PLoS ONE (Jan 2015)

Intra-Arterial Transplantation of Allogeneic Mesenchymal Stem Cells Mounts Neuroprotective Effects in a Transient Ischemic Stroke Model in Rats: Analyses of Therapeutic Time Window and Its Mechanisms.

  • Atsuhiko Toyoshima,
  • Takao Yasuhara,
  • Masahiro Kameda,
  • Jun Morimoto,
  • Hayato Takeuchi,
  • Feifei Wang,
  • Tatsuya Sasaki,
  • Susumu Sasada,
  • Aiko Shinko,
  • Takaaki Wakamori,
  • Mihoko Okazaki,
  • Akihiko Kondo,
  • Takashi Agari,
  • Cesario V Borlongan,
  • Isao Date

DOI
https://doi.org/10.1371/journal.pone.0127302
Journal volume & issue
Vol. 10, no. 6
p. e0127302

Abstract

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ObjectiveIntra-arterial stem cell transplantation exerts neuroprotective effects for ischemic stroke. However, the optimal therapeutic time window and mechanisms have not been completely understood. In this study, we investigated the relationship between the timing of intra-arterial transplantation of allogeneic mesenchymal stem cells (MSCs) in ischemic stroke model in rats and its efficacy in acute phase.MethodsAdult male Wistar rats weighing 200 to 250 g received right middle cerebral artery occlusion (MCAO) for 90 minutes. MSCs (1 × 10(6) cells/ 1 ml PBS) were intra-arterially injected at either 1, 6, 24, or 48 hours (1, 6, 24, 48 h group) after MCAO. PBS (1 ml) was intra-arterially injected to control rats at 1 hour after MCAO. Behavioral test was performed immediately after reperfusion, and at 3, 7 days after MCAO using the Modified Neurological Severity Score (mNSS). Rats were euthanized at 7 days after MCAO for evaluation of infarct volumes and the migration of MSCs. In order to explore potential mechanisms of action, the upregulation of neurotrophic factor and chemotactic cytokine (bFGF, SDF-1α) induced by cell transplantation was examined in another cohort of rats that received intra-arterial transplantation at 24 hours after recanalization then euthanized at 7 days after MCAO for protein assays.ResultsBehavioral test at 3 and 7 days after transplantation revealed that stroke rats in 24h group displayed the most robust significant improvements in mNSS compared to stroke rats in all other groups (p'sConclusionsThese results suggest that intra-arterial allogeneic transplantation of MSCs provides post-stroke functional recovery and reduction of infarct volumes in ischemic stroke model of rats. The upregulation of bFGF and SDF-1α likely played a key mechanistic role in enabling MSC to afford functional effects in stroke. MSC transplantation at 24 hours after recanalization appears to be the optimal timing for ischemic stroke model, which should guide the design of clinical trials of cell transplantation for stroke patients.