• 대한치과교정학회지
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• 제33권3호
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• pp.199-210
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• 2003

치아이동 시 발생하는 골흡수에서 이미 여러 cytokine의 중요성이 강조된 바 있으며 이 가운데 interleukin-6는 구강 및 연골조직 등에서 많은 연구의 초점이 되어 왔으나 확실한 기전은 아직까지 정확히 확립되어 있지 못하다 골흡수 시 조골세포에서 유리되는 interleukin-6 (IL-6)와 nitric oxide (NO) 등이 골흡수의 조절자로 최근 대두되고 있으며 Mitogen-activated Protein kinase (MAPK)의 활성화로 인해 염증성 cytokine등이 유리될 수 있음이 최근 macrophage 등에서 증명된 바 있다. 그러므로 치아이동을 비롯한 구강 내 여러 염증의 조건에서 골흡수의 대표인자인 IL-6및 NO유리가 MAPK등의 활성 등을 통해 조절될 수 있는 가능성을 시사하고 있다. 본 연구에서 조골세포 특징을 대부분 가지고 있는 조골세포주 MC3T3El에서 p-38 MAP kinase을 매개로 NO와 IL-6가 유리됨을 확인하고자 하였다. $10\%$ Fetal Bovine Serum이 첨가된 -MEM 배양액으로 배양한 조골세포주인 MC3T3El 세포에 tumor necrosis $factor-\alpha(TNF-\alpha)$, $interferon-\gamma(IFN-\gamma)$ 및 lipopolysacchalide(LPS) 등의 단독처리 시 NO와 IL-6의 증가는 확인되지 않았으나 $TNF-\alpha/IFN-\gamma$ 혹은 $LPS/IFN-\gamma$ 등의 처치시 NO와 IL-6의 유의한 증가를 보였으며, NO발현에 직접 관여하는 inducible nitric oxide synthase (iNOS)와 IL-6 단백질 및 mRNA의 발현을 관찰하였다. 또한 specific p-38 MAP kinase inhibitor인 SB203580의 NO와 IL-6의 생성 억제를 관찰하고 단백질과 mRNA발현억제를 통해서도 확인함으로써 SB203580은 transcription 단계에서 NO와 IL-6의 생성을 조절하고 있음을 시사하여 주고 있다. $TNF-\alpha/IFN-\gamma$ 혹은 $LPS/IFN-\gamma$ 처치 시 p-38 MAP Kinase의 활성을 관찰하였으나 단독 처치 시 역시 P-38 MAP Kinase의 활성을 확인함으로써 NO와 IL-6생성기전에는 p-38 MAP Kinase이외에 다른 인자 역시 관여하고 있음을 보여주고 있다. 본 연구에서는 치아 등의 골조직의 구성 세포인 조골세포에서 NO와 IL-6유리를 확인하였으며, 또한 이들의 생성기전중의 하나로 p-38 MAP Kinase가 transcription 단계에서 관여하고 있음을 확인하였다.

• Communications for Statistical Applications and Methods
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• 제17권3호
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• pp.441-450
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• 2010

In this paper we consider the problem of forecasting binomial time series, modelled by the binomial autoregressive model. This paper considers proposed by McKenzie (1985) and is extended to a higher order by $Wei{\ss}$(2009). Since the binomial autoregressive model is a Markov chain, we can apply the earlier work of Bu and McCabe (2008) for integer valued autoregressive(INAR) model to the binomial autoregressive model. We will discuss how to compute the h-step-ahead forecast of the conditional probabilities of $X_{T+h}$ when T periods are used in fitting. Then we obtain the maximum likelihood estimator of binomial autoregressive model and use it to derive the maximum likelihood estimator of the h-step-ahead forecast of the conditional probabilities of $X_{T+h}$. The methodology is illustrated by applying it to a data set previously analyzed by $Wei{\ss}$(2009).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.617-624
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• 2007

Insulin-like growth factor(IGF) is the most abundant growth factor in bone matrix. Recent studies have shown that it can sensitize apoptotic cell death of osteoblasts. Thus, this study investigated whether IGF-II aggravates irradiation-induced cell death of osteoblasts. Cultured MC3T3 osteoblasts were irradiated and IGF-II was added at the concentration of 50 ng/ml immediately after the irradiation. Cell viability was measured by MTT assay. Changes in cell death and cell cycle were analyzed by flow cytometry. The expression of proapoptotic gene bax and antiapoptotic gene bcl-2 was quantified by real time RT-PCR and Western blot. A dose of 30 Gy caused G2/M arrest and increased cell death through both necrosis and apoptosis, while irradiation from 4 to 10 Gy little affected cell cycle and death. IGF-II treatment reduced cell viability without stimulating cell proliferation and changing cell cycle. Combined treatment of IGF-II with irradiation decreased cell viability and proliferation and increased cell death along with G2/M arrest. These effects were not different from those of irradiation only. At transcriptional and protein levels, IGF-II treatment did not affect bax and bcl-2 expression, whereas irradiation increased the expression ofbax without changes in bcl-2. IGF-II in combination with irradiation showed similar findings. These results suggest that IGF-II could modulate apoptotic cell death through mechanisms other than an imbalance between bax and bcl-2 gene expression, although its effect was overridden by irradiation.

