• The Korean Journal of Physiology and Pharmacology
• /
• 제26권4호
• /
• pp.239-253
• /
• 2022

Epithelial-mesenchymal transition (EMT) is known to be involved in airway remodeling and fibrosis of bronchial asthma. However, the molecular mechanisms leading to EMT have yet to be fully clarified. The current study was designed to reveal the potential mechanism of microRNA-21 (miR-21) and poly (ADP-ribose) polymerase-1 (PARP-1) affecting EMT through the PI3K/AKT signaling pathway. Human bronchial epithelial cells (16HBE cells) were transfected with miR-21 mimics/inhibitors and PARP-1 plasmid/small interfering RNA (siRNA). A dual luciferase reporter assay and biotin-labeled RNA pull-down experiments were conducted to verify the targeting relationship between miR-21 mimics and PARP-1. The migration ability of 16HBE cells was evaluated by Transwell assay. Quantitative real-time polymerase chain reaction and Western blotting experiments were applied to determine the expression of Snail, ZEB1, E-cadherin, N-cadherin, Vimentin, and PARP-1. The effects of the PI3K inhibitor LY294002 on the migration of 16HBE cells and EMT were investigated. Overexpression of miR-21 mimics induced migration and EMT of 16HBE cells, which was significantly inhibited by overexpression of PARP-1. Our findings showed that PARP-1 was a direct target of miR-21, and that miR-21 targeted PARP-1 to promote migration and EMT of 16HBE cells through the PI3K/AKT signaling pathway. Using LY294002 to block PI3K/AKT signaling pathway resulted in a significant reduction in the migration and EMT of 16HBE cells. These results suggest that miR-21 promotes EMT and migration of HBE cells by targeting PARP-1. Additionally, the PI3K/AKT signaling pathway might be involved in this mechanism, which could indicate its usefulness as a therapeutic target for asthma.

• 한국경제지리학회지
• /
• 제12권4호
• /
• pp.295-318
• /
• 2009

이 연구는 초국적 이주자의 미시적 이주배경과 의사결정과정을 결혼이주자, 이주노동자, 전문직 이주자, 외국인 유학생 등 4가지 이주유형별로 분석하고자 한다. 분석 결과, 첫째 본인의 직업이나 가정의 경제수준 및 소득원 등 미시적 이주 배경에 있어 결혼이주자와 이주노동자는 상대적으로 낮은 지위를 나타낸 반면, 전문직 이주자와 외국인 유학생은 높은 수준을 보였다. 둘째, 한국에 관한 이미지에 있어 지리적 인접성에서는 이주노동자가 가장 가깝게 느낀 반면, 문화적 유사성에 있어서는 결혼이주자가 이주노동자에 비해 다소 더 상이하게 인식하고 있다. 이주노동자와 외국인 유학생은 한국의 생활환경에 대해 다른 유형들보다 좋은 이미지를 가지고 있지만, 이주노동자는 한국의 기술 수준을 높게 평가한 반면, 외국인 유학생은 교육 수준을 상대적으로 낮게 평가했다. 셋째, 이주의 용이성 측면에서, 결혼이주자는 낮은 점수를 보였으며, 이주노동자와 전문직 이주자는 한국의 취업환경을 상대적으로 좋게 평가하고 있다. 넷째, 4가지 유형의 외국인 이주자들 모두에서 스스로 이주를 결정했다는 비율이 다른 사람들의 영향에 의해 결정했다는 비율보다도 더 높았다. 또한 전문직 이 주자는 다른 유형들에 비해 다른 국가를 방문한 경험이 월등히 높았지만, 결혼이주자와 외국인 유학생은 해외 거주 가족들과의 연계를 부분적으로 활용한 것으로 추정된다.

