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Keane PM, Poynton FE, Hall JP, Clark IP, Sazanovich IV, Towrie M, Gunnlaugsson T, Quinn SJ, Cardin CJ, Kelly JM. Monitoring guanine photo-oxidation by enantiomerically resolved Ru(II) dipyridophenazine complexes using inosine-substituted oligonucleotides. Faraday Discuss 2016; 185:455-69. [PMID: 26426601 DOI: 10.1039/c5fd00085h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The intercalating [Ru(TAP)2(dppz)](2+) complex can photo-oxidise guanine in DNA, although in mixed-sequence DNA it can be difficult to understand the precise mechanism due to uncertainties in where and how the complex is bound. Replacement of guanine with the less oxidisable inosine (I) base can be used to understand the mechanism of electron transfer (ET). Here the ET has been compared for both Λ- and Δ-enantiomers of [Ru(TAP)2(dppz)](2+) in a set of sequences where guanines in the readily oxidisable GG step in {TCGGCGCCGA}2 have been replaced with I. The ET has been monitored using picosecond and nanosecond transient absorption and picosecond time-resolved IR spectroscopy. In both cases inosine replacement leads to a diminished yield, but the trends are strikingly different for Λ- and Δ-complexes.
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Keane PM, Kelly JM. Ground and excited state interactions of metalloporphyrin PtTMPyP4 with polynucleotides [poly(dG-dC)]2 and [poly(dA-dT)]2. Photochem Photobiol Sci 2016; 15:980-7. [PMID: 27377608 DOI: 10.1039/c6pp00105j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The ground- and excited-state interactions of Pt(ii) meso-tetrakis(4-N-methylpyridyl)porphyrin (PtTMPyP4) with polynucleotides [poly(dG-dC)]2 and [poly(dA-dT)]2 have been investigated using UV/visible, circular dichroism, and steady-state and time-resolved emission spectroscopy. PtTMPyP4 intercalates into [poly(dG-dC)]2 with K∼ 10(6) M(-1). When bound to [poly(dG-dC)]2 in aerated solution there is a six-fold emission enhancement with 18 nm red-shift in emission maximum. Emission lifetimes are biexponential. In the presence of [poly(dA-dT)]2 at least two distinct groove-binding modes are observed, depending on the binding ratio. In [poly(dA-dT)]2 the emission intensity increases by a maximum factor of 17 with no shift in the emission spectrum. Three exponentials were required for lifetime fitting. The lower extent of emission enhancement in the presence of [poly(dG-dC)]2 suggests that a slow electron transfer may take place to guanine, which is significantly less efficient than that previously observed for PtTMPyP4 in the presence of guanosine 5'-monophosphate (GMP). The results are compared to those previously recorded with free base H2TMPyP4.
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Kishore KG, Ghashghaei O, Estarellas C, Mestre MM, Monturiol C, Kielland N, Kelly JM, Francisco AF, Jayawardhana S, Muñoz-Torrero D, Pérez B, Luque FJ, Gámez-Montaño R, Lavilla R. Insertion of Isocyanides into N−Si Bonds: Multicomponent Reactions with Azines Leading to Potent Antiparasitic Compounds. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201604109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Kishore KG, Ghashghaei O, Estarellas C, Mestre MM, Monturiol C, Kielland N, Kelly JM, Francisco AF, Jayawardhana S, Muñoz-Torrero D, Pérez B, Luque FJ, Gámez-Montaño R, Lavilla R. Insertion of Isocyanides into N−Si Bonds: Multicomponent Reactions with Azines Leading to Potent Antiparasitic Compounds. Angew Chem Int Ed Engl 2016; 55:8994-8. [DOI: 10.1002/anie.201604109] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Indexed: 12/31/2022]
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80
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Poynton FE, Hall JP, Keane PM, Schwarz C, Sazanovich IV, Towrie M, Gunnlaugsson T, Cardin CJ, Cardin DJ, Quinn SJ, Long C, Kelly JM. Direct observation by time-resolved infrared spectroscopy of the bright and the dark excited states of the [Ru(phen) 2(dppz)] 2+ light-switch compound in solution and when bound to DNA. Chem Sci 2016; 7:3075-3084. [PMID: 29997799 PMCID: PMC6005197 DOI: 10.1039/c5sc04514b] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 01/26/2016] [Indexed: 02/01/2023] Open
Abstract
The [Ru(phen)2(dppz)]2+ complex (1) is non-emissive in water but is highly luminescent in organic solvents or when bound to DNA, making it a useful probe for DNA binding. To date, a complete mechanistic explanation for this "light-switch" effect is still lacking. With this in mind we have undertaken an ultrafast time resolved infrared (TRIR) study of 1 and directly observe marker bands between 1280-1450 cm-1, which characterise both the emissive "bright" and the non-emissive "dark" excited states of the complex, in CD3CN and D2O respectively. These characteristic spectral features are present in the [Ru(dppz)3]2+ solvent light-switch complex but absent in [Ru(phen)3]2+, which is luminescent in both solvents. DFT calculations show that the vibrational modes responsible for these characteristic bands are predominantly localised on the dppz ligand. Moreover, they reveal that certain vibrational modes of the "dark" excited state couple with vibrational modes of two coordinating water molecules, and through these to the bulk solvent, thus providing a new insight into the mechanism of the light-switch effect. We also demonstrate that the marker bands for the "bright" state are observed for both Λ- and Δ-enantiomers of 1 when bound to DNA and that photo-excitation of the complex induces perturbation of the guanine and cytosine carbonyl bands. This perturbation is shown to be stronger for the Λ-enantiomer, demonstrating the different binding site properties of the two enantiomers and the ability of this technique to determine the identity and nature of the binding site of such intercalators.