• Food Science and Biotechnology
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• 제14권5호
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• pp.593-598
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• 2005

Osteoporosis is recognized as one of the major hormonal deficiency diseases, especially in menopausal women and the elderly. When the estrogen level is reduced in the body, local factors, which are known to be related with bone resorption, are increased and promote osteoclastogenesis. In our previous study, we validated the estrogenicity of silkworm pupa. In this study, we investigated the effect of silkworm pupa extract (SPE) on the function of osteoblastic MC3T3-E1 cells. SPE (10 and $50\;{\mu}g/mL$) significantly elevated cell viability, alkaline phosphatase (ALP) activity, and collagen content in the cells. The effect of SPE ($50\;{\mu}g/mL$) in increasing cell viability, ALP activity, and collagen content was completely inhibited by the presence of $10^{-6}\;M$ of cycloheximide and $10^{-6}\;M$ of tamoxifen, suggesting that SPE's effect results from a newly synthesized, protein component and that it might be partly involved in estrogen action. Furthermore, we examined the effect of SPE on the $H_2O_2-induced$ apoptosis and production of local factors in osteoblasts. Treatment with SPE ($50\;{\mu}g/mL$) decreased the 0.2 mM $H_2O_2-induced$ apoptosis and the production of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6 and nitric oxide (NO) in osteoblasts. Our data indicate that the enhancement of osteoblast function by silkworm pupa may prevent osteoporosis and inflammatory bone diseases.

• Biomolecules & Therapeutics
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• 제20권1호
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• pp.89-95
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• 2012

Poncirus trifoliata fruit (PTF) affects the digestive and cardiovascular systems, and kidney function. The authors studied the effects of ethyl acetate (EtOAc) extract of PTF on the activities of osteoblasts and in an animal model. The main compounds of the EtOAc extract, naringin and poncirin have been confirmed by HPLC and NMR analysis. Effects of osteoblastic differentiation were measured by alkaline phosphatase (ALP) activity, osteopontin (OPN) protein expression and osteoprotegerin (OPG) mRNA expression in MC3T3-E1 cells. Also, osteoclast differentiation was measured by multinucleated cells (MNCs) formation through tartrate resistance acid phosphatase (TRAP)-positive staining. Bone mineral density (BMD) was measured before and after treatment with EtOAc extract of PTF in prednisolone-induced osteoporotic mice. Dexamethasone (DEX) decreased OPN and OPG expression level in MC3T3-E1 cells and ALP activity was decreased by DEX dose-dependently. EtOAc extract of PTF recovered the levels of ALP activity, and the expression of OPN and OPG in MC3T3-E1 cells treated with DEX. In osteoclast differentiation, multinucleated TRAP-positive cell formation was significantly suppressed by the EtOAc extract of PTF. Total body BMD was restored by EtOAc extract of PTF in prednisolone-induced osteoporotic mice. In conclusion, EtOAc extract of PTF recovered DEX-mediated deteriorations in osteoblastic and osteoclastic functions, and increased BMD in glucocorticoid-induced osteoporosis.

• Nutrition Research and Practice
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• 제15권5호
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• pp.579-590
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• 2021

BACKGROUND/OBJECTIVES: Petasites japonicus Maxim (P. japonicus) has been used as an edible and medicinal plant and contains many bioactive compounds. The purpose of this study is to investigate the effect of P. japonicus on osteogenesis. MATERIALS/METHODS: The leaves and stems of P. japonicus were separated and extracted with hot water or ethanol, respectively. The total phenolic compound and total polyphenol contents of each extract were measured, and alkaline phosphatase (ALP) activity of each extract was evaluated to determine their effect on bone metabolism. To investigate the effect on osteoblast differentiation of the aqueous extract of P. japonicus leaves (AL), which produced the highest ALP activity among the tested extracts, collagen content was measured using the Sirius Red staining method, mineralization using the Alizarin Red S staining method, and osteocalcin production through enzyme-linked immunosorbent assay analysis. Also, real-time reverse transcription polymerase chain reaction was performed to investigate the mRNA expression levels of Runt-related transcriptional factor 2 (Runx2) and Osterix. RESULTS: Among the 4 P. japonicus extracts, AL had the highest values in all of the following measures: total phenolic compounds, total polyphenols, and ALP activity, which is a major biomarker of osteoblast differentiation. The AL-treated MC3T3-E1 cells showed significant increases in induced osteoblast differentiation, collagen synthesis, mineralization, and osteocalcin production. In addition, mRNA expressions of Runx2 and Osterix, transcription factors that regulate osteoblast differentiation, were significantly increased. CONCLUSIONS: These results suggest that AL can regulate osteoblasts differentiation, at least in part through Runx2 and Osterix. Therefore, it is highly likely that P. japonicus will be useful as an alternate therapeutic for the prevention and treatment of osteoporosis.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.1989-1996
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• 2015

