Expression mechanism of tryptophan hydroxylase 1 in mouse islets during pregnancy.

Iida, Hitoshi,Ogihara, Takeshi,Min, Mun-kyeong,Hara, Akemi,Kim, Yeong Gi,Fujimaki, Kyoko,Tamaki, Motoyuki,Fujitani, Yoshio,Kim, Hail,Watada, Hirotaka Journal of Endocrinology (Ltd. by Guarantee) 2015 Journal of molecular endocrinology Vol.55 No.1

<P>Serotonin signaling plays key roles in augmentation of pancreatic β-cell function during pregnancy. Increased expression of tryptophan hydroxylase 1 (Tph1), a rate-limiting enzyme for serotonin synthesis by lactogenic hormones, is involved in this phenomenon. To investigate its mechanisms, we here performed 5'-RACE and identified β-cell-specific transcription initiation sites for Tph1. Prolactin enhanced the expression of mRNA containing these exons; however, reporter gene plasmids containing the proximal 5'-flanking region of these exons did not show prolactin responsiveness in MIN6 cells. Prolactin-induced Tph1 expression was inhibited by a Jak2 inhibitor and was partially inhibited by an MEK1/2 or PI3K inhibitor. Therefore, we analyzed interferon γ-activated sequences (GAS) and found GAS-A about 9-kbp upstream of the transcription start site. The reporter gene plasmid containing the GAS-A region linked to a heterologous promoter showed increased promoter activity by prolactin, which was inhibited by the forced expression of a dominant-negative mutant form of Stat5A and a Jak2 inhibitor. Chromatin immunoprecipitation analysis showed that prolactin treatment augmented Stat5 binding to the GAS-A region in MIN6 cells, as well as in isolated mouse islets, and that Stat5 recognized the GAS-A region in pregnant mouse islets. In addition, the transactivation activity of Stat5 was enhanced by prolactin through the Erk and PI3K pathways in MIN6 cells. Finally, serotonin expression was attenuated in islets of β-cell-specific Stat5-deficient mice compared with that of control littermates during pregnancy. Our findings suggest that prolactin-induced Tph1 expression is mediated by the activation of Jak2/Stat5, Erk, and PI3K pathways in β cells.</P>

열처리 방법에 따른 표고버섯의 이화학적 특성 및 영양학적 분석

이중규(Jung-Gyu Lee),김광일(Kwang-Il Kim),황인국(In-Guk Hwang),유선미(Seon-Mi Yoo),민상기(Sang-Gi Min),최미정(Mi-Jung Choi) 한국식품영양과학회 2015 한국식품영양과학회지 Vol.44 No.6

본 연구는 열수 침지, 증기 및 볶음 처리가 표고버섯에 미치는 이화학적 분석 및 영양성분 분석을 통해 최적 열처리 조건을 확립하고자 진행하였다. 소비자들이 상품을 평가할 때 1차적으로 먼저 관찰되는 색도와 경도를 측정하고 추가로 pH 측정 등으로 인한 이화학적 결과로 최적 조건을 선정한 뒤에 그 조건들에 대해서 영양학적 및 미생물 검사를 실시하였다. 색도는 열처리 시간이 길어질수록 색의 변색 정도가 증가하여 뚜렷한 차이를 나타내었다. pH 값은 열수 침지 처리의 경우 pH 증가량이 가장 높았으며 처리 시간이 지속될수록 pH가 증가하는 경향을 나타내었다. 다른 처리군의 경우 일정 시간의 처리 시간 이후에는 유의적인 차이를 보이지 않았다. 경도에서는 열수 침지와 볶음 처리의 경우 1분 이내의 열처리만으로도 경도가 감소하는 경향을 보였으며, 증기처리의 경우 1분 동안 경도가 유지되는 결과를 보였다. 일반성분 분석 결과는 증기 처리가 가장 원물에 가까운 결과를 나타냈다. 유기산 함량은 증기 처리에서 유기산 함량 감소율이 가장 낮았다. 또한 3분간 증기 처리를 하였을 때 미생물의 사멸 효과가 가장 높았다. 열수 침지 처리나 볶음 처리의 경우 전체적으로 증기 처리한 시료에 비해서 영양성분 함량이 줄어드는 경향을 나타냈다. 따라서 표고버섯을 증기 처리방법으로 열처리하는 것이 다른 열처리군에 비해서 최적으로 나타났다. 하지만 본 연구에서는 물리화학 및 영양학적 성분의 변화만을 분석하였기 때문에 실제 식품 산업이나 공정에 적용하기 위해서는 대용량 처리 시에 발생하는 문제들과 관련된 추가적인 연구를 필요로 할 것이다. In the food industry, thermal treatment is an important process for extending shelf-life of foods. However, heating process affects the physicochemical, nutritional, and microbial properties of foodstuff such as color, texture, pH, and proximate compositions. This study was conducted to select an optimal thermal treatment by observing physicochemical, nutritional, and microbial effects of shiitake mushrooms with different thermal treatment methods. Shiitake mushrooms were washed and sliced equally (5 cm×0.5 cm×0.5 cm) and then heat-treated by three methods. Samples were heated in 100°C boiling water, steamed for 10 min, or pan fried at 130°C for 4 min. Total color difference values showed significantly increasing tendency with treatment time. For pH values, boiling water-treated mushrooms showed increasing tendency according to increased thermal treatment. For the results of hardness, boiling water or pan frying-treated mushrooms showed reduced tendency within 1 min. In the case of steam-treated mushrooms, hardness values were maintained for 1 min. Organic acid contents of steam-treated sample showed the lowest value among treatments. For microbial counts, steam-treated samples for 3 min showed the lowest value. Consequently, the results of this study suggest that steam treatment could be the optimal thermal treatment to minimize quality loss of shiitake mushrooms.

