• Archives of Plastic Surgery
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• v.32 no.5
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• pp.599-606
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• 2005

Clinical application of the cartilage formed by tissue engineering is of no practical use due to the failure of long-term structural integrity maintenance. One of the important factors for integrity maintenance is the biomaterial for a scaffold. The purpose of this study is to evaluate the difference between polylactic-co-glycolic acids (PLGA) and chitosan as scaffolds. Human auricular chondrocytes were isolated, cultured, and seeded on the scaffolds, which were implanted in the back of nude mice. Eight animals were sacrificed at 4, 8, 12, 16, and 24 weeks after implantation respectively. In gross examination and histological findings, the volume of chondrocyte-PLGA complexes was decreased rapidly. The volume of chondrocyte-chitosan complexes was well maintained with a slow decrease rate. The expression of type II collagen protein detected by immunohistochemistry and western blots became weaker with time in the chondrocyte-PLGA complexes. However, the expression in the chondrocyte-chitosan complexes was strong for the whole period. Collagen type II gene expressions using RT-PCR showed a similar pattern. In conclusion, these results suggest that chitosan is a superior scaffold in cartilage tissue engineering in terms of structural integrity maintenance. It is expected that chitosan scaffold may become one of the most useful scaffolds for cartilage tissue engineering.

• Journal of Life Science
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• v.28 no.10
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• pp.1132-1139
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• 2018

The stability of diverse cellular proteins in eukaryotes is regulated via ubiquitination. Moreover, E3 ligase plays a crucial role in determining substrate specificity and transfers ubiquitins into the substrates during the ubiquitination process. As a type of multi-subunit E3 ligase, cullin4 (CUL4)-based E3 ligase (CRL4) complex is involved in a variety of cellular processes, such as hormonal and stress responses in plants. In spite of several reports on the versatile roles of CRL4 in various signalings in Arabidopsis, CRL4's function in rice has been poorly known. To learn about CRL4-mediated cellular processes in rice in more detail, OsCUL4 that exhibits the highest homology with Arabidopsis CUL4 was isolated, and its expression patterns in various tissues and in response to plant hormones and abiotic stresses were monitored. Exogenous application of ABA or cytokinin increased the transcript levels of the OsCUL4 gene. Moreover, OsCUL4 was significantly upregulated in response to drought and salt stresses. These findings imply that OsCUL4 may be functionally related to ABA- and/or cytokinin-mediated cellular responses. OsCUL4 directly interacted with OsDDB1, an adaptor protein of CRL4, indicating that OsCUL4 can act as a scaffold protein of CRL4. An expression study on the OsCUL4 gene from this report could be used as a starting point to elucidate cellular responses in which a CRL4-mediated ubiquitination process is involved in rice.

• Macromolecular Research
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• v.14 no.5
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• pp.565-572
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• 2006

Recombinant human bone morphogenic protein-2 (rhBMP-2), which is known as one of the major local stimuli for osteogenic differentiation, was immobilized on the surface of hyaluronic acid (HA)-modified poly$(\varepsilon-caprolactone)$ (PCL) (HA-PCL) scaffolds to improve the attachment, proliferation, and differentiation of human bone marrow stem cells (hBMSCs) for bone tissue engineering. The rhBMP-2 proteins were directly immobilized onto the HA-modified PCL scaffolds by the chemical grafting the amine groups of proteins to carboxylic acid groups of HA. The amount of covalently bounded rhBMP-2 was measured to 1.6 pg/mg (rhBMP/HA-PCL scaffold) by using a sandwich enzyme-linked immunosorbant assay. The rhBMP-2 immobilized HA-modified-PCL scaffold exhibited the good colonization, by the newly differentiated osteoblasts, with a statistically significant increase of the rhBMP-2 release and alkaline phosphatase activity as compared with the control groups both PCL and HA-PCL scaffolds. We also found enhanced mineralization and elevated osteocalcin detection for the rhBMP-2 immobilized HA-PCL scaffolds, in vitro.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2004.11a
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• pp.203-209
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• 2004

Molecular docking using Lamarckian genetic algorithm of AutoDock 3.0 (AD3) was employed to understand in retrospect the selectivity of phenylaminopyrimidine (PAP) derivatives against the kinase domain c-Abl, implicated in chronic myelogenous leukemia (CML). The energetics of protein-ligand complex was scored using AD3 to identify active drug conformations while Ligplot and ligand protein contact (LPC) programs were used to probe schematic molecular recognition of the bound inhibitor to the protein. Results signify correlation between model and crystal structures of STI-571 compound or Imatinib (IM), a PAP derivative and now clinically proven for its efficacy in CML. A prospect active form Abl inhibitor scaffold from matlystatin class of compounds will be published elsewhere.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.51-52
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• 2009

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.175.2-175.2
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• 2003

Inhibition of the protein-modifying enzyme farnesyltransferase is considered as a major emerging strategy in cancer therapy because of the involvement of farnesylated proteins in oncogensis. We studied the structure-activity relationship of a novel class of CAAX-peptidomimetic farnesyltransferase inhibitors based on the benzophenone scaffold. FlexX docking of inhibitors confirmed reasonable fit of the molecule into the peptide binding site of farnesyltransferase. We also performed a virtual screening with LeadQuest chemical library databases to idenfity novel inhibitors of farnesyltransferase. (omitted)

• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.309-314
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• 2004

in this study, hybrid bioreactor was used to apply physical stimuli in cell culture. Effect of the applied physical stimuli on the growth and differentiation of MC3T3-El cell in a three-dimensional Chitosan scaffold were studied by using the hybrid bioreactor. The hybrid bioreactor for physical stimulus was specially designed to apply uniaxial cyclic compressive and shear strain. Physical stimulus was applied over a period of 14 days with 150 cycles per day at a frequency of 0.5Hz. Strain magnitude was 2.5% of the scaffold size. Control group and physically stimulated group of the MC3T3-El tell were incubated and harvested at the indicated times (Day 6, 8, 10, 12, 14). The total amount of protein, which obtained information of cell growth, was determined by Lowey method. Alkaline phosphatase activity was examined by ELISA. Physically stimulated group using the hybrid bioreactor was increased in alkaline phosphatase activity comparing with control group. The nodule formation and calcium deposit of the physical stimuli group which resulted in cell differentiation was faster than that of control group.

• Journal of the Korean Magnetic Resonance Society
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• v.24 no.3
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• pp.86-90
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• 2020

Iron-sulfur (Fe-S) clusters are one of the most ancient yet essential cofactors mediating various essential biological processes. In prokaryotes, Fe-S clusters are generated via several distinctive biogenesis mechanisms, among which the ISC (Iron-Sulfur Cluster) mechanism plays a house-keeping role to satisfy cellular needs for Fe-S clusters. The Escherichia coli ISC mechanism is maintained by several essential protein factors, whose structural characterization has been of great interest to reveal mechanistic details of the Fe-S cluster biogenesis mechanisms. In particular, nuclear magnetic resonance (NMR) spectroscopic approaches have contributed much to elucidate dynamic features not only in the structural states of the protein components but also in the interaction between them. The present minireview discusses recent advances in elucidating structural features of IscU, the key player in the E. coli ISC mechanism. IscU accommodates exceptional structural flexibility for its versatile activities, for which NMR spectroscopy was particularly successful. We expect that understanding to the structural diversity of IscU provides critical insight to appreciate functional versatility of the Fe-S cluster biogenesis mechanism.

• Journal of Life Science
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• v.17 no.12
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• pp.1627-1633
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• 2007

c-Jun N-terminal kinase (JNK)-interacting protein 1 (JIP1), also known as Islet-brain 1 (IB1), is a scaffold protein that is highly expressed in neurons and pancreatic ${\beta}-cells$. In this study subcellular localization of JIP was investigated in cultured rat hippocampal neurons using an antibody that recognize all variants of JIP1, JIP-2 and JIP-3. The overall expression profile of JIP is punctate throughout soma and dendrites. Statistic analysis showed that $54.8{\pm}4.0%\;and\;94.1{\pm}4.5%$ of total JIP immunopuncta overlapped with those of excitatory postsynaptic markers SD-95 and ${\alpha}Camik$, respectively. In contrast, only $8.6{\pm}0.5%\;and\;7.3{\pm}0.5%$ of JIP clusters overlapped with those of inhibitory postsynaptic markers glycine receptor (GlyR) and gephyrin, respectively. JIP clusters overlapped or juxtaposed with SV2 but not GAD, markers for general and inhibitory nerve terminals, respectively. A substantial fraction $(29.3{\pm}1.0%)$ of flotillin immunopuncta, a marker for lipid rafts, clusters overlapped with those of JIP. In addition, JIP was highly expressed in some select ends of dendrites but minimal in axons. These data suggest important roles of JIP in excitatory postsynaptic sites, lipid rafts and dendritic ends.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.302-310
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• 2022

Recently, in human medicine and veterinary medicine, interest in synthetic bone graft is increasing. Among them, bone morphogenic protein (BMP) is currently being actively researched and applied to clinical trials. However, BMP has the disadvantage of being expensive and easily absorbed into surrounding tissues. Therefore, BMP requires the use of small amounts and rhBMP (recombinant human bone morphogenetic protein)-2 carriers that can be released slowly. Hydrogel has the property of swelling a large amount of water inside when it is aqueous solution, and when it is, it consists of more than 90 percent water. Using these properties, hydrogels are often used as rhBMP-2 carrier. The scaffold used in this study is a hydrogel made from which keratin is extracted using human hair and based on it. In this study, we wanted to see the effect of bone formation in the calvarial defect model by using keratin-based hydrogel made with human hair as a scaffold. The experiment was conducted by dividing 3 groups a total of 12 mice. Calvarial bone defect is set to all 4 mm diameters. Bone formation was evaluated by using gross evaluation, micro-computed tomography (micro-CT), immunohistochemistry. Groups using keratin-based hydrogel were significantly observed compared to Group 1s, and the most bone formations were found when rhBMP-2 and hydrogel were used. This represents the superiority of the functions of the rhBMP-2 carrier by a new material, keratin-based hydrogel. Through gross evaluation, micro-CT, and immunohistochemistry, we can confirm that keratin-based hydrogel is a useful rhBMP-2 carrier.