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81
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Keane PM, Baptista FR, Gurung SP, Devereux SJ, Sazanovich IV, Towrie M, Brazier JA, Cardin CJ, Kelly JM, Quinn SJ. Long-Lived Excited-State Dynamics of i-Motif Structures Probed by Time-Resolved Infrared Spectroscopy. Chemphyschem 2016; 17:1281-7. [PMID: 26879336 DOI: 10.1002/cphc.201501183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Indexed: 01/22/2023]
Abstract
UV-generated excited states of cytosine (C) nucleobases are precursors to mutagenic photoproduct formation. The i-motif formed from C-rich sequences is known to exhibit high yields of long-lived excited states following UV absorption. Here the excited states of several i-motif structures have been characterized following 267 nm laser excitation using time-resolved infrared spectroscopy (TRIR). All structures possess a long-lived excited state of ∼300 ps and notably in some cases decays greater than 1 ns are observed. These unusually long-lived lifetimes are attributed to the interdigitated DNA structure which prevents direct base stacking overlap.
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Poulsen BC, Estalayo-Adrián S, Blasco S, Bright SA, Kelly JM, Williams DC, Gunnlaugsson T. Luminescent ruthenium polypyridyl complexes with extended ‘dppz’ like ligands as DNA targeting binders and cellular agents. Dalton Trans 2016; 45:18208-18220. [DOI: 10.1039/c6dt03792e] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
DNA-binding and phototoxicity of Ru(ii) complexes with ligands derived from pyrazinodipyridophenazine and either phen or TAP as ancillary ligands are reported.
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83
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Foscolos AS, Papanastasiou I, Foscolos GB, Tsotinis A, Kellici TF, Mavromoustakos T, Taylor MC, Kelly JM. New hydrazones of 5-nitro-2-furaldehyde with adamantanealkanohydrazides: synthesis and in vitro trypanocidal activity. MEDCHEMCOMM 2016. [DOI: 10.1039/c6md00035e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A range of hydrazones of 5-nitro-2-furaldehyde with adamantane alkanohydrazides was synthesized and their trypanocidal activity was evaluated.
