Effect of nicotine on fibroblast beta 1 integrin expression and distribution in vitro.
BACKGROUND
Integrins are a family of transmembrane cell surface glycoproteins, and those with the beta 1-subunit function in both cell-to-cell and cell-to-substrate adhesion. The purpose of this study was to determine nicotine's effect on the expression and distribution of the beta 1 integrin subunit on the human gingival fibroblast cell surface.


METHODS
Pure nicotine was diluted in medium to the following concentrations: 0 (control), 0.025, 0.05, 0.1, 0.2, and 0.4 microM. Human gingival fibroblasts (HFG) were grown for 24 hours in each concentration and fluorescein-labeled with a mouse monoclonal anti-human beta 1 antibody and secondarily incubated with a urease-labeled anti-mouse IgG antibody. After a final wash, the cells were incubated with urea/bromcresol blue substrate for 15 minutes at 37 degrees C and measured in a microplate reader at 570 nm.


RESULTS
The integrin beta 1-subunit was detected on the HGF surface membrane by fluorescence labeling, and cell-enzyme-linked immunosorbent assay testing demonstrated its decreased expression with increasing nicotine concentrations that were statistically different at the concentrations of 0.2 and 0.4 microM versus controls (P < 0.05).


CONCLUSIONS
Nicotine concentrations of 0.2 and 0.4 microM significantly decrease beta 1 integrin expression in human gingival fibroblasts that may affect cell-cell and cell-substratum adhesion during wound healing.
Austin
G W
GW
Canadian Forces Dental Services, CFB Edmonton, AB.
Cuenin
M F
MF
Hokett
S D
SD
Peacock
M E
ME
Sutherland
D E
DE
Erbland
J F
JF
Billman
M A
MA
D000704:Analysis of Variance; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000187:drug effects / Q000235:genetics; D001485:Basement Membrane / Q000187:drug effects / Q000648:ultrastructure; D001962:Bromcresol Purple; D002448:Cell Adhesion; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000187:drug effects / Q000648:ultrastructure; D005347:Fibroblasts / Q000187:drug effects* / Q000648:ultrastructure; D005353:Fibronectins / Q000187:drug effects; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D005456:Fluorescent Dyes; D015870:Gene Expression; D005881:Gingiva / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D007074:Immunoglobulin G; D007202:Indicators and Reagents; D019012:Integrin beta1 / Q000187:drug effects* / Q000235:genetics; D007797:Laminin / Q000187:drug effects; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D013223:Statistics as Topic; D014510:Urease
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D005353:Fibronectins; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007074:Immunoglobulin G; D007202:Indicators and Reagents; D019012:Integrin beta1; D007797:Laminin; D018722:Nicotinic Agonists; D001962:Bromcresol Purple; D009538:Nicotine; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; D014510:Urease; D016650:Fluorescein-5-isothiocyanate