The Experts below are selected from a list of 171 Experts worldwide ranked by ideXlab platform
Yoshihiko Sawa - One of the best experts on this subject based on the ideXlab platform.
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Matrix metalloproteinase-2 degrades fibrillin-1 and fibrillin-2 of Oxytalan fibers in the human eye and periodontal ligaments in vitro.
Acta Histochemica Et Cytochemica, 2013Co-Authors: Megumi Kawagoe, Yoshihiko Sawa, Eichi Tsuruga, Hiroyuki IshikawaAbstract:Oxytalan fibers are distributed in the eye and periodontal ligaments (PDL). The ciliary zonule, known as Zinn’s zonule, in the eye is composed of Oxytalan fibers, which are bundles of microfibrils consisting mainly of fibrillin-1 and fibrillin-2. As turnover of Oxytalan fibers is slow during life, their degradation mechanism remains unclarified. This study was performed to examine degradation pattern of fibrillin-1 and fibrillin-2 by experimental MMP activation. We cultured human non-pigmented ciliary epithelial cells (HNPCEC) and PDL fibroblasts for 7 days, then treated them with concanavalin A to activate matrix metalloproteinase (MMP)-2, and examined the degradation of fibrillin-1 and fibrillin-2 for 72 hr using immunofluorescence. At 7 days of HNPCEC culture, fibrillin-1-positive fibers were observed, some of which merged with fibrillin-2. After MMP-2 activation, fibrillin-1-positive fibers became thin and disappeared by 72 hr, while fibrillin-2-positive fibers disappeared almost completely within 24 hr. At 7 days of PDL fibroblast culture, fibrillin-1-positive fibers were mostly merged with fibrillin-2. After MMP-2 activation, fibrillin-1-positive fibers became thin by 24 hr and had almost disappeared by 48 hr, while fibrillin-2-positive fibers decreased constantly after 24 hr. A MMP-2 inhibitor completely suppressed these degradations. These results suggest that the patterns of fibrillin-1 and fibrillin-2 degradation differ between the eye and the PDL, possibly reflecting the sensitivity of fibrillin-1 and fibrillin-2 of each type of Oxytalan fiber against MMP-2.
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Latent transforming growth factor-β binding protein 2 negatively regulates coalescence of Oxytalan fibers induced by stretching stress.
Connective tissue research, 2012Co-Authors: Eichi Tsuruga, Yuji Hatakeyama, Kyoko Oka, Keitaro Isokawa, Yoshihiko SawaAbstract:Oxytalan fibers are extracellular matrix components consisting of pure microfibrils. However, the mechanism whereby Oxytalan fibers develop is not fully understood. We have previously reported that in human periodontal ligament (PDL) fibroblasts subjected to stretching stress, bundles of Oxytalan fibers coalesce under the control of fibulin-5. Latent transforming growth factor-β binding protein 2 (LTBP-2) is known to bind to fibulin-5. The purpose of this study was to clarify the role of LTBP-2 in the coalescence of Oxytalan fibers. We subjected PDL fibroblasts to stretching in order to examine the effects of LTBP-2 on the coalescence of Oxytalan fibers in cell/matrix layers. Interaction of LTBP-2 with fibulin-5 was examined by immunoprecipitation assay, and changes in LTBP-2 deposition upon stretching were investigated by Western blotting and immunofluorescence assays. We used small interfering RNA against LTBP-2 in PDL cell culture and examined the appearance of Oxytalan fibers on the basis of immunoflu...
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Intracellular interaction of EMILIN-1 with fibrillin-1 in human periodontal ligament cells
Orthodontic Waves, 2012Co-Authors: Yuka Nakatomi, Yoshinori Yamauchi, Kaori Yamanouchi, Kazuki Nakashima, Yoshihiko Sawa, Megumi Kawagoe, Eichi Tsuruga, Hiroyuki IshikawaAbstract:Abstract The elastic system fibers comprise Oxytalan, elaunin and elastic fibers, differing in their relative microfibril and elastin contents. Human periodontal ligaments (PDLs) contain Oxytalan fibers (pure microfibrils), which are composed mainly of fibrillin-1, the major component of microfibrils. We recently demonstrated that EMILIN-1, located at the interface between elastin and microfibrils, controls the amount of fibrillin-1 assembly in PDL fibroblast cell/matrix layers [8] , although the mechanism involved was unclear. We subjected cultured PDL fibroblasts to immunofluorescence and immunoprecipitation assays in order to examine the intracellular interaction of EMILIN-1 with fibrillin-1. Immunofluorescence showed that EMILIN-1 was colocalized with fibrillin-1, both inside and outside the cells. Additionally, EMILIN-1 formed a complex with fibrillin-1 in the intracellular fraction. These results suggest that EMILIN-1 may form complexes with fibrillin-1 in cellular vesicles, thus contributing effectively to the initial assembly of pericellular fibrillin-1 during the process of Oxytalan fiber formation.
