IOVS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Originally published In Press as doi:10.1167/iovs.07-1666 on July 18, 2008
 (Investigative Ophthalmology and Visual Science. 2008;49:5353-5365.)
© 2008 by The Association for Research in Vision and Ophthalmology, Inc.
DOI:  10.1167/iovs.07-1666
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Movies
Right arrow All Versions of this Article:
iovs.07-1666v1
49/12/5353    most recent
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Google Scholar
Right arrow Articles by Aga, M.
Right arrow Articles by Acott, T. S.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Aga, M.
Right arrow Articles by Acott, T. S.

Specialized Podosome- or Invadopodia-like Structures (PILS) for Focal Trabecular Meshwork Extracellular Matrix Turnover

Mini Aga, John M. Bradley, Kate E. Keller, Mary J. Kelley, and Ted S. Acott

From the Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.

PURPOSE. There are distinctive areas of colocalization of matrix metalloproteinase (MMP)-2 and -14 on trabecular meshwork (TM) cells that resemble podosomes or invadopodia. Studies were conducted to determine whether TM cells exhibit podosome- or invadopodia-like structures (PILS) and whether they produce focal extracellular matrix (ECM) turnover.

METHODS. Porcine and human TM cells and perfused anterior segment organ cultures were studied. Localization of PILS components on TM cells and in sections from anterior segments was determined by immunohistochemistry and confocal microscopy. Cells were grown on type I collagen labeled with fluorescein isothiocyanate (FITC) for degradation analysis. Confocal time lapse images were taken of labeled TM cells on FITC-collagen.

RESULTS. Immunostaining for MMP-2, MMP-14, and the typical PILS components cortactin, caldesmon, {alpha}-actinin, N-WASP, Arp-3, and cdc42 colocalized on these distinctive structures. Integrin-{alpha}V and -β1, fibronectin, and versican colocalized with PILS components. TM cells on FITC-conjugated collagen developed focal regions of degradation. Time-lapse imaging showed dramatic and controlled movement of TM cell processes during this ECM degradation and fragment internalization. MMP-2, MMP-14, and cortactin colocalized at regions that appear to be PILS on cells within the outflow pathway in sections of human anterior segments.

CONCLUSIONS. TM cells exhibit areas where PILS components colocalize with MMP-2 and -14. Similar structures are found in sections, suggesting that PILS occur in situ in the outflow pathway. The collagen degradation suggests that PILS may serve as focal sites for targeted ECM turnover, an event linked to modifications of aqueous outflow resistance and intraocular pressure homeostasis.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2008 by the Association for Research in Vision and Ophthalmology