다양한 냉동 및 해동공정 조합이 표고버섯의 품질에 미치는 영향

심준보 ( Jun Bo Shim ),조연지 ( Yeon Ji Jo ),최미정 ( Mi Jung Choi ),민상기 ( Sang Gi Min ),유선미 ( Seon Mi Yoo ),천지연 ( Ji Yeon Chun ) 한국산업식품공학회 2015 산업 식품공학 Vol.19 No.3

본 연구는 다양한 냉동방법(강제송풍식냉동, 극저온냉동, 일반냉동)과 해동방법(자연해동, 유수해동, 초음파해동, 전자레인지해동)을 조합하여 처리했을 때 표고버섯의 물리적 품질에 미치는 영향을 관찰하고, 표고버섯의 품질을 유지하는 가장 효과적인 냉·해동 공정을 탐색하는 것이 목적이었다. 급속냉동법(강제송풍식냉동, 극저온냉동)으로 처리한 경우 표고버섯의 해동감량, 보수력, 수분함량은 큰 변화 없이 품질을 유지 하는데 효과적인 것으로 관찰되었다. 특히 보수력은 저속냉동(일반냉동) 및 저속해동(자연해동) 처리의 유무가 영향을 미치는 것으로 나타났다. 전단력의 경우 냉동방법에 의한 영향보다, 전처리 및 해동방법에 더 영향을 받는 것을 판단된다. pH 및 색도는 냉동방법 및 해동방법에 따라 거의 차이가 없는 것으로 관찰되었다. 표고버섯의 물리적 특성을 효과적으로 유지 할 수 있는 처리 조합은 급속냉동(극저온냉동) 및 급속해동(유수해동, 초음파해동, 전자레인지해동)을 한 경우이며, 또한 유지하고 하는 물리적 특성에 따라 냉동 및 해동방법을 다양하게 조합하여 처리한다면, 식품의 품질을 보존하는데 더욱 효과적일 것으로 사료된다. In this study, the potential of various freezing and thawing combinations was investigated for frozen storage of mushroom (Lentinula edodes). Lentinula edodes were sliced (5×5×50 mm) and then blanched in boiling water for 1 min. Samples were frozen by either natural air convection freezing (NCF, -24℃), air-blast freezing (ABF, -45℃), or liquid nitrogen freezing (LNF, -100℃). Frozen Lentinula edodes were thawed to a central temperature of 4℃ using either flowing water thawing (FT, 10℃), microwave thawing (MT, 400 W), sonication thawing (ST, 40 kHz, 10℃), or natural air convection thawing (NT, 20±5℃). In LNF Lentinula edodes, MT showed the most rapid thawing within 2.5 min followed by ST (30 min), FT (37 min), and NT (75 min). Quality attributes were evaluated by thawing loss, texture (hardness), water content, water holding capacity, pH, and color. A combination of LNF and MT induced the lowest thawing loss among tested combinations of each freezing and thawing. Thawing loss of frozen Lentinula edodes by LNF method was the lowest by MT. pH values NT of ABF method were significantly higher than blanched Lentinula edodes. In our study, MT minimized the quality changes of frozen Lentinula edodes when it was combined with ABF or LNF.

