Downregulated gene expression of TGF-βs in diabetic oral wound healing

Healing of tooth extraction sockets in poorly controlled diabetic patients is often delayed and accompanied by severe infection. The exact cellular and molecular mechanisms underlying the pathogenesis of this complication are still not fully understood.The purpose of this study was to investigate molecular changes associated with delayed oral wound healing in diabetes.Six to eight weeks old male type 2 diabetes and age matched control inbred mice were used and maxillary molar tooth extractions were performed. At 4 and 7 days after tooth extraction, the edentulous mucosa of the mice were harvested, and analyzed for histology and gene expression of key wound healing factors.In the diabetic model, histological analysis showed that epithelial tissue migration for wound closure was delayed after tooth extraction compared to the control. Quantitative real-time PCR revealed that expression of the TGF-β1, TGF-β2, TGF-β3, TGFβRII and TGFβRIII genes was significantly downregulated in the diabetic model at 4 and 7 days after tooth extraction.These results suggest that delayed wound healing of oral mucosa in diabetes may be associated with decreased expression levels of these regulatory genes which play important roles in controlling epithelial wound closure.