• The Journal of Korean Academy of Prosthodontics
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• v.43 no.6
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• pp.751-763
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• 2005

Statement of problem. To improve a direct implant fixation to the bone, various strategies have been developed focusing on the surface of materials. The surface quality of the implant depends on the chemical, physical, mechanical and topographical properties of the surface. The different properties will interact with each other and a change in thickness of the oxide layer may also result in a change in surface energy, the surface topography and surface, chemical composition. However, there is limited the comprehensive study with regard to changed surface and biologic behavior of osteoblast by anodization. Purpose of study. The aim of this study was to analyze the characteristics of an oxide layer formed and to evaluate the cellular biologic behaviors on titanium by anodic oxidation (anodization) by cellular proliferation, differentiation, ECM formation and gene expression. And the phospholipase activity was measured on the anodized surface as preliminary study to understand how surface properties of Ti implant are transduced into downstream cellular events. Methods and Materials. The surface of a commercially pure titanium(Grade 2) was modified by anodic oxidation. The group 1 samples had a machined surface and other three experimental specimens were anodized under a constant voltage of 270 V(Group 2), 350 V(Group 3), and 450 V(Group 4). The specimen characteristics were inspected using the following five categories; the surface morphology, the surface roughness, the thickness of oxide layer, the crystallinity, and the chemical composition of the oxide layer. Cell numbers were taken as a marker for cell proliferation. While the expression of alkaline phosphatase and Runx2 (Cbfa1) was used as early differentiation marker for osteoblast. The type I collagen production was determined, which constitutes the main structural protein of the extracellular matrix. Phospholipase $A_2$ and D activity were detected. Results. (1) The anodized titanium had a porous oxide layer, and there was increase in both the size and number of pores with increasing anodizing voltage. (2) With increasing voltage, the surface roughness and thickness of the oxide film increased significantly (p<0.01), the $TiO_2$phase changed from anatase to rutile. During the anodic oxidization, Ca and P ions were more incorporated into the oxide layer. (3) The in vitro cell responses of the specimen were also dependant on the oxidation conditions. With increasing voltage, the ALP activity, type I collagen production, and Cbfa 1 gene expression increased significantly (p<0.01), while the cell proliferation decreased. (4) In preliminary study on the relation of surface property and phospholipase, PLD activity was increased but $PLA_2$ activity did not changed according to applied voltage. Conclusion. The anodized titanium shows improved surface characteristics than the machined titanium. The surface properties acquired by anodization appear to give rise more mature osteoblast characteristics and might result in increased bone growth, and contribute to the achievement of a tight fixation. The precise mechanism of surface property signaling is not known, may be related to phospholipase D.

• The Korean Journal of Zoology
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• v.26 no.4
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• pp.235-251
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• 1983

Several approaches have been made to access the mechanism of fusion in chick myoblast in vitro. Lactoperoxidase-catalyzed iodination was applied to labell cell surface proteins during myogenesis. Quantitative as well as qualitative changes were observed in $^131$I surface components of prefusion and postfusion cells. Two proteins with a molecular weight of 165K and 93K daltons were observed to appear at the onset of fusion as compared to prefusion stage. At the same time, 245K dalton protein decreased whereas the low molecular weight proteins increased consistently. The decrease of high molecular weight proteins appears to be associated with the cell cycle of myoblast during differentiation. The increased appearance of low molecular weight proteins might be due to the proteolytic cleavage of the high molecular weight proteins. Examination of intracellulr cAMP levels during fusion has revealed that a large but transient increase in cAMP occurs before the onset of fusion. This result suggests a causal relationship between the increase of cAMP and the onset of fusion, and further, that differentiating myoblasts are synthronized to a high degree. During the course of myoblast differentiation, at least four lowe molecular weight proteins, which different from major surface proteins iodinated, were identifiable in the culture medium. These proteins could be ascribed to be released from the membrane by proteolytic cleavage of surface proteins in the course of myoblast fusion. The significance of cell surface alterations and the released proteins during the fusion, the involvement of cAMP in the onset of fusion and the possibility that fusion is promoted by external factor(s) are discussed.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6073-6080
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• 2015

