• Molecules and Cells
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• 제19권2호
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• pp.232-238
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• 2005

Corneal endothelial cells play an important role in maintaining the transparency and ionic balance of the cornea. Inflammation causes many changes in the intracellular and extracellular environment of the cornea, including acidosis. We examined the relationship between changes in extracellular pH and expression of cyclooxygenase-2 in cultured bovine corneal endothelial cells. When extracellular pH ($[pH]_o$) was reduced to pH 6.4, COX-2 mRNA increased, with a peak at 2 h. This was blocked by pretreatment with actinomycin D and incubation with spermine NONOate (SPER/NO, a nitric oxide donor). Exposure to the $H^+$ ionophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP), also raised COX-2 mRNA levels. CCCP-induced COX-2 mRNA expression was also reduced by SPER/NO. These results were confirmed immuno-cytochemically. These data demonstrate that COX-2 expression is stimulated by the lowering of extracellular pH that could result from bacterial infection, and that this is countered by over-production of nitric oxide, which could also result from bacterial infection.

• Reproductive and Developmental Biology
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• 제36권1호
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• pp.13-19
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• 2012

In order to provide the basis for developing practical mouse embryonic stem cells (mESCs) culture method, how the endogenous level of self-renewal-stimulating factor genes was altered in the mESCs by different extracellular signaling was investigated in this study. For different extracellular signaling, mESCs were cultured in 2 dimension (D), 3D and integrin-stimulating 3D culture system in the presence or absence of leukemia inhibitory factor (LIF) and transcriptional level of $Lif$, $Bmp4$ and $Wnt3a$ was evaluated in the mESCs cultured in each system. The expression of three genes was significantly increased in 3D system relative to 2D system under LIF-containing condition, while only $Wnt3a$ expression was increased by 3D culture under LIF-free condition. Stimulation of integrin signaling in mESCs within 3D system with exogenous LIF significantly up-regulated transcriptional level of $Bmp4$, but did not induce transcriptional regulation of $Lif$ and $Wnt3a$. In the absence of LIF inside 3D system, the expression of $Lif$ and $Bmp4$ was significantly increased by integrin signaling, while it significantly decreased $Wnt3a$ expression. Finally, the signal from exogenous LIF significantly caused increased expression of $Lif$ in 2D system, decreased expression of $Bmp4$ in both 2D and 3D system, and decreased expression of $Wnt3a$ in integrin-stimulating 3D system. From these results, we identified that endogenous expression level of self-renewal-stimulating factor genes in mESCs could be effectively regulated through artificial and proper manipulation of extracellular signaling. Moreover, synthetic 3D niche stimulating endogenous secretion of self-renewal-stimulating factors will be able to help develop growth factor-free maintenance system of mESCs.

• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.275-287
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• 2013

Although, one of the etiologies of localized lipodystrophy of the subcutaneous connective tissue (cellulite) is the histological alternation of adipose tissue, the characteristics of expression of the components of extracellular matrix (ECM) components during adipogenesis are not uncovered. In this study, the effects of caffeine and Ishige okamurae originated diphlorethohydroxycarmalol (DPHC) on the expression of extracellualr fibers was analyzed with quantitative RT-PCR during differentiation induction of mouse subcutaneous adipose derived stem cells (msADSC) into adipocyte. The expression levels of Col1a, Col3a1, and Col61a were decreased by the adipogenci induction in a time-dependent manners. However, Col2a mRNA and Col4a1 mRNA expressions were oposit to them. Caffeine and DPHC stimulated the changes of the expression of these collagens. Eln mRNA expression was increased by induction. DPHC stimulated the expression of it. Mfap5 mRNA expression was deceased in both adipogenic cell and matured adipocytes. Caffeine suppressed the expression of Mfap5 but the effect of DPHC was different by the concentration. The expression of bioglycan, decorin, and lumican were also modified by caffeine and DPHC in a concentration-dependent manner. Based on this study, we revealed firstly the effects of caffeine and DPHC on the expression of collagens, elastin, and glycoproteins during adipogenesis of msADSCs. Those results suggest that DPHC may have antiadipogenic effect and has more positive effets on normal adipose tissue generation and work as suppressor the abnormality of ECM structure. Such results indicate that DPHC can be applied in keeping the stability of the ECM of adipogenic tissues.

