• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.271-279
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• 2018

Previous studies to elucidate the etiology of cyclosporine(Cs)-induced gingival overgrowth in children have not completely excluded all factors that may cause differences among individuals. This study examined the effect of cyclosporine on the metabolism of type 1 collagen(CoL-I) in experimental models that controlled the effects of biological variations on individuals. Five 5-week-old male Sprague-Dawley rats were administered Cs by gastric feeding for 6 weeks. Gingival specimens were harvested from the mandibular posterior area before beginning Cs administration and at 2, 4, and 6 weeks thereafter. Gingival fibroblasts were cultured from all the 20 biopsies collected from the gingiva. Half of the fibroblasts collected prior to the Cs administration were designated as Control. The other half of the fibroblasts were treated with Cs in vitro and called in vitro test group(Tt). The fibroblasts collected 2, 4, and 6 weeks after the Cs administration were called in vivo test groups : T2, T4, T6, respectively. Immunofluorescence microscopy was used to detect CoL-I in all the fibroblasts. CoL-I was analyzed at both the gene and protein expression levels by real-time polymerase chain reaction and western blotting. Changes in CoL-I before and after Cs treatment were evaluated from the gingiva of each rat. There was no significant difference in gene expression of CoL-I in the control and test groups. CoL-I protein expression levels of fibroblasts increased in in vitro Cs treatment for each individual, and also increased in in vivo Cs treatment. In this study, the experimental method that control biological variations that can occur due to differences among individuals was useful. Subsequent studies on other factors besides CoL-I and in-depth studies in humans are needed.

• Journal of Korean Dental Science
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• v.7 no.2
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• pp.80-86
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• 2014

Purpose: Current common method of cytotoxicity evaluation for elastomeric impression materials use animal based cell lines, which the clinical relevance has been often questioned. Hence, the purpose of this study was to examine the difference in results with both human based and animal based fibroblast cell line. Materials and Methods: Three types of fibroblast cells were used in this study; conventional mouse fibroblasts of L929, human gingival fibroblasts (HGF-1), and immortalized human oral fibrobalsts (hTERT-hNOF). Test on extract and test by direct contact using different commercially available elastomeric impression materials were carried out according to the international standards. Result: There was significant difference in cell viability between types of fibroblasts cell used, where HGF-1 showed highest cell viability and L929 the lowest. Conclusion: Within the limitation of this study, careful consideration must be given when selecting the cells and interpreting the results for cytotoxicity evaluation of elastomeric impression materials, where use of human based cell lines such as hTERT-hNOF would be appropriate for both ease of cytotoxicity test and clinical relevance.

• International Journal of Oral Biology
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• v.30 no.3
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• pp.105-110
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• 2005

Periodontitis is a chronic infectious disease that leads to the destruction, one of the major cause of tooth loss in human. Osteoclast Differentiation Factor(ODF), also called as Receptor activator of NF-${\kappa}B$ ligand(RANKL), a surface-associated ligand on bone marrow stromal cells and osteoblasts, activates its cognate receptor RANK on osteoclast progenitor cells, which leads to differentiation of these mononucleated precursor cells. Osteoprotegerin(OPG), a decoy receptor, is released from stromal cells and osteoblasts to inhibit the interaction between RANKL and RANK. The experiment for the effect of pregnancy on gingival health showed greater gingival inflammation and edema during pregnancy, despite similar plaque index. There should be many factors affecting the periodontal health in pregnancy. In this experiment, we examined the direct effects of sex hormones(estrogen and progesterone) on the ODF/OPG expression in human gingival fibroblasts and periodontal ligament cells at the serum concentration of pregnancy. The ratio was high in the 1st trimester of pregnancy by estrogen and in the late 2nd trimester by progesterone. Therefore, the local periodontal destruction might be accelerated by these hormonal effect on the periodontal cells.

