Preparation of neural progenitors from bone marrow and umbilical cord blood

Dual-function hybrid nanoparticles with gene silencing and anti-inflammatory effects

Background: Nanocarriers loaded with siRNA can be administered intranasally to provide a noninvasive, safe alternative to direct intracerebral or intrathecal infusions. Dual-function nanocarriers can also be designed to deliver several payloads that address different components of the pathological process. Aim: To design and test a hybrid nanocarrier with the capacity to lower Huntington's Disease gene (HTT) expression and prevent or diminish inflammation. Methods: Novel hybrid nanoparticles were fabricated using a chitosan-based matrix core loaded with siRNA and an outer shell consisting of a lipid composition containing cannabidiol. Results: Incubation of hybrid nanoparticles in mesenchymal stem cell cultures obtained from a YAC128 transgenic mouse modeling Huntington's disease resulted in effective lowering of mutant HTT gene expression and reduced levels of expression of the proinflammatory cytokine IL-6. Conclusion: A novel hybrid nanocarrier system with dual actions is effective in lowering HTT gene expression and attenuating inflammatory processes.

Fasudil may induce the differentiation of bone marrow mesenchymal stem cells into neuron‑like cells via the Wnt/β‑catenin pathway

Bone mesenchymal stem cells (MSCs) are an excellent donor graft source due to their potential for self-renewal and multidirectional differentiation. However, it is difficult to obtain high quality MSCs and to induce them to differentiate into neuron-like cells. Fasudil, a Rho kinase inhibitor, exhibits therapeutic potential in spinal cord injuries and stroke. The present study investigated the effect of fasudil on the differentiation of MSCs into neuron-like cells. MSCs were obtained from rat femur marrow, expanded in culture medium, and used at the third passage for subsequent experiments. MSCs were pre-induced with 10 ng/ml basic fibroblast growth factor (bFGF) for 24 h, which was followed by induction with fasudil. A control untreated group and a group treated with fasudil + XAV939, a Wnt/β-catenin pathway inhibitor, were also used in the present study. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis and immunofluorescence staining were performed in order to detect neuron-specific markers, including neuron-specific enolase (NSE), nestin and neurofilament-M (NF-M). Following induction with fasudil, neuron-like cell morphology was observed. In the fasudil + XAV939 and control groups, no obvious changes in cell shape were observed. The results of RT-qPCR, western blot analysis and immunofluorescence staining indicated that expression of the neuron-specific markers NSE, nestin and NF-M was detected in the fasudil group. The differentiation of MSCs into neuron-like cells induced by fasudil was eliminated when the Wnt/β-catenin pathway was inhibited. The present study demonstrated that fasudil may induce MSCs to differentiate into neuron-like cells, however further studies are required to determine the specific mechanisms involved in the effect of fasudil on the Wnt/β-catenin pathway. In addition, further research is required to examine the functional characteristics of the induced neuron-like cells, in order to establish their suitability for clinical treatments in the future.

Phase I-II Clinical Trial Assessing Safety and Efficacy of Umbilical Cord Blood Mononuclear Cell Transplant Therapy of Chronic Complete Spinal Cord Injury

Umbilical cord blood-derived mononuclear cell (UCB-MNC) transplants improve recovery in animal spinal cord injury (SCI) models. We transplanted UCB-MNCs into 28 patients with chronic complete SCI in Hong Kong (HK) and Kunming (KM). Stemcyte Inc. donated UCB-MNCs isolated from human leukocyte antigen (HLA ≥4:6)-matched UCB units. In HK, four patients received four 4-μl injections (1.6 million cells) into dorsal entry zones above and below the injury site, and another four received 8-μl injections (3.2 million cells). The eight patients were an average of 13 years after C5-T10 SCI. Magnetic resonance diffusion tensor imaging of five patients showed white matter gaps at the injury site before treatment. Two patients had fiber bundles growing across the injury site by 12 months, and the rest had narrower white matter gaps. Motor, walking index of SCI (WISCI), and spinal cord independence measure (SCIM) scores did not change. In KM, five groups of four patients received four 4-μl (1.6 million cells), 8-μl (3.2 million cells), 16-μl injections (6.4 million cells), 6.4 million cells plus 30 mg/kg methylprednisolone (MP), or 6.4 million cells plus MP and a 6-week course of oral lithium carbonate (750 mg/day). KM patients averaged 7 years after C3-T11 SCI and received 3-6 months of intensive locomotor training. Before surgery, only two patients walked 10 m with assistance and did not need assistance for bladder or bowel management before surgery. The rest could not walk or do their bladder and bowel management without assistance. At about a year (41-87 weeks), WISCI and SCIM scores improved: 15/20 patients walked 10 m ( p = 0.001) and 12/20 did not need assistance for bladder management ( p = 0.001) or bowel management ( p = 0.002). Five patients converted from complete to incomplete (two sensory, three motor; p = 0.038) SCI. We conclude that UCB-MNC transplants and locomotor training improved WISCI and SCIM scores. We propose further clinical trials.

