• Molecules and Cells
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• 제40권9호
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• pp.643-654
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• 2017

Autophagy is a degradation pathway in eukaryotic cells in which aging proteins and organelles are sequestered into double-membrane vesicles, termed autophagosomes, which fuse with vacuoles to hydrolyze cargo. The key step in autophagy is the formation of autophagosomes, which requires different kinds of vesicles, including COPII vesicles and Atg9-containing vesicles, to transport lipid double-membranes to the phagophore assembly site (PAS). In yeast, the cis-Golgi localized t-SNARE protein Sed5 plays a role in endoplasmic reticulum (ER)-Golgi and intra-Golgi vesicular transport. We report that during autophagy, sed5-1 mutant cells could not properly transport Atg8 to the PAS, resulting in multiple Atg8 dots being dispersed into the cytoplasm. Some dots were trapped in the Golgi apparatus. Sed5 regulates the anterograde trafficking of Atg9-containing vesicles to the PAS by participating in the localization of Atg23 and Atg27 to the Golgi apparatus. Furthermore, we found that overexpression of SFT1 or SFT2 (suppressor of sed5 ts) rescued the autophagy defects in sed5-1 mutant cells. Our data suggest that Sed5 plays a novel role in autophagy, by regulating the formation of Atg9-containing vesicles in the Golgi apparatus, and the genetic interaction between Sft1/2 and Sed5 is essential for autophagy.

• Journal of Animal Science and Technology
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• 제51권6호
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• pp.493-502
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• 2009

Glucose is a major source of metabolic fuel and lipid and protein syntheses. Transport of glucose into the cell is regulated by an action of glucose transport.associated transporters, especially solute carriers 2A (Slc2a, protein symbol GLUT). The present study was focused on examination of mRNA expression of various Slc2a isoforms in the epididymis during postnatal development. Total RNAs isolated from different epididymal segments (caput, corpus, and caudal epididymis) were utilized for real-time polymerase chain reaction analyses. Results showed that Slc2a 1, 3, 4, 5, and 8 were expressed in the entire epididymal regions. In addition, the abundance of these Slc2a isoforms' transcripts was different within each epididymal regions. Moreover, the present study showed differential expression of these Slc2a isoforms among different epididymal segments according to postnatal ages. The current study suggests that glucose transport in the epididymis via various Slc2a isoforms would be necessary for maintenance of the epididymal functions.

• 약학회지
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• 제49권1호
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• pp.60-67
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• 2005

Nonclassical aminobenz[cd]indole antifolates 4, 5 and 6, in which the glutamic acid moiety of the classical antifolates is substituted by 2-phenylglycinamide or 3-aminobenzamide, were synthesized and their in vitro antitumor activity was evaluated. The purpose of this substitution is that the lipophilicity is enhanced due to the aromatic ring of the target compounds for the passive transport through lipid membrane of cells while the hydrogen bonding of the amide is retained in the active site of the enzyme, thymidylate synthase, where the glutamate is originally present. The target compounds were highly cytotoxic against tumor cell lines of murine and human origin with micromolar to nanomolar $IC_{50}$ values. Most effective was compound 4 ($N^6-methyl-N^6$-[4-[(${\alpha}$(S)-aminocarbonylbenzyl) aminocarbonyl]benzyl]-2,6-diaminobenz[cd]indole)with $IC_{50}$ of 2 nM against SW480, human colon adenocarcinoma cell line, which is 650-fold more potent than the reference compound 3.

• 대한약리학회지
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• 제21권2호
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• pp.79-89
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• 1985

