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중간엽줄기세포 증식을 위한 누에 실샘 유래 무혈청 배지 첨가제
차현명 ( Hyun Myoung Cha ),김선미 ( Sun Mi Kim ),최용수 ( Yong Soo Choi ),박지성 ( Ji Sung Park ),임진혁 ( Jin Hyeok Lim ),황슬기 ( Seul Gee Hwang ),김동일 ( Dong Il Kim ) 한국조직공학과 재생의학회 2015 조직공학과 재생의학 Vol.12 No.1s
Mesenchymal stem cells (MSCs) are must be cultured in chemically defined, xeno-free culture system for cell-based therapies. One major overcome for their clinical use is the unsafety of fetal bovine serum (FBS), which is a crucial part of all media currently used for the culture of MSCs. Previously, we developed novel methods the production of silkworm gland hydrolysate (SGH). Also, we showed the effect of the SGH on the cell growth promotion. We demonstrated whether the characteristics of MSCs were maintained in the serum-free media containing SGH during long-term cultivation. The results of microscopic observation showed that the morphology of stem cells were not different between the media containing 10% FBS and 1 mg/mL SGH. After the long-term culture of MSCs in serum-free media containing SGH, the rate of MSCs growth was well maintained. The analysis of anti-apoptotic effect of SGH showed that early apoptosis of MSCs was reduced by 3.7-fold. Furthermore, MSCs specific surface markers and stemness gene expression (Nanog, Sox2) were preserved as that of MSCs in the media containing 10% FBS. In conclusion, we demonstrate that the SGH can be used as useful supplement for MSCs cultivation in serumfree media.
형질전환 Chinese Hamster Ovary 세포에서 Albumin-erythropoietin의 생산시 Silkworm Gland Hydrolysate의 효과
최민호(Min-Ho Choi),차현명(Hyun-Myoung Cha),김선미(Sun-Mi Kim),최용수(Yong-Soo Choi),김동일(Dong-Il Kim) 한국생물공학회 2013 KSBB Journal Vol.28 No.2
To date, various strategies have been studied to increase specific productivity in Chinese hamster ovary (CHO) cell cultures. Also, albumin-fusion platform is being applied to other important bioactive peptides with short half-lives. Here, we investigated the effects of silkworm gland hydrolysate (SGH) on the production of albumin-erythropoietin (Alb-EPO) in transgenic CHO cells. The viable cell density of CHO cells was increased by 13% in the medium containing 1 mg/mL SGH higher than in the control medium without SGH. In addition, the production of Alb-EPO was also 1.26-fold enhanced by reducing the early apoptosis of CHO cells. In conclusion, SGH could be used as a useful supplement for the enhancement of recombinant protein production.
α2,6-Sialyltransferase 과발현을 통한 인간형 시알산 부가 hCTLA4-Ig 생산 CHO 세포주 제작
임진혁(Jin-Hyuk Lim),차현명(Hyun-Myoung Cha),박혜진(Heajin Park),김하형(Ha Hyung Kim),김동일(Dong-Il Kim) 한국생물공학회 2017 KSBB Journal Vol.32 No.3
Sialylation is important in producing therapeutic proteins such as antibody, cytokine and fusion protein. Thus, enhancement of sialylation is usually performed in CHO cell cultures. α2,6-Sialyltransferase (ST), which plays a key role in the attachment of α2,6-sialic acid, is present in human cells but not in Chinese hamster ovary (CHO) cells. Overexpression of α2,6-ST can be used for enhancing the degree of sialylation and achieving human-like glycosylation. In this study, we constructed CHO cells producing human cytotoxic T-lymphocyte antigen4-immunoglobulin (hCTLA4-Ig) as well as α2,6- ST. Transfected CHO cells were selected using G418 and stable cell line was established. Profiles of viable cell density and hCTLA4-Ig titer in an overexpressed cell line were similar to those of a wild-type cell line. It was confirmed that the total amount of sialic acid was increased and α2,6-sialic acid was attached to the terminal residues of N-glycan of hCTLA4-Ig by ESI-LC-MS. Compared to 100% of α2,3-sialic acid in wild type cells, 70.9% of total sialylated N-glycans were composed of α2,6-sialic acid in transfected cells. In conclusion, overexpression of α2,6-ST in CHO cells led to the increase of both the amount of total sialylated N-glycan and the content of α2,6- sialic acid, which is more resemble to human-like structure of glycosylation.
