Cyclosporine A inhibits the expression of membrane type-I matrix metalloproteinase in gingiva

Antioxidants protect against gingival overgrowth induced by cyclosporine A

OBJECTIVE

We investigated the importance of reactive oxygen species (ROS) on developing gingival overgrowth (GO) and then introduced the antioxidant strategy to prevent, or even reduce GO.

BACKGROUND

Gingival overgrowth is a common side effect of the patients receiving cyclosporine A (CsA), an immune suppressant. Although it has been broadly investigated, the exact pathogenesis of the induced GO is still uncertain.

METHODS

We cultured human primary gingival fibroblasts and used animal model of GO to investigate the ameliorative effects of antioxidants on CsA-induced GO. To examine the CsA-induced oxidative stress, associated genes and protein expression, and the overgrown gingiva of rats by using immunocytochemistry, confocal laser scanning microscopy, real-time PCR, ELISA, gelatin zymography, gingival morphological, and immunohistochemical analysis.

RESULTS

We found for the first time that ROS was responsible for the CsA-induced oxidative stress and TGF-β1 expression in human primary gingival fibroblasts, as well as the GO of rats. The antioxidants (oxidative scavenger of vitamin E and an antioxidative enzyme inducer of hemin) ameliorated CsA-induced pathological and morphological alterations of GO without affected the CsA-suppressed il-2 expression in rats. CsA-induced oxidative stress, HO-1, TGF-β1, and type II EMT were also rescued by antioxidants treatment.

CONCLUSIONS

We concluded that CsA repetitively stimulating the production of ROS is the cause of CsA-GO which is ameliorated by treating antioxidants, including vitamin E and sulforaphane. Furthermore, the immunosuppressive effect of CsA is not interfered by antioxidant treatments in rats. This finding may thus help the clinician devise better prevention strategies in patients susceptible to GO.

Cyclosporin A suppresses Porphyromonas gingivalis lipopolysaccharide induced matrix metalloproteinases activities in the co-culture of human gingival fibroblasts and monocyte cell line THP-1

Cyclosporine-A (CsA) is a widely used immunosuppressant. In this study, we explore the pathway through which CsA suppressed the Porphyromonas gingivalis lipopolysaccharide (P.g-LPS)-induced increase in matrix metalloproteinase (MMP) activities in co-cultured human gingival fibroblasts (HGFs) and THP-1 monocytes. In the co-culture, we found that CsA inhibited the expression of cyclophilin A (CyPA), CD147 and the activities of MMPs, which were all induced by P.g-LPS. We also found that P.g-LPS and recombinant human CyPA increased activation of ERK1/2 and IκB (an NF-κB inhibitory protein), but CsA and the anti-CD147 antibody significantly inhibited these effects. Taken together, CsA in the presence of P.g-LPS might suppress MMP activities by blocking the CyPA/CD147 interaction that results in the inhibition of ERK1/2 and NF-κB signaling by interfering with the phosphorylation of ERK1/2 and IκB.

Concomitant coiling reduces metalloproteinase levels in flow diverter-treated aneurysms but anti-inflammatory treatment has no effect

Background and purpose

Flow diverters (FD) can cause rare but devastating delayed aneurysm ruptures in which matrix metalloproteinases (MMPs) have been potentially implicated. Concomitant coiling or anti-inflammatory medications have been proposed to prevent the risk of delayed ruptures. The aim of this study was to evaluate concomitant coiling and ciclosporin in regulating the expression of MMPs in FD-treated aneurysms.

Materials and methods

Elastase-induced aneurysms were created in 20 rabbits. Aneurysms were treated with (1) FD alone; (2) FD with concomitant coiling; (3) FD+ ciclosporin; or (4) left untreated as controls. At sacrifice, MMP levels were analyzed by zymography. Kruskal–Wallis one-way non-parametric ANOVA was performed for each enzyme. If significant results were observed for the Kruskal–Wallis test, pairwise group comparisons were performed using Dunn's test with Bonferroni multiple-testing correction.

