• Development and Reproduction
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• v.21 no.2
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• pp.131-138
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• 2017

This study was conducted to investigate stimulatory effect of epidermal growth factor (EGF) on nuclear maturation and the expression level of EGF-receptor (EGFR), GM-130 (a marker of Golgi apparatus), transport protein Sec61 subunit beta ($Sec61{\beta}$), and coatomer protein complex subunit gamma 2 (COPG2) in porcine oocytes. The cumulus-oocyte complexes were collected from follicle with 3-6 mm in diameter. They were incubated in medium with/without EGF for 22 h (IVM I) and subsequently incubated hormone-free medium with/without EGF for 22 h (IVM II). Nuclear maturation state was checked by aceto-orcein stain. Protein expression of EGFR, GM-130, $Sec61{\beta}$, and COPG2 were measured by immunofluorescence. In results, nuclear maturation of oocytes in EGF non-treated oocytes were significantly lower than EGF-treated groups at IVM I or IVM II stage (P<0.05), whereas maturational rate in EGF treatment groups at both of IVM stage was higher in among the all treatment groups (P<0.05). EGFR, GM-130, $Sec61{\beta}$ and COPG2 were expressed in the cytoplasm of oocytes. Especially, GM-130 and EGFR were strongly expressed, but $Sec61{\beta}$ and COPG2 were weakly expressed in cortical area of cytoplasm. The protein level of GM-130, $Sec61{\beta}$, and COPG2 were significantly higher in the EGF-treated groups (P<0.05). However EGFR was no difference between non EGF-treated groups and control. In conclusion, EGF plays an important role in the systems for oocyte maturation with endoplasmic reticulum and Golgi apparatus. In addition, the protein levels of $Sec61{\beta}$ and COPG2 could be changed by EGF in the porcine oocytes during maturation.

• BMB Reports
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• v.34 no.6
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• pp.537-543
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• 2001

In the present study, an in vitro ELISA system to assess the interaction between Src homology (SH)2 domains and phosphotyrosine that contain peptides was established using purified GST-conjugated SH2 proteins and synthetic biotinylated phosphotyrosine that contain oligopeptides. The SH2 domains bound the relevant phosphopeptides that were immobilized in the streptavidin-coated microtiter plate in a highly specific and dose-dependent manner. The epidermal growth factor receptor (EGFR)-, T antigen (T Ag)-, and platelet-derived growth factor receptor (PDGFR)-derived phosphopeptides interacted with the growth factor receptor binding protein (Grb)2/SH2, Lck/SH2, and phosphatidyl inositol 3-kinase (PI3K) p85/SH2, respectively. No cross-reactions were observed. Competitive inhibition experiments showed that a short phosphopeptide of only four amino acids was long enough to determine the binding specificity. Optimal concentrations of the GST-SH2 fusion protein and phosphopeptide in this new ELISA system for screening the binding blockers were chosen at 2nM and 500nM, respectively. When two candidate compounds were tested in our ELISA system, they specifically inhibited the Lck/SH2 and/or p85/SH2 binding to the relevant phosphopeptides. Our results indicate that this ELISA system could be used as an easy screening method for the discovery of specific binding blockers of protein-protein interactions via SH2 domains.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.17-18
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• 2003

Although flounder is one of the most important marine fish for aquaculture in Korea, feeding the flounder in commercial farms depends mainly on moist pellet in which over 70% frozen fishes (e.g. frozen horse mackerel) are incorporated in its formulation. Therefore, for further expansion of flounder farming, it is essential to employ practical formulated feeds that can support reasonable growth. Development of nutritionally balanced and cost-effective feeds is dependant on the information about nutritional requirement and feed utilization of the species. Nutrient and energy source in feed are needed for the growth and maintenance of fish. Protein is probably the most important nutrient affecting fish growth and feed cost. Therefore, it is essential to determine the optimum dietary protein level for the growth of fish, both its high proportion in the feed and because it is the main factor in determining feed cost. Dietary energy level is also critical because protein source in the feed is utilized as an energy source when the feed deficient in energy is fed to fish, whereas when the feed excess in energy is fed to fish, feed consumption decreased and resulted in growth reduction due to lack of other necessary nutrients for normal growth. Improper dietary protein, energy levels and/or their ratio will lead to an increase of fish production cost and deterioration of water quality resulting from wasted feed; thus, they are important in formulating commercial feed. Dietary lipids play important roles in providing energy and essential fatty acid for normal growth and survival of fish. Although carbohydrates are not essential nutrients for carnivorous fish, these compounds play important roles as a low-cost energy source for protein sparing and also as a feed binder. Nutrition researches for flounder have identified its requirements of protein, lipid and essential fatty acid, vitamin, and minerals for normal growth. Other studies have also been carried out to investigate the utilization of the protein, lipid and carbohydrate sources. Based on these nutritional information obtained, practical feed formulations have been studied for improve aquaculture production of flounder. The results of the researches on utilization of dietary protein, lipid and carbohydrate by flounder are discussed in this review.

