• Biomolecules & Therapeutics
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• 제14권2호
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• pp.110-113
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• 2006

We tested effect of sarcotride A, a bioactive cyclitol derivative from a marine sponge, on membrane potential in C6 glioma cells. Membrane potential was estimated by measuring fluorescence change of DiBAC-loaded glioma cells. Sarcotride A increased membrane potential in a concentration-dependent manner. We tested effects of pertussis toxin, U73122, EIPA, and $Na^+-free$ media on sarcotride A-induced increase of membrane potential to investigate involvement of G proteins, phospholipase C, $Na^+/H^+$ exchanger, and $Na^+$ channels. However, we were not able to observe any significant effect of those pharmacological inhibitors, excluding the involvement of the molecules as candidate targets or signaling molecules of sarcotride A-induced increase of membrane potential. Further investigation is necessary to elucidate action mechanism of sarcotride A.

• Molecules and Cells
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• 제45권5호
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• pp.284-290
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• 2022

Exosome, a type of nanoparticles also known as small extracellular vesicles are gaining attention as novel therapeutics for various diseases because of their ability to deliver genetic or bioactive molecules to recipient cells. Although many pharmaceutical companies are gradually developing exosome therapeutics, numerous hurdles remain regarding manufacture of clinical-grade exosomes for therapeutic use. In this mini-review, we will discuss the manufacturing challenges of therapeutic exosomes, including cell line development, upstream cell culture, and downstream purification process. In addition, developing proper formulations for exosome storage and, establishing good manufacturing practice facility for producing therapeutic exosomes remains as challenges for developing clinical-grade exosomes. However, owing to the lack of consensus regarding the guidelines for manufacturing therapeutic exosomes, close communication between regulators and companies is required for the successful development of exosome therapeutics. This review shares the challenges and perspectives regarding the manufacture and quality control of clinical grade exosomes.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.183-183
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• 2006

Hyaluronic acid and chitosan-based poly(ethylene oxide) (HA-PEO and Chitosan-PEO) hydrogels have been employed as unique biomedical polymeric materials with properties such as bioactivity from polysaccharide, biocompatibility of HA and chitosan as well as PEO and control release of bioactive molecules from the hydrogel itself. We here examine in situ hydrogels based on hyaluronic acid and chitosan in terms of their synthesis, mechanical properties, morphologies and in vitro cellular interactions on their surface and inside. In vivo bone regeneration of HA-PEO and Chitosan-PEO hydrogels was compared with in mouse model.

• Molecules and Cells
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• 제28권6호
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• pp.545-551
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• 2009

Mitogen-activated protein kinases (MAPK) affect the activation of activator protein-1 (AP-1), which plays an important role in regulating a range of cellular processes. However, the roles of these signaling factors on hydrogen peroxide ($H_2O_2$)-induced cell death are unclear. This study examined the effects of $H_2O_2$ on the activation of MAPK and AP-1 by exposing the cells to $H_2O_2$ generated by either glucose oxidase or a bolus addition. Exposing BJAB or Jurkat cells to $H_2O_2$ affected the activities of MAPK differently according to the method of $H_2O_2$ exposure. $H_2O_2$ increased the AP-1-DNA binding activity in these cells, where continuously generated $H_2O_2$ led to an increase in mainly the c-Fos, FosB and c-Jun proteins. The c-Jun-$NH_2$-terminal kinase (JNK)-mediated activation of c-Jun was shown to be related to the $H_2O_2$-induced cell death. However, the suppression of $H_2O_2$-induced oxidative stress by either JNK inhibitor or c-Jun specific antisense transfection was temporary in the cells exposed to glucose oxidase but not to a bolus $H_2O_2$. This was associated with the disruption of death signaling according to the severe and prolonged depletion of reduced glutathione. Overall, these results suggest that $H_2O_2$ may decide differently the mode of cell death by affecting the intracellular redox state of thiol-containing antioxidants, and this depends more closely on the duration exposed to $H_2O_2$ than the concentration of this agent.

• Journal of Ginseng Research
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• 제46권2호
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• pp.304-314
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• 2022

Background: Ginsenosides are biologically active components of ginseng and have various functions. In this study, we investigated the immunomodulatory activity of a ginseng product generated from ginseng powder (GP) via enzymatic bioconversion. This product, General Bio compound K-10 mg solution (GBCK10S), exhibited increased levels of minor ginsenosides, including ginsenoside-F1, compound K, and compound Y. Methods: The immunomodulatory properties of GBCK10S were confirmed using mice and a human natural killer (NK) cell line. We monitored the expression of molecules involved in immune responses via enzyme-linked immunosorbent assay, flow cytometry, NK cell-targeted cell destruction, quantitative reverse-transcription real-time polymerase chain reaction, and Western blot analyses. Results: Oral administration of GBCK10S significantly increased serum immunoglobulin M levels and primed splenocytes to express pro-inflammatory cytokines such as interleukin-6, tumor necrosis factor-α, and interferon-γ. Oral administration of GBCK10S also activated NK cells in mice. Furthermore, GBCK10S treatment stimulated a human NK cell line in vitro, thereby increasing granzyme B gene expression and activating STAT5. Conclusion: GBCK10S may have potent immunostimulatory properties and can activate immune responses mediated by B cells, Th1-type T cells, and NK cells.

