MECHANISMS OF LYSOSOMAL ENZYME RELEASE FROM LEUKOCYTES EXPOSED TO IMMUNE COMPLEXES AND OTHER PARTICLES

1971 ◽  
Vol 134 (3) ◽  
pp. 149-165 ◽  
Author(s):  
Gerald Weissmann ◽  
Robert B. Zurier ◽  
Paul J. Spieler ◽  
Ira M. Goldstein

Human PMN release lysosomal enzymes (ß-glucuronidase, acid phosphatase) when exposed to immune complexes, but do not release cytoplasmic LDH. The cells remain viable, and failure of LDH to appear in supernatants is not due to selective absorption or inactivation. Release of enzymes is not due to platelet contamination and is only partially enhanced by fresh serum. The selective release of lysosomal enzymes after uptake of complexes resembles that induced by inert particles of zymosan, and can be distinguished from the concurrent release of all enzymes after cell death induced by membrane-lytic crystals of MSU. Uptake of complexes, zymosan, or MSU particles is accompanied by concomitant increases in C-1 oxidation of glucose. Although MSU-induced damage can be retarded by the presence of Tris buffer, immune complexes and zymosan selectively release lysosomal hydrolases in the presence or absence of Tris buffer. Agents which elevate the level, within cells, of cAMP (PGE1, theophylline, 2-CA) and cAMP itself inhibit the selective extrusion of acid hydrolases from leukocytes without affecting the viability of cells. Leukocytes may respond to immune particles by regurgitating a portion of their lysosomal hydrolases during phagocytosis.

1973 ◽  
Vol 58 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Robert B. Zurier ◽  
Sylvia Hoffstein ◽  
Gerald Weissmann

In order to study mechanisms underlying selective enzyme release from human leukocytes during phagocytosis, the effects were studied of compounds which affect microtubule integrity or the accumulation of cyclic nucleotides. Human leukocytes selectively extrude lysosomal enzymes (ß-glucuronidase) from viable cells during phagocytosis of zymosan or immune complexes, or upon encounter with immune complexes dispersed along a non-phagocytosable surface such as a millipore filter. In each circumstance, lysosomal enzyme release was reduced by previous treatment of cells with pharmacological doses of drugs which disrupt microtubules (e.g. 10-3–10-5 M colchicine) or with agents which affect accumulation of adenosine 3'5'-monophosphate (cAMP) (e.g. 10-3 M cyclic nucleotides and 2.8 x 10-4–2.8 x 10-6 M prostaglandin E (PGE) and A (PGA) compounds). Preincubation of cells with 5 µg/ml cytochalasin B resulted in complete inhibition of zymosan ingestion, but not of adherence of zymosan particles to plasma membranes or selective enzyme release. In this system, in which enzyme release was independent of particle uptake, preincubation of cells with colchicine, vinblastine, dibutyryl cAMP, or PGE1 also reduced extrusion of lysosomal enzymes. When cell suspensions were incubated with membrane-lytic crystals of monosodium urate (MSU), cytoplasmic as well as lysosomal enzymes were released with subsequent death of the cells. However, enzyme release followed phagocytosis of crystals (as measured by enhanced C-1 oxidation of glucose) and was due to "perforation from within" of the lysosomal membrane, rather than lysis by crystals of the plasma membrane. Enzyme release after MSU ingestion was also reduced when cells were treated with pharmacological doses of the test agents. When cells were killed by Triton X-100, acting on the plasma membrane, C-1 oxidation of glucose was abolished and enzyme release could not be inhibited pharmacologically. These observations suggest that lysosomal enzyme release from human phagocytes can be an active process which accompanies plasma membrane stimulation, is independent of cell death, and may be controlled by cyclic nucleotides and agents which affect microtubules.


