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Barszczewska-Pietraszek G, Drzewiecka M, Czarny P, Skorski T, Śliwiński T. Polθ Inhibition: An Anticancer Therapy for HR-Deficient Tumours. Int J Mol Sci 2022; 24:ijms24010319. [PMID: 36613762 PMCID: PMC9820168 DOI: 10.3390/ijms24010319] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/15/2022] [Accepted: 12/17/2022] [Indexed: 12/28/2022] Open
Abstract
DNA polymerase theta (Polθ)-mediated end joining (TMEJ) is, along with homologous recombination (HR) and non-homologous end-joining (NHEJ), one of the most important mechanisms repairing potentially lethal DNA double-strand breaks (DSBs). Polθ is becoming a new target in cancer research because it demonstrates numerous synthetically lethal interactions with other DNA repair mechanisms, e.g., those involving PARP1, BRCA1/2, DNA-PK, ATR. Inhibition of Polθ could be achieved with different methods, such as RNA interference (RNAi), CRISPR/Cas9 technology, or using small molecule inhibitors. In the context of this topic, RNAi and CRISPR/Cas9 are still more often applied in the research itself rather than clinical usage, different than small molecule inhibitors. Several Polθ inhibitors have been already generated, and two of them, novobiocin (NVB) and ART812 derivative, are being tested in clinical trials against HR-deficient tumors. In this review, we describe the significance of Polθ and the Polθ-mediated TMEJ pathway. In addition, we summarize the current state of knowledge about Polθ inhibitors and emphasize the promising role of Polθ as a therapeutic target.
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Affiliation(s)
| | - Małgorzata Drzewiecka
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Piotr Czarny
- Department of Medical Biochemistry, Medical University of Lodz, 92-216 Lodz, Poland
| | - Tomasz Skorski
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Tomasz Śliwiński
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
- Correspondence: ; Tel.: +48-42-635-44-86
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Joharji H, Alaidaros F, Koujan H, Hamad A, Almaghrabi RS, Zidan A, Broering D, Al-Jedai A. A Case Report of Successful Use of Twice-Daily Letermovir in the Treatment of Resistant Cytomegalovirus in a Small Bowel Transplant Recipient. Transplant Proc 2022; 54:1679-1681. [PMID: 35842318 DOI: 10.1016/j.transproceed.2022.04.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/12/2022] [Indexed: 11/19/2022]
Abstract
Cytomegalovirus (CMV) is considered one of the most notable pathogens that affect patients after solid organ transplantation (SOT), especially small bowel transplant patients with a risk of high mortality rate. Its management relies historically on the use of CMV DNA polymerase inhibitors (namely, ganciclovir and valganciclovir). Second-line options include foscarnet and cidofovir, which are highly nephrotoxic and thus less preferred and only used in ganciclovir intolerance or resistance cases. Letermovir is a novel antiviral agent approved for CMV prophylaxis in hematopoietic stem cell transplant, but not for SOT (neither for prophylaxis nor for treatment). We report the first case on the successful use of letermovir in treating CMV disease in a small bowel transplant patient who failed to achieve viral clearance due to ganciclovir resistance and severe intolerance to foscarnet.
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Affiliation(s)
- Hala Joharji
- Organ Transplant Center of Excellence, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fatima Alaidaros
- Organ Transplant Center of Excellence, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hamzah Koujan
- Organ Transplant Center of Excellence, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Alaa Hamad
- Organ Transplant Center of Excellence, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Reem S Almaghrabi
- Organ Transplant Center of Excellence, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ahmed Zidan
- Organ Transplant Center of Excellence, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Deiter Broering
- Organ Transplant Center of Excellence, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ahmed Al-Jedai
- Organ Transplant Center of Excellence, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
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Takano N, Seike M, Sugano T, Matsuda K, Hisakane K, Yoshikawa A, Nakamichi S, Noro R, Gemma A. A Novel Molecular Target in EGFR-mutant Lung Cancer Treated With the Combination of Osimertinib and Pemetrexed. Anticancer Res 2022; 42:709-722. [PMID: 35093869 DOI: 10.21873/anticanres.15529] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM Synergistic effects of epidermal growth factor receptor tyrosine kinase inhibitors and chemotherapy have been reported. Here, we evaluated the therapeutic potential of combining osimertinib with pemetrexed and investigated the molecular mechanisms. MATERIALS AND METHODS We analyzed the antitumor effects of osimertinib± pemetrexed in PC-9 and H1975 cells. Gene expression on exposure to osimertinib±pemetrexed was assessed in these cultured cells. Cell lines resistant to osimertinib±pemetrexed were established to explore mechanisms of resistance. RESULTS Osimertinib+pemetrexed treatment delayed the emergence of resistance relative to monotherapy in vitro and in vivo. Expression of the anti-apoptotic gene PLK1 was down-regulated in PC-9 and H1975 exposed to osimertinib+ pemetrexed, whereas it was up-regulated in resistant cells. Furthermore, inhibition of PLK1 induced apoptosis and inhibited proliferation of resistant cells. CONCLUSION Blocking PLK1 contributes to mediating the synergistic anti-proliferative effect of osimertinib+pemetrexed. PLK1 over-expression may be a critical mechanism for acquired resistance to osimertinib+pemetrexed.
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Affiliation(s)
- Natsuki Takano
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Masahiro Seike
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Teppei Sugano
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Kuniko Matsuda
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Kakeru Hisakane
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Akiko Yoshikawa
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Shinji Nakamichi
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Rintaro Noro
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Akihiko Gemma
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
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Ríos-Meléndez S, Valadez-Hernández E, Delgadillo C, Luna-Guevara ML, Martínez-Núñez MA, Sánchez-Pérez M, Martínez-Y-Pérez JL, Arroyo-Becerra A, Cárdenas L, Bibbins-Martínez M, Maldonado-Mendoza IE, Villalobos-López MA. Pseudocrossidium replicatum (Taylor) R.H. Zander is a fully desiccation-tolerant moss that expresses an inducible molecular mechanism in response to severe abiotic stress. Plant Mol Biol 2021; 107:387-404. [PMID: 34189708 PMCID: PMC8648698 DOI: 10.1007/s11103-021-01167-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 06/10/2021] [Indexed: 05/04/2023]
Abstract
KEY MESSAGE The moss Pseudocrossidium replicatum is a desiccation-tolerant species that uses an inducible system to withstand severe abiotic stress in both protonemal and gametophore tissues. Desiccation tolerance (DT) is the ability of cells to recover from an air-dried state. Here, the moss Pseudocrossidium replicatum was identified as a fully desiccation-tolerant (FDT) species. Its gametophores rapidly lost more than 90% of their water content when exposed to a low-humidity atmosphere [23% relative humidity (RH)], but abscisic acid (ABA) pretreatment diminished the final water loss after equilibrium was reached. P. replicatum gametophores maintained good maximum photosystem II (PSII) efficiency (Fv/Fm) for up to two hours during slow dehydration; however, ABA pretreatment induced a faster decrease in the Fv/Fm. ABA also induced a faster recovery of the Fv/Fm after rehydration. Protein synthesis inhibitor treatment before dehydration hampered the recovery of the Fv/Fm when the gametophores were rehydrated after desiccation, suggesting the presence of an inducible protective mechanism that is activated in response to abiotic stress. This observation was also supported by accumulation of soluble sugars in gametophores exposed to ABA or NaCl. Exogenous ABA treatment delayed the germination of P. replicatum spores and induced morphological changes in protonemal cells that resembled brachycytes. Transcriptome analyses revealed the presence of an inducible molecular mechanism in P. replicatum protonemata that was activated in response to dehydration. This study is the first RNA-Seq study of the protonemal tissues of an FDT moss. Our results suggest that P. replicatum is an FDT moss equipped with an inducible molecular response that prepares this species for severe abiotic stress and that ABA plays an important role in this response.
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Affiliation(s)
- Selma Ríos-Meléndez
- Laboratorio de Genómica Funcional y Biotecnología de Plantas, Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, C.P. 90700, Tepetitla de Lardizábal, Tlaxcala, México
| | - Emmanuel Valadez-Hernández
- Laboratorio de Genómica Funcional y Biotecnología de Plantas, Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, C.P. 90700, Tepetitla de Lardizábal, Tlaxcala, México
| | - Claudio Delgadillo
- Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Maria L Luna-Guevara
- Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, C.P. 72000, Puebla, Puebla, México
| | - Mario A Martínez-Núñez
- UMDI-Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, C.P. 97302, Mérida, Yucatán, México
| | - Mishael Sánchez-Pérez
- Unidad de Análisis Bioinformáticos, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, C.P. 62210, Cuernavaca, Morelos, México
| | - José L Martínez-Y-Pérez
- Centro de Investigación en Genética y Ambiente, Universidad Autónoma de Tlaxcala, C.P. 90210, Ixtacuixtla, Tlaxcala, México
| | - Analilia Arroyo-Becerra
- Laboratorio de Genómica Funcional y Biotecnología de Plantas, Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, C.P. 90700, Tepetitla de Lardizábal, Tlaxcala, México
| | - Luis Cárdenas
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, C.P. 62210, Cuernavaca, Morelos, México
| | - Martha Bibbins-Martínez
- Laboratorio de Genómica Funcional y Biotecnología de Plantas, Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, C.P. 90700, Tepetitla de Lardizábal, Tlaxcala, México
| | - Ignacio E Maldonado-Mendoza
- Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional, Unidad Sinaloa, Instituto Politécnico Nacional, C.P. 81049, Guasave, Sinaloa, México
| | - Miguel Angel Villalobos-López
- Laboratorio de Genómica Funcional y Biotecnología de Plantas, Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, C.P. 90700, Tepetitla de Lardizábal, Tlaxcala, México.
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Taglialatela A, Leuzzi G, Sannino V, Cuella-Martin R, Huang JW, Wu-Baer F, Baer R, Costanzo V, Ciccia A. REV1-Polζ maintains the viability of homologous recombination-deficient cancer cells through mutagenic repair of PRIMPOL-dependent ssDNA gaps. Mol Cell 2021; 81:4008-4025.e7. [PMID: 34508659 PMCID: PMC8500949 DOI: 10.1016/j.molcel.2021.08.016] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 05/29/2021] [Accepted: 08/11/2021] [Indexed: 12/11/2022]
Abstract
BRCA1/2 mutant tumor cells display an elevated mutation burden, the etiology of which remains unclear. Here, we report that these cells accumulate ssDNA gaps and spontaneous mutations during unperturbed DNA replication due to repriming by the DNA primase-polymerase PRIMPOL. Gap accumulation requires the DNA glycosylase SMUG1 and is exacerbated by depletion of the translesion synthesis (TLS) factor RAD18 or inhibition of the error-prone TLS polymerase complex REV1-Polζ by the small molecule JH-RE-06. JH-RE-06 treatment of BRCA1/2-deficient cells results in reduced mutation rates and PRIMPOL- and SMUG1-dependent loss of viability. Through cellular and animal studies, we demonstrate that JH-RE-06 is preferentially toxic toward HR-deficient cancer cells. Furthermore, JH-RE-06 remains effective toward PARP inhibitor (PARPi)-resistant BRCA1 mutant cells and displays additive toxicity with crosslinking agents or PARPi. Collectively, these studies identify a protective and mutagenic role for REV1-Polζ in BRCA1/2 mutant cells and provide the rationale for using REV1-Polζ inhibitors to treat BRCA1/2 mutant tumors.
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Affiliation(s)
- Angelo Taglialatela
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Giuseppe Leuzzi
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Vincenzo Sannino
- DNA Metabolism Laboratory, IFOM, FIRC Institute for Molecular Oncology, Milan, Italy; Department of Oncology and Hematology-Oncology, University of Milan, Milan, Italy
| | - Raquel Cuella-Martin
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Jen-Wei Huang
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Foon Wu-Baer
- Institute for Cancer Genetics, Department of Pathology & Cell Biology, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Richard Baer
- Institute for Cancer Genetics, Department of Pathology & Cell Biology, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Vincenzo Costanzo
- DNA Metabolism Laboratory, IFOM, FIRC Institute for Molecular Oncology, Milan, Italy; Department of Oncology and Hematology-Oncology, University of Milan, Milan, Italy
| | - Alberto Ciccia
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA.
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Krause K, Pyrczak-Felczykowska A, Karczewska M, Narajczyk M, Herman-Antosiewicz A, Szalewska-Pałasz A, Nowicki D. Dietary Isothiocyanates, Sulforaphane and 2-Phenethyl Isothiocyanate, Effectively Impair Vibrio cholerae Virulence. Int J Mol Sci 2021; 22:10187. [PMID: 34638525 PMCID: PMC8508596 DOI: 10.3390/ijms221910187] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/09/2021] [Accepted: 09/20/2021] [Indexed: 12/02/2022] Open
Abstract
Vibrio cholerae represents a constant threat to public health, causing widespread infections, especially in developing countries with a significant number of fatalities and serious complications every year. The standard treatment by oral rehydration does not eliminate the source of infection, while increasing antibiotic resistance among pathogenic V. cholerae strains makes the therapy difficult. Thus, we assessed the antibacterial potential of plant-derived phytoncides, isothiocyanates (ITC), against V. cholerae O365 strain. Sulforaphane (SFN) and 2-phenethyl isothiocyanate (PEITC) ability to inhibit bacterial growth was assessed. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values indicate that these compounds possess antibacterial activity and are also effective against cells growing in a biofilm. Tested ITC caused accumulation of stringent response alarmone, ppGpp, which indicates induction of the global stress response. It was accompanied by bacterial cytoplasm shrinkage, the inhibition of the DNA, and RNA synthesis as well as downregulation of the expression of virulence factors. Most importantly, ITC reduced the toxicity of V. cholerae in the in vitro assays (against Vero and HeLa cells) and in vivo, using Galleria mellonella larvae as an infection model. In conclusion, our data indicate that ITCs might be considered promising antibacterial agents in V. cholerae infections.