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Intracellular interaction of EMILIN-1 with fibrillin-1 in human periodontal ligament cells
Orthodontic Waves, 2012Co-Authors: Yuka Nakatomi, Yoshinori Yamauchi, Kaori Yamanouchi, Kazuki Nakashima, Yoshihiko Sawa, Megumi Kawagoe, Eichi Tsuruga, Hiroyuki IshikawaAbstract:The elastic system fibers comprise Oxytalan, elaunin and elastic fibers, differing in their relative microfibril and elastin contents. Human periodontal ligaments (PDLs) contain Oxytalan fibers (pu...
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Stretch stimuli increase fibulin-5/EMILIN-1 complex on Oxytalan fibers in human periodontal ligament cells
Orthodontic Waves, 2011Co-Authors: Kazuki Nakashima, Yoshinori Yamauchi, Yuka Nakatomi, Yoshihiko Sawa, Eichi Tsuruga, Sachio Tamaoki, Yuichiro Hata, Hiroyuki IshikawaAbstract:Abstract Periodontal ligaments (PDLs) are continuously exposed to various functional forces, such as tooth movement and occlusal loading. Human PDLs comprise elastic system fibers as well as collagen fibers. The elastic system fibers in turn comprise Oxytalan, elaunin and elastic fibers, which differ in their relative microfibril and elastin contents. Human PDLs contain Oxytalan fibers (pure microfibrils), which are composed mainly of fibrillin-1 (the major component of microfibrils). We have previously reported that bundles of Oxytalan fibers in cultured PDL cells coalesce in response to mechanical strain, and that this coalescence is controlled by fibulin-5. However, the relationship between fibulin-5 and other fibrillin-1-binding molecules is unclear. In the present study we investigated whether fibulin-5 and EMILIN-1 (both of which are fibrillin-1-binding molecules) contribute to the formation of Oxytalan fibers upon exposure to mechanical strain. We subjected PDL cells to stretching in order to examine the role of fibulin-5 and EMILIN-1 in the formation of Oxytalan fibers in cell/matrix layers. We examined the relationship between fibulin-5 and EMILIN-1 in PDL cell cultures using immunofluorescence and immunoprecipitation assay. Immunofluorescence showed that fibulin-5 and EMILIN-1 were colocalized on fibrillin-1-positive Oxytalan fibers. Fibulin-5 formed a complex with EMILIN-1, and stretching increased the amount of this complex relative to cells that were not subjected to stretching. These results suggest that the expression of the fibulin-5/EMILIN-1 complex is upregulated in response to tension strain, and may control the formation of Oxytalan fibers in PDLs.
Eichi Tsuruga - One of the best experts on this subject based on the ideXlab platform.
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Matrix Metalloproteinase-2 Activated by Ultraviolet-B Degrades Human Ciliary Zonules In Vitro
Acta histochemica et cytochemica, 2021Co-Authors: Yuki Shiroto, Keitaro Isokawa, Ryo Saga, Hironori Yoshino, Yoichiro Hosokawa, Eichi TsurugaAbstract:The ciliary zonules, also known as the zonules of Zinn, help to control the thickness of the lens during focusing. The ciliary zonules are composed of Oxytalan fibers, which are synthesized by human nonpigmented ciliary epithelial cells (HNPCEC). The ciliary zonules are exposed to ultraviolet (UV), especially UV-A and UV-B, throughout life. We previously demonstrated that UV-B, but not UV-A, degrades fibrillin-1- and fibrillin-2-positive Oxytalan fibers. However, the mechanism by which UV-B degrades Oxytalan fibers remains unknown. In this study, we investigate the involvement of matrix metalloproteinase-2 (MMP-2) in the UV-B-induced degradation of fibrillin-1- and fibrillin-2-positive Oxytalan fibers in cultured HNPCECs. Enzyme-linked immunosorbent assay revealed that UV-B irradiation at levels of 100 and 150 mJ/cm2 significantly increased the level of active MMP-2. Notably, MMP-2 inhibitors completely suppressed the degradation of fibrillin-1- and fibrillin-2-positive Oxytalan fibers. In addition, we show that UV-B activates MMP-2 via stress-responsive kinase p38. Taken together, the results suggest that UV-B activates a production of active type of MMP-2 via the p38 pathway, and subsequently, an active-type MMP-2 degrades the fibrillin-1- and fibrillin-2-positive Oxytalan fibers in cultured HNPCECs.
