Observed impacts of insulin therapy on callus cell transforming growth factor-beta 1 expression in diabetic rats.

ABSTRACT

The expression of transforming growth factor-beta 1 (TGF-ß1) inside the callus cells of diabetic rats and the impact of insulin therapy on its expression and biomechanics was investigated. The rats were randomly divided as follows an insulin therapy group (IT), a diabetic model group (DM), and a non-diabetic control group (NC). Bone specimens from each group were extracted at different times for immunohistochemical observation of the expression of TGF-ß1. Concurrently, the destruction torque and torsional stiffness were detected at different times. One to four weeks after fracture, TGF-ß1 was widely expressed in fractured callus cells and periosteal proliferating cells, while the expression inside diabetic cells was significantly reduced. The expression of TGF-ß1 decreased over the first 68 weeks, and the mature bone cells never expressed TGF-ß1. The destruction torque (Nm) detected in the 6th week revealed that there was a statistically significant difference between the DM, NC, and IT groups (P < 0.01). In conclusion, TGF-ß1 expression was significantly reduced inside the callus cells of diabetic rats. Insulin therapy increased TGF-ß1 expression inside the callus cells of diabetic rats and improved the biomechanical characteristics of the callus.