Results

Significant differences were observed among groups for pro-MMP9 (p=0.0337). Pairwise comparison demonstrated higher levels of pro-MMP9 with concomitant coiling compared with untreated aneurysms (p=0.012), with higher though not significantly different levels of pro-MMP9 in FD with concomitant coiling versus FD alone. While not statistically significant, trends were noted regarding differences in active-MMP9 across groups, with a lower level of active-MMP9 with concomitant coiling compared with the other FD groups. No significant differences were observed for pro- or active-MMP2 across groups, or for FD + ciclosporin compared with FD alone.

Conclusions

FD implantation increases the level of pro-MMP9 expression in aneurysms. Provocative trends regarding modulation of active-MMP9 expression with concomitant coiling suggest the need for larger confirmatory preclinical studies. Anti-inflammatory treatment with ciclosporin appears to have a minimal biological effect.

Trial registration number

R01NS076491

Molecular and clinical aspects of drug-induced gingival overgrowth

Drug-induced gingival overgrowth is a tissue-specific condition and is estimated to affect approximately one million North Americans. Lesions occur principally as side-effects from phenytoin, nifedipine, or ciclosporin therapy in approximately half of the people who take these agents. Due to new indications for these drugs, their use continues to grow. Here, we review the molecular and cellular characteristics of human gingival overgrowth lesions and highlight how they differ considerably as a function of the causative drug. Analyses of molecular signaling pathways in cultured human gingival fibroblasts have provided evidence for their unique aspects compared with fibroblasts from the lung and kidney. These findings provide insights into both the basis for tissue specificity and into possible therapeutic opportunities which are reviewed here. Although ciclosporin-induced gingival overgrowth lesions exhibit principally the presence of inflammation and little fibrosis, nifedipine- and especially phenytoin-induced lesions are highly fibrotic. The increased expression of markers of gingival fibrosis, particularly CCN2 [also known as connective tissue growth factor (CTGF)], markers of epithelial to mesenchymal transition, and more recently periostin and members of the lysyl oxidase family of enzymes have been documented in phenytoin or nifedipine lesions. Some oral fibrotic conditions such as leukoplakia and oral submucous fibrosis, after subsequent additional genetic damage, can develop into oral cancer. Since many pathways are shared, the study of gingival fibrosis and comparisons with characteristics and molecular drivers of oral cancer would likely enhance understandings and functional roles of molecular drivers of these oral pathologies.

Mechanism of drug-induced gingival overgrowth revisited: a unifying hypothesis

Drug-induced gingival overgrowth (DIGO) is a disfiguring side effect of anti-convulsants, calcineurin inhibitors, and calcium channel blocking agents. A unifying hypothesis has been constructed which begins with cation flux inhibition induced by all three of these drug categories. Decreased cation influx of folic acid active transport within gingival fibroblasts leads to decreased cellular folate uptake, which in turn leads to changes in matrix metalloproteinases metabolism and the failure to activate collagenase. Decreased availability of activated collagenase results in decreased degradation of accumulated connective tissue which presents as DIGO. Studies supporting this hypothesis are discussed.

Serum cyclophilin A concentrations in renal transplant recipients receiving cyclosporine A: clinical implications for gingival overgrowth

OBJECTIVE

The aim of this study was to investigate the clinical factors in relation to the cyclosporine A (CsA) induced gingival overgrowth (GO).

STUDY DESIGN

Seventy-three participants were assigned as GO+ and GO-. Factors including demographic, pharmacological, gingival variables and the serum cyclophilin A (CyPA) concentration were analyzed.

RESULTS

The occurrence of GO was 39.72%. Papillary bleeding index (PBI) had a significantly higher risk of GO than plaque index (PI), the ratio of CsA to CyPA, and serum CyPA concentration (odds ratio = 364.323, 25.791, 1.002, 0.096, respectively). The severity of GO correlated with PI, the ratio of CsA to CyPA, PBI, serum concentrations of CsA and CyPA (r = 0.366, 0.355, 0.344, 0.305, and -0.232, respectively).

CONCLUSIONS

Since a cross-sectional study is not able to explain whether plaque and inflammation are the cause or consequence of GO, the ratio of CsA to CyPA may be a valuable marker for predicting GO.

