title: Inhibition of NAD(P)H oxidase reduces fibronectin expression in stroke-prone renovascular hypertensive rat brain.
abstract: 1. The aim of the present study was to test the hypothesis that in vivo chronic inhibition of NAD(P)H oxidase reduces cerebrovascular fibronectin expression in stroke-prone renovascular hypertensive rats (RHRSP). 2. The RHRSP model was induced by two clips and NAD(P)H oxidase was inhibited with apocynin. The mRNA and protein expression of NAD(P)H oxidase subunit p22(phox) in brains of RHRSP and Sprague-Dawley (control) rats was determined using real-time reverse transcription-polymerase chain reaction, western blot and immunohistochemistry. The expression of fibronectin protein was localized immunohistochemically in cerebral vessels and then quantified by western blot. 3. Cerebrovascular fibronectin levels in RHRSP (n = 6) were significantly higher than control (n = 5) levels 8 weeks after operation (1.29 +/- 0.04 vs 1.15 +/- 0.02, respectively; P = 0.007). The p22(phox) immunopositive reactivity was localized in the cerebral vasculature of control rats and RHRSP. Furthermore, chronic treatment of RHRSP with apocynin, a selective NAD(P)H oxidase inhibitor, in the drinking water for 4 weeks (1.5 mmol/L, 5 weeks after operation) resulted in a significant decrease in the expression of p22(phox) protein (0.85 +/- 0.01 vs 0.93 +/- 0.01 in non-treated RHRSP; n = 5; P = 0.002), with a concomitant reduction of fibronectin levels in the cerebral vasculature (1.31 +/- 0.03 vs 1.56 +/- 0.05 in non-treated RHRSP; n = 5; P = 0.002). No significant differences were detected in the expression of p22(phox) mRNA and protein between RHRSP (4 and 8 weeks after renal artery constriction) and the control group. 4. These findings suggest that the chronic inhibition of NAD(P)H oxidase in vivo by apocynin reduces cerebrovascular fibronectin levels, which may lessen hypertensive cerebrovascular fibrosis.
authors.affiliation: Stroke Center and Department of Neurology, First Affiliated Hospital, Sun Yat-Sen University, No. 58 Zhongshan 2 Road, Guangzhou 510080, China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Cui
authors.forename: Alex F
authors.initials: AF
authors.lastname: Chen
authors.forename: Zongpei
authors.initials: Z
authors.lastname: Jiang
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Wu
authors.forename: Jianwen
authors.initials: J
authors.lastname: Lin
authors.forename: Hongmei
authors.initials: H
authors.lastname: Wen
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Zeng
mesh_terms: D000098:Acetophenones / Q000008:administration & dosage / Q000494:pharmacology; D000284:Administration, Oral; D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D015153:Blotting, Western; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D002536:Cerebral Arteries / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism*; D006978:Hypertension, Renovascular / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D007150:Immunohistochemistry; D008297:Male; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020521:Stroke / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
chemical_list: D000098:Acetophenones; D004791:Enzyme Inhibitors; D005353:Fibronectins; C056165:acetovanillone; D006631:Amine Oxidase (Copper-Containing); D019255:NADPH Oxidases; C515768:Cyba protein, rat