Background: Melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24), a unique tumor suppressor gene, has killing activity in a broad spectrum of cancer cells. Herein, plasmids producing mda-7 proteins fused to different RGD peptides (full RGD4C and shortened RGD, tRGD) were evaluated for apoptosis induction with a hepatocellular carcinoma cell line, Hep-G2. The study aim was to improve the apoptosis potency of mda-7 by tethering to RGD peptides. Materials and Methods: Three plasmids including mda-7, mda-7-RGD and mda-7-tRGD genes beside a control vector were transfected into Hep-G2 cells. After 72 hours incubation, cell viability was evaluated by MTT assay. In addition, the rate of apoptosis was analyzed by flow cytometry using PI/annexin staining. To detect early events in apoptosis, 18 hours after transfection, expression of the BAX gene was quantified by real time PCR. Modeling of proteins was also performed to extrapolate possible consequences of RGD modification on their structures and subsequent attachment to receptors. Results and Conclusions: In MTT assays, while all mda-7 forms showed measurable inhibition of proliferation, unmodified mda-7 protein exhibited most significant effect compared to control plasmid (P<0.001). Again, flow cytometry analysis showed a significant apoptosis induction by simple mda-7 gene but not for those RGD-fused mda-7 proteins. These findings were also supported by expression analysis of BAX gene (P<0.001). Protein modelling analysis revealed that tethering RGD at the end of IL-24/Mda7 disrupt attachment to cognate receptor, IL-20R1/IL-20R2. In conclusion, fusion of RGD4C and shortened RGD peptides to carboxyl terminal of mda7, not only reduce apoptosis property in vitro but also disrupt receptor attachment as demonstrated by protein modelling.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.4
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• pp.419-427
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• 2008

The present study aimed to investigate the osteogenic potentials of differentiated osteoblast-like cells (DOCs) induced from bone marrow-derived mesenchymal stem cells (MSCs) on ${\beta}-tricalcium$ phosphate (${\beta}-TCP$) with recombinant human bone morphogenetic protein (rhBMP-2) in vitro. Osteoblast differentiation was induced in confluent cultures by adding 100 nM dexamethasone, 10 mM ${\beta}$-glycerophosphate, 50 mM L-ascorbic acid. The Alizarin red S staining and reverse transcriptase-polymerase chain reaction (RT-PCR) were perfomed to examine the mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), receptor activator for nuclear factor ${\kappa}B$ ligand (RANKL), runt-related transcription factor 2 (RUNX2), collagen-Ⅰ (COL-Ⅰ). There were no significant differences in the osteogenic potentials of DOCs induced from MSCs on ${\beta}-TCP(+/-)$. According to the incubation period, there were significant increasing of Alizadin red S staining in the induction 3 weeks. The mRNA expression of ALP, RUNX2, and RANKL were higher in DOCs/${\beta}-TCP(-)$ than DOCs/${\beta}-TCP(+)$. According to rhBMP-2 concentrations, the mRNA expression of BSP was significantly increased in DOCs/${\beta}-TCP(+)$ compared to that of DOCs/${\beta}-TCP(-)$ on rhBMP 10 ng/ml. Our study presented the ${\beta}-TCP$ will have the possibility that calcium phosphate directly affect the osteoblastic differentiation of the bone marrowderived MSCs.

