Brief Report: Robo1 Regulates the Migration of Human Subventricular Zone Neural Progenitor Cells During Development.

PubMed

Guerrero-Cazares, Hugo; Lavell, Emily; Chen, Linda; Schiapparelli, Paula; Lara-Velazquez, Montserrat; Capilla-Gonzalez, Vivian; Clements, Anna Christina; Drummond, Gabrielle; Noiman, Liron; Thaler, Katrina; Burke, Anne; Quiñones-Hinojosa, Alfredo

2017-07-01

Human neural progenitor cell (NPC) migration within the subventricular zone (SVZ) of the lateral ganglionic eminence is an active process throughout early brain development. The migration of human NPCs from the SVZ to the olfactory bulb during fetal stages resembles what occurs in adult rodents. As the human brain develops during infancy, this migratory stream is drastically reduced in cell number and becomes barely evident in adults. The mechanisms regulating human NPC migration are unknown. The Slit-Robo signaling pathway has been defined as a chemorepulsive cue involved in axon guidance and neuroblast migration in rodents. Slit and Robo proteins expressed in the rodent brain help guide neuroblast migration from the SVZ through the rostral migratory stream to the olfactory bulb. Here, we present the first study on the role that Slit and Robo proteins play in human-derived fetal neural progenitor cell migration (hfNPC). We describe that Robo1 and Robo2 isoforms are expressed in the human fetal SVZ. Furthermore, we demonstrate that Slit2 is able to induce a chemorepellent effect on the migration of hfNPCs derived from the human fetal SVZ. In addition, when Robo1 expression is inhibited, hfNPCs are unable to migrate to the olfactory bulb of mice when injected in the anterior SVZ. Our findings indicate that the migration of human NPCs from the SVZ is partially regulated by the Slit-Robo axis. This pathway could be regulated to direct the migration of NPCs in human endogenous neural cell therapy. Stem Cells 2017;35:1860-1865. © 2017 AlphaMed Press.

Age-specific function of α5β1 integrin in microglial migration during early colonization of the developing mouse cortex.

PubMed

Smolders, Sophie Marie-Thérèse; Swinnen, Nina; Kessels, Sofie; Arnauts, Kaline; Smolders, Silke; Le Bras, Barbara; Rigo, Jean-Michel; Legendre, Pascal; Brône, Bert

2017-07-01

Microglia, the immune cells of the central nervous system, take part in brain development and homeostasis. They derive from primitive myeloid progenitors that originate in the yolk sac and colonize the brain mainly through intensive migration. During development, microglial migration speed declines which suggests that their interaction with the microenvironment changes. However, the matrix-cell interactions allowing dispersion within the parenchyma are unknown. Therefore, we aimed to better characterize the migration behavior and to assess the role of matrix-integrin interactions during microglial migration in the embryonic brain ex vivo. We focused on microglia-fibronectin interactions mediated through the fibronectin receptor α5β1 integrin because in vitro work indirectly suggested a role for this ligand-receptor pair. Using 2-photon time-lapse microscopy on acute ex vivo embryonic brain slices, we found that migration occurs in a saltatory pattern and is developmentally regulated. Most importantly, there is an age-specific function of the α5β1 integrin during microglial cortex colonization. At embryonic day (E) 13.5, α5β1 facilitates migration while from E15.5, it inhibits migration. These results indicate a developmentally regulated function of α5β1 integrin in microglial migration during colonization of the embryonic brain. © 2017 Wiley Periodicals, Inc.

Role of the p55-gamma subunit of PI3K in ALK-induced cell migration: RNAi-based selection of cell migration regulators.

PubMed

Seo, Minchul; Kim, Jong-Heon; Suk, Kyoungho

2017-05-04

Recently, unbiased functional genetic selection identified novel cell migration-regulating genes. This RNAi-based functional selection was performed using 63,996 pooled lentiviral shRNAs targeting 21,332 mouse genes. After five rounds of selection using cells with accelerated or impaired migration, shRNAs were retrieved and identified by half-hairpin barcode sequencing using cells with the selected phenotypes. This selection process led to the identification of 29 novel cell migration regulators. One of these candidates, anaplastic lymphoma kinase (ALK), was further investigated. Subsequent studies revealed that ALK promoted cell migration through the PI3K-AKT pathway via the p55γ regulatory subunit of PI3K, rather than more commonly used p85 subunit. Western blot and immunohistochemistry studies using mouse brain tissues revealed similar temporal expression patterns of ALK, phospho-p55γ, and phospho-AKT during different stages of development. These data support an important role for the p55γ subunit of PI3K in ALK-induced cell migration during brain development.

Galectin-3 maintains cell motility from the subventricular zone to the olfactory bulb

PubMed Central

Comte, Isabelle; Kim, Yongsoo; Young, Christopher C.; van der Harg, Judith M.; Hockberger, Philip; Bolam, Paul J.; Poirier, Françoise; Szele, Francis G.

2011-01-01

The adult brain subventricular zone (SVZ) produces neuroblasts that migrate through the rostral migratory stream (RMS) to the olfactory bulb (OB) in a specialized niche. Galectin-3 (Gal-3) regulates proliferation and migration in cancer and is expressed by activated macrophages after brain injury. The function of Gal-3 in the normal brain is unknown, but we serendipitously found that it was expressed by ependymal cells and SVZ astrocytes in uninjured mice. Ependymal cilia establish chemotactic gradients and astrocytes form glial tubes, which combine to aid neuroblast migration. Whole-mount preparations and electron microscopy revealed that both ependymal cilia and SVZ astrocytes were disrupted in Gal3−/− mice. Interestingly, far fewer new BrdU+ neurons were found in the OB of Gal3−/− mice, than in wild-type mice 2 weeks after labeling. However, SVZ proliferation and cell death, as well as OB differentiation rates were unaltered. This suggested that decreased migration in vivo was sufficient to decrease the number of new OB neurons. Two-photon time-lapse microscopy in forebrain slices confirmed decreased migration; cells were slower and more exploratory in Gal3−/− mice. Gal-3 blocking antibodies decreased migration and dissociated neuroblast cell–cell contacts, whereas recombinant Gal-3 increased migration from explants. Finally, we showed that expression of phosphorylated epidermal growth factor receptor (EGFR) was increased in Gal3−/− mice. These results suggest that Gal-3 is important in SVZ neuroblast migration, possibly through an EGFR-based mechanism, and reveals a role for this lectin in the uninjured brain. PMID:21693585

CCL11 promotes migration and proliferation of mouse neural progenitor cells.

PubMed

Wang, Feifei; Baba, Nobuyasu; Shen, Yuan; Yamashita, Tatsuyuki; Tsuru, Emi; Tsuda, Masayuki; Maeda, Nagamasa; Sagara, Yusuke

2017-02-07

Neonatal hypoxia-ischemia induces massive brain damage during the perinatal period, resulting in long-term consequences to central nervous system structural and functional maturation. Although neural progenitor cells (NPCs) migrate through the parenchyma and home in to injury sites in the rodent brain, the molecular mechanisms are unknown. We examined the role of chemokines in mediating NPC migration after neonatal hypoxic-ischemic brain injury. Nine-day-old mice were exposed to a 120-minute hypoxia following unilateral carotid occlusion. Chemokine levels were quantified in mouse brain extract. Migration and proliferation assays were performed using embryonic and infant mouse NPCs. The neonatal hypoxic-ischemic brain injury resulted in an ipsilateral lesion, which was extended to the cortical and striatal areas. NPCs migrated toward an injured area, where a marked increase of CC chemokines was detected. In vitro studies showed that incubation of NPCs with recombinant mouse CCL11 promoted migration and proliferation. These effects were partly inhibited by a CCR3 antagonist, SB297006. Our data implicate an important effect of CCL11 for mouse NPCs. The effective activation of NPCs may offer a promising strategy for neuroregeneration in neonatal hypoxic-ischemic brain injury.

Brain-Derived Neurotrophic Factor Promotes Vasculature-Associated Migration of Neuronal Precursors toward the Ischemic Striatum

PubMed Central

Grade, Sofia; Weng, Yuan C.; Snapyan, Marina; Kriz, Jasna; Malva, João O.; Saghatelyan, Armen

2013-01-01

Stroke induces the recruitment of neuronal precursors from the subventricular zone (SVZ) into the ischemic striatum. In injured areas, de-routed neuroblasts use blood vessels as a physical scaffold to their migration, in a process that resembles the constitutive migration seen in the rostral migratory stream (RMS). The molecular mechanism underlying injury-induced vasculature-mediated migration of neuroblasts in the post-stroke striatum remains, however, elusive. Using adult mice we now demonstrate that endothelial cells in the ischemic striatum produce brain-derived neurotrophic factor (BDNF), a neurotrophin that promotes the vasculature-mediated migration of neuronal precursors in the RMS, and that recruited neuroblasts maintain expression of p75NTR, a low-affinity receptor for BDNF. Reactive astrocytes, which are widespread throughout the damaged area, ensheath blood vessels and express TrkB, a high-affinity receptor for BDNF. Despite the absence of BDNF mRNA, we observed strong BDNF immunolabeling in astrocytes, suggesting that these glial cells trap extracellular BDNF. Importantly, this pattern of expression is reminiscent of the adult RMS, where TrkB-expressing astrocytes bind and sequester vasculature-derived BDNF, leading to the entry of migrating cells into the stationary phase. Real-time imaging of cell migration in acute brain slices revealed a direct role for BDNF in promoting the migration of neuroblasts to ischemic areas. We also demonstrated that cells migrating in the ischemic striatum display higher exploratory behavior and longer stationary periods than cells migrating in the RMS. Our findings suggest that the mechanisms involved in the injury-induced vasculature-mediated migration of neuroblasts recapitulate, at least partially, those observed during constitutive migration in the RMS. PMID:23383048

Time-lapse imaging of neuroblast migration in acute slices of the adult mouse forebrain.

PubMed

Khlghatyan, Jivan; Saghatelyan, Armen

2012-09-12

There is a substantial body of evidence indicating that new functional neurons are constitutively generated from an endogenous pool of neural stem cells in restricted areas of the adult mammalian brain. Newborn neuroblasts from the subventricular zone (SVZ) migrate along the rostral migratory stream (RMS) to their final destination in the olfactory bulb (OB). In the RMS, neuroblasts migrate tangentially in chains ensheathed by astrocytic processes using blood vessels as a structural support and a source of molecular factors required for migration. In the OB, neuroblasts detach from the chains and migrate radially into the different bulbar layers where they differentiate into interneurons and integrate into the existing network. In this manuscript we describe the procedure for monitoring cell migration in acute slices of the rodent brain. The use of acute slices allows the assessment of cell migration in the microenvironment that closely resembling to in vivo conditions and in brain regions that are difficult to access for in vivo imaging. In addition, it avoids long culturing condition as in the case of organotypic and cell cultures that may eventually alter the migration properties of the cells. Neuronal precursors in acute slices can be visualized using DIC optics or fluorescent proteins. Viral labeling of neuronal precursors in the SVZ, grafting neuroblasts from reporter mice into the SVZ of wild-type mice, and using transgenic mice that express fluorescent protein in neuroblasts are all suitable methods for visualizing neuroblasts and following their migration. The later method, however, does not allow individual cells to be tracked for long periods of time because of the high density of labeled cells. We used a wide-field fluorescent upright microscope equipped with a CCD camera to achieve a relatively rapid acquisition interval (one image every 15 or 30 sec) to reliably identify the stationary and migratory phases. A precise identification of the duration of the stationary and migratory phases is crucial for the unambiguous interpretation of results. We also performed multiple z-step acquisitions to monitor neuroblasts migration in 3D. Wide-field fluorescent imaging has been used extensively to visualize neuronal migration. Here, we describe detailed protocol for labeling neuroblasts, performing real-time video-imaging of neuroblast migration in acute slices of the adult mouse forebrain, and analyzing cell migration. While the described protocol exemplified the migration of neuroblasts in the adult RMS, it can also be used to follow cell migration in embryonic and early postnatal brains.

ProBDNF inhibits collective migration and chemotaxis of rat Schwann cells.

PubMed

Ding, You-Quan; Li, Xuan-Yang; Xia, Guan-Nan; Ren, Hong-Yi; Zhou, Xin-Fu; Su, Bing-Yin; Qi, Jian-Guo

2016-10-01

Schwann cell migration, including collective migration and chemotaxis, is essential for the formation of coordinate interactions between Schwann cells and axons during peripheral nerve development and regeneration. Moreover, limited migration of Schwann cells imposed a serious obstacle on Schwann cell-astrocytes intermingling and spinal cord repair after Schwann cell transplantation into injured spinal cords. Recent studies have shown that mature brain-derived neurotrophic factor, a member of the neurotrophin family, inhibits Schwann cell migration. The precursor form of brain-derived neurotrophic factor, proBDNF, was expressed in the developing or degenerating peripheral nerves and the injured spinal cords. Since "the yin and yang of neurotrophin action" has been established as a common sense, proBDNF would be expected to promote Schwann cell migration. However, we found, in the present study, that exogenous proBDNF also inhibited in vitro collective migration and chemotaxis of RSC 96 cells, a spontaneously immortalized rat Schwann cell line. Moreover, proBDNF suppressed adhesion and spreading of those cells. At molecular level, proBDNF inhibits F-actin polymerization and focal adhesion dynamics in cultured RSC 96 cells. Therefore, our results suggested a special case against the classical opinion of "the yin and yang of neurotrophin action" and implied that proBDNF might modulate peripheral nerve development or regeneration and spinal cord repair through perturbing native or transplanted Schwann cell migration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lesion-induced increase in survival and migration of human neural progenitor cells releasing GDNF

PubMed Central

Behrstock, Soshana; Ebert, Allison D.; Klein, Sandra; Schmitt, Melanie; Moore, Jeannette M.; Svendsen, Clive N.

2009-01-01

The use of human neural progenitor cells (hNPC) has been proposed to provide neuronal replacement or astrocytes delivering growth factors for brain disorders such as Parkinson’s and Huntington’s disease. Success in such studies likely requires migration from the site of transplantation and integration into host tissue in the face of ongoing damage. In the current study, hNPC modified to release glial cell line derived neurotrophic factor (hNPCGDNF) were transplanted into either intact or lesioned animals. GDNF release itself had no effect on the survival, migration or differentiation of the cells. The most robust migration and survival was found using a direct lesion of striatum (Huntington’s model) with indirect lesions of the dopamine system (Parkinson’s model) or intact animals showing successively less migration and survival. No lesion affected differentiation patterns. We conclude that the type of brain injury dictates migration and integration of hNPC which has important consequences when considering transplantation of these cells as a therapy for neurodegenerative diseases. PMID:19044202

CD8+ T Cells Primed in the Periphery Provide Time-Bound Immune-Surveillance to the Central Nervous System

PubMed Central

Young, Kevin G.; MacLean, Susanne; Dudani, Renu; Krishnan, Lakshmi; Sad, Subash

2016-01-01

After vaccination, memory CD8+ T cells migrate to different organs to mediate immune surveillance. In most nonlymphoid organs, following an infection, CD8+ T cells differentiate to become long-lived effector-memory cells, thereby providing long-term protection against a secondary infection. In this study, we demonstrated that Ag-specific CD8+ T cells that migrate to the mouse brain following a systemic Listeria infection do not display markers reminiscent of long-term memory cells. In contrast to spleen and other nonlymphoid organs, none of the CD8+ T cells in the brain reverted to a memory phenotype, and all of the cells were gradually eliminated. These nonmemory phenotype CD8+ T cells were found primarily within the choroid plexus, as well as in the cerebrospinal fluid-filled spaces. Entry of these CD8+ T cells into the brain was governed primarily by CD49d/VCAM-1, with the majority of entry occurring in the first week postinfection. When CD8+ T cells were injected directly into the brain parenchyma, cells that remained in the brain retained a highly activated (CD69hi) phenotype and were gradually lost, whereas those that migrated out to the spleen were CD69low and persisted long-term. These results revealed a mechanism of time-bound immune surveillance to the brain by CD8+ T cells that do not reside in the parenchyma. PMID:21715683

IFN-γ promotes transendothelial migration of CD4+ T cells across the blood-brain barrier.

PubMed

Sonar, Sandip Ashok; Shaikh, Shagufta; Joshi, Nupura; Atre, Ashwini N; Lal, Girdhari

2017-10-01

Transendothelial migration (TEM) of Th1 and Th17 cells across the blood-brain barrier (BBB) has a critical role in the development of experimental autoimmune encephalomyelitis (EAE). How cytokines produced by inflammatory Th1 and Th17 cells damage the endothelial BBB and promote transendothelial migration of immune cells into the central nervous system (CNS) during autoimmunity is not understood. We therefore investigated the effect of various cytokines on brain endothelial cells. Among the various cytokines tested, such as Th1 (IFN-γ, IL-1α, IL-1β, TNF-α, IL-12), Th2 (IL-3, IL-4, IL-6 and IL-13), Th17 (IL-17A, IL-17F, IL-21, IL-22, IL-23, GM-CSF) and Treg-specific cytokines (IL-10 and TGF-β), IFN-γ predominantly showed increased expression of ICAM-1, VCAM-1, MAdCAM-1, H2-K b and I-A b molecules on brain endothelial cells. Furthermore, IFN-γ induced transendothelial migration of CD4 + T cells from the apical (luminal side) to the basal side (abluminal side) of the endothelial monolayer to chemokine CCL21 in a STAT-1-dependent manner. IFN-γ also favored the transcellular route of TEM of CD4 + T cells. Multicolor immunofluorescence and confocal microscopic analysis showed that IFN-γ induced relocalization of ICAM-1, PECAM-1, ZO-1 and VE-cadherin in the endothelial cells, which affected the migration of CD4 + T cells. These findings reveal that the IFN-γ produced during inflammation could contribute towards disrupting the BBB and promoting TEM of CD4 + T cells. Our findings also indicate that strategies that interfere with the activation of CNS endothelial cells may help in controlling neuroinflammation and autoimmunity.

Effects of atelocollagen on neural stem cell function and its migrating capacity into brain in psychiatric disease model.

PubMed

Yoshinaga, Toshihiro; Hashimoto, Eri; Ukai, Wataru; Ishii, Takao; Shirasaka, Tomohiro; Kigawa, Yoshiyasu; Tateno, Masaru; Kaneta, Hiroo; Watanabe, Kimihiko; Igarashi, Takeshi; Kobayashi, Seiju; Sohma, Hitoshi; Kato, Tadafumi; Saito, Toshikazu

2013-10-01

Stem cell therapy is well proposed as a potential method for the improvement of neurodegenerative damage in the brain. Among several different procedures to reach the cells into the injured lesion, the intravenous (IV) injection has benefit as a minimally invasive approach. However, for the brain disease, prompt development of the effective treatment way of cellular biodistribution of stem cells into the brain after IV injection is needed. Atelocollagen has been used as an adjunctive material in a gene, drug and cell delivery system because of its extremely low antigenicity and bioabsorbability to protect these transplants from intrabody environment. However, there is little work about the direct effect of atelocollagen on stem cells, we examined the functional change of survival, proliferation, migration and differentiation of cultured neural stem cells (NSCs) induced by atelocollagen in vitro. By 72-h treatment 0.01-0.05% atelocollagen showed no significant effects on survival, proliferation and migration of NSCs, while 0.03-0.05% atelocollagen induced significant reduction of neuronal differentiation and increase of astrocytic differentiation. Furthermore, IV treated NSCs complexed with atelocollagen (0.02%) could effectively migrate into the brain rather than NSC treated alone using chronic alcohol binge model rat. These experiments suggested that high dose of atelocollagen exerts direct influence on NSC function but under 0.03% of atelocollagen induces beneficial effect on regenerative approach of IV administration of NSCs for CNS disease.

Signaling through three chemokine receptors triggers the migration of transplanted neural precursor cells in a model of multiple sclerosis.

