To better define critical functions of the hyaluronan receptor CD44 in cartilage.
Articular chondrocytes and cartilage tissue slices were treated with CD44 sequence-specific antisense phosphorothioate oligonucleotides. CD44 expression was probed by immunofluorescence microscopy, enzyme-linked immunosorbent assay, and Western blotting.
Antisense oligonucleotides demonstrated a dose- and time-dependent inhibition of CD44 protein expression; negative controls showed no effect. Similar to osteoarthritic cartilage, antisense-treated cartilage slices displayed a near-total loss of stainable proteoglycan-rich matrix.
CD44 expression is needed for maintenance of cartilage homeostasis.