Ice-binding proteins (IBPs) can inhibit ice recrystallization (IR), a major cause of cell death during cryopreservation. IBPs are hypothesized to improve cell viability after cryopreservation by alleviating the cryoinjury caused by IR. In our previous studies, we showed that supplementation of the freezing medium with the recombinant IBP of the Arctic yeast Glaciozyma sp. (designated as LeIBP) could reduce post-thaw hemolysis of human red blood cells and increase the survival of cryopreserved diatoms. Here, we showed that LeIBP could improve the viability of cryopreserved mammalian cells. Human cervical cancer cells (HeLa), mouse fibroblasts (NIH/3T3), human preosteoblasts (MC3T3-E1), Chinese hamster ovary cells (CHO-K1), and human keratinocytes (HaCaT) were evaluated. These mammalian cells were frozen in dimethyl sulfoxide (DMSO)/fetal bovine serum (FBS) solution with or without 0.1 mg/ml LeIBP at a cooling rate of -1℃/min in a -80℃ freezer overnight. The minimum effective concentration (0.1 mg/ml) of LeIBP was determined, based on the viability of HeLa cells after treatment with LeIBP during cryopreservation and the IR inhibition assay results. The post-thaw viability of mammalian cells was examined. In all cases, cell viability was significantly enhanced by more than 10% by LeIBP supplementation in 5% DMSO/5% FBS: viability increased by 20% for HeLa cells, 28% for NIH/3T3 cells, 21% for MC3T3-E1, 10% for CHO-K1, and 20% for HaCaT. Furthermore, addition of LeIBP reduced the concentrations of toxic DMSO and FBS down to 5%. Therefore, we demonstrated that LeIBP can increase the viability of cryopreserved mammalian cells by inhibiting IR.

• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.375-390
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• 2000

The purpose of this study is to evaluate the expression ofIGF-I, considered as the mediator of action of estrogen, and IGF-IA and IGF-IB, alternative slicing form of IGF-I, using $17{\beta}-estradiol$ in MC3T3-E1 cells. We observed the effect on type I collagen and osteopontin gene expression and DNA synthetic activity of MC3T3-E1 cells, added by estrogen, IGF-I and combination and the interactionon proliferation and differentiation of MC3T3-E1 cells. The results were as follows :RT-PCR experiment for observing timedependantIGF-I gene expression patternshowed IGF-IA and IB gene expression in both of control and test group. In these IGF-IA gene expression was appeared predominantly. In control, IGF-I geneexpression level was maintained until 24hr and then decreased gradually. In testgroup, IGF-I gene expression level increased as time goes by. Experiment measuring DNA synthetic activity, as it is added by $17{\beta}-estradiol$, IGF-I and combination, showed that first day , there was the tendency of more increase of synthetic activity in all test group than control but no statical significance(P>0.05), and third day, there was more increase of DNA synthetic activity in $17{\beta}-estradiol$ group and combination group and it was statically significant. (P<0.005) Experiment for observing type I collagen gene expression pattern showed more increase of expression in $17{\beta}-estradiol$ group than control and no significant difference in IGF-I group and combination group. Experiment for observing osteopontin gene expression pattern showed no significant difference in control and test group. In conclusion, $17{\beta}-estradiol$ in MC3T3- E1 cells increased IGF-I gene and DNA synthetic activity simultaneously, therefore it appeared that IGF-I is related to the action of estrogen. Combination treatment of IGF-I and $17{\beta}-estradiol$ has effect on cell proliferation but this effect is lower than IGF-I or $17{\beta}-estradiol$ alone. However, combination treatment has not great effect on type I collagen or osteopontin gene expression thus little effect of cell differentiation.

• 대한기계학회논문집A
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• 제34권4호
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• pp.457-465
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• 2010

본 연구에서는 McVetty 와 Monkman-Grant 의 모델에 기초하여 만들어진 새로운 크리프 수명예측 모델인 Taylor 급수(T-S) 모델을 제안하였다. 본 모델은 회귀분석에서 발생하는 오차를 줄이기 위하여 McVetty 모델에서 sinh 함수를 Taylor 급수에 의해 변환한 후 첫 3 개항을 취한 것으로서 모델중의 상수 값은 통계학적 방법인 최대가능성 기법을 이용하여 결정되었다. T-S 모델을 이용하여 Alloy 617 의 크리프 수명을 예측한 결과 Eno, 지수함수 및 Larson-Miller(L-M) 방법에 비해 더 정확한 예측을 하는 것으로 나타났다. 또한 T-S 모델은 특정 온도에서 크리프 수명 예측을 할 수 있는 등온 T-S(IT-S) 모델로 표현될 수 있었으며, IT-S 모델은 Alloy 617 의 장시간 크리프 수명예측에서 가장 좋은 예측을 하는 것으로 나타났다.

• 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.