Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.6.4 (chondroitinase)
 2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myofibroblasts play an important role in fibrogenesis. Myofibroblasts secrete several components of the extracellular matrix, including decorin. To clarify the properties of decorin synthesized by myofibroblasts, we have purified and characterized decorin secreted into culture medium by the myofibroblast cell line MRC-5. Decorin was purified by successive chromatography steps using Hitrap Q and Superdex 200. Purified decorin showed a broad band on SDS-polyacrylamide gel electrophoresis, which was resolved into two smaller molecular weight bands after digestion with chondroitinase ABC. Further digestion with N-glycanase resolved these two bands into a single band, indicating that the N-glycation pattern of decorin is heterogeneous. The N-terminal amino acid sequence analysis of the purified protein and its reactivity towards an antibody raised against a C-terminal peptide of decorin indicate that MRC-5 cells secrete full-length decorin into the culture medium. To characterize the glycosaminoglycan chains attached to decorin, glycosaminoglycans from the purified protein were treated with chondroitinase ACI, chondroitinase ACII, chondroitinase ABC and chondroitinase B. The resulting disaccharides were analyzed by chromatography, which indicated that decorin secreted by MRC-5 cells is a dermatan sulfate proteoglycan. In conclusion, the decorin secreted by MRC-5 cells has similar characteristics to the decorin expressed in several tissues. Thus, culturing MRC-5 cells may be highly useful for studying the role of decorin and myofibroblasts in fibrosis.
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PMID:Purification and characterization of decorin from the culture media of MRC-5 cells. 1514 41

Tendonitis and tendon rupture have been reported to occur during or following therapy with fluoroquinolone antibiotics. Though the pathogenesis is unknown, several studies suggest that fluoroquinolone antibiotics alter proteoglycan content in soft tissues, including tendons, and thereby alter collagen fibrillogenesis. To better understand the mechanism of action of fluoroquinolones, we studied the effects of enrofloxacin, a widely used fluoroquinolone in veterinary medicine, on avian tendon cell cultures established from gastrocnemius tendons from 18-day-old chicken embryos. We found that cell proliferation was progressively inhibited with increasing concentrations of enrofloxacin. This was accompanied by changes in morphology, extracellular matrix content and collagen fibril formation as detected by electron microscopy. We also observed a 35% decrease in the content of total monosaccharides in enrofloxacin-treated cells. The ratio of individual monosaccharides was also altered in enrofloxacin-treated cells. Enrofloxacin also induced the synthesis of small amounts of keratan sulfate in tendon cells. Moreover we observed enrofloxacin-induced changes in glycosylation of decorin, the most abundant tendon proteoglycan, resulting in the emergence of multiple lower molecular bands that were identifiable as decorin after chondroitinase ABC and N-glycanase treatment of extracts from enrofloxacin-treated cells. Medium conditioned by enrofloxacin-treated cells contained less decorin than did medium conditioned by control cells. We hypothesize that enrofloxacin induces either changes in the number of N-linked oligosaccharides attached to the core protein of decorin or changes in decorin degradation process. In conclusion, our data suggest that enrofloxacin affects cell proliferation and extracellular matrix through changes in glycosylation.
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PMID:The effects of enrofloxacin on decorin and glycosaminoglycans in avian tendon cell cultures. 1514 65


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