leupeptins and Granuloma

Inflammation involves the sequential activation of signaling pathways leading to the production of both pro- and anti-inflammatory mediators. Although much attention has focused on pro-inflammatory pathways that initiate inflammation, relatively little is known about the mechanisms that switch off inflammation and resolve the inflammatory response. The transcription factor NF-kappaB is thought to have a central role in the induction of pro-inflammatory gene expression and has attracted interest as a new target for the treatment of inflammatory disease. We show here that NF-kappaB activation in leukocytes recruited during the onset of inflammation is associated with pro-inflammatory gene expression, whereas such activation during the resolution of inflammation is associated with the expression of anti-inflammatory genes and the induction of apoptosis. Inhibition of NF-kappaB during the resolution of inflammation protracts the inflammatory response and prevents apoptosis. This suggests that NF-kappaB has an anti-inflammatory role in vivo involving the regulation of inflammatory resolution.

Topics: Animals; Anti-Infective Agents; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; bcl-2-Associated X Protein; Carrageenan; Cysteine Endopeptidases; Female; Granuloma; Inflammation; Leukocytes; Leupeptins; Male; Mice; Multienzyme Complexes; NF-kappa B; Nitriles; Pleurisy; Proteasome Endopeptidase Complex; Protein Binding; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Pyrrolidines; Rats; Sulfones; Thiocarbamates; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Suppressor Protein p53

Cathepsin B isolated from carrageenin-induced granuloma tissue was separated into two peaks (one large and one small) on CM-cellulose column chromatography. The cathepsin B activities from the peritoneal macrophages and polymorphonuclear leukocytes were eluted at the positions identical to those of the larger (P-D and the smaller (P-II) peaks, respectively. Similarly, the cathepsin B activities in the P-I and P-II fractions from granuloma tissue corresponded to those from macrophages and leukocytes, respectively, in isoelectric focusing in polyacrylamide gel. Both the cathepsin B activities were completely inhibited by iodoacetamide and leupeptin, but phenylmethanesulfonyl fluoride and o-phenanthroline were ineffective. The molecular weight of the cathepsin B of the cellular origin and granuloma tissue was approximately 24,000 by gel filtration. The pI value of cathepsin B in the P-I and P-II fractions from granuloma tissue was 5.09 and 5.18, respectively. These results strongly suggest that two types of cathepsin B in granuloma tissue may be different in cellular origin and may be isozymes.

Topics: Animals; Carrageenan; Cathepsins; Connective Tissue Diseases; Granuloma; Iodoacetamide; Leukocytes; Leupeptins; Macrophages; Male; Rats; Rats, Inbred Strains