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Stem and progenitor cells provide a promising therapeutic strategy for amyotrophic lateral sclerosis (ALS). To comparatively evaluate the therapeutic potentials of human bone marrow-derived mesodermal stromal cells (hMSCs) and umbilical cord blood cells (hUBCs) in ALS, we transplanted hMSCs and hUBCs and their neuroectodermal derivatives (hMSC-NSCs and hUBC-NSCs) into the ALS mouse model over-expressing the G93A mutant of the human SOD1 gene. We used a standardized protocol similar to clinical studies by performing a power calculation to estimate sample size prior to transplantation, matching the treatment groups for gender and hSOD-G93A gene content, and applying a novel method for directly injecting 100,000 cells into the CSF (the cisterna magna). Ten days after transplantation we found many cells within the subarachnoidal space ranging from frontal basal cisterns back to the cisterna magna, but only a few cells around the spinal cord. hMSCs and hMSC-NSCs were also located within the Purkinje cell layer. Intrathecal cell application did not affect survival times of mice compared to controls. Consistently, time of disease onset and first pareses, death weight, and motor neuron count in lumbar spinal cord did not vary between treatment groups. Interestingly, transplantation of hMSCs led to an increase of pre-symptomatic motor performance compared to controls in female animals. The negative outcome of the present study is most likely due to insufficient cell numbers within the affected brain regions (mainly the spinal cord). Further experiments defining the optimal cell dose, time point and route of application and particularly strategies to improve the homing of transplanted cells towards the CNS region of interest are warranted to define the therapeutic potential of mesodermal stem cells for the treatment of ALS.

The aim of our study was to investigate whether a human neural stem cell line derived from umbilical cord blood (HUCB-NSC) can serve as a reliable test model for developmental neurotoxicity (DNT). We assessed the sensitivity of HUCB-NSCs at different developmental stages to a panel of neurotoxic (sodium tellurite, methylmercury chloride, cadmium chloride, chlorpyrifos, and L-glutamate) and non-neurotoxic (acetaminophen, theophylline, and D-glutamate) compounds. In addition, we investigated the effect of some compounds on key neurodevelopmental processes like cell proliferation, apoptotic cell death, and neuronal and glial differentiation. Less differentiated HUCB-NSCs were generally more sensitive to neurotoxicants, with the notable exception of L-glutamate, which showed a higher toxicity to later stages. The relative potencies of the compounds were: cadmium chloride > methylmercury chloride ) chlorpyrifos ) L-glutamate. Fifty nanomolar methylmercury chloride (MeHgCl) inhibited proliferation and induced apoptosis in early-stage cells. At the differentiated stage, 1 lM MeHgCl induced selective loss of S100b-expressing astrocytic cells. One millimolar L-glutamate did not influence the early stages of HUCB-NSC development, but it affected late stages of neuronal differentiation. A valuable system for in vitro DNT assessment should be able to discriminate between neurotoxic and non-neurotoxic compounds and show different susceptibilities to chemicals according to developmental stage and cell lineage. Although not exhaustive, this work shows that the HUCB-NSC model fulfils these criteria and may serve as a human in vitro model for DNT priority setting. STEM

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BackgroundThe purpose of the study was to evaluate the long-term clinical tracking of magnetically labeled stem cells after intracerebroventricular transplantation as well as to investigate in vitro feasibility for magnetic guidance of cell therapy within large fluid compartments.MethodAfter approval by our Institutional Review Board, an 18-month-old patient, diagnosed as being in a vegetative state due to global cerebral ischemia, underwent cell transplantation to the frontal horn of the lateral ventricle, with umbilical cord blood-derived stem cells labeled with superparamagnetic iron oxide (SPIO) contrast agent. The patient was followed over 33 months with clinical examinations and MRI. To evaluate the forces governing the distribution of cells within the fluid compartment of the ventricular system in vivo, a gravity-driven sedimentation assay and a magnetic field-driven cell attraction assay were developed in vitro.ResultsTwenty-four hours post-transplantation, MR imaging (MRI) was able to detect hypointense cells in the occipital horn of the lateral ventricle. The signal gradually decreased over 4 months and became undetectable at 33 months. In vitro, no significant difference in cell sedimentation between SPIO-labeled and unlabeled cells was observed (p = NS). An external magnet was effective in attracting cells over distances comparable to the size of human lateral ventricles.ConclusionsMR imaging of SPIO-labeled cells allows monitoring of cells within lateral ventricles. While the initial biodistribution is governed by gravity-driven sedimentation, an external magnetic field may possibly be applied to further direct the distribution of labeled cells within large fluid compartments such as the ventricular system.

Transplantation of neural stem/precursor cells has recently been proposed as a promising, albeit still controversial, approach to brain repair. Human umbilical cord blood could be a source of such therapeutic cells, proven beneficial in several preclinical models of stroke. Intracerebroventricular infusion of neutrally committed cord blood-derived cells allows their broad distribution in the CNS, whereas additional labeling with iron oxide nanoparticles (SPIO) enables to follow the fate of engrafted cells by MRI. A 16-month-old child at 7 months after the onset of cardiac arrest-induced global hypoxic/ischemic brain injury, resulting in a permanent vegetative state, was subjected to intracerebroventricular transplantation of the autologous neutrally committed cord blood cells. These cells obtained by 10-day culture in vitro in neurogenic conditions were tagged with SPIO nanoparticles and grafted monthly by three serial injections (12 × 10(6) cells/0.5 ml) into lateral ventricle of the brain. Neural conversion of cord blood cells and superparamagnetic labeling efficiency was confirmed by gene expression, immunocytochemistry, and phantom study. MRI examination revealed the discrete hypointense areas appearing immediately after transplantation in the vicinity of lateral ventricles wall with subsequent lowering of the signal during entire period of observation. The child was followed up for 6 months after the last transplantation and his neurological status slightly but significantly improved. No clinically significant adverse events were noted. This report indicates that intracerebroventricular transplantation of autologous, neutrally committed cord blood cells is a feasible, well tolerated, and safe procedure, at least during 6 months of our observation period. Moreover, a cell-related MRI signal persisted at a wall of lateral ventricle for more than 4 months and could be monitored in transplanted brain hemisphere.

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Stem cell-based regenerative neurology is an emerging concept for treatment of diseases of central nervous system. Among variety of proposed procedures, one of the most promising is refilling of cystic cavities of injured brain parenchyma with artificial neural tissue. Recent studies revealed that after allogenic transplantation in rodents these tissue-engineered entities were shown efficient in repair of hypoxic/ischemic brain injury. Human umbilical cord blood (HUCB) was recognized to be an efficient and noncontroversial source of neural stem cells (NSC). The main purpose of this study was to generate HUCB-derived neural artificial tissue and investigate their functional properties. Neural organoids formed on human-originated biodegradable scaffolds within 3 weeks and resembled niche structure where immature stem cells (Oct4+ and Sox2+) and proliferating neuroblasts (Nestin+, GFAP+, and Ki67+) were present. Such aggregates were placed on multi-electrode chips and differentiated toward mature neurons (TUJ1+ and MAP2+). These three-dimensional aggregates in contrast to two-dimensional cultures formed functional circuits and generated spontaneous field/action potentials. Our results indicate that three-dimensional environment facilitates maturation of HUCB-derived NSC what should be considered regarding regenerative medicine application.