• The Korean Journal of Physiology and Pharmacology
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• 제16권6호
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• pp.393-398
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• 2012

Mast cells are involved in allergic responses, protection against pathogens and autoimmune diseases. Dexamethasone (Dex) and other glucocorticoids suppress $Fc{\varepsilon}RI$-mediated release of inflammatory mediators from mast cells. The inhibition mechanisms were mainly investigated on the downstream signaling of Fc receptor activations. Here, we addressed the effects of Dex on Fc receptor expressions in rat mast cell line RBL-2H3. We measured mRNA levels of Fc receptors by real-time PCR. As expected, Dex decreased the mRNA levels of activating Fc receptor for IgE ($Fc{\varepsilon}R$) I and increased the mRNA levels of the inhibitory Fc receptor for IgG $Fc{\gamma}RIIb$. Interestingly, Dex stimulated transcriptions of other activating receptors such as Fc receptors for IgG ($Fc{\gamma}R$) I and $Fc{\gamma}RIII$. To investigate the mechanisms underlying transcriptional regulation, we employed a transcription inhibitor actinomycin D and a translation inhibitor cycloheximide. The inhibition of protein synthesis without Dex treatment enhanced $Fc{\gamma}RI$ and $Fc{\gamma}RIII$ mRNA levels potently, while $Fc{\varepsilon}RI$ and $Fc{\gamma}RIIb$ were minimally affected. Next, we examined expressions of the Fc receptors on cell surfaces by the flow cytometric method. Only $Fc{\gamma}RIIb$ protein expression was significantly enhanced by Dex treatment, while $Fc{\gamma}RI$, $Fc{\gamma}RIII$ and $Fc{\varepsilon}RI$ expression levels were marginally changed. Our data showed, for the first time, that Dex regulates Fc receptor expressions resulting in augmentation of the inhibitory receptor $Fc{\gamma}RIIb$.

• 대한한방소아과학회지
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• 제38권1호
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• pp.1-9
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• 2024

Objective The purpose of this study was to confirm the effects of Galgeunhwanggeumhwangryeon-tang (PSCG) extract on skin moisturizing, antibacterial, and tight junction recovery in atopic dermatitis-induced mice. Methods In this study, we used 4-week-old NC/Nga mice divided into four groups: control (Ctrl), lipid barrier elimination (LBE), dexamethasone (Dx) after lipid barrier elimination (DEX), and PSCG after lipid barrier elimination (PSC). Ten rats were assigned to each treatment group. Three days after drug administration following lipid barrier elimination, ceramide kinase, caspase 14, sodium hydrogen antiporter (NHE), cathelicidin, claudin, and toll-like receptor (TLR)-2 were observed to confirm the restoration of skin moisturizer production, antimicrobial barriers, and tight junctions in the skin barrier. Results Ceramide kinase and caspase 14 positive reaction were significantly higher in PSC than in LBE and DEX. Both NHE and cathelicidin showed higher positive reactions in PSC than in LBE and DEX. Claudin, and TLR-2 showed higher levels of positive staining in the PSC group than in the LBE and DEX groups. Conclusion It was confirmed that the PSCG extract can have the potential to restore the damaged skin barrier in atopic dermatitis.

• 생명과학회지
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• 제24권12호
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• pp.1356-1363
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• 2014

