1
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Frew J, Baradaran-Heravi A, Balgi AD, Wu X, Yan TD, Arns S, Shidmoossavee FS, Tan J, Jaquith JB, Jansen-West KR, Lynn FC, Gao FB, Petrucelli L, Feldman HH, Mackenzie IR, Roberge M, Nygaard HB. Premature termination codon readthrough upregulates progranulin expression and improves lysosomal function in preclinical models of GRN deficiency. Mol Neurodegener 2020; 15:21. [PMID: 32178712 PMCID: PMC7075020 DOI: 10.1186/s13024-020-00369-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 01/14/2020] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
Background Frontotemporal lobar degeneration (FTLD) is a devastating and progressive disorder, and a common cause of early onset dementia. Progranulin (PGRN) haploinsufficiency due to autosomal dominant mutations in the progranulin gene (GRN) is an important cause of FTLD (FTLD-GRN), and nearly a quarter of these genetic cases are due to a nonsense mutation. Premature termination codons (PTC) can be therapeutically targeted by compounds allowing readthrough, and aminoglycoside antibiotics are known to be potent PTC readthrough drugs. Restoring endogenous PGRN through PTC readthrough has not previously been explored as a therapeutic intervention in FTLD. Methods We studied whether the aminoglycoside G418 could increase PGRN expression in HEK293 and human induced pluripotent stem cell (hiPSC)-derived neurons bearing the heterozygous S116X, R418X, and R493X pathogenic GRN nonsense mutations. We further tested a novel substituted phthalimide PTC readthrough enhancer in combination with G418 in our cellular models. We next generated a homozygous R493X knock-in hiPSC isogenic line (R493X−/− KI), assessing whether combination treatment in hiPSC-derived neurons and astrocytes could increase PGRN and ameliorate lysosomal dysfunction relevant to FTLD-GRN. To provide in vivo proof-of-concept of our approach, we measured brain PGRN after intracerebroventricular administration of G418 in mice expressing the V5-tagged GRN nonsense mutation R493X. Results The R418X and R493X mutant GRN cell lines responded to PTC readthrough with G418, and treatments increased PGRN levels in R493X−/− KI hiPSC-derived neurons and astrocytes. Combining G418 with a PTC readthrough enhancer increased PGRN levels over G418 treatment alone in vitro. PGRN deficiency has been shown to impair lysosomal function, and the mature form of the lysosomal protease cathepsin D is overexpressed in R493X−/− KI neurons. Increasing PGRN through G418-mediated PTC readthrough normalized this abnormal lysosomal phenotype in R493X−/− KI neuronal cultures. A single intracerebroventricular injection of G418 induced GRN PTC readthrough in 6-week-old AAV-GRN-R493X-V5 mice. Conclusions Taken together, our findings suggest that PTC readthrough may be a potential therapeutic strategy for FTLD caused by GRN nonsense mutations.
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Affiliation(s)
- Jonathan Frew
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alireza Baradaran-Heravi
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aruna D Balgi
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Xiujuan Wu
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tyler D Yan
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Steve Arns
- adMare BioInnovations, Vancouver, British Columbia, Canada
| | | | - Jason Tan
- adMare BioInnovations, Vancouver, British Columbia, Canada
| | | | | | - Francis C Lynn
- Department of Surgery, University of British Columbia, Faculty of Medicine, Vancouver, British Columbia, Canada
| | - Fen-Biao Gao
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | | | - Howard H Feldman
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Neurosciences, University of California, San Diego, San Diego, CA, USA
| | - Ian R Mackenzie
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michel Roberge
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Haakon B Nygaard
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada.