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84
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Di Pietro O, Vicente-García E, Taylor MC, Berenguer D, Viayna E, Lanzoni A, Sola I, Sayago H, Riera C, Fisa R, Clos MV, Pérez B, Kelly JM, Lavilla R, Muñoz-Torrero D. Multicomponent reaction-based synthesis and biological evaluation of tricyclic heterofused quinolines with multi-trypanosomatid activity. Eur J Med Chem 2015; 105:120-37. [PMID: 26479031 PMCID: PMC4638191 DOI: 10.1016/j.ejmech.2015.10.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/28/2015] [Accepted: 10/06/2015] [Indexed: 11/28/2022]
Abstract
Human African trypanosomiasis (HAT), Chagas disease and leishmaniasis, which are caused by the trypanosomatids Trypanosoma brucei, Trypanosoma cruzi and Leishmania species, are among the most deadly neglected tropical diseases. The development of drugs that are active against several trypanosomatids is appealing from a clinical and economic viewpoint, and seems feasible, as these parasites share metabolic pathways and hence might be treatable by common drugs. From benzonapthyridine 1, an inhibitor of acetylcholinesterase (AChE) for which we have found a remarkable trypanocidal activity, we have designed and synthesized novel benzo[h][1,6]naphthyridines, pyrrolo[3,2-c]quinolines, azepino[3,2-c]quinolines, and pyrano[3,2-c]quinolines through 2–4-step sequences featuring an initial multicomponent Povarov reaction as the key step. To assess the therapeutic potential of the novel compounds, we have evaluated their in vitro activity against T. brucei, T. cruzi, and Leishmania infantum, as well as their brain permeability, which is of specific interest for the treatment of late-stage HAT. To assess their potential toxicity, we have determined their cytotoxicity against rat myoblast L6 cells and their AChE inhibitory activity. Several tricyclic heterofused quinoline derivatives were found to display an interesting multi-trypanosomatid profile, with one-digit micromolar potencies against two of these parasites and two-digit micromolar potency against the other. Pyranoquinoline 39, which displays IC50 values of 1.5 μM, 6.1 μM and 29.2 μM against T. brucei, L. infantum and T. cruzi, respectively, brain permeability, better drug-like properties (lower lipophilicity and molecular weight and higher CNS MPO desirability score) than hit 1, and the lowest AChE inhibitory activity of the series (IC50 > 30 μM), emerges as an interesting multi-trypanosomatid lead, amenable to further optimization particularly in terms of its selectivity index over mammalian cells. Novel classes of tricyclic heterofused quinolines have been synthesized. Their 2–4-step syntheses involve a multicomponent Povarov reaction as the key step. Some compounds exhibit single digit micromolar potencies against 2 trypanosomatids. All compounds with multi-trypanosomatid activity can cross the blood–brain barrier. Most compounds with multi-trypanosomatid activity have drug like properties.
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Hall JP, Poynton FE, Keane PM, Gurung SP, Brazier JA, Cardin DJ, Winter G, Gunnlaugsson T, Sazanovich IV, Towrie M, Cardin CJ, Kelly JM, Quinn SJ. Combining X-ray crystallography and ultrafast infrared spectroscopy – monitoring photo-induced guanine oxidation by [Ru(TAP) 2(dppz)] 2+. Acta Crystallogr A Found Adv 2015. [DOI: 10.1107/s205327331509275x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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86
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Keane PM, Poynton FE, Hall JP, Sazanovich IV, Towrie M, Gunnlaugsson T, Quinn SJ, Cardin CJ, Kelly JM. Frontispiz: Reversal of a Single Base-Pair Step Controls Guanine Photo-Oxidation by an Intercalating Ruthenium(II) Dipyridophenazine Complex. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201582961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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87
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Keane PM, Poynton FE, Hall JP, Sazanovich IV, Towrie M, Gunnlaugsson T, Quinn SJ, Cardin CJ, Kelly JM. Frontispiece: Reversal of a Single Base-Pair Step Controls Guanine Photo-Oxidation by an Intercalating Ruthenium(II) Dipyridophenazine Complex. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/anie.201582961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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88
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Kleemann DO, Kelly JM, Rudiger SR, McMillen IC, Morrison JL, Zhang S, MacLaughlin SM, Smith DH, Grimson RJ, Jaensch KS, Brien FD, Plush KJ, Hiendleder S, Walker SK. Effect of periconceptional nutrition on the growth, behaviour and survival of the neonatal lamb. Anim Reprod Sci 2015. [PMID: 26220681 DOI: 10.1016/j.anireprosci.2015.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Periconceptional nutrition (PCN) can influence foetal hypothalamo-pituitary adrenal (HPA) axis function and alter cortisol secretion with possible consequences for maturation and growth of major organs, gestation length and behaviour. We examined effects of PCN on phenotype and survival of the neonatal lamb in 466 Merino ewes allocated to treatments providing 70%, 100% and 150% respectively, of maintenance requirements for 17 days prior and 6 days after insemination. Gestation length and birth weight for lambs in PCN treatment groups was similar (P > 0.05) but low PCN decreased the size of the neonate (crown-rump-length and metacarpal length P < 0.05). A subset of lambs euthanased at 5 days of age further showed that low PCN decreased the amount of peri-renal fat (P < 0.05) and increased liver mass (P < 0.05) while high PCN increased neck thymus and ovary mass (P < 0.05). Neonatal lambs from low PCN ewes returned faster to their mothers after release (P < 0.05) and contacted the udder in the shortest time (P < 0.05). Significant interactions between PCN treatment and sex (P < 0.05) and between PCN treatment and ewe age (P < 0.05) were also observed for time lambs took to follow the ewe. Survival of lambs was similar but potential differences may have been masked by favourable weather conditions. In conclusion, this study provides evidence of significant changes in lamb growth and development dependent on PCN and, for the first time, links these changes with significant changes in behaviour of the neonate. The impact of these effects on lamb survival and potential reproductive capacity of female offspring remains to be determined.
