The effect of new potent selective inhibitors of protein kinase C on the neutrophil respiratory burst

Twomey, Breda M.; Muid, R.E.; Nixon, John; Sedgwick, A. D.; Wilkinson, Sandra E.; Dale, M. Maureen

doi:10.1016/0006-291x(90)90795-o

Cited by 78 publications

(30 citation statements)

References 25 publications

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“…The staining profiles were similar using mAbs MEL-14 or T28.45, which recognize epitopes in the lectin and EGF domains, respectively (25). The effect of PDBu was completely inhibited by inclusion of staurosporine or the specific protein kinase C inhibitor, Ro 31-8220 (24), in the assay (Table I and data not shown). PDBu did not affect the expression of other cell surface adhesion molecules such as ␣4 integrins, CD44, or LFA-1 (Table I) or of CD45, MHC antigens, CD4, and CD3 (data not shown).…”

Section: Resultsmentioning

confidence: 64%

Metalloproteinase-mediated Regulation of L-selectin Levels on Leucocytes

Preece

Murphy²,

Ager

1996

Journal of Biological Chemistry

197

139

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Leucocyte (L)-selectin can be proteolytically cleaved in the membrane proximal extracellular region to yield a soluble fragment that contains the functional lectin and epidermal growth factor domains. A variety of stimuli are known to stimulate L-selectin shedding including chemoattractants, phorbol esters, and L-selectin cross-linking; however, the enzymes that regulate L-selectin expression are not characterized. In this study we have used phorbol ester to stimulate endoproteolytic release of L-selectin and identified a major role for a cell surface metalloproteinase (L-selectin sheddase) in this process.The hydroxamic acid-based inhibitor of zinc-dependent matrix metalloproteinases Ro 31-9790 completely prevented shedding of cell surface L-selectin from leucocytes in mouse, rat, and man. L-selectin was susceptible to cleavage by known matrix metalloproteinases. Recombinant human fibroblast collagenase (MMP1) reduced the number of L-selectin-positive lymphocytes to a similar extent as phorbol ester activation, and stromelysin (MMP3) had a partial effect on L-selectin expression. Gelatinases A (MMP2) and B (MMP9) were without effect. Lymphocytes did not express fibroblast collagenase or stromelysin at the cell surface, and tissue inhibitor of metalloproteinases (TIMP) did not affect L-selectin levels. L-selectin sheddase was not detected in media harvested from phorbol ester-stimulated lymphocytes and was only able to cleave L-selectin in the cis but not the trans configuration.These results suggest that endoproteolytic release of L-selectin from the leucocyte surface is mediated by a metalloproteinase (L-selectin sheddase), which is distinguishable from known matrix metalloproteinases. Understanding the regulation of L-selectin sheddase will be critical for controlling leucocyte migration from the blood.Leucocyte (L)-selectin is a member of the selectin family of adhesion molecules, which are highly restricted in their distribution to leucocytes (L-and P-selectin) or vascular endothelial cells (E-and P-selectin) (1). A specialized role for the selectins in mediating the binding of leucocytes from flowing blood has been demonstrated for all three selectins (2-7). L-selectin was first identified in 1983 as a peripheral lymph node homing receptor, which mediated the binding of lymphocytes to high endothelial venules and their subsequent migration into peripheral lymph nodes of mice (8). L-selectin also mediates the binding of neutrophils to acutely inflamed postcapillary venules in the mesentery (7, 9) and subsequent migration into the peritoneal cavity (10). The critical role of L-selectin in regulating the migration of leucocytes has been confirmed recently in studies of L-selectin "knockout mice" (11).Of the selectins, L-selectin shows the unique property of being proteolytically cleaved in the membrane-proximal extracellular region to yield a soluble fragment that contains the known functional lectin and EGF 1 domains. This provides a rapid mechanism for regulating L-selectin levels on leucocytes and, therefo...

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Section: Resultsmentioning

confidence: 64%

Metalloproteinase-mediated Regulation of L-selectin Levels on Leucocytes

Preece

Murphy²,

Ager

1996

Journal of Biological Chemistry

197

139

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“…Both events are inhibited by Ro 31-8220 with comparable potency. The half-maximal concentration of Ro 31-8220 necessary to inhibit PMA-induced effects on cell morphology and phosphorylation in Walker carcinosarcoma cells, approximately 0.1 pM, is somewhat lower than that necessary for half-maximal inhibition of diacylglycerolinduced oxidative burst in human neutrophils (0.3 pM; Twomey et al, 1990). Half-maximal in vitro effects of Ro 31-8220 on purified PKC occur at about 10 nM.…”

Section: Influence Of Pkc Inhibitors On Pma-induced Effectsmentioning

confidence: 98%

Inhibition of protein kinase C-dependent protein phosphorylation correlates with increased polarity and locomotion in Walker 256 carcinosarcoma cells

1996

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“…5A). Nevertheless, because of the uncertain specificity of the TPA down-regulation, the study was extended by using a specific PKC inhibitor Ro-31-8220, which acts as an ATP-competitive inhibitors of PKC and has been extensively used for studying the role of PKC in cell signaling (56,57). Preincubation of the cells with Ro-31-8220 completely inhibited the stimulation of p70…”

Section: Role Of H 2 O 2 In P70mentioning

confidence: 99%