Functions of non-coding RNAs in the osteogenic differentiation of human periodontal ligament-derived cells / 华西口腔医学杂志

Human periodontal ligament-derived cells serve as an important source of seeding cells in periodontal regenerative medicine, and their osteogenic potential is closely related to alveolar bone repair and periodontal regeneration. Non-coding RNA (ncRNA), such as microRNA, long non-coding RNA, and circular RNA, play important roles in the regu-lation of osteogenic genes in human periodontal ligament-derived cells. In this review, we summarize the target genes, path-ways, and functions of the ncRNA network during osteogenic differentiation of periodontal ligament-derived cells.

Effect of procyanidin B2 on inflammatory mediators of human periodontal ligament cells / 上海交通大学学报（医学版）

Objective: To investigate the effects of procyanidin B2 on the expression of inflammatory mediators in human periodontal ligament cells (hPDLCs) induced by Porphyromonas gingivalis lipopolysaccharide (LPS). Methods: hPDLCs were cultured using tissue explant method in vitro. The effect of procyanidin B2 on the cell viability of hPDLCs was detected by MTT assay. hPDLCs were stimulated by P. gingivalis LPS after treatment with procyanidin B2 for 1 h. The expressions of IL-1β, IL-6, and IL-8 mRNA and proteins were detected by real-time PCR and ELISA assay. Reactive oxygen species (ROS) in the cytoplasm was observed under fluorescence microscope. Nitric oxide (NO) in the supernatant was detected by Griess assay. Results: 100.00 µg/mL procyanidin B2 could enhance the cell viability of hPDLCs. Procyanidin B2 could inhibit the expressions of IL-1β, IL-6, and IL-8 mRNA and proteins in hPDLCs. It could also downregulate ROS and NO in hPDLCs induced by P. gingivalis LPS. Conclusion: Procyanidin B2 can play an anti-inflammatory role by inhibiting inflammatory mediators in hPDLCs induced by P. gingivalis LPS.

Effect of Dexamethasone on the Expression of Interleukin?6 and Interleukin?8 in Human Periodontal Ligament Cells / 中国医科大学学报

Objective To explore the effect of dexamethasone(Dex)treatment on the expression of interleukin(IL)?6 and IL?8 in human peri?odontal ligament cells(hPDLCs). Methods hPDLCs were subjected to one of the following treatments for 24 h or 48 h:10-9 mol/L Dex;10-6 mol/L Dex;10μg/mL Porphyromonas gingivalis(P. g)?lipopolysaccharide(LPS);10-9 mol/L Dex+10μg/mL P. g?LPS;10-6 mol/L Dex+10μg/mL P. g?LPS;or 0.1%absolute ethyl alcohol(control). Protein and mRNA expression was detected using ELISA and real?time PCR ,respectively. Results At 24 h and at 48 h,IL?6 and IL?8 protein expression in the 10-9 mol/L Dex?and 10-6 mol/L Dex?treated groups was significantly lower than that in the control group(P<0.05). At 48 h,IL?6 mRNA expression in the 10-9 mol/L Dex?and 10-6 mol/L Dex?treated groups was signifi?cantly lower than that in the control group(P<0.05),while IL?8 mRNA expression in the 10-6 mol/L Dex?treated group was significantly higher than that in the control group(P<0.05). At 24 h and at 48 h,IL?6 protein and mRNA expression in the 10-9 mol/L Dex+10μg/mL P. g?LPS?treated group and the 10-6 mol/L Dex+10μg/mL P. g?LPS?treated group was significantly lower than that in the 10μg/mL P. g?LPS?treated group (P<0.05). At 24 h,IL?8 protein expression in the 10-9 mol/L Dex+10μg/mL P. g?LPS?treated group and the 10-6 mol/L Dex+10μg/mL P. g?LPS?treated group was significantly lower than that in the 10μg/mL P. g?LPS?treated group(P<0.05),while no such significant difference exist?ed at 48 h. At 48 h,IL?8 mRNA expression in the 10-6 mol/L Dex+10μg/mL P. g?LPS?treated group was significantly higher than that in the 10μg/mL P. g?LPS?treated group(P<0.05). Conclusion Dex inhibits the innate and P. g?LPS?induced expression of IL?6 in hPDLCs. However, Dex exerts profound effects on IL?8 expression,and treatment with high doses of Dex may promote IL?8 expression over an extended period.