28개의 아미노산으로 이루어져 있는 Ghrelin은 위 기저부의 X/A-유사 신경내분비 세포에서 주로 합성 분비되는 물질로 음식의 섭취나 비만, 에너지 항상성 등을 조절하는 역할을 하며, 이러한 Ghrelin 활성화는 수용체인 G-protein coupled growth hormone secretagogue receptor-1a (GHS-R1a)와 결합을 통해 일어난다. 최근 보고된 자료에 따르면, ghrelin과 수용체는 위나 시상하부, 뇌하수체 등뿐만 아니라 T 세포나 단핵구 및 대식세포 등 면역 세포에서도 생성되며, 염증반응을 유도하는 사이토카인의 생성을 억제하는 역할을 한다. 또한 흉선의 퇴화 등 면역기관에 있어서도 중요한 호르몬으로 보고되고 있지만 그 기전이나 기능에 대한 연구가 아직 미미한 실정이다. 본 연구에서는 흉선에서 T 세포의 성숙이나 세포활성을 억제하는 물질로 알려져 있는 덱사메타손(Dexamethasone; DEX)으로 세포사멸을 유도시킨 흉선세포에 ghrelin을 처리하여 세포사멸 억제효과를 알아보았다. 그 결과 Ghrelin은 세포사멸에 중요 단백질인 Caspase-3와 PARP 및 Bim의 활성화가 in vivo 및 in vitro 모두에서 효과적으로 저해됨을 확인할 수 있었으며, 이러한 세포사멸의 억제효과는 ghrelin을 처리할 경우 DEX에 의해 활성화된 Glucocorticoid 수용체(GR)의 인산화의 억제와 HSP90 등과 복합체를 이루고 있는 GR이 활성화되면서 분해되는 과정을 억제시켜 결과적으로 핵 안으로 이동하는 과정을 억제하는 기전을 통해 나타남을 알 수 있었다. 이러한 결과 등을 통해 볼 때, ghrelin은 약물이나 체내 생리적 스트레스 등으로 인해 발생하는 흉선 내 면역세포들의 세포사멸에 도움을 줄 것으로 사료되며, 나아가 이로 인한 흉선위축을 보호할 수 있는 치료 후보물질로서의 연구를 기대할 수 있으리라 사료된다.

• Journal of Oral Medicine and Pain
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• 제25권3호
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• pp.279-289
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• 2000

현대에는 날로 복잡해지는 생활양식의 변화에 따라 다양한 스트레스에 노출되고 그로 인한 면역계, 신경계 또는 각종 장기의 기능이상이 점차로 증가되고 있다. 최근 치과에 내원하는 환자들 중 구강건조증을 호소하는 환자들의 다수는 스트레스에 노출되어 있고, 임상적으로도 방사선 타액선 기능 검사에서 타액선, 특히 악하선의 기능이 현저하게 저하되어 있는 소견을 관찰할 수 있 다. 더욱이 이는 타액선 조영술에서 이미 보고된 바 있는 면역성 질환인 $Sj\ddot{o}gren$ 증후군과는 다른 양상으로 관찰되고 있어, 이에 본인은 백서에 스트레스와 관련이 깊은 내분비적 환경 변화를 유도함으로써 이와같은 변화가 악하선 조직의 병리적 변화와 어떠한 연관성을 갖는 지를 관찰하고자 본 실험을 시행하였다. 생후 7주된 Sprague-Dawley계 웅성 백서(165-209g/bw) 40마리를 2 개의 실험군(부신 제거군 : ADX 군, 부신 제거 후 dexamethasone 투여군 : DEX 군)으로 나누어 실험하였다. ADX 군은 외과적으로 부신을 제거한 후 다른 조건을 부여하지 않았고, DEX 군은 외과적으로 부신을 제거한 후 매일 dexamethasone($1.5*10^{-46}mg/g$ I.V./day)을 투여하였으며, 이들을 각각 실험 후 즉시, 1일, 3일, 5일, 7일에 희생시켰다. 그 후에는 즉시 악하선을 적출하여 면역조직화학법으로 Clusterin의 발현 정도 및 부위를 관찰하였다. 그 결과는 다음과 같았다. 1. 광학현미경 하에서, 양 군 모두 유의할만한 조직학적 변화는 관찰되지 않았다. 2. ADX 군에서는 실험기간 전반에 걸쳐 도관세포와 선포세포에서 clusterin이 발현되었다. 3. DEX 군에서는 소수의 선세포에서 국소적으로 clusterin이 관찰되었으나, 전반적으로 도관세포, 선포세포에서 공히 clusterin이 관찰되지 않았다. 부신을 제거한 군에서는 실험기간 전반에 걸쳐 clusterin이 발현되었는데, 이는 clusterin이 스트레스의 생리적 반응의 결과로서 세포보호작용을 한다는 사실에 기초하여 볼 때, 부신을 제거하였을 때도 스트레스를 받았을 때와 같은 영향이 백서의 악하선에 가해졌을 것으로 생각된다. 반면, 부신제거후 glucocorticoid agonist인 dexamethasone을 투여하였을 때, clusterin이 감소 내지 관찰되지 않았던 것은 부신제거에 의해 악하선에 가해졌던 영향을 dexamethasone이 길항하여 나타난 결과로 볼 수 있어, 스트레스에 의해 부신으로부터 분비되는 glucocorticoid가 타액선을 보호하는데 중요한 작용을 하는 것을 시사한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권1호
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• pp.16-23
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• 2005

