• Reproductive and Developmental Biology
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• v.37 no.2
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• pp.79-83
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• 2013

Matrix metalloproteinases (MMPs) have been known to affect to cell migration, proliferation, morphogenesis and apoptosis by degrading the extracellular matrix. In the previous studies, undifferentiated mouse embryonic stem cells (ESCs) were successfully proliferated inside the extracellular matrix (ECM) analog-conjugated three-dimensional (3D) poly ethylene glycol (PEG)-based hydrogel. However, there is no report about MMP secretion in ESCs, which makes it difficult to understand and explain how ESCs enlarge space and proliferate inside 3D PEG-based hydrogel constructed by crosslinkers containing MMP-specific cleavage peptide sequence. Therefore, we investigated what types of MMPs are released from undifferentiated ESCs and how extracellular signals derived from various niche conditions affect MMP expression of ESCs at the transcriptional level. Results showed that undifferentiated ESCs expressed specifically MMP2 and MMP3 mRNAs. Transcriptional up-regulation of MMP2 was caused by the 3D scaffold, and activation of integrin inside the 3D scaffold upregulated MMP2 mRNAs synergistically. Moreover, mouse embryonic fibroblasts (MEFs) on 2D matrix and 3D scaffold induced upregulation of MMP3 mRNAs, and activation of integrins through conjugation of extracellular matrix (ECM) analogs with 3D scaffold upregulated MMP3 mRNAs synergistically. These results suggest that successful proliferation of ESCs inside the 3D PEG-based hydrogel may be caused by increase of MMP2 and MMP3 expression resulting from 3D scaffold itself as well as activation of integrins inside the 3D PEG-based scaffold.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.51-63
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• 1994

There has been many attempts to develop a method that can regenerate periodontal tissues that were lost due to periodontal diseasd, but none of them was completely successful. This study was designed to investigate the healing and regeneration of periodontal tissue when bone substitutes such as porous replamineform hydroxyapatite and porous resorbable calcium carbonate were used in combination with oxidized cellulose membrane and collagen absorbable hemostat, compared to a control where only oxidized cellulose membrane or collagen absorbable hemostat were used. Chronic periodontitis was induced on mandibular premolars of and adult dog by placing orthodontic elastic ligatures for 10 weeks. After flap operation, the control group were received oxidized cellulose membrane (control- I )or collagen absorbable hemostat (control- II) only, while one experimental group was given either porous replamineform hydroxyapatite or porous resorbable calcium carbonate in addition to oxidized cellulose membrane (Experimental I-A, I-B), and another experimental group was treated by using either porous replamineform hydroxyapatite or porous resorbable calcium carbonate in addition to collagen absorbable hemostat. (Experimental II-A, II-B) After 56 weeks, healing was histologically analyzed with the following results. 1. Apical migration of junctional epithelium was observed only in areas coronal to the notch for both control and experimental group. 2. Inflammatory cell infiltration was not observed in any groups. 3. Oxidized cellulose membrane and collagen absorbable hemostat were completely resorbed. 4. Newly-formed cementum was observed up to the level where junctional epithelium was located, for both control and experimental groups. 5. Bone formation was limited of the middle portion of the notch in the control group, where as experimental groups showed bone formation up to the level of implant materials coronal to the notch. 6. Minute resorption of apically located portions of implanted materials was observed in experimental group I-B and II-B only.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.87-97
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• 1994

The ultimate goal of periodontal therapy is to fully reconstruct the periodontal attachment apparatus. Commonly used techniques for treatment of infrabony defects include a combination of root planing, curettage and root treatment. To prevent the apical migration of epithelial cells, the technique of guided tissue regeneration is used. The aim of this study is to compare the effects of root treatment with Citric acid & Tetracycline and Guided tissue regeneration in dogs. Experimental periodontitis was induced by the ligation of orthodontic elastic threads in the upper right and left premolars 3, 4 of five adult dogs for 6 weeks. 4 types of procedures were performed as follows; 1) Control graup : Mucoperiosteal flap 2) Experinental I : GTR used Gore-tex(R) membrane 3) Experinental II : Root treatment with citric acid (PHl) 4) Experinental III : Root treatment with tetracycline HCl (50mg/ml) There after, dogs were serially sacrificed at the 1, 2, 4, 5, 8 weeks, and the specimens were prepared, and stained with hematoxylin-eosin for the light microscopic evaluation. The results of this study were as follows; 1. Junctional epithelium reached to the notch through the furcation area in control group at 8 weeks. 2. In the aspects of the inflammatory cell infiltration, control group showed severe aggregation than experimental group I, II, III through the experimental period 3. New cementum was observed over the notch from 5 weeks in experimental group II 4. In the aspects of the amount of new bone formation, experimental group was better than control group, but there was not significant differences among the experimental group, I, II, III

• Clinical and Experimental Reproductive Medicine
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• v.45 no.1
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• pp.10-16
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• 2018