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Keane PM, Poynton FE, Hall JP, Sazanovich IV, Towrie M, Gunnlaugsson T, Quinn SJ, Cardin CJ, Kelly JM. Reversal of a Single Base-Pair Step Controls Guanine Photo-Oxidation by an Intercalating Ruthenium(II) Dipyridophenazine Complex. Angew Chem Int Ed Engl 2015; 54:8364-8. [PMID: 26096623 PMCID: PMC4985698 DOI: 10.1002/anie.201502608] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/20/2015] [Indexed: 01/05/2023]
Abstract
Small changes in DNA sequence can often have major biological effects. Here the rates and yields of guanine photo‐oxidation by Λ‐[Ru(TAP)2(dppz)]2+ have been compared in 5′‐{CCGGATCCGG}2 and 5′‐{CCGGTACCGG}2 using pico/nanosecond transient visible and time‐resolved IR (TRIR) spectroscopy. The inefficiency of electron transfer in the TA sequence is consistent with the 5′‐TA‐3′ versus 5′‐AT‐3′ binding preference predicted by X‐ray crystallography. The TRIR spectra also reveal the differences in binding sites in the two oligonucleotides.
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Keane PM, Poynton FE, Hall JP, Sazanovich IV, Towrie M, Gunnlaugsson T, Quinn SJ, Cardin CJ, Kelly JM. Reversal of a Single Base-Pair Step Controls Guanine Photo-Oxidation by an Intercalating Ruthenium(II) Dipyridophenazine Complex. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502608] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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91
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Taylor MC, Lewis MD, Francisco AF, Wilkinson SR, Kelly JM. The Trypanosoma cruzi vitamin C dependent peroxidase confers protection against oxidative stress but is not a determinant of virulence. PLoS Negl Trop Dis 2015; 9:e0003707. [PMID: 25875298 PMCID: PMC4395405 DOI: 10.1371/journal.pntd.0003707] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 03/17/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The neglected parasitic infection Chagas disease is rapidly becoming a globalised public health issue due to migration. There are only two anti-parasitic drugs available to treat this disease, benznidazole and nifurtimox. Thus it is important to identify and validate new drug targets in Trypanosoma cruzi, the causative agent. T. cruzi expresses an ER-localised ascorbate-dependent peroxidase (TcAPx). This parasite-specific enzyme has attracted interest from the perspective of targeted chemotherapy. METHODOLOGY/PRINCIPAL FINDINGS To assess the importance of TcAPx in protecting T. cruzi from oxidative stress and to determine if it is essential for virulence, we generated null mutants by targeted gene disruption. Loss of activity was associated with increased sensitivity to exogenous hydrogen peroxide, but had no effect on susceptibility to the front-line Chagas disease drug benznidazole. This suggests that increased oxidative stress in the ER does not play a significant role in its mechanism of action. Homozygous knockouts could proceed through the entire life-cycle in vitro, although they exhibited a significant decrease in their ability to infect mammalian cells. To investigate virulence, we exploited a highly sensitive bioluminescence imaging system which allows parasites to be monitored in real-time in the chronic stage of murine infections. This showed that depletion of enzyme activity had no effect on T. cruzi replication, dissemination or tissue tropism in vivo. CONCLUSIONS/SIGNIFICANCE TcAPx is not essential for parasite viability within the mammalian host, does not have a significant role in establishment or maintenance of chronic infections, and should therefore not be considered a priority for drug design.
