• Biomolecules & Therapeutics
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• 제19권2호
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• pp.206-210
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• 2011

Natural Killer (NK) cells are the lymphocytes that are derived from hematopoietic stem cells, developed in the bone marrow from hematopoietic stem cells (HSC) by sequential acquisition of functional surface receptors, and express the repertoire of inhibitory and activating receptors. Recently, Osteopontin (OPN) has been identified as a critical factor for differentiation of natural killer cells. However, the detailed mechanism of OPN-induced NK differentiation has been still to be elucidated. Here, we determined the signaling pathway and possible receptor for OPN in NK differentiation. OPN induced expression of Bcl-2 and activation of Erk kinase. Inhibition of Erk pathway decreased the effect of OPN on NK differentiation. In addition, the expression of integrin ${\alpha}9$ was significantly increased by OPN during NK differentiation, suggesting the possible role of a major signaling molecule for OPN- induced NK differentiation.

• 대한수의학회지
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• 제55권4호
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• pp.233-240
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• 2015

Although the effects of the rice bran have recently been investigated, there is no information regarding platelet physiology available. However, it is well known that fermented natural plants have a beneficial effect on cardiovascular diseases. Therefore, this study was conducted to investigate whether fermented rice bran extract (FRBE) with several plants (Artemisia princeps, Angelica Gigantis Radix, Cnidium officinale, and Camellia sinensis) affected agonist-induced platelet aggregation, and if so, what the underlying mechanism of its activity was. We performed several experiments, including in vitro platelet aggregation, intracellular calcium concentration and adenosine triphosphate release. In addition, the activation of integrin ${\alpha}_{II}b{\beta}3$ was determined using fibrinogen binding. Thrombus formation was also evaluated in vivo using an arterio-venous shunt model. The FRBE inhibited collagen-induced platelet aggregation in a concentration-dependent manner. FRBE significantly and dose dependently attenuated thrombus formation using rat arterio-venous shunt. FRBE suppressed the intracellular calcium mobilization in collagen-stimulated platelets. We also found that FRBE inhibited extracellular stimuli-responsive kinase 1/2, p38-mitogen-activated protein kinases and c-Jun N-terminal kinase phosphorylation. These results suggested that FRBE inhibited collagen-induced platelet aggregation, which was mediated by modulation of downstream signaling molecules. In conclusion, FRBE could be developed as a functional food against aberrant platelet activation-related cardiovascular diseases.

• 대한소아치과학회지
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• 제36권4호
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• pp.586-590
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• 2009

Leukocyte adhesion deficiency type I(LAD I)은 혈관 내피 세포에 백혈구가 부착하는 과정에 결함이 발생하여 혈관에서 감염부위로의 백혈구의 이주가 방해되어 발생하는 질환으로, 재발성 감염증과 백혈구 증가증을 보이는 희귀 질환이다. 피부와 점막의 괴사성 감염, 장내 패혈증, 제대염, 중이염, 뇌수막염 등의 임상 증상을 보이며, 이러한 환자들의 주요한 구강 내 증상은 심각한 치주 질환과 치조골 소실, 치주낭 형성, 유치열과 영구치열의 부분적 또는 전체적 조기 상실을 보인다. 본 증례는 심한 사춘기전 치주염 소견을 보이는 LAD type I환자로 국소적, 전신적 감염을 예방하기 위해 정기적인 치과 내원으로 치면 세균막 관리를 시행하였다. 감염 시 항생제 투여 및 세균 도말 검사를 시행하였다.

• BMB Reports
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• 제31권1호
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• pp.64-69
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• 1998

Recent studies have suggested that integrin (CR3) participates in the signal transduction pathways of certain GPI-anchored phagocytic receptors including $Fc{\gamma}RIIIB$. One consequence of this functional linkage is an inducible association between CR3 and cortical microfilaments that is triggered by $Fc{\gamma}RIIIB$ binding to immobilized immune complexes (IC). That this signaling event requires the co-expression of $Fc{\gamma}RIIIB$ with CR3 was documented by the use of NIH 3T3 transfectants expressing both CR3 and $Fc{\gamma}RIIIB$ (clone 3-23), CR3 alone (clone 3-19), and $Fc{\gamma}RIIIB$ alone (clone 3-15). Pretreatment of 3-23 cells with protein kinase inhibitors such as staurosporine and methyl 2,5-dihydroxycinnamate (MDHC) blocked IC-stimulated CR3 microfilament proximity without affecting the extent to which $Fc{\gamma}RIIIB$ constrains the lateral membrane mobility of a subset of CR3 on the cell surface (as measured in fluorescence recovery after photobleaching experiments). These data support that CR3 and $Fc{\gamma}RIIIB$ molecules are physically and functionally associated and that ligation of FcgRIIIB triggers CR3-dependent signal transduction.