PubMed

Cohen, Mikhal E; Fainstein, Nina; Lavon, Iris; Ben-Hur, Tamir

2014-09-01

Multiple sclerosis (MS) is a multifocal disease, and precursor cells need to migrate into the multiple lesions in order to exert their therapeutic effects. Therefore, cell migration is a crucial element in regenerative processes in MS, dictating the route of delivery, when cell transplantation is considered. We have previously shown that inflammation triggers migration of multi-potential neural precursor cells (NPCs) into the white matter of experimental autoimmune encephalomyelitis (EAE) rodents, a widely used model of MS. Here we investigated the molecular basis of this attraction. NPCs were grown from E13 embryonic mouse brains and transplanted into the lateral cerebral ventricles of EAE mice. Transplanted NPC migration was directed by three tissue-derived chemokines. Stromal cell-derived factor-1α, monocyte chemo-attractant protein-1 and hepatocyte growth factor were expressed in the EAE brain and specifically in microglia and astrocytes. Their cognate receptors, CXCR4, CCR2 or c-Met were constitutively expressed on NPCs. Selective blockage of CXCR4, CCR2 or c-Met partially inhibited NPC migration in EAE brains. Blocking all three receptors had an additive effect and resulted in profound inhibition of NPC migration, as compared to extensive migration of control NPCs. The inflammation-triggered NPC migration into white matter tracts was dependent on a motile NPC phenotype. Specifically, depriving NPCs from epidermal growth factor (EGF) prevented the induction of glial commitment and a motile phenotype (as indicated by an in vitro motility assay), hampering their response to neuroinflammation. In conclusion, signaling via three chemokine systems accounts for most of the inflammation-induced, tissue-derived attraction of transplanted NPCs into white matter tracts during EAE. Copyright © 2014. Published by Elsevier B.V.

Rescue of neuronal migration deficits in a mouse model of fetal Minamata disease by increasing neuronal Ca2+ spike frequency.

PubMed

Fahrion, Jennifer K; Komuro, Yutaro; Li, Ying; Ohno, Nobuhiko; Littner, Yoav; Raoult, Emilie; Galas, Ludovic; Vaudry, David; Komuro, Hitoshi

2012-03-27

In the brains of patients with fetal Minamata disease (FMD), which is caused by exposure to methylmercury (MeHg) during development, many neurons are hypoplastic, ectopic, and disoriented, indicating disrupted migration, maturation, and growth. MeHg affects a myriad of signaling molecules, but little is known about which signals are primary targets for MeHg-induced deficits in neuronal development. In this study, using a mouse model of FMD, we examined how MeHg affects the migration of cerebellar granule cells during early postnatal development. The cerebellum is one of the most susceptible brain regions to MeHg exposure, and profound loss of cerebellar granule cells is detected in the brains of patients with FMD. We show that MeHg inhibits granule cell migration by reducing the frequency of somal Ca(2+) spikes through alterations in Ca(2+), cAMP, and insulin-like growth factor 1 (IGF1) signaling. First, MeHg slows the speed of granule cell migration in a dose-dependent manner, independent of the mode of migration. Second, MeHg reduces the frequency of spontaneous Ca(2+) spikes in granule cell somata in a dose-dependent manner. Third, a unique in vivo live-imaging system for cell migration reveals that reducing the inhibitory effects of MeHg on somal Ca(2+) spike frequency by stimulating internal Ca(2+) release and Ca(2+) influxes, inhibiting cAMP activity, or activating IGF1 receptors ameliorates the inhibitory effects of MeHg on granule cell migration. These results suggest that alteration of Ca(2+) spike frequency and Ca(2+), cAMP, and IGF1 signaling could be potential therapeutic targets for infants with MeHg intoxication.

Rescue of neuronal migration deficits in a mouse model of fetal Minamata disease by increasing neuronal Ca2+ spike frequency

PubMed Central

Fahrion, Jennifer K.; Ohno, Nobuhiko; Littner, Yoav; Raoult, Emilie; Galas, Ludovic; Vaudry, David; Komuro, Hitoshi

2012-01-01

In the brains of patients with fetal Minamata disease (FMD), which is caused by exposure to methylmercury (MeHg) during development, many neurons are hypoplastic, ectopic, and disoriented, indicating disrupted migration, maturation, and growth. MeHg affects a myriad of signaling molecules, but little is known about which signals are primary targets for MeHg-induced deficits in neuronal development. In this study, using a mouse model of FMD, we examined how MeHg affects the migration of cerebellar granule cells during early postnatal development. The cerebellum is one of the most susceptible brain regions to MeHg exposure, and profound loss of cerebellar granule cells is detected in the brains of patients with FMD. We show that MeHg inhibits granule cell migration by reducing the frequency of somal Ca2+ spikes through alterations in Ca2+, cAMP, and insulin-like growth factor 1 (IGF1) signaling. First, MeHg slows the speed of granule cell migration in a dose-dependent manner, independent of the mode of migration. Second, MeHg reduces the frequency of spontaneous Ca2+ spikes in granule cell somata in a dose-dependent manner. Third, a unique in vivo live-imaging system for cell migration reveals that reducing the inhibitory effects of MeHg on somal Ca2+ spike frequency by stimulating internal Ca2+ release and Ca2+ influxes, inhibiting cAMP activity, or activating IGF1 receptors ameliorates the inhibitory effects of MeHg on granule cell migration. These results suggest that alteration of Ca2+ spike frequency and Ca2+, cAMP, and IGF1 signaling could be potential therapeutic targets for infants with MeHg intoxication. PMID:22411806

Nitrosoureas inhibit the stathmin-mediated migration and invasion of malignant glioma cells.

PubMed

Liang, Xing-Jie; Choi, Yong; Sackett, Dan L; Park, John K

2008-07-01

Malignant gliomas are the most common primary intrinsic brain tumors and are highly lethal. The widespread migration and invasion of neoplastic cells from the initial site of tumor formation into the surrounding brain render these lesions refractory to definitive surgical treatment. Stathmin, a microtubule-destabilizing protein that mediates cell cycle progression, can also regulate directed cell movement. Nitrosoureas, traditionally viewed as DNA alkylating agents, can also covalently modify proteins such as stathmin. We therefore sought to establish a role for stathmin in malignant glioma cell motility, migration, and invasion and determine the effects of nitrosoureas on these cell movement-related processes. Scratch wound-healing recovery, Boyden chamber migration, Matrigel invasion, and organotypic slice invasion assays were performed before and after the down-regulation of cellular stathmin levels and in the absence and presence of sublethal nitrosourea ([1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea]; CCNU) concentrations. We show that decreases in stathmin expression lead to significant decreases in malignant glioma cell motility, migration, and invasion. CCNU, at a concentration of 10 micromol/L, causes similar significant decreases, even in the absence of any effects on cell viability. The direct inhibition of stathmin by CCNU is likely a contributing factor. These findings suggest that the inhibition of stathmin expression and function may be useful in limiting the spread of malignant gliomas within the brain, and that nitrosoureas may have therapeutic benefits in addition to their antiproliferative effects.

Shp2 Acts Downstream of SDF-1α/CXCR4 in Guiding Granule Cell Migration During Cerebellar Development

PubMed Central

Hagihara, Kazuki; Zhang, Eric E.; Ke, Yue-Hai; Liu, Guofa; Liu, Jan-Jan; Rao, Yi; Feng, Gen-Sheng

2009-01-01

Shp2 is a non-receptor protein tyrosine phosphatase containing two Src homology 2 (SH2) domains that is implicated in intracellular signaling events controlling cell proliferation, differentiation and migration. To examine the role of Shp2 in brain development, we created mice with Shp2 selectively deleted in neural stem/progenitor cells. Homozygous mutant mice exhibited early postnatal lethality with defects in neural stem cell self-renewal and neuronal/glial cell fate specification. Here we report a critical role of Shp2 in guiding neuronal cell migration in the cerebellum. In homozygous mutants, we observed reduced and less foliated cerebellum, ectopic presence of external granule cells and mispositioned Purkinje cells, a phenotype very similar to that of mutant mice lacking either SDF-1α or CXCR4. Consistently, Shp2-deficient granule cells failed to migrate toward SDF-1α in an in vitro cell migration assay, and SDF-1α treatment triggered a robust induction of tyrosyl phosphorylation on Shp2. Together, these results suggest that although Shp2 is involved in multiple signaling events during brain development, a prominent role of the phosphatase is to mediate SDF-1α/CXCR4 signal in guiding cerebellar granule cell migration. PMID:19635473

Gonadotropin-releasing hormone immunoreactivity in the adult and fetal human olfactory system.

PubMed

Kim, K H; Patel, L; Tobet, S A; King, J C; Rubin, B S; Stopa, E G

1999-05-01

Studies in fetal brain tissue of rodents, nonhuman primates and birds have demonstrated that cells containing gonadotropin-releasing hormone (GnRH) migrate from the olfactory placode across the nasal septum into the forebrain. The purpose of this study was to examine GnRH neurons in components of the adult and fetal human olfactory system. In the adult human brain (n=4), immunoreactive GnRH was evident within diffusely scattered cell bodies and processes in the olfactory bulb, olfactory nerve, olfactory cortex, and nervus terminalis located on the anterior surface of the gyrus rectus. GnRH-immunoreactive structures showed a similar distribution in 20-week human fetal brains (n=2), indicating that the migration of GnRH neurons is complete at this time. In 10-11-week fetal brains (n=2), more cells were noted in the nasal cavity than in the brain. Our data are consistent with observations made in other species, confirming olfactory derivation and migration of GnRH neurons into the brain from the olfactory placode. Copyright 1999 Elsevier Science B.V.

Cystatin C takes part in melanoma-microglia cross-talk: possible implications for brain metastasis.

PubMed

Moshe, Adi; Izraely, Sivan; Sagi-Assif, Orit; Prakash, Roshini; Telerman, Alona; Meshel, Tsipi; Carmichael, Thomas; Witz, Isaac P

2018-05-02

The development of melanoma brain metastasis is largely dependent on mutual interactions between the melanoma cells and cells in the brain microenvironment. Here, we report that the extracellular cysteine protease inhibitor cystatin C (CysC) is involved in these interactions. Microglia-derived factors upregulated CysC secretion by melanoma. Similarly, melanoma-derived factors upregulated CysC secretion by microglia. Whereas CysC enhanced melanoma cell migration through a layer of brain endothelial cells, it inhibited the migration of microglia cells toward melanoma cells. CysC was also found to promote the formation of melanoma three-dimensional structures in matrigel. IHC analysis revealed increased expression levels of CysC in the brain of immune-deficient mice bearing xenografted human melanoma brain metastasis compared to the brain of control mice. Based on these in vitro and in vivo experiments we hypothesize that CysC promotes melanoma brain metastasis. Increased expression levels of CysC were detected in the regenerating brain of mice after stroke. Post-stroke brain with melanoma brain metastasis showed an even stronger expression of CysC. The in vitro induction of stroke-like conditions in brain microenvironmental cells increased the levels of CysC in the secretome of microglia cells, but not in the secretome of brain endothelial cells. The similarities between melanoma brain metastasis and stroke with respect to CysC expression by and secretion from microglia cells suggest that CysC may be involved in shared pathways between brain metastasis and post-stroke regeneration. This manifests the tendency of tumor cells to highjack physiological molecular pathways in their progression.

Mechanical confinement triggers glioma linear migration dependent on formin FHOD3

PubMed Central

Monzo, Pascale; Chong, Yuk Kien; Guetta-Terrier, Charlotte; Krishnasamy, Anitha; Sathe, Sharvari R.; Yim, Evelyn K. F.; Ng, Wai Hoe; Ang, Beng Ti; Tang, Carol; Ladoux, Benoit; Gauthier, Nils C.; Sheetz, Michael P.

2016-01-01

Glioblastomas are extremely aggressive brain tumors with highly invasive properties. Brain linear tracks such as blood vessel walls constitute their main invasive routes. Here we analyze rat C6 and patient-derived glioma cell motility in vitro using micropatterned linear tracks to mimic blood vessels. On laminin-coated tracks (3–10 μm), these cells used an efficient saltatory mode of migration similar to their in vivo migration. This saltatory migration was also observed on larger tracks (50–400 μm in width) at high cell densities. In these cases, the mechanical constraints imposed by neighboring cells triggered this efficient mode of migration, resulting in the formation of remarkable antiparallel streams of cells along the tracks. This motility involved microtubule-dependent polarization, contractile actin bundles and dynamic paxillin-containing adhesions in the leading process and in the tail. Glioma linear migration was dramatically reduced by inhibiting formins but, surprisingly, accelerated by inhibiting Arp2/3. Protein expression and phenotypic analysis indicated that the formin FHOD3 played a role in this motility but not mDia1 or mDia2. We propose that glioma migration under confinement on laminin relies on formins, including FHOD3, but not Arp2/3 and that the low level of adhesion allows rapid antiparallel migration. PMID:26912794

Nitrosoureas Inhibit the Stathmin Mediated Migration and Invasion of Malignant Glioma Cells

PubMed Central

Liang, Xing-Jie; Choi, Yong; Sackett, Dan L.; Park, John K.

2008-01-01

Malignant gliomas are the most common primary intrinsic brain tumors and are highly lethal. The widespread migration and invasion of neoplastic cells from the initial site of tumor formation into the surrounding brain render these lesions refractory to definitive surgical treatment. Stathmin, a microtubule destabilizing protein that mediates cell cycle progression, can also regulate directed cell movement. Nitrosoureas, traditionally viewed as DNA alkylating agents, can also covalently modify proteins such as stathmin. We therefore sought to establish a role for stathmin in malignant glioma cell motility, migration, and invasion and determine the effects of nitrosoureas on these cell movement related processes. Scratch-wound healing recovery, Boyden chamber migration, Matrigel invasion, and organotypic slice invasion assays were performed before and after the down regulation of cellular stathmin levels and in the absence and presence of sub-lethal nitrosourea (CCNU; [1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea]) concentrations. We demonstrate that decreases in stathmin expression lead to significant decreases in malignant glioma cell motility, migration, and invasion. CCNU, at a concentration of 10 μM, causes similar significant decreases, even in the absence of any effects on cell viability. The direct inhibition of stathmin by CCNU is likely a contributing factor. These findings suggest that the inhibition of stathmin expression and function may be useful in limiting the spread of malignant gliomas within the brain and that nitrosoureas may have therapeutic benefits in addition to their anti-proliferative effects. PMID:18593927

CB2 Receptor Activation Inhibits Melanoma Cell Transmigration through the Blood-Brain Barrier

PubMed Central

Haskó, János; Fazakas, Csilla; Molnár, Judit; Nyúl-Tóth, Ádám; Herman, Hildegard; Hermenean, Anca; Wilhelm, Imola; Persidsky, Yuri; Krizbai, István A.

2014-01-01

During parenchymal brain metastasis formation tumor cells need to migrate through cerebral endothelial cells, which form the morphological basis of the blood-brain barrier (BBB). The mechanisms of extravasation of tumor cells are highly uncharacterized, but in some aspects recapitulate the diapedesis of leukocytes. Extravasation of leukocytes through the BBB is decreased by the activation of type 2 cannabinoid receptors (CB2); therefore, in the present study we sought to investigate the role of CB2 receptors in the interaction of melanoma cells with the brain endothelium. First, we identified the presence of CB1, CB2(A), GPR18 (transcriptional variant 1) and GPR55 receptors in brain endothelial cells, while melanoma cells expressed CB1, CB2(A), GPR18 (transcriptional variants 1 and 2), GPR55 and GPR119. We observed that activation of CB2 receptors with JWH-133 reduced the adhesion of melanoma cells to the layer of brain endothelial cells. JWH-133 decreased the transendothelial migration rate of melanoma cells as well. Our results suggest that changes induced in endothelial cells are critical in the mediation of the effect of CB2 agonists. Our data identify CB2 as a potential target in reducing the number of brain metastastes originating from melanoma. PMID:24815068

Migratory potential of transplanted glial progenitors as critical factor for successful translation of glia replacement therapy: The gap between mice and men.

PubMed

Srivastava, Rohit K; Bulte, Jeff W M; Walczak, Piotr; Janowski, Miroslaw

2018-05-01

Neurological disorders are a major threat to public health. Stem cell-based regenerative medicine is now a promising experimental paradigm for its treatment, as shown in pre-clinical animal studies. Initial attempts have been on the replacement of neuronal cells only, but glial progenitors (GPs) are now becoming strong alternative cellular therapeutic candidates to replace oligodendrocytes and astrocytes as knowledge accumulates about their important emerging role in various disease processes. There are many examples of successful therapeutic outcomes for transplanted GPs in small animal models, but clinical translation has proved to be challenging due to the 1,000-fold larger volume of the human brain compared to mice. Human GPs transplanted into the mouse brain migrate extensively and can induce global cell replacement, but a similar extent of migration in the human brain would only allow for local rather than global cell replacement. We review here the mechanisms that govern cell migration, which could potentially be exploited to enhance the migratory properties of GPs through cell engineering pre-transplantation. We furthermore discuss the (dis)advantages of the various cell delivery routes that are available, with particular emphasis on intra-arterial injection as the most suitable route for achieving global cell distribution in the larger brain. Now that therapeutic success has proven to be feasible in small animal models, future efforts will need to be directed to enhance global cell delivery and migration to make bench-to-bedside translation a reality. © 2017 Wiley Periodicals, Inc.

Human brain metastatic stroma attracts breast cancer cells via chemokines CXCL16 and CXCL12.

PubMed

Chung, Brile; Esmaeili, Ali A; Gopalakrishna-Pillai, Sailesh; Murad, John P; Andersen, Emily S; Kumar Reddy, Naveen; Srinivasan, Gayathri; Armstrong, Brian; Chu, Caleb; Kim, Young; Tong, Tommy; Waisman, James; Yim, John H; Badie, Behnam; Lee, Peter P

2017-01-01

The tumor microenvironment is composed of heterogeneous populations of cells, including cancer, immune, and stromal cells. Progression of tumor growth and initiation of metastasis is critically dependent on the reciprocal interactions between cancer cells and stroma. Through RNA-Seq and protein analyses, we found that cancer-associated fibroblasts derived from human breast cancer brain metastasis express significantly higher levels of chemokines CXCL12 and CXCL16 than fibroblasts from primary breast tumors or normal breast. To further understand the interplay between cancer cells and cancer-associated fibroblasts from each site, we developed three-dimensional organoids composed of patient-derived primary or brain metastasis cancer cells with matching cancer-associated fibroblasts. Three-dimensional CAF aggregates generated from brain metastasis promote migration of cancer cells more effectively than cancer-associated fibroblast aggregates derived from primary tumor or normal breast stromal cells. Treatment with a CXCR4 antagonist and/or CXCL16 neutralizing antibody, alone or in combination, significantly inhibited migration of cancer cells to brain metastatic cancer-associated fibroblast aggregates. These results demonstrate that human brain metastasis cancer-associated fibroblasts potently attract breast cancer cells via chemokines CXCL12 and CXCL16, and blocking CXCR6-CXCL16/CXCR4-CXCL12 receptor-ligand interactions may be an effective therapy for preventing breast cancer brain metastasis.

T-Lymphocytes Traffic into the Brain across the Blood-CSF Barrier: Evidence Using a Reconstituted Choroid Plexus Epithelium

PubMed Central

Strazielle, Nathalie; Creidy, Rita; Malcus, Christophe; Boucraut, José; Ghersi-Egea, Jean-François

2016-01-01

An emerging concept of normal brain immune surveillance proposes that recently and moderately activated central memory T lymphocytes enter the central nervous system (CNS) directly into the cerebrospinal fluid (CSF) via the choroid plexus. Within the CSF space, T cells inspect the CNS environment for cognate antigens. This gate of entry into the CNS could also prevail at the initial stage of neuroinflammatory processes. To actually demonstrate T cell migration across the choroidal epithelium forming the blood-CSF barrier, an in vitro model of the rat blood-CSF barrier was established in an “inverse” configuration that enables cell transmigration studies in the basolateral to apical, i.e. blood/stroma to CSF direction. Structural barrier features were evaluated by immunocytochemical analysis of tight junction proteins, functional barrier properties were assessed by measuring the monolayer permeability to sucrose and the active efflux transport of organic anions. The migratory behaviour of activated T cells across the choroidal epithelium was analysed in the presence and absence of chemokines. The migration pathway was examined by confocal microscopy. The inverse rat BCSFB model reproduces the continuous distribution of tight junction proteins at cell margins, the restricted paracellular permeability, and polarized active transport mechanisms, which all contribute to the barrier phenotype in vivo. Using this model, we present experimental evidence of T cell migration across the choroidal epithelium. Cell migration appears to occur via a paracellular route without disrupting the restrictive barrier properties of the epithelial interface. Apical chemokine addition strongly stimulates T cell migration across the choroidal epithelium. The present data provide evidence for the controlled migration of T cells across the blood-CSF barrier into brain. They further indicate that this recruitment route is sensitive to CSF-borne chemokines, extending the relevance of this migration pathway to neuroinflammatory and neuroinfectious disorders which are typified by elevated chemokine levels in CSF. PMID:26942913

T-Lymphocytes Traffic into the Brain across the Blood-CSF Barrier: Evidence Using a Reconstituted Choroid Plexus Epithelium.

