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Long‐term cyclosporin A exposure suppresses cathepsin‐B and ‐L activity in gingival fibroblasts
Author(s) -
Yamaguchi Mayumi,
Naruishi Koji,
YamadaNaruishi Hisa,
Omori Kazuhiro,
Nishimura Fusanori,
Takashiba Shogo
Publication year - 2004
Publication title -
journal of periodontal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 83
eISSN - 1600-0765
pISSN - 0022-3484
DOI - 10.1111/j.1600-0765.2004.00746.x
Subject(s) - cathepsin l , connective tissue , cathepsin b , cathepsin , cathepsin d , proteases , chemistry , microbiology and biotechnology , endocrinology , medicine , biology , enzyme , pathology , biochemistry
Background: Gingival overgrowth is a common side‐effect following administration of cyclosporin A. We reported previously that lysosomal protease cathepsin‐L activity, but not cathepsin‐B, was significantly suppressed by short‐term cyclosporin A exposure in human gingival fibroblasts. Although this suppression may lead to decreased degradation of gingival connective tissue, a net increase in matrix proteins, and gingival overgrowth, the effects of cyclosporin A need to be more elucidated, considering the long‐term use for patients following organ transplantation. Objective: The aim of the present study was to evaluate the effects of clinically relevant doses of cyclosporin A on cultured human gingival fibroblasts. We evaluated the effects of long‐term cyclosporin A exposure on cell proliferation, mRNA expression of various proteases and both cathepsin‐B and ‐L activity in human gingival fibroblasts. Materials and Methods: Human gingival fibroblasts were isolated from three donors' healthy gingiva and cultured from five to eight passages with or without 200 ng/ml of cyclosporin A. Proliferative activity of cyclosporin A‐treated cells was examined using MTT assay. Total RNA and cellular proteins were collected for semi‐quantitative reverse transcription‐polymerase chain reaction (RT‐PCR) analysis and for measurement of the cathepsin‐B and ‐L activity. Results: Long‐term cyclosporin A exposure had no effects on cell proliferation. Accumulation of cathepsin‐B, ‐H and ‐L mRNA was markedly suppressed by long‐term cyclosporin A exposure, whereas accumulation of another lysosomal enzyme N ‐acetyl‐β‐ d ‐glucosaminidase mRNA, which is involved in remodeling of gingival epithelium, was not apparently impaired in cyclosporin A‐treated cells. Accumulation of matrix metalloprotease‐1 (MMP‐1) and tissue inhibitor of matrix metalloprotease‐1 (TIMP‐1) mRNA, which are involved in remodeling of extracellular matrix, also was not impaired. In addition, we demonstrated that long‐term cyclosporin A exposure significantly suppressed not only the activity of the active form of cathepsin‐(B + L) compared to the activity in non‐treated cells ( p = 0.0458), but also the activity of the active form of cathepsin‐B ( p < 0.0001) in human gingival fibroblasts. Conclusion: The decreased ability of protein degradation by not only cathepsin‐L but also cathepsin‐B is, at least, one of the several factors developing the cyclosporin A‐induced gingival overgrowth.