• KSBB Journal
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• v.23 no.3
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• pp.205-212
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• 2008

The efficient soluble expression of human epidermal growth factor (hEGF) was achieved by using functional fusion partners in cytoplasm and periplasm of Escherichia coli (E. coli). hEGF was over-expressed in inactive inclusion body form in cytoplasm of E. coli due to improper disulfide bond formation and hydrophobic interaction, yielding about 5.9 mg/L in flask culture. Six functional fusion partners were introduced by linking to N-terminal part of hEGF gene for the high-level expression of soluble and active hEGF in cytoplasm and peri plasm region. Three fusion partners for cytoplasmic expression such as acidic tail of synuclein (ATS), thioredoxin (Trx) and lipase, and three fusion partners for periplasmic expression such as periplasmic cystein oxidoreductases (DsbA and DsbC) and maltose binding protein (MBP) were investigated. hEGF fused with ATS and DsbA showed over 90% of solubility in cytoplasm and periplasm, respectively. Especially DsbA was found to be an efficient fusion partner for soluble and high-level expression of hEGF, yielding about 18.1 mg/L and three-fold higher level compared to that of insoluble non-fusion hEGF in cytoplasm. Thus, heterologous proteins containing complex disulfide bond and many hydrophobic amino acids can effectively be produced as an active form in E. coli by introducing a suitable peptide or protein.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.197-203
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• 2001

A fusion protein, consisting of human epidermal growth factor as a recognition domain and human angiogenin as a toxin domain, can be used as a targeted therapeutic against breast cancer cells among others. The fusion protein was expressed as inclusion body in recombinant E. coli, and when the conventional, solution-phase refolding process was used the refolding yield was very low due to severe aggregation, probably due to the opposite surface charge due to vastly different pI values of each domain. Solid-phase refolding process exploiting ionic interactions between the solid matrix and the protein was tried, but the ionic binding yield was very low regardless of the resins and pH conditions used. To provide higher affinity toward the solid matrix, six lysine residues were tagged to the N -terminus of the hEGF domain When the cation exchange resins such as heparin- or CM-Sepharose were used as the matrix, the adsorption capacity increased 2.5-3 times and the subsequent refolding yield increased nearly IS times compared to the conventional process.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.1-5
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• 2002

A fusion protein, consisting of a human epidermal growth factor (hEGF) as the recognition domain and human angiogenin as the toxin domain, can be used as a targeted therapeutic against breast cancer cells among others. The fusion protein was expressed as inclusion body in recombinant E. coli, and when the conventional, solution-phase refolding process was used the refolding yield was very low due to severe aggregation. It was probably because of the opposite electric charge at a neutral pH resulting from the vastly different pI values of each domain. The solid-phase refolding process that exploited the ionic interactions between ionic exchanger surface and the fusion protein was tried, but the adsorption yield was also very low, below $ 30\%$, regardless of the resins and pH conditions used. Therefore, to provide a higher ionic affinity toward the solid matrix, six lysine residues were tagged to the N-terminus of the hEGF domain. When heparin-Sepharose was used as the matrix, the adsorption capacity increased 2.5-3 times to about $88\%$. Besides the intrinsic affinity of angiogenin to heparin, the poly-lysine tag provided additional ionic affinity. And the subsequent refolding yield increased nearly 13-fold, from ca. $4.8\%$ in the conventional refolding of the untagged fusion protein to $63.6\%$. The process was highly reproducible. The refolded protein in the column eluate retained RNase bioactivity of angiogenin.

• KSBB Journal
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• v.13 no.3
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• pp.295-302
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• 1998

Human Erythropoietin (EPO) gene is cloned in quail fibrosarcoma cell, QT35. Because molecular weight of EPO is similar to that of serum albumin, cell culture with serum containing medium makes purification of EPO very difficult. Using fractional factorial study, we have developed serum free medium for the recombinant QT35 cell lines, QT N4D4 and QT SY-IMP, which have cloned EPO with glutamine synthetase (GS) gene amplification system and with puromycin selective marker, respectively. Among the seven frequently used medium components, fibronectin, BSA, and EGF were the most important for EPO production. However, sufficient fibronectin supplement to the medium did not make any good attachment of QT35 to culture plate over 3 days. Therefore, to maximize EPO production, we attempted a medium-shift at confluence from serum containing medium to serum free medium(QT SFM6). Using the medium-shift protocol with QT SFM6, nearly the same productivity of EPO was achieved comparing with that without medium-shift. This result was true in both QT35 cell lines in three types of culture, i.e. T flask, microcarrier and roller bottle cultures.

