Expression des ARN codant pour les sous‐unités α et β des intégrines dans la parodontite et dans l'hyperplasie gingivale induite par la ciclosporine A.

Background: Variation of integrin expression in healthy and diseased gingiva revealed a potential biological role for these cell matrix receptors during gingival remodeling. Aim: Here we determined the level of RNA and tissue localization of different integrin subunits in periodontitis and cyclosporin A‐induced gingival overgrowth. Methods: The level of expression was determined by Reverse Transcriptase Polymerase Chain Reaction in 12 periodontitis‐affected patients, four patients exhibiting severe cyclosporin A‐induced gingival overgrowth and seven healthy patients as controls. Results: The RNA encoding for β1, α2 and α5 integrin subunits were reduced in periodontitis gingiva. The reduction observed was stronger in cyclosporin A‐treated patients as compared to the healthy controls, while RNA encoding for α1 subunit was increased. The RNA encoding for α6 integrin was only reduced in cyclosporin A‐treated gingiva. Immunohistochemistry showed that i) integrin α2 expression is restricted to the gingival epithelium of cyclosporin A‐treated patients, ii) the reduction of α6 integrin expression in cyclosporin A‐treated gingiva is due to loss of expression at focal contacts and iii) β1 integrin is evenly distributed in the three populations with an intensity decrease in periodontitis and cyclosporin A‐treated gingiva. Conclusion: Taken together these results showed a role for the integrin receptors in periodontal diseases and cyclosporin A‐induced gingival overgrowth.