Accelerated functional recovery after skeletal muscle ischemia–reperfusion injury using freshly isolated bone marrow cells

BackgroundRelatively little information exists regarding the usefulness of bone marrow–derived cells for skeletal muscle ischemia–reperfusion injury (I/R), especially when compared with I/R that occurs in other tissues. The objectives of this study were to evaluate the ability of freshly isolated bone marrow cells to home to injured skeletal muscle and to determine their effects on muscle regeneration.Materials and methodsFreshly isolated lineage-depleted bone marrow cells (Lin− BMCs) were injected intravenously 2 d after I/R. Bioluminescent imaging was used to evaluate cell localization for up to 28 d after injury. Muscle function, the percentage of fibers with centrally located nuclei, and the capillary-to-fiber ratio were evaluated 14 d after delivery of either saline (Saline) or saline containing Lin− BMCs (Lin− BMCs).ResultsBioluminescence was higher in the injured leg than the contralateral control leg for up to 7 d after injection (P < 0.05) suggestive of cell homing to the injured skeletal muscle. Fourteen days after injury, there was a significant improvement in maximal tetanic torque (40% versus 22% deficit; P < 0.05), a faster rate of force production (+dP/dt) (123.6 versus 94.5 Nmm/S; P < 0.05), and a reduction in the percentage of fibers containing centrally located nuclei (40 versus 17%; P < 0.05), but no change in the capillary-to-fiber ratio in the Lin− BMC as compared with the Saline group.ConclusionsThe homing of freshly isolated BMCs to injured skeletal muscle after I/R is associated with an increase in functional outcomes.