Empty mesoporous silica particles significantly delay disease progression and extend survival in a mouse model of ALS.

Amyotrophic lateral sclerosis (ALS) is a devastating incurable neurological disorder characterized by motor neuron (MN) death and muscle dysfunction leading to mean survival time after diagnosis of only 2-5 years. A potential ALS treatment is to delay the loss of MNs and disease progression by the delivery of trophic factors. Previously, we demonstrated that implanted mesoporous silica nanoparticles (MSPs) loaded with trophic factor peptide mimetics support survival and induce differentiation of co-implanted embryonic stem cell (ESC)-derived MNs. Here, we investigate whether MSP loaded with peptide mimetics of ciliary neurotrophic factor (Cintrofin), glial-derived neurotrophic factor (Gliafin), and vascular endothelial growth factor (Vefin1) injected into the cervical spinal cord of mutant SOD1 mice affect disease progression and extend survival. We also transplanted boundary cap neural crest stem cells (bNCSCs) which have been shown previously to have a positive effect on MN survival in vitro and in vivo. We show that mimetic-loaded MSPs and bNCSCs significantly delay disease progression and increase survival of mutant SOD1 mice, and also that empty particles significantly improve the condition of ALS mice. Our results suggest that intraspinal delivery of MSPs is a potential therapeutic approach for the treatment of ALS.

Boundary Cap Neural Crest Stem Cells Promote Survival of Mutant SOD1 Motor Neurons.

ALS is a devastating disease resulting in degeneration of motor neurons (MNs) in the brain and spinal cord. The survival of MNs strongly depends on surrounding glial cells and neurotrophic support from muscles. We previously demonstrated that boundary cap neural crest stem cells (bNCSCs) can give rise to neurons and glial cells in vitro and in vivo and have multiple beneficial effects on co-cultured and co-implanted cells, including neural cells. In this paper, we investigate if bNCSCs may improve survival of MNs harboring a mutant form of human SOD1 (SOD1G93A) in vitro under normal conditions and oxidative stress and in vivo after implantation to the spinal cord. We found that survival of SOD1G93A MNs in vitro was increased in the presence of bNCSCs under normal conditions as well as under oxidative stress. In addition, when SOD1G93A MN precursors were implanted to the spinal cord of adult mice, their survival was increased when they were co-implanted with bNCSCs. These findings show that bNCSCs support survival of SOD1G93A MNs in normal conditions and under oxidative stress in vitro and improve their survival in vivo, suggesting that bNCSCs have a potential for the development of novel stem cell-based therapeutic approaches in ALS models.

Boundary cap neural crest stem cell transplants contribute Mts1/S100A4-expressing cells in the glial scar.

AIM: During development, boundary cap neural crest stem cells (bNCSCs) assist sensory axon growth into the spinal cord. Here we repositioned them to test if they assist regeneration of sensory axons in adult mice after dorsal root avulsion injury. MATERIALS & METHODS: Avulsed mice received bNCSC or human neural progenitor (hNP) cell transplants and their contributions to glial scar formation and sensory axon regeneration were analyzed with immunohistochemistry and transganglionic tracing. RESULTS: hNPs and bNCSCs form similar gaps in the glial scar, but unlike hNPs, bNCSCs contribute Mts1/S100A4 (calcium-binding protein) expression to the scar and do not assist sensory axon regeneration. CONCLUSION: bNCSC transplants contribute nonpermissive Mts1/S100A4-expressing cells to the glial scar after dorsal root avulsion.