• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.188-201
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• 1996

One of the initial events required for periodontal regeneration is the attachment, spreading and proliferation of fibroblasts at the healing sites. These have been reported that minocycline stimulates the attachment of gingival fibroblasts and periodontal ligament cells and $TGF-{\beta}1$ enhances the proliferation of periodontal ligament cells. The purpose of this study was to evaluate and confirm the effect of minocycline and $TGF-{\beta}1$ on human gingival fibroblasts and periodontal ligament cells. That gingival fibroblasts and periodontal ligament cells used in this study were obtained from the explants of healthy periodontal ligaments and gingival tissues of extracted 3rd molars or premolar teeth extracted from the patients with orthodontic treatment. The cells were cultured in ${\alpha}-MEM$(minimal essential medium) supplemented with antibiotics and FBS(fetal bovine serum) at $37^{\circ}C$ in a humidified atmosphere of 5% carbon dioxide-95% air. Cells were used between the 5th to 8th passage in this study. The attachment and activity of both cells were evaluated by MTT assay. The results were as follows: 1. Maximum gingival fibroblast attachment was seen at a $50{\mu}g/ml$ dose of minocycline, while maximum periodontal ligament cell attachment was seen at a $100{\mu}g/ml$, and exposure of both cells to minocycline above maximal attachment dose results in a decline from maximum attachment. 2. The activity values of both cells tested minocycline were below to the control activity values at all concentrations. 3. The attachment values of both cells tested $TGF-{\beta}1$ were below or similar to control attachment values. On the above the findings, minocycline stimulated the cell attachment of gingival fibroblasts and periodontal ligament cells and $TGF-{\beta}1$ enhances the cell activity of periodontal ligament cells.

• Molecules and Cells
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• 제22권1호
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• pp.70-77
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• 2006

Platelets are anucleate cytoplasmic fragments derived from bone marrow megakaryocytes, and endothelial cells constitute the barrier between bloodstream and adjacent tissues. Although platelets are thought to regulate the biological functions of endothelial cells, the molecular mechanisms involved are poorly understood. With human umbilical vein endothelial cells and freshly isolated platelets, we established an in vitro model of platelet-induced endothelial cell proliferation. Platelets stimulated endothelial cell proliferation in a dose-dependent manner and transwell experiments with semi-permeable membranes suggested that direct cell-to-cell contacts were required. We developed mAbs against platelets and selected a mAb that blocks their proliferative effect. We purified the antigen by immunoprecipitation and identified it by Q-TOF MS analysis as the tetraspanin CD9. Since both platelets and endothelial cells expressed CD9 strongly on their surfaces we carried out a pre-treatment experiment that showed that CD9 molecules on the endothelial cells participate in the mitogenic effect of the platelets. The inhibitory effect of our mAb was comparable to that of a well-known functional anti-CD9 mAb. These results suggest that the tetraspanin CD9 plays an important role in endothelial regeneration.

• Journal of Periodontal and Implant Science
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• 제35권2호
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• pp.289-298
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• 2005

Bone morphogenetic protein-7(BMP-7), a member of the transforming growth factor superfamily, stimulates osteoblast differentiation and bone formation. There are lots of evidences supporting a direct participation of periodontal ligament(PDL) cells on periodontal tissue regeneration. The purpose of this study was to evaluate the effect of recombinant human(rh) BMP-7 on primary rat PDL cells in vitro, with special focus on the ability of bone formation. The PDL cells were cultured with rhBMP-7 at the concentration of 0, 10, 25, 50, 100 and 200ng/ml for MTT assay. We evaluated the alkaline phosphatase activity at 3 and 5 days of incubation and the ability to produce mineralized nodules of rat PDL cells at 14 days of cell culture in concentration of 0, 10, 25, 50 and 100ng/ml. The cell activity was not reduced in cells treated with BMP-7 at $10{\sim}100ng/ml$, whereas the cell activity was reduced in the concentration of 200ng/ml than the control at day 1 and 3(p<0.01). At 3 and 5 day, alkaline phosphatase activity was significantly increased in cells treated with BMP-7 at 50ng/ml and 100ng/ml(p<0.05). The area of mineralized bone nodule was greater in cells treated with BMP-7 at 50 and 100 ng/ml than the control(p<0.01). These results suggest that rhBMP-7 stimulate rat PDL cells to differentiate toward osteoblast phenotype and secretion of the extracellular matrix of rat PDL cells.

