Changes in the Thickness of Rat Nerve Sheaths after Single Subperineural Administration of Rat Bone Marrow Mesenchymal Stem Cells

The sheaths of the damaged peripheral nerve of Wistar-Kyoto rats were studied after single subperineural administration of bromodeoxyuridine (BrdU)-labeled bone marrow mesenchymal stem cells (MSC) from the same rats. The sciatic nerve was damaged by ligation for 40 sec directly before MSC administration. BrdU+ MSC were identified in the recipient nerve within 1 week after transplantation and were detected not only in the endoneurium, but also in the epineurium and perineurium. It was found that single administration of MSC into the damaged nerve trunk led to an almost 2-fold increase in the thickness of its sheaths (perineurium and epineurium) in comparison with the control group (ligation). It can be hypothesized that MSC induce thickening of nerve sheaths through the production of factors that stimulate angiogenesis and adipogenesis.