• KSBB Journal
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• v.17 no.2
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• pp.153-157
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• 2002

A fusion protein, consisting of a human epidermal growth factor as the recognition domain and human angiogenin as the toxin domain, can be used as a targeted therapeutic against breast cancer cells among others. The fusion protein was expressed as an inclusion body in recombinant E. coli, yet when the conventional solution-phase refolding process was used the refolding yield was very low due to severe aggregation, probably because of the opposite surface charge resulting from the vastly different pl values of each domain. Accordingly the solid-phase refolding process, which exploits the ionic interactions between a solid matrix and the protein, was tried, however the ionic binding yield was also very low regardless of the resins and pH conditions used. Therefore, to provide a higher affinity toward the solid matrix, six Iysine residues were tagged to the N-terminus of the hEGF domain. When cation exchange resins, such as heparin- or CM-Sepharose, were used as the matrix, the adsorption capacity increased 2.5~3-fold and the subsequent refolding yield increased nearly 15-fold compared to the conventional process. A similat result was also obtained when an Ni-NTA metal affinity resin was used.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.145-150
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• 2009

This study was conducted to examine the effects of human follicular fluid and gonadotropin (FSH+HCG+rhEGF) on in vitro maturation, fertilization and development of human immature oocytes. Cumulus-oocyte complexes (COCs) were collected following for in vitro fertilization and embryo transfer (IVF-ET) cycles of the patients. At the time of oocytes collection, oocytes were classified into MII, MI and GV in accordance with their appearance (MII: Fully mature oocyte at metaphase II of meiosis; MI: Nearly mature oocytes at metaphase I of meiosis; GV: Immature oocytes at prophase I of meiosis). After controlled ovarian stimulation using gonadotropin(FSH) and human chorionic gonadotropin (HCG) in 70 ICSI cycles, 158 MI to MII matured oocytes were intracytoplasmic sperm injection (ICSI) ${\sim}4$ h after in vitro culture and 553 MII oocytes were ICSI after denudation. The aspirated MI and GV oocytes were cultured in culture medium containing 10% (v/v) serum protein substitute (SPS), 10% (v/v) human follicular fluid (hFF) and 10% (v/v) serum protein substitute (SPS)+1 IU/ml FSH+10 IU/ml HCG+10 ng/ml recombinant human epidermal growth factor (rhEGF). The maturation rate of immature oocytes was similar among the three group. When maturation medium was supplemented with 10% SPS, 10% hFF or gonadotropins, the fertilization rate of in vitro matured oocytes was higher in 10% SPS (80.0%), but there was no statistical significance (78.2%; hFF, 76.9%; gonadotropin, p>0.05). The development rate of human embryos developed to $6{\sim}8$ cells were not significant difference in the medium containing SPS, hFF and gonadotropins (65.6%, 65.9% and 66.7%). The results of these study suggest that human follicular fluid and gonadotropins supplemented in the culture medium was not effected on the in vitro maturation, fertilization and development of human immature oocytes.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.249-254
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• 2009

Objective: The aim of this study was to compare the fertilization and cleavage rates of human in vitro matured oocytes after fertilized by conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Methods: A total of 135 GV stage oocytes were obtained from 59 women who received ovarian stimulation and IVF during Jan 2007 to Oct 2008. Ovarian hyperstimulation was performed using hMG or recombinant FSH with GnRH antagonist and then ovulation triggered by recombinant hCG. The immature oocytes obtained from stimulation cycles were cultured in IVM medium up to 48 hrs; commercial medium supplemented with rFSH 75 mIU/mL, rhCG 0.5 IU/mL and rEGF 10 ng/mL. The in vitro matured oocytes were fertilized by conventional IVF (41 GV oocytes) or ICSI method (94 GV oocytes). Results: Maturation rate were 51.2% and 59.6% in conventional IVF group and ICSI group, respectively. There was no significant difference in fertilization rates between two groups; 71.4% and 80.4%, respectively. The cleavage rate was also similar in two groups. Conclusion: The presented data suggest that conventional IVF has comparable fertilization and cleavage potential compared with ICSI as the insemination method of immature human oocytes obtained from stimulated cycle.

