• Title/Summary/Keyword: Protein and energy metabolism

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Stress Responses through Heat Shock Transcription Factor in S. cerevisiae

  • Hahn, Ji-Sook;Hu, Zhanzhi;Thiele, Dennis J.;Lyer, Vishwanath R.
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2005.05a
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    • pp.105-109
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    • 2005
  • Heat Shock Transcription Factor (HSF), and the promoter heat Shock Element (HSE), are among the most highly conserved transcriptional regulatory elements in nature. HSF mediates the transcriptional response of eukaryotic cells to heat, infection and inflammation, pharmacological agents, and other stresses. While HSF is essential for cell viability in yeast, oogenesis and early development in Drosophila, extended life-span in C. elegans, and extra-embryonic development and stress resistance in mammals, little is known about its full range of biological target genes. We used whole genome analyses to identify virtually all of the direct transcriptional targets of yeast HSF, representing nearly three percent of the genomic loci. The majority of the identified loci are heat-inducibly bound by yeast HSF, and the target genes encode proteins that have a broad range of biological functions including protein folding and degradation, energy generation, protein secretion, maintenance of cell integrity, small molecule transport, cell signaling, and transcription. Approximately 30% of the HSF direct target genes are also induced by the diauxic shift, in which glucose levels begin to be depleted. We demonstrate that phosphorylation of HSF by Snf1 kinase is responsible for expression of a subset of HSF targets upon glucose starvation.

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Effects of dietary energy sources on early postmortem muscle metabolism of finishing pigs

  • Li, Yanjiao;Yu, Changning;Li, Jiaolong;Zhang, Lin;Gao, Feng;Zhou, Guanghong
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.12
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    • pp.1764-1772
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    • 2017
  • Objective: This study investigated the effects of different dietary energy sources on early postmortem muscle metabolism of finishing pigs. Methods: Seventy-two barrow ($Duroc{\times}Landrace{\times}Yorkshire$, DLY) pigs ($65.0{\pm}2.0kg$) were allotted to three iso-energetic and iso-nitrogenous diets: A (44.1% starch, 5.9% crude fat, and 12.6% neutral detergent fibre [NDF]), B (37.6% starch, 9.5% crude fat, and 15.4% NDF) or C (30.9% starch, 14.3% crude fat, and 17.8% NDF). After the duration of 28-day feeding experiment, 24 pigs (eight per treatment) were slaughtered and the M. longissimus lumborum (LL) samples at 45 min postmortem were collected. Results: Compared with diet A, diet C resulted in greater adenosine triphosphate and decreased phosphocreatine (PCr) concentrations, greater activity of creatine kinase and reduced percentage bound activities of hexokinase (HK), and pyruvate kinase (PK) in LL muscles (p<0.05). Moreover, diet C decreased the phosphor-AKT level and increased the hydroxy-hypoxia-inducible $factor-1{\alpha}$ ($HIF-1{\alpha}$) level, as well as decreased the bound protein expressions of HK II, PKM2, and lactate dehydrogenase A (p<0.05). Conclusion: Diet C with the lowest level of starch and the highest levels of fat and NDF could enhance the PCr utilization and attenuate glycolysis early postmortem in LL muscle of finishing pigs.

Comparison of the Effects of Pharmacopuncture Extracts with Hominis placenta Pharmacopuncture and Wild Ginseng Pharmacopuncture on the Differentiation of C2C12 Myoblasts into Myotubes through Regulation of the AMPK/SIRT1 Signaling Pathway (자하거약침액과 산삼약침액의 C2C12 근아세포에서의 AMPK/SIRT1 신호전달을 통한 근 분화 유도 및 에너지 대사 증진 효과 비교)

  • Ji Hye Hwang;Hyo Won Jung
    • Journal of Korean Medicine for Obesity Research
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    • v.23 no.2
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    • pp.60-68
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    • 2023
  • Objectives: This study was conducted to compare the effects of Hominis placenta (Jahage, J) and wild ginseng (SanSam, S) pharmacopuncture drugs on muscle differentiation and energy metabolism regulation in C2C12 myotubes. Methods: The C2C12 myoblasts were differentiated into myotubes for 5 days by replacing in medium containing 2% horse serum and then treated with J and S pharmacopuncture extract at different concentrations for 24 hr. The expression of myosin heavy chain and energy metabolism-regulating factors, myosin heavy chain (MHC), nuclear respiratory factor-1 (NRF-1), and proliferator-activated receptor γ coactivator-1 alpha (PGC-1α) were determined in C2C12 myotubes by western blot. Additionally, the phosphorylation of AMPK and the expression of mitochondrial biogenesis, including sirtuin 1 (SIRT1) were determined in the myotubes. Results: As a result, treatment with J and S pharmacopuncture extract at 0.1 and 1 mg/mL increased the MHC expression in C2C12 myotubes compared with non-treated cells, but only S pharmacopuncture was shown a significant and distinct increase in the expression. Expression of TFAM and NRF-1 was also shown significant increases in S and J pharmacopuncture in C2C12 myotubes compared to non-treated cells. The phosphorylation of AMPK and the expression of PGC-1α and SIRT1 showed increased expression in S and J pharmacopuncture compared to non-treated cells. The effect of low-dose of J pharmacopuncture on the phosphorylated adenosine monophosphate-activated protein kinase (AMPK) and PGC-1α expression was greater than that of S pharmacopuncture. Conclusions: In conclusion, both J and S pharmacopuncture promote muscle differentiation in C2C12 myoblasts into myotubes and energy metabolism through the AMPK/SIRT1 signaling pathway. This indicates that the pharmacopuncture with tonic herbal medicines can help to improve skeletal muscle function.

