AUB ScholarWorks

Radiation-induced DNA damage in podocytes : role of SMPDL3b in ATM nuclear shuttling

Show simple item record Francis, Marina Simon 2022-09-29T13:27:04Z 2022-09-29T13:27:04Z 2019 2019
dc.identifier.other b25883203
dc.description Thesis. M.Sc. American University of Beirut. Department of Anatomy, Cell Biology and Physiological Sciences. Faculty of Medicine 2019. W 4 F819r 2019; Advisor: Dr. Youssef Zeidan, Assistant Professor, Department of Radiation Oncology ; Committee members: Dr. Alessia Fornoni, Professor Chief, Katz Family Division of Nephrology and Hypertension, Director, Peggy and Harold Katz Family Drug Discovery Center, Miller School of Medicine, University of Miami ; Dr. Assaad Eid, Associate Professor, Department of Anatomy, Cell Biology, and Physiological Sciences ; Dr. Rosalyn Jurjus, Associate Professor, Department of Anatomy, Cell Biology, and Physiological Sciences.
dc.description Includes bibliographical references (leaves 63-71)
dc.description.abstract Radiotherapy (RT) is the primary, non-invasive treatment for over 50percent of cancer patients. Despite its curative potential, RT can induce damage in normal healthy tissues surrounding the tumor. The kidneys are radiosensitive organs, hence dose-limiting for RT targeting abdominal and paraspinal tumors. Excessive radiation doses to the kidneys ultimately lead to radiation nephropathy. In fact, podocytes are key players in the pathogenesis of radiation-induced proteinuria. Prior work points to a potential role for the lipid modifying enzyme, SMPDL3b, in regulating the response of podocytes to radiation injury. Aim: Our current study aims to determine the role of SMPDL3b in DNA double strand breaks (DSBs) repair after radiation injury. Methods: WT (wild-type) and OE (SMPDL3b overexpressors) immortalized human podocytes were used for this study. Differentiated cultured cells were irradiated and the treatment was stopped at selected time points. -H2AX and p-ATM nuclear foci were quantified by confocal microscopy after immunofluorescence (IF) staining. Further investigations on ATM nuclear shuttling were performed on isolated nuclear and cytoplasmic fractions through Western Blotting. Cell survival was assessed by quantifying the protein expression of p-p53 (ser15) and cleaved caspase 3. Furthermore, liquid chromatography – mass spectrometry (LC-MS) analysis was used for the assessment of radiation-induced changes in nuclear sphingolipids in both WT and OE cells. The impact of ceramide-1-phosphate (C1P) or ZOPRA pre-treatments on DSBs recognition and repair through ATM nuclear shuttling was also assessed by IF staining. Viability of irradiated WT and OE podocytes after treatments was assessed by MTT assay. Results: After assessing the kinetics of -H2AX and p-ATM nuclear foci appearance- disappearance in both cell lines, we established that SMPDL3b overexpression in podocytes enhances DSBs recognition and repair by modulating ATM nuclear shuttling. Western Blotting analysis on isolated nuclear and cy
dc.format.extent 1 online resource (71 leaves)
dc.language.iso eng
dc.subject.classification F819r 2019
dc.subject.lcsh Dissertations, Academic.||Tumor Suppressor Protein p53.||Sphingolipids.||Ceramides.||Radiation Injuries.||DNA Breaks, Double-Stranded.
dc.title Radiation-induced DNA damage in podocytes : role of SMPDL3b in ATM nuclear shuttling
dc.type Thesis
dc.contributor.department Department of Anatomy, Cell Biology and Physiological Sciences
dc.contributor.institution American University of Beirut
dc.contributor.authorFaculty Faculty of Medicine

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search AUB ScholarWorks


My Account