Berberine's effect on periodontal tissue degradation by matrix metalloproteinases: an in vitro and in vivo experiment

Periodontal disease involves tissue destruction caused by interactions among bacterial antigens and inflammatory mediators including matrix metalloproteinases (MMPs). Berberine, an isoquinoline alkaloid isolated from medicinal herbs, can inhibit the degradative action of extracellular MMPs. The effect of berberine on the periodontal expression of MMPs was examined in vitro and in vivo. Gelatinolytic activity of pro-MMP-2, MMP-2, and MMP-9 in the human gingival fibroblast and/or U-937 was compared after treatment with Porphyromonas gingivalis lipopolysaccharide (P.g. LPS) in four medias containing 0, 1, 10 and 100μM of berberine each. Twelve animals were divided into three groups for the study: (A) non-ligation, (B) ligation, and (C) ligation-plus-berberine (75mg/kg berberine by gastric lavage daily); and the effect of berberine on periodontal destruction was evaluated in the ligature-induced periodontitis in rats for 8 days by micro computerized tomography (micro-CT), histology and immunohistochemistry (IHC). An enhancing effect of P.g. LPS on MMP activities was identified, with a greater effect on fibroblasts/U937 co-culture than on either culture alone. When berberine was added to the LPS-treated cultures, the activities of MMPs were significantly reduced in dose-dependent manner. In the animals, the trends of the following parameters were compared. 1. Micro-CT distances between cemento-enamel junction (CEJ) and dental alveolar bone crest: B>C>A. 2. Histometrically measured crest bone levels: B>C>A. 3. Amount of collagen deposited in tissue areas: A>C>B. 4. Attachment loss: B>C≈A. 5. Connective tissue (CT) attachment: B>either A or C. 6. Expression of cells stained positive for MMP-2 and -9 by IHC: B>C>A. In conclusion, berberine demonstrated in vitro an inhibitory effect on P.g. LPS-enhanced MMP activities of HGF and U937 macrophages, reducing in vivo gingival tissue degradation in periodontitic rats. We thus propose that berberine may slow periodontal degradation through the regulation of MMPs in periodontitis induced by bacterial plaque.

Crosstalk between Shh and TGF-β signaling in cyclosporine-enhanced cell proliferation in human gingival fibroblasts

BACKGROUND

Immunosuppressant cyclosporine-A induces gingival hyperplasia, which is characterized by increased fibroblast proliferation and overproduction of extracellular matrix components and regulated by transforming growth factor-beta (TGF-β). The TGF-β and Sonic hedgehog (Shh) pathways both mediate cell proliferation. Crosstalk between these pathways in cancer has recently been proposed, but the hierarchical pattern of this crosstalk remains unclear. In normal fibroblasts, a TGF-β-stimulating Shh pattern was observed in induced fibrosis. However, Shh pathway involvement in cyclosporine-enhanced gingival proliferation and the existence of crosstalk with the TGF-β pathway remain unclear.

METHODOLOGY/PRINCIPAL FINDINGS

Cyclosporine enhanced mRNA and protein levels of TGF-β and Shh in human gingival fibroblasts (RT-PCR and western blotting). A TGF-β pathway inhibitor mitigated cyclosporine-enhanced cell proliferation and an Shh pathway inhibitor attenuated cyclosporine-enhanced proliferation in fibroblasts (MTS assay and/or RT-PCR of PCNA). Exogenous TGF-β increased Shh expression; however, exogenous Shh did not alter TGF-β expression. The TGF-β pathway inhibitor mitigated cyclosporine-upregulated Shh expression, but the Shh pathway inhibitor did not alter cyclosporine-upregulated TGF-β expression.

CONCLUSIONS/SIGNIFICANCE

The TGF-β and Shh pathways mediate cyclosporine-enhanced gingival fibroblast proliferation. Exogenous TGF-β increased Shh expression, and inhibition of TGF-β signaling abrogated the cyclosporine-induced upregulation of Shh expression; however, TGF-β expression appeared unchanged by enhanced or inhibited Shh signaling. This is the first study demonstrating the role of Shh in cyclosporine-enhanced gingival cell proliferation; moreover, it defines a hierarchical crosstalk pattern in which TGF-β regulates Shh in gingival fibroblasts. Understanding the regulation of cyclosporine-related Shh and TGF-β signaling and crosstalk in gingival overgrowth will clarify the mechanism of cyclosporine-induced gingival enlargement and help develop targeted therapeutics for blocking these pathways, which can be applied in pre-clinical and clinical settings.

