Effect of subarachnoid bone marrow mesenchymal stem cell transplantation on chronic neuropathic pain in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of transplantation of bone marrow mesenchymal stem cells (MSCs) in subarachnoid space on chronic neuropathic pain in rats. Methods One hundred and forty female SD rats weighing 180-200 g were used in this study. Chronic neuropathic pain (NP) was induced by ligation and separation of tibial and common fibular nerves (SNI). Two weeks after the surgery the animals were randomly divided into4 groups (n=35 each):group Ⅰ NP; group Ⅱ NP+ MSC (MSCs); group Ⅲ NP+ phosphate buffer saline (PBS) and group Ⅳ NP+ bone marrow monocyte (BNMCs). MSCs 10 μl, PBS 10 μl and BNMCs 10 μl were injected into subaraclmoid space at 2 weeks after surgery in group Ⅱ , Ⅲ and Ⅳ respectively. Paw withdrawal threshold to yon Frey filament stimulation (PWT) was measured before surgery (T0, baseline), at 2 weeks after surgery (T1) and 1, 2, 3, 4 and 5 weeks after subarachnoid injection (T2-6). Five animals were killed at T1-6 in each group and their lumbar enlargements were removed for determination of BDNF mRNA expression. Results PWT was significantly decreased by SNI at T1 in all 4 groups, and at T2-6 in group Ⅰ , Ⅲ and Ⅳ as compared with the baseline at T0 (P ＜ 0.05). Subarachnoid MSC transplantation significantly reduced mechanical hyperalgesia at T2-6 and up-regulated BDNF mRNA expression at T2-4 as compared with that at T1 (P ＜0.05). There was no significant change in PWT and BDNF mRNA expression after subarachnoid PBS and BNMCs injection in group Ⅲ and Ⅳ (P ＞ 0.05). Compared with group Ⅰ , PWT was significantly increased and BDNF mRNA expression was up-regulated in group Ⅱ (P ＜ 0.05), but no significant change in PBS and BNMCs was found in group Ⅲ (P ＞ 0.05) .Conclusion Up-regulation of BDNF mRNA expression in the spinal cord may be involved in the amelioration of chronic neuropathic pain by subarachnoid bone marrow mesenchymal stem cell transplantation.