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Affiliation(s)
- Klaudyna Krause
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland; (K.K.); (M.K.); (A.S.-P.)
| | | | - Monika Karczewska
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland; (K.K.); (M.K.); (A.S.-P.)
| | - Magdalena Narajczyk
- Department of Electron Microscopy, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland;
| | - Anna Herman-Antosiewicz
- Department of Medical Biology and Genetics, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland;
| | - Agnieszka Szalewska-Pałasz
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland; (K.K.); (M.K.); (A.S.-P.)
| | - Dariusz Nowicki
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland; (K.K.); (M.K.); (A.S.-P.)
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Hurmach VV, Platonov MO, Prylutska SV, Scharff P, Prylutskyy YI, Ritter U. C 60 fullerene against SARS-CoV-2 coronavirus: an in silico insight. Sci Rep 2021; 11:17748. [PMID: 34493768 PMCID: PMC8423725 DOI: 10.1038/s41598-021-97268-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 08/24/2021] [Indexed: 01/18/2023] Open
Abstract
Based on WHO reports the new SARS-CoV-2 coronavirus is currently widespread all over the world. So far > 162 million cases have been confirmed, including > 3 million deaths. Because of the pandemic still spreading across the globe the accomplishment of computational methods to find new potential mechanisms of virus inhibitions is necessary. According to the fact that C60 fullerene (a sphere-shaped molecule consisting of carbon) has shown inhibitory activity against various protein targets, here the analysis of the potential binding mechanism between SARS-CoV-2 proteins 3CLpro and RdRp with C60 fullerene was done; it has resulted in one and two possible binding mechanisms, respectively. In the case of 3CLpro, C60 fullerene interacts in the catalytic binding pocket. And for RdRp in the first model C60 fullerene blocks RNA synthesis pore and in the second one it prevents binding with Nsp8 co-factor (without this complex formation, RdRp can't perform its initial functions). Then the molecular dynamics simulation confirmed the stability of created complexes. The obtained results might be a basis for other computational studies of 3CLPro and RdRp potential inhibition ways as well as the potential usage of C60 fullerene in the fight against COVID-19 disease.
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Affiliation(s)
- Vasyl V Hurmach
- Taras Shevchenko National University of Kyiv, Kyiv, 01601, Ukraine
| | - Maksim O Platonov
- Institute of Molecular Biology and Genetics of NASU, Kyiv, 03143, Ukraine
| | - Svitlana V Prylutska
- Taras Shevchenko National University of Kyiv, Kyiv, 01601, Ukraine
- National University of Life and Environmental Science of Ukraine, Kyiv, 03041, Ukraine
| | - Peter Scharff
- Institute of Chemistry and Biotechnology, Technical University of Ilmenau, 98693, Ilmenau, Germany
| | | | - Uwe Ritter
- Institute of Chemistry and Biotechnology, Technical University of Ilmenau, 98693, Ilmenau, Germany.
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Zahn KE, Jensen RB. Polymerase θ Coordinates Multiple Intrinsic Enzymatic Activities during DNA Repair. Genes (Basel) 2021; 12:1310. [PMID: 34573292 PMCID: PMC8470613 DOI: 10.3390/genes12091310] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 07/13/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 11/16/2022] Open
Abstract
The POLQ gene encodes DNA polymerase θ, a 2590 amino acid protein product harboring DNA-dependent ATPase, template-dependent DNA polymerase, dNTP-dependent endonuclease, and 5'-dRP lyase functions. Polymerase θ participates at an essential step of a DNA double-strand break repair pathway able to join 5'-resected substrates by locating and pairing microhomologies present in 3'-overhanging single-stranded tails, cleaving the extraneous 3'-DNA by dNTP-dependent end-processing, before extending the nascent 3' end from the microhomology annealing site. Metazoans require polymerase θ for full resistance to DNA double-strand break inducing agents but can survive knockout of the POLQ gene. Cancer cells with compromised homologous recombination, or other DNA repair defects, over-utilize end-joining by polymerase θ and often over-express the POLQ gene. This dependency points to polymerase θ as an ideal drug target candidate and multiple drug-development programs are now preparing to enter clinical trials with small-molecule inhibitors. Specific inhibitors of polymerase θ would not only be predicted to treat BRCA-mutant cancers, but could thwart accumulated resistance to current standard-of-care cancer therapies and overcome PARP-inhibitor resistance in patients. This article will discuss synthetic lethal strategies targeting polymerase θ in DNA damage-response-deficient cancers and summarize data, describing molecular structures and enzymatic functions.
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Affiliation(s)
- Karl E. Zahn
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
- Repare Therapeutics, 7210 Rue Frederick Banting, Montreal, QC H4S 2A1, Canada
| | - Ryan B. Jensen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
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Ma JY, Feng X, Xie FY, Li S, Chen LN, Luo SM, Yin S, Ou XH. Double-strand breaks induce short-scale DNA replication and damage amplification in the fully grown mouse oocytes. Genetics 2021; 218:iyab054. [PMID: 33792683 PMCID: PMC8225347 DOI: 10.1093/genetics/iyab054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 02/05/2021] [Accepted: 03/26/2021] [Indexed: 12/20/2022] Open
Abstract
Break-induced replication (BIR) is essential for the repair of DNA double-strand breaks (DSBs) with single ends. DSBs-induced microhomology-mediated BIR (mmBIR) and template-switching can increase the risk of complex genome rearrangement. In addition, DSBs can also induce the multi-invasion-mediated DSB amplification. The mmBIR-induced genomic rearrangement has been identified in cancer cells and patients with rare diseases. However, when and how mmBIR is initiated have not been fully and deeply studied. Furthermore, it is not well understood about the conditions for initiation of multi-invasion-mediated DSB amplification. In the G2 phase oocyte of mouse, we identified a type of short-scale BIR (ssBIR) using the DNA replication indicator 5-ethynyl-2'-deoxyuridine (EdU). These ssBIRs could only be induced in the fully grown oocytes but not the growing oocytes. If the DSB oocytes were treated with Rad51 or Chek1/2 inhibitors, both EdU signals and DSB marker γH2A.X foci would decrease. In addition, the DNA polymerase inhibitor Aphidicolin could inhibit the ssBIR and another inhibitor ddATP could reduce the number of γH2A.X foci in the DSB oocytes. In conclusion, our results showed that DNA DSBs in the fully grown oocytes can initiate ssBIR and be amplified by Rad51 or DNA replication.
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Affiliation(s)
- Jun-Yu Ma
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Xie Feng
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou 510515, China
| | - Feng-Yun Xie
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Sen Li
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Lei-Ning Chen
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Shi-Ming Luo
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Shen Yin
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao 266109, China
| | - Xiang-Hong Ou
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510320, China
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Ramachandran S, Ma TS, Griffin J, Ng N, Foskolou IP, Hwang MS, Victori P, Cheng WC, Buffa FM, Leszczynska KB, El-Khamisy SF, Gromak N, Hammond EM. Hypoxia-induced SETX links replication stress with the unfolded protein response. Nat Commun 2021; 12:3686. [PMID: 34140498 PMCID: PMC8211819 DOI: 10.1038/s41467-021-24066-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 05/31/2021] [Indexed: 02/07/2023] Open
Abstract
Tumour hypoxia is associated with poor patient prognosis and therapy resistance. A unique transcriptional response is initiated by hypoxia which includes the rapid activation of numerous transcription factors in a background of reduced global transcription. Here, we show that the biological response to hypoxia includes the accumulation of R-loops and the induction of the RNA/DNA helicase SETX. In the absence of hypoxia-induced SETX, R-loop levels increase, DNA damage accumulates, and DNA replication rates decrease. Therefore, suggesting that, SETX plays a role in protecting cells from DNA damage induced during transcription in hypoxia. Importantly, we propose that the mechanism of SETX induction in hypoxia is reliant on the PERK/ATF4 arm of the unfolded protein response. These data not only highlight the unique cellular response to hypoxia, which includes both a replication stress-dependent DNA damage response and an unfolded protein response but uncover a novel link between these two distinct pathways.
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Affiliation(s)
- Shaliny Ramachandran
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Tiffany S Ma
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Jon Griffin
- Department of Molecular Biology and Biotechnology, Healthy Lifespan and Neuroscience Institute, Firth Court, University of Sheffield, Sheffield, UK
- Department of Histopathology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Natalie Ng
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Iosifina P Foskolou
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Ming-Shih Hwang
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Pedro Victori
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Wei-Chen Cheng
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Francesca M Buffa
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Katarzyna B Leszczynska
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
- Laboratory of Molecular Neurobiology, Neurobiology Center, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Sherif F El-Khamisy
- Department of Molecular Biology and Biotechnology, Healthy Lifespan and Neuroscience Institute, Firth Court, University of Sheffield, Sheffield, UK
- Institute of Cancer Therapeutics, University of Bradford, Bradford, UK
| | - Natalia Gromak
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Ester M Hammond
- Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK.
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11
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Zatreanu D, Robinson HMR, Alkhatib O, Boursier M, Finch H, Geo L, Grande D, Grinkevich V, Heald RA, Langdon S, Majithiya J, McWhirter C, Martin NMB, Moore S, Neves J, Rajendra E, Ranzani M, Schaedler T, Stockley M, Wiggins K, Brough R, Sridhar S, Gulati A, Shao N, Badder LM, Novo D, Knight EG, Marlow R, Haider S, Callen E, Hewitt G, Schimmel J, Prevo R, Alli C, Ferdinand A, Bell C, Blencowe P, Bot C, Calder M, Charles M, Curry J, Ekwuru T, Ewings K, Krajewski W, MacDonald E, McCarron H, Pang L, Pedder C, Rigoreau L, Swarbrick M, Wheatley E, Willis S, Wong AC, Nussenzweig A, Tijsterman M, Tutt A, Boulton SJ, Higgins GS, Pettitt SJ, Smith GCM, Lord CJ. Polθ inhibitors elicit BRCA-gene synthetic lethality and target PARP inhibitor resistance. Nat Commun 2021; 12:3636. [PMID: 34140467 PMCID: PMC8211653 DOI: 10.1038/s41467-021-23463-8] [Citation(s) in RCA: 144] [Impact Index Per Article: 48.0] [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: 03/17/2021] [Accepted: 04/30/2021] [Indexed: 02/05/2023] Open
Abstract
To identify approaches to target DNA repair vulnerabilities in cancer, we discovered nanomolar potent, selective, low molecular weight (MW), allosteric inhibitors of the polymerase function of DNA polymerase Polθ, including ART558. ART558 inhibits the major Polθ-mediated DNA repair process, Theta-Mediated End Joining, without targeting Non-Homologous End Joining. In addition, ART558 elicits DNA damage and synthetic lethality in BRCA1- or BRCA2-mutant tumour cells and enhances the effects of a PARP inhibitor. Genetic perturbation screening revealed that defects in the 53BP1/Shieldin complex, which cause PARP inhibitor resistance, result in in vitro and in vivo sensitivity to small molecule Polθ polymerase inhibitors. Mechanistically, ART558 increases biomarkers of single-stranded DNA and synthetic lethality in 53BP1-defective cells whilst the inhibition of DNA nucleases that promote end-resection reversed these effects, implicating these in the synthetic lethal mechanism-of-action. Taken together, these observations describe a drug class that elicits BRCA-gene synthetic lethality and PARP inhibitor synergy, as well as targeting a biomarker-defined mechanism of PARPi-resistance.
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Affiliation(s)
- Diana Zatreanu
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Helen M R Robinson
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Omar Alkhatib
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Marie Boursier
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Harry Finch
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Lerin Geo
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Diego Grande
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Vera Grinkevich
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Robert A Heald
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Sophie Langdon
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Jayesh Majithiya
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Claire McWhirter
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Niall M B Martin
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Shaun Moore
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Joana Neves
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Eeson Rajendra
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Marco Ranzani
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Theresia Schaedler
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Martin Stockley
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Kimberley Wiggins
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Rachel Brough
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Sandhya Sridhar
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Aditi Gulati
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Nan Shao
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Luned M Badder
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Daniela Novo
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Eleanor G Knight
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Rebecca Marlow
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Syed Haider
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Elsa Callen
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | | | - Joost Schimmel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Remko Prevo
- Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, UK
| | - Christina Alli
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Amanda Ferdinand
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Cameron Bell
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Peter Blencowe
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Chris Bot
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Mathew Calder
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Mark Charles
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Jayne Curry
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Tennyson Ekwuru
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Katherine Ewings
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Wojciech Krajewski
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ellen MacDonald
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Hollie McCarron
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Leon Pang
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Chris Pedder
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Laurent Rigoreau
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Martin Swarbrick
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ed Wheatley
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Simon Willis
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ai Ching Wong
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Andre Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Marcel Tijsterman
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Andrew Tutt
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Simon J Boulton
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
- The Francis Crick Institute, London, UK
| | - Geoff S Higgins
- Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, UK
| | - Stephen J Pettitt
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK.
