nelander S, Biassoni V, Bongarzone I, Verderio P, Massimino M, Magni R, Pizzamiglio S, Ciniselli C, Taverna E, De Bortoli M, Luchini A, Liotta L, Barzano E, Spreafico F, Visse E, Sanden E, Darabi A, Siesjo P, Jackson S, Cohen K, Lin D, Burger P, Rodriguez F, Yao X, Liucheng R, Qin L, Na T, Meilin W, Zhengdong Z, Yongjun F, Pfeifer S, Nister M, de Stahl TD, Basmaci E, Orphanidou-Vlachou E, Brundler MA, Sun Y, Davies N, Wilson M, Pan X, Arvanitis T, Grundy R, Peet A, Eden C, Ju B, Phoenix T, Nimmervoll B, Tong Y, Ellison D, Lessman C, Taylor M, Gilbertson R, Folgiero V, del Bufalo F, Carai A, Cefalo MG, Citti A, Rutella S, Locatelli F, Mastronuzzi A, Maher O, Khatua S, Zaky W, Lourdusamy A, Meijer L, Layfield R, Grundy R, Jones DTW, Capper D, Sill M, Hovestadt V, Schweizer L, Lichter P, Zagzag D, Karajannis MA, Aldape KD, Korshunov A, von Deimling A, Pfister S, Chakrabarty A, Feltbower R, Sheridon E, Hassan H, Shires M, Picton S, Hatziagapiou K, Braoudaki M, Lambrou GI, Tsorteki F, Tzortzatou-Stathopoulou F, Bethanis K, Gemou-Engesaeth V, Chi SN, Bandopadhayay P, Janeway K, Pinches N, Malkin H, Kieran MW, Manley PE, Green A, Goumnerova L, Ramkissoon S, Harris MH, Ligon KL, Kahlert U, Suarez M, Maciaczyk J, Bar E, Eberhart C, Kenchappa R, Krishnan N, Forsyth P, McKenzie B, Pisklakova A, McFadden G, Kenchappa R, Forsyth P, Pan W, Rodriguez L, Glod J, Levy JM, Thompson J, Griesinger A, Amani V, Donson A, Birks D, Morgan M, Handler M, Foreman N, Thorburn A, Lulla RR, Laskowski J, Fangusaro J, DiPatri AJ, Alden T, Tomita T, Vanin EF, Goldman S, Soares MB, Remke M, Ramaswamy V, Wang X, Jorgensen F, Morrissy AS, Marra M, Packer R, Bouffet E, Pfister S, Jabado N, Taylor M, Cole B, Rudzinski E, Anderson M, Bloom K, Lee A, Leary S, Leprivier G, Remke M, Rotblat B, Agnihotri S, Kool M, Derry B, Pfister S, Taylor MD, Sorensen PH, Dobson T, Busschers E, Taylor H, Hatcher R, Fangusaro J, Lulla R, Goldman S, Rajaram V, Das C, Gopalakrishnan V. TUMOUR BIOLOGY. Neuro Oncol 2014; 16:i137-i145. [PMCID: PMC4046298 DOI: 10.1093/neuonc/nou082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023] Open
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Joseph J, Basu D, Dandapani M, Krishnan N. Are nurse-conducted brief interventions (NCBIs) efficacious for hazardous or harmful alcohol use? A systematic review. Int Nurs Rev 2014; 61:203-10. [PMID: 24645911 DOI: 10.1111/inr.12096] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM The aim of this study was to compare the efficacy of nurse-conducted brief interventions in reducing alcohol consumption, by looking at with treatment as usual compared with other treatments and general physician-delivered brief interventions within the literature. BACKGROUND Globally, the consumption of alcohol is at a worrying level and has significant effects on health when consumed to excess. Numerous studies have reported that brief intervention is effective in reducing excessive drinking. However, evidence on the efficacy of such interventions by nurses is still inconclusive. METHODS We included randomized controlled trials of brief interventions in which nurses were primarily involved as therapists, and were designed to achieve a reduction in alcohol consumption and related problems. We used online searches to locate randomized controlled trials in this area published from 1995 till 2012. FINDINGS Eleven trials were found meeting inclusion criteria, comparing nurse-conducted brief interventions with a control group or with other treatments. Five trials reported a statistically significant reduction in alcohol consumption in the intervention group with 6-12-month follow-up period and two trials concluded that brief interventions delivered by nurses was as efficacious as by physicians. IMPLICATIONS FOR NURSING POLICY The findings of the review have important policy implications for the preparation of nurses as therapists for brief interventions to reduce excessive drinking in a broad range of settings such as primary healthcare and hospital settings. The adoption of this intervention into contemporary nursing practice should be considered by the International Council of Nurses and nurses around the world as, according to the literature, it provides an evidence base for the independent functioning of nurses within the realms of nursing profession and addiction medicine. CONCLUSION The results of the review suggest that nurse-conducted brief interventions are an effective strategy for reducing alcohol consumption. We advocate more rigorous randomized controlled trials to underpin its efficacy in both research and real life scenario.
