• The Korean Journal of Physiology and Pharmacology
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• 제1권1호
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• pp.27-34
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• 1997

In the present study, it was aimed to further indentify the intracellular action mechansm of cromakalim and levcromakalim in the porcine coronary artery. In intact porcine coronary arterial strips loaded with fura-2/AM, acetylcholine caused an increase in intracellular free $Ca^{2+}$ $([Ca^{2+}]_i)$ in association with a contraction in a concentration-dependent manner. Cromakalim (1 ${\mu}M$) caused a reduction in acetylcholine-induced increased $[Ca^{2+}]_i$ not only in the mormal physiological salt solution (PSS) but also in $Ca^{2+}$-free PSS (containing 1 mM EGTA). In the skinned strips prepared by exposure of tissue to 20 .${\mu}M$ B-escin, inositol 1,4,5-trisphosphate ($IP_3$) evoked an increase in $[Ca^{2+}]_i$, but it was without effect on the intact strips. The $IP_3$-induced increase in $[Ca^{2+}]_i$ was inhibited by cromakalim by 78% and levcromakalim by 59% (1 .${\mu}M$, each). Pretreatment with glibenclamide (a blocker of ATP-sensitive $K^+$ channels, 10 .${\mu}M$) and apamin (a blocker of small conductance $Ca^{2+}$-activated $K^+$ channels, 1 .${\mu}M$) strongly blocked the effect of cromakalim and levcromakalim. However, charybdotoxin (a blocker of large conductance $Ca^{2+}$-activated $K^+$ channels, 1 .${\mu}M$) was without effect. In addition, cromakalim inhibited the $GTP{\gamma}S$ (100 .${\mu}M$, non-hydrolysable analogue of GTP)-induced increase in $[Ca^{2+}]_i$. Based on these results, it is suggested that cromakalim and levcromakalim exert a potent vasorelaxation, in part, by acting on the $K^+$ channels of the intracellular sites (e.g., sarcoplasmic reticulum membrane), thereby, resulting in decrease in release of $Ca^{2+}$ from the intracellular storage site.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제18권3호
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• pp.187-192
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• 2015

Purpose: Measurement of serum ceruloplasmin level is the first step in screening for Wilson's disease (WD). Despite the rarity of WD in the general population, ceruloplasmin levels are routinely measured through hepatitis screening in both adults and children. Herein, we evaluated the diagnostic value of ceruloplasmin for the diagnosis of WD among children with hepatitis. Methods: We retrospectively reviewed data on serum ceruloplasmin levels measured as a serologic marker for patients with hepatitis at Asan Medical Center (Seoul, Korea) between from January 2004 to November 2013. The diagnosis of WD was confirmed by the identification of pathogenic variants in the ATP7B gene. To determine the diagnostic accuracy of ceruloplasmin, receiver operation characteristic (ROC) curves were constructed and the area under curve (AUC) were calculated. Results: Measurements of serum ceruloplasmin were performed in 2,834 children who had hepatitis. Among these, 181 (6.4%) children were diagnosed with WD. The sensitivity, specificity, and accuracy of a ceruloplasmin level of <20 mg/dL in the discrimination of WD were 93.4%, 84.2%, and 84.8%, respectively. In this study, 418 (14.7%) false-positive cases and 12 (0.4%) false-negative cases were noted. Using a ROC curve, a ceruloplasmin level of ${\leq}16.6mg/dL$ showed the highest AUC value (0.956) with a sensitivity of 91.2%, a specificity of 94.9%, and an accuracy of 94.7%. Conclusion: The measurement of serum ceruloplasmin was frequently used for the screening of WD in children, despite a low positive rate. The diagnostic value of ceruloplasmin may be strengthened by adopting a new lower cut-off level.