• Annals of Pediatric Endocrinology and Metabolism
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• v.23 no.4
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• pp.204-209
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• 2018

Purpose: Growth hormone transduction defect (GHTD) is characterized by severe short stature, impaired STAT3 (signal transducer and activator of transcription-3) phosphorylation and overexpression of the cytokine inducible SH2 containing protein (CIS) and p21/CIP1/WAF1. To investigate the role of p21/CIP1/WAF1 in the negative regulation of the growth hormone (GH)/GH receptor and Epidermal Growth Factor (EGF)/EGF Receptor pathways in GHTD. Methods: Fibroblast cultures were developed from gingival biopsies of 1 GHTD patient and 1 control. The protein expression and the cellular localization of p21/CIP1/WAF1 was studied by Western immunoblotting and immunofluorescence, respectively: at the basal state and after induction with $200-{\mu}g/L$ human GH (hGH) (GH200), either with or without siRNA CIS (siCIS); at the basal state and after inductions with $200-{\mu}g/L$ hGH (GH200), $1,000-{\mu}g/L$ hGH (GH1000) or 50-ng/mL EGF. Results: After GH200/siCIS, the protein expression and nuclear localization of p21 were reduced in the patient. After successful induction of GH signaling (control, GH200; patient, GH1000), the protein expression and nuclear localization of p21 were reduced. After induction with EGF, p21 translocated to the cytoplasm in the control, whereas in the GHTD patient it remained located in the nucleus. Conclusion: In the GHTD fibroblasts, when CIS is reduced, either after siCIS or after a higher dose of hGH (GH1000), p21's antiproliferative effect (nuclear localization) is also reduced and GH signaling is activated. There also appears to be a positive relationship between the 2 inhibitors of GH signaling, CIS and p21. Finally, in GHTD, p21 seems to participate in the regulation of both the GH and EGF/EGFR pathways, depending upon its cellular location.

• Korean Journal of Veterinary Research
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• v.46 no.2
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• pp.97-105
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• 2006

All-trans retinoic acid (AtRA) induces growth inhibition and apoptosis in a variety of tumer cells, including MCF-7 cells. Insulin-like growth factors (IGFs) system has been reported to be associated with the development of cancer. Although MCF-7 cell with AtRA is to be the major stimulus for the cell growth and apoptosis, the mechanism of insulin-like growth factor-I (IGF-I)/insulin-like growth factor binding protein-3 (IGFBP-3) system remains to be elucidated. Thus, this study was conducted to the effect of AtRA on the gene expression and level of IGF-I and IGFBP-3. In addition, we investigated the involvement of PKC-${\delta}$ on the IGF-I and IGFBP-3 secretion in MCF-7 cell. AtRA(${\geq}10^{-7}M$) decreased the IGF-1 secretion and mRNA expressions, but increased IGFBP-3 secretion and mRNA expressions in MCF-7 cells. Especially, the treatment of AtRA at 72 hours caused a significant reduction in the IGF-I secretion and mRNA expressions but increment in IGFBP-3 secretion and mRNA expressions (p < 0.05). $10^{-7}M$ AtRA activated PKC-${\delta}$ that is one among PKC-$\iota$, ${\alpha}$, ${\lambda}$ and ${\delta}$ in MCF-7 cell. Rotllerin, a PKC-${\delta}$ inhibitor, blocked AtRA-induced inhibition of the IGF-I and mRNA expressions, and increase of lGFBP-3 and mRNA expressions in MCF-7 cell. Together, AtRA inhibited the IGF-I secretion and mRNA expressions, but increased IGFBP-3 secretion and mRNA expressions in MCF-7 cell. Furthermore, AtRA-induced alteration of IGF-I, IGFBP-3 secretion, and the gene expressions were mediated via PKC-${\delta}$ activity.

• Journal of Animal Science and Technology
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• v.58 no.10
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• pp.37.1-37.10
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• 2016

Background: Providing of insufficient nutrients limits the potential growth of pig, while feeding of excessive nutrients increases the economic loss and causes environment pollution. For these reasons, phase feeding had been introduced in swine farm for improving animal production. This experiment was conducted to evaluate the effects of dietary energy levels and phase feeding by protein levels on growth performance, blood profiles and carcass characteristics in growing-finishing pigs. Methods: A total of 128 growing pigs ([Yorkshire ${\times}$ Landrace] ${\times}$ Duroc), averaging $26.62{\pm}3.07kg$ body weight, were assigned in a $2{\times}4$ factorial arrangement with 4 pigs per pen. The first factor was two dietary energy level (3,265 kcal of ME/kg or 3,365 kcal of ME/kg), and the second factor was four different levels of dietary protein by phase feeding (1growing(G)-2finishing(F) phases, 2G-2F phases, 2G-3F phases and 2G-3F phases with low CP requirement). Results: In feeding trial, there was no significant difference in growth performance. The BUN concentration was decreased as dietary protein level decreased in 6 week and blood creatinine was increased in 13 week when pigs were fed diets with different dietary energy level. The digestibility of crude fat was improved as dietary energy levels increased and excretion of urinary nitrogen was reduced when low protein diet was provided. Chemical compositions of longissimus muscle were not affected by dietary treatments. In backfat thickness ($P_2$) at 13 week, pigs fed high energy diet had thicker backfat thickness (P = 0.06) and pigs fed low protein diet showed the trend of backfat thinness reduction (P = 0.09). In addition, water holding capacity was decreased (P = 0.01) and cooking loss was increased (P = 0.07) as dietary protein level reduced. When pigs were fed high energy diet with low subdivision of phase feeding, days to 120 kg market weight was reached earlier compared to other treatments. Conclusion: Feeding the low energy diet and subdivision of growing-finishing phase by dietary protein levels had no significant effect on growth performance and carcass characteristics. Also, phase feeding with low energy and low protein diet had no negative effects on growth performance, carcass characteristics but economical profits was improved.