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Stretching Induces the Rearrangement of the Periodontal Ligament Cells without Altering the Orientation of Oxytalan Fibers Relative to the Cell Axis in Vitro
Open Journal of Stomatology, 2016Co-Authors: Sachio Tamaoki, Yoshinori Yamauchi, Kaori Yamanouchi, Kazuki Nakashima, Eichi Tsuruga, Takahiro Fujita, Hiroyuki O. IshikawaAbstract:The periodontal ligament (PDL) contains Oxytalan fibers as well as collagen fibers, which helps it to withstand the mechanical stress to which it is constantly exposed. The Oxytalan fibers are produced by PDL fibroblasts. However, the arrangement of PDL fibroblasts and the orientation of Oxytalan fibers relative to the fibroblast cell axis have not been investigated under the condition of mechanical stress. We hypothesized that such stress would alter the arrangement and orientation of these cells and their Oxytalan fibers. The aim of this study was to evaluate the effects of stretching strain on PDL fibroblasts, focusing on the cellular arrangement and orientation of Oxytalan fibers relative to the long cell axis in cell/matrix layers by staining the major component of the fibers, fibrillin-1. The angle between the long cell axis and the Oxytalan fibers was approximately 70 degrees under both non-stretching and stretching conditions. Moreover, stretching induced the rearrangement of the cells. This is the first study to demonstrate that stretching induces the rearrangement of the PDL fibroblasts without altering the angle between the long cell axis and the Oxytalan fibers. These results may reflect the orientation of Oxytalan fibers in the PDL under the condition of mechanical stress.
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Matrix metalloproteinase-2 degrades fibrillin-1 and fibrillin-2 of Oxytalan fibers in the human eye and periodontal ligaments in vitro.
Acta Histochemica Et Cytochemica, 2013Co-Authors: Megumi Kawagoe, Yoshihiko Sawa, Eichi Tsuruga, Hiroyuki IshikawaAbstract:Oxytalan fibers are distributed in the eye and periodontal ligaments (PDL). The ciliary zonule, known as Zinn’s zonule, in the eye is composed of Oxytalan fibers, which are bundles of microfibrils consisting mainly of fibrillin-1 and fibrillin-2. As turnover of Oxytalan fibers is slow during life, their degradation mechanism remains unclarified. This study was performed to examine degradation pattern of fibrillin-1 and fibrillin-2 by experimental MMP activation. We cultured human non-pigmented ciliary epithelial cells (HNPCEC) and PDL fibroblasts for 7 days, then treated them with concanavalin A to activate matrix metalloproteinase (MMP)-2, and examined the degradation of fibrillin-1 and fibrillin-2 for 72 hr using immunofluorescence. At 7 days of HNPCEC culture, fibrillin-1-positive fibers were observed, some of which merged with fibrillin-2. After MMP-2 activation, fibrillin-1-positive fibers became thin and disappeared by 72 hr, while fibrillin-2-positive fibers disappeared almost completely within 24 hr. At 7 days of PDL fibroblast culture, fibrillin-1-positive fibers were mostly merged with fibrillin-2. After MMP-2 activation, fibrillin-1-positive fibers became thin by 24 hr and had almost disappeared by 48 hr, while fibrillin-2-positive fibers decreased constantly after 24 hr. A MMP-2 inhibitor completely suppressed these degradations. These results suggest that the patterns of fibrillin-1 and fibrillin-2 degradation differ between the eye and the PDL, possibly reflecting the sensitivity of fibrillin-1 and fibrillin-2 of each type of Oxytalan fiber against MMP-2.
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Progressive bundling of fibrillin microfibrils into Oxytalan fibers in the chick presumptive dermis.