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2
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Shen Y, Zeglinski MR, Turner CT, Raithatha SA, Wu Z, Russo V, Oram C, Hiroyasu S, Nabai L, Zhao H, Bozin T, Westendorf K, Kopko I, Huang R, Arns S, Tan J, Zeng H, Boey A, Liggins R, Jaquith J, Cameron DR, Papp A, Granville DJ. Topical small molecule granzyme B inhibitor improves remodeling in a murine model of impaired burn wound healing. Exp Mol Med 2018; 50:1-11. [PMID: 29849046 PMCID: PMC5976625 DOI: 10.1038/s12276-018-0095-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [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: 01/28/2018] [Revised: 03/01/2018] [Accepted: 03/16/2018] [Indexed: 11/09/2022] Open
Abstract
Granzyme B (GzmB) is a serine protease that has long been thought to function exclusively in lymphocyte-mediated apoptosis. In recent years, this paradigm has been revisited due to the recognition that GzmB accumulates in the extracellular milieu in many autoimmune and chronic inflammatory disorders, and contributes to impaired tissue remodeling due to the cleavage of extracellular matrix proteins. Knockout studies suggest that GzmB-mediated cleavage of decorin (DCN) contributes to impaired collagen fibrillogenesis and remodeling. As DCN is anti-fibrotic and contributes to reduced hypertrophic scarring, GzmB-induced DCN cleavage could play a role in wound healing following burn injury. In the present study, a novel, gel-formulated, first-in-class small-molecule inhibitor of GzmB, VTI-1002, was assessed in a murine model of impaired, diabetic burn wound healing. VTI-1002 exhibited high specificity, potency, and target selectivity. Gel-formulated VTI-1002 was able to penetrate the stratum corneum and was retained in the skin with minimal systemic absorption. Daily topical administration of VTI-1002 gel for 30 days following thermal injury showed significantly accelerated wound closure, increased DCN protein levels, and collagen organization that was translated into significantly increased wound tensile strength compared to controls. Overall, VTI-1002 gel was well-tolerated in vivo and no adverse events were observed. Topical application of VTI-1002 represents a novel therapeutic approach for the treatment of cutaneous burn wounds.
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Affiliation(s)
- Yue Shen
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.,International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada.,viDA Therapeutics, Inc., Vancouver, BC, Canada
| | - Matthew R Zeglinski
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.,International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Christopher T Turner
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.,International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Sheetal A Raithatha
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.,viDA Therapeutics, Inc., Vancouver, BC, Canada
| | - Zhenguo Wu
- Imaging Unit, Integrative Oncology Department, BC Cancer Agency Research Centre, Vancouver, BC, Canada.,Photomedicine Institute, Department of Dermatology and Skin Science, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
| | - Valerio Russo
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.,International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Cameron Oram
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.,International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Sho Hiroyasu
- International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Layla Nabai
- International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Hongyan Zhao
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.,International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Tatjana Bozin
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Kathryn Westendorf
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.,viDA Therapeutics, Inc., Vancouver, BC, Canada
| | - Irina Kopko
- Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Rachel Huang
- Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Steve Arns
- Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Jason Tan
- Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Haishan Zeng
- Imaging Unit, Integrative Oncology Department, BC Cancer Agency Research Centre, Vancouver, BC, Canada.,Photomedicine Institute, Department of Dermatology and Skin Science, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
| | - Anthony Boey
- Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Richard Liggins
- Centre for Drug Research and Development, Vancouver, BC, Canada
| | - James Jaquith
- Centre for Drug Research and Development, Vancouver, BC, Canada
| | | | - Anthony Papp
- BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - David J Granville
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada. .,International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada. .,BC Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada. .,viDA Therapeutics, Inc., Vancouver, BC, Canada.
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3
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Arns S, Tan J, Sun S, Galey A, Zisman N, Ross F, Udechukwu J, Dercho S, Gusti V, Paquette J, Wennekes T, Webb M, Bourque E, Withers SG, Liggins R. Corrigendum to "Assessing the oral bioavailability of difluorosialic acid prodrugs, potent viral neuraminidase inhibitors, using a snapshot PK screening assay" [Bioorg. Med. Chem. Lett. 25 (2015) 2505-2509]. Bioorg Med Chem Lett 2016; 26:S0960-894X(16)30679-5. [PMID: 27381085 DOI: 10.1016/j.bmcl.2016.06.068] [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: 11/22/2022]
Affiliation(s)
- Steve Arns
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada.