다양한 전처리 방법에 따른 양파의 이화학 및 영양학적 특성 분석

김광일 ( Kwang Il Kim ),황인국 ( In Guk Hwang ),유선미 ( Seon Mi Yu ),민상기 ( Sang Gi Min ),이상윤 ( Sang Yoon Lee ),최미정 ( Mi Jung Cho ) 한국산업식품공학회 2014 산업 식품공학 Vol.18 No.4

본 연구는 양파를 열처리 법 중에서 열수침지, 증기 및 볶음 처리에 따른 이화학적 및 영양학적 특성을 분석한 논문으로 열처리가 양파에 미치는 영향을 비교하고자 하였다. 상품을 구매할 때 1차적인 구매요소인 색도 및 경도측정과 추가적으로 pH와 조직관찰 결과로 최적조건 선정 후 영양학적 및 미생물 검사를 실시하였다. 열처리를 하지 않은 대조구에 비해 짧은 시간의 열처리에서는 더 진하고 선명한 색을 띠었으나, 장시간동안 처리한 열처리 시료는 색의 침착을 보였다. 원물과 처리구의 색은 열처리 시간에 따라 뚜렷한 차이를 나타냈고, 경도는 열처리 시간에 따라 짧은 시간에서는 분해효소의 불활성화로 유지 및 증가했지만, 3분 이상 처리하였을 때는 감소 경향을 나타냈고, 볶음처리는 짧은 시간으로도 물성이 연화됐다. 비타민은 열수 및 증기처리 1~2분 처리는 14% 정도 감소했지만 그 이상 처리 시에는 23~28% 범위로 큰 감소율을 보였으며, 유리당 및 유기산의 경우 열수침지 및 증기처리에서 손실을 보였지만, 볶음처리에서는 유지하거나 증가하는 경향을 나타냈다. 특히 유리당에서 열수침지 처리 시 높은 감소율을 나타냈다. Peroxidase activity 변화는 모든 처리구에서 75% 이상의 불활성화를 나타냈고, 특히 열수침지 및 증기 처리한 모든 시료에서 90% 이상의 불활성화를 나타내며 볶음처리보다 높은 불활성화율을 보였다. 미생물 측정한 결과 열수 침지 3분 이상 및 볶음처리 210초 이상 처리시 미생물 검출이 안됐으며, 증기처리 시료는 2분 처리만으로 사멸된 것을 관찰했다. 양파의 열처리 조건은 증기처리법으로 2분 동안 처리하는 것이 다른 처리법에서 처리한 시간들에 비해 최적으로 나타났다. 열처리 방법 별 각각의 최적 처리 시간을 가지고 있어, 높은 효율성이나 산업적으로 이용하려면 최적의 전처리 방법과 처리 시간을 산정하는 것이 중요하다. The pre-thermal treatment, or blanching, is an important process to minimize quality changes during main cooking or storage. In this study, three types of pre-thermal treatments were applied to onions to observe quality changes in their physicochemical, nutritional, and microbial properties. The washed and sliced onions were treated by hot-water immersion (100oC, 1~10 min), steaming (100oC, 1~10 min) and stir-frying with oil (180oC, 10~80 sec). The onions were cooled and wiped with gauze. The results showed that the total color difference of the treated sample increased to 18-23 units compared to that of the fresh control. The pH value of the onion was not significantly different with the exception of the stir-fried samples. The hardness of the onion tended to decrease depending on the treatment time. The micro-structures of onions treated by hot-water immersion and steaming were damaged above 2 min whereas stir-fried onions showed structural damage above 210 sec. In the analysis of the nutritional changes in the onion, the ascorbic acid content of the blanched treatments were lower than that of fresh onion and the free sugar contests showed a similar pattern excluding the stir-fried onions. In the organic acid content assay, the succinic acid content of the treated onion sample had significantly decreased compared with other organic acid contents (p<0.05). The peroxidase activities of the blanched treatments by hot-water immersion and steaming were inactivated by more than 92%, whereas only 76% inactivity was achieved by the stir-frying treatment. The mesophilic and psychrotrophic bacteria counts of the treated onion were not detected or decreased to near a 3-log scale, and yeast was detected only the sample treated by the stir-frying for 1 min. In particular, neither bacteria nor yeast counts in all onion samples by steam treatment were detected. Consequently, the results demonstrated that steam treatment for 2 min could be the optimal pre-thermal condition for onions to minimize the quality changes and increase safety.

