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Araújo D, Gonçalves B, Vilas Boas D, Rodrigues ME, Henriques M, Silva S. Combined Application of Antisense Oligomers to Control Transcription Factors of Candida albicans Biofilm Formation. Mycopathologia 2023:10.1007/s11046-023-00734-0. [PMID: 37099227 DOI: 10.1007/s11046-023-00734-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/29/2023] [Indexed: 04/27/2023]
Abstract
Antisense oligomers (ASOs) have been little exploited to control determinants of Candida albicans virulence. Biofilm formation is an important virulence factor of C. albicans, that is regulated by a complex network of transcription factors (such as EFG1, BRG1 and ROB1). Thus, the main goal of this work was to project ASOs, based on the 2'-OMethyl chemical modification, to target BRG1 and ROB1 mRNA and to validate its application either alone or in combination with the EFG1 mRNA target, to reduce C. albicans biofilm formation. The ability of ASOs to control gene expression was evaluate by qRT-PCR. The effect on biofilm formation was determined by the total biomass quantification, and simultaneously the carbohydrates and proteins reduction on extracellular matrix. It was verified that all the oligomers were able to reduce the levels of gene expression and the ability of C. albicans to form biofilms. Furthermore, the combined application of the cocktail of ASOs enhances the inhibition of C. albicans biofilm formation, minimizing biofilm thickness by reducing the quantity of matrix content (protein and carbohydrate). So, our work confirms that ASOs are useful tools for research and therapeutic development on the control of Candida species biofilm formation.
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Affiliation(s)
- D Araújo
- Centre of Biological Engineering, LMaS-Laboratório de Microbiologia Aplicada à Saúde, CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
- LABBELS, Associate Laboratory, Braga/Guimarães, Portugal.
| | - B Gonçalves
- Centre of Biological Engineering, LMaS-Laboratório de Microbiologia Aplicada à Saúde, CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
- LABBELS, Associate Laboratory, Braga/Guimarães, Portugal
| | - D Vilas Boas
- Centre of Biological Engineering, LMaS-Laboratório de Microbiologia Aplicada à Saúde, CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
- LABBELS, Associate Laboratory, Braga/Guimarães, Portugal
| | - M E Rodrigues
- Centre of Biological Engineering, LMaS-Laboratório de Microbiologia Aplicada à Saúde, CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
- LABBELS, Associate Laboratory, Braga/Guimarães, Portugal
| | - M Henriques
- Centre of Biological Engineering, LMaS-Laboratório de Microbiologia Aplicada à Saúde, CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
- LABBELS, Associate Laboratory, Braga/Guimarães, Portugal
| | - S Silva
- Centre of Biological Engineering, LMaS-Laboratório de Microbiologia Aplicada à Saúde, CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
- INIAV, IP-National Institute for Agrarian and Veterinary, Rua Dos Lagidos, Lugar da Madalena, Vairão, Vila Do Conde, Portugal
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Barbosa A, Araújo D, Henriques M, Silva S. The combined application of the anti-RAS1 and anti-RIM101 2'-OMethylRNA oligomers enhances Candida albicans filamentation control. Med Mycol 2021; 59:1024-1031. [PMID: 34097057 DOI: 10.1093/mmy/myab033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/12/2021] [Accepted: 06/02/2021] [Indexed: 01/30/2023] Open
Abstract
Whereas antisense oligomers (ASOs) have been successfully utilized to control gene expression, they have been little exploited to control Candida albicans virulence's determinants. Filamentation is an important virulence factor of C. albicans, and RAS1 and RIM101 genes are involved in its regulation. Thus, the main goal of this work was to project ASOs, based on 2'-OMethyl chemical modification, to target RAS1 and RIM101 mRNA and to validate its application either alone or in combination, to reduce Candida filamentation in different human body fluids.It was verified that both, anti-RAS1 2'OMe and anti-RIM101 2'OMe oligomers, were able to reduce the levels of RAS1 and RIM101 genes' expression and to significantly reduce C. albicans filamentation. Furthermore, the combined application of anti-RAS1 2'OMe oligomer and anti-RIM101 2'OMe oligomer enhances the control of C. albicans filamentation in artificial saliva and urine.Our work confirms that ASOs are useful tools for research and therapeutic development on the control of candidiasis. LAY ABSTRACT This work aimed to project antisense oligomers to control Candida albicans filamentation. The results revealed that the projected oligomers, anti-RAS1 2'OMe and anti-RIM101 2'OMe, were able to control RAS1 and RIM101 gene expression and to significantly reduce C. albicans filamentation.
