Immunohistochemical Characterization of Elastic System Fibers in Rat Molar Periodontal Ligament

Abstract

S U M M A R Y Among elastic system fibers, oxytalan fibers are known as a ubiquitous component of the periodontal ligament, but the localization and role of elastin-containing fibers, i.e., elastic and elaunin fibers, has yet to be clarified. In this study, we immunohistochemically investigated the localization of elastin and fibrillin, major proteins of elastin-containing fibers in the periodontal ligament of rat lower first molars. At the light microscope level, distribution of elastin-positive fibers was not uniform but often concentrated in the vicinity of blood vessels in the apical region of the ligament. In contrast, fibrillin-positive fibers were more widely distributed throughout the ligament, and the pattern of their distribution was comparable to the reported distribution of oxytalan fibers. At the ultrastructural level, assemblies or bundles of abundant fibrillin-containing microfibrils were intermingled with a small amount of elastin. This observation indicated that elastin-positive fibers observed under the light microscope were elaunin fibers. No mature elastic fibers, however, were found in the ligament. These results show that the major components of elastic system fibers in the periodontal ligament of the rat mandibular first molar were oxytalan and elaunin fibers, suggesting that the elastic system fibers play a role in the mechanical protection of the vascular system.

ADAMTSL6β Protein Rescues Fibrillin-1 Microfibril Disorder in a Marfan Syndrome Mouse Model through the Promotion of Fibrillin-1 Assembly

“…However, the importance of the molecular mechanisms governing fibrillin-1 assembly during organogenesis has been hampered by the unanswered issue of the actual factor that drives microfibril assembly. Our present study demonstrates that ADAMTSL6␤, an inducing factor for microfibril assembly (18), regulates development and regeneration of PDL. Furthermore, ADAMTSL6␤-mediated fibrillin-1 microfibril assembly may accelerate the sequestration of large latent complexes of TGF-␤ or active TGF-␤, thereby negatively regulating the expression of TGF-␤ regulatory targets, such as periostin (35,42).…”

Fibroelastic Components of the Vesicourethral Junction of Rats in the Aging Process

“…This concurs with the findings of Kajikawa et al;Cotta-Pereira et al (1976) and Sawada et al (2006), the elaunin fibers, in turn, are ultrastructurally characterized by being composed of scarce amorphous material scattered amid the microtubular component, as previously shown by CottaPereira et al (1976CottaPereira et al ( , 1977. However, the oxytalan fibers are represented by bundles of microtubules arranged in parallel, confirming the findings of Simmons & Avery (1980), De Carvalho & Line (1996, Chopard et al (1998) and Chopard & Gerhard (2000).…”

Marfan syndrome and its disorder in periodontal tissues

“…This was also shown by in vitro studies that cultured gingival fibroblasts expressed both microfibrils and elastin (Tsuruga et al, 2002a), and PDL-cells only expressed microfibrils, fibrillin-1 and fibrillin-2 (Tsuruga et al, 2002b). The immunolocalization of elastin and fibrillins in the rat PDL is reported (Sawada et al, 2006). It is shown that a small amount of elastin is localized in the apical region of the PDL.…”