Effect of transforming growth factor-beta1, interleukin-6, and interferon-gamma on the expression of type I collagen, heat shock protein 47, matrix metalloproteinase (MMP)-1 and MMP-2 by fibroblasts from normal gingiva and hereditary gingival fibromatosis

Induction of RANTES and CCR5 through NF-κB Activation via MAPK Pathway in Aged Rat Gingival Tissues

Chemokine and chemokine receptor expression in gingival tissues plays a central role in periodontal disease during aging. In the present study, we explored the modulation of chemokines and chemokine receptors expression in aging rat gingival tissues. In the 24-month-old (Old) rat gingival tissues, RANTES and CCR5 mRNA and protein levels were 2-4 fold increased over those of the 6-month-old (Young) rats. The Old rats had considerable enhancement of all three of the studied MAPK activities: extracellular signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. These results suggest that age-related increases in RANTES and CCR5 expression are associated with increased IkappaBalpha, nuclear NF-kappaB, and MAPK activity in gingival tissues.

Upregulation of Transforming Growth Factor-β1 and Vascular Endothelial Growth Factor Gene and Protein Expression in Cyclosporin-Induced Overgrown Edentulous Gingiva in Rats

BACKGROUND

To examine the effects of cyclosporin A (CsA) on the expression of growth factors in induced gingival overgrowth with limited contributing factors arising from local inflammation caused by bacterial plaque, this study of gingival overgrowth was designed on the edentulous ridge of rats.

METHODS

After a 3-week healing period following maxillary molar extractions, 16 five-week-old male Sprague-Dawley rats were assigned to CsA and control groups. Animals in the CsA group were fed 30 mg/kg CsA daily, whereas the control rats received a mineral oil vehicle instead. After 4 weeks, all animals were sacrificed, and the morphology of edentulous ridges was recorded by dental impression. The gingivae on the left-hand side were dissected and stored for mRNA analysis, whereas the gingivae on the right-hand side were fixed in 4% paraformaldehyde for immunohistochemistry (IHC) analysis of transforming growth factor-beta1 (TGF-beta1), platelet-derived growth factor beta (PDGF-beta), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF).

RESULTS

The edentulous gingivae were enlarged and the body weights were reduced in the CsA-treated animals compared to controls. The mRNA expressions of TGF-beta1, IGF-1, and VEGF were higher in the gingivae of the CsA group than in the control group. In addition, a greater mRNA expression (7.21-fold) of VEGF was demonstrated in the CsA group than in the control group by real-time polymerase chain reaction (PCR). The percentages of cells staining positive for TGF-beta1 and VEGF were significantly greater in the CsA rats than in the control rats.

CONCLUSIONS

Greater mRNA expression and positive staining for TGF-beta1 and VEGF were observed in the edentulous gingivae of rats that received CsA. Therefore, CsA may upregulate TGF-beta1 and VEGF gene expression and protein secretion in CsA-induced gingival overgrowth.

Hereditary Gingival Fibromatosis: Report of a Five-Generation Family Using Cellular Proliferation Analysis

BACKGROUND

Hereditary gingival fibromatosis (HGF) is an uncommon condition characterized by an accumulation of extracellular matrix resulting in a fibrotic enlargement of the gingiva. The goal of this article is to describe one kindred affected with HGF and discuss the diagnosis, treatment, and control of the disease. The pattern of inheritance, histopathologic characteristics, and proliferative potential of epithelial and mesenchymal cells of HGF are also emphasized.

METHODS

To characterize the pattern of inheritance and the clinical appearance of gingival overgrowth, 117 family members were examined. The recurrence risk was estimated by the use of a genetic analysis program. Immunohistochemistry against the proliferating cell nuclear antigen (PCNA) and pKi-67 was performed to assess cellular proliferation of normal gingiva (NG) and HGF cells.