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Affiliation(s)
- Ana Barbosa
- LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Daniela Araújo
- LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Mariana Henriques
- LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Sónia Silva
- LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
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Höfle L, Biedenkopf D, Werner BT, Shrestha A, Jelonek L, Koch A. Study on the efficiency of dsRNAs with increasing length in RNA-based silencing of the Fusarium CYP51 genes. RNA Biol 2020. [PMID: 31814508 DOI: 10.1101/824953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
Previously, we have demonstrated that transgenic Arabidopsis and barley plants, expressing a 791 nucleotide (nt) dsRNA (CYP3RNA) that targets all three CYP51 genes (FgCYP51A, FgCYP51B, FgCYP51C) in Fusarium graminearum (Fg), inhibited fungal infection via a process designated as host-induced gene silencing (HIGS). More recently, we have shown that spray applications of CYP3RNA also protect barley from fungal infection via a process termed spray-induced gene silencing (SIGS). Thus, RNAi technology may have the potential to revolutionize plant protection in agriculture. Therefore, successful field application will require optimization of RNAi design necessary to maximize the efficacy of the RNA silencing construct for making RNAi-based strategies a realistic and sustainable approach in agriculture. Previous studies indicate that silencing is correlated with the number of siRNAs generated from a dsRNA precursor. To prove the hypothesis that silencing efficiency is correlated with the number of siRNAs processed out of the dsRNA precursor, we tested in a HIGS and SIGS approach dsRNA precursors of increasing length ranging from 400 nt to 1500 nt to assess gene silencing efficiency of individual FgCYP51 genes. Concerning HIGS-mediated disease control, we found that there is no significant correlation between the length of the dsRNA precursor and the reduction of Fg infection on CYP51-dsRNA-expressing Arabidopsis plants. Importantly and in clear contrast to HIGS, we measured a decrease in SIGS-mediated Fg disease resistance that significantly correlates with the length of the dsRNA construct that was sprayed, indicating that the size of the dsRNA interferes with a sufficient uptake of dsRNAs by the fungus.
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Affiliation(s)
- L Höfle
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Giessen, Germany
| | - D Biedenkopf
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Giessen, Germany
| | - B T Werner
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Giessen, Germany
| | - A Shrestha
- Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institute, Braunschweig, Germany
| | - L Jelonek
- Institute of Bioinformatics and Systems Biology, Justus Liebig University, Giessen, Germany
| | - A Koch
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Giessen, Germany
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Abstract
Candida albicans has remained the main etiological agent of candidiasis, challenges clinicians with high mortality and morbidity. The emergence of resistance to antifungal drugs, toxicity and lower efficacy have all contributed to an urgent need to develop alternative drugs aiming at novel targets in C. albicans. Targeting the production of virulence factors, which are essential processes for infectious agents, represents an attractive substitute for the development of newer anti-infectives. The present review highlights the recent developments made in the understanding of the pathogenicity of C. albicans. Production of hydrolytic enzymes, morphogenesis and biofilm formation, along with their molecular and metabolic regulation in Candida are discussed with regard to the development of novel antipathogenic drugs against candidiasis. Over the last decade, candidiasis has remained a major problematic disease worldwide. In spite of the existence of many antifungal drugs, the treatment of such diseases has still remained unsuccessful due to drug inefficacy. Therefore, there is a need to discover antifungals with different modes of action, such as antipathogenic drugs against Candida albicans. Here, we describe how various types of virulence factors such as proteinase, phospholipase, hemolysin, adhesion, morphogenesis and biofilm formation, could be targeted to develop novel therapeutics. We can inhibit production of these virulence factors by controlling their molecular/metabolic regulation.