Antioxidant Activity and Whitening Effect of Lindera erythrocarpa Extract

Min ?Chul Kang,Ryeo Kyeoung Ko,Ju-Yeop Lee,Haeng-Bum Kim,Bong-Seok Kim,Jong-Heon Han,Seong-Hyun An,Gi-Ok Kim 한국생물공학회 2008 한국생물공학회 학술대회 Vol.2008 No.10

Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta

Sung Hee Park,Jae Hyeong Kim,Sang Gi Min,Yeon Ji Jo,Ji Yeon Chun 한국축산식품학회 2015 한국축산식품학회지 Vol.35 No.2

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water (170°C, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of ≤ 500 Da hydrolysates from porcine placenta, but addition of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.

오존 처리에 의해 산소 작용기가 도입된 활성탄소의 세슘 흡착 특성

채은선 ( Eunseon Chae ),민충기 ( Chung Gi Min ),임채훈 ( Chaehun Lim ),이영석 ( Young-seak Lee ) 한국공업화학회 2024 공업화학 Vol.35 No.1

세슘은 높은 수용성으로 인하여 인체에 쉽게 침투하여 암 또는 DNA의 변형을 유발하는 잠재적인 독성 오염물질이다. 본 연구에서는 활성탄소의 세슘 흡착 능력을 향상시키고자 오존 처리를 통하여 활성탄소 표면에 산소 작용기를 도입하였다. 오존 처리 시간의 증가에 따라 활성탄소 표면의 산소함량이 증가하였다. 이후 활성탄소와 세슘 사이의 정전기적 상호작용이 더욱 원활하게 이루어져 모든 시료의 세슘 이온 흡착 효율이 향상되었다. 특히 반응기 내부 오존 농도를 50000 ppm으로 하여 7 min 동안 오존 처리한 시료는 약 12%의 높은 산소 작용기 함량을 보이며 97.6%의 가장 높은 세슘 제거 효율을 보였다. 한편, 5 min 동안 처리된 시료는 7 min간 반응한 시료와 비교하여 0.3%의 근소한 세슘 제거율 차이를 보였으며, 이는 오존 기체의 반응 특성으로 인한 두 시료의 표면화학적 유사성에 기인한다. 그러나, 오존 처리된 활성탄소의 세슘 흡착 성능은 활성탄소의 비표면적 및 기공 구조도 중요하지만 표면에 도입된 산소 작용기 양이 주된 영향을 미치는 것으로 판단된다. Cesium is a potential toxic contaminant due to its high solubility, which allows it to easily penetrate the human body and potentially induce cancer or DNA mutations. In this study, oxygen functional groups were introduced on activated carbons (ACs) by ozone treatment to enhance the cesium adsorption capacity. As the ozone treatment time increased, the oxygen content on the ACs surface increased. Subsequently, the electrostatic interaction between ACs and cesium enhanced, resulting in higher cesium ion adsorption efficiency across all samples. In particular, the sample treated with ozone for 7 minutes at an internal ozone concentration of 50000 ppm had roughly 12% greater oxygen functional group content and the highest cesium removal effectiveness (97.6%). Meanwhile, samples treated for 5 minutes showed a 0.3% cesium removal rate difference compared to those treated for 7 minutes, which was caused by the surface chemical similarity of the two samples due to the reactive characteristics of ozone gas. However, the cesium adsorption performance of ozonated activated carbon seems to be mainly influenced by the amount of oxygen functional groups introduced to the surface, although the specific surface area and pore structure of the activated carbon are also important.

Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta

Park, Sung Hee,Kim, Jae-Hyeong,Min, Sang-Gi,Jo, Yeon-Ji,Chun, Ji-Yeon Korean Society for Food Science of Animal Resource 2015 한국축산식품학회지 Vol.35 No.2

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water ($170^{\circ}C$, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of $\leq$ 500 Da hydrolysates from porcine placenta, but addition of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.

