• IMMUNE NETWORK
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• 제21권3호
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• pp.23.1-23.16
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• 2021

Chemokines are key factors that influence the migration and maintenance of relevant immune cells into an infected tissue or a tumor microenvironment. Therefore, it is believed that the controlled administration of chemokines in the tumor microenvironment may be an effective immunotherapy against cancer. Previous studies have shown that CCL3, also known as macrophage inflammatory protein 1-alpha, facilitates the recruitment of dendritic cells (DCs) for the presentation of tumor Ags and promotes T cell activation. Here, we investigated the role of CCL3 in regulating the tumor microenvironment using a syngeneic mouse tumor model. We observed that MC38 tumors overexpressing CCL3 (CCL3-OE) showed rapid regression compared with the wild type MC38 tumors. Additionally, these CCL3-OE tumors showed an increase in the proliferative and functional tumor-infiltrating T cells. Furthermore, PD-1 immune checkpoint blockade accelerated tumor regression in the CCL3-OE tumor microenvironment. Next, we generated a modified CCL3 protein for pre-clinical use by fusing recombinant CCL3 (rCCL3) with a non-cytolytic hybrid Fc (HyFc). Administering a controlled dose of rCCL3-HyFc via subcutaneous injections near tumors was effective in tumor regression and improved survival along with activated myeloid cells and augmented T cell responses. Furthermore, combination therapy of rCCL3-HyFc with PD-1 blockade exhibited prominent effect to tumor regression. Collectively, our findings demonstrate that appropriate concentrations of CCL3 in the tumor microenvironment would be an effective adjuvant to promote anti-tumor immune responses, and suggest that administering a long-lasting form of CCL3 in combination with PD-1 blockers can have clinical applications in cancer immunotherapy.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.416-422
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• 2013

PURPOSE. This study was performed to define attachment and growth behavior of osteoblast-like cells and evaluate the gene expression on zirconia compared to titanium. MATERIALS AND METHODS. MC3T3-E1 cells were cultured on (1) titanium and (2) zirconia discs. The tetrazolium-based colorimetric assay (MTT test) was used for examining the attachment of cells. Cellular morphology was examined by scanning electron microscopy (SEM) and alkaline phosphatase (ALP) activity was measured to evaluate the cell differentiation rate. Mann-Whitney test was used to assess the significance level of the differences between the experimental groups. cDNA microarray was used for comparing the 20215 gene expressions on titanium and zirconia. RESULTS. From the MTT assay, there was no significant difference between titanium and zirconia (P>.05). From the SEM image, after 4 hours of culture, cells on both discs were triangular or elongated in shape with formation of filopodia. After 24 hours of culture, cells on both discs were more flattened and well spread compared to 4 hours of culture. From the ALP activity assay, the optical density of E1 cells on titanium was slightly higher than that of E1 cells on zirconia but there was no significant difference (P>.05). Most of the genes related to cell adhesion showed similar expression level between titanium and zirconia. CONCLUSION. Zirconia showed comparable biological responses of osteoblast-like cells to titanium for a short time during cell culture period. Most of the genes related to cell adhesion and signal showed similar expression level between titanium and zirconia.

• Korean Journal of Mathematics
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• 제32권1호
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• pp.43-57
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• 2024

Given a domain X and a collection H of functions h : X → {0, 1}, the Vapnik-Chervonenkis (VC) dimension of H measures its complexity in an appropriate sense. In particular, the fundamental theorem of statistical learning says that a hypothesis class with finite VC-dimension is PAC learnable. Recent work by Fitzpatrick, Wyman, the fourth and seventh named authors studied the VC-dimension of a natural family of functions ℋ'²_t(E) : 𝔽²_q → {0, 1}, corresponding to indicator functions of circles centered at points in a subset E ⊆ 𝔽²_q. They showed that when |E| is large enough, the VC-dimension of ℋ'²_t(E) is the same as in the case that E = 𝔽²_q. We study a related hypothesis class, ℋ^d_t(E), corresponding to intersections of spheres in 𝔽^d_q, and ask how large E ⊆ 𝔽^d_q needs to be to ensure the maximum possible VC-dimension. We resolve this problem in all dimensions, proving that whenever |E| ≥ C_dq^d-1/(d-1) for d ≥ 3, the VC-dimension of ℋ^d_t(E) is as large as possible. We get a slightly stronger result if d = 3: this result holds as long as |E| ≥ C_3q^7/3. Furthermore, when d = 2 the result holds when |E| ≥ C_2q^7/4.

