The upregulation of cystatin C in human gingival fibroblasts stimulated with cyclosporine A.
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.


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).


CONCLUSIONS
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.
Tsai
C-H
CH
Department of Pathology, Chung Shan Medical University Hospital, Taichung, Taiwan.
Yang
S-F
SF
Huang
F-M
FM
Chang
Y-C
YC
D016976:Aggregatibacter actinomycetemcomitans / Q000502:physiology; D002478:Cells, Cultured; D016572:Cyclosporine / Q000009:adverse effects*; D055316:Cystatin C / Q000032:analysis / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005881:Gingiva / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D019214:Gingival Overgrowth / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D018836:Inflammation Mediators / Q000494:pharmacology; D053583:Interleukin-1beta / Q000494:pharmacology; D016966:Porphyromonas gingivalis / Q000502:physiology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D015854:Up-Regulation
C525030:CST3 protein, human; D055316:Cystatin C; D007166:Immunosuppressive Agents; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D014409:Tumor Necrosis Factor-alpha; D016572:Cyclosporine