| | - Jason Tan
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Sharon Sun
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Adam Galey
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Natalia Zisman
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Fiona Ross
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jenna Udechukwu
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Samantha Dercho
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Vionarica Gusti
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jay Paquette
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Tom Wennekes
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Murray Webb
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Elyse Bourque
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Stephen G Withers
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Richard Liggins
- The Center for Drug Research and Development, 4th Floor-2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
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4
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Arns S, Balgi AD, Shimizu Y, Pfeifer TA, Kumar N, Shidmoossavee FS, Sun S, Tai SSH, Agafitei O, Jaquith JB, Bourque E, Niikura M, Roberge M. Novel spirothiazamenthane inhibitors of the influenza A M2 proton channel. Eur J Med Chem 2016; 120:64-73. [PMID: 27187859 DOI: 10.1016/j.ejmech.2016.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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: 10/05/2015] [Revised: 05/04/2016] [Accepted: 05/05/2016] [Indexed: 01/19/2023]
Abstract
The development of treatments for influenza that inhibit the M2 proton channel without being susceptible to the widespread resistance mechanisms associated with the adamantanes is an ongoing challenge. Using a yeast high-throughput yeast growth restoration assay designed to identify M2 channel inhibitors, a single screening hit was uncovered. This compound (3), whose structure was incorrectly identified in the literature, is an inhibitor with similar potency to amantadine against WT M2. A library of derivatives of 3 was prepared and activity against WT M2 and the two principal mutant strains (V27A and S31N) was assessed in the yeast assay. The best compounds were further evaluated in an antiviral plaque reduction assay using engineered WT, V27A and S31N M2 influenza A strains with otherwise identical genetic background. Compound 63 was found to inhibit all three virus strains in this cell based antiviral assay at micromolar concentrations, possibly through a mechanism other than M2 inhibition.
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Affiliation(s)
- Steve Arns
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Aruna D Balgi
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Yoko Shimizu
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Tom A Pfeifer
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Nag Kumar
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | | | - Sharon Sun
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Sheldon S-H Tai
- Faculty of Heath Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Olga Agafitei
- Faculty of Heath Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - James B Jaquith
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Elyse Bourque
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Masahiro Niikura
- Faculty of Heath Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Michel Roberge
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.
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5
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Arns S, Tan J, Sun S, Galey A, Zisman N, Ross F, Udechukwu J, Dercho S, Gusti V, Paquette J, Webb M, Bourque E, Withers SG, Liggins R. Assessing the oral bioavailability of difluorosialic acid prodrugs, potent viral neuraminidase inhibitors, using a snapshot PK screening assay. Bioorg Med Chem Lett 2015; 25:2505-9. [DOI: 10.1016/j.bmcl.2015.04.059] [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] [Received: 02/25/2015] [Revised: 04/17/2015] [Accepted: 04/20/2015] [Indexed: 10/23/2022]
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6
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Liu CC, Hu S, Chen G, Georgiou J, Arns S, Kumar NS, Young RN, Grynpas MD. Novel EP4 receptor agonist-bisphosphonate conjugate drug (C1) promotes bone formation and improves vertebral mechanical properties in the ovariectomized rat model of postmenopausal bone loss. J Bone Miner Res 2015; 30:670-80. [PMID: 25284325 DOI: 10.1002/jbmr.2382] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/29/2014] [Accepted: 09/11/2014] [Indexed: 11/12/2022]
Abstract
Current treatments for postmenopausal osteoporosis aim to either promote bone formation or inhibit bone resorption. The C1 conjugate drug represents a new treatment approach by chemically linking the antiresorptive compound alendronate (ALN) with the anabolic agent prostanoid EP4 receptor agonist (EP4a) through a linker molecule (LK) to form a conjugate compound. This enables the bone-targeting ability of ALN to deliver EP4a to bone sites and mitigate the systemic side effects of EP4a, while also facilitating dual antiresorptive and anabolic effects. In vivo hydrolysis is required to release the EP4a and ALN components for pharmacological activity. Our study investigated the in vivo efficacy of this drug in treating established bone loss using an ovariectomized (OVX) rat model of postmenopausal osteopenia. In a curative experiment, 3-month-old female Sprague-Dawley rats were OVX, allowed to lose bone for 7 weeks, then treated for 6 weeks. Treatment groups consisted of C1 conjugate at low and high doses, vehicle-treated OVX and sham, prostaglandin E2 (PGE2 ), and mixture of unconjugated ALN-LK and EP4a to assess the effect of conjugation. Results showed that weekly administration of C1 conjugate dose-dependently increased bone volume in trabecular bone, which partially or completely reversed OVX-induced bone loss in the lumbar vertebra and improved vertebral mechanical strength. The conjugate also dose-dependently stimulated endocortical woven bone formation and intracortical resorption in cortical bone, with high-dose treatment increasing the mechanical strength but compromising the material properties. Conjugation between the EP4a and ALN-LK components was crucial to the drug's anabolic efficacy. To our knowledge, the C1 conjugate represents the first time that a combined therapy using an anabolic agent and the antiresorptive compound ALN has shown significant anabolic effects which reversed established osteopenia.
