• The Korean Journal of Physiology and Pharmacology
• /
• 제9권4호
• /
• pp.187-193
• /
• 2005

Several signal transduction pathways have been implicated in ischemic preconditioning induced by the activation of ATP-sensitive $K^+$ $(K_{ATP})$ channels. We examined whether protein kinase C (PKC) modulated the activity of $K_{ATP}$ channels by recording $K_{ATP}$ channel currents in rabbit ventricular myocytes using patch-clamp technique and found that phorbol 12,13-didecanoate (PDD) enhanced pinacidil-induced $K_{ATP}$ channel activity in the cell-attached configuration; and this effect was prevented by bisindolylmaleimide (BIM). $K_{ATP}$ channel activity was not increased by $4{\alpha}-PDD$. In excised insideout patches, PKC stimulated $K_{ATP}$ channels in the presence of 1 mM ATP, and this effect was abolished in the presence of BIM. Heat-inactivated PKC had no effect on channel activity. PKC-induced activation of $K_{ATP}$ channels was reversed by PP2A, and this effect was not detected in the presence of okadaic acid. These results suggest that PKC activates $K_{ATP}$ channels in rabbit ventricular myocytes.

• East Asian mathematical journal
• /
• 제39권1호
• /
• pp.65-73
• /
• 2023

In this paper, we present an optimal control strategy to prevent the EMT process by downregulating the level of overexpressed β-catenin in the cytoplasm. To do this, we propose a mathematical model that expresses relationship between the Wnt signaling pathway and TGF-β in cancer cells. We also define an optimal control problem considering the side effects that occur simultaneously with the method for controlling the concentration of β-catenin. Finally numerical simulations show that treatment effect is quantitatively changes depending on the concentration of core proteins of the Wnt signaling pathway.

• Nutrition Research and Practice
• /
• 제7권1호
• /
• pp.15-21
• /
• 2013

Leaf of Sasa borealis, a species of bamboo, has been reported to exhibit anti-hyperglycemic effect. However, its antidiabetic mechanism is not fully understood. In this study, we examined whether an extract of S. borealis activates AMP-activated protein kinase (AMPK) and exerts anti-hyperglycemic effects. Treatment with the S. borealis extract increased insulin signaling and phosphorylation of AMPK and stimulated the expression of its downstream targets, including $PPAR{\alpha}$, ACO, and CPT-1 in C2C12 cells and $PPAR{\alpha}$ in HepG2 cells. However, inhibition of AMPK activation attenuated insulin signaling and prevented the stimulation of AMPK target genes. The S. borealis extract increased glucose uptake in C2C12 cells and suppressed expression of the gluconeogenic gene, PEPCK in HepG2 cells. The extract significantly reduced blood glucose and triglyceride levels in STZ-induced diabetic mice. The extract enhanced AMPK phosphorylation and increased Glut-4 expression in the skeletal muscle of the mice. These findings demonstrated that the S. borealis extract exerts its anti-hyperglycemic effect through activation of AMPK and enhancement of insulin signaling.

• International Journal of Safety
• /
• 제8권2호
• /
• pp.31-36
• /
• 2009

In accordance with the development of recent computer technology, railway signaling software became more complex for the intellectualization. Therefore the importance and dependency of railway signaling system on the computer software is getting more increased further, and the testing for the safety and reliability of railway signaling system software became more important. It is started to become influential as very important issue for the reliability and safety of vital embedded software like railway signaling system. The software coding which can have an effect on the safety at the coding level of software shall not be included preferentially, for the safety of software, and must be checked. This thesis suggested an automated testing tool for coding rules on this railway signaling system software, and presented its applied result for railway signaling system software. The testing items in the implemented tool had referred to the international standards in relation to the software for railway system and MISRA-C standards. This automated testing tool for railway signaling system can be utilized at the assessment stage for railway signaling system software also, and it is anticipated that it can be utilized usefully at the software development stage also.

• The Korean Journal of Physiology and Pharmacology
• /
• 제25권3호
• /
• pp.197-206
• /
• 2021

Carnosol is a phenolic diterpene phytochemical found in rosemary and sage with reported anti-microbial, anti-oxidant, anti-inflammatory, and anti-carcinogenic activities. This study aimed to investigate the effect of carnosol on the lineage commitment of mouse bone marrow-derived mesenchymal stem cells (mBMSCs) into osteoblasts and adipocytes. Interestingly, carnosol stimulated the early commitment of mBMSCs into osteoblasts in dose-dependent manner as demonstrated by increased levels of alkaline phosphatase activity and Alizarin red staining for matrix mineralization. On the other hand, carnosol significantly suppressed adipogenesis of mBMSCs and downregulated both early and late markers of adipogenesis. Carnosol showed to induce osteogenesis in a mechanism mediated by activating BMP signaling pathway and subsequently upregulating the expression of BMPs downstream osteogenic target genes. In this context, treatment of mBMSCs with LDN-193189, BMPR1 selective inhibitor showed to abolish the stimulatory effect of carnosol on BMP2-induced osteogenesis. In conclusion, our data identified carnosol as a novel osteoanabolic phytochemical that can promote the differentiation of mBMSCs into osteoblasts versus adipocytes by activating BMP-signaling.

• 생약학회지
• /
• 제49권4호
• /
• pp.285-290
• /
• 2018

Harmine, a beta-carboline alkaloid isolated from the seeds of Peganum harmala has been reported as a promising drug candidate for cancer therapy. However, the effect of harmine on breast cancer remains still unclear. In this study, the effect of harmine on the cell proliferation, migration, and invasion of breast cancer MDA-MB231 cells and the underlying mechanism were investigated. The results indicated that harmine inhibited the proliferation MDA-MB231 cells in a dose-dependent manner and markedly suppressed migration and invasion of MDA-MB231 cells. The mechanism involved in part through Notch signaling. The Notch activity was significantly inhibited by harmine treatment and harmine suppressed the expression of Jagged1 which is a key ligand to activate Notch signaling. These findings suggest a novel mechanism of harmine on anti-cancer activity and harmine may act as a potential therapeutic drug for breast cancer treatment.

