Fig. 4

Western blots depicting the expression of decorin and biglycan after proteoglycan extraction from non-chondrodystrophic (NCD) and chondrodystrophic (CD) canine intervertebral disc (IVD) nucleus pulposus (NP). For each Western blot, lane (a) is undigested (U) proteoglycan extract from NCD (mongrel) and lane (c) is from CD (beagle) canine NP. Lanes (b) and (d) depict the detection of the specific small leucine-rich proteoglycan (SLRP) indicated above after digestion (D) with chondroitinase ABC and keratinase in NCD canine (lane b) and CD canine (lane d). a The decorin core protein is visualized appropriately at the 43 kDa molecular weight after digestion (lane b), with a clear, single band found from NCD NP extracts. NP extracts from CD canines (lane d) reveal fragmentation of decorin with multiple lower molecular weight bands visualized at 30, 25–20, and 17–15 kDa. b The biglycan core protein provides a clear, single band at the 45 kDa molecular weight in the NCD NP extract; however, the CD NP extract reveals multiple fragments of the core protein visualized at 37–35, 28, and 25 kDa