Proliferation Of Neural Precursor Cells Research Articles

Effects of ATP and NGF on Proliferation and Migration of Neural Precursor Cells.

Purinergic receptors belong to the most ancient neurotransmitter system. While their relevance in neurotransmission is well characterized, it has become clear that they have many other cellular functions. During development, they participate in regulation of proliferation and differentiation of stem cells. Here, we used rat embryonic telencephalon neurosphere cultures to detect purinergic P2 receptor subtype expression and possible synergistic actions of these receptors with NGF. Neurospheres proliferate in the presence of EGF and FGF-2; however, upon depletion of these growth factors, they migrate and differentiate into neurons and glial phenotypes. Expression patterns of P2X and P2Y receptors changed along neural differentiation. Gene expression of P2X2-7 and P2Y1,2,4,6,12,14 receptors was confirmed in undifferentiated and neural-differentiated neurospheres, with an up-regulation of P2X2 and P2X6 subtypes, together with a down-regulation of P2X4, P2X7 and P2Y subtypes upon induction to differentiation. BrdU-labeling and subsequent flow cytometry analysis was used to measure cell proliferation, which was increased by chronic exposure to NGF and increasing concentrations of ATP, in line with the expression levels of PCNA. Furthermore, a synergistic effect on proliferation was observed in conditions of co-incubation with ATP and NGF. While ATP and NGF independently promoted neural migration, no inter-relation between these factors was detected for this cellular process. As conclusion, an unknown synergism of ATP and NGF in proliferation is described. Future efforts may elucidate the underlying mechanisms of the interrelationship of ATP and NGF during neurogenesis.

Bradykinin-induced inhibition of proliferation rate during neurosphere differentiation: consequence or cause of neuronal enrichment?

Neural stem cells proliferate and differentiate into neurons and glial cells, being responsible for embryonic and postnatal development of the central nervous system (CNS) as well as for regeneration in the adult brain. These cells also play a key role in maintaining the physiological integrity of the CNS in face of injury or disease. The previous study has demonstrated that bradykinin (BK) treatment simultaneously induces neuronal enrichment (indicating that BK contributes to neurogenesis) and reduced proliferation rates during in vitro differentiation of rat embryonic telencephalon neural precursor cells (NPCs). Here, we provide a mechanism for the unresolved question whether (i) the low rate of proliferation is owed to enhanced neurogenesis or, conversely, (ii) the alteration of the population ratio could result from low proliferation of NPCs and glial cells. In agreement with the previous study, BK promoted neuron-specific β3-tubulin and MAP2 expression in differentiating embryonic mouse neurospheres, whereas glial protein expression and global proliferation rates decreased. Furthermore, BK augmented the global frequency of cells in G0 -phase of cell cycle after differentiation. Heterogeneous cell populations were observed at this stage, including neurons that always remaining a quiescent state (G0 -phase). It is noteworthy that BK did not interfere with proliferation of any particular cell type, evidenced by coimmunostaining for nestin, β3-tubulin, glial fibrillary acidic protein (GFAP), and 5-ethynyl-2'-deoxyuridine (EdU). Thus, we conclude that neuronal enrichment is owing only to the fostering of neurogenesis, and that the low proliferation rate on the seventh day of differentiation is a consequence and not the cause of BK-induced neuronal enrichment.

Hippocampal structure and function are maintained despite severe innate peripheral inflammation.

Chronic peripheral inflammation mediated by cytokines such as TNFα, IL-1β, and IL-6 is associated with psychiatric disorders like depression and anxiety. However, it remains elusive which distinct type of peripheral inflammation triggers neuroinflammation and affects hippocampal plasticity resulting in depressive-like behavior. We hypothesized that chronic peripheral inflammation in the human TNF-α transgenic (TNFtg) mouse model of rheumatoid arthritis spreads into the central nervous system and induces depressive state manifested in specific behavioral pattern and impaired adult hippocampal neurogenesis. TNFtg mice showed severe erosive arthritis with increased IL-1β and IL-6 expression in tarsal joints with highly elevated human TNF-α levels in the serum. Intriguingly, IL-1β and IL-6 mRNA levels were not altered in the hippocampus of TNFtg mice. In contrast to the pronounced monocytosis in joints and spleen of TNFtg mice, signs of hippocampal microgliosis or astrocytosis were lacking. Furthermore, locomotion was impaired, but there was no locomotion-independent depressive behavior in TNFtg mice. Proliferation and maturation of hippocampal neural precursor cells as well as survival of newly generated neurons were preserved in the dentate gyrus of TNFtg mice despite reduced motor activity and peripheral inflammatory signature. We conclude that peripheral inflammation in TNFtg mice is mediated by chronic activation of the innate immune system. However, severe peripheral inflammation, though impairing locomotor activity, does not elicit depressive-like behavior. These structural and functional findings indicate the maintenance of hippocampal immunity, cellular plasticity, and behavior despite peripheral innate inflammation.