• 벤처창업연구
• /
• 제13권3호
• /
• pp.113-124
• /
• 2018

본 연구는 전문가와 일반인 관객의 평가가 영화 흥행성과에 미치는 영향을 신호 이론(Signaling Theory)과 정보 비대칭(Information Asymmetry) 논의를 기반으로 실증 분석하였다. 영화에 대한 평가가 영화 흥행 성과에 대한 기존 연구는 주로 전문가나 일반인 관객 중 한 주체의 평가에만 중점을 두어 이들의 효과에 대해 설명함으로써 신호의 효과성(Signaling effectiveness)를 검증하는 데에는 다소 미흡한 점이 있었다. 또한 시간이 지남에 따라 변화하는 영화 평가의 추이에 대해서는 분석이 제대로 이루어지고 있지 않아, 영화 평점의 신호 효과성을 깊이 있게 밝히는 데에는 제한적이었다. 따라서 본 연구는 1) 전문가 평가와 일반인 평가의 차이점과 2) 시간의 흐름에 따른 평가의 변화의 추이가 영화 성과에 영향을 미칠 것으로 보고 이들 간의 관계를 밝히고자 하였다. 이를 위하여, 영화진흥위원회와 네이버를 토대로 2003년부터 2012년까지 개봉했던 1,141개 한국 영화 데이터와 이들에 대한 평점을 수집하여 분석을 실시하였다. 실증 분석 결과, 영화 개봉 전 전문가의 평가는 영화 흥행 성적에 영향을 미치지 않으며, 개봉 후에는 일반인의 평가가 전문가의 평가보다 영화 성과에 긍정적인 영향을 미치는 것으로 나타났다. 또한 시간이 지남에 따라 영화에 대한 긍정적인 평가가 증가할수록 영화 흥행 성적은 향상되는 것을 보여주었다.

• Nutrition Research and Practice
• /
• 제16권4호
• /
• pp.419-434
• /
• 2022

BACKGROUND/OBJECTIVES: Benign prostatic hyperplasia (BPH) is the most common prostate disease and one of the most common chronic diseases caused by aging in men. On the other hand, there has been no research on BPH using Abeliophyllum distichum Nakai (A. distichum). Therefore, this study investigated the effects of A. distichum on BPH. MATERIALS/METHODS: A. distichum leaves were extracted with distilled water, 70% ethanol, and 95% hexane as solvents. Subsequently, the inhibitory effects of each A. distichum extract on androgen receptor (AR) signaling were evaluated in vitro. The testosterone-induced BPH model was then used to confirm the efficacy of A. distichum leaves in 70% ethanol extract (ADLE). RESULTS: ADLE had the strongest inhibitory effect on AR signaling. A comparison of the activity of ADLE by harvest time showed that the leaves of A. distichum harvested in autumn had a superior inhibitory effect on AR signaling to those harvested at other times. In the BPH rat model, the administration of ADLE reduced the prostate size and prostate epithelial cell thickness significantly and inhibited AR signaling. Subsequently, the administration of ADLE also reduced the expression of growth factors, thereby inactivating the PI3K/AKT pathway. CONCLUSIONS: An analysis of the efficacy of ADLE to relieve BPH showed that the ethanol extract grown in autumn exhibited the highest inhibitory ability of the androgen-signaling related factors in vitro. ADLE also inhibited the expression of growth factors by inhibiting the expression of the androgen-signaling related factors in vivo. Overall, ADLE is proposed as a functional food that is effective in preventing BPH.

• 경영정보학연구
• /
• 제25권2호
• /
• pp.103-123
• /
• 2023

e-커머스 플랫폼 문헌에서 유효한 관점 중 하나는 정보 비대칭 상황에서의 판매자 신호전략이다. 본 연구에서는 판매자의 신호전략이 소비자의 의사결정에 미치는 영향을 체계적으로 탐색하기 위해 신호이론과 쇼핑목표이론을 기반으로 연구모델을 구성하였다. 구체적으로 소비자의 쇼핑 목표에 따라 판매자가 제공하는 신호 효과(i.e., 평판, 온라인 구전 비율, 가격)에 차이가 있는지 분석하였다. 실증분석을 위해서는 대표적인 e-커머스 플랫폼인 아마존을 대상으로 26,246개의 데이터를 수집하여 가우시안 코플라 방법을 활용하였다. 분석결과, 판매자가 제공하는 신호는 수익에 긍정적인 영향을 미치는 것으로 나타났으며, 이러한 효과는 소비자의 쇼핑목표에 따라 조절되는 것으로 분석되었다. 본 연구는 쇼핑목표이론을 기반으로 소비자가 입력하는 키워드에 따라 판매자의 신호전략 효과에 차이가 있다는 점을 발견함으로써 신호이론 및 전자상거래 문헌에 기여하였다.

• 전기학회논문지
• /
• 제66권5호
• /
• pp.877-884
• /
• 2017

A method of common earth, which is proposed by French Railway(SNCF) and is applied to high speed railway, minimizes the effect of the traction return current from tracks so that trackside electric devices can be protected and operation and maintenance staffs are kept out from injury in an electric railway environment. According to it, all the new domestic electric railway lines are replaced from existing individual earth method to the common earth method. In this paper, we analyze the correlation between common earth method and traction return current to prove whether the common earth has surely contributed to minimize the effect of the traction return current. The analysis was done based on the measurement of the traction return current at the domestic high speed railway line.