Histochemical examination on principal collagen fibers in periodontal ligaments of ascorbic acid-deficient ODS-od/od rats. (3rd July 2019)

• Record Type: Journal Article
• Authors: Hasegawa, Tomoka; Miyamoto-Takasaki, Yukina; Abe, Miki; Qiu, Zixuan; Yamamoto, Tomomaya; Yimin, ; Yoshida, Taiji; Yoshino, Hirona; Hongo, Hiromi; Yokoyama, Ayako; Sasaki, Muneteru; Kuroshima, Shinichiro; Hara, Kuniko; Kobayashi, Masatoshi; Akiyama, Yasuhiro; Maeda, Takeyasu; Luiz de Freitas, Paulo Henrique; Li, Minqi; Amizuka, Norio
• Is Part Of: Microscopy. Volume 68:Number 5(2019)
• Page Start: 349
• Page End: 358
• Publication Date: 2019-07-03
• Subjects: periodontal ligament -- ascorbic acid -- collagen fibril -- reticular fibril -- histochemistry; Microscopy -- Periodicals; 502.825
• DOI: 10.1093/jmicro/dfz021
• Languages: English
• ISSNs: 2050-5698

Abstract

Abstract: In this study, we aimed to clarify the role of ascorbic acid in collagen synthesis in periodontal ligaments using osteogenic disorder Shionogi (ODS)/ShiJcl- od/od rats lacking L-gulonolactone oxidase. These rats cannot synthesize ascorbic acid in vivo . Eight-week-old ODS/ShiJcl- od/od male rats were administered ascorbic acid solution at a concentration of 200 mg/dL (control group, n = 6) or ascorbic acid solution at concentration of 0.3 mg/dL (insufficient group, n = 12). Six rats of the insufficient group were then given with ascorbic acid solution at concentration of 200 mg/dL for additional 3 weeks (rescued group, n = 6), and then, their mandibles were histochemically examined. Consequently, the insufficient group specimens were seen to possess fewer collagen fibers, and silver impregnation revealed numerous fine, reticular fiber-like fibrils branching off from collagen in the periodontal ligaments. In control group, faint immunoreactivities for matrix metalloproteinase (MMP)2 and cathepsin H were seen in the periphery of blood vessels and throughout the ligament, respectively. In contrast, in the insufficient group, intense MMP2-immunoreactivity was observed to be associated with collagen fibrils in the periodontal ligaments, and cathepsin H-immunopositivity was seen in ligamentous cells. The rescued group showed abundant collagen fibers filling the periodontal ligament space. Under transmission electron microscopy, ligamentous fibroblasts incorporated collagen fibrils into tubular endosomes/lysosomes while simultaneously synthesizing collagen fibril bundles. Thus, ascorbic acid insufficiency affected the immunolocalization of cathepsin H and MMP2; however, ligamentous fibroblasts appear to possess the potential to synthesize collagen fibers when supplied with ascorbic acid.