title: Use of staurosporine, an actin-modifying agent, to enhance fibrochondrocyte matrix gene expression and synthesis.
abstract: Modulation of the actin cytoskeleton in chondrocytes has been used to prevent or reverse dedifferentiation and to enhance protein synthesis. We have hypothesized that an actin-modifying agent, staurosporine, could be used with fibrochondrocytes to increase the gene expression and synthesis of critical fibrocartilage proteins. A range of concentrations (0.1-100 nM) was applied to fibrochondrocytes in monolayer and evaluated after 24 h and after 4 days. High-dose staurosporine treatment (10-100 nM) increased cartilage oligomeric matrix protein 60- to 500-fold and aggrecan gene expression two-fold. This effective range of staurosporine was then applied to scaffoldless tissue-engineered fibrochondrocyte constructs for 4 weeks. Whereas glycosaminoglycan synthesis was not affected, collagen content doubled, from 27.6 +/- 8.8 microg in the untreated constructs to 55.2 +/- 12.2 microg per construct with 100 nM treatment. When analyzed for specific collagens, the 10-nM group showed a significant increase in collagen type I content, whereas collagen type II was unaffected. A concomitant dose-dependent reduction was noted in construct contraction, reflecting the actin-disrupting action of staurosporine. Thus, staurosporine increases the gene expression for important matrix proteins and can be used to enhance matrix production and reduce contraction in tissue-engineered fibrocartilage constructs.
authors.affiliation: Department of Bioengineering, Rice University, Houston, TX, USA.
authors.forename: Gwendolyn M
authors.initials: GM
authors.lastname: Hoben
authors.forename: Kyriacos A
authors.initials: KA
authors.lastname: Athanasiou
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis* / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects*; D007150:Immunohistochemistry; D008297:Male; D010590:Phalloidine / Q000378:metabolism; D013194:Staining and Labeling; D019311:Staurosporine / Q000494:pharmacology*; D013997:Time Factors; D023822:Tissue Engineering
chemical_list: D000199:Actins; D016326:Extracellular Matrix Proteins; D010590:Phalloidine; D003094:Collagen; D019311:Staurosporine