Microglia-derived IL-1β triggers p53-mediated cell cycle arrest and apoptosis in neural precursor cells.

Neurogenesis persists in the adult brain and can contribute to learning and memory processes and potentially to regeneration and repair of the affected nervous system. Deregulated neurogenesis has been observed in neuropathological conditions including neurodegenerative diseases, trauma and stroke. However, the survival of neural precursor cells (NPCs) and newly born neurons is adversely affected by the inflammatory environment that arises as a result of microglial activation associated with injury or disease processes. In the present study, we have investigated the mechanisms by which microglia affect NPC proliferation and survival. Importantly, we demonstrate that interleukin-1β (IL-1β) produced by lipopolysaccharide/interferon-γ-activated microglia is necessary to induce cell cycle arrest and apoptosis in NPCs in vitro. Mechanistically, we show that IL-1β activates the tumor suppressor p53 through an oxidative stress-dependent mechanism resulting in p53-mediated induction of the cyclin-dependent kinase inhibitor p21 and the proapoptotic Bcl-2 (B-cell lymphoma-2) family members Puma (p53-upregulated modulator of apoptosis) and Noxa. Furthermore, we demonstrate that cell cycle arrest and apoptosis induced by recombinant IL-1β or activated microglia is attenuated in p53-deficient NPCs. Finally, we have determined that IL-1β induces NPC death via the p53-dependent induction of Puma leading to the activation of a Bax (Bcl-2-associated X protein)-mediated mitochondrial apoptotic pathway. In summary, we have elucidated a novel role for p53 in the regulation of NPC proliferation and survival during neuroinflammatory conditions that could be targeted to promote neurogenesis and repair in a number of neurological conditions.

Downregulation of survivin regulates adult hippocampal neurogenesis and apoptosis, and inhibits spatial learning and memory following traumatic brain injury

Survivin, a unique member of the inhibitor of the apoptosis protein (IAP) family, has been suggested to play a crucial role in promoting the cell cycle and mediates mitosis during embryonic development. However, the role of survivin following traumatic brain injury (TBI) in adult neurogenesis and apoptosis in the mouse dentate gyrus (DG) remains only partially understood. We adopted adenovirus-mediated RNA interference (RNAi) as a means of suppressing the expression of survivin and observed its effects on adult regeneration and neurological function in mice after brain injury. The mice were subjected to TBI, and the ipsilateral hippocampus was then examined using reverse transcription polymerase chain reaction (RT-PCR) and Western blotting analyses. Brain slices were stained for 5′-bromo-2′-deoxyuridine (BrdU) and doublecortin (DCX). Our data showed that survivin knockdown inhibits the proliferation and differentiation of neural precursor cells (NPCs) in the DG of the hippocampus soon after TBI. Furthermore, downregulation of survivin results in a significant increase in programmed cell death in the DG, as assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and 4′,6-diamidino-2-phenylindole (DAPI) double staining. The Morris water maze (MWM) test was adopted to evaluate neurological function, which confirmed that knockdown of survivin worsened the memory capacity that was already compromised following TBI. Survivin in adult mice brains after TBI can be successfully down-regulated by RNAi, which inhibited adult hippocampal neurogenesis, promoted apoptotic cell death, and resulted in a negative role in the recovery of dysfunction following injury.

Chondroitin Sulfate Proteoglycans Negatively Modulate Spinal Cord Neural Precursor Cells by Signaling Through LAR and RPTPσ and Modulation of the Rho/ROCK Pathway.

