Polymorphonuclear neutrophils release 35S-labelled proteoglycans into cartilage during frustrated phagocytosis.
Rabbit peritoneal polymorphonuclear neutrophils (PMN), incubated in medium containing [35S]sulphate, incorporated 35S into proteoglycan and protein fractions. Approximately 46% of the 35S-labelled macromolecules associated with the PMN cells after 1 h of incubation were recovered in a cytoplasmic granule extract, the majority being present in azurophil granules. Analysis of the azurophil granule fraction showed that approximately 90% of the 35S-labelled macromolecules were proteoglycans. When challenged with heat-aggregated rabbit gamma-globulin in the presence of cytochalasin B and cGMP, PMN were induced to release granular enzymes but did not release 35S-labelled proteoglycans into the incubation medium. When incubated with articular cartilage slices, PMN released their granule 35S-labelled proteoglycan into the medium and into the cartilage matrix. Granule enzymes and 35S-labelled granule proteoglycan were extracted from the cartilage tissue after incubation and 35S-labelled macromolecules were detected in the cartilage tissue by autoradiography.
Gardiner
E E
EE
Department of Biochemistry, Monash University, Clayton, Australia.
Mok
S S
SS
Sriratana
A
A
Robinson
H C
HC
Veitch
B J
BJ
Lowther
D A
DA
Handley
C J
CJ
D000818:Animals; D001345:Autoradiography; D002358:Cartilage, Articular / Q000378:metabolism*; D015550:Cell Degranulation; D002478:Cells, Cultured; D003594:Cytoplasmic Granules / Q000201:enzymology; D005966:Glucuronidase / Q000378:metabolism*; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism*; D010587:Phagocytosis; D011509:Proteoglycans / Q000378:metabolism*; D011817:Rabbits; D005719:gamma-Globulins / Q000378:metabolism
D011509:Proteoglycans; D005719:gamma-Globulins; D005966:Glucuronidase