• 한국산림과학회지
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• 제78권4호
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• pp.372-380
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• 1989

주요(主要) 조림수종(造林樹種)의 하나인 현사시나무를 Agrobacterium rhizogenes의 agropine 계통(系統)인 A4를 이용(利用)하여 유전적(遺傳的)으로 형질전환(形質轉換)시켰다. 형질전환(形質轉換) 여부는 조직(組織)내의 opine(agropine) 존재를 분석(分析)하여 확인(確認)하였다. 형질전환(形質轉換)으로 얻어진 hairy root는 1/4MS+sucrose 30g/L에서 가장 좋은 생장(生長)을 보였으며, 식물체(植物體) 재분화(再分化)는 BAP 0.5mg/l를 첨가한 MS배지(培地)에 배양(培養)하였을 때 가장 좋은 결과(結果)를 얻었다. 재분화(再分化)된 식물체(植物體)는 뿌리가 많고 형태적(形態的)으로 변형(變形)되어 정상의 식물(植物)과 구별(區別)할 수 있었다. 부분적(部分的)으로 뿌리부분(部分)만 형질전환(形質轉換) 시킴으로써 보다 많은 뿌리를 가진 개체(個體)로 만들 수 있었고 이는 임목(林木)의 지상부(地下部) 형질개량(形質改良)에 유리(有利)한 것으로 나타났다.

• Experimental and Molecular Medicine
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• 제50권11호
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• pp.2.1-2.16
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• 2018

Supplementation of mesenchymal stem cells (MSCs) at sites of bone resorption is required for bone homeostasis because of the non-proliferation and short lifespan properties of the osteoblasts. Calcium ions ($Ca^{2+}$) are released from the bone surfaces during osteoclast-mediated bone resorption. However, how elevated extracellular $Ca^{2+}$ concentrations would alter MSCs behavior in the proximal sites of bone resorption is largely unknown. In this study, we investigated the effect of extracellular $Ca^{2+}$ on MSCs phenotype depending on $Ca^{2+}$ concentrations. We found that the elevated extracellular $Ca^{2+}$ promoted cell proliferation and matrix mineralization of MSCs. In addition, MSCs induced the expression and secretion of osteopontin (OPN), which enhanced MSCs migration under the elevated extracellular $Ca^{2+}$ conditions. We developed in vitro osteoclast-mediated bone resorption conditions using mouse calvaria bone slices and demonstrated $Ca^{2+}$ is released from bone resorption surfaces. We also showed that the MSCs phenotype, including cell proliferation and migration, changed when the cells were treated with a bone resorption-conditioned medium. These findings suggest that the dynamic changes in $Ca^{2+}$ concentrations in the microenvironments of bone remodeling surfaces modulate MSCs phenotype and thereby contribute to bone regeneration.

• Biomolecules & Therapeutics
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• 제27권1호
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• pp.25-33
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• 2019

Mesenchymal stem cells are classified as multipotent stem cells, due to their capability to transdifferentiate into various lineages that develop from mesoderm. Their popular appeal as cell-based therapy was initially based on the idea of their ability to restore tissue because of their differentiation potential in vitro; however, the lack of evidence of their differentiation to target cells in vivo led researchers to focus on their secreted trophic factors and their role as potential powerhouses on regulation of factors under different immunological environments and recover homeostasis. To date there are more than 800 clinical trials on humans related to MSCs as therapy, not to mention that in animals is actively being applied as therapeutic resource, though it has not been officially approved as one. But just as how results from clinical trials are important, so is to reveal the biological mechanisms involved on how these cells exert their healing properties to further enhance the application of MSCs on potential patients. In this review, we describe characteristics of MSCs, evaluate their benefits as tissue regenerative therapy and combination therapy, as well as their immunological properties, activation of MSCs that dictate their secreted factors, interactions with other immune cells, such as T cells and possible mechanisms and pathways involved in these interactions.

• 한국자원식물학회지
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• 제35권4호
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• pp.508-514
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• 2022

Bulbophyllum auricomum Lindl. is very popular among orchid growers due to the attractive fragrance of its flowers and has become an endangered orchid in Myanmar. In this study, we carried out an aseptic technique that can be used to conserve this endangered orchid species. The seeds of B. auricomum Lindl. were obtained from artificial pollination and cultured in MS basal medium for seed germination. The effect of coconut water and BAP in MS basal medium on callus induction was investigated. The highest callus induction was found at 2.0 mg/L BAP. The maximum growth of protocorm-like bodies (PLBs) was evaluated, and the best response was observed on MS medium supplemented with 150 mL/L coconut water at pH 5.6. MS basal medium supplemented with 150 mL/L coconut water along with 2.0 mg/L BAP and 1.0 mg/L NAA (MCBN) showed the highest number of plantlets at 15℃ at the second week of culture. At the second and third week of culture, MS medium supplemented with 2.0 mg/L BAP and 1.0 mg/L NAA (MBN) showed the best result in terms of the number of leaves and the longest leaves at 15℃ and 25℃, respectively. The present study showed evidence of successful in vitro propagation of B. auricomum Lindl.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.36-36
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• 2021

