PROTEIN-KINASE-C REGULATES TNF-ALPHA PRODUCTION BY HUMAN MONOCYTES

被引：0

作者：

PRABHAKAR, U ^{[1
]}

LIPSHUTZ, D ^{[1
]}

PULLEN, M ^{[1
]}

TURCHIN, H ^{[1
]}

KASSIS, S ^{[1
]}

NAMBI, P ^{[1
]}

机构：

[1] SMITHKLINE BEECHAM PHARMACEUT,DEPT RENAL PHARMACOL,KING OF PRUSSIA,PA 19406

来源：

EUROPEAN CYTOKINE NETWORK | 1993年 / 4卷 / 01期

关键词：

TNF-ALPHA TUMOR NECROSIS FACTOR-ALPHA; PKC-PROTEIN KINASE-C; LPS-LIPOPOLYSACCHARIDE;

D O I：

暂无

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Tumor Necrosis Factor alpha (TNFalpha) is a cytokine mediator that is produced primarily by activated monocytes/macrophages in response to endotoxin/ lipopolysaccharide (LPS) as well as other stimuli. The second messenger systems that regulate the synthesis and release of TNFalpha are not clearly defined. In the present study, the role of protein kinase C (PKC) in the production of TNFalpha was investigated in human peripheral blood monocytes stimulated with either LPS or zymosan. Two broad spectrum protein kinase inhibitors (staurosporine and K252a) and two PKC specific inhibitors (calphostin C and chelerythrine), were used as probes to delineate the involvement of PKC in the production of TNFalpha. The results indicate that inhibition of PKC diminished LPS- or zymosan- induced TNFalpha production in a concentration-dependent manner. The IC50 values for the inhibition of TNFalpha production were 0.2 nM for staurosporine, and 20 nM for K252a, Calphostin C and chelerythrine. Furthermore, long term PMA treatment of these cells (to abrogate PKC-mediated responses) resulted in a significant reduction of stimuli-induced TNFalpha production. LPS and zymosan also induced an increase in membrane associated PKC activity in human monocytes, which could be inhibited by pretreatment of the cells with calphostin C. Finally, western blot analysis with PKC isoform-specific antibodies demonstrates that the alpha and xi are the predominent isoforms expressed in human monocytes. These data strongly suggest that an initial step in TNFalpha production by human monocytes challenged with physiological stimulants, such as LPS and zymosan, involves a PKC-dependent mechanism.

引用

页码：31 / 37

页数：7