아미노산 수송체 TAT1에 의한 방향족 아미노산의 수송특성

김윤배(Youn Bae Kim),최봉규(Bong Kyu Choi),김종근(Jong Keun Kim),정규용(Kyu Yong Jung),김명수(Myong Soo Kim),윤정훈(Jung Hoon Yoon),박주철(Joo Cheol Park),국중기(Joong Ki Kook),정해만(Hae Man Jung),김생곤(Saeng Gon Kim),최은상(Eun Sa 한국식품영양과학회 2002 한국식품영양과학회지 Vol.31 No.5

hTAT1에 의해 수송되는 방향족 아미노산들의 수송특성을 밝히기 위해 hTAT1의 cRNA를 미세주입한 Xenopus laevis oocyte에서 hTAT1에 의해 유도되는 방향족 아미노산의 uptake를 여러 조건 하에서 관찰하였다. hTAT1은 L-[¹⁴C]tryptophan의 uptake를 유도하였으며, 그 uptake는 Na^+-과 Cl^--비의존적이었다. hTAT1은 L-[¹⁴C]tryptophan의 uptake를 시간-의존적으로 유도함을 알 수 있었다. hTAT1에 의한 L-[¹⁴C] tryptophan의 uptake는 방향족 아미노산인 phenylalanine, tyrosine 및 tryptophan에 의해서 억제되었으며, hTAT1에 의한 아미노산들의 uptake 실험에서 L-[¹⁴C]phenylalanine, L-[¹⁴C]tyrosine 및 L-[¹⁴C]tryptophan의 수송을 확인하였다. hTAT1에 의한 L-[¹⁴C]tryptophan의 uptake는 포화되었으며, K_m치는 452.2±27.8 μM, V_max 값은 2.1±0.3 pmol/oocyte/min이었다. L-[¹⁴C]tyrosine 및 L-[¹⁴C]phenylalanine의 K_m치는 각각 636.3±59.4 μM과 740.5±96.7 μM이었다. 실험용액의 pH 5.5에서 8.5까지의 변화는 hTAT1에 의한 L-[¹⁴C]tryptophan의 uptake에 별다른 영향을 미치지 못하였다. hTAT1의 cRNA를 미세주입한 oocyte에서 배양시간 의존적인 L-[¹⁴C] tryptophan의 efflux를 볼 수 있었으며, 이 efflux는 oocyte 외 용액의 tryptophan 존재 유무에는 영향을 받지 않았다. 따라서 본 연구의 결과로 hTAT1이 상피세포로부터 혈류로의 방향족 아미노산의 수송에 중요한 역할을 할 것으로 사료된다. The T-type amino acid transporter 1 (TAT1) is a Na^+-independent amino acid transporter which selectively transports aromatic amino acids subserving the amino acid transport system T. To understand the transport properties of aromatic amino acids by human TAT1 (hTAT1), we have examined the hTAT1-mediated aromatic amino acid transports using a Xenopus laevis oocyte expression system. When expressed in Xenopus laevis oocytes, hTAT1 induced L-[¹⁴C]tryptophan transport which was not dependent on Na^+ or Cl^- in the medium. Uptake was timedependent and exhibited a linear dependence on incubation time up to 30 min. The L-[¹⁴C]tryptophan uptake was highly inhibited by L-isomers of tryptophan, tyrosine and phenylalanine, whereas other L-amino acids did not inhibit hTAT1-mediated L-[¹⁴C]tryptophan uptake. The hTAT1 induced the relatively low-affinity transport of aromatic amino acids such as L-[¹⁴C]tryptophan, L-[¹⁴C]tyrosine and L-[¹⁴C]phenylalanine (K_m values: 450~750 μM), consistent with the properties of classical amino acid transport system T. The L-[¹⁴C]tryptophan uptake did not show any remarkable pH dependence within the pH range of 5.5 to 8.5. The time-dependent efflux of L-[¹⁴C]tryptophan was detected from the oocytes expressing hTAT1, which was not affected by the presence or absence of L-tryptophan in the extracellular medium, indicating that hTAT1-mediated transport is due to the facilitated diffusion. Expression of hTAT1 in Xenopus laevis oocytes induced the transport of tryptophan, tyrosine and phenylalanine, indicating that hTAT1 is a transporter subserving system T. These results suggest that hTAT1 has essential roles in the absorption of aromatic amino acids from epithelial cells to the blood stream. Because hTAT1 is proposed to be crucial to the efficient absorption of aromatic amino acids from intestine and kidney, its defect such as blue diaper syndrome could be involved in the disruption of aromatic amino acid transport.

