• Biomedical Science Letters
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• v.18 no.2
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• pp.104-111
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• 2012

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases which degrade extracellular matrix (ECM) during embryogenesis, wound healing, and tissue remodeling. Dysregulation of MMP activity is also associated with various pathological inflammatory conditions. In this study, we examined the expression pattern of MMPs during PMA-induced differentiation of THP-1 monocytic cells into macrophages. We found that MMP1, MMP8, MMP3, MMP10, MMP12, MMP19, MMP9, and MMP7 were upregulated during differentiation whereas MMP2 remained unchanged. Expression of MMPs increased in a time-dependent manner; MMP1, MMP8, MMP3, MMP10, and MMP12 increased beginning at 60 hr post PMA treatment whereas MMP19, MMP9, and MMP7 increased beginning at 24 hr post PMA treatment. To identify signal transduction pathways involved in PMA-induced upregulation of MMPs, we treated PMA-differentiated THP-1 cells with specific inhibitors for PKC, MEK1, NF-${\kappa}B$, PI3K, p38 MAPK and PLC. We found that inhibition of the MEK1 pathway blocked PMA-induced upregulation of all MMPs to varying degrees except for MMP-2. In addition, expression of select MMPs was inhibited by PI3K, p38 MAPK and PLC inhibitors. In conclusion, we show that of the MMPs examined, most MMPs were up-regulated during differentiation of monocyte into macrophage via the MEK1 pathway. These results provide basic information for studying MMPs expression during macrophage differentiation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.1
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• pp.92-97
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• 2005

Inhibition of inflammatory response, acceleration of basal cell growth, and balanced synthesis of extracellular matrix (ECM) are important in healing of cutaneous open wounds. In order to evaluate the healing effects of water extracts of Radix Astragali (the root of Astragalus membranaceus (Fisch.)) on open wound at early stage, the experimental open wounds were generated on the dorsal sides of SD rats under anesthesia. The boiled-water extracts of Radix Astragali $(100{\mu}l)$, soaked into an occlusive film dressing were applied once a day for eleven consecutive days. The healing process was assessed by measuring macroscopic appearance and wound areas of the open wounds. The molecular aspects of healing process by Radix Astragali extracts were also investigated by Hematoxylin-Eosin (H-E) double staining and immunohistological staining of collagen type I in the healed skin area, implying cell density and linear alignment of the granulation tissue, and ECM synthesis and its remodeling, respectively. The Astragali radix extracts were found to significantly accelerate the cutaneous wound healing by suppressing the inflammation and stimulating the basal cell growth in wounded area, as compared to epidermal growth factor (EGF).

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.317-324
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• 1996

Osteoclast has been known as a primary responsible cell for the bone resorption. The activation of osteoclast, therefore, may be the key event in the regulation of bone growth and remodeling. Various factors were reported to have influence on the resorbing activity of osteoclast in organ culture. Among those factors, transforming growth factor-$\beta$ (TGF-$\beta$) has been known to have a profound effect on bone metabolism. Since a large amount of TGF-$\beta$ presents in bone tissue, it may be important for the understanding the regulatory mechanism of bone resorption to elucidate the effect of TGF-$\beta$ on the osteoclast. We have reported the dlsaggregated chick embryonic osteoclast culture as an useful assay method for determining the resorption activity of osteoclast. In this culture, we found that TGF-$\beta$ significantly enhaced the osteoclastic bone resorption activity. We also found that the timulatory effect seemed to be an indirect one that is mediated by other cells. As nordihydroguaiaretic acid significantly inhibited the TGF-$\beta$1-induced osteoclastic bone resorption, we suggest that the lipoxygenase derivative of arachidonic acid may participate in the action of TGF-$\beta$ as a paracrine or an autocrine mediator.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.1
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• pp.43-66
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• 1997