PubMed

Strazielle, Nathalie; Creidy, Rita; Malcus, Christophe; Boucraut, José; Ghersi-Egea, Jean-François

2016-01-01

An emerging concept of normal brain immune surveillance proposes that recently and moderately activated central memory T lymphocytes enter the central nervous system (CNS) directly into the cerebrospinal fluid (CSF) via the choroid plexus. Within the CSF space, T cells inspect the CNS environment for cognate antigens. This gate of entry into the CNS could also prevail at the initial stage of neuroinflammatory processes. To actually demonstrate T cell migration across the choroidal epithelium forming the blood-CSF barrier, an in vitro model of the rat blood-CSF barrier was established in an "inverse" configuration that enables cell transmigration studies in the basolateral to apical, i.e. blood/stroma to CSF direction. Structural barrier features were evaluated by immunocytochemical analysis of tight junction proteins, functional barrier properties were assessed by measuring the monolayer permeability to sucrose and the active efflux transport of organic anions. The migratory behaviour of activated T cells across the choroidal epithelium was analysed in the presence and absence of chemokines. The migration pathway was examined by confocal microscopy. The inverse rat BCSFB model reproduces the continuous distribution of tight junction proteins at cell margins, the restricted paracellular permeability, and polarized active transport mechanisms, which all contribute to the barrier phenotype in vivo. Using this model, we present experimental evidence of T cell migration across the choroidal epithelium. Cell migration appears to occur via a paracellular route without disrupting the restrictive barrier properties of the epithelial interface. Apical chemokine addition strongly stimulates T cell migration across the choroidal epithelium. The present data provide evidence for the controlled migration of T cells across the blood-CSF barrier into brain. They further indicate that this recruitment route is sensitive to CSF-borne chemokines, extending the relevance of this migration pathway to neuroinflammatory and neuroinfectious disorders which are typified by elevated chemokine levels in CSF.

Indications for cellular migration from the central nervous system to its draining lymph nodes in CD11c-GFP+ bone-marrow chimeras following EAE.

PubMed

Schiefenhövel, Fridtjof; Immig, Kerstin; Prodinger, Carolin; Bechmann, Ingo

2017-07-01

The concept as to how the brain maintains its immune privilege has initially been based on observations that it is lacking classical lymph vessels and later, the absence of dendritic cells (DC). This view has been challenged by several groups demonstrating drainage/migration of injected tracers and cells into cervical lymph nodes (CLNs) and the presence of brain antigens in CLNs in the course of various brain pathologies. Using CD11c-diphtheria toxin receptor (DTR)-green fluorescent protein (GFP) transgenic (tg) mice, we have shown the existence of CD11c + cells, a main DC marker, within the brain parenchyma. Since injecting tracers or cells may cause barrier artefacts, we have now transplanted wild type (wt)-bone marrow (BM) to lethally irradiated CD11c-DTR-GFP tg mice to restrict the CD11c-DTR-GFP + population to the brain and induced experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). We observed ramified GFP + cells in the olfactory bulb, the cribriform plate, the nasal mucosa and superficial CLNs. We measured a significant increase of host gfp genomic DNA (gDNA) levels in lymph nodes (LNs) previously described as draining stations for the central nervous system (CNS). Using flow cytometry analysis, we observed an increase of the percentage of CD11c-GFP + cells in brain parenchyma in the course of EAE which is most likely due to an up-regulation of CD11c of resident microglial cells since levels of gfp gDNA did not increase. Our data supports the hypothesis that brain-resident antigen presenting cells (APC) are capable of migrating to CNS-draining LNs to present myelin-associated epitopes.

Conserved pattern of tangential neuronal migration during forebrain development.

PubMed

Métin, Christine; Alvarez, Chantal; Moudoux, David; Vitalis, Tania; Pieau, Claude; Molnár, Zoltán

2007-08-01

Origin, timing and direction of neuronal migration during brain development determine the distinct organization of adult structures. Changes in these processes might have driven the evolution of the forebrain in vertebrates. GABAergic neurons originate from the ganglionic eminence in mammals and migrate tangentially to the cortex. We are interested in differences and similarities in tangential migration patterns across corresponding telencephalic territories in mammals and reptiles. Using morphological criteria and expression patterns of Darpp-32, Tbr1, Nkx2.1 and Pax6 genes, we show in slice cultures of turtle embryos that early cohorts of tangentially migrating cells are released from the medial ganglionic eminence between stages 14 and 18. Additional populations migrate tangentially from the dorsal subpallium. Large cohorts of tangentially migrating neurons originate ventral to the dorsal ventricular ridge at stage 14 and from the lateral ganglionic eminence from stage 15. Release of GABAergic cells from these regions was investigated further in explant cultures. Tangential migration in turtle proceeds in a fashion similar to mammals. In chimeric slice culture and in ovo graft experiments, the tangentially migrating cells behaved according to the host environment - turtle cells responded to the available cues in mouse slices and mouse cells assumed characteristic migratory routes in turtle brains, indicating highly conserved embryonic signals between these distant species. Our study contributes to the evaluation of theories on the origin of the dorsal cortex and indicates that tangential migration is universal in mammals and sauropsids.

Stem cells distribution, cellular proliferation and migration in the adult Austrolebias charrua brain.

PubMed

Torres-Pérez, Maximiliano; Rosillo, Juan Carlos; Berrosteguieta, Ines; Olivera-Bravo, Silvia; Casanova, Gabriela; García-Verdugo, José Manuel; Fernández, Anabel Sonia

2017-10-15

Our previous studies demonstrated that Austrolebias charrua annual fish is an excellent model to study adult brain cell proliferation and neurogenesis due to the presence of active and fast neurogenesis in several regions during its short lifespan. Our main goal was to identify and localize the cells that compose the neurogenic areas throughout the Austrolebias brain. To do this, we used two thymidine halogenated analogs to detect cell proliferation at different survival times: 5-chloro-2'-deoxyuridine (CldU) at 1day and 5-iodo-2'-deoxyuridine (IdU) at 30days. Three types of proliferating cells were identified: I - transient amplifying or fast cycling cells that uptake CldU; II - stem cells or slow cycling cells, that were labeled with both CldU and IdU and did not migrate; and III - migrant cells that uptake IdU. Mapping and 3D-reconstruction of labeled nuclei showed that type I and type II cells were preferentially found close to ventricle walls. Type III cells appeared widespread and migrating in tangential and radial routes. Use of proliferation markers together with Vimentin or Nestin evidenced that type II cells are the putative stem cells that are located at the ventricular lumen. Double label cells with IdU+ and NeuN or HuC/D allowed us identify migrant neurons. Quantitation of labeled nuclei indicates that the proportion of putative stem cells is around 10% in all regions of the brain. This percentage of stem cells suggests the existence of a constant brain cell population in Austrolebias charrua that seems functional to the maintainance of adult neurogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

Glial cell activation, recruitment, and survival of B-lineage cells following MCMV brain infection.

PubMed

Lokensgard, James R; Mutnal, Manohar B; Prasad, Sujata; Sheng, Wen; Hu, Shuxian

2016-05-20

Chemokines produced by reactive glia drive migration of immune cells and previous studies from our laboratory have demonstrated that CD19(+) B cells infiltrate the brain. In this study, in vivo and in vitro experiments investigated the role of reactive glial cells in recruitment and survival of B-lineage cells in response to (murine cytomegalovirus) MCMV infection. Flow cytometric analysis was used to assess chemokine receptor expression on brain-infiltrating B cells. Real-time RT-PCR and ELISA were used to measure chemokine levels. Dual-immunohistochemical staining was used to co-localize chemokine production by reactive glia. Primary glial cell cultures and migration assays were used to examine chemokine-mediated recruitment. Astrocyte: B cell co-cultures were used to investigate survival and proliferation. The chemokine receptors CXCR3, CXCR5, CCR5, and CCR7 were detected on CD19(+) cells isolated from the brain during MCMV infection. In particular, CXCR3 was found to be elevated on an increasing number of cells over the time course of infection, and it was the primary chemokine receptor expressed at 60 days post infection Quite different expression kinetics were observed for CXCR5, CCR5, and CCR7, which were elevated on the highest number of cells early during infection and decreased by 14, 30, and 60 days post infection Correspondingly, elevated levels of CXCL9, CXCL10, and CXCL13, as well as CCL5, were found within the brains of infected animals, and only low levels of CCL3 and CCL19 were detected. Differential expression of CXCL9/CXCL10 and CXCL13 between microglia and astrocytes was apparent, and B cells moved towards supernatants from MCMV-infected microglia, but not astrocytes. Pretreatment with neutralizing Abs to CXCL9 and CXCL10 inhibited this migration. In contrast, neutralizing Abs to the ligand of CXCR5 (i.e., CXCL13) did not significantly block chemotaxis. Proliferation of brain-infiltrating B cells was detected at 7 days post infection and persisted through the latest time tested (60 days post infection). Finally, astrocytes produce BAFF (B cell activating factor of the TNF family) and promote proliferation of B cells via cell-to-cell contact. CXCR3 is the primary chemokine receptor on CD19(+) B cells persisting within the brain, and migration to microglial cell supernatants is mediated through this receptor. Correspondingly, microglial cells produce CXCL9 and CXCL10, but not CXCL13. Reactive astrocytes promote B cell proliferation.

SDF1 regulates leading process branching and speed of migrating interneurons

PubMed Central

Lysko, Daniel E.; Putt, Mary; Golden, Jeffrey A.

2011-01-01

Cell migration is required for normal embryonic development, yet how cells navigate complex paths while integrating multiple guidance cues remains poorly understood. During brain development, interneurons migrate from the ventral ganglionic eminence to the cerebral cortex within several migratory streams. They must exit these streams to invade the cortical plate. While SDF1-signaling is necessary for normal interneuron stream migration, how they switch from tangential stream migration to invade the cortical plate is unknown. Here we demonstrate that SDF1-signaling reduces interneuron branching frequency by reducing cAMP levels via a Gi-signaling pathway using an in vitro mouse explant system, resulting in the maintenance of stream migration. Blocking SDF1-signaling, or increasing branching frequency, results in stream exit and cortical plate invasion in mouse brain slices. These data support a novel model to understand how migrating interneurons switch from tangential migration to invade the cortical plate in which reducing SDF1-signaling increases leading process branching and slows the migration rate, permitting migrating interneurons to sense cortically directed guidance cues. PMID:21289183

Detachment of Chain-Forming Neuroblasts by Fyn-Mediated Control of cell-cell Adhesion in the Postnatal Brain.

PubMed

Fujikake, Kazuma; Sawada, Masato; Hikita, Takao; Seto, Yayoi; Kaneko, Naoko; Herranz-Pérez, Vicente; Dohi, Natsuki; Homma, Natsumi; Osaga, Satoshi; Yanagawa, Yuchio; Akaike, Toshihiro; García-Verdugo, Jose Manuel; Hattori, Mitsuharu; Sobue, Kazuya; Sawamoto, Kazunobu

2018-05-09

In the rodent olfactory system, neuroblasts produced in the ventricular-subventricular zone of the postnatal brain migrate tangentially in chain-like cell aggregates toward the olfactory bulb (OB) through the rostral migratory stream (RMS). After reaching the OB, the chains are dissociated and the neuroblasts migrate individually and radially toward their final destination. The cellular and molecular mechanisms controlling cell-cell adhesion during this detachment remain unclear. Here we report that Fyn, a nonreceptor tyrosine kinase, regulates the detachment of neuroblasts from chains in the male and female mouse OB. By performing chemical screening and in vivo loss-of-function and gain-of-function experiments, we found that Fyn promotes somal disengagement from the chains and is involved in neuronal migration from the RMS into the granule cell layer of the OB. Fyn knockdown or Dab1 (disabled-1) deficiency caused p120-catenin to accumulate and adherens junction-like structures to be sustained at the contact sites between neuroblasts. Moreover, a Fyn and N-cadherin double-knockdown experiment indicated that Fyn regulates the N-cadherin-mediated cell adhesion between neuroblasts. These results suggest that the Fyn-mediated control of cell-cell adhesion is critical for the detachment of chain-forming neuroblasts in the postnatal OB. SIGNIFICANCE STATEMENT In the postnatal brain, newly born neurons (neuroblasts) migrate in chain-like cell aggregates toward their destination, where they are dissociated into individual cells and mature. The cellular and molecular mechanisms controlling the detachment of neuroblasts from chains are not understood. Here we show that Fyn, a nonreceptor tyrosine kinase, promotes the somal detachment of neuroblasts from chains, and that this regulation is critical for the efficient migration of neuroblasts to their destination. We further show that Fyn and Dab1 (disabled-1) decrease the cell-cell adhesion between chain-forming neuroblasts, which involves adherens junction-like structures. Our results suggest that Fyn-mediated regulation of the cell-cell adhesion of neuroblasts is critical for their detachment from chains in the postnatal brain. Copyright © 2018 the authors 0270-6474/18/384599-12$15.00/0.

Recapitulating in vivo-like plasticity of glioma cell invasion along blood vessels and in astrocyte-rich stroma.

PubMed

Gritsenko, Pavlo; Leenders, William; Friedl, Peter

2017-10-01

Diffuse invasion of glioma cells into the brain parenchyma leads to nonresectable brain tumors and poor prognosis of glioma disease. In vivo, glioma cells can adopt a range of invasion strategies and routes, by moving as single cells, collective strands and multicellular networks along perivascular, perineuronal and interstitial guidance cues. Current in vitro assays to probe glioma cell invasion, however, are limited in recapitulating the modes and adaptability of glioma invasion observed in brain parenchyma, including collective behaviours. To mimic in vivo-like glioma cell invasion in vitro, we here applied three tissue-inspired 3D environments combining multicellular glioma spheroids and reconstituted microanatomic features of vascular and interstitial brain structures. Radial migration from multicellular glioma spheroids of human cell lines and patient-derived xenograft cells was monitored using (1) reconstituted basement membrane/hyaluronan interfaces representing the space along brain vessels; (2) 3D scaffolds generated by multi-layered mouse astrocytes to reflect brain interstitium; and (3) freshly isolated mouse brain slice culture ex vivo. The invasion patterns in vitro were validated using histological analysis of brain sections from glioblastoma patients and glioma xenografts infiltrating the mouse brain. Each 3D assay recapitulated distinct aspects of major glioma invasion patterns identified in mouse xenografts and patient brain samples, including individually migrating cells, collective strands extending along blood vessels, and multicellular networks of interconnected glioma cells infiltrating the neuropil. In conjunction, these organotypic assays enable a range of invasion modes used by glioma cells and will be applicable for mechanistic analysis and targeting of glioma cell dissemination.

Microglial migration and interactions with dendrimer nanoparticles are altered in the presence of neuroinflammation.

PubMed

Zhang, Fan; Nance, Elizabeth; Alnasser, Yossef; Kannan, Rangaramanujam; Kannan, Sujatha

2016-03-22

Microglial cells have been implicated in neuroinflammation-mediated injury in the brain, including neurodevelopmental disorders such as cerebral palsy (CP) and autism. Pro-inflammatory activation of microglial cells results in the impairment of their neuroprotective functions, leading to an exaggerated, ongoing immune dysregulation that can persist long after the initial insult. We have previously shown that dendrimer-mediated delivery of an anti-inflammatory agent can attenuate inflammation in a rabbit model of maternal inflammation-induced CP and significantly improve the motor phenotype, due to the ability of the dendrimer to selectively localize in activated microglia. To elucidate the interactions between dendrimers and microglia, we created an organotypic whole-hemisphere brain slice culture model from newborn rabbits with and without exposure to inflammation in utero. We then used this model to analyze the dynamics of microglial migration and their interactions with dendrimers in the presence of neuroinflammation. Microglial cells in animals with CP had an amoeboid morphology and impaired cell migration, demonstrated by decreased migration distance and velocity when compared to cells in healthy, age-matched controls. However, this decreased migration was associated with a greater, more rapid dendrimer uptake compared to microglial cells from healthy controls. This study demonstrates that maternal intrauterine inflammation is associated with impaired microglial function and movement in the newborn brain. This microglial impairment may play a role in the development of ongoing brain injury and CP in the offspring. Increased uptake of dendrimers by the "impaired" microglia can be exploited to deliver drugs specifically to these cells and modulate their functions. Host tissue and target cell characteristics are important aspects to be considered in the design and evaluation of targeted dendrimer-based nanotherapeutics for improved and sustained efficacy. This ex vivo model also provides a rapid screening tool for evaluation of the effects of various therapies on microglial function.

Antiglioma activity of curcumin-loaded lipid nanoparticles and its enhanced bioavailability in brain tissue for effective glioblastoma therapy.

PubMed

Kundu, Paromita; Mohanty, Chandana; Sahoo, Sanjeeb K

2012-07-01

Glioblastoma, the most aggressive form of brain and central nervous system tumours, is characterized by high rates proliferation, migration and invasion. The major road block in the delivery of drugs to the brain is the blood-brain barrier, along with the expression of various multi-drug resistance (MDR) proteins that cause the efflux of a wide range of chemotherapeutic drugs. Curcumin, a herbal drug, is known to inhibit cellular proliferation, migration and invasion and induce apoptosis of glioma cells. It also has the potential to modulate MDR in glioma cells. However, the greatest challenge in the administration of curcumin stems from its low bioavailability and high rate of metabolism. To circumvent the above pitfalls of curcumin we have developed curcumin-loaded glyceryl monooleate (GMO) nanoparticles (NP) coated with the surfactant Pluronic F-68 and vitamin E D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) for brain delivery. We demonstrated that our curcumin-loaded NPs inhibit cellular proliferation, migration and invasion along with a higher percentage of cell cycle arrest and telomerase inhibition, thus leading to a greater percentage apoptotic cell death in glioma cells compared with native curcumin. An in vivo study demonstrated enhanced bioavailability of curcumin in blood serum and brain tissue when delivered by curcumin-loaded GMO NPs compared with native curcumin in a rat model. Thus, curcumin-loaded GMO NPs can be used as an effective delivery system to overcome the challenges of drug delivery to the brain, providing a new approach to glioblastoma therapy. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

NADPH oxidase 2-derived reactive oxygen species signal contributes to bradykinin-induced matrix metalloproteinase-9 expression and cell migration in brain astrocytes

PubMed Central

2012-01-01

Background Matrix metalloproteinase-9 (MMP-9) plays a crucial role in pathological processes of brain inflammation, injury, and neurodegeneration. Moreover, bradykinin (BK) induces the expression of several inflammatory proteins in brain astrocytes. Recent studies have suggested that increased oxidative stress is implicated in the brain inflammation and injury. However, whether BK induced MMP-9 expression mediated through oxidative stress remains virtually unknown. Herein we investigated the role of redox signals in BK-induced MMP-9 expression in rat brain astrocytes (RBA-1 cells). Results In the study, we first demonstrated that reactive oxygen species (ROS) plays a crucial role in BK-induced MMP-9 expression in cultured brain astrocytes (in vitro) and animal brain tissue (in vivo) models. Next, BK-induced MMP-9 expression is mediated through a Ca2+-mediated PKC-α linking to p47phox/NADPH oxidase 2 (Nox2)/ROS signaling pathway. Nox2-dependent ROS generation led to activation and up-regulation of the downstream transcriptional factor AP-1 (i.e. c-Fos and c-Jun), which bound to MMP-9 promoter region, and thereby turned on transcription of MMP-9 gene. Functionally, BK-induced MMP-9 expression enhanced astrocytic migration. Conclusions These results demonstrated that in RBA-1 cells, activation of AP-1 (c-Fos/c-Jun) by the PKC-α-mediated Nox2/ROS signals is essential for up-regulation of MMP-9 and cell migration enhanced by BK. PMID:23176293

The role of myosin II in glioma invasion: A mathematical model

PubMed Central

Lee, Wanho; Lim, Sookkyung; Kim, Yangjin

2017-01-01

Gliomas are malignant tumors that are commonly observed in primary brain cancer. Glioma cells migrate through a dense network of normal cells in microenvironment and spread long distances within brain. In this paper we present a two-dimensional multiscale model in which a glioma cell is surrounded by normal cells and its migration is controlled by cell-mechanical components in the microenvironment via the regulation of myosin II in response to chemoattractants. Our simulation results show that the myosin II plays a key role in the deformation of the cell nucleus as the glioma cell passes through the narrow intercellular space smaller than its nuclear diameter. We also demonstrate that the coordination of biochemical and mechanical components within the cell enables a glioma cell to take the mode of amoeboid migration. This study sheds lights on the understanding of glioma infiltration through the narrow intercellular spaces and may provide a potential approach for the development of anti-invasion strategies via the injection of chemoattractants for localization. PMID:28166231

Proliferation zones in the axolotl brain and regeneration of the telencephalon

PubMed Central

2013-01-01

Background Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. Results There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. Conclusion There is a continual generation of neuronal cells from neural progenitor cells located within the ventricular zone of the axolotl brain. Variable rates of proliferation were detected across brain regions. These neural progenitor cells appear to mediate telencephalic tissue regeneration through an injury-induced olfactory cue. Identification of this cue is our future goal. PMID:23327114

Proliferation zones in the axolotl brain and regeneration of the telencephalon.

