Adenovirus mediated gene delivery of tissue inhibitor of metalloproteinases-3 induces death in retinal pigment epithelial cells.
BACKGROUND
Sorsby's fundus dystrophy (SFD) and age related macular degeneration (ARMD) are retinal diseases associated with a high level of accumulation of mutant and wild type TIMP-3, respectively, in Bruch's membrane. The pathogenic role of TIMP-3 in these diseases is uncertain, but causative mutations have been identified in the TIMP-3 gene of patients with SFD. Recent reports that TIMP-3 causes apoptosis in certain cell types and not in others prompted the authors to investigate whether TIMP-3 causes apoptosis in cultured retinal pigment epithelium (RPE) cells.


METHODS
RPE and MCF-7 cells (as a positive control) were initially infected with replication deficient adenovirus, to overexpress beta-galactosidase (RAdLacZ) or TIMP-3 (RAdTIMP-3). TIMP-3 was detected by western blotting and ELISA. Cell viability was defined by cell counts. ISEL was used to investigate the mechanism of cell death.


RESULTS
Cultured RPE cells produced small quantities of endogenous TIMP-3 and remained viable. However, overexpression of TIMP-3 caused a dose related death of RPE cells. The mechanism of cell death was apoptosis.


CONCLUSIONS
The previously unreported finding of TIMP-3 induced apoptosis of RPE cells may account for some of the early features seen in SFD and ARMD.
Majid
Mohammed A
MA
Institute of Ophthalmology, University of Bristol, Bristol Eye Hospital, Lower Maudlin Street Bristol BS1 2LX, UK.
Smith
Valerie A
VA
Easty
David L
DL
Baker
Andrew H
AH
Newby
Andrew C
AC
D000256:Adenoviridae / Q000235:genetics; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D002452:Cell Count; D002460:Cell Line; D002470:Cell Survival; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005654:Fundus Oculi; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D010857:Pigment Epithelium of Eye / Q000473:pathology*; D012164:Retinal Diseases / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism*; D014161:Transduction, Genetic / Q000379:methods; D019076:Transgenes / Q000235:genetics; D014407:Tumor Cells, Cultured
D019717:Tissue Inhibitor of Metalloproteinase-3