Human gingival fibroblasts (hGFs) were reported to play an important role in inflammatory reactions to lipopolysaccharide (LPS) from P.gingivalis in the periodontal connective tissue. Although the biostimulatory effects of hyperbaric oxygen therapy, such as anti-inflammatory activity, have been reported, the pathological mechanism is not completely understood. This study examined the changes in the inflammatory cytokine profiles, which are produced after exposure to hyperbaric oxygen in P.gingivalis LPS-treated human gingival fibroblasts, and subsequently to examine the mitogen activated protein kinase (MAPK) pathway involved in cytokine production. Gingival fibroblasts with or without P.gingivalis LPS were exposed to hyperbaric oxygen, and the cytokine profiles in the supernatant were observed using a human inflammation antibody array. The expression of cyclooxyginase-2 (COX-2) protein, phosphorylation of extracellular signal-regulated kinase (ERK1/2), p38, and c-Jun-N-terminal kinase (JNK) MAPK by western blot analysis, and the amount of prostaglandin E2 (PGE2) in the supernatant by an enzyme-linked immunoassay were determined. COX-2 protein expression and PGE2productionwereincreasedsignificantlyintheP. gingivalis LPS-treated group, and were decreased by treating P. gingivalis LPS with hyperbaric oxygen. Treatment of P. gingivalis LPS in the gingival fibroblasts led an increase in the amount of pro-inflammatory-related cytokines interleukin-6 (IL-6) and IL-8 released, whereas hyperbaric oxygen inhibits the irrelease. Ananalysis of the MAPK signal transduction showed that hyperbaric oxygen induced a significant decrease in the level of P38 phosphorylation regardless of the presence or absence of LPS. In addition, hyperbaric oxygen promoted JNK phosphorylation, significantly in the presence of LPS. Hyperbaric oxygen can inhibit pro-inflammatory cytokines and mediate the MAPK signal pathway, and appears to be useful as an anti-inflammatory tool.

To investigate the differential expression of genes by 635nm LEDs irradiation in arachidonic acid-treated human gingival fibroblasts, cDNA microarray was carried out. Human gingival fibroblasts were primary cultured and arachidonic acid was treated to induce inflammation. 635nm of wave length was used for LEDs irradiation. The experimental group was categorized into four group ; control, only LEDs irradiation group, only arachidonic acid-treated group and arachidonic acid-treated with LEDs irradiation group. The expression of 8,078 genes were increased and the expression of 7,103 genes were decreased in only LEDs irradiation group. For arachidonic acid-treated with LEDs irradiation group, the expression of 6,815 genes were increased, while the expression of 8,031 genes were decreased comparing with only arachidonic acid-treated group. IL-13alpha2 receptor was the most expressed gene in LEDs irradiation group comparing with control, followed by MMP3. Genes which the most down regulated was BIRC3 in LEDs irradiation group. PLAB genes was the most up-regulated in arachidonic acid treated with LEDs irradation group, followed by ranked RARRES1. Considering the classification by cell function, genes associated with signal transduction were the most affected by LEDs irradiation, followed by the genes associated with nucleoside, nucleotide and nucleic acid metabolism. In arachidonic acid treated with LEDs irradiation, genes associated with signal transduction and protein metabolism were affected. Taken together, LEDs irradiation could affect various biological process and could identify many genes related to LEDs irradiation, which could be used for clinical application.