Objective: Placental oxidative stress is known to be a factor that contributes to pregnancy failure. The aim of this study was to determine whether selenium could induce antioxidant gene expression and regulate invasive activity and mitochondrial activity in trophoblasts, which are a major cell type of the placenta. Methods: To understand the effects of selenium on trophoblast cells exposed to hypoxia, the viability and invasive activity of trophoblasts were analyzed. The expression of antioxidant enzymes was assessed by reverse-transcription polymerase chain reaction. In addition, the effects of selenium treatment on mitochondrial activity were evaluated in terms of adenosine triphosphate production, mitochondrial membrane potential, and reactive oxygen species levels. Results: Selenium showed positive effects on the viability and migration activity of trophoblast cells when exposed to hypoxia. Interestingly, the increased heme oxygenase 1 expression under hypoxic conditions was decreased by selenium treatment, whereas superoxide dismutase expression was increased in trophoblast cells by selenium treatment for 72 hours, regardless of hypoxia. Selenium-treated trophoblast cells showed increased mitochondrial membrane potential and decreased reactive oxygen species levels under hypoxic conditions for 72 hours. Conclusion: These results will be used as basic data for understanding the mechanism of how trophoblast cells respond to oxidative stress and how selenium promotes the upregulation of related genes and improves the survival rate and invasive ability of trophoblasts through regulating mitochondrial activity. These results suggest that selenium may be used in reproductive medicine for purposes including infertility treatment.

• Animal cells and systems
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• v.16 no.2
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• pp.104-113
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• 2012

The nucleolus is a distinct nuclear territory involved in the compartmentalization of nuclear functions. There is some evidence of a relationship between nuclear fragmentation during spermatogenesis and chromatoid body (CB) formation. The CB is a typical cytoplasmic organelle of haploid germ cells, and is involved in RNA and protein accumulation for later germ-cell differentiation. The goal of this study was to qualitatively and quantitatively describe the nucleolar cycle during the spermatogenesis of $Phrynops$ $geoffroanus$ (Reptilia Testudines), and compare this nucleolar fragmentation with CB formation in this species through the use of cytochemical and ultrastructural analysis. Qualitative analysis showed a fragmentation of the nuclear material after pachytene of the first meiotic division in the primary spermatocytes. Quantitative analysis of the nucleolar cycle revealed a significant difference in the number of nucleoli and in the size of the nucleolus between spermatogonia and early spermatids. Using ultrastructural analysis, we recorded the beginning of the CB formation process in the cytoplasm of primary spermatocytes at the same time as when nuclear fragmentation occurs. In the cytoplasm of primary spermatocytes, the CB was observed in association with mitochondrial aggregates and the Golgi complex. In the cytoplasm of early spermatids, the CB was observed in association with lipid droplets. In conclusion, our data show that the nucleolus plays a role in the CB formation process. During spermatogenesis of $P.$ $geoffroanus$, the CB is involved in some important biological processes, including acrosome formation and mitochondrial migration to the spermatozoon tail and middle piece region.

• Molecules and Cells
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• v.24 no.2
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• pp.240-246
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• 2007

The ${\beta}2$ integrins on leukocytes play important roles in cell adhesion, migration and phagocytosis. One of the ${\beta}2$ integrins, ${\alpha}X{\beta}2$ (CD11c/CD18), is known to bind ligands such as fibrinogen, Thy-1 and iC3b, but its function is not well characterized. To understand its biological roles, we attempted to identify novel ligands. The functional moiety of ${\alpha}X{\beta}2$, the ${\alpha}X$ I-domain, was found to bind plasminogen, the zymogen of plasmin, with moderate affinity ($1.92{\times}10^{-6}M$) in the presence of $Mg^{2+}$ or $Mn^{2+}$. The ${\beta}D-{\alpha}5$ loop of the ${\alpha}X$ I-domain proved to be responsible for binding, and lysine residues ($Lys^{242}$, $Lys^{243}$) in the loop were the most important for recognizing plasminogen. An excess amount of the lysine analog, 6-aminohexanoic acid, inhibited ${\alpha}X$ I-domain binding to plasminogen, indicating that binding is lysine-dependent. The results of this study indicate that leukocytes regulate plasminogen activation, and consequently plasmin activities, through an interaction with ${\alpha}X{\beta}2$ integrin.

