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Prion diseases are irreversible progressive neurodegenerative diseases,leading to severe incapacity and death. They are characterized in the brain by prion amyloid deposits,vacuolisation,astrocytosis,neuronal degeneration,and by cognitive,behavioural and physical impairments. There is no treatment for these disorders and stem cell therapy therefore represents an interesting new approach. Gains could not only result from the cell transplantation,but also from the stimulation of endogenous neural stem cells (NSC) or by the combination of both approaches. However,the development of such strategies requires a detailed knowledge of the pathology,particularly concerning the status of the adult neurogenesis and endogenous NSC during the development of the disease. During the past decade,several studies have consistently shown that NSC reside in the adult mammalian central nervous system (CNS) and that adult neurogenesis occurs throughout the adulthood in the subventricular zone of the lateral ventricle or the Dentate Gyrus of the hippocampus. Adult NSC are believed to constitute a reservoir for neuronal replacement during normal cell turnover or after brain injury. However,the activation of this system does not fully compensate the neuronal loss that occurs during neurodegenerative diseases and could even contribute to the disease progression. We investigated here the status of these cells during the development of prion disorders. We were able to show that NSC accumulate and replicate prions. Importantly,this resulted in the alteration of their neuronal fate which then represents a new pathologic event that might underlie the rapid progression of the disease. View Publication

X-linked dystonia-parkinsonism (XDP) is a hereditary neurodegenerative disorder involving a progressive loss of striatal medium spiny neurons. The mechanisms underlying neurodegeneration are not known,in part because there have been few cellular models available for studying the disease. The XDP haplotype consists of multiple sequence variations in a region of the X chromosome containingTAF1,a large gene with at least 38 exons,and a multiple transcript system (MTS) composed of five unconventional exons. A previous study identified an XDP-specific insertion of a SINE-VNTR-Alu (SVA)-type retrotransposon in intron 32 ofTAF1,as well as a neural-specific TAF1 isoform,N-TAF1,which showed decreased expression in post-mortem XDP brain compared with control tissue. Here,we generated XDP patient and control fibroblasts and induced pluripotent stem cells (iPSCs) in order to further probe cellular defects associated with this disease. As initial validation of the model,we compared expression ofTAF1and MTS transcripts in XDP versus control fibroblasts and iPSC-derived neural stem cells (NSCs). Compared with control cells,XDP fibroblasts exhibited decreased expression ofTAF1transcript fragments derived from exons 32-36,a region spanning the SVA insertion site. N-TAF1,which incorporates an alternative exon (exon 34'),was not expressed in fibroblasts,but was detectable in iPSC-differentiated NSCs at levels that were ∼threefold lower in XDP cells than in controls. These results support the previous findings that N-TAF1 expression is impaired in XDP,but additionally indicate that this aberrant transcription might occur in neural cells at relatively early stages of development that precede neurodegeneration. View Publication

Schizophrenia has been considered a devastating clinical syndrome rather than a single disease. Nevertheless,the mechanisms behind the onset of schizophrenia have been only partially elucidated. Several studies propose that levels of trace elements are abnormal in schizophrenia; however,conflicting data generated from different biological sources prevent conclusions being drawn. In this work,we used synchrotron radiation X-ray microfluorescence spectroscopy to compare trace element levels in neural progenitor cells (NPCs) derived from two clones of induced pluripotent stem cell lines of a clozapine-resistant schizophrenic patient and two controls. Our data reveal the presence of elevated levels of potassium and zinc in schizophrenic NPCs. Neural cells treated with valproate,an adjunctive medication for schizophrenia,brought potassium and zinc content back to control levels. These results expand the understanding of atomic element imbalance related to schizophrenia and may provide novel insights for the screening of drugs to treat mental disorders. ?? 2014 Elsevier B.V. View Publication

