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dc.contributor.advisor Kakarougkas, Andreas Mounir, Mie Mohamed 2020-09-13T13:24:03Z Fall 2020 en_US 2020-09-13
dc.description.abstract Magnetite nanoparticles particulate matter pollution is escalating in large cities like New Mexico, Manchester city, Cairo, and New Delhi. Combustion derived Magnetite nanoparticles was found deposited in internal vital organs of deceased residents of urban areas. A great deal of research focused on the genotoxic and cytotoxic effects of Magnetite Nanoparticles (MNPs). In our work we focus on the mechanisms employed in DNA repair of higher chromatin structures. We employed the sensitive analysis of anti γ-H2AX to detect and monitor the repair of DSBs following exposure to MNPs. A 2- fold delay in the repair of heterochromatin associated DSBs in comparison with euchromatin was detected. The slow repairing heterochromatin γ-H2AX foci were found almost exclusively at the peripheries of the chromocenters, marking the physical barrier that the compacted chromatin impose on the extension of the DNA repair signal. The heterochromatin associated DSBs constituted 10.3% of the original DSBs initially introduced, similarly the fraction of DSBs that requires ATM for DNA repair constitutes about 10-25%. No visible structural changes happened in heterochromatin chromocentres during the repair. On Inhibition of ATM a repair defect in the heterochromatin DSBs was evident post exposure to MNPs, comparable to the repair defect imparted after exposure to Neocarzinostatin (NCS). This repair defect could not be compensated by other PIKKs (ATR and DNA PKcs). Therefore, ATM is essential for the transient relaxation of the nucleosome to allow the extension of the DNA repair machinery. Individuals lacking a functional ATM protein, will lack the ATM dependent chromatin relaxation and extension of repair machinery. So, they would be prone to accumulate mutations in the repetitive satellite pericentromeres, centromeres and telomeres, imparting a MNPs sensitivity to those individuals. en_US
dc.format.extent 081 p. en_US
dc.format.medium theses en_US
dc.language.iso en en_US
dc.rights Author retains all rights with regard to copyright. en
dc.subject Magnetite Nanoparticles en_US
dc.subject Particulate Matter en_US
dc.subject Ataxia telangiectasia mutated en_US
dc.subject Double Strand Breaks en_US
dc.subject DNA repair en_US
dc.subject Heterochromatin en_US
dc.subject.lcsh Thesis (M.S.)--American University in Cairo en_US
dc.title Role of Ataxia Telangiectasia mutated in the repair of Magnetite Nanoparticles induced double strand breaks associated with Heterochromatin en_US
dc.type Text en_US
dc.subject.discipline Biotechnology en_US
dc.rights.access This item is restricted for 2 years from the date issued en_US
dc.contributor.department American University in Cairo. Dept. of Biology en_US
dc.embargo.lift 2022-09-13T13:24:03Z
dc.description.irb American University in Cairo Institutional Review Board approval is not necessary for this item, since the research is not concerned with living human beings or bodily tissue samples. en_US
dc.contributor.committeeMember Gad, Mohamed Zakaria
dc.contributor.committeeMember Abdelnaser, Anwar
dc.contributor.committeeMember Zada, Suher
dc.contributor.committeeMember Kakarougkas, Andreas

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  • Theses and Dissertations [1863]
    This collection includes theses and dissertations authored by American University in Cairo graduate students.

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