Effects of Luteolinl on the Proliferation and Differentiation in Human Periodontal Ligament Cells / 沈阳医学院学报

Objective:To evaluate the biological effects of Luteolinl on the proliferation and differentiation in human periodontal ligament cells (PDLC) . Methods:MTT, ALP kit and Q-PCR was used to detect the expression of osteogenesis related gene. Results:Luteolinl (100, 10, 1, 0.1, 0.01μmol/L) could increase the proliferation of PDLC, and there were significant differences compared with control group (P<0.05) . The ALP Kit results showed that Luteolinl could increase the ALP actiuty of PDLC (P<0.05) . The Q-PCR results showed that Luteolin could increase the expression of ALP and RUNX2 (P<0.05) . Conclution:At proper concentration,Luteolinl can increase the proliferation and differentiation of PDLC.

Effects of proanthocyanidin, a crosslinking agent, on physical and biological properties of collagen hydrogel scaffold

OBJECTIVES: The purpose of the present study was to evaluate the effects of proanthocyanidin (PAC), a crosslinking agent, on the physical properties of a collagen hydrogel and the behavior of human periodontal ligament cells (hPDLCs) cultured in the scaffold. MATERIALS AND METHODS: Viability of hPDLCs treated with PAC was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The physical properties of PAC treated collagen hydrogel scaffold were evaluated by the measurement of setting time, surface roughness, and differential scanning calorimetry (DSC). The behavior of the hPDLCs in the collagen scaffold was evaluated by cell morphology observation and cell numbers counting. RESULTS: The setting time of the collagen scaffold was shortened in the presence of PAC (p < 0.05). The surface roughness of the PAC-treated collagen was higher compared to the untreated control group (p < 0.05). The thermogram of the crosslinked collagen exhibited a higher endothermic peak compared to the uncrosslinked one. Cells in the PAC-treated collagen were observed to attach in closer proximity to one another with more cytoplasmic extensions compared to cells in the untreated control group. The number of cells cultured in the PAC-treated collagen scaffolds was significantly increased compared to the untreated control (p < 0.05). CONCLUSIONS: Our results showed that PAC enhanced the physical properties of the collagen scaffold. Furthermore, the proliferation of hPDLCs cultured in the collagen scaffold crosslinked with PAC was facilitated. Conclusively, the application of PAC to the collagen scaffold may be beneficial for engineering-based periodontal ligament regeneration in delayed replantation.

Evaluation of the Viability of Rat Periodontal Ligament Cells after Storing at 0℃/2 MPa Condition up to One Week: In Vivo MTT Method

PURPOSE: The aim of this study was to evaluate the rat periodontal ligament cell viability under 0℃/2 MPa condition up to one week using in vivo 3-(4,5-dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT) assay. MATERIALS AND METHODS: As soon as 110 upper molar teeth of rats were extracted, they were stored in Hartman's solution under 0℃/2 MPa condition for 1, 2, 3, 4, and 7 days each. All specimens were treated with in vivo MTT assay and the value of optical density was measured by ELISA reader. These values were statistically analyzed by one-way ANOVA. RESULT: There was no statistical difference on MTT value between immediate and 1 day storage group. There were statistically significant differences between 1 day and 2 days tsorage, 2 and 3 days storage groups, respectively. Teeth of 3,4, and 7 days storage groups showed significantly lower MTT valuesc ompared with shorter period storage groups. CONCLUSION: When the MTT values were substituted in standard curve, 1 day storage group at 0℃/2 MPa condition showed 68% cell viability when compared with immediate group. It dropped to 13% at 2 days, and to less than 5% at 3 days or more.