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK.
| | - Graeme C M Smith
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK.
| | - Christopher J Lord
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK.
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK.
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Abstract
In the last few years, several new direct-acting influenza antivirals have been licensed, and others have advanced in clinical development. The increasing diversity of antiviral classes should allow an adequate public health response should a resistant virus to one agent or class widely circulate. One new antiviral, baloxavir marboxil, has been approved in the United States for treatment of influenza in those at high risk of developing influenza-related complications. Except for intravenous zanamivir in European Union countries, no antivirals have been licensed specifically for the indication of severe influenza or hospitalized influenza. This review addresses recent clinical developments involving selected polymerase inhibitors, neuraminidase inhibitors, antibody-based therapeutics, and host-directed therapies. There are many knowledge gaps for most of these agents because some data are not published and multiple pivotal studies are in progress at present. This review also considers important clinical research issues, including regulatory pathways, study designs, endpoints, and target populations encountered during the clinical development of novel therapeutics.
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Affiliation(s)
- John H Beigel
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20892-9826, USA
| | - Frederick G Hayden
- Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
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13
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Schrempf A, Slyskova J, Loizou JI. Targeting the DNA Repair Enzyme Polymerase θ in Cancer Therapy. Trends Cancer 2021; 7:98-111. [PMID: 33109489 DOI: 10.1016/j.trecan.2020.09.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/21/2020] [Accepted: 09/28/2020] [Indexed: 12/21/2022]
Abstract
Targeted cancer therapies represent a milestone towards personalized treatment as they function via inhibition of cancer-specific alterations. Polymerase θ (POLQ), an error-prone translesion polymerase, also involved in DNA double-strand break (DSB) repair, is often upregulated in cancer. POLQ is synthetic lethal with various DNA repair genes, including known cancer drivers such as BRCA1/2, making it essential in homologous recombination-deficient cancers. Thus, POLQ represents a promising target in cancer therapy and efforts for the development of POLQ inhibitors are actively underway with first clinical trials due to start in 2021. This review summarizes the journey of POLQ from a backup DNA repair enzyme to a promising therapeutic target for cancer treatment.
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Affiliation(s)
- Anna Schrempf
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090 Vienna, Austria; Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Jana Slyskova
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090 Vienna, Austria; Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria.
| | - Joanna I Loizou
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090 Vienna, Austria; Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria.
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14
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Oliveira RF, Ferreira GA, Ghanem VC, Corrêa-Dantas PE, Ghanem RC. Transepithelial Surface Ablation With Mitomycin C for the Treatment of Chronic Central Corneal Scars Following Adenoviral Keratoconjunctivitis. J Refract Surg 2020; 36:55-61. [PMID: 31917852 DOI: 10.3928/1081597x-20191203-01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 11/27/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess visual and refractive outcomes and recurrence rates of subepithelial infiltrates after corneal surface ablation with mitomycin C (MMC) 0.02% for the treatment of chronic corneal scars following epidemic keratoconjunctivitis and to compare these results with a control group receiving only medical treatment. METHODS This was a retrospective case series enrolling patients with central corneal scars following epidemic keratoconjunctivitis. Patients were divided into two groups: (1) control with clinical follow-up and refractive correction with glasses or rigid gas-permeable contact lenses when necessary and (2) transepithelial phototherapeutic keratectomy (PTK) with MMC 0.02%, combined with photorefractive keratectomy (PRK) in selected cases (treatment group). Signs and symptoms, corrected distance visual acuity (CDVA) in logMAR units, manifest and cycloplegic refraction, and depth of the corneal opacities were assessed. RESULTS Thirty-five eyes of 27 patients (11 men [40.7%] and 16 women [59.3%]) were enrolled, with a mean follow-up of 54.4 ± 19.7 and 27.5 ± 22.8 months in the control and treatment groups, respectively. Mean improvement in CDVA was 0.13 ± 0.17 logMAR (P = .007) in the control group and 0.29 ± 0.24 logMAR (P = .001) in the treatment group. Intergroup comparison showed a greater improvement in the treatment group (P = .041). Mean hyperopic shift induced in the treatment group was +0.46 ± 1.20 diopters. The recurrence rate of subepithelial infiltrates was 77.7% in the control group and 11.7% in the treatment group throughout the follow-up (54.4 ± 19.7 and 27.5 ± 22.8 months, respectively). CONCLUSIONS Corneal surface ablation with MMC 0.02% was efficient in treating corneal scars following adenoviral epidemic keratoconjunctivitis, with greater visual improvement in comparison to clinical treatment and a decreased rate of infiltrate recurrence. [J Refract Surg. 2020;36(1):55-61.].
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15
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Abstract
With CA16, enterovirus-71 is the causative agent of hand foot and mouth disease (HFMD) which occurs mostly in children under 5 years-old and responsible of several outbreaks since a decade. Most of the time, HFMD is a mild disease but can progress to severe complications such as meningitis, brain stem encephalitis, acute flaccid paralysis (AFP) and even death; EV71 has been identified in all severe cases. Therefore, it is actually one of the most public health issues that threatens children's life. [Formula: see text] is a protease which plays important functions in EV71 infection. To date, a lot of [Formula: see text] inhibitors have been tested but none of them has been approved yet. Therefore, a drug screening is still an utmost importance in order to treat and/or prevent EV71 infections. This work highlights the EV71 life cycle, [Formula: see text] functions and [Formula: see text] inhibitors recently screened. It permits to well understand all mechanisms about [Formula: see text] and consequently allow further development of drugs targeting [Formula: see text]. Thus, this review is helpful for screening of more new [Formula: see text] inhibitors or for designing analogues of well known [Formula: see text] inhibitors in order to improve its antiviral activity.
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Affiliation(s)
- Rominah Onintsoa Diarimalala
- National 111 Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Sino-German Biomedical Center, Hubei University of Technology, Wuhan, China
| | - Meichun Hu
- National 111 Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Sino-German Biomedical Center, Hubei University of Technology, Wuhan, China
| | - Yanhong Wei
- National 111 Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Sino-German Biomedical Center, Hubei University of Technology, Wuhan, China
| | - Kanghong Hu
- National 111 Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Sino-German Biomedical Center, Hubei University of Technology, Wuhan, China
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16
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Hu Y, Wang Z, Chen Z, Pan L. Switching the activity of Taq polymerase using clamp-like triplex aptamer structure. Nucleic Acids Res 2020; 48:8591-8600. [PMID: 32644133 PMCID: PMC7470972 DOI: 10.1093/nar/gkaa581] [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] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/31/2020] [Accepted: 06/27/2020] [Indexed: 01/22/2023] Open
Abstract
In nature, allostery is the principal approach for regulating cellular processes and pathways. Inspired by nature, structure-switching aptamer-based nanodevices are widely used in artificial biotechnologies. However, the canonical aptamer structures in the nanodevices usually adopt a duplex form, which limits the flexibility and controllability. Here, a new regulating strategy based on a clamp-like triplex aptamer structure (CLTAS) was proposed for switching DNA polymerase activity via conformational changes. It was demonstrated that the polymerase activity could be regulated by either adjusting structure parameters or dynamic reactions including strand displacement or enzymatic digestion. Compared with the duplex aptamer structure, the CLTAS possesses programmability, excellent affinity and high discrimination efficiency. The CLTAS was successfully applied to distinguish single-base mismatches. The strategy expands the application scope of triplex structures and shows potential in biosensing and programmable nanomachines.
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Affiliation(s)
- Yingxin Hu
- Key Laboratory of Image Information Processing and Intelligent Control of Education Ministry of China, School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- College of Information Science and Technology, Shijiazhuang Tiedao University, Shijiazhuang, Hebei 050043, China
| | - Zhiyu Wang
- Key Laboratory of Image Information Processing and Intelligent Control of Education Ministry of China, School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Zhekun Chen
- Key Laboratory of Image Information Processing and Intelligent Control of Education Ministry of China, School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Linqiang Pan
- To whom correspondence should be addressed. Tel: +86 27 87556070; Fax: +86 27 87543130;
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17
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Iwasaki RS, Batey RT. SPRINT: a Cas13a-based platform for detection of small molecules. Nucleic Acids Res 2020; 48:e101. [PMID: 32797156 PMCID: PMC7515716 DOI: 10.1093/nar/gkaa673] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [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: 06/08/2020] [Revised: 07/15/2020] [Accepted: 07/31/2020] [Indexed: 12/19/2022] Open
Abstract
Recent efforts in biological engineering have made detection of nucleic acids in samples more rapid, inexpensive and sensitive using CRISPR-based approaches. We expand one of these Cas13a-based methods to detect small molecules in a one-batch assay. Using SHERLOCK-based profiling of in vitrotranscription (SPRINT), in vitro transcribed RNA sequence-specifically triggers the RNase activity of Cas13a. This event activates its non-specific RNase activity, which enables cleavage of an RNA oligonucleotide labeled with a quencher/fluorophore pair and thereby de-quenches the fluorophore. This fluorogenic output can be measured to assess transcriptional output. The use of riboswitches or proteins to regulate transcription via specific effector molecules is leveraged as a coupled assay that transforms effector concentration into fluorescence intensity. In this way, we quantified eight different compounds, including cofactors, nucleotides, metabolites of amino acids, tetracycline and monatomic ions in samples. In this manner, hundreds of reactions can be easily quantified in a few hours. This increased throughput also enables detailed characterization of transcriptional regulators, synthetic compounds that inhibit transcription, or other coupled enzymatic reactions. These SPRINT reactions are easily adaptable to portable formats and could therefore be used for the detection of analytes in the field or at point-of-care situations.
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Affiliation(s)
- Roman S Iwasaki
- Department of Biochemistry, University of Colorado, Boulder, CO 80309-0596, USA
| | - Robert T Batey
- Department of Biochemistry, University of Colorado, Boulder, CO 80309-0596, USA
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18
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Kim YJ, Cubitt B, Cai Y, Kuhn JH, Vitt D, Kohlhof H, de la Torre JC. Novel Dihydroorotate Dehydrogenase Inhibitors with Potent Interferon-Independent Antiviral Activity against Mammarenaviruses In Vitro. Viruses 2020; 12:v12080821. [PMID: 32751087 PMCID: PMC7472048 DOI: 10.3390/v12080821] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 06/27/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/22/2022] Open
Abstract
Mammarenaviruses cause chronic infections in rodents, which are their predominant natural hosts. Human infection with some of these viruses causes high-consequence disease, posing significant issues in public health. Currently, no FDA-licensed mammarenavirus vaccines are available, and anti-mammarenavirus drugs are limited to an off-label use of ribavirin, which is only partially efficacious and associated with severe side effects. Dihydroorotate dehydrogenase (DHODH) inhibitors, which block de novo pyrimidine biosynthesis, have antiviral activity against viruses from different families, including Arenaviridae, the taxonomic home of mammarenaviruses. Here, we evaluate five novel DHODH inhibitors for their antiviral activity against mammarenaviruses. All tested DHODH inhibitors were potently active against lymphocytic choriomeningitis virus (LCMV) (half-maximal effective concentrations [EC50] in the low nanomolar range, selectivity index [SI] > 1000). The tested DHODH inhibitors did not affect virion cell entry or budding, but rather interfered with viral RNA synthesis. This interference resulted in a potent interferon-independent inhibition of mammarenavirus multiplication in vitro, including the highly virulent Lassa and Junín viruses.
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Affiliation(s)
- Yu-Jin Kim
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; (Y.-J.K.); (B.C.)
| | - Beatrice Cubitt
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; (Y.-J.K.); (B.C.)
| | - Yingyun Cai
- Integrated Research Facility at Fort Detrick (IRF-Frederick), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, MD 21702, USA; (Y.C.); (J.H.K.)
| | - Jens H. Kuhn
- Integrated Research Facility at Fort Detrick (IRF-Frederick), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, MD 21702, USA; (Y.C.); (J.H.K.)
| | - Daniel Vitt
- Immunic Therapeutics, New York City, NY 10036, USA; (D.V.); (H.K.)
| | - Hella Kohlhof
- Immunic Therapeutics, New York City, NY 10036, USA; (D.V.); (H.K.)
| | - Juan C. de la Torre
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; (Y.-J.K.); (B.C.)
- Correspondence:
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Han YJ, Ren ZG, Li XX, Yan JL, Ma CY, Wu DD, Ji XY. Advances and challenges in the prevention and treatment of COVID-19. Int J Med Sci 2020; 17:1803-1810. [PMID: 32714083 PMCID: PMC7378666 DOI: 10.7150/ijms.47836] [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] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/17/2020] [Indexed: 02/07/2023] Open
Abstract
Since the end of 2019, a new type of coronavirus pneumonia (COVID-19) caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has been spreading rapidly throughout the world. Previously, there were two outbreaks of severe coronavirus caused by different coronaviruses worldwide, namely Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). This article introduced the origin, virological characteristics and epidemiological overview of SARS-CoV-2, reviewed the currently known drugs that may prevent and treat coronavirus, explained the characteristics of the new coronavirus and provided novel information for the prevention and treatment of COVID-19.
