• BMB Reports
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• 제41권7호
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• pp.485-494
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• 2008

The Wnt signaling network, which is composed of Wnt ligands, receptors, antagonists, and intracellular signaling molecules, has emerged as a powerful regulator of cell fate, proliferation, and function in multicellular organisms. Over the past two decades, the critical role of Wnt signaling in embryonic cartilage and bone development has been well established, and much has been learnt regarding the role of Wnt signaling in chondrogenesis and cartilage development. However, relatively little is known about the role of Wnt signaling in adult articular cartilage and degenerative cartilage tissue. This review will briefly summarize recent advances in Wnt regulation of chondrogenesis and hypertrophic maturation of chondrocytes, and review data concerning the role of Wnt signaling in the maintenance and degeneration of articular chondrocytes and cartilage.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권1호
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• pp.1-8
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• 2001

This study was designed to localize the distribution of basic fibroblast growth factor(bFGF) in the developing rat condylar region and to elucidate the associated function of bFGF in the condyle development. The condyles of temporomandibular joint of Sprague-Dawley rats (27g of weight) were used. The tissues were examined with electron microscope and immunohistochemical method. The results were as follows: 1. The developing condylar region are divided in to 5 zones apparently: proliferative, maturation, hypertrophic, calcifying, and ossification zones. 2. The cells in the proliferative zone are condensed and have under-developed cell organells in the cytoplasm. This zone shows a strong immunoreactivity of bFGF. 3. The cells in the maturation zone are typical chondroblasts showing well-developed cell organells and round nucleus. The cartilaginous matrix does not show the immunoreactivity of bFGF, while the chondroblasts show the immunoreactivity. 4. The cells in the hypertrophic zone show hypertrophic change having the degenerated cell organelles and small nucleus. There are no immunoreactivity of bFGF in this zone except the nucleus and endoplasmic region showing mild immunoreactivity. 5, The cells in the calcifying zone show hypertrophic change and cell organelles are disappeared. The cells are surrounded by the calcified cartilaginous matrix. There are no immunoreactivity of bFGF in this zone except the endoplasmic region showing mild immunoreactivity. 6. In the zone of bone formation, chondroblasts are disappeared. Newly differentiated osteoblasts secreting osteoid around the calcified cartilaginous matrix. The bone marrow shows the immunoreactivity of bFGF, while the bone matrix does not show the immunoreactivity of bFGF.

• BMB Reports
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• 제56권9호
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• pp.496-501
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• 2023

Elongation of most bones occur at the growth plate through endochondral ossification in postnatal mammals. The maturation of chondrocyte is a crucial factor in longitudinal bone growth, which is regulated by a complex network of paracrine and endocrine signaling pathways. Here, we show that a phytochemical sulfuretin can stimulate hypertrophic chondrocyte differentiation in vitro and in vivo. We found that sulfuretin stabilized nuclear factor (erythroid-derived 2)-like 2 (Nrf2), stimulated its transcriptional activity, and induced expression of its target genes. Sulfuretin treatment resulted in an increase in body length of zebrafish larvae and induced the expression of chondrocyte markers. Consistently, a clinically available Nrf2 activator, dimethyl fumarate (DMF), induced the expression of hypertrophic chondrocyte markers and increased the body length of zebrafish. Importantly, we found that chondrocyte gene expression in cell culture and skeletal growth in zebrafish stimulated by sulfuretin were significantly abrogated by Nrf2 depletion, suggesting that such stimulatory effects of sulfuretin were dependent on Nrf2, at least in part. Taken together, these data show that sulfuretin has a potential use as supporting ingredients for enhancing bone growth.

• Applied Microscopy
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• 제28권1호
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• pp.91-105
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• 1998

The present study is undertaken to investigate the hypertrophical changes of the corpus allatum (corpora allata, CA) after the ovariectomy in Blattella germanica. In particular, the ultrastructural aspects of the normal and ovariectomized conditions, and induced factors of the hypertrophic phenomenon are focused. Ultrastructure of the CA from an immediately emergent adult is similar to that of the last larval stage that has stopped secreting juvenile hormone. The CA is composed of undifferentiated cells, exhibiting an electron-lucent matrix, a few mitochondria and less smooth endoplasmic reticulum. The karyoplasm occupy most of the cytoplasm. Electron-dense materials are filled with the intercellular spaces and gap junctions are also found. Almost no ultrastructural changes have been noticed during seven days until the oviposition. However, considerable changes in structure have been detected soon after the oviposition. Mitochondria are increased dramatically in number and cristae, and changed to the filamentous form with a high electron density. In addition, Golgi complexes, microtubules, and polysomes are also increased. After an oviposition, the total volume of the CA are decreased again. The volume of the CA are increased continuously, hypertrophy, after the ovariectomy. Morphological aspects of the CA in an early stage after the removal are similar to the structure of the secondary egg maturation. Large and electron dense globules are observed in the ovariectomized CA cytoplasms and they are present in those cells for a long period of time. Yet such a hypertrophical phenomenon occur only in the specific cells. The hypertrophy are caused by hollowing the part of the CA cells and later filling such site with polysomes. In 42 days after the ovariectomy, the nuclear membranes disappear in the CA cells, thus, exhibiting the prokaryotic-like features. Some results of the current study will contribute to the establishment of the model that explain unusual changes accompanied by certain treatment in insects and/or further in animals.

• 한국수산과학회지
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• 제19권1호
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• pp.83-91
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• 1986

1983년 9월부터 1984년 8월까지 부산시 해운대 동백섬의 조간대에서 채집된 노래미. Agrammus agrammus를 대상으로 생식소의 발달과 간의 활성변화관계를 파악하기 위해 간숙도지수(HSI)의 연간변화를 조사하였고 아울러 생식주기에 따른 간세포의 활성변화를 광학 및 전자현미경적 방법에 의해 조사하였다. 간숙도지수(HSI)의 연간변화는 수컷의 경우 뚜렸하지 않으나 암컷의 경우는 추계에 증가하기 시작하여 난소가 성숙하는 동계에 최대에 이른다. 암컷에 있어서 난모세포들이 난황물질을 축적하는 시기에는 간세포들의 크기는 점차로 커지며 핵과 인도 역시 커진다. 이때에 글리코겐과 지방적들의 양은 점차로 감소되나 호염기성의 핵산물질(RNA)은 증가된다. 또한 간세포질내에는 조면소포체들이 발달 증가하는데 이들은 단백질합성과 vitellogenin 축적에 관여하고 핵근처에 나타나는 골지체는 lipoprotein 합성에 중요한 역할을 하는 것으로 간주된다. 방난 직전의 암컷의 간세포질내에는 글리코겐과 지방적들이 급격히 감소되나 호염기성물질(RNA)은 세포질의 주변구역에서 특히 고농도로 나타나고 있다. 그러나 방난 이후에는 이와 반대의 현상이 관찰된다. 수컷의 경우는 성적으로 성숙해 감에 따라 간세포질내에 호염기성물질이 점차로 증가하며, 암컷과 달리 글리코겐과 지방적의 양도 다량으로 관찰된다. 반면, 방정기 이후에는 간세포질내의 호염기성물질은 감소된다.