• Journal of Plant Biology
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• 제36권1호
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• pp.1-8
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• 1993

Polyamine contents and the activities of their main biosynthetic enzymes, arginine decarboxylase (ADC) and ornithine decarboxylase(ODC), were investigated in Populus leaf segments during adventitious shoot regeneration with the addition of 1 millimolar polyamine synthesis inhibitors. From the study of polyamine synthesis inhibitors, ODC was found to be the principal route of polyamine biosynthesis in adventitious shoot regeneration of Populus leaf segments. The ADC inhibitor difluoromethyl arginine(DFMA) and ODC inhibitor difluoromethyl ornithine(DFMO) strongly reduced the putrescine content. On the contarary, DCHA, an inhibitor of spermidine synthase, increased it. Spermidine content was decreased with the treatment of each polyamine synthesis inhibitor, but the inhibitory effect of DCHA was stronger than any other polyamine inhibitor. The decreased polyamine level by polyamine synthesis inhibitors was restored with the exogenously applied polyamine. Comparing the polyamine contents with the adventitious shoot regeneration rate, were observed a close correlation between spermidine content and adventitious shoot regeneration of Populus leaf segments.

• Journal of Plant Biology
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• 제37권1호
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• pp.101-109
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• 1994

Chlamydomonas reinhardtii 배우체 유도기 동안에 polyamine 생합성 억제제인 MGBG[methylglyoxal bis-(guanylhydrazone); SAMDC 억제제] 1mM 처리구와 정상 대조구에서의 polyamine 함량 변화와 Chlamydomonas의 ct-DNA methylation과의 상호 연관성을 조사한 결과, 전반적으로 137C(＋)와 137C(-)의 정상 대조구에서 polyamine 수준은 배우체 유도기 전반에 걸쳐서 감소추세로 나타났으나, 특히 137C(＋)가 137C(-)보다 polyamine 함량이 많았으며 동시에 감소량도 컸다. 1mM MGBG 처리구에서는 137C(＋)의 spermidine 함량이 정상 대조구보다 증가하였다. In vitro에서 ctDNA methylation에 대한 MGBG의 영향은 정상 대조구에서보다도 1mM MGBG 처리구에서 약 20-30%의 ctDNA methylation 감소를 나타내었다. 또한, MGBG는 in vitro에서 DNA methylase에 대하여 억제효과를 나타내어TEk.

• 식물조직배양학회지
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• 제21권2호
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• pp.105-110
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• 1994

olyamine 합성 저해제와 polyamine이 부정근 형성에 미치는 영향을 알아보고자 대두 자엽 절편을 이용하여 5$\times$$10^{-6}$ M NAA와 5$\times$$10^{-7}$ M kinetin으로 조성한 부정근 형성 배지에 polyamine 합성 저해제와 Polyamine을 처리하여 Polymine 저해제에 의한 부정근 형성 억제와 부정근 형성능회복을 조사하였다. 부정근 형성 배지에 $\alpha$-difluoromethylornithine (DFMO), $\alpha$-difluorornethyla.ginine (DFMA), cyclohexyl ammonium sulfate(CHA), dicyclohexylamine(DCHA) 및 methylglyoxal-bis (guanylhydrazone) (MGBG)등의 polyamine 합성 저해제를 $10^{-4}$ -$10^{-2}$ M농도로 단용 또는 혼용 처리한 결과 $10^{-3}$ M MGBG에서 부정근 형성이 가장 억제되었으며 $10^{-3}$ M MGBG에 각 Polyamine을 처리한 결과 spermine $10^{-5}$ M을 동시 처리시 부정근 형성능이 다소 회복되었다. Polyamine 함량은 대조구에 비하여 각 실험구에서 배양 초기에 급격히 증가하였으며 spermine 동시 처리구에서 각 polyamine 함량의 증가가 가장 현저하였다.

