Increased in vitro lysosomal function in oxidative stress-induced cell lines.
Exposure of mammalian cells to oxidative stress alters lysosomal enzymes. Through cytochemical analysis of lysosomes with LysoTracker, we demonstrated that the number and fluorescent intensity of lysosome-like organelles in HeLa cells increased with exposure to hydrogen peroxide (H₂O₂), 6-hydroxydopamine (6-OHDA), and UVB irradiation. The lysosomes isolated from HeLa cells exposed to three oxidative stressors showed the enhanced antimicrobial activity against Escherichia coli. Further, when lysosomes that were isolated from HeLa cells exposed by oxidative stress were treated to normal HeLa cells, the viability of the HeLa cells was drastically reduced, suggesting increased in vitro lysosomal function (i.e., antimicrobial activity, apoptotic cell death). In addition, we also found that cathepsin B and D were implicated in increased in vitro lysosomal function when isolated from HeLa cells exposed by oxidative stress. Decrease in cathepsin B activity and increase in cathepsin D activity were observed in lysosomes isolated from HeLa cells after treatment with H₂O₂, 6-ODHA, or UVB, but cathepsin B and D were not the sole factors to induce cell death by in vitro lysosomal function. Therefore, these studies suggest a new approach to use lysosomes as antimicrobial agents and as new materials for treating cancer cell lines.
Graduate School of Semiconductor and Chemical Engineering, Chonbuk National University, 664-14 Deokjin-dong, 1Ga Deokjin-Gu, Jeonju 561-756, South Korea.
Jihee
J
Yoon
Seung Hyuck
SH
Bang
Jin-Soo
JS
Park
Suk-Tai
ST
Chang
Yang-Hoon
YH
Kim
Jiho
J
Min
D017209:Apoptosis; D002401:Cathepsin B / Q000378:metabolism; D002402:Cathepsin D / Q000378:metabolism; D006367:HeLa Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D018384:Oxidative Stress / Q000187:drug effects / Q000528:radiation effects; D014466:Ultraviolet Rays
D006861:Hydrogen Peroxide; D002401:Cathepsin B; D002402:Cathepsin D