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Affiliation(s)
- Yan-Jie Han
- Kaifeng Key Laboratory for Infectious Diseases and Biosafety, School of Basic Medical Science, Henan University, Kaifeng, Henan 475004, China
- Henan International Joint Laboratory of Nuclear Protein Regulation, School of Basic Medical Science, Henan University, Kaifeng, Henan 475004, China
- Clinical Laboratory and Functional Laboratory, Kaifeng Central Hospital, Kaifeng, Henan 475000, China
| | - Zhi-Guang Ren
- Kaifeng Key Laboratory for Infectious Diseases and Biosafety, School of Basic Medical Science, Henan University, Kaifeng, Henan 475004, China
- Henan International Joint Laboratory of Nuclear Protein Regulation, School of Basic Medical Science, Henan University, Kaifeng, Henan 475004, China
| | - Xin-Xin Li
- Clinical Laboratory and Functional Laboratory, Kaifeng Central Hospital, Kaifeng, Henan 475000, China
| | - Ji-Liang Yan
- Clinical Laboratory and Functional Laboratory, Kaifeng Central Hospital, Kaifeng, Henan 475000, China
| | - Chun-Yan Ma
- Clinical Laboratory and Functional Laboratory, Kaifeng Central Hospital, Kaifeng, Henan 475000, China
| | - Dong-Dong Wu
- Kaifeng Key Laboratory for Infectious Diseases and Biosafety, School of Basic Medical Science, Henan University, Kaifeng, Henan 475004, China
- Henan International Joint Laboratory of Nuclear Protein Regulation, School of Basic Medical Science, Henan University, Kaifeng, Henan 475004, China
- School of Stomatology, Henan University, Kaifeng, Henan 475004, China
| | - Xin-Ying Ji
- Kaifeng Key Laboratory for Infectious Diseases and Biosafety, School of Basic Medical Science, Henan University, Kaifeng, Henan 475004, China
- Henan International Joint Laboratory of Nuclear Protein Regulation, School of Basic Medical Science, Henan University, Kaifeng, Henan 475004, China
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Abstract
Chronic Hepatitis B Virus infections afflict >250 million people and kill nearly 1 million annually. Current non-curative therapies are dominated by nucleos(t)ide analogs (NAs) that profoundly but incompletely suppress DNA synthesis by the viral reverse transcriptase. Residual HBV replication during NA therapy contributes to maintenance of the critical nuclear reservoir of the HBV genome, the covalently-closed circular DNA, and to ongoing infection of naive cells. Identification of next-generation NAs with improved efficacy and safety profiles, often through novel prodrug approaches, is the primary thrust of ongoing efforts to improve HBV replication inhibitors. Inhibitors of the HBV ribonuclease H, the other viral enzymatic activity essential for viral genomic replication, are in preclinical development. The complexity of HBV's reverse transcription pathway offers many other potential targets. HBV's protein-priming of reverse transcription has been briefly explored as a potential target, as have the host chaperones necessary for function of the HBV reverse transcriptase. Improved inhibitors of HBV reverse transcription would reduce HBV's replication-dependent persistence mechanisms and are therefore expected to become a backbone of future curative combination anti-HBV therapies.
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Affiliation(s)
| | - Cyril B Dousson
- Ai-biopharma, Medicinal Chemistry Department, Montpellier, France.
| | - John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, USA.
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21
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Skidmore AM, Adcock RS, Jonsson CB, Golden JE, Chung DH. Benzamidine ML336 inhibits plus and minus strand RNA synthesis of Venezuelan equine encephalitis virus without affecting host RNA production. Antiviral Res 2020; 174:104674. [PMID: 31816348 PMCID: PMC6935354 DOI: 10.1016/j.antiviral.2019.104674] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/27/2019] [Accepted: 12/03/2019] [Indexed: 12/13/2022]
Abstract
Venezuelan equine encephalitis virus (VEEV) is an alphavirus that is endemic to the Americas. VEEV outbreaks occur periodically and cause encephalitis in both humans and equids. There are currently no therapeutics or vaccines for treatment of VEEV in humans. Our group has previously reported on the development of a benzamidine VEEV inhibitor, ML336, which shows potent antiviral activity in both in vitro and in vivo models of infection. In cell culture experiments, ML336 inhibits viral RNA synthesis when added 2-4 h post-infection, and mutations conferring resistance occur within the viral nonstructural proteins (nsP2 and nsP4). We hypothesized that ML336 targets an activity of the viral replicase complex and inhibits viral RNA synthesis. To test this hypothesis, we employed various biochemical and cellular assays. Using structural analogues of ML336, we demonstrate that the cellular antiviral activity of these compounds correlates with their inhibition of viral RNA synthesis. For instance, the IC50 of ML336 for VEEV RNA synthesis inhibition was determined as 1.1 nM, indicating potent anti-RNA synthesis activity in the low nanomolar range. While ML336 efficiently inhibited VEEV RNA synthesis, a much weaker effect was observed against the Old World alphavirus Chikungunya virus (IC50 > 4 μM), agreeing with previous data from a cell based assay. Using a tritium incorporation assay, we demonstrated that there was no significant inhibition of cellular transcription. With a combination of fluorography, strand-specific qRT-PCR, and tritium incorporation, we demonstrated that ML336 inhibits the synthesis of the positive sense genomic, negative sense template, and subgenomic RNAs of VEEV. Based on these results, we propose that the mechanism of action for this class of antiviral compounds is inhibition of viral RNA synthesis through interaction with the viral replicase complex.
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Affiliation(s)
- Andrew M Skidmore
- Department of Microbiology and Immunology, University of Louisville, 505 South Hancock St, Room 642 C, Louisville, KY, USA.
| | - Robert S Adcock
- Center of Predictive Medicine, University of Louisville, 505 South Hancock St, Room 617, Louisville, KY, USA.
| | - Colleen B Jonsson
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, 858 Madison Ave, Room 810 B, Memphis, TN, USA.
| | - Jennifer E Golden
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Dr, Room 7123, Madison, WI, USA.
| | - Dong-Hoon Chung
- Department of Microbiology and Immunology, University of Louisville, 505 South Hancock St, Room 642 C, Louisville, KY, USA; Center of Predictive Medicine, University of Louisville, 505 South Hancock St, Room 617, Louisville, KY, USA.
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22
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Prestes EB, Stoco PH, de Moraes MH, Moura H, Grisard EC. Messenger RNA levels of the Polo-like kinase gene (PLK) correlate with cytokinesis in the Trypanosoma rangeli cell cycle. Exp Parasitol 2019; 204:107727. [PMID: 31344389 DOI: 10.1016/j.exppara.2019.107727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 03/23/2019] [Revised: 07/06/2019] [Accepted: 07/21/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Trypanosoma rangeli is a protozoan parasite that is non-virulent to the mammalian host and is morphologically and genomically related to Trypanosoma cruzi, whose proliferation within the mammalian host is controversially discussed. OBJECTIVES We aimed to investigate the T. rangeli cell cycle in vitro and in vivo by characterizing the timespan of the parasite life cycle and by proposing a molecular marker to assess cytokinesis. METHODOLOGY The morphological events and their timing during the cell cycle of T. rangeli epimastigotes were assessed using DNA staining, flagellum labelling and bromodeoxyuridine incorporation. Messenger RNA levels of four genes previously associated with the cell cycle of trypanosomatids (AUK1, PLK, MOB1 and TRACK) were evaluated in the different T. rangeli forms. FINDINGS T. rangeli epimastigotes completed the cell cycle in vitro in 20.8 h. PLK emerged as a potential molecular marker for cell division, as its mRNA levels were significantly increased in exponentially growing epimastigotes compared with growth-arrested parasites or in vitro-differentiated trypomastigotes. PLK expression in T. rangeli can be detected near the flagellum protrusion site, reinforcing its role in the cell cycle. Interestingly, T. rangeli bloodstream trypomastigotes exhibited very low mRNA levels of PLK and were almost entirely composed of parasites in G1 phase. MAIN CONCLUSIONS Our work is the first to describe the T. rangeli cell cycle in vitro and proposes that PLK mRNA levels could be a useful tool to investigate the T. rangeli ability to proliferate within the mammalian host bloodstream.
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Affiliation(s)
- Elisa Beatriz Prestes
- Laboratórios de Protozoologia e de Bioinformática, MIP/CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Laboratório de Inflamação e Imunidade, IMPG/CCS, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Patrícia Hermes Stoco
- Laboratórios de Protozoologia e de Bioinformática, MIP/CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Milene Höehr de Moraes
- Laboratórios de Protozoologia e de Bioinformática, MIP/CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Hércules Moura
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Edmundo Carlos Grisard
- Laboratórios de Protozoologia e de Bioinformática, MIP/CCB, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
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da Silva Duarte V, Giaretta S, Campanaro S, Treu L, Armani A, Tarrah A, Oliveira de Paula S, Giacomini A, Corich V. A Cryptic Non-Inducible Prophage Confers Phage-Immunity on the Streptococcus thermophilus M17PTZA496. Viruses 2018; 11:v11010007. [PMID: 30583530 PMCID: PMC6356513 DOI: 10.3390/v11010007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/14/2018] [Accepted: 12/19/2018] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus is considered one of the most important species for the dairy industry. Due to their diffusion in dairy environments, bacteriophages can represent a threat to this widely used bacterial species. Despite the presence of a CRISPR-Cas system in the S. thermophilus genome, some lysogenic strains harbor cryptic prophages that can increase the phage-host resistance defense. This characteristic was identified in the dairy strain S. thermophilus M17PTZA496, which contains two integrated prophages 51.8 and 28.3 Kb long, respectively. In the present study, defense mechanisms, such as a lipoprotein-encoding gene and Siphovirus Gp157, the last associated to the presence of a noncoding viral DNA element, were identified in the prophage M17PTZA496 genome. The ability to overexpress genes involved in these defense mechanisms under specific stressful conditions, such as phage attack, has been demonstrated. Despite the addition of increasing amounts of Mitomycin C, M17PTZA496 was found to be non-inducible. However, the transcriptional activity of the phage terminase large subunit was detected in the presence of the antagonist phage vB_SthS-VA460 and of Mitomycin C. The discovery of an additional immune mechanism, associated with bacteriophage-insensitive strains, is of utmost importance, for technological applications and industrial processes. To our knowledge, this is the first study reporting the capability of a prophage integrated into the S. thermophilus genome expressing different phage defense mechanisms. Bacteriophages are widespread entities that constantly threaten starter cultures in the dairy industry. In cheese and yogurt manufacturing, the lysis of Streptococcus thermophilus cultures by viral attacks can lead to huge economic losses. Nowadays S. thermophilus is considered a well-stablished model organism for the study of natural adaptive immunity (CRISPR-Cas) against phage and plasmids, however, the identification of novel bacteriophage-resistance mechanisms, in this species, is strongly desirable. Here, we demonstrated that the presence of a non-inducible prophage confers phage-immunity to an S. thermophilus strain, by the presence of ltp and a viral noncoding region. S. thermophilus M17PTZA496 arises as an unconventional model to study phage resistance and potentially represents an alternative starter strain for dairy productions.
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Affiliation(s)
- Vinícius da Silva Duarte
- Department of Microbiology, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, Campus Universitário, Viçosa-MG 36570-900, Brazil.
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| | - Sabrina Giaretta
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| | | | - Laura Treu
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
- Department of Biology, University of Padova, 35121 Padova, Italy.
| | - Andrea Armani
- Venetian Institute of Molecular Medicine, 35129 Padova, Italy.
| | - Armin Tarrah
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| | | | - Alessio Giacomini
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
| | - Viviana Corich
- Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, 35020 Legnaro, Italy.
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Zhang P, Zhai S, Chang J, Guo JT. In Vitro Anti-hepatitis B Virus Activity of 2',3'-Dideoxyguanosine. Virol Sin 2018; 33:538-544. [PMID: 30421112 PMCID: PMC6335223 DOI: 10.1007/s12250-018-0065-7] [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: 08/05/2018] [Accepted: 10/11/2018] [Indexed: 11/30/2022] Open
Abstract
2',3'-dideoxyguanosine (DoG) has been demonstrated to inhibit duck hepatitis B virus (DHBV) replication in vivo in a duck model of HBV infection. In the current study, the in vitro antiviral effects of DoG on human and animal hepadnaviruses were investigated. Our results showed that DoG effectively inhibited HBV, DHBV, and woodchuck hepatitis virus (WHV) replication in hepatocyte-derived cells in a dose-dependent manner, with 50% effective concentrations (EC50) of 0.3 ± 0.05, 6.82 ± 0.25, and 23.0 ± 1.5 μmol/L, respectively. Similar to other hepadnaviral DNA polymerase inhibitors, DoG did not alter the levels of intracellular viral RNA but induced the accumulation of a less-than-full-length viral RNA species, which was recently demonstrated to be generated by RNase H cleavage of pgRNA. Furthermore, using a transient transfection assay, DoG showed similar antiviral activity against HBV wild-type, 3TC-resistant rtA181V, and adefovir-resistant rtN236T mutants. Our results suggest that DoG has potential as a nucleoside analogue drug with anti-HBV activity.
