• Molecules and Cells
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• 제37권9호
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• pp.685-690
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• 2014

Osteoclasts are large polykaryons that have the unique capacity to degrade bone and are generated by the differentiation of myeloid lineage progenitors. To identify the genes involved in osteoclast development, we performed microarray analysis, and we found that carboxypeptidase E (CPE), a prohormone processing enzyme, was highly upregulated in osteoclasts compared with their precursors, bone marrow-derived macrophages (BMMs). Here, we demonstrate a novel role for CPE in receptor activator of NF-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. The overexpression of CPE in BMMs increases the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts and the expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1), which are key regulators in osteoclastogenesis. Furthermore, employing CPE knockout mice, we show that CPE deficiency attenuates osteoclast formation. Together, our data suggest that CPE might be an important modulator of RANKL-induced osteoclast differentiation.

• International Journal of Oral Biology
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• 제31권2호
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• pp.67-72
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• 2006

Nitric oxide(NO) is a labile, uncharged, reactive radical that functions as a sensitive mediator of intercellular communication in diverse tissues. It has been reported that NO is produced by osteoblast and these results may suggest that NO is integrally involved in the regulation of osteoclast formation and osteoclast resorption activity by osteoblastic cells. We examined the effect of cytokines on NO release by mouse bone marrow cell. We also examined the effects of cytokines and sodium nitroprusside(SNP) on the formation of osteoclast-like cell from mouse bone marrow cells in culture. Cytokines stimulated NO production of mouse bone marrow cells, and N-nitro-L-arginine methyl ester, a specific inhibitor of NO synthase, suppressed the cytokine-induced NO production. SNP showed dual action in the generation of osteoclasts. The addition of $30{\mu}M$ SNP inhibited the formation of tartrate resistant acid phosphatase(TRAP)(+) multinucleated cell, whereas lower concentration($3{\mu}M$) of SNP enhanced it. Although the precise action of NO remains to be elucidated in detail, the action of NO in osteoclast generation in our studies seems to be associated, at least in part, with bone metabolism and bone pathophysiology.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.11-20
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• 2019

Ecklonia cava, an edible marine brown alga (Laminariaceae), is a rich source of bioactive compounds such as fucoidan and phlorotannins. Ecklonia cava extract (ECE) was prepared using 70% ethanol extraction and ECE contained 67% and 10.6% of total phlorotannins and dieckol, respectively. ECE treatment significantly inhibited receptor activator of nuclear $factor-{\kappa}B$ ligand (RANKL)-induced osteoclast differentiation of RAW 264.7 cells and pit formation in bone resorption assay (p <0.05). Moreover, it suppressed RANKL-induced $NF-{\kappa}B$ and mitogen-activated protein kinase signaling in a dose dependent manner. Downregulated osteoclast-specific gene (tartrate-resistant acid phosphatase, cathepsin K, and matrix metalloproteinase-9) expression and osteoclast proliferative transcriptional factors (nuclear factor of activated T cells-1 and c-fos) confirmed ECE-mediated suppression of osteoclastogenesis. ECE treatment ($100{\mu}g/ml$) increased heme oxygenase-1 expression by 2.5-fold and decreased intercellular reactive oxygen species production during osteoclastogenesis. The effective inhibition of RANKL-stimulated osteoclast differentiation and oxidative stress by ECE suggest that ECE has therapeutic potential in alleviating osteoclast-associated disorders.

• 한국식품영양과학회지
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• 제44권4호
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• pp.532-539
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• 2015

파골세포의 분화에 대한 시금치 추출물의 영향을 확인하고자 RANKL을 처리한 RAW264.7 세포에서 세포독성, TRAP(+) 다핵세포의 형성, 파골세포 분화 관련 유전자의 발현, 그리고 단백질 발현을 확인하였다. 물과 25, 50, 75 및 100% 에탄올 시금치 추출물의 세포독성을 측정한 결과 모든 추출물들이 $100{\mu}g/mL$ 이하의 농도에서 RAW264.7 세포에 독성을 유발하지 않았다. TRAP 염색을 통해 TRAP(+) 다핵세포의 수와 효소 활성을 측정한 결과 물 추출물을 제외한 모든 추출물이 대조군에 비해 분화 억제 및 효소 활성 저해 효과가 있었다. 특히 $100{\mu}g/mL$ 농도의 100% 에탄올 추출물은 RANKL만 처리한 대조군과 비교해 80%의 유의한 TRAP(+) 다핵세포 숫자 감소와 44%의 TRAP 효소 활성 저해율을 보였다. 시금치 에탄올 추출물은 RANKL에 의한 파골세포 분화의 지표가 되는 관련유전자인 NFAT, c-FOS, cathepsin K 및 TRAP의 발현을 억제하였다. 또한 단백질 수준에서 시금치 에탄올 추출물은 RANKL에 의해 증가된 NFATc1의 발현을 현저히 감소시키는 것으로 확인되었고, 또한 c-FOS의 활성화 형태인 인산화된 c-FOS의 발현뿐만 아니라 인산화되지 않은 비활성의 c-FOS 발현도 감소시켰다. 반면 파골세포의 분화에 직간접적인 영향을 미친다고 알려진 MAPK 중 ERK의 활성에는 거의 영향을 미치지 않는 것으로 보아 시금치 에탄올 추출물은 c-FOS의 활성, 비활성형 전체를 감소시킴으로 파골세포 분화를 감소시키는 것으로 확인되었다.

