Distribution of type VI collagen expression in synovial tissue and cultured synoviocytes: relation to fibronectin expression.

Type vi collagen—specific messenger rna is expressed constitutively by cultured human synovial fibroblasts and is suppressed by interleukin–1

“…That type VI collagen is indeed an extractable component of the human synovial extracellular matrix has now been confirmed (lo), and studies utilizing immunofluorescence and immunogold staining suggest that it is in fact the major matrix protein of the synovial lining layer (9,34). Our current studies confirm and extend these findings, demonstrating that the synovial fibroblast, a major cellular component of the synovial lining, constitutively and abundantly expresses type VI collagen-specific mRNA.…”

“…Our current studies confirm and extend these findings, demonstrating that the synovial fibroblast, a major cellular component of the synovial lining, constitutively and abundantly expresses type VI collagen-specific mRNA. The demonstration of immunofluorescent staining for type VI collagen in the matrices of cells freshly dispersed from synovial tissue (34) supports the concept that synovial fibroblasts secrete intact type VI collagen protein.…”

“…This observation indicates that the type VI collagen-synthesizing capacity of synovial fibroblasts is not disease specific and supports a functional role for this protein in both normal and diseased states. Intact RA synovial tissues, nonetheless, demonstrate much stronger staining for type VI collagen protein than do OA and normal synovia (9,34), an observation that is most likely explained by the increased numbers of matrix-synthesizing cells in RA synovium. The possibility that the type VI collagensynthesizing capacity of the synovial fibroblast could be regulated by local factors in the inflammatory environment must also be considered, however.…”

Synovial fibroblasts self‐direct multicellular lining architecture and synthetic function in three‐dimensional organ culture

“…A primary function of fibroblasts is the production and organization of the ECM. Given their capacity to produce matrix components and matrix‐degrading enzymes as well as their ability to direct fibrillogenesis, FLS are thought to be major participants in the continuous process of matrix remodeling (5–12, 52). We now provide evidence that FLS are capable of autonomously establishing a complex basement membrane–like ECM in vitro that resembles the lining architecture in vivo.…”

“…FLS are major participants in all aspects of the active, continuous process of maintaining the synovial ECM. Histochemical studies show that FLS produce matrix components, such as fibronectin, collagens, laminin, tenascin, and the proteoglycans (5–11). FLS also direct matrix component assembly via cell surface expression of integrin species, such as α5β1 and α V β3 (1, 12).…”