• The Korean Journal of Physiology and Pharmacology
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• 제9권3호
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• pp.173-177
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• 2005

The purpose of this study was to discern the critical point in skeletal muscle fatty acid oxidation by changing plasma free fatty acids (FFA) level in rat. In the study, 3 key steps in lipid oxidation were examined after changing plasma FFA level by acipimox. The rates of both palmitate and palmitoylcarnitine oxidation were decreased by decrease of plasma FFA level, however, carnitine palmitoyl transferase (CPT) 1 activity was not changed, suggesting CPT1 activity may not be involved in the fatty acid oxidation at the early phase of plasma FFA change. In the fasted rats, ${\beta}-hydroxy$ acyl-CoA dehydrogenase (${\beta}$-HAD) activity was depressed to a similar extent as palmitate oxidation by a decrease of plasma FFA level. This suggested that ${\beta}-oxidation$ might be an important process to regulate fatty acid oxidation at the early period of plasma FFA change. Citrate synthase activity was not altered by the change of plasma FFA level. In conclusion, the critical step in fatty acids oxidation of skeletal muscles by the change of plasma FFA level by acipimox in fasting rats might be the ${\beta}-oxidation$ step rather than CPT1 and TCA cycle pathways.

• BMB Reports
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• 제43권3호
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• pp.170-175
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• 2010

Chaperone;Glutathione peroxidase;Peroxiredoxin;Schizosaccharomyces pombe;Thioredoxin peroxidase;To investigate the differences in the functional roles of peroxiredoxins (Prxs) and glutathione peroxidase (GPx) of Schizosaccharomyces pombe, we examined the peroxidase and molecular chaperone properties of the recombinant proteins. TPx (thioredoxin peroxidase) exhibited a capacity for peroxide reduction with the thioredoxin system. GPx also showed thioreoxin-dependent peroxidase activity rather than GPx activity. The peroxidase activity of BCP (bacterioferritin comigratory protein) was similar to that of TPx. However, peroxidase activity was not observed for PMP20 (peroxisomal membrane protein 20). TPx, PMP20, and GPx inhibited thermal aggregation of citrate synthase at 43$^{\circ}C$, but BCP failed to inhibit the aggregation. The chaperone activities of PMP20 and GPx were weaker than that of TPx. The peroxidase and chaperone properties of TPx, BCP, and GPx of the fission yeast are similar to those of Saccharomyces cerevisiae. The fission yeast PMP20 without thioredoxin-dependent peroxidase activity may act as a molecular chaperone.

• The Korean Journal of Physiology and Pharmacology
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• 제25권3호
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• pp.227-237
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• 2021

Carbon monoxide (CO) is a cardioprotectant and potential cardiovascular therapeutic agent. Human cardiac fibroblasts (HCFs) are important determinants of myocardial structure and function. Large-conductance Ca2+-activated K+ (BK) channel is a potential therapeutic target for cardiovascular disease. We investigated whether CO modulates BK channels and the signaling pathways in HCFs using whole-cell mode patch-clamp recordings. CO-releasing molecules (CORMs; CORM-2 and CORM-3) significantly increased the amplitudes of BK currents (IBK). The CO-induced stimulating effects on IBK were blocked by pre-treatment with specific nitric oxide synthase (NOS) blockers (L-NG-monomethyl arginine citrate and L-NG-nitroarginine methyl ester). 8-bromo-cyclic GMP increased IBK. KT5823 (inhibits PKG) or ODQ (inhibits soluble guanylate cyclase) blocked the CO-stimulating effect on IBK. Moreover, 8-bromo-cyclic AMP also increased IBK, and pre-treatment with KT5720 (inhibits PKA) or SQ22536 (inhibits adenylate cyclase) blocked the CO effect. Pre-treatment with N-ethylmaleimide (a thiol-alkylating reagent) also blocked the CO effect on IBK, and DL-dithiothreitol (a reducing agent) reversed the CO effect. These data suggest that CO activates IBK through NO via the NOS and through the PKG, PKA, and S-nitrosylation pathways.