C57BL/KsJ-db/db 제2형 당뇨병 마우스에서 발아일품벼 추출물의 항당뇨효과

이연리(Youn Ri Lee),우관식(Koan Sik Woo),황인국(In Guk Hwang),김현영(Hyun Young Kim),이상훈(Sang Hoon Lee),김윤배(Yun Bae Kim),이준수(Junsoo Lee),정헌상(Heon Sang Jeong) 한국식품영양과학회 2012 한국식품영양과학회지 Vol.41 No.3

본 연구에서는 제2형 당뇨병 모델인 C57BLKS/J-db/db마우스에서 발아일품벼 추출물의 농도별로 급여한 후 혈당조절에 미치는 영향을 알아보고자 조사하였다. C57BLKS/J-db/db 마우스에게 급여한 발아일품벼 추출물의 양에 따라 5군 즉, 정상군(Normal Control: NC), 당뇨대조군(Diabetic Control: DC), 1% 발아벼 추출물 급여군(DM-1% GIRRE), 0.5% 발아벼 추출물 급여군(DM-0.5%GIRRE), 0.25% 발아벼 추출물 급여군(DM-0.25%GIRRE)으로 나누었다. 8주 동안 매일 식이 섭취량과 음료섭취량 및 매주 체중과 공복혈당을 측정하고 마지막 주에 경구포도당 부하검사(OGTT)를 실시하였으며, 부검 시 혈액을 채취하여 혈청인슐린 농도와 당화혈색소를 측정하였다. 그 결과, DM-1% GIRRE군에서 당뇨유발에 의한 체중감소 및 당뇨 증상 중에 다음(poly-dipsia), 다식(polyphasia) 등이 어느 정도 완화되고 있음을 알 수 있다. DM-1%GIRRE군에서 당뇨동물의 공복 혈당, 경구 내당능 검사, 혈중 HbA1c 수준을 유의적으로 낮추었지만, 혈장 인슐린 농도는 당뇨실험군들 간에는 차이가 나타나지 않았다. 이상의 결과를 종합해보면 발아일품벼 추출물의 급여가 혈당상승을 억제하는 효과가 있는 것으로 생각되며 그 기전에 대해서는 향후 추가 연구가 필요하다고 본다. This study was performed to investigate the effect of germinated Ilpum rough rice extract on blood glucose in C57BL/KsJ-db/db mice. The mice were divided into several groups: normal control (NC), diabetic control (DC), those fed with 0.25% germinated Ilpum rough rice extract (DM-0.25%GIRRE), those fed with 0.5% germinated Ilpum roughrice extract (DM-0.5%GIRRE) and those fed with 1% germinated Ilpum rough rice extract (DM-1%GIRRE). After 8 weeks of treatment, body weight, water intake, and diet intake of the DM-1%GIRRE group were significantly lower than the other DM groups. Blood glucose levels of the DM-1%GIRRE group were significantly lower compared to the DC group. Fasting blood glucose HbA1c level and total glucose tolerance test were significantly lower in the DM-1%GIRRE groups compared to the DC group. There was no significant difference in serum insulin level among each group. Therefore, the results of this study demonstrate that germinated Ilpum rough rice extract alleviates many of the symptoms of diabetes in genetically obese mice and may offer a possibility as a therapeutic supplement for the normalization of blood glucose levels in humans with hyperglycemia. It may also have beneficial effects in patients with non-insulin-dependent diabetes mellitus.