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Affiliation(s)
- Careesa C Liu
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
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7
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Abstract
A methodology for the efficient conversion of aromatic sulfonamides into their mono-nitro derivatives using tert-butyl nitrite is reported. The reaction exhibits a high degree of chemoselectivity for sulfonamide functionalized aryl systems, even in the presence of other sensitive or potentially reactive functionalities.
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Affiliation(s)
- Brenden Kilpatrick
- Center for Drug Research and Development, 2405 Westbrook Mall, Fourth Floor, Vancouver, BC, Canada, V6T 1Z3
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8
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Palmowski M, Arns S, Rix A, Gremse F, Doleschel D, Kiessling F, Lederle W. Versagen der Apoptose-Bildgebung mittels Annexin in der Erfassung antiangiogener Therapieeffekte. ROFO-FORTSCHR RONTG 2011. [DOI: 10.1055/s-0031-1279089] [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: 10/18/2022]
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9
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Donohue E, Tovey A, Vogl AW, Arns S, Sternberg E, Young RN, Roberge M. Inhibition of autophagosome formation by the benzoporphyrin derivative verteporfin. J Biol Chem 2010; 286:7290-300. [PMID: 21193398 DOI: 10.1074/jbc.m110.139915] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Autophagy enables cells to degrade and recycle cytoplasmic materials both as a housekeeping mechanism and in response to extracellular stress such as nutrient deprivation. Recent studies indicate that autophagy also functions as a protective mechanism in response to several cancer therapy agents, making it a prospective therapeutic target. Few pharmacological inhibitors suitable for testing the therapeutic potential of autophagy inhibition in vivo are known. An automated microscopy assay was used to screen >3,500 drugs and pharmacological agents and identified one drug, verteporfin, as an inhibitor of autophagosome accumulation. Verteporfin is a benzoporphyrin derivative used in photodynamic therapy, but it inhibits autophagy without light activation. Verteporfin did not inhibit LC3/Atg8 processing or membrane recruitment in response to autophagic stimuli, but it inhibited drug- and starvation-induced autophagic degradation and the sequestration of cytoplasmic materials into autophagosomes. Transient exposure to verteporfin in starvation conditions reduced cell viability whereas cells in nutrient-rich medium were unaffected by drug treatment. Analysis of structural analogs indicated that the activity of verteporfin requires the presence of a substituted cyclohexadiene at ring A of the porphyrin core but that it can tolerate a number of large substituents at rings C and D. The existence of an autophagy inhibitor among FDA-approved drugs should facilitate the investigation of the therapeutic potential of autophagy inhibition in vivo.
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Affiliation(s)
- Elizabeth Donohue
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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10
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Hooper J, Sauer ELO, Arns S, Woo TK, Barriault L. On the Origin of Altered Diastereomeric Ratios for Anionic versus Neutral Reaction Conditions in the Oxy-Cope/Ene Reaction: An Interplay of Experiment and Computational Modeling. Chemistry 2010; 16:14124-30. [PMID: 20957622 DOI: 10.1002/chem.201001302] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- James Hooper
- Centre for Catalysis Research and Innovation, Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, K1N 6N5 ON, Canada
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11
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12
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Arns S, Lebrun ME, Grisé, CM, Denissova I, Barriault L. Diastereoselective Construction of Quaternary Carbons Directed via Macrocyclic Ring Conformation: Formal Synthesis of (−)-Mesembrine. J Org Chem 2007; 72:9314-22. [DOI: 10.1021/jo701833v] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Steve Arns
- Department of Chemistry, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario, Canada K1N 6N5
| | - Marie-Eve Lebrun
- Department of Chemistry, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario, Canada K1N 6N5
| | - Christiane M. Grisé,
- Department of Chemistry, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario, Canada K1N 6N5
| | - Irina Denissova
- Department of Chemistry, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario, Canada K1N 6N5
| | - Louis Barriault
- Department of Chemistry, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario, Canada K1N 6N5
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13
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Abstract
Tandem reactions have emerged as powerful strategies to synthesize complex structures, in particular, processes involving pericyclic reactions. This article describes recent advancement by our group in the development of novel tandem pericyclic reactions aimed at constructing diterpene frameworks.