• 생명과학회지
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• 제30권5호
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• pp.468-475
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• 2020

본 연구에서는 홍국색소의 항산화 활성 및 조골세포의 분화에 미치는 영향을 검토하였다. 홍국색소의 항산화 활성은 DPPH radical 소거능, ABTS radical 소거능 및 SOD 유사 활성을 측정하여 평가하였다. 홍국색소의 DPPH radical 및 ABTS radical 소거 활성은 농도 의존적으로 증가하였으며, 특히 1,000 ㎍/ml 농도에서 각각 94% 및 99%의 최대 활성을 나타내었다. 또한 SOD 유사 활성을 검토한 결과에서, 홍국색소 1,000 ㎍/ml 농도에서 62%의 최대 활성을 나타내었다. 우선 홍국색소 1~1,000 ㎍/ml의 농도에서 세포독성을 검토하기 위해 MTT assay를 실시한 결과, 1~100 ㎍/ml 농도의 범위에서 세포 독성은 나타나지 않았다. ALP 활성은 1~100 ㎍/ml 농도에서 농도의 존적으로 증가하였으며, 100 ㎍/ml의 농도에서 최대 124%의 활성을 나타내었다. 또한, 석회화 형성능 시험에서도 대조군 대비 모든 농도에서 유의적으로 증가하는 경향이 나타났으며, 100 ㎍/ml의 농도에서 대조군 대비 1.5배의 석회화 형성 결과가 나타났다. 이러한 결과를 통해 홍국색소는 항산화 활성이 우수하며, 조골세포 분화에 긍정적인 영향을 줌으로써 골다공증 예방 소재로서의 개발 가능성을 가진 부가가치가 높은 천연물 소재로 활용 가능할 것으로 생각된다.

• Restorative Dentistry and Endodontics
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• 제44권2호
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• pp.17.1-17.10
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• 2019

Objectives: Root resorption is an unexpected complication after replantation procedures. Combining anti-osteoclastic medicaments with retrograde root filling materials may avert this resorptive activity. The purpose of this study was to assess effects of a cathepsin K inhibitor with calcium silicate-based cements on osteoclastic activity. Methods: MC3T3-E1 cells were cultured for biocompatibility analyses. RAW 264.7 cells were cultured in the presence of the receptor activator of nuclear factor-kappa B and lipopolysaccharide, followed by treatment with Biodentine (BIOD) or ProRoot MTA with or without medicaments (Odanacatib [ODN], a cathepsin inhibitor and alendronate, a bisphosphonate). After drug treatment, the cell counting kit-8 assay and Alizarin red staining were performed to evaluate biocompatibility in MC3T3-E1 cells. Reverse-transcription polymerase chain reaction, tartrate-resistant acid phosphatase (TRAP) staining and enzyme-linked immunosorbent assays were performed in RAW 264.7 cells to determine the expression levels of inflammatory cytokines, interleukin $(IL)-1{\beta}$, IL-6, tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) and prostaglandin E2 (PGE2). Data were analyzed by one-way analysis of variance and Tukey's post hoc test (p < 0.05). Results: Biocompatibility results showed that there were no significant differences among any of the groups. RAW 264.7 cells treated with BIOD and ODN showed the lowest levels of $TNF-{\alpha}$ and PGE2. Treatments with BIOD + ODN were more potent suppressors of inflammatory cytokine expression (p < 0.05). Conclusion: The cathepsin K inhibitor with calcium silicate-based cement inhibits osteoclastic activity. This may have clinical application in preventing inflammatory root resorption in replanted teeth.

• Nutrition Research and Practice
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• 제1권1호
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• pp.29-35
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• 2007

Trace mineral studies involving metal ion chelators have been conducted in investigating the response of gene and protein expressions of certain cell lines but a few had really focused on how these metal ion chelators could affect the availability of important trace minerals such as Zn, Mn, Fe and Cu. The aim of the present study was to investigate the availability of Zn for the treatment of MC3T3-E1 osteoblast-like cells and the availability of some trace minerals in the cell culture media components after using chelexing resin in the FBS and the addition of N,N,N',N'-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN, membrane-permeable chelator) and diethylenetriaminepentaacetic acid (DTPA, membrane-impermeable chelator) in the treatment medium. Components for the preparation of cell culture medium and Zn-treated medium have been tested for Zn, Mn, Fe and Cu contents by atomic absorption spectrophotometer or inductively coupled plasma spectrophotometer. Also, the expression of bone-related genes (ALP, Runx2, PTH-R, ProCOL I, OPN and OC) was measured on the cellular Zn depletion such as chelexing or TPEN treatment. Results have shown that using the chelexing resin in FBS would significantly decrease the available Zn (p<0.05) $(39.4{\pm}1.5{\mu}M\;vs\;0.61{\pm}10.15{\mu}M)$ and Mn (p<0.05) $(0.74{\pm}0.01{\mu}M\;vs\;0.12{\pm}0.04{\mu}M)$. However, levels of Fe and Cu in FBS were not changed by chelexing FBS. The use of TPEN and DTPA as Zn-chelators did not show significant difference on the final concentration of Zn in the treatment medium (0, 3, 6, 9, $12{\mu}M$) except for in the addition of higher $15{\mu}M\;ZnCl_2$ which showed a significant increase of Zn level in DTPA-chelated treatment medium. Results have shown that both chelators gave the same pattern for the expression of the five bone-related genes between Zn and Zn+, and TPEN-treated experiments, compared to chelex-treated experiment, showed lower bone-related gene expression, which may imply that TPEN would be a stronger chelator than chelex resin. This study showed that TPEN would be a stronger chelator compared to DTPA or chelex resin and TPEN and chelex resin exerted cellular zinc depletion to be enough for cell study for Zn depletion.