• Biomolecules & Therapeutics
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• 제5권3호
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• pp.265-271
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• 1997

Since the advent of chemotherapy, certain types of cancer have been particularly resistant to chemotherapeutic treatment. One of the most well-studied types of resistance is resistance to multiple struc-turally dissimialr hydrophobic chemotherapeutic agents, or multidrug resistance (MDR). We found that MDR cells (KBV20C, KB7D) being highly resistant to colchicine, etoposide, and vincristine were found to have very low level of putrescine and low level of spermidine than the drug sensitive parental cells (KB) but they had almost same level of spermine as the drug sensitive cells. Although both MDR and drug sensitive cells had almost same rate of polyamine uptake, MDR cells were much more sensitive to an inhibitor of polyamine synthesis, methylglyoxal-bis guanylhydrazone (MGBG), suggesting that MDR cells might be defective in polyamine synthesis. These results also suggest that HGBG can be used for treatment of MDR in vivo.

• 한국동물학회지
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• 제34권2호
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• pp.173-180
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• 1991

생쥐 대식세포의 감염균 치사활성과 종양 치사활성에 미치는 Polyamine 생합성 억제의 영향을 알아보기 위하여 ornithine의 억제제인 $\alpha$ -Difluoromethylomithine (DFMO)과 S-adenosylmethionine decarboxylase의 억제제인 methylhlyoxal bis(guanylhydrazone)(MGBG)을 in vitro 또는 in vivo에서 처리하였다. 대시세포의 감염균 치사활성의 지표로서 화학발광(chemiluminescence)과 nitroblue tetrazolium(NBT)의 환원정도를 측정한 결과, 염증유발물질인 thioglycollate(TG)와 세균이 세포내 독소인 liopopolysac- charide(LPS)를 주사하였거나 BCG를 감염시킨 후 측정된 화학 발광의 수준은 TG, LPS, BCG의 순으로 증가하였다. 그러나 이런 화학발생의 수준은 DFMO를 경구투여 하였을 때 전체적으로 감소하였고, 이 세포에 의한 NBT 환원정도 또한 DFMO와 MGBG의 in vitro 처리에 의하여 감소되었다. 한편 BDG로 활성화시킨 대식세포의 종양 괴사인자분비에 의한 종양치사 및 종양세포와의 부착에 의한 직접적 치사정도를 측정한 결과, polyamine생합성억제제의 처리농도를 증가시킴에 따라 그 정도는 감소하였지만, 외부에서 polyamine인 putrescene을 처리 하였을 때 회복되었다. 위의 결과로부터 대식세포내의 polyamine 생합성은 이 세포의 최적 활성화와 과정에 필요한 것으로 생각된다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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• pp.100-100
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• 2002

• Molecules and Cells
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• 제20권1호
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• pp.127-135
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• 2005

The uptake of putrescine, spermidine and spermine by Fortner's hamster amelanocytic melanoma AMEL-3 cells was observed in this study to be time-dependent, temperature-sensitive, pH-dependent and saturable. Metabolic poisons nullified polyamine uptake, an indication that this is an energy-requiring mechanism. The presence of $Na^+$ ions was found to be requisite to full activity. Valinomycin, gramicidin, monensin and the calcium ionophore calcimycin were also observed to inhibit the process substantially. The transporter active site would seem to contain sulfhydryl groups. Other diamines and polyamine analogues, as well as cationic diamidines, suppressed putrescine uptake. The presence of the ornithine decarboxylase inhibitor DFMO in the culture medium induced putrescine inflows. Putrescine, in turn, induced the negative expression of the carrier, thus suggesting that this influx mechanism is governed by up/down regulation. The cationic diamidine CGP 40215A and its analogue CGP039937A competitively inhibited putrescine transport, with Ki values of 1.9 and $15{\mu}M$, respectively. The role of polyamine uptake in these cultures is discussed.

• BMB Reports
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• 제28권3호
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• pp.191-196
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• 1995

The role of polyamines in skeletal myoblast differentiation was investigated using the polyamine metabolic inhibitor methylglyoxal bis(guanylhydrazone)(MGBG). Concentrations of intracellular free spermidine and spermine increased 2 to 2.5-fold at the onset of myoblast fusion. The systhesis of actin, and creatine kinase activity both dramatically increased during myotube formation. However, MGBG at a concentration of 0.5 mM not only abolished the increase of intracellular free polyamines, but also reduced cell fusion to almost half the level of untreated cells, without noticeable morphological alteration. The production of actin, and creatine kinase activity were almost completely abolished by MGBG. The inhibition of myoblast fusion by MGBG was partially recovered with 0.1 mM of spermidine or spermine added externally. Results indicate that polyamines are necessary for normal myoblast differentiation. Since the first indication of myoblast differentiation is alignment of muscle cells and membrane fusion of adjacent cells, and since polyamine depletion completely inhibited the synthesis of actin, which might be associted with membranes, polyamine might be involved in myoblast differentiation through membrane reorganization events.

