Stem cells and neuroprotection: understanding the players

Reparative effects of neural stem cells in neonatal rats with hypoxic-ischemic injury are not influenced by host sex

BACKGROUND

Gender is increasingly recognized as an important influence on brain development, disease susceptibility, and response to pharmacologic/rehabilitative treatments. In regenerative medicine, it remains entirely unknown whether there is an interaction between transplanted stem cells and host gender that might bias efficacy and safety in some patients but not others.

METHODS

We examined the role of recipient gender in a neonatal rat hypoxic-ischemic injury (HII) model, treated with female human neuronal stem cells (hNSCs), labeled with superparamagnetic iron oxide particles implanted into the contralateral cerebral ventricle. We monitored HII evolution (by magnetic resonance imaging, histopathology, behavioral testing) and hNSC fate (migration, replication, viability).

RESULTS

Recipient gender after implantation did not influence the volume or location of ischemic injury (1, 30, or 90 d) or behavior (90 d). Superparamagnetic iron oxide labeling did not influence HII evolution. Implantation had its greatest benefit on mild/moderate injuries, which remained stable rather than increasing as in severe HII as is the natural history for such lesions.

CONCLUSION

Our results suggest that hNSC treatment (including using hNSCs that are prelabeled with iron to allow tracking in real time by magnetic resonance imaging) would be equally safe and effective for male and female human newborns with mild-to-moderate HII.

Polybutylcyanoacrylate nanoparticle-mediated neurotrophin-3 gene delivery for differentiating iPS cells into neurons

Guided neuronal differentiation of induced pluripotent stem cells (iPSCs) with genetic regulation is an important issue in biomedical research and in clinical practice for nervous regeneration and repair. To enhance the intracellular delivery of plasmid DNA (pDNA), polybutylcyanoacrylate (PBCA) nanoparticles (NPs) were employed to mediate the transport of neurotrophin-3 (NT-3) into iPSCs. The ability of iPSCs to differentiate into neuronal lineages was shown by immunofluorescent staining, western blotting, and flow cytometry. By transmission electron microscopy, we found that PBCA NPs could efficiently grasp pDNA, thereby increasing the particle size and conferring a negative surface charge. In addition, the treatments with PBCA NP/NT-3 complexes enhanced the expression of NT-3, TrkC, NH-H, NSE, and PSD95 by differentiating iPSCs. Neurons produced from iPSCs were incapable of returning to pluripotency, demonstrating with a series of differentiation scheme for adipogenesis and osteogenesis. The pretreatment with PBCA NP/NT-3 complexes can be one of critical biotechnologies and effective delivery systems in gene transfection to accelerate the differentiation of iPSCs into neurons.

Enhancement of angiogenic effect of co-transfection human NGF and VEGF genes in rat bone marrow mesenchymal stem cells

The current study explored the feasibility and efficacy of co-transfection of the human nerve growth factor (NGF) and vascular endothelial growth factor 165 (VEGF165) genes in rat bone marrow mesenchymal stem cells (BMSCs). The obtained hNGF and vascular endothelial growth factor (VEGF) cDNAs were cloned into the pEGFP-C1 expression vector to construct the recombinant vectors. Co-transfection in rat BMSCs was performed and the expressions of both genes were detected by RT-PCR, Western blot, and enzyme-linked immunospecific assay. The biological activity of recombinant NGF and VEGF proteins was confirmed using the Chick Chorioallantoic Membrane (CAM) assay. NGF and VEGF genes could be expressed successfully in rat BMSCs. The recombinant NGF and VEGF from the rat BMSCs showed a more significant synergetic biological activity compared with single recombinant NGF or VEGF. These findings demonstrate that the co-transfection of hNGF+VEGF genes can enhance the angiogenic effect in vivo.