Systemic sclerosis fibroblasts inhibit in vitro angiogenesis by MMP-12-dependent cleavage of the endothelial cell urokinase receptor.
Failure of endothelial cells to develop new vessels in response to hypoxia is a distinctive feature of systemic sclerosis (SSc) in the avascular phase. We have previously shown that SSc endothelial cells over-express matrix metalloproteinase-12 (MMP-12), which blocks angiogenesis by cleavage of the endothelial urokinase-type plasminogen activator receptor (uPAR). In the present study, we have investigated whether over-expression of MMP-12 and of angiostatic factors, or hypo-expression of angiogenic factors by SSc fibroblasts, contributes to impaired angiogenesis in SSc. Dermal fibroblasts were isolated from healthy subjects (N-Fb) and patients with diffuse SSc (SSc-Fb). Angiogenesis of target normal human microvascular endothelial cells (H-MVECs) was assayed by Matrigel invasion, cell proliferation, and capillary morphogenesis. uPAR cleavage and MMP-12 activity were evaluated by western blotting. We show that the over-expression of MMP-12 by SSc-Fb determines uPAR cleavage in H-MVECs. Conditioned medium from SSc-Fb impaired H-MVEC proliferation, invasion, and capillary morphogenesis. Anti-MMP-12 antibodies restored such impairment. Altered expression of angiostatic/angiogenic factors, including transforming growth factor beta1, did not account for SSc-Fb-dependent impairment of angiogenesis. The over-expression of MMP-12 by both SSc-Fb and SSc endothelial cells indicates that MMP-12 over-production may have a critical pathogenic role in SSc-associated vascular alterations.
Serratì
S
S
Department of Experimental Pathology and Oncology - DENOTHE, Centre for the Study at Molecular and Clinical Level of Chronic, Degenerative and Neoplastic Diseases to Develop Novel Therapies, University of Florence, Italy.
Cinelli
M
M
Margheri
F
F
Guiducci
S
S
Del Rosso
A
A
Pucci
M
M
Fibbi
G
G
Bazzichi
L
L
Bombardieri
S
S
Matucci-Cerinic
M
M
Del Rosso
M
M
D015153:Blotting, Western; D049109:Cell Proliferation; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D003094:Collagen; D017077:Culture Media, Conditioned; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005347:Fibroblasts / Q000502:physiology*; D006801:Humans; D007797:Laminin; D008297:Male; D053508:Matrix Metalloproteinase 12 / Q000096:biosynthesis / Q000502:physiology*; D018919:Neovascularization, Physiologic; D011509:Proteoglycans; D011956:Receptors, Cell Surface / Q000378:metabolism*; D055293:Receptors, Urokinase Plasminogen Activator; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012595:Scleroderma, Systemic / Q000378:metabolism / Q000503:physiopathology*
D017077:Culture Media, Conditioned; D004338:Drug Combinations; D007797:Laminin; C524898:PLAUR protein, human; D011509:Proteoglycans; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; C059485:matrigel; D003094:Collagen; D053508:Matrix Metalloproteinase 12