Multipotent adult neural precursor cells (NPCs) have tremendous intrinsic potential to repair the damaged spinal cord. However, evidence shows that the regenerative capabilities of endogenous and transplanted NPCs are limited in the microenvironment of spinal cord injury (SCI). We previously demonstrated that injury-induced upregulation of matrix chondroitin sulfate proteoglycans (CSPGs) restricts the survival, migration, integration, and differentiation of NPCs following SCI. CSPGs are long-lasting components of the astroglial scar that are formed around the lesion. Our recent in vivo studies demonstrated that removing CSPGs from the SCI environment enhances the potential of transplanted and endogenous adult NPCs for spinal cord repair; however, the mechanisms by which CSPGs regulate NPCs remain unclear. In this study, using in vitro models recapitulating the extracellular matrix of SCI, we investigated the direct role of CSPGs in modulating the properties of adult spinal cord NPCs. We show that CSPGs significantly decrease NPCs growth, attachment, survival, proliferation, and oligodendrocytes differentiation. Moreover, using genetic models, we show that CSPGs regulate NPCs by signaling on receptor protein tyrosine phosphate sigma (RPTPσ) and leukocyte common antigen-related phosphatase (LAR). Intracellularly, CSPGs inhibitory effects are mediated through Rho/ROCK pathway and inhibition of Akt and Erk1/2 phosphorylation. Downregulation of RPTPσ and LAR and blockade of ROCK in NPCs attenuates the inhibitory effects of CSPGS. Our work provide novel evidence uncovering how upregulation of CSPGs challenges the response of NPCs in their post-SCI niche and identifies new therapeutic targets for enhancing NPC-based therapies for SCI repair.

Copolymer-1 promotes neurogenesis and improves functional recovery after acute ischemic stroke in rats.

Stroke triggers a systemic inflammatory response that exacerbates the initial injury. Immunizing with peptides derived from CNS proteins can stimulate protective autoimmunity (PA). The most renowned of these peptides is copolymer-1 (Cop-1) also known as glatiramer acetate. This peptide has been approved for use in the treatment of multiple sclerosis. Cop-1-specific T cells cross the blood-brain barrier and secrete neurotrophins and anti-inflammatory cytokines that could stimulate proliferation of neural precursor cells and recruit them to the injury site; making it an ideal therapy for acute ischemic stroke. The aim of this work was to evaluate the effect of Cop-1 on neurogenesis and neurological recovery during the acute phase (7 days) and the chronic phase of stroke (60 days) in a rat model of transient middle cerebral artery occlusion (tMCAo). BDNF and NT-3 were quantified and infarct volumes were measured. We demonstrated that Cop-1 improves neurological deficit, enhances neurogenesis (at 7 and 60 days) in the SVZ, SGZ, and cerebral cortex through an increase in NT-3 production. It also decreased infarct volume even at the chronic phase of tMCAo. The present manuscript fortifies the support for the use of Cop-1 in acute ischemic stroke.

Protective effects of resveratrol on the inhibition of hippocampal neurogenesis induced by ethanol during early postnatal life

Ethanol (EtOH) exposure during early postnatal life triggers obvious neurotoxic effects on the developing hippocampus and results in long-term effects on hippocampal neurogenesis. Resveratrol (RSV) has been demonstrated to exert potential neuroprotective effects by promoting hippocampal neurogenesis. However, the effects of RSV on the EtOH-mediated impairment of hippocampal neurogenesis remain undetermined. Thus, mice were pretreated with RSV and were later exposed to EtOH to evaluate its protective effects on EtOH-mediated toxicity during hippocampal development. The results indicated that a brief exposure of EtOH on postnatal day 7 resulted in a significant impairment in hippocampal neurogenesis and a depletion of hippocampal neural precursor cells (NPCs). This effect was attenuated by pretreatment with RSV. Furthermore, EtOH exposure resulted in a reduction in spine density on the granular neurons of the dentate gyrus (DG), and the spines exhibited a less mature morphological phenotype characterized by a higher proportion of stubby spines and a lower proportion of mushroom spines. However, RSV treatment effectively reversed these responses. We further confirmed that RSV treatment reversed the EtOH-induced down-regulation of hippocampal pERK and Hes1 protein levels, which may be related to the proliferation and maintenance of NPCs. Furthermore, EtOH exposure in the C17.2 NPCs also diminished cell proliferation and activated apoptosis, which could be reversed by pretreatment of RSV. Overall, our results suggest that RSV pretreatment protects against EtOH-induced defects in neurogenesis in postnatal mice and may thus play a critical role in preventing EtOH-mediated toxicity in the developing hippocampus.

Impairments in cognition and neural precursor cell proliferation in mice expressing constitutively active glycogen synthase kinase-3.

