Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2005-5-23
pubmed:abstractText
One of the early features of diabetic retinopathy is the alteration of the blood-retinal barrier (BRB), which may involve the breakdown of endothelial cell tight junctions. The aim of this study was to examine the expression of extracellular proteinases in an animal model of early diabetic retinopathy and to determine their role in the alteration of the BRB. Matrix metalloproteinase (MMP) expression was studied in the retinas of rats with 12 weeks of diabetes. The role of MMPs in regulating tight junction function was investigated in retinal endothelial and pigment epithelial cells by measuring transepithelial electrical resistance (TER). The retinas of diabetic animals demonstrated elevated levels of MMP-2, MMP-9 and MMP-14 messenger RNA. A significant increase in the production of MMP-9 was seen when cells were exposed to high glucose conditions. Both cell types treated with purified MMP-2 or MMP-9 were found to have alterations of tight junction function as shown by decreased TER. Western blot analysis of cell extracts treated with MMP-2 or MMP-9, revealed specific degradation of the tight junction protein, occludin. Results suggest that elevated expression of MMPs in the retina may facilitate an increase in vascular permeability by a mechanism involving proteolytic degradation of the tight junction protein occludin followed by disruption of the overall tight junction complex.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0023-6837
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
597-607
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:15711567-Animals, pubmed-meshheading:15711567-Blood-Retinal Barrier, pubmed-meshheading:15711567-Blotting, Western, pubmed-meshheading:15711567-Cattle, pubmed-meshheading:15711567-Cell Line, pubmed-meshheading:15711567-Cell Membrane Permeability, pubmed-meshheading:15711567-Diabetes Mellitus, Experimental, pubmed-meshheading:15711567-Diabetic Retinopathy, pubmed-meshheading:15711567-Disease Models, Animal, pubmed-meshheading:15711567-Dose-Response Relationship, Drug, pubmed-meshheading:15711567-Drug Combinations, pubmed-meshheading:15711567-Electric Impedance, pubmed-meshheading:15711567-Endothelium, Vascular, pubmed-meshheading:15711567-Gene Expression Regulation, Enzymologic, pubmed-meshheading:15711567-Glucose, pubmed-meshheading:15711567-Humans, pubmed-meshheading:15711567-Mannose, pubmed-meshheading:15711567-Matrix Metalloproteinases, pubmed-meshheading:15711567-Membrane Proteins, pubmed-meshheading:15711567-Pigment Epithelium of Eye, pubmed-meshheading:15711567-RNA, Messenger, pubmed-meshheading:15711567-Rats, pubmed-meshheading:15711567-Rats, Sprague-Dawley, pubmed-meshheading:15711567-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:15711567-Tight Junctions
pubmed:year
2005
pubmed:articleTitle
Matrix metalloproteinases in early diabetic retinopathy and their role in alteration of the blood-retinal barrier.
pubmed:affiliation
Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural