Histological study on the role of bone marrow-derived mesenchymal stem cells on the sciatic nerve and the gastrocnemius muscle in a model of sciatic nerve crush injury in albino rats

Background Peripheral nerve injury is a common and devastating complication after trauma leading to irreversible impairment, or even complete functional loss of the affected limb. Sciatic nerve crush is one of the most common models of peripheral nerve injury in rodents. Mesenchymal stem cells have become a very attractive source of cell implantation for neural tissue engineering. Aim of the work The aim of this study was to evaluate the role of bone marrow-derived mesenchymal stem cells (BMMSCs) in the injured sciatic nerve and subsequent innervated muscle. Materials and methods BMMSCs were isolated, cultured, and characterized from the long bones of 15 albino rats of average 100 g. Thirty adult albino rats weighing 200–250 g were used and were divided into three groups of 10 rats each. Group I underwent a sham operation and served as the control group. Group II underwent crush injury of the sciatic nerve. Group III underwent crush injury of the sciatic nerve and then they were injected after 1 week with a single dose of BMMSCs. The rats in all groups were sacrificed in two different time intervals. Light and electron microscopic studies were conducted. Morphometric and statistical studies were also conducted. Results Histological examination of group II rats showed structural changes of the sciatic nerve, including degeneration of the axons and myelin sheath with proliferation of Schwann cells. This was associated with a significant decrease in S-100 immune reaction. The gastrocnemius muscle showed areas of loss of striations and disorganized sarcomeres. Injection of BMMSCs revealed regeneration of axons and myelin sheath by proliferating Schwann cells with a significant increase in S-100 immune reaction. Subsequently, there was an improvement in muscle fibers. Conclusion BMMSCs have relevant therapeutic potential in an animal model of axonal injury and might represent a valuable tool for stem-cell-based therapy in inflammatory and degenerative diseases of the peripheral nervous system.