Abstract
The purpose of the present study was to examine the expression of Toll‑like receptor 4 (TLR4) on mast cells in gingival tissues of human chronic periodontitis. A total of 68 donors, including 23 with mild chronic periodontitis, 25 with advanced chronic periodontitis and 20 healthy controls, were included in the present study. Gingival specimens from the donors were fixed in 4% neutral formalin, stained with hematoxylin and eosin for histologic observation, stained for immunohistochemical identification of TLR4 in gingival tissues, and stained with double immunofluorescence for the identification of TLR4 on mast cells in gingival tissues. The results revealed that the expression of TLR4 in the gingival tissues and on mast cells in the gingival tissues of patients with chronic periodontitis were significantly higher, compared with those of the normal control group (P<0.05). The expression levels of TLR4 in the gingival tissues and on mast cells in patients with advanced chronic periodontitis were significantly higher, compared with those in patients with mild chronic periodontitis (P<0.05). In conclusion, the expression of TLR4 in gingival tissues and on mast cells increased with the severity of chronic periodontitis, suggesting that TLR4, particularly mast cell TLR4, may be important in the disease process of human chronic periodontitis.