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New molecular systems for APDT in agronomy
Abstracts / Photodiagnosis and Photodynamic Therapy 17 (2017) A4–A78
A43
Poster PA-005 A genetics-based approach to studying photodynamic inactivation in Escherichia coli K12 I. Lutter ∗ , M. Walther, S. Fischer, J. Cullum Department of Genetics, Technical University of Kaiserslautern, Germany The well-developed genetics of Escherichia coli K12 allow the study of factors protecting bacteria against photodynamic inactivation (PDI) and potential resistance mechanisms. We screened the whole Keio collection [1], a library of singlegene knock-out mutants of E. coli, for PDI sensitivity using the photosensitizer Chlorin e6 [2]. This screening showed that mutants of the outer-membrane exporter gene (tolC) were hyper-sensitive consistent with more accumulation of photosensitizer in the cells. Surprisingly, mutants lacking catalase activities (katG and ahpF) did not show hyper-sensitivity to PDI. Indeed, in a (tolC) genetic background, the mutants showed increased resistance. It was hypothesized that the higher hydrogen peroxide levels in such mutants induced protection systems. A major response of E. coli to hydrogen peroxide is the induction of the OxyR-regulon. We therefore introduced knock-out mutations of some of the genes of the OxyR-regulon into a (tolC)(katG)(ahpF) strain and assayed the resulting strains for hyper-sensitivity to PDI. The role of the OxyR-regulon in providing protection against PDI and the potential for the development of resistance will be discussed.
Fig. 1. Schematic structure of tested anionic porphyrins.
Fig. 2. Association between PS, nanoparticles and tag.
References
http://dx.doi.org/10.1016/j.pdpdt.2017.01.095
innovative bio-inspired platform. In that purpose, photosensitizer will be encapsulated into lignin (a natural, non-toxic and poorly valorized biopolymer) [7] nanoparticles in order to ensure their entry into cell cytoplasm (Fig. 2). First results will be also presented.
Poster PA-006
References
[1] T. Baba, et al., Mol. Syst. Biol. 2 (1) (2006) 0008. [2] J.-H. Park, et al., Lasers Med. Sci. 25 (2010) 705–710.
New molecular systems for APDT in agronomy S. Leroy-Lhez ∗ , G. Marchand, C.A. Calliste, N. Villandier, C. Riou Université de Limoges, Laboratoire de Chimie des Substances Naturelles, EA 1069, Limoges, France Biodiversity and environment preservation as well as human health safety are main societal challenges. In agronomy, a particular focus remains the search for new compounds able to fight pathogens that dramatically reduce crop yields. These new molecules should not be toxic for wildlife excepted pathogens, biodegradable and non-polluting groundwater. In that context, photodynamic treatments, already used for different applications [1–3] and still few studied for applications in the agronomic domain, [4] open up a scope of possibilities. While porphyrins upon illumination are known to be toxic or even lethal on mammal cells or microorganisms (e.g. bacteria and fungi), we recently evidenced that they can also kill plant cells (Tobacco Bright Yellow-2 cells) [5] but only alter tomato plantlet development without killing them [6] relying on their chemical structure. Thus, all together these results support their use in an agronomic antimicrobial photodynamic treatment (APDT). In line with these previous studies, the synthesis, characterization and effects of anionic porphyrins on plant cells will be exposed (Fig. 1). With the objective to develop this methodology to non-hydro soluble porphyrins and therefore to natural photosensitizers such as Protoporphyrin IX or purpurine-18, we currently work on an
[1] K. Plaetzer, M. Berneburg, T. Kiesslich, T. Maisch, BioMed Research International, Hindawi Publishing Corporation, 2013. [2] L.L. Benov, Med. Princ. Pract. 24 (2015) 14–28. [3] T. Maisch, Photochem. Photobiol. Sci. 14 (2015) 1518–1526. [4] H.D. De Menezes, A.C. Pereira, G.T.P. Brancini, H.C. De Leão, N.S. Massola Júnior, L. Bachmann, M. Wainwright, J.K. Bastos, G.U.L. Braga, J. Photochem. Photobiol. B 131 (2014) 74–83. [5] C. Riou, C.A. Calliste, A. Da Silva, D. Guillaumot, O. Rezazgui, S. Sol, S. Leroy-Lhez, Photochem. Photobiol. Sci. 13 (2014) 621–625. [6] D. Guillaumot, M. Issawi, A. Da Silva, S. Leroy-Lhez, V. Sol, C. Riou, J. Photochem. Photobiol. B 156 (2016) 69–78. [7] M. Norgren, H. Edlund, Curr. Opin. Colloid Interface Sci. 19 (2014) 409–416.