The evaluation of periodontal ligament cells of rat teeth after low-temperature preservation under high pressure / 대한치과보존학회지

The purpose of this study was to evaluate the viability of periodontal ligament cells of rat teeth after low-temperature preservation under high pressure by means of MTT assay, WST-1 assay. 12 teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both side of the first and second maxillary molars were extracted as atraumatically as possible under tiletamine anesthesia. The experimental groups were group 1 (Immediate extraction), group 2 (Slow freezing under pressure of 3 MPa), group 3 (Slow freezing under pressure of 2 MPa), group 4 (Slow freezing under no additional pressure), group 5 (Rapid freezing in liquid nitrogen under pressure of 2 MPa), group 6 (Rapid freezing in liquid nitrogen under no additional pressure), group 7 (low-temperature preservation at 0degrees C under pressure of 2 MPa), group 8 (low-temperature preservation at 0degrees C under no additional pressure), group 9 (low-temperature preservation at -5degrees C under pressure of 90 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in 37degrees C water bath, then MTT assay, WST-1 assay were processed. One way ANOVA and Tukey HSD method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 7 (0degrees C/2 MPa) showed higher viability of periodontal ligament cells than other group (2-6, 8) and this was statistically significant (p < 0.05), but showed lower viability than group 1, immediate extraction group (no statistical significance). By the results of this study, low-temperature preservation at 0degrees C under pressure of 2 MPa suggest the possibility for long term preservation of teeth.

Biocompatibility of bioaggregate cement on human pulp and periodontal ligament (PDL) derived cells / 대한치과보존학회지

OBJECTIVES: This study was performed to investigate the biocompatibility of newly introduced Bioaggregate on human pulp and PDL cells. MATERIALS AND METHODS: Cells were collected from human pulp and PDL tissue of extracted premolars. Cell culture plate was coated either with Bioaggregate or white MTA, then the same number of cells were poured to cell culture dishes. Cell attachment and growth was examined under a phase microscope after 1,3 and 7 days of seeding. Cell viability was measured and the data was analyzed using Student t-test and one way ANOVA. RESULTS: Both types of cells used in this study were well attached and grew healthy on Bioaggregate and MTA coated culture dishes. No cell inhibition zone was observed in Bioaggregate group. There was no statistical difference of viable cells between bioaggreagte and MTA groups. CONCLUSIONS: Bioaggregate appeared to be biocompatible compared with white MTA on human pulp and PDL cells.

Influence of baicalin on the expression of receptor activator of nuclear factor-κB ligand and osteoprotegerin in human periodontal ligament cells / 药物分析学报

Objective To study the effect of baicalin on the expression of receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in cultured human periodontal ligament (HPDL) cells. Methods Small interfering RNA (siRNA) eukaryotic expression vector targeted transforming growth factor βⅡ receptor (TGF-β RⅡ) was constructed and transfected into T cells. HPDL cells with T cells transfected with siRNA or not were placed in the culture medium that had been added with lipopolysaccharide (LPS) and baicalin. The obtained solution was divided into six groups according to the components (group Ⅰ: HPDL cells+LPS+T cells transfected with siRNA1+baicalin;group Ⅱ: HPDL cells+LPS+T cells transfected with siRNA1; group Ⅲ: HPDL cells+LPS+T cells+baicalin; group Ⅳ: HPDL cells+LPS+T cells; group Ⅴ: HPDL cells+baicalin; group Ⅵ: HPDL cells) and was cultured for 48 hours. RT-PCR was used to observe the effect of baicalin on the expression of OPG-RANKL in HPDL cells. Results The ratio of RANKL/OPG in group Ⅰ was lower than that in group Ⅱ (P<0.01) and higher than that in group Ⅲ (P<0.01); The ratio of RANKL/OPG in gronp Ⅲ was lower than that in group Ⅳ (P<0.01); the ratio of RANKL/ OPG in group Ⅳ was higher than that in group Ⅵ (P<0.01); the ratio of RANKL/OPG in group Ⅴ was lower than TGF-β signaling transduction plays an important role in the effect of baicalin on the RANKL/OPG ratio in HPDL cells.

Influence of baicalin on the expression of receptor activator of nuclear factor-κB ligand and osteoprotegerin in human periodontal ligament cells / 西安交通大学学报·英文版