Current progress in the derivation and therapeutic application of neural stem cells

Neural stem cells (NSCs) have a unique role in neural regeneration. Cell therapy based on NSC transplantation is a promising tool for the treatment of nervous system diseases. However, there are still many issues and controversies associated with the derivation and therapeutic application of these cells. In this review, we summarize the different sources of NSCs and their derivation methods, including direct isolation from primary tissues, differentiation from pluripotent stem cells and transdifferentiation from somatic cells. We also review the current progress in NSC implantation for the treatment of various neural defects and injuries in animal models and clinical trials. Finally, we discuss potential optimization strategies for NSC derivation and propose urgent challenges to the clinical translation of NSC-based therapies in the near future.

Neural stem cells-trends and advances

For many years, accepted dogma held that brain is a static organ with no possibility of regeneration of cells in injured or diseased human brain. However, recent preclinical reports have shown regenerative potential of neural stem cells using various injury models. This has resulted in renewed hope for those suffering from spinal cord injury and neural damage. As the potential of stem cell therapy gained impact, these claims, in particular, led to widespread enthusiasm that acute and chronic injury of the nervous system would soon be a problem of the past. The devastation caused by injury or diseases of the brain and spinal cord led to wide premature acceptance that "neural stem cells (NSCs)" derived from embryonic, fetal or adult sources would soon be effective in reversing neural and spinal trauma. However, neural therapy with stem cells has not been realized to its fullest extent. Although, discrete population of regenerative stem cells seems to be present in specific areas of human brain, the function of these cells is unclear. However, similar cells in animals seem to play important role in postnatal growth as well as recovery of neural tissue from injury, anoxia, or disease.

Hippocampal neurogenesis and the brain repair response to brief stereotaxic insertion of a microneedle

We tested the hypothesis that transient microinjury to the brain elicits cellular and humoral responses that stimulate hippocampal neurogenesis. Brief stereotaxic insertion and removal of a microneedle into the right hippocampus resulted in (a) significantly increased expression of granulocyte-colony stimulating factor (G-CSF), the chemokine MIP-1a, and the proinflammatory cytokine IL12p40; (b) pronounced activation of microglia and astrocytes; and (c) increase in hippocampal neurogenesis. This study describes immediate and early humoral and cellular mechanisms of the brain's response to microinjury that will be useful for the investigation of potential neuroprotective and deleterious effects of deep brain stimulation in various neuropsychiatric disorders.

Accelerated and enhanced effect of CCR5-transduced bone marrow neural stem cells on autoimmune encephalomyelitis

The suppressive effect of neural stem cells (NSCs) on experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), has been reported. However, the migration of NSCs to inflammatory sites was relatively slow as was the onset of rather limited clinical benefit. Lack of, or low expression of particular chemokine receptors on NSCs could be an important factor underlying the slow migration of NSCs. To enhance the therapeutic effect of NSCs, in the present study we transduced bone marrow (BM)-derived NSCs with CCR5, a receptor for CCL3, CCL4, and CCL5, chemokines that are abundantly produced in CNS-inflamed foci of MS/EAE. After i.v. injection, CCR5-NSCs rapidly reached EAE foci in larger numbers, and more effectively suppressed CNS inflammatory infiltration, myelin damage, and clinical EAE than GFP-NSCs used as controls. CCR5-NSC-treated mice also exhibited augmented remyelination and neuron/oligodendrocyte repopulation compared to PBS- or GFP-NSC-treated mice. We inferred that the critical mechanism underlying enhanced effect of CCR5-transduced NSCs on EAE is the early migration of chemokine receptor-transduced NSCs into the inflamed foci. Such migration at an earlier stage of inflammation enables NSCs to exert more effective immunomodulation, to reduce the extent of early myelin/neuron damage by creating a less hostile environment for remyelinating cells, and possibly to participate in the remyelination/neural repopulation process. These features of BM-derived transduced NSCs, combined with their easy availability (the subject's own BM) and autologous properties, may lay the groundwork for an innovative approach to rapid and highly effective MS therapy.