RESULTS

Examination of the family pedigree demonstrated an autosomal dominant trait of inheritance, and a sibling recurrence risk of 0.085 and an offspring recurrence risk of 0.078, indicating that HGF was a consequence of genetic alteration with low penetrance. Unaffected and affected members transmitted the disease to their offspring. The affected patients showed a generalized but mild gingival overgrowth. Surgical treatment consisted of a combination of gingivectomy and gingivoplasty. Histologic examination showed that the gingival lesions of all patients were quite similar, with increased amounts of collagen fiber bundles in the connective tissue. Immunohistochemistry revealed that the proliferative potential of epithelial cells was significantly higher in the HGF group compared to the NG group, whereas mesenchymal cells from both groups were negative for the proliferative markers.

CONCLUSION

Our data demonstrated that, in the studied family, HGF is transmitted by an autosomal dominant pattern with incomplete disease penetrance, and although the gingival enlargement resulted from an excessive accumulation of collagen fibers, HGF is characterized by an increase in the proliferation rate of epithelial cells.

Identification of the Difference in Extracellular Matrix and Adhesion Molecules of Cultured Human Gingival Fibroblasts Versus Juvenile Hyaline Fibromatosis Gingival Fibroblasts Using cDNA Microarray Analysis

BACKGROUND

A difference from the normal range in collagen profile and perivascular hyaline deposition in the dermis and gingiva has been demonstrated histopathologically in juvenile hyaline fibromatosis (JHF), which is an autosomal recessive disease. The aim of this study was to understand the mechanism of gingival overgrowth in JHF, and to observe differences in the expression of genes regulating extracellular matrix organization.

METHODS

Human gingival fibroblasts (GF) were obtained from individuals who have clinically healthy gingival tissue. JHF-GF were obtained from a patient who underwent a gingivectomy. Cultured fibroblast cells were examined visually using a phase contrast microscope. Total RNA from both cell types was isolated, and after biotin-deoxyuridine triphosphate (dUTP) labeling of cDNA, hybridization was performed with a pathway-specific gene expression profiling array membrane. Extracellular matrix (ECM) and adhesion molecule (AM) mRNA expressions in GF and JHF-GF were analyzed, and microarray data on genes modulating ECM remodeling were confirmed with reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Cell morphology differences were observed between fibroblast types. Although type I collagen gene expression levels were almost the same, decreased type IV collagen expression was noted in JHF-GF versus GF. Decreased matrix metalloproteinase (MMP) and increased tissue inhibitor of matrix metalloproteinase (TIMP) transcripts were noted in JHF-GF versus GF. Increased fibronectin and decreased laminin mRNA expression were observed in JHF-GF when compared to GF. The present findings suggest that GF and JHF-GF differ not only morphologically but also in the expression level of ECM and AM genes involving connective tissue turnover and remodeling.

CONCLUSIONS

Results from these analyses may be helpful to clarify the nature of overgrowth mechanisms, especially regarding enzymes and their inhibitors. This information is important in understanding the remodeling of ECM. The gingival overgrowth that is observed in JHF patients may be explained by a decreased level of MMPs and increased blockage of MMPs with TIMPs.

Cyclosporin But Not Tacrolimus Significantly Increases Salivary Cytokine Contents in Rats

BACKGROUND

Cyclosporin (CsA) and tacrolimus (FK-506) are immunosuppressive drugs that specifically inhibit T-cell activation via calcineurin inhibition. Gingival overgrowth is a common side effect following the administration of CsA. The severity of gingival overgrowth seen in patients taking FK-506 is less than that observed with CsA. Little is known about the involvement of saliva in drug-induced gingival overgrowth. The purpose of this study was to investigate the salivary contents of tumor growth factor beta1 (TGF-beta1), epidermal growth factor (EGF), and interleukin-6 (IL-6) as well as the hystometry of gingival tissue obtained from rats treated with either FK-506 or CsA.

METHODS

For 30 or 60 days rats received daily subcutaneous injection doses of either CsA or FK-506 (10 mg/kg). The concentrations of TGF-beta1, EGF, and IL-6 in saliva were determined by enzyme-linked immunosorbent assay, and after histological processing, the oral epithelium and connective tissue were assessed at the region of the lower first molars.