Objective: To study the effect of baicalin on the expression of receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in cultured human periodontal ligament (HPDL) cells. Methods: Small interfering RNA (siRNA) eukaryotic expression vector targeted transforming growth factor βII receptor (TGF-β R II) was constructed and transfected into T cells. HPDL cells with T cells transfected with siRNA or not were placed in the culture medium that had been added with lipopolysaccharide (LPS) and baicalin. The obtained solution was divided into six groups according to the components (group I: HPDL cells+LPS+ T cells transfected with siRNA1 + baicalin; group II: HPDL cells+LPS+T cells transfected with siRNA1; group III: HPDL cells+LPS+T cells+baicalin; group IV: HPDL cells+LPS+T cells; group V: HPDL cells+baicalin; group VI: HPDL cells) and was cultured for 48 hours. RT-PCR was used to observe the effect of baicalin on the expression of OPG-RANKL in HPDL cells. Results: The ratio of RANKL/OPG in group I was lower than that in group II (P<0.01) and higher than that in group III (P<0.01); The ratio of RANKL/OPG in group III was lower than that in group IV (P<0.01); the ratio of RANKL/OPG in group IV was higher than that in group VI (P<0.01); the ratio of RANKL/OPG in group V was lower than that in group VI (P<0.05). Conclusion: Circled digit one Baicalin could decrease the ratio of RANKL/OPG in HPDL cells. Circled digit two The TGF-β signaling transduction plays an important role in the effect of baicalin on the RANKL/OPG ratio in HPDL cells. Circled digit three Baicalin acts not only through TGF-β to regulate RANKL/OPG in HPDL cells, but also through other pathways.

The efficacy of programmed cryo-preservation under pressure in rat periodontal ligament cells / 대한치과보존학회지

The purpose of this study was to evaluate the viability of periodontal ligament cells in rat teeth using slow cryo-preservation method under pressure by means of MTT assay and WST-1 assay. Eighteen teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both sides of the first and second maxillary molars were extracted as atraumatically as possible under Tiletamine anesthesia. The experimental groups were group 1 (Immediate control), group 2 (Cold preservation at 4degrees C for 1 week), group 3 (Slow freezing), group 4 (Slow freezing under pressure of 3 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in 37degrees C water bath, then MTT assay and WST-1 assay were processed. One way ANOVA and Tukey method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 4 showed significantly higher viability of periodontal ligament cells than group 2 and 3 (p < 0.05), but showed lower viability than immediate control group. By the results of this study, slow cryo-preservation method under pressure suggests the possibility for long term cryo-preservation of the teeth.

Evaluation of the viability of periodontal ligament cell in rat teeth using slow cryopreservation method with magnetic field / 대한치과보존학회지

The purpose of this study was to evaluate the viability of periodontal ligament cell in rat teeth using slow cryopreservation method with magnetic field through MTT assay and TUNEL test. For each group, 12 teeth of 4 weeks old white female Sprague-Dawley rat were used for MTT assay, and 6 teeth in TUNEL test. The Maxillary left and right, first and second molars were extracted as atraumatically as possible under tiletamine anesthesia. The experimental groups were group1 (immediately extraction), group 2 (cold preservation at 4degrees C for 1 week), group 3 (rapid cryopreservation in liquid nitrogen), group 4 (slow cryopreservation with magnetic field of 1 G), and group 5 (slow cryopreservation). F medium was used as preservation medium and 10% DMSO as cryoprotectant. After preservation and thawing, the MTT assay and TUNEL test were processed. One way ANOVA and Scheffe method were performed at the 95% level of confidence. The value of optical density obtained after MTT analysis was divided by the value of eosin staining for tissue volume standardization. In both MTT assay and TUNEL test, it had showed no significant difference among group 3, 4, and 5. And group 3 had showed higher viability of periodontal ligament cell than group 2. From this study, slow cryopreservation method with magnetic field can be used as one of cryopreservation methods.

Effects of various NSAIDs on prostaglandin synthesis and cellular configuration of human periodontal ligament cells

The present study was designed to evaluate effects of the commonly used NSAIDs(acetaminophen, aspirin, and ibuprofen) on human periodontal ligament cells. Human periodontal ligament cells were grown from a cell line provided by Kyungpook National University. Effects of NSAIDs on the proliferation of human periodontal ligament cells were assessed using MTT assays. And then PGE2 concentrations were determined by ELISA and the changes of cellular configuration were found by electron micrograph. The results were as follows; 1. The MTT assay demonstrated that the commonly used NSAIDs(acetaminophen, aspirin, and ibuprofen) had not significant cytotoxic effect on human periodontal ligament cells. 2. NSAIDs inhibited the PGE2 synthesis of human periodontal ligament cells compared with the control group. These inhibitory effects had no significant differences with NSAID type and concentration. 3. Electron micrographs of human periodontal ligament cells treated with NSAIDs showed more narrow and irregular shape.