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Affiliation(s)
- J Joseph
- SUM Nursing College (SNC), Siksha 'O'Anusandhan University, Odisha, India
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Moxley MA, Sanyal N, Krishnan N, Tanner JJ, Becker DF. Evidence for hysteretic substrate channeling in the proline dehydrogenase and Δ1-pyrroline-5-carboxylate dehydrogenase coupled reaction of proline utilization A (PutA). J Biol Chem 2013; 289:3639-51. [PMID: 24352662 DOI: 10.1074/jbc.m113.523704] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PutA (proline utilization A) is a large bifunctional flavoenzyme with proline dehydrogenase (PRODH) and Δ(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH) domains that catalyze the oxidation of l-proline to l-glutamate in two successive reactions. In the PRODH active site, proline undergoes a two-electron oxidation to Δ(1)-pyrroline-5-carboxlylate, and the FAD cofactor is reduced. In the P5CDH active site, l-glutamate-γ-semialdehyde (the hydrolyzed form of Δ(1)-pyrroline-5-carboxylate) undergoes a two-electron oxidation in which a hydride is transferred to NAD(+)-producing NADH and glutamate. Here we report the first kinetic model for the overall PRODH-P5CDH reaction of a PutA enzyme. Global analysis of steady-state and transient kinetic data for the PRODH, P5CDH, and coupled PRODH-P5CDH reactions was used to test various models describing the conversion of proline to glutamate by Escherichia coli PutA. The coupled PRODH-P5CDH activity of PutA is best described by a mechanism in which the intermediate is not released into the bulk medium, i.e., substrate channeling. Unexpectedly, single-turnover kinetic experiments of the coupled PRODH-P5CDH reaction revealed that the rate of NADH formation is 20-fold slower than the steady-state turnover number for the overall reaction, implying that catalytic cycling speeds up throughput. We show that the limiting rate constant observed for NADH formation in the first turnover increases by almost 40-fold after multiple turnovers, achieving half of the steady-state value after 15 turnovers. These results suggest that EcPutA achieves an activated channeling state during the approach to steady state and is thus a new example of a hysteretic enzyme. Potential underlying causes of activation of channeling are discussed.
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Affiliation(s)
- Michael A Moxley
- From the Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 and
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Lowe D, Higgins R, Krishnan N. Meeting report: 2nd international conference: antibody incompatible transplantation and transplant infectious disease. Int J Immunogenet 2013; 40:439-44. [PMID: 23919843 DOI: 10.1111/iji.12082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 06/12/2013] [Accepted: 07/15/2013] [Indexed: 02/04/2023]
Abstract
The 2nd International Conference on Antibody Incompatible Transplantation and Transplant Infectious Disease took place at the University of Warwick on 23rd and 24th November 2012. The aims of the meeting were to discuss the pertinent clinical and laboratory issues surrounding antibody incompatible transplantation and to provide a contemporary analysis of transplant infectious disease. This report summarises the key points discussed at the meeting.
