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ALTERATIONS IN P53 AND CATHEPSIN D FOLLOWING HYDROGEN PEROXIDE EXPOSURE IN PC12 CELLS
Author(s) -
Shelton Taaj Kawanza,
Womble Tracy,
Mason Ceceile,
Anderson Nicole
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.lb78-b
Subject(s) - apoptosis , viability assay , tunel assay , oxidative stress , programmed cell death , chemistry , microbiology and biotechnology , western blot , cathepsin b , cathepsin , biology , biochemistry , enzyme , gene
BACKGROUND Oxidative stress induced‐apoptosis increases the expression of certain transcriptional factors and protein expression in the cell. Specifically, P53, which is a DNA transcriptional factor, plays an important role in the regulation of apoptosis (programmed cell death) and increases in expression following oxidative stress. Cathepsin D (CD), and Cathepsin B (CB), which are lysosomal proteases, are also associated with apoptosis as seen in the expression change during oxidative stress induced‐apoptosis. Interestingly, P53 is a transcriptional factor for CD and is believed that CB regulates p53. PURPOSE In this study our objective is to look at the regulation of CD by p53 and CB. METHODS In each experiment PC12 cells were treated with 100ìM H2O2 for 30min, 4hrs, 12hrs, and 24hrs. Pifithrin, (p53 inhibitor) and Papstatin A (Cathepsin D inhibitor) were also used to determine the role of P53 and CD following H2O2. Cell viability was measured by MTS. Apoptosis was determined using TUNEL staining. CD, CB, and p53 expression was quantified using western blot analysis. RESULTS H2O2 caused a decrease in cell viability in a concentration dependent manner. Western Blot analysis showed the temporal expression of phospho‐P53 and CD following exposure to 100ìM of H2O2. Interestingly, an increase in cell viability and a reduction in CD expression was observed following exposure to H2O2 along with P53 inhibition. CONCLUSION These results suggest P53 and CD may be involved in a common pathway of cell death following H2O2 exposure. Research supported by NIH/NIGMS/MBRS S06GM08111 and RCMI/NIH RR03020