• Molecular & Cellular Toxicology
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• 제2권1호
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• pp.67-73
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• 2006

In previous studies, it has been discovered that cancer cells not only overexpress regulatory subunit I (Rl)/protein kinase type I (PKA-I) but also secrete outside the cell an extracellular form of PKA (ECPKA) and that the ECPKA secretion detected in patients' serum is obviously greater than that found in non-cancer patients or healthy subjects. We now found that ECPKA elicits the formation of serum autoantibodies that can serve as a cancer diagnostic and prognostic marker. To measure the presence of anti-ECPKA autoantibody in the human sera, basic methodology for ECPKA assay was established an enzyme-linked immunosorbent assay (ELISA). We obtained serum samples from 199 patients with different types of cancer, and also obtained 31 serum samples to compare with ECPKA concentrations from non-cancer patients and 119 normal volunteers. Compared with normal or non-cancer patient sera, we found that the frequency of anti-ECPKA autoantibody was significantly higher in cancer patients (88%) than in those without cancer (17%). Furthermore the presence of anti-ECPKA autoantibodies in the serum of cancer patients was highly correlated with the site of metastasis. The immunoassay developed for anti-ECPKA antibodies is highly sensitive and specific. Therefore, this discovery of an autoantibody-based cancer diagnostic may have serious clinical application and may become an important advance over current technology.

• Journal of Ginseng Research
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• 제47권4호
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• pp.583-592
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• 2023

Background: Alcohol is one of the most commonly used psychoactive drugs. Due to its addictive characteristics, many people struggle with the side effects of alcohol. Korean Red Ginseng (KRG) is a traditional herbal medicine that is widely used to treat various health problems. However, the effects and mechanisms of KRG in alcohol-induced responses remain unclear. Therefore, the purpose of this study was to investigate the effects of KRG in alcohol-induced responses. Methods: We investigated two aspects: alcohol-induced addictive responses and spatial working memory impairments. To determine the effects of KRG in alcohol-induced addictive responses, we performed conditioned place preference tests and withdrawal symptom observations. To assess the effects of KRG in alcohol-induced spatial working memory impairment, Y-maze, Barnes maze, and novel object recognition tests were performed using mice after repeated alcohol and KRG exposure. To investigate the potential mechanism of KRG activity, gas chromatography-mass spectrometry and western blot analysis were performed. Results: KRG-treated mice showed dose-dependent restoration of impaired spatial working memory following repeated alcohol exposure. Furthermore, withdrawal symptoms to alcohol were reduced in mice treated with KRG and alcohol. The PKA-CREB signaling pathway was activated after alcohol administration, which was reduced by KRG. However, the levels of inflammatory cytokines were increased by alcohol and decreased by KRG. Conclusion: Taken together, KRG may alleviate alcohol-induced spatial working memory impairments and addictive responses through anti-neuroinflammatory activity rather than through the PKA-CREB signaling pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제9권5호
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• pp.299-304
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• 2005

Cardiac hypertrophy contributes an increased risk to major cerebrovascular events. However, the molecular mechanisms underlying cerebrovascular dysfunction during cardiac hypertrophy have not yet been characterized. In the present study, we examined the molecular mechanism of isoproterenol (ISO)-evoked activation of Ras/Raf/MAPK pathways as well as PKA activity in cerebral artery of rabbits, and we also studied whether the activations of these signaling pathways were altered in cerebral artery, during ISO-induced cardiac hypertrophy compared to heart itself. The results show that the mRNA level of c-fos (not c-jun and c-myc) in heart and these genes in cerebral artery were considerably increased during cardiac hypertrophy. These results that the PKA activity and activations of Ras/Raf/ERK cascade as well as c-fos expression in rabbit heart during cardiac hypertrophy were consistent with previous reports. Interestingly, however, we also showed a novel finding that the decreased PKA activity might have differential effects on Ras and Raf expression in cerebral artery during cardiac hypertrophy. In conclusion, there are differences in molecular mechanisms between heart and cerebral artery during cardiac hypertrophy when stimulated with β2 adrenoreceptor (AR), suggesting a possible mechanism underlying cerebrovascular dysfunction during cardiac hypertrophy.

• Journal of Ginseng Research
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• 제45권5호
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• pp.555-564
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• 2021

Background: Ginsenosides of Panax ginseng are used to enhance skin health and beauty. The present study aimed to investigate the potential use of ginsenoside Rf (Rf) from Panax ginseng as a new anti-pigmentation agent. Methods: The anti-melanogenic effects of Rf were explored. The transcriptional activity of the cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) and the expression levels of tyrosinase, microphthalmia-associated transcription factor (MITF), and tyrosinase-related proteins (Tyrps) were evaluated in melanocytes and UV-irradiated ex vivo human skin. Results: Rf significantly inhibited Forskolin (FSK) or UV-stimulated melanogenesis. Consistently, cellular tyrosinase activity and levels of MITF, tyrosinase, and Tyrps were downregulated. Furthermore, Rf suppressed MITF promoter activity, which was stimulated by FSK or CREB-regulated transcription coactivator 3 (CRTC3) overexpression. Increased CREB phosphorylation and protein kinase A (PKA) activity induced by FSK were also mitigated in the presence of Rf. Conclusion: Rf can be used as a reliable anti-pigmentation agent, which has a scientifically confirmed and reproducible action mechanism, via inhibition of CREB/MITF pathway.

• 한국미생물·생명공학회지
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• 제43권2호
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• pp.105-111
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• 2015

지충이 물 추출물을 알긴산 분해능을 가진 V. crassostreae PKA 1002 유래 조효소액을 이용하여 가수분해시킨 후 pH, 색도 및 항산화 활성의 변화를 살펴보았다. 지충이 물 추출물과 조효소액을 30℃에서 0, 3, 6, 12 및 24시간 반응시켜 환원당 생성능과 점도의 변화를 살펴본 결과, 환원당 생성능은 반응 6시간에서 357.82 μg/ml로 가장 높아졌으며, 점도는 0시간에서 1.57 cp에서 반응 6시간에서 1.22 cP로 가장 낮아져 6시간에서 최적분해 조건임을 확인하였다. 최적 조건에서 pH 및 색도는 지충이 물 추출물과 효소분해물이 각각 6.11과 6.15로 유의적인 차이를 보이지 않았으며, 색도는 효소분해물이 물 추출물보다 명도는 감소하고 적색도 및 황색도는 모두 증가하는 것을 확인하였다. TPC 함량은 지충이물 추출물과 효소분해물이 2.54 및 2.55 mg/g으로 유의적인 차이를 보이지 않았다. DPPH 라디칼 소거능 측정 결과, 지충이 효소분해물이 0.05−5 mg/ml 농도에서 물 추출물보다 낮은 DPPH 라디칼 소거능을 보였다. 반면, chelating effect 측정 결과, 0.05−5 mg/ml 농도에서 효소분해물의 활성이 물 추출물보다 유의적으로 높아짐을 확인하였다. Reducing power 측정 결과, 0.005−1 mg/ml 농도에서 지충이 물 추출물과 효소분해물간 유의적인 차이를 보이지 않았다. 따라서 지충이 효소분해물은 지충이 물 추출물보다 금속봉쇄력의 활성이 증진됨을 확인하여, 주로 DPPH 라디칼 소거능에서 항산화 활성을 나타낸 지충이 물 추출물과 달리 금속봉쇄력작용에 의해 항산화 활성을 나타냄을 확인하였다.

• 한국환경성돌연변이발암원학회지
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• 제22권2호
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• pp.65-69
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• 2002

To elucidate the effect of microsphere coinjection on the administration of oligodeoxynucleotides (ODN), we have investigated biodistribution of ［S-35］-labeled antisense ODN targeted to cAMP-dependent protein kinase (PKA) RI-$\alpha$ subunit in nude mice xenografted with WiDr (human colon cancer, ATCC CCL218). The strategy of using microsphere has been proposed for cancer treatment as a carrier of therapeutic ODN so that it could offer an advantage with respect to maintaining constant ODN levels in blood and obtaining higher therapeutic ODN concentration at tumor sites. Comparative biodistribution studies were performed in nude mice (female, 20 g of body weight, n = 4-6) xenografted with WiDr cancer cells, when 0.1 $\mu$Ci (specific activity, 2.94 mCi/$\mu$mole) of ［S-35］-labeled RI-$\alpha$ antisense ODN was injected alone or with microsphere (PLG-18, polylactic copolymer with cationic surfactant DDAB18). Peak tumor uptake of ［S-35］-labeled ODN was significantly increased from 17.7% (at 6 h) of injected dose per gram of tissue (ID/g) to 42.5% (at 24 h) ID/g when microsphere was coinjected with ODN. The different biodistribution in the kidney accumulation (e.g., 100.2% ID/g for ODN alone and 54.9%/ID/g for microshpere coinjection) may contribute to higher blood concentration (e.g., 21.5%ID/$m\ell$ for ODN alone and 37.5%ID/$m\ell$ for microsphere coinjection) of radiolabeled ODN. Of importance is the fact that the whole body retention of radioactivity increased with microsphere coinjection from 50.8%ID/g to 68.0%ID/g after 24-h of injection. This decreased kidney accumulation and increased whole body retention of ［S-35］-labeled ODN resulted in a significant improvement of ODN targeting to the tumor site. In conclusion, the coinjection of microsphere appears to be an important carrier system in vehiculation of antisense oligonucleotide to the tumor tissue in vivo.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.9-14
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• 2016

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.