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Höfle L, Biedenkopf D, Werner BT, Shrestha A, Jelonek L, Koch A. Study on the efficiency of dsRNAs with increasing length in RNA-based silencing of the Fusarium CYP51 genes. RNA Biol 2020; 17:463-473. [PMID: 31814508 DOI: 10.1080/15476286.2019.1700033] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Previously, we have demonstrated that transgenic Arabidopsis and barley plants, expressing a 791 nucleotide (nt) dsRNA (CYP3RNA) that targets all three CYP51 genes (FgCYP51A, FgCYP51B, FgCYP51C) in Fusarium graminearum (Fg), inhibited fungal infection via a process designated as host-induced gene silencing (HIGS). More recently, we have shown that spray applications of CYP3RNA also protect barley from fungal infection via a process termed spray-induced gene silencing (SIGS). Thus, RNAi technology may have the potential to revolutionize plant protection in agriculture. Therefore, successful field application will require optimization of RNAi design necessary to maximize the efficacy of the RNA silencing construct for making RNAi-based strategies a realistic and sustainable approach in agriculture. Previous studies indicate that silencing is correlated with the number of siRNAs generated from a dsRNA precursor. To prove the hypothesis that silencing efficiency is correlated with the number of siRNAs processed out of the dsRNA precursor, we tested in a HIGS and SIGS approach dsRNA precursors of increasing length ranging from 400 nt to 1500 nt to assess gene silencing efficiency of individual FgCYP51 genes. Concerning HIGS-mediated disease control, we found that there is no significant correlation between the length of the dsRNA precursor and the reduction of Fg infection on CYP51-dsRNA-expressing Arabidopsis plants. Importantly and in clear contrast to HIGS, we measured a decrease in SIGS-mediated Fg disease resistance that significantly correlates with the length of the dsRNA construct that was sprayed, indicating that the size of the dsRNA interferes with a sufficient uptake of dsRNAs by the fungus.
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Affiliation(s)
- L Höfle
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Giessen, Germany
| | - D Biedenkopf
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Giessen, Germany
| | - B T Werner
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Giessen, Germany
| | - A Shrestha
- Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institute, Braunschweig, Germany
| | - L Jelonek
- Institute of Bioinformatics and Systems Biology, Justus Liebig University, Giessen, Germany
| | - A Koch
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Giessen, Germany
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Araújo D, Azevedo NM, Barbosa A, Almeida C, Rodrigues ME, Henriques M, Silva S. Application of 2'-OMethylRNA' Antisense Oligomer to Control Candida albicans EFG1 Virulence Determinant. MOLECULAR THERAPY-NUCLEIC ACIDS 2019; 18:508-517. [PMID: 31671344 PMCID: PMC6838528 DOI: 10.1016/j.omtn.2019.09.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/26/2019] [Accepted: 09/12/2019] [Indexed: 11/18/2022]
Abstract
Antisense oligomers and their analogs have been successfully utilized to silence gene expression for the treatment of many human diseases; however, the control of yeast’s virulence determinants has never been exploited before. In this sense, this work is based on the key hypothesis that if a pathogen’s genetic sequence is a determinant of virulence, it will be possible to synthesize a nucleic acid mimic based on antisense therapy (AST) that will bind to the mRNA produced, blocking its translation into protein and, consequently, reducing the pathogen virulence phenotype. EFG1 is an important determinant of virulence that is involved in the regulation of the Candida albicans switch from yeast to filamentous form. Thus, our main goal was to design and synthesize an antisense oligonucleotide (ASO) targeting the EFG1 mRNA and to validate its in vitro applicability. The results show that the anti-EFG1 2′-OMethylRNA (2′OMe) oligomer was able to significantly reduce the levels of EFG1 gene expression and of Efg1p protein translation (both approximately 60%), as well as effectively prevent filamentation of C. albicans cells (by 80%). Moreover, it was verified that anti-EFG1 2′OMe keeps the efficacy in different simulated human body fluids. Undeniably, this work provides potentially valuable information for future research into the management of Candida infections, regarding the development of a credible and alternative method to control C. albicans infections, based on AST methodology.
