• 치위생과학회지
• /
• 제11권1호
• /
• pp.55-61
• /
• 2011

최근에 Odontogenic ameloblast-associated protein (ODAM)은 MMP-20의 발현을 조절하여 법랑모세포 분화와 법랑질의 석회화에 중요한 역할을 한다고 보고되었다. 그러나 이에 대한 명확한 기전은 알려져 있지 않다. 그러므로 이 연구의 목적은 법랑모세포 분화와 법랑질의 석회화 과정에서의 ODAM의 생물학적 기능과 신호 전달 경로를 찾고자 하였다. Ameloblast-lineage cells (ALCs)를 이용하여 ODAM 재조합 단백질을 생성하고 ODAM 과발현 (ODAM overexpressing) 또는 ODAM 억제(ODAM silencing) 세포주를 만들었다. 세포들은 2주 동안 분화 배지에서 ODAM 재조합 단백질을 처리한 군과 처리하지 않는 군으로 나누어 배양하였다. ODAM의 신호 전달 경로를 확인하기 위하여, ALCs에 BMP2와 BMP receptor 1B (BMPR-1B) 억제제인 BAMBI 재조합 단백질을 처리하였고, 또한 BMPR-1B siRNA 이용하여 BMPR-1B의 발현을 억제하였다. 단백질 발현은 western blot 이용하여 분석하였다. 석회화는 sense ODAM 과발현 세포와 ODAM 재조합 단백질을 첨가한 법랑모세포 세포주에서 증진되었다. 또한 ALP 활성화는 sense ODAM 과발현 세포와 ODAM 정제된 단백질를 첨가한 법랑모세포 세포주에서 뚜렷하게 증진되었다. 기관발생과 관련이 있는 BMPR-IB와 석회화 과정과 관련된 CBP2는 ODAM 과발현을 유도한 경우에는 발현이 증가되었으나, ODAM 발현을 억제시킨 경우에는 발현이 현저히 감소하였다. 이상 실험의 결과는 법랑질 형성과정에서 ODAM이 법랑질 석회화를 증진시킬 수 있음을 시사한다.

• Journal of Korean Dental Science
• /
• 제8권2호
• /
• pp.74-81
• /
• 2015

Purpose: In osteoclast differentiation, actin-rich membrane protrusions play a crucial role in cell adhesion. Odontogenic ameloblast-associated protein (Odam) contributes to cell adhesion by inducing actin rearrangement. Odam-mediated RhoA activity may play a significant role in multinucleation of osteoclasts. However, the precise function of Odam in osteoclast cell adhesion and differentiation remains largely unknown. Here, we identify a critical role for Odam in inducing osteoclast adhesion and differentiation. Materials and Methods: The expression of Odam in osteoclasts was evaluated by immunohistochemistry. Primary mouse bone marrow and RAW264.7 cells were used to test the cell adhesion and actin ring formation induced by Odam. Result: Odam was expressed in osteoclasts around alveolar bone. Odam transfection induced actin filament rearrangement and cell adhesion compared with the control or collagen groups. Overexpression of Odam promoted actin stress fiber remodeling and cell adhesion, resulting in increased osteoclast fusion. Conclusion: These results suggest that Odam expression in primary mouse osteoclasts and RAW264.7 cells promotes their adhesion, resulting in the induction of osteoclast differentiation.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권12호
• /
• pp.3257-3274
• /
• 2012

Broadcast routing has become an important research field for vehicular ad-hoc networks (VANETs) recently. However, the packet delivery rate is generally low in existing VANET broadcast routing protocols. Therefore, the design of an appropriate broadcast protocol based on the features of VANET has become a crucial part of the development of VANET. This paper analyzes the disadvantage of existing broadcast routing protocols in VANETs, and proposes an improved algorithm (namely ODAM-C) based on the ODAM (Optimized Dissemination of Alarm Messages) protocol. The ODAM-C algorithm improves the packet delivery rate by two mechanisms based on the forwarding features of ODAM. The first distance-based mechanism reduces the possibility of packet loss by considering the angles between source nodes, forwarding nodes and receiving nodes. The second mechanism increases the redundancy of forwarding nodes to guarantee the packet success delivery ratio. We show by analysis and simulations that the proposed algorithm can improve packet delivery rate for vehicular networks compared against two widely-used existing protocols.

