• 한국정보기술학회 영문논문지
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• 제9권1호
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• pp.103-113
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• 2019

Motivation: Polymerized actin-based cytoskeletal structures are crucial in shape, dynamics, and resilience of a cell. For example, dynamical actin-containing ruffles are located at leading edges of cells and have a significant impact on cell motility. Other filamentous actin (F-actin) bundles, called stress fibers, are essential in cell attachment and detachment. For this reason, their mechanistic understanding provides crucial information to solve practical problems related to cell interactions with materials in tissue engineering. Detecting and counting actin-based structures in a cellular ensemble is a fundamental first step. In this research, we suggest a new method to characterize F-actin wrapping fibers from confocal fluorescence image stacks. As fluorescently labeled F-actin often envelope the fibers, we first propose to segment these fibers by diminishing an energy based on maximum flow and minimum cut algorithm. The actual actin is detected through the use of bilateral filtering followed by a thresholding step. Later, concave actin bundles are detected through a graph-based procedure that actually determines if the considered actin filament is enclosing the fiber.

• BMB Reports
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• 제35권6호
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• pp.562-567
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• 2002

In order to find the cellular interaction factors of the Heliothis armigera nuclear polyhedrosis virus capsid protein VP39, a Heliothis armigera cell cDNA library was constructed. Then VP39 was used as bait. The host actin gene was isolated from the cDNA library with the yeast two-hybrid system. This demonstrated that VP39 could interact with its host actin in yeast. In order to corroborate this interaction in vivo, the vp39 gene was fused with the green fluorescent protein gene in plasmid pEGFP39. The fusion protein was expressed in the Hz-AM1 cells under the control of the Autographa californica multiple nucleopolyhedrovirus immediate early gene promoter. The host actin was labeled specifically by the red fluorescence substance, tetramethy rhodamine isothicyanete-phalloidin. Observation under a fluorescence microscopy showed that VP39, which was indicated by green fluorescence, began to appear in the cells 6 h after being transfected with pEGFP39. Red actin cables were also formed in the cytoplasm at the same time. Actin was aggregated in the nucleus 9 h after the transfection. The green and red fluorescence always appeared in the same location of the cells, which demonstrated that VP39 could combine with the host actin. Such a combination would result in the actin skeleton rearrangement.

• 한국발생생물학회지:발생과생식
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• 제26권1호
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• pp.23-36
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• 2022

Pharyngeal pouches, a series of outgrowths of the pharyngeal endoderm, are a key epithelial structure governing facial skeleton development in vertebrates. Pouch formation is achieved through collective cell migration and rearrangement of pouch-forming cells controlled by actin cytoskeleton dynamics. While essential transcription factors and signaling molecules have been identified in pouch formation, regulators of actin cytoskeleton dynamics have not been reported yet in any vertebrates. Cofilin1-like (Cfl1l) is a fish-specific member of the Actin-depolymerizing factor (ADF)/Cofilin family, a critical regulator of actin cytoskeleton dynamics in eukaryotic cells. Here, we report the expression and function of cfl1l in pouch development in zebrafish. We first showed that fish cfl1l might be an ortholog of vertebrate adf, based on phylogenetic analysis of vertebrate adf and cfl genes. During pouch formation, cfl1l was expressed sequentially in the developing pouches but not in the posterior cell mass in which future pouch-forming cells are present. However, pouches, as well as facial cartilages whose development is dependent upon pouch formation, were unaffected by loss-of-function mutations in cfl1l. Although it could not be completely ruled out a possibility of a genetic redundancy of Cfl1l with other Cfls, our results suggest that the cfl1l expression in the developing pouches might be dispensable for regulating actin cytoskeleton dynamics in pouch-forming cells.