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Affiliation(s)
- D Lowe
- Department of Histocompatibility and Immunogenetics, NHS Blood and Transplant, Birmingham, UK
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Krishnan N, Bencze G, Cohen P, Tonks NK. The anti-inflammatory compound BAY-11-7082 is a potent inhibitor of protein tyrosine phosphatases. FEBS J 2013; 280:2830-41. [PMID: 23578302 DOI: 10.1111/febs.12283] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 04/06/2013] [Accepted: 04/08/2013] [Indexed: 02/07/2023]
Abstract
The families of protein tyrosine phosphatases (PTPs) and protein tyrosine kinases (PTKs) function in a coordinated manner to regulate signal transduction events that are critical for cellular homeostasis. Aberrant tyrosine phosphorylation, resulting from disruption of either PTP or PTK function, has been shown to be the cause of major human diseases, including cancer and diabetes. Consequently, the characterization of small-molecule inhibitors of these kinases and phosphatases may not only provide molecular probes with which to define the significance of particular signaling events, but also may have therapeutic implications. BAY-11-7082 is an anti-inflammatory compound that has been reported to inhibit IκB kinase activity. The compound has an α,β-unsaturated electrophilic center, which confers the property of being a Michael acceptor; this suggests that it may react with nucleophilic cysteine-containing proteins, such as PTPs. In this study, we demonstrated that BAY-11-7082 was a potent, irreversible inhibitor of PTPs. Using mass spectrometry, we have shown that BAY-11-7082 inactivated PTPs by forming a covalent adduct with the active-site cysteine. Administration of the compound caused an increase in protein tyrosine phosphorylation in RAW 264 macrophages, similar to the effects of the generic PTP inhibitor sodium orthovanadate. These data illustrate that BAY-11-7082 is an effective pan-PTP inhibitor with cell permeability, revealing its potential as a new probe for chemical biology approaches to the study of PTP function. Furthermore, the data suggest that inhibition of PTP function may contribute to the many biological effects of BAY-11-7082 that have been reported to date.
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Affiliation(s)
- Navasona Krishnan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724-2208, USA
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Pundir J, Krishnan N, Siozos A, Uwins C, Kopeika J, Khalaf Y, El-Toukhy T. Peri-operative morbidity associated with abdominal myomectomy for very large fibroid uteri. Eur J Obstet Gynecol Reprod Biol 2013; 167:219-24. [PMID: 23290249 DOI: 10.1016/j.ejogrb.2012.12.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Revised: 07/12/2012] [Accepted: 12/10/2012] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the safety of abdominal myomectomy for very large fibroid uteri, and to assess the effect of relevant confounding variables on the occurrence of major peri-operative complications. STUDY DESIGN A cohort study of 200 abdominal myomectomies for fibroid uteri of 16 gestational weeks or greater. Logistic regression analysis was used to examine the influence of important clinical variables on the risk of complications. A systematic literature search was conducted for evidence related to peri-operative morbidity associated with abdominal myomectomy for very large fibroid uteri. RESULTS The mean (±standard deviation) uterine size was 21±5 weeks. The overall rate of major complications was 30%. Peri-operative bleeding necessitating blood transfusion occurred in 49 (24.5%) cases. During surgery, two patients had bowel injury, two had bladder injury, seven women returned to theatre and two (1%) had hysterectomy. Four patients were re-admitted within 14 days of surgery. Multivariable logistic regression analysis showed that the risk of major complications was significantly higher in cases with a uterine size of 20 gestational weeks or more [odds ratio (OR) 3.4, 95% confidence interval (CI) 1.1-10.2; p=0.03], where 10 or more fibroids were removed (OR 3.5, 95% CI 1.1-10.8; p=0.05) and where midline skin incision was required (OR 6.1, 95% CI 1.7-22.3; p=0.006). On comparison of primary vs repeat abdominal myomectomy, there was significantly higher blood loss (mean 1023±1112 ml vs 579±787 ml; p=0.02) and risk of major complications in the repeat myomectomy group (40% vs 5%; p<0.001). The systematic review identified only one study that reported a comparable risk of major complications related to abdominal myomectomy for very large fibroid uteri. CONCLUSION The risk of organ injury, hysterectomy, re-operation or hospital re-admission after abdominal myomectomy for very large fibroid uteri is low, but the procedure is associated with a significant risk of bleeding necessitating blood transfusion. This risk is increased after repeat myomectomy, and in patients with a uterine size of 20 gestational weeks or larger, requiring removal of 10 or more fibroids, and requiring a midline skin incision.