• Archives of Pharmacal Research
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• 제29권3호
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• pp.224-234
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• 2006

We employed human SK-MEL-28 cells as a model system to identify cellular proteins that accompany N-(4-methyl)phenyl-O-(4-methoxy)phenyl-thionocarbamate (MMTC)-induced apoptosis based on a proteomic approach. Cell viability tests revealed that SK-MEL-28 skin cancer cells underwent more cell death than normal HaCaT cells in a dose-dependent manner after treatment with MMTC. Two-dimensional electrophoresis in conjunction with matrixassisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry analysis or computer matching with a protein database further revealed that the MMTC-induced apoptosis is accompanied by increased levels of caspase-1, checkpoint suppressor-1, caspase-4, NF-kB inhibitor, AP-2, c-Jun-N-terminal kinase, melanoma inhibitor, granzyme K, G1/S specific cyclin D3, cystein rich protein, Ras-related protein Rab-37 or Ras-related protein Rab-13, and reduced levels of EMS (oncogene), ATP synthase, tyrosine-phosphatase, Cdc25c, 14-3-3 protein or specific structure of nuclear receptor. The migration suppressing effect of MMTC on SK-MEL-28 cell was tested. MMTC suppressed the metastasis of SK-MEL-8 cells. It was also identified that MMTC had little angiogenic effect because it did not suppress the proliferation of HUVEC cell line. These results suggest that MMTC is a novel chemotherapeutic and metastatic agents against the SK-MEL-28 human melanoma cell line.

• BMB Reports
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• 제36권6호
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• pp.545-551
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• 2003

A cDNA of bovine brain glutamate dehydrogenase (GDH) was isolated from a cDNA library by recombinant PCR. The isolated cDNA has an open-reading frame of 1677 nucleotides, which codes for 559 amino acids. The expression of the recombinant bovine brain GDH enzyme was achieved in E. coli. BL21 (DE3) by using the pET-15b expression vector containing a T7 promoter. The recombinant GDH protein was also purified and characterized. The amino acid sequence was found 90% homologous to the human GDH. The molecular mass of the expressed GDH enzyme was estimated as 50 kDa by SDS-PAGE and Western blot using monoclonal antibodies against bovine brain GDH. The kinetic parameters of the expressed recombinant GDH enzymes were quite similar to those of the purified bovine brain GDH. The $K_m$ and $V_{max}$ values for $NAD^+$ were 0.1 mM and $1.08\;{\mu}mol/min/mg$, respectively. The catalytic activities of the recombinant GDH enzymes were inhibited by ATP in a concentration-dependent manner over the range of 10 - $100\;{\mu}M$, whereas, ADP increased the enzyme activity up to 2.3-fold. These results indicate that the recombinant-expressed bovine brain GDH that is produced has biochemical properties that are very similar to those of the purified GDH enzyme.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1355-1363
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• 2009

In the present study, the neuroprotective effects of astaxanthin on $H_2O_2$-mediated apoptotic cell death, using cultured mouse neural progenitor cells (mNPCs), were investigated. To cause apoptotic cell death, mNPCs were pretreated with astaxanthin for 8 h and followed by treatment of 0.3 mM $H_2O_2$. Pretreatment of mNPCs with astaxanthin significantly inhibited $H_2O_2$-mediated apoptosis and induced cell growth in a dose-dependent manner. In Western blot analysis, astaxanthin-pretreated cells showed the activation of p-Akt, p-MEK, p-ERK, and Bcl-2, and the reduction of p-P38, p-SAPK/JNK, Bax, p-GSK3b, cytochrome c, caspase-3, and PARP. Because $H_2O_2$ triggers caspases activation, this study examined whether astaxanthin can inhibit caspases activation in $H_2O_2$-treated mNPCs. After $H_2O_2$ treatment, caspases activities were prominently increased, but astaxanthin pretreatment significantly inhibited $H_2O_2$-mediated caspases activation. Astaxanthin pretreatment also significantly recovered the ATP production ability of $H_2O_2$-treated cells. These findings indicate that astaxanthin inhibits $H_2O_2$-mediated apoptotic features in mNPCs. Inhibition assays with SB203580 ($10\;{\mu}M$, a specific inhibitor of p38) and PD98059 ($10\;{\mu}M$, a specific inhibitor of MEK) clearly showed that astaxanthin can inhibit $H_2O_2$-mediated apoptotic death via modulation of p38 and MEK signaling pathways.

• 한국작물학회지
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• 제60권1호
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• pp.114-122
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• 2015

침종 기간과 침종 후 발아의 유무에 따른 단백질 발현을 이차원전기영동을 이용하여 단백질 발현양상을 확인하고 비교 분석한 결과, 침종 기간과 침종 후 발아의 유무에 따른 단백질 발현 양상은 전반적으로 매우 유사하였으며, 주요 단백질의 발현에는 차이가 없었다. 침종 기간에 따른 품종별 단백질 발현 양상은 침종 기간이 길어짐에 따라 단백질 발현정도가 점차 증가되는 것을 확인할 수 있었다. 공시품종들 중 황금콩, 단엽콩, Peking이 다른 품종들에 비하여 침종 4일후에 단백질 발현정도가 급격히 증가하는 것을 알 수 있었다. 침종 후 발아 유무에 따른 단백질 발현양상은 소수의 단백질 spot들을 제외하고는 전반적으로 모든 공시 품종들에서 발아한 종자에서의 단백질 발현정도는 미발아 종자에서보다 높게 확인되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.521-527
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• 1998

An important property of the intestine is the ability to secrete fluid. The intestinal secretion is regulated by a number of substances including vasoactive intestinal peptide (VIP), ATP and different inflammatory mediators. One of the most important secretagogues is adenosine during inflammation. However, the controversy concerning the underlying mechanism of adenosine-stimulated $Cl^-$ secretion in intestinal epithelial cells still continues. To investigate the effect of adenosine on $Cl^-$ secretion and its underlying mechanism in the rabbit colon mucosa, we measured short circuit current ($I_{SC}$) under automatic voltage clamp with DVC-1000 in a modified Ussing chamber. Adenosine, when added to the basolateral side of the muocsa, increased $I_{SC}$ in a dose-dependent manner. The adenosine-stimulated $I_{SC}$ response was abolished when $Cl^-$ in the bath solution was replaced completely with gluconate. In addition, the $I_{SC}$ response was inhibited by a basolateral Na-K-Cl cotransporter blocker, bumetanide, and by apical $Cl^-$ channel blockers, dephenylamine-2-carboxylate (DPC), 5-nitro-2-(3-phenyl-propylamino)-benzoate (NPPB), glibenclamide. Amiloride, an epithelial $Na^+$ channel blocker, and 4,4-diisothiocyanato-stilbene-2,2-disulphonate (DIDS), a $Ca^{2+}-activated$ $Cl^-$ channel blocker, had no effect. In the mucosa pre-stimulated with forskolin, adenosine did not show any additive effect, whereas carbachol resulted in a synergistic potentiation of the $I_{SC}$ response. The adenosine response was inhibited by 10 ${\mu}M$ H-89, an inhibitor of protein kinase A. These results suggest that the adenosine-stimulated $I_{SC}$ response is mediated by basolateral to apical $Cl^-$ secretion through a cAMP-dependent $Cl^-$ channel. The rank order of potencies of adenosine receptor agonists was $5'-(N-ethylcarboxamino)adenosine(NECA)＞N^6-(R-phenylisopropyl)adenosine(R-$ PIA)＞2-[p-(2-carbonylethyl)-phenyl-ethylamino]-5'-N-ethylcarboxaminoadenosine(CGS21680). From the above results, it can be concluded that adenosine interacts with the $A_{2b}$ adenosine receptor in the rabbit colon mucosa and a cAMP-dependent signalling mechanism underlies the stimulation of $Cl^-$ secretion.

• KSBB Journal
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• 제24권3호
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• pp.259-266
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• 2009

AfsR2 과발현 S. lividans TK21을 이용하여 DNA microarray를 수행하였다. 그 결과, phosphate starvation과 관련 있는 42개의 유전자들이 up-regulated 되었으며, 특히 SCO4139 (pstB, phosphate ABC transport system ATP-binding protein)와 SCO4142 (pstS, phosphate-binding protein precursor)는 afsR2가 phosphate와 같은 nutrient starvation에 적극적으로 관여한다는 것을 나타내며, SCO4228 (putative phosphate transport system regulatory protein)은 기존에 수행되었던 2D-electrophoresis 연구나 afsS null S. coelicolor를 이용한 DNA microarray 연구에서도 공통적으로 보고되었던 유전자로서 phosphate lilitation에 대한 afsR2의 효과가 지속적으로 검증되고 있음을 뜻한다. 또한 afsR2 과발현을 통해서 sigma factor인 SCO2954 (sigL)과 SCO5147 (sigE)의 발현이 유도되었으며 두 유전자의 구조적인 특징을 고려해 보았을 때 afsR2가 RNA polymerase와의 linker로서의 역할을 추측해 볼 수 있다. 뿐만 아니라 whi 관련 유전자들의 발현 또한 afsR2에 의해 증가되었다. 이는 afsR2가 단순히 2차 대사물질 생합성 조절에만 관여하는 것이 아니라 형태적 분화에 작용함으로써 최종적으로 여러 2차 대사물질의 합성을 유도한다고 말할 수 있다. 이러한 결과들을 토대로 afsR2가 기존에 항생제 생합성에만 관여하는 global regulatory 조절인자가 아닌 방선균이 stationary phase로 전환되는 시점에서 형태적 분화에 영향을 미치고 phosphate limitation stress를 줄여주는 2차 대사의 key-factor regulatory 유전자임을 알 수 있다.

• Journal of Yeungnam Medical Science
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• 제7권1호
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• pp.39-50
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• 1990

세포막의 정보전달기전중 phosphoinositide system은 정보가 전달될때 phospholipase C 효소의 작용으로 phosphatidyl inositol bisphosphate로부터 inositol triphosphate($IP_3$)와 diacylglycerol이 생성되며 $IP_3$는 다시 $IP_3$kinase에 의해 inositol tetrakisphosphate($IP_4$)로 되어 이차전령 물로서 작용한다. 본 연구는 $IP_3$kinase효소가 $Ca^{2+}$와 calmodulin에 의해 활성화되는 성질을 이용하여 calmodulin을 정제하고 $IP_3$kinase효소와의 친화도를 비교 관찰하였다. Calmodulin정제는 phenyl-Sepharose resin을 이용하여 column chromatography를 시행하여 정제확인하였으며 분자량이 17,000임을 SDS-polyacrylamide gel 전기영동으로 확인하였다. 정제된 calmodulin을 affigel column에 결합시킨 gel에 소의 뇌로부터 분리한 $IP_3$kinase효소가 담긴 시료를 calmodulin-affigel column에 적용하여 결합 및 유출정도를 비교하였으며 $Ca^{2+}$이 든 buffer에서 친화도가 가장 컸으며 유출은 EGTA용액에서 일부 유출되었으며 calmodulin/$Ca^{2+}$이 든 buffer에선 강한 유출정도를 관찰하였다. 그러나 calmodulin/$Ca^{2+}$는 $IP_3$kinase효소의 활성을 증가시키며 calmodulin이 단백질이어서 정제면에서 효소와의 분리가 쉽지않아 여러 다른 detergent를 적용하였으나 0.2% chaps buffer에서 집중된 유출을 관찰하였다.

• Journal of Microbiology and Biotechnology
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• 제32권9호
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• pp.1154-1167
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• 2022

In this study, we investigated the anti-amnesic effect of Korean red pine (Pinus densiflora) bark extract (KRPBE) against amyloid beta_1-42 (Aβ_1-42)-induced neurotoxicity. We found that treatment with KRPBE improved the behavioral function in Aβ-induced mice, and also boosted the antioxidant system in mice by decreasing malondialdehyde (MDA) content, increasing superoxide dismutase (SOD) activities, and reducing glutathione (GSH) levels. In addition, KRPBE improved the cholinergic system by suppressing reduced acetylcholine (ACh) content while also activating acetylcholinesterase (AChE), regulating the expression of choline acetyltransferase (ChAT), postsynaptic density protein-95 (PSD-95), and synaptophysin. KRPBE also showed an ameliorating effect on cerebral mitochondrial deficit by regulating reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and ATP levels. Moreover, KRPBE modulated the expression levels of neurotoxicity indicators Aβ and phosphorylated tau (p-tau) and inflammatory cytokines TNF-α, p-IκB-α, and IL-1β. Furthermore, we found that KRPBE improved the expression levels of neuronal apoptosis-related markers BAX and BCl-2 and increased the expression levels of BDNF and p-CREB. Therefore, this study suggests that KRPBE treatment has an anti-amnestic effect by modulating cholinergic system dysfunction and neuroinflammation in Aβ_1-42-induced cognitive impairment in mice.