Immunolocalization of s100a4 and alpha-sma in gingival tissues of patients with gingival hypertrophy due to orthodontic treatment: preliminary study

Objective: to determine the presence and distribution of markers of the epithelial-mesenchymal transition (EMT) (S-100A4 and alpha-smooth muscle actin-alpha-SMA) in gingival tissues of patients affected by Gingival hypertrophy (GH) due to orthodontics. GH is an exaggerated increase in gingival tissue whose pathogenesis is unknown. However, it has been reported that the epithelial-mesenchymal transition as a process involved in other types of GH. Materials and methods: descriptive study that included the analysis of gingival tissues of healthy individuals (n = 6) and patients with GH by orthodontic treatment (n = 6). Before gingival surgery, the patients underwent a periodontal hygiene phase. The gingival tissue samples obtained were processed and embedded in paraffin. The cuts were made with a microtome and deposited on polysine adhesion slides. Histological hematoxylin-eosin staining was performed. The identification and location of S-100A4 and alpha-SMA markers was determined by immunohistochemistry with monoclonal antibodies. The reading of the findings was carried out by oral pathologists. Results: in healthy individuals, an S100A4 label was observed in Langerhans cells, while alpha-SMA was identified in the vascular endothelium of all samples analysed. However, in patients with GH due to orthodontics, they registered an intense staining of S100A4 in gingival fibroblasts, Langerhans cells, vascular endothelium, and areas adjacent to the rupture of blood vessel. a-SMA expression in GO was detected in the vascular endothelium and gingival fibroblasts. Conclusion: the differential immunostaining of EMT markers in gingival tissues of patients with orthodontic GH suggests an eventual role of EMT in the pathogenesis of this pathology.