Estrogen Receptor α Regulates Dlx3-Mediated Osteoblast Differentiation

Lee, Sung Ho,Oh, Kyo-Nyeo,Han, Younho,Choi, You Hee,Lee, Kwang-Youl Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.2

Estrogen receptor ${\alpha}$ (ER-${\alpha}$), which is involved in bone metabolism and breast cancer, has been shown to have transcriptional targets. Dlx3 is essential for the skeletal development and plays an important role in osteoblast differentiation. Various osteogenic stimulators and transcription factors can induce the protein expression of Dlx3. However, the regulatory function of ER-${\alpha}$ in the Dlx3 mediated osteogenic process remains unknown. Therefore, we investigated the regulation of Dlx3 and found that ER-${\alpha}$ is a positive regulator of Dlx3 transcription in BMP2-induced osteoblast differentiation. We also found that ER-${\alpha}$ interacts with Dlx3 and increases its transcriptional activity and DNA binding affinity. Furthermore, we demonstrated that the regulation of Dlx3 activity by ER-${\alpha}$ is independent of the ligand (estradiol) binding domain. These results indicate that Dlx3 is a novel target of ER-${\alpha}$, and that ER-${\alpha}$ regulates the osteoblast differentiation through modulation of Dlx3 expression and/or interaction with Dlx3.

3D-QSAR method on indole and pyrrole inhibitors of monoamine oxidase type A

Lee, Younho,Lim, Yoongho Taylor Francis 2009 MOLECULAR SIMULATION Vol.35 No.15

<P> Monoamine oxidase A (MAO-A) converts norepinephrine and serotonin to an oxidative form. These monoamine neurotransmitters have important roles in depression. The MAO-A inhibitors have been discovered for neurodegenerative disease therapy. In order to design novel MAO-A inhibitors, in this study, the quantitative structure-activity relationships for the combined series of indoles and pyrroles were elucidated and the structural conditions to show good inhibitory effects on MAO-A were derived. This result can help us design new inhibitors irrespective of their specific moiety.</P>

Sensor Node Localization by Three Mobile Anchors in the Wireless Sensor Networks

LEE, Seunghak,KIM, Namgi,KIM, Heeyoul,LEE, Younho,YOON, Hyunsoo The Institute of Electronics, Information and Comm 2011 IEICE transactions on information and systems Vol.94 No.10

<P>For the deployment of sensor networks, the sensor localization, which finds the position of sensor nodes, is very important. Most previous localization schemes generally use the GPS signal for the sensor localization. However, the GPS signal is unavailable when there is an obstacle between the sensor nodes and satellites. Therefore, in this paper, we propose a new localization scheme which does not use the GPS signal. The proposed scheme localizes the sensors by using three mobile anchors. Because the three mobile anchors collaboratively move by themselves, it is self-localizable and can be adopted even when the sensors are randomly and sparsely deployed in the target field.</P>

Efficient Approach for Mitigating Mobile Phishing Attacks

LEE, Hyungkyu,LEE, Younho,SEO, Changho,YOON, Hyunsoo Institute of Electronics, Information and Communic 2018 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.eb101 No.9

Pin1 enhances adipocyte differentiation by positively regulating the transcriptional activity of PPARγ

( Younho Han ),( Sung Ho Lee ),( Minjin Bahn ),( Chang-yeol Yeo ),( Kwang Youl Lee ) 전남대학교 약품개발연구소 2016 약품개발연구지 Vol.25 No.-

