Purpose: Mesenchymal stem cells (MSCs) have demonstrated great promises for the treatment of ischemic stroke. Previously, we identified a new source of MSCs located in the inferior turbinate. We investigated therapeutic potentials of human turbinate- derived mesenchymal stem cells (hTMSCs) in ischemic stroke.
Methods: Ischemic stroke was induced by the intraluminal occlusion of middle cerebral artery (MCAo) for 50 minutes in rats. At one day after MCAo, hTMSCs, adipose tissue-derived MSCs (AdMSCs), or phosphate buffered saline (PBS) were transplanted into the striatum. Functional recovery was assessed by repeating behavioral tests including modified neurologic severity score and corner test. At 14 days after MCAo, brains were stained with hematoxylin and eosin (H&E) for measuring infarct volume. The survival of grafted MSCs was evaluated by immunohistochemistry to human nuclei (hNU). Immunohistochemistry with anti-doublecortin (anti-DCX) was performed to assess hippocampal neurogenesis.
Results: Transplantation of hTMSCs following MCAo showed improvements of neurologic function, which was comparable with that of AdMSCs. H&E staining showed no difference in infarct volume among 3 groups. Regarding the survival of grafted MSCs, the number of hNU-expressing cells was not different between hTMSCs- and AdMSCs-treated groups. Finally, hTMSCs increased the number of subgranular DCX-positive cells compared to PBS-treated controls, without affecting hilar ectopic migration of newborn neurons.
Conclusion: hTMSCs could improve functional recovery following ischemic stroke, of which efficacy was similar to AdMSCs. Although hTMSCs showed comparable infarct size and survival of grafted MSCs, transplantation of hTMSCs could upregulate subgranular neurogenesis with no impact on ectopically migrating newborn neurons.
Keywords: Mesenchymal stem cells; Neurogenesis; Rats; Stroke; Transplantation; Turbinates.