Dental implant may be immediately placed in postextraction socket which has alveolar bone defect. The purpose of this study was to compare the bone regeneration and bone quality around defects adjacent to implants that were placed into extraction sockets according to EFEB, GTAM barrier and GTAM barrier with DFDB. Mandibular P2, P3 and P4 were extracted bilaterally in dogs, and buccal defects were created about 4mm in depth and 3.3mm in width. Screwed pure titanium implants, 3.8mm in diameter and 10mm in length, were placed into the extraction sockets. The experimental groups were divided into four groups : the G group was covered with a GTAM barrier on the defective area, the D+G group was filled with DFEB and covered with a GTAM barrier, the D group was filled with DFDB only and the control group was sutured without any special treatment on the defective area. The experimental animals were killed after 12 weeks and specimens were prepared for light microscopic evaluation and fluorescent dyes were administered daily for 2 weeks after implantation, and injected on the 4th and 11th week for fluorescent microscopic examination to observe new bone formation and bone remodeling. The new Bone height of the buccal defect was measured and compared with the another for bone gain and the removal torque for the implant was measured for the comparison of bone density and bone-implant osseointegration. Results obtained were as follows : 1. Experimental groups showed bone regeneration in oder from D+G, G, D group and control. D+G and G group was significantly from D group and control(P<0.01). 2. In the defective area of control the regenerated alveolar bone showed poorly developed lamellated structure and fibrous tissue intervention into the bone-implant interface but the others showed well developed lamellated structure and osseointegration. 3. All implant groups showed no significaant difference in the removal torque for implant(P>0.05) These results suggest that immediate implants placed in defective sockets were successfully osseointegrated and utilizing placed in defective sockets were successfully osseointegrated and utilizing not only the combination of GTAM and DFDB but also only the GTAM was favorable for the predictable regeneration of the defective area.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.557-564
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• 2000

The bone graft materials can be grossly divided into autogenous bone, allogenic bone, xenogenic bone, and alloplastic material. Much care was given to other bone graft materials away from autogenous bone due to its additional operation for harvesting, delayed resorption and limitation of quantity. Demineralized freeze-dried bone(DFDB) and hydroxyapatite are the representatives of bone graft materials. As resorbable hydroxyapatite is developed in these days, the disadvantage of nonresorbability can be overcome. So we planned to study on the strength and the bone formation at the rats calvarial defects of DFDB graft and those of the composite graft with DFDB and resorbable hydroxyapatite. We used the 16 male rats weighting range from 250 to 300 gram bred under the same environment during same period. After we made the 6mm diameter calvarial defect, we filled the DFDB in 8 rats and DFDB and resorbable hydroxyapatite in another 8 rats. We sacrificed them at the postoperative 1 month and 2 months with the periostium observed. As soon as the specimens were delivered, we measured the compressive forces to break the normal calvarial area and the newly formed bone in calvarial defect area using Instron(Model Autograph $S-2000^{(R)}$, Shimadzu, Japan). The rest of the specimens were stained with H&E(Hematoxylin & Eosin) and evaluated with the light microscope. So we got the following results. 1. In every rats, there was no significant difference between the measured forces of normal bone area and those of the bone graft area. 2. In 1 month, the measured forces at DFDB graft group were higher than those of the DFDB and resorbable hydroxyapatite composite graft group(P<0.05). 3. In 2 months, there was no significant differences between the measured forces of DFDB graft group and those of the DFDB and resorbable hydroxyapatite composite graft group. 4. In lightmicroscopic examination, most of the grafted DFDB were transformed into bone in 1 month and a large numbers of hydroxyapatite crystal were observed in DFDB and resorbable hydroxyapatite composite graft group in 1 month. 5. Both group showed no inflammatory reaction in 1 month. And hydroxyapatite crystals had a tight junction without soft tissue invagination when consolidated with newly formed bone. 6. In both groups, newly formed bone showed the partial bone remodeling and the lamellar bone structures and some of reversal lines were observed in 2 months. From the above results, it is suggested that DFDB and resorbable hydroxyapatite composite graft group had a better resistance to compressive force in early stage than DFDB graft group, but there would be no significant difference between two groups after some period. And it is suggested that the early stage of bone formation procedure of DFDB and resorbable hydroxyapatite composite graft group was slight slower than that of DFDB graft group, but there would be no significant difference between two groups after some period.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.2
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• pp.166-175
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• 2016

