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Nitric oxide attenuates the enhanced expression of Giα proteins in vascular smooth muscle cells from spontaneously hypertensive rats: molecular mechanisms (1065.15)
Author(s) -
Sarkar Oli,
Paul Ravinder,
AnandSrivastava Madhu B.
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1065.15
Subject(s) - snap , nadph oxidase , p22phox , vascular smooth muscle , chemistry , peroxynitrite , endocrinology , medicine , nitric oxide , oxidative stress , biochemistry , superoxide , enzyme , smooth muscle , computer graphics (images) , computer science
We have previously shown that the nitric oxide donor, SNAP, decreased the expression of Giα proteins and associated functions in A10 vascular smooth muscle cells. The present study was undertaken to investigate if SNAP can also decrease the expression of Giα proteins and associated signaling in aortic vascular smooth muscle cells (VSMC) from 12‐week‐old Wistar‐Kyoto (WKY) and Spontaneously Hypertensive rats (SHR) and to further explore the underlying mechanism(s). Treatment of VSMC with SNAP (100 µM) for 24h decreased the expression of Giα‐2, ‐3 proteins. This decrease was subverted by inhibiting peroxynitrite with wither Mn (III) tetrakis (4‐benzoic acid) porphyrin (MnTBAP) or uric acid, and by inhibiting MEK with PD98059. However, inhibition of guanylate cyclase by 1H‐(1, 2, 4) oxadiazolo (4, 3‐a) quinoxalin‐1‐one (ODQ) was unable to restore the SNAP‐induced decrease in Giα‐2, ‐3. In addition, the enhanced activity of NADPH oxidase and protein levels of its subunits (Nox‐4, p47phox and p22phox) were decreased by SNAP. The decreased expression of NADPH oxidase subunits was restored towards control levels by MnTBAP. Furthermore, SNAP treatment decreased the enhanced levels of O2‐, TBARS and protein carbonyl in SHR to control levels. SNAP also attenuated the increased phospholyration of PDGFR, EGFR and IGF‐1R and c‐Src. These results suggest that SNAP decreased the enhanced expression of Giα proteins in VSMC from SHR by attenuating the increased oxidative stress, growth factor receptor activation and ensuing ERK1/2 signaling and not by a cGMP‐dependent mechanism. Grant Funding Source : CIHR