scholarly journals The selective release of phospholipase A2 by resident mouse peritoneal macrophages

1981 ◽  
Vol 200 (2) ◽  
pp. 441-444 ◽  
Author(s):  
P D Wightman ◽  
M E Dahlgren ◽  
P Davies ◽  
R J Bonney

Resident mouse peritoneal macrophages have three phospholipase activities: a phospholipase A2 active at pH 4.5, a Ca2+-dependent phospholipase A2 active at pH 8.5 and a phosphatidylinositol-specific phospholipase C activity. When macrophages are exposed to zymosan in culture, the cellular activity of pH-4.5 phospholipase A2 is diminished in a manner dependent on zymosan concentration and time of exposure, whereas the cellular activities of pH-8.5 phospholipase A2 and phospholipase C remain unchanged. The depletion of pH-4.5 phospholipase A2 activity from the cell is paralleled by a quantitative recovery of this activity in the culture medium in a manner similar to the cellular depletion and extracellular recovery of two lysosomal enzymes. This release is specifically elicited by an inflammatory substance such as zymosan, since macrophages incubated with 6 micrometer latex spheres retain pH-4.5 phospholipase A2 activity and lysosomal enzyme activities intracellularly.

1980 ◽  
Vol 188 (3) ◽  
pp. 933-936 ◽  
Author(s):  
D W Riches ◽  
D R Stanworth

Cultured mouse peritoneal macrophages were found to release substantial amounts of lysosomal beta-glucuronidase and beta-glactosidase activites when exposed to millimolar concentrations of various primary aliphatic monoamines. With methylamine, ethylamine, propylamine and butylamine, lysosomal enzyme release was selective, but further increases in the aliphatic chain length resulted in the compounds becoming lytic. By contrast, structurally related primary aliphatic diamines proved to be inactive at inducing both selective and lytic lysosomal-enzyme discharge.


1981 ◽  
Vol 197 (2) ◽  
pp. 523-526 ◽  
Author(s):  
Paul D. Wightman ◽  
Mary Ellen Dahlgren ◽  
James C. Hall ◽  
Philip Davies ◽  
Robert J. Bonney

Resident mouse peritoneal macrophages contain a phospholipase C of high activity that is specific for phosphatidylinositol. The activity has a neutral pH optimum, is Ca2+-dependent and has a maximum reaction velocity of 525nmol/h per mg of protein. Certain phenothiazines are potent inhibitors of this activity.


1975 ◽  
Vol 142 (4) ◽  
pp. 903-913 ◽  
Author(s):  
E L Pesanti ◽  
S G Axline

Intracellular lysosomal fusion has been evaluated in cultivated mouse peritoneal macrophages by measurement of transfer of acid phosphatase to polyvinyltoluene (PVT)-containing phagolysosomes. Enzyme transfer was found to be directly and significantly related to the uptake of PVT and to be independent of time allowed for phagolysosome formation over time periods of 15 min to 18 h. In addition, the extent of transfer of lysosomal enzyme to phagolysosomes was unaffected by treatment of the cells with 10(-6) M colchicine, a dose which eradicates morphologically identifiable microtubules in this cell type within 2 h. The data indicate that intracellular fusion of lysosomes with phagosomes in the macrophage does not require formed microtubules and suggest that fusion occurs promptly after interiorization of inert particles.


1981 ◽  
Vol 193 (2) ◽  
pp. 589-605 ◽  
Author(s):  
M J Banda ◽  
Z Werb

Macrophage elastase was purified from tissue-culture medium conditioned by inflammatory mouse peritoneal macrophages. Characterized as a secreted neutral metalloproteinase, this enzyme was shown to be catalytically and immunochemically distinct from the mouse pancreatic and mouse granulocyte elastases, both of which are serine proteinases. Inhibition profiles, production of nascent N-terminal leucine residues and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of degraded elastin indicated that macrophage elastase is an endopeptidase, with properties of a metalloproteinase, rather than a serine proteinase. Macrophage elastase was inhibited by alpha 2-macroglobulin, but not by alpha 1-proteinase inhibitor. Macrophage elastase was resolved into three chromatographically distinct forms. The predominant form had mol.wt. 22 000 and was purified 4100-fold. Purification of biosynthetically radiolabelled elastase indicated that this form represented less than 0.5% of the secreted protein of macrophages. Approx. 800% of the starting activity was recovered after purification. Evidence was obtained for an excess of an endogenous inhibitor masking more than 80% of the secreted activity.