PubMed

Maden, Malcolm; Manwell, Laurie A; Ormerod, Brandi K

2013-01-17

Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. There is a continual generation of neuronal cells from neural progenitor cells located within the ventricular zone of the axolotl brain. Variable rates of proliferation were detected across brain regions. These neural progenitor cells appear to mediate telencephalic tissue regeneration through an injury-induced olfactory cue. Identification of this cue is our future goal.

The Calcium-Sensing Receptor and Integrins in Cellular Differentiation and Migration

PubMed Central

Tharmalingam, Sujeenthar; Hampson, David R.

2016-01-01

The calcium-sensing receptor (CaSR) is a widely expressed homodimeric G-protein coupled receptor structurally related to the metabotropic glutamate receptors and GPRC6A. In addition to its well characterized role in maintaining calcium homeostasis and regulating parathyroid hormone release, evidence has accumulated linking the CaSR with cellular differentiation and migration, brain development, stem cell engraftment, wound healing, and tumor growth and metastasis. Elevated expression of the CaSR in aggressive metastatic tumors has been suggested as a potential novel prognostic marker for predicting metastasis, especially to bone tissue where extracellular calcium concentrations may be sufficiently high to activate the receptor. Recent evidence supports a model whereby CaSR-mediated activation of integrins promotes cellular migration. Integrins are single transmembrane spanning heterodimeric adhesion receptors that mediate cell migration by binding to extracellular matrix proteins. The CaSR has been shown to form signaling complexes with the integrins to facilitate both the movement and differentiation of cells, such as neurons during normal brain development and tumor cells under pathological circumstances. Thus, CaSR/integrin complexes may function as a universal cell migration or homing complex. Manipulation of this complex may be of potential interest for treating metastatic cancers, and for developmental disorders pertaining to aberrant neuronal migration. PMID:27303307

Girdin Is an Intrinsic Regulator of Neuroblast Chain Migration in the Rostral Migratory Stream of the Postnatal Brain

PubMed Central

Wang, Yun; Kaneko, Naoko; Asai, Naoya; Enomoto, Atsushi; Isotani-Sakakibara, Mayu; Kato, Takuya; Asai, Masato; Murakumo, Yoshiki; Ota, Haruko; Hikita, Takao; Namba, Takashi; Kuroda, Keisuke; Kaibuchi, Kozo; Ming, Guo-li; Song, Hongjun; Sawamoto, Kazunobu; Takahashi, Masahide

2017-01-01

In postnatally developing and adult brains, interneurons of the olfactory bulb (OB) are continuously generated at the subventricular zone of the forebrain. The newborn neuroblasts migrate tangentially to the OB through a well defined pathway, the rostral migratory stream (RMS), where the neuroblasts undergo collective migration termed “chain migration.” The cell-intrinsic regulatory mechanism of neuroblast chain migration, however, has not been uncovered. Here we show that mice lacking the actin-binding Akt substrate Girdin (a protein that interacts with Disrupted-In-Schizophrenia 1 to regulate neurogenesis in the dentate gyrus) have profound defects in neuroblast chain migration along the RMS. Analysis of two gene knock-in mice harboring Girdin mutants identified unique amino acid residues in Girdin’s C-terminal domain that are responsible for the regulation of neuroblast chain migration but revealed no apparent requirement of Girdin phosphorylation by Akt. Electron microscopic analyses demonstrated the involvement of Girdin in neuroblast cell–cell interactions. These findings suggest that Girdin is an important intrinsic factor that specifically governs neuroblast chain migration along the RMS. PMID:21632933

Expression profiles of inka2 in the murine nervous system.

PubMed

Iwasaki, Yumi; Yumoto, Takahito; Sakakibara, Shin-Ichi

2015-01-01

Dynamic rearrangement of the actin cytoskeleton impacts many cellular characteristics in both the developing and adult central nervous systems (CNS), including the migration and adhesion of highly motile neural progenitor cells, axon guidance of immature neurons, and reconstruction of synaptic structures in the adult brain. Inka1, a known regulator of actin cytoskeleton reconstruction, is predominantly expressed by the neural crest cell lineage and regulates the migration and differentiation of these cells. In the present study, we identified a novel gene, designated as inka2, which is related to inka1. Inka2/fam212b is an evolutionarily conserved gene found in different vertebrate species and constitutes a novel gene family together with inka1. Northern blot analysis showed that inka2 mRNA was highly enriched in the nervous system. The spatiotemporal propagation cell profiles of those cells that expressed inka2 transcripts were compatible with those of Olig2-positive oligodendrocyte progenitor cells, which originate in the ventral ventricular zone during embryogenesis. Intense expression of inka2 was also noted in the proliferative neuronal progenitors in the developing cerebellum. On the other hand, immature newborn neurons in the embryonic brain showed no expression of inka2, except for the cells residing in the marginal zone of the embryonic telencephalon, which is known to contain transient cells including the non-subplate pioneer neurons and Cajal-Retzius cells. As brain development proceeds during the postnatal stage, inka2 expression emerged in some populations of immature neurons, including the neocortical pyramidal neurons, hippocampal pyramidal neurons, and granule cells migrating in the cerebellar cortex. In the adult brain, the expression of inka2 was interestingly confined in terminally differentiated neurons in the restricted forebrain regions. Taken together, as a novel regulator of actin cytoskeletons in the CNS, inka2 may be involved in multiple actin-driven processes, including cell migration and establishment of neuronal polarity. Copyright © 2015 Elsevier B.V. All rights reserved.

Brain size and limits to adult neurogenesis.

PubMed

Paredes, Mercedes F; Sorrells, Shawn F; Garcia-Verdugo, Jose M; Alvarez-Buylla, Arturo

2016-02-15

The walls of the cerebral ventricles in the developing embryo harbor the primary neural stem cells from which most neurons and glia derive. In many vertebrates, neurogenesis continues postnatally and into adulthood in this region. Adult neurogenesis at the ventricle has been most extensively studied in organisms with small brains, such as reptiles, birds, and rodents. In reptiles and birds, these progenitor cells give rise to young neurons that migrate into many regions of the forebrain. Neurogenesis in adult rodents is also relatively widespread along the lateral ventricles, but migration is largely restricted to the rostral migratory stream into the olfactory bulb. Recent work indicates that the wall of the lateral ventricle is highly regionalized, with progenitor cells giving rise to different types of neurons depending on their location. In species with larger brains, young neurons born in these spatially specified domains become dramatically separated from potential final destinations. Here we hypothesize that the increase in size and topographical complexity (e.g., intervening white matter tracts) in larger brains may severely limit the long-term contribution of new neurons born close to, or in, the ventricular wall. We compare the process of adult neuronal birth, migration, and integration across species with different brain sizes, and discuss how early regional specification of progenitor cells may interact with brain size and affect where and when new neurons are added. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

Spatial distribution and cellular composition of adult brain proliferative zones in the teleost, Gymnotus omarorum

PubMed Central

Olivera-Pasilio, Valentina; Peterson, Daniel A.; Castelló, María E.

2014-01-01

Proliferation of stem/progenitor cells during development provides for the generation of mature cell types in the CNS. While adult brain proliferation is highly restricted in the mammals, it is widespread in teleosts. The extent of adult neural proliferation in the weakly electric fish, Gymnotus omarorum has not yet been described. To address this, we used double thymidine analog pulse-chase labeling of proliferating cells to identify brain proliferation zones, characterize their cellular composition, and analyze the fate of newborn cells in adult G. omarorum. Short thymidine analog chase periods revealed the ubiquitous distribution of adult brain proliferation, similar to other teleosts, particularly Apteronotus leptorhynchus. Proliferating cells were abundant at the ventricular-subventricular lining of the ventricular-cisternal system, adjacent to the telencephalic subpallium, the diencephalic preoptic region and hypothalamus, and the mesencephalic tectum opticum and torus semicircularis. Extraventricular proliferation zones, located distant from the ventricular-cisternal system surface, were found in all divisions of the rombencephalic cerebellum. We also report a new adult proliferation zone at the caudal-lateral border of the electrosensory lateral line lobe. All proliferation zones showed a heterogeneous cellular composition. The use of short (24 h) and long (30 day) chase periods revealed abundant fast cycling cells (potentially intermediate amplifiers), sparse slow cycling (potentially stem) cells, cells that appear to have entered a quiescent state, and cells that might correspond to migrating newborn neural cells. Their abundance and migration distance differed among proliferation zones: greater numbers and longer range and/or pace of migrating cells were associated with subpallial and cerebellar proliferation zones. PMID:25249943

Cabazitaxel operates anti-metastatic and cytotoxic via apoptosis induction and stalls brain tumor angiogenesis.

PubMed

Ghoochani, Ali; Hatipoglu Majernik, Gökce; Sehm, Tina; Wach, Sven; Buchfelder, Michael; Taubert, Helge; Eyupoglu, Ilker Y; Savaskan, Nicolai

2016-06-21

Taxanes target microtubules and are clinically established chemotherapeutic agents with proven efficacy in human cancers. Cabazitaxel (XRP-6258, Jevtana®) is a second generation semisynthetic taxane with high chemotherapeutic potential in prostate cancer. There, cabazitaxel can overcome docetaxel-resistant prostate cancer. Here, we tested the effects of cabazitaxel on glioma cells, and non-transformed cells such as neurons and astrocytes. Cabazitaxel operates highly toxic in various human glioma cells at nanomolar concentrations. In contrast, primary astrocytes and neurons are not affected by this agent. Cabazitaxel disrupts cytoskeletal F-actin fibers and induces apoptotic cell death in gliomas. Moreover, cabazitaxel displayed highest efficacy in inhibiting glioma cell migration and invasion. Here we demonstrate that cabazitaxel inhibited tumor migration already at 1 nM. We also tested cabazitaxel in the ex vivo VOGiM assay. Cabazitaxel stalled glioma growth and at the same time inhibited tumor-induced angiogenesis. In summary, we found that cabazitaxel operates as an apoptosis-inducing gliomatoxic agent with strongest effects on migration and invasive growth. Thus, our report uncovered cabazitaxel actions on gliomas and on the brain tumor microenvironment. These data reveal novel aspects for adjuvant approaches when applied to brain tumor patients.

Cabazitaxel operates anti-metastatic and cytotoxic via apoptosis induction and stalls brain tumor angiogenesis

PubMed Central

Ghoochani, Ali; Majernik, Gökce Hatipoglu; Sehm, Tina; Wach, Sven; Buchfelder, Michael; Taubert, Helge

2016-01-01

Taxanes target microtubules and are clinically established chemotherapeutic agents with proven efficacy in human cancers. Cabazitaxel (XRP-6258, Jevtana®) is a second generation semisynthetic taxane with high chemotherapeutic potential in prostate cancer. There, cabazitaxel can overcome docetaxel-resistant prostate cancer. Here, we tested the effects of cabazitaxel on glioma cells, and non-transformed cells such as neurons and astrocytes. Cabazitaxel operates highly toxic in various human glioma cells at nanomolar concentrations. In contrast, primary astrocytes and neurons are not affected by this agent. Cabazitaxel disrupts cytoskeletal F-actin fibers and induces apoptotic cell death in gliomas. Moreover, cabazitaxel displayed highest efficacy in inhibiting glioma cell migration and invasion. Here we demonstrate that cabazitaxel inhibited tumor migration already at 1 nM. We also tested cabazitaxel in the ex vivo VOGiM assay. Cabazitaxel stalled glioma growth and at the same time inhibited tumor-induced angiogenesis. In summary, we found that cabazitaxel operates as an apoptosis-inducing gliomatoxic agent with strongest effects on migration and invasive growth. Thus, our report uncovered cabazitaxel actions on gliomas and on the brain tumor microenvironment. These data reveal novel aspects for adjuvant approaches when applied to brain tumor patients. PMID:27203678

Paracrine factors of human mesenchymal stem cells increase wound closure and reduce reactive oxygen species production in a traumatic brain injury in vitro model.

PubMed

Torrente, D; Avila, M F; Cabezas, R; Morales, L; Gonzalez, J; Samudio, I; Barreto, G E

2014-07-01

Traumatic brain injury (TBI) consists of a primary and a secondary insult characterized by a biochemical cascade that plays a crucial role in cell death in the brain. Despite the major improvements in the acute care of head injury victims, no effective strategies exist for preventing the secondary injury cascade. This lack of success might be due to that most treatments are aimed at targeting neuronal population, even if studies show that astrocytes play a key role after a brain damage. In this work, we propose a new model of in vitro traumatic brain-like injury and use paracrine factors released by human mesenchymal stem cells (hMSCs) as a neuroprotective strategy. Our results demonstrate that hMSC-conditioned medium increased wound closure and proliferation at 12 h and reduced superoxide production to control conditions. This was accompanied by changes in cell morphology and polarity index, as both parameters reflect the ability of cells to migrate toward the wound. These findings indicate that hMSC is an important regulator of oxidative stress production, enhances cells migration, and shall be considered as a useful neuroprotective approach for brain recovery following injury. © The Author(s) 2014.

EGFRvIII-specific chimeric antigen receptor T cells migrate to and kill tumor deposits infiltrating the brain parenchyma in an invasive xenograft model of glioblastoma.

PubMed

Miao, Hongsheng; Choi, Bryan D; Suryadevara, Carter M; Sanchez-Perez, Luis; Yang, Shicheng; De Leon, Gabriel; Sayour, Elias J; McLendon, Roger; Herndon, James E; Healy, Patrick; Archer, Gary E; Bigner, Darell D; Johnson, Laura A; Sampson, John H

2014-01-01

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults and is uniformly lethal. T-cell-based immunotherapy offers a promising platform for treatment given its potential to specifically target tumor tissue while sparing the normal brain. However, the diffuse and infiltrative nature of these tumors in the brain parenchyma may pose an exceptional hurdle to successful immunotherapy in patients. Areas of invasive tumor are thought to reside behind an intact blood brain barrier, isolating them from effective immunosurveillance and thereby predisposing the development of "immunologically silent" tumor peninsulas. Therefore, it remains unclear if adoptively transferred T cells can migrate to and mediate regression in areas of invasive GBM. One barrier has been the lack of a preclinical mouse model that accurately recapitulates the growth patterns of human GBM in vivo. Here, we demonstrate that D-270 MG xenografts exhibit the classical features of GBM and produce the diffuse and invasive tumors seen in patients. Using this model, we designed experiments to assess whether T cells expressing third-generation chimeric antigen receptors (CARs) targeting the tumor-specific mutation of the epidermal growth factor receptor, EGFRvIII, would localize to and treat invasive intracerebral GBM. EGFRvIII-targeted CAR (EGFRvIII+ CAR) T cells demonstrated in vitro EGFRvIII antigen-specific recognition and reactivity to the D-270 MG cell line, which naturally expresses EGFRvIII. Moreover, when administered systemically, EGFRvIII+ CAR T cells localized to areas of invasive tumor, suppressed tumor growth, and enhanced survival of mice with established intracranial D-270 MG tumors. Together, these data demonstrate that systemically administered T cells are capable of migrating to the invasive edges of GBM to mediate antitumor efficacy and tumor regression.

Stem cell recruitment of newly formed host cells via a successful seduction? Filling the gap between neurogenic niche and injured brain site.

PubMed

Tajiri, Naoki; Kaneko, Yuji; Shinozuka, Kazutaka; Ishikawa, Hiroto; Yankee, Ernest; McGrogan, Michael; Case, Casey; Borlongan, Cesar V

2013-01-01

Here, we report that a unique mechanism of action exerted by stem cells in the repair of the traumatically injured brain involves their ability to harness a biobridge between neurogenic niche and injured brain site. This biobridge, visualized immunohistochemically and laser captured, corresponded to an area between the neurogenic subventricular zone and the injured cortex. That the biobridge expressed high levels of extracellular matrix metalloproteinases characterized initially by a stream of transplanted stem cells, but subsequently contained only few to non-detectable grafts and overgrown by newly formed host cells, implicates a novel property of stem cells. The transplanted stem cells manifest themselves as pathways for trafficking the migration of host neurogenic cells, but once this biobridge is formed between the neurogenic site and the injured brain site, the grafted cells disappear and relinquish their task to the host neurogenic cells. Our findings reveal that long-distance migration of host cells from the neurogenic niche to the injured brain site can be achieved through transplanted stem cells serving as biobridges for initiation of endogenous repair mechanisms. This is the first report of a stem cell-paved "biobridge". Indeed, to date the two major schools of discipline in stem cell repair mechanism primarily support the concept of "cell replacement" and bystander effects of "trophic factor secretion". The present novel observations of a stem cell seducing a host cell to engage in brain repair advances basic science concepts on stem cell biology and extracellular matrix, as well as provokes translational research on propagating this stem cell-paved biobridge beyond cell replacement and trophic factor secretion for the treatment of traumatic brain injury and other neurological disorders.

Ferrociphenol lipid nanocapsule delivery by mesenchymal stromal cells in brain tumor therapy.

PubMed

Roger, Mathilde; Clavreul, Anne; Huynh, Ngoc Trinh; Passirani, Catherine; Schiller, Paul; Vessières, Anne; Montero-Menei, Claudia; Menei, Philippe

2012-02-14

The prognosis of patients with malignant glioma remains extremely poor despite surgery and improvements in radio- and chemo-therapies. Thus, treatment strategies that specifically target these tumors have the potential to greatly improve therapeutic outcomes. "Marrow-isolated adult multilineage inducible" cells (MIAMI cells) are a subpopulation of mesenchymal stromal cells (MSCs) which possess the ability to migrate to brain tumors. We have previously shown that MIAMI cells were able to efficiently incorporate lipid nanocapsules (LNCs) without altering either their stem cell properties or their migration capacity. In this study, we assessed whether the cytotoxic effects of MIAMI cells loaded with LNCs containing an organometallic complex (ferrociphenol or Fc-diOH) could be used to treat brain tumors. The results showed that MIAMI cells internalized Fc-diOH-LNCs and that this internalization did not induce MIAMI cell death. Furthermore, Fc-diOH-LNC-loaded MIAMI cells produced a cytotoxic effect on U87MG glioma cells in vitro. This cytotoxic effect was validated in vivo after intratumoral injection of Fc-diOH-LNC-loaded MIAMI cells in a heterotopic U87MG glioma model in nude mice. These promising results open up a new field of treatment in which cellular vehicles and nanoparticles can be combined to treat brain tumors. Copyright © 2011 Elsevier B.V. All rights reserved.

Hepatocyte growth factor/c-MET axis-mediated tropism of cord blood-derived unrestricted somatic stem cells for neuronal injury.