• Molecules and Cells
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• v.26 no.4
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• pp.338-343
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• 2008

An embryonic stem cell is a powerful tool for investigation of early development in vitro. The study of embryonic stem cell mediated neuronal differentiation allows for improved understanding of the mechanisms involved in embryonic neuronal development. We investigated expression profile changes using time course cDNA microarray to identify clues for the signaling network of neuronal differentiation. For the short time course microarray data, pattern analysis based on the quadratic regression method is an effective approach for identification and classification of a variety of expressed genes that have biological relevance. We studied the expression patterns, at each of 5 stages, after neuronal induction at the mRNA level of embryonic stem cells using the quadratic regression method for pattern analysis. As a result, a total of 316 genes (3.1%) including 166 (1.7%) informative genes in 8 possible expression patterns were identified by pattern analysis. Among the selected genes associated with neurological system, all three genes showing linearly increasing pattern over time, and one gene showing decreasing pattern over time, were verified by RT-PCR. Therefore, an increase in gene expression over time, in a linear pattern, may be associated with embryonic development. The genes: Tcfap2c, Ttr, Wnt3a, Btg2 and Foxk1 detected by pattern analysis, and verified by RT-PCR simultaneously, may be candidate markers associated with the development of the nervous system. Our study shows that pattern analysis, using the quadratic regression method, is very useful for investigation of time course cDNA microarray data. The pattern analysis used in this study has biological significance for the study of embryonic stem cells.

• The Korea Journal of Herbology
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• v.36 no.5
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• pp.81-91
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• 2021

Objectives : Osteoporosis is a systemic skeletal disease that decreases bone density and increases the risk of fractures. Bisphosphonates and SERMs are mainly used to treat osteoporosis, but, long-term use increases the risk of side effects such as jaw bone necrosis and breast cancer. Therefore, it is necessary to develop a therapeutic agent for a natural product with few side effects. Water extract of Lonicerae Japonicae Flos (wLF) was mainly found to have anti-cancer and anti-inflammatory effects. However, the effect of wLF on osteoporosis has not been elucidated. Therefore, this experiment investigated the effect of wLF on osteoclasts, osteoblasts and osteoporosis models. Methods : In order to study the effect of wLF on osteoporosis, the OVX-induced rat model was used for in vivo study. After 8 weeks, we measured body weight, uterine weight, liver weight, femur weight, bone density, trabecular area and tibia ash weight. To determine the effect of wLF on osteoclast differentiation, we measured the number of TRAP-positive cells and TRAP activity. To examine the effect of wLF on the expression of osteoblast-related genes, we measured the mRNA expression of alkaline phosphatase (ALP, Alpl) and osteocalcin (OCN, Bglap2). Results : In vivo experiment, wLF inhibited the reduction of femur weight, trabecular area, bone density and tibia ash weight. In vitro experiment, wLF had no significant effect on osteoclast differentiation. However, wLF increased the mRNA expression of Alpl and Bglap2 in MC3T3-E1 cell. Conclusions : This result suggested that wLF may be used for the treatment and prevention of postmenopausal osteoporosis.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.522-526
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• 2000

We tried to mass-propagate Prunus yedoensis from Jeju through tissue culture. We investigated the effect of bud collection time, the concentration of $NH_4NO_3$ in media and plant growth regulators(BAP, $GA_3$ and IBA) on the differentiation of winter buds. Buds, taken in February, flushed well regardless of various in vitro conditions. Bud flushing rate was significantly different depending on the collection time. BAP appeared to be effective on bud flushing. Sixty percent of buds taken in October flushed on the media containing $3.0mg/{\ell}$ BAR. No buds flushed on the medium supplemented with IBA. Buds, after flushing in BAP media, grew as foliated shoots and showed a rosette of leaves. When $GA_3$ supplemented to the BAP-containing media as a higher concentration than that of BAP, shoots elongated and developed into normal shoots. The combination of BAP $1.0mg/{\ell}$ and $GA_3$ $2.0mg/{\ell}$ is most recommendable for shoot elongation.