심근 세포의 칼슘 조절에 중요한 역할을 하는 sarcoplasmic reticulum (SR)의 칼슘운반 능력이 허혈 심근에서 현저히 억제됨이 알려져 있다. 이와같은 허혈 심근에서의 SR 칼슘운반승력 저하에 유독성 산소 대사물이 관여할 것으로 생각되고 있으나 그 기전에 관하여는 아직 알려진 바 없다. 본 연구에서는 그 기전의 일단을 규명하기 위하여 산틴 산화효소계에 의하여 발생된 유독성 산소대사물긴 돼지 심실근에서 추출한 sarcoplasmic reticulum의 칼슘흡수 및 막지질 과산화, sulfhydryl group 그리고 단백질 변성에 미치는 영향을 관찰하여 다음과 같은 결과를 얻었다. 1) 산틴 산화 효소계와 반응시킨 sarcopl smic reticulum의 칼슘흡수는 반응시간 경과에 따라 현저히 억제되었다. 2) sarcoplasmic reticulum 막지질 과산화는 산딘 산화 효소계에 의하여 현저히 증가되었다 3) 항산화제 ${\beta}$-phenylenediamine은 막지질 과산화의 증가는 효과적으로 억제하였으나, 칼슘흡수 억제는 부분적으로 회복시켰다. 4) 산틴 산화 효소계에 의하여 SH-group은 현저히 감소되었으며, 항산화제 첨가에 의하여 그 감소가 일부 억제되었다. 5) sarcoplasmic reticulum을 DTNB로 처리하여 SH-group을 산소 대사물에 의한 산화반응으로부터 보호했을 경우 칼슘흡수의 억제가 부분적으로 방지되었다. 6) Sephadex G-200 크로마토그라피 상에서 산틴 산화효소계와 반응시킨 sarcoplasmic reticulum의 단백질분해가 관찰되었다. 7) 단백질의 polymerization은 관찰되지 않았으며, 아울러 polymerization을 억제하는 semicarbazide로 칼슘흡수 감소를 방지하지 못하였다. 이상의 결과에서 유독성 산소대사물에 의한 sarcoplasmic reticulum의 칼슘흡수 억제는 sarcoplasmic reticulum의 막지질 과산화, SH-group의 산화 및 막 반백절의 분해 등으로 초래되는 복합적인 기전으로 추정되었다.

• Journal of Acupuncture Research
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• 제20권6호
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• pp.128-139
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• 2003

Juglans sinensis Dode has been reported to have antioxidant activity. However, the effect of Juglans sinensis Dode aquacupuncture(JS) on reactive oxygen species(ROS)-induced alterations in membrane transport function in renal tubular cells. This study was performed to evaluate the effect of JS on the organic hydroperoxide t-butylhydroperoxide(tBHP)-induced inhibition of $Na^+$-dependent phosphate($Na^+$-Pi) uptake in opossum kidney (OK) cells, an established renal proximal epithelial cell line. tBHP inhibited $Na^+$-Pi uptake in a time-dependent manner. The inhibitory effect of tBHP was prevented by JS over concentration range of 0.05-1mg/100ml in a dose-dependent manner. Kinetic studies showed that tBHP caused an decrease in Vmax for $Na^+$-Pi uptake without any a significant change in Km. $Na^+$-dependent phosphonoformic acid binding, a irreversible inhibitor of renal $Na^+$-Pi uptake, was decreased by tBHP treatment. The reduction in Vmax and phosphonoformic acid binding by tBHP was prevented by JS. tBHP induced lipid peroxidation and its effect was completely inhibited by JS and antioxidant N,N'-diphenyl-p-phenylenediamine. These data suggest that the oxidant inhibits phosphate uptake by a reduction in the number of active carrier across the membrane. JS may prevent oxidant-induced inhibition of membrane transport function by a mechanism similar to antioxidants in renal epithelial cells. Although the precise constituents remain to be explored, JS may be employed as a useful candidate herb for drug development to prevent and treat oxidant-mediated renal failure.

• Nutrition Research and Practice
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• 제18권5호
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• pp.633-646
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• 2024