• Biomolecules & Therapeutics
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• 제14권2호
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• pp.67-74
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• 2006

EoL-1 cells differentiate into eosinophils in the presence of n-butyrate, but the mechanism has remained to be elucidated. Because n-butyrate can inhibit histone deacetylases, we hypothesized that the inhibition of histone deacetylases induces the differentiation of EoL-1 cells into eosinophils. In this study, using n-butyrate and two other histone deacetylase inhibitors, apicidin and trichostatin A, we have analyzed the relationship between the inhibition of histone deacetylases and the differentiation into eosinophils in EoL-1 cells. It was demonstrated that apicidin and n-butyrate induced a continuous acetylation of histones H4 and H3, inhibited the proliferation of EoL-1 cells, and induced the expression of markers for mature eosinophils such as integrin ${\beta}7$, CCR1, and CCR3 on EoL-1 cells, while trichostatin A evoked a transient acetylation of his tones and induced no differentiation into eosinophils. These findings suggest that the continuous inhibition of histone deacetylases in EoL-1 cells induces the differentiation into mature eosinophils.

• 한국발생생물학회지:발생과생식
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• 제6권1호
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• pp.1-6
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• 2002

세포외기질(exrtracellular matrix, ECM)에 의한 생쥐 초기 배아의 발생 조절 현상의 기작 규명을 위한 연구의 일환으로 Engelbreth-Holm-Swarm(EHS) mouse sarcoma의 세포외기질로부터 추출한 ECM 복합체인 Matrigel의 성장인자 제거형(GFR-Matrigel)을 생쥐 포배에 처리한 후 mitogen activated protein kinase (MAPK, ERK1/2) 활성 의 변화를 조사하였다. Matrigel 처리 후 10분 이내에 배아의 MAPK 활성이 유의하게 증가하였고, 60분 후에도 유의하게 높은 활성을 유지하였다. 한편 MAPK cascade의 저해제인 PD098059를 전처리한 경우 Matrigel에 의한 MAPK 활성의 증가가 관찰되지 않았다. Matrigel 배양액 내에서 12시간 동안 배양한 포배의 MAPK 활성은 대조군과는 현격한 차이를 보였다. 이러한 결과로부터 ECM에 의한 생쥐초기 배아의 발생 촉진효과 발현기작에는 하위 신호전달 과정의 MAPK 활성화 과정이 관여하는 것으로 사료된다.

• Reproductive and Developmental Biology
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• 제37권2호
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• pp.79-83
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• 2013

Matrix metalloproteinases (MMPs) have been known to affect to cell migration, proliferation, morphogenesis and apoptosis by degrading the extracellular matrix. In the previous studies, undifferentiated mouse embryonic stem cells (ESCs) were successfully proliferated inside the extracellular matrix (ECM) analog-conjugated three-dimensional (3D) poly ethylene glycol (PEG)-based hydrogel. However, there is no report about MMP secretion in ESCs, which makes it difficult to understand and explain how ESCs enlarge space and proliferate inside 3D PEG-based hydrogel constructed by crosslinkers containing MMP-specific cleavage peptide sequence. Therefore, we investigated what types of MMPs are released from undifferentiated ESCs and how extracellular signals derived from various niche conditions affect MMP expression of ESCs at the transcriptional level. Results showed that undifferentiated ESCs expressed specifically MMP2 and MMP3 mRNAs. Transcriptional up-regulation of MMP2 was caused by the 3D scaffold, and activation of integrin inside the 3D scaffold upregulated MMP2 mRNAs synergistically. Moreover, mouse embryonic fibroblasts (MEFs) on 2D matrix and 3D scaffold induced upregulation of MMP3 mRNAs, and activation of integrins through conjugation of extracellular matrix (ECM) analogs with 3D scaffold upregulated MMP3 mRNAs synergistically. These results suggest that successful proliferation of ESCs inside the 3D PEG-based hydrogel may be caused by increase of MMP2 and MMP3 expression resulting from 3D scaffold itself as well as activation of integrins inside the 3D PEG-based scaffold.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.262-270
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• 2017