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Affiliation(s)
- Daniela Araújo
- LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Nuno Miguel Azevedo
- LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Ana Barbosa
- LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Carina Almeida
- LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; INIAV, IP-National Institute for Agrarian and Veterinary Research, Rua dos Lagidos, Lugar da Madalena, Vairão, 4485-655 Vila do Conde, Portugal
| | - Maria Elisa Rodrigues
- LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Mariana Henriques
- LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Sónia Silva
- LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
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Majumdar R, Rajasekaran K, Cary JW. RNA Interference (RNAi) as a Potential Tool for Control of Mycotoxin Contamination in Crop Plants: Concepts and Considerations. FRONTIERS IN PLANT SCIENCE 2017; 8:200. [PMID: 28261252 PMCID: PMC5306134 DOI: 10.3389/fpls.2017.00200] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/02/2017] [Indexed: 05/20/2023]
Abstract
Mycotoxin contamination in food and feed crops is a major concern worldwide. Fungal pathogens of the genera Aspergillus. Fusarium, and Penicillium are a major threat to food and feed crops due to production of mycotoxins such as aflatoxins, 4-deoxynivalenol, patulin, and numerous other toxic secondary metabolites that substantially reduce the value of the crop. While host resistance genes are frequently used to introgress disease resistance into elite germplasm, either through traditional breeding or transgenic approaches, such resistance is often compromised by the evolving pathogen over time. RNAi-based host-induced gene silencing of key genes required by the pathogen for optimal growth, virulence and/or toxin production, can serve as an alternative, pre-harvest approach for disease control. RNAi represents a robust and efficient tool that can be used in a highly targeted, tissue specific manner to combat mycotoxigenic fungi infecting crop plants. Successful transgenic RNAi implementation depends on several factors including (1) designing vectors to produce double-stranded RNAs (dsRNAs) that will generate small interfering RNA (siRNA) species for optimal gene silencing and reduced potential for off-target effects; (2) availability of ample target siRNAs at the infection site; (3) efficient uptake of siRNAs by the fungus; (4) siRNA half-life and (5) amplification of the silencing effect. This review provides a critical and comprehensive evaluation of the published literature on the use of RNAi-based approaches to control mycotoxin contamination in crop plants. It also examines experimental strategies used to better understand the mode of action of RNAi with the aim of eliminating mycotoxin contamination, thereby improving food and feed safety.
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Izgü F, Altinbay D, Türeli AE. In VitroSusceptibilities ofCandidaspp. to Panomycocin, a Novel Exo-β-1,3-Glucanase Isolated fromPichia anomalaNCYC 434. Microbiol Immunol 2013; 51:797-803. [PMID: 17895596 DOI: 10.1111/j.1348-0421.2007.tb03975.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Panomycocin, the killer toxin of Pichia anomala NCYC 434 (K5), is a 49 kDa monomeric glycoprotein with exo-beta-1,3-glucanase activity (patent pending). In this study we evaluated the in vitro activity of panomycocin against a panel of 109 human isolates of seven different pathogenic Candida spp. using microdilution and time-kill methods. Panomycocin was most active against C. tropicalis, C. pseudotropicalis and C. glabrata with MIC(90) values of 1 microg/ml. It displayed significant activity against C. albicans and C. parapsilosis with MIC(90) values of 4 and 2 microg/ml, respectively. For C. krusei, the MIC(90) value was 8 microg/ml. Panomycocin was fungicidal against all the tested Candida spp. The MFC values were only one or 2 dilutions higher than the MICs with the exception of C. krusei isolates with MFCs greater than or equal to 4xMIC. Results of this study indicated that panomycocin could be considered as a natural antifungal agent against Candida infections and has significant potential for further investigation.
