• Korean Journal of Microbiology
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• v.52 no.1
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• pp.1-9
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• 2016

A unique Schizosaccharomyces pombe $TrxR^+$ gene encoding thioredoxin reductase (TrxR) was found to be positively regulated by stress-inducing agents through the stress-responsive transcription factor Pap1. In the present study, the protective roles of S. pombe TrxR were evaluated using the TrxR-overexpressing recombinant plasmid pHSM10. In the presence of hydrogen peroxide ($H_2O_2$) and superoxide anion-generating menadione (MD), S. pombe TrxR increased cellular growth and the total glutathione (GSH) level, while it reduced levels of intracellular reactive oxygen species (ROS). The nitric oxide (NO) levels of the TrxR-overexpressing cells, in the presence of $H_2O_2$ and MD, were maintained to be similar to those of the corresponding non-treated cells. Although S. pombe TrxR was able to scavenge NO generated by sodium nitroprusside (SNP), it had no significant modulating effects on cellular growth, ROS levels, or the total GSH level of SNP-exposed yeast cells, compared with the differences in those of the two non-treated cell cultures. TrxR increased the cellular growth and total GSH level, which were diminished by nitrogen starvation. It also scavenged ROS and NO produced during nitrogen starvation. Taken together, the S. pombe TrxR protects against oxidative, nitrosative, and nutritional stresses.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.396-413
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• 1996

Current acceptable methods for promoting periodontal regeneration are based on removal of diseased soft tissue. root treatment, guided tissue regeneration, introduction of new graft materials and biological mediators. Insulin-like growth factor-I(IGF-I) and Platelet-derived growth factor-BB(PDGF-BB), the members of the polypeptuyde growth factor family have been reported as the biological mediators which regulate a variety cellular matrix biologic activities of wound healing process including the cell proliferation, migration and extracellular matrix synthesis.The purposes of this study is to evaluate the combination effects of IGF-I and PDGF-BB on the cellular activity of the periodontal ligament cells to act as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were prepared from the first premolar tooth extracted for the orthodontic treatment and were cultured in DMEM containing 10% FBS at the $37^{\circ}C$, 5% CO2 incubator. Author measured the DNA synthetic activity, and total protein, collagen and noncollagenous protein synthetic activities according to the concentration of 10,100ng/ml IGF-I and1,10 ng/ml PDGF-BB in combination. The results were as follows: Significantly increased in the 1 ng/ml PDGF-BB alone compared to the 10 ng/ml PDGF-BB alone(P<0.01) and in the 1 ng/ml PDGF-BB and 10, 100ng/ml IGF-I in combination compared to the 1 ng/ml PDGF-BB alone(P<0.05, P<0.0l). The synthetic activity of the total protein and collagen is significantly increased like to the synthetic activity of the DNA(P<0.05). The synthetic activity of the noncollagenous protein is increased according to the concentration of IGF_I, but not statistically statistically significant(P>0.05). The percent of the collagen is significantly in the 1ng/ml PDGF-BB and 10ng/ml IGF-I in combination compared to the 1ng/ml PDGF-BB alone(P<0.05) and in the 10ng/ml IGF-I in combination compared to the 10ng/ml PDGF-BB alone(P<0.05). The synthetic activity of the DNA is In conclusions, the percent study shows that PDGF-BB and IGF-I in combination have a potentiality to enhance the DNA synthesis and the total protein and collagen synthesis of The periodontal ligament cells, especially it is more significant in the low concentration of PDGF-BB compared to the high one. Thus, the PDGF-BB and IGF-I in combination may have important roles in promotion of periodontal litgment healing, and consequently, may useful for clinical application in periodontal regenerative procedures.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.395-402
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• 2005

