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The Journal of Organic Chemistry Nov 2022A mild and efficient method for preparation of 3-sulfenyl and 3-selenyl coumarins and quinolinones mediated by artificial light or sunlight is presented. The elaborated...
A mild and efficient method for preparation of 3-sulfenyl and 3-selenyl coumarins and quinolinones mediated by artificial light or sunlight is presented. The elaborated protocol highlights the use of nonyl acridine orange as a photocatalyst to generate a sulfenyl radical from thiols that is further trapped by a heterocycle. The utility of the protocol is justified by a diverse scope of thiols, including short cysteine-containing peptides. The same reaction conditions can be applied for preparation of 3-selenyl coumarins and quinolinones. Various protected and unprotected selenocysteine-containing peptides were successfully utilized demonstrating high tolerance for amino acids with sensitive groups (Arg, Lys, Trp, His, and Tyr).
Topics: Acridine Orange; Coumarins; Quinolones; Prospective Studies; Peptides; Cysteine
PubMed: 36310352
DOI: 10.1021/acs.joc.2c01803 -
Biomedicines Aug 2022Current multimodal treatment of bone metastases is partially effective and often associated with side effects, and novel therapeutic options are needed. Acridine orange...
Current multimodal treatment of bone metastases is partially effective and often associated with side effects, and novel therapeutic options are needed. Acridine orange is a photosensitizing molecule that accumulates in acidic compartments. After photo- or radiodynamic activation (AO-PDT or AO-RDT), acridine orange can induce lysosomal-mediated cell death, and we explored AO-RDT as an acid-targeted anticancer therapy for bone metastases. We used osteotropic carcinoma cells and human osteoclasts to assess the extracellular acidification and invasiveness of cancer cells, acridine orange uptake and lysosomal pH/stability, and the AO-RDT cytotoxicity in vitro. We then used a xenograft model of bone metastasis to compare AO-RDT to another antiacid therapeutic strategy (omeprazole). Carcinoma cells showed extracellular acidification activity and tumor-derived acidosis enhanced cancer invasiveness. Furthermore, cancer cells accumulated acridine orange more than osteoclasts and were more sensitive to lysosomal death. In vivo, omeprazole did not reduce osteolysis, whereas AO-RDT promoted cancer cell necrosis and inhibited tumor-induced bone resorption, without affecting osteoclasts. In conclusion, AO-RDT was selectively toxic only for carcinoma cells and effective to impair both tumor expansion in bone and tumor-associated osteolysis. We therefore suggest the use of AO-RDT, in combination with the standard antiresorptive therapies, to reduce disease burden in bone metastasis.
PubMed: 36009451
DOI: 10.3390/biomedicines10081904 -
BioMed Research International 2019Musculoskeletal sarcomas are rare and aggressive human malignancies affecting bones and soft tissues with severe consequences, in terms of both morbidity and mortality....
Musculoskeletal sarcomas are rare and aggressive human malignancies affecting bones and soft tissues with severe consequences, in terms of both morbidity and mortality. An innovative technique that combines photodynamic surgery (PDS) and therapy (PDT) with acridine orange has been recently suggested, showing promising results. However, due to the low incidence of sarcoma in humans, this procedure has been attempted only in pilot studies and stronger evidence is needed. Naturally occurring tumors in cats are well-established and advantageous models for human cancers. Feline injection-site sarcoma (FISS) shares with human musculoskeletal sarcomas a mesenchymal origin and an aggressive behavior with a high relapse rate. Furthermore, wide surgical excision is not always possible due to the size and site of development. We assessed the feasibility and the effectiveness of PDS and PDT with acridine orange to prevent FISS recurrence by treating a short case series of cats. For PDS, the surgical field was irrigated with an acridine orange solution and exposed to UV light to enlighten the residual tumor tissue, and the resultant fluorescent areas were trimmed. For PDT, before wound closure, the field was again irrigated with acridine orange solution and exposed to visible light to get the antitumoral cytocidal effect. The procedure was easy to perform and well tolerated, we did not observe any major complications, and all the surgical resection margins were free of disease. Finally, at follow-up, all treated patients did not show evidence of tumor recurrence and had a significantly higher event-free survival rate in respect to a control group treated only by surgery. In conclusion, by this study we demonstrated that, in FISS, PDS and PDT with acridine orange may improve local tumor control, granting a better outcome, and we laid the foundation to validate its effectiveness for the treatment of human musculoskeletal sarcomas.
