Two kinds of stem cell nasal transplantation for treating white matter injury in premature rat infants / 中国组织工程研究

BACKGROUND: Stem cell transplantation has a significant neuroprotective effect on neurological diseases. Current transplantation methods such as arteriovenous transplantation and brain stereotactic transplantation are not suitable for clinical application in preterm infants. OBJECTIVE: To explore the feasibility of nasal transplantation of human umbilical cord mesenchymal stem cells and human neural stem cells for the treatment of white matter injury in premature rat infants. METHODS: Human umbilical cord mesenchymal stem cells were prepared from human umbilical cord tissue, and human neural stem cells were prepared from human embryonic brain tissue. In vitro migration of two kinds of cells was assessed by Transwell method. Forty 3-day-old Sprague-Dawley rats were randomly divided into sham operation group, model control group, human umbilical cord mesenchymal stem cell transplantation group and human neural stem cell transplantation group, with 10 rats in each group. Rats in all groups except the sham operation group were treated with right common carotid artery ligation and hypoxia for 90 minutes to establish a rat model of white matter injury in the preterm infant. Totally 1×106 cells were delivered intranasally in the transplantation group at 3 days after injury. Each nostril was infused with 5×105, and each nostril was infused once. On day 7 after injury, MBP immunofluorescence staining was used to detect the expression of myelin basic protein in the white matter of the brain to identify the damage of the white matter injury model. At 24 hours after transplantation, human umbilical cord mesenchymal stem cell migration was detected by anti-HuNu immunohistochemical method and human neural stem cell migration was detected by CM-Dil fluorescent labeling method. RESULTS AND CONCLUSION: (1) On day 7 after modeling, compared with the normal side, the positive area of MBP decreased in cingulate band, corpus callosum and external capsule of the affected side in the model of brain white matter injury in preterm infants (P < 0.05), indicating a successful modeling. (2) In vitro experiments showed that the migration rate of human neural stem cells was the same as that of human umbilical cord mesenchymal stem cells. (3) At 24 hours after the nasal transplantation, human umbilical cord mesenchymal stem cells migrated to the cortex, corpus callosum and hippocampus on the normal side and the damaged side, and human neural stem cells migrated to the damaged cortex, corpus callosum and hippocampus, and human umbilical cord mesenchymal stem cells migrated more than human neural stem cells. (4) Overall, these findings indicate that 24 hours after the nasal transplantation, human umbilical cord mesenchymal stem cells could survive and migrate to the normal side and the injury side, and human neural stem cells could survive and migrate to the injury side; and the migration of human umbilical cord mesenchymal stem cells was more extensive than that of human neural stem cells.

Effects of paraquat on the proliferation of human neural stem cells via DNA methylation / 中华劳动卫生职业病杂志

Objective@#To investigate the effects of Paraquat on neural stem cell proliferation in vitro and explore the its mechanism based on DNA methylation pathway.@*Methods@#Nestin, β-tubulin III, and glial fibrillary acidic protein (GFAP) were detected by indirect immunofluorescence assay to evaluate self renewal and differentiation potentia of ReNcell CX human neural stem. The cells were treated with terminal concentrations of 0, 5, 25, 50, and 100μmol/L PQ for 24 hours, and the cells were induced by 50 μmol/L PQ for different time (6, 12, 24, 48 h). Cell viability was determined by MTT assay. The proliferation of neural stem cells was evaluated using Sox2/Brdu and Nestin/Brdu double immunofluorescence staining. The global DNA methylation level was assayed by MethyflashTM methylated DNA Quantification kit. The expression levels of Dnmts mRNA and protein were analyzed by quantitative reverse transcription polymerase chain reaction(qRT-PCR) and Western blot, respectively.@*Results@#Immunofluorescence showed that nestin was primarily expressed in proliferative neural stem cell and peotein biomarkers (β-tubulin III, GFAP) for neuron and astrocyte were expressed in differentiated cells. MTT assay showed PQ induced cell survival rate decrease in a time and dose dependent manner. Double immunfluorescence staining of cells showed colocalization of Sox2 and Brdu. The percentage of Brdu/Sox2 positive cells was significantly lower in the PQ-exposed (25, 50, 100μmol/L PQ treatment) groups compared to control (P<0.05); Meanwhile, The percentage of Brdu/Nestin positive cells was also significantly lower in the PQ-exposed(50,100μmol/L PQ treatment) groups compared to control (P<0.05). The results of global DNA methylation revealed a significant decrease in PQ-exposed groups (P<0.05). Western blot showed that compared with control group, the protein and mRNA levels of Dnmt1, Dnmt3a in PQ-exposed group were significantly decreased (P<0.05), but there was a significant increase in expression level of Dnmt3b in 50, 100 μmol/L PQ-treated group(P<0.05).@*Conclusion@#Paraquat could inhibite the proliferation of human neural stem cells through reducing the level of DNA methylation reaction by suppressing the protein expression and transcription of DNA methylated transferase(Dnmts).

