The formation of ε-(γ-glutamyl)-lysine bonds is associated with collagen degradation in CIA. Images (40× magnification) of representative zones of synovial membrane/cartilage from articular tissue sections of control and arthritic rats at different times (18, 28, and 32 days) after immunization with type II collagen. Tissues were immunostained with (A) ε-(γ-glutamyl)-lysine bond antibody and hematoxylin or (B) degraded collagen antibody. Associated graphs show relative labeling intensity calculated from six random fields for each tissue section in the synovial membrane (upper graphs) or in the cartilage (lower graphs). Each column represents mean value ± SEM of total fields from two different tissue sections per individual rat (Ctl, n = 4; CIA, n = 8). (C) Representative images (10× magnification) of immunostaining of ε-(γ-glutamyl)-lysine bonds (red), degraded collagen (blue), and double labeling (purple) in successive CIA tissue sections (*cartilage; **bone).
Lauzier et al. Arthritis Research & Therapy 2012 14:R159 doi:10.1186/ar3899