Selection of optimal passage of bone marrow-derived mesenchymal stem cells for stem cell therapy in patients with amyotrophic lateral sclerosis.

Mesenchymal stem cells (MSCs) obtained from bone marrow (BM) are currently used as an alternative therapy in amyotrophic lateral sclerosis (ALS) patients. Selection of optimal passages of autologous BM-derived MSCs during long-term in vitro expansion is important for clinical trials in patients with ALS. We isolated and expanded MSCs from the BM of eight ALS patients to analyze the growth kinetics, differentiation potential, cellular surface antigen expression, karyotype modifications and secretion of various cytokines during long-term culture. The morphology and size of the cells changed from small and spindle-like cells to large and polygonal types in later passages. The growth rate of the MSCs was highest in the third passage, followed by a gradual decrease. There were no special modifications of cell surface antigens or the karyotype of the MSCs from the first to the tenth passage. MSCs in the fourth passage were differentiated into adipocytes, osteocytes and chondrocytes. When we analyzed the cultured media of MSCs at the third, fifth, seventh and ninth passages, IL-6, VEGF and IL-8 showed high expression, with more than 50pg/10,000 cells at these passages; however, their expression progressively decreased with additional passages. In addition, secretion of IL-15, GM-CSF, IL-10, PDGF-bb, G-CSF, IL-1beta, basic FGF and IFN-gamma gradually decreased over prolonged culture. We suggest that MSCs at earlier passages are more suitable for stem cell therapy in ALS patients because of their stability and more potent anti-inflammatory and neuroprotective properties.

Implantation of human umbilical cord-derived mesenchymal stem cells as a neuroprotective therapy for ischemic stroke in rats.

In the present study, we examined the neuroprotective effects and mechanisms of implanted human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in ischemic stroke. hUC-MSCs were isolated from the endothelial/subendothelial layers of the human umbilical cord and cultured. Twenty days after the induction of in vitro neuronal differentiation, about 77.4% of the inoculated hUC-MSCs displayed morphological features of neurons and expressed neuronal cell markers like TU-20, Trk A, NeuN, and NF-M. However, functionally active neuronal type channels were not detected by electrophysiological examination. Before, during, or one day after in vitro neuronal differentiation, the hUC-MSCs produced granulocyte-colony stimulating factor, vascular endothelial growth factor, glial cell line-derived neurotrophic factor, and brain-derived neurotrophic factor. In an in vivo study, implantation of the hUC-MSCs into the damaged hemisphere of immunosuppressed ischemic stroke rats improved neurobehavioral function and reduced infarct volume relative to control rats. Three weeks after implantation, most of the implanted hUC-MSCs were present in the damaged hemisphere; some of these cells expressed detectable levels of neuron-specific markers. Nestin expression in the hippocampus was increased in the hUC-MSC-implanted group relative to the control group. Since the hUC-MSCs were both morphologically differentiated into neuronal cells and able to produce neurotrophic factors, but had not become functionally active neuronal cells, the improvement in neurobehavioral function and the reduction of infarct volume might be related to the neuroprotective effects of hUC-MSCs rather than the formation of a new network between host neurons and the implanted hUC-MSCs.