Pin1 is a peptidylprolyl cis/trans isomerase and it has a unique enzymatic activity of catalyzing isom-erization of the peptide bond between phospho-serine/threonine and proline. Through the conforma-tional change of its substrates, Pin1 regulates diverse biological processes including adipogenesis. In mouse embryonic fibroblasts and 3T3-L1 preadipocytes, overexpression of Pin1 enhances adipocyte differentiation whereas inhibition of Pin1 activity suppresses it. However, the precise functions of Pin1 during adipogenesis are not clear. In the present study, we investigated the potential targets of Pin1 during adipogenesis. We found that Pin1 interacts directly with and regulates the transcriptional activity of PPARγ, a key regulator of adipogenesis. In addition, ERK activity and Ser273 of PPARγ, a potential ERK phosphorylation target site, are important for the regulation of PPARγ function by Pin1 3T3-L1 cells. Taken together our results suggest a novel regulatory mechanism of pin1 during adipogensis. In which Pin1 enhances adipocyte differentiation by regulating the function of PPARΥ. ⓒ 2016 Elsevier lreland Ltd. All rights reserved.

Berberine bioisostere Q8 compound stimulates osteoblast differentiation and function <i>in vitro</i>

Han, Younho,Jin, Yifeng,Lee, Sung Ho,Khadka, Daulat Bikram,Cho, Won-Jea,Lee, Kwang Youl ACADEMIC PRESS 2017 PHARMACOLOGICAL RESEARCH Vol.119 No.-

<P><B>Abstract</B></P> <P>The Q8 compound is a unique derivative of berberine. The present study investigated the functional role of Q8 to evaluate its potential for use in bone regeneration, especially in osteoblast differentiation. The safe concentration of Q8 increased BMP4-induced alkaline phosphatase (ALP) activity, and induced RNA expression of ALP, bone sialoprotein (BSP), and osteocalcin (OC). The activities of ALP-, BSP- and OC-luciferase reporters were also increased by Q8. During osteoblast differentiation, Q8 stabilized the Runx2 and Osterix protein abundance by blocking the ubiquitin-proteasome pathway, which in turn promoted Runx2 and Osterix induced transcriptional activity and subsequently increased the osteoblast differentiation. Meanwhile, depletion of Runx2 and Osterix markedly abolished the bone anabolic effect of Q8 on osteoblast differentiation. To evaluate the signal transduction pathway involved in the Q8-mediated regulation of Runx2 and Osterix, we examined the reporter assay using various kinase inhibitors. Treatment with a protein kinase A (PKA) inhibitor, H89 inhibited the Q8-mediated regulation of Runx2 and Osterix. Based on these findings, this study demonstrates that Q8 promotes the osteoblast differentiation by stabilization of Runx2/Osterix through the increased activation of PKA signaling. The enhancement of osteoblast function by Q8 may contribute to the prevention for osteoporosis.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