BACKGROUND Congenital human cytomegalovirus (HCMV) infection,a leading cause of birth defects,is most often manifested as neurological disorders. The pathogenesis of HCMV-induced neurological disorders is,however,largely unresolved,primarily because of limited availability of model systems to analyze the effects of HCMV infection on neural cells. METHODS An induced pluripotent stem cell (iPSC) line was established from the human fibroblast line MRC5 by introducing the Yamanaka's four factors and then induced to differentiate into neural stem/progenitor cells (NSPCs) by dual inhibition of the SMAD signaling pathway using Noggin and SB-431542. RESULTS iPSC-derived NSPCs (NSPC/iPSCs) were susceptible to HCMV infection and allowed the expression of both early and late viral gene products. HCMV-infected NSPC/iPSCs underwent apoptosis with the activation of caspase-3 and -9 as well as positive staining by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). Cytochrome c release from mitochondria to cytosol was observed in these cells,indicating the involvement of mitochondrial dysfunction in their apoptosis. In addition,phosphorylation of proteins involved in the unfolded protein response (UPR),such as PKR-like eukaryotic initiation factor 2a kinase (PERK),c-Jun NH2-terminal kinase (JNK),inositol-requiring enzyme 1 (IRE1),and the alpha subunit of eukaryotic initiation factor 2 (eIF2$$) was observed in HCMV-infected NSPC/iPSCs. These results,coupled with the finding of increased expression of mRNA encoding the C/EBP-homologous protein (CHOP) and the detection of a spliced form of X-box binding protein 1 (XBP1) mRNA,suggest that endoplasmic reticulum (ER) stress is also involved in HCMV-induced apoptosis of these cells. CONCLUSIONS iPSC-derived NSPCs are thought to be a useful model to study HCMV neuropathogenesis and to analyze the mechanisms of HCMV-induced apoptosis in neural cells. View Publication

Adipose tissue stem cells (ADSCs) would be an attractive autologous cell source. However,ADSCs require invasive procedures,and has potential complications. Recently,urine stem cells (USCs) have been proposed as an alternative stem cell source. In this study,we compared USCs and ADSCs collected from the same patients on stem cell characteristics and capacity to differentiate into various cell lineages to provide a useful guideline for selecting the appropriate type of cell source for use in clinical application. The urine samples were collected via urethral catheterization,and adipose tissue was obtained from subcutaneous fat tissue during elective laparoscopic kidney surgery from the same patient (n = 10). Both cells were plated for primary culture. Cell proliferation,colony formation,cell surface markers,immune modulation,chromosome stability and multi-lineage differentiation were analyzed for each USCs and ADSCs at cell passage 3,5,and 7. USCs showed high cell proliferation rate,enhanced colony forming ability,strong positive for stem cell markers expression,high efficiency for inhibition of immune cell activation compared to ADSCs at cell passage 3,5,and 7. In chromosome stability analysis,both cells showed normal karyotype through all passages. In analysis of multi-lineage capability,USCs showed higher myogenic,neurogenic,and endogenic differentiation rate,and lower osteogenic,adipogenic,and chondrogenic differentiation rate compared to ADSCs. Therefore,we expect that USC can be an alternative autologous stem cell source for muscle,neuron and endothelial tissue reconstruction instead of ADSCs. View Publication

Insulin-like growth factor 1 (IGF-1) enhances cellular proliferation and reduces apoptosis during the early differentiation of bone marrow derived mesenchymal stem cells (BMSCs) into neural progenitor-like cells (NPCs) in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). BMSCs were differentiated in three groups of growth factors: (A) EGF + bFGF,(B) EGF + bFGF + IGF-1,and (C) without growth factor. To unravel the molecular mechanisms of the NPCs derivation,microarray analysis using GeneChip miRNA arrays was performed. The profiles were compared among the groups. Annotated microRNA fingerprints (GSE60060) delineated 46 microRNAs temporally up-regulated or down-regulated compared to group C. The expressions of selected microRNAs were validated by real-time PCR. Among the 46 microRNAs,30 were consistently expressed for minimum of two consecutive time intervals. In Group B,only miR-496 was up-regulated and 12 microRNAs,including the let-7 family,miR-1224,miR-125a-3p,miR-214,miR-22,miR-320,miR-708,and miR-93,were down-regulated. Bioinformatics analysis reveals that some of these microRNAs (miR-22,miR-214,miR-125a-3p,miR-320 and let-7 family) are associated with reduction of apoptosis. Here,we summarize the roles of key microRNAs associated with IGF-1 in the differentiation of BMSCs into NPCs. These findings may provide clues to further our understanding of the mechanisms and roles of microRNAs as key regulators of BMSC-derived NPC maintenance. View Publication

