Long-term cyclosporin A exposure suppresses cathepsin-B and -L activity in gingival fibroblasts.

Abstract

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-beta-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.

• Authors: Mayumi Yamaguchi, Koji Naruishi, Hisa Yamada-Naruishi, Kazuhiro Omori, Fusanori Nishimura, Shogo Takashiba
• Journal: Journal of periodontal research (J Periodontal Res) Vol. 39 Issue 5 Pg. 320-6 (Oct 2004) ISSN: 0022-3484 [Print] United States
• PMID: 15324353 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cysteine Proteinase Inhibitors
• Immunosuppressive Agents
• RNA, Messenger
• Cyclosporine
• Cathepsins
• Cysteine Endopeptidases
• Cathepsin B
• CTSL protein, human
• Cathepsin L

Topics

• Cathepsin B (antagonists & inhibitors, metabolism)
• Cathepsin L
• Cathepsins (antagonists & inhibitors, metabolism)
• Cell Division (drug effects)
• Cells, Cultured
• Cyclosporine (pharmacology)
• Cysteine Endopeptidases
• Cysteine Proteinase Inhibitors (pharmacology)
• Fibroblasts (cytology, drug effects, enzymology)
• Gingiva (cytology, drug effects, enzymology)
• Humans
• Immunosuppressive Agents (pharmacology)
• RNA, Messenger (analysis)
• Reverse Transcriptase Polymerase Chain Reaction
• Time Factors