http://dx.doi.org/10.1016/j.pdpdt.2017.01.096 Poster PA-007 An overview on the impact of cationic phthalocyanine complexes for inactivation of drug-resistant microorganisms V. Mantareva ∗ , I. Angelov, M. Aliosman, I. Stoineva, V. Kussovski Institute of Organic Chemistry with Centre of Phytochemistry, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria Antimicrobial photodynamic therapy (a-PDT) characterizes as non-invasive curative method which is more on experimental level than the conventional application in practice. The proce-
A43
Poster PA-005 A genetics-based approach to studying photodynamic inactivation in Escherichia coli K12 I. Lutter ∗ , M. Walther, S. Fischer, J. Cullum Department of Genetics, Technical University of Kaiserslautern, Germany The well-developed genetics of Escherichia coli K12 allow the study of factors protecting bacteria against photodynamic inactivation (PDI) and potential resistance mechanisms. We screened the whole Keio collection [1], a library of singlegene knock-out mutants of E. coli, for PDI sensitivity using the photosensitizer Chlorin e6 [2]. This screening showed that mutants of the outer-membrane exporter gene (tolC) were hyper-sensitive consistent with more accumulation of photosensitizer in the cells. Surprisingly, mutants lacking catalase activities (katG and ahpF) did not show hyper-sensitivity to PDI. Indeed, in a (tolC) genetic background, the mutants showed increased resistance. It was hypothesized that the higher hydrogen peroxide levels in such mutants induced protection systems. A major response of E. coli to hydrogen peroxide is the induction of the OxyR-regulon. We therefore introduced knock-out mutations of some of the genes of the OxyR-regulon into a (tolC)(katG)(ahpF) strain and assayed the resulting strains for hyper-sensitivity to PDI. The role of the OxyR-regulon in providing protection against PDI and the potential for the development of resistance will be discussed.
Fig. 1. Schematic structure of tested anionic porphyrins.
Fig. 2. Association between PS, nanoparticles and tag.
References
http://dx.doi.org/10.1016/j.pdpdt.2017.01.095
innovative bio-inspired platform. In that purpose, photosensitizer will be encapsulated into lignin (a natural, non-toxic and poorly valorized biopolymer) [7] nanoparticles in order to ensure their entry into cell cytoplasm (Fig. 2). First results will be also presented.
Poster PA-006
References
[1] T. Baba, et al., Mol. Syst. Biol. 2 (1) (2006) 0008. [2] J.-H. Park, et al., Lasers Med. Sci. 25 (2010) 705–710.
New molecular systems for APDT in agronomy S. Leroy-Lhez ∗ , G. Marchand, C.A. Calliste, N. Villandier, C. Riou Université de Limoges, Laboratoire de Chimie des Substances Naturelles, EA 1069, Limoges, France Biodiversity and environment preservation as well as human health safety are main societal challenges. In agronomy, a particular focus remains the search for new compounds able to fight pathogens that dramatically reduce crop yields. These new molecules should not be toxic for wildlife excepted pathogens, biodegradable and non-polluting groundwater. In that context, photodynamic treatments, already used for different applications [1–3] and still few studied for applications in the agronomic domain, [4] open up a scope of possibilities. While porphyrins upon illumination are known to be toxic or even lethal on mammal cells or microorganisms (e.g. bacteria and fungi), we recently evidenced that they can also kill plant cells (Tobacco Bright Yellow-2 cells) [5] but only alter tomato plantlet development without killing them [6] relying on their chemical structure. Thus, all together these results support their use in an agronomic antimicrobial photodynamic treatment (APDT). In line with these previous studies, the synthesis, characterization and effects of anionic porphyrins on plant cells will be exposed (Fig. 1). With the objective to develop this methodology to non-hydro soluble porphyrins and therefore to natural photosensitizers such as Protoporphyrin IX or purpurine-18, we currently work on an
[1] K. Plaetzer, M. Berneburg, T. Kiesslich, T. Maisch, BioMed Research International, Hindawi Publishing Corporation, 2013. [2] L.L. Benov, Med. Princ. Pract. 24 (2015) 14–28. [3] T. Maisch, Photochem. Photobiol. Sci. 14 (2015) 1518–1526. [4] H.D. De Menezes, A.C. Pereira, G.T.P. Brancini, H.C. De Leão, N.S. Massola Júnior, L. Bachmann, M. Wainwright, J.K. Bastos, G.U.L. Braga, J. Photochem. Photobiol. B 131 (2014) 74–83. [5] C. Riou, C.A. Calliste, A. Da Silva, D. Guillaumot, O. Rezazgui, S. Sol, S. Leroy-Lhez, Photochem. Photobiol. Sci. 13 (2014) 621–625. [6] D. Guillaumot, M. Issawi, A. Da Silva, S. Leroy-Lhez, V. Sol, C. Riou, J. Photochem. Photobiol. B 156 (2016) 69–78. [7] M. Norgren, H. Edlund, Curr. Opin. Colloid Interface Sci. 19 (2014) 409–416.
http://dx.doi.org/10.1016/j.pdpdt.2017.01.096 Poster PA-007 An overview on the impact of cationic phthalocyanine complexes for inactivation of drug-resistant microorganisms V. Mantareva ∗ , I. Angelov, M. Aliosman, I. Stoineva, V. Kussovski Institute of Organic Chemistry with Centre of Phytochemistry, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria Antimicrobial photodynamic therapy (a-PDT) characterizes as non-invasive curative method which is more on experimental level than the conventional application in practice. The proce-