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Affiliation(s)
- Pinghu Zhang
- Institute of Translational Medicine and Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou, 225001 China
- Baruch S. Blumberg Institute, Hepatitis B Foundation, Doylestown, PA 18902 USA
- Qinghai Himalayan Experimental Animal Center, Xining, 810006 China
| | - Shuo Zhai
- Institute of Translational Medicine and Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou, 225001 China
| | - Jinhong Chang
- Baruch S. Blumberg Institute, Hepatitis B Foundation, Doylestown, PA 18902 USA
| | - Ju-Tao Guo
- Baruch S. Blumberg Institute, Hepatitis B Foundation, Doylestown, PA 18902 USA
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25
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Kawale AS, Akopiants K, Valerie K, Ruis B, Hendrickson EA, Huang SYN, Pommier Y, Povirk LF. TDP1 suppresses mis-joining of radiomimetic DNA double-strand breaks and cooperates with Artemis to promote optimal nonhomologous end joining. Nucleic Acids Res 2018; 46:8926-8939. [PMID: 30113698 PMCID: PMC6158748 DOI: 10.1093/nar/gky694] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [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: 02/15/2018] [Revised: 07/18/2018] [Accepted: 07/29/2018] [Indexed: 01/04/2023] Open
Abstract
The Artemis nuclease and tyrosyl-DNA phosphodiesterase (TDP1) are each capable of resolving protruding 3'-phosphoglycolate (PG) termini of DNA double-strand breaks (DSBs). Consequently, both a knockout of Artemis and a knockout/knockdown of TDP1 rendered cells sensitive to the radiomimetic agent neocarzinostatin (NCS), which induces 3'-PG-terminated DSBs. Unexpectedly, however, a knockdown or knockout of TDP1 in Artemis-null cells did not confer any greater sensitivity than either deficiency alone, indicating a strict epistasis between TDP1 and Artemis. Moreover, a deficiency in Artemis, but not TDP1, resulted in a fraction of unrepaired DSBs, which were assessed as 53BP1 foci. Conversely, a deficiency in TDP1, but not Artemis, resulted in a dramatic increase in dicentric chromosomes following NCS treatment. An inhibitor of DNA-dependent protein kinase, a key regulator of the classical nonhomologous end joining (C-NHEJ) pathway sensitized cells to NCS, but eliminated the sensitizing effects of both TDP1 and Artemis deficiencies. These results suggest that TDP1 and Artemis perform different functions in the repair of terminally blocked DSBs by the C-NHEJ pathway, and that whereas an Artemis deficiency prevents end joining of some DSBs, a TDP1 deficiency tends to promote DSB mis-joining.
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Affiliation(s)
- Ajinkya S Kawale
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Konstantin Akopiants
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Kristoffer Valerie
- Department of Radiation Oncology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Brian Ruis
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Shar-yin N Huang
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 5068, Bethesda, MD 20892-4255, USA
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 5068, Bethesda, MD 20892-4255, USA
| | - Lawrence F Povirk
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
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Van der Jeught K, Xu HC, Li YJ, Lu XB, Ji G. Drug resistance and new therapies in colorectal cancer. World J Gastroenterol 2018; 24:3834-3848. [PMID: 30228778 PMCID: PMC6141340 DOI: 10.3748/wjg.v24.i34.3834] [Citation(s) in RCA: 343] [Impact Index Per Article: 57.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/25/2018] [Accepted: 07/16/2018] [Indexed: 02/06/2023] Open
Abstract
Colorectal cancer (CRC) is often diagnosed at an advanced stage when tumor cell dissemination has taken place. Chemo- and targeted therapies provide only a limited increase of overall survival for these patients. The major reason for clinical outcome finds its origin in therapy resistance. Escape mechanisms to both chemo- and targeted therapy remain the main culprits. Here, we evaluate major resistant mechanisms and elaborate on potential new therapies. Amongst promising therapies is α-amanitin antibody-drug conjugate targeting hemizygous p53 loss. It becomes clear that a dynamic interaction with the tumor microenvironment exists and that this dictates therapeutic outcome. In addition, CRC displays a limited response to checkpoint inhibitors, as only a minority of patients with microsatellite instable high tumors is susceptible. In this review, we highlight new developments with clinical potentials to augment responses to checkpoint inhibitors.
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Affiliation(s)
- Kevin Van der Jeught
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Han-Chen Xu
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Yu-Jing Li
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Xiong-Bin Lu
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, United States
- Indiana University Melvin and Bren Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Guang Ji
- Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
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Li D, Fu W, Swaminathan S. Continuous DNA replication is required for late gene transcription and maintenance of replication compartments in gammaherpesviruses. PLoS Pathog 2018; 14:e1007070. [PMID: 29813138 PMCID: PMC5993329 DOI: 10.1371/journal.ppat.1007070] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [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: 04/10/2018] [Revised: 06/08/2018] [Accepted: 05/02/2018] [Indexed: 12/11/2022] Open
Abstract
Late gene transcription in herpesviruses is dependent on viral DNA replication in cis but the mechanistic basis for this linkage remains unknown. DNA replication results in demethylated DNA, topological changes, removal of proteins and recruitment of proteins to promoters. One or more of these effects of DNA replication may facilitate late gene transcription. Using 5-azacytidine to promote demethylation of DNA, we demonstrate that late gene transcription cannot be rescued by DNA demethylation. Late gene transcription precedes significant increases in DNA copy number, indicating that increased template numbers also do not contribute to the linkage between replication and late gene transcription. By using serial, timed blockade of DNA replication and measurement of late gene mRNA accumulation, we demonstrate that late gene transcription requires ongoing DNA replication. Consistent with these findings, blocking DNA replication led to dissolution of DNA replication complexes which also contain RNA polymerase II and BGLF4, an EBV protein required for transcription of several late genes. These data indicate that ongoing DNA replication maintains integrity of a replication-transcription complex which is required for recruitment and retention of factors necessary for late gene transcription. Herpesviruses exhibit both latent and lytic replication cycles. Gammaherpesviruses such as Kaposi’s sarcoma-associated herpesvirus and Epstein Barr virus undergo lytic replication when they reactivate from latency. During this process, when infectious virions are produced, an orderly cascade of gene expression occurs. Late lytic genes, which primarily encode structural components of the virion, are only transcribed after replication of the DNA genome has occurred. Unlike early lytic genes, late gene transcription is tightly linked to viral DNA replication; if viral DNA replication is blocked, late gene mRNA accumulation is severely inhibited. The mechanism by which late gene transcription is linked to DNA replication has remained elusive. In this paper we show that a process of continuous DNA replication is required. If one blocks DNA replication, further transcription also ceases, indicating that concurrent DNA replication is required to maintain late transcription. We also show that when DNA replication is blocked, the nuclear complexes in which herpesviruses are replicating dissociate. These replication complexes also serve as factories of viral transcription. When the complexes disperse, proteins required for transcription dissociate from the DNA replication machinery. These data indicate that ongoing DNA replication is necessary to maintain the physical and functional integrity of these structures. Our study provides new insight into this linkage that ensures coordination between viral replication and late gene expression.
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Affiliation(s)
- Dajiang Li
- Division of Infectious Diseases, Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Wenmin Fu
- Division of Infectious Diseases, Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Sankar Swaminathan
- Division of Infectious Diseases, Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Medicine, George E. Wahlen Veterans Affairs Medical Center, Salt Lake City, Utah, United States of America
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28
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Milligan GN, White M, Zavala D, Pyles RB, Sarathy VV, Barrett ADT, Bourne N. Spectrum of activity testing for therapeutics against all four dengue virus serotypes in AG129 mouse models: Proof-of-concept studies with the adenosine nucleoside inhibitor NITD-008. Antiviral Res 2018; 154:104-109. [PMID: 29665374 DOI: 10.1016/j.antiviral.2018.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/21/2018] [Accepted: 04/13/2018] [Indexed: 12/20/2022]
Abstract
Dengue is a mosquito-borne disease of global public health importance caused by four genetically and serologically related viruses (DENV-1 to DENV-4). Efforts to develop effective vaccines and therapeutics for dengue have been slowed by the paucity of preclinical models that mimic human disease. DENV-2 models in interferon receptor deficient AG129 mice were an important advance but only allowed testing against a single DENV serotype. We have developed complementary AG129 mouse models of severe disseminated dengue infection using strains of the other three DENV serotypes. Here we used the adenosine nucleoside inhibitor NITD-008 to show that these models provide the ability to perform comparative preclinical efficacy testing of candidate antivirals in vivo against the full-spectrum of DENV serotypes. Although NITD-008 was effective in modulating disease caused by all DENV serotypes, the variability in protection among DENV serotypes was greater than expected from differences in activity in in vitro testing studies emphasizing the need to undertake spectrum of activity testing to help in prioritization of candidate compounds for further development.
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Affiliation(s)
- Gregg N Milligan
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Mellodee White
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Diana Zavala
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Richard B Pyles
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Vanessa V Sarathy
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Alan D T Barrett
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Nigel Bourne
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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Peng J, Yang P, Zhang Q, Jiang Q. Tilapia adropin: the localization and regulation of growth hormone gene expression in pituitary cells. Peptides 2017; 97:1-7. [PMID: 28917652 DOI: 10.1016/j.peptides.2017.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 08/27/2017] [Accepted: 09/10/2017] [Indexed: 02/08/2023]
Abstract
The peptide hormone adropin, encoded by the energy homeostasis-associated (Enho) gene, plays a role in energy homeostasis and the control of vascular function. The aim of this study was to examine the role of adropin in growth hormone (GH) gene expression at the pituitary level in tilapia. As a first step, the antiserum for the tilapia adropin was produced, and its specificity was confirmed by antiserum preabsorption and immunohistochemical staining in the tilapia pituitary. Adropin could be detected immunocytochemically in the proximal pars distalis (PPD) of the tilapia pituitary. In primary cultures of tilapia pituitary cells, tilapia adropin was effective in increasing GH mRNA levels. However, removal of endogenous adropin by immunoneutralization using adropin antiserum inhibited GH gene expression. In parallel experiments, pituitary cells co-treated with ovine pituitary adenylate cyclase activating polypeptide 38 (oPACAP38) and adropin showed a similar increase level compared to those treated with oPACAP38 alone, whereas insulin-like growth factor 1 (IGF1) not only had an inhibitory effect on basal GH mRNA levels, but also could abolish adropin stimulation of GH gene expression. In pituitary cells pretreated with actinomycin D, the half-life of GH mRNA was enhanced by adropin. Taken together, these findings suggest that adropin may serve as a novel local stimulator for GH gene expression in tilapia pituitary.
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Affiliation(s)
- JianPeng Peng
- Key Laboratory of Bio-resources and Eco-environmaent of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Ping Yang
- Key Laboratory of Bio-resources and Eco-environmaent of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Qianli Zhang
- Key Laboratory of Bio-resources and Eco-environmaent of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Quan Jiang
- Key Laboratory of Bio-resources and Eco-environmaent of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China.
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Cavaiuolo M, Kuras R, Wollman F, Choquet Y, Vallon O. Small RNA profiling in Chlamydomonas: insights into chloroplast RNA metabolism. Nucleic Acids Res 2017; 45:10783-10799. [PMID: 28985404 PMCID: PMC5737564 DOI: 10.1093/nar/gkx668] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 07/18/2017] [Accepted: 07/28/2017] [Indexed: 12/20/2022] Open
Abstract
In Chlamydomonas reinhardtii, regulation of chloroplast gene expression is mainly post-transcriptional. It requires nucleus-encoded trans-acting protein factors for maturation/stabilization (M factors) or translation (T factors) of specific target mRNAs. We used long- and small-RNA sequencing to generate a detailed map of the transcriptome. Clusters of sRNAs marked the 5' end of all mature mRNAs. Their absence in M-factor mutants reflects the protection of transcript 5' end by the cognate factor. Enzymatic removal of 5'-triphosphates allowed identifying those cosRNA that mark a transcription start site. We detected another class of sRNAs derived from low abundance transcripts, antisense to mRNAs. The formation of antisense sRNAs required the presence of the complementary mRNA and was stimulated when translation was inhibited by chloramphenicol or lincomycin. We propose that they derive from degradation of double-stranded RNAs generated by pairing of antisense and sense transcripts, a process normally hindered by the traveling of the ribosomes. In addition, chloramphenicol treatment, by freezing ribosomes on the mRNA, caused the accumulation of 32-34 nt ribosome-protected fragments. Using this 'in vivo ribosome footprinting', we identified the function and molecular target of two candidate trans-acting factors.
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Affiliation(s)
- Marina Cavaiuolo
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Richard Kuras
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Francis‐André Wollman
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Yves Choquet
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Olivier Vallon
- Unité Mixte de Recherche 7141, CNRS/UPMC, Institut de Biologie Physico-Chimique, F-75005 Paris, France
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31
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Radiske A, Gonzalez MC, Conde-Ocazionez SA, Feitosa A, Köhler CA, Bevilaqua LR, Cammarota M. Prior Learning of Relevant Nonaversive Information Is a Boundary Condition for Avoidance Memory Reconsolidation in the Rat Hippocampus. J Neurosci 2017; 37:9675-9685. [PMID: 28887385 PMCID: PMC6596618 DOI: 10.1523/jneurosci.1372-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/13/2017] [Accepted: 08/28/2017] [Indexed: 01/07/2023] Open
Abstract
Reactivated memories can be modified during reconsolidation, making this process a potential therapeutic target for posttraumatic stress disorder (PTSD), a mental illness characterized by the recurring avoidance of situations that evoke trauma-related fears. However, avoidance memory reconsolidation depends on a set of still loosely defined boundary conditions, limiting the translational value of basic research. In particular, the involvement of the hippocampus in fear-motivated avoidance memory reconsolidation remains controversial. Combining behavioral and electrophysiological analyses in male Wistar rats, we found that previous learning of relevant nonaversive information is essential to elicit the participation of the hippocampus in avoidance memory reconsolidation, which is associated with an increase in theta- and gamma-oscillation power and cross-frequency coupling in dorsal CA1 during reactivation of the avoidance response. Our results indicate that the hippocampus is involved in memory reconsolidation only when reactivation results in contradictory representations regarding the consequences of avoidance and suggest that robust nesting of hippocampal theta-gamma rhythms at the time of retrieval is a specific reconsolidation marker.SIGNIFICANCE STATEMENT Posttraumatic stress disorder (PTSD) is characterized by maladaptive avoidance responses to stimuli or behaviors that represent or bear resemblance to some aspect of a traumatic experience. Disruption of reconsolidation, the process by which reactivated memories become susceptible to modifications, is a promising approach for treating PTSD patients. However, much of what is known about fear-motivated avoidance memory reconsolidation derives from studies based on fear conditioning instead of avoidance-learning paradigms. Using a step-down inhibitory avoidance task in rats, we found that the hippocampus is involved in memory reconsolidation only when the animals acquired the avoidance response in an environment that they had previously learned as safe and showed that increased theta- and gamma-oscillation coupling during reactivation is an electrophysiological signature of this process.
