Platelet isoforms of platelet-derived growth factor stimulate fibroblasts to contract collagen matrices.
Fibroplasia and angiogenesis are essential components of tissue repair when substantial tissue has been lost at a site of injury. Platelets and monocyte/macrophages accumulate at these sites and release a variety of growth factors that are thought to initiate and sustain the repair. Often the involved tissue contracts, a process that can markedly reduce the amount of fibroplasia and angiogenesis necessary for the reestablishment of organ integrity. Such tissue contraction occurs over hours or days, a much slower time course than the rapid, reversible contraction of muscle tissue. Fibroblasts, which are rich in f-actin bundles, appear to be responsible for wound contraction. However, the signals that stimulate contraction are not known. Using cultured fibroblasts, which are also rich in f-actin bundles, we demonstrate the platelet and monocyte isoforms of platelet-derived growth factor (PDGF; AB and BB) but not PDGF-AA, can stimulate fibroblasts to contract collagen matrix in a time course similar to that of wound contraction. In addition, PDGF appears to be the predominant fibroblast/collagen gel contraction activity released from platelets. Vasoactive agonists known to stimulate smooth and striated muscle contraction do not stimulate fibroblast-driven collagen gel contraction.
Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206.
R A
RA
Clark
J M
JM
Folkvord
C E
CE
Hart
M J
MJ
Murray
J M
JM
McPherson
D008841:Actin Cytoskeleton / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000502:physiology*; D003238:Connective Tissue / Q000502:physiology; D005109:Extracellular Matrix / Q000276:immunology*; D005347:Fibroblasts / Q000502:physiology*; D005782:Gels; D006801:Humans; D010982:Platelet-Derived Growth Factor / Q000031:analogs & derivatives / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology
D005782:Gels; D010982:Platelet-Derived Growth Factor; D011994:Recombinant Proteins; D003094:Collagen