RESULTS

The levels of TGF-beta1, EGF, and IL-6 in saliva were not significantly altered by any of the treatments after 30 days. After 60 days of treatment with CsA, gingival overgrowth and significant increase in salivary TGF-beta1, EGF, and IL-6 concentrations were observed; no statistically significant changes were induced by FK-506.

CONCLUSION

Within the limits of this experimental study, it can be concluded that CsA, but not FK-506, induced gingival overgrowth associated with an increase of the salivary levels of the cytokines TGF-beta1, EGF, and IL-6.

Gingival fibromatosis and significant tooth eruption delay in an 11-year-old male: a 30-month follow-up

This case report describes the dental management of an unusual case of idiopathic gingival fibromatosis with multiple impacted primary teeth, and the absence of eruption of permanent teeth, in an 11-year-old boy and at the 30-month follow-up. The patient presented with severely enlarged gingival tissues affecting both arches and multiple retained and non-erupted primary teeth. He had already been subjected to localized gingivectomies at the ages of 7 and 9 years. He had no known syndrome and there was no family history of any similar disorder. The patient was treated under general anaesthesia to remove the excessive gingival tissues using apically positioned flaps. During the surgical procedure, over-retained and unerupted impacted primary teeth were extracted in order to facilitate the eruption of the permanent successors. Two years postoperatively, there was no recurrence of the gingival enlargement. Overdentures were then constructed because none of the permanent teeth had yet erupted. Furthermore, pre-eruptive coronal resorption was detected radiographically affecting the crown of the unerupted 36. Thirty months postoperatively, no recurrence of gingival enlargement was seen, but the permanent teeth had still not erupted.

Adjunctive subantimicrobial dose doxycycline: effect on clinical parameters and gingival crevicular fluid transforming growth factor-beta levels in severe, generalized chronic periodontitis

BACKGROUND

At present there is limited data concerning the efficacy of non-surgical periodontal therapy supplemented with subantimicrobial dose doxycycline (SDD) in the treatment of severe, generalized periodontitis. The purpose of the present study was to evaluate the effect of adjunctive SDD therapy on clinical periodontal parameters and gingival crevicular fluid (GCF) transforming growth factor-beta1 (TGF-beta1) levels in patients with severe, generalized chronic periodontitis over a 6-month period.

METHODS

Thirty-five patients with severe, generalized periodontitis and 11 periodontally healthy subjects were included in the present study. Patients received full-mouth supragingival debridment at baseline and randomized to take either SDD b.i.d. or placebo b.i.d. for 3 months. Patients received root planing and oral hygiene instruction once a week for four consecutive weeks. Clinical measurements including probing depth (PD), clinical attachment level, papilla bleeding index and plaque index and GCF sampling were performed at baseline, 3 and 6 months. The GCF TGF-beta1 levels were analysed by enzyme-linked immunosorbent assay.

RESULTS

Thirteen patients in both study groups completed the 6-month trial. Following scaling and root planing (SRP) plus SDD and SRP plus placebo therapy significant improvements in clinical periodontal parameters of both groups were observed (p<0.025). In the SDD group a significantly higher percentage (%73.4) of deep pockets resolved (PD reduction > or =3 mm from baseline) when compared with placebo group (%49.7) at 6 months (p<0.05). At baseline there were no significant differences in GCF TGF-beta1 levels between three groups. Both total amount and concentration of GCF TGF-beta1 in SDD and placebo groups increased when compared with baseline at 3 months. However, only GCF TGF-beta1 levels of SDD group was significantly higher than baseline (p<0.025) and placebo group (p<0.017) at 3 months. At 6 months GCF TGF-beta1 levels of both groups were similar to baseline levels (p<0.025).

CONCLUSIONS

These data indicate that combination of SDD with non-surgical therapy improves clinical parameters of periodontal disease and increases GCF TGF-beta1 levels together with a decrease in prevalence of residual pockets in patients with severe, generalized chronic periodontitis. Increased GCF TGF-beta1 levels following SDD therapy might suggest a novell pleiotrophic mechanism for tetracyclines to inhibit connective tissue breakdown.

Expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic stellate cells during rat hepatic fibrosis and its intervention by IL-10

AIM

To investigate the expression of matrix metallopr-oteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10 (IL-10).

METHODS

Hepatic fibrosis was induced by CCl(4) administration and 60 male Sprague-Dawley rats were randomly divided into normal control group (group N, 8 rats), CCl(4)-induced group (group C, 28 rats) and IL-10-treated group (group I, 24 rats). At the beginning of the 7(th) and 11(th) wk, rats in each group were routinely perfused with pronase E and type IV collagenase through portal vein catheter and the suspension was centrifuged by 11% Nycodenz density gradient to isolate hepatic stellate cells (HSCs). RT-PCR was used to analyze mRNA of MMP-2 and TIMP-1 from freshly isolated cells. Densitometric data were standardized with beta-actin signals. Immunocytochemistry was performed to detect MMP-2 and TIMP-1 expression in HSC cultured for 72 h.

RESULTS

Compared to group N in the 7(th) wk, MMP-2 and TIMP-1 mRNA increased in group C (P = 0.001/0.001) and group I (P = 0.001/0.009). The level of MMP-2 and TIMP-1 mRNA in group I was significantly lower than that in group C (P = 0.001/0.001). In the 11(th) wk, MMP-2 mRNA in group I was still lower than that in group C (P = 0.005), but both dropped compared with that in the 7(th) week (P = 0.001/0.004). TIMP-1 mRNA in group I was still lower than that in group C (P = 0.001), and increased in group C (P = 0.001) while decreased in group I (P = 0.042) compared with that in the 7(th) wk. Same results were found by immunocytochemistry.

CONCLUSION

Expression of MMP-2 and TIMP-1 is increased in hepatic fibrosis. IL-10 exhibits an antifibrogenic effect by suppressing MMP-2 and TIMP-1 expression.

Proliferation of Fibroblasts Cultured From Normal Gingiva and Hereditary Gingival Fibromatosis Is Dependent on Fatty Acid Synthase Activity

BACKGROUND

Fatty acid synthase (FAS) is the enzyme that synthesizes palmitate from malonyl-CoA and acetyl-CoA. Recent studies have shown that FAS is overexpressed in human cancers and that its activity is necessary for cell proliferation. Hereditary gingival fibromatosis (HGF) is a genetic disease manifested as a progressive enlargement of the gingiva. The pathogenesis of this condition is not understood; however, a proliferative advantage of HGF fibroblasts in comparison with cells from normal gingiva (NG) has been described. The aim of this study was to investigate the role of FAS in NG and HGF fibroblast proliferation.

METHODS

NG and HGF fibroblasts had their proliferative potential assessed by automated cell counting and immunocytochemistry against Ki-67 or proliferating cell nuclear antigen (PCNA). The production of FAS, androgen receptor (AR), and ErbB2 was analyzed by Western blot and the pattern of FAS expression studied by immunocytochemistry. FAS activity was blocked by the specific inhibitor cerulenin.

RESULTS

Higher proliferation rates were found in fibroblasts isolated from HGF than from NG. HGF fibroblasts with greater proliferative potential produced more FAS and AR than the cell lines with lower growth rates, and all studied cell lines produced similar amounts of the ErbB2 protein. In addition, the FAS inhibitor cerulenin was able to significantly reduce the proliferation of both NG and HGF cells.

CONCLUSIONS

These results show that FAS is expressed by gingival fibroblasts and that highly proliferative HGF cells produced more FAS and AR than the other fibroblast cell lines. Moreover, FAS inhibition significantly reduced both NG and HGF fibroblast growth, suggesting a role for the androgen-driven fatty acid biosynthesis in their proliferation.

Effect of low-power laser irradiation on protein synthesis and ultrastructure of human gingival fibroblasts

BACKGROUND AND OBJECTIVES

Low-power lasers improve wound healing. Cell proliferation and protein secretion are important steps of this process. The aim of this study was to analyze both protein synthesis and ultrastructural morphology of human gingival fibroblasts irradiated by a low-power laser.