Anatomical record (Hoboken N.J. : 2007), 2012Co-Authors: Keizo Shinozuka, Eichi Tsuruga, Yosuke Yamazaki, Maki Yuguchi, Taku Toriumi, Rie Suzuki, Keitaro IsokawaAbstract:Dorsoventral fibers in the presumptive dermis of the chick limb bud reported first by Hurle's group in 1989 are now revealed as bundles of fibrillin microfibrils (Isokawa et al., 2004). The bundles, which could be called Oxytalan fibers at the light microscopic level, are aligned perpendicularly to the overlying ectoderm and form a unique fiber array, originating directly from the basal lamina. This well-oriented organization is beneficial in examining the process of in vivo bundling of microfibrils into Oxytalan fibers. In this study, sections through the presumptive limb dermis were preferentially prepared from chick embryos at Days 4–6 (ED4-6). Immunohistochemically, fibrillin-positive dots representing cross-sectioned surfaces of individual fibers, increased in size from ED4 to 6, but their number per unit area remained constant. Ultrastructurally, a single Oxytalan fiber at ED4 consisted of ∼15 microfibrils; the latter number increased fourfold from ED4 to 5 and threefold from ED5 to 6. Oxytalan fibers were all closely associated with mesenchymal cell; notably, the fibers at ED5 and 6 were held in a shallow ditch on the cell body or by lamellipodial cytoplasmic protrusion. In the sites of cell–fiber adhesion, microfibrils in the periphery of an Oxytalan fiber appeared to adhere directly or by means of short flocculent strands to a nearby cell membrane; the latter showed a thickening of plasmalemma and its undercoat, indicating the presence of adhesive membrane specification. These findings suggest that the bundling of microfibrils is a progressive and closely cell-associated process. Anat Rec, 2013. © 2012 Wiley Periodicals, Inc.
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Latent transforming growth factor-β binding protein 2 negatively regulates coalescence of Oxytalan fibers induced by stretching stress.
Connective tissue research, 2012Co-Authors: Eichi Tsuruga, Yuji Hatakeyama, Kyoko Oka, Keitaro Isokawa, Yoshihiko SawaAbstract:Oxytalan fibers are extracellular matrix components consisting of pure microfibrils. However, the mechanism whereby Oxytalan fibers develop is not fully understood. We have previously reported that in human periodontal ligament (PDL) fibroblasts subjected to stretching stress, bundles of Oxytalan fibers coalesce under the control of fibulin-5. Latent transforming growth factor-β binding protein 2 (LTBP-2) is known to bind to fibulin-5. The purpose of this study was to clarify the role of LTBP-2 in the coalescence of Oxytalan fibers. We subjected PDL fibroblasts to stretching in order to examine the effects of LTBP-2 on the coalescence of Oxytalan fibers in cell/matrix layers. Interaction of LTBP-2 with fibulin-5 was examined by immunoprecipitation assay, and changes in LTBP-2 deposition upon stretching were investigated by Western blotting and immunofluorescence assays. We used small interfering RNA against LTBP-2 in PDL cell culture and examined the appearance of Oxytalan fibers on the basis of immunoflu...
A. Sculean - One of the best experts on this subject based on the ideXlab platform.
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Regeneration of Oxytalan fibres in different types of periodontal defects: a histological study in monkeys.
Journal of periodontal research, 2010Co-Authors: A. Sculean, Thorkild Karring, Nikolaos Donos, Elmar Reich, M. BrecxAbstract:The aim of the present study was to investigate in monkeys the regrowth of Oxytalan fibres in different types of acute and chronic periodontal defects following regenerative periodontal treatment. One-wall intrabony and mandibular furcation III-defects were produced surgically in 3 monkeys (Macaca fascicularis). After a 6-wk dental plaque accumulation period the defects were exposed using a full thickness flap procedure. The granulation tissue was removed and the root surfaces were scaled and planed. Additionally, fenestration-type defects were produced at the vestibular surfaces of the maxillary and mandibular canines by surgically removing the vestibular bone plates and the root cementum. Subsequently, the defects were treated with guided tissue regeneration (GTR), enamel matrix proteins (EMP), combination of EMP and GTR or with coronally repositioned flaps. The postoperative care included tooth cleaning once a week during the experiment. After 5 months the animals were sacrificed and and the block sections were embedded in paraffin. Eight μm histological sections were cut and stained with the oxone-aldehydefuchsin-Halmi method. The results revealed that in all specimens where a regenerated periodontal ligament could be observed newly formed Oxytalan fibers were present. They had a mainly apico-occlusal orientation and were localized closer to the cementum than to the alveolar bone. The regenerated Oxytalan fibers had a similar morphological appearance than those observed in the original periodontal ligament regardless of the treatment modality by which regeneration was accomplished. Their presence was related to that of newly formed cementum suggesting a strong relationship between these 2 tissues. The neoformation of Oxytalan fibres can thus be observed in some types of periodontal defects where the cementum and the periodontal ligament have been regenerated. © Munksgaard, 1998.