CHO 세포 배양을 통한 Recombinant Human Erythropoietin의 생산에서 저혈청 배지와 배양 첨가물질이 미치는 영향
이경선(Kyung-Sun Lee),차현명(Hyun-Myoung Cha),임진혁(Jin-Hyuk Lim),김동일(Dong-Il Kim) 한국생물공학회 2017 KSBB Journal Vol.32 No.2
Mammalian cell cultures have been used extensively to produce proteins for therapeutic agent because of their ability to perform post-translational modification including glycosylation. To produce recombinant protein, many factors and parameter are considered such as media composition, host cell type, and culture process. In this study, recombinant human erythropoietin (rhEPO) producing cell line was established by using glutamine synthetase system. To reduce serum concentration in media, we compared direct adaptation with step adaptation. Cell growth was faster in step adaptation. In low-level serum media, there were insufficient glucose for cell growth. Thus, we added glucose in low-level serum media from 2 g/L to 4.5 g/L. Titer of rhEPO was higher than other conditions at 4.5 g/L of glucose. Additionally, Nmethyl-D-aspartate (NMDA), 13-cis-retinal, and pluronic F-68 (PF-68) were added to enhance productivity in CHO cell cultures. In conclusion, we applied CHO cell producing rhEPO to low-level of serum in media using step-adaptation. Also, we confirmed positive effect of NMDA, 13-cis-retinal, and PF-68.
CHO 세포에서 누에 혈림프 유래 Storage-protein 2의 세포응집 및 세포사멸 억제 효과
임진혁(Jin-Hyuk Lim),차현명(Hyun-Myoung Cha),김지훈(Z-Hun Kim),최용수(Yong-Soo Choi),김동일(Dong-Il Kim) 한국생물공학회 2016 KSBB Journal Vol.31 No.1
Chinese hamster ovary (CHO) cells have been widely used for production of various recombinant proteins such as cytokines and monoclonal antibodies. The cell aggregation and cell death in CHO cell culture directly affect cell viability, and productivity and quality of products. In this study, we investigated preventing effects of storage-protein 2 (SP2) derived from silkworm hemolymph on cell aggregation and cell death in CHO cell culture producing albumin-erythropoietin (Alb-EPO). The viable cell density in the culture supplemented with 2 mg/mL SP2 was 1.71-fold higher than that in control culture. Increased titer of Alb-EPO was also found in the culture with SP2. Morphology of CHO cells in SP2 supplemented cultures did not differ from that of control. In addition, the cell aggregation rate of the SP2 cultures was reduced 20% compared to the control. Finally, we confirmed that the apoptosis was strongly suppressed by addition of SP2 in the cultures. These results clearly demonstrate that SP2 can be served as an effective supplement for enhancing titer of Alb-EPO via reducing cell aggregation and cell death.
연골세포와 중간엽줄기세포의 3차원 Co-culture를 통한 연골화 향상
황슬기(Seul-Gee Hwang),차현명(Hyun-Myoung Cha),임진혁(Jin-Hyuk Lim),이지희(Ji-Hee Lee),심혜은(Hye-Eun Shim),김동일(Dong-Il Kim) 한국생물공학회 2016 KSBB Journal Vol.31 No.2
Two-dimensional cultivation is typically used for cell growth, but the method reduces the characteristics of chondrocytes and stem cells, and limits culture area. Therefore, development of three-dimensional culture method is needed to mimic in vivo environment, improve quality of cells and scale-up efficiently. Improving proliferation and chondrogenesis is available by co-culture of chondrocytes and mesenchymal stem cells (MSCs) that leads to interaction between two kinds of cells. However, the co-culture has problems that permeability of sphere diminishes as aggregate size increased and ratio of two kinds of cells composing each spheres is different. In this work, co-cultivation method using controlled sphere composed of chondrocytes and MSCs was established and enhanced chondrogenesis. Periosteum-derived progenitor cells (PDPCs) that are appropriate for cell therapy source of articular cartilage were used as MSCs. Controlled spheres were formed in the hanging-drop plates and shifted for being induced chondrogenesis in 35-mm non-adhesive culture dishes at a rotation rate of 60 rpm. After inducing chondrogenesis, gene expressions related with chondrogenesis were found to be improved and it was apparent that the utilization of controlled spheres promoted chondrogenesis. As a result, available numbers of cells per unit area were increased and chondrogenic differentiation ability was improved compared to typical two-dimensional culture. This approach shows the potential in cartilage regeneration as it can provide sufficient numbers of chondrocytes.
유전자재조합 CHO 세포에서 Histone Deacetylase Inhibitor를 이용한 Albumin-erythropoietin 생산성 증진
김수진(Su-Jin Kim),서준석(Joon-Serk Seo),최성훈(Sung-Hun Choi),차현명(Hyun-Myoung Cha),임진혁(Jin-Hyuk Lim),신수아(Soo-Ah Shin),김동일(Dong-Il Kim) 한국생물공학회 2015 KSBB Journal Vol.30 No.1
Chinese hamster ovary (CHO) cells are the most widely used mammalian host for the commercial production of recombinant proteins. However, they show relatively low yields of recombinant proteins in comparison with microbial cells. Various strategies have been tried to overcome this drawback. The acetyl moieties are attached to the N-terminus of histone by histone acetyltransferase (HAT) while histone deacetylase (HDAC) removes histone-bound acetyl groups. HDAC inhibitor (HDACi), such as sodium butyrate, sodium propionate and valproic acid, can enhance specific productivity of CHO cells. Human albumin-erythropoietin (Alb-EPO) is a novel 105 kDa protein comprising recombinant human EPO fused to human albumin. In this study, we examined the effects of HDACi on the production of Alb-EPO in CHO cells with various concentrations in the range of 0-1 mM. The results showed that sodium butyrate was found to be the best HDACi for enhancing productivity. It enhanced not only the production of Alb-EPO but also the apoptosis of recombinant CHO cells.