• International Journal of Oral Biology
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• 제30권1호
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• pp.9-15
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• 2005

Recently, we reported that high extracellular calcium increased receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) expression via p44/42 mitogen-activated protein kinase (p44/42 MAPK) activation in mouse osteoblasts. However, the mechanism for p44/42 MAPK activation by high extracellular calcium is unclear. In this study, we examined the role of intracellular calcium increase in high extracellular calcium-induced RANKL induction and p44/42 MAPK activation. Primary cultured mouse calvarial osteoblasts were used. RANKL expression was highly induced by 10 mM calcium treatment. Ionomycin, a calcium ionophore, also increased RANKL expression and activated p44/42 MAPK. U0126, an inhibitor of MEK1/2, an upstream activator of p44/42 MAPK, blocked the RANKL induction by both high extracellular calcium and ionomycin. High extracellular calcium increased the phosphorylation of proline-rich tyrosine kinase 2 (Pyk2), one of the known upstream regulators of p44/42 MAPK activation. Bisindolylmaleimide, an inhibitor of protein kinase C, did not block RANKL induction and p44/42 MAPK activation induced by high extracellular calcium. 2-Aminoethoxydiphenyl borate, an inhibitor of inositol 1,4,5-trisphosphate (IP3) receptor, blocked the RANKL induction by high extracellular calcium. It also partially suppressed the activation of Pyk2 and p44/42 MAPK. Cyclosporin A, an inhibitor of calcineurin, also inhibited high calcium-induced RANKL expression in dose dependent manner. However, cyclosporin A did not affect the activation of Pyk2 and p44/42 MAPK by high extracellular calcium treatment. These results suggest that 1) the increase in intracellular calcium via IP3-mediated calcium release is necessary for RANKL induction by high extracellular calcium treatment, 2) Pyk2 activation, but not protein kinase C, following the increase in intracellular calcium might be involved in p44/42 MAPK activation, and 3) calcineurin-NFAT activation by the increase in intracellular calcium is involved in RANKL induction by high extracellular calcium treatment.

• International Journal of Oral Biology
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• 제40권3호
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• pp.127-133
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• 2015

The salivary gland undergoes complex process of growth and differentiation of the branching morphogenesis of ductal system during the prenatal and early postnatal periods which are regulated by various elements in the extracellular matrix. Extracellular matrix metalloproteinase inducer (EMMPRIN) is a cell adhesion molecule. In the present study, localization and expression of EMMPRIN in development and effects of chorda-lingual denervation and cyclosporine A (CsA) treatment on the EMMPRIN expression were investigated. Immunohistochemistry, RT-PCR and Western blot were used to determine expression level. Immunohistochemistry revealed that EMMPRIN was localized specifically in the cytoplasm of ductal cells, not acini of the submandibular gland all the postnatal periods. At prenatal day 18, when the formation of ducts was not definite, no immunoreactivity was observed. Both Western blot and RT-PCR analyses revealed that EMMPRIN expression was maintained up to postnatal day 7, decreased after postnatal day 10. The EMMPRIN expression was upregulated by the surgical denervation of the chorda-lingual nerve in the gland as well as by the CsA treatment. The present study suggests that EMMPRIN is a crucial molecule for maintaining physiological functions of the salivary gland.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.517-521
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• 2013

Background Diabetes is characterized by chronic hyperglycemia, which can increase reactive oxygen species (ROS) production by the mitochondrial electron transport chain. The formation of ROS induces oxidative stress and activates oxidative damage-inducing genes in cells. No research has been published on oxidative damage-related extracellular superoxide dismutase (EC-SOD) protein levels in human diabetic skin. We investigated the expression of EC-SOD in diabetic skin compared with normal skin tissue in vivo. Methods The expression of EC-SOD protein was evaluated by western blotting in 6 diabetic skin tissue samples and 6 normal skin samples. Immunohistochemical staining was also carried out to confirm the EC-SOD expression level in the 6 diabetic skin tissue samples. Results The western blotting showed significantly lower EC-SOD protein expression in the diabetic skin tissue than in the normal tissue. Immunohistochemical examination of EC-SOD protein expression supported the western blotting analysis. Conclusions Diabetic skin tissues express a relatively small amount of EC-SOD protein and may not be protected against oxidative stress. We believe that EC-SOD is related to the altered metabolic state in diabetic skin, which elevates ROS production.