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Presence of Oxytalan fibers in human regenerated periodontal ligament
Journal of clinical periodontology, 1999Co-Authors: A. Sculean, Nikolaos Donos, Péter Windisch, Elmar Reich, István Gera, M. Brecx, Thorkild KarringAbstract:The aim of the present study was to investigate whether Oxytalan fibers are formed in the regenerated human periodontal ligament. 6 patients, each of them exhibiting an advanced intrabony defect, were treated with a bioresorbable membrane according to the GTR-principle. Following a healing period of 6 months, the teeth were extracted together with their surrounding soft and hard tissues and subsequently fixed in 10% buffered formalin. Following decalcification in EDTA, the specimens were embedded in paraffin and 8-microm histological sections were cut in the mesio-distal direction, parallel to the long axes of the teeth. The sections were stained with hematoxylin and eosin, or with the oxone-aldehyde-fuchsin-Halmi staining method and examined in the light microscope. A regenerated periodontal ligament containing newly-formed Oxytalan fibers was observed in all specimens. Many of them inserted into the newly formed cementum on the root surface. It is concluded that Oxytalan fibers are formed de novo in human regenerated periodontal ligament tissue.
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THE REGENERATIVE POTENTIAL OF Oxytalan FIBERS : AN EXPERIMENTAL STUDY IN THE MONKEY
Journal of clinical periodontology, 1997Co-Authors: A. Sculean, Thorkild Karring, J. Theilade, N. LioubavinaAbstract:Although a number of studies have described the Oxytalan fibers as being a natural component of the periodontal ligament, little information exists about the regenerative potential of these connective tissue fibers. The aim of the present study was to examine whether Oxytalan fibers have the capacity to reform after regenerative periodontal therapy. Intrabony defects were produced surgically at the mesial aspects of teeth 37, 35, 45, 47 and at the distal aspects of teeth 11, 21, 31, 41 in one monkey (Macaca fascicularis). After 3 months, the defects were exposed using a full-thickness flap procedure. The root surfaces were debrided and subsequently PDGF-growth factors were placed in the defects. 4 of the 8 sites were covered with a bioresorbable membrane before closure of the wound. Post-surgically, antibiotics were given systemically for 1 week, and tooth cleaning was carried out 1x a week during the entire experimental period. After 5 months, the animal was sacrificed and the oral tissues were fixed by perfusion with 10% buffered formalin. Specimens containing the defects and surrounding tissues were dissected free and histological sections were cut in the mesio-distal direction, parallel to the long axes of the teeth. The sections were stained with hematoxylin and eosin or with the oxone-aldehyde-fuchsin-Halmi staining method and subsequently examined in the light and in the electron microscope. The results revealed that new Oxytalan fibers oriented mainly in an apico-occlusal direction had developed in the regenerated periodontal ligament. Many of the newly-formed fibers were inserted into the new cementum, thus suggesting a strong relationship between this tissue and the Oxytalan fibers. It is concluded that the regenerated periodontal ligament connective tissue formed after surgery contains Oxytalan fibers similar to those present in the original tissue. These results demonstrate that Oxytalan fibers develop de novo in the newly-formed periodontal ligament.
Takaaki Yanagisawa - One of the best experts on this subject based on the ideXlab platform.
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Immunohistochemical characterization of elastic system fibers in rat molar periodontal ligament
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society, 2006Co-Authors: Takashi Sawada, Yuu Sugawara, Tomohiro Asai, Natsuko Aida, Takaaki Yanagisawa, Kazumasa Ohta, Sadayuki InoueAbstract: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.
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Development of Oxytalan fibers in the rat molar periodontal ligament.
