title: Heat shock induces apoptosis through reactive oxygen species involving mitochondrial and death receptor pathways in corneal cells.
abstract: Although many studies have been performed to elucidate the molecular consequences of ultraviolet irradiation, little is known about the effect of infrared radiation on ocular disease. In addition to photons, heat is generated as a consequence of infrared irradiation, and heat shock is widely considered to be an environmental stressor. Here, we are the first to investigate the biological effect of heat shock on Statens Seruminstitut Rabbit Cornea (SIRC) cells. Our results indicate that heat shock exhibits effective cell proliferation inhibition by inducing apoptosis. Heat shock triggers the mitochondrial apoptotic pathway indicated by a change in Bax/Bcl-2 ratios, resulting in caspase-9 activity. In addition, heat shock triggered the death receptor apoptotic pathway indicated by a change in Fas ligand expression, resulting in caspase-8 activity. Furthermore, we also found that generation of reactive oxygen species (ROS) is a critical mediator in heat shock-induced apoptosis. In addition, the antioxidant vitamin C significantly decreased heat shock-mediated apoptosis. Taken together, these findings suggest a critical role for ROS involving mitochondrial and death receptor pathways in heat shock-mediated apoptosis of cornea cells.
authors.affiliation: Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Hsu
authors.forename: Hsin-Su
authors.initials: HS
authors.lastname: Yu
authors.forename: Hsien-Chung
authors.initials: HC
authors.lastname: Lin
authors.forename: Kwou-Yeung
authors.initials: KY
authors.lastname: Wu
authors.forename: Rei-Cheng
authors.initials: RC
authors.lastname: Yang
authors.forename: Po-Lin
authors.initials: PL
authors.lastname: Kuo
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects*; D020169:Caspases / Q000378:metabolism; D049109:Cell Proliferation / Q000528:radiation effects; D002478:Cells, Cultured; D060527:Corneal Keratocytes / Q000378:metabolism / Q000473:pathology*; D004591:Electrophoresis, Polyacrylamide Gel; D053222:Fas Ligand Protein / Q000378:metabolism; D006358:Hot Temperature; D020287:In Situ Nick-End Labeling; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D053218:Receptors, Death Domain / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013997:Time Factors
chemical_list: D053222:Fas Ligand Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D053218:Receptors, Death Domain; D020169:Caspases