랫드에서 potassium bromate에 의한 신장 및 간의 산화적 손상에 대한 홍삼 사포닌의 방어효과

황석연(Seok-Youn Hwang),강은경(Eun Kyung Kang),위재준(Jae Joon Wee),경종수(Jong-Su Kyung),조정희(Jung-Hee Cho),김윤배(Yun-Bae Kim) 한국실험동물학회 2004 Laboratory Animal Research Vol.20 No.3

Potassium bromate (KBrO₃), used as a food additive in bakery, has been found to cause problems due to its strong pro-oxidant property. It has been reported that Panax ginseng possesses protective effects against a variety of oxidative damage induced by chemicals such as carbon tetrachloride, acetaminophen, chrome or hyperoxia. Therefore, this study was carried out to investigate the effect of Korean red ginseng saponin (RGS) against oxidative damage induced by KBrO₃ based on the parameters in blood, tissues and urine. Male Sprague-Dawley rats were orally administered with RGS (75 ㎎/㎏) for 2 days, challenged intraperitoneally with KBrO₃ (300 ㎎/㎏) 2 hr after the final administration of RGS, and 48 hr later, blood, kidney and liver tissues, and urine were collected. In hematological analysis, KBrO₃ remarkably increased white blood cells, which was somewhat reduced by treatment with RGS. In blood biochemistry, KBrO₃ markedly increased serum creatinine, blood urea nitrogen, aspartate aminotransferase and alkaline phosphatase, while it decreased uric acid and Ca⁺⁺ levels, indicative of renal and hepatic toxicities. Such changes were greatly attenuated by RGS treatment. Also, RGS recovered KBrO₃-induced decrease in K⁺ level, although it did not affect the changes in Cl⁻ and osmolarity. In addition, the increases in malondialdehyde contents in kidneys and liver caused by KBrO₃ were fully reversed by RGS. Furthermore, urinary excretion profiles of malondialdehyde and its adducts were affected by RGS treatment; i.e., whereas an increase in excretion of N-ε-(2-propenal)lysine following KBrO₃ challenge was markedly lowered, N-α-acetyl-ε-(2-propenal)lysine and free malondialdehyde were greatly increased by RGS administration. Summarizing the above results, it is suggested that RGS exert protective effect against the renal and hepatic toxicities of KBrO₃ by not only reducing oxidative radical reactions, but also enhancing renal excretion of toxic by-products.

구강 편평세포암종 KB 세포에서 아미노산 수송억제제 BCH에 의한 세포성장 억제

윤정훈(Jung Hoon Yoon),김윤배(Youn Bae Kim),김도경(Do Kyung Kim) 한국식품영양과학회 2003 한국식품영양과학회지 Vol.32 No.5

구강 편평세포암종 KB 세포를 이용하여 아미노산 수송계 L 억제제인 BCH의 세포 성장억제에 미치는 효과를 밝히기 위해, KB 세포에서 uptake 실험, MTT 분석 및 DNA fragmentation 분석 등을 시행하여 다음과 같은 결과를 얻었다. KB 세포에서는 아미노산 수송계 L 중에서 LAT1과 그 보조인자 4F2hc를 통해 BCH 및 중성 아미노산들이 수송되었다. BCH는 시간과 농도에 의존적으로 KB 세포의 성장을 억제시켰다. BCH를 처리한 실험군에서 DNA fragmentation 현상은 볼 수 없었다. 본 연구의 결과로서 구강암 세포주인 구강 편평세포암종 KB 세포에서 LAT1과 그 보조인자 4F2hc를 통해 BCH 및 중성 아미노산의 수송이 이루어지고 있다는것을 확인할 수 있었으며 BCH는 이 LAT1을 차단하여 중성 아미노산들의 세포 내 고갈을 유도함으로서 KB 세포 성장의 억제를 유도하는 것으로 사료된다. Amino acid transporters play an important role in supplying nutrients to normal and cancer cells for cell proliferation. System L is a major transport system responsible for the Na^+ -independent, large neutral amino acids including several essential amino acids. L-type amino acid transporter 1 (LAT1), an isoform of system L amino acid transporter, is highly expressed presumably to support their continuous growth and proliferation in malignant tumors. 2-Aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) is a model compound for study of amino acid transporter as a system L selective inhibitor. In the present study, we examined whether BCH induced growth inhibition in KB human oral squamous carcinoma cell line or not. The uptake of L-[¹⁴C]leucine by KB cells is inhibited by BCH in a concentration dependent manner with a IC_(50) value of 75.3±6.2 μM and a Ki value of 98.7±4.1 μM. The growth of KB cells is inhibited by BCH in time dependent manner and concentration dependent manner with a IC_(50) value of 11.1±0.8 mM. In the DNA of KB cells treated with the various concentrations and various periods of BCH, the characteristic ladders associated with DNA fragmentation were not observed. These results suggest that BCH inhibits the growth of KB oral epidermoid carcinoma cells through the inhibition of transport of neutral amino acids into cells without DNA break down. This phenomenon will be a new rationale for anti-cancer therapy.