Cyclosporine-A inhibits MMP-2 and -9 activities in the presence of Porphyromonas gingivalis lipopolysaccharide: an experiment in human gingival fibroblast and U937 macrophage co-culture

BACKGROUND AND OBJECTIVE

Studies have shown that bacterial plaque and the associated gingival inflammation increase the severity of gingival overgrowth induced by cyclosporine-A (CsA). This in vitro study aimed to evaluate the effect of CsA on the activities of MMPs from the co-culture of human gingival fibroblasts and U937 macrophages in the presence or absence of Porphyromonas gingivalis lipopolysaccharide (LPS).

MATERIAL AND METHODS

Activities of pro-MMP-2, MMP-2 and pro-MMP-9 in the supernatants of independent cultures and co-cultures were examined by zymography. RT-PCR was selected to evaluate the expression of mRNA for membrane type-1 (MT1) MMP in the co-cultures.

RESULTS

Activities of MMPs in the co-cultures were significantly greater when compared with any of the independent cultures. Lipopolysaccharide significantly increased the MMP activities in a dose-dependent manner in the co-cultures, whereas CsA inhibited these activities. In the presence of both CsA and LPS, the MMP activities inhibited by CsA could still be observed in the co-cultures. In the individual cultures, in contrast, the CsA-inhibited MMP activities, in the presence of LPS, were minimally detected. The mRNA expression of MT1-MMP was significantly enhanced after LPS treatment; however, this enhancement was inhibited by CsA.

CONCLUSION

This study demonstrated that, in co-cultures of human gingival fibroblasts and U937 macrophages, CsA could inhibit MMP activities in the presence of P. gingivalis LPS. It might be part of the underlying reason for the persistent overgrowth of gingiva seen when bacterial plaque and local inflammation are present during CsA therapy.

Antioxidant effects of antioxidant biofactor on reactive oxygen species in human gingival fibroblasts

The purpose of this study was to investigate the effects of antioxidant biofactor (AOB) on reactive oxygen species (ROS). Generation of superoxide radical (O₂^•−) and hydroxyl radical (^•OH) was determined using an electron spin resonance (ESR) spin-trapping method. AOB was added at different concentrations to these free radical generating systems. The generation of both O₂^•− and ^•OH was scavenged by the addition of AOB in a dose-dependent manner. These results indicate that AOB has strong antioxidant properties against these radicals. We further investigated the anti-oxidative effect of AOB on human gingival fibroblasts (HGFs). HGFs were treated for 3 h with α-MEM containing a combination of AOB and H₂O₂ (AOB + H₂O₂ group), containing H₂O₂ (H₂O₂ group), or containing AOB alone (AOB group). Non-stimulated HGFs were used as a control group. The number of surviving cells was in the order of the AOB group > control group > AOB + H₂O₂ group > H₂O₂ group. The level of expression of type I collagen mRNA and production of collagen were also in the order of the AOB group > control group > AOB + H₂O₂ group > H₂O₂ group. In conclusion, our results suggest that AOB may protect HGFs against oxidative stress by reducing stress-induced ROS.

Extracellular matrix molecules: potential targets in pharmacotherapy

The extracellular matrix (ECM) consists of numerous macromolecules classified traditionally into collagens, elastin, and microfibrillar proteins, proteoglycans including hyaluronan, and noncollagenous glycoproteins. In addition to being necessary structural components, ECM molecules exhibit important functional roles in the control of key cellular events such as adhesion, migration, proliferation, differentiation, and survival. Any structural inherited or acquired defect and/or metabolic disturbance in the ECM may cause cellular and tissue alterations that can lead to the development or progression of disease. Consequently, ECM molecules are important targets for pharmacotherapy. Specific agents that prevent the excess accumulation of ECM molecules in the vascular system, liver, kidney, skin, and lung; alternatively, agents that inhibit the degradation of the ECM in degenerative diseases such as osteoarthritis would be clinically beneficial. Unfortunately, until recently, the ECM in drug discovery has been largely ignored. However, several of today's drugs that act on various primary targets affect the ECM as a byproduct of the drugs' actions, and this activity may in part be beneficial to the drugs' disease-modifying properties. In the future, agents and compounds targeting directly the ECM will significantly advance the treatment of various human diseases, even those for which efficient therapies are not yet available.