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Affiliation(s)
- J Pundir
- Assisted Conception Unit, Guy's and St. Thomas' NHS Trust, London, UK.
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Meermeier N, Krishnan N. Circadian regulation of cellular homeostasis--implications for cell metabolism and clinical diseases. Med Hypotheses 2012; 79:17-24. [PMID: 22521428 DOI: 10.1016/j.mehy.2012.03.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 03/25/2012] [Indexed: 01/07/2023]
Abstract
The major pathways involving nutrient and energy metabolism including cellular homeostasis are profoundly impacted by the circadian clock, which orchestrates diurnal rhythms in physiology and behavior. While the links between circadian and metabolic rhythms are unclear, recent studies imply a close link between the two with one feeding back on the other. In this discussion, we present the hypothesis that circadian clocks likely contribute to cellular homeostasis, especially proteostasis, through regulation of metabolic rhythms, which in turn feed-back on circadian oscillators. The disruption of circadian clocks leads to altered metabolic rhythms and metabolic disease states as a result of altered cellular homeostasis.
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Affiliation(s)
- N Meermeier
- Department of Microbiology, 220 Nash Hall, Oregon State University, Corvallis, OR 97331, United States.
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Krishnan N, Fu C, Pappin DJ, Tonks NK. H2S-Induced sulfhydration of the phosphatase PTP1B and its role in the endoplasmic reticulum stress response. Sci Signal 2011; 4:ra86. [PMID: 22169477 DOI: 10.1126/scisignal.2002329] [Citation(s) in RCA: 333] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Although originally considered toxic, hydrogen sulfide (H(2)S) has been implicated in mediating various biological processes. Nevertheless, its cellular targets and mode of action are not well understood. Protein tyrosine phosphatases (PTPs), which regulate numerous signal transduction pathways, use an essential cysteine residue at the active site, which is characterized by a low pK(a) and is susceptible to reversible oxidation. Here, we report that PTP1B was reversibly inactivated by H(2)S, in vitro and in cells, through sulfhydration of the active-site cysteine residue. Unlike oxidized PTP1B, the sulfhydrated enzyme was preferentially reduced in vitro by thioredoxin, compared to glutathione or dithiothreitol. Sulfhydration of PTP1B in cells required the presence of cystathionine γ-lyase (CSE), a critical enzyme in H(2)S production, and resulted in inhibition of phosphatase activity. Suppression of CSE decreased H(2)S production and decreased the phosphorylation of tyrosine-619 in PERK [protein kinase-like endoplasmic reticulum (ER) kinase], thus reducing its activation in response to ER stress. PERK, which phosphorylates the eukaryotic translational initiation factor 2, leading to attenuation of protein translation, was a direct substrate of PTP1B. In addition, CSE knockdown led to activation of the nonreceptor tyrosine kinase SRC, previously shown to be mediated by PTP1B. These effects of suppressing H(2)S production on the response to ER stress were abrogated by a small-molecule inhibitor of PTP1B. Together, these data define a signaling function for H(2)S in inhibiting PTP1B activity and thereby promoting PERK activity during the response to ER stress.