Myoblast-derived neuronal cells form glutamatergic neurons in the mouse cerebellum

Production of neurons from non-neural cells has far-reaching clinical significance. We previously found that myoblasts can be converted to a physiologically active neuronal phenotype by transferring a single recombinant transcription factor, REST-VP16, which directly activates target genes of the transcriptional repressor, REST. However, the neuronal subtype of M-RV cells and whether they can establish synaptic communication in the brain have remained unknown. M-RV cells engineered to express green fluorescent protein (M-RV-GFP) had functional ion channels but did not establish synaptic communication in vitro. However, when transplanted into newborn mice cerebella, a site of extensive postnatal neurogenesis, these cells expressed endogenous cerebellar granule precursors and neuron proteins, such as transient axonal glycoprotein-1, neurofilament, type-III β-tubulin, superior cervical ganglia-clone 10, glutamate receptor-2, and glutamate decarboxylase. Importantly, they exhibited action potentials and were capable of receiving glutamatergic synaptic input, similar to the native cerebellar granule neurons. These results suggest that M-RV-GFP cells differentiate into glutamatergic neurons, an important neuronal subtype, in the postnatal cerebellar milieu. Our findings suggest that although activation of REST-target genes can reprogram myoblasts to assume a general neuronal phenotype, the subtype specificity may then be directed by the brain microenvironment.

Physicochemical control of adult stem cell differentiation: shedding light on potential molecular mechanisms

Realization of the exciting potential for stem-cell-based biomedical and therapeutic applications, including tissue engineering, requires an understanding of the cell-cell and cell-environment interactions. To this end, recent efforts have been focused on the manipulation of adult stem cell differentiation using inductive soluble factors, designing suitable mechanical environments, and applying noninvasive physical forces. Although each of these different approaches has been successfully applied to regulate stem cell differentiation, it would be of great interest and importance to integrate and optimally combine a few or all of the physicochemical differentiation cues to induce synergistic stem cell differentiation. Furthermore, elucidation of molecular mechanisms that mediate the effects of multiple differentiation cues will enable the researcher to better manipulate stem cell behavior and response.

Future of cord blood for non-oncology uses

For the last 5 years cord blood (CB) has been under intense experimental investigation in in vitro differentiation models and in preclinical animal models ranging from bone to muscle regeneration, cardiovascular diseases including myocardial and peripheral arterial disease, stroke and Parkinson's disease. On the basis of its biological advantages, CB can be an ideal source for tissue regeneration. However, in the hype of the so-called 'plasticity', many cell types have been characterized either on cell surface Ag expression alone or by RNA expression only, and without detailed characterization of genetic pathways; frequently, cells are defined without analysis of cellular function in vitro and in vivo, and the definition of the lineage of origin and cells have not been defined in preclinical studies. Here, we explore not only the most consistent data with regard to differentiation of CB cells in vitro and in vivo, but also show technical limitations, such as why in contrast to cell populations isolated from fresh CB, cryopreserved CB is not the ideal source for tissue regeneration. By taking advantage of numerous CB units discarded due to lack of sufficient hematopoietic cells for clinical transplantation, new concepts to produce off-the-shelf products are presented as well.

Autologous umbilical cord blood mononuclear cell transplantation preserves right ventricular function in a novel model of chronic right ventricular volume overload

We aimed to evaluate the feasibility and efficacy of autologous umbilical cord blood mononuclear cell (UCMNC) transplantation on right ventricular (RV) function in a novel model of chronic RV volume overload. Four-month-old sheep (n = 20) were randomized into cell (n = 10) and control groups (n = 10). After assessment of baseline RV function by the conductance catheter method, a transannular patch (TAP) was sutured to the right ventricular outflow tract (RVOT). Following infundibulotomy the ring of the pulmonary valve was transected without cardiopulmonary bypass. UCMNC implantation (8.22 +/- 6.28 x 10(7)) in the cell group and medium injection in the control group were performed into the RV myocardium around the TAP. UCMNCs were cultured for 2 weeks after fluorescence-activated cell sorting (FACS) analysis for CD34 antigen. Transthoracic echocardiography (TTE) and computed tomography were performed after 6 weeks and 3 months, respectively. RV function was assessed 3 months postoperatively before the hearts were excised for immunohistological examinations. FACS analysis revealed 1.2 +/- 0.22% CD34(+) cells within the isolated UCMNCs from which AcLDL(+) endothelial cells were cultured in vitro. All animals survived surgery. TTE revealed grade II-III pulmonary regurgitation in both groups. Pressure-volume loops under dobutamine stress showed significantly improved RV diastolic function in the cell group (dP/dt(min): p = 0.043; E(ed): p = 0.009). CD31 staining indicated a significantly enhanced number of microvessels in the region of UCMNC implantation in the cell group (p < 0.001). No adverse tissue changes were observed. TAP augmentation and pulmonary annulus distortion without cardiopulmonary bypass constitutes a valid large animal model mimicking the surgical repair of tetralogy of Fallot. Our results indicate that the chronically volume-overloaded RV profits from autologous UCMNC implantation by enhanced diastolic properties with a probable underlying mechanism of increased angiogenesis.