오이 추출물에 존재하는 Superoxide Dismutase의 열안정성

김은애(Eun-Ae Kim),김기남(Gi-Nahm Kim),길지은(Ji-Eun Kil),이민경(Min-Kyung Lee),김석환(Suk-Hwan Kim),서정식(Chung-Sik Suh),박인식(Inshik Park) 한국식품영양과학회 1999 한국식품영양과학회지 Vol.27 No.6

오이속의 조효소액에 존재하는 Superoxide dismutase(SOD)활성의 pH 안정성은 pH 8.0에서 가장 안정하였고 pH5.0~9.0 사이의 범위에서는 비교적 안정하였다. 최적 온도는 25℃였고 열 안정성은 60℃까지는 안정하였다. 100℃에서 5분간 보관하였을 경우에는 12%만이 남아있었다. 오이에 존재하는 SOD 활성이 섭취 후에도 안정한가를 확인하기 위한 실험에서는 위속의 pH와 동일하도록 오이속의 조효소액의 pH를 2.0으로 변형시킨 후 36.7℃에서 3시간 동안 보관 후에 잔존활성이 10%였고, 장내의 환경인 pH 7.0으로 바꾸어 6시간 동안 둔 후 잔존하는 SOD의 활성은 25%로 활성이 증가되었다. 다양한 열처리 후에 잔존하는 오이의 SOD활성은 오이속은 데치기에서(끓는 물에서 2분) 25%, 껍질은 찌는 동안에(3분) 53%, 그리고 속과 껍질로 분리하지 않은 오이는 데치기에서 27%의 활성잔존률을 보였다. 4℃에서는 20일간 보관한 후에 오이속의 조효소액은 81%활성이 있었고, 30℃에서는 17%의 활성이 남아 있었다. 투석한 결과 SOD의 활성은 변화가 없었으므로 오이속에 존재하는 SOD는 적어도 분자량이 12,000 이상의 물질로 추정된다. The superoxide dismutase(SOD) in peeled pericarp of cucumber was most stable at pH 8.0 and relatively stabe between pH 5.0 and 9.0. The enzyme was stable up to 60℃ and retained 12% by heat treatment at 100℃ for 5 min. At pH 2.0, the peeled pericarp enzyme activity was decreased to 10% by incubation for 3 hrs. However, the enzyme activity was increased above 25% after incubating the enzyme at pH 7.0 for 6 hrs. Retention of SOD activity in cucumber by various heating methods was also measured. The residual SOD activities of peeled pericarp and whole cucumber was estimated to be 25% and 27% after blanching (2 min), respectively. The skin enzyme retained 53% of its activity after steaming (3 min). When the peeled peri carp enzyme was incubated at 4℃ for 20 days, the enzyme activity remained about 81%. However, when the enzyme incubated at 30℃ for 20 days, the peeled pericarp enzyme activity decreased to 17% of its original activity. The enzyme activity of peeled pericarp cucumber was not changed after exhaustive dialysis for 3 days, which indicated that the SOD activity in cucumber seems to have molecular weight above 12,000.

Synthesis and biodistribution of 18F-labeled α-, β- and ω-fluorohexadecanoic acid

Yun-Sang Lee,Young Joo Kim,Gi Jeong Cheon,Jae Min Jeong 대한방사성의약품학회 2018 Journal of radiopharmaceuticals and molecular prob Vol.4 No.2

ω-[18F]-Fluorohexadecanoic acid (FHA) has been used for imaging of fatty acid metabolism of myocardium. To increase retention of radiolabeled fatty acid by blocking β-oxidation, methyl branched analogues have been used. In this experiment, we tried to synthesize 18F-labeled α-, β- and ω-FHA for imaging of the myocardial fatty acid metabolism. We synthesized α-, β- and ω-mesylated methyl hexadecanoates and labeled with 18F by reacting with [18F]TBAF in acetonitrile at 80ºC for 10 min. Methyl ester group was removed by 1 M NaOH at 80ºC for 5 min. The yields of α-[18F] and ω-[18F]FHA were 25.5 and 45.5%, respectively [EOS]. However, β-[18F] FHA was not labeled at all due to a fast elimination reaction. The biodistribution study in ICR-mice showed that ω-[18F]FHA has higher myocardial uptake and lower liver uptake than α-[18F]FHA. The electron-withdrawing effect of fluorine at α- position is believed to be the major factor affecting the biodistribution