The overexpression of PKCdelta is involved in vascular endothelial growth factor-resistant apoptosis in cultured primary sinusoidal endothelial cells.
We have previously reported that primary sinusoidal endothelial cells from the rat liver are highly dependent on VEGF for cell proliferation in in vitro culture. However, even in the presence of VEGF, essentially all the SE cells could not survive longer than 7 days, leading to growth factor-resistant cell death. The death had characteristics typical of apopotosis, such as DNA fragmentation, staining with TUNEL reagent and nuclear condensation. We found that the cell death was blocked by the treatment of TPA in a dose-dependent manner and was preceded by a remarkable increase in PKCdelta at a protein level. Furthermore, PKCdelta-specific inhibitor, Rottrelin, significantly suppressed this VEGF-resistant apoptosis of cultured SE cells, whereas conventional PKC-specific inhibitor, Go6976 could not. TPA was found to downregulate the overexpression of PKCdelta. Thus, we suggest that the VEGF-resistant apoptosis is a new type of endothelial cell death and that PKCdelta is an essential mediator for this process.
Takahashi
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T
Department of Genetics, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan. shibuya@ims.u-tokyo.ac.jp
Shibuya
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D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D001578:Benzopyrans / Q000494:pharmacology; D002227:Carbazoles / Q000494:pharmacology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016228:Endothelial Growth Factors / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008222:Lymphokines / Q000494:pharmacology*; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D051745:Protein Kinase C-delta; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D000098:Acetophenones; D001578:Benzopyrans; D002227:Carbazoles; D016228:Endothelial Growth Factors; D004791:Enzyme Inhibitors; D007211:Indoles; D007527:Isoenzymes; D008222:Lymphokines; D011994:Recombinant Proteins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; C081021:Go 6976; C085746:rottlerin; C497260:Prkcd protein, rat; C497258:PRKCD protein, human; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D013755:Tetradecanoylphorbol Acetate