• BMB Reports
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• 제46권6호
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• pp.328-333
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• 2013

Many bioactive molecules like recombinant human bone morphogenetic protein 2 (rhBMP-2) have been developed for mineralized bone grafts, for which proper scaffolds are necessary to successfully apply the bioactive molecules. In this study, we tested the osteogenic efficacy of rhBMP-2 produced in-house in combination with gelatin sponge as the scaffold carrier in a rabbit radial defect model. The efficacy of the rhBMP-2 was determined by alkaline phosphatase activity assay of C2C12 cells. Two groups of ten rabbits each were treated with rhBMP-2/gelatin sponge, or gelatin sponge only. At 4 weeks, rhBMP-2/gelatin sponge grafts showed more bone regeneration than gelatin sponge grafts, as determined by X-ray radiography, micro-computed tomography, and histological analyses. At 8 weeks, rhBMP-2/gelatin sponge grafts exerted much stronger osteogenic effects. The study demonstrates the improved osteogenic efficacy of the rhBMP-2/gelatin sponge grafts in a rabbit radial bone defect model acting as a bone-inductive material.

• Korean Chemical Engineering Research
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• 제61권2호
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• pp.287-295
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• 2023

Iron nanoparticles (Fe-NPs) were synthesized employing Lagenaria siceraria (LS) leaf aqueous extract as a reducing and capping medium to remove methylene blue (MB) dye and have antibacterial properties against G-negative (Escherichia coli) and G-positive bacteria (Staphylococcus aureus). The formation of LS-Fe-NPs (Lagenaria-siceraria-iron-nanoparticles) was confirmed by a change in color from pale yellow to dark brown. Characterization techniques, such as particle size analysis (PSA), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), were employed to prove nano spherical particles of size range between 80-100 nm. Phytochemicals and the presence of iron in LS-Fe-NPs nanoparticles were proved by UV-visible spectrophotometry. Further, Fourier transform infrared spectroscopy (FTIR) analysis results confirmed the existence of bioactive molecules in the plants. The magnetic property was analyzed using a vibrating sample magnetometer (VSM), which displayed that the synthesized nanoparticles were superparamagnetic and exhibiting a saturation magnetization of 12.5 emu/g. Synthesized magnetic nanoparticles were used in methylene blue (MB) dye removal through adsorption. About 83% of 100 mg/L MB dye was removed within 120 min at pH 6 with a maximum adsorption capacity of 246.8 mg/g. Antibacterial efficacy of LS-Fe-NPs was screened against G-negative (Escherichia coli) and G-positive bacteria (Staphylococcus aureus), respectively, and found that LS-Fe-NPs were effective against Staphylococcus aureus.

• Natural Product Sciences
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• 제23권3호
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• pp.157-161
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• 2017

Reserpine is a well-known medicine for the treatment of hypertension, however the role of reserpine in cell signaling is not fully understood. Here, we report that reserpine treatment induces the phosphorylation of AMP activated protein kinase (AMPK) at threonine 172 (T172) in PC12 cells. Phosphorylation of AMPK T172 is regulated by upstream signaling molecules, and the increase of phospho-T172 indicates that AMPK is activated. When we examined the FOXO3a dependent transcription by using the FHRE-Luc reporter assay, reserpine treatment repressed the FHRE-Luc reporter activity in a dose dependent manner. Finally, we showed that reserpine treatment induced the phosphorylation of AMPK as well as cell death in MCF-7 cells. These results suggest that AMPK is a potential cellular target of reserpine.

• IMMUNE NETWORK
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• 제15권1호
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• pp.44-49
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• 2015

Interactions between microbes and epithelial cells in the gastrointestinal tract are closely associated with regulation of intestinal mucosal immune responses. Recent studies have highlighted the modulation of mucosal immunity by microbe-derived molecules such as ATP and short-chain fatty acids. In this study, we undertook to characterize the expression of the ATP-gated $P2X_7$ receptor ($P2X_7R$) on M cells and its role in gastrointestinal mucosal immune regulation because it was poorly characterized in Peyer's patches, although purinergic signaling via $P2X_7R$ and luminal ATP have been considered to play an important role in the gastrointestinal tract. Here, we present the first report on the expression of $P2X_7R$ on M cells and characterize the role of $P2X_7R$ in immune enhancement by ATP or LL-37.

• Journal of Microbiology and Biotechnology
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• 제30권11호
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• pp.1651-1658
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• 2020

Since Zika virus (ZIKV) was first detected in Uganda in 1947, serious outbreaks have occurred globally in Yap Island, French Polynesia and Brazil. Even though the number of infections and spread of ZIKV have risen sharply, the pathogenesis and replication mechanisms of ZIKV have not been well studied. ZIKV, a recently highlighted Flavivirus, is a mosquito-borne emerging virus causing microcephaly and the Guillain-Barre syndrome in fetuses and adults, respectively. ZIKV polyprotein consists of three structural proteins named C, prM and E and seven nonstructural proteins named NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5 in an 11-kb single-stranded positive sense RNA genome. The function of individual ZIKV genes on the host innate immune response has barely been studied. In this study, we investigated the modulations of the NF-κB promoter activity induced by the MDA5/RIG-I signaling pathway. According to our results, two nonstructural proteins, NS2A and NS4A, dramatically suppressed the NF-κB promoter activity by inhibiting signaling factors involved in the MDA5/RIG-I signaling pathway. Interestingly, NS2A suppressed all components of MDA5/RIG-I signaling pathway, but NS4A inhibited most signaling molecules, except IKKε and IRF3-5D. In addition, both NS2A and NS4A downregulated MDA5-induced NF-κB promoter activity in a dosedependent manner. Taken together, our results suggest that NS2A and NS4A signifcantly antagonize MDA5/RIG-I-mediated NF-κB production, and these proteins seem to be controlled by different mechanisms. This study could help understand the mechanisms of how ZIKV controls innate immune responses and may also assist in the development of ZIKV-specific therapeutics.