Stem Cell Transplantation Methods

Nerve growth factor promotes in vitro proliferation of neural stem cells from tree shrews

Neural stem cells promote neuronal regeneration and repair of brain tissue after injury, but have limited resources and proliferative ability in vivo. We hypothesized that nerve growth factor would promote in vitro proliferation of neural stem cells derived from the tree shrews, a primate-like mammal that has been proposed as an alternative to primates in biomedical translational research. We cultured neural stem cells from the hippocampus of tree shrews at embryonic day 38, and added nerve growth factor (100 μg/L) to the culture medium. Neural stem cells from the hippocampus of tree shrews cultured without nerve growth factor were used as controls. After 3 days, fluorescence microscopy after DAPI and nestin staining revealed that the number of neurospheres and DAPI/nestin-positive cells was markedly greater in the nerve growth factor-treated cells than in control cells. These findings demonstrate that nerve growth factor promotes the proliferation of neural stem cells derived from tree shrews.

White matter dementia

White matter dementia (WMD) is a syndrome introduced in 1988 to highlight the potential of cerebral white matter disorders to produce cognitive loss of sufficient severity to qualify as dementia. Neurologists have long understood that such a syndrome can occur, but the dominance of gray matter as the locus of higher function has strongly directed neurobehavioral inquiry to the cerebral cortex while white matter has received less attention. Contemporary neuroimaging has been crucial in enabling the recognition of white matter abnormalities in a host of disorders, and the correlation of these changes with cognitive performance. Comprising about half the brain, white matter is prominently or exclusively involved in well over 100 disorders, in each of which white matter dysfunction can potentially cause or contribute to dementia. Neuropsychological findings from ten categories of white matter disorder lead to a convergence of findings that document remarkable neurobehavioral commonality among the dementias produced. More recently, the syndrome of mild cognitive dysfunction (MCD) has been introduced to expand the concept of WMD by proposing a precursor syndrome related to early white matter neuropathology. WMD and MCD inform the understanding of how white matter contributes to normal and abnormal cognition, and the specific neuroanatomic focus of these syndromes may enhance the diagnosis and treatment of many disabling disorders that do not primarily implicate the cerebral cortex. Forming essential connections within widely distributed neural networks, white matter is critical for rapid and efficient information transfer that complements the information processing of gray matter. As neuroimaging continues to advance, further information on white matter structure can be expected, and behavioral neurology will play a central role in elucidating the functional significance of these emerging data. By emphasizing the contribution of myelinated systems to higher function, the study of white matter and cognition represents investigation of the basic neuroscience of human behavior.

The co-transduction of Nurr1 and Brn4 genes induces the differentiation of neural stem cells into dopaminergic neurons

Fetal brain tissue can be used in cell replacement therapy for PD (Parkinson's disease), but there is a poor donor supply of this tissue. NSCs (neural stem cells) may overcome this problem as they can be isolated and expanded in vitro. However, the usage of NSCs is limited because the differentiation of NSCs into specific dopaminergic neurons has proven difficult. In the present study, we investigated the effect of Nurr1 (nuclear receptor related factor 1), a transcription factor specific for the development and maintenance of the midbrain dopaminergic neurons on inducing the differentiation of NSCs into TH (tyrosine hydroxylase) immunoreactive dopaminergic neurons. Nonetheless, these cells exhibited an immature neuronal morphology with small cell bodies and short neurite processes, and they seldom expressed DAT (dopamine transporter), a late marker of mature dopaminergic neurons. However, forced co-expression of Nurr1 with Brn4, a member of the POU domain family of transcription factors, caused immature Nurr1-induced dopaminergic neurons to differentiate into morphologically and phenotypically more mature neurons. Thus the enriched generation of mature dopaminergic neurons by forced expression of Nurr1 with Brn4 may be of future importance in NSC-based cell replacement therapy for PD.

Stem cell therapy for neonatal brain injury: perspectives and challenges

Cerebral palsy is a major health problem caused by brain damage during pregnancy, delivery, or the immediate postnatal period. Perinatal stroke, intraventricular hemorrhage, and asphyxia are the most common causes of neonatal brain damage. Periventricular white matter damage (periventricular leukomalacia) is the predominant form in premature infants and the most common antecedent of cerebral palsy. Stem cell treatment has proven effective in restoring injured organs and tissues in animal models. The potential of stem cells for self-renewal and differentiation translates into substantial neuroprotection and neuroregeneration in the animal brain, with minimal risks of rejection and side effects. Stem cell treatments described to date have used neural stem cells, embryonic stem cells, mesenchymal stem cells, umbilical cord stem cells, and induced pluripotent stem cells. Most of these treatments are still experimental. In this review, we focus on the efficacy of stem cell therapy in animal models of cerebral palsy, and discuss potential implications for current and future clinical trials.

The transfection of multipotent neural precursor/stem cell transplant populations with magnetic nanoparticles

Multipotent neural precursor/stem cells (NPCs) are a major transplant population with key properties to promote repair in several neuropathological conditions. Magnetic nanoparticle (MNP)-based vector systems, in turn, offer a combination of key benefits for cell therapies including (i) safety (ii) delivery of therapeutic biomolecules (DNA/siRNA) enhanceable by 'magnetofection' approaches (iii) magnetic cell targeting of MNP-labelled cells to injury sites and (iv) non-invasive imaging of MNP-labelled transplant populations for cell tracking. However, the applications of the versatile MNP platform for NPC transplantation therapies have received limited attention so far. We have evaluated the potential of MNP vectors for gene transfer to NPCs using a neurosphere culture model system; we also assessed repeat transfection ("multifection") and repeat transfection plus applied magnetic field ("magneto-multifection") strategies [to enhance transfection efficiency]. We show for the first time that MNPs can safely mediate single/combinatorial gene delivery to NPCs. Multifection approaches significantly enhanced transfection with negligible toxicity; no adverse effects were observed on stem cell proliferation/differentiation. "Multifected" NPCs survived and differentiated in 3D neural tissue arrays post-transplantation. Our findings demonstrate that MNPs offer a simple and robust alternative to the viral vector systems currently used widely to transfect neural stem cells in neurobiology/neural transplantation research.