Fig. 5
From: Increased caveolin-1 in intervertebral disc degeneration facilitates repair
Caveolin-1 expression and apoptosis levels are increased during canine intervertebral disc (IVD) degeneration. a Terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end (TUNEL) assay and immunohistochemical staining for caveolin-1. Part of a healthy canine nucleus pulposus (NP) (Thompson grade I) and a severely degenerated canine NP (Thompson grade V) with brown apoptotic notochordal cell (NC) nuclei (TUNEL) and brown NC membranes and cytoplasm (caveolin-1). b The mean TUNEL ratio (the proportion of positively stained TUNEL nuclei in the NP) per Thompson degeneration score of canine IVDs. Apoptosis levels increased during canine IVD degeneration in chondrodystrophic (CD) and nonchondrodystrophic (NCD) dogs. The r values indicate the partial correlation between the mean TUNEL ratio and IVD degeneration grade (Thompson grade range I–V) for CD and NCD dogs. *p < 0.05 (significance indicated for changes related to Thompson grade). c The mean caveolin-1 ratio (the proportion of the total NP surface area that stained positive for caveolin-1) per Thompson degeneration score of canine IVDs. The r values indicate the partial correlation between the mean caveolin-1 ratio and IVD degeneration grade (Thompson score range II–V) for CD and NCD dogs. Caveolin-1 protein expression increases during canine IVD degeneration in CD and NCD dogs. *p < 0.05 (significance indicated for changes related to Thompson grade). n = 37 IVD samples from 16 dogs