Hydrogen peroxide induces lysosomal protease alterations in PC12 cells.
Alterations in lysosomal proteases have been implicated in many neurodegenerative diseases. The current study demonstrates a concentration-dependent decrease in PC12 cell viability and transient changes in cystatin C (CYSC), cathepsin B (CATB), cathepsin D (CATD) and caspase-3 following exposure to H2O2. Furthermore, activation of CATD occurred following exposure to H2O2 and cysteine protease suppression, while inhibition of CATD with pepstatin A significantly improved cell viability. Additionally, significant PARP cleavage, suggestive of caspase-3-like activity, was observed following H2O2 exposure, while inhibition of caspase-3 significantly increased cell viability compared to H2O2 administration alone. Collectively, our data suggest that H2O2 induced cell death is regulated at least in part by caspase-3 and CATD. Furthermore, cysteine protease suppression increases CATD expression and activity. These studies provide insight for alternate pathways and potential therapeutic targets of cell death associated with oxidative stress and lysosomal protease alterations.
Lee
Daniel C
DC
College of Pharmacy & Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA.
Mason
Ceceile W
CW
Goodman
Carl B
CB
Holder
Maurice S
MS
Kirksey
Otis W
OW
Womble
Tracy A
TA
Severs
Walter B
WB
Palm
Donald E
DE
D000818:Animals; D053148:Caspase 3 / Q000378:metabolism*; D002401:Cathepsin B / Q000378:metabolism*; D002402:Cathepsin D / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D055316:Cystatin C; D015891:Cystatins / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008247:Lysosomes / Q000187:drug effects* / Q000201:enzymology*; D018384:Oxidative Stress; D016716:PC12 Cells; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D051381:Rats
C525032:Cst3 protein, rat; D055316:Cystatin C; D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D011065:Poly(ADP-ribose) Polymerases; C505410:Casp3 protein, rat; D053148:Caspase 3; D002401:Cathepsin B; D002402:Cathepsin D