Topics: Acridine Orange; Animals; Cats; Female; Humans; Male; Muscle Neoplasms; Photochemotherapy; Sarcoma
PubMed: 31360726
DOI: 10.1155/2019/8275935 -
Molecular Neurodegeneration Dec 2022Microglia regulate the response to injury and disease in the brain and spinal cord. In white matter diseases microglia may cause demyelination. However, how microglia...
BACKGROUND
Microglia regulate the response to injury and disease in the brain and spinal cord. In white matter diseases microglia may cause demyelination. However, how microglia respond and regulate demyelination is not fully understood.
METHODS
To understand how microglia respond during demyelination, we fed mice cuprizone-a potent demyelinating agent-and assessed the dynamics of genetically fate-mapped microglia. We then used single-cell RNA sequencing to identify and track the microglial subpopulations that arise during demyelination. To understand how microglia contribute to the clearance of dead oligodendrocytes, we ablated microglia starting at the peak of cuprizone-induced cell death and used the viability dye acridine orange to monitor apoptotic and lytic cell morphologies after microglial ablation. Lastly, we treated serum-free primary microglial cultures to model distinct aspects of cuprizone-induced demyelination and assessed the response.
RESULTS
The cuprizone diet generated a robust microglial response by week 4 of the diet. Single-cell RNA sequencing at this time point revealed the presence of several cuprizone-associated microglia (CAM) clusters. These clusters expressed a transcriptomic signature indicative of cytokine regulation and reactive oxygen species production with altered lysosomal and metabolic changes consistent with ongoing phagocytosis. Using acridine orange to monitor apoptotic and lytic cell death after microglial ablation, we found that microglia preferentially phagocytose lytic carcasses. In culture, microglia exposed to lytic carcasses partially recapitulated the CAM state, suggesting that phagocytosis contributes to this distinct microglial state during cuprizone demyelination.
CONCLUSIONS
Microglia serve multiple roles during demyelination, yet their transcriptomic state resembles other neurodegenerative conditions. The phagocytosis of cellular debris is likely a universal cause for a common neurodegenerative microglial state.
Topics: Animals; Mice; Cuprizone; Microglia; Demyelinating Diseases; Transcriptome; Acridine Orange; Mice, Inbred C57BL; Disease Models, Animal
PubMed: 36514132
DOI: 10.1186/s13024-022-00584-2 -
Chemical Communications (Cambridge,... Nov 2022Molecular de-aggregation was observed at the air/water interface of aqueous microdroplets. We probed this phenomenon using dyes such as Rhodamine 6G (R6G), Rhodamine B,...
Molecular de-aggregation was observed at the air/water interface of aqueous microdroplets. We probed this phenomenon using dyes such as Rhodamine 6G (R6G), Rhodamine B, acridine orange, and fluorescein, which show aggregation-induced shift in fluorescence. The fluorescence micrographs of microdroplets derived from the aqueous solutions of these dyes show that they are monomeric at the air/water interface, but highly aggregated at the core. We propose that rapid evaporation of the solvent influences the de-aggregation of molecules at the air-water interface of the microdroplets.
Topics: Rhodamines; Fluorescein; Acridine Orange; Spectrometry, Fluorescence; Water; Coloring Agents
PubMed: 36250601
DOI: 10.1039/d2cc04587g -
Anatomia, Histologia, Embryologia Jan 2021Significant increases in male infertility and the still unresolved questions on the compatibility and interpretation of current methods in infertility diagnostics call...
