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Dagnino L. Ubiquitylated histone H2A: a molecular Jekyll and Hyde in the epidermis. Tissue Barriers 2024; 12:2236007. [PMID: 37459858 PMCID: PMC11262237 DOI: 10.1080/21688370.2023.2236007] [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: 07/03/2023] [Accepted: 07/08/2023] [Indexed: 07/23/2024] Open
Abstract
The epidermis of the skin provides a barrier between the organism and the external environment. It is constantly subjected to physical and chemical insults, and thus susceptible to wounding and to neoplastic transformation. Long-lasting epigenetic modifications in epidermal stem cells are now shown to link responses to skin injuries with cell priming for carcinoma development, through regulation of histone H2A ubiquitylation.
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Affiliation(s)
- Lina Dagnino
- Department of Physiology and Pharmacology, Department of Oncology, London Health Research Institute, Children’s Health Research Institute, The University of Western Ontario, London, Ontario, Canada
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Zou J, Mitra K, Anees P, Oettinger D, Ramirez JR, Veetil AT, Gupta PD, Rao R, Smith JJ, Kratsios P, Krishnan Y. A DNA nanodevice for mapping sodium at single-organelle resolution. Nat Biotechnol 2024; 42:1075-1083. [PMID: 37735265 PMCID: PMC11004682 DOI: 10.1038/s41587-023-01950-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 08/15/2023] [Indexed: 09/23/2023]
Abstract
Cellular sodium ion (Na+) homeostasis is integral to organism physiology. Our current understanding of Na+ homeostasis is largely limited to Na+ transport at the plasma membrane. Organelles may also contribute to Na+ homeostasis; however, the direction of Na+ flow across organelle membranes is unknown because organellar Na+ cannot be imaged. Here we report a pH-independent, organelle-targetable, ratiometric probe that reports lumenal Na+. It is a DNA nanodevice containing a Na+-sensitive fluorophore, a reference dye and an organelle-targeting domain. By measuring Na+ at single endosome resolution in mammalian cells and Caenorhabditis elegans, we discovered that lumenal Na+ levels in each stage of the endolysosomal pathway exceed cytosolic levels and decrease as endosomes mature. Further, we find that lysosomal Na+ levels in nematodes are modulated by the Na+/H+ exchanger NHX-5 in response to salt stress. The ability to image subcellular Na+ will unveil mechanisms of Na+ homeostasis at an increased level of cellular detail.
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Affiliation(s)
- Junyi Zou
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Koushambi Mitra
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
| | - Palapuravan Anees
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
| | - Daphne Oettinger
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Joseph R Ramirez
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Aneesh Tazhe Veetil
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Priyanka Dutta Gupta
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Rajini Rao
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jayson J Smith
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
- Department of Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Paschalis Kratsios
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
- Department of Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Yamuna Krishnan
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA.
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Mechanisms of Resistance to Photodynamic Therapy (PDT) in Vulvar Cancer. Int J Mol Sci 2022; 23:ijms23084117. [PMID: 35456936 PMCID: PMC9028356 DOI: 10.3390/ijms23084117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/04/2022] [Accepted: 04/06/2022] [Indexed: 02/06/2023] Open
Abstract
Photodynamic therapy (PDT) is a valuable treatment method for vulvar intraepithelial neoplasia (VIN). It allows for the treatment of a multifocal disease with minimal tissue destruction. 5-Aminolevulinic acid (5-ALA) is the most commonly used prodrug, which is converted in the heme pathway to protoporphyrin IX (PpIX), an actual photosensitizer (PS). Unfortunately, not all patients treated with PDT undergo complete remission. The main cause of their failure is resistance to anticancer therapy. In many cancers, resistance to various anticancer treatments is correlated with increased activity of the DNA repair protein apurinic/apyrimidinic endonuclease 1 (APE1). Enhanced activity of drug pumps may also affect the effectiveness of therapy. To investigate whether multidrug resistance mechanisms underlie PDT resistance in VIN, porphyrins were isolated from sensitive and resistant vulvar cancer cells and their culture media. APE1 activity was measured, and survival assay after PDT combined with APE1 inhibitor was performed. Our results revealed that resistant cells accumulated and effluxed less porphyrins than sensitive cells, and in response to PDT, resistant cells increased APE1 activity. Moreover, PDT combined with inhibition of APE1 significantly decreased the survival of PDT-resistant cells. This means that resistance to PDT in vulvar cancer may be the result of alterations in the heme synthesis pathway. Moreover, increased APE1 activity may be essential for the repair of PDT-mediated DNA damage, and inhibition of APE1 activity may increase the efficacy of PDT.
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