Brain glycogen synthase kinase-3 (GSK3) is hyperactive in several neurological conditions that involve impairments in both cognition and neurogenesis. This raises the hypotheses that hyperactive GSK3 may directly contribute to impaired cognition, and that this may be related to deficiencies in neural precursor cells (NPC). To study the effects of hyperactive GSK3 in the absence of disease influences, we compared adult hippocampal NPC proliferation and performance in three cognitive tasks in male and female wild-type (WT) mice and GSK3 knockin mice, which express constitutively active GSK3. NPC proliferation was ~40% deficient in both male and female GSK3 knockin mice compared with WT mice. Environmental enrichment (EE) increased NPC proliferation in male, but not female, GSK3 knockin mice and WT mice. Male and female GSK3 knockin mice exhibited impairments in novel object recognition, temporal order memory, and coordinate spatial processing compared with gender-matched WT mice. EE restored impaired novel object recognition and temporal ordering in both sexes of GSK3 knockin mice, indicating that this repair was not dependent on NPC proliferation, which was not increased by EE in female GSK3 knockin mice. Acute 1 h pretreatment with the GSK3 inhibitor TDZD-8 also improved novel object recognition and temporal ordering in male and female GSK3 knockin mice. These findings demonstrate that hyperactive GSK3 is sufficient to impair adult hippocampal NPC proliferation and to impair performance in three cognitive tasks in both male and female mice, but these changes in NPC proliferation do not directly regulate novel object recognition and temporal ordering tasks.

NFAT transcription factors regulate survival, proliferation, migration, and differentiation of neural precursor cells.

The study of factors that regulate the survival, proliferation, and differentiation of neural precursor cells (NPCs) is essential to understand neural development as well as brain regeneration. The Nuclear Factor of Activated T Cells (NFAT) is a family of transcription factors that can affect these processes besides playing key roles during development, such as stimulating axonal growth in neurons, maturation of immune system cells, heart valve formation, and differentiation of skeletal muscle and bone. Interestingly, NFAT signaling can also promote cell differentiation in adults, participating in tissue regeneration. The goal of the present study is to evaluate the expression of NFAT isoforms in NPCs, and to investigate its possible role in NPC survival, proliferation, migration, and differentiation. Our findings indicate that NFAT proteins are active not only in neurogenic brain regions such as hippocampus and subventricular zone (SVZ), but also in cultured NPCs. The inhibition of NFAT activation with the peptide VIVIT reduced neurosphere size and cell density in NPC cultures by decreasing proliferation and increasing cell death. VIVIT also decreased NPC migration and differentiation of astrocytes and neurons from NPCs. In addition, we identified NFATc3 as a predominant NFAT isoform in NPC cultures, finding that a constitutively-active form of NFATc3 expressed by adenoviral infection reduces NPC proliferation, stimulates migration, and is a potent inducer of NPC differentiation into astrocytes and neurons. In summary, our work uncovers active roles for NFAT signaling in NPC survival, proliferation and differentiation, and highlights its therapeutic potential for tissue regeneration.

Effect of G-CSF and TPO on HIBD in neonatal rats.

To observe effect of granulocyte colony-stimulating factor (G-CSF) and restructure human thrombopoietin on hypoxic-ischemic brain damage (HIBD) in new born rats. A total of 60 neonatal SD rats were selected and divided into 4 groups, with 15 in each group. Group A served as control group. Rats of Groups B-D were prepared for HIBD model by ligation of left common carotid artery combined with hypoxia method. Rats of Group A were only completed with free left common carotid artery without ligation and hypoxia operation. After HIBD model preparation, Group B was administrated with subcutaneous injection of normal saline for placebo treatment; Group C was administrated with cervical subcutaneous injection of 0.5 μg/10 g granulocyte colony stimulating factor (G-CSF) for 5 d (Once a day); Group D was administrated with intraperitoneal injection of 15 U/10 g recombinant human thromobopoietin (rhTPO) for treatment. After modeling for 7, 14 and 21 d, 5 rats were sacrificed in each group, respectively. Brain quality damage (%) conditions of experimental animals in each group were compared in different time points, and cerebral histopathological changes of each group were observed. Expression of nestin in rats of each group was detected by immunohistochemical method. After modeling for 7, 14 and 21 d, brain quality damages (%) of Groups B, C and D were significant higher than that of in Group A (P<0.05), while brain quality damage (%) degree of Group B was the highest in different time points, followed by Groups D and C, respectively. It was significant different compared among groups (P<0.05). The histopathological observation showed that degrees of brain damages in Groups C and D were significant lower than that of in Group B. After modeling for 7, 14 and 21 d, nestin positive cell populations in Groups B, C, and D were significant higher than Group A (P<0.05). Nestin cell populations of Group C in different time points were significant higher than Groups B and D (P<0.05). There was no significant difference in nestin positive cell populations in the above time points between Groups B and D (P>0.05). Both G-CSF and TPO can protect the nervous system of HIBD neonatal rats. G-CSF can promote the proliferation and differentiation of neural precursor cells to decrease the degeneration and necrosis of nerve cell. TPO can obviously ameliorate morphology index of HIBD rats. Through regulating ratio of TIMP-1 and MMP-9, TPO can maintain the integrity of blood brain barrier to relieve the occurrence of brain damage.