Significant increases in male infertility and the still unresolved questions on the compatibility and interpretation of current methods in infertility diagnostics call for new protocols. Morphology, genome damage, RNA content and quantity are currently in practice as the major parameters in evaluation of sperm quality. However, results of various methods are not always in mutual concordance. In this study, in vivo acridine orange (AO) staining, which is presently in application in the estimation of genome damage in reticulocytes, was adjusted for spermatozoa staining. Ten men suffering from oligoasthenoteratozoospermia (OAT) and 10 healthy fertile men were analysed using in vivo AO staining. Microscopic analysis was performed by fluorescent and confocal fluorescent microscopy. Our results show that this method preserves spermatozoa membranes, which enables new insight into spermatozoa genome damage, RNA content in residual cytoplasm, damage of neck area with mitochondrion and tail pathology. The introduced method explains the difference between results of sperm DNA fragmentation assay and the globally used AO staining and opens new options for the development of automated systems. In conclusion, the results of our study offer (a) an innovative approach to the analysis of spermatozoa pathology, (b) enable localization and quantification of RNA in residual cytoplasm, (c) a significant contribution to research of aetiology of infertility in men, (d) open new perspectives for the automatization of sperm quality estimation and (e) improve the personalized approach in the selection of in vitro fertilization protocols.
Topics: Acridine Orange; Humans; Infertility, Male; Male; Microscopy, Fluorescence; RNA; Sperm Motility; Spermatozoa; Staining and Labeling
PubMed: 32840006
DOI: 10.1111/ahe.12606 -
Nucleic Acids Research Apr 2018The ordered structure of UV chromophores in DNA resembles photosynthetic light-harvesting complexes in which quantum coherence effects play a major role in highly...
The ordered structure of UV chromophores in DNA resembles photosynthetic light-harvesting complexes in which quantum coherence effects play a major role in highly efficient directional energy transfer. The possible role of coherent excitons in energy transport in DNA remains debated. Meanwhile, energy transport properties are greatly important for understanding the mechanisms of photochemical reactions in cellular DNA and for DNA-based artificial nanostructures. Here, we studied energy transfer in DNA complexes formed with silver nanoclusters and with intercalating dye (acridine orange). Steady-state fluorescence measurements with two DNA templates (15-mer DNA duplex and calf thymus DNA) showed that excitation energy can be transferred to the clusters from 21 and 28 nucleobases, respectively. This differed from the DNA-acridine orange complex for which energy transfer took place from four neighboring bases only. Fluorescence up-conversion measurements showed that the energy transfer took place within 100 fs. The efficient energy transport in the Ag-DNA complexes suggests an excitonic mechanism for the transfer, such that the excitation is delocalized over at least four and seven stacked bases, respectively, in one strand of the duplexes stabilizing the clusters. This result demonstrates that the exciton delocalization length in some DNA structures may not be limited to just two bases.
Topics: Acridine Orange; Animals; Cattle; DNA; Energy Transfer; Fluorescence; Nanostructures; Nucleic Acid Conformation; Photosynthesis; Quantum Theory; Silver; Ultraviolet Rays
PubMed: 29186575
DOI: 10.1093/nar/gkx1185 -
Turkish Journal of Urology Jan 2018The questionable effectiveness of routine sperm parameters in determining male factor infertility problems and increasing the success rates of assisted reproductive... (Review)
Review
The questionable effectiveness of routine sperm parameters in determining male factor infertility problems and increasing the success rates of assisted reproductive techniques have led to the investigation of more detailed sperm parameters that could affect the male fertility and reproduction. Thus, the effects of different sperm parameters such as sperm DNA integrity was started to be investigated thanks to the previously described methods such as single cell gel electrophoresis (COMET) assay, sperm chromatin structure assay (SCSA), acridine orange test (AOT), terminal deoxynucleotidyl transferase-mediated deoxyuridine (TdT) triphosphate (dUTP) nick end labeling (TUNEL) assay and sperm chromatin dispersion (SCD) test. However, studying on sperm DNA might be very complex because the sperm DNA differs from the somatic cell DNA with its unique structure. Also, the sperm DNA undergoes many changes during spermatogenesis and it is condensed by being packaged tightly with different types and numbers of protamines in different species. Despite all these difficulties, these methods provide important information about the reasons and consequences of DNA damages in sperm and the effects of these damages on reproduction.