• Nutrition Research and Practice
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• 제17권4호
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• pp.660-669
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• 2023

BACKGROUND/OBJECTIVES: To investigate the effect and regulatory mechanism of resveratrol supplementation on the mitochondrial energy metabolism of rats with exercise-induced fatigue. MATERIALS/METHODS: Forty-eight Sprague-Dawley male rats were divided randomly into a blank control group (C), resveratrol group (R), exercise group (E), and exercise and resveratrol group (ER), with 12 rats in each group. Group ER and group E performed 6-wk swimming training with 5% wt-bearing, 60 min each time, 6 days a wk. Group ER was given resveratrol 50 mg/kg by gavage one hour after exercise; group R was only given resveratrol 50 mg/kg by gavage; group C and group E were fed normally. The same volume of solvent was given by gavage every day. RESULTS: Resveratrol supplementation could reduce the plasma blood urea nitrogen content, creatine kinase activity, and malondialdehyde content in the skeletal muscle, increase the total superoxide dismutase activity in the skeletal muscle, and improve the fatigue state. Resveratrol supplementation could improve the activities of Ca²⁺-Mg²⁺-ATPase, Na⁺-K⁺-ATPase, succinate dehydrogenase, and citrate synthase in the skeletal muscle. Furthermore, resveratrol supplementation could up-regulate the sirtuin 1 (SIRT1)-proliferator-activated receptor gamma coactivator-1α (PGC-1α)-nuclear respiratory factor 1 pathway. CONCLUSIONS: Resveratrol supplementation could promote mitochondrial biosynthesis via the SIRT1/PGC-1α pathway, increase the activity of the mitochondrial energy metabolism-related enzymes, improve the antioxidant capacity of the body, and promote recovery from exercise-induced fatigue.

• Nutrition Research and Practice
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• 제11권2호
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• pp.121-129
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• 2017

BACKGROUND/OBJECTIVES: The study was conducted to evaluate the effects of dietary leucine supplementation on mitochondrial biogenesis and energy metabolism in the liver of normal birth weight (NBW) and intrauterine growth-retarded (IUGR) weanling piglets. MATERIALS/METHODS: A total of sixteen pairs of NBW and IUGR piglets from sixteen sows were selected according to their birth weight. At postnatal day 14, all piglets were weaned and fed either a control diet or a leucine-supplemented diet for 21 d. Thereafter, a $2{\times}2$ factorial experimental design was used. Each treatment consisted of eight replications with one piglet per replication. RESULTS: Compared with NBW piglets, IUGR piglets had a decreased (P < 0.05) hepatic adenosine triphosphate (ATP) content. Also, IUGR piglets exhibited reductions (P < 0.05) in the activities of hepatic mitochondrial pyruvate dehydrogenase (PDH), citrate synthase (CS), ${\alpha}$-ketoglutarate dehydrogenase (${\alpha}$-KGDH), malate dehydrogenase (MDH), and complexes I and V, along with decreases (P < 0.05) in the concentration of mitochondrial DNA (mtDNA) and the protein expression of hepatic peroxisome proliferator-activated receptor-${\gamma}$ coactivator $1{\alpha}$ (PGC-$1{\alpha}$). Dietary leucine supplementation increased (P < 0.05) the content of ATP, and the activities of CS, ${\alpha}$-KGDH, MDH, and complex V in the liver of piglets. Furthermore, compared to those fed a control diet, piglets given a leucine-supplemented diet exhibited increases (P < 0.05) in the mtDNA content and in the mRNA expressions of sirtuin 1, PGC-$1{\alpha}$, nuclear respiratory factor 1, mitochondrial transcription factor A, and ATP synthase, $H^+$ transporting, mitochondrial F1 complex, ${\beta}$ polypeptide in liver. CONCLUSIONS: Dietary leucine supplementation may exert beneficial effects on mitochondrial biogenesis and energy metabolism in NBW and IUGR weanling piglets.