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Affiliation(s)
- Steve Arns
- Department of Chemistry, 10 Marie Curie, University of Ottawa, Ottawa, Ontario, CanadaK1N 6N5
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14
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Tsefrikas VM, Arns S, Merner PM, Warford CC, Merner BL, Scott LT, Bodwell GJ. Benzo[a]acecorannulene: Surprising Formation of a New Bowl-Shaped Aromatic Hydrocarbon from an Attempted Synthesis of 1,2-Diazadibenzo[d,m]corannulene. Org Lett 2006; 8:5195-8. [PMID: 17078676 DOI: 10.1021/ol061554v] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
[Structure: see text] Flash vacuum pyrolysis of 7,10-bis(2-bromophenyl)acenaphtho[1,2-d]pyridazine (C26H14Br2N2) has resulted in a surprising transformation, including dinitrogen loss, to give benzo[a]acecorannulene, a novel C26H12 bowl-shaped fullerene fragment.
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Affiliation(s)
- Vikki M Tsefrikas
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada AlB 3X7
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15
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Abstract
Herein, we describe the synthesis of advanced intermediate 39 on the path towards the total synthesis of teucrolivin A (3) in 16 steps from commercially available 1,3-cyclohexadiene. We have constructed the trans-decalin core of the natural product 3 as a single diastereomer using a tandem oxy-Cope/Claisen/ene cascade and in doing so have incorporated sufficient functionality to allow completion of the total synthesis.
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Affiliation(s)
- Steve Arns
- Department of Chemistry, 10 Marie-Curie, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
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16
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Kierdorf HP, Leue C, Arns S. Lactate- or bicarbonate-buffered solutions in continuous extracorporeal renal replacement therapies. Kidney Int Suppl 1999:S32-6. [PMID: 10560802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
BACKGROUND Continuous renal replacement therapies (CRRTs) are well accepted for critically ill patients with acute renal failure (ARF). Today, daily fluid exchange in CRRT reaches 30 to 40 liter and more. Therefore, the composition of the substitution/dialysate fluid, often primarily developed either for intermittent treatment or for peritoneal dialysis, becomes more relevant. Lactate (30 to 45 mmol/liter) is frequently used as the buffer because of the high stability of this substance. However, lactate is thought to have negative effects on metabolic and hemodynamic parameters. METHODS Published data for different substitution fluids are presented with respect to acidosis and lactate concentration, uremia, and hemodynamic and metabolic alterations. RESULTS Only a few studies compare substitution fluids with different buffers. Uremia and acidosis (pH, base excess) were sufficiently controlled during CRRT with an exchange volume of in average 30 liters using either buffer. If patients with severe liver failure and lactic acidosis were excluded, no difference in hemodynamic and metabolic parameters between the solutions occurred. The plasma lactate concentration was elevated during lactate use in some cases, but lactate levels remained within normal limits in patients without liver impairment. The bicarbonate concentration in the solutions should exceed 35 to 40 mmol/liter, as in some cases the buffer capacity of the solutions was inadequate. In patients with severe liver failure or lactic acidosis, solutions with lactate buffer were shown not to be indicated. CONCLUSION In patients with reduced lactate metabolism, for example, concomitant severe liver failure, after liver transplantation or in lactic acidosis, bicarbonate-buffered solutions should be used. In nearly all other cases of critically ill patients with ARF, lactate-buffered solutions may be used as well as bicarbonate solutions.
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Affiliation(s)
- H P Kierdorf
- Department of Internal Medicine II, University Clinic of the Technical University Aachen, Germany.
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