PubMed

Trapp, Thorsten; Kögler, Gesine; El-Khattouti, Abdelouahid; Sorg, Rüdiger V; Besselmann, Michael; Föcking, Melanie; Bührle, Christian P; Trompeter, Ingo; Fischer, Johannes C; Wernet, Peter

2008-11-21

An under-agarose chemotaxis assay was used to investigate whether unrestricted somatic stem cells (USSC) that were recently characterized in human cord blood are attracted by neuronal injury in vitro. USSC migrated toward extracts of post-ischemic brain tissue of mice in which stroke had been induced. Moreover, apoptotic neurons secrete factors that strongly attracted USSC, whereas necrotic and healthy neurons did not. Investigating the expression of growth factors and chemokines in lesioned brain tissue and neurons and of their respective receptors in USSC revealed expression of hepatocyte growth factor (HGF) in post-ischemic brain and in apoptotic but not in necrotic neurons and of the HGF receptor c-MET in USSC. Neuronal lesion-triggered migration was observed in vitro and in vivo only when c-MET was expressed at a high level in USSC. Neutralization of the bioactivity of HGF with an antibody inhibited migration of USSC toward neuronal injury. This, together with the finding that human recombinant HGF attracts USSC, document that HGF signaling is necessary for the tropism of USSC for neuronal injury. Our data demonstrate that USSC have the capacity to migrate toward apoptotic neurons and injured brain. Together with their neural differentiation potential, this suggests a neuroregenerative potential of USSC. Moreover, we provide evidence for a hitherto unrecognized pivotal role of the HGF/c-MET axis in guiding stem cells toward brain injury, which may partly account for the capability of HGF to improve function in the diseased central nervous system.

Cancer-associated fibroblast promote transmigration through endothelial brain cells in three-dimensional in vitro models.

PubMed

Choi, Yoon Pyo; Lee, Joo Hyun; Gao, Ming-Qing; Kim, Baek Gil; Kang, Suki; Kim, Se Hoon; Cho, Nam Hoon

2014-11-01

Brain metastases are associated with high morbidity as well as with poor prognosis and survival in breast cancer patients. Despite its clinical importance, metastasis of breast cancer cells through the blood-brain barrier (BBB) is poorly understood. The objective of our study was to investigate whether cancer-associated fibroblasts (CAFs) play crucial roles in breast cancer brain metastasis. Using a cell adhesion assays, in vitro BBB permeability and transmigration assays and soft agar colony formation assays, we investigated the physical roles of CAFs in breast cancer brain metastasis. We also performed immunofluorescence, flow cytometric analysis, Droplet Digital PCR and Simon™ Simple Western System to confirm changes in expression levels. We established two novel three-dimensional (3D) culture systems using a perpendicular slide chamber and applying 3D embedded culture method to reflect brain metastasis conditions. With a newly developed device, CAFs was proven to promote cell adhesion to human brain microvascular endothelial cells, in vitro BBB permeability and transmigration and colony formation of breast cancer cells. Furthermore, CAFs enhanced the invasive migration of breast cancer cells in two kinds of 3D cultures. These 3D models also reliably recapitulate the initial steps of BBB transmigration, micro-metastasis and colonization. Expression of integrin α5β1 and αvβ3, c-MET and α2,6-siayltransferase was increased in breast cancer cells that migrated through the BBB. In conclusion, based on our in vitro BBB and co-culture models, our data suggest that CAFs may play a role in breast cancer brain metastasis. © 2014 UICC.

NADPH oxidase-mediated redox signal contributes to lipoteichoic acid-induced MMP-9 upregulation in brain astrocytes

PubMed Central

2012-01-01

Background Lipoteichoic acid (LTA) is a component of gram-positive bacterial cell walls and may be elevated in the cerebrospinal fluid of patients suffering from meningitis. Among matrix metalloproteinases (MMPs), MMP-9 has been observed in patients with brain inflammatory diseases and may contribute to the pathology of brain diseases. Moreover, several studies have suggested that increased oxidative stress is implicated in the pathogenesis of brain inflammation and injury. However, the molecular mechanisms underlying LTA-induced redox signal and MMP-9 expression in brain astrocytes remain unclear. Objective Herein we explored whether LTA-induced MMP-9 expression was mediated through redox signals in rat brain astrocytes (RBA-1 cells). Methods Upregulation of MMP-9 by LTA was evaluated by zymographic and RT-PCR analyses. Next, the MMP-9 regulatory pathways were investigated by pretreatment with pharmacological inhibitors or transfection with small interfering RNAs (siRNAs), Western blotting, and chromatin immunoprecipitation (ChIP)-PCR and promoter activity reporter assays. Moreover, we determined the cell functional changes by migration assay. Results These results showed that LTA induced MMP-9 expression via a PKC(α)-dependent pathway. We further demonstrated that PKCα stimulated p47phox/NADPH oxidase 2 (Nox2)-dependent reactive oxygen species (ROS) generation and then activated the ATF2/AP-1 signals. The activated-ATF2 bound to the AP-1-binding site of MMP-9 promoter, and thereby turned on MMP-9 gene transcription. Additionally, the co-activator p300 also contributed to these responses. Functionally, LTA-induced MMP-9 expression enhanced astrocytic migration. Conclusion These results demonstrated that in RBA-1 cells, activation of ATF2/AP-1 by the PKC(α)-mediated Nox(2)/ROS signals is essential for upregulation of MMP-9 and cell migration enhanced by LTA. PMID:22643046

p53 Mutation suppresses adult neurogenesis in medaka fish (Oryzias latipes)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isoe, Yasuko; Okuyama, Teruhiro; Taniguchi, Yoshihito

2012-07-13

Highlights: Black-Right-Pointing-Pointer Progenitor migration is accompanied by an increase in their numbers in the adult brain. Black-Right-Pointing-Pointer p53 Mutation suppressed an increase in the number of the migrated progenitors. Black-Right-Pointing-Pointer The decreased progenitor number is not due to enhanced cell death. Black-Right-Pointing-Pointer p53 Mutation did not affect proliferation of stem cells. -- Abstract: Tumor suppressor p53 negatively regulates self-renewal of neural stem cells in the adult murine brain. Here, we report that the p53 null mutation in medaka fish (Oryzias latipes) suppressed neurogenesis in the telencephalon, independent of cell death. By using 5-bromo-29-deoxyuridine (BrdU) immunohistochemistry, we identified 18 proliferation zonesmore » in the brains of young medaka fish; in situ hybridization showed that p53 was expressed selectively in at least 12 proliferation zones. We also compared the number of BrdU-positive cells present in the whole telencephalon of wild-type (WT) and p53 mutant fish. Immediately after BrdU exposure, the number of BrdU-positive cells did not differ significantly between them. One week after BrdU-exposure, the BrdU-positive cells migrated from the proliferation zone, which was accompanied by an increased number in the WT brain. In contrast, no significant increase was observed in the p53 mutant brain. Terminal deoxynucleotidyl transferase (dUTP) nick end-labeling revealed that there was no significant difference in the number of apoptotic cells in the telencephalon of p53 mutant and WT medaka, suggesting that the decreased number of BrdU-positive cells in the mutant may be due to the suppression of proliferation rather than the enhancement of neural cell death. These results suggest that p53 positively regulates neurogenesis via cell proliferation.« less

The chemokine CXCL16 induces migration and invasion of glial precursor cells via its receptor CXCR6.

PubMed

Hattermann, Kirsten; Ludwig, Andreas; Gieselmann, Volkmar; Held-Feindt, Janka; Mentlein, Rolf

2008-09-01

Chemokines are implicated in developmental and inflammatory processes in the brain. The transmembrane chemokine CXCL16 is produced in brain endothelial and reactive astroglial cells and released by shedding. Its receptor CXCR6 is detected during brain development highest at postnatal day 6, found in glial precursor cells differentiated from neural stem cells and in an A2B5-positive glial precursor cell line. Their stimulation by soluble CXCL16 induces the PI3-kinase/Akt and Erk pathways resulting in the activation of the transcription factor AP-1. As biological responses, soluble CXCL16 upregulates its own receptor, increases cell proliferation, stimulates cell migration in wound-healing and in spheroid confrontation assays. Invasion of CXCR6-positive glial cells into CXCL16-expressing spheroids can be blocked by sheddase inhibitors and CXCL16-antibody. Since CXCL16 is induced by cytokines at sites of inflammation, neurodegeneration, ischemia and malignant transformation, it should attract CXCR6-positive glial precursor cells, enhance their invasion and proliferation and thus favor astrogliosis.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation.

PubMed

Ravindran, Ethiraj; Hu, Hao; Yuzwa, Scott A; Hernandez-Miranda, Luis R; Kraemer, Nadine; Ninnemann, Olaf; Musante, Luciana; Boltshauser, Eugen; Schindler, Detlev; Hübner, Angela; Reinecker, Hans-Christian; Ropers, Hans-Hilger; Birchmeier, Carmen; Miller, Freda D; Wienker, Thomas F; Hübner, Christoph; Kaindl, Angela M

2017-04-01

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation

PubMed Central

Yuzwa, Scott A.; Hernandez-Miranda, Luis R.; Musante, Luciana; Boltshauser, Eugen; Schindler, Detlev; Hübner, Angela; Reinecker, Hans-Christian; Ropers, Hans-Hilger; Miller, Freda D.; Hübner, Christoph; Kaindl, Angela M.

2017-01-01

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder. PMID:28453519

Regulation of endogenous neural stem/progenitor cells for neural repair—factors that promote neurogenesis and gliogenesis in the normal and damaged brain

PubMed Central

Christie, Kimberly J.; Turnley, Ann M.

2012-01-01

Neural stem/precursor cells in the adult brain reside in the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the dentate gyrus in the hippocampus. These cells primarily generate neuroblasts that normally migrate to the olfactory bulb (OB) and the dentate granule cell layer respectively. Following brain damage, such as traumatic brain injury, ischemic stroke or in degenerative disease models, neural precursor cells from the SVZ in particular, can migrate from their normal route along the rostral migratory stream (RMS) to the site of neural damage. This neural precursor cell response to neural damage is mediated by release of endogenous factors, including cytokines and chemokines produced by the inflammatory response at the injury site, and by the production of growth and neurotrophic factors. Endogenous hippocampal neurogenesis is frequently also directly or indirectly affected by neural damage. Administration of a variety of factors that regulate different aspects of neural stem/precursor biology often leads to improved functional motor and/or behavioral outcomes. Such factors can target neural stem/precursor proliferation, survival, migration and differentiation into appropriate neuronal or glial lineages. Newborn cells also need to subsequently survive and functionally integrate into extant neural circuitry, which may be the major bottleneck to the current therapeutic potential of neural stem/precursor cells. This review will cover the effects of a range of intrinsic and extrinsic factors that regulate neural stem/precursor cell functions. In particular it focuses on factors that may be harnessed to enhance the endogenous neural stem/precursor cell response to neural damage, highlighting those that have already shown evidence of preclinical effectiveness and discussing others that warrant further preclinical investigation. PMID:23346046

Fused cerebral organoids model interactions between brain regions.

PubMed

Bagley, Joshua A; Reumann, Daniel; Bian, Shan; Lévi-Strauss, Julie; Knoblich, Juergen A

2017-07-01

Human brain development involves complex interactions between different regions, including long-distance neuronal migration or formation of major axonal tracts. Different brain regions can be cultured in vitro within 3D cerebral organoids, but the random arrangement of regional identities limits the reliable analysis of complex phenotypes. Here, we describe a coculture method combining brain regions of choice within one organoid tissue. By fusing organoids of dorsal and ventral forebrain identities, we generate a dorsal-ventral axis. Using fluorescent reporters, we demonstrate CXCR4-dependent GABAergic interneuron migration from ventral to dorsal forebrain and describe methodology for time-lapse imaging of human interneuron migration. Our results demonstrate that cerebral organoid fusion cultures can model complex interactions between different brain regions. Combined with reprogramming technology, fusions should offer researchers the possibility to analyze complex neurodevelopmental defects using cells from neurological disease patients and to test potential therapeutic compounds.

Human Cytomegalovirus IE2 Protein Disturbs Brain Development by the Dysregulation of Neural Stem Cell Maintenance and the Polarization of Migrating Neurons.

PubMed

Han, Dasol; Byun, Sung-Hyun; Kim, Juwan; Kwon, Mookwang; Pleasure, Samuel J; Ahn, Jin-Hyun; Yoon, Keejung

2017-09-01

Despite the high incidence of severe defects in the central nervous system caused by human cytomegalovirus (HCMV) congenital infection, the mechanism of HCMV neuropathogenesis and the roles of individual viral genes have not yet been fully determined. In this study, we show that the immediate-early 2 (IE2) protein may play a key role in HCMV-caused neurodevelopmental disorders. IE2-transduced neural progenitor cells gave rise to neurospheres with a lower frequency and produced smaller neurospheres than control cells in vitro , indicating reduction of self-renewal and expansion of neural progenitors by IE2. At 2 days after in utero electroporation into the ventricle of the developing brain, a dramatically lower percentage of IE2-expressing cells was detected in the ventricular zone (VZ) and cortical plate (CP) compared to control cells, suggesting that IE2 concurrently dysregulates neural stem cell maintenance in the VZ and neuronal migration to the CP. In addition, most IE2 + cells in the lower intermediate zone either showed multipolar morphology with short neurites or possessed nonradially oriented processes, whereas control cells had long, radially oriented monopolar or bipolar neurites. IE2 + callosal axons also failed to cross the midline to form the corpus callosum. Furthermore, we provide molecular evidence that the cell cycle arrest and DNA binding activities of IE2 appear to be responsible for the increased neural stem cell exit from the VZ and cortical migrational defects, respectively. Collectively, our results demonstrate that IE2 disrupts the orderly process of brain development in a stepwise manner to further our understanding of neurodevelopmental HCMV pathogenesis. IMPORTANCE HCMV brain pathogenesis has been studied in limited experimental settings, such as in vitro HCMV infection of neural progenitor cells or in vivo murine CMV infection of the mouse brain. Here, we show that IE2 is a pivotal factor that contributes to HCMV-induced abnormalities in the context of the embryonic brain using an in utero gene transfer tool. Surprisingly, IE2, but not HCMV IE1 or murine CMV ie3, interferes pleiotropically with key neurodevelopmental processes, including neural stem cell regulation, proper positioning of migrating neurons, and the callosal axon projections important for communication between the hemispheres. Our data suggest that the wide spectrum of clinical outcomes, ranging from mental retardation to microcephaly, caused by congenital HCMV infection can be sufficiently explained in terms of IE2 action alone. Copyright © 2017 American Society for Microbiology.

In Situ Activation of Antigen-Specific CD8+ T Cells in the Presence of Antigen in Organotypic Brain Slices1

PubMed Central

Ling, Changying; Verbny, Yakov I.; Banks, Matthew I.; Sandor, Matyas; Fabry, Zsuzsanna

2012-01-01

The activation of Ag-specific T cells locally in the CNS could potentially contribute to the development of immune-mediated brain diseases. We addressed whether Ag-specific T cells could be stimulated in the CNS in the absence of peripheral lymphoid tissues by analyzing Ag-specific T cell responses in organotypic brain slice cultures. Organotypic brain slice cultures were established 1 h after intracerebral OVA Ag microinjection. We showed that when OVA-specific CD8+ T cells were added to Ag-containing brain slices, these cells became activated and migrated into the brain to the sites of their specific Ags. This activation of OVA-specific T cells was abrogated by the deletion of CD11c+ cells from the brain slices of the donor mice. These data suggest that brain-resident CD11c+ cells stimulate Ag-specific naive CD8+ T cells locally in the CNS and may contribute to immune responses in the brain. PMID:18523307

Profilin1 activity in cerebellar granule neurons is required for radial migration in vivo

PubMed Central

Kullmann, Jan A; Wickertsheim, Ines; Minnerup, Lara; Costell, Mercedes; Friauf, Eckhard; Rust, Marco B

2015-01-01

Neuron migration defects are an important aspect of human neuropathies. The underlying molecular mechanisms of such migration defects are largely unknown. Actin dynamics has been recognized as an important determinant of neuronal migration, and we recently found that the actin-binding protein profilin1 is relevant for radial migration of cerebellar granule neurons (CGN). As the exploited brain-specific mutants lacked profilin1 in both neurons and glial cells, it remained unknown whether profilin1 activity in CGN is relevant for CGN migration in vivo. To test this, we capitalized on a transgenic mouse line that expresses a tamoxifen-inducible Cre variant in CGN, but no other cerebellar cell type. In these profilin1 mutants, the cell density was elevated in the molecular layer, and ectopic CGN occurred. Moreover, 5-bromo-2′-deoxyuridine tracing experiments revealed impaired CGN radial migration. Hence, our data demonstrate the cell autonomous role of profilin1 activity in CGN for radial migration. PMID:25495756

Tracking stem cell migration and survival in brain injury: current approaches and future prospects.

PubMed

Darkazalli, Ali; Levenson, Cathy W

2012-10-01

In recent years, stem cell-mediated therapies have gained considerable ground as potential treatments for a wide variety of brain pathologies including traumatic brain injury, stroke and neurodegenerative diseases. Despite extensive preclinical studies, many of these therapies have not been fully translated into viable clinical approaches. This is partly due to our inability to reliably track and monitor transplanted stem cells longitudinally over long periods of time in vivo. In this review, we discuss the predominant histological cell tracing methodologies, such as immunohistochemistry, and fluorescent cellular dyes and proteins, and compare them to emerging cellular imaging technologies. We show that advances in magnetic resonance imaging (MRI) have resulted in opportunities to use this technology to further our understanding of stem cell characteristics and behaviors in vivo. While MRI may not completely replace conventional cell tracking methods in pre-clinical, mechanistic work, it is clear that it has the potential to function as a powerful diagnostic tool for tracking stem cell migration and survival as well as for evaluating the efficacy of stem cell-mediated therapies.

αB-crystallin: a Novel Regulator of Breast Cancer Metastasis to the Brain

PubMed Central

Malin, Dmitry; Strekalova, Elena; Petrovic, Vladimir; Deal, Allison M.; Ahmad, Abraham Al; Adamo, Barbara; Miller, C. Ryan; Ugolkov, Andrey; Livasy, Chad; Fritchie, Karen; Hamilton, Erika; Blackwell, Kimberly; Geradts, Joseph; Ewend, Matt; Carey, Lisa; Shusta, Eric V.; Anders, Carey K.; Cryns, Vincent L.

2013-01-01

Purpose Basal-like breast tumors are typically (ER/PR/HER2) triple-negative and are associated with a high incidence of brain metastases and poor clinical outcomes. The molecular chaperone αB-crystallin is predominantly expressed in triple-negative breast cancer (TNBC) and contributes to an aggressive tumor phenotype in preclinical models. We investigated the potential role of αB-crystallin in brain metastasis in TNBC. Experimental Design αB-crystallin expression in primary breast carcinomas and brain metastases was analyzed by immunohistochemistry among breast cancer patients with brain metastases. αB-crystallin was overexpressed or silenced in two different TNBC cell lines. The effects on cell adhesion to human brain microvascular endothelial cells (HBMECs) or extracellular matrix proteins, transendothelial migration, and transmigration across a HBMEC/astrocyte co-culture blood-brain barrier (BBB) model were examined. Additionally, the effects of overexpressing or silencing αB-crystallin on brain metastasis in vivo were investigated using orthotopic TNBC models. Results In a cohort of women with breast cancer brain metastasis, αB-crystallin expression in primary breast carcinomas was associated with poor overall survival and poor survival after brain metastasis, even among TNBC patients. Stable overexpression of αB-crystallin in TNBC cells enhanced adhesion to HBMECs, transendothelial migration, and BBB transmigration in vitro, while silencing αB-crystallin inhibited these events. αB-crystallin promoted adhesion of TNBC cells to HBMECs at least in part through an α3β1 integrin-dependent mechanism. αB-crystallin overexpression promoted brain metastasis, while silencing αB-crystallin inhibited brain metastasis in orthotopic TNBC models. Conclusion αB-crystallin is a novel regulator of brain metastasis in TNBC and represents a potential biomarker and drug target for this aggressive disease. PMID:24132917

αB-crystallin: a novel regulator of breast cancer metastasis to the brain.

