-
Cytometry. Part a : the Journal of the... Jun 2020Briefly depicted are the publications in CYTOMETRY that received the highest frequency of citations. Among them are seminal papers describing application of...
Briefly depicted are the publications in CYTOMETRY that received the highest frequency of citations. Among them are seminal papers describing application of metachromatic fluorochrome acridine orange to differentially stain DNA versus RNA or to analyze susceptibility of DNA in situ to denaturation; both features being markers of different sections of the cell cycle including identification of noncycling quiescent cells. The papers reviewing detection of cyclins D1, E, A or B1, each in relation to cell cycle phase, were also among the highly cited ones. The highest citation rates received publications describing development of the TUNEL methodology to detect apoptotic DNA fragmentation, and more recently expression of ϒH2AX to reveal DNA damage. © 2020 International Society for Advancement of Cytometry.
Topics: Acridine Orange; Cell Cycle; DNA; Flow Cytometry; Fluorescent Dyes
PubMed: 32511890
DOI: 10.1002/cyto.a.24043 -
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 -
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 -
International Journal of Molecular... Jan 2023Swim-up selected human sperm were incubated with 7 ng F-neuroprostanes (F-NeuroPs) for 2 and 4 h. Sperm motility and membrane mitochondrial potential (MMP) were...
Swim-up selected human sperm were incubated with 7 ng F-neuroprostanes (F-NeuroPs) for 2 and 4 h. Sperm motility and membrane mitochondrial potential (MMP) were evaluated. The percentage of reacted acrosome was assessed by pisum sativum agglutinin (PSA). Chromatin integrity was detected using the acridine orange (AO) assay and localization of the ryanodine receptor was performed by immunofluorescence analysis. Sperm progressive motility ( = 0.02) and the percentage of sperm showing a strong MMP signal ( = 0.012) significantly increased after 2 h F-NeuroP incubation compared to control samples. The AO assay did not show differences in the percentage of sperm with dsDNA between treated or control samples. Meanwhile, a significantly higher number of sperm with reacted acrosomes was highlighted by PSA localization after 4 h F-NeuroP incubation. Finally, using an anti-ryanodine antibody, the immunofluorescence signal was differentially distributed at 2 and 4 h: a strong signal was evident in the midpiece and postacrosomal sheath (70% of sperm) at 2 h, whereas a dotted one appeared at 4 h (53% of sperm). A defined concentration of F-NeuroPs in seminal fluid may induce sperm capacitation via channel ions present in sperm cells, representing an aid during in vitro sperm preparation that may increase the positive outcome of assisted fertilization.
Topics: Humans; Male; Neuroprostanes; Sperm Motility; Seeds; Spermatozoa; Acrosome; Acridine Orange
PubMed: 36674450
DOI: 10.3390/ijms24020935 -
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 -
Experimental Eye Research Mar 2014Simultaneous non-invasive visualization of blood vessels and nerves in patients can be obtained in the eye. The retinal vasculature is a target of many retinopathies....
Simultaneous non-invasive visualization of blood vessels and nerves in patients can be obtained in the eye. The retinal vasculature is a target of many retinopathies. Inflammation, readily manifest by leukocyte adhesion to the endothelial lining, is a key pathophysiological mechanism of many retinopathies, making it a valuable and ubiquitous target for disease research. Leukocyte fluorography has been extensively used in the past twenty years; however, fluorescent markers, visualization techniques, and recording methods have differed between studies. The lack of detailed protocol papers regarding leukocyte fluorography, coupled with lack of uniformity between studies, has led to a paucity of standards for leukocyte transit (velocity, adherence, extravasation) in the retina. Here, we give a detailed description of a convenient method using acridine orange (AO) and a commercially available scanning laser ophthalmoscope (SLO, HRA-OCT Spectralis) to view leukocyte behavior in the mouse retina. Normal mice are compared to mice with acute and chronic inflammation. This method can be readily adopted in many research labs.
