Linked Life Data

8282048

Source:http://linkedlifedata.com/resource/pubmed/id/8282048

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1994-2-15
pubmed:abstractText
Retinal capillaries are composed of endothelial cells resting on a basement membrane, in which are embedded pericytes. In diabetes mellitus, the basement membrane becomes thickened, and there is a loss of pericytes. The relative contributions of endothelial cells and pericytes to the synthesis of extracellular matrix proteins which are components of the basement membrane are not well-characterized. To determine how a selective loss of pericytes might affect the composition of retinal capillary basement membranes, we used primary cultures of bovine retinal capillary endothelial cells and pericytes to determine the forms and quantify the amounts of laminin and fibronectin synthesized and secreted by these cell types as well as to determine how high glucose concentrations alter these parameters. Results of ELISAs showed that pericyte cell/matrix layers contained nearly ten times more fibronectin than endothelial cells (288 +/- 24 vs. 34 +/- 5 ng micrograms-1 DNA, P < 0.001), but the amounts of laminin were similar. D-glucose (40 mM) tripled the amount of fibronectin incorporated into the endothelial cell/matrix layer (102 +/- 4 vs. 34 +/- 5 ng micrograms-1 DNA, P < 0.05), but had a lesser effect on pericytes. The non-metabolizable analogue L-glucose, also increased the amount of fibronectin incorporated in both pericyte and endothelial cell/matrix layers. The effects of D- and L-glucose on fibronectin secreted into the medium by both cell types were similar to the effects on incorporation of fibronectin into cell/matrix layers. Glucose had no effect on laminin synthesis. [35S]methionine radiolabeling and immunoprecipitation showed that pericytes and endothelial cells synthesize different forms of fibronectin. Both pericytes and endothelial cells synthesized an A and two B chains of laminin which were of similar apparent size, but the two cell types post-translationally modified the subunits differently. We conclude that pericytes and endothelial cells may contribute different forms and amounts of fibronectin and laminin to the retinal capillary basement membrane, so the preferential loss of pericytes in diabetes could result in basement membrane abnormalities which might lead to endothelial cell dysfunction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0014-4835
pubmed:author
pubmed:issnType
Print
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
609-21
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Regulation of fibronectin and laminin synthesis by retinal capillary endothelial cells and pericytes in vitro.
pubmed:affiliation
Diabetes Division, University of Texas Health Science Center at San Antonio 78284-7886.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't