PubMed

Malin, Dmitry; Strekalova, Elena; Petrovic, Vladimir; Deal, Allison M; Al Ahmad, Abraham; Adamo, Barbara; Miller, C Ryan; Ugolkov, Andrey; Livasy, Chad; Fritchie, Karen; Hamilton, Erika; Blackwell, Kimberly; Geradts, Joseph; Ewend, Matt; Carey, Lisa; Shusta, Eric V; Anders, Carey K; Cryns, Vincent L

2014-01-01

Basal-like breast tumors are typically (ER/PR/HER2) triple-negative and are associated with a high incidence of brain metastases and poor clinical outcomes. The molecular chaperone αB-crystallin is predominantly expressed in triple-negative breast cancer (TNBC) and contributes to an aggressive tumor phenotype in preclinical models. We investigated the potential role of αB-crystallin in brain metastasis in TNBCs. αB-crystallin expression in primary breast carcinomas and brain metastases was analyzed by immunohistochemistry among patients with breast cancer with brain metastases. αB-crystallin was overexpressed or silenced in two different TNBC cell lines. The effects on cell adhesion to human brain microvascular endothelial cells (HBMEC) or extracellular matrix proteins, transendothelial migration, and transmigration across a HBMEC/astrocyte coculture blood-brain barrier (BBB) model were examined. In addition, the effects of overexpressing or silencing αB-crystallin on brain metastasis in vivo were investigated using orthotopic TNBC models. In a cohort of women with breast cancer brain metastasis, αB-crystallin expression in primary breast carcinomas was associated with poor overall survival and poor survival after brain metastasis, even among patients with TNBC. Stable overexpression of αB-crystallin in TNBC cells enhanced adhesion to HBMECs, transendothelial migration, and BBB transmigration in vitro, whereas silencing αB-crystallin inhibited these events. αB-crystallin promoted adhesion of TNBC cells to HBMECs, at least in part, through an α3β1 integrin-dependent mechanism. αB-crystallin overexpression promoted brain metastasis, whereas silencing αB-crystallin inhibited brain metastasis in orthotopic TNBC models. αB-crystallin is a novel regulator of brain metastasis in TNBC and represents a potential biomarker and drug target for this aggressive disease.

Inhibition of β2-adrenergic receptor reduces triple-negative breast cancer brain metastases: The potential benefit of perioperative β-blockade.

PubMed

Choy, Cecilia; Raytis, John L; Smith, David D; Duenas, Matthew; Neman, Josh; Jandial, Rahul; Lew, Michael W

2016-06-01

In response to recent studies, we investigated an association between perioperative β-blockade and breast cancer metastases. First, a retrospective study examining perioperative β-blocker use and cancer recurrence and metastases was conducted on 1,029 patients who underwent breast cancer surgery at the City of Hope Cancer Center between 2000 and 2010. We followed the clinical study and examined proliferation, migration, and invasion in vitro of primary and brain-metastatic breast cancer cells in response to β2-activation and inhibition. We also investigated in vivo the metastatic potential of propranolol-treated metastatic cells. For stage II breast cancer patients, perioperative β-blockade was associated with decreased cancer recurrence using Cox regression analysis (hazard's ratio =0.51; 95% CI: 0.23-0.97; p=0.041). Triple-negative (TN) brain-metastatic cells were found to have increased β2-adrenergic receptor mRNA and protein expression relative to TN primary cells. In response to β2-adrenergic receptor activation, TN brain-metastatic cells also exhibited increased cell proliferation and migration relative to the control. These effects were abrogated by propranolol. Propranolol decreased β2-adrenergic receptor-activated invasion. In vivo, propranolol treatment of TN brain-metastatic cells decreased establishment of brain metastases. Our results suggest that stress and corresponding β2-activation may promote the establishment of brain metastases of TN breast cancer cells. In addition, our data suggest a benefit to perioperative β-blockade during surgery-induced stress with respect to breast cancer recurrence and metastases.

Inhibition of β2-adrenergic receptor reduces triple-negative breast cancer brain metastases: The potential benefit of perioperative β-blockade

PubMed Central

CHOY, CECILIA; RAYTIS, JOHN L.; SMITH, DAVID D.; DUENAS, MATTHEW; NEMAN, JOSH; JANDIAL, RAHUL; LEW, MICHAEL W.

2016-01-01

In response to recent studies, we investigated an association between perioperative β-blockade and breast cancer metastases. First, a retrospective study examining perioperative β-blocker use and cancer recurrence and metastases was conducted on 1,029 patients who underwent breast cancer surgery at the City of Hope Cancer Center between 2000 and 2010. We followed the clinical study and examined proliferation, migration, and invasion in vitro of primary and brain-metastatic breast cancer cells in response to β2-activation and inhibition. We also investigated in vivo the metastatic potential of propranolol-treated metastatic cells. For stage II breast cancer patients, perioperative β-blockade was associated with decreased cancer recurrence using Cox regression analysis (hazard's ratio =0.51; 95% CI: 0.23–0.97; p=0.041). Triple-negative (TN) brain-metastatic cells were found to have increased β2-adrenergic receptor mRNA and protein expression relative to TN primary cells. In response to β2-adrenergic receptor activation, TN brain-metastatic cells also exhibited increased cell proliferation and migration relative to the control. These effects were abrogated by propranolol. Propranolol decreased β2-adrenergic receptor-activated invasion. In vivo, propranolol treatment of TN brain-metastatic cells decreased establishment of brain metastases. Our results suggest that stress and corresponding β2-activation may promote the establishment of brain metastases of TN breast cancer cells. In addition, our data suggest a benefit to perioperative β-blockade during surgery-induced stress with respect to breast cancer recurrence and metastases. PMID:27035124

Microglia Activate Migration of Glioma Cells through a Pyk2 Intracellular Pathway

PubMed Central

Rolón-Reyes, Kimberleve; Kucheryavykh, Yuriy V.; Cubano, Luis A.; Inyushin, Mikhail; Skatchkov, Serguei N.; Eaton, Misty J.; Harrison, Jeffrey K.; Kucheryavykh, Lilia Y.

2015-01-01

Glioblastoma is one of the most aggressive and fatal brain cancers due to the highly invasive nature of glioma cells. Microglia infiltrate most glioma tumors and, therefore, make up an important component of the glioma microenvironment. In the tumor environment, microglia release factors that lead to the degradation of the extracellular matrix and stimulate signaling pathways to promote glioma cell invasion. In the present study, we demonstrated that microglia can promote glioma migration through a mechanism independent of extracellular matrix degradation. Using western blot analysis, we found upregulation of proline rich tyrosine kinase 2 (Pyk2) protein phosphorylated at Tyr579/580 in glioma cells treated with microglia conditioned medium. This upregulation occurred in rodent C6 and GL261 as well as in human glioma cell lines with varying levels of invasiveness (U-87MG, A172, and HS683). siRNA knock-down of Pyk2 protein and pharmacological blockade by the Pyk2/focal-adhesion kinase (FAK) inhibitor PF-562,271 reversed the stimulatory effect of microglia on glioma migration in all cell lines. A lower concentration of PF-562,271 that selectively inhibits FAK, but not Pyk2, did not have any effect on glioma cell migration. Moreover, with the use of the CD11b-HSVTK microglia ablation mouse model we demonstrated that elimination of microglia in the implanted tumors (GL261 glioma cells were used for brain implantation) by the local in-tumor administration of Ganciclovir, significantly reduced the phosphorylation of Pyk2 at Tyr579/580 in implanted tumor cells. Taken together, these data indicate that microglial cells activate glioma cell migration/dispersal through the pro-migratory Pyk2 signaling pathway in glioma cells. PMID:26098895

MicroRNA-145 is downregulated in glial tumors and regulates glioma cell migration by targeting connective tissue growth factor.

PubMed

Lee, Hae Kyung; Bier, Ariel; Cazacu, Simona; Finniss, Susan; Xiang, Cunli; Twito, Hodaya; Poisson, Laila M; Mikkelsen, Tom; Slavin, Shimon; Jacoby, Elad; Yalon, Michal; Toren, Amos; Rempel, Sandra A; Brodie, Chaya

2013-01-01

Glioblastomas (GBM), the most common and aggressive type of malignant glioma, are characterized by increased invasion into the surrounding brain tissues. Despite intensive therapeutic strategies, the median survival of GBM patients has remained dismal over the last decades. In this study we examined the expression of miR-145 in glial tumors and its function in glioma cells. Using TCGA analysis and real-time PCR we found that the expression of miR-145/143 cluster was downregulated in astrocytic tumors compared to normal brain specimens and in glioma cells and glioma stem cells (GSCs) compared to normal astrocytes and neural stem cells. Moreover, the low expression of both miR-145 and miR-143 in GBM was correlated with poor patient prognosis. Transfection of glioma cells with miR-145 mimic or transduction with a lentivirus vector expressing pre-miR 145 significantly decreased the migration and invasion of glioma cells. We identified connective tissue growth factor (CTGF) as a novel target of miR-145 in glioma cells; transfection of the cells with this miRNA decreased the expression of CTGF as determined by Western blot analysis and the expression of its 3'-UTR fused to luciferase. Overexpression of a CTGF plasmid lacking the 3'-UTR and administration of recombinant CTGF protein abrogated the inhibitory effect of miR-145 on glioma cell migration. Similarly, we found that silencing of CTGF decreased the migration of glioma cells. CTGF silencing also decreased the expression of SPARC, phospho-FAK and FAK and overexpression of SPARC abrogated the inhibitory effect of CTGF silencing on cell migration. These results demonstrate that miR-145 is downregulated in glial tumors and its low expression in GBM predicts poor patient prognosis. In addition miR-145 regulates glioma cell migration by targeting CTGF which downregulates SPARC expression. Therefore, miR-145 is an attractive therapeutic target for anti-invasive treatment of astrocytic tumors.

MACF1 regulates the migration of pyramidal neurons via microtubule dynamics and GSK-3 signaling

PubMed Central

Ka, Minhan; Jung, Eui-Man; Mueller, Ulrich; Kim, Woo-Yang

2014-01-01

Neuronal migration and subsequent differentiation play critical roles for establishing functional neural circuitry in the developing brain. However, the molecular mechanisms that regulate these processes are poorly understood. Here, we show that microtubule actin crosslinking factor 1 (MACF1) determines neuronal positioning by regulating microtubule dynamics and mediating GSK-3 signaling during brain development. First, using MACF1 floxed allele mice and in utero gene manipulation, we find that MACF1 deletion suppresses migration of cortical pyramidal neurons and results in aberrant neuronal positioning in the developing brain. The cell autonomous deficit in migration is associated with abnormal dynamics of leading processes and centrosomes. Furthermore, microtubule stability is severely damaged in neurons lacking MACF1, resulting in abnormal microtubule dynamics. Finally, MACF1 interacts with and mediates GSK-3 signaling in developing neurons. Our findings establish a cellular mechanism underlying neuronal migration and provide insights into the regulation of cytoskeleton dynamics in developing neurons. PMID:25224226

MACF1 regulates the migration of pyramidal neurons via microtubule dynamics and GSK-3 signaling.

PubMed

Ka, Minhan; Jung, Eui-Man; Mueller, Ulrich; Kim, Woo-Yang

2014-11-01

Neuronal migration and subsequent differentiation play critical roles for establishing functional neural circuitry in the developing brain. However, the molecular mechanisms that regulate these processes are poorly understood. Here, we show that microtubule actin crosslinking factor 1 (MACF1) determines neuronal positioning by regulating microtubule dynamics and mediating GSK-3 signaling during brain development. First, using MACF1 floxed allele mice and in utero gene manipulation, we find that MACF1 deletion suppresses migration of cortical pyramidal neurons and results in aberrant neuronal positioning in the developing brain. The cell autonomous deficit in migration is associated with abnormal dynamics of leading processes and centrosomes. Furthermore, microtubule stability is severely damaged in neurons lacking MACF1, resulting in abnormal microtubule dynamics. Finally, MACF1 interacts with and mediates GSK-3 signaling in developing neurons. Our findings establish a cellular mechanism underlying neuronal migration and provide insights into the regulation of cytoskeleton dynamics in developing neurons. Copyright © 2014 Elsevier Inc. All rights reserved.

Analysis of Histone Deacetylase-Dependent Effects on Cell Migration Using the Stripe Assay.

PubMed

Mertsch, Sonja; Thanos, Solon

2017-01-01

For normal embryonic development/morphogenesis, cell migration and homing are well-orchestrated and important events requiring specific cellular mechanisms. In diseases such as cancer deregulated cell migration represents a major problem. Therefore, numerous efforts are under way to understand the molecular mechanisms of tumor cell migration and to generate more efficient tumor therapies. Cell migration assays are one of the most commonly used functional assays. The wound-healing assay or the Boyden chamber assay are variations of these assays. Nearly all of them are two-dimensional assays and the cells can only migrate on one substrate at a time. This is in contrast to the in vivo situation where the cells are faced simultaneously with different surfaces and interact with different cell types. To approach this in vivo situation we used a modified version of the stripe assay designed by Bonhoeffer and colleagues to examine mechanisms of axonal guidance. The design of this assay allows cells to decide between two different substrates offered at the same time. Utilizing alternating neuronal substrates for migration analyses we can partially mimic the complex in vivo situation for brain tumor cells. Here we describe the detailed protocol to perform a modified version of the stripe assay in order to observe substrate-dependent migration effects in vitro, to analyze the effect of Rho-dependent kinases (ROCKS), of histone deacetylases (HDACs) and of other molecules on glioma cells.

Guiding intracortical brain tumour cells to an extracortical cytotoxic hydrogel using aligned polymeric nanofibres

NASA Astrophysics Data System (ADS)

Jain, Anjana; Betancur, Martha; Patel, Gaurangkumar D.; Valmikinathan, Chandra M.; Mukhatyar, Vivek J.; Vakharia, Ajit; Pai, S. Balakrishna; Brahma, Barunashish; MacDonald, Tobey J.; Bellamkonda, Ravi V.

2014-03-01

Glioblastoma multiforme is an aggressive, invasive brain tumour with a poor survival rate. Available treatments are ineffective and some tumours remain inoperable because of their size or location. The tumours are known to invade and migrate along white matter tracts and blood vessels. Here, we exploit this characteristic of glioblastoma multiforme by engineering aligned polycaprolactone (PCL)-based nanofibres for tumour cells to invade and, hence, guide cells away from the primary tumour site to an extracortical location. This extracortial sink is a cyclopamine drug-conjugated, collagen-based hydrogel. When aligned PCL-nanofibre films in a PCL/polyurethane carrier conduit were inserted in the vicinity of an intracortical human U87MG glioblastoma xenograft, a significant number of human glioblastoma cells migrated along the aligned nanofibre films and underwent apoptosis in the extracortical hydrogel. Tumour volume in the brain was significantly lower following insertion of aligned nanofibre implants compared with the application of smooth fibres or no implants.

Correlative STED and Atomic Force Microscopy on Live Astrocytes Reveals Plasticity of Cytoskeletal Structure and Membrane Physical Properties during Polarized Migration

PubMed Central

Curry, Nathan; Ghézali, Grégory; Kaminski Schierle, Gabriele S.; Rouach, Nathalie; Kaminski, Clemens F.

2017-01-01

The plasticity of the cytoskeleton architecture and membrane properties is important for the establishment of cell polarity, adhesion and migration. Here, we present a method which combines stimulated emission depletion (STED) super-resolution imaging and atomic force microscopy (AFM) to correlate cytoskeletal structural information with membrane physical properties in live astrocytes. Using STED compatible dyes for live cell imaging of the cytoskeleton, and simultaneously mapping the cell surface topology with AFM, we obtain unprecedented detail of highly organized networks of actin and microtubules in astrocytes. Combining mechanical data from AFM with optical imaging of actin and tubulin further reveals links between cytoskeleton organization and membrane properties. Using this methodology we illustrate that scratch-induced migration induces cytoskeleton remodeling. The latter is caused by a polarization of actin and microtubule elements within astroglial cell processes, which correlates strongly with changes in cell stiffness. The method opens new avenues for the dynamic probing of the membrane structural and functional plasticity of living brain cells. It is a powerful tool for providing new insights into mechanisms of cell structural remodeling during physiological or pathological processes, such as brain development or tumorigenesis. PMID:28469559

In vivo Postnatal Electroporation and Time-lapse Imaging of Neuroblast Migration in Mouse Acute Brain Slices

PubMed Central

Oudin, Madeleine Julie; Doherty, Patrick; Lalli, Giovanna

2013-01-01

The subventricular zone (SVZ) is one of the main neurogenic niches in the postnatal brain. Here, neural progenitors proliferate and give rise to neuroblasts able to move along the rostral migratory stream (RMS) towards the olfactory bulb (OB). This long-distance migration is required for the subsequent maturation of newborn neurons in the OB, but the molecular mechanisms regulating this process are still unclear. Investigating the signaling pathways controlling neuroblast motility may not only help understand a fundamental step in neurogenesis, but also have therapeutic regenerative potential, given the ability of these neuroblasts to target brain sites affected by injury, stroke, or degeneration. In this manuscript we describe a detailed protocol for in vivo postnatal electroporation and subsequent time-lapse imaging of neuroblast migration in the mouse RMS. Postnatal electroporation can efficiently transfect SVZ progenitor cells, which in turn generate neuroblasts migrating along the RMS. Using confocal spinning disk time-lapse microscopy on acute brain slice cultures, neuroblast migration can be monitored in an environment closely resembling the in vivo condition. Moreover, neuroblast motility can be tracked and quantitatively analyzed. As an example, we describe how to use in vivo postnatal electroporation of a GFP-expressing plasmid to label and visualize neuroblasts migrating along the RMS. Electroporation of shRNA or CRE recombinase-expressing plasmids in conditional knockout mice employing the LoxP system can also be used to target genes of interest. Pharmacological manipulation of acute brain slice cultures can be performed to investigate the role of different signaling molecules in neuroblast migration. By coupling in vivo electroporation with time-lapse imaging, we hope to understand the molecular mechanisms controlling neuroblast motility and contribute to the development of novel approaches to promote brain repair. PMID:24326479

Engraftment of Human Mesenchymal Stem Cells in a Rat Photothrombotic Cerebral Infarction Model : Comparison of Intra-Arterial and Intravenous Infusion Using MRI and Histological Analysis

PubMed Central

Byun, Jun Soo; Kim, Jae Kyun; Jung, Jisung; Ha, Bon Chul; Park, Serah

2013-01-01

Objective This study aimed to evaluate the hypotheses that administration routes [intra-arterial (IA) vs. intravenous (IV)] affect the early stage migration of transplanted human bone marrow-derived mesenchymal stem cells (hBM-MSCs) in acute brain infarction. Methods Male Sprague-Dawley rats (n=40) were subjected to photothrombotic infarction. Three days after photothrombotic infarction, rats were randomly allocated to one of four experimental groups [IA group : n=12, IV group : n=12, superparamagnetic iron oxide (SPIO) group : n=8, control group : n=8]. All groups were subdivided into 1, 6, 24, and 48 hours groups according to time point of sacrifice. Magnetic resonance imaging (MRI) consisting of T2 weighted image (T2WI), T2* weighted image (T2*WI), susceptibility weighted image (SWI), and diffusion weighted image of rat brain were obtained prior to and at 1, 6, 24, and 48 hours post-implantation. After final MRI, rats were sacrificed and grafted cells were analyzed in brain and lung specimen using Prussian blue and immunohistochemical staining. Results Grafted cells appeared as dark signal intensity regions at the peri-lesional zone. In IA group, dark signals in peri-lesional zone were more prominent compared with IV group. SWI showed largest dark signal followed by T2*WI and T2WI in both IA and IV groups. On Prussian blue staining, IA administration showed substantially increased migration and a large number of transplanted hBM-MSCs in the target brain than IV administration. The Prussian blue-positive cells were not detected in SPIO and control groups. Conclusion In a rat photothrombotic model of ischemic stroke, selective IA administration of human mesenchymal stem cells is more effective than IV administration. MRI and histological analyses revealed the time course of cell migration, and the numbers and distribution of hBM-MSCs delivered into the brain. PMID:24527188

Morphoregulatory functions of the RNA-binding motif protein 3 in cell spreading, polarity and migration.