• Molecules and Cells
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• 제45권12호
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• pp.963-975
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• 2022

Exogenous polyamines are able to induce life span and improve glucose homeostasis and insulin sensitivity. However, the effects of exogenous polyamines on adipocyte differentiation and which polyamine transporters mediate them have not been elucidated yet. Here, we identified for the first time that exogenous polyamines can clearly stimulate adipocyte differentiation through polyamine transporters, solute carrier family 3 member A2 (SLC3A2) and SLC7A1. Exogenous polyamines markedly promote 3T3-L1 adipocyte differentiation by increasing the intracellular lipid accumulation and the expression of both adipogenic and lipogenic genes in a concentration-dependent manner. In particular, exogenous putrescine mainly regulates adipocyte differentiation in the early and intermediate stages. Moreover, we have assessed the expression of polyamine transporter genes in 3T3-L1 preadipocytes and adipocytes. Interestingly, the putrescine-induced adipocyte differentiation was found to be significantly suppressed in response to a treatment with a polyamine transporter inhibitor (AMXT-1501). Furthermore, knockdown experiments using siRNA that specifically targeted SLC3A2 or SLC7A2, revealed that both SLC3A2 and SLC7A2 act as important transporters in the cellular importing of exogenous putrescine. Thus, the exogenous putrescine entering the adipocytes via cellular transporters is involved in adipogenesis through a modulation of both the mitotic clonal expansion and the expression of master transcription factors. Taken together, these results suggest that exogenous polyamines (such as putrescine) entering the adipocytes through polyamine transporters, can stimulate adipogenesis.

• 식물조직배양학회지
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• 제21권6호
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• pp.327-332
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• 1994

MGBG와 에틸렌 저해제가 대두 자엽 부정근 형성에 미치는 영향을 알아보고자 에틸렌 생성량과 내생 polyamine 함량을 조사하였다. 대두 자엽 절편을 부정근 형성 배지에 2주간 배양하면서 관찰한 결과 많은 양의 부정근이 형성되었으나 $10^{-3}$ M MGBG를 처리하면 부정근 형성이 거의 억제되었다. 그러나 MGBG + spermine, MGBG + Cocl$_2$ 및 MGBG + spermine + Coc1$_2$를 농도별로 처리한 경우 부정근 형성 억제가 회복되었다. $10^{-3}$ M MGBG에 spermine을 농도별로 처리한 경우 $10^{-5}$ M의 spermine 혼합 처리시 다소회복되었다. $10^{-3}$ M MGBG +$10^{-5}$ M spermine + $10^{-4}$ M Coc1$_2$ 처리구에서는 부정근 회복능이 $10^{-3}$ M MGBG +$10^{-5}$ M spermine 처리구에 비하여 현저히 증가하였다. 또한 에틸렌 생성량과 polyamine 함량을 $10^{-3}$M MGBG, $10^{-3}$ M MGBG +$10^{-5}$ M spermine, $10^{-3}$ M MGBG +$10^{-4}$ M CoCl$_2$및 $10^{-3}$ M MGBG +$10^{-5}$ M spermine + $10^{-4}$ M Coc1$_2$처리구에서 조사한 결과 $10^{-3}$ M MGBG 단독 처리구에서 에틸렌 생성량이 가장 높았으며, spermidine과 spermine의 함량은 가장 낮았다. 부정근 형성능이 다소 회복된 $10^{-3}$ M MGBG+ $10^{-5}$M spermine 혼합처리구에서의 에틸렌 생성량은 대조구보다는 다소 높게 나타났다. 부정근 회복능이 가장 높았던 $10^{-3}$ M MGBG+ $10^{-5}$ M spermine + $10^{-4}$ M Cocl$_2$ 혼합처리구에서 에틸렌 생성량은 가장 낮게 나타났으며, polyamine 함량은 가장 높게 나타났다.