Effects of nicotine on periodontal ligament fibroblasts in vitro

Abstract

Cigarette smoking is associated with increased incidence of periodontal disease and poor response to therapy. In the present study, we examined the effects of nicotine on several functions of periodontal ligament fibroblasts (PDLF): proliferation, attachment, alkaline phosphatase production and chemotaxis. Nicotine concentrations varying from 5 ng/ml to 250 microg/ml were tested. Proliferation of cells was studied by the incorporation of 3H-thymidine, and a dose-dependent inhibition was observed with concentrations > or =100 ng/ml. Similar results were observed when studying the attachment of the cells on plastic surfaces, using a colorimetric method. The inhibition of attachment was even more evident after 6 h incubation of the cells with nicotine. The activity of alkaline phosphatase, as determined with the substrate p-nitrophenyl phosphate, in both conditioned medium (CM) and cellular extract (CE), was also significantly decreased in a concentration-related fashion. Finally, the chemotaxis of PDLE as examined by a modification of the Boyden's blind-well chamber technique, was inhibited in a dose-dependent manner. The degree of inhibition varied from 15% with the lowest concentration of nicotine (50 ng/ml), to almost 90% with the highest (5 microg/ml). The results show that nicotine can have direct adverse effects on various functions of the periodontal cells.

Nicotine inhibits myofibroblast differentiation in human gingival fibroblasts

“…A recent investigation using dermal fibroblasts and cigarette smoke had increased focal adhesions and increased vinculin with decreased migration [Wong and Martins-Green, 2004]. Whereas, using human periodontal ligament fibroblasts, it was found that nicotine inhibited cell attachment in a dosedependent manner [Giannopoulou et al, 1999]. Similar results were obtained from another study that demonstrated nicotine inhibited periodontal ligament fibroblast proliferation and attachment [James et al, 1999].…”

Smoking and periodontal tissues: a review

“…In general, nicotine has been reported to adversely affect proliferation, attachment and chemotaxis of periodontal ligament cells, and induce pro-inflammatory cytokine production by human gingival fibroblasts synergistically with lipopolysaccharide from Escherichia coli and P. gingivalis. [38][39][40] In a rat model, the impact of cigarette compounds on the periodontal tissues showed a greater bone loss in the ligated teeth of the groups that received nicotine when compared to the control group. 41,42 This evidence suggests that nicotine alone could affect periodontal bone loss resulting from periodontitis.…”

A influência da nicotina na densidade de colágeno em cicatrizes cutâneas, em ratos

“…Os fibroblastos sofreriam tanto na sua estrutura 15-17 quanto na proliferação e diferenciação 13,15,16,[18][19][20] . Nestes estudos estão descritas deficiências da síntese do colágeno 15,17,18,22,23 .…”

“…Fang e Svoboda, estudando fibroblastos humanos, cultivados com diferentes concentrações de nicotina, observaram que existia inibição da diferenciação dos fibroblastos a miofibroblastos e atribuíram a isto a diminuição da contração das feridas 14 . São relatadas modificações citoplasmáticas, degeneração e inatividade dos fibroblastos [15][16][17] , além da diminuição do número destas células e da sua diferenciação 13,15,16,[18][19][20] . Estes efeitos foram também descritos nos osteoblastos, afetando a reconstituição após fraturas 21 .…”