Topics: Acridine Orange; Animals; Blood Flow Velocity; Cell Movement; Diabetes Mellitus, Type 1; Fluorescein Angiography; Fluorescent Dyes; Leukocytes; Male; Mice; Mice, Inbred C57BL; Mice, Inbred NOD; Microscopy, Confocal; Ophthalmoscopes; Regional Blood Flow; Retinal Artery; Retinal Vasculitis; Retinal Vein; Tomography, Optical Coherence; Vascular Endothelial Growth Factor A; Video Recording
PubMed: 24333760
DOI: 10.1016/j.exer.2013.12.002 -
The Canadian Veterinary Journal = La... Oct 2021Intraoperative acridine orange-photodynamic therapy (AO-PDT) and cribriform plate irradiation are used to treat canine intranasal tumors. The purpose of this study was...
Intraoperative acridine orange-photodynamic therapy (AO-PDT) and cribriform plate irradiation are used to treat canine intranasal tumors. The purpose of this study was to evaluate the effects of AO-PDT on intranasal tumors and the recurrence rate of tumors after this treatment. Treatments with AO-PDT were performed on 38 dogs through a narrow window of the dorsal nasal cavity. The median progression-free interval was 12 mo and recurrence was detected in 21 dogs. Based on computed tomography, recurrence in 16 dogs was biased to the following areas: lateral ( = 10), medial ( = 2), ventral ( = 0), rostral ( = 0), and caudal ( = 8). Side effects were mild and included subcutaneous emphysema and rhinitis. The median survival time was 24 mo. Although AO-PDT with cribriform irradiation is an effective treatment for intranasal tumors, AO-PDT techniques should be improved to treat the nasal cavity more uniformly and thoroughly.
Topics: Acridine Orange; Animals; Dog Diseases; Dogs; Neoplasm Recurrence, Local; Osteosarcoma; Photochemotherapy; Treatment Outcome
PubMed: 34602642
DOI: No ID Found -
Journal of Andrology 1992The relationship between thiol-disulfide status and acridine orange fluorescence of testicular, epididymal, and ejaculated spermatozoa in several mammalian species was...
The relationship between thiol-disulfide status and acridine orange fluorescence of testicular, epididymal, and ejaculated spermatozoa in several mammalian species was investigated. Spermatozoa were fixed with acetic alcohol, stained with acridine orange, and examined with a fluorescence microscope. The majority of the nuclei of testicular spermatozoa of the hamster, mouse, and rabbit exhibited red acridine orange fluorescence. The proportion of sperm nuclei with red acridine orange fluorescence decreased as the spermatozoa descended the epididymis. Red acridine orange fluorescence was replaced by green acridine orange fluorescence. The site in the epididymis where 100% of the nuclei exhibited green fluorescence was the distal caput in the mouse, the corpus in the rabbit, and the proximal cauda in the hamster. In semen samples from men with proven fertility, normal semen parameters, or both, about 60% to 90% of the nuclei exhibited green acridine orange fluorescence. The proportion of sperm nuclei exhibiting green acridine orange fluorescence was higher in the spermatozoa pellet (containing highly motile spermatozoa) obtained by centrifugation through a Percoll gradient. From experiments using disulfide-reducing, thiol-oxidizing and thiol-detecting agents, we concluded that sperm nuclei fluoresce red when they are treated with acid while their DNA-associated protamines are poor in disulfides. Under such conditions, DNA is vulnerable to denaturation. Acridine orange binds to denatured (single-stranded) DNA as aggregates and emits red fluorescence. In contrast, when sperm nuclei are treated with acid while their DNA-associated protamines are rich in disulfides, DNA is resistant to denaturation. Acridine orange binds to native (double-stranded) DNA as a monomer and emits green fluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Acridine Orange; Animals; Bridged Bicyclo Compounds; Cell Nucleus; Cricetinae; DNA; Disulfides; Epididymis; Fluorescent Dyes; Humans; Male; Mesocricetus; Mice; Mice, Inbred C57BL; Microscopy, Electron; Protamines; Rabbits; Spermatozoa; Sulfhydryl Compounds; Testis
PubMed: 1399837
DOI: No ID Found -
The Canadian Veterinary Journal = La... May 2019Canine intranasal carcinomas are almost always malignant. Surgery alone often results in rapid tumor regrowth. Radiotherapy is the treatment of choice for dogs with...
