HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Alcazar, O. Articles by Marin-Castaño, M. E. Search for Related Content PubMed PubMed Citation Articles by Alcazar, O. Articles by Marin-Castaño, M. E.

MMP-14 and TIMP-2 Overexpression Protects against Hydroquinone-Induced Oxidant Injury in RPE: Implications for Extracellular Matrix Turnover

¹From the Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida; and the ²Duke Center for Macular Diseases, Duke University Eye Center, Durham, North Carolina.

PURPOSE. To investigate whether overexpression of MMP-14 and/or TIMP-2 would overcome the effect of nonlethal oxidant injury with hydroquinone (HQ) on MMP-2 activity.

METHODS. Human MMP-14 and TIMP2 cDNA were cloned into a mammalian expression vector. Transient transfections were performed on human ARPE-19 cells. The cells were incubated 48 hours after transfection with a nonlethal dose of HQ for either 6 or 18 hours and then were collected for protein determination or RNA isolation. MMP-2 protein and activity were determined by Western blot and zymography. The extracellular matrix (ECM) components type I and type IV collagen and laminin were analyzed by Western blot analysis and real-time PCR.

RESULTS. HQ for 6 hours modestly decreased MMP-2. MMP-2 recovered only after co-overexpression of MMP-14 and TIMP-2, but activity further decreased after HQ for 18 hours. MMP-14 or TIMP-2 overexpression alone contributed as much as the co-overexpression to the recovery of MMP-2 activity. MMP-2 protein seemed not to be altered. Type I collagen and laminin transcriptional levels remained unaffected, whereas type IV collagen transcripts decreased with HQ. Transfection with MMP-14 and/or TIMP-2 contributed to the return of type IV collagen levels to normal. On the other hand, type I and IV collagens and laminin protein accumulated after HQ treatment, an effect prevented by transfection.

CONCLUSIONS. MMP-14 and TIMP2 contribute to the maintenance of adequate levels of MMP-2 activity in ARPE-19 cells after oxidant injury. In addition, changes in ECM components may result as a consequence of MMP-2 activity and may be relevant to the progression of dry AMD.