The mRNA phenotype of a human RPE cell line at replicative senescence.
OBJECTIVE
To explore the changes in expression of a set of genes in a single retinal pigment epithelial (RPE) cell line and two fibroblast cell lines as controls under culture conditions previously used for the analysis of senescent gene expression.


METHODS
A single human RPE cell line, which had previously been characterized using known markers of senescence, and two fibroblast cell lines were grown to replicative exhaustion. The mRNA phenotype of genes known to be altered by senescence were studied by quantitative Northern analysis.


RESULTS
The mRNA phenotype of cells changes at replicative senescence yielding a synthetic phenotype which is similar to cells found in repairing wounds. Of the genes studied, urokinase-type plasminogen activator and plasminogen activator inhibitor-1 were regulated in RPE cells similar to fibroblasts at senescence. The largest changes noted for any single gene were the upregulation of insulin growth factor binding protein 2, and the downregulation of collagen I alpha 2, basic fibroblast growth factor, and fibroblast growth factor-5.


CONCLUSIONS
This study demonstrates an altered mRNA phenotype of a human RPE cell line grown to replicative exhaustion. This analysis of a single cell line emphasizes the variability of results based on a single cell line or tissue specimen and indicates the need for additional study.
Matsunaga
H
H
Department of Ophthalmology, University of California-Davis, Davis, CA 95616-8794, USA.
Handa
J T
JT
Gelfman
C M
CM
Hjelmeland
L M
LM
D015152:Blotting, Northern; D002455:Cell Division; D002460:Cell Line; D016922:Cellular Senescence; D003094:Collagen / Q000378:metabolism; D024042:Collagen Type I; D005136:Eye Proteins; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D051521:Fibroblast Growth Factor 5; D005346:Fibroblast Growth Factors / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D015870:Gene Expression; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000378:metabolism; D006801:Humans; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000378:metabolism; D009414:Nerve Growth Factors; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D011509:Proteoglycans / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015843:Serpins / Q000378:metabolism; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism; D000099174:Pigment Epithelium-Derived Factor
D003094:Collagen; D024042:Collagen Type I; D005136:Eye Proteins; D016222:Fibroblast Growth Factor 2; D051521:Fibroblast Growth Factor 5; D005346:Fibroblast Growth Factors; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D018971:Insulin-Like Growth Factor Binding Protein 2; D009414:Nerve Growth Factors; D017395:Plasminogen Activator Inhibitor 1; D011506:Proteins; D011509:Proteoglycans; D012333:RNA, Messenger; D015843:Serpins; D019717:Tissue Inhibitor of Metalloproteinase-3; D014568:Urokinase-Type Plasminogen Activator; D000099174:Pigment Epithelium-Derived Factor; C496449:FGF5 protein, human; C071927:perlecan