Proteasome regulation of the chromodomain protein MRG-1 controls the balance between proliferative fate and differentiation in the C. elegans germ line.

The level of stem cell proliferation must be tightly controlled for proper development and tissue homeostasis. Multiple levels of gene regulation are often employed to regulate stem cell proliferation to ensure that the amount of proliferation is aligned with the needs of the tissue. Here we focus on proteasome-mediated protein degradation as a means of regulating the activities of proteins involved in controlling the stem cell proliferative fate in the C. elegans germ line. We identify five potential E3 ubiquitin ligases, including the RFP-1 RING finger protein, as being involved in regulating proliferative fate. RFP-1 binds to MRG-1, a homologue of the mammalian chromodomain-containing protein MRG15 (MORF4L1), which has been implicated in promoting the proliferation of neural precursor cells. We find that C. elegans with reduced proteasome activity, or that lack RFP-1 expression, have increased levels of MRG-1 and a shift towards increased proliferation in sensitized genetic backgrounds. Likewise, reduction of MRG-1 partially suppresses stem cell overproliferation. MRG-1 levels are controlled independently of the spatially regulated GLP-1/Notch signalling pathway, which is the primary signal controlling the extent of stem cell proliferation in the C. elegans germ line. We propose a model in which MRG-1 levels are controlled, at least in part, by the proteasome, and that the levels of MRG-1 set a threshold upon which other spatially regulated factors act in order to control the balance between the proliferative fate and differentiation in the C. elegans germ line.

Unraveling the role of Cdk1 in postnatal neurogenesis

Event Abstract Back to Event Unraveling the role of Cdk1 in postnatal neurogenesis Quentin Marlier1*, Sebastien Verteneuil1*, Renaud Vandenbosch1, Nicolas Caron2, Philipp Kaldis3, Laurent Nguyen1 and Brigitte Malgrange1 1 GIGA Neurosciences-University of Liege, Belgium 2 Affichem, France 3 Institute of Molecular and Cell Biology, Singapore Age-related neurological disorders, including stroke and neurodegenerative diseases are becoming a major health care problem in many countries as average life expectancy is increasing. One appealing therapeutic strategy to treat neurological disorders would consist of recruiting endogenous neural precursor cells (NPCs) to replace the lost neurons. NPCs are present in two specific areas of the postnatal brain, the dentate gyrus (DG) of the hippocampus and the subventricular zone (SVZ) of the lateral ventricles. These NPCs give rise to neurons throughout life, a phenomenon termed postnatal neurogenesis. A prerequisite for the development of new therapeutic strategies involving postnatal NPCs is a better understanding of their molecular regulation. In this context, both extrinsic factors and intrinsic factors have been identified. For instance, the family of cell cycle regulators cyclin-dependent kinases (Cdks) are key regulators of postnatal neurogenesis since genetic invalidation of interphase Cdk2 or Cdk6 leads to a decrease of NPCs proliferation. Here, we investigated the role of Cdk1, an essential Cdk for M-phase in several tissues, in postnatal neurogenesis. Towards that purpose, we crossed mice bearing a conditional Cdk1 allele (Cdk1lox) with mice expressing a tamoxifen-inducible form of the Cre-recombinase under the control of the Sox2 promoter (Sox2CreER), allowing us to specifically delete Cdk1 in Sox2+ NPCs in the postnatal brain. Following Cdk1 loss, our preliminary results show a decrease in the percentage of proliferating Sox2+ cells as well as a decrease in the number of phospho-histone H3+ (ph-h3) in the DG, but there is no difference in the number of cells positive for the apoptotic marker activated-caspase 3. Interestingly, we also observed a long-term depletion of the pool of Sox2+ in the absence of Cdk1. Altogether, these data suggest a crucial role for Cdk1 in postnatal neurogenesis, but further investigations are required to identify its precise requirement in this process. Keywords: adult neurogenesis, Cell Cycle, Cdk1, Neural Stem Cells, proliferation Conference: 11th National Congress of the Belgian Society for Neuroscience, Mons, Belgium, 22 May - 22 May, 2015. Presentation Type: Poster presentation Topic: Neuroscience Citation: Marlier Q, Verteneuil S, Vandenbosch R, Caron N, Kaldis P, Nguyen L and Malgrange B (2015). Unraveling the role of Cdk1 in postnatal neurogenesis. Front. Neurosci. Conference Abstract: 11th National Congress of the Belgian Society for Neuroscience. doi: 10.3389/conf.fnins.2015.89.00069 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Apr 2015; Published Online: 05 May 2015. * Correspondence: Mr. Quentin Marlier, GIGA Neurosciences-University of Liege, Liège, 4000, Belgium, quentin.marlier@ulg.ac.be Mr. Sebastien Verteneuil, GIGA Neurosciences-University of Liege, Liège, 4000, Belgium, sebastien.verteneuil@hotmail.fr Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Quentin Marlier Sebastien Verteneuil Renaud Vandenbosch Nicolas Caron Philipp Kaldis Laurent Nguyen Brigitte Malgrange Google Quentin Marlier Sebastien Verteneuil Renaud Vandenbosch Nicolas Caron Philipp Kaldis Laurent Nguyen Brigitte Malgrange Google Scholar Quentin Marlier Sebastien Verteneuil Renaud Vandenbosch Nicolas Caron Philipp Kaldis Laurent Nguyen Brigitte Malgrange PubMed Quentin Marlier Sebastien Verteneuil Renaud Vandenbosch Nicolas Caron Philipp Kaldis Laurent Nguyen Brigitte Malgrange Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

