TY - JOUR
T1 - Vitamin C-induced activation of phospholipase D in lung microvascular endothelial cells
T2 - Regulation by MAP kinases
AU - Varadharaj, Saradhadevi
AU - Steinhour, Emily
AU - Hunter, Melissa G.
AU - Watkins, Tonya
AU - Baran, Christopher P.
AU - Magalang, Ulysses
AU - Kuppusamy, Periannan
AU - Zweier, Jay L.
AU - Marsh, Clay B.
AU - Natarajan, Viswanathan
AU - Parinandi, Narasimham L.
PY - 2006/9
Y1 - 2006/9
N2 - Our earlier studies have shown that vitamin C at pharmacological doses (mM) induces loss of redox-dependent viability in bovine lung microvascular endothelial cells (BLMVECs) that is mediated by oxidative stress. Therefore, here, we investigated the vitamin C-induced activation of the lipid signaling enzyme, phospholipase D (PLD) in BLMVECs. Monolayer cultures of BLMVECs were treated with vitamin C (0-10 mM) for different time periods (0-2 h) and the activity of PLD was determined. Vitamin C induced activation of PLD in BLMVECs in a time- and dose-dependent fashion that was significantly attenuated by antioxidants, p38 mitogen-activated protein kinase (p38 MAPK)-specific inhibitor (SB203580), extracellular signal-regulated protein kinase (ERK)-specific inhibitor (PD98059), and transient transfection of cells with dominant-negative (DN)-p38 MAPK and DN-ERK1/ERK2. Vitamin C also induced phosphorylation and enhanced the activities of p38 MAPK and ERK in BLMVECs in a time-dependent fashion. It was also evident that vitamin C induced translocation of PLD1 and PLD2, association of p38 MAPK and ERK with PLD1 and PLD2, threonine phosphorylation of PLD1 and PLD2 and SB203580- and PD98059-inhibitable threonine phosphorylation of PLD1 in BLMVECs. Transient transfection of BLMVECs with DN-p38 MAPK and DN-ERK1/ERK2 resulted in marked attenuation of vitamin C-induced phosphorylation of threonine in PLD1 and PLD2. We, for the first time, showed that vitamin C at pharmacological doses, activated PLD in the lung microvascular ECs through oxidative stress and MAPK activation.
AB - Our earlier studies have shown that vitamin C at pharmacological doses (mM) induces loss of redox-dependent viability in bovine lung microvascular endothelial cells (BLMVECs) that is mediated by oxidative stress. Therefore, here, we investigated the vitamin C-induced activation of the lipid signaling enzyme, phospholipase D (PLD) in BLMVECs. Monolayer cultures of BLMVECs were treated with vitamin C (0-10 mM) for different time periods (0-2 h) and the activity of PLD was determined. Vitamin C induced activation of PLD in BLMVECs in a time- and dose-dependent fashion that was significantly attenuated by antioxidants, p38 mitogen-activated protein kinase (p38 MAPK)-specific inhibitor (SB203580), extracellular signal-regulated protein kinase (ERK)-specific inhibitor (PD98059), and transient transfection of cells with dominant-negative (DN)-p38 MAPK and DN-ERK1/ERK2. Vitamin C also induced phosphorylation and enhanced the activities of p38 MAPK and ERK in BLMVECs in a time-dependent fashion. It was also evident that vitamin C induced translocation of PLD1 and PLD2, association of p38 MAPK and ERK with PLD1 and PLD2, threonine phosphorylation of PLD1 and PLD2 and SB203580- and PD98059-inhibitable threonine phosphorylation of PLD1 in BLMVECs. Transient transfection of BLMVECs with DN-p38 MAPK and DN-ERK1/ERK2 resulted in marked attenuation of vitamin C-induced phosphorylation of threonine in PLD1 and PLD2. We, for the first time, showed that vitamin C at pharmacological doses, activated PLD in the lung microvascular ECs through oxidative stress and MAPK activation.
KW - Ascorbic acid
KW - Endothelial cell
KW - MAPK signaling
KW - Oxidative stress
KW - Phospholipase D
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U2 - 10.1016/j.cellsig.2005.10.019
DO - 10.1016/j.cellsig.2005.10.019
M3 - Article
C2 - 16376521
AN - SCOPUS:33744930097
SN - 0898-6568
VL - 18
SP - 1396
EP - 1407
JO - Cellular Signalling
JF - Cellular Signalling
IS - 9
ER -