In considering the healing process of injured periodontal tissue, healing rate would be influenced by the cellular activity of periodontal fibroblasts(PDLFs). In addition, the reattachment among PDLFs should be induced for healing process. The purpose of this study was to evaluate the effects of epidermal growth factor(EGF) on the proliferation and attachment of PDLFs and to verify the efficacy of EGF as a storage media or a pre-replantation conditioner of traumatically avulsed tooth. Human recombinant epidermal growth factor(hrEGF) and human periodontal fibroblasts from first premolar were prepared. At first, MTT assay was done to evaluate the toxic effect on human periodontal fibroblast and the maximum cellular growth of EGF. Cellular proliferation rate was then compared between control group and 10ng/ml EGF added group. Also, western blot was done to evaluate the expression of fibronectin in both groups. The results were as follows: 1. From MTT assay, EGF showed no toxic effect on PDL fibroblasts. The highest proliferation was shown at 10ng/ml EGF. 2. In 10ng/ml EGF added group, the degree of proliferation of PDLFs was significantly higher than that in control group. 3. Fibronectin expression of EGF added group was also significantly higher than that of control group. From this study we could conclude that EGF enhanced the regeneration rate of periodontal fibroblast, which could be used as a pretreatment agent or a storage media for traumatically avulsed teeth.

• Molecules and Cells
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• v.37 no.6
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• pp.480-486
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• 2014

Growth restriction by antibiotics is a common feature that pathogenic bacteria must overcome for survival. The struggle of bacteria to escape from growth restriction eventually results in development of antibiotic-resistance through the expression of a set of genes. Here we found that some physiologically important transcriptional regulators of Pseudomonas aeruginosa including QscR, a quorum sensing (QS) receptor, SoxR, a superoxide sensor-regulator, and AntR, a regulator of anthranilate-related secondary metabolism, are activated by various growth-restricted conditions. We generated the growth-restricted conditions by various methods, such as overexpression of PA2537 and treatment with antibiotics or disinfectants. The overexpression of PA2537, encoding an acyltransferase homologue, tightly restricted the growth of P. aeruginosa and significantly activated QscR during the growth restriction. Similarly, treatments with gentamycin, tetracycline, and ethanol also activated QscR near their minimal inhibitory concentrations (MICs). Some non-QS regulators, such as AntR and SoxR, were also activated near the MICs in the same conditions. However, LasR and PqsR, other QS receptors of P. aeruginosa, were not activated, suggesting that only a specific set of transcriptional regulators is activated by growth restriction. Since paraquat, a superoxide generator, significantly activated QscR and AntR, we suggest that the oxidative stress generated by growth restriction may be partly involved in this phenomenon.

• Journal of Life Science
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• v.10 no.1
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• pp.40-44
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• 2000

The SNF2/SW ATPase/helicase family comprises proteins form a variety of species with in vivo functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. Here, we reported the characterization of h게2+gene which was iolated by PCR amplification using the conserved domain of SNF2 motifs. Sequence analysis of PCR product showed striking evolutionary conservation among the SNF2 family of proteins. Two transcripts of 6.7 and 3.4 Lb were detected by Northern blot analysis. furthermore, the intensities of these two bands were increased by ultraviolet(UV) irradiation. These results indicate that the hrp2+ is a novel member of the SNF2 family of proteins and is one of the UV-inducible genes in S. pombe. To determine the level of transcripts of hrp2+ gene during cellular growth, Northern blot analysis were performed. This result indicates that the level of hrp2+transcript reached its maximum before cells entered the exponential growth phase. This suggests that hrp2+ gene is experssed mainly at the early stage of cell growth.

• Molecules and Cells
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• v.27 no.5
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• pp.503-513
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• 2009

Proteoglycans located in basement membranes, the nanostructures underling epithelial and endothelial layers, are unique in several respects. They are usually large, elongated molecules with a collage of domains that share structural and functional homology with numerous extracellular matrix proteins, growth factors and surface receptors. They mainly carry heparan sulfate side chains and these contribute not only to storing and preserving the biological activity of various heparan sulfate-binding cytokines and growth factors, but also in presenting them in a more "active configuration" to their cognate receptors. Abnormal expression or deregulated function of these proteoglycans affect cancer and angiogenesis, and are critical for the evolution of the tumor microenvironment. This review will focus on the functional roles of the major heparan sulfate proteoglycans from basement membrane zones: perlecan, agrin and collagen XVIII, and on their roles in modulating cancer growth and angiogenesis.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1532-1539
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• 2014