• Archives of Pharmacal Research
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• v.29 no.2
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• pp.159-164
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• 2006

The protective properties of Satureja hortensis L. on the rat lymphocytes DNA lesions were tested. Lymphocytes were isolated from blood samples taken from healthy rats. DNA breaks and resistance to $H_{2}O_{2}$-induced damage were measured with the comet assay. Rat lymphocytes were incubated in S. hortensis ethanolic extract (SHE) (0.05, 0.1, 0.5, 1.0, and 2.5 mg/mL), essential oil (SHEO)(0.05, 0.1, 0.5, 1.0, and 2.5 ${mu}L/mL$), $H_{2}O_{2}$ (50, 100, and 200 ${\mu}M$), a combination of $H_{2}O_{2}$ (200 mM) with either SHE (1.0, 2.5 mg/mL) or SHEO (1.0, 2.5 ${\mu}L/mL$) at $4^{\circ}C$ for 30 min, and the extent of DNA migration was measured using a single-cell microgel electrophoresis technique under alkaline conditions. Treatment of rat lymphocytes with SHE or SHEO resulted in significant reduction of $H_{2}O_{2}$-induced DNA damage compared to controls. SHE exhibited a significant (P<0.01) inhibitory effect on oxidative DNA damage at 2.5 mg/mL. SHEO (1.0 and 2.5 ${\mu}L/mL$) also showed significant inhibitory effects (P<0.01) on $H_{2}O_{2}$ induced chromosomal damage. In conclusion both the ethanolic extract and the essential oil of the plant reversed the oxidative damage to rat lymphocytes induced by hydrogen peroxide.

• Journal of Periodontal and Implant Science
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• v.30 no.4
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• pp.803-814
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• 2000

Current acceptable methods of promoting periodontal regeneration are basis of removal of diseased soft tissue, root treatment, guided tissue regeneration, graft materials, biological mediators. Platelet Rich Plasma have been reported as a biological mediator which regulate activities of wound healing progress including cell proliferation, migration, and metabolism. The purpose of this study is to evaluate the possibility of using the Platelet Rich Plasma as a regeneration promoting agent for furcation involvement defect. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on mandibular third(P3), forth(P4) and fifth(P5) premolar. 2 month later experimental group were PRP plus bovine bone and bovine bone only. After 4, 8 weeks, the animals were sacrificed by perfusion technique. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. At 4 weeks after surgery, there were rapid osteogenesis phenomenon on the defected area of the Platelet Rich Plasma plus bovine bone group and early trabeculation pattern was made with new osteoid tissue produced by activated osteoblast. Bone formation was almost completed to the fornix of furcation by 4 weeks after surgery. In conclusion, Platelet Rich Plasma can promote rapid osteogenesis during early stage of periodontal tissue regeneration.

• Journal of Periodontal and Implant Science
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• v.40 no.2
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• pp.49-55
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• 2010

Purpose: The purpose of this study was to preliminarily evaluate the influence of diabetes mellitus (DM) on periodontal tissue without establishment of periodontitis. Methods: Seven-week-old db/db mice were used for the diabetic experimental group and systematically healthy mice of the same age were used as controls. After 1 week of acclimatization, the animals were sacrificed for hard and soft tissue evaluation. The pattern of bone destruction was evaluated by stereomicroscope evaluation with alizarin red staining and radiographic evaluation by microscopic computerized tomography images. Histological evaluation was performed with hematoxylin and eosin stain for evaluation of soft tissue changes. Results: In both stereomicroscope evaluation and radiograph image analysis, aggressive form of bone destruction was observed in diabetic animals when compared to the systematically healthy controls. In histological evaluation, apical migration of junctional epithelium with slight inflammatory cell infiltration was observed with disarrangement of connective tissue fibers. Conclusions: Within the limits of this study, diabetic animals presented distortion in periodontal attachment and an aggressive bone loss pattern when compared to the healthy controls, suggesting that DM has an independent effect on periodontal tissue destruction irrespective of the presence or absence of periodontal disease.

• Journal of Ginseng Research
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• v.44 no.1
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• pp.67-78
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• 2020

Background: Gintonin (GT), a novel ginseng-derived exogenous ligand of lysophosphatidic acid (LPA) receptors, has been shown to induce cell proliferation and migration in the hippocampus, regulate calcium-dependent ion channels in the astrocytes, and reduce β-amyloid plaque in the brain. However, whether GT influences autophagy in cortical astrocytes is not yet investigated. Methods: We examined the effect of GT on autophagy in primary cortical astrocytes using immunoblot and immunocytochemistry assays. Suppression of specific proteins was performed via siRNA. LC3 puncta was determined using confocal microscopy. Results: GT strongly upregulated autophagy marker LC3 by a concentration- as well as time-dependent manner via G protein-coupled LPA receptors. GT-induced autophagy was further confirmed by the formation of LC3 puncta. Interestingly, on pretreatment with an mammalian target of rapamycin (mTOR) inhibitor, rapamycin, GT further enhanced LC3-II and LC3 puncta expression. However, GT-induced autophagy was significantly attenuated by inhibition of autophagy by 3-methyladenine and knockdown Beclin-1, Atg5, and Atg7 gene expression. Importantly, when pretreated with a lysosomotropic agent, E-64d/peps A or bafilomycin A1, GT significantly increased the levels of LC3-II along with the formation of LC3 puncta. In addition, GT treatment enhanced autophagic flux, which led to an increase in lysosome-associated membrane protein 1 and degradation of ubiquitinated p62/SQSTM1. Conclusion: GT induces autophagy via mTOR-mediated pathway and elevates autophagic flux. This study demonstrates that GT can be used as an autophagy-inducing agent in cortical astrocytes.