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Pundir J, Krishnan N, Siozos T, Uwins C, Khalaf Y, El-Toukhy T. Morbidity and long term reproductive outcome after abdominal myomectomy for very large fibroid uteri of 16 weeks or more. Fertil Steril 2011. [DOI: 10.1016/j.fertnstert.2011.07.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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McAlindon TE, Nuite M, Krishnan N, Ruthazer R, Price LL, Burstein D, Griffith J, Flechsenhar K. Change in knee osteoarthritis cartilage detected by delayed gadolinium enhanced magnetic resonance imaging following treatment with collagen hydrolysate: a pilot randomized controlled trial. Osteoarthritis Cartilage 2011; 19:399-405. [PMID: 21251991 DOI: 10.1016/j.joca.2011.01.001] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 12/23/2010] [Accepted: 01/03/2011] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine whether either of two magnetic resonance imaging approaches - delayed gadolinium enhanced magnetic resonance imaging of cartilage (dGEMRIC), or T2 mapping - can detect short-term changes in knee hyaline cartilage among individuals taking a formulation of collagen hydrolysate. DESIGN Single center, prospective, randomized, placebo-controlled, double-blind, pilot trial of collagen hydrolysate for mild knee osteoarthritis (OA). Participants were allowed to continue the prior analgesic use. The primary outcome was change in dGEMRIC T1 relaxation time in the cartilage regions of interest at the 24-week timepoint. Secondary endpoints included the change in dGEMRIC T1 relaxation time between baseline and 48 weeks, the change in T2 relaxation time at 0, 24 and 48 weeks, the symptom and functional measures obtained at each of the visits, and overall analgesic use. RESULTS Among a sample of 30 randomized subjects the dGEMRIC score increased in the medial and lateral tibial regions of interest (median increase of 29 and 41 ms respectively) in participants assigned to collagen hydrolysate but decreased (median decline 37 and 36 ms respectively) in the placebo arm with the changes between the two groups at 24 weeks reaching significance. No other significant changes between the two groups were seen in the other four regions, or in any of the T2 values or in the clinical outcomes. CONCLUSIONS These preliminary results suggest that the dGEMRIC technique may be able to detect change in proteoglycan content in knee cartilage among individuals taking collagen hydrolysate after 24 weeks.
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Affiliation(s)
- T E McAlindon
- Division of Rheumatology, Tufts Medical Center, Box 406, 800 Washington Street, Boston, MA 02111, USA.
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Lowe D, Higgins R, Zehnder D, Hathaway M, Hamer R, Krishnan N, Briggs D. THE SINGNIFICANCE OF IGG SUBCLASSES IN HLA ANTIBODY INCOMPATIBLE KIDNEY TRANSPLANTATION. Transplantation 2010. [DOI: 10.1097/00007890-201007272-00514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Krishnan N, Ramanathan S, Sasidharan S, Murugaiyah V, Mansor S. Antimicrobial Activity Evaluation of Cassia spectabilis Leaf Extracts. INT J PHARMACOL 2010. [DOI: 10.3923/ijp.2010.510.514] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Hubbard EM, Krishnan N, Ramachandran VS. Reduced crowding with illusory contours supports an attentional locus for crowding. J Vis 2010. [DOI: 10.1167/2.7.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Higgins R, Zehnder D, Chen K, Lowe D, McKinnell J, Lam FT, Kashi H, Tan LC, Imray C, Fletcher S, Krishnan N, Hamer R, Briggs D. The histological development of acute antibody-mediated rejection in HLA antibody-incompatible renal transplantation. Nephrol Dial Transplant 2009; 25:1306-12. [DOI: 10.1093/ndt/gfp610] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Krishnan N, Jeong DG, Jung SK, Ryu SE, Xiao A, Allis CD, Kim SJ, Tonks NK. Dephosphorylation of the C-terminal tyrosyl residue of the DNA damage-related histone H2A.X is mediated by the protein phosphatase eyes absent. J Biol Chem 2009; 284:16066-16070. [PMID: 