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Affiliation(s)
- Fatih Izgü
- Department of Biological Sciences, Middle East Technical University, Ankara, Turkey.
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Moazeni M, Khorramizadeh MR, Teimoori-Toolabi L, Noorbakhsh F, Fallahi AA, Rezaie S. Down-regulation of the ALS3 gene as a consequent effect of RNA-mediated silencing of the EFG1 gene in Candida albicans. IRANIAN BIOMEDICAL JOURNAL 2012. [PMID: 23183615 DOI: 10.6091/ibj.1093.2012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND The most important virulence factor which plays a central role in Candida albicans pathogenesis is the ability of this yeast to alternate between unicellular yeast and filamentous hyphal forms. Efg1 protein is thought to be the main positive regulating transcription factor, which is responsible for regulating hyphal-specific gene expression under most conditions. ALS3 is one of the Efg1-associated genes encoding a multi-functional adhesive polypeptide, which mediates adherence to diverse host substrates. In this study, the EFG1 gene was knocked down by using synthetic siRNA in C. albicans and the regulation in ALS3 as one of the Efg1-dependent genes was investigated. METHOD The 19-nucleotide siRNA was designed based on cDNA sequence of EFG1 gene in C. albicans. Transfection was performed using modified- plyethylen glycol/LiAc method. To quantify the level of EFG1 and the hyphal-specific ALS3 gene expression, the cognate EFG1 and ALS3 mRNA were measured in C. albicans by quantitative real-time RT-PCR. RESULTS Fluorescent microscopy pictures indicated that transfection was performed successfully. Also, according to relative expression software tool, expression of EFG1 gene was decreased significantly with 500 nM siRNA as well as 1 µM siRNA (P<0.05). However, more significant down-regulations were observed in the expression of ALS3 in both concentrations of 500 nM and 1 µM siRNA (P<0.05). CONCLUSION In conclusion, we demonstrated the down-regulation of ALS3 gene as a consequent of applying EFG1-specific siRNA in C. albicans. This may lead us to design anti-fungal-specific agents in order to face with C. albicans-associated infections.
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Affiliation(s)
- Maryam Moazeni
- Div. of Molecular Biology, Dept. of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Khorramizadeh
- Dept. of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ladan Teimoori-Toolabi
- 3Dept. of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Fatemeh Noorbakhsh
- Dep. of Biology, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran
| | - Ali Akbar Fallahi
- Div. of Molecular Biology, Dept. of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Sassan Rezaie
- Div. of Molecular Biology, Dept. of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.,Dept. of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Moazeni M, Khoramizadeh MR, Kordbacheh P, Sepehrizadeh Z, Zeraati H, Noorbakhsh F, Teimoori-Toolabi L, Rezaie S. RNA-Mediated Gene Silencing in Candida albicans: Inhibition of Hyphae Formation by Use of RNAi Technology. Mycopathologia 2012; 174:177-85. [DOI: 10.1007/s11046-012-9539-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 03/19/2012] [Indexed: 11/29/2022]
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Zhang L, Leibowitz MJ, Zhang Y. Antisense oligonucleotides effectively inhibit the co-transcriptional splicing of a Candida group I intron in vitro and in vivo: Implications for antifungal therapeutics. FEBS Lett 2009; 583:734-8. [PMID: 19185575 DOI: 10.1016/j.febslet.2009.01.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 01/02/2009] [Accepted: 01/15/2009] [Indexed: 11/27/2022]
Abstract
Self-splicing of group I intron from the 26S rRNA of Candida albicans is essential for maturation of the host RNA. Here, we demonstrated that the co-transcriptional splicing of the intron in vitro was blocked by antisense oligonucleotides (AONs) targeting the P3-P7 core of the intron. The core-targeted AON effectively and specifically inhibited the intron splicing from its host RNA in living C. albicans. Furthermore, flow cytometry experiments showed that the growth inhibition was caused by a fungicidal effect. For the first time, we showed that an AON targeting the ribozyme core folding specifically inhibits the endogenous ribozyme splicing in living cells and specifically kills the intron-containing fungal strains, which sheds light on the development of antifungal drugs in the future.