A Potential Therapy Using Engineered Stem Cells Prevented Malignant Melanoma in Cellular and Xenograft Mouse Models / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: In the present study, human neural stem cells (hNSCs) with tumor-tropic behavior were used as drug delivery vehicle to selectively target melanoma. A hNSC line (HB1.F3) was transduced into two types: one expressed only the cytosine deaminase (CD) gene (HB1.F3. CD) and the other expressed both CD and human interferon-β (IFN-β) genes (HB1.F3.CD. IFN-β). MATERIALS AND METHODS: This study verified the tumor-tropic migratory competence of engineered hNSCs on melanoma (A375SM) using a modified Boyden chamber assay in vitro and CM-DiI staining in vivo. The antitumor effect of HB1.F3.CD and HB1.F3.CD.IFN-β on melanoma was also confirmed using an MTT assay in vitro and xenograft mouse models. RESULTS: A secreted form of IFN-β from the HB1.F3.CD.IFN-β cells modified the epithelial-mesenchymal transition (EMT) process and metastasis of melanoma. 5-Fluorouracil treatment also accelerated the expression of the pro-apoptotic protein BAX and decelerated the expression of the anti-apoptotic protein Bcl-xL on melanoma cell line. CONCLUSION: Our results illustrate that engineered hNSCs prevented malignant melanoma cells from proliferating in the presence of the prodrug, and the form that secreted IFN-β intervened in the EMT process and melanoma metastasis. Hence, neural stem cell-directed enzyme/prodrug therapy is a plausible treatment for malignant melanoma.

Amyloid-beta oligomers regulate the properties of human neural stem cells through GSK-3beta signaling

Alzheimer's disease (AD) is the most common cause of age-related dementia. The neuropathological hallmarks of AD include extracellular deposition of amyloid-beta peptides and neurofibrillary tangles that lead to intracellular hyperphosphorylated tau in the brain. Soluble amyloid-beta oligomers are the primary pathogenic factor leading to cognitive impairment in AD. Neural stem cells (NSCs) are able to self-renew and give rise to multiple neural cell lineages in both developing and adult central nervous systems. To explore the relationship between AD-related pathology and the behaviors of NSCs that enable neuroregeneration, a number of studies have used animal and in vitro models to investigate the role of amyloid-beta on NSCs derived from various brain regions at different developmental stages. However, the Abeta effects on NSCs remain poorly understood because of conflicting results. To investigate the effects of amyloid-beta oligomers on human NSCs, we established amyloid precursor protein Swedish mutant-expressing cells and identified cell-derived amyloid-beta oligomers in the culture media. Human NSCs were isolated from an aborted fetal telencephalon at 13 weeks of gestation and expanded in culture as neurospheres. Human NSCs exposure to cell-derived amyloid-beta oligomers decreased dividing potential resulting from senescence through telomere attrition, impaired neurogenesis and promoted gliogenesis, and attenuated mobility. These amyloid-beta oligomers modulated the proliferation, differentiation and migration patterns of human NSCs via a glycogen synthase kinase-3beta-mediated signaling pathway. These findings contribute to the development of human NSC-based therapy for AD by elucidating the effects of Abeta oligomers on human NSCs.

In vivo Tracking of Human Neural Stem Cells Following Transplantation into a Rodent Model of Ischemic Stroke

BACKGROUND AND OBJECTIVES: Ischemic stroke caused by middle cerebral artery occlusion (MCAo) is the major type of stroke, but there are currently very limited options for cure. It has been shown that neural stem cells (NSCs) or neural precursor cells (NPCs) can survive and improve neurological deficits when they are engrafted in animal models of various neurological diseases. However, how the transplanted NSCs or NPCs are act in vivo in the injured or diseased brain is largely unknown. In this study, we utilized magnetic resonance imaging (MRI) techniques in order to understand the fates of human NSCs (HB1.F3) following transplantation into a rodent model of MCAo. METHODS AND RESULTS: HB1.F3 human NSCs were pre-labeled with ferumoxides (Feridex(R))-protamine sulfate complexes, which were visualized and examined by MRI up to 9 weeks after transplantation. Migration of the transplanted cells to the infarct area was further confirmed by histological methods. CONCLUSIONS: Based on these observations, we speculate that the transplanted NSCs have the extensive migratory ability to the injured site, which will in turn contribute to functional recovery in stroke.