1973 ◽  
Vol 134 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Philip Davies ◽  
Anthony C. Allison ◽  
A. David Haswell

1. Cytochalasin B (10μg/ml) enhances the release of rabbit polymorphonuclear leucocyte lysosomal acid hydrolases induced by retinol (vitamin A alcohol). 2. This effect is seen at doses of the vitamin that cause selective release of acid hydrolases and those causing more general enzyme release indicated by the loss of lactate dehydrogenase. 3. Cytochalasin B (2–50μg/ml) has no effect on the release of sedimentable acid hydrolases of intact granules obtained from disrupted polymorphonuclear leucocytes. 4. Cytochalasin B (2–10μg/ml) causes a time- and dose-dependent release of mouse peritoneal macrophage acid hydrolases. 5. This effect is selective at all doses of cytochalasin B used, since no release of lactate dehydrogenase, malate dehydrogenase and leucine 2-naphthylamidase was detected. 6. Treatment with cytochalasin B at doses of up to 10μg/ml for as long as 72h did not significantly change the total activities of any of the enzymes measured. 7. The lack of toxicity of cytochalasin B was shown by dye-exclusion tests and its failure to release radioactive colloidal gold stored in secondary lysosomes.


1971 ◽  
Vol 49 (2) ◽  
pp. 170-176 ◽  
Author(s):  
I. D. Desai

The nutritional role of intestinal lysosomal enzymes in the regulation of reversible adaptation to starvation and realimentation by various dietary treatments is investigated. When rats were starved for periods ranging from 72 to 120 h, the specific activity of the representative lysosomal hydrolases, viz. acid phosphatase, β-glucuronidase, β-galactosidase, arylsulfatase, and cathepsin D of small intestinal mucosa, progressively increased reaching levels two to four times higher than the fed controls. During the starvation period of only 72 h, more than 60% of the intestinal weight and about 75% of the mucosal protein was lost. On realimentation with a complete diet such as laboratory rat chow, the specific activity of the intestinal lysosomal enzymes rapidly returned to normal and the lost weight of the intestinal tissue and of the body as a whole was restored. The regulatory effect of major dietary nutrients such as carbohydrates, proteins, and fats on the starvation-induced breakdown of the intestinal tissue reserves is presented and discussed. The findings of this study indicate that changes in the specific activity of the intestinal lysosomal enzymes are associated with adaptive processes requiring rapid turnover of body tissues for maintenance and survival of the animal during starvation and/or during conditions when dietary supply of certain nutrients is limited.


1973 ◽  
Vol 132 (2) ◽  
pp. 267-282 ◽  
Author(s):  
Alfred Goldstone ◽  
Harold Koenig

1. The following fractions were prepared from rat kidney and characterized ultrastructurally, biochemically and enzymically: (a) an ordinary rough microsomal (RM1) fraction; (b) a special rough microsomal (RM2) fraction enriched seven- to nine-fold in acid hydrolases over the homogenate; (c) a smooth microsomal (SM) fraction; (d) a Golgi (GM) fraction enriched 2.5-fold in acid hydrolases and 10-, 15- and 20-fold in sialyltransferase, N-acetyl-lactosamine synthetase and galactosyltransferase respectively; (e) a lysosomal (L) fraction enriched 15- to 23-fold in acid hydrolases. The frequency of Golgi sacs and tubules seen in the electron microscope and the specific activity of the three glycosyltransferases in these fractions increased in the order: RM2<RM1<SM<GM. 2. Five lysosomal hydrolases, acid phosphatase, β-N-acetyl-hexosaminidase, β-galactosidase, β-glucuronidase and arylsulphatase, were characterized in these fractions with respect to (a) solubility on freeze–thawing and (b) electrophoretic mobility in polyacrylamide gels. 3. In the RM2 fraction each of these hydrolases occurred largely or exclusively as a single bound basic form coincident with cationic glycoprotein bands in gels (Goldstone et al., 1973). 4. In the L fraction these hydrolases were present largely as soluble, acidic (anionic) forms. 5. The solubility, electrophoretic heterogeneity and anodic mobility of these hydrolases increased progressively in subcellular fractions in the order: RM2<RM1<SM<GM<L. 6. These findings, together with evidence cited in the text showing that N-acetylneuraminic acid residues are responsible for the solubility and electronegative charge of these acidic forms and incorporation of these residues into the Golgi apparatus, support the following scheme for the biosynthesis of lysosomal enzymes. Each hydrolase is synthesized as a bound basic glycoprotein enzyme in a restricted portion of the rough endoplasmic reticulum. The soluble, acidic forms are generated as the nascent glycoprotein enzymes migrate through the Golgi apparatus through the attachment of sugar sequences containing N-acetylneuraminic acid.


