BACKGROUND AND OBJECTIVE: Cystatin C is a 13 kDa non-glycosylated, basic protein belonging to the cystatin family. It is consistently and dramatically upregulated in a variety of fibrotic diseases. However, little is known about the correlation between cystatin C and cyclosporine A-induced gingival overgrowth. The aim of this study was to compare cystatin C expression in normal, healthy gingival tissues and cyclosporine A-induced gingival overgrowth specimens and further explore the potential mechanism that may result in cystatin C expression. MATERIAL AND METHODS: Fifteen cyclosporine A-induced gingival overgrowth specimens and five normal gingival tissues were examined by immunohistochemistry. Three human gingival fibroblast (HGF) strains were established from crown-lengthening surgery. The reverse transcriptase-polymerase chain reaction was used to investigate the effects on HGFs exposed to cyclosporine A. In addition, predominant periodontal pathogens (Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis) and proinflammatory cytokines (interleukin-1alpha and tumor necrosis factor-alpha) were added to seek the possible regulatory mechanisms of cystatin C expression. RESULTS: The cystatin C staining in gingival tissue was stronger in the cyclosporine A-induced gingival overgrowth group than in the normal gingival group (p < 0.05). Intensive staining for cystatin C expression was observed mainly in the cytoplasm of fibroblasts, epithelial cells and inflammatory cells. Moreover, cystatin C expression was significantly higher in cyclosporine A-induced gingival overgrowth specimens with higher levels of inflammatory infiltrates (p < 0.05). A concentration of 200 ng/mL cyclosporine A was found to increase cystatin C expression in HGFs in a time-dependent manner (p < 0.05). The addition of periodontal pathogens and proinflammatory cytokines significantly increased the expression of cystatin C compared with cyclosporine A alone (p < 0.05). CONCLUSION: The increased ability of protein accumulation by cystatin C is one of several factors mediating cyclosporine A-induced gingival overgrowth. In addition, cyclosporine A may predispose to gingival overgrowth in inflammatory environments.
BACKGROUND AND OBJECTIVE:Cystatin C is a 13 kDa non-glycosylated, basic protein belonging to the cystatin family. It is consistently and dramatically upregulated in a variety of fibrotic diseases. However, little is known about the correlation between cystatin C and cyclosporine A-induced gingival overgrowth. The aim of this study was to compare cystatin C expression in normal, healthy gingival tissues and cyclosporine A-induced gingival overgrowth specimens and further explore the potential mechanism that may result in cystatin C expression. MATERIAL AND METHODS: Fifteen cyclosporine A-induced gingival overgrowth specimens and five normal gingival tissues were examined by immunohistochemistry. Three human gingival fibroblast (HGF) strains were established from crown-lengthening surgery. The reverse transcriptase-polymerase chain reaction was used to investigate the effects on HGFs exposed to cyclosporine A. In addition, predominant periodontal pathogens (Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis) and proinflammatory cytokines (interleukin-1alpha and tumor necrosis factor-alpha) were added to seek the possible regulatory mechanisms of cystatin C expression. RESULTS: The cystatin C staining in gingival tissue was stronger in the cyclosporine A-induced gingival overgrowth group than in the normal gingival group (p < 0.05). Intensive staining for cystatin C expression was observed mainly in the cytoplasm of fibroblasts, epithelial cells and inflammatory cells. Moreover, cystatin C expression was significantly higher in cyclosporine A-induced gingival overgrowth specimens with higher levels of inflammatory infiltrates (p < 0.05). A concentration of 200 ng/mL cyclosporine A was found to increase cystatin C expression in HGFs in a time-dependent manner (p < 0.05). The addition of periodontal pathogens and proinflammatory cytokines significantly increased the expression of cystatin C compared with cyclosporine A alone (p < 0.05). CONCLUSION: The increased ability of protein accumulation by cystatin C is one of several factors mediating cyclosporine A-induced gingival overgrowth. In addition, cyclosporine A may predispose to gingival overgrowth in inflammatory environments.