Oxygen modulates the release of urokinase and plasminogen activator inhibitor-1 by retinal pigment epithelial cells

Jonathan T. Erichsen, John Jarvis-Evans, Asud Khaliq, Mike Boulton

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The aims of this study were to examine the effect of oxygen, in the presence or absence of exogenous growth factors, on the release of plasminogen activators and plasminogen activator inhibitor-1 by cultured human retinal pigment epithelial cells. Antigen and activity levels of urokinase, tissue plasminogen activator and plasminogen activator inhibitor were measured in conditioned media after cells were exposed to three different oxygen environments: hypoxia, normoxia and hyperoxia. Overall proteolytic balance was determined by zymography. The effects of exogenous basic fibroblast growth factor and transforming growth factor-beta were also examined. it was found that retinal pigment epithelial cells released urokinase, tissue plasminogen activator and plasminogen activator inhibitor in measurable quantities. After 48 h, urokinase levels were highest at normoxia, reaching 7.2ng/106 cells ( ± 2.0 SEM), whereas plasminogen activator inhibitor 1 levels were highest at hyperoxia, reaching 67.5ng/106 cells ( ± 3.7 SEM). Tissue plasminogen activator levels were minimal ( <0.5ng/106 cells) and unaffected by both oxygen and growth factors. Overall proteolytic activity was also greatest at normoxia. Fibroblast growth factor stimulated urokinase production dose-dependently, but plasminogen activator inhibitor only minimally. Transforming growth factor-beta stimulated plasminogen activator inhibitor production dose-dependently but urokinase only at higher concentrations. These results suggest that both oxygen tension and growth factors may interact to modulate the proteolytic properties of the human retinal pigment epithelium.

Original languageEnglish (US)
Pages (from-to)237-247
Number of pages11
JournalInternational Journal of Biochemistry and Cell Biology
Volume33
Issue number3
DOIs
StatePublished - 2001
Externally publishedYes

Fingerprint

Retinal Pigments
Plasminogen Activator Inhibitor 1
Urokinase-Type Plasminogen Activator
Plasminogen Inactivators
Epithelial Cells
Oxygen
Tissue Plasminogen Activator
Intercellular Signaling Peptides and Proteins
Hyperoxia
Transforming Growth Factor beta
Scanning electron microscopy
Fibroblast Growth Factors
Retinal Pigment Epithelium
Plasminogen Activators
Fibroblast Growth Factor 2
Conditioned Culture Medium
Antigens

Keywords

  • Oxygen
  • Plasminogen activator
  • Plasminogen activator inhibitor-1
  • Retinal pigment epithelial cells

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology

Cite this

Oxygen modulates the release of urokinase and plasminogen activator inhibitor-1 by retinal pigment epithelial cells. / Erichsen, Jonathan T.; Jarvis-Evans, John; Khaliq, Asud; Boulton, Mike.

In: International Journal of Biochemistry and Cell Biology, Vol. 33, No. 3, 2001, p. 237-247.

Research output: Contribution to journalArticle

Erichsen, Jonathan T. ; Jarvis-Evans, John ; Khaliq, Asud ; Boulton, Mike. / Oxygen modulates the release of urokinase and plasminogen activator inhibitor-1 by retinal pigment epithelial cells. In: International Journal of Biochemistry and Cell Biology. 2001 ; Vol. 33, No. 3. pp. 237-247.
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