• 한국가시화정보학회:학술대회논문집
• /
• 한국가시화정보학회 2004년도 Proceedings of 2004 Korea-Japan Joint Seminar on Particle Image Velocimetry
• /
• pp.119-124
• /
• 2004

Experimental study was conducted to characterize the flow effect of particle migration in a microchannel which can be used to deliver small amount of liquids, drugs, biological agents and particles in microfluidic devices. Fluorescent particles of $1\{mu}m$ diameter were used to obtain velocity profiles of the fluid in which large particles of $10\{mu}m$ diameter were suspended at different volume fraction of 0.6 and $0.8\%$. Measurements were obtained by using micro-PIV system which contains a Nd:YAG laser with a light of 532-nm wavelength, an inverted epi-fluorescent microscope and a cooled CCD camera to record particle images. The volume fraction of $\phi$ and the particle Reynolds number $Re_p$Rep were used as a parameter to assess the influence of the velocity profile of the suspensions. To expect the slip velocity between the particle and fluids, experiments were carried out at low volume fraction. It was shown that the velocity profile was not influenced by Rep but influenced by the volume fraction, which is in similar trend with the previous study.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1404-1408
• /
• 2008

The migration and proliferation of vascular endothelial cells (VEC), which play an important role in vascular remodeling, are known to be regulated by hemodynamic forces in the blood vessels. When shear stresses of 2, 6, 15 dynes/$cm^2$ are applied on mouse micro-VEC in vitro, cells surprisingly migrate against the flow direction at all conditions. While higher flow rate imposes more resistance against the cells, reducing their migration speed, the horizontal component of the velocity parallel to the flow increases with the flow rate, indicating the higher alignment of cells in the direction parallel to the flow at a higher shear stress. In addition, cells exhibit substrate stiffness and calcium dependent migration behavior, which can be explained by polarized remodeling in the mechanosensitive pathway under shear stress.

• 한국생산제조학회지
• /
• 제18권3호
• /
• pp.321-327
• /
• 2009

This paper studied the influences of the main design parameter-the expansion angle and the material properties of the self-expansion anterior cruciate ligament fixation device on the contact condition with the bone and the initial stability of the device. Using finite element analysis, the stress distributions of the ring part of the device and the wall of the bone tunnel were calculated. And the micro-migration of the device by the pull-out force was calculated. From the analysis results, it was found that when designing the self-expansion type anterior cruciate ligament fixation device, it is desirable to use the material having higher Young's modulus and to design the fixation device that all wedges uniformly maintain contact with bone to obtain initial stability after operation.

• 한국임상수의학회지
• /
• 제9권1호
• /
• pp.317-322
• /
• 1992

This trial is concerned with practical application of a M. C. that was injected Into the horse's muscle in order to make a effective identification by computer compatible. Following results were obtained through the study of histopathologic changes, migration of M. C. and possible problems about practical application. 1. Muscle romboideus cervicalis(site 'A') was thought to be the best Injection site of M. C. in the horse. 2. There were no the exact interface between the M. C. and surrounding tissue. It seemed to be why the implanted transponder was located in the muscle fascia. 3. No evidence of migration in the tissues was found through the radiographs taken after implantation 4. There were no clinical disorder and interference with racing performance. 5. ID 100 from Trovan, Co. had some advantages comparing with TX 1400 L from Destron, Co. These are, for instance, the long readout distance and the easy application of computer in the field practive.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권2호
• /
• pp.885-889
• /
• 2013

microRNAs (miRNAs) are small non-coding RNAs that regulate gene expression through post-transcriptional interactions with mRNA. miRNAs have recently emerged as key regulators of various cancers. Although miR-27a has been implicated in several other cancers, its role in hepatitis B virus-related hepatocellular carcinoma (HCC) is unknown. In this study, we showed miR-27a to be frequently up-regulated in HCC tissues and HCC cell lines (HepG2 and Huh7). Overexpression of miR-27a enhanced cell proliferation, promoted migration and invasion, and activated cell cycling in HepG2 and Huh7 cells. In summary, our results suggest that up-regulation of miR-27a may play an oncogenic role in the development of HCC and might thus be a new therapeutic target in HCC patients.

