• Restorative Dentistry and Endodontics
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• 제21권2호
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• pp.546-558
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• 1996

The purpose of this vitro study was to evaluate the activity of human pulpal cells to adhesive glycoprotein-coated and non-coated culture dishes. Well known adhesive glycoproteins were used, such as type I collagen, type IV collagen, fibronectin, laminin, and vitronectin. Each adhesive glycoproteins applied onto the culture dishes. In this study, the protein coated and non-coated dishes were classified as each groups. Human pulpal cells cultured onto each groups. After 24 hours, 48 hours, 72 hours incubation time, radioactivity with scintillation counter for evaluation of the activity of human pulpal cells. The results as follows : 1. After 24 hours incubation time, activity of human pulpal cells were best in laminin-coated group among groups. Then fibronectin, type I collagen group were better, and all proteins were better than control. 2. After 48 hours incubation time, activity of human pulpal cells were best in fibronectin coated group. 3. After 72 hours incubation time, activity of human pulpal cells were not significantly different in all of adhesive glycoproteins. 4. After 24 hours incubation time, activity of human pulpal cells were best in fibronectin and laminin coated group. Activity of human pulpal cells in type I collagen coated group were better after 24 hours incubation time then 48 hours incubation time.

• 구강회복응용과학지
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• 제20권1호
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• pp.31-41
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• 2004

The osseointegration in implant therapy is achieved following general wound healing mechanism. Platelet play a major role in wound healing process. In addition to blood clot formation, they secrete many growth factors which regulate the attachment, proliferation and differentiation of nearly all cell types. The use of these growth factors is now known to be very effective methods to improve the cellular activity. Platelet-rich plasma which is made with the newly developed technique concentrating platelets 3-folds or more is also proven to be very effective method to stimulate and accelerate the healing of bone and soft tissue. Previous study proved that platelet-rich plasma enhanced the cellular attachment by inducing fibronectin, vitronectin from osteoblast. So, this study was aimed to investigate the effect of platelet-rich plasma on the cellular proliferation and differentiation in vitro. The effect on the proliferation was evaluated by MTT assay. To evaluate autocrine and paracrine effect, conditioned medium was made and compared. By measuring alkaline phosphatase activity, the effect on the cellular differentiation was evaluated. The results were as following: The cellular proliferation of osteoblast cell line increased depending on the concentration of platelet-rich plasma and conditioned medium. The alkaline phosphatase activity increased depending on the concentration of platelet-rich plasma and conditioned medium. These findings imply that platelet-rich plasma enhance the cellular proliferation and differentiation and maximize the cellular activity by using the autocrine and paracrine effect.

• Archives of Pharmacal Research
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• 제29권8호
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• pp.691-698
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• 2006

Although glucocorticoids are known to affect osteoclast differentiation and function, there have been conflicting reports about the effect of glucocorticoids on osteoclast formation, leading to the assumption that microenvironment and cell type influence their action. We explored the effect of the synthetic glucocorticoid analog dexamethasone on the formation of osteoclasts. Dexamethasone inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts without affecting the formation of TRAP-positive mononuclear cells in a coculture of mouse osteoblasts and bone marrow cells. Dexamethasone did not inhibit mRNA expression levels of the receptor activator of nuclear factor-kB ligand and osteoprotegerin, the essential regulators of osteoclastogenesis. Dexamethasone down-regulated the expression of ${\beta}_3$ integrin mRNA and protein but did not alter expression of other osteoclast differentiation marker genes. Both dexamethasone and echistatin, a ${\beta}_3$ integrin function blocker, inhibited TRAP-positive multinucleated osteoclast formation but not TRAP-positive mononuclear cell formation. These results suggest that dexamethasone inhibits the formation of multinucleated osteoclasts, at least in part, through the down-regulation of ${\beta}_3$ integrin, which plays an important role in the formation of multinucleated osteoclasts.

• BMB Reports
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• 제52권11호
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• pp.659-664
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• 2019

Vav1 is a Rho/Rac guanine nucleotide exchange factor primarily expressed in hematopoietic cells. In this study, we investigated the potential role of Vav1 in osteoclast (OC) differentiation by comparing the ability of bone marrow mononuclear cells (BMMCs) obtained from Vav1-deficient ($Vav1^{-/-}$) and wild-type (WT) mice to differentiate into mature OCs upon stimulation with macrophage colony stimulating factor and receptor activator of nuclear kappa B ligand in vitro. Our results suggested that Vav1 deficiency promoted the differentiation of BMMCs into OCs, as indicated by the increased expression of tartrate-resistant acid phosphatase, cathepsin K, and calcitonin receptor. Therefore, Vav1 may play a negative role in OC differentiation. This hypothesis was supported by the observation of more OCs in the femurs of $Vav1^{-/-}$ mice than in WT mice. Furthermore, the bone status of $Vav1^{-/-}$ mice was analyzed in situ and the femurs of $Vav1^{-/-}$ mice appeared abnormal, with poor bone density and fewer number of trabeculae. In addition, Vav1-deficient OCs showed stronger adhesion to vitronectin, an ${\alpha}_v{\beta}_3$ integrin ligand important in bone resorption. Thus, Vav1 may inhibit OC differentiation and protect against bone resorption.