Evaluation of the radiopacity and cytotoxicity of resinous root canal sealers / 대한치과보존학회지

The aim of this study was to evaluate the radiopacity and cytotoxicity of three resin-based (AH 26, EZ fill and AD Seal), a zinc oxide-eugenol-based (ZOB Seal), and a calcium hydroxide-based (Sealapex) root canal sealers. Specimens, 10 mm in diameter and 1 mm in thickness, were radiographed simultaneously with an aluminum step wedge using occlusal films, according to ISO 6876/2001 standards. Radiographs were digitized, and the radiopacity of sealers was compared to the different thicknesses of the aluminum step wedge, using the Scion image software. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of each material was determined in immortalized human periodontal ligament (IPDL) cells. The results demonstrated that EZ fill was the most radiopaque sealer, while Sealapex was the least radiopaque (p 0.05). These results indicate that resin-based root canal sealer is more biocompatible and has advantage in terms of radiopacity.

Effects of berberine hydrochloride on secretion of interleukin-6 from human periodontal ligament cells cultured in vitro / 上海第二医科大学学报

Objective To observe the effects of berberine hydrochloride on the secretion of interleukin-6(IL-6)from human periodontal ligament cells(PDLCs)cultured in vitro.Methods Periodontal ligament tissues were isolated from extracted human premolars,and PDLCs were cultured in vitro.After identification by immunohistochemistry technique,human PDLCs were divided into LPS group and NLPS group according to whether lipopolysaccharide(LPS,50 ?g/mL)was contained in cell culture media.Then in accordance with the final concentrations of berberine hydrochloride in cell culture media(0,0.010,0.020,and 0.030 g/L),the groups were subdivided into LPS and NLPS control group,LPS1 and NLPS1 group,LPS2 and NLPS2 group,LPS3 and NLPS3 group.IL-6 contents in supernatants of each group were determined by enzyme-linked immunosorbent assay,and statistical analysis and comparison were conducted as well.Results Compared with corresponding LPS and NLPS groups,IL-6 contents in supernatants of LPS3 group and NLPS3 group reduced markedly(P

Evaluation of periodontal ligament cell viability in rat teeth according to various extra-oral dry storage times using MTT assay / 대한치과보존학회지

The purpose of this study was to verify the usefulness of MTT analysis as a tool of measurement of the periodontal ligament cell viability from the extracted rat molar. A total of 80 Sprague-Dawley white female rat of 4 week-old with a body weight of 100 grams were used. The maxillary left and right, first and second molars were extracted under Ketamine anesthesia. Twenty-four teeth of each group (divided as five groups depending upon the time-lapse after extraction such as immediate, 10, 20, 40 and 60 minutes) were immersed in 200 microl of MTT solution (0.5 mg/ml) and processed for optical density measurements . Another 10 teeth of each group were treated as same as above and sectioned at 10 microm for microscopic examination. All measurements values were divided by the value of hematoxylin-eosin staining which represented the volume of each corresponding samples. Immediate and 10 minute groups showed highest MTT values followed by 20, 40, and 60 minutes consecutively. Statistical significance (p < 0.05) existed between all groups except in immediate versus 10 minute groups and 40 versus 60 minutes. Histological findings also showed similar findings with MTT results in crystal shape and crystal numbers between the experimental groups. These data indicate that in vivo MTT analysis may be of value for evaluation of the periodontal ligament cell viability without time- consuming cell culturing processes.

Role of MAP kinase on MMP-13 expression in rat periodontal ligament cells / 대한치주과학회지

No abstract available.

Inhibition of mRANKL Expression by Doxycycline in Rat Periodontal Ligament Cells / 대한치주과학회지