• 한국미생물·생명공학회지
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• 제44권4호
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• pp.557-562
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• 2016

치주질환은 만성염증성 질환으로 치조골소실을 일으켜 성인치아상실을 유발하는 요인 중 하나이다. 그람 음성세균인 Aggregatibacter actinomycetemcomitans와 Porphyromonas gingivalis는 치주질환환자의 병소에서 쉽게 동정된다. 지질다당체(Lipopolysaccharide; LPS)는 그람 음성세균의 핵심 독력인자로 알려져 있다. 이러한 세균과 LPS는 파골세포에 의한 골소실을 조절하는 요인 중 하나이다. 그러므로 본 연구에서는 동물모델을 활용하여 A. actinomycetemcomitans와 P. gingivalis의 의한 골소실 여부를 확인하고, 기전규명을 위하여 A. actinomycetemcomitans, P. gingivalis, A. actinomycetemcomitans와 P. gingivalis에서 분리한 LPS에 의한 파골세포분화 영향을 연구하였다. 열사멸한 A. actinomycetemcomitans (HKAa)와 열사멸한 P. gingivalis (HKPg)가 복강으로 투여된 쥐의 대퇴골은 대조군에 비해 감소된 골량을 보여주었다. 이러한 골소실의 증가가 파골세포분화 때문인지 확인하기 위해 파골세포분화를 연구한 결과, bone marrow-derived macrophage (BMM)의 RANKL-매개 파골세포분화를 감소시켰으나, committed osteoclast precursor의 파골세포분화를 유도함을 확인하였다. 세균에 의한 파골세포분화 결과와 동일하게 A. actinomycetemcomitans와 P. gingivalis에서 분리한 LPS 역시 RANKL-매개 파골세포분화는 감소시키고, committed osteoclast precursor의 파골세포분화를 유도하였다. 결과적으로 치주원인균인 A. actinomycetemcomitans와 P. gingivalis는 committed osteoclast precursor의 파골세포분화를 증가시키는데, 이 세균들의 LPS가 핵심 역할을 수행하는 것으로 판단되며 이를 통해 골 흡수를 유발함을 알 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제3권6호
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• pp.539-546
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• 1999

Bone is a complex tissue in which resorption and formation continue throughout life. The bone tissue contains various types of cells, of which the bone forming osteoblasts and bone resorbing osteoclasts are mainly responsible for bone remodeling. Periodontal disease represents example of abnormal bone remodeling. Osteoclasts are multinucleated cells present only in bone. It is believed that osteoclast progenitors are hematopoietic origin, and they are recruited from hematopoietic tissues such as bone marrow and circulating blood to bone. Cells present in the osteoclast microenvironment include marrow stromal cells, osteoblasts, macrophages, T-lymphocytes, and marrow cells. These cells produce cytokines that can affect osteoclast formation. In vitro model systems using bone marrow cultures have demonstrated that $IL-l{\beta},\;IL-3,\;TNF-{\alpha},$ bFGF can stimulate the formation of osteoclasts. In contrast, IL-4 inhibits osteoclast formation. Knowledge of cytokines and bFGF that affect osteoclast formation and their capacity to modulate the bone-resorbing process should provide critical insights into normal calcium homeostasis and disorders of bone turnover such as periodontal disease, osteoporosis and Paget's disease.

