Experimental chemonucleolysis with recombinant human matrix metalloproteinase 7 in human herniated discs and dogs.

BACKGROUND CONTEXT: Chemonucleolysis has been proposed as a less invasive technique than surgery for patients with lumbar disc herniation. Once chymopapain had been approved as a chemonucleolysis drug, it was withdrawn because of serious complications. A novel agent with fewer complications would be desirable. PURPOSE: The purpose of this study was to investigate the effects of recombinant human matrix metalloproteinase 7 (rhMMP-7) in experimental chemonucleolysis in vitro and in vivo and examine its effects on tissue damage. STUDY DESIGN: The study design is the experimental study using human herniated discs and enzyme substrates in vitro and dogs in vivo. METHODS: The effects of rhMMP-7 on the degradation of human herniated discs were examined by measuring the wet weight in vitro. The correlations between the decrease in wet weight by rhMMP-7 and the conditions associated with herniated discs were also analyzed. The effects of rhMMP-7 on the proteoglycan and water contents were respectively examined with alcian blue staining and T2-weighted magnetic resonance imaging at 7 days after intradiscal injection in dogs. The distribution of [125I]-labeled rhMMP-7 was investigated by autoradioluminography at 7 days after intradiscal injection in dogs. An epidural injection study with rhMMP-7 was performed to evaluate the effects on the tissue damage around the discs at 1 and 13 weeks after the treatment in dogs. The Type 1 and 2 collagen cleavage rates were measured and compared with those of aggrecan in vitro. RESULTS: Recombinant human matrix metalloproteinase 7 concentration dependently decreased the wet weight of herniated discs in vitro. The decrease in wet weight of the discs by rhMMP-7 did not significantly correlate with the conditions associated with herniated discs. Intradiscal injection of rhMMP-7 reduced the proteoglycan and water contents, with an increase in the serum keratan sulfate levels. Radioactivity of [125I]-labeled rhMMP-7 was detected in the nucleus pulposus and annulus fibrosus but not in the muscle. Epidural injection of rhMMP-7 had no effect on the injection site or the nerve tissues. The Type 1 and 2 collagen cleavage rates of rhMMP-7 were 1,000-fold weaker than those of aggrecan. CONCLUSIONS: This study demonstrated experimental chemonucleolysis with rhMMP-7 in vitro and in vivo. The effects of rhMMP-7 were not affected by the conditions associated with herniated discs. The epidural injection study together with the autoradioluminography and in vitro enzyme assay suggests that intradiscal injection of rhMMP-7 may not induce tissue damage around the discs because of its distribution and substrate selectivity. Recombinant human matrix metalloproteinase 7 may be a novel and promising chemonucleolysis agent.

Mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2) as an antiinflammatory target: discovery and in vivo activity of selective pyrazolo[1,5-a]pyrimidine inhibitors using a focused library and structure-based optimization approach.

A novel class of mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2) inhibitors was discovered through screening a kinase-focused library. A homology model of MAPKAP-K2 was generated and used to guide the initial SAR studies and to rationalize the observed selectivity over CDK2. An X-ray crystal structure of a compound from the active series bound to crystalline MAPKAP-K2 confirmed the predicted binding mode. This has enabled the discovery of a series of pyrazolo[1,5-a]pyrimidine derivatives showing good in vitro cellular potency as anti-TNF-α agents and in vivo efficacy in a mouse model of endotoxin shock.

SF2809 compounds, novel chymase inhibitors from Dactylosporangium sp. 1. Taxonomy, fermentation, isolation and biological properties.

Six novel chymase inhibitors, SF2809-I, SF2809-II, SF2809-III, SF2809-IV, SF2809-V and SF2809-VI, were isolated from the fermentation broth of an actinomycete strain SF2809. The strain was identified as Dactylosporangium sp. by morphological, chemotaxonomical and phylogenetic studies. These six novel compounds inhibited recombinant human chymase in the range between IC50 of 0.014 and 7.3 microM. However, they showed little or no inhibitory activity against chymotrypsin or cathepsin G, even though these two and chymase belong to the chymotryptic serine protease family. This result indicates that these compounds work as specific chymase inhibitors.

SF2809 compounds, novel chymase inhibitors from Dactylosporangium sp. 2. Structural elucidation.

Novel chymase inhibitors, SF2809-I, II, III, IV, V and VI, were isolated from the fermentation broth of Dactylosporangium sp. SF2809, and their structures were determined by spectroscopic analyses. SF2809 compounds commonly contain a substituted indole moiety and a quinolinone moiety. The two moieties are connected to a methylene carbon in SF2809-I and III. The other compounds, SF2809-II, IV, V and VI, have an additional moiety, a p-hydroxyphenyl group or a phenyl group. In these compounds, all of three moieties are connected to a methine carbon. Furthermore, studies concerning the stereochemistry of SF2809-V revealed that the isolated compound was racemic, and the isomer possessing (R)-configuration was about thirty times more potent than another isomer.