Biochemical and Biophysical Research Communications
Protein kinase C β and δ isoenzymes mediate cholesterol accumulation in PMA-activated macrophages
Section snippets
Materials and methods
PKC inhibitors. PKC pseudosubstrate myristoylated peptide inhibitors for α + β (P-205) and ε (P-223), HBDDE, RO 32-0432, Go6976, and Go6983 were obtained from Biomol. PKC pseudosubstrate myristoylated peptide inhibitors for theta (#539636) and eta (#539602) and Go6850 were obtained from Calbiochem. LY333531 was obtained from Alexis. The non-PKC inhibitors genistein and H89 were obtained from Biomol.
Culture of human monocyte-derived macrophages. Human monocytes were purified with counterflow
Kinase dependency of PMA-stimulated macrophage cholesterol accumulation
Previously we showed that PMA-stimulated macrophage cholesterol accumulation during incubation with native LDL could be inhibited with broad specificity PKC inhibitors [6]. To learn whether other protein kinase classes functioned in PMA-stimulated cholesterol accumulation we tested the effects of genistein, a pan tyrosine kinase inhibitor, and HA89, a cyclic AMP-dependent protein kinase (PKA) inhibitor, on this process. Neither of these protein kinase inhibitors significantly decreased
Discussion
Macrophage foam cell formation has been thought to occur only by receptor-mediated uptake of modified LDL. We recently showed that PMA-activated macrophages take up native LDL through receptor-independent fluid-phase macropinocytosis and form foam cells due to massive accumulation of LDL-derived cholesterol [6], [7]. In this report, we have identified β and some additional PKC isoenzyme, most likely δ, as mediators of PMA-stimulated macrophage cholesterol accumulation. These two PKC isoenzymes
Acknowledgment
We thank Rani Rao for technical assistance, and the Department of Transfusion Medicine, Clinical Center, National Institutes of Health, for providing elutriated monocytes. This research was supported in part by the Intramural Research Program of the NIH, NHLBI.
References (41)
- et al.
Macrophage foam cell formation with native low density lipoprotein
J. Biol. Chem.
(2002) - et al.
Macropinocytosis is the endocytic pathway that mediates macrophage foam cell formation with native low density lipoprotein
J. Biol. Chem.
(2005) - et al.
Constitutive receptor-independent low density lipoprotein uptake and cholesterol accumulation by macrophages differentiated from human monocytes with macrophage-colony-stimulating factor (M-CSF)
J. Biol. Chem.
(2006) - et al.
Plasmin-mediated macrophage reversal of low density lipoprotein aggregation
J. Biol. Chem.
(2000) - et al.
A simple method for the isolation and purification of total lipids from animal tissues
J. Biol. Chem.
(1957) - et al.
Procedure for determination of free and total cholesterol in micro- or nanogram amounts suitable for studies with cultured cells
J. Lipid Res.
(1978) - et al.
Protein measurement with the folin phenol reagent
J. Biol. Chem.
(1951) - et al.
The bisindolylmaleimide GF 109203X is a potent and selective inhibitor of protein kinase C
J. Biol. Chem.
(1991) - et al.
Selective inhibition of protein kinase C isozymes by the indolocarbazole Go6976
J. Biol. Chem.
(1993) - et al.
A myristoylated pseudosubstrate peptide, a novel protein kinase C inhibitor
J. Biol. Chem.
(1993)
2,2′,3,3′,4,4′-Hexahydroxy-1,1′-biphenyl-6,6′-dimethanol dimethyl ether (HBDDE)-induced neuronal apoptosis independent of classical protein kinase C alpha or gamma inhibition
Biochem. Pharmacol.
Rac is required for constitutive macropinocytosis by dendritic cells but does not control its downregulation
Curr. Biol.
Cell surface receptors activate p21-activated kinase 1 via multiple Ras and PI3-kinase-dependent pathways
Cell. Signal.
Protein kinase C (PKC) betaII induces cell invasion through a Ras/Mek-, PKC iota/Rac 1-dependent signaling pathway
J. Biol. Chem.
Protein kinase C delta specifically associates with phosphatidylinositol 3-kinase following cytokine stimulation
J. Biol. Chem.
Protein kinase C beta II specifically binds to and is activated by F-actin
J. Biol. Chem.
Protein kinase C induces actin reorganization via a Src- and Rho-dependent pathway
J. Biol. Chem.
Activation of protein kinase C beta II by the stereo-specific phosphatidylserine receptor is required for phagocytosis of apoptotic thymocytes by resident murine tissue macrophages
J. Biol. Chem.
Lipoprotein cholesterol and atherosclerosis
Curr. Mol. Med.
Macrophage foam cells and atherosclerosis
Front. Biosci.
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