• Journal of Ginseng Research
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• 제40권3호
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• pp.278-284
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• 2016

Background: The ginsenoside Rb1 (Rb1) is the most abundant compound in the root of Panax ginseng. Recent studies have shown that Rb1 has a neuroprotective effect. However, the mechanisms underlying this effect are still unknown. Methods: We used stable isotope labeling with amino acids in cell culture, combined with quantitative mass spectrometry, to explore a potential protective mechanism of Rb1 in ${\beta}$-amyloid-treated neuronal cells. Results: A total of 1,231 proteins were commonly identified from three replicate experiments. Among these, 40 proteins were significantly changed in response to Rb1 pretreatment in ${\beta}$-amyloid-treated neuronal cells. Analysis of the functional enrichments and protein interactions of altered proteins revealed that actin cytoskeleton proteins might be linked to the regulatory mechanisms of Rb1. The CAP1, CAPZB, TOMM40, and DSTN proteins showed potential as molecular target proteins for the functional contribution of Rb1 in Alzheimer's disease (AD). Conclusion: Our proteomic data may provide new insights into the protective mechanisms of Rb1 in AD.

• 동의생리병리학회지
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• 제24권1호
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• pp.74-79
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• 2010

Osteoclasts are bone-resorbing giant cells that differentiate from hematopoietic cells of the monocyte/macrophages. Excessive osteoclast differentiation leads to gradual loss of bone mass causing fracture of the skeleton. The aim of this study was to develop a drug candidates for the treatment of osteoporosis. RANKL-induced osteoclast differentiation was dose-dependently inhibited by myricetin. Myricetin inhibited the expression of c-Fos, NFATc1, and TRAP in BMMs treated with RANKL. Myricetin disrupted the structure of actin ring and suppressed osteoclastic bone resorption. Also, myricetin induced apoptosis in mature osteoclasts. Myricetin inhibited the phosphorylation of ERK in mature osteoclasts treated with M-CSF. The activation of caspase-9 and caspase-3 was increased by myricetin treatment. Our results suggest that myricetin may be an effective agent to prevent bone diseases such as osteoporosis.

• 대한화장품학회지
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• 제50권2호
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• pp.111-118
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• 2024

각질형성세포의 증식과 이동에 의한 상피화 과정은 빠른 상처 치유에 중요하다. 스트레스 호르몬인 코티솔의 증가는 세포 증식과 이동을 억제하여 치유 과정을 늦추는 것으로 알려져 있다. 본 연구는 뛰어난 상처치유 효능으로 알려진 병풀과 항스트레스성 식물로 알려진 로즈마리와의 복합물을 통해 코티솔에 의해서 지연된 상처치유를 촉진할 수 있는 원료를 개발하고자 한다. 항스트레스성 식물인 로즈마리 잎 추출물은 코티솔의 생산에 관여하는 효소인 11β-HSD1의 활성을 억제함을 확인하였다. 병풀과 로즈마리 잎 추출 혼합물(AlfaCalm)은 병풀 추출물보다 코티솔에 의해 지연된 각질형성세포의 이동을 우수하게 촉진시켰다. AlfaCalm는 actin skeleton의 이완에 중요한 인자인 CDC42 발현과 필로포디아(filopodia)를 증가시켰다. 이 결과를 통해, AlfaCalm이 스트레스 상황에서 상처를 효과적으로 치료하는 소재로 활용될 수 있음을 제시한다.

• Nutrition Research and Practice
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• 제9권2호
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• pp.117-122
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• 2015

BACKGROUND/OBJECTIVES: Curcumin, a major component of the Curcuma species, contains antioxidant and anti-inflammatory properties. Although it was found to induce apoptosis in cancer cells, the functional role of curcumin as well as its molecular mechanism in anti-inflammatory response, particularly in intestinal cells, has been less investigated. The intestine epithelial barrier is the first barrier and the most important location for the substrate coming from the lumen of the gut. SUBJECTS/METHODS: We administered curcumin treatment in the human intestinal epithelial cell lines, T84 and Caco-2. We examined endoplasmic reticulum (ER) stress response by thapsigargin, qPCR of XBP1 and BiP, electrophysiology by wild-type cholera toxin in the cells. RESULTS: In this study, we showed that curcumin treatment reduces ER stress and thereby decreases inflammatory response in human intestinal epithelial cells. In addition, curcumin confers protection without damaging the membrane tight junction or actin skeleton change in intestine epithelial cells. Therefore, curcumin treatment protects the gut from bacterial invasion via reduction of ER stress and anti-inflammatory response in intestinal epithelial cells. CONCLUSIONS: Taken together, our data demonstrate the important role of curcumin in protecting the intestine by modulating ER stress and inflammatory response post intoxication.