Date of Award


Publication Type

Master Thesis

Degree Name



Chemistry and Biochemistry

First Advisor

S. Pandey


Pure sciences, Biological sciences



Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.


In response to external oxidative stress/DNA damaging agents, mammalian cells may choose one of the following pathways to avoid propagation of the damaged cells: repair the DNA and proceed with the normal cell cycle; trigger apoptosis; or undergo senescence to block cell division. Working with NHFs, we have observed that quiescent fibroblasts, unlike dividing fibroblasts, do not undergo apoptosis when subjected to a high dose of external oxidative stress but become senescent instead. Our results have indicated that p21 and MnSOD over-expression in quiescent cells is highly correlated to resistance to external oxidative stress and senescence induction. Furthermore, we observed that fibroblasts harvested from individuals diagnosed with Alzheimer's disease have a higher amount of endogenous ROS and double stranded DNA breaks than NHFs, leading to an earlier onset of replicative senescence. Consistent with higher ROS levels, AD fibroblasts have up-regulated expression of MnSOD and decreased levels of non-selenium glutathione peroxidase.