Endothelin-1 is a potent stimulator of alpha1beta1 integrin-mediated collagen matrix remodeling by rat mesangial cells.
Endothelin-1 (ET) is known to stimulate mesangial cell (MC) proliferation, extracellular matrix (ECM) synthesis, and thereby contribute to the progression of glomerulonephritis (GN). To clarify the molecular and cellular mechanisms of how ET is involved in the development of glomerular sclerosis, we investigated the influence of ET on the MC-alpha1beta1 integrin-mediated collagen matrix reorganization using a collagen gel contraction assay. ET enhanced MC-alpha1beta1 integrin-mediated gel contraction in a dose-dependent manner. Addition of the endothelin A (ETA) receptor antagonist, BQ123, into collagen gels abolished ET-induced gel contraction by MC. Cell behavior involved in ET-induced gel contraction was investigated in combination with function-blocking anti-alpha1-integrin antibody. Migration and adhesion assays revealed that ET stimulated alpha1beta1 integrin-mediated MC migration but did not influence cell adhesion to type I collagen (collagen I). Integrin-function blocking studies using anti-alpha1 integrin antibody indicated that MC-alpha1beta1 integrin is required not only for collagen-dependent migration, but also for gel contraction. Zymography showed that ET increased MC matrix metalloproteinase-2 (MMP-2) activity in a dose-dependent manner during MC-induced gel contraction process. Finally, flow cytometry analysis indicated that ET did not affect the cell surface expression of the MC-alpha1beta1 integrin within the collagen gel. These data suggested that ET promotes collagen matrix reorganization through the enhancement of MC-alpha1beta1 integrin-dependent migration and MMP-2 activity. We therefore conclude that ET is a potential molecule inducing pathological collagen matrix remodeling observed in progressive GN.
Kitamura
A
A
Department of Pediatrics, School of Medicine, University of Tokushima, Kuramoto-cho-3-chome, Tokushima 770-8504, Japan.
Kagami
S
S
Urushihara
M
M
Kondo
S
S
Yoshizumi
M
M
Tamaki
T
T
Kuroda
Y
Y
D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000378:metabolism / Q000494:pharmacology*; D005782:Gels / Q000737:chemistry; D005920:Glomerular Mesangium / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D039222:Integrin alpha1beta1 / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D019332:Endothelin-1; D005782:Gels; D039222:Integrin alpha1beta1; D003094:Collagen; D020778:Matrix Metalloproteinase 2