Selective Susceptibility of Human Dopaminergic Neural Stem Cells to Dopamine-Induced Apoptosis

Dysfunctions of ubiquitin-proteasome system and toxicity of dopamine have been known as the key mechanisms in the pathogenesis of Parkinson's disease (PD) and proteasome inhibitors are widely used in experimental models of PD to reproduce cell death of dopaminergic neurons. In the present study, immortalized human neural stem cells (HB1.F3, F3) and those transfected with human aromatic acid decarboxylase gene (F3.AADC), were used to investigate the mechanism of selective dopaminergic neuronal cell death mediated by dopamine or proteasome inhibitors. Flow cytometric analysis revealed that F3.AADC was more susceptible to dopamine than parental F3 cell which does not carry dopaminergic phenotype. The dopamine-induced apoptosis was mediated by activation of caspases 3 and 9 and cleavage of PARP. Proteasome inhibitors also induced apoptosis in dose-dependent manner but there was no difference between cell types. Prolonged exposure to subtoxic dose of proteasome inhibitors further enhanced dopamine-induced apoptosis in the F3.AADC, and increased presence of alpha-synuclein and ubiquitin-positive inclusions was noted in the cytoplasm of apoptotic cells by immunocytochemistry. These findings indicate that dopaminergic cells are selectively susceptible to dopamine toxicity and prolonged suppression of proteasome system further enhances selective sensitivity to dopamine toxicity. Chronic subtoxic proteasomal dysfunction of dopaminergic cells might contribute to selective cell death of dopaminergic neurons during the pathogenesis of Parkinson's disease.

Characterization of Ionic Currents in Human Neural Stem Cells

The profile of membrane currents was investigated in differentiated neuronal cells derived from human neural stem cells (hNSCs) that were obtained from aborted fetal cortex. Whole-cell voltage clamp recording revealed at least 4 different currents: a tetrodotoxin (TTX)-sensitive Na+ current, a hyperpolarization-activated inward current, and A-type and delayed rectifier-type K+ outward currents. Both types of K+ outward currents were blocked by either 5 mM tetraethylammonium (TEA) or 5 mM 4-aminopyridine (4-AP). The hyperpolarization-activated current resembled the classical K+ inward current in that it exhibited a voltage-dependent block in the presence of external Ba2+ (30micrometer) or Cs+ (3micrometer). However, the reversal potentials did not match well with the predicted K+ equilibrium potentials, suggesting that it was not a classical K+ inward rectifier current. The other Na+ inward current resembled the classical Na+ current observed in pharmacological studies. The expression of these channels may contribute to generation and repolarization of action potential and might be regarded as functional markers for hNSCs-derived neurons.

Experimental study of human neural stem cells transplantation for treatment of cerebral ischemia in rats / 临床神经病学杂志

Objective To explore the effect of human neural stem cells(hNSCs) transplantation to treat cerebral ischemic rats and the status of transplanted hNSCs in the ischemic brain tissue of these rats.Methods Human neural stem cells were separated from 10~13 weeks brains of human embryo and were cultured and induced to differentiate. The middle cerebral artery occlusion rat models were made and the human neural stem cells were transplanted through tail vein 1 day later. Neurological Severity Scores (NSS) tests were undertaken in two groups after transplantation. Immunohistochemistry was used to check the differentiation and migration of human neural stem cells in vitro and vivo.Results Neural stem cells from human embryonic brains had been successfully cultured. These cells formed typical neurospheres in suspension, and the majorities expressed nestin. Three weeks later, the neurological function of rats that received transplantation recovered much better than the rats without transplantation, as evidenced by NSS ( P

THE DIFFERENTIATION OF HUMAN NEURAL STEM CELLS INTO DOPAMINERGIC NEURONS INDUCED BY IL-1?AND COMBINATION OF IL-1?,IL-11,LIF AND GDNF / 解剖学报

Objective To evaluate the effects of IL-1? and combination of IL-1?,IL-11,LIF and GDNF on inducing human neural stem cells(hNSCs)to differentiate into dopaminergic(DA)neurons in vitro. Methods A great deal of neurospheres was obtained by the technology of serum-free culturing and single-cell cloning,and was splitted into 3 groups,which were cultured in different media.In control group,the differentiation medium used only contained 10%FBS.In IL-1? group,the medium contained IL-1? and 10%FBS.In united factors group,the medium contained IL-1?,10%FBS supplemental with IL-11,LIF and GDNF.After 3 weeks,the tyrosine hydroxylase(TH)positive cells were detected by using immunofluorescence,and image processing about the number,the induced differentiational rate,the cell bodies' areas and the cells' perimeters of TH positive neurons was carried out.TH/MAP-2 double-immunofluorescence labeling was used to calculate the percentage of DA neurons in total neurons. Results In the control group,there were few TH positive neurons with poorly developed morphology.The presence of IL-1? induced more DA neurons,but these cells were still immature.In the united factors group,the number of maturer TH positive DA neurons was the most. Conclusion IL-1? has an obvious effect on inducing hNSCs derived from human fetal mescenphalon to DA neurons.The utilization of IL-1?,IL-11,LIF and GDNF in combination has a cooperative effect on inducing differentiation of hNSCs to mature DA neurons.