Abstract: Objective: To explore effects of periodontitis on stromal nucleated cell number of adipose tissue in obese individuals using DAPI-DiI double-staining. Methods: Diet-induced obesity (16 weeks on diet) and periodontitis (5-day ligation) combined mouse models were established. Cell nuclei and membrane in epididymal adipose tissue were stained by DAPI and DiI, respectively, followed by analysis on effects of obesity and periodontitis on nucleated cell number. Results: DAPI-DiI double-staining clearly demonstrated cell nuclei and adipocyte outline in adipose tissue relative to hematoxylin and eosin and toluidine blue staining methods. Nucleated cell number was significantly enhanced by obesity (P < 0.05) but not affected by periodontitis (P > 0.05). Conclusion: Short-term periodontal infection has no significant impact on obesity-related stromal hyperplasia in adipose tissue. DAPI-DiI double-staining may be helpful for adipose tissue histology including nucleated cell counting.

Key words: Obesity, periodontal diseases, adipose tissue, nucleated cell, fluorescence staining