• International Journal of Oral Biology
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• v.32 no.1
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• pp.35-43
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• 2007

Tooth loss in elderly is mainly caused by alveolar bone loss via severe periodontitis. Although the severity of periodontitis is known to be affected by age, the aging process or the genetic changes during the aging of periodontal tissue cells are not well characterized. In this study, we investigated the effect of in vitro aging on the change of gene expression pattern in periodontal fibroblasts. Gingival fibroblasts (GF) and periodontal ligament fibroblasts (PDL) were obtained from two young patients and replicative senescence was induced by sequential subcultivation. When more than 90% cells were positively stained with senescence-associated ${\beta},-galactosidase$, those cells were regarded as aged cells. In aged GF and PDL, the level of phosphorylated retinoblastoma (RB) and $p16^{INK4A}$ protein was significantly decreased and increased, respectively. However, the protein level of p53 and p21, well known senescence-inducing genes, did not increase in aged GF and PDL. Although $p27^{Kip1}$ and $p15^{INK4B}$, another cyclin-dependent kinase inhibitors, were reported to be involved in replicative senescence of human cells, they were decreased in aged GF and PDL. Because senescent cells showed flattened and enlarged cell shape and are known to have increased focal adhesion, we examined the protein level of several integrins. Aged GF and PDL showed increased protein level of integrin ${\alpha}2$, ${\alpha}v$, and ${\beta}1$. When the gene expression profiles of actively proliferating young cells and aged cells were compared by cDNA microarray of 3,063 genes and were confirmed by reverse transcription-polymerase chain reaction, 7 genes and 15 genes were significantly and commonly increased and decreased, respectively, in aged GF and PDL. Among them, included are the genes that were known to be involved in the regulation of cell cycle, gene transcription, or integrin signaling. The change of gene expression pattern in GF and PDL was minimally similar to that of oral keratinocyte. These results suggest that $p16^{INK4A}/RB$ might be involved in replicative senescence of periodontal fibroblasts and the change of gene expression profile during aging process is cell type specific.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.787-801
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• 2001

The molecular mechanisms control the function of PDL(periodonta1 ligament) cells and/or fibroblasts remain unclear. PDLsl7, PDL-specific gene, had previousely　identified the cDNA for a novel protein from cultured　PDL fibroblasts using subtraction hybridization between gingival fibroblasts and　PDL fibroblasts. The purpose　of this study was to determine the regulation by growth factors and cytokines on　PDLsl7 gene expression in　cultured human periodontal ligament cells and observe the immunohistochemical　localization of PDLsl7 protein in various tissues of mouse. Primary PDL fibroblasts isolated by scraping the root of the extracted human mandibular third molars. The cells were incubated with various concentration of human recombinant $IL-1{\beta}$, PDGF-BB and TGF\;${\beta}$ for 48h nd 2 weeks. At each time point total RNA was extracted and the levels of transcription ere assessed by reverse transcription-polymerase chain reaction (RT-PCR assay). polyclonal antiserum raised against PDLsl7 peptides, CLSVSYNRSYQINE and SEAVHETDLHDGC, were made, and stained the tooth, periodontium, developing bone, bone marrow and mid-palatal suture of the mouse. The results were as follows. 1. PDLsl7 mRNA levels were increased in response to PDGF (10ng/ml) and $TGF\;{\beta}$(20ng/ml) after treatment of the $IL-1{\beta}$, PDGF-BB and $TGF{\beta}$for 48 h. 2. PDLsl7 was up-regulated only by $TGF{\beta}$(20 ng/ml) after treatment of the $IL-1{\beta}$, PDGF-BB and $TGF\;{\beta}$ for 2 weeks and unchanged by the other stimulants. 3. PDLsl7 was a novel protein coding the 142 amino acid peptides in the ORF and the nucleotide sequences of the obtained cDNA from RT-PCR was exactly same as the nucleotides of the database. 4. Immunohistochemical analysis showed that PDLsl7 is preferentially expressed in the PDL, differentiating osteoblast-like cells and stromal cells of the bone marrow in the adult mouse. 5. The expression of PDLsl7 protein was barely detectable in gingival fibroblasts, hematopoetic cells of the bone marrow and mature osteocytes of the alveolar bone. These results suggest that PDLsl7 might upregulated by PDGF-BB or $TGF{\beta}$ and acts at the initial stage of differentiation when the undifferentiated mesenchymal cells in the bone marrow and PDL differentiate into multiple cell types. However, more research needs to be performed to gain a better understanding of the exact function of PDLsl7 during the differentiation of bone marrow mesenchymal and PDL cells.

• Journal of Periodontal and Implant Science
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• v.17 no.1
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• pp.106-106
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• 1987

• Journal of Periodontal and Implant Science
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• v.18 no.2
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• pp.126.1-126.1
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• 1988

• Journal of Periodontal and Implant Science
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• v.21 no.2
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• pp.188.2-188.2
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• 1991

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.71.2-71.2
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• 2006

• Journal of Periodontal and Implant Science
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• v.18 no.1
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• pp.116.1-116.1
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• 1988