PubMed

Pilotte, J; Kiosses, W; Chan, S W; Makarenkova, H P; Dupont-Versteegden, E; Vanderklish, P W

2018-05-09

RNA-binding proteins are emerging as key regulators of transitions in cell morphology. The RNA-binding motif protein 3 (RBM3) is a cold-inducible RNA-binding protein with broadly relevant roles in cellular protection, and putative functions in cancer and development. Several findings suggest that RBM3 has morphoregulatory functions germane to its roles in these contexts. For example, RBM3 helps maintain the morphological integrity of cell protrusions during cell stress and disease. Moreover, it is highly expressed in migrating neurons of the developing brain and in cancer invadopodia, suggesting roles in migration. We here show that RBM3 regulates cell polarity, spreading and migration. RBM3 was present in spreading initiation centers, filopodia and blebs that formed during cell spreading in cell lines and primary myoblasts. Reducing RBM3 triggered exaggerated spreading, increased RhoA expression, and a loss of polarity that was rescued by Rho kinase inhibition and overexpression of CRMP2. High RBM3 expression enhanced the motility of cells migrating by a mesenchymal mode involving extension of long protrusions, whereas RBM3 knockdown slowed migration, greatly reducing the ability of cells to extend protrusions and impairing multiple processes that require directional migration. These data establish novel functions of RBM3 of potential significance to tissue repair, metastasis and development.

Therapeutics with SPION-labeled stem cells for the main diseases related to brain aging: a systematic review.

PubMed

Alvarim, Larissa T; Nucci, Leopoldo P; Mamani, Javier B; Marti, Luciana C; Aguiar, Marina F; Silva, Helio R; Silva, Gisele S; Nucci-da-Silva, Mariana P; DelBel, Elaine A; Gamarra, Lionel F

2014-01-01

The increase in clinical trials assessing the efficacy of cell therapy for structural and functional regeneration of the nervous system in diseases related to the aging brain is well known. However, the results are inconclusive as to the best cell type to be used or the best methodology for the homing of these stem cells. This systematic review analyzed published data on SPION (superparamagnetic iron oxide nanoparticle)-labeled stem cells as a therapy for brain diseases, such as ischemic stroke, Parkinson's disease, amyotrophic lateral sclerosis, and dementia. This review highlights the therapeutic role of stem cells in reversing the aging process and the pathophysiology of brain aging, as well as emphasizing nanotechnology as an important tool to monitor stem cell migration in affected regions of the brain.

Involvement of PUMA in pericyte migration induced by methamphetamine.

PubMed

Zhang, Yanhong; Zhang, Yuan; Bai, Ying; Chao, Jie; Hu, Gang; Chen, Xufeng; Yao, Honghong

2017-07-01

Mounting evidence indicates that methamphetamine causes blood-brain barrier damage, with emphasis on endothelial cells. The role of pericytes in methamphetamine-induced BBB damage remains unknown. Our study demonstrated that methamphetamine increased the migration of pericytes from the endothelial basement membrane. However, the detailed mechanisms underlying this process remain poorly understood. Thus, we examined the molecular mechanisms involved in methamphetamine-induced pericyte migration. The results showed that exposure of C3H/10T1/2 cells and HBVPs to methamphetamine increased PUMA expression via activation of the sigma-1 receptor, MAPK and Akt/PI3K pathways. Moreover, methamphetamine treatment resulted in the increased migration of C3H/10T1/2 cells and HBVPs. Knockdown of PUMA in pericytes transduced with PUMA siRNA attenuated the methamphetamine-induced increase in cell migration through attenuation of integrin and tyrosine kinase mechanisms, implicating a role of PUMA in the migration of C3H/10T1/2 cells and HBVPs. This study has demonstrated that methamphetamine-mediated pericytes migration involves PUMA up-regulation. Thus, targeted studies of PUMA could provide insights to facilitate the development of a potential therapeutic approach for alleviation of methamphetamine-induced pericyte migration. Copyright © 2017. Published by Elsevier Inc.

Migratory capabilities of human umbilical cord blood-derived neural stem cells (HUCB-NSC) in vitro.

PubMed

Janowski, Miroslaw; Lukomska, Barbara; Domanska-Janik, Krystyna

2011-01-01

Many types of neural progenitors from various sources have been evaluated for therapy of CNS disorders. Prerequisite for success in cell therapy is the ability for transplanted cells to reach appropriate target such as stroke lesion. We have established neural stem cell line from human umbilical cord blood neural stem (HUCB-NSC). In the present study we evaluated migratory capabilities of cells (HUCB-NSC) and the presence of various migration-related receptors. Immunocytochemical analysis revealed abundant expression of CXCR4, PDGFR-alpha, PDGFR-beta, c-Met, VEGFR, IGF-1R and PSA-NCAM receptors in non-adherent population of HUCB-NSC cultured in serum free (SF) conditions (SF cells). Biological activity of selected receptors was confirmed by HUCB-NSC in vitro migration towards SDF-1 and IGF-1 ligands. Additionally, rat brain-derived homogenates have been assessed for their chemoattractive activity of HUCB-NSC. Our experiments unveiled that brain tissue was more attracted for HUCB-NSC than single ligands with higher potency of injured than intact brain. Moreover, adherent HUCB-NSC cultured in low serum (LS) conditions (LS cells) were employed to investigate an impact of different extracellular matrix (ECM) proteins on cell motility. It turned out that laminin provided most permissive microenvironment for cell migration, followed by fibronectin and gelatin. Unexpected nuclear localization of CXCR4 in SF cells prompted us to characterize intracellular pattern of this expression in relation to developmental stage of cells cultured in different conditions. Continuous culture of LS cells revealed cytoplasmatic pattern of CXCR4 expression while HUCB-NSC cultured in high serum conditions (HS cells) resulted in gradual translocation of CXCR4 from nucleus to cytoplasm and then to arising processes. Terminal differentiation of HUCB-NSC was followed by CXCR4 expression decline.

Tumor cell migration screen identifies SRPK1 as breast cancer metastasis determinant.

PubMed

van Roosmalen, Wies; Le Dévédec, Sylvia E; Golani, Ofra; Smid, Marcel; Pulyakhina, Irina; Timmermans, Annemieke M; Look, Maxime P; Zi, Di; Pont, Chantal; de Graauw, Marjo; Naffar-Abu-Amara, Suha; Kirsanova, Catherine; Rustici, Gabriella; Hoen, Peter A C 't; Martens, John W M; Foekens, John A; Geiger, Benjamin; van de Water, Bob

2015-04-01

Tumor cell migration is a key process for cancer cell dissemination and metastasis that is controlled by signal-mediated cytoskeletal and cell matrix adhesion remodeling. Using a phagokinetic track assay with migratory H1299 cells, we performed an siRNA screen of almost 1,500 genes encoding kinases/phosphatases and adhesome- and migration-related proteins to identify genes that affect tumor cell migration speed and persistence. Thirty candidate genes that altered cell migration were validated in live tumor cell migration assays. Eight were associated with metastasis-free survival in breast cancer patients, with integrin β3-binding protein (ITGB3BP), MAP3K8, NIMA-related kinase (NEK2), and SHC-transforming protein 1 (SHC1) being the most predictive. Examination of genes that modulate migration indicated that SRPK1, encoding the splicing factor kinase SRSF protein kinase 1, is relevant to breast cancer outcomes, as it was highly expressed in basal breast cancer. Furthermore, high SRPK1 expression correlated with poor breast cancer disease outcome and preferential metastasis to the lungs and brain. In 2 independent murine models of breast tumor metastasis, stable shRNA-based SRPK1 knockdown suppressed metastasis to distant organs, including lung, liver, and spleen, and inhibited focal adhesion reorganization. Our study provides comprehensive information on the molecular determinants of tumor cell migration and suggests that SRPK1 has potential as a drug target for limiting breast cancer metastasis.

Continuous Time Random Walk and Migration-Proliferation Dichotomy of Brain Cancer

NASA Astrophysics Data System (ADS)

Iomin, A.

A theory of fractional kinetics of glial cancer cells is presented. A role of the migration-proliferation dichotomy in the fractional cancer cell dynamics in the outer-invasive zone is discussed and explained in the framework of a continuous time random walk. The main suggested model is based on a construction of a 3D comb model, where the migration-proliferation dichotomy becomes naturally apparent and the outer-invasive zone of glioma cancer is considered as a fractal composite with a fractal dimension Dfr < 3.

EphrinB3 restricts endogenous neural stem cell migration after traumatic brain injury.

PubMed

Dixon, Kirsty J; Mier, Jose; Gajavelli, Shyam; Turbic, Alisa; Bullock, Ross; Turnley, Ann M; Liebl, Daniel J

2016-11-01

Traumatic brain injury (TBI) leads to a series of pathological events that can have profound influences on motor, sensory and cognitive functions. Conversely, TBI can also stimulate neural stem/progenitor cell proliferation leading to increased numbers of neuroblasts migrating outside their restrictive neurogenic zone to areas of damage in support of tissue integrity. Unfortunately, the factors that regulate migration are poorly understood. Here, we examine whether ephrinB3 functions to restrict neuroblasts from migrating outside the subventricular zone (SVZ) and rostral migratory stream (RMS). We have previously shown that ephrinB3 is expressed in tissues surrounding these regions, including the overlying corpus callosum (CC), and is reduced after controlled cortical impact (CCI) injury. Our current study takes advantage of ephrinB3 knockout mice to examine the influences of ephrinB3 on neuroblast migration into CC and cortex tissues after CCI injury. Both injury and/or ephrinB3 deficiency led to increased neuroblast numbers and enhanced migration outside the SVZ/RMS zones. Application of soluble ephrinB3-Fc molecules reduced neuroblast migration into the CC after injury and limited neuroblast chain migration in cultured SVZ explants. Our findings suggest that ephrinB3 expression in tissues surrounding neurogenic regions functions to restrict neuroblast migration outside the RMS by limiting chain migration. Copyright © 2016 Michael Boutros, German Cancer Research Center, Heidelberg, Germany. Published by Elsevier B.V. All rights reserved.

Nuclear receptor TLX regulates cell cycle progression in neural stem cells of the developing brain.

PubMed

Li, Wenwu; Sun, Guoqiang; Yang, Su; Qu, Qiuhao; Nakashima, Kinichi; Shi, Yanhong

2008-01-01

TLX is an orphan nuclear receptor that is expressed exclusively in vertebrate forebrains. Although TLX is known to be expressed in embryonic brains, the mechanism by which it influences neural development remains largely unknown. We show here that TLX is expressed specifically in periventricular neural stem cells in embryonic brains. Significant thinning of neocortex was observed in embryonic d 14.5 TLX-null brains with reduced nestin labeling and decreased cell proliferation in the germinal zone. Cell cycle analysis revealed both prolonged cell cycles and increased cell cycle exit in TLX-null embryonic brains. Increased expression of a cyclin-dependent kinase inhibitor p21 and decreased expression of cyclin D1 provide a molecular basis for the deficiency of cell cycle progression in embryonic brains of TLX-null mice. Furthermore, transient knockdown of TLX by in utero electroporation led to precocious cell cycle exit and differentiation of neural stem cells followed by outward migration. Together these results indicate that TLX plays an important role in neural development by regulating cell cycle progression and exit of neural stem cells in the developing brain.

Nuclear Receptor TLX Regulates Cell Cycle Progression in Neural Stem Cells of the Developing Brain

PubMed Central

Li, Wenwu; Sun, Guoqiang; Yang, Su; Qu, Qiuhao; Nakashima, Kinichi; Shi, Yanhong

2008-01-01

TLX is an orphan nuclear receptor that is expressed exclusively in vertebrate forebrains. Although TLX is known to be expressed in embryonic brains, the mechanism by which it influences neural development remains largely unknown. We show here that TLX is expressed specifically in periventricular neural stem cells in embryonic brains. Significant thinning of neocortex was observed in embryonic d 14.5 TLX-null brains with reduced nestin labeling and decreased cell proliferation in the germinal zone. Cell cycle analysis revealed both prolonged cell cycles and increased cell cycle exit in TLX-null embryonic brains. Increased expression of a cyclin-dependent kinase inhibitor p21 and decreased expression of cyclin D1 provide a molecular basis for the deficiency of cell cycle progression in embryonic brains of TLX-null mice. Furthermore, transient knockdown of TLX by in utero electroporation led to precocious cell cycle exit and differentiation of neural stem cells followed by outward migration. Together these results indicate that TLX plays an important role in neural development by regulating cell cycle progression and exit of neural stem cells in the developing brain. PMID:17901127

Microglial Dynamics During Human Brain Development

PubMed Central

Menassa, David A.; Gomez-Nicola, Diego

2018-01-01

Microglial cells are thought to colonize the human cerebrum between the 4th and 24th gestational weeks. Rodent studies have demonstrated that these cells originate from yolk sac progenitors though it is not clear whether this directly pertains to human development. Our understanding of microglial cell dynamics in the developing human brain comes mostly from postmortem studies demonstrating that the beginning of microglial colonization precedes the appearance of the vasculature, the blood–brain barrier, astrogliogenesis, oligodendrogenesis, neurogenesis, migration, and myelination of the various brain areas. Furthermore, migrating microglial populations cluster by morphology and express differential markers within the developing brain and according to developmental age. With the advent of novel technologies such as RNA-sequencing in fresh human tissue, we are beginning to identify the molecular features of the adult microglial signature. However, this is may not extend to the much more dynamic and rapidly changing antenatal microglial population and this is further complicated by the scarcity of tissue resources. In this brief review, we first describe the various historic schools of thought that had debated the origin of microglial cells while examining the evidence supporting the various theories. We then proceed to examine the evidence we have accumulated on microglial dynamics in the developing human brain, present evidence from rodent studies on the functional role of microglia during development and finally identify limitations for the used approaches in human studies and highlight under investigated questions. PMID:29881376

Layered hydrogels accelerate iPSC-derived neuronal maturation and reveal migration defects caused by MeCP2 dysfunction

NASA Astrophysics Data System (ADS)

Zhang, Zhen-Ning; Freitas, Beatriz C.; Qian, Hao; Lux, Jacques; Acab, Allan; Trujillo, Cleber A.; Herai, Roberto H.; Nguyen Huu, Viet Anh; Wen, Jessica H.; Joshi-Barr, Shivanjali; Karpiak, Jerome V.; Engler, Adam J.; Fu, Xiang-Dong; Muotri, Alysson R.; Almutairi, Adah

2016-03-01

Probing a wide range of cellular phenotypes in neurodevelopmental disorders using patient-derived neural progenitor cells (NPCs) can be facilitated by 3D assays, as 2D systems cannot entirely recapitulate the arrangement of cells in the brain. Here, we developed a previously unidentified 3D migration and differentiation assay in layered hydrogels to examine how these processes are affected in neurodevelopmental disorders, such as Rett syndrome. Our soft 3D system mimics the brain environment and accelerates maturation of neurons from human induced pluripotent stem cell (iPSC)-derived NPCs, yielding electrophysiologically active neurons within just 3 wk. Using this platform, we revealed a genotype-specific effect of methyl-CpG-binding protein-2 (MeCP2) dysfunction on iPSC-derived neuronal migration and maturation (reduced neurite outgrowth and fewer synapses) in 3D layered hydrogels. Thus, this 3D system expands the range of neural phenotypes that can be studied in vitro to include those influenced by physical and mechanical stimuli or requiring specific arrangements of multiple cell types.

Characterization of multiciliated ependymal cells that emerge in the neurogenic niche of the aged zebrafish brain.

PubMed

Ogino, Takashi; Sawada, Masato; Takase, Hiroshi; Nakai, Chiemi; Herranz-Pérez, Vicente; Cebrián-Silla, Arantxa; Kaneko, Naoko; García-Verdugo, José Manuel; Sawamoto, Kazunobu

2016-10-15

In mammals, ventricular walls of the developing brain maintain a neurogenic niche, in which radial glial cells act as neural stem cells (NSCs) and generate new neurons in the embryo. In the adult brain, the neurogenic niche is maintained in the ventricular-subventricular zone (V-SVZ) of the lateral wall of lateral ventricles and the hippocampal dentate gyrus. In the neonatal V-SVZ, radial glial cells transform into astrocytic postnatal NSCs and multiciliated ependymal cells. On the other hand, in zebrafish, radial glial cells continue to cover the surface of the adult telencephalic ventricle and maintain a higher neurogenic potential in the adult brain. However, the cell composition of the neurogenic niche of the aged zebrafish brain has not been investigated. Here we show that multiciliated ependymal cells emerge in the neurogenic niche of the aged zebrafish telencephalon. These multiciliated cells appear predominantly in the dorsal part of the ventral telencephalic ventricular zone, which also contains clusters of migrating new neurons. Scanning electron microscopy and live imaging analyses indicated that these multiple cilia beat coordinately and generate constant fluid flow within the ventral telencephalic ventricle. Analysis of the cell composition by transmission electron microscopy revealed that the neurogenic niche in the aged zebrafish contains different types of cells, with ultrastructures similar to those of ependymal cells, transit-amplifying cells, and migrating new neurons in postnatal mice. These data suggest that the transformation capacity of radial glial cells is conserved but that its timing is different between fish and mice. J. Comp. Neurol. 524:2982-2992, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Linking the Primary Cilium to Cell Migration in Tissue Repair and Brain Development

PubMed Central

Veland, Iben Rønn; Lindbæk, Louise; Christensen, Søren Tvorup

2014-01-01

Primary cilia are unique sensory organelles that coordinate cellular signaling networks in vertebrates. Inevitably, defects in the formation or function of primary cilia lead to imbalanced regulation of cellular processes that causes multisystemic disorders and diseases, commonly known as ciliopathies. Mounting evidence has demonstrated that primary cilia coordinate multiple activities that are required for cell migration, which, when they are aberrantly regulated, lead to defects in organogenesis and tissue repair, as well as metastasis of tumors. Here, we present an overview on how primary cilia may contribute to the regulation of the cellular signaling pathways that control cyclic processes in directional cell migration. PMID:26955067

Stem cell-based therapies for tumors in the brain: are we there yet?

PubMed Central

Shah, Khalid

2016-01-01

Advances in understanding adult stem cell biology have facilitated the development of novel cell-based therapies for cancer. Recent developments in conventional therapies (eg, tumor resection techniques, chemotherapy strategies, and radiation therapy) for treating both metastatic and primary tumors in the brain, particularly glioblastoma have not resulted in a marked increase in patient survival. Preclinical studies have shown that multiple stem cell types exhibit inherent tropism and migrate to the sites of malignancy. Recent studies have validated the feasibility potential of using engineered stem cells as therapeutic agents to target and eliminate malignant tumor cells in the brain. This review will discuss the recent progress in the therapeutic potential of stem cells for tumors in the brain and also provide perspectives for future preclinical studies and clinical translation. PMID:27282399

Live Imaging of Glial Cell Migration in the Drosophila Eye Imaginal Disc

PubMed Central

Cafferty, Patrick; Xie, Xiaojun; Browne, Kristen; Auld, Vanessa J.

2009-01-01

Glial cells of both vertebrate and invertebrate organisms must migrate to final target regions in order to ensheath and support associated neurons. While recent progress has been made to describe the live migration of glial cells in the developing pupal wing (1), studies of Drosophila glial cell migration have typically involved the examination of fixed tissue. Live microscopic analysis of motile cells offers the ability to examine cellular behavior throughout the migratory process, including determining the rate of and changes in direction of growth. Paired with use of genetic tools, live imaging can be used to determine more precise roles for specific genes in the process of development. Previous work by Silies et al. (2) has described the migration of glia originating from the optic stalk, a structure that connects the developing eye and brain, into the eye imaginal disc in fixed tissue. Here we outline a protocol for examining the live migration of glial cells into the Drosophila eye imaginal disc. We take advantage of a Drosophila line that expresses GFP in developing glia to follow glial cell progression in wild type and in mutant animals. PMID:19590493

Regulation of brain tumor dispersal by NKCC1 through a novel role in focal adhesion regulation.