Cryopreservation has been broadly used as an efficient method for a long-term conservation for many types of plants especially vegetatively propagated plants. Among several cryopreservation methods, a droplet-vitrification was the most widely applicable and efficient method. Studies have developed protocols for strawberry using droplet-vitrification method and suggested the practical use of the protocol for large number of germplasm with a little modification. In this study, the droplet vitrification method of shoot tip has been tested on 31 accessions provided around the world. Shoot tips were precultured on Murashige and Skoog (MS) liquid medium supplemented with 0.3~0.5M sucrose. Precultured explants were osmoprotected with loading solution, 35% of PVS3 (C4, 17.5% glycerol and 17.5% sucrose) for 40 min and exposed to dehydration solution, PVS3 (B1, 50% glycerol and 50% sucrose) for 60 min. Then, the explants were transferred onto droplets containing 2.5 uL PVS3 on sterilized aluminum foils prior to direct immersion in liquid nitrogen (LN) for 1hr. The cryopreserved shoot tips were rapidly warmed in a water bath at 40C and then unloaded in MS with 0.8M sucrose for 40 min. The shoot tips were cultured in NH₄NO₃-free MS post culture medium for 2 weeks. Subsequently, the explants were moved to the MS medium for 6 weeks and evaluated the regrowth rate. By this droplet-vitrification protocol, twenty-four accessions showed at least 40% regrowth rate. Out of 24 accessions, 'Nonsan1ho' had the highest regeneration rate of 85.8% and 'Jumbo pureberry' had the lowest with 42.1%.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권1호
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• pp.38-50
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• 2013

Purpose: The aim of this study is to evaluate the effect and potential of electron beam (E-beam) irradiation treatment to the synthetic bony mixtures composed of hydroxyapatite (HA; Bongros$^{(R)}$, Bio@ Co., Korea) and tricalcium phosphate (${\beta}$-TCP, Sigma-Aldrich Co., USA), mixed at various ratios and of type I collagen (Rat tail, BD Biosciences Co., Sweden) as an organic matrix. Methods: We used 1.0~2.0 MeV linear accelerator and 2.0 MeV superconductive linear accelerator (power 100 KW, pressure 115 kPa, temperature $-30{\sim}120^{\circ}C$, sensor sensitivity 0.1~1.2 mV/kPa, generating power sensitivity 44.75 mV/kPa, supply voltage $5{\pm}0.25$ V) with different irradiation dose, such as 1, 30 and 60 kGy. Structural changes in this synthetic bone material were studied in vitro, by scanning electron microscopy (SEM), elementary analysis and field emission scanning electron microscope (FE-SEM), attenuated total reflection (ATR), and electron spectroscopy for chemical analysis (ESCA). Results: The large particular size of HA was changed after E-beam irradiation, to which small particle of TCP was engaged with organic collagen components in SEM findings. Conclusion: The important new in vitro data to be applicable as the substitutes of artificial bone materials in dental and medical fields will be able to be summarized.

• Journal of Plant Biotechnology
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• 제29권4호
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• pp.259-264
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• 2002

쪽파의 배발생 캘러스 유도에는 2,4-D의 단독첨가가 보다 효과적이었으나, 2,4-D의 농도가 높을수록 기형배의 배발생율이 높았다. BA를 혼합첨가하였을 때는 기형배가 보다 많이 발생하였다. 배형성을 위한 외식편으로는 경정이 가장 좋았으며 그 다음 인편, 엽조직 순이었다. 또한 0.09 M의 sucrose를 첨가한 배지에서 배발생 callus 유기가 가장 좋았다. 2,4-D와 BA의 농도가 상이한 배지에서 유기된 배발생 callus로부터 재분화된 식물체의 염색체 변이율은 8∼33.3%였으며, 4배체와 2배체＋4배체의 혼수체가 나타났다. 염색체 변이율은 인편 유래의 식물체에서 18.7%로 가장 높았다. 경정 부위에서 유기된 배발생 callus는 33.5%로 식물체 재분화율이 높았지만, 염색체 변이율은 7.0% 정도로 낮았다. 또한 0.26 M sucrose배지에서 배양한 식물체에서 염색체 변이율이 높았으며. 0.09∼0.20 M sucrose배지에서 분화된 식물체에서 염색체 변이율은 15.2∼16.6%로 거의 안정적이었다.