19351884 DOI: 10.1074/jbc.c900032200] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In mammalian cells, the DNA damage-related histone H2A variant H2A.X is characterized by a C-terminal tyrosyl residue, Tyr-142, which is phosphorylated by an atypical kinase, WSTF. The phosphorylation status of Tyr-142 in H2A.X has been shown to be an important regulator of the DNA damage response by controlling the formation of gammaH2A.X foci, which are platforms for recruiting molecules involved in DNA damage repair and signaling. In this work, we present evidence to support the identification of the Eyes Absent (EYA) phosphatases, protein-tyrosine phosphatases of the haloacid dehalogenase superfamily, as being responsible for dephosphorylating the C-terminal tyrosyl residue of histone H2A.X. We demonstrate that EYA2 and EYA3 displayed specificity for Tyr-142 of H2A.X in assays in vitro. Suppression of eya3 by RNA interference resulted in elevated basal phosphorylation and inhibited DNA damage-induced dephosphorylation of Tyr-142 of H2A.X in vivo. This study provides the first indication of a physiological substrate for the EYA phosphatases and suggests a novel role for these enzymes in regulation of the DNA damage response.
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Affiliation(s)
- Navasona Krishnan
- From the Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Dae Gwin Jeong
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, 52 Eoeun-Dong, Yuseong-Gu, Daejeon 305-333, Korea
| | - Suk-Kyeong Jung
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, 52 Eoeun-Dong, Yuseong-Gu, Daejeon 305-333, Korea
| | - Seong Eon Ryu
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, 52 Eoeun-Dong, Yuseong-Gu, Daejeon 305-333, Korea
| | - Andrew Xiao
- Laboratory of Chromatin Biology, The Rockefeller University, New York, New York 10065
| | - C David Allis
- Laboratory of Chromatin Biology, The Rockefeller University, New York, New York 10065
| | - Seung Jun Kim
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, 52 Eoeun-Dong, Yuseong-Gu, Daejeon 305-333, Korea.
| | - Nicholas K Tonks
- From the Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724.
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Krishnan N, Ananthakrishnan R, Augustine S, Vijayalakshmi NK, Gopi PG, Kumaraswami V, Narayanan PR. Impact of advocacy on the tuberculosis management practices of private practitioners in Chennai City, India. Int J Tuberc Lung Dis 2009; 13:112-118. [PMID: 19105888] [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: 05/27/2023] Open
Abstract
BACKGROUND Innovative schemes to ensure the participation of private practitioners (PPs) in the Revised National Tuberculosis Control Programme (RNTCP) are necessary to identify and treat all patients with tuberculosis (TB). We developed a novel public-private mix (PPM) model to encourage PPs to practise DOTS and participate in the RNTCP while retaining their patients. METHODS The Resource Group for Education and Advocacy for Community Health (REACH) developed and implemented the programme in partnership with the Chennai local health authority and the Tuberculosis Research Centre, Chennai, India. PPs were sensitised to the RNTCP and DOTS through a one-to-one approach or group meetings, and were assisted in referring patients. Surveys were carried out at baseline and at the completion of the study to assess changes in attitudes and practices. RESULTS Six hundred PPs underwent sensitisation about the RNTCP, after which the proportion of PPs adopting DOTS increased significantly (P < 0.001), and the majority (72.8%) used sputum testing for diagnosing TB. The proportion of PPs who used X-ray alone for diagnosis declined to 16.0% from a baseline of 45.4%. CONCLUSIONS This PPM model, which emphasises sustained advocacy for DOTS and allows PPs to retain private patients, looks promising and needs to be tested at other sites.
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Affiliation(s)
- N Krishnan
- Resource Group for Education and Advocacy for Community Health, Chennai, India.