• 지역연구
• /
• 제11권1호
• /
• pp.31-60
• /
• 1995

The distribution of economic activity over a mutually exclusive and exhaustive categorical industry-region matrix is modeled as a composition of two random components: the probability-like share distribution of jobs and the dynamic evolution of absolute aggregates. The former describes the individual activity location choice by comparing the predicted profitability of the current industry-region pair against that of all other alternatives based on the available information on industry-specific, region specific, or activity specific attributes. The latter describes the time evolution of macro-level aggregates using a dynamic reduced from model. With the seperation of micro choice behavior and macro dynamic aggregate constraint, the usual independence and identicality assumptions become consistent with the activity share distribution, hence multi-regional industrial migration can be represented by a set of probability evolution equations in a conservative Markovian from. We call this a Micro-Macro Composition Approach since the product of the aggregate prediction and the predicted activity share distribution gives the predicted activity distribution gives the predicted activity distribution which explicitly considers the underlying individual choice behavior. The model can be applied to interesting practical problems such as the plant location choice of multinational enterprise, the government industrial ploicy to attract international firms, and the optimal tax-transfer mix to influence activity location choice. We consider the latter as an example.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권6호
• /
• pp.3751-3755
• /
• 2013

Backgroud and Aims: MicroRNA-206 has proven to be down-regulated in many human malignancies in correlation with tumour progression. Our study aimed to characterize miR-206 contributions to initiation and malignant progression of human osteosarcoma. Methods: MiR-206 expression was detected in human osteosarcoma cell 1ine MG63, human normal osteoblastic cell line hFOB 1.19, and paired osteosarcoma and normal adjacent tissues from 65 patients using quantitative RT-PCR. Relationships of miR-206 levels to clinicopathological characteristics were also investigated. Moreover, miR-206 mimics and negative control siRNA were transfected into MG63 cells to observe effects on cell viability, apoptosis, invasion and migration. Results: We found that miR-206 was down-regulated in the osteosarcoma cell line MG63 and primary tumor samples, and decreased miR-206 expression was significantly associated with advanced clinical stage, T classification, metastasis and poor histological differentiation. Additionally, transfection of miR-206 mimics could reduce MG-63 cell viability, promote cell apoptosis, and inhibit cell invasion and migration. Conclusions: These findings indicate that miR-206 may have a key role in osteosarcoma pathogenesis and development. It could serve as a useful biomarker for prediction of osteosarcoma progression, and provide a potential target for gene therapy.

• 수산해양기술연구
• /
• 제30권4호
• /
• pp.251-262
• /
• 1994

The speed of vertical migration and the volume backscattering strength of the scattering layers during the evening and morning transitions between day and night were measured in November 1990-1992 in thermally stratified waters of the East China Sea. Acoustical measurements were carried out using a scientific echo-sounder operating at t재 frequencies of 25 and 100kHz, and using an echo-integration system connected with a micro-computer. Biological sampling was accomplished by bottom trawling to identify fish species recorded on the echo sounder, and the species and length compositions were determined. The values of scattering strength were allocated to group of fishes according to the fish traces on the echo recording paper and the species composition of trawl catches. The vertical velocities of migration derived from the changes in the depths and the values of peak scattering strength of the dense layer vertically migrating toward the bottom or toward the surface. The trawl data suggest that snailfish and fishing frog were the most abundant fishes in all research stations. As sunrise approached, the fish formed a strong concentration just above the thermocline. The the highest values of scattering strength in the entire water column appeared in the depth strata above the thermocline just before the begining of downward migration. As soon as the fish began to migrate downwards across the thermocline, the values of the scattering strength in the depth strata above the thermocline rapidly decreased, while the values for the scattering layer moving slowly toward the bottom gradually increased. During the 1992 surveys, the speed of the vertical migration was estimated to be 0.38m/min in the upward migration and 0.32m/min in the downward migration, respectively. That is the rate of vertical migration was slightly higher at dusk than at dawn. Similar migration patterns were observed on different stations and under different weather conditions during the surveys in 1990.