Abstract
Oxidized low-density lipoprotein (OX-LDL) contributes significantly to the development of atherosclerosis. However, the mechanisms of OX-LDL-induced vascular smooth muscle cell (VSMC) proliferation are not completely understood. Therefore, we investigated the effect of OX-LDL on cell proliferation associated with a specific pattern of mitogen-activated protein kinase (MAPK) by [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in canine cultured VSMCs. OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in a time- and concentration-dependent manner in VSMCs. Pretreatment of these cells with pertussis toxin (PTX) for 24 hours attenuated the OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation, indicating that these responses were mediated through a receptor coupled to a PTX-sensitive G protein. In cells pretreated with PMA for 24 h and with either the PKC inhibitor staurosporine or the tyrosine kinase inhibitor genistein for 1h, substantially reduced the [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in response to OX-LDL. Removal of Ca2+ by addition of BAPTA/AM plus EGTA significantly inhibited OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation, indicating the requirement of Ca2+ for these responses. OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation was completely inhibited by PD98059 (an inhibitor of MEK1/2) and SB203580 (an inhibitor of p38 MAPK). Furthermore, we also showed that overexpression of dominant negative mutants of Ras (RasN17) and Raf (Raf-301) completely suppressed MEK1/2 and p42/p44 MAPK activation induced by OX-LDL and PDGF-BB, indicating that Ras and Raf may be required for activation of these kinases. Taken together, these results suggest that the mitogenic effect of OX-LDL is mediated through a PTX-sensitive G-protein-coupled receptor that involves the activation o Ras/Raf/MEK/MAPK pathway similar to those of PDGF-BB in canine cultured VSMCs. Copyright (C) 2000 Elsevier Science Inc.
| Original language | English |
|---|---|
| Pages (from-to) | 205-214 |
| Number of pages | 10 |
| Journal | Cellular Signalling |
| Volume | 12 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 2000 |
| Externally published | Yes |
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Keywords
- Ca
- Mitogen-activated protein kinase (MAPK)
- Oxidized low-density lipoprotein (OX-LDL)
- Pertussis toxin (PTX)
- Platelet-derived growth factor (PDGF)
- Protein kinase C (PKC)
- Tyrosine kinase
- Vascular smooth muscle cells (VSMCs)
ASJC Scopus subject areas
- Cell Biology
Cite this
Activation of mitogen-activated protein kinase by oxidized low-density lipoprotein in canine cultured vascular smooth muscle cells. / Yang, Chuen Mao; Chiu, Chi Tso; Wang, Chuan Chawn; Chien, Chin Sung; Hsiao, Li Der; Lin, Chih Chung; Tu, Ming Tze; Pan, Shiow Lin.
In: Cellular Signalling, Vol. 12, No. 4, 04.2000, p. 205-214.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Activation of mitogen-activated protein kinase by oxidized low-density lipoprotein in canine cultured vascular smooth muscle cells
AU - Yang, Chuen Mao
AU - Chiu, Chi Tso
AU - Wang, Chuan Chawn
AU - Chien, Chin Sung
AU - Hsiao, Li Der
AU - Lin, Chih Chung
AU - Tu, Ming Tze
AU - Pan, Shiow Lin
PY - 2000/4
Y1 - 2000/4
N2 - Oxidized low-density lipoprotein (OX-LDL) contributes significantly to the development of atherosclerosis. However, the mechanisms of OX-LDL-induced vascular smooth muscle cell (VSMC) proliferation are not completely understood. Therefore, we investigated the effect of OX-LDL on cell proliferation associated with a specific pattern of mitogen-activated protein kinase (MAPK) by [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in canine cultured VSMCs. OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in a time- and concentration-dependent manner in VSMCs. Pretreatment of these cells with pertussis toxin (PTX) for 24 hours attenuated the OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation, indicating that these responses were mediated through a receptor coupled to a PTX-sensitive G protein. In cells pretreated with PMA for 24 h and with either the PKC inhibitor staurosporine or the tyrosine kinase inhibitor genistein for 1h, substantially reduced the [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in response to OX-LDL. Removal of Ca2+ by addition of BAPTA/AM plus EGTA significantly inhibited OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation, indicating the requirement of Ca2+ for these responses. OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation was completely inhibited by PD98059 (an inhibitor of MEK1/2) and SB203580 (an inhibitor of p38 MAPK). Furthermore, we also showed that overexpression of dominant negative mutants of Ras (RasN17) and Raf (Raf-301) completely suppressed MEK1/2 and p42/p44 MAPK activation induced by OX-LDL and PDGF-BB, indicating that Ras and Raf may be required for activation of these kinases. Taken together, these results suggest that the mitogenic effect of OX-LDL is mediated through a PTX-sensitive G-protein-coupled receptor that involves the activation o Ras/Raf/MEK/MAPK pathway similar to those of PDGF-BB in canine cultured VSMCs. Copyright (C) 2000 Elsevier Science Inc.
AB - Oxidized low-density lipoprotein (OX-LDL) contributes significantly to the development of atherosclerosis. However, the mechanisms of OX-LDL-induced vascular smooth muscle cell (VSMC) proliferation are not completely understood. Therefore, we investigated the effect of OX-LDL on cell proliferation associated with a specific pattern of mitogen-activated protein kinase (MAPK) by [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in canine cultured VSMCs. OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in a time- and concentration-dependent manner in VSMCs. Pretreatment of these cells with pertussis toxin (PTX) for 24 hours attenuated the OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation, indicating that these responses were mediated through a receptor coupled to a PTX-sensitive G protein. In cells pretreated with PMA for 24 h and with either the PKC inhibitor staurosporine or the tyrosine kinase inhibitor genistein for 1h, substantially reduced the [3H]thymidine incorporation and p42/p44 MAPK phosphorylation in response to OX-LDL. Removal of Ca2+ by addition of BAPTA/AM plus EGTA significantly inhibited OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation, indicating the requirement of Ca2+ for these responses. OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation was completely inhibited by PD98059 (an inhibitor of MEK1/2) and SB203580 (an inhibitor of p38 MAPK). Furthermore, we also showed that overexpression of dominant negative mutants of Ras (RasN17) and Raf (Raf-301) completely suppressed MEK1/2 and p42/p44 MAPK activation induced by OX-LDL and PDGF-BB, indicating that Ras and Raf may be required for activation of these kinases. Taken together, these results suggest that the mitogenic effect of OX-LDL is mediated through a PTX-sensitive G-protein-coupled receptor that involves the activation o Ras/Raf/MEK/MAPK pathway similar to those of PDGF-BB in canine cultured VSMCs. Copyright (C) 2000 Elsevier Science Inc.
KW - Ca
KW - Mitogen-activated protein kinase (MAPK)
KW - Oxidized low-density lipoprotein (OX-LDL)
KW - Pertussis toxin (PTX)
KW - Platelet-derived growth factor (PDGF)
KW - Protein kinase C (PKC)
KW - Tyrosine kinase
KW - Vascular smooth muscle cells (VSMCs)
UR - http://www.scopus.com/inward/record.url?scp=0033994374&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033994374&partnerID=8YFLogxK
U2 - 10.1016/S0898-6568(99)00087-X
DO - 10.1016/S0898-6568(99)00087-X
M3 - Article
C2 - 10781927
AN - SCOPUS:0033994374
VL - 12
SP - 205
EP - 214
JO - Cellular Signalling
JF - Cellular Signalling
SN - 0898-6568
IS - 4
ER -