Yersinia enterocolitica is a well-known foodborne pathogen causing gastrointestinal infections worldwide. The strain Y. enterocolitica FORC_002 was isolated from the gill of flatfish (plaice) and its genome was sequenced. The genomic DNA consists of 4,837,317 bp with a GC content of 47.1%, and is predicted to contain 4,221 open reading frames, 81 tRNA genes, and 26 rRNA genes. Interestingly, genomic analysis revealed pathogenesis and host immune evasion-associated genes encoding guanylate cyclase (Yst), invasin (Ail and Inv), outer membrane protein (Yops), autotransporter adhesin A (YadA), RTX-like toxins, and a type III secretion system. In particular, guanylate cyclase is a heat-stable enterotoxin causing Yersinia-associated diarrhea, and RTX-like toxins are responsible for attachment to integrin on the target cell for cytotoxic action. This genome can be used to identify virulence factors that can be applied for the development of novel biomarkers for the rapid detection of this pathogen in foods.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.122.2-122.2
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• 2016

Surface topographical cues has been highlighted to control the fate of neural stem cells (NSCs). Herein we developed a hierarchically patterned substrate (HPS) platform for regulating NSC differentiation. The HPS induced cytoskeleton alignment and highly activated focal adhesion in hNSCs as indicated by enhanced expression of focal adhesion proteins such as focal adhesion kinase (FAK) and vinculin. hNSCs cultured on HPS exhibited enhanced neuronal differentiation compared to flat group. We also developed a graphene oxide (GO)-based hierarchically patterned substrates (GPS) that promote focal adhesion formation and neuronal differentiation of hNSCs. Enhanced focal adhesion and differentiation of hNSCs on the HPS was reversed by blocking the ${\beta}1$ integrin binding and mechanotransduction-associated signals including Rho-associated protein kinase (ROCK) and extracellular-regulated kinase (ERK) pathway, which may suggest a potential mechanism of beneficial effects of HPS. In addition, hNSCs on the HPS differentiated into functional neurons exhibiting sodium currents and action potentials as confirmed by whole cell patch-clamping analysis. The hierarchical topography can direct differentiation of NSCs towards functional neurons, and therefore would be an important element for the design of functional biomaterials for neural tissue regeneration applications.

• 대한치과보철학회지
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• 제45권3호
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• pp.375-381
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• 2007

Statement of problem. Prior to determining an optimal width of micropatterned grooves provided on titanium substrata, we have done a pilot study using surface topographies in combined microm and submicrom levels. Purpose. The purpose of this study was twofold 1) to assess the proliferation and 2) to analyze the expression of genes encoding the intracellular signaling proteins involved in cell-substratum adhesions and adhesion-dependent G1 phase cell cycle progression of human gingival fibroblasts plated on smooth and microgrooved/acid-etched titanium substrata. Material and methods. Three groups of titanium discs as NE0 (smooth Ti substrata), E15 (Ti substrata with microgrooves of $15{\mu}m$ of spacing and $3.5{\mu}m$ in depth and with further acidetching), and E30 (Ti substrata with microgrooves of $30{\mu}m$ spacing and $3.5{\mu}m$ in depth and with further acid-etching) served as the human gingival fibroblasts' substrata. Viability and proliferation of fibroblasts were determined using an XTT assay. Gene expressions of fibronectin, ${\alpha}5$ integrin, CDK4, and $p27^{kip}$ were analyzed in RT-PCR. Cell-substratum interactions were analyzed in SEM. Results. From the XTT assay at 24 h incubation, the mean optical density (OD) value of E15 was significantly greater than the values of E30 and NE0. At 48 and 96 h however, the mean OD values of E30 were significantly greater than the values of E15 and NE0. No differences in the expression of PCR transcripts at 96 h incubations were noted between groups, whereas at 48 h, an unexpected increase in the expression of all the transcripts were noted in E15 compared with other two groups. Fibroblasts were observed to orient and adhere inside the microgrooves. Conclusion. Micropatterned grooves and acid-etching on Ti substrata alter viability and gene expression of adhered human gingival fibroblasts.