BACKGROUND/OBJECTIVES: Cladophora glomerata extract (CGE), rich in polyphenols, was reported to exhibit antidiabetic and renoprotective effects by modulating the functions of protein kinases-mediated organic anion transporter 1 (Oat1) and 3 (Oat3) in rats with type 2 diabetes mellitus (T2DM). Nevertheless, the antioxidant effects of CGE on such renoprotection have not been investigated. This study examined the mechanisms involved in the antioxidant effects of CGE on renal organic anion transport function in an in vivo study. MATERIALS/METHODS: Diabetes was induced in the rats through a high-fat diet combined with a single dose of 40 mg/kg body weight (BW) streptozotocin. Subsequently, normal-diet rats were supplemented with a vehicle or 1,000 mg/kg BW of CGE, while T2DM rats were supplemented with a vehicle, CGE, or 200 mg/kg BW of vitamin C for 12 weeks. The study evaluated the general characteristics of T2DM and renal oxidative stress markers. The renal organic transport function was assessed by measuring the para-aminohippurate (PAH) uptake using renal cortical slices and renal inflammatory cytokine expression in the normal diet (ND) and ND + CGE treated groups. RESULTS: CGE supplementation significantly reduced hyperglycemia, hypertriglyceridemia, insulin resistance, and renal lipid peroxidation in T2DM rats. This was accompanied by the normalization of high expressions of renal glutathione peroxidase and nuclear factor kappa B by CGE and vitamin C. The renal anti-inflammation of CGE was evidenced by the reduction of tumor necrosis factor-1α and interleukin-1β. CGE directly blunted sodium nitroprusside-induced renal oxidative/nitrosative stresses and mediated the PAH uptake in the normally treated CGE in rats was particularly noteworthy. These data also correlated with reduced nitric oxide production, highlighting the potential of CGE as a therapeutic agent for managing T2DM-related renal complications. CONCLUSION: These findings suggest that CGE has antidiabetic effects and directly prevents diabetic nephropathy through oxidative/nitrosative stress pathways.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.871-884
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• 2009

Gene expression profiling is a useful tool for identifying critical genes and pathways in metabolism. The objective of this study was to determine the major differences in the expression of genes associated with metabolism and metabolic regulation in liver and mammary tissues of lactating cows. We used the Michigan State University bovine metabolism (BMET) microarray; previously, we have designed a bovine metabolism-focused microarray containing known genes of metabolic interest using publicly available genomic internet database resources. This is a high-density array of 70mer oligonucleotides representing 2,349 bovine genes. The expression of 922 genes was different at p<0.05, and 398 genes (17%) were differentially expressed by two-fold or more with 222 higher in liver and 176 higher in mammary tissue. Gene ontology categories with a high percentage of genes more highly expressed in liver than mammary tissues included carbohydrate metabolism (glycolysis, glucoenogenesis, propanoate metabolism, butanoate metabolism, electron carrier and donor activity), lipid metabolism (fatty acid oxidation, chylomicron/lipid transport, bile acid metabolism, cholesterol metabolism, steroid metabolism, ketone body formation), and amino acid/nitrogen metabolism (amino acid biosynthetic process, amino acid catabolic process, urea cycle, and glutathione metabolic process). Categories with more genes highly expressed in mammary than liver tissue included amino acid and sugar transporters and MAPK, Wnt, and JAK-STAT signaling pathways. Real-time PCR analysis showed consistent results with those of microarray analysis for all 12 genes tested. In conclusion, microarray analyses clearly identified differential gene expression profiles between hepatic and mammary tissues that are consistent with the differences in metabolism of these two tissues. This study enables understanding of the molecular basis of metabolic adaptation of the liver and mammary gland during lactation in bovine species.

• Korean Journal of Acupuncture
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• 제29권2호
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• pp.260-270
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• 2012