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Affiliation(s)
- Libin Zhang
- State Key Laboratory of Virology and Department of Biochemistry and Molecular Biology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
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Hamad M. Antifungal Immunotherapy and Immunomodulation: A Double-hitter Approach to Deal with Invasive Fungal Infections. Scand J Immunol 2008; 67:533-43. [DOI: 10.1111/j.1365-3083.2008.02101.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Park M, Bruice TC. Binding properties of positively charged deoxynucleic guanidine (DNG), AgTgAgTgAgT and DNG/DNA chimeras to DNA. Bioorg Med Chem Lett 2008; 18:3488-91. [PMID: 18514514 DOI: 10.1016/j.bmcl.2008.05.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 05/07/2008] [Accepted: 05/08/2008] [Indexed: 11/24/2022]
Abstract
The melting properties of hexameric oligonucleotide AgTgAgTgAgT, in which the phosphodiester linkages of the DNA have been replaced by guanidium linkages, have been evaluated. Using the juvenile esterase gene as a target, the binding of a 20-mer DNG/DNA chimera that includes AgTgAgTgAgT is more than 10(5.7) stronger than the binding of 20-mer composed solely of DNA.
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Affiliation(s)
- Myunji Park
- Department of Chemistry and Biochemistry, University of Califonia at Santa Barbara, CA 93106, USA
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Tijerina P, Mohr S, Russell R. DMS footprinting of structured RNAs and RNA-protein complexes. Nat Protoc 2008; 2:2608-23. [PMID: 17948004 DOI: 10.1038/nprot.2007.380] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We describe a protocol in which dimethyl sulfate (DMS) modification of the base-pairing faces of unpaired adenosine and cytidine nucleotides is used for structural analysis of RNAs and RNA-protein complexes (RNPs). The protocol is optimized for RNAs of small to moderate size (< or = 500 nt). The RNA or RNP is first exposed to DMS under conditions that promote formation of the folded structure or complex, as well as 'control' conditions that do not allow folding or complex formation. The positions and extents of modification are then determined by primer extension, polyacrylamide gel electrophoresis and quantitative analysis. From changes in the extent of modification upon folding or protein binding (appearance of a 'footprint'), it is possible to detect local changes in the secondary and tertiary structure of RNA, as well as the formation of RNA-protein contacts. This protocol takes 1.5-3 d to complete, depending on the type of analysis used.
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Affiliation(s)
- Pilar Tijerina
- Department of Chemistry and Biochemistry and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, USA
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17
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Woodson SA. Structure and assembly of group I introns. Curr Opin Struct Biol 2005; 15:324-30. [PMID: 15922592 DOI: 10.1016/j.sbi.2005.05.007] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Revised: 04/21/2005] [Accepted: 05/09/2005] [Indexed: 11/29/2022]
Abstract
Self-splicing group I introns have served as a model for RNA catalysis and folding for over two decades. New three-dimensional structures now bring the details into view. Revelations include an unanticipated turn in the RNA backbone around the guanosine-binding pocket. Two metal ions in the active site coordinate the substrate and phosphates from all three helical domains.
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Affiliation(s)
- Sarah A Woodson
- TC Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218-2685, USA.
