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.
Ramaswamy et al. Arthritis Research & Therapy 2012 14:R49 doi:10.1186/ar3762