Timing of Intra-Arterial Neural Stem Cell Transplantation After Hypoxia–Ischemia Influences Cell Engraftment, Survival, and Differentiation

Abstract

Background and Purpose-Intra-arterial neural stem cell (NSC) transplantation shows promise as a minimally invasive therapeutic option for stroke. We assessed the effect of timing of transplantation on cell engraftment, survival, and differentiation. Methods-Mouse NSCs transduced with a green fluorescent protein and renilla luciferase reporter gene were transplanted into animals 6 and 24 hours and 3, 7, and 14 days after hypoxia-ischemia (HI). Bioluminescent imaging was used to assess cell survival at 6 hours and 4 and 7 days after transplantation. Immunohistochemistry was used to assess NSC survival and phenotypic differentiation 1 month after transplantation. NSC receptor expression and brain gene expression were evaluated using real-time reverse transcription-quantitative polymerase chain reaction to elucidate mechanisms of cell migration. Boyden chamber assays were used to assess cell migratory potential in vitro. Results-NSC transplantation 3 days after HI resulted in significantly higher cell engraftment and survival at 7 and 30 days compared with all other groups (PϽ0.05). Early transplantation at 6 and 24 hours after HI resulted in significantly higher expression of glial fibrillary acidic protein (Pϭ0.0140), whereas late transplantation at 7 and 14 days after HI resulted in higher expression of ␤-tubulin (PϽ0.0001). Corroborating the high cell engraftment 3 days after HI was robust expression of vascular cell adhesion molecule-1, CCL2, and CXCL12 in brain homogenates 3 days after HI. Conclusion-Intra-arterial transplantation 3 days after HI results in the highest cell engraftment. Early transplantation ofNSCs leads to greater differentiation into astrocytes, whereas transplantation at later time points leads to greater differentiation into neurons. (Stroke. 2012;43:1624-1631.)Key Words: animal models Ⅲ cell transplantation Ⅲ cerebral infarct Ⅲ experimental Ⅲ stem cells I ntravascular transplantation of neural stem cells (NSCs) represents a promising therapeutic opportunity for stroke. [1][2][3][4][5][6] Several studies have demonstrated cell engraftment and functional recovery in rodent models of hypoxia-ischemia, 1,4,7 and these treatments are being evaluated for safety and efficacy in humans. 8,9 After cerebral ischemia, circulating peripheral immune cells are recruited by a chemoattractive gradient. 10 -14 Using a similar mechanism, NSCs are able to use endogenous adhesion and chemoattractant molecules to extravasate from the vascular compartment and migrate to the ischemic lesion. 1,10 -12,15-18 We have previously studied the mechanism of NSC homing to the ischemic penumbra, implicating the adhesion molecule vascular cell adhesion molecule-1 (VCAM-1) 1 and the chemokines CCL2 and CXCL12 in this process. 7 We also demonstrated increased NSC engraftment using intra-arterial delivery compared with intravenous delivery, 19 and the absence of microstrokes after NSC injection. 5 However, the optimal timing of intra-arterial NSC transplantation remains largely uncharacterized. If intravascular NSC therap...

BDNF Pretreatment of Human Embryonic-Derived Neural Stem Cells Improves Cell Survival and Functional Recovery after Transplantation in Hypoxic–Ischemic Stroke

“…5). Previous data from our lab and others have found that SDF-1 is highly upregulated 3 days after stroke (15,35), and the interaction of SDF-1 with CXCR4 plays an important role in facilitating migration of cells in the ischemic brain (36). Our data corroborates recent evidence that overexpression of CXCR4 in intravascularly transplanted mesenchymal stem cells improves engraftment (37), and we postulate that the significant change in migratory ability of NSCs seen after BDNF pretreatment could contribute to greater cell engraftment.…”

“…Representative sections were 400 µm apart (five representative sections, three from the cortex, two from the hippocampus; each representative section 400 µm apart, for a total of 2 mm of brain analyzed) and chosen by an investigator blinded to treatment groups. ROIs in peri-infarct regions were chosen based on previous data from our lab illustrating the commonly affected regions of the brain after HI stroke (30,35). A different blinded investigator then performed the unbiased counting of SC-121 + cells.…”

Spatiotemporal PET Imaging of Dynamic Metabolic Changes After Therapeutic Approaches of Induced Pluripotent Stem Cells, Neuronal Stem Cells, and a Chinese Patent Medicine in Stroke

“…Immunohistochemical and immunofluorescence staining verified that iPSCs and NSCs migrated to the area close to the ischemic area, where they expressed the mature neuronal marker NeuN, mature astrocyte marker GFAP, and endothelial cell marker vWF. These findings corroborate other previous studies (on NSCs or iPSCs used individually), which demonstrated that stem cells survived, migrated, and differentiated into mature neurons (26) or angiogenic cells (19) and improved functional recovery via promoting vascular endothelial growth factor expression and enhancing endogenous plasticity in the injured brain (27). Transplantation of iPSCs could improve the motor function, reduce infarct size, attenuate inflammation cytokines, and mediate neuroprotection after ischemic stroke (10,28).…”

Optimization of time for neural stem cells transplantation for brain stroke in rats

“…Hence, the time of cellular intervention post ischemic insult is integral to the accomplishment of the desired prognosis. Although methodical and in-depth studies to ascertain optimal intermission between stroke to cell transplantation are still wanting in the literature, various research groups have performed cell transplantation from hours to weeks after ischemic stroke (36,37). Our study was aimed to ascertain the optimal time for cell therapy after stroke in terms of attenuation of cell apoptosis in the host tissue and overall improved neurological performance.…”