Objectives : Hippocampus, a region of temporal lobe, plays an important role in the pathogenic mechanisms of brain diseases such as Alzheimer's disease, depression and temporal lobe epilepsy. This research is designed to investigate hippocampal changes after acupuncture stimulation at Shinmun(HT7) using 2-dimensional gel electrophoresis(2-DE). Methods : On postnatal-day 15, rat pups were randomly devided into Normal(NOR) or HT7 group. All of Pups kept with their mothers for 7 days, but pups in HT7 group received acupuncture stimulation at HT7 daily. On postnatal-day 21, hippocampus of each rat pup was dissceted 30 minutes after last acupuncture stimulation and the protein expressions were investigated using 2-DE. Results : After acupuncture stimulation at HT7, expression of 20 proteins were significantly increased. Succinate semialdehyde dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase-like, transketolase, aconitate hydratase and phosphoglucomutase-1 were related to glucose methabolism. Eukaryotic initiation factor(eIF) 4A-II, eIF 4A-III, mitochondrial Tu translation elongation factor and chain A of crystal structure of the 70-Kda heat shock cognate protein involve in the protein synthesis in ribosome. Tubulin ${\beta}$-4 chain, tubulin T ${\beta}$-15 and tubulin ${\alpha}$-1B chain comprise cytoskeleton. Glutathione S-transferase(GST) ${\omega}$-1, GST P and GST Yb-3 can reduce oxidative stress. ${\beta}$-soluble N-ethylmaleimide-sensitive fusion protein attachment protein is required for vesicular transport between the endoplasmic reticulum and the Golgi apparatus, glycerol-3-phosphate dehydrogenase plays a major role in lipid biosynthesis, creatine kinase U-type catalyses the conversion of creatine and consumes adenosine triphosphate to create phosphocreatine and adenosine diphosphate. Platelet-activating factor acetylhydrolase IB subunit alpha and voltage depedent anion-selective channel protein 2 were also increased. Conclusions : The results suggest that acupuncture stimulation at HT7 may enhance glucose and lipid metabolism, protein synthesis, cytoskeletal substance and anti-oxidative stress in hippocampus.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.544-551
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• 2003

Interactive effects of UV-B and Cd on growth, pigment, photosynthesis, and lipid peroxidation have been studied in Anabaena, Microcystis, and Nostoc; all the tested cyanobacteria showed differential sensitivity to different dosage of UV-B and Cd alone as well as in combination. Phycocyanin was severely affected by UV-B and Cd by all the strains; the degree of pigment bleaching was most pronounced in Anabaena followed by Microcystis and Nostoc. $UV-B_2+Cd_2$ produced nearly 83, 78, and 65% inhibition of phycocyanin in Anabaena, Microcystis, and Nostoc, respectively. The above treatment also significantly decreased the contents of Chl ${\alpha}$ and carotenoid. Presence of capsule in Microcystis protected the phycocyanin bleaching as compared to decapsulated cells. Laboratory-grown Microcystis revealed about 75 and 80% inhibition, following $UV-B_2+Cd_2$ treatment, respectively. in capsulated and decapsulated cells. Damage caused by Cd was more pronounced than UV-B. Inhibition of photosynthesis did occur in all the test strains, being maximum in Anabaena. PS II was the most sensitive component of the electron transport chain, showing 84, 80, and 70% inhibition in Anabaena, Microcystis, and Nostoc, respectively. As compared to control, significant lipid peroxidation (6.5-fold higher) was observed in Anabaena with $UV-B_2+Cd_2$, $^{14}C-uptake$ was more susceptible to Cd and Uv-B than oxygen-evolution. Approximately 84, 80, and 76% inhibition of $^{14}C-uptake$ was observed in Anabaena, Microcystis, and Nostoc, respectively. Similarly, $UV-B_2+Cd_2$ inhibited APT content of Anabaena by 87%. This ,study suggests that inhibition of carbon fixation was due to decreased ATP content of the test cyanobacteria by UV-B+Cd, where Anabaena was the most sensitive and Nostoc the most tolerant.

• Molecules and Cells
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• 제43권1호
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• pp.48-57
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• 2020

The microalga Chlamydomonas reinhardtii accumulates triacylglycerols (TAGs) in lipid droplets under stress conditions, such as nitrogen starvation. TAG biosynthesis occurs mainly at the endoplasmic reticulum (ER) and requires fatty acid (FA) substrates supplied from chloroplasts. How FAs are transferred from chloroplast to ER in microalgae was unknown. We previously reported that an Arabidopsis thaliana ATP-binding cassette (ABC) transporter, AtABCA9, facilitates FA transport at the ER during seed development. Here we identified a gene homologous to AtABCA9 in the C. reinhardtii genome, which we named CrABCA2. Under nitrogen deprivation conditions, CrABCA2 expression was upregulated, and the CrABCA2 protein level also increased. CrABCA2 knockdown lines accumulated less TAGs and CrABCA2 overexpression lines accumulated more TAGs than their untransformed parental lines. Transmission electron microscopy showed that CrABCA2 was localized in swollen ER. These results suggest that CrABCA2 transports substrates for TAG biosynthesis to the ER during nitrogen starvation. Our study provides a potential tool for increasing lipid production in microalgae.