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Higgins R, Hamer R, Briggs D, Krishnan N, Fletcher S, Short A, Lowe D, McSorley K, Zehnder D. DOUBLE FILTRATION PLASMAPHERESIS FACILITATES HLA ANTIBODY INCOMPATIBLE RENAL TRANSPLANTATION, BUT IS LESS EFFECTIVE DURING ANTIBODY RESYNTHESIS POST-TRANSPLANTATION. Transplantation 2008. [DOI: 10.1097/01.tp.0000332340.71206.d0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Higgins R, Zehnder D, Chen K, Fletcher S, Kashi H, Tan LC, Imray C, Lam FT, Hamer R, Krishnan N. TREATMENT OF ACUTE ANTIBODY-MEDIATED REJECTION; SPECIFIC ANTI-T LYMPHOCYTE THERAPY IS EFFECTIVE, WHILE SPECIFIC ANTI-B LYMPHOCYTE THERAPY IS NOT. Transplantation 2008. [DOI: 10.1097/01.tp.0000331112.79328.8a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Krishnan N, Dickman MB, Becker DF. Proline modulates the intracellular redox environment and protects mammalian cells against oxidative stress. Free Radic Biol Med 2008; 44:671-81. [PMID: 18036351 PMCID: PMC2268104 DOI: 10.1016/j.freeradbiomed.2007.10.054] [Citation(s) in RCA: 248] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 10/25/2007] [Accepted: 10/30/2007] [Indexed: 10/22/2022]
Abstract
The potential of proline to suppress reactive oxygen species (ROS) and apoptosis in mammalian cells was tested by manipulating intracellular proline levels exogenously and endogenously by overexpression of proline metabolic enzymes. Proline was observed to protect cells against H(2)O(2), tert-butyl hydroperoxide, and a carcinogenic oxidative stress inducer but was not effective against superoxide generators such as menadione. Oxidative stress protection by proline requires the secondary amine of the pyrrolidine ring and involves preservation of the glutathione redox environment. Overexpression of proline dehydrogenase (PRODH), a mitochondrial flavoenzyme that oxidizes proline, resulted in 6-fold lower intracellular proline content and decreased cell survival relative to control cells. Cells overexpressing PRODH were rescued by pipecolate, an analog that mimics the antioxidant properties of proline, and by tetrahydro-2-furoic acid, a specific inhibitor of PRODH. In contrast, overexpression of the proline biosynthetic enzymes Delta(1)-pyrroline-5-carboxylate (P5C) synthetase (P5CS) and P5C reductase (P5CR) resulted in 2-fold higher proline content, significantly lower ROS levels, and increased cell survival relative to control cells. In different mammalian cell lines exposed to physiological H(2)O(2) levels, increased endogenous P5CS and P5CR expression was observed, indicating that upregulation of proline biosynthesis is an oxidative stress response.
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Affiliation(s)
- Navasona Krishnan
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588
| | - Martin B. Dickman
- Institute for Plant Genomics and Biotechnology, Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843
| | - Donald F. Becker
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588
- Corresponding Author: Department of Biochemistry, University of Nebraska, N258 Beadle Center, Lincoln, NE 68588, Tel. 402-472-9652; Fax. 402-472-7842;
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Abstract
Proline dehydrogenase (PRODH) and Delta(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH) catalyze the two-step oxidation of proline to glutamate. They are distinct monofunctional enzymes in all eukaryotes and some bacteria but are fused into bifunctional enzymes known as proline utilization A (PutA) in other bacteria. Here we report the first structure and biochemical data for a monofunctional PRODH. The 2.0-A resolution structure of Thermus thermophilus PRODH reveals a distorted (betaalpha)(8) barrel catalytic core domain and a hydrophobic alpha-helical domain located above the carboxyl-terminal ends of the strands of the barrel. Although the catalytic core is similar to that of the PutA PRODH domain, the FAD conformation of T. thermophilus PRODH is remarkably different and likely reflects unique requirements for membrane association and communication with P5CDH. Also, the FAD of T. thermophilus PRODH is highly solvent-exposed compared with PutA due to a 4-A shift of helix 8. Structure-based sequence analysis of the PutA/PRODH family led us to identify nine conserved motifs involved in cofactor and substrate recognition. Biochemical studies show that the midpoint potential of the FAD is -75 mV and the kinetic parameters for proline are K(m) = 27 mm and k(cat) = 13 s(-1). 3,4-Dehydro-l-proline was found to be an efficient substrate, and l-tetrahydro-2-furoic acid is a competitive inhibitor (K(I) = 1.0 mm). Finally, we demonstrate that T. thermophilus PRODH reacts with O(2) producing superoxide. This is significant because superoxide production underlies the role of human PRODH in p53-mediated apoptosis, implying commonalities between eukaryotic and bacterial monofunctional PRODHs.