PubMed: 29484219
DOI: 10.5152/tud.2018.49321 -
Biochimie Jan 2018KRAS is often found mutated in lethal cancers and should be an important target for anticancer drug development. However, no effective inhibitor has been reported so...
KRAS is often found mutated in lethal cancers and should be an important target for anticancer drug development. However, no effective inhibitor has been reported so far, prompting the scientific community to describe the RAS proteins as nearly "undruggable". Recent approaches developed to modulate KRAS protein expression comprises the targeting of G-quadruplex (G4) structures formed within the nuclease hypersensitive element of KRAS promoter region, by designing small and specific ligands to stabilize the tertiary fold and reduce gene expression. In this work, we report in vitro and in silico studies of novel acridine orange (AO) derivatives (C-C), developed as G4 stabilizing agents. The results show that the ligands bind with high affinity and stabilize KRAS22-RT G4 with modest specificity over duplex DNA. The most promising ligand C stabilizes the structure by ≈ 40 °C. Molecular docking using NMR-derived distance restraints reveal atomic details about the ligand structural features in the interaction with KRAS22-RT G4. In vitro studies with HeLa cells show that the ligands are cytotoxic with IC50 values between 0.9 μM and 5.7 μM. Moreover, the ligands tend to localize in the nucleus as shown by confocal fluorescence microscopy. Overall, these results show that the reported AO ligands display favourable properties as G4 ligands and this study provides structural detail for the development of lead KRAS G4 ligands.
Topics: Acridine Orange; Biological Transport; Cell Proliferation; Fluorescent Dyes; G-Quadruplexes; HeLa Cells; Humans; Intracellular Space; Ligands; Proto-Oncogene Proteins p21(ras)
PubMed: 29129745
DOI: 10.1016/j.biochi.2017.11.004 -
Acta Histochemica May 2019New tools are desirable to examine the metabolic state of individual cells within tissues. We proposed a fluorescence-based procedure consisting of acridine orange...
New tools are desirable to examine the metabolic state of individual cells within tissues. We proposed a fluorescence-based procedure consisting of acridine orange staining and fast green counterstaining (AO-FG) to improve the selectivity of the former for nucleic acids (acridine orange stains both DNA and RNA with different fluorescence colors), with no interference from proteins. We compared this test with the biochemical quantification of the relative amounts of RNA and DNA in selected rat ventral prostate samples and PC3 cells. The epithelium of the prostate gland is highly active metabolically for the production of secretions. Differences in AO-RNA staining were revealed and correlated with the metabolic state of the epithelium. Specificity was confirmed by RNase A. To assess how AO-FG staining correlates with the metabolic state of the cell, we cultured PC3 cells in different concentrations of glucose and measured the ratios between the amounts of RNA and DNA. In parallel, similar cultures were subjected to AO-FG, and the staining pattern correlated closely (r=0.886) with the obtained biochemical results. The results confirmed that the combined use of AO and FG is useful for detecting DNA and RNA simultaneously, as well as for assessing quantitatively the transcriptional activity of individual cells and their changes in response to experimental manipulation.
Topics: Animals; DNA; Humans; Male; Microscopy, Fluorescence; PC-3 Cells; RNA; Rats; Rats, Wistar
PubMed: 30954273
DOI: 10.1016/j.acthis.2019.03.010