Abstract
In this study, we demonstrate that challenge of endothelial cells (EC) with NaF, a recognized G protein activator and protein phosphatase inhibitor, leads to a significant Erk activation, with increased phosphorylation of the well-known Erk substrate caldesmon. Inhibition of the Erk MAPK, MEK, by U0126 produces a marked decrease in NaF-induced caldesmon phosphorylation. NaF transiently increases the activity of the MEK kinase known as Raf-1 (∼3- to 4-fold increase over basal level), followed by a sustained Raf-1 inhibition (∼3- to 4-fold decrease). Selective Raf-1 inhibitors (ZM-336372 and Raf-1 inhibitor 1) significantly attenuate NaF-induced Erk and caldesmon phosphorylation. Because we have previously shown that Ca2+/ calmodulin-dependent protein kinase II (CaMKII) participates in Erk activation in thrombin-challenged cells, we next explored if CaMKII is involved in NaF-induced EC responses. We found that in NaF-treated EC, CaMKII activity increases in a time-dependent manner with maximal activity at 10 min (∼4-fold increase over a basal level). Pretreatment with KN93, a specific CaMKII inhibitor, attenuates NaF-induced barrier dysfunction and Erk phosphorylation. The Rho inhibitor C3 exotoxin completely abolishes NaF-induced CaMKII activation. Collectively, these data suggest that sequential activation of Raf-1, MEK, and Erk is modulated by Rho-dependent CaMKII activation and represents important NaF-induced signaling response. Caldesmon phosphorylation occurring by an Erk-dependent mechanism in NaF-treated pulmonary EC may represent a link between NaF stimulation and contractile responses of endothelium.
| Original language | English (US) |
|---|---|
| Pages (from-to) | L1139-L1145 |
| Journal | American Journal of Physiology - Lung Cellular and Molecular Physiology |
| Volume | 290 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 1 2006 |
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Keywords
- Cytoskeleton
- Intracellular signaling in endothelium
- Mitogen-activated protein kinase
ASJC Scopus subject areas
- Physiology
- Pulmonary and Respiratory Medicine
- Physiology (medical)
- Cell Biology
Cite this
Mechanism of fluoride-induced MAP kinase activation in pulmonary artery endothelial cells. / Bogatcheva, Natalia V.; Wang, Peiyi; Birukova, Anna A.; Verin, Alexander D.; Garcia, Joe G.N.
In: American Journal of Physiology - Lung Cellular and Molecular Physiology, Vol. 290, No. 6, 01.06.2006, p. L1139-L1145.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mechanism of fluoride-induced MAP kinase activation in pulmonary artery endothelial cells
AU - Bogatcheva, Natalia V.
AU - Wang, Peiyi
AU - Birukova, Anna A.
AU - Verin, Alexander D.
AU - Garcia, Joe G.N.
PY - 2006/6/1
Y1 - 2006/6/1
N2 - In this study, we demonstrate that challenge of endothelial cells (EC) with NaF, a recognized G protein activator and protein phosphatase inhibitor, leads to a significant Erk activation, with increased phosphorylation of the well-known Erk substrate caldesmon. Inhibition of the Erk MAPK, MEK, by U0126 produces a marked decrease in NaF-induced caldesmon phosphorylation. NaF transiently increases the activity of the MEK kinase known as Raf-1 (∼3- to 4-fold increase over basal level), followed by a sustained Raf-1 inhibition (∼3- to 4-fold decrease). Selective Raf-1 inhibitors (ZM-336372 and Raf-1 inhibitor 1) significantly attenuate NaF-induced Erk and caldesmon phosphorylation. Because we have previously shown that Ca2+/ calmodulin-dependent protein kinase II (CaMKII) participates in Erk activation in thrombin-challenged cells, we next explored if CaMKII is involved in NaF-induced EC responses. We found that in NaF-treated EC, CaMKII activity increases in a time-dependent manner with maximal activity at 10 min (∼4-fold increase over a basal level). Pretreatment with KN93, a specific CaMKII inhibitor, attenuates NaF-induced barrier dysfunction and Erk phosphorylation. The Rho inhibitor C3 exotoxin completely abolishes NaF-induced CaMKII activation. Collectively, these data suggest that sequential activation of Raf-1, MEK, and Erk is modulated by Rho-dependent CaMKII activation and represents important NaF-induced signaling response. Caldesmon phosphorylation occurring by an Erk-dependent mechanism in NaF-treated pulmonary EC may represent a link between NaF stimulation and contractile responses of endothelium.
AB - In this study, we demonstrate that challenge of endothelial cells (EC) with NaF, a recognized G protein activator and protein phosphatase inhibitor, leads to a significant Erk activation, with increased phosphorylation of the well-known Erk substrate caldesmon. Inhibition of the Erk MAPK, MEK, by U0126 produces a marked decrease in NaF-induced caldesmon phosphorylation. NaF transiently increases the activity of the MEK kinase known as Raf-1 (∼3- to 4-fold increase over basal level), followed by a sustained Raf-1 inhibition (∼3- to 4-fold decrease). Selective Raf-1 inhibitors (ZM-336372 and Raf-1 inhibitor 1) significantly attenuate NaF-induced Erk and caldesmon phosphorylation. Because we have previously shown that Ca2+/ calmodulin-dependent protein kinase II (CaMKII) participates in Erk activation in thrombin-challenged cells, we next explored if CaMKII is involved in NaF-induced EC responses. We found that in NaF-treated EC, CaMKII activity increases in a time-dependent manner with maximal activity at 10 min (∼4-fold increase over a basal level). Pretreatment with KN93, a specific CaMKII inhibitor, attenuates NaF-induced barrier dysfunction and Erk phosphorylation. The Rho inhibitor C3 exotoxin completely abolishes NaF-induced CaMKII activation. Collectively, these data suggest that sequential activation of Raf-1, MEK, and Erk is modulated by Rho-dependent CaMKII activation and represents important NaF-induced signaling response. Caldesmon phosphorylation occurring by an Erk-dependent mechanism in NaF-treated pulmonary EC may represent a link between NaF stimulation and contractile responses of endothelium.
KW - Cytoskeleton
KW - Intracellular signaling in endothelium
KW - Mitogen-activated protein kinase
UR - http://www.scopus.com/inward/record.url?scp=33744797358&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33744797358&partnerID=8YFLogxK
U2 - 10.1152/ajplung.00161.2005
DO - 10.1152/ajplung.00161.2005
M3 - Article
C2 - 16414982
AN - SCOPUS:33744797358
VL - 290
SP - L1139-L1145
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
SN - 0363-6135
IS - 6
ER -