TY - JOUR
T1 - Molecular species analysis of 1,2-diglycerides stimulated by α-thrombin in cultured fibroblasts
AU - Pessin, M. S.
AU - Raben, D. M.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1989
Y1 - 1989
N2 - Diglycerides derived from the phospholipase C-mediated hydrolysis of phosphoinositides are implicated as important mediators of agonist-induced responses, including the stimulation of cell division. α-Thrombin-stimulated proliferation of fibroblasts is associated with a sustained increase in cellular diglycerides, while the hydrolysis of phosphoinositides is transient (Wright, T.M., Rangan, L.A., Shin, H.S., and Raben, D.M. (1988) J. Biol. Chem. 263, 9374-9380). A rigorous assessment of this apparent discrepancy requires an analysis of the molecular species of the lipids involved. In this report, we have analyzed the molecular species of 1,2-diglycerides present in quiescent and α-thrombin-stimulated IIC9 Chinese hamster embryo fibroblasts. The molecular species profiles of the stimulated diglycerides were compared to the profiles of molecular species contained in cellular phospholipids. We demonstrate that 1) stimulation of IIC9 cells by α-thrombin results in an increase in the levels of diglyceride molecular species already present in control, quiescent cultures, without the addition of new species or the complete loss of existing species; 2) the diglycerides present in control cultures as well as in cultures stimulated with α-thrombin are all ester-linked; and 3) while the phosphoinositides contribute a significant proportion of the diglycerides generated 15 s following α-thrombin addition, phosphatidylcholine contributes most of the diglycerides generated after 5 min and 1 h.
AB - Diglycerides derived from the phospholipase C-mediated hydrolysis of phosphoinositides are implicated as important mediators of agonist-induced responses, including the stimulation of cell division. α-Thrombin-stimulated proliferation of fibroblasts is associated with a sustained increase in cellular diglycerides, while the hydrolysis of phosphoinositides is transient (Wright, T.M., Rangan, L.A., Shin, H.S., and Raben, D.M. (1988) J. Biol. Chem. 263, 9374-9380). A rigorous assessment of this apparent discrepancy requires an analysis of the molecular species of the lipids involved. In this report, we have analyzed the molecular species of 1,2-diglycerides present in quiescent and α-thrombin-stimulated IIC9 Chinese hamster embryo fibroblasts. The molecular species profiles of the stimulated diglycerides were compared to the profiles of molecular species contained in cellular phospholipids. We demonstrate that 1) stimulation of IIC9 cells by α-thrombin results in an increase in the levels of diglyceride molecular species already present in control, quiescent cultures, without the addition of new species or the complete loss of existing species; 2) the diglycerides present in control cultures as well as in cultures stimulated with α-thrombin are all ester-linked; and 3) while the phosphoinositides contribute a significant proportion of the diglycerides generated 15 s following α-thrombin addition, phosphatidylcholine contributes most of the diglycerides generated after 5 min and 1 h.
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M3 - Article
C2 - 2542285
AN - SCOPUS:0024346109
SN - 0021-9258
VL - 264
SP - 8729
EP - 8738
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 15
ER -