Expression of RNAs encoding for α and β integrin subunits in periodontitis and in cyclosporin A gingival overgrowth

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 beta1, alpha2 and alpha5 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 alpha1 subunit was increased. The RNA encoding for alpha6 integrin was only reduced in cyclosporin A-treated gingiva. Immunohistochemistry showed that i) integrin alpha2 expression is restricted to the gingival epithelium of cyclosporin A-treated patients, ii) the reduction of alpha6 integrin expression in cyclosporin A-treated gingiva is due to loss of expression at focal contacts and iii) beta1 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.