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Belashov AV, Zhikhoreva AA, Salova AV, Belyaeva TN, Litvinov IK, Kornilova ES, Semenova IV, Vasyutinskii OS. Automatic segmentation of lysosomes and analysis of intracellular pH with Radachlorin photosensitizer and FLIM. Biochem Biophys Res Commun 2024; 710:149835. [PMID: 38574457 DOI: 10.1016/j.bbrc.2024.149835] [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] [Received: 01/23/2024] [Revised: 03/17/2024] [Accepted: 03/25/2024] [Indexed: 04/06/2024]
Abstract
We report application of the fluorescence lifetime imaging microscopy (FLIM) for analysis of distributions of intracellular acidity using a chlorin-e6 based photosensitizer Radachlorin. An almost two-fold increase of the photosensitizer fluorescence lifetime in alkaline microenvironments as compared to acidic ones allowed for clear distinguishing between acidic and alkaline intracellular structures. Clusterization of a phasor plot calculated from fits of the FLIM raw data by two Gaussian distributions provided accurate automatic segmentation of lysosomes featuring acidic contents. The approach was validated in colocalization experiments with LysoTracker fluorescence in living cells of four established lines. The dependence of photosensitizer fluorescence lifetime on microenvironment acidity allowed for estimation of pH inside the cells, except for the nuclei, where photosensitizer does not penetrate. The developed method is promising for combined application of the photosensitizer for both photodynamic treatment and diagnostics.
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Affiliation(s)
- A V Belashov
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
| | - A A Zhikhoreva
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
| | - A V Salova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - T N Belyaeva
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - I K Litvinov
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - E S Kornilova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - I V Semenova
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia.
| | - O S Vasyutinskii
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
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Knab A, Anwer AG, Pedersen B, Handley S, Marupally AG, Habibalahi A, Goldys EM. Towards label-free non-invasive autofluorescence multispectral imaging for melanoma diagnosis. JOURNAL OF BIOPHOTONICS 2024; 17:e202300402. [PMID: 38247053 DOI: 10.1002/jbio.202300402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/11/2023] [Accepted: 12/31/2023] [Indexed: 01/23/2024]
Abstract
This study focuses on the use of cellular autofluorescence which visualizes the cell metabolism by monitoring endogenous fluorophores including NAD(P)H and flavins. It explores the potential of multispectral imaging of native fluorophores in melanoma diagnostics using excitation wavelengths ranging from 340 nm to 510 nm and emission wavelengths above 391 nm. Cultured immortalized cells are utilized to compare the autofluorescent signatures of two melanoma cell lines to one fibroblast cell line. Feature analysis identifies the most significant and least correlated features for differentiating the cells. The investigation successfully applies this analysis to pre-processed, noise-removed images and original background-corrupted data. Furthermore, the applicability of distinguishing melanomas and healthy fibroblasts based on their autofluorescent characteristics is validated using the same evaluation technique on patient cells. Additionally, the study tentatively maps the detected features to underlying biological processes. This research demonstrates the potential of cellular autofluorescence as a promising tool for melanoma diagnostics.
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Affiliation(s)
- Aline Knab
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, Australia
| | - Ayad G Anwer
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, Australia
| | - Bernadette Pedersen
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales, Australia
- Melanoma Institute Australia, The University of Sydney, Sydney, New South Wales, Australia
| | - Shannon Handley
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, Australia
| | - Abhilash Goud Marupally
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, Australia
| | - Abbas Habibalahi
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, Australia
| | - Ewa M Goldys
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, Australia
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