Reconstruction Culture System Simulating Human Synovium: A Three-dimensional Collagen Gel Culture of Synoviocytes.

Abstract

ABSTRACT. Wedeveloped a reconstruction culture system simulating humansynovium to investigate the synoviocytes in a more physiological condition. This system with two types of dishes provided the two separated spaces corresponding to the joint cavity and nutrient vessels. The isolated normal synoviocytes were cultured in type-I collagen gel with a layer-seeded on top in a smaller inner dish with a porous bottom, which was placed in a larger outer dish. Weadded hyaluronic acid solution to the space on the gel to makean environmentclose to the physiological joint cavity. The space between the inner and outer dishes was filled with a complete medium to nourish the synoviocytes through the porous filter (Experiment 1). In addition, to examine cell-to-cell interaction, we created a co-culture model by mixing synoviocytes and peripheral blood mononuclear cells in the collagen gel matrix (Experiment 2). In this way we could reconstruct the synovium in vitro. The synoviocytes could survive and maintain their characteristics for four weeks of culture. In Experiment 1, almost all the cells were similar to type B synovial cells by histological, immunohistochemical and electron microscopic observations. In Experiment 2, the spherical cells in abundance of lysosomes like type A synovial cells appeared sporadically in the lining layer. Immunohistochemically, the majority of cultured cells expressed CD68and matrix metalloproteinase 3. This culture system promises to be of use in investigating the pathogenesis of various joint diseases.Humansynovium is comprised of lining and sub-lining layers with loose connective tissue. The lining layer consists of a few macrophage-like type A and manyfibroblast-like type B synovial cells (4, 5). These lining cells are nourished primarily via the blood circulation in the sub-lining layer (4), and are also influenced by joint fluid (1, 19). It has been pointed out, meanwhile, that extracellular matrix, e.g., collagen and fibronectin, in the sub-lining layers is involved in the regulation of the proliferation and function of synovial cells (1 1, 14, 17, 24). In the sub-lining layer, fibroblasts and a small number of mononuclear cells exist under physiological conditions, and in chronic synovitis the infiltrations of inflammatory cells are recognized histologically (4, 7, 10).The investigation of the complex interactions between synovial cells, inflammatory cells and joint fluid promises to contribute to the advance of the pathology and treatment in various joint diseases (7, 10, ll, 12, 16). A conventional culture system, using a monolayer culture of synovial fibroblasts, cannot offer a physiological condition of synovium described above. One of the authors (22) reported that a collagen gel culture system could provide an environment more similar to that in vivo. This system could reconstruct the structures of many types of tissues, i.e., skin, cornea, thyroid follicles, or pulmonary alveoli. However, as yet it has not been applied to the reconstruction of synovium. Wedeveloped a reconstruct...

Review of In Vitro Models and Development and Initial Validation of a Novel Co-Culture Model for the Study of Osteoarthritis

“…Monolayer chondrocyte cultures, three-dimensional chondrocyte cultures, articular cartilage explant cultures, synoviocyte cultures, and synovial explant cultures have been employed in the study of OA [2,[12][13][14][15][16][17][18]20,21,[23][24][25][26]30,31,[33][34][35]39,40]. Monolayer chondrocyte cultures, three-dimensional chondrocyte cultures, articular cartilage explant cultures, synoviocyte cultures, and synovial explant cultures have been employed in the study of OA [2,[12][13][14][15][16][17][18]20,21,[23][24][25][26]30,31,[33][34][35]39,40].…”