• Journal of Mushroom
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• v.16 no.2
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• pp.103-110
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• 2018

The purpose of this study is to discover a food material having anti-obesity effects and to disseminate information on the effects of the material to people who are interested in anti-obesity. For this study, 11 kinds of Auricularia (wood ear) spp., including 8 strains of Auricularia auricula-polytricha, and 3 strains of A. auricula-judae, were presented by the Jeollanamdo Agricultural Research & Extension Services. 3T3-L1 (preadipocyte cell) was used for identifying the inhibition effect on adipocyte differentiation. As a result, this study found that all the extracts had slightly different degrees of inhibition effects on adipocyte differentiation. Among the A. auricula-polytricha strains, strain 21001 showed the most significant effect (4.58%), and the inhibition effect of strain 21002 (4.43%) was the greatest among A. auricula-judae strains. Overall, the inhibition effect of A. auricula-polytricha strains was greater than that of A. auricula-judae strains. The results of mRNA and protein analysis also demonstrated that the inhibition effect of A. auricula-polytricha 21001 was superior to that of any other strains. An in vivo study using 56 ICR mice (6w, male), was performed for 4 weeks. A. auricula-polytricha 21001, which exhibited the most significant effect in the in vitro study was used to compose six different types of feeds. Daily body weight gain of the high-fat diet containing 0.2% 21001 extract feeding group was $0.22{\pm}0.08g$ (*p < 0.05), and it was 31.25% lower than that of the high-fat diet feeding group ($0.32{\pm}0.06$). Internal organ weight measurement and blood analysis were performed immediately after animal sacrifice. The results proved that treatment with more than 0.1% of A. auricula-polytricha strain 21001 could significantly reduce (more than *p < 0.05) the weight of liver and epididymal fat, and levels of glucose, total cholesterol, AST, and ALT in blood.

• Journal of Periodontal and Implant Science
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• v.49 no.6
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• pp.366-381
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• 2019

Purpose: The purpose of this study was to evaluate the effectiveness of conventional sandblasted, large-grit, acid-etched (SLA) surface coated with a pH buffering solution based on surface wettability, blood protein adhesion, osteoblast affinity, and platelet adhesion and activation. Methods: Titanium discs and implants with conventional SLA surface (SA), SLA surface in an aqueous calcium chloride solution (CA), and SLA surface with a pH buffering agent (SOI) were prepared. The wetting velocity was measured by the number of threads wetted by blood over an interval of time. Serum albumin adsorption was tested using the bicinchoninic acid assay and by measuring fluorescence intensity. Osteoblast activity assays (osteoblast adhesion, proliferation, differentiation, mineralization, and migration) were also performed, and platelet adhesion and activation assays were conducted. Results: In both the wetting velocity test and the serum albumin adsorption assay, the SOI surface displayed a significantly higher wetting velocity than the SA surface (P=0.000 and P=0.000, respectively). In the osteoblast adhesion, proliferation, differentiation, and mineralization tests, the mean values for SOI were all higher than those for SA and CA. On the osteoblast migration, platelet adhesion, and activation tests, SOI also showed significantly higher values than SA (P=0.040, P=0.000, and P=0.000, respectively). Conclusions: SOI exhibited higher hydrophilicity and affinity for proteins, cells, and platelets than SA. Within the limits of this study, it may be concluded that coating an implant with a pH buffering agent can induce the attachment of platelets, proteins, and cells to the implant surface. Further studies should be conducted to directly compare SOI with other conventional surfaces with regard to its safety and effectiveness in clinical settings.

• BMB Reports
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• v.41 no.4
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• pp.287-293
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• 2008

In a yeast two-hybrid screen, we identified the microtubule-destabilizing protein SCG10 as a potential effector protein of $BRI_3$. The association was verified using GST pull-down, Co-IP, and their perinuclear co-localization. The analysis of in vitro microtubule polymerization/depolymerization showed that the binding of $BRI_3$ to SCG10 effectively blocked the ability of SCG10 to induce microtubule disassembly, as determined by turbidimetric assays. In intact PC12 cells, $BRI_3$ exhibited the ability to stabilize the microtubule network and attenuate the microtubule-destabilizing activity of SCG10. Furthermore, co-expression of $BRI_3$ with SCG10 attenuated SCG10-mediated PC12 cell neurite outgrowth induced by NGF. These results identify a novel connection between a neuron-specific BRI protein and the cytoskeletal network, suggesting possible roles of BRI3 in the process of neuronal differentiation.