Many researchers are interested in wound healing in the t reatment of burns, prevention of post surgical adhesions and cosmetic s urgery by excess collagen production and scar formatlOn Synthetic epidermal substi tutes with cultured epi thelial cells seem to be an attractive strategy since keratinocytes have been demonstrated to modulate fibroblast growth and collagen synthesis. Bioa bsorbable and biocompatible chitosan structurally mimics hyaluronic acid. Recently, a bio compatible synthesi zecl ch itosa n-PVP(polyvinyl pyrrolidone) hydrogels demonstrated in vitro biocompat ibi li ty for bio medical applications . However. there is no re port on this hydrogeJ"s ability to modulate human gingival fibroblast growth. The purpose of this study were to investigate different growth modulation between human gingival fibroblast and normal human oral keratinocyte by chitosan- PVP hydrogel, and to apply this biocompatible synthetic polymer to oral and maxillofacial wound healing. We have synthesized a hydrogel from chitosan-PVP and examined its effect on human gingival fibroblast growth modulation in vitro. Non-toxic and biocompatible hydrogel with human gingival fi broblasts and epithelial cells was tested by MTT assay. HGF showed a higher growth proliferation than that of NHOK after cell seeding. In MTT assay, 30% hydrogel leach out products showed a higher cellular viability in NHOK than that of any other products. In MTT assay, 30% hyclrogel leach out products showed relatively lower cellular viability of HGF ln growth profile, NHOK showed about 7 fo lcls higher than HGF after 1 day, while about 2 fo lds higher after 5 days. And also NHOK showed above about 70% cell ular via bility from 1 to 7 days. It suggested that Chitosan-PVP hydrogel would inhibit relatively the growth of HGF and s timulate the growth of NHOK_ This phenomenon may prove to be of use in wound management 0 1' oral and maxillofacial area as epitheli al substitutes.

Periodontitis is a chronic infectious disease that leads to periodontal destruction, and is one of the major causes of tooth loss in humans. The osteoclast differentiation factor (ODF), which is also known as the receptor activator of the NF-kB ligand (RANKL), is a surface-associated ligand on bone marrow stromal cells and osteoblasts. RANKL activates its cognate receptor, RANK, on osteoclast progenitor cells, which leads to the differentiation of mononucleated precursor cells. Osteoprotegerin (OPG) is a decoy receptor that is released from stromal cells and osteoblasts to inhibit the interaction between RANKL and RANK. Although the precise mechanism of bone loss in periodontitis is unknown, the differentiation and activation of osteoclasts by OPG-ODF-RANK signaling might play the role in periodontal bone destruction. The relationship between the concentration of sex hormones and the expression of ODF and OPG was examined by treating human gingival fibroblasts and periodontal ligament cells with the normal serum concentration of estrogen or progesterone during menstruation or at menopause. The ODF/OPG relative ratio was elevated at the concentration observed during ovulation in human gingival fibroblasts and at the concentration observed between ovulation and menstruation in periodontal ligament cells treated with estrogen. However, the ratio was <1 at all concentrations in both cells treated with progesterone. In the case of menopause simulated by estrogen depletion, the ratio was <1 in human gingival fibroblasts but >1 in periodontal ligament cells.

The process 0 1' wound healing needs the deposition of collagen and non-collagenous compounds, followed by the remodelling of extracellul ar matrix Recently, it has known that LEDs irradiation can help wound healing to accelerate the cell proliferation. But its mec hanism is not elucidated yot. The purpose of the present study is to observe the expression level of extracellular matrix by 635nm LEDs ir radiation. Human gingival fibroblasts were primary cultured, treated arac hidonic acid (때 and followed by LEDs irradiation. To observe the mRNA expression of extracellular matrix, cDNA mlcroarray was ca n‘ ied out 1n present study, 3 experimental groups were categorized into control, AA-treated group, and AA-treated with LEDs irradiation group. The differential expressions of MMP-1, -2, -3, - 10, - 11, -14, -16, - 17, -25 and TIMP-1, -2, -3. -4 were observed. Especially, mRNA expression of T1MP-3 was 10 fold decreased in arach idonic acid -treated with 635nm LEDs irradiation group. Finally, LEDs irradation can affect the expression level of MMPs and TIMPs, which lead to prolifer ation of gingival fibroblasts and result in would healing

