Quantitative Evaluation of the Factors Affecting the Process of Fibroblast-Mediated Collagen Gel Contraction by Separating the Process into Three Phases

The role of glycochains of cell surface glycoproteins in the cell to collagen interaction was examined by studying the effect of lectins on the fibroblast-mediated collagen gel contraction. Lectins of Phaseolus vulgaris agglutinin (PHA), concanavalin A (ConA), lentil seed agglutinin (LCA), pea agglutinin (PSA), Ricinus communis agglutinin-60 (RCA), and wheat germ agglutinin (WGA) dose-dependently inhibited gel contraction, while lectins of mushroom agglutinin (ABA), peanut agglutinin (PNA), pokeweed mitogen (PWM), and soybean agglutinin (SBA) did not. Of these lectins, PHA seemed to be worthy of further analysis, because PHA, but not other lectins, inhibited spreading of fibroblasts on collagen fibrils but not on plastic or gelatin, suggesting that cell-surface glycoproteins responsive to the lectin are involved in the specific binding of fibroblasts to native collagen fibrils. The inhibitory effect of PHA-E4, an isolectin of PHA, was more intense than that of PHA-L4, another isolectin of PHA. The collagen gel contraction was also inhibited by tunicamycin and monensin in a concentration-dependent and reversible manner. These results strongly suggest that PHA-E4-reactive glycoproteins of the fibroblast surface play an important role in cell to collagen binding during the gel contraction. Five membrane proteins including beta 1 subunits of the integrin family were obtained by affinity chromatography with PHA-E4.

Download Full-text

Impaired collagen gel contraction with cultured skin fibroblasts from patients with systemic sclerosis

Scandinavian Journal of Rheumatology ◽

10.1080/030097400750001932 ◽

2000 ◽

Vol 29 (2) ◽

pp. 124-126

Author(s):

Noritsugu Morino, Toshihide Mimura,

Keyword(s):

Systemic Sclerosis ◽

Collagen Gel ◽

Skin Fibroblasts ◽

Cultured Skin ◽

Collagen Gel Contraction

Download Full-text

Matrix metalloproteinase-1 and -9 activation by plasmin regulates a novel endothelial cell-mediated mechanism of collagen gel contraction and capillary tube regression in three-dimensional collagen matrices

Journal of Cell Science ◽

10.1242/jcs.114.5.917 ◽

2001 ◽

Vol 114 (5) ◽

pp. 917-930 ◽

Cited By ~ 2

Author(s):

G.E. Davis ◽

K.A. Pintar ◽

Allen, R. Salazar ◽

S.A. Maxwell

Keyword(s):

Extracellular Matrix ◽

Endothelial Cells ◽

Endothelial Cell ◽

Three Dimensional ◽

Collagen Gel ◽

Plasminogen Activators ◽

Collagen Matrices ◽

Collagen Gel Contraction ◽

Blocking Antibodies ◽

Pai 1

Here, we describe a new function for plasmin and matrix metalloproteinases (MMPs), which is to regulate the regression of capillary tubes in three-dimensional extracellular matrix environments. Using a well-described capillary morphogenesis system in three-dimensional collagen matrices, a new model of capillary regression has been established by adding plasminogen to the culture medium. Plasminogen is converted to plasmin by endothelial cell plasminogen activators which then induces matrix metalloproteinase-dependent collagen gel contraction and capillary regression. Plasminogen addition results in activation of MMP-1 and MMP-9, which then results in collagen proteolysis followed by capillary regression. The endothelial cells undergo apoptosis following gel contraction as detected by flow cytometric analysis as well as by detectable caspase-3 cleavage and caspase-dependent cleavage of the actin cytoskeletal regulatory protein, gelsolin. In addition, directly correlating with the contraction response, tyrosine phosphorylation of p130cas, an adapter protein in the focal adhesion complex, is observed followed by disappearance of the protein. Proteinase inhibitors that block MMPs (TIMP-1 or TIMP-2), plasminogen activators (PAI-1) or plasmin (aprotinin) completely block the gel contraction and regression process. In addition, chemical inhibitors of MMPs that block capillary regression also block MMP-1 and MMP-9 activation suggesting that a key element in this regression response is the molecular control of MMP activation by endothelial cells. Blocking antibodies directed to MMP-1 or MMP-9 interfere with capillary regression while blocking antibodies directed to PAI-1 accelerate capillary regression suggesting that endogenous synthesis of PAI-1 negatively regulates this process. These data present a novel system to study a new mechanism that may regulate regression of capillary tubes, namely, plasmin and MMP-mediated degradation of extracellular matrix.

Download Full-text