Mitochondrial dysfunction is a hallmark of secondary neuroinflammatory responses and neuronal death in
spinal cord injury (SCI). Even though mitochondria-based
therapy is an attractive therapeutic option for SCI, the efficacy of
transplantation of allogeneic mitochondria in the treatment of SCI remains unclear. Herein, we determined the
therapeutic effects of mitochondrial
transplantation in the traumatic SCI rats. Compressive SCI was induced by applying an
aneurysm clip on the T10 spinal cord of rats. A 100-μg bolus of soleus-derived allogeneic mitochondria labeled with fluorescent tracker was transplanted into the injured spinal cords. The results showed that the transplanted mitochondria were detectable in the injured spinal cord up to 28 days
after treatment. The rats which received mitochondrial
transplantation exhibited better recovery of locomotor and sensory functions than those who did not. Both the expression of
dynamin-related
protein 1 and severity of
demyelination in the injured cord were reduced in the mitochondrial transplanted groups. Mitochondrial
transplantation also alleviated SCI-induced cellular apoptosis and
inflammation responses. These findings suggest that
transplantation of allogeneic mitochondria at the early stage of SCI reduces mitochondrial fragmentation, neuroapoptosis,
neuroinflammation, and generation of oxidative stress, thus leading to improved functional recovery following traumatic SCI.