Metallothionein protects retinal pigment epithelial cells against apoptosis and oxidative stress.
The retina expresses metallothionein (MT) which has been reported to protect cells against oxidative stress and apoptosis. The types of MT expressed by human retinal cells were identified by laser capture microdissection and RT--PCR and it was found that MT-2a is expressed by retinal pigment epithelial (RPE) cells, photoreceptor cells, inner nuclear layer cells and ganglion cells while MT-1a is expressed by RPE cells and MT-3 by cells of the neural retina. MT is induced in cultured human RPE cells under stress conditions such as the presence of glucocorticoids, interleukin-1/TNF alpha, oxygen and TGF beta 1. Cultured human D407 RPE cells were transfected with plasmids that allowed the expression of MT to be controlled via the tet operator protein by the level of tetracycline in the medium. These experiments showed that elevation of MT levels by transfection of RPE cells protects them against toxic levels of cadmium, heme- and iron-induced oxidation and UV light-induced apoptosis.
Lu
Huasheng
H
Department of Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC 29208, USA.
Hunt
Diana Margaret
DM
Ganti
Ramapriya
R
Davis
Alberta
A
Dutt
Kamla
K
Alam
Jawed
J
Hunt
Richard C
RC
D017209:Apoptosis / Q000502:physiology* / Q000528:radiation effects; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology* / Q000502:physiology; D005786:Gene Expression Regulation; D006801:Humans; D007124:Immunoenzyme Techniques; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018384:Oxidative Stress / Q000502:physiology*; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014466:Ultraviolet Rays
D012333:RNA, Messenger; D008668:Metallothionein