It is commonly acknowledged that bone morphogenic protein (BMP-2) functions as a potential osteogenic inducer in bone formation. Recently, several papers reported that bone marrow-derived stem cell (BMSC) from human is not responsive to BMP-2 in comparison to high capacity of BMP-2 in the osteoinduction of stromal cell derived from bone marrow of rodent animals such as rat or mouse. In this study, we characterized BMSC derived from 11 years old donor for the responsiveness to rhBMP-2, dexamethasone (Dex) and 1,25-dihydroxyvitamin D (vitamin D), in order to analyze their function in the early osteogenesis. The effect of over mentioned agents was evaluated by means of assessing alkaline phosphatase (ALP) activity/staining, RT-PCR analysis and von Kossa staining. In addition, we analyzed the meaning of expressed several osteoblastic markers such as alkaline phosphatase, collagen typeI, osteopontin, bone sialoprotein and osteocalcin with relation to either differentiation or mineralization. Only in the presence of Dex, human BMSC could commit osteoblastic differentiation and matrix mineralization, and either BMP-2 or vitamin D treatment was not able to induce. But BMP-2 or Vitamin D showed potential synergy effect with Dex. ALP and bone sialoprotein were clearly expressed in response of Dex treatment compared to weak expression of osteopontin in early osteogenesis. Therefore, we expect that this study will contribute partly to elucidiating early osteogenesis mechanism in human, but variations among bone marrow donors must be considered through further study.

• Journal of Ginseng Research
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• 제39권1호
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• pp.46-53
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• 2015

Background: Glucocorticoids (GCs) are commonly used in many chemotherapeutic protocols and play an important role in the normal regulation of bone remodeling. However, the prolonged use of GCs results in osteoporosis, which is partially due to apoptosis of osteoblasts and osteocytes. In this study, effects of Korean Red Ginseng (KRG) on GC-treated murine osteoblastic MC3T3-E1 cells and a GC-induced osteoporosis mouse model were investigated. Methods: MC3T3-E1 cells were exposed to dexamethasone (Dex) with or without KRG and cell viability was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Realtime polymerase chain reaction was performed to evaluate the apoptotic gene expression; osteogenic gene expression and alkaline phosphatase (ALP) activity were also measured. Western blotting was performed to evaluate the mitogen-activated protein kinase (MAPK) proteins. A GC-induced osteoporosis animal model was used for in vivo study. Results and conclusion: The MTT assay revealed that Korean Red Ginseng (KRG) prevents loss of cell viability caused by Dex-induced apoptosis in MC3T3E1 cells. Real-time polymerase chain reaction data showed that groups treated with both Dex and KRG exhibited lower mRNA levels of caspase-3 and -9, whereas the mRNA levels of Bcl2, IAPs, and XIAP increased. Moreover, groups treated with both Dex and KRG demonstrated increased mRNA levels of ALP, RUNX2, and bone morphogenic proteins as well as increased ALP activity in MC3T3-E1 cells, compared to cells treated with Dex only. In addition, KRG increased protein kinase B (AKT) phosphorylation and decreased c-Jun N-terminal kinase (JNK) phosphorylation. Moreover, microcomputed tomography analysis of the femurs showed that GC implantation caused trabecular bone loss. However, a significant reduction of bone loss was observed in the KRG-treated group. These results suggest that the molecular mechanism of KRG in the GC-induced apoptosis may lead to the development of therapeutic strategies to prevent and/or delay osteoporosis.

• 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.