There is no genetic activity information with the functions of dental pulp and periodontal ligament in human. The purpose of this study was to identify the gene-expression profiles of, and the molecular biological differences between periodontal ligament and dental pulp obtained from human permanent teeth. cDNA microarray analysis identified 347 genes with a fourfold or greater difference in expression level between the two tissue types 83 and 264, of which were more plentiful in periodontal ligament and dental pulp, respectively. Periodontal ligament exhibited strong expression of genes related to collagen synthesis (FAP), collagen degradation (MMP3, MMP9, and MMP13), and bone development and remodeling (SSP1, BMP3, ACP5, CTSK, and PTHLH). Pulp exhibited strong expression of genes associated with calcium ions (CALB1, SCIN, and CDH12) and the mineralization and formation of enamel and dentin (SPARC/SPOCK3, PHEX, AMBN, and DSPP). Among these genes, SPP1, SPARC/SPOCK3, AMBN, and DSPP were well known in dental research. However, the other genes are the newly found and it may help to find a good source of regenerative therapy if further study is performed.

• Journal of dental hygiene science
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• v.5 no.3
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• pp.97-103
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• 2005

Irritation fibroma (IF) is the most common tumor-like oral lesion that is evolved by proliferation of collagen in response to chronic irritation. Oral leukoplakia (OL) is considered as precancerous lesion characterized by proliferation of epithelial cells due to chronic irritation, smoking and drinking. TGF-${\beta}1$ and EGFR are important factors that play an essential role in extracellular matrix remodeling during normal wound healing process. The epithelial reaction by chronic irritation may be connected with pathogenesis of IF and OL. In the present study, we examined the expression of TGF-${\beta}1$ and EGFR in the IF and OL using immunohistochemistry. We used 88 cases of IF, 44 cases of OL and 9 cases of normal oral mucosa as normal control. TGF-${\beta}1$ was decreased in the epithelium of IF and OL. As for EGFR, the epithelial cells revealed the increased positive expression in IF and OL. In case of OL, the Spearman correlation coefficient of TGF-${\beta}1$ and EGFR was -0.10 (p< 0.05), which showed weak correlation. In the fibrous tissue, TGF-${\beta}1$ was increased only in IF. The expression difference of TGF-${\beta}1$ and EGFR may be involved in the pathogenesis of IF and OL.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.95-110
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• 1992

Much progress has been made in understanding the subcellular events of the human lung injuries after acute exposure to environmental air pollutants. Host of those events represent oxidative damages mediated by reactive oxygen species such as superoxide, hydrogen peroxide, and the hydroxy, free radical. Recently, nitric oxide (NO) was found to be endogenously produced by endothelial cells and cells of the reticulo-endothelial system as endothelialderived relaxation factor (EDRF) which is a vasoactive and neurotransmitter substance. Together with superoxide, NO can form another strong oxidant, peroxonitrite. The relative importance of exogenous sources of $N0/N0_2$ and endogenous production of NO by the EDRF producing enzymes in the oxidative stresses to the heman lung has to be elucidated. The exact events leading to chronic irreversible damage are still yet to be known. From chronic exposure to oxidant gases, progressive epithelial and interstitial damages develop. Type I epithelial cells become thicker and cover a smaller average alveolar surface area while thee II cells proliferate instead. Under acute damages, the extent of loss of the alveolar epithelial cell lining, especially type II cells appears to be a good predictor of the ensuing irreversible damage to alveolar compartment. Interstitial matrix undergo remodeling during chronic exposure with increased collagen fibers and interstitial fibroblasts. However, Inany of these changes can be reversed after cessation of exposure. Among chronic lung injuries, genetic damages and repair responses received particular attention in view of the known increased lung cancer risks from exposure to several air pollutants. Heavy metals from foundry emission, automobile traffics, and total suspended particulate, especially polycystic aromatic hydrocarbons have been positively linked with the development of lung cancer. Asbestos in another air pollutant with known risk of lung cancer and mesothelioma, but asbestos fibers are nonauthentic in most bioassays. Studies using the electron spin resonance spin trapping method show that the presence of iron in asbestos accelerates the production of the hydroxy, radical in vitro. Interactions of these reactive oxygen species with particular cellular components and disruption of cell defense mechanisms still await further studies to elucidate the carcinogenic potential of asbestos fibers of different size and chemical composition. The distribution of inhaled pollutants and the magnitude of their eventual effects on the respiratory tract are determined by pollutant-independent physical factors such as anatomy of the respiratory tract and level and pattern of breathing, as well as by pollutant-specific phyco-chemical factors such as the reactivity, solubility, and diffusivity of the foreign gas in mucus, blood and tissue. Many of these individual factors determining dose can be quantified in vitro. However, mathematical models based on these factors should be validated for its integrity by using data from intact human lungs.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1102-1116
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• 2012