• The Journal of Advanced Prosthodontics
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• 제10권2호
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• pp.147-154
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• 2018

PURPOSE. This study was performed to evaluate the osteogenic potential of 3mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) and niobium oxide containing Y-TZPs with specific ratios, new (Y,Nb)-TZPs, namely YN4533 and YN4533/Al20 discs. MATERIALS AND METHODS. 3Y-TZP, YN4533 and YN4533/Al20 discs (15 mm diameter and 1 mm thickness) were prepared and their average surface roughness ($R_a$) and surface topography were analyzed using 3-D confocal laser microscope (CLSM) and scanning electron microscope (SEM). Mouse pre-osteoblast MC3T3-E1 cells were seeded onto all zirconia discs and evaluated with regard to cell attachment and morphology by (CLSM), cell proliferation by PicoGreen assay, and cell differentiation by Reverse-Transcription PCR and Quantitative Real-Time PCR, and alkaline phosphatase (Alp) staining. RESULTS. The cellular morphology of MC3T3-E1 pre-osteoblasts was more stretched on a smooth surface than on a rough surface, regardless of the material. Cellular proliferation was higher on smooth surfaces, but there were no significant differences between 3Y-TZP, YN4533, and YN4533/Al20. Osteoblast differentiation patterns on YN4533 and YN4533/Al20 were similar to or slightly higher than seen in 3Y-TZP. Although there were no significant differences in bone marker gene expression (alkaline phosphatase and osteocalcin), Alp staining indicated better osteoblast differentiation on YN4533 and YN4533/Al20 compared to 3Y-TZP. CONCLUSION. Based on these results, niobium oxide containing Y-TZPs have comparable osteogenic potential to 3Y-TZP and are expected to be suitable alternative ceramics dental implant materials to titanium for aesthetically important areas.

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.187-199
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• 1999

Bone remodeling is characterized by the continuing processes of osteoblast-mediated bone formation and osteoclast-mediated bone resorption. Bone metabolism is tightly regulated at the local level by networks of hormones, cytokines, and other factors. In pathological conditions of bone remodeling, including osteoporosis and periodontal diseases, inflammatory cytokines and local mediators are responsible for enhancement of osteoclast resorption and inhibition of repair at the sites of bone resorption. TNF-${\alpha}$ is a pleiotropic hormone with actions on the differentiation, growth, and functional activities of normal and malignant cells from numerous tissues. TNF-${\alpha}$ has been proposed as a local mediator of the control of bone turnover in situations of chronic inflammation, and it has been assumed that the local source of TNF-${\alpha}$ is the monocyte in the adjacent bone marrow or the local circulation. TNF-${\alpha}$ is a potent inducer of bone resorption. TNF-${\alpha}$ is known to induce the activation of apoptotic signaling pathway, which leads to the apoptosis of bone cells. We demonstrated that treatment of murine osteoblastic MC3T3E1 cells with TNF-${\alpha}$ decreases proliferation as well as alkaline phosphatase (ALP) activity in a dose depenent manner. In addition, TNF-${\alpha}$ increases osteoclast-like cell formation in $1{\alpha}$, 25(OH)2D3 or PGE2-treated bone marrow cell culture. When cells were cultured in TNF-${\alpha}$ free ${\alpha}$-MEM, this inhibitory effect of ALP activity was reversible up to 10 ng/ml TNF-${\alpha}$, in contrast, at the 20 ng/ml TNF-${\alpha}$, irreversible. In this concentration, TNF-${\alpha}$ may induce apoptosis in MC3T3E1 cells. In this study, TNF-${\alpha}$ induces apoptosis resulting in chromosomal DNA fragmentation, preceded by JNK/SAPKs and caspase-3 activation. Our present results show that JNK/SAPKs and caspase-3 are activated by TNF-${\alpha}$, suggesting that the JNK/SAPKs and caspase-3 participate in the bone resorption, associated with apoptosis.