The neuron regrowth is associated with the proliferation of neural precursor cells after leukemia inhibitory factor administration following spinal cord injury in mice.

ObjectivesTo explore whether LIF could promote the proliferation of neural precursor cells (NPCs) and to analyze the correlation between increased NPCs and FluoroGold (FG) labeled neurons in mice after spinal cord injury (SCI).MethodsMotor behavior was assessed using Rotarod and Platform Hang tests; neurons in the corticospinal and rubrospinal systems were labeled with FG, NPCs were immustained with nestin-FITC conjugate. The numbers of FG-labeled neurons and NPCs were estimated, and the correlation between FG-labeled neurons and NPCs was assessed.ResultsMice in the SCI group showed negligible recovery of locomotor behavior; in contrast, mice in the LIF group showed a statically significant improvement. Both FG-labeled neurons and NPCs were significantly increased in the LIF group compared to the SCI group, and this increase in FG-labeled neurons and NPCs showed a clear association above the lesion level.ConclusionsLIF could promote locomotive behaviors in mice post-SCI by encouraging the proliferation of NPCs; LIF may in fact be a potential cytokine for the induction of NPCs post-SCI.

Prenatal Exposure to Autism-Specific Maternal Autoantibodies Alters Proliferation of Cortical Neural Precursor Cells, Enlarges Brain, and Increases Neuronal Size in Adult Animals.

Autism spectrum disorders (ASDs) affect up to 1 in 68 children. Autism-specific autoantibodies directed against fetal brain proteins have been found exclusively in a subpopulation of mothers whose children were diagnosed with ASD or maternal autoantibody-related autism. We tested the impact of autoantibodies on brain development in mice by transferring human antigen-specific IgG directly into the cerebral ventricles of embryonic mice during cortical neurogenesis. We show that autoantibodies recognize radial glial cells during development. We also show that prenatal exposure to autism-specific maternal autoantibodies increased stem cell proliferation in the subventricular zone (SVZ) of the embryonic neocortex, increased adult brain size and weight, and increased the size of adult cortical neurons. We propose that prenatal exposure to autism-specific maternal autoantibodies directly affects radial glial cell development and presents a viable pathologic mechanism for the maternal autoantibody-related prenatal ASD risk factor.