• Journal of Microbiology and Biotechnology
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• 제3권2호
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• pp.65-72
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• 1993

A heterologous gene expression and secretion system using a methylotrophic yeast, Hansenula polymorpha was developed for the production of anticoagulant hirudin. Hirudin gene was expressed under the control of a strong and inducible methanol oxidase (MOX or AOX) promoter. The mating factor a pre-pro leader sequence of Saccharomyces cerevisiae was employed for hirudin to be secreted into the extracellular medium. Hirudin expression cassette was introduced into three strains of H. polymorpha, A16, HPBl and DLl which have different genetic backgrounds. This expression cassette was stably integrated into the host chromosomal DNA. Biologically active and mature hirudin was efficiently expressed and secreted into the extracellular medium. About 19 mg/L of hirudin was found in the culture supernatant in the case of a two-copy integrant of the strain HPBl under suboptimal culture conditions.

• BMB Reports
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• 제44권1호
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• pp.40-45
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• 2011

Extracellular superoxide dismutase (EC-SOD) is an antioxidant enzyme that protects cells and tissues from extracellular damage by eliminating superoxide anion radicals produced during metabolism. Two different forms of EC-SOD exist, and their different enzyme activities are a result of different disulfide bond patterns. Although only two folding variants have been discovered so far, five folding variants are theoretically possible. Therefore, we constructed five different mutant EC-SOD expression vectors by substituting cysteine residues with serine residues and evaluated their expression levels and enzyme activities. The mutant EC-SODs were expressed at lower levels than that of wild-type EC-SOD, and all of the mutants exhibited inhibited extracellular secretion, except for C195S ECSOD. Finally, we demonstrated that co-expression of wild-type EC-SOD and any one of the mutant EC-SODs resulted in reduced secretion of wild-type EC-SOD. We speculate that mutant EC-SOD causes malfunctions in systems such as antioxidant systems and sensitizes tissues to ROS-mediated diseases.

• The Korean Journal of Physiology and Pharmacology
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• 제22권5호
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• pp.513-523
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• 2018

The tumor microenvironment greatly influences cancer cell characteristics, and acidic extracellular pH has been implicated as an essential factor in tumor malignancy and the induction of drug resistance. Here, we examined the characteristics of gastric carcinoma (GC) cells under conditions of extracellular acidity and attempted to identify a means of enhancing treatment efficacy. Acidic conditions caused several changes in GC cells adversely affecting chemotherapeutic treatment. Extracellular acidity did inhibit GC cell growth by inducing cell cycle arrest, but did not induce cell death at pH values down to 6.2, which was consistent with down-regulated cyclin D1 and up-regulated p21 mRNA expression. Additionally, an acidic environment altered the expression of atg5, HSPA1B, collagen XIII, collagen XXAI, slug, snail, and zeb1 genes which are related to regulation of cell resistance to cytotoxicity and malignancy, and as expected, resulted in increased resistance of cells to multiple chemotherapeutic drugs including etoposide, doxorubicin, daunorubicin, cisplatin, oxaliplatin and 5-FU. Interestingly, however, acidic environment dramatically sensitized GC cells to apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Consistently, the acidity at pH 6.5 increased mRNA levels of DR4 and DR5 genes, and also elevated protein expression of both death receptors as detected by immunoblotting. Gene silencing analysis showed that of these two receptors, the major role in this effect was played by DR5. Therefore, these results suggest that extracellular acidity can sensitize TRAIL-mediated apoptosis at least partially via DR5 in GCs while it confers resistance to various type of chemotherapeutic drugs.

• 생명과학회지
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• 제19권5호
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• pp.561-565
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• 2009

인간조직인자는 혈액응고인자 factor VII 과 복합체를 형성하며 연속적인 혈액응고 연쇄반응을 촉매하는 효소 활성체이다. 복합체 형성에 필수적인 이 조직인자의 세포 외 부분이, 기존의 융합 단백질 및 히스티딘 말단이 없는 새로운 발현 벡터에 의해 대장균 내에서 과량 발현 되었다. 봉입체 형태로 발현된 재조합 인간조직인자는 DEAE-Sephacel 크로마토그라피 기술을 적용하여 분리, 정제 및 구조적 복원이 동시에 시도 되었다. 정제된 재조합 단백질은 SDS-PAGE 분석에서 순수한 형태로 나타났으며, 생물학적 활성도 또한 기존의 조직인자와 거의 동등함을 보였다. 본 연구의 발현 및 정제 시스템은 이전의 보고에서 보여진 방법들에 비해 단백질 분해효소를 사용하지 않아 추가적인 크로마토그라피 과정이 필요 없어 좀 더 효율적이기 때문에 기존의 발현 시스템에 대해 대체할 수 있는 매우 유용한 방법으로 제공된다.