미성숙 마우스에 Bisphenol A 노출시 신경내분비계에서 에스트로겐 수용체 발현 및 신경행동 변화

성민제(Min Jae Seoung),신임철(Im Cheol Shin),이윷모(Yoot Mo Lee),손동주(Dong Ju Son),송연숙(Youn Sook Song),전계현(Kei Hyun Jeon),김윤배(Yun Bae Kim),이법준(Beum Jun Lee),김대중(Dae Joong Kim),윤영원(Young Won Yun),김태성(Tae Seong K 한국독성학회 2004 Toxicological Research Vol.20 No.3

A large number of chemical pollutants including phthalates, alkylphenolic compounds<br/> and organochlorine pesticides have the ability to disrupt endocrine function in animals, and alter cognitive<br/> function. Because hormone mediated events play an important role in central nervous system<br/> development and function, the changes in cognitive function seem to be mediated by the endocrinelike<br/> action of these chemicals. The present study therefore was designed to investigate effect of<br/> bisphenol A (BPA), an endocrine disrupting chemical on neuro-behavial patterns, and expression of<br/> estrogen receptors and tyrosine hydroxylase, a limiting enzyme of dopamine synthesis pathway. BPA<br/> was treated orally for 3 weeks into 3 week old mice, and then the neuro-behavial patterns (stereotype<br/> behaviors such as jumping rearing and forepaw tremor, climbing behavior, tail flick, rotarod and<br/> locomotor activity), and the expression of estrogen receptors and tyrosine hydroxylase were determined<br/> every 3 week for 9 weeks. During the treatment of BPA, the food uptake and body weight<br/> increase were not significantly changed. BPA resulted in the increased stereotype behaviors (jumping,<br/> rearing and forepaw tremor) 6 or 9 weeks after treatment. The time response to tail flick and<br/> locomotor activity were decreased by the treatment of BPA, whereas the time for rotarod was<br/> increased by the treatment of BPA. The expression of estrogen receptor alpha and beta was<br/> increased in the brain and pituitary gland. Maximum expression was found in the brain after 9 week<br/> of 100 mg/kg BPA treatment and in the pituitary gland after 6 week of 100 mg/kg BPA treatment.<br/> Tyrosine hydroxylase was increased in dose and time dependent manners in the brain but no change<br/> was found in the pituitary gland. The present data show that exposure of BPA in the young mice<br/> could alter expression of estrogen receptors and dopamine synthesis pathway, thereby modulate<br/> neuro-behavial patterns (increase of stereotype behaviors but decrease locomotor activity).

랫드에서 단일시험법을 이용한 반하 물추출물의 생식독성시험

이기남,유욱준,백인정,연정민,남상섭,이범준,남상윤,김윤배,강현규,안병우,김대중,황방연,노재섭,홍정섭,성하정,김순선,조대현,윤영원 충북대학교 동물의학연구소 2006 Journal of Biomedical and Translational Research Vol.7 No.1

본문참조