• 생명과학회지
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• 제31권8호
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• pp.778-785
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• 2021

오이 씨앗의 발아는 세포의 지방체내 저장지방의 분해 결과인 acyl-CoA의 글라이옥시좀으로 이동 후 베타 산화의 결과물인 acetyl-CoA의 글라이옥실산 회로로의 유입과 지방의 유동으로 촉발된다. Acetyl-CoA는 글라이옥실산 회로의 가동을 위한 탄소원을 제공하며 시트르산과 말산을 생성하며 글라이옥실산 회로의 작동을 유도한다. 지방 저장 종자의 발아에 있어서 글라이옥실산 회로는 필수적 요소이며, 그 결과물인 말산 및 숙신산의 미토콘드리아로의 이동은 TCA 회로의 가동과 옥살초산의 생성 및 세포질로의 유동으로 PEPCK에 의한 당신생을 가능하게 한다. 즉, 저장 지방을 원료로 여러 대사물질의 생산 및 이동과 다중의 대사경로를 통하여 발아 시 사용 가능한 에너지원인 포도당의 형태로 전환이 이루어진다. 이에 동반하여 많은 유전자의 발현 조절이 이루어지고, 세포내 소기관 특히 미소체로 대표되는 글라이옥시좀은 말산 합성효소(malate synthase)와 이소 시트르산 분해효소(isocitrate lyase)로 특화된다. 또 다른 acetyl-CoA의 유동은 carnitine을 매개로 하는 BOU (A BOUT DE SOUFFLE)의 작동이다. 이것은 카니틴의 대사와 관련하여 고등식물의 발달과 대사과정에서의 중요성이 확인된 것으로 사료된다.

• Parasites, Hosts and Diseases
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• 제55권6호
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• pp.643-652
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• 2017

Calreticulin (CALR), a multifunctional protein thoroughly researched in mammals, comprises N-, P-, and C-domain and has roles in calcium homeostasis, chaperoning, clearance of apoptotic cells, cell adhesion, and also angiogenesis. In this study, the spatial and temporal expression patterns of the Opisthorchis viverrini CALR gene were analyzed, and calcium-binding and chaperoning properties of recombinant O. viverrini CALR (OvCALR) investigated. OvCALR mRNA was detected from the newly excysted juvenile to the mature parasite by RT-PCR while specific antibodies showed a wide distribution of the protein. OvCALR was localized in tegumental cell bodies, testes, ovary, eggs, Mehlis' gland, prostate gland, and vitelline cells of the mature parasite. Recombinant OvCALR showed an in vitro suppressive effect on the thermal aggregation of citrate synthase. The recombinant OvCALR C-domain showed a mobility shift in native gel electrophoresis in the presence of calcium. The results imply that OvCALR has comparable function to the mammalian homolog as a calcium-binding molecular chaperone. Inferred from the observed strong immunostaining of the reproductive tissues, OvCALR should be important for reproduction and might be an interesting target to disrupt parasite fecundity. Transacetylase activity of OvCALR as reported for calreticulin of Haemonchus contortus could not be observed.

• Nutrition Research and Practice
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• 제5권3호
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• pp.205-213
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• 2011

