Alcohol-containing mouthrinses influence the integrin expression on cultured Hgfs.

Objectives: The use of mouthrinses in daily oral and dental care is strongly encouraged. However most commercially available mouthrinses, contain alcohol in their formulation. The presence of an oral enzymatic metabolism of alcohol, due to an enzymatic imbalance, allows the accumulation in the oral tissue of the toxic intermediate acetaldehyde. Previously we investigated the cytotoxic "in vitro" effect of the acetaldehyde on HGFs and PDLFs, the main cellular components of the connective oral tissue, particularly on their cytoskeletal structures. Now, in order to better define the mechanism of injury due to acetaldehyde on oral connective tissue, we investigated the effect in integrin expression on cultured human gingival fibroblasts (HGFs) following acetaldehyde exposure. The integrins encompass a family of cell surface molecules, which play a key role on reciprocal interaction between intracellular cytoskeleton and extracellular matrix. Methods: HGFs obtained from healthy human gingiva were seeded onto culture dishes containing acetaldehyde at concentration ranges from 0.1mM to 10mM. Untreated cultured cells were used as control. After 3hrs of incubation in acetaldehyde, RNA was extracted from treated and untreated cells. The expression of a2, a5 and b1 integrin subunits was analysed by RT-PCR. In addition indirect immunofluorescence technique was utilised to identify the same integrin subunits by using anti-human a2, a5 and b1 integrin monoclonal antibodies. Results: A dose dependent acetaldehyde influence on mRNAs encoding for a2, a5 and b1 integrin subunits was detected with both the molecular and the immunocytochemical approach. Conclusions: Acetaldehyde induce an altered compartmentalization process in which the integrin molecules are produced but are not appropriately transferred to the cell membrane. Acetaldehyde effects on integrin expression may impair HGF ability to adhere to the extracellular matrix which affect the connective tissue survival. Consequently we suggest that the mouthrinses should be used under medical prescription and should be alcohol-free .