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotes stimulation of wound healing have been well known, there are few reports about molecular mechanism associated with cell cycle by LED irradiation. The purpose of present study was to examine the molecular event in cell cycle of LED irradiation on primary human gingival fibroblast(hGF) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635nm, and manufactured that energy density was 5mW/cm2 on sample surface. The hGF were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 8 and 24 hour after irradiation. To investigate the molecular mechanisms associated with cell cycle, growth phase was determined by flow cytometry and mRNA expression of cyclin A, cyclin B, cyclin D1, cyclin E, cdc2, PCNA, p18, p27, p21, and p53 were determined by real time RT-PCR. Flow cytometric analysis demonstrated the percentage of cells in the G1 and S phase were decreased, but the G2 phase increased, which showed cells irradiated by LED were transitioned from S to G2 phase. For mRNA expression, cyclin B, cdc2, PCNA and p53 were increased at 0 hour after irradiation, and most of cell cycle molecules were increased at 8 hour after irradiation. At 24 hour after irradiation, cyclin A, cyclin E, PCNA and p18 were increased. Taken together, LED irradiation induced proliferation of hGF cells through transition from S to G2 phase.

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-xB 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.

The aim of this study was to investigate the cytotoxicity of dental casting gold alloys. Recently, "biocompatability" is considered the most important requirement of dental materials. Dental metals and alloys were estimated by quantity of released ions, which had influenced to living tissues. The requirement of using normal human cells for cytoxicity strudy were abruptly increased. We used the cultured normal human gingival fibroblasts to estimate the cytotoxicity of dental casting gold alloys. The product of S company(Korea, AIGIS-SOFT, AIGIS-PLUS, AIGIS-A, AIGIS-PT, experimental group) and D company's (German, Biocclus inlay, Biolor SG, Stabilor NF Ⅳ, Degulor B, control group) dental casting gold alloys were used. The morphological investigation, hemolysis test, MTT assay and SRB assay were done in vitro. In vivo, inflammatory reaction in rat was examined for 2 weeks. 1. In the result of cytotoxicity assay, there were some differences but was no significancy among the results between two group's hemolysis, MTT and SRB assay. 2. The gingival fibroblasts attached to the surface of dental casting gold alloy showed various features and increased in number as the time had passed. 3. In vivo, chronic inflammatory cell infiltration was prominent from 3 days to 1 week and inflammation was reduced as time had gone. From the aboving results, there were no significant differences in cytoxicity depending on the ratio of gold content, but showed differences depending on the ratio of total precious and non-precious metal content between two groups. In vitro study showed few differences in inflamation reaction.

Eugenol (4-allyl-2-methoxyphenol) is a phenol derivative and generally used in dental treatment. A few investigator reported that eugen이-induced C)πoto잉city by apopto디c pathway, but it is not yet well understood In the present study, to investigate the eugenol-induced cytoto잉city by apoptosis, we have examined the apoptotic molecules and pathway in primary human gingival fibroblast (HGF) and human salivary gland cells (HSG). To identify apoptotic cell death, 3-(4,5-dimethylthiazol-2-yl)-2 ,5-diphenyl tetrazolium bromide (MTT) reduction assay with or without N-acetylcysteine (NAC), and the morphological study by propidium iodide (pI) staining were screened. And to investigate the apoptotic pathway, reverse transcriptase-polymerase chain reaction (RT-PCR) for apoptotic molecules and caspase aαivity assay were performed. Both M1T reduction assay and an addition of NAC showed that eugenol act as a pro-oxidant led to cell death. With the morphological study, both cells showed apoptotic change by nuclear fragmentation and/or chromatin condensations. With the apoptotic machinery study, the Bax and Bcl-2 mRNA expression were not detected in HGF. But, for HSG, the increased expression of Bax with decreased of Bcl-2 was observed. And the expression of Apaf-l was not detected or nα significantly increased in HGF and HSG, respectively. With measure of caspase activity, there was no change of caspase activities in HGF. But, for HSG, there was decrease of caspase 9 activity and increased caspase 3 activity. We suggest eugenol-treated HGF underwent apoptosis independent of Bcl family and caspase. However, for eugenol-πeated HSG, apoptosis occurred via Bcl famiIy and caspase pathway.