Immunohistochemical study of cyclosporin-induced gingival overgrowth in renal transplant recipients

The role of inflammation and apoptosis in cyclosporine A-induced gingival overgrowth

Cyclosporin A(CsA) - induced gingival overgrowth(GO) is a current problem of tissue-specific mechanism which is still incompletely explained. The apoptotic process has been of particular interest like a new concept in the etiology of this unwanted effect. The aim of our study was to detect the level of apoptosis, expression bcl-2 and p53, associated with the different doses of CsA. in gingival stroma. A cohort of 84 kidney transplant recipients was divided into four subgroups based on average daily dose of therapeutically applied CsA (Neoral®), (100 mg, 125 mg, 150 mg and 175 mg). The control group consisted of 21 patients, clinically diagnosed with periodontitis, who were not subjected to any medicamentous treatment causing gingival overgrowth. The following indexes were analyzed: plaque index (PI), index of gingival inflammation (GI) according to Loe-Silnes, and gingival overgrowth index (GOI) according to MacGaw et al. The tissue samples were subjected to a semiquantitative analysis to detect apoptotical cells and immunohistochemically stained to detect the expression of the bcl-2 and p53 proteins. The difference in percentage of apoptotic cells between the group taking 175 mg and other subgroups, as well as the control group was statistically significant (p<0.05). There was a significant difference in percentage of expression bcl-2 between the 175 mg group compared to the other three subgroups and the control (p=0.001). However, a statistically significant positive correlation between the medicament dose, p53, apoptosis, and bcl-2 was registered (p<0.05). Inflammation plays the most important role in the induction of apoptosis and proliferation in gingival tissues.

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.

Immunohistochemical Evaluation of Ki-67 Expression and Apoptosis in Cyclosporin A-Induced Gingival Overgrowth

BACKGROUND

This study was planned to evaluate cell division rate and apoptosis by immunohistochemical and in situ hybridization techniques in cyclosporin A (CsA)-induced gingival overgrowth tissue samples to determine whether these processes played a role in the pathogenesis of this condition.

METHODS

Fourteen CsA-induced overgrowth tissues from renal transplant recipients, 10 control tissues from patients with plaque-induced gingivitis, and 14 control tissues from systemically and periodontally healthy subjects were evaluated. In patient groups, clinical periodontal recordings and tissue sampling were performed before initiation of any periodontal intervention. Numbers of Ki-67-positive cells/field and apoptotic cells/field in formalin-fixed/paraffin-embedded tissue sections were determined. Data were evaluated by one-way analysis of variance, post hoc Sidak test with modified Bonferroni correction, and Pearson correlation analysis. Three phenytoin- and five nifedipine-induced overgrowth tissues were also processed in the same way, and findings in these tissue specimens were evaluated as case series.

RESULTS

The number of keratinocytes was significantly greater in the CsA-induced gingival overgrowth group than in the healthy control group (P <0.05). Cells labeled by in situ end labeling, namely the apoptotic cells, were significantly fewer in the CsA group than in the gingivitis and healthy control groups (P <0.01). Overall, statistically significant positive correlations were found between the numbers of Ki-67-positive cells and probing depth and hyperplastic, bleeding, and plaque indices (P <0.01). Phenytoin and nifedipine samples exhibited obviously higher expression of Ki-67-positive cells than the CsA, gingivitis, and healthy control groups.

CONCLUSION

Our findings suggest that decreased apoptosis may have a more prominent role than increased cell division in the pathogenesis of CsA-induced gingival overgrowth.

A potential role of EMMPRIN by regulating ECM degradation in periodontitis

Periodontitis are characterized by the destruction of the extracellular matrix (ECM) of periodontal tissues. Matrix metalloproteinases (MMPs) play an important role in the degradation of ECM. But until now, it is not clear about the regulation of MMPs expression level in periodontitis. EMMPRIN is a 58 kDa, highly glycosylated, transmembrane molecule belonging to the immunoglobin superfamily, which interacts with fibroblasts to stimulate the expression of MMPs. It is logical to postulate that EMMPRIN may play a critical role in the regulation of MMPs participating the destruction of periodontal ECM in periodontitis. The hypothesis will provide the brand-new direction that we may prevent and treat the periodontitis by regulating the expression of EMMPRIN in host aspect.

Lip hypertrophy secondary to cyclosporine treatment: a rare adverse effect and treatment considerations

Gingival hypertrophy is a well-known and extensively documented undesirable side effect of cyclosporine in posttransplant patients. However, severe lip enlargement associated with cyclosporine is less recognized and has seldom been reported in the literature. Lip enlargement may lead to social, physical, and psychological stress, especially in the older childhood and adolescent age groups. We present a case of marked lip hypertrophy and concomitant gingival hypertrophy secondary to cyclosporine (Neoral) treatment in a pediatric bilateral lung transplant recipient. We also discuss the various side effects and treatment considerations available including more recent substitution therapy. Cyclosporine has most effectively and conclusively enabled transplantation of solid organs by reducing transplant-associated morbidity. We believe clinicians should be knowledgeable and aware of lip hypertrophy associated with cyclosporine use. This rare and less understood adverse effect should be recognized during the clinical evaluation of the posttransplant patient.

The effect of cyclosporin on cell division and apoptosis in human oral keratinocytes

BACKGROUND AND OBJECTIVE

Gingival overgrowth (GO) is a side-effect of cyclosporin A (CsA) therapy and is characterised by enlargement of the gingiva with epithelial thickening and overproduction of extracellular matrix components. The pathogenesis of the epithelial thickening in GO remains obscure. The objective of the present study was to investigate the effects of CsA on the growth of oral epithelial cells in vitro and to test the hypothesis that CsA influences apoptosis in these cells.

MATERIAL AND METHODS

Cyclosporin was cocultured with an immortalized normal human oral keratinocyte cell line (HOK-16B), an epitheloid cervical carcinoma cell line (HeLa) and primary oral keratinocytes. Cell division was quantified using a CyQUANT kit. Apoptosis was induced using tumour necrosis factor-alpha (TNF-alpha) and assayed by analysis of caspase-3 activity. Expression of the anti-apoptotic protein, Bcl-2, was measured by western blotting.

RESULTS

CsA exhibited a dose- and time-dependent inhibition of cell division in all three keratinocyte cell cultures. Significantly, HOK-16B cells treated with high doses of CsA (10 alphag/ml) did not recover their proliferative capacity 3 d after withdrawal of CsA, indicating that CsA-induced inhibition of growth is not temporary. Concentrations of CsA that inhibited cell division (1 microg/ml) did not have any effect on constitutive or TNF-alpha -induced apoptosis or Bcl-2 expression in HOK-16B cells.

CONCLUSION

CsA inhibits oral epithelial cell division and this effect is not associated with changes in apoptosis in these cells. The action of CsA on oral epithelial cells may be associated with a long-lasting stress signal, which might account for some of the pathological effects of this drug.