Transcript co-variance with Nestin in two mouse genetic reference populations identifies Lef1 as a novel candidate regulator of neural precursor cell proliferation in the adult hippocampus

Adult neurogenesis, the lifelong production of new neurons in the adult brain, is under complex genetic control but many of the genes involved remain to be identified. In this study, we have integrated publicly available gene expression data from the BXD and CXB recombinant inbred mouse lines to discover genes co-expressed in the adult hippocampus with Nestin, a common marker of the neural precursor cell population. In addition, we incorporated spatial expression information to restrict candidates to genes with high differential gene expression in the hippocampal dentate gyrus. Incorporating data from curated protein-protein interaction databases revealed interactions between our candidate genes and those already known to be involved in adult neurogenesis. Enrichment analysis suggested a link to the Wnt/β-catenin pathway, known to be involved in adult neurogenesis. In particular, our candidates were enriched in targets of Lef1, a modulator of the Wnt pathway. In conclusion, our combination of bioinformatics approaches identified six novel candidate genes involved in adult neurogenesis; Amer3, Eya3, Mtdh, Nr4a3, Polr2a, and Tbkbp1. Further, we propose a role for Lef1 transcriptional control in the regulation of adult hippocampal precursor cell proliferation.

Fluoxetine regulates neurogenesis in vitro through modulation of GSK-3β/β-catenin signaling.

Background:It is generally accepted that chronic treatment with antidepressants increases hippocampal neurogenesis, but the molecular mechanisms underlying their effects are unknown. Recently, glycogen synthase kinase-3 beta (GSK-3β)/β-catenin signaling was shown to be involved in the mechanism of how antidepressants might influence hippocampal neurogenesis.Methods:The aim of this study was to determine whether GSK-3β/β-catenin signaling is involved in the alteration of neurogenesis as a result of treatment with fluoxetine, a selective serotonin reuptake inhibitor. The mechanisms involved in fluoxetine’s regulation of GSK-3β/β-catenin signaling pathway were also examined.Results:Our results demonstrated that fluoxetine increased the proliferation of embryonic neural precursor cells (NPCs) by up-regulating the phosphorylation of Ser9 on GSK-3β and increasing the level of nuclear β-catenin. The overexpression of a stabilized β-catenin protein (ΔN89 β-catenin) significantly increased NPC proliferation, while inhibition of β-catenin expression in NPCs led to a significant decrease in the proliferation and reduced the proliferative effects induced by fluoxetine. The effects of fluoxetine-induced up-regulation of both phosphorylation of Ser9 on GSK-3β and nuclear β-catenin were significantly prevented by the 5-hydroxytryptamine-1A (5-HT1A) receptor antagonist WAY-100635.Conclusions:The results demonstrate that fluoxetine may increase neurogenesis via the GSK-3β/β-catenin signaling pathway that links postsynaptic 5-HT1A receptor activation.

The capsaicin receptor TRPV1 as a novel modulator of neural precursor cell proliferation.

The capsaicin receptor (TRPV1, transient receptor potential vanilloid type 1) was first discovered in the peripheral nervous system as a detector of noxious chemical and thermal stimuli including the irritant chili pepper. Recently, there has been increasing evidence of TRPV1 expression in the central nervous system. Here, we show that TRPV1 is expressed in neural precursor cells (NPCs) during postnatal development, but not in the adult. However, expression of TRPV1 is induced in the adult in paradigms linked to an increase in neurogenesis, such as spatial learning in the Morris water maze or voluntary exercise. Loss of TRPV1 expression in knockout mice leads to an increase in NPC proliferation. Functional TRPV1 expression has been confirmed in cultured NPCs. Our results indicate that TRPV1 expression influences both postnatal and activity-induced neurogenesis in adulthood.

P053 - Osteopontin and Oncostatin M increase significantly in Iranian relapsing-remitting multiple sclerosis patients