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Affiliation(s)
- Tommi A. White
- Department of Biochemistry, University of Missouri-Columbia, Columbia, MO 65211
| | - Navasona Krishnan
- Department of Biochemistry, Redox Biology Center, University of Nebraska, Lincoln, NE 68588
| | - Donald F. Becker
- Department of Biochemistry, Redox Biology Center, University of Nebraska, Lincoln, NE 68588
| | - John J. Tanner
- Department of Biochemistry, University of Missouri-Columbia, Columbia, MO 65211
- Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211
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Navarathna DHMLP, Hornby JM, Krishnan N, Parkhurst A, Duhamel GE, Nickerson KW. Effect of farnesol on a mouse model of systemic candidiasis, determined by use of a DPP3 knockout mutant of Candida albicans. Infect Immun 2007; 75:1609-18. [PMID: 17283095 PMCID: PMC1865729 DOI: 10.1128/iai.01182-06] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [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: 11/20/2022] Open
Abstract
This work extends our previous observation that the fungus Candida albicans secretes micromolar levels of farnesol and that accumulation of farnesol in vitro prevents the yeast-to-mycelium conversion in a quorum-sensing manner. What does farnesol do in vivo? The purpose of this study was to determine the role of farnesol during infection with a well-established mouse model of systemic candidiasis with C. albicans A72 administered by tail vein injection. This question was addressed by altering both endogenous and exogenous farnesol. For endogenous farnesol, we created a knockout mutation in DPP3, the gene encoding a phosphatase which converts farnesyl pyrophosphate to farnesol. This mutant (KWN2) produced six times less farnesol and was ca. 4.2 times less pathogenic than its SN152 parent. The strain with DPP3 reconstituted (KWN4) regained both its farnesol production levels and pathogenicity. These mutants (KWN1 to KWN4) retained their full dimorphic capability. With regard to exogenous farnesol, farnesol was administered either intraperitoneally (i.p.) or orally in the drinking water. Mice receiving C. albicans intravenously and farnesol (20 mM) orally had enhanced mortality (P < 0.03). Similarly, mice (n = 40) injected with 1.0 ml of 20 mM farnesol i.p. had enhanced mortality (P < 0.03), and the onset of mortality was 30 h sooner than for mice which received a control injection without farnesol. The effect of i.p. farnesol was more pronounced (P < 0.04) when mice were inoculated with a sublethal dose of C. albicans. These mice started to die 4 days earlier, and the percent survival on day 6 postinoculation (p.i.) was five times lower than for mice receiving C. albicans with control i.p. injections. In all experiments, mice administered farnesol alone or Tween 80 alone remained normal throughout a 14-day observation period. Finally, beginning at 12 h p.i., higher numbers of C. albicans cells were detected in kidneys from mice receiving i.p. farnesol than in those from mice receiving control i.p. injections. Thus, reduced endogenous farnesol decreased virulence, while providing exogenous farnesol increased virulence. Taken together, these data suggest that farnesol may play a role in disease pathogenesis, either directly or indirectly, and thus may represent a newly identified virulence factor.
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