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Kearney TM, Donnelly C, Kelly JM, O'Callaghan EP, Fox CR, Gavin AT. Validation of the completeness and accuracy of the Northern Ireland Cancer Registry. Cancer Epidemiol 2015; 39:401-4. [PMID: 25770641 DOI: 10.1016/j.canep.2015.02.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 02/18/2015] [Accepted: 02/19/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND It has been suggested that inaccuracies in cancer registries are distorting UK survival statistics. This study compared the Northern Ireland Cancer Registry (NICR) database of living patients, with independent data held by Northern Ireland's General Practitioners (GPs) to compare and validate the recorded diagnoses and dates held by the registry. METHODS All 387 GP practice managers were invited to participate. 100 practices (25.84%) responded. Comparisons were made for 17,102 patients, equivalent to 29.08% of the living patients (58,798) extracted from the NICR between 1993 and 2010. RESULTS There were no significant differences (p>0.05) between the responding and nonresponding GP patient profiles for age, marital status or deprivation score. However, the responding GPs included more female patients (p=0.02). NICR data accuracy was high, 0.08% of GP cancer patients (n=15) were not included in registry records and 0.02% (n=2) had a diagnosis date which varied more than 2 weeks from GP records (3 weeks and 5 months). The NICR had recorded two different tumour types and three different tumour statuses (benign vs. malignant) to the GPs. CONCLUSION This comparison demonstrates a high level of accuracy within the NICR and that the survival statistics based on this data can be relied upon.
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Keane PM, Poynton FE, Hall JP, Clark IP, Sazanovich IV, Towrie M, Gunnlaugsson T, Quinn SJ, Cardin CJ, Kelly JM. Enantiomeric Conformation Controls Rate and Yield of Photoinduced Electron Transfer in DNA Sensitized by Ru(II) Dipyridophenazine Complexes. J Phys Chem Lett 2015; 6:734-738. [PMID: 26262495 DOI: 10.1021/jz502743q] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Photosensitized oxidation of guanine is an important route to DNA damage. Ruthenium polypyridyls are very useful photosensitizers, as their reactivity and DNA-binding properties are readily tunable. Here we show a strong difference in the reactivity of the two enantiomers of [Ru(TAP)2(dppz)](2+), by using time-resolved visible and IR spectroscopy. This reveals that the photosensitized one-electron oxidation of guanine in three oligonucleotide sequences proceeds with similar rates and yields for bound Δ-[Ru(TAP)2(dppz)](2+), whereas those for the Λ enantiomer are very sensitive to base sequence. It is proposed that these differences are due to preferences of each enantiomer for different binding sites in the duplex.
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Sola I, Castellà S, Viayna E, Galdeano C, Taylor MC, Gbedema SY, Pérez B, Clos MV, Jones DC, Fairlamb AH, Wright CW, Kelly JM, Muñoz-Torrero D. Synthesis, biological profiling and mechanistic studies of 4-aminoquinoline-based heterodimeric compounds with dual trypanocidal-antiplasmodial activity. Bioorg Med Chem 2015; 23:5156-67. [PMID: 25678015 DOI: 10.1016/j.bmc.2015.01.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 01/16/2015] [Accepted: 01/19/2015] [Indexed: 12/13/2022]
Abstract
Dual submicromolar trypanocidal-antiplasmodial compounds have been identified by screening and chemical synthesis of 4-aminoquinoline-based heterodimeric compounds of three different structural classes. In Trypanosoma brucei, inhibition of the enzyme trypanothione reductase seems to be involved in the potent trypanocidal activity of these heterodimers, although it is probably not the main biological target. Regarding antiplasmodial activity, the heterodimers seem to share the mode of action of the antimalarial drug chloroquine, which involves inhibition of the haem detoxification process. Interestingly, all of these heterodimers display good brain permeabilities, thereby being potentially useful for late stage human African trypanosomiasis. Future optimization of these compounds should focus mainly on decreasing cytotoxicity and acetylcholinesterase inhibitory activity.