Adverse effect of alcohol on neural function has been well documented. Especially,the teratogenic effect of alcohol on neurodevelopment during embryogenesis has been demonstrated in various models,which could be a pathologic basis for fetal alcohol spectrum disorders (FASDs). While the developmental defects from alcohol abuse during gestation have been described,the specific mechanisms by which alcohol mediates these injuries have yet to be determined. Recent studies have shown that alcohol has significant effect on molecular and cellular regulatory mechanisms in embryonic stem cell (ESC) differentiation including genes involved in neural development. To test our hypothesis that alcohol induces molecular alterations during neural differentiation we have derived neural precursor cells from pluripotent human ESCs in the presence or absence of ethanol treatment. Genome-wide transcriptomic profiling identified molecular alterations induced by ethanol exposure during neural differentiation of hESCs into neural rosettes and neural precursor cell populations. The Database for Annotation,Visualization and Integrated Discovery (DAVID) functional analysis on significantly altered genes showed potential ethanol's effect on JAK-STAT signaling pathway,neuroactive ligand-receptor interaction,Toll-like receptor (TLR) signaling pathway,cytokine-cytokine receptor interaction and regulation of autophagy. We have further quantitatively verified ethanol-induced alterations of selected candidate genes. Among verified genes we further examined the expression of P2RX3,which is associated with nociception,a peripheral pain response. We found ethanol significantly reduced the level of P2RX3 in undifferentiated hESCs,but induced the level of P2RX3 mRNA and protein in hESC-derived NPCs. Our result suggests ethanol-induced dysregulation of P2RX3 along with alterations in molecules involved in neural activity such as neuroactive ligand-receptor interaction may be a molecular event associated with alcohol-related peripheral neuropathy of an enhanced nociceptive response. View Publication

There is growing interest in developing drugs that specifically target glioblastoma tumor-initiating cells (TICs). Current cell culture methods,however,cannot cost-effectively produce the large numbers of glioblastoma TICs required for drug discovery and development. In this paper we report a new method that encapsulates patient-derived primary glioblastoma TICs and grows them in 3 dimension thermoreversible hydrogels. Our method allows long-term culture (˜50 days,10 passages tested,accumulative ˜>10(10)-fold expansion) with both high growth rate (˜20-fold expansion/7 days) and high volumetric yield (˜2.0%A-%10(7)%cells/ml) without the loss of stemness. The scalable method can be used to produce sufficient,affordable glioblastoma TICs for drug discovery. View Publication

Low cell recovery rate of human embryonic stem cells (hESCs) resulting from cryopreservation damages leads to the difficulty in their successful commercialization of clinical applications. Hence in this study,sensitivity of human embryonic stem cells (hESCs) to different cooling rates,ice seeding and cryoprotective agent (CPA) types was compared and cell viability and recovery after cryopreservation under different cooling conditions were assessed. Both extracellular and intracellular ice formation were observed. Reactive oxidative species (ROS) accumulation of hESCs was determined. Cryopreservation of hESCs at 1 °C/min with the ice seeding and at the theoretically predicted optimal cooling rate (TPOCR) led to lower level of intracellular ROS,and prevented irregular and big ice clump formation compared with cryopreservation at 1 °C/min. This strategy further resulted in a significant increase in the hESC recovery when glycerol and 1,2-propanediol were used as the CPAs,but no increase for Me2SO. hESCs after cryopreservation under all the tested conditions still maintained their pluripotency. Our results provide guidance for improving the hESC cryopreservation recovery through the combination of CPA type,cooling rate and ice seeding. View Publication

Ring chromosomes are structural aberrations commonly associated with birth defects,mental disabilities and growth retardation. Rings form after fusion of the long and short arms of a chromosome,and are sometimes associated with large terminal deletions. Owing to the severity of these large aberrations that can affect multiple contiguous genes,no possible therapeutic strategies for ring chromosome disorders have been proposed. During cell division,ring chromosomes can exhibit unstable behaviour leading to continuous production of aneuploid progeny with low viability and high cellular death rate. The overall consequences of this chromosomal instability have been largely unexplored in experimental model systems. Here we generated human induced pluripotent stem cells (iPSCs) from patient fibroblasts containing ring chromosomes with large deletions and found that reprogrammed cells lost the abnormal chromosome and duplicated the wild-type homologue through the compensatory uniparental disomy (UPD) mechanism. The karyotypically normal iPSCs with isodisomy for the corrected chromosome outgrew co-existing aneuploid populations,enabling rapid and efficient isolation of patient-derived iPSCs devoid of the original chromosomal aberration. Our results suggest a fundamentally different function for cellular reprogramming as a means of /`chromosome therapy/' to reverse combined loss-of-function across many genes in cells with large-scale aberrations involving ring structures. In addition,our work provides an experimentally tractable human cellular system for studying mechanisms of chromosomal number control,which is of critical relevance to human development and disease. View Publication