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Affiliation(s)
- Andressa Radiske
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, RN 59056-450 Natal, Brazil
| | - Maria Carolina Gonzalez
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, RN 59056-450 Natal, Brazil
| | - Sergio A Conde-Ocazionez
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, RN 59056-450 Natal, Brazil
| | - Anatildes Feitosa
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, RN 59056-450 Natal, Brazil
| | - Cristiano A Köhler
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, RN 59056-450 Natal, Brazil
| | - Lia R Bevilaqua
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, RN 59056-450 Natal, Brazil
| | - Martín Cammarota
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, RN 59056-450 Natal, Brazil
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Pedroza-García JA, Mazubert C, Del Olmo I, Bourge M, Domenichini S, Bounon R, Tariq Z, Delannoy E, Piñeiro M, Jarillo JA, Bergounioux C, Benhamed M, Raynaud C. Function of the Plant DNA Polymerase Epsilon in Replicative Stress Sensing, a Genetic Analysis. Plant Physiol 2017; 173:1735-1749. [PMID: 28153919 PMCID: PMC5338674 DOI: 10.1104/pp.17.00031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 01/30/2017] [Indexed: 05/17/2023]
Abstract
Faithful transmission of the genetic information is essential in all living organisms. DNA replication is therefore a critical step of cell proliferation, because of the potential occurrence of replication errors or DNA damage when progression of a replication fork is hampered causing replicative stress. Like other types of DNA damage, replicative stress activates the DNA damage response, a signaling cascade allowing cell cycle arrest and repair of lesions. The replicative DNA polymerase ε (Pol ε) was shown to activate the S-phase checkpoint in yeast in response to replicative stress, but whether this mechanism functions in multicellular eukaryotes remains unclear. Here, we explored the genetic interaction between Pol ε and the main elements of the DNA damage response in Arabidopsis (Arabidopsis thaliana). We found that mutations affecting the polymerase domain of Pol ε trigger ATR-dependent signaling leading to SOG1 activation, WEE1-dependent cell cycle inhibition, and tolerance to replicative stress induced by hydroxyurea, but result in enhanced sensitivity to a wide range of DNA damaging agents. Using knock-down lines, we also provide evidence for the direct role of Pol ε in replicative stress sensing. Together, our results demonstrate that the role of Pol ε in replicative stress sensing is conserved in plants, and provide, to our knowledge, the first genetic dissection of the downstream signaling events in a multicellular eukaryote.
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Affiliation(s)
- José-Antonio Pedroza-García
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Christelle Mazubert
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Ivan Del Olmo
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Mickael Bourge
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Séverine Domenichini
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Rémi Bounon
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Zakia Tariq
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Etienne Delannoy
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Manuel Piñeiro
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - José A Jarillo
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Catherine Bergounioux
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Moussa Benhamed
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.)
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
| | - Cécile Raynaud
- Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Évry, Université Paris-Saclay, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.);
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, 91405 Orsay, France (J.A.P.-G., C.M., S.D., R.B., Z.T., E.D., C.B., M.B., C.R.);
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM 28223-Pozuelo de Alarcón (Madrid), Spain (I.d.O., M.P., J.A.J.); and
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France (M.B.)
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Abstract
Maternal-to-zygotic transition is an event that developmental control of early embryos is switched from oocyte-derived factors to the zygotic genome. Ability to inhibit DNA replication, transcription, and translation is an important tool in studying events, such as zygotic genome activation, during embyogenesis. Here, we describe approaches to block DNA replication, transcription, and translation using chemical inhibitors. Then we also demonstrate how the transcript level of a maternally inherited gene, ten-eleven translocation methylcytosine dioxygenase 3, responses to the chemical treatments.
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Affiliation(s)
- Kyungjun Uh
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Kiho Lee
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, USA.
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34
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Liang X, Fan R, Sun J, Shaikh J, Taneja A, Gupta S, Hamed K. Effect of Telbivudine Versus Other Nucleos(t)ide Analogs on HBeAg Seroconversion and Other Outcomes in Patients with Chronic Hepatitis B: A Network Meta-Analysis. Adv Ther 2016; 33:519-31. [PMID: 26921204 PMCID: PMC4846711 DOI: 10.1007/s12325-016-0305-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [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: 01/14/2016] [Indexed: 12/20/2022]
Abstract
INTRODUCTION A comprehensive and up-to-date network meta-analysis (NMA) helps to determine the comparative efficacies of nucleos(t)ide analogs (NAs) in patients with chronic hepatitis B (CHB). The aim of this NMA was to assess the efficacy of telbivudine versus adefovir, entecavir, lamivudine, and tenofovir in nucleos(t)ide-naïve hepatitis B e antigen (HBeAg)-positive patients with CHB. METHODS A systematic review was conducted to search Medline, Medline-In Process, EMBASE, and the Cochrane Central Register of Controlled Trials databases for publications of randomized controlled trials (RCTs). NMA was performed to compare the efficacy outcomes of telbivudine versus other approved NAs at 1- and 2-year time points. RESULTS A total of 75 RCTs were included in the systematic review. At the 1-year time point, telbivudine was associated with significantly higher rates of: (1) HBeAg seroconversion than adefovir [odds ratio (OR) 1.99 (95% credible interval (CrI): 1.05, 3.45)], entecavir [OR 2.00 (95% CrI: 1.44, 2.82)] and lamivudine [OR 1.49 (95% CrI: 1.10, 2.03)]; (2) HBeAg loss than entecavir [OR 1.85 (95% CrI: 1.28, 2.76)] and lamivudine [OR 1.62 (95% CrI: 1.20, 2.24)]; (3) alanine aminotransferase (ALT) normalization than lamivudine [OR 1.50 (95% CrI: 1.05, 2.21)]; and (4) hepatitis B virus (HBV) DNA suppression than adefovir [OR 2.77 (95% CrI: 1.28, 5.45)] and lamivudine [OR 2.97 (95% CrI: 1.99, 4.53)]. At the 2-year time point, the relative efficacy outcomes were not statistically significant. CONCLUSION At 1 year, telbivudine was superior to adefovir, entecavir and lamivudine in HBeAg seroconversion, and to entecavir and lamivudine in HBeAg loss. Telbivudine was also superior to lamivudine in ALT normalization and to adefovir and lamivudine in suppressing HBV DNA levels. FUNDING Novartis Pharma AG.
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Affiliation(s)
- Xieer Liang
- Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Rong Fan
- Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jian Sun
- Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | | | | | | | - Kamal Hamed
- Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA.
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Harrison PL, Abdel-Rahman MA, Strong PN, Tawfik MM, Miller K. Characterisation of three alpha-helical antimicrobial peptides from the venom of Scorpio maurus palmatus. Toxicon 2016; 117:30-6. [PMID: 27019370 DOI: 10.1016/j.toxicon.2016.03.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [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: 12/18/2015] [Revised: 03/04/2016] [Accepted: 03/23/2016] [Indexed: 11/19/2022]
Abstract
Scorpion venoms provide a rich source of anti-microbial peptides. Here we characterise three from the venom of Scorpion maurus palmatus. Smp13 is biologically inactive, despite sharing homology with other antimicrobial peptides, probably because it lacks a typically charged structure. Both Smp-24 and Smp-43 have broad spectrum antimicrobial activity, disrupting bacterial membranes. In addition, there is evidence that Smp24 may inhibit DNA synthesis in Bacillus subtilis. Smp24 haemolysed red blood cells but in contrast, Smp43 was non-haemolytic. The introduction of a flexible Gly-Val-Gly hinge into the middle of Smp24 did not alter the haemolytic activity of Smp24 (as might have been predicted from earlier studies with Pandinin2 (Pin2), although C-terminal truncation of Smp-24 reduced its haemolytic activity, in agreement with earlier Pin 2 studies. Smp24 and its derivatives, as well as Smp-43, were all cytotoxic (ATP release assay) toward mammalian HepG2 liver cells. Our results highlight the beneficial effect of helical-hinge-helical conformation on promoting prokaryotic selectivity of long chain scorpion AMPs, as well as the importance of examining a wide range of mammalian cell types in cytotoxicity testing.
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Affiliation(s)
- Patrick L Harrison
- Biomedical Research Centre, Biosciences Division, Sheffield Hallam University, Sheffield, UK
| | | | - Peter N Strong
- Biomedical Research Centre, Biosciences Division, Sheffield Hallam University, Sheffield, UK
| | - Mohamed M Tawfik
- Biomedical Research Centre, Biosciences Division, Sheffield Hallam University, Sheffield, UK
| | - Keith Miller
- Biomedical Research Centre, Biosciences Division, Sheffield Hallam University, Sheffield, UK.
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36
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Tidball AM, Neely MD, Chamberlin R, Aboud AA, Kumar KK, Han B, Bryan MR, Aschner M, Ess KC, Bowman AB. Genomic Instability Associated with p53 Knockdown in the Generation of Huntington's Disease Human Induced Pluripotent Stem Cells. PLoS One 2016; 11:e0150372. [PMID: 26982737 PMCID: PMC4794230 DOI: 10.1371/journal.pone.0150372] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [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: 05/07/2015] [Accepted: 02/13/2016] [Indexed: 12/20/2022] Open
Abstract
Alterations in DNA damage response and repair have been observed in Huntington's disease (HD). We generated induced pluripotent stem cells (iPSC) from primary dermal fibroblasts of 5 patients with HD and 5 control subjects. A significant fraction of the HD iPSC lines had genomic abnormalities as assessed by karyotype analysis, while none of our control lines had detectable genomic abnormalities. We demonstrate a statistically significant increase in genomic instability in HD cells during reprogramming. We also report a significant association with repeat length and severity of this instability. Our karyotypically normal HD iPSCs also have elevated ATM-p53 signaling as shown by elevated levels of phosphorylated p53 and H2AX, indicating either elevated DNA damage or hypersensitive DNA damage signaling in HD iPSCs. Thus, increased DNA damage responses in the HD genotype is coincidental with the observed chromosomal aberrations. We conclude that the disease causing mutation in HD increases the propensity of chromosomal instability relative to control fibroblasts specifically during reprogramming to a pluripotent state by a commonly used episomal-based method that includes p53 knockdown.
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Affiliation(s)
- Andrew M. Tidball
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37240, United States of America
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, United States of America
| | - M. Diana Neely
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37240, United States of America
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, United States of America
| | - Reed Chamberlin
- Genetics Associates Inc., Nashville, TN, 37203, United States of America
| | - Asad A. Aboud
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37240, United States of America
| | - Kevin K. Kumar
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37240, United States of America
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, United States of America
| | - Bingying Han
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37240, United States of America
| | - Miles R. Bryan
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37240, United States of America
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, United States of America
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, United States of America
| | - Kevin C. Ess
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, United States of America
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, 37240, United States of America
| | - Aaron B. Bowman
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37240, United States of America
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, United States of America
- Center in Molecular Toxicology, Vanderbilt University, Nashville, TN, 37232, United States of America
- * E-mail:
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37
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Zou Q, Wu M, Zhong L, Fan Z, Zhang B, Chen Q, Ma F. Development of a Xeno-Free Feeder-Layer System from Human Umbilical Cord Mesenchymal Stem Cells for Prolonged Expansion of Human Induced Pluripotent Stem Cells in Culture. PLoS One 2016; 11:e0149023. [PMID: 26882313 PMCID: PMC4755601 DOI: 10.1371/journal.pone.0149023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/26/2016] [Indexed: 02/06/2023] Open
Abstract
Various feeder layers have been extensively applied to support the prolonged growth of human pluripotent stem cells (hPSCs) for in vitro cultures. Among them, mouse embryonic fibroblast (MEF) and mouse fibroblast cell line (SNL) are most commonly used feeder cells for hPSCs culture. However, these feeder layers from animal usually cause immunogenic contaminations, which compromises the potential of hPSCs in clinical applications. In the present study, we tested human umbilical cord mesenchymal stem cells (hUC-MSCs) as a potent xeno-free feeder system for maintaining human induced pluripotent stem cells (hiPSCs). The hUC-MSCs showed characteristics of MSCs in xeno-free culture condition. On the mitomycin-treated hUC-MSCs feeder, hiPSCs maintained the features of undifferentiated human embryonic stem cells (hESCs), such as low efficiency of spontaneous differentiation, stable expression of stemness markers, maintenance of normal karyotypes, in vitro pluripotency and in vivo ability to form teratomas, even after a prolonged culture of more than 30 passages. Our study indicates that the xeno-free culture system may be a good candidate for growth and expansion of hiPSCs as the stepping stone for stem cell research to further develop better and safer stem cells.
