A method to cleave target molecules in a neocartilage.

The mechanical function of many matrix molecules is unknown. A common method to determine whether a molecule is a load-carrying structural molecule is to measure the mechanical properties of a tissue, digest the tissue with an enzyme specific for cleaving that molecule, and then remeasure the mechanical properties. A limitation of this technique is that there are no specific lytic enzymes for most molecules of interest.

Effect of decorin and dermatan sulfate on the mechanical properties of a neocartilage.

Decorin is known to influence the size of collagen fibrils in ligaments and tendons and it has been hypothesized to provide a structural link between collagen fibrils in connective tissues, including cartilage. Coincidently, mechanical properties of skin, ligament, and tendons are altered in decorin knockout mice, suggesting it may influence the structural properties of tissue or tissue matrix organization. To further examine the role of decorin in the extracellular matrix development and subsequent material properties of cartilage, tissue (neocartilage) was grown in a 3D culture model using a pure population of genetically modified chondrocytes stably overexpressing decorin (DCN) or decorin lacking dermatan sulfate (MDCN).

Effect of dermatan sulfate on the indentation and tensile properties of articular cartilage.

Objective: This paper examines the hypothesis that the dermatan sulfate (DS) chain on decorin is a load carrying element in cartilage and that its damage or removal will alter the material properties.

Methods: To test this hypothesis, indentation and tensile testing of cartilage from bovine patella were performed before and after digestion with chondroitinase B (cB). Removal of significant amounts of DS by cB digestion was verified by Western blot analysis of proteoglycans extracted from whole and sectioned specimens.

Influence of bone morphogenetic protein-2 on the extracellular matrix, material properties, and gene expression of long-term articular chondrocyte cultures: loss of chondrocyte stability.

The aim of this study was to determine the effects of bone morphogenetic protein-2 (BMP-2) on articular chondrocyte tissues grown as monolayers in vitro for up to 8 weeks. Articular chondrocytes were isolated from New Zealand White rabbits and plated in monolayer cultures. The cultures were supplemented with 100 ng/mL of BMP-2 for up to 8 weeks and the extracellular matrix (ECM) composition, material properties, and messenger RNA (mRNA) expression were analyzed.

Collagen 11a1 is indirectly activated by lymphocyte enhancer-binding factor 1 (Lef1) and negatively regulates osteoblast maturation.

Alpha 1 (XI) collagen (Col11a1) is essential for normal skeletal development. Mutations in Col11a1 cause Marshall and Stickler syndromes, both of which are characterized by craniofacial abnormalities, nearsightedness and hearing deficiencies. Despite its link to human diseases, few studies have described factors that control Col11a1 transcription.