Adenovirus mediated gene delivery of tissue inhibitor of metalloproteinases-3 induces death in retinal pigment epithelial cells
- 1Institute of Ophthalmology, University of Bristol, Bristol Eye Hospital, Lower Maudlin Street Bristol BS1 2LX, UK
- 2Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Marlborough Road, Bristol BS2 8HW, UK
- Correspondence to: Mohammed A Majid, Institute of Ophthalmology, University of Bristol, Bristol Eye Hospital, Lower Maudlin St, Bristol BS1 2LX, UK; m.a.majid{at}bris.ac.uk
- Accepted 22 August 2001
Abstract
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 β-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.
Conclusion: 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.