• Journal of Periodontal and Implant Science
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• 제34권2호
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• pp.333-344
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• 2004

The enamel matrix derivative (EMD) has been recently used in the periodontal regenerative techniques. The present study was established to investigate the influence of EMD on human periodontal ligament cells using expression of mRNA of periodontal ligament specific gene (PDLs)17, PDLs22, type I collagen when EMD applied to periodontal ligament cells. Periodontal ligament cells were obtained from a healthy periodontium and cultured in Dulbecco's modified Eagle's medium (DMEM) plus 10% fetal bovine serum and ${\beta}-glycerophosphate$ with ascorbic acid. Test groups were two; One adds EMD in culture media and another added EMD and Dexamethasone (DEX) in culture media. Positive control group added DEX in culture media, and negative control group adds niether of EMD nor DEX. $Emdogain^{(R)}$ (Biora, Sweden, 30 mg/ml) was diluted by 75 ${\mu}g/ml$ concentration to culture media. For reverse transcription-polymerase chain reaction (RT-PCR), total RNA isolated on days 0, 7, 14 and 21. mRNA of PDLs17 was expressed on days 14 and 21 in EMD or DEX group, and expressed on days 7, 14 and 21 in EMD plus DEX group, the other side, expressed on days 21 in negative control group. mRNA of PDLs22 expressed on days 7, 14 and 21 in EMD group, and expressed on days 14 and 21 in DEX group, and expressed on days 7, 14 and 21 in EMD plus DEX group. Negative control group expressed on days 14 and 21. Type I collagen was expressed on all days and all groups. These results indicate that EMD promotes differentiation of periodontal ligament cells, and this is considered to offer basis that can apply EMD to periodontal tissue regeneration technique.

• Molecules and Cells
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• 제39권8호
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• pp.631-638
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• 2016

Glutathione peroxidase 3 (GPx3), an antioxidant enzyme, acts as a modulator of redox signaling, has immunomodulatory function, and catalyzes the detoxification of reactive oxygen species (ROS). GPx3 has been identified as a tumor suppressor in many cancers. Although hyper-methylation of the GPx3 promoter has been shown to down-regulate its expression, other mechanisms by which GPx3 expression is regulated have not been reported. The aim of this study was to further elucidate the mechanisms of GPx3 regulation. GPx3 gene analysis predicted the presence of ten glucocorticoid response elements (GREs) on the GPx3 gene. This result prompted us to investigate whether GPx3 expression is regulated by the glucocorticoid receptor (GR), which is implicated in tumor response to chemotherapy. The corticosteroid dexamethasone (Dex) was used to examine the possible relationship between GR and GPx3 expression. Dex significantly induced GPx3 expression in H1299, H1650, and H1975 cell lines, which exhibit low levels of GPx3 expression under normal conditions. The results of EMSA and ChIP-PCR suggest that GR binds directly to GRE 6 and 7, both of which are located near the GPx3 promoter. Assessment of GPx3 transcription efficiency using a luciferase reporter system showed that blocking formation of the GR-GRE complexes reduced luciferase activity by 7-8-fold. Suppression of GR expression by siRNA transfection also induced down-regulation of GPx3. These data indicate that GPx3 expression can be regulated independently via epigenetic or GR-mediated mechanisms in lung cancer cells, and suggest that GPx3 could potentiate glucocorticoid (GC)-mediated anti-infla-mmatory signaling in lung cancer cells.

• Biomolecules & Therapeutics
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• 제21권6호
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• pp.481-486
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• 2013

Macrophages play a role in innate immune responses to various foreign antigens. Many products from primary tumors influence the activation and transmigration of macrophages. Here, we investigated a migration of macrophages stimulated with cancer cell culture-conditioned medium (CM). Macrophage activation by treatment with CM of B16F10 cells were judged by the increase in protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). The location where macrophages were at 4 h-incubation with control medium or CM was different from where they were at 5 h-incubation in culture dish. Percentage of superimposed macrophages at every 1 h interval was gradually increased by CM treatment as compared to control. Total coverage of migrated track expressed in coordinates was smaller and total distance of migration was shorter in CM-treated macrophages than that in control. Rac1 activity in CM-treated macrophages was also decreased as compared to that in control. When macrophages were treated with CM in the presence of dexamethasone (Dex), an increase in COX2 protein levels, and a decrease in Rac1 activity and total coverage of migration were reversed. In the meanwhile, biphasic changes were detected by Dex treatment in section distance of migration at each time interval, which was more decreased at early time and then increased at later time. Taken together, data demonstrate that macrophage motility could be reduced in accordance with activation in response to cancer cell products. It suggests that macrophage motility could be a novel marker to monitor cancer-associated inflammatory diseases and the efficacy of anti-inflammatory agents.