During embryo implantation in pigs, the uterine endometrium undergoes dramatic morphological and functional changes accompanied with dynamic gene expression. Since the greatest amount of embryonic losses occur during this period, it is essential to understand the expression and function of genes in the uterine endometrium. Although many reports have studied gene expression in the uterine endometrium during the estrous cycle and pregnancy, the pattern of global gene expression in the uterine endometrium in response to the presence of a conceptus (embryo/fetus and associated extraembryonic membranes) has not been completely determined. To better understand the expression of pregnancy-specific genes in the endometrium during the implantation period, we analyzed global gene expression in the endometrium on day (D) 12 and D15 of pregnancy and the estrous cycle using a microarray technique in order to identify differentially expressed endometrial genes between D12 of pregnancy and D12 of the estrous cycle and between D15 of pregnancy and D15 of the estrous cycle. Results showed that the global pattern of gene expression varied with pregnancy status. Among 23,937 genes analyzed, 99 and 213 up-regulated genes and 92 and 231 down-regulated genes were identified as differentially expressed genes (DEGs) in the uterine endometrium on D12 and D15 of pregnancy compared to D12 and D15 of the estrous cycle, respectively. Functional annotation clustering analysis showed that those DEGs included genes involved in immunity, steroidogenesis, cell-to-cell interaction, and tissue remodeling. These findings suggest that the implantation process regulates differential endometrial gene expression to support the establishment of pregnancy in pigs. Further analysis of the genes identified in this study will provide insight into the cellular and molecular bases of the implantation process in pigs.

• Journal of Life Science
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• v.25 no.5
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• pp.585-593
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• 2015

Stress fiber (SF) alteration is mediated by cellular receptors, which, upon interaction with the extracellular counterpart, signal to the actin cytoskeleton for remodeling. This association is mediated by a variety of scaffold and signaling factors, which control the mechanical and signaling activities of the interaction site. The heterotrimeric transmembrane lymphotoxin α1β2 (LTα1β2), a member of the tumor necrosis factor (TNF) family of cytokines, including soluble homotrimeric lymphotoxin (LT α), plays an important role in lymphoid tissue architecture. Ligation between LTα1β2 and the lymphotoxin β receptor (LTβR) activates signal-cascade in fibroblastic reticular cells (FRCs). We found LTβR stimulation using an agonistic anti-LTβR antibody alone or combined with LTα or TNFα induced changes in the actin and plasticity of cells. To clarify the involvement of myosin underlying the alteration, we analyzed the effect of myosin light chain kinase (MLCK) with an MLCK inhibitor (ML7), the phosphorylation level of myosin light chains (MLC), and the level of phospho-myosin phosphatase target subunit 1 (MYPT1) after treatment with an agonistic anti-LTβR antibody for cytoskeleton reorganization in FRCs. The inhibition of MLCK activity induced changes in the actin cytoskeleton organization and cell morphology in FRC. In addition, we showed the phosphorylation of MLC and MYPT1 was reduced by LTβR stimulation in cells. A DNA chip revealed the LTβR stimulation of FRC down-regulated transcripts of myosin and actin components. Collectively, these results suggest LTβR stimulation is linked to myosin regarding SF alteration in FRC.