Synthetic smooth muscle cell phenotype is associated with increased nicotinamide adenine dinucleotide phosphate oxidase activity: effect on collagen secretion.
OBJECTIVE
Smooth muscle cells (SMCs) from prosthetic vascular grafts secrete higher levels of collagen than aortic SMCs under basal conditions and during incubation with oxidized low-density lipoprotein. We postulated that reactive oxygen species (ROS) contributed to the observed difference. The objective of this study was to assess the effect of ROS on collagen secretion by aortic and graft SMCs and explore the mechanism involved.


METHODS
SMCs isolated from canine aorta or Dacron thoracoabdominal grafts were incubated with 6-anilinoquinoline-5,8-quinone (LY83583), an agent that induces superoxide production. Type I collagen in the conditioned medium was measured by enzyme-linked immunosorbent assay, and superoxide anion production was measured by lucigenin assay.


RESULTS
LY83583 stimulated a rapid increase in collagen production by graft SMCs that paralleled the LY83583-induced increase in superoxide production. The increase in both collagen and superoxide was greater in graft SMCs than aortic SMCs. Collagen and superoxide production were inhibited by superoxide scavengers. Nicotinamide adenine dinucleotide phosphate (NADPH) induced significantly more superoxide production by graft SMCs than aortic SMCs, suggesting that the NADPH oxidase system was more active in graft SMCs. NADPH oxidase inhibitors blocked the superoxide and collagen production induced by LY83583.


CONCLUSIONS
In SMCs, the synthetic phenotype is associated with increased NADPH oxidase activity and elevated superoxide production in response to an oxidative stress. Superoxide, in turn, leads to increased collagen production.


CONCLUSIONS
The inflammatory process after prosthetic vascular graft implantation causes oxidative stress that can stimulate collagen production by graft SMCs, contributing to the progression of intimal hyperplasia. The exaggerated response of graft SMCs to oxidative stress offers a potential target for therapeutic interventions.
Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Rajendra
R
Patel
Jeffry D
JD
Cardneau
Scott M
SM
Colles
Linda M
LM
Graham
D000634:Aminoquinolines / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism*; D003408:Cresols / Q000494:pharmacology; D003497:Cyclic N-Oxides / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D006830:Hydralazine / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009861:Onium Compounds / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D010641:Phenotype; D011093:Polyethylene Terephthalates; D011474:Prosthesis Design; D013481:Superoxides / Q000378:metabolism*; D013997:Time Factors; D015854:Up-Regulation
D000634:Aminoquinolines; D024042:Collagen Type I; D003408:Cresols; D003497:Cyclic N-Oxides; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D009861:Onium Compounds; D011093:Polyethylene Terephthalates; D013481:Superoxides; D006830:Hydralazine; C007517:diphenyleneiodonium; C041715:6-anilino-5,8-quinolinedione; D019255:NADPH Oxidases; C003959:TEMPO; C034047:2-cresol