Faculty Collaboration Database

Maspin increases extracellular plasminogen activator activity associated with corneal fibroblasts and myofibroblasts. Exp Eye Res 2011 Nov;93(5):618-27

Date

08/04/2011

Pubmed ID

21810423

Pubmed Central ID

PMC3221939

DOI

10.1016/j.exer.2011.07.008

Scopus ID

2-s2.0-81355161428 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

Maspin, an inhibitor of cell migration and a stimulator of adhesion of cells to the ECM, is synthesized and released by corneal keratocytes into the extracellular matrix. When the cornea is wounded, the quiescent stromal keratocytes underlying the wound undergo apoptosis and cells adjacent to this apoptotic area convert to fibroblasts or myofibroblasts. This study explores the effect of extracellular maspin on the plasminogen-plasminogen activator system of corneal stromal cells following wounding. Treatment of corneal fibroblasts and myofibroblasts with r-maspin increased extracellular but not cell-associated tissue-type plasminogen activator (tPA), urinary-type plasminogen activator (uPA) or plasminogen activator inhibitor-1 (PAI-1). Despite the extracellular increase in PAI-1, the net effect of maspin treatment was an increase in plasminogen activation. At physiological levels, maspin did not alter uPA or tPA mRNA levels, in these cells. The increase in pro and active uPA was due to decreased clearance in the presence of maspin for myofibroblasts but not for fibroblasts. The clearance of pro and active tPA was normal in fibroblasts indicating different mechanisms for the increase of these homologous enzymes in the two cell types. Increased generation of plasmin by maspin treated corneal stromal fibroblasts and myofibroblasts led to conversion of plasminogen to active plasmin degradation products and angiostatin-like molecules. This study suggests that extracellular maspin increased pro and active uPA and tPA released by corneal fibroblasts and myofibroblasts on the short time scale of 1-4 h, but by 24 h there was no increase over the levels produced without maspin. This augmentation of plasminogen activator activity increases plasmin activation and angiostatin generation. It further indicates that the effect of maspin on uPA and tPA levels is cell type dependent.

Author List

Warejcka DJ, Narayan M, Twining SS

Author

Sally S. Twining PhD Assistant Dean, Professor in the Biochemistry department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Angiostatins
Blotting, Western
Cells, Cultured
Corneal Stroma
Cycloheximide
Fibroblasts
Humans
Myofibroblasts
Plasminogen Activator Inhibitor 1
Plasminogen Activators
Real-Time Polymerase Chain Reaction
Recombinant Proteins
Serine Proteinase Inhibitors
Serpins
Tissue Plasminogen Activator
Urokinase-Type Plasminogen Activator
Wound Healing