Journal of periodontal research, 2002Co-Authors: Keiji Tashiro, Takashi Sawada, Sadayuki Inoue, Takaaki YanagisawaAbstract:Although Oxytalan fibers are known to be a ubiquitous component of the periodontal ligament, little information has been available concerning their organization in the developing periodontal ligament. In the present study, growth and distribution of Oxytalan fibers were examined in the developing periodontal ligament of rat molars aged 11, 14, 19, 21 and 28 days. A quantitative analysis of the fibers was made and the spatial relationship between the fibers and blood vessels was studied by means of a three-dimensional reconstruction of serial sections. At the beginning of root formation, Oxytalan fibers appeared at first as dot-like structures around the root sheath as well as in areas very close to blood vessels. These structures were resolved in the electron microscope to be made up of 12-nm-wide microfibrils in the vicinity of the surface of the cells of the root sheath. In the process of development, these dot-like structures elongated into entities with helical appearances. As the development further proceeded, longer Oxytalan fibers were produced in the apico-occlusal direction along with blood vessels. Quantitative analysis showed that an increase in Oxytalan fibers coincided with an increase in the density of the vascular network in the developing periodontal ligament. Based on the results of the present study, the role of Oxytalan fibers in the developing periodontal ligament may be in the maintenance of the integrity of the vascular system as previously suggested.
Hiroyuki Ishikawa - One of the best experts on this subject based on the ideXlab platform.
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Matrix metalloproteinase-2 degrades fibrillin-1 and fibrillin-2 of Oxytalan fibers in the human eye and periodontal ligaments in vitro.
Acta Histochemica Et Cytochemica, 2013Co-Authors: Megumi Kawagoe, Yoshihiko Sawa, Eichi Tsuruga, Hiroyuki IshikawaAbstract:Oxytalan fibers are distributed in the eye and periodontal ligaments (PDL). The ciliary zonule, known as Zinn’s zonule, in the eye is composed of Oxytalan fibers, which are bundles of microfibrils consisting mainly of fibrillin-1 and fibrillin-2. As turnover of Oxytalan fibers is slow during life, their degradation mechanism remains unclarified. This study was performed to examine degradation pattern of fibrillin-1 and fibrillin-2 by experimental MMP activation. We cultured human non-pigmented ciliary epithelial cells (HNPCEC) and PDL fibroblasts for 7 days, then treated them with concanavalin A to activate matrix metalloproteinase (MMP)-2, and examined the degradation of fibrillin-1 and fibrillin-2 for 72 hr using immunofluorescence. At 7 days of HNPCEC culture, fibrillin-1-positive fibers were observed, some of which merged with fibrillin-2. After MMP-2 activation, fibrillin-1-positive fibers became thin and disappeared by 72 hr, while fibrillin-2-positive fibers disappeared almost completely within 24 hr. At 7 days of PDL fibroblast culture, fibrillin-1-positive fibers were mostly merged with fibrillin-2. After MMP-2 activation, fibrillin-1-positive fibers became thin by 24 hr and had almost disappeared by 48 hr, while fibrillin-2-positive fibers decreased constantly after 24 hr. A MMP-2 inhibitor completely suppressed these degradations. These results suggest that the patterns of fibrillin-1 and fibrillin-2 degradation differ between the eye and the PDL, possibly reflecting the sensitivity of fibrillin-1 and fibrillin-2 of each type of Oxytalan fiber against MMP-2.
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Intracellular interaction of EMILIN-1 with fibrillin-1 in human periodontal ligament cells
Orthodontic Waves, 2012Co-Authors: Yuka Nakatomi, Yoshinori Yamauchi, Kaori Yamanouchi, Kazuki Nakashima, Yoshihiko Sawa, Megumi Kawagoe, Eichi Tsuruga, Hiroyuki IshikawaAbstract:Abstract The elastic system fibers comprise Oxytalan, elaunin and elastic fibers, differing in their relative microfibril and elastin contents. Human periodontal ligaments (PDLs) contain Oxytalan fibers (pure microfibrils), which are composed mainly of fibrillin-1, the major component of microfibrils. We recently demonstrated that EMILIN-1, located at the interface between elastin and microfibrils, controls the amount of fibrillin-1 assembly in PDL fibroblast cell/matrix layers [8] , although the mechanism involved was unclear. We subjected cultured PDL fibroblasts to immunofluorescence and immunoprecipitation assays in order to examine the intracellular interaction of EMILIN-1 with fibrillin-1. Immunofluorescence showed that EMILIN-1 was colocalized with fibrillin-1, both inside and outside the cells. Additionally, EMILIN-1 formed a complex with fibrillin-1 in the intracellular fraction. These results suggest that EMILIN-1 may form complexes with fibrillin-1 in cellular vesicles, thus contributing effectively to the initial assembly of pericellular fibrillin-1 during the process of Oxytalan fiber formation.