정지혜(Ji-Hye Jung),황정욱(Jung Wook Hwang),김호진(Hojin Kim),차현명(Hyun-Myoung Cha),김동일(Dong-Il Kim),최용수(Yong-Soo Choi) 한국생물공학회 2013 KSBB Journal Vol.28 No.3
Silkworm-derived silk materials which contain 45 to 55% protein (18 amino acids, including 8 essential amino acids) have free radical-scavenging activities. In the present study, we investigated the whitening and anti-aging effects of silkworm gland under various conditions with B16F1 melanoma cells and human dermal fibroblasts. To evaluate the toxicity of soluble gland hydrolysate (SGH), mouse-derived B16F1 melanoma cells were treated with 0.2~5 mg/mL, cytotoxicity was not observed at all concentrations. The tyrosinase and elastase activities were significantly decreased as dosage levels of SGH increased. In addition, cell death was decreased by treated with SGH and antioxidative activity was the most effective in the SGH treatment. These findings suggest that SGH may be used as a potential functional biomaterial in having the skin whitening effect and anti-aging activity by inhibition of tyrosinase and elastase activities.
CHO 세포 배양에서 UDP-N-acetylglucosamine의 합성 증진을 통한 albumin-erythropoietin의 시알산 증대
한혜진(Hye-Jin Han),이지희(Ji-Hee Lee),차현명(Hyun-Myoung Cha),임진혁(Jin-Hyuk Lim),김동일(Dong-Il Kim) 한국생물공학회 2021 KSBB Journal Vol.36 No.1
Sialylation is a major factor to determine half-life of glycoproteins and sialic acid content of glycoprotein was effectively increased by supplementation of nucleotide sugar precursors during cell cultures. So it is necessary to investigate the effect on glycan may be different when two or more precursors are fed in combination. Albumin-erythropoietin (Alb-EPO) can form a tetra-antennary structure and up to 14 sialic acids can be attached depending on the antennary structure of glycan. It is possible to increase the sialic acid contents of Alb-EPO by promoting the formation of the antennary structure of glycans. In this study, uridine and N-acetylglucosamine (GlcNAc) were added to Chinese hamster ovary (CHO) cell cultures to enhance the synthesis of uridine diphosphate N-acetylglucosamine (UDP-GlcNAc). Also, manganese ion, which is a cofactor of glycosyltransferases or UDPGlcNAc biosynthesis, was added in the form of MnCl₂. By optimizing the feeding concentrations of uridine and GlcNAc with response surface methodology based on central composite design to reduce the negative impact on cell growth and productivity. Cell growth was observed similar and then productivity and sialic acid content of Alb-EPO were enhanced 1.21-fold and 1.69-fold higher than that of the control, respectively. These results suggest that the combined feeding of uridine, GlcNAc, and MnCl₂ is an effective strategy to enhance the sialic acid content of glycoproteins in CHO cell cultures.
CHO 세포의 2단계 배양을 통한 Albumin-erythropoietin의 시알산 증대
임진혁(Jin-Hyuk Lim),신수아(Soo-Ah Shin),차현명(Hyun-Myoung Cha),김동일(Dong-Il Kim) 한국생물공학회 2016 KSBB Journal Vol.31 No.4
In glycoprotein, Terminal sialic acid residues of Nlinked glycan are imperative things because they prevent the recognition from asialoglycoprotein-receptor that affect the half-life of glycoproteins. So establishment of culture process for enhancing sialic acid is important to maximize sialic acid contents of glycoprotein. In this study, we investigated effects of biphasic culture of Chinese hamster ovary (CHO) cells producing albumin-erythropoietin to increase sialylation. Biphasic cultures were performed with shift of CO₂ concentrations and temperatures at day 5 when viable cell density was decreased and sialidase was started to be released by cell lysis. The examined temperature set points were 33, 35 and 37℃ respectively and the CO₂ concentration was 1, 5, 10 and 15%. We confirmed that sialidase activity was the lowest in biphasic culture that was shifted from normal culture condition to 1% of CO₂ and 33℃ on day 5. However, the temperature and concentration of CO₂ have little effect on activity of α2,3-sialyltransferase. Also, sialic acid contents were enhanced 1.13-fold higher than that in control culture. In conclusion, Biphasic cultivation in CHO cells led to inhibition of sialidase activity and increases of sialylated glycan.