tretinoin and Hemiplegia

We induced neural cells by treating cynomolgus monkey embryonic stem (ES) cells with retinoic acid. The treated cells mainly expressed betaIIItubulin. They further differentiated into neurons expressing neurofilament middle chain (NFM) in elongated axons. Half of the cells differentiated into Islet1+ motoneurons in vitro. The monkey ES-derived neural cells were transplanted to hemiplegic mice with experimental brain injury mimicking stroke. The neural cells that had grafted into periventricular area of the mice distributed extensively over the injured cortex. Some of the transplanted cells expressed the neural stem/progenitor marker nestin 2 days after transplantation. The cells expressed markers characteristic of mature motoneurons 28 days after transplantation. Mice with the neural cell graft gradually recovered motor function, whereas control animals remained hemiplegic. This is the first demonstration that neural cells derived from nonhuman primate ES cells have the ability to restore motor function in an animal model of brain injury.

Topics: Animals; Biomarkers; Brain Damage, Chronic; Cell Differentiation; Cell Line; Cell Movement; Cerebral Infarction; Disease Models, Animal; Female; Graft Survival; Hemiplegia; Intermediate Filament Proteins; Macaca fascicularis; Mice; Mice, Inbred C57BL; Nerve Tissue Proteins; Nestin; Neurofilament Proteins; Neurons; Recovery of Function; Stem Cell Transplantation; Stem Cells; Stroke; Treatment Outcome; Tretinoin

We have treated undifferentiated mouse embryonic stem (ES) cells with all-trans retinoic acid (RA) to induce differentiation in vitro into neuron-like cells with good cell viability for use as a graft. Furthermore, we asked whether the RA-induced neuron-like cells restored neurological dysfunction. To this end, the cells were transplanted into right hemiplegia model of mice, developed by a cryogenic injury of motor cortex. Motor function of the recipients was gradually improved, whereas little improvement was observed in control mice. The lesion showed clustering of mature and almost mature neuron-like cells in mice transplanted with the RA-treated cells. The grafted cells had synaptic vesicles. This finding may suggest their maturation and synaptic connection in the recipient brain. Even though further study is necessary to elucidate molecular and cellular mechanisms responsible for the functional recovery, we consider that the ES cells may have advantage for use as a donor source in various neurological disorders including motor dysfunction.

Topics: Animals; Antineoplastic Agents; Brain Injuries; Brain Tissue Transplantation; Cell Differentiation; Endothelium, Vascular; Hemiplegia; Mice; Mice, Inbred C57BL; Motor Cortex; Movement; Neurons; Recovery of Function; Stem Cell Transplantation; Stem Cells; Tretinoin

Embryonic stem (ES) cells are expected to be a potential donor source for neural transplantation. We have obtained motoneuron-enriched neural progenitor cells by culturing mouse ES cells with retinoic acid (RA). The cells also expressed mRNA of a neurotrophic factor, neurotrophin-3 (NT-3). The left motor cortex area of mice was damaged by cryogenic brain injury, and the neural cells were transplanted underneath the injured motor cortex, neighboring to the paraventricular region. We found that the cells expressing neuronal phenotypes not only remained close to the implantation site, but also exhibited substantial migration penetrating into the damaged lesion, in a seemingly directed manner up to cortical region. We found that some of the neural cells differentiated into Islet1-positive motoneurons. It seems likely that the ability of the ES cell-derived neural progenitor cells to respond in vivo to guidance cues and signals that can direct their migration and differentiation may contribute to functional recovery of the recipient mice. We found that an "island of the mature neuronal cells" of recipient origin emerged in the damaged motor cortex. This may be associated with the neuroprotective effects of the ES cell-derived neural cells. The ES cells differentiated into CD31+ vasculoendothelial cells with the RA treatment in vitro. Furthermore, the grafted cells may provide sufficient neurotrophic factors such as NT-3 for neuroprotection and regeneration. The grafted neural cells that migrated into residual cortex and differentiated into neurons had purposefully elongated axons that were stained with anti-neurofilament middle chain (NFM) antibody. Our study suggests that motoneurons can be induced from ES cells, and ES cells become virtually an unlimited source of cells for experimental and clinical neural cell transplantation.

Topics: Animals; Axons; Cell Differentiation; Cell Line; Cell Movement; Cells, Cultured; Embryo, Mammalian; Endothelium, Vascular; Flow Cytometry; Hemiplegia; Immunohistochemistry; Mice; Mice, Inbred C57BL; Motor Cortex; Motor Neurons; Neurons; Phenotype; Platelet Endothelial Cell Adhesion Molecule-1; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stem Cell Transplantation; Stem Cells; Time Factors; Tretinoin