Osteoblast or bone marrow stromal cell-derived RANKL is the major effector molecule essential for osteoclastogenesis. Previous studies have shown that tetracyclines have beneficial therapeutic effects in the prevention and treatment of inflammatory bone disease including periodontal disease. Periodontal ligament cells are thought not only to play an important role in the progression of periodontal disease, but to play an important role in alveolar bone remodeling. Previous studies indicated that receptor activation of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) are expressed in periodontal ligament cells by pro-inflammatory cytokine, such as IL-1beta and TNF-alpha . This study was designed to investigate the inhibitory effect of doxycycline on RANKL and OPG mRNA in rat periodontal ligament cells induced by IL-1beta(1 ng/ml). The results are as follows; 1. MTT assay showed that doxycycline at the concentration of 1-50 microgram/ml didn't result in statistically significant cell death at day 1 and 3 . 2. RANKL mRNA expression was increased to 2.6 folds by IL-1beta. When cells were treated with doxycycline (50 microgram/ml), IL-1beta-induced mRANKL expression was reduced by 33%. In contrast to RANKL, OPG mRNA expression was not inhibited by pre-treatment with doxycycline. These results suggest that doxycycline decrease the expression of mRANKL resulting in regulation of osteoclastogenesis in rat periodontal ligament cells.

Evaluation of periodontal ligament cell viability in rat teeth after frozen preservation using in-vivo MTT assay / 대한치과보존학회지

The purpose of this study was to examine the viability of PDL cells in rat molars by using in vivo MTT assay, which was used to compare fast cryopreservation group by liquid nitrogen (-196degrees C) with 4degrees C cold preservation group. A total of 74 Sprague-Dawley white female rats of 4 week-old with a body weight of 100 grams were used. The maxillary left and right, first and second molars were extracted as atraumatically as possible under ketamine anesthesia. Ten teeth of each group were divided as six experimental groups depending upon the preservation. Cryopreservation groups were Group 1 (5% DMSO 6% HES in F medium), Group 2 (10% DMSO in F medium), Group 3 (5% DMSO 6% HES in Viaspan(R)), Group 4 (10% DMSO in Viaspan(R)) which were cryopreserved for 1 week and cold preservation groups were Group 5 (F medium), Group 6 (Viaspan(R)) at 4degrees C for 1 week. Immediate extraction group was used as a control. After preservation and thawing, the in vivo MTT assay was processed. Two way ANOVA and Duncan's Multiple Range Test was performed at the 95% level of confidence. Another 2 teeth of each group were treated as the same manner and frozen sections 10 microm thick for microscopic observation. The value of optical density obtained after in vivo MTT analysis was divided by the value of eosin staining for tissue volume standardization. Group 1, 2 had significantly higher optical density than Group 3 and 4 which had the lowest OD value. Group 6 had higher OD value than in Group 5 (P < 0.05). Histological findings of periodontal ligament cell, after being stained with MTT solution were consistent with the in vivo MTT assay results. In this study, the groups which were frozen with DMSO as a cryoprotectant and the groups with F medium showed the best results.

Screening of genes differentially expressed in cultured human periodontal ligament cells and human gingival fibroblasts / 대한치주과학회지

Periodontal ligament(PDL) cells and human gingival fibroblasts(HGFs) play important roles in development, regeneration, normal function, and pathologic alteration. PDL cells and HGFs have the similarity related with general characteristics of fibroblast such as spindle shaped morphology, the presence of vimentin intermediate filament and the synthesis of interstitial collagens and fibronectin. There were many studies about the differences between PDL cells and HGFs, but they were not about whole gene level. In this study, we tried to explain the differences of gene expression profiles between PDL cells and HGFs, and the differences among three individuals by screening gene expression patterns of PDL cells and HGFs, using cDNA microarray. Although there were some variants among three experiments, a set of genes were consistentely and differentially expressed in one cell type. Among 3,063 genes, 49 genes were more highly expressed in PDL cells and 12 genes were more highly expressed in HGFs. The genes related with cell structure and motility were expressed more highly in PDL cells. These are cofilin 1, proteoglycan 1 secretory granule, collagen type I(alpha1), adducin gamma subunit, collagen type III(alpha1), fibronectin, lumican(keratan sulfate proteoglycan), and alpha-smooth muscle actin. Tissue inhibitor of metalloproteinase known as the enzyme controlling extracellular matrix with matrix metalloproteinase is more highly expressed in PDL cells, osteoprotegerin known as osteoclastogenesis inhibitory factor is more highly expressed in HGFs. We performed northern blot to verify cDNA microarray results on selected genes such as tissue inhibitor of metalloproteinase, fibronectin, osteoprogeterin. The result of northern blot analysis showed that each cell expressed the genes in similar pattern with cDNA microarray result. This result indicates that cDNA microarray is a reliable method in screening of gene expression profiles.