Osteoblasts from the sclerotic subchondral bone downregulate aggrecan but upregulate metalloproteinases expression by chondrocytes. This effect is mimicked by interleukin-6, − 1beta and oncostatin M pre-treated non-sclerotic osteoblasts - Sanchez, C; Deberg, M A; Piccardi, N (Osteoarthritis Cartilage, 2005)