• Development and Reproduction
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• v.6 no.1
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• pp.31-35
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• 2002

The major urinary proteins(MUPs) of mice that bind hydrophobic molecules known as pheromones are regulated in part by the actions of growth hormone. The expression of the MUPs was therefore investigated in transgenic mice that express a human growth hormone-releasing factor gene from a metallothionein gene promoter(MT-GRF) and as a result have elevated growth hormone levels. MUPs were severely down-regulated in the urine of these animals compared to normal mice or to control transgenic mice expressing another gene(the inhibin a subunit) from the same metallothionein promoter(MT-Inh) and more MUPs disappeared in male mice than female ones. MUPs were also down-regulated in the urine of the UT-GRF-injected mice. In addition, it was observed that the urine of the MT-GRF mice included a high molecular weight protein that co-migrates with the major serum protein albumin, indicating an impairment in glomerular filtration within the kidney. The urinary loss of serum proteins was more severe in male MT-GRF mice than female ones. Thus the overexpression of human GRF mimics changes observed in MUP protein expression and glomerular function in other models of growth hormone hypersecretion with sex-dependent differential effects.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.239-241
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• 2003

Several nutrients in feed are needed for growth and maintenance of fish and protein among them is probably the most important factor influencing its growth and determining feed cost due to high Proportion. Besides, dietary energy level is critical because protein source in the feed was utilized as energy source when the feed deficient in energy was fed to fish, whereas when the feed excess in energy was fed to fish, feed consumption decreased and resulted in growth reduction due to lack of necessary other nutrients for the normal growth (Lovell 1989). (omitted)

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.267-282
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• 2000

Cytochrome P45O (CYP) 2E1 catalyzes the metabolism of a wide variety of therapeutic agents, procarcinogens, and low molecular weight solvents. CYP2E1-catalyzed metabolism may cause toxicity or DNA damage through the production of toxic metabolites, oxygen radicals, and lipid peroxidation. CYP2E1 also plays a role in the metabolism of endogenous compounds including fatty acids and ketone bodies. The regulation of CYP2E1 expression is complex, and involves transcriptional, post-transcriptional, translational, and post-translational mechanisms. CYP2E1 is transcriptionally activated in the first few hours after birth. Xenobiotic inducers elevate CYP2E1 protein levels through both increased translational efficiency and stabilization of the protein from degradation, which appears to occur primarily through ubiquitination and proteasomal degradation. CYP2E1 mRNA and protein levels are altered in response to pathophysiologic conditions by hormones including insulin, glucagon, growth hormone, and leptin, and growth factors including epidermal growth factor and hepatocyte growth factor, providing evidence that CYP2E1 expression is under tight homeostatic control.

• BMB Reports
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• v.37 no.2
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• pp.153-158
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• 2004

The acid-labile subunit (ALS) is known to interact with the IGF binding protein (IGFBP) in the presence of insulin-like growth factors (IGFs). Studies, however, indicate that ALS forms a doublet with IGFBP3, independent of IGFs. To characterize the structural domain required for the IGF-free ALS-IGFBP3 interaction, seven recombinant human IGFBP3 mutants were generated: three deletion mutants and four site-specific mutants that had altering N-terminal regions of IGFBP3. ALS and IGFBP3 mRNAs were co-injected into Xenopus oocytes, and their products were cross-linked and immunoprecipitated using antisera against ALS or IGFBP3. Among the deletion mutants, the mutant of D40 (deleted in 11-40th amino acids) exerted no effect in the interaction with ALS, while D60 (${\Delta}11$-60) demonstrated a moderate reduction. D88 (${\Delta}11$-88), however, showed a significant decrease. In the case of site-specific mutants, the mutation that alterated the IGF binding site (codons 56 or 80) exerted a significant reduction in the interaction, whereas codons 72 or 87 showed no significant change in the interaction with ALS. The stability of the ALS-IGFBP3 interaction was analyzed according to a time-dependent mode. Consistent with the binding study, mutants on the IGF binding sites (56 or 80) consistently show a weakness in the ALS-IGFBP3 interaction when compared to the mutants that covered the non-IGF binding sites (72 or 87). This study suggests that the N-terminal of IGFBP3, especially the IGF binding site, plays an important role in interacting with ALS as well as in stabilizing the dual complex, independent of IGFs.