Influence of bone marrow mesenchymal stem cells transplantation on the expression of AMPA receptor protein in rats with spinal cord injury / 中华创伤杂志

ABSTRACT

Objective To observe the influence of bone marrow mesenchymal stem cells (BMSCs) transplantation on the expression of alpha-amino hydroxymethyl-oxazole propionic acid (AMPA) receptors GluR1 and GluR2 in rats with spinal cord injury (SCI) so as to investigate the potential anti- chronic stress mechanism of BMSCs transplantation in treatment of rats with spinal cord injury.Methods A total of 48 adult male SD rats were equally divided into three groupscontrol group,treatment group and model group.The rats in the model and treatment group underwent lower thoracic SCI with the modified Allen' s method,and the rats in control group received only laminectomy.At day 7 after thoracic SCI,100 μl of Hank's buffered saline solution containing 1.0 × 106 BMSCs was injected into the subarachnoid space from L4-L5 intervertebral space in the treatment group and control group,and the same amount of Hank' s buffered saline solution was injected in the model group.The motor function of the rat posterior limbs was assessed by Basso-Beattie-Bresnahan (BBB) scale before and after operation.Half of the rats were anesthetized at days 14 and 28 postoperatively to harvest brains which were frozen and cut in a cryostat to detect the expressions of GluR1 and GluR2 proteins by immunohistochemistry.Results After BMSCs transplantation,the motor function of the posterior limbs in the treatment group was improved progressively.At day 14 after transplantation,the number of GluR1-positive cells of the model and treatment group was higher than that of the control group in the hippocampus CA1 region (P ＜0.05,P ＜0.01 respectively) ; GluR2-positive cells had the similar tendency,without significant difference(P ＞ 0.05 ).At the 28th day after transplantation,GluR1 positive cells of the model group were higher than those of the control group in CA1,CA3,DG regions and those of the treatment group in CA1,CA3 regions (P ＜0.05,P ＜0.01,respectively) ; GluR1 positive cells of the model and treatment group were higher than their counterpart at day 14 after grafting procedure,with significant difference (P ＜0.05,P ＜0.01,respectively).GluR2 positive cells of the treatment group were higher than those of the control group in the basolateral amygdale (BLA) (P ＜0.05 ) and had similar tendency with GluR1 expression in other regions ( P ＞ 0.05 ).Conclusion BMSCs transplantation implies a potential antichronic stress mechanism of SCI rats,since it can improve the motor function of posterior limbs in rats with lower thoracic SCI and regulate the expressions of AMPA receptor GluR1 and GluR2.