Figure 2

Mild osteoarthritis observed in dominant-negative transforming growth factor β type II receptor mice. Sections from 20-week-old control (A), (C) and (E) and dominant-negative transforming growth factor β type II receptor (DNIIR) (B), (D) and (F) tibiae (n = 3 control and 3 DNIIR) were stained with H & E (A) and (B), toluidine blue (C) and (D) and Sirius red/polarized light microscopy (E) and (F) to determine the extent of osteoarthritis (n = 3 controls and 3 DNIIR). Fibrillation at the surface (B), focal cationic matrix stain depletion (D), cell clusters (D, arrow and inset) and disorganized and increased collagen fibers (F, arrows) are shown.