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Disney MD, Stephenson R, Wright TW, Haidaris CG, Turner DH, Gigliotti F. Activity of Hoechst 33258 against Pneumocystis carinii f. sp. muris, Candida albicans, and Candida dubliniensis. Antimicrob Agents Chemother 2005; 49:1326-30. [PMID: 15793106 PMCID: PMC1068638 DOI: 10.1128/aac.49.4.1326-1330.2005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hoechst 33258 is a compound that binds nucleic acids. We report that Hoechst 33258 exhibits antimicrobial activity against Pneumocystis carinii f. sp. muris in a mouse model for P. carinii pneumonia and against Candida albicans and Candida dubliniensis in vitro. Relative to saline treatment, a 14-day, daily treatment of mice with 37.5 mg of Hoechst 33258/kg of body weight after inoculation with P. carinii reduced by about 100-fold the number of P. carinii organisms detected by either PCR or by microscopy after silver staining. For comparison, treatment based on a dose of 15 to 20 mg of the trimethoprim component in trimethoprim-sulfamethoxazole/kg reduced the number of P. carinii by about fourfold. In vitro inhibition of P. carinii group I intron splicing was observed with a 50% inhibitory concentration (IC50) of 30 microM in 2 or 4 mM Mg2+, suggesting RNA as a possible target. However, Hoechst 33258 inhibits growth of Candida strains with and without group I introns. IC50s ranged from 1 to 9 microM for strains with group I introns and were 12 and 32 microM for two strains without group I introns. These studies demonstrate that compounds that bind fungal nucleic acids have the potential to be developed as new therapeutics for Pneumocystis and possibly other fungi, especially if they could be directed to structures that are not present in mammalian cells, such as self-splicing introns.
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Affiliation(s)
- Matthew D Disney
- Department of Chemistry, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA
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Mathews DH, Disney MD, Childs JL, Schroeder SJ, Zuker M, Turner DH. Incorporating chemical modification constraints into a dynamic programming algorithm for prediction of RNA secondary structure. Proc Natl Acad Sci U S A 2004; 101:7287-92. [PMID: 15123812 PMCID: PMC409911 DOI: 10.1073/pnas.0401799101] [Citation(s) in RCA: 1082] [Impact Index Per Article: 54.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Indexed: 11/18/2022] Open
Abstract
A dynamic programming algorithm for prediction of RNA secondary structure has been revised to accommodate folding constraints determined by chemical modification and to include free energy increments for coaxial stacking of helices when they are either adjacent or separated by a single mismatch. Furthermore, free energy parameters are revised to account for recent experimental results for terminal mismatches and hairpin, bulge, internal, and multibranch loops. To demonstrate the applicability of this method, in vivo modification was performed on 5S rRNA in both Escherichia coli and Candida albicans with 1-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluene sulfonate, dimethyl sulfate, and kethoxal. The percentage of known base pairs in the predicted structure increased from 26.3% to 86.8% for the E. coli sequence by using modification constraints. For C. albicans, the accuracy remained 87.5% both with and without modification data. On average, for these sequences and a set of 14 sequences with known secondary structure and chemical modification data taken from the literature, accuracy improves from 67% to 76%. This enhancement primarily reflects improvement for three sequences that are predicted with <40% accuracy on the basis of energetics alone. For these sequences, inclusion of chemical modification constraints improves the average accuracy from 28% to 78%. For the 11 sequences with <6% pseudoknotted base pairs, structures predicted with constraints from chemical modification contain on average 84% of known canonical base pairs.