이미지 왜곡을 줄인 이진 이미지 인증을 위한 정보 은닉 기법

이윤호(Younho Lee),김병호(Byoungho Kim) 한국정보과학회 2009 정보과학회논문지 : 시스템 및 이론 Vol.36 No.2

본 연구에서는 삽입되는 정보에 의한 이미지의 왜곡을 최소화하는 이미지 인증을 위한 정보은닉 기법을 제안한다. 제안 방법은 해밍 코드를 이용한 메시지 삽입 방법을 이용하여 적은 화소의 왜곡만으로 많은 양의 인증 정보의 삽입이 가능하다. 또한 정보 삽입으로 인한 이미지 영역의 훼손을 줄이기 위해 Yang 등이 제안한 변조 가능 기준(flippablity criteria)에 의해 선택된 변조 가능 화소(flippable pixel) 만을 정보 삽입에 사용한다. 마지막으로, 인증 정보가 각 변조 가능 화소에 삽입되는 순서를 은폐함으로써, 적법한 검증자가 아닐 경우, 이미지로부터 인증 정보를 추출해 내기 어렵게 한다. 제안 방법의 우수성을 보이기 위해, 기존 연구들과 반전되는 화소의 수, 오탐율에 대하여 비교 분석을 수행하며 그 결과로써 제안 방법이 적은 양의 화소값의 변화만으로 매우 낮은 오탐율을 보장함을 보인다. 이에 부가하여, 다양한 이진 이미지에 대해 제안 방법과 Yang 등의 방법을 적용하여 정보를 삽입하는 실험을 수행한다. 실험 결과에 대한 이미지 영역 분석을 통해 제안 방법이 이전의 방법보다 적은 왜곡을 갖게 됨을 보이고, 최근에 제안된 이진 이미지 정보 은닉 방법에 대한 공격에도 이전의 방법들보다 좀 더 안정성이 있음을 보인다. This paper proposes a new data hiding scheme for binary image authentication with minimizing the distortion of host image. Based on the Hamming-Code-Based data embedding algorithm, the proposed scheme makes it possible to embed authentication information into host image with only flipping small number of pixels. To minimize visual distortion, the proposed scheme only modifies the values of the flippable pixels that are selected based on Yang et al's flippablity criteria. In addition to this, by randomly shuffling the bit-order of the authentication information to be embedded, only the designated receiver, who has the secret key that was used for data embedding, can extract the embedded data. To show the superiority of the proposed scheme, the two measurement metrics, the miss detection rate and the number of flipped pixels by data embedding, are used for the comparison analysis between the proposed scheme and the previous schemes. As a result of analysis, it has been shown that the proposed scheme flips smaller number of pixels than the previous schemes to embed the authentication information of the same bit-length. Moreover, it has been shown that the proposed scheme causes smaller visual distortion and more resilient against recent steg-analysis attacks than the previous schemes by the experimental results.

X.509 대리 인증서 환경에서 위임 추적 기능을 제공하는 ID 기반 암호 시스템 기반 권한 위임 프로토콜

이윤호(Younho Lee),김병호(Byungho Kim) 한국정보과학회 2008 정보과학회논문지 : 시스템 및 이론 Vol.35 No.9·10

계산적 그리드 환경에서 개체간 권한 위임 및 Single Sign-on 의 목적을 위해 사용되고 있는 X.509 대리 인증서 표준은 추적 불가능성으로 인한 잠재적인 보안 위협 및 권한 위임자와 권한 대리자간의 다수의 대화식 (Interactive) 통신으로 야기 되는 비효율성에 노출되어 있다. 본 논문에서는 이러한 두가지 문제점을 해결하면서 기존의 X.509 대리 인증서 표준의 장점을 그대로 유지할 수 있는 권한 위임 프로토콜을 제안한다. 제안 방법은 ID 기반 서명 알고리즘 및 키 생성 방법을 권한 위임 과정에 적용시켜 권한 대리키로 사용한다. 이러한 결과 권한 대리자와 권한 위임자간의 통신 횟수를 줄일 수 있다. 본 제안프로토콜을 계산적 그리드 환경에 적용시키면, 연속된 위임 과정으로 생성되는 대리 인증서 사슬의 참여자를 알 수 있음으로써 생기는 보안성 향상 뿐만 아니라 광대역 네트워크상에서 진행되는 위임 과정의 통신량 및 횟수를 줄일 수 있으므로 결과적으로 계산적 그리드 환경의 성능 향상에 기여하게 된다. Currently, the X.509 proxy certificate is widely used to delegate an entity's right to another entity in the computational grid environment. However it has two drawbacks: the potential security threat caused by intraceability of a delegation chain and the inefficiency caused by an interactive communication between the right grantor and the right grantee on the delegation protocol. To address these problems for computational grids, we propose a new delegation protocol without additional cost. We use an ID-based key generation technique to generate a proxy private key which is a means to exercise the delegated signing right. By applying the ID-based key generation technique, the proposed protocol has the delegation traceability and the non-interactive delegation property. Since the right delegation occurs massively in the computational grid environment, our protocol can contribute the security enhancement by providing the delegation traceability and the efficiency enhancement by reducing the inter-domain communication cost.