Although growth rate is one of the main economic traits of concern in pig production, there is limited knowledge on its epigenetic regulation, such as DNA methylation. In this study, we conducted methyl-CpG binding domain protein-enriched genome sequencing (MBD-seq) to compare genome-wide DNA methylation profile of small intestine and liver tissue between fast- and slow-growing weaning piglets. The genome-wide methylation pattern between the two different growing groups showed similar proportion of CpG (regions of DNA where a cytosine nucleotide occurs next to a guanine nucleotide in the linear sequence) coverage, genomic regions, and gene regions. Differentially methylated regions and genes were also identified for downstream analysis. In canonical pathway analysis using differentially methylated genes, pathways (triacylglycerol pathway, some cell cycle related pathways, and insulin receptor signaling pathway) expected to be related to growth rate were enriched in the two organ tissues. Differentially methylated genes were also organized in gene networks related to the cellular development, growth, and carbohydrate metabolism. Even though further study is required, the result of this study may contribute to the understanding of epigenetic regulation in pig growth.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3631-3634
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• 2013

MicroRNAs (MiRNAs) play important roles in coordinating a variety of cellular processes and abnormal expression has been linked to the occurrence of several cancers. The miRNA miR-451 is downregulated in colorectal carcinoma (CRC) cells, suggested by several research groups including our own. In this study, synthetic miR-451 mimics were transfected into the SW620 human CRC cell line using Lipofectamine 2000 and expression of miR-451 was analyzed by real time PCR, while expression of CAB39, LKB1, AMPK, AKT, PI3K and Bcl2 was analyzed by Western blot, and cell growth was detected by MTT assay. In comparison to the controls, a significant increase in the expression of miR-451 was associated with significantly decreased expression of CAB39, LKB1, AMPK, AKT, PI3K and Bcl2. The capacity of cell proliferation was significantly decreased by miR-451 expression, which also inhibited cell growth. Our study confirmed that miR-451 has a repressive role in CRC cells by inhibiting cell growth through down-regulating the P13K/AKT pathway.

• The korean journal of orthodontics
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• v.22 no.2 s.37
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• pp.309-325
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• 1992

The purpose of this study was to evaluate the effect of intrinsic factor and extrinsic factor for growth of the mandibular condylar cartilage of 4 day-old rats in a serum-free medium for 1, 4, 7, 14 days. They were compared with normal growth in vivo and with growth of spheno-occipital synchondrosis in serum-free medium. The cellular kinetics of cartilages were evaluated by auto-radiography of tritiated thymidine. 1. Condylar cartilage was enlarged with rounded head on day 14 of experiment while in vivo the rounded-headed shape changed into functionally flattened appearance. 2. On day 14 of experiment, a severe reduction of the proliferative zone and a considerable increase of the hypertrophic zone were observed while in normal control group endochondrol bone formation and bone marrow were observed. 3. The proliferative activity in the proliferative zone of condylar cartilage detected by $^3H-thymidine$ incorporation was lower than that of normal control group and decreased more than that of spheno-occipital synchondrosis, but it continued during the 14 days of culture. 4. The continued maintenance of condylar cartilage and morphologic change were disturbed in this culture system, but cell division within the proliferative zone was continued and probably linked to intrinsic factor.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.3
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• pp.185-191
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• 2008

While indirect targeting strategies using reporter-genes are taking center stage in current molecular imaging research, another vital strategy has long involved direct imaging of specific receptors using radiolabeled ligands. Recently, there is renewal of immense interest in this area with particular attention to the epidermal growth factor receptor (EGFR), a transmembrane glycoprotein critically involved in the regulation of many cellular functions and malignancies. Recently, two novel classes of EGFR-targeting anticancer drugs have entered clinical trials with great expectations. These are monoclonal antibodies such as cetuximab that target the extracellular domain, and small molecule tyrosine kinase inhibitors such as gefitinib (lressa) and erlotinib (Tarceva) that target the catalytic domain of the receptor. However, early results have showed disappointing survival benefits, disclosing a major challenge for this therapeutic strategy; namely, the need to identify tumors that are most likely to respond to the agents. To address this important clinical issue, several noninvasive imaging techniques are under investigation including radiolabeled probes based on small molecule tyrosine kinase inhibitors, anti-EGFR antibodies, and EGF peptides. This review describes the current status, limitations, and future prospects in the development of radiotracer methods for EGFR imaging.