Time filter

Source Type

Jeonju, South Korea

Shin Y.-J.,Jeonju Biomaterials Institute | Lee N.-J.,Chonbuk National University | Kim J.,Jeonju Biomaterials Institute | An X.-H.,CheBiGen Inc | And 2 more authors.
Enzyme and Microbial Technology

Human interleukin-12 (hIL-12), a heterodimeric cytokine comprised of p35 and p40 subunits, was generated previously via tobacco cell suspension culture at a maximum concentration of only 175 μg/L. In order to improve the productivity, the rice α-amylase 3D promoter (Ramy3D) was utilized in order to express recombinant protein at high levels under sucrose starvation conditions. The hIL-12 gene was cloned into the rice expression vector under the control of the Ramy3D promoter. Transgenic rice calli were prepared via particle bombardment-mediated transformation and were screened for rhIL-12p70 expression using ELISA. Western blot and bioassay results confirmed that rhIL-12p70 was expressed and secreted into the culture medium as a functionally active heterodimeric form, and the productivity of rhIL-12p70 was estimated as 12.7. mg/L, which is approximately 73-fold higher than was observed with the tobacco cell culture system [Kwon TH, Seo JE, Kim J, Lee JH, Jang YS, Yang MS. Expression and secretion of the heterodimeric protein interleukin-12 in plant cell suspension culture. Biotechnol Bioeng 2003;81:870-5]. However, the secreted rhIL-12p70 proved unstable in the medium, and degraded rapidly after day 13. In order to stabilize the secreted rhIL-12p70, three stabilizing polymers were tested (polyethylene glycol, polyvinylpyrrolidone, and gelatin). Gelatin was the most effective in stabilizing the secreted rhIL-12p70. After the addition of 2% (w/v) gelatin, the maximum rhIL-12p70 concentration reached 31.0. mg/L, representing a 2.5-fold increase over the control. © 2009 Elsevier Inc. Source

Lee S.-W.,Sejong University | Youn H.,Sejong University | Kim E.-J.,Dankook University | Um S.-J.,Sejong University | Um S.-J.,CheBiGen Inc
Molecular Cell

Despite the importance of retinoic acid (RA) signaling and histone monoubiquitination in determining cell fate, the underlying mechanism linking the two processes is poorly explored. We describe that additional sex comb-like 1 (ASXL1) represses RA receptor activity by cooperating with BRCA1-associated protein 1 (BAP1), which contains the ubiquitin C-terminal hydrolase (UCH) domain. Both the UCH- and ASXL1-binding domains of BAP1 were required for cooperation. In contrast to Drosophila BAP1, mammalian BAP1 cleaved ubiquitin from histone H2B. As supported by BAP1 mutants, ASXL1 was critical for BAP1 recruitment to chromatin and its activation therein. ASXL1 requirement was supported using Asxl1 null mice embryonic fibroblasts. Both ASXL1 and BAP1 were downregulated during RA-induced P19 cell differentiation with concomitant increase of ubiquitinated H2B, leading to activation of Hox genes. Our data demonstrate the critical role of ASXL1 cooperation with BAP1 in cell differentiation through the regulation of RA signaling associated with H2B ubiquitination. © 2013 Elsevier Inc. Source

Jang S.H.,Chonbuk National University | Kim S.H.,Chonbuk National University | Lee H.Y.,Chonbuk National University | Jang S.H.,CheBiGen Inc | And 7 more authors.
International Journal of Medicinal Mushrooms

Ophiocordyceps sinensis is a natural fungus that has been valued as a health food and traditional Chinese medicine for centuries. The fungus is parasitic and colonizes insect larva. Naturally occurring O. sinensis thrives at high altitude in cold and grassy alpine meadows on the Himalayan mountain ranges. Wild O. sinensis is becoming increasingly rare in its natural habitats, and its price is out of reach for clinical practice. For these reasons, development of a standardized alternative is a great focus of research to allow the use of O. sinensis as a medicine. To develop an alternative for wild O. sinensis, a refined standardized extract, CBG-CS-2, was produced by artificial fermentation and extraction of the mycelial strain Paecilomyces hepiali CBG-CS-1, which originated from wild O. sinensis. In this study, we analyzed the in vivo immune-modulating effect of CBG-CS-2 in mice. Oral administration of CBG-CS-2 supported splenocyte stimulation and enhanced Th1-type cytokine expression from the splenocytes. Importantly, the same treatment significantly enhanced the natural killer cell activity of the splenocytes. Finally, oral administration of CBG-CS-2 enhanced the potential for inflammatory responses. Together, these findings indicate that the mycelial culture extract prepared from O. sinensis exhibited immune-modulating activity and suggest its possible use in the treatment of diseases caused by abnormal immune function. © 2015 Begell House, Inc. Source

Byun S.,University of Minnesota | Byun S.,Seoul National University | Byun S.,Korea University | Shin S.H.,University of Minnesota | And 22 more authors.

Combination chemotherapy for the treatment of pancreatic cancer commonly employs gemcitabine with an EGFR inhibitor such as erlotinib. Here, we show that the retinoic acid derivative, ABPN, exhibits more potent anticancer effects than erlotinib, while exhibiting less toxicity toward noncancerous human control cells. Low micromolar concentrations of ABPN induced apoptosis in BxPC3 and HPAC pancreatic cancer cell lines, concomitant with a reduction in phosphorylated EGFR as well as decreased ErbB3, Met and BRUCE protein levels. The degradation of ErbB3 is a result of proteasomal degradation, possibly due to the ABPN-dependent upregulation of Nrdp1. Administration of ABPN showed significant reductions in tumor size when tested using a mouse xenograft model, with higher potency than erlotinib at the same concentration. Analysis of the tumors demonstrated that ABPN treatment suppressed ErbB3 and Met and induced Nrdp1 in vivo. The data suggest that ABPN may be more suitable in combination chemotherapy with gemcitabine than the more widely used EGFR inhibitor, erlotinib. © The Author 2015. Source

Park S.-Y.,Wonkwang University | Jung S.-J.,Chonbuk National University | Ha K.-C.,Healthcare Claims & Management Inc. | Sin H.-S.,CheBiGen Inc | And 3 more authors.
Oriental Pharmacy and Experimental Medicine

Cordyceps (CS) is a traditional Chinese herb with various biological effects that include immune modulation. CBG-CS-2 is a strain, Paecilomyces hepiali, of the Cordyceps spp. The anti-inflammatory effects of CBG-CS-2 were investigated. The water-soluble fraction of CBG-CS-2 has high anti-inflammatory activity in LPS-induced Raw264.7 macrophages. We tested the role of CBG-CS-2 on the anti-inflammation cascade in LPS-stimulated Raw264.7 cells. CBG-CS-2 significantly decreased NO production, iNOS expression, and pro-inflammatory cytokine secretion in a dose-dependent manner. To investigate the mechanism by which CBG-CS-2 inhibits NO, iNOS, and pro-inflammatory cytokines, we examined the activities of NF-κB and AP-1 in LPS-activated macrophages. The results demonstrate that CBG-CS-2 suppresses the production and expression of NO, iNOS, and pro-inflammatory cytokines in LPS-activated macrophages via inhibition of NF-κB and AP-1, which may play an important role in inflammation. These findings suggest that CBG-CS-2 has modulatory effects on the inflammatory system in macrophages, and that it can serve as a useful anti-inflammatory dietary supplement or drug. © 2014, The Author(s). Source

Discover hidden collaborations