• 대한소아치과학회지
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• 제25권3호
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• pp.635-648
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• 1998

The clinical use of fluoride with a well known osteogenic action in osteoporotic patients is rational, because this condition is characterized by impaired bone formation. However, its anabolic effect has not been demonstrated well in vitro. The purpose of this study was to investigate the effects of sodium fluoride on the physiological role of osteoblastic cell. Osteoblastic cells were isolated from fetal rat calvaria. The results were as follows : 1. Mineralized nodules were shown in osteoblastic cell cultures, which had been maintained in the presence of ascorbic acid and ${\beta}-glycerophosphate$ up to 21 days. When cultures were treated with pulses of 48 hr duration before apparent mineralization was occurring, 2-fold increased in their number was detected. 2. Alkaline phosphatase activity of osteoblastic cells was inhibited by sodium fluoride in dose dependent manner. 3. The effect of sodium fluoride on the osteoblastic cell proliferation was measured by the incorporation of $[^3H]$-thymidine into DNA. As a result, sodium fluoride at $1{\sim}100{\mu}M$ increased the $[^3H]$-thymidine incorporation into DNA in a dose dependent manner. 4. The signaling mechanism activated by sodium fluoride dose-dependently enhanced the tyrosine phosphorylation of the adaptor molecule $Shc^{p66}$ and their association with Grb2, one of earlier events in a MAP kinase activation pathway cascade used by a significant subset of G protein-coupled receptors. 5. The phosphorylation of CREB(cAMP response element binding protein)was inhibited by the sodium fluoride in MC3T3E1 cells. In conclusion, the results of this study suggested that the mitogenic effect of the sodium fluoride in MC3T3E1 cell was stimulated in a dose-dependent manner and suggested "an important role for the interaction between She and Grb2" in controlling the proliferation of osteoblasts.

• 한국식품영양과학회지
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• 제40권11호
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• pp.1532-1536
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• 2011

본 연구에서는 사철쑥 추출물의 항산화 효과 및 $H_2O_2$로 유도한 산화적 스트레스 상황에서 조골세포의 증식 및 분화에 미치는 영향을 분석하여 산화적 스트레스에 대한 사철쑥추출물의 조골세포 보호효과 및 골 질환 관련 항산화소재로서의 이용가능성에 대해 확인하였다. 항산화 능력을 알아보기 위해 총 페놀 함량, 총 플라보노이드 함량, DPPH radical 소거능, ABTS radical 소거능을 측정하였다. 그 결과 총 페놀 함량 및 총 플라보노이드 함량은 각각 90.19${\pm}$2.03 mg/g 과 11.10${\pm}$0.38 mg/g으로 나타났고 DPPH와 ABTS radical 50% 소거 활성의 농도는 105.80${\pm}$4.27와 251.48${\pm}$14.00 ${\mu}g$/mL였다. 이를 바탕으로 사철쑥은 항산화 기능을 하는 페놀 및 플라보노이드를 가지고 있으며 항산화 활성이 있으므로 조골세포에서 산화적 스트레스에 대해 보호효과를 가질 것이라 기대되었다. 산화적 스트레스 상황에서 사철쑥 추출물이 조골세포의 증식에 미치는 영향은 MTT assay를 통해 분화에 미치는 영향은 분화 지표인 ALP 활성, 석회화를 측정하여 알아보았다. 그 결과 사철쑥 추출물은 산화적 스트레스로 인해 감소된 세포의 증식률을 유의적으로 증가시켰고 산화적 스트레스 상황의 분화된 세포의 증식률도 유의적으로 증가시켰다. 분화의 지표인 ALP 활성은 모든 농도에서 활성이 유의적으로 증가하였고 석회화 또한 유의적으로 증가하였다. 증식률 및 두 개의 분화지표인 ALP 활성, 석회화 모두 사철쑥 추출물 200 ${\mu}L$ 농도일 때 가장 높은 활성을 보였다. 사철쑥 추출물이 항산화 활성이 있고 산화적 스트레스 상황의 조골세포의 증식과 분화를 증가시키는 결과로 미루어 볼 때 사철쑥 추출물의 항산화 활성이 산화적 스트레스 상황의 조골세포를 보호하는 역할을 한다고 볼 수 있다. 이상의 연구결과 사철쑥 추출물은 항산화 작용을 통해 $H_2O_2$로 유도된 산화적 스트레스 상황에서 조골세포의 증식 및 분화를 촉진하고 손상 및 활성 감소를 억제하여 산화적 스트레스에 대해 보호하는 효과가 있는 것을 확인할 수 있었다. 이러한 결과로 보아 산화적 스트레스에 대한 조골세포의 보호효과 및 골 질환 관련 항산화소재로서 사철쑥이 이용가능성이 있다고 사료된다.