BACKGROUND: The over-production of superoxide (O(2)(-)) derived from NADPH oxidase (NOX) plays a central role in cardiovascular diseases. By contrast, nitric oxide (NO) and prostacyclin (PGI(2)) are vasculoprotective. The effect of the NO donor, NONOate and iloprost on O(2)(-) formation, p47(phox) and Rac(1) activation in human vascular smooth muscle cells (hVSMCs) was investigated. METHODS: hVSMCs were incubated with 10nM thromboxane A(2) analogue, U46619 for 16h, and then with apocynin (a NOX inhibitor), NONOate or iloprost for 1h and O(2)(-) measured spectrophometrically. The role of cyclic AMP and cyclic GMP was examined by co-incubation of drugs with protein kinase (PK) A and G inhibitors listed above. Rac(1) was studied using pull-down assays. RESULTS: NONOate and iloprost inhibited O(2)(-) formation, acutely, effects blocked by inhibition of PKG and PKA, respectively. Rac(1) and p47(phox) activation and translocation to the plasma membrane was completely inhibited by NONOate and iloprost, effects again reversed by co-incubation with PKG or PKA inhibitors. CONCLUSIONS: NO and PGI(2) block the acute activity of NOX in hVSMCs via the cGMP-PKG axis (for NO) and by the cAMP-PKA axis (for iloprost) through inhibition of Rac(1) and p47(phox) translocation. These findings have implications in the pathophysiology and treatment of CVD.
BACKGROUND: The over-production of superoxide (O(2)(-)) derived from NADPH oxidase (NOX) plays a central role in cardiovascular diseases. By contrast, nitric oxide (NO) and prostacyclin (PGI(2)) are vasculoprotective. The effect of the NO donor, NONOate and iloprost on O(2)(-) formation, p47(phox) and Rac(1) activation in human vascular smooth muscle cells (hVSMCs) was investigated. METHODS: hVSMCs were incubated with 10nM thromboxane A(2) analogue, U46619 for 16h, and then with apocynin (a NOX inhibitor), NONOate or iloprost for 1h and O(2)(-) measured spectrophometrically. The role of cyclic AMP and cyclic GMP was examined by co-incubation of drugs with protein kinase (PK) A and G inhibitors listed above. Rac(1) was studied using pull-down assays. RESULTS:NONOate and iloprost inhibited O(2)(-) formation, acutely, effects blocked by inhibition of PKG and PKA, respectively. Rac(1) and p47(phox) activation and translocation to the plasma membrane was completely inhibited by NONOate and iloprost, effects again reversed by co-incubation with PKG or PKA inhibitors. CONCLUSIONS: NO and PGI(2) block the acute activity of NOX in hVSMCs via the cGMP-PKG axis (for NO) and by the cAMP-PKA axis (for iloprost) through inhibition of Rac(1) and p47(phox) translocation. These findings have implications in the pathophysiology and treatment of CVD.
Authors: Matthew J Eagleton; David A Peterson; Vita V Sullivan; Karen J Roelofs; John A Ford; James C Stanley; Gilbert R Upchurch Journal: J Surg Res Date: 2002-05-01 Impact factor: 2.192
Authors: M A Hassan Talukder; Mohammad T Elnakish; Fuchun Yang; Yoshinori Nishijima; Mazin A Alhaj; Murugesan Velayutham; Hamdy H Hassanain; Jay L Zweier Journal: Am J Physiol Heart Circ Physiol Date: 2012-11-16 Impact factor: 4.733
Authors: S Muzaffar; N Shukla; M Bond; G B Sala-Newby; A C Newby; G D Angelini; J Y Jeremy Journal: Br J Pharmacol Date: 2008-07-28 Impact factor: 8.739
Authors: Trinity J Bivalacqua; Thomas E Sussan; Melina A Gebska; Travis D Strong; Dan E Berkowitz; Shyam Biswal; Arthur L Burnett; Hunter C Champion Journal: J Urol Date: 2008-12-17 Impact factor: 7.450
Authors: Nilima Shukla; Giuseppe Rossoni; Matthew Hotston; Anna Sparatore; Piero Del Soldato; Valerio Tazzari; Raj Persad; Gianni D Angelini; Jamie Y Jeremy Journal: BJU Int Date: 2009-03-26 Impact factor: 5.588