Canine intranasal carcinomas are almost always malignant. Surgery alone often results in rapid tumor regrowth. Radiotherapy is the treatment of choice for dogs with intranasal tumors. Here, we retrospectively assessed treatment of intranasal carcinoma by marginal tumor resection followed by intraoperative acridine orange (AO) photodynamic therapy (PDT) and cribriform plate electron-beam intraoperative radiotherapy (IORT). Fourteen canine cases were assessed, 12 of which had stage I tumors, one with stage III, and one with stage IV. Recurrence was detected in 8, with a median recurrence from the time of treatment of 6 months (range: 3 to 16 months). The median progression-free survival time and overall survival time after treatment were 13 and 22 months, respectively. Adverse events were mild. Marginal tumor resection followed by intraoperative AO-PDT and cribriform plate electron-beam IORT may increase the tumor control time in dogs with marginally resectable intranasal malignant tumors beyond that incurred by surgery alone.
Topics: Acridine Orange; Animals; Combined Modality Therapy; Dog Diseases; Dogs; Electrons; Intraoperative Care; Neoplasm Recurrence, Local; Photochemotherapy; Retrospective Studies
PubMed: 31080264
DOI: No ID Found -
Cell Communication and Signaling : CCS Oct 2022Frameshift mutations in LRPAP1 are responsible for autosomal recessive high myopia in human beings but its underlying mechanism remains elusive. This study aims to...
BACKGROUND
Frameshift mutations in LRPAP1 are responsible for autosomal recessive high myopia in human beings but its underlying mechanism remains elusive. This study aims to investigate the effect of LRPAP1 defect on ocular refractive development and its involved mechanism.
METHODS
A lrpap1 mutant zebrafish line with homozygous frameshift mutation was generated by CRISPR/Cas9 technology and confirmed by Sanger sequencing. The ocular refractive phenotype was analyzed by calculating the relative refractive error (RRE) with vivo photography and histological analysis at different development stages, together with examining ocular structure change via transmission electron microscopy. Further, RNA sequencing and bioinformatics analysis were performed. The potentially involved signaling pathway as well as the interacted protein were investigated in vivo.
RESULTS
The lrpap1 homozygous mutant zebrafish line showed myopic phenotype. Specifically, the mutant lines showed larger eye axial length-to-body length in one-month old individuals and a myopic shift with an RRE that changed after two months. Collagen fibers became thinning and disordered in the sclera. Further, RNA sequencing and bioinformatics analysis indicated that apoptosis signaling was activated in mutant line; this was further confirmed by acridine orange and TUNEL staining. Moreover, the expression of TGF-β protein was elevated in the mutant lines. Finally, the treatment of wild-type embryos with a TGF-β agonist aggravated the degree of eyeball apoptosis; conversely, the use of a TGF-β inhibitor mitigated apoptosis in mutant embryos.
CONCLUSION
The study provides functional evidence of a link between lrpap1 and myopia, suggesting that lrpap1 deficiency could lead to myopia through TGF-β-induced apoptosis signaling. Video abstract.
Topics: Animals; Humans; Acridine Orange; Apoptosis; Collagen; Myopia; Sclera; Transforming Growth Factor beta; Zebrafish; LDL-Receptor Related Protein-Associated Protein; Zebrafish Proteins
PubMed: 36261846
DOI: 10.1186/s12964-022-00970-9