• International Journal of Oral Biology
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• 제32권3호
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• pp.85-91
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• 2007

Dlx3 is a homeodomain protein and is known to playa role in development and differentiation of many tissues. Deletion of four base pairs in DLX3 (NT3198) is causally related to tricho-dento-osseous (TDO) syndrome (OMIM # 190320), a genetic disorder manifested by taurodontism, hair abnormalities, and increased bone density in the cranium. Although the observed defects of TDO syndrome involves bone, little is known about the role of Dlx3 in bone remodeling process. In this study, we examined the effect of wild type DLX3 (wtDlx3) expression on osteoclast differentiation and compared it with that of 4-BP DEL DLX3 (TDO mtDlx3). To examine whether Dlx3 is expressed during RANKL-induced osteoclast differentiation, RAW264.7 cells were cultured in the presence of receptor activator of nuclear factor-B ligand (RANKL). Dlx3 protein level increased slightly after RANKL treatment for 1 day and peaked when the fusion of prefusion osteoclasts actively progressed. When wtDlx3 and TDO mtDlx3 were overexpressed in RAW264.7 cells, they enhanced RANKL-induced osteoclastogenesis and the expression of osteoclast differentiation marker genes such as calcitonin receptor, vitronectin receptor and cathepsin K. Since osteoclast differentiation is critically regulated by the balance between RANKL and osteoprotegerin (OPG), we examined the effect of Dlx3 overexpression on expression of RANKL and OPG in C2C12 cells in the presence of bone morphogenetic protein 2. Overexpression of wtDlx3 enhanced RANKL mRNA expression while slightly suppressed OPG expression. However, TDO mtDlx3 did not exert significant effects. This result suggests that inability of TDO mtDlx3 to regulate expression of RANKL and OPG may contribute to increased bone density in TDO syndrome patients. Taken together, it is suggested that Dlx3 playa role as a positive regulator of osteoclast differentiation via up-regulation of osteoclast differentiation-associated genes in osteoclasts, as well as via increasing the ratio of RANKL to OPG in osteoblastic cells.

• 폴리머
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• 제30권5호
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• pp.445-452
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• 2006

본 연구에서는 슈반세포와 다양한 세포 부착인자로 코팅된 고분자 표면과의 상호관계에 대해 연구하였다. 세포 접착인자로 알려진 피브로넥틴, 피브리노겐, 라미닌, 비트로넥틴, 폴리-D-라이신 및 폴리-L-라이신을 PLGA 필름에 코팅하고 물 접촉각 측정과 ESCA 분석을 실시해 표면특성을 평가하구 접착인자로 코팅하거나 하지 않은 PLGA 필름의 표면에 슈반세포를 배양한 후 세포 계수와 SEM 관찰을 통해 세포 부착과 성장을 알아보았다. 세포 계수 결과에서 세포 부착은 PLGA 표면의 단백질 흡착과 관련 있음을 확인할 수 있었으며, 세포의 성장은 배양액의 우태아혈청 함량의 영향을 받는 것으로 나타났다. 이러한 결과를 통해 슈반세포의 접착과 성장이 특정한 세포 접착인자에 의해 영향을 받음을 알 수 있었다. 본 실험의 결과를 통해 조직공학적 신경 재생에 응용하기 위한 신경유도관의 개발에서 세포의 부착과 성장을 향상시키기 위해서는 세포의 종류 및 배양조건에 따라 신경유도관이 적절한 표면환경을 제공해야 함이 필수적임을 알 수 있었다.

• Journal of Ginseng Research
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• 제40권1호
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• pp.76-85
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• 2016

Background: Binding of adhesive proteins (i.e., fibrinogen, fibronectin, vitronectin) to platelet integrin glycoprotein IIb/IIIa (${\alpha}IIb/{\beta}3$) by various agonists (thrombin, collagen, adenosine diphosphate) involve in strength of thrombus. This study was carried out to evaluate the antiplatelet effect of total saponin from Korean Red Ginseng (KRG-TS) by investigating whether KRG-TS inhibits thrombin-induced binding of fibrinogen and fibronectin to ${\alpha}IIb/{\beta}3$. Methods: We investigated the effect of KRG-TS on phosphorylation of vasodilator-stimulated phosphoprotein (VASP) and dephosphorylation of phosphatidylinositol 3-kinase (PI3K) and Akt, affecting binding of fibrinogen and fibronectin to ${\alpha}IIb/{\beta}3$, and clot retraction. Results: KRG-TS had an antiplatelet effect by inhibiting the binding of fibrinogen and fibronectin to ${\alpha}IIb/{\beta}3$ via phosphorylation of VASP ($Ser^{157}$), and dephosphorylation of PI3K and Akt on thrombin-induced platelet aggregation. Moreover, A-kinase inhibitor Rp-8-Br-cyclic adenosine monophosphates (cAMPs) reduced KRG-TS-increased VASP ($Ser^{157}$) phosphorylation, and increased KRG-TS-inhibited fibrinogen-, and fibronectin-binding to ${\alpha}IIb/{\beta}3$. These findings indicate that KRG-TS interferes with the binding of fibrinogen and fibronectin to ${\alpha}IIb/{\beta}3$ via cAMP-dependent phosphorylation of VASP ($Ser^{157}$). In addition, KRG-TS decreased the rate of clot retraction, reflecting inhibition of ${\alpha}IIb/{\beta}3$ activation. In this study, we clarified ginsenoside Ro (G-Ro) in KRG-TS inhibited thrombin-induced platelet aggregation via both inhibition of $[Ca^{2+}]_i$ mobilization and increase of cAMP production. Conclusion: These results strongly indicate that KRG-TS is a beneficial herbal substance inhibiting fibrinogen-, and fibronectin-binding to ${\alpha}IIb/{\beta}3$, and clot retraction, and may prevent platelet ${\alpha}IIb/{\beta}3$-mediated thrombotic disease. In addition, we demonstrate that G-Ro is a novel compound with antiplatelet characteristics of KRG-TS.