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Affiliation(s)
- David H Mathews
- Center for Human Genetics and Molecular Pediatric Disease, The Aab Institute of Biomedical Sciences, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 703, Rochester, NY 14642, USA
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Disney MD, Childs JL, Turner DH. New approaches to targeting RNA with oligonucleotides: inhibition of group I intron self-splicing. Biopolymers 2004; 73:151-61. [PMID: 14691946 DOI: 10.1002/bip.10520] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
RNA is one class of relatively unexplored drug targets. Since RNAs play a myriad of essential roles, it is likely that new drugs can be developed that target RNA. There are several factors that make targeting RNA particularly attractive. First, the amount of information about the roles of RNA in essential biological processes is currently being expanded. Second, sequence information about targetable RNA is pouring out of genome sequencing efforts at unprecedented levels. Third, designing and screening potential oligonucleotide therapeutics to target RNA is relatively simple. The use of oligonucleotides in cell culture, however, presents several challenges such as oligonucleotide uptake and stability, and selective targeting of genes of interest. Here, we review investigations aimed at targeting RNA with oligonucleotides that can circumvent several of these potential problems. The hallmark of the strategies discussed is the use of short oligonucleotides, which may have the advantage of higher cellular uptake and improved binding selectivity compared to longer oligonucleotides. These strategies have been applied to Group I introns from the mammalian pathogens Pneumocystis carinii and Candida albicans. Both are examples of fungal infections that are increasing in number and prevalence.
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Affiliation(s)
- Matthew D Disney
- Department of Chemistry, and the Center for Human Genetics and Molecular Pediatric Disease, University of Rochester, Rochester, NY 14627-0216, USA
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Childs JL, Poole AW, Turner DH. Inhibition of Escherichia coli RNase P by oligonucleotide directed misfolding of RNA. RNA (NEW YORK, N.Y.) 2003; 9:1437-45. [PMID: 14624000 PMCID: PMC1370498 DOI: 10.1261/rna.5780503] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Oligonucleotide directed misfolding of RNA (ODMiR) uses short oligonucleotides to inhibit RNA function by exploiting the ability of RNA to fold into different structures with similar free energies. It is shown that the 2'-O-methyl oligonucleotide, m(CAGCCUACCCGG), can trap Escherichia coli RNase P RNA (M1 RNA) in a nonfunctional structure in a transcription mixture containing RNase P protein (C5 protein). At about 200 nM, the 12-mer thus inhibits 50% of pre-tRNA processing by RNase P. Roughly 10-fold more 12-mer is required to inhibit RNase P containing full-length, renatured RNase P RNA. Diethyl pyrocarbonate modification in the presence of 12-mer reveals increased modification of sites in and interacting with P4, suggesting a structural rearrangement of a large pseudoknot important for catalytic activity. Thus, the ODMiR method can be applied to RNAs even when folding is facilitated by a cognate protein.
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Affiliation(s)
- Jessica L Childs
- Departments of Chemistry, University of Rochester, Rochester, New York 14627, USA
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De Backer MD, Van Dijck P. Progress in functional genomics approaches to antifungal drug target discovery. Trends Microbiol 2003; 11:470-8. [PMID: 14557030 DOI: 10.1016/j.tim.2003.08.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Antifungal drug discovery is starting to benefit from the enormous advances in the genomics field, which have occurred in the past decade. As traditional drug screening on existing targets is not delivering the long-awaited potent antifungals, efforts to use novel genetics and genomics-based strategies to aid in the discovery of novel drug targets are gaining increased importance. The current paradigm in antifungal drug target discovery focuses on basically two main classes of targets to evaluate: genes essential for viability and virulence or pathogenicity factors. Here we report on recent advances in genetics and genomics-based technologies that will allow us not only to identify and validate novel fungal drug targets, but hopefully in the longer run also to discover potent novel therapeutic agents. Fungal pathogens have typically presented significant obstacles when subjected to genetics, but the creativity of scientists in the anti-infectives field and the cross-talk with scientists in other areas is now yielding exciting new tools and technologies to tackle the problem of finding potent, specific and non-toxic antifungal therapeutics.
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Affiliation(s)
- Marianne D De Backer
- Johnson & Johnson Pharmaceuticals Group, Licensing and New Business Development, Technology Licensing, Turnhoutseweg 30, B-2340, Beerse, Belgium.
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Current awareness on yeast. Yeast 2003. [DOI: 10.1002/yea.947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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