Defects in Tendon, Ligament, and Enthesis in Response to Genetic Alterations in Key Proteoglycans and Glycoproteins: A Review

Figure 4

Remodeling of the PDL of incisors is defective in 𝑃𝑜𝑠𝑡𝑛^−/− mice. H&E-stained PDL section from 12week 𝑃𝑜𝑠𝑡𝑛^+/+ (a) and 𝑃𝑜𝑠𝑡𝑛^−/− (b) mice. Arrows indicate the shear zone, which is the boundary between the TR (tooth-related) and AR (alveolus-related) regions. The shear zone is clearly visible in 12 week old 𝑃𝑜𝑠𝑡𝑛^+/+ mouse (a) and absent in 𝑃𝑜𝑠𝑡𝑛^−/− mouse (b). TEM of the incisor PDL shows evidence of digestion of collagen fibers in 𝑃𝑜𝑠𝑡𝑛^+/+ (c) but undigested and abundant collagen bundles in 𝑃𝑜𝑠𝑡𝑛^−/− mice (d). De, dentin; Al, alveolar bone. (Reprinted from Kii et al., 2006 [102], with permission, Elsevier 2006, and thanks to Dr. A. Kudo for his generous approval.)