PubMed

Garzon-Muvdi, Tomas; Schiapparelli, Paula; ap Rhys, Colette; Guerrero-Cazares, Hugo; Smith, Christopher; Kim, Deok-Ho; Kone, Lyonell; Farber, Harrison; Lee, Danielle Y; An, Steven S; Levchenko, Andre; Quiñones-Hinojosa, Alfredo

2012-01-01

Glioblastoma (GB) is a highly invasive and lethal brain tumor due to its universal recurrence. Although it has been suggested that the electroneutral Na(+)-K(+)-Cl(-) cotransporter 1 (NKCC1) can play a role in glioma cell migration, the precise mechanism by which this ion transporter contributes to GB aggressiveness remains poorly understood. Here, we focused on the role of NKCC1 in the invasion of human primary glioma cells in vitro and in vivo. NKCC1 expression levels were significantly higher in GB and anaplastic astrocytoma tissues than in grade II glioma and normal cortex. Pharmacological inhibition and shRNA-mediated knockdown of NKCC1 expression led to decreased cell migration and invasion in vitro and in vivo. Surprisingly, knockdown of NKCC1 in glioma cells resulted in the formation of significantly larger focal adhesions and cell traction forces that were approximately 40% lower than control cells. Epidermal growth factor (EGF), which promotes migration of glioma cells, increased the phosphorylation of NKCC1 through a PI3K-dependant mechanism. This finding is potentially related to WNK kinases. Taken together, our findings suggest that NKCC1 modulates migration of glioma cells by two distinct mechanisms: (1) through the regulation of focal adhesion dynamics and cell contractility and (2) through regulation of cell volume through ion transport. Due to the ubiquitous expression of NKCC1 in mammalian tissues, its regulation by WNK kinases may serve as new therapeutic targets for GB aggressiveness and can be exploited by other highly invasive neoplasms.

Modeled microgravity suppressed invasion and migration of human glioblastoma U87 cells through downregulating store-operated calcium entry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Zi-xuan; Rao, Wei; Wang, Huan

Glioblastoma is the most common brain tumor and is characterized with robust invasion and migration potential resulting in poor prognosis. Previous investigations have demonstrated that modeled microgravity (MMG) could decline the cell proliferation and attenuate the metastasis potential in several cell lines. In this study, we studied the effects of MMG on the invasion and migration potentials of glioblastoma in human glioblastoma U87 cells. We found that MMG stimulation significantly attenuated the invasion and migration potentials, decreased thapsigargin (TG) induced store-operated calcium entry (SOCE) and downregulated the expression of Orai1 in U87 cells. Inhibition of SOCE by 2-APB or stromalmore » interaction molecule 1 (STIM1) downregulation both mimicked the effects of MMG on the invasion and migration potentials in U87 cells. Furthermore, upregulation of Orai1 significantly weakened the effects of MMG on the invasion and migration potentials in U87 cells. Therefore, these findings indicated that MMG stimulation inhibited the invasion and migration potentials of U87 cells by downregulating the expression of Orai1 and sequentially decreasing the SOCE, suggesting that MMG might be a new potential therapeutic strategy in glioblastoma treatment in the future. - Highlights: • Modeled microgravity (MMG) suppressed migration and invasion in U87 cells. • MMG downregulated the SOCE and the expression of Orai1. • SOCE inhibition mimicked the effects of MMG on migration and invasion potentials. • Restoration of SOCE diminished the effects of MMG on migration and invasion.« less

Acid Sphingomyelinase-Derived Ceramide Regulates ICAM-1 Function during T Cell Transmigration across Brain Endothelial Cells.

PubMed

Lopes Pinheiro, Melissa A; Kroon, Jeffrey; Hoogenboezem, Mark; Geerts, Dirk; van Het Hof, Bert; van der Pol, Susanne M A; van Buul, Jaap D; de Vries, Helga E

2016-01-01

Multiple sclerosis (MS) is a chronic demyelinating disorder of the CNS characterized by immune cell infiltration across the brain vasculature into the brain, a process not yet fully understood. We previously demonstrated that the sphingolipid metabolism is altered in MS lesions. In particular, acid sphingomyelinase (ASM), a critical enzyme in the production of the bioactive lipid ceramide, is involved in the pathogenesis of MS; however, its role in the brain vasculature remains unknown. Transmigration of T lymphocytes is highly dependent on adhesion molecules in the vasculature such as intercellular adhesion molecule-1 (ICAM-1). In this article, we hypothesize that ASM controls T cell migration by regulating ICAM-1 function. To study the role of endothelial ASM in transmigration, we generated brain endothelial cells lacking ASM activity using a lentiviral shRNA approach. Interestingly, although ICAM-1 expression was increased in cells lacking ASM activity, we measured a significant decrease in T lymphocyte adhesion and consequently transmigration both in static and under flow conditions. As an underlying mechanism, we revealed that upon lack of endothelial ASM activity, the phosphorylation of ezrin was perturbed as well as the interaction between filamin and ICAM-1 upon ICAM-1 clustering. Functionally this resulted in reduced microvilli formation and impaired transendothelial migration of T cells. In conclusion, in this article, we show that ASM coordinates ICAM-1 function in brain endothelial cells by regulating its interaction with filamin and phosphorylation of ezrin. The understanding of these underlying mechanisms of T lymphocyte transmigration is of great value to develop new strategies against MS lesion formation. Copyright © 2015 by The American Association of Immunologists, Inc.

Brain-Derived Neurotrophic Factor Induces Cell Survival and the Migration of Murine Adult Hippocampal Precursor Cells During Differentiation In Vitro.

PubMed

Ortiz-López, Leonardo; Vega-Rivera, Nelly Maritza; Babu, Harish; Ramírez-Rodríguez, Gerardo Bernabé

2017-01-01

The generation of new neurons during adulthood involves local precursor cell migration and terminal differentiation in the dentate gyrus. These events are influenced by the hippocampal microenvironment. Brain-derived neurotrophic factor (BDNF) is relevant for hippocampal neuronal development and behavior. Interestingly, studies that have been performed in controlled in vitro systems that involve isolated precursor cells that were derived from the dentate gyrus (AHPCs) have shown that BDNF induces the activation of the TrkB receptor and, consequentially, might activate signaling pathways that favor survival and neuronal differentiation. Based on the fact that the cellular events of AHPCs that are induced by single factors can be studied in this controlled in vitro system, we investigated the ability of BDNF and the involvement of protein kinase C (PKC), as one of the TrkB-downstream activated signaling proteins, in the regulation of migration, here reflected by motility, of AHPCs. Precursor cells were cultured following a concentration-response curve (1-640 ng/ml) for 24 or 96 h. We found that BDNF favored cell survival without altering the viability under culture proliferative conditions of the AHPCs. Concomitantly, glial- and neuronal-differentiated precursor cells increased as a consequence of survival promoted by BDNF. Additionally, pharmacological approaches showed that BDNF (40 ng/ml)-induced migration of AHPCs was blocked with the compounds K252a and GF109203x, which prevent the activation of TrkB and PKC, respectively. The results indicate that in the in vitro migration of differentiated AHPCs it is involved the BDNF and TrkB cascade. Our results provide additional information about the mechanism by which BDNF impacts adult neurogenesis in the hippocampus.

Targeted Deletion of Sox10 by Wnt1-cre Defects Neuronal Migration and Projection in the Mouse Inner Ear

PubMed Central

Mao, YanYan; Reiprich, Simone; Wegner, Michael; Fritzsch, Bernd

2014-01-01

Sensory nerves of the brainstem are mostly composed of placode-derived neurons, neural crest-derived neurons and neural crest-derived Schwann cells. This mixed origin of cells has made it difficult to dissect interdependence for fiber guidance. Inner ear-derived neurons are known to connect to the brain after delayed loss of Schwann cells in ErbB2 mutants. However, the ErbB2 mutant related alterations in the ear and the brain compound interpretation of the data. We present here a new model to evaluate exclusively the effect of Schwann cell loss on inner ear innervation. Conditional deletion of the neural crest specific transcription factor, Sox10, using the rhombic lip/neural crest specific Wnt1-cre driver spares Sox10 expression in the ear. We confirm that neural crest-derived cells provide a stop signal for migrating spiral ganglion neurons. In the absence of Schwann cells, spiral ganglion neurons migrate into the center of the cochlea and even out of the ear toward the brain. Spiral ganglion neuron afferent processes reach the organ of Corti, but many afferent fibers bypass the organ of Corti to enter the lateral wall of the cochlea. In contrast to this peripheral disorganization, the central projection to cochlear nuclei is normal. Compared to ErbB2 mutants, conditional Sox10 mutants have limited cell death in spiral ganglion neurons, indicating that the absence of Schwann cells alone contributes little to the embryonic survival of neurons. These data suggest that neural crest-derived cells are dispensable for all central and some peripheral targeting of inner ear neurons. However, Schwann cells provide a stop signal for migratory spiral ganglion neurons and facilitate proper targeting of the organ of Corti by spiral ganglion afferents. PMID:24718611

Autologous adipose tissue-derived stromal cells for treatment of spinal cord injury.

PubMed

Kang, Soo-Kyung; Shin, Myung-Joo; Jung, Jin Sup; Kim, Yong Geun; Kim, Cheul-Hong

2006-08-01

Isolated rat adipose tissue-derived stromal cells (rATSCs) contain pluripotent cells that can be differentiated into a variety of cell lineages, including neural cells. Recent work has shown that ATSCs can make neurosphere-like clumps and differentiate into neuron-like cells expressing neuronal markers, but their therapeutic effect is unclear. Here we report that intravenous infusion of oligodendrocyte precursor cells (OPCs) derived from rATSC autograft cells sources improve motor function in rat models of spinal cord injury (SCI). After 4-5 weeks, transplanted rATSC-OPC cells survived and migrated into the injured region of SCI very efficiently (30-35%) and migrated cells were partially differentiated into neurons and oligodendrocyte. Also, we found some of the engrafted OPCs migrated and integrated in the kidney, brain, lung, and liver through the intravenous system. Behavioral analysis revealed the locomotor functions of OPC-autografted SCI rats were significantly restored. Efficient migration of intravenously engrafted rATSC-OPCs cells into SCI lesion suggests that SCI-induced chemotaxic factors facilitate migration of rATSC-OPCs. Here, we verified that engrafted rATSCs and SCI-induced chemotaxic factors indeed play an important role in proliferation, migration, and differentiation of endogeneous spinal cord-derived neural progenitor cells in the injured region. In transplantation paradigms, the interaction between engrafted rATSC-OPCs and endogeneous spinal cord-derived neuronal progenitor cells will be important in promoting healing through fate decisions, resulting in coordinated induction of cell migration and differentiation.

Desmethylanhydroicaritin isolated from Sophora flavescens, shows antitumor activities in U87MG cells via inhibiting the proliferation, migration and invasion.

PubMed

Kang, Chang-Won; Kim, Nan-Hee; Jung, Huyn Ah; Choi, Hyung-Wook; Kang, Min-Jae; Choi, Jae-Sue; Kim, Gun-Do

2016-04-01

This study is the first report of the antitumor activities of desmethylanhydroicaritin (DMAI) isolated from Sophora flavescens on U87MG cells. Human glioblastoma is one of the most aggressive malignant type of brain tumors and highly diffuses to around normal brain tissues. DMAI showed anti-proliferation effects on U87MG cells at the concentration of 30μM, however did not affect to HEK-293 cells. DMAI induced anti-proliferation effects via ERK/MAPK, PI3K/Akt/mTOR signal pathway and G2/M phase cell cycle arrest. DMAI led to morphological change and inhibition of filapodia formation through regulation of Rac 1 and Cdc 42. In addition, migration and invasion of U87MG cells were inhibited by DMAI via down-regulation of matrix metalloproteinase (MMP) -2 and MMP -9 expressions and activities. Our results suggest that DMAI has a potential as a therapeutic agent against glioblastoma cells. Copyright © 2016 Elsevier B.V. All rights reserved.

Delphinidin inhibits BDNF-induced migration and invasion in SKOV3 ovarian cancer cells.

PubMed

Lim, Won-Chul; Kim, Hyunhee; Kim, Young-Joo; Park, Seung-Ho; Song, Ji-Hye; Lee, Ki Heon; Lee, In Ho; Lee, Yoo-Kyung; So, Kyeong A; Choi, Kyung-Chul; Ko, Hyeonseok

2017-12-01

Brain-derived neurotrophic factor (BDNF), the TrkB ligand, is associated with aggressive malignant behavior, including migration and invasion, in tumor cells and a poor prognosis in patients with various types of cancer. Delphinidin is a diphenylpropane-based polyphenolic ring structure-harboring compound, which exhibits a wide range of pharmacological activities, anti-tumor, anti-oxidant, anti-inflammatory, anti-angiogenic and anti-mutagenic activity. However, the possible role of delphinidin in the cancer migration and invasion is unclear. We investigated the suppressive effect of delphinidin on the cancer migration and invasion. Thus, we found that BDNF enhanced cancer migration and invasion in SKOV3 ovarian cancer cell. To exam the inhibitory role of delphinidin in SKOV3 ovarian cancer migration and invasion, we investigated the use of delphinidin as inhibitors of BDNF-induced motility and invasiveness in SKOV3 ovarian cancer cells in vitro. Here, we found that delphinidin prominently inhibited the BDNF-induced increase in cell migration and invasion of SKOV3 ovarian cancer cells. Furthermore, delphinidin remarkably inhibited BDNF-stimulated expression of MMP-2 and MMP-9. Also, delphinidin antagonized the phosphorylation of Akt and nuclear translocation of NF-κB permitted by the BDNF in SKOV3 ovarian cancer cells. Taken together, our findings provide new evidence that delphinidin suppressed the BDNF-induced ovarian cancer migration and invasion through decreasing of Akt activation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transport of cargo from periphery to brain by circulating monocytes.

PubMed

Cintron, Amarallys F; Dalal, Nirjari V; Dooyema, Jeromy; Betarbet, Ranjita; Walker, Lary C

2015-10-05

The misfolding and aggregation of the Aβ peptide - a fundamental event in the pathogenesis of Alzheimer׳s disease - can be instigated in the brains of experimental animals by the intracranial infusion of brain extracts that are rich in aggregated Aβ. Recent experiments have found that the peripheral (intraperitoneal) injection of Aβ seeds induces Aβ deposition in the brains of APP-transgenic mice, largely in the form of cerebral amyloid angiopathy. Macrophage-type cells normally are involved in pathogen neutralization and antigen presentation, but under some circumstances, circulating monocytes have been found to act as vectors for the transport of pathogenic agents such as viruses and prions. The present study assessed the ability of peripheral monocytes to transport Aβ aggregates from the peritoneal cavity to the brain. Our initial experiments showed that intravenously delivered macrophages that had previously ingested fluorescent nanobeads as tracers migrate primarily to peripheral organs such as spleen and liver, but that a small number also reach the brain parenchyma. We next injected CD45.1-expressing monocytes from donor mice intravenously into CD45.2-expressing host mice; after 24h, analysis by fluorescence-activated cell sorting (FACS) and histology confirmed that some CD45.1 monocytes enter the brain, particularly in the superficial cortex and around blood vessels. When the donor monocytes are first exposed to Aβ-rich brain extracts from human AD cases, a subset of intravenously delivered Aβ-containing cells migrate to the brain. These experiments indicate that, in mouse models, circulating monocytes are potential vectors by which exogenously delivered, aggregated Aβ travels from periphery to brain, and more generally support the hypothesis that macrophage-type cells can participate in the dissemination of proteopathic seeds. Copyright © 2015 Elsevier B.V. All rights reserved.

Overexpression of Large-Conductance Calcium-Activated Potassium Channels in Human Glioblastoma Stem-Like Cells and Their Role in Cell Migration.

PubMed

Rosa, Paolo; Sforna, Luigi; Carlomagno, Silvia; Mangino, Giorgio; Miscusi, Massimo; Pessia, Mauro; Franciolini, Fabio; Calogero, Antonella; Catacuzzeno, Luigi

2017-09-01

Glioblastomas (GBMs) are brain tumors characterized by diffuse invasion of cancer cells into the healthy brain parenchyma, and establishment of secondary foci. GBM cells abundantly express large-conductance, calcium-activated potassium (BK) channels that are thought to promote cell invasion. Recent evidence suggests that the GBM high invasive potential mainly originates from a pool of stem-like cells, but the expression and function of BK channels in this cell subpopulation have not been studied. We investigated the expression of BK channels in GBM stem-like cells using electrophysiological and immunochemical techniques, and assessed their involvement in the migratory process of this important cell subpopulation. In U87-MG cells, BK channel expression and function were markedly upregulated by growth conditions that enriched the culture in GBM stem-like cells (U87-NS). Cytofluorimetric analysis further confirmed the appearance of a cell subpopulation that co-expressed high levels of BK channels and CD133, as well as other stem cell markers. A similar association was also found in cells derived from freshly resected GBM biopsies. Finally, transwell migration tests showed that U87-NS cells migration was much more sensitive to BK channel block than U87-MG cells. Our data show that BK channels are highly expressed in GBM stem-like cells, and participate to their high migratory activity. J. Cell. Physiol. 232: 2478-2488, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

β5 Integrin Up-Regulation in Brain-Derived Neurotrophic Factor Promotes Cell Motility in Human Chondrosarcoma

PubMed Central

Li, Te-Mao; Fong, Yi-Chin; Liu, Shan-Chi; Chen, Po-Chun; Tang, Chih-Hsin

2013-01-01

Chondrosarcoma is a primary malignant bone cancer, with a potent capacity to invade locally and cause distant metastasis; it has a poor prognosis and shows a predilection for metastasis to the lungs. Brain derived neurotrophic factor (BDNF) is a small-molecule protein from the neurotrophin family of growth factors that is associated with the disease status and outcomes of cancers. However, the effect of BDNF on migration activity in human chondrosarcoma cells is mostly unknown. Here, we found that human chondrosarcoma tissues showed significant expression of BDNF, which was higher than that in normal cartilage and primary chondrocytes. We also found that BDNF increased the migration and expression of β5 integrin in human chondrosarcoma cells. In addition, knockdown of BDNF expression markedly inhibited migratory activity. BDNF-mediated migration and β5 integrin up-regulation were attenuated by antibody, inhibitor, or siRNA against the TrkB receptor. Pretreatment of chondrosarcoma cells with PI3K, Akt, and NF-κB inhibitors or mutants also abolished BDNF-promoted migration and integrin expression. The PI3K, Akt, and NF-κB signaling pathway was activated after BDNF treatment. Taken together, our results indicate that BDNF enhances the migration of chondrosarcoma by increasing β5 integrin expression through a signal transduction pathway that involves the TrkB receptor, PI3K, Akt, and NF-κB. BDNF thus represents a promising new target for treating chondrosarcoma metastasis. PMID:23874483

Tumor cell migration screen identifies SRPK1 as breast cancer metastasis determinant

PubMed Central

van Roosmalen, Wies; Le Dévédec, Sylvia E.; Golani, Ofra; Smid, Marcel; Pulyakhina, Irina; Timmermans, Annemieke M.; Look, Maxime P.; Zi, Di; Pont, Chantal; de Graauw, Marjo; Naffar-Abu-Amara, Suha; Kirsanova, Catherine; Rustici, Gabriella; Hoen, Peter A.C. ‘t; Martens, John W.M.; Foekens, John A.; Geiger, Benjamin; van de Water, Bob

2015-01-01

Tumor cell migration is a key process for cancer cell dissemination and metastasis that is controlled by signal-mediated cytoskeletal and cell matrix adhesion remodeling. Using a phagokinetic track assay with migratory H1299 cells, we performed an siRNA screen of almost 1,500 genes encoding kinases/phosphatases and adhesome- and migration-related proteins to identify genes that affect tumor cell migration speed and persistence. Thirty candidate genes that altered cell migration were validated in live tumor cell migration assays. Eight were associated with metastasis-free survival in breast cancer patients, with integrin β3–binding protein (ITGB3BP), MAP3K8, NIMA-related kinase (NEK2), and SHC-transforming protein 1 (SHC1) being the most predictive. Examination of genes that modulate migration indicated that SRPK1, encoding the splicing factor kinase SRSF protein kinase 1, is relevant to breast cancer outcomes, as it