REGULATION OF RETINAL PIGMENTED EPITHELIAL ECMS

Project: Research project

Description

As a step in unraveling the functions of the extracellular matricies (ECMs)
produced by the retina pigment epithelium (RPE) studies of the
proteoglycans and matrix metalloproteinases (MMPs) of cultured human RPE
cells are proposed. RPE cells are involved in the production and
maintenance of Bruch's membrane and the interphotoreceptor matrix. These
ECMs, which have been implicated in several retinal pathologies, have been
subjected to moderate scrutiny and several components have been identified. The studies presented in this proposal are focused on 1) the RPE
proteoglycans, 2) their biosynthesis and turnover and 3) the regulation of
these processes. Direct biochemical analysis, supplemented by studies with protein and anti-
peptide antibodies and oligonucleotide probes, will be used to characterize
RPE proteoglycan core proteins and their glycosaminoglycan sidechains.
Biochemical analysis, immunoprecipitation, immunoblots of Western
transfers, Northern analysis and dot blots will be used to study the
localization and interaction of these proteoglycans with RPE cells and to
establish their basal biosynthesis and turnover patterns. To investigate the initiation of ECM turnover, a family of MMPs will be
studied. RPE cells were shown to secrete MMP-1 (interstitial collagenase),
MMP-2 (gelatinase), MMP-3 (stromelysin) and the tissue inhibitor of
metalloproteinases (TIMP). Purification and characterization of the MMPs
including their substrate specificities, metal requirements, kinetics,
multiple glycosylation and activation forms, interactions with TIMPs and
activity upon RPE ECM components are proposed. These biochemical methods, antibodies and oligonucleotide probes will then
be used to investigate the regulation of the biosynthesis and turnover of
these and other ECM components by RPE cells. In addition to select
cellular modulators and growth factors, intact and degraded fragments of
several ECM components, particularly those containing "growth factor-like"
motifs, will be evaluated as potential regulators of the RPE and of its
ECMs. Understanding the nature and behavior of RPE ECMs, is an important
prerequisite for determining the functions and behaviors of these ECMs in
the normal and in the pathological retina.
StatusFinished
Effective start/end date8/1/897/31/94

Funding

  • National Institutes of Health: $119,670.00
  • National Institutes of Health: $133,237.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health

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retina
epithelium
pigments
interstitial collagenase
oligonucleotide probes
proteoglycans
metalloproteinases
biosynthesis
growth factors
stromelysin 1
cells
gelatinase A
antibodies
glycosaminoglycans
glycosylation
substrate specificity
proteins
metals
peptides
kinetics

ASJC

  • Medicine(all)