Background/objectives Osteopontin is a multitasking secreted protein with a bold role in autoimmune processes. It is a pro-inflammatory cytokine implicating in cell–matrix and cell–cell interactions, inflammation, recruitment, survival. Thus, it is crucial for T helper-1 immunity. A therapeutic-based study demonstrated that Natalizumab binding to a4-subunit of a4-B1 integrin reduces cell adhesion of invasive immune cells to the endothelium of the central nervous system. The a4-B1 is an osteopontin binding partner. Consequently, it seems that a reduction of osteopontin can ameliorate multiple sclerosis relapses. Oncostatin m is an interleukin-6 family member secreted by variety of immune and none immune cells suggesting roles for oncostatin m in physiological and pathological conditions such as regulation of prostaglandin expression in astrocytes, involvement in dendritic cell's activities, neutrophil recruitment, immunosuppression, inhibition of proliferation of neural precursor cells, and enhancement of oligodendrocytes progenitor cell activity in demyelinated sites. In this study, we assessed these markers in Iranian relapsing-remitting multiple sclerosis patient's plasma level according to the healthy controls. Design and methods One hundred and twenty relapsing-remitting multiple sclerosis patients and 60 healthy subjects with no neurodegenerative disease background were included. Blood samples were gathered and enzyme-linked immonosurbent assay was done using “Booster” and “Eastbiopharm” ELISA kits and micro-plate reader. Statistical analysis was performed by SPSS 16. Results There was a significant difference between the cases and the controls for both osteopontin and oncostatin m protein expression (P-value<0.05). Conclusions Osteopontin and Oncostatin M are two inflammatory markers in multiple sclerosis with some anti-inflammatory features as well. As the primary study, we evaluated the protein level in plasma and compared to the healthy donors which was quite successful. For future studies, we suggest gene expression methods and also investigations on their variations in Iranian patients in-order to gain more knowledge and finally suggest diagnosing and therapeutic paths for such mediators Osteopontin is a multitasking secreted protein with a bold role in autoimmune processes. It is a pro-inflammatory cytokine implicating in cell–matrix and cell–cell interactions, inflammation, recruitment, survival. Thus, it is crucial for T helper-1 immunity. A therapeutic-based study demonstrated that Natalizumab binding to a4-subunit of a4-B1 integrin reduces cell adhesion of invasive immune cells to the endothelium of the central nervous system. The a4-B1 is an osteopontin binding partner. Consequently, it seems that a reduction of osteopontin can ameliorate multiple sclerosis relapses. Oncostatin m is an interleukin-6 family member secreted by variety of immune and none immune cells suggesting roles for oncostatin m in physiological and pathological conditions such as regulation of prostaglandin expression in astrocytes, involvement in dendritic cell's activities, neutrophil recruitment, immunosuppression, inhibition of proliferation of neural precursor cells, and enhancement of oligodendrocytes progenitor cell activity in demyelinated sites. In this study, we assessed these markers in Iranian relapsing-remitting multiple sclerosis patient's plasma level according to the healthy controls. One hundred and twenty relapsing-remitting multiple sclerosis patients and 60 healthy subjects with no neurodegenerative disease background were included. Blood samples were gathered and enzyme-linked immonosurbent assay was done using “Booster” and “Eastbiopharm” ELISA kits and micro-plate reader. Statistical analysis was performed by SPSS 16. There was a significant difference between the cases and the controls for both osteopontin and oncostatin m protein expression (P-value<0.05). Osteopontin and Oncostatin M are two inflammatory markers in multiple sclerosis with some anti-inflammatory features as well. As the primary study, we evaluated the protein level in plasma and compared to the healthy donors which was quite successful. For future studies, we suggest gene expression methods and also investigations on their variations in Iranian patients in-order to gain more knowledge and finally suggest diagnosing and therapeutic paths for such mediators

CS-30 * PROTEIN KINASE CK2 IS IMPORTANT FOR THE FUNCTION OF GLIOBLASTOMA BRAIN TUMOR INITIATING CELLS

Casein kinase 2 (CK2) is an ubiquitously expressed serine/threonine kinase composed of two catalytic subunits (α and/or α') and two regulatory (β) subunits. The expression and kinase activity of protein kinase CK2 are elevated in many different cancers, including glioblastoma (GBM). Brain tumor initiating cells (BTICs) are a subset of cells that are tumorigenic and are considered to promote the resistance of GBM to current therapies. Previously our lab has reported that CK2 activity promotes prosurvival signaling in GBM; however, the role of CK2 in BTICs has not been examined. In this study, we found that the expression of CK2α was increased in CD133+ BTICs compared to CD133− cells from GBM xenografts. We found that GBM cells are sensitive to cell death caused by CX-4945, an ATP-competitive inhibitor of CK2. Inhibition of CK2 also reduced the frequency of CD133+ BTICs over the course of 7 days, indicating a role for CK2 in BTIC persistence and survival. Additionally, using an in vitro limiting dilution assay, we found that CX-4945 reduced neurosphere formation in bulk cells from GBM xenografts. On the other hand, inhibition of CK2 had no effect on the proliferation or neurosphere formation of normal murine neural precursor cells. We are currently investigating the mechanism of cell death and reduced neurosphere formation and have found a reduction in the constitutive activation of signal transduction pathways dysregulated in GBM including NF-kB and MAPK pathways. Due to the integration of CK2 in multiple signaling pathways important for BTIC survival, protein kinase CK2 is a promising target in GBM.