• 치위생과학회지
• /
• 제21권1호
• /
• pp.45-51
• /
• 2021

Background: Periodontal disease, also known as gum disease, is a major dental inflammatory disease with a very high prevalence; it is the main cause of tooth loss. Therefore, diagnostic biomarkers that can monitor gum inflammation are important for oral healthcare. Since the gingival crevicular fluid (GCF) adequately reflects changes in the periodontal environment, they have become a target for the development of effective diagnostic biomarkers for periodontitis. In the present study, the level of the target molecules suggested as diagnostic biomarkers for periodontitis were analyzed in GCF samples collected from healthy individuals and periodontitis patients. In addition, useful targets for the diagnosis of periodontitis were evaluated. Methods: GCF samples were collected from healthy individuals and periodontitis patients using absorbent paper points. SDS-PAGE and Coomassie staining were performed for protein analysis. The protein concentrations of GCF specimens were determined using the Bradford method. The levels of the target molecules appropriate for diagnosing periodontal disease were measured by ELISA, according to the manufacturer's protocol. Results: The protein concentration of GCF collected from periodontitis patients was 3.72 fold higher than that in an equal volume of GCF collected from healthy individuals. ELISA analysis showed that the level of interukin-6 (IL-6), IL-8, metalloproteinases 2 (MMP-2), MMP-9, tumor necrosis factor-alpha (TNF-α), azurocidin, and odontogenic ameloblast-associated protein (ODAM) were higher in the GCF samples from the periodontitis patients than in those from the healthy individuals. However, the level of IL-6 and TNF-α were relatively low (> 5 pg/ml). The prostaglandin E2 (PGE2) levels were not significantly different between the two GCF samples. Conclusion: These results indicate that IL-8, MMP-2, MMP-9, azurocidin, and ODAM are potentially useful diagnostic biomarkers for periodontitis; combining multiple biomarkers will improve the diagnostic accuracy of periodontitis.

• Nuclear Medicine and Molecular Imaging
• /
• 제41권2호
• /
• pp.118-131
• /
• 2007

Neurotransmitter imaging with radiopharmaceuticals plays major role for understanding of neurological and psychiatric disorders such as Parkinson's disease and depression. Radiopharmaceuticals for neurotransmitter imaging can be divided to dopamine transporter imaging radiopharmaceuticals and serotonin trnasporter imaging radiopharmaceuticals. Many kinds of new dopamine transporter imaging radiopharmcaeuticals has a tropane ring and they showed different biological properties according to the substituted functional group on tropane ring. After the first clinical trials with $[^{123}I]{\beta}-CIT$, alkyl chain substituent introduced to tropane ring amine to decrease time for imaging acquisition and to increase selectivity. From these results, $[^{123}I]PE2I$, [18F]FE-CNT, $[^{123}I]FP-CIT$ and $[^{18}F]FP-CIT$ were developed and they showed high uptake on the dopamine transporter rich regions and fast peak uptake equilibrium time within 4 hours after injection. $[^{11}C]McN$ 5652 was developed for serotonin trnasporter imaging but this compound showed slow kinetics and high background radioactivity. To overcome these problems, new diarylsulfide backbone derivatives such as ADAM, ODAM, AFM, and DASB were developed. In these candidates, $[^{11}C]AFM$ and $[^{11}C]DASB$ showed high binding affinity to serotonin transporter and fast in vivo kinetics. This paper gives an overview of current status on dopamine and serotonin transporter imaging radiopharmaceuitcals and the development of new lead compounds as potential radiopharmaceuticals by medicinal chemistry.