The relationship between the change of Osx and Dlx5 expressed in the callus and fracture healing in type 2 diabetes rats

Liu Zhen-dong; Cai Xu; Wang Kui-xiang; Zhang Yuan-jun; Liu Zhi-tao

doi:10.3969/j.issn.2095-4344.2015.11.012

Abstract：BACKGROUND:Experiments have shown that the expression levels of Osx and Dlx5 may have some relationships with fracture healing disorder. OBJECTIVE:To probe into the relationship between the change of expression of Osx and Dlx5 in the calus of type 2 diabetes rats and fracture healing disorder. METHODS:We selected 32 Sprague-Dawley rats with proper weight in 8 weeks age. They were randomly assigned into two groups: the experimental group (n=18) was fed with high fat and sugar diet for 8 weeks, and then received intraperitoneal injection of streptozotocin to induce diabetic models; the control group was fed with normal diet and received intraperitoneal injection of the same dose of citric acid. Two weeks later, al the rats were used to establish left tibia traction fracture models with orthopedic external fixator. We extended the external fixator at a proper length per day. The animals were sacrificed at 15 days after establishment of traction fracture models. The blood specimens were evaluated for biochemical detection. X-ray was used to observe the growth of calus. The calus tissues from the left tibia were taken for histological observation and the expression of Dlx5 and Osx in the calus was detected. RESULTS AND CONCLUSION:X-ray results showed that the amount of calus tissues in the experimental group was significantly reduced. The hematoxylin-eosin staining of the calus tissue revealed that the microcolumn formation in the experimental group was significantly reduced compared with the control group; the area of primary matrixfront was lightly colored. The calus histological quantitative analysis showed that in the experimental group the area of new calus decreased and more adipose cels presented in the proximal fracture <br> end compared with the control group (P < 0.01). QPCR displayed that the expression of Osx and Dlx5 was lower in the experimental group than the control group (P < 0.05). These findings indicate that the poorer fracture healing in type 2 diabetes than the normal rats may be associated with the decrease of Osx and Dlx5 expression.