Effects of Synchronization of Carbohydrate and Protein Supply in Total Mixed Ration with Korean Rice Wine Residue on Ruminal Fermentation, Nitrogen Metabolism and Microbial Protein Synthesis in Holstein Steers

  • Piao, Min Yu;Kim, Hyun-J.;Seo, J.K.;Park, T.S.;Yoon, J.S.;Kim, K.H.;Ha, Jong-K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.11
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    • pp.1568-1574
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    • 2012
  • Three Holstein steers in the growing phase, each with a ruminal cannula, were used to test the hypothesis that the synchronization of the hourly rate of carbohydrate and nitrogen (N) released in the rumen would increase the amount of retained nitrogen for growth and thus improve the efficiency of microbial protein synthesis (EMPS). In Experiment 1, in situ degradability coefficients of carbohydrate and N in feeds including Korean rice wine residue (RWR) were determined. In Experiment 2, three total mixed ration (TMR) diets having different rates of carbohydrate and N release in the rumen were formulated using the in situ degradability of the feeds. All diets were made to contain similar contents of crude protein (CP) and neutral detergent fiber (NDF) but varied in their hourly pattern of nutrient release. The synchrony index of the three TMRs was 0.51 (LS), 0.77 (MS) and 0.95 (HS), respectively. The diets were fed at a restricted level (2% of the animal's body weight) in a $3{\times}3$ Latin-square design. Synchronizing the hourly supply of energy and N in the rumen did not significantly alter the digestibility of dry matter, organic matter, crude protein, NDF or acid detergent fiber (ADF) (p>0.05). The ruminal $NH_3$-N content of the LS group at three hours after feeding was significantly higher (p<0.05) than that of the other groups; however, the mean values of ruminal $NH_3$-N, pH and VFA concentration among the three groups were not significantly different (p>0.05). In addition, the purine derivative (PD) excretion in urine and microbial-N production (MN) among the three groups were not significantly different (p>0.05). In conclusion, synchronizing dietary energy and N supply to the rumen did not have a major effect on nutrient digestion or microbial protein synthesis (MPS) in Holstein steers.

Impact of inhibitors of amino acid, protein, and RNA synthesis on C allocation in the diatom Chaetoceros muellerii: a FTIR approach

  • Giordano, Mario;Norici, Alessandra;Beardall, John
    • ALGAE
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    • v.32 no.2
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    • pp.161-170
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    • 2017
  • Fourier Transform Infrared (FTIR) spectroscopy was used to study carbon allocation patterns in response to N-starvation in the nearly ubiquitous diatom Chaetoceros muellerii. The role of gene expression, protein synthesis and transamination on the organic composition of cells was tested by using specific inhibitors. The results show that inhibition of key processes in algal metabolism influence the macromolecular composition of cells and and prior cell nutritional state can influence a cell's response to changing nutrient availability. The allocation of C can thus lead to different organic composition depending on the nutritional context, with obvious repercussions for the trophic web. This also shows that C allocation in algal cells is highly flexible and that C (and the energy associated with its allocation) can be variably and rapidly partitioned in algal cells in response to relatively short term perturbations. Furthermore, the data confirm and extend the utility of infrared spectroscopy as a probe of the metabolic state of autotrophic cells.

Highly Polymorphic Bovine Leptin Gene

  • Yoon, D.H.;Cho, B.H.;Park, B.L.;Choi, Y.H.;Cheong, H.S.;Lee, H.K.;Chung, E.R.;Cheong, I.C.;Shin, H.D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.11
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    • pp.1548-1551
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    • 2005
  • The leptin, an anti-obesity protein, is a hormone protein expressed and secreted mainly from adipocyte tissue, and involved in regulation of body weight, food intake and energy metabolism. In an effort to discover polymorphism(s) in genes whose variant(s) might be implicated in phenotypic traits of growth, we have sequenced exons and their boundaries of leptin gene including 1,000 bp upstream of promoter region with twenty-four unrelated Korean cattle. Fifty-seven sequence variants were identified: fourteen in 5' flanking region, twenty-seven in introns, eight in exons, and eight in 3' flanking region. By pair-wise linkage analysis among polymorphisms, ten sets of SNPs were in absolute linkage disequilibrium (LD) (|D'| = 1 and $r^2$ = 1). Among variants identified, thirty-six SNPs were newly identified, and twenty-one SNPs, which were reported in other breeds, were also confirmed in Korean cattle. The allele frequencies of variants were quite different among breeds. The information from SNPs of bovine leptin gene could be useful for further genetic studies of this gene.

