Effect of peripheral blood mononuclear cells on spinal motor neurons after end-to-end anastomosis of transected sciatic nerves in rats / 中华创伤杂志

ABSTRACT

Objective To investigate the effects of peripheral blood mononuclear cells (PBMCs) on spinal motor neurons after end-to-end anastomosis of transected sciatic nerves in rats and further explore the possible mechanisms concerned.Methods A total of 30 SD rats were randomly divided into five groupsblank control group,sciatic nerve transaction group (model group),nerve anastomosis after sciatic nerve transaction (anastomosis group),nerve anastomosis with PBMCs treatment after sciatic nerve transaction (PBMCs group),and nerve anastomosis with solvent control treatment after sciatic nervetransaction (solvent control group),with six rats per group.Except for the rats in blank control group,transection of the left sciatic nerves conducted 0.5 cm under the piriformis muscle was performed in all animals,immediately followed by end-to-end anastomosis of sciatic nerves in anastomosis,PBMCs and solvent control groups.The rats in PBMCs group were given 0.2 ml PBMCs (1 × 107 PBMCs) at anastomosis,and the rats in solvent control group were injected with 0.2 ml PRMI-1640.After rats were on regular diet for 4 weeks,morphological examination was performed by HE staining and the counting of apoptotic cells was evaluated by TdT mediated dUTP nick end labeling (TUNEL) staining.The protein expression of brain derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF) were detected by Western blot.Results In model group,HE staining showed that most of the spinal motor neurons became vacuoles with karyopyknosis and cytomorphosis.In anastomosis group and solvent control group,some spinal motor neurons had contraction,deformation and even plasmolysis,with vacuoles status of cytoplasm,karyopyknosis in some cells.In PBMCs group,some spinal motor neurons were normal with nucleus in the middle while some other spinal motor neurons were seen plasmolysis and vacuoles status of cytoplasm.Through TUNEL,the numbers of apoptotic cells were 0.44 ± 0.10 in blank control group,5.78 ± 1.11 in model group,5.22 ±0.51 in anastomosis group,2.56-± 0.42 in the PBMCs group,and 3.78 ± 0.19 in solvent control group,respectively.Compared with blank control group,the apoptosis of spinal motor neurons was significantly increased in model group (P ＜ 0.05).Compared with model group,the apoptosis of spinal motor neurons was significantly decreased in treatment groups except anastomosis group (P ＜ 0.05).Compared with solvent control group,the apoptosis of spinal motor neurons was significantly decreased in PBMCs group (P ＜ 0.05).The BDNF protein levels of the spinal cord tissue were 1.83 ± 0.72 in blank control group,1.35 ± 0.46 in model group,1.29 ± 0.44 in anastomosis group,1.87 ± 0.55 in PMBCs group,and 1.22 ± 0.50 in solvent control group,respectively.Compared with blank control group,the protein expression of BDNF was decreased in model group (P ＜ 0.05).Compared with model group,the protein levels of BDNF and GDNF were increased in PMBCs group (P ＜ 0.05).There was no significant difference between anastomosis group and solvent control group in regard of protein levels of BDNF and GDNF (P ＞ 0.05).Conclusions The transaction of sciatic nerves may induce injury and apoptosis of the spinal motor neurons.End-to-end anastomosis combined with PMBCs can effectively ameliorate apoptosis of the spinal motor neurons,the mechanism of which may be related to PMBCs that may enhance protein levels of BDNF and GDNF in spinal cord.