title: Inhibition of cyclooxygenase-2 modulates phenotypic switching of vascular smooth muscle cells during increased aortic blood flow.
abstract: This study investigates the interactions between cyclooxygenase (COX-2) and vascular smooth muscle cell (VSMC) phenotypic switching, the two important coupling mechanisms of the vasculature on arterial remodeling in response to high laminal shear stress. High aortic blood flow was induced by creating a fistula in the abdominal aorta and the adjacent IVC of anesthetized rats. Celecoxib, a selective COX-2 inhibitor (25 mg/kg/day), was fed in the chow, and animals were killed 8 weeks later. Blood flow, vasoreactivity and morphological changes in the aorta proximal to the fistula were measured. Concentrations of collagen, expression of desmin and smooth muscle myosin heavy chain (SM-MHC)-II in the aorta were determined. Celecoxib significantly increased aortic blood flow and reduced the contraction responses of aorta. Decreased medial thickness, presence of intimal thickening and derangement of elastic lamina were found in the aortic section of celecoxib-treated animals. Celecoxib significantly reduced the tissue content of collagen and upregulated expression of SM-MHC-II and desmin in the high-flow aorta. Inhibition of COX-2 enzymatic activity in the aorta exposed to higher blood flow resulted in increased blood flow and vascular remodeling. These functional changes were accomplished by VSMC phenotypic switching and reduced biosynthesis of collagen.
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Tainan Municipal Hospital, Tainan, Taiwan.
authors.forename: Jun-Neng
authors.initials: JN
authors.lastname: Roan
authors.forename: Yu-Chuan
authors.initials: YC
authors.lastname: Tsai
authors.forename: I-Wen
authors.initials: IW
authors.lastname: Chen
authors.forename: Shih-Wei
authors.initials: SW
authors.lastname: Chang
authors.forename: Chien-Chi
authors.initials: CC
authors.lastname: Huang
authors.forename: Chen-Fuh
authors.initials: CF
authors.lastname: Lam
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000201:enzymology / Q000503:physiopathology; D001164:Arteriovenous Fistula / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D000068579:Celecoxib; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D052246:Cyclooxygenase 2 Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D003893:Desmin / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D018995:Myosin Heavy Chains / Q000378:metabolism; D024462:Myosin Type II / Q000378:metabolism; D010641:Phenotype; D011720:Pyrazoles / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D003893:Desmin; D011720:Pyrazoles; D013449:Sulfonamides; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; D024462:Myosin Type II; D018995:Myosin Heavy Chains; D000068579:Celecoxib