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Intracellular interaction of EMILIN-1 with fibrillin-1 in human periodontal ligament cells
Orthodontic Waves, 2012Co-Authors: Yuka Nakatomi, Yoshinori Yamauchi, Kaori Yamanouchi, Kazuki Nakashima, Yoshihiko Sawa, Megumi Kawagoe, Eichi Tsuruga, Hiroyuki IshikawaAbstract:The elastic system fibers comprise Oxytalan, elaunin and elastic fibers, differing in their relative microfibril and elastin contents. Human periodontal ligaments (PDLs) contain Oxytalan fibers (pu...
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Stretch stimuli increase fibulin-5/EMILIN-1 complex on Oxytalan fibers in human periodontal ligament cells
Orthodontic Waves, 2011Co-Authors: Kazuki Nakashima, Yoshinori Yamauchi, Yuka Nakatomi, Yoshihiko Sawa, Eichi Tsuruga, Sachio Tamaoki, Yuichiro Hata, Hiroyuki IshikawaAbstract:Abstract Periodontal ligaments (PDLs) are continuously exposed to various functional forces, such as tooth movement and occlusal loading. Human PDLs comprise elastic system fibers as well as collagen fibers. The elastic system fibers in turn comprise Oxytalan, elaunin and elastic fibers, which differ in their relative microfibril and elastin contents. Human PDLs contain Oxytalan fibers (pure microfibrils), which are composed mainly of fibrillin-1 (the major component of microfibrils). We have previously reported that bundles of Oxytalan fibers in cultured PDL cells coalesce in response to mechanical strain, and that this coalescence is controlled by fibulin-5. However, the relationship between fibulin-5 and other fibrillin-1-binding molecules is unclear. In the present study we investigated whether fibulin-5 and EMILIN-1 (both of which are fibrillin-1-binding molecules) contribute to the formation of Oxytalan fibers upon exposure to mechanical strain. We subjected PDL cells to stretching in order to examine the role of fibulin-5 and EMILIN-1 in the formation of Oxytalan fibers in cell/matrix layers. We examined the relationship between fibulin-5 and EMILIN-1 in PDL cell cultures using immunofluorescence and immunoprecipitation assay. Immunofluorescence showed that fibulin-5 and EMILIN-1 were colocalized on fibrillin-1-positive Oxytalan fibers. Fibulin-5 formed a complex with EMILIN-1, and stretching increased the amount of this complex relative to cells that were not subjected to stretching. These results suggest that the expression of the fibulin-5/EMILIN-1 complex is upregulated in response to tension strain, and may control the formation of Oxytalan fibers in PDLs.
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EMILIN-1 regulates the amount of Oxytalan fiber formation in periodontal ligaments in vitro
Connective tissue research, 2010Co-Authors: Yuka Nakatomi, Kazuki Nakashima, Yoshihiko Sawa, Eichi Tsuruga, Hiroyuki IshikawaAbstract:The elastic system fibers comprise Oxytalan, elaunin, and elastic fibers, differing in their relative microfibril and elastin contents. Among them, human periodontal ligament (PDL) contains only Oxytalan fibers (pure microfibrils). Elastin microfibril interface-located protein-1 (EMILIN-1) is localized at the interface between microfibrils and elastin. We hypothesized that EMILIN-1 may contribute to the formation of Oxytalan fibers. We used a small interfering RNA (siRNA) for EMILIN-1 in PDL cell culture to examine the extracellular deposition of fibrillin-1 (the major component of microfibrils). EMILIN-1 was labeled on microfibrils positive for fibrillin-1 and was colocalized with fibrillin-1 upon immunoprecipitation assay. EMILIN-1 suppression reduced the level of fibrillin-1 deposition to 23% of the control, and this was responsible for the diminution of fibrillin-1 deposition revealed by immunofluorescence. These results suggest that EMILIN-1 may regulate the formation of Oxytalan fibers and play a ro...