1978 ◽  
Vol 173 (2) ◽  
pp. 433-439 ◽  
Author(s):  
P Willcox

1. Secretion of the lysosomal enzyme beta-N-acetylglucosaminidase (EC 3.2.1.30) by normal human fibroblast cultures was linear with respect to time up to 96h. 2. Two forms of the A isoenzyme of beta-N-acetylglucosaminidase were found in the culture medium. One form was similar to the isoenzyme found in other extracellular fluids, such as plasma and tears, the other resembled the intracellular (lysosomal) enzyme. The presence of the two isoenzymes in the culture medium appears to reflect two distinct secretory processes. 3. It is suggested that plasma acid hydrolases may be destined for incorporation into lysosomes in a manner analogous to that described for the packaging of lysosomal enzymes by fibroblasts.


1980 ◽  
Vol 152 (5) ◽  
pp. 1236-1247 ◽  
Author(s):  
C A Rouzer ◽  
W A Scott ◽  
A L Hamill ◽  
Z A Cohn

A method for the radiochemical assay of LTC production by mouse peritoneal macrophages in vitro is presented. The method involves labeling macrophages in culture with [5,6,8,9,11,12,14,15-3H]20:4 followed by stimulation of arachidonic acid (20:4) release under the experimental conditions desired. Radiolabeled leukotriene C (LTC) is recovered from the culture medium by extraction and silicic acid chromatography in 40% yield with full retention of biological activity. Because this LTC is radiochemically pure, the quantity of LTC release may be estimated from the amount of radioactivity in the sample. Use of the radioassay to study parameters affecting LTC synthesis by macrophages indicated that the time course of LTC synthesis and its relationship to the dose of a phagocytic stimulus (zymosan) were very similar to those of prostaglandin (PG) release. LTC release was also similar to that of PG in that lower levels of both metabolites were produced by Corynebacterium parvum-elicited macrophages than by resident cells. Finally, LTC release was stimulated in response to a challenge with antigen-antibody complexes, but lower maximal levels were attained than those with zymosan. The data presented here are consistent with the hypothesis that challenge of macrophages with a phagocytic stimulus leads to the release of 20:4 by an inducible phospholipase. Cyclooxygenase and lipoxygenase then compete for the released 20:4, leading to the production of PG, hydroxyeicosatetraenoic acids, and LTC.


1998 ◽  
Vol 26 (02) ◽  
pp. 133-141 ◽  
Author(s):  
Zhan-Jun Pang ◽  
Mei Zhou ◽  
Yuan Chen ◽  
Jennifer Wan

The aim of this study is to examine whether polysaccharide krestin, a protein-bound polysaccharide, can prevent the progression of therosclerosis and lipoperoxidative injury caused by oxidatively modified low density lipoprotein (Ox-LDL) to macrophages. The alterations of GSHPx (glutathione peroxidase), SOD (superoxide dismutase) activity and NO (nitric oxide) release in PSK-treated mouse peritoneal macrophages, and the effect of LPS on them were investigated. With peritoneal injection of PSK, the following were observed in the mouse peritoneal macrophages: 1) an increase in SeGSHPx activity, 2) elevation in non-SeGSHPx and SOD activity; 3) the enzyme activities were further improved by addition of lipopolysaccharide (LPS); and 4) much NO was found to be released by PSK-treated mouse peritoneal macrophages stimulated by LPS.


Sign in / Sign up

Export Citation Format

Share Document