TY - JOUR
T1 - Hydrogen peroxide acts as relaxing factor in human vascular smooth muscle cells independent of map-kinase and nitric oxide
AU - Palen, Desiree I.
AU - Ouhtit, Allal
AU - Belmadani, Souad
AU - Lucchesi, Pamela A.
AU - Matrougui, Khalid
PY - 2006
Y1 - 2006
N2 - We previously showed that hydrogen peroxide (H2O2) induced resistance artery relaxation independent of endothelium. Thus, in this study we investigated the mechanism of relaxation induced by H2O 2 on human renal vascular smooth muscle cell (HVSMC). HVSMC were stimulated with H2O2 and/or angiotensin II (Ang II), proline-rich-tyrosine-kinase-2 (PYK2), ERK1/2 MAP-Kinase, and myosin light chain 20 phosphorylation (Lc20) were assessed using Western blot analysis in the presence of potassium channel blockers, MAP-Kinase, and nitric oxide synthesis (NOS) inhibitors. H2O2 increased PYK2 and ERK1/2 phosphorylation, and at the same time decreased Lc20 phosphorylation. AngII increased phosphorylation of PYK2, ERK1/2 and Lc20, whereas, the pretreatment of HVSMC with H2O2 decreased Lc20 phosphorylation induced by AngII. MEK inhibition, decreased ERK1/2 phosphorylation, but had no effect on the inhibition of phosphorylation of Lc20 induced by H2O2. The inhibition of Ca2+-dependent K+ channels (BKCa) and NOS did not block the decrease of Lc20 phosphorylation in response to H 2O2. On the other hand, pretreatment of HVSMC with 60 mM of KCl, increased rather than decreased Lc20 phosphorylation in response to H2O2. This study shows the evidence that H 2O2 acts as a relaxing factor and as an activator of PYK2 and ERK1/2 in Human renal VSMC. The relaxation induced by H2O 2 is independent of BKCa, ERK1/2 MAP-Kinase and NOS pathways. The relaxing effect to H2O2 changes to contracting effect when the potassium channels are compromised.
AB - We previously showed that hydrogen peroxide (H2O2) induced resistance artery relaxation independent of endothelium. Thus, in this study we investigated the mechanism of relaxation induced by H2O 2 on human renal vascular smooth muscle cell (HVSMC). HVSMC were stimulated with H2O2 and/or angiotensin II (Ang II), proline-rich-tyrosine-kinase-2 (PYK2), ERK1/2 MAP-Kinase, and myosin light chain 20 phosphorylation (Lc20) were assessed using Western blot analysis in the presence of potassium channel blockers, MAP-Kinase, and nitric oxide synthesis (NOS) inhibitors. H2O2 increased PYK2 and ERK1/2 phosphorylation, and at the same time decreased Lc20 phosphorylation. AngII increased phosphorylation of PYK2, ERK1/2 and Lc20, whereas, the pretreatment of HVSMC with H2O2 decreased Lc20 phosphorylation induced by AngII. MEK inhibition, decreased ERK1/2 phosphorylation, but had no effect on the inhibition of phosphorylation of Lc20 induced by H2O2. The inhibition of Ca2+-dependent K+ channels (BKCa) and NOS did not block the decrease of Lc20 phosphorylation in response to H 2O2. On the other hand, pretreatment of HVSMC with 60 mM of KCl, increased rather than decreased Lc20 phosphorylation in response to H2O2. This study shows the evidence that H 2O2 acts as a relaxing factor and as an activator of PYK2 and ERK1/2 in Human renal VSMC. The relaxation induced by H2O 2 is independent of BKCa, ERK1/2 MAP-Kinase and NOS pathways. The relaxing effect to H2O2 changes to contracting effect when the potassium channels are compromised.
KW - Angiotensin II
KW - EDHF
KW - EDRF
KW - HVSMC
KW - Hydrogen Peroxide
KW - Signaling
UR - http://www.scopus.com/inward/record.url?scp=33744492856&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33744492856&partnerID=8YFLogxK
U2 - 10.2741/1987
DO - 10.2741/1987
M3 - Article
C2 - 16720330
AN - SCOPUS:33744492856
SN - 2768-6701
VL - 11
SP - 2526
EP - 2534
JO - Frontiers in Bioscience
JF - Frontiers in Bioscience
IS - SUPPL. 2
ER -