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.995-1005
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• 1999

Alveolar bone destruction is a character-istic of periodontal disease. Treponema denticola are found in significantly increased numbers in the sites affected with periodontal disease. In order to clarify the role of T. denticola in destruction of alveo-lar bone in periodontal disease, this study was undertaken to determine the effect of sonicated extract of T. denticola on osteo-clast differentiation in co-culture system of mouse bone marrow cells and calvaria cells. The ability of osteoclast formation was estimated by counting the number of tar-tartrate resistant acid phosphatase(TRAP) positive cells. Sonicated extract of this bacteria stimulated osteoclast formation in a dose dependent manner(p<0.05). Indomathacin, an inhibitor of prostaglandin synthesis, decreased osteoclast formation induced by sonicated extract of this bacte-bacteria(p<0.05). Extract-induced osteoclast formation was decreased, when sonicated extract of bacteria was heated(p<0.05). These findings suggest that T. denticola induces osteoclast differentiation, and protein component of this bacteria and $PGE_2$ may play an important role in this process.

• 대한세포병리학회지
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• 제18권1호
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• pp.69-73
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• 2007

Mammary carcinoma with osteoclast-like giant cells is an unusual neoplasm characterized by giant cells, mononuclear stromal cells, and hemorrhage accompanying a low grade carcinoma. We present the cytological findings in a case of invasive ductal carcinoma with osteoclast-like giant cells that was initially confused with a fibroadenoma, due to its well-demarcated and soft mass and the young age of the patient. A 28-year-old female presented with a 4.5 cm, well demarcated, soft and nontender mass in the right breast. Fine needle aspiration cytology (FNAC) showed a combination of low grade malignant epithelial cell clusters and osteoclast-like giant cells. The atypical epithelial cells were present in cohesive sheets and clusters. Osteoclast-like giant cells and bland-looking mononuclear cells were scattered. An histological examination revealed the presence of an invasive ductal carcinoma with osteoclast-like giant cells. We report here the cytological findings of this rare carcinoma in a very young woman. The minimal atypia of the epithelial cells and its soft consistency may lead to a false negative diagnosis in a young woman. The recognition that osteoclastlike giant cells are rarely present in a low grade carcinoma, but not in benign lesion, can assist the physician in making a correct diagnosis.

• Molecules and Cells
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• 제43권1호
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• pp.34-47
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• 2020

The circadian clock regulates various physiological processes, including bone metabolism. The nuclear receptors Reverbs, comprising Rev-erbα and Rev-erbβ, play a key role as transcriptional regulators of the circadian clock. In this study, we demonstrate that Rev-erbs negatively regulate differentiation of osteoclasts and osteoblasts. The knockdown of Rev-erbα in osteoclast precursor cells enhanced receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation, as well as expression of nuclear factor of activated T cells 1 (NFATc1), osteoclast-associated receptor (OSCAR), and tartrate-resistant acid phosphatase (TRAP). The overexpression of Rev-erbα leads to attenuation of the NFATc1 expression via inhibition of recruitment of c-Fos to the NFATc1 promoter. The overexpression of Rev-erbα in osteoblast precursors attenuated the expression of osteoblast marker genes including Runx2, alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC). Rev-erbα interfered with the recruitment of Runx2 to the promoter region of the target genes. Conversely, knockdown of Rev-erbα in the osteoblast precursors enhanced the osteoblast differentiation and function. In addition, Rev-erbα negatively regulated osteoclast and osteoblast differentiation by suppressing the p38 MAPK pathway. Furthermore, intraperitoneal administration of GSK4112, a Rev-erb agonist, protects RANKL-induced bone loss via inhibition of osteoclast differentiation in vivo. Taken together, our results demonstrate a molecular mechanism of Rev-erbs in the bone remodeling, and provide a molecular basis for a potential therapeutic target for treatment of bone disease characterized by excessive bone resorption.

• 생약학회지
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• 제53권1호
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• pp.42-48
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• 2022

In order to maintain bone homeostasis, it is necessary to balance bone resorption and remodeling through the differentiation of osteoclasts that absorb old bone and osteoblasts that form new bone. However, bone resorption due to excessive osteoclast differentiation is a major cause of osteoporosis and controlling excessive osteoclast differentiation has been known as a treatment strategy for osteoporosis. Therefore, in this study, the effect of an ethanol extract of Sphaerotylus antarcticus Kirkpatrick, 1907 (SAE), polar-derived sponge with unknown biological activity, on the osteoclast differentiation process of RANKL-induced RAW264.7 cells and the generated ROS was evaluated. In the study results, SAE down-regulated the formation and function of RANKL-induced osteoclasts and osteoclast differentiation specific proteins, genes in a concentration-dependent manner. In addition, it was possible to confirm the result of restoring the lost antioxidant enzyme along with down-regulation of ROS generated by RANKL. Therefore, in this study, we propose the possibility of SAE as a potential regulator of osteoporosis due to excessive osteoclast differentiation and report the biological value of the diversity of marine-derived natural products by identifying the first biological activity against SAE that is not yet known.