인지기능저하 노인의 자기돌봄과 영향요인 탐색

이연호 ( Younho Lee ) 인문사회 21 2023 인문사회 21 Vol.14 No.1

연구 목적: 본 논문은 인지기능저하 노인의 치매 예방과 삶의 통제력 확보를 위해 자기돌봄의 특성과 자기돌봄에 미치는 영향요인을 탐색하고자 하였다. 연구 방법: 제8차 고령화연구패널조사를 활용하여 총 1,432명의 인지기능저하 노인 특성을 살펴보고, 인구사회학적, 관계적, 경제적, 건강 및 기능적 요인으로 분류하여 자기돌봄의 영향요인을 서열로지스틱 회귀분석을 실시하였다. 연구 내용: 인지기능저하 노인의 자기돌봄 특성과 자기돌봄에 미치는 영향요인을 검증하였다. 결론 및 제언: 인지기능저하 노인들의 경우, 인구사회학적 변인과 관련하여 성별, 최종학력, 근로유무, 거주지역, 모임참여횟수가 자기돌봄에 영향을 미치는 것으로 나타났다. 건강 및 기능관련 변인에서는 통증으로 인한 일상생활의 어려움과 우울증 유무가 유의미한 영향을 미치는 것으로 나타났다. 인지기능저하 노인 집단의 퇴화 또는 노쇄 속도를 늦추기 위해 자기돌봄 특성과 이에 미치는 영향요인을 정책과 자기돌봄 지원 서비스 및 프로그램 설계시 고려할 필요가 있다. The purpose of this study is to empirically analyze the characteristics of self-care behavior of the elderly with mild cognitive impairment and the factors affecting self-care. The characteristics of the 1,432 elderly with mild cognitive impairment were presented and the factors influencing self-care were classified into demographic, socioeconomic, relational, health and functional factors using the 8th Aging Research Panel Survey. A logistic regression analysis was conducted. The characteristics of self-care and factors affecting self-care of the elderly with mild cognitive impairment were verified. As a result of the analysis, it was found that in the case of the elderly with mild cognitive impairment, gender, final education, working status, residential area, and the number of participation in social clubs affect self-care. In health and functional factors, it was found that difficulties in daily life due to pain and the presence of depression had a significant effect. It is necessary to consider self-care and factors affecting it in the elderly care policy to slow the rate of deterioration or labor reduction of the elderly group with mild cognitive impairment.

Regulatory effects of 4-methoxychalcone on adipocyte differentiation through PPARγ activation and reverse effect on TNF-α in 3T3-L1 cells

Han, Younho,Lee, Sung Ho,Lee, Ik-Soo,Lee, Kwang Youl Elsevier 2017 Food and chemical toxicology Vol.106 No.1

<P><B>Abstract</B></P> <P>Chalcones, the biosynthetic precursors of flavonoids and isoflavonoids abundant in edible plants, possess a number of pharmacological properties, and there is growing evidence that chalcone derivatives inhibit TNF-α mediated insulin resistance. The aim of the present study was to define the effects of 4-methoxychalcone (4-MC) on adipocyte differentiation and to determine the underlying molecular mechanism. We investigated the effects of 4-MC on adipocyte differentiation and lipid accumulation, and expression of adipogenic genes in 3T3-L1 cells. Additionally, treatment with 4-MC significantly increased the PPARγ-induced transcriptional activity and 4-MC also enhanced the DNA binding affinity of PPARγ to the proliferator-activated receptor response elements (PPRE) at target promoters. Next, we tested the effect of 4-MC on the inhibition induced by TNF-α on adipocyte differentiation. Treatment with 4-MC enhanced the lipid accumulation and strongly up-regulated the expression of adipogenic markers, including PPARγ, aP2, FAS, and adiponectin during adipocyte differentiation. Finally, 4-MC attenuated the inhibitory effect of TNF-α on adipocyte differentiation and adiponectin expression and subsequently regulated the expression and secretion of various adipokines that are involved in insulin sensitivity. This study clearly demonstrates that 4-MC enhanced adipocyte differentiation, in part, by its potent effects on PPARγ activation and by its reverse effect on TNF-α.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>