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95
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Pikramenou Z, Weinstein J, Pan Q, Lewis F, Bassani DM, Würthner F, Moucheron C, Slota M, Díaz-Moscoso A, Karlsson J, Basílio N, Adams D, Scandola F, Bohne C, Lemon C, Campagna S, Rohacova J, Ohashi K, Plötz PA, Monti F, Kelly JM, Keane P, Gibson E, Lemercier G, Ruggi A, Cucinotta F, Gust D, Bradberry S, Vos J, Pistolis G, Mauro M, Tuite E, De Cola L, Ceroni P, Maneiro M, Galoppini E, Gunnlaugsson T. Self-organization of photo-active nanostructures: general discussion. Faraday Discuss 2015; 185:529-48. [DOI: 10.1039/c5fd90092a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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96
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Ceroni P, Pikramenou Z, Prodi L, Pan Q, Adams D, Weinstein J, Lewis F, Bohne C, Vlcek A, Bassani DM, de Silva AP, Moucheron C, Nocera D, Díaz-Moscoso A, Padilla M, Lemon C, Campagna S, Bradberry S, Galoppini E, Plötz PA, Kelly JM, Rohacova J, Harriman A, Keane P, Gust D, Vos J, Mauro M, De Cola L, Nambalan Sivaraman SK, Lemercier G, Osborne S, Monti F. Luminescence sensing and imaging: general discussion. Faraday Discuss 2015; 185:311-35. [DOI: 10.1039/c5fd90090e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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97
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Bohne C, Pan Q, Ceroni P, Börjesson K, Rohacova J, Lewis F, Vlcek A, Bassani DM, Würthner F, Sartorel A, de Silva AP, Nocera D, Scandola F, Lemon C, Allain C, Brudvig GW, Marchesan S, Sundstrom V, Campagna S, Sheehan SW, Plötz PA, Monti F, Kelly JM, Gibson E, Maneiro M, Harriman A, Ruggi A, Galoppini E, Thummel R, Weinstein J, Vos J, Ishitani O, Gust D, Díaz-Moscoso A. Natural and artificial photosynthesis: general discussion. Faraday Discuss 2015; 185:187-217. [DOI: 10.1039/c5fd90089a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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98
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Hall JP, Sanchez-Weatherby J, Alberti C, Quimper CH, O'Sullivan K, Brazier JA, Winter G, Sorensen T, Kelly JM, Cardin DJ, Cardin CJ. Controlled dehydration of a ruthenium complex-DNA crystal induces reversible DNA kinking. J Am Chem Soc 2014; 136:17505-12. [PMID: 25393319 DOI: 10.1021/ja508745x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Hydration-dependent DNA deformation has been known since Rosalind Franklin recognized that the relative humidity of the sample had to be maintained to observe a single conformation in DNA fiber diffraction. We now report for the first time the crystal structure, at the atomic level, of a dehydrated form of a DNA duplex and demonstrate the reversible interconversion to the hydrated form at room temperature. This system, containing d(TCGGCGCCGA) in the presence of Λ-[Ru(TAP)2(dppz)](2+) (TAP = 1,4,5,8-tetraazaphenanthrene, dppz = dipyrido[3,2-a:2',3'-c]phenazine), undergoes a partial transition from an A/B hybrid to the A-DNA conformation, at 84-79% relative humidity. This is accompanied by an increase in kink at the central step from 22° to 51°, with a large movement of the terminal bases forming the intercalation site. This transition is reversible on rehydration. Seven data sets, collected from one crystal at room temperature, show the consequences of dehydration at near-atomic resolution. This result highlights that crystals, traditionally thought of as static systems, are still dynamic and therefore can be the subject of further experimentation.
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Sola I, Artigas A, Taylor MC, Gbedema SY, Pérez B, Clos MV, Wright CW, Kelly JM, Muñoz-Torrero D. Synthesis and antiprotozoal activity of oligomethylene- and p-phenylene-bis(methylene)-linked bis(+)-huprines. Bioorg Med Chem Lett 2014; 24:5435-8. [DOI: 10.1016/j.bmcl.2014.10.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/04/2014] [Accepted: 10/08/2014] [Indexed: 01/24/2023]
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Lewis MD, Francisco AF, Taylor MC, Kelly JM. A new experimental model for assessing drug efficacy against Trypanosoma cruzi infection based on highly sensitive in vivo imaging. ACTA ACUST UNITED AC 2014; 20:36-43. [PMID: 25296657 PMCID: PMC4361455 DOI: 10.1177/1087057114552623] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The protozoan Trypanosoma cruzi is the causative agent of Chagas disease, one of the world’s major neglected infections. Although development of improved antiparasitic drugs is considered a priority, there have been no significant treatment advances in the past 40 years. Factors that have limited progress include an incomplete understanding of pathogenesis, tissue tropism, and disease progression. In addition, in vivo models, which allow parasite burdens to be tracked throughout the chronic stage of infection, have been lacking. To address these issues, we have developed a highly sensitive in vivo imaging system based on bioluminescent T. cruzi, which express a red-shifted luciferase that emits light in the tissue-penetrating orange-red region of the spectrum. The exquisite sensitivity of this noninvasive murine model has been exploited to monitor parasite burden in real time throughout the chronic stage, has allowed the identification of the gastrointestinal tract as the major niche of long-term infection, and has demonstrated that chagasic heart disease can develop in the absence of locally persistent parasites. Here, we review the parameters of the imaging system and describe how this experimental model can be incorporated into drug development programs as a valuable tool for assessing efficacy against both acute and chronic T. cruzi infections.
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