• YAKHAK HOEJI
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• v.40 no.5
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• pp.491-500
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• 1996

The organ distribution and pharmacokinetics of DWP401, a recombinant human epidermal growth factor (rhEGF), were compared after single and repeated subcutaneous administration ( 50${\mu}$/kg, 10${\mu}g$Ci/kg of $^{125}I$-DWP401, twice a day for 7 consecutive days) to rats. The pharmacokinetic parameters such as AUC and terminal half-life were similar between two different administration. During repeated administration, the plasma concentration of DWP401 seemed to be constant when the plasma was collected at 15 min after each dosing. The TCA-precipitated radioactivities in thyroid, liver, kidney, and stomach were higher than those of other organs studied after both single and repeated administration. The TCA-precipitated radioactivities after repeated administration in several organs, such as thyroid, stomach, prostate, adrenal, eye ball, and testis were higher than those after single administration. But, according to the observations using gel filtration chromatography and antibody binding assay, the radioactivities in thyroid and stomach were not primarily due to the intact DWP401 or its metabolites but due to the $^{125}I$-thyroxine binding protein. In conclusion, it can be suggested that DWP401 is metabolized to each amino acid or small polypeptides, and there was no significant changes in pharmacokinetics or any indications for accumulation of DWP401 in rat plasma and organs after repeated treatment.

• BMB Reports
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• v.50 no.2
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• pp.58-59
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• 2017

The beneficial paracrine roles of mesenchymal stem cells (MSCs) in tissue repair have potential in therapeutic strategies against various diseases. However, the key therapeutic factors secreted from MSCs and their exact molecular mechanisms of action remain unclear. In this study, the cell-free secretome of umbilical cord-derived MSCs showed significant anti-fibrotic activity in the mouse models of liver fibrosis. The involved action mechanism was the regulation of hepatic stellate cell activation by direct inhibition of the $TGF{\beta}$/Smad-signaling. Antagonizing the milk fat globule-EGF factor 8 (MFGE8) activity blocked the anti-fibrotic effects of the MSC secretome in vitro and in vivo. Moreover, MFGE8 was secreted by MSCs from the umbilical cord as well as other tissues, including teeth and bone marrow. Administration of recombinant MFGE8 protein alone had a significant anti-fibrotic effect in two different models of liver fibrosis. Additionally, MFGE8 downregulated $TGF{\beta}$ type I receptor expression by binding to ${\alpha}v{\beta}3$ integrin on HSCs. These findings revealed the potential role of MFGE8 in modulating $TGF{\beta}$-signaling. Thus, MFGE8 could serve as a novel therapeutic agent for liver fibrosis.

• YAKHAK HOEJI
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• v.41 no.3
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• pp.328-334
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• 1997

Pharmacokinetics of DWP401, a recombinant human epidermal growth factor (rhEGF), was studied using radioimmunoassay (RIA) and $^{125}I$-DWP401 in rats. When DWP401 was adm inistered i.v. at doses of 50 and 500 mcg/kg, the plasma DWP401 disappeared biiexponentially with terminal half life of 4.7 and 92.8 min. The $C_{max}$ and $T_{max}$ after s.c. administration of ti at doses of 50 and 500 ${\mu}g$/kg were determined to be 23.6 and 17.5 ng/ml at 50 ${\mu}g$/kg, and 261.4 ng/ml and 36.8 min, respectively. Both the total urinary and biliary recoveries of intact DWP401 2343 very low (<0.4%), probably due to its extensive degradation in the body. the concentration ratio of DWP401 between the organ and plasma decreased especially in the liver and kidney as the dose and time after the dose increased. For example, the liver/plasma and kidney/plasma concentration ratio of DWP401 at 2.5 min after i.v. doses of 50 ${\mu}g$/kg were comparable and much larger than unity. But, the ratio at 2.5 min after i.v. doses of 500${\mu}g$/kg was much larger in the kidney that in than in the liver. These results suggest that the systemic administration of DWP401 might be subject to rapid and extensive clearance from circulation within several hour after main distrbution to liver and kidney.