STUDY DESIGN/MATERIALS AND METHODS

The cell line FMM1 was grown in nutritional deficit. Laser irradiation was carried out with a gallium-aluminum-arsenate (Ga-Al-As) diode laser (904 nm, 120 mW, energy density of 3 J/cm(2)). The protein synthesis analysis and ultrastructural morphology of control (non-irradiated) and irradiated cultures were obtained.

RESULTS

There were changes in the structure of cytoplasm organelles of treated cells. The procollagen was not altered by the laser irradiation; however, there were a significant reduction of the amount of protein in the DMEM conditioned by irradiated cells.

CONCLUSIONS

Low-power laser irradiation causes ultrastructural changes in cultured fibroblasts. We suggest that these alterations may lead to disturbances in the collagen metabolism.

The Influence of Enamel Matrix Derivative Associated With Insulin-Like Growth Factor-I on Periodontal Ligament Fibroblasts

BACKGROUND

Enamel matrix derivative (EMD) has recently been shown to promote periodontal regeneration in vivo. Insulin-like growth factor-I (IGF-I) is a potent modulator of periodontal regeneration stimulating cell proliferation, differentiation, synthesis of type I collagen, and non-collagenous proteins. However, the biochemical effects of these factors on periodontal ligament (PDL) fibroblasts are not completely understood. The objective of the present study was to evaluate the effect of EMD, IGF-I, and the combination of these two factors on the proliferation, adhesion, migration, and expression of type I collagen in PDL fibroblasts.

METHODS

The proliferation rate was measured by automated cell counting and immunohistochemical expression of proliferating cell nuclear antigen (PCNA). The cell adhesion was analyzed by a colorimetric assay and cell migration was measured in Boyden chambers. Type I collagen expression and production was determined by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

The results indicated that the proliferation of PDL fibroblasts was significantly stimulated by EMD and EMD plus IGF-I in a dose- and time-dependent manner. EMD, IGF-I, and the combination of both factors had no effects on cellular migration and adhesion or expression and production of type I collagen.

CONCLUSION

Our results showed that EMD, IGF-I, and the combination of both factors stimulated PDL fibroblast proliferation, whereas these factors did not affect adhesion, migration, or expression of type I collagen of these cells.

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Cyclosporin A induces proliferation in human gingival fibroblasts via induction of transforming growth factor-beta1

BACKGROUND

Cyclosporin A (CsA) is a widely used immunosuppressant that causes significant side effects including gingival overgrowth. The pathogenesis of this condition is not fully understood; however, recent studies show that CsA regulates the transcription of several cytokines including transforming growth factor-beta 1 (TGF-beta1). In this study, we evaluated the effects of CsA and TGF-beta1 on human normal gingival (NG) fibroblast proliferation, and explored a possible autocrine stimulation of TGF-beta1 as a cellular regulator of proliferation induced by CsA in NG fibroblasts.

METHODS

NG fibroblast cell lines were incubated with increasing concentrations of CsA or TGF-beta1 and the proliferation index determined by automatic cell counting, BrdU incorporation, PCNA expression, and mitotic potential. To determine the effect of TGF-beta1 on the proliferation rate of NG fibroblasts under CsA treatment, NG fibroblast cultures were simultaneously treated with CsA and antisense oligonucleotides against the translation-start site of the TGF-beta1 mRNA.

RESULTS

Treatment of NG fibroblasts with CsA or TGF-beta1 significantly stimulated the cell proliferation in a dose-dependent manner. Furthermore, neutralization of TGF-beta1 production in CsA-treated NG fibroblasts inhibited CsA's effect on NG fibroblast proliferation, demonstrating an autocrine stimulatory effect of TGF-beta1 in CsA-treated NG fibroblast proliferation.

CONCLUSION

The results presented here suggest that CsA stimulatory induction of NG fibroblast proliferation is mediated via TGF-beta1 in an autocrine fashion.