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Induction of cyclooxygenase‐2 mRNA and protein expression in human gingival fibroblasts stimulated with nicotine
Author(s) -
Chang YuChao,
Tsai ChungHung,
Yang ShyhHwang,
Liu ChiaMing,
Chou MingYung
Publication year - 2003
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 - 10.1034/j.1600-0765.2003.00681.x
Subject(s) - nicotine , cyclooxygenase , messenger rna , western blot , gene expression , prostaglandin e2 , periodontitis , chemistry , pharmacology , andrology , microbiology and biotechnology , enzyme , medicine , endocrinology , biology , biochemistry , gene
Background: Cigarette smoking is a major risk factor in the development and further progression of periodontal diseases. COX‐2 is an inducible enzyme believed to be responsible for prostaglandin synthesis at site of inflammation. Currently, there is limited information on the regulation of COX‐2 expression in smoking‐associated periodontal disease. Objectives: The aim of the present study was to investigate the effects of nicotine on the expression of cyclooxygenase‐2 (COX‐2) mRNA gene and protein in cultured human gingival fibroblasts (HGFs). Furthermore, to elucidate whether induction of COX‐2 may be associated with nicotine‐ induced cytotoxicity, NS‐398 (a selective COX‐2 inhibitor), was added to test its protective effect. Methods: The quantitative reverse‐transcriptase polymerase chain reaction and Western blot assays were used to investigate the effects of human HGFs exposed to nicotine. In addition, NS‐398 was added to test how it modulated the effects of nicotine. Results: The exposure of quiescent human HGFs to nicotine resulted in the induction of COX‐2 mRNA expression. The levels of the COX‐2 mRNAs increased about 1.5 and 2.5 fold after exposure to 2.5 and 15 m m nicotine for 2 h ( P < 0.05), respectively. Moreover, the peak of COX‐2 mRNA levels induced by nicotine was 10 m m at 2 h incubation period. Investigations of the time dependence of COX‐2 mRNA expression in nicotine‐treated HGFs revealed a rapid accumulation of the transcript, a signal first detectable at 30 min and diminished to control level after 8 h. In addition, 10 m m nicotine also induced COX‐2 protein expression in HGFs. The kinetics of this response showed that COX‐2 was detectable at 4 h and diminished nearly to control level after 24 h. NS‐398 at non‐cytotoxic dose is not able to prevent nicotine‐induced cytotoxicity. Conclusions: Taken together, the activation of COX‐2 expression by nicotine suggests a potential role for nicotine in the pathogenesis of smoking‐associated periodontal disease. In addition, nicotine‐induced cytotoxicity is not directly via the induction of COX‐2 expression.