Exercise training (ET) and selenium (SEL) were evaluated either individually or in combination (COMBI) for their effects on expression of glucose (AMPK, PGC- $1{\alpha}$, GLUT-4) and lactate metabolic proteins (LDH, MCT-1, MCT-4, COX-IV) in heart and skeletal muscles in a rodent model (Goto-Kakisaki, GK) of diabetes. Forty GK rats either remained sedentary (SED), performed ET, received SEL, ($5\;{\mu}mol{\cdot}kg$ body $wt^{-1}{\cdot}day^{-1}$) or underwent both ET and SEL treatment for 6 wk. ET alone, SEL alone, or COMBI resulted in a significant lowering of lactate, glucose, and insulin levels as well as a reduction in HOMA-IR and AUC for glucose relative to SED. Additionally, ET alone, SEL alone, or COMBI increased glycogen content and citrate synthase (CS) activities in liver and muscles. However, their effects on glycogen content and CS activity were tissue-specific. In particular, ET alone, SEL alone, or COMBI induced upregulation of glucose (AMPK, PGC-la, GLUT-4) and lactate (LDH, MCT-1, MCT-4, COX-IV) metabolic proteins relative to SED. However, their effects on glucose and lactate metabolic proteins also appeared to be tissue-specific. It seemed that glucose and lactate metabolic protein expression was not further enhanced with COMBI compared to that of ET alone or SEL alone. These data suggest that ET alone or SEL alone or COMBI represent a practical strategy for ameliorating aberrant expression of glucose and lactate metabolic proteins in diabetic GK rats.

• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.212-217
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• 2011

${\alpha}$ and ${\beta}$-subunits (ApCpnA and ApCpnB) are group II chaperonins from the hyperthermophilic archaeum Aeropyrum pernix K1, specialized in preventing the aggregation and inactivation of substrate proteins under conditions of transient heat stress. In the present study, the cooperativity of ${\alpha}$- and ${\beta}$-subunits from the A. pernix K1 was investigated. The ApCpnA and ApCpnB chaperonin genes were overexpressed in E. coli Rosetta and Codonplus (DE3), respectively. Each of the recombinant ${\alpha}$- and ${\beta}$-subunits was purified to 92% and 94% by using anionexchange chromatography. The cooperative activity between purified ${\alpha}$- and ${\beta}$-subunits was examined using citrate synthase (CS), alcohol dehydrogenase (ADH), and malate dehydrogenase (MDH) as substrate proteins. The addition of both ${\alpha}$- and ${\beta}$-subunits could effectively protect CS and ADH from thermal aggregation and inactivation at $43^{\circ}C$ and $50^{\circ}C$, respectively, and MDH from thermal inactivation at $80^{\circ}C$C and $85^{\circ}C$. Moreover, in the presence of ATP, the protective effects of ${\alpha}$- and ${\beta}$-subunits on CS from thermal aggregation and inactivation, and ADH from thermal aggregation, were more enhanced, whereas cooperation between chaperonins and ATP in protection activity on ADH and MDH (at $85^{\circ}C$) from thermal inactivation was not observed. Specifically, the presence of both ${\alpha}$- and ${\beta}$- subunits could effectively protect MDH from thermal inactivation at $80^{\circ}C$ in an ATP-dependent manner.

• 대한한의학회지
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• 제27권2호
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• pp.211-224
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• 2006

Objectives : This study was performed to investigate the effects of Pinelliae rhizoma on blood serum lipids and skeletal muscle fatty acid metabolism of obese Zucker rats. Methods : Experimental groups were divided into normal Zucker rats (lean control; non-treated), obese Zucker rats (fat control; non-treated) and Pinelliae rhizoma oral feeding obese Zucker rats (fat control; treated) for 6 separate experiments. Pinelliae rhizoma was investigated for effects on total body weight, serum glucose content, total cholesterol and triglyceride content, free fatty acid content, PPARalpha, CS and beta-HAD. Results : 1. Triglycerides in blood serum showed a greater decrease in the Pinellia rhizoma oral feeding group than the overweight control group. 2. PPARa showed a significant increase in the Pinelliae rhizoma oral feeding group over the overweight control group in skeletal muscles of SOL and EDL: as for protein FABPc, the Pinelliae rhizomaoral feeding group saw a greater significant increase than the overweight control group in the skeletal muscles of SOL. 3. CS activity showed a greater increase for the Pinelliae rhizoma oral feeding group than the overweight control group in EDL Conclusions : As the experiment's results show, Pinelliae rhizoma effectively decreased the weight and triglycerides of the obese mouse, and somewhat affects the fat oxidation in the skeletal muscles.