1979 ◽  
Vol 34 (1-2) ◽  
pp. 90-95 ◽  
Author(s):  
Fouad M. Fouad ◽  
D. Waldron-Edward

Abstract The results show that incubation of gastric mucosal cells from rat at pH ~4.5 or in the presence of aspirin is associated with a specific increase in the activity of some acid-hydrolases. Intracellular glycoproteins, isolated by non-degradative techniques from rat or dog fundic mucosal cells, were found to be potential bio-substrates for these acid-hydrolyses. This may suggest that cleavage of the carbohydrate moieties of the intracellular and mucosal cell wall glycoproteins is a fundamental step in the development of gastric ulceration. A model for gastric lesions is proposed and discussed in the light of the results obtained.


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.


Blood ◽  
1998 ◽  
Vol 91 (3) ◽  
pp. 1044-1058 ◽  
Author(s):  
A.-M. Cieutat ◽  
P. Lobel ◽  
J.T. August ◽  
L. Kjeldsen ◽  
H. Sengeløv ◽  
...  

Abstract During granulocyte differentiation in the bone marrow (BM), neutrophilic leukocyte precursors synthesize large amounts of lysosomal enzymes. These enzymes are sequestered into azurophilic storage granules until used days later for digestion of phagocytized microorganisms after leukocyte emigration to inflamed tissues. This azurophil granule population has previously been defined as a primary lysosome, ie, a membrane-bound organelle containing acid hydrolases that have not entered into a digestive event. In this study, azurophil granules were purified and shown to contain large amounts of mannose 6-phosphate-containing glycoproteins (Man 6-P GP) but little lysosome-associated membrane proteins (LAMP). In addition, the fine structural localization of Man 6-P GP and LAMP was investigated at various stages of maturation in human BM and blood. Man 6-P GP were present within the azurophilic granules at all stages of maturation and in typical multivesicular bodies (MVB) as well as in multilaminar compartments (MLC), identified by their content of concentric arrays of internal membranes. LAMP was absent in all identified granule populations, but was consistently found in the membranes of vesicles, MVB, and MLC. The latter compartment has not been previously described in this cell type. In conclusion, the azurophilic granules, which contain an abundance of lysosomal enzymes and Man 6-P GP, lack the LAMP glycoproteins. By current criteria, they therefore cannot be classified as lysosomes, but rather may have the functional characteristics of a regulated secretory granule. Rather, the true lysosomes of the resting neutrophil are probably the MVB and MLC. Finally, the typical “dense bodies” or mature lysosomes described in other cells are not present in resting neutrophils.


1968 ◽  
Vol 46 (3) ◽  
pp. 499-502 ◽  
Author(s):  
B. M. Hegdekar

Female rats of the Long-Evans hooded strain, 4–6 months old and weighing 275–300 grams, were subjected to unilateral nephrectomy and the acid phosphatase activity in the remaining kidney was studied at the end of 24, 48, 72 hours, and 8 days respectively. Most of the acid phosphatase was found in the particulate fraction in normal kidneys. The enzyme activity in the soluble fraction was found to have increased the second day after the operation, but decreased to the original level by the end of 72 hours. The free activity of the lysosomal fraction also increased by the end of second postoperative day. A change in the permeability of the lysosomal membrane before the enzyme release was observed. The probable role of lysosomal enzymes in the initiation of mitotic divisions during compensatory renal hyperplasia is discussed.


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