Effects of Mesenchymal Stromal Cells on the Neuropathic Pain Induced by Chronic Constriction Injury in Rats

Background: Neuropathic pain remains a persistent clinical problem and characterized by mechanical allodynia and heat hyperalgesia. Chronic pain conditions are among the major health problems which are difficult to treat. Bone marrow-derived mesenchymal stromal cells (BMSCs) have generated great interest as an option for cell-based therapy. BMSCs are easy to isolate and expand ex vivo. Clinical studies show that direct injection of BMSCs does not produce side effects as rejection and is well tolerated by the immune system. Methods: Neuropathic pain model in rats was developed with the ligation of the sciatic nerve. BMSCs were isolated from femur and tibia aspirates of rats and kept in culture media. rBMSCs were injected locally into injured sciatic nerve area of rats and efficiency of the therapy was observed with thermal sensitivity and motor functions for 4 weeks after injection of rBMSCs. Results: After injection into injured area rBMSCs were located in sciatic nerve tissue. In the present study, we showed that a single systemic local injection (into the lesion site) of rBMSCs reversed pain hypersensitivity in rats after injury and decreased the pain symptoms for 2 weeks and these effects got back in 4 weeks. Discussion: Our results revealed that single injection of rBMSCs showed relief of pain in short-term follow-up and further booster injection needed for long term prolonged therapeutic approach.