The Interface Between ER and Mitochondria: Molecular Compositions and Functions

  • Lee, Soyeon;Min, Kyung-Tai
    • Molecules and Cells
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    • v.41 no.12
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    • pp.1000-1007
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    • 2018
  • Mitochondria and endoplasmic reticulum (ER) are essential organelles in eukaryotic cells, which play key roles in various biological pathways. Mitochondria are responsible for ATP production, maintenance of $Ca^{2+}$ homeostasis and regulation of apoptosis, while ER is involved in protein folding, lipid metabolism as well as $Ca^{2+}$ homeostasis. These organelles have their own functions, but they also communicate via mitochondrial-associated ER membrane (MAM) to provide another level of regulations in energy production, lipid process, $Ca^{2+}$ buffering, and apoptosis. Hence, defects in MAM alter cell survival and death. Here, we review components forming the molecular junctions of MAM and how MAM regulates cellular functions. Furthermore, we discuss the effects of impaired ER-mitochondrial communication in various neurodegenerative diseases.

EGCG Blocked Phenylephrin-Induced Hypertrophy in H9C2 Cardiomyocytes, by Activating AMPK-Dependent Pathway

  • Cai, Yi;Zhao, Li;Qin, Yuan;Wu, Xiao-Qian
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.3
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    • pp.203-210
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    • 2015
  • AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism. Previous studies have shown that activation of AMPK results in suppression of cardiac myocyte hypertrophy via inhibition of the p70S6 kinase (p70S6K) and eukaryotic elongation factor-2 (eEF2) signaling pathways. Epigallocatechin-3-gallate (EGCG), the major polyphenol found in green tea, possesses multiple protective effects on the cardiovascular system including cardiac hypertrophy. However, the molecular mechanisms has not been well investigated. In this study, we found that EGCG could significantly reduce natriuretic peptides type A (Nppa), brain natriuretic polypeptide (BNP) mRNA expression and decrease cell surface area in H9C2 cardiomyocytes stimulated with phenylephrine (PE). Moreover, we showed that AMPK is activated in H9C2 cardiomyocytes by EGCG, and AMPK-dependent pathway participates in the inhibitory effects of EGCG on cardiac hypertrophy. Taken together, our findings provide the first evidence that the effect of EGCG against cardiac hypertrophy may be attributed to its activation on AMPK-dependent signaling pathway, suggesting the therapeutic potential of EGCG on the prevention of cardiac remodeling in patients with pressure overload hypertrophy.

Recent Advances in Cancer Cachexia (암성 악액질의 최신 지견)

  • Choi, Sang-Gyu
    • Asian Oncology Nursing
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    • v.11 no.1
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    • pp.20-25
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    • 2011
  • Purpose: The study was aimed to review and understand the meaning of cancer cachexia. Methods: Using the keywords "cachexia" and "cancer cachexia" 30 oncology research published from 1974 to 2009 were selected for the review. Results: The mechanism of cancer cachexia has not been fully understood, but various pathogenesis appears to be involved in the development cachexia including altered metabolism of carbohydrate, lipid, and protein associated with cytokines and hormone. As a result, muscle strength, food intake and resting energy expenditure (REE) are reduced. Most medications for the treatment of cachexia show debating results except some drugs such as megace. Supportive care including nutritional education, nursing care, and social support are found another effective treatment options. Conclusion: The results of this study would help oncology nurses to understand the mechanism of cancer cachexia and its management.

EFFECTS OF FRUCTO-OLIGOSACCHARIDES ON MILK-YIELD AND MILK-COMPONENTS OF DAIRY COWS

  • Kobayashi, S.;Eida, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.3 no.1
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    • pp.21-25
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    • 1990
  • Fructo-oligosaccharides are found in many plants, such as onion, burdock and wheat. They are not well hydrolyzed by digestive enzymes in animals, but are peculiarly assimilated by Bifidobacterium and some useful bacteria. In our previous experiment (Kobayashi et al., 1987) it was suggested that they were effective in decreasing energy loss in the metabolism of dairy calves. In the present study, the effects of fructo-oligosaccharides on body weight, milk-yield and milk-components (fat, protein and solids-not-fat) were investigated in dairy cows. Lactating cows were fed a standard diet containing fructoligo saccharides at 18.70g, 9.35g and 0.0g (control) per 100kg body weight, day for three weeks. Neither treatments significantly affected any of the parameters examined. The fructo-oligosaccharides were assumed to be hydrolyzed by rumen microorganisms and hardly to affect the bacterium florae in the intestines of the lactating cows.