Angiotensin II and PDGF-BB stimulate beta(1)-integrin-mediated adhesion and spreading in human VSMCs.
beta(1)-Integrins play an important role for adhesion and spreading of human smooth muscle cells. In the present study we examined the influence of angiotensin II and platelet-derived growth factor (PDGF)-BB on beta(1)-integrin-dependent functions of human smooth muscle cells obtained from iliac arteries. Treatment of these cells with PDGF-BB (20 ng/mL) and Angiotensin II (1 micromol/L) did not change beta(1)-integrin expression up to 48 hours as analyzed by flow cytometry and reverse transcription polymerase chain reaction. beta(1)-integrins predominantly mediated adhesion of human smooth muscle cells to collagen I (79.7+/-4.4%, P<0.01) and fibronectin (66. 6+/-2.4%, P<0.01). Treatment of smooth muscle cells with Angiotensin II (1 micromol/L) and PDGF-BB (20 ng/mL) significantly increased the adhesion to collagen I by 56.5% and 44.3%, respectively, and to fibronectin by 49.6% and 36.4%, respectively (all P<0.05). Angiotensin II-induced effects were mediated by the AT(1) receptor. The PDGF-BB mediated increase of adhesion was inhibited in the presence of genestein, a tyrosine-kinase inhibitor and by protein kinase C downregulation with phorbol 12-myristate 13-acetate. Spreading of smooth muscle cells also was beta(1)-integrin dependent on collagen I and alpha(5)beta(1)-integrin dependent on fibronectin. Angiotensin II and PDGF-BB increased cell spreading on fibronectin up to 276% and 318%, respectively, and on collagen I up to 133% and 138% (all P<0.05). These increases were significantly inhibited by blocking antibodies against beta(1)-integrin, alpha(5)-integrin on fibronectin, the AT(1) receptor blocker irbesartan, and genestein. The present data demonstrate that angiotensin II and as well PDGF-BB enhance beta(1)-integrin-dependent adhesion and spreading of human vascular smooth muscle cells. Furthermore, the experiments with PDGF suggest an involvement of protein kinase C activation leading to these enhanced effects.
Kappert
K
K
Department of Medicine/Cardiology, Charité, Campus Virchow Klinikum, Humboldt Universität Berlin and Deutsches Herzzentrum Berlin, Germany.
Schmidt
G
G
Doerr
G
G
Wollert-Wulf
B
B
Fleck
E
E
Graf
K
K
D000804:Angiotensin II / Q000494:pharmacology*; D000925:Anticoagulants / Q000494:pharmacology*; D015703:Antigens, CD / Q000235:genetics; D000959:Antihypertensive Agents / Q000494:pharmacology; D001011:Aorta / Q000166:cytology; D000077214:Becaplermin; D001713:Biphenyl Compounds / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D003094:Collagen / Q000494:pharmacology; D046508:Culture Techniques; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005353:Fibronectins / Q000494:pharmacology; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D007083:Iliac Artery / Q000166:cytology; D007093:Imidazoles / Q000494:pharmacology; D039482:Integrin alpha5; D019012:Integrin beta1 / Q000235:genetics; D000077405:Irbesartan; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D020574:Proto-Oncogene Proteins c-sis; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013777:Tetrazoles / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D000925:Anticoagulants; D015703:Antigens, CD; D000959:Antihypertensive Agents; D001713:Biphenyl Compounds; D002273:Carcinogens; D004791:Enzyme Inhibitors; D005353:Fibronectins; D007093:Imidazoles; D039482:Integrin alpha5; D019012:Integrin beta1; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D011725:Pyridines; D012333:RNA, Messenger; D013777:Tetrazoles; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; C073402:PD 123319; D000077214:Becaplermin; D003094:Collagen; D019833:Genistein; D000077405:Irbesartan; D013755:Tetradecanoylphorbol Acetate