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Affiliation(s)
- Qing Zou
- Research Center for Stem Cell and Regenerative Medicine, Sichuan Neo-life Stem Cell Biotech INC., Chengdu, Sichuan, China
- Center for Stem Cell Research & Application, Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, Sichuan, China
| | - Mingjun Wu
- Research Center for Stem Cell and Regenerative Medicine, Sichuan Neo-life Stem Cell Biotech INC., Chengdu, Sichuan, China
| | - Liwu Zhong
- Research Center for Stem Cell and Regenerative Medicine, Sichuan Neo-life Stem Cell Biotech INC., Chengdu, Sichuan, China
| | - Zhaoxin Fan
- Research Center for Stem Cell and Regenerative Medicine, Sichuan Neo-life Stem Cell Biotech INC., Chengdu, Sichuan, China
| | - Bo Zhang
- Research Center for Stem Cell and Regenerative Medicine, Sichuan Neo-life Stem Cell Biotech INC., Chengdu, Sichuan, China
| | - Qiang Chen
- Research Center for Stem Cell and Regenerative Medicine, Sichuan Neo-life Stem Cell Biotech INC., Chengdu, Sichuan, China
- Center for Stem Cell Research & Application, Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, Sichuan, China
- * E-mail: (FM); (QC)
| | - Feng Ma
- Research Center for Stem Cell and Regenerative Medicine, Sichuan Neo-life Stem Cell Biotech INC., Chengdu, Sichuan, China
- Center for Stem Cell Research & Application, Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, Sichuan, China
- State Key Laboratory of Experimental Hematology, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
- State Key Laboratory of Biotherapy, Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- * E-mail: (FM); (QC)
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Mak M, Zaman MH, Kamm RD, Kim T. Interplay of active processes modulates tension and drives phase transition in self-renewing, motor-driven cytoskeletal networks. Nat Commun 2016; 7:10323. [PMID: 26744226 PMCID: PMC4714927 DOI: 10.1038/ncomms10323] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [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: 05/06/2015] [Accepted: 11/27/2015] [Indexed: 12/23/2022] Open
Abstract
The actin cytoskeleton--a complex, nonequilibrium network consisting of filaments, actin-crosslinking proteins (ACPs) and motors--confers cell structure and functionality, from migration to morphogenesis. While the core components are recognized, much less is understood about the behaviour of the integrated, disordered and internally active system with interdependent mechano-chemical component properties. Here we use a Brownian dynamics model that incorporates key and realistic features--specifically actin turnover, ACP (un)binding and motor walking--to reveal the nature and underlying regulatory mechanisms of overarching cytoskeletal states. We generate multi-dimensional maps that show the ratio in activity of these microscopic elements determines diverse global stress profiles and the induction of nonequilibrium morphological phase transition from homogeneous to aggregated networks. In particular, actin turnover dynamics plays a prominent role in tuning stress levels and stabilizing homogeneous morphologies in crosslinked, motor-driven networks. The consequence is versatile functionality, from dynamic steady-state prestress to large, pulsed constrictions.
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Affiliation(s)
- Michael Mak
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts 02215, USA
| | - Muhammad H. Zaman
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts 02215, USA
- Howard Hughes Medical Institute, Boston University, Boston, Massachusetts 02215, USA
| | - Roger D. Kamm
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Taeyoon Kim
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, Indiana 47907, USA
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Abstract
The current standard of care for hepatitis C therapy is the combination of direct-acting antiviral (DAA) agents. These orally administered medications target the viral proteins and halt the hepatitis C virus lifecycle. Despite high cure rates with these novel drugs, virologic failure with DAAs are of mounting concern as real-world sustained virologic response 12 rates seem lower than expected. The mechanisms of virologic failure to DAAs are likely multifactorial, including baseline resistance variants, the efficacy of the agents used, and host factors. Salvage therapy for DAA virologic failures is an area of emerging research.
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Affiliation(s)
- Vanessa Costilla
- Department of Hepatology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Neha Mathur
- Department of Hepatology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Julio A Gutierrez
- Department of Hepatology, The Texas Liver Institute, University of Texas Health Science Center at San Antonio, 607 Camden, San Antonio, TX 78215, USA.
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Painter RE, Adam GC, Arocho M, DiNunzio E, Donald RGK, Dorso K, Genilloud O, Gill C, Goetz M, Hairston NN, Murgolo N, Nare B, Olsen DB, Powles M, Racine F, Su J, Vicente F, Wisniewski D, Xiao L, Hammond M, Young K. Elucidation of DnaE as the Antibacterial Target of the Natural Product, Nargenicin. ACTA ACUST UNITED AC 2015; 22:1362-73. [PMID: 26456734 DOI: 10.1016/j.chembiol.2015.08.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 08/10/2015] [Accepted: 08/25/2015] [Indexed: 01/14/2023]
Abstract
Resistance to existing classes of antibiotics drives the need for discovery of novel compounds with unique mechanisms of action. Nargenicin A1, a natural product with limited antibacterial spectrum, was rediscovered in a whole-cell antisense assay. Macromolecular labeling in both Staphylococcus aureus and an Escherichia coli tolC efflux mutant revealed selective inhibition of DNA replication not due to gyrase or topoisomerase IV inhibition. S. aureus nargenicin-resistant mutants were selected at a frequency of ∼1 × 10(-9), and whole-genome resequencing found a single base-pair change in the dnaE gene, a homolog of the E. coli holoenzyme α subunit. A DnaE single-enzyme assay was exquisitely sensitive to inhibition by nargenicin, and other in vitro characterization studies corroborated DnaE as the target. Medicinal chemistry efforts may expand the spectrum of this novel mechanism antibiotic.
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Affiliation(s)
- Ronald E Painter
- In vitro Pharmacology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Gregory C Adam
- Screening and Protein Sciences, Merck Research Laboratories, North Wales, PA 19454, USA
| | - Marta Arocho
- Medicinal Chemistry, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Edward DiNunzio
- In vitro Pharmacology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Robert G K Donald
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Karen Dorso
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Olga Genilloud
- Centro de Investigación Básica (CIBE), Merck Sharp & Dhome de España, S.A., 28027 Madrid, Spain
| | - Charles Gill
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Michael Goetz
- Medicinal Chemistry, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Nichelle N Hairston
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Nicholas Murgolo
- Discovery Pharmacogenomics, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Bakela Nare
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - David B Olsen
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Maryann Powles
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Fred Racine
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Jing Su
- Medicinal Chemistry, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Francisca Vicente
- Centro de Investigación Básica (CIBE), Merck Sharp & Dhome de España, S.A., 28027 Madrid, Spain
| | - Douglas Wisniewski
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Li Xiao
- Medicinal Chemistry, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Milton Hammond
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA
| | - Katherine Young
- Infectious Disease Biology, Merck Research Laboratories, Kenilworth, NJ 07033, USA.
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41
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Pakkianathan BC, Singh NK, König S, Krishnan M. Antiapoptotic activity of 30 kDa lipoproteins family from fat body tissue of silkworm, Bombyx mori. Insect Sci 2015; 22:629-638. [PMID: 24591444 DOI: 10.1111/1744-7917.12119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/22/2014] [Indexed: 06/03/2023]
Abstract
The family of 30 kDa lipoproteins (LP1-5) is abundant in silkworm pupa fat body (FB) and hemolymph. One of its members, the 29 kDa protein decreased in concentration from peripheral (PP) FB tissue but was sustained in perivisceral (PV) FB tissue at the time of apoptosis. This study investigated the correlation of the 30 kDa proteins with FB apoptosis. Two protein fractions were purified, a 29 and a 30/31 kDa protein fraction, and they were used to test for activity against actinomycin D-induced apoptosis in the FB tissues. Concentrations as little as 50 μg/mL of the 29 kDa protein fraction efficiently inhibited apoptosis. Less antiapoptotic activity was detected for the higher MW fraction; DNA fragmentation was observed in FB tissue treated with 50 μg/mL of the 30/31 kDa fraction. The viability of the cells in the 29 kDa protein-supplemented culture was 40% higher than in the 31 kDa protein-supplemented culture. However, the 30 kDa lipoproteins were not able to prevent scheduled FB degeneration during silkworm metamorphosis. Thus, it is hypothesized that the antiapoptotic 29 kDa protein needs to be proteolytically degraded by a regulatory mechanism to allow programmed cell death of FB tissue.
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Affiliation(s)
| | - Nitin Kumar Singh
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, India
| | - Simone König
- Integrated Functional Genomics, Interdisciplinary Center for Clinical Research, University of Münster, Germany
| | - Muthukalingan Krishnan
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, India
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42
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Bolshakova A, Magnusson KE, Pinaev G, Petukhova O. EGF-induced dynamics of NF-κB and F-actin in A431 cells spread on fibronectin. Histochem Cell Biol 2015; 144:223-35. [PMID: 25990946 DOI: 10.1007/s00418-015-1331-5] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2015] [Indexed: 01/15/2023]
Abstract
To evaluate the role of actin cytoskeleton in the regulation of NF-κB transcription factor, we analyzed its involvement in the intracellular transport and nuclear translocation of the NF-κB RelA/p65 subunit in A431 epithelial cells stimulated with fibronectin and EGF. Live cell imaging and confocal microscopy showed that EGF activated the movement of RelA/p65 in the cytoplasm. Upon cell adhesion to fibronectin, RelA/p65 concentrated onto stress fibers, and EGF stimulated its subsequent allocation to membrane ruffles, newly organized stress fibers, and discrete cytoplasmic actin-rich patches. These patches also contained α-actinin-1 and α-actinin-4, vinculin, paxillin, α-tubulin, and PI3-kinase. Cytochalasin D treatment resulted in RelA/p65 redistribution to actin-containing aggregates, with the number of cells with RelA/p65-containing clusters in the cytoplasm increasing under the effect of EGF. Furthermore, EGF proved to induce RelA/p65 accumulation in the nucleus after cell pretreatment with actin-stabilizing and actin-destabilizing agents, which was accompanied by changes in its DNA-binding activity after either EGF stimulation or cytochalasin D treatment. Thus, EGF treatment of A431 cells results in simultaneous nuclear RelA/p65 translocation and cytoplasmic redistribution, with part of RelA/p65 pool forming a very tight association with actin-rich structures. Apparently, nuclear transport is independent on drug stabilization or destabilization of the actin.
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Affiliation(s)
- Anastasia Bolshakova
- Department of Cell Cultures, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., St. Petersburg, 194064, Russia
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43
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Abstract
Members of the eukaryotic PIEZO family (the human orthologs are noted hPIEZO1 and hPIEZO2) form cation-selective mechanically-gated channels. We characterized the selectivity of human PIEZO1 (hPIEZO1) for alkali ions: K+, Na+, Cs+ and Li+; organic cations: TMA and TEA, and divalents: Ba2+, Ca2+, Mg2+ and Mn2+. All monovalent ions permeated the channel. At a membrane potential of -100 mV, Cs+, Na+ and K+ had chord conductances in the range of 35–55 pS with the exception of Li+, which had a significantly lower conductance of ~ 23 pS. The divalents decreased the single-channel permeability of K+, presumably because the divalents permeated slowly and occupied the open channel for a significant fraction of the time. In cell-attached mode, 90 mM extracellular divalents had a conductance for inward currents carried by the divalents of: 25 pS for Ba2+ and 15 pS for Ca2+ at -80 mV and 10 pS for Mg2+ at -50 mV. The organic cations, TMA and TEA, permeated slowly and attenuated K+ currents much like the divalents. As expected, the channel K+ conductance increased with K+ concentration saturating at ~ 45 pS and the KD of K+ for the channel was 32 mM. Pure divalent ion currents were of lower amplitude than those with alkali ions and the channel opening rate was lower in the presence of divalents than in the presence of monovalents. Exposing cells to the actin disrupting reagent cytochalasin D increased the frequency of openings in cell-attached patches probably by reducing mechanoprotection.
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Affiliation(s)
- Radhakrishnan Gnanasambandam
- State University of New York at Buffalo, Department of Physiology and Biophysics, Buffalo, New York, United States of America
- * E-mail:
| | - Chilman Bae
- State University of New York at Buffalo, Department of Physiology and Biophysics, Buffalo, New York, United States of America
| | - Philip A. Gottlieb
- State University of New York at Buffalo, Department of Physiology and Biophysics, Buffalo, New York, United States of America
| | - Frederick Sachs
- State University of New York at Buffalo, Department of Physiology and Biophysics, Buffalo, New York, United States of America
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44
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Stölting G, de Oliveira RC, Guzman RE, Miranda-Laferte E, Conrad R, Jordan N, Schmidt S, Hendriks J, Gensch T, Hidalgo P. Direct interaction of CaVβ with actin up-regulates L-type calcium currents in HL-1 cardiomyocytes. J Biol Chem 2015; 290:4561-4572. [PMID: 25533460 PMCID: PMC4335199 DOI: 10.1074/jbc.m114.573956] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [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: 04/14/2014] [Revised: 12/05/2014] [Indexed: 12/14/2022] Open
Abstract
Expression of the β-subunit (CaVβ) is required for normal function of cardiac L-type calcium channels, and its up-regulation is associated with heart failure. CaVβ binds to the α1 pore-forming subunit of L-type channels and augments calcium current density by facilitating channel opening and increasing the number of channels in the plasma membrane, by a poorly understood mechanism. Actin, a key component of the intracellular trafficking machinery, interacts with Src homology 3 domains in different proteins. Although CaVβ encompasses a highly conserved Src homology 3 domain, association with actin has not yet been explored. Here, using co-sedimentation assays and FRET experiments, we uncover a direct interaction between CaVβ and actin filaments. Consistently, single-molecule localization analysis reveals streaklike structures composed by CaVβ2 that distribute over several micrometers along actin filaments in HL-1 cardiomyocytes. Overexpression of CaVβ2-N3 in HL-1 cells induces an increase in L-type current without altering voltage-dependent activation, thus reflecting an increased number of channels in the plasma membrane. CaVβ mediated L-type up-regulation, and CaVβ-actin association is prevented by disruption of the actin cytoskeleton with cytochalasin D. Our study reveals for the first time an interacting partner of CaVβ that is directly involved in vesicular trafficking. We propose a model in which CaVβ promotes anterograde trafficking of the L-type channels by anchoring them to actin filaments in their itinerary to the plasma membrane.
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Affiliation(s)
- Gabriel Stölting
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | | | - Raul E Guzman
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Erick Miranda-Laferte
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Rachel Conrad
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Nadine Jordan
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Silke Schmidt
- the Institut für Neurophysiologie, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Johnny Hendriks
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Thomas Gensch
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Patricia Hidalgo
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and.
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45
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Calderano SG, Drosopoulos WC, Quaresma MM, Marques CA, Kosiyatrakul S, McCulloch R, Schildkraut CL, Elias MC. Single molecule analysis of Trypanosoma brucei DNA replication dynamics. Nucleic Acids Res 2015; 43:2655-65. [PMID: 25690894 PMCID: PMC4357695 DOI: 10.1093/nar/gku1389] [Citation(s) in RCA: 24] [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] [Indexed: 11/25/2022] Open
Abstract
Eukaryotic genome duplication relies on origins of replication, distributed over multiple chromosomes, to initiate DNA replication. A recent genome-wide analysis of Trypanosoma brucei, the etiological agent of sleeping sickness, localized its replication origins to the boundaries of multigenic transcription units. To better understand genomic replication in this organism, we examined replication by single molecule analysis of replicated DNA. We determined the average speed of replication forks of procyclic and bloodstream form cells and we found that T. brucei DNA replication rate is similar to rates seen in other eukaryotes. We also analyzed the replication dynamics of a central region of chromosome 1 in procyclic forms. We present evidence for replication terminating within the central part of the chromosome and thus emanating from both sides, suggesting a previously unmapped origin toward the 5′ extremity of chromosome 1. Also, termination is not at a fixed location in chromosome 1, but is rather variable. Importantly, we found a replication origin located near an ORC1/CDC6 binding site that is detected after replicative stress induced by hydroxyurea treatment, suggesting it may be a dormant origin activated in response to replicative stress. Collectively, our findings support the existence of more replication origins in T. brucei than previously appreciated.
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Affiliation(s)
- Simone Guedes Calderano
- Laboratório Especial de Ciclo Celular, Instituto Butantan, São Paulo, SP 05503-900, Brasil Center of Toxins, Immune Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP 05503-900, Brasil
| | - William C Drosopoulos
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Marina Mônaco Quaresma
- Laboratório Especial de Ciclo Celular, Instituto Butantan, São Paulo, SP 05503-900, Brasil Center of Toxins, Immune Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP 05503-900, Brasil
| | - Catarina A Marques
- The Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G128TA, UK
| | | | - Richard McCulloch
- The Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G128TA, UK
| | - Carl L Schildkraut
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Maria Carolina Elias
- Laboratório Especial de Ciclo Celular, Instituto Butantan, São Paulo, SP 05503-900, Brasil Center of Toxins, Immune Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP 05503-900, Brasil
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Abstract
Deregulated DNA replication occurs in cancer where it contributes to genomic instability. This process is a target of cytotoxic therapies. Chemotherapies exploit high DNA replication in cancer cells by modifying the DNA template or by inhibiting vital enzymatic activities that lead to slowing or stalling replication fork progression. Stalled replication forks can be converted into toxic DNA double-strand breaks resulting in cell death, i.e., replication stress. While likely crucial for many cancer treatments, replication stress is poorly understood due to its complexity. While we still know relatively little about the role of replication stress in cancer therapy, technical advances in recent years have shed new light on the effect that cancer therapeutics have on replication forks and the molecular mechanisms that lead from obstructed fork progression to cell death. This chapter will give an overview of our current understanding of replication stress in the context of cancer therapy.
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Affiliation(s)
- Panagiotis Kotsantis
- School of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Rebecca M Jones
- School of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Martin R Higgs
- School of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Eva Petermann
- School of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
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Pirkmajer S, Kulkarni SS, Tom RZ, Ross FA, Hawley SA, Hardie DG, Zierath JR, Chibalin AV. Methotrexate promotes glucose uptake and lipid oxidation in skeletal muscle via AMPK activation. Diabetes 2015; 64:360-9. [PMID: 25338814 PMCID: PMC5703413 DOI: 10.2337/db14-0508] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Methotrexate (MTX) is a widely used anticancer and antirheumatic drug that has been postulated to protect against metabolic risk factors associated with type 2 diabetes, although the mechanism remains unknown. MTX inhibits 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase (ATIC) and thereby slows the metabolism of 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranosyl-5'-monophosphate (ZMP) and its precursor AICAR, which is a pharmacological AMPK activator. We explored whether MTX promotes AMPK activation in cultured myotubes and isolated skeletal muscle. We found MTX markedly reduced the threshold for AICAR-induced AMPK activation and potentiated glucose uptake and lipid oxidation. Gene silencing of the MTX target ATIC activated AMPK and stimulated lipid oxidation in cultured myotubes. Furthermore, MTX activated AMPK in wild-type HEK-293 cells. These effects were abolished in skeletal muscle lacking the muscle-specific, ZMP-sensitive AMPK-γ3 subunit and in HEK-293 cells expressing a ZMP-insensitive mutant AMPK-γ2 subunit. Collectively, our findings underscore a role for AMPK as a direct molecular link between MTX and energy metabolism in skeletal muscle. Cotherapy with AICAR and MTX could represent a novel strategy to treat metabolic disorders and overcome current limitations of AICAR monotherapy.
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Affiliation(s)
- Sergej Pirkmajer
- Department of Molecular Medicine and Surgery, Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Sameer S Kulkarni
- Department of Molecular Medicine and Surgery, Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Robby Z Tom
- Department of Molecular Medicine and Surgery, Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Fiona A Ross
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Simon A Hawley
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - D Grahame Hardie
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Juleen R Zierath
- Department of Molecular Medicine and Surgery, Integrative Physiology, Karolinska Institutet, Stockholm, Sweden Department of Physiology and Pharmacology, Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Alexander V Chibalin
- Department of Molecular Medicine and Surgery, Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
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48
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Saiko P, Steinmann MT, Schuster H, Graser G, Bressler S, Giessrigl B, Lackner A, Grusch M, Krupitza G, Bago-Horvath Z, Jaeger W, Fritzer-Szekeres M, Szekeres T. Epigallocatechin gallate, ellagic acid, and rosmarinic acid perturb dNTP pools and inhibit de novo DNA synthesis and proliferation of human HL-60 promyelocytic leukemia cells: Synergism with arabinofuranosylcytosine. Phytomedicine 2015; 22:213-22. [PMID: 25636891 DOI: 10.1016/j.phymed.2014.11.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [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: 07/14/2014] [Revised: 11/13/2014] [Accepted: 11/14/2014] [Indexed: 06/04/2023]
Abstract
Epigallocatechin gallate (EGCG), ellagic acid (EA) and rosmarinic acid (RA) are natural polyphenols exerting cancer chemopreventive effects. Ribonucleotide reductase (RR; EC 1.17.4.1) converts ribonucleoside diphosphates into deoxyribonucleoside diphosphates being essential for DNA replication, which is why the enzyme is considered an excellent target for anticancer therapy. EGCG, EA, and RA dose-dependently inhibited the growth of human HL-60 promyelocytic leukemia cells, exerted strong free radical scavenging potential, and significantly imbalanced nuclear deoxyribonucleoside triphosphate (dNTP) concentrations without distinctly affecting the protein levels of RR subunits (R1, R2, p53R2). Incorporation of (14)C-cytidine into nascent DNA of tumor cells was also significantly lowered, being equivalent to an inhibition of DNA synthesis. Consequently, treatment with EGCG and RA attenuated cells in the G0/G1 phase of the cell cycle, finally resulting in a pronounced induction of apoptosis. Sequential combination of EA and RA with the first-line antileukemic agent arabinofuranosylcytosine (AraC) synergistically potentiated the antiproliferative effect of AraC, whereas EGCG plus AraC yielded additive effects. Taken together, we show for the first time that EGCG, EA, and RA perturbed dNTP levels and inhibited cell proliferation in human HL-60 promyelocytic leukemia cells, with EGCG and RA causing a pronounced induction of apoptosis. Due to these effects and synergism with AraC, these food ingredients deserve further preclinical and in vivo testing as inhibitors of leukemic cell proliferation.
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Affiliation(s)
- Philipp Saiko
- Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Marie-Thérèse Steinmann
- Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Heike Schuster
- Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Geraldine Graser
- Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Sabine Bressler
- Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Benedikt Giessrigl
- Department of Pathology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Andreas Lackner
- Department of Medicine I, Division of Cancer Research, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Michael Grusch
- Department of Medicine I, Division of Cancer Research, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Georg Krupitza
- Department of Pathology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Zsuzsanna Bago-Horvath
- Department of Pathology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Walter Jaeger
- Department of Clinical Pharmacy and Diagnostics, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
| | - Monika Fritzer-Szekeres
- Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Thomas Szekeres
- Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
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49
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Garro HA, Pungitore CR. Coumarins as Potential Inhibitors of DNA Polymerases and Reverse Transcriptases. Searching New Antiretroviral and Antitumoral Drugs. Curr Drug Discov Technol 2015; 12:66-79. [PMID: 26179474 DOI: 10.2174/1570163812666150716111719] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [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: 06/04/2023]
Abstract
Human Immunodeficiency Virus (HIV) is the viral agent of Acquired Immunodeficiency Syndrome (AIDS), and at present, there is no effective vaccine against HIV. Reverse Transcriptase (RT) is an essential enzyme for retroviral replication, such as HIV as well as for other RNA infectious viruses like Human T lymphocyte virus. Polymerases act in DNA metabolism, modulating different processes like mitosis, damage repair, transcription and replication. It has been widely documented that DNA Polymerases and Reverse Transcriptases serve as molecular targets for antiviral and antitumoral chemotherapy. Coumarins are oxygen heterocycles that are widely distributed throughout the plant kingdom. Natural coumarins have attraction due to their bioactive properties such as tumor promotion inhibitory effects, and anti-HIV activity. Coumarins and derivates exhibit potent inhibitory effects on HIV-1 replication in lymphocytes and compounds isolated from Calophyllum inophyllum or DCK derivates showed inhibitory activity against human RT. Furthermore, natural isocoumarins isolated from cultures of fungi or hydroxycoumarins were able to inhibit human DNA polymerase. In view of their importance as drugs and biologically active natural products, and their medicinally useful properties, extensive studies have been carried out on the synthesis of coumarin compounds in recent years. Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs), a class of antiretroviral chemotherapeutic agents, act by binding to an allosteric pocket showing, generally, low toxicity. This work tries to summarize the investigation about natural and synthetic coumarins with the ability to inhibit key enzymes that play a crucial role in DNA metabolism and their possible application as antiretroviral and antitumoral agents.
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Affiliation(s)
- Hugo A Garro
- Department of Chemistry, Faculty of Chemistry, Biochemistry and Pharmacy. University of San Luis, P.O. 5700, San Luis, Argentine.
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50
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Chang ZQ, Li J, Zhai QQ. Evaluation on activity of cytochrome p450 enzymes in turbot via a probe drug cocktail. J Aquat Anim Health 2014; 26:272-277. [PMID: 25369285 DOI: 10.1080/08997659.2014.938868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cytochrome P450s (CYPs) are the main catalytic enzymes for metabolism by a variety of endogenous and exogenous substrates in mammals, fish, insects, etc. We evaluated the application of a multidrug cocktail on changes in CYP1, CYP2, and CYP3 activity in Turbot Scophthalmus maximus. The probe drugs were a combination of caffeine (5 mg/kg body weight), dapsone (5 mg/kg), and chlorzoxazone (10 mg/kg). After a single intraperitoneal injection of the cocktail, the concentration of all three probe drugs in the plasma increased quickly to a peak and then decreased gradually over 24 h. Pharmacokinetic profiles of the three probe drugs were determined using a noncompartmental analysis, and the typical parameters were calculated. In the assay for CYP induction, pretreatment with rifampicin significantly reduced the typical pharmacokinetic metrics for caffeine and chlorzoxazone, but not dapsone, indicating that the activity of CYP1 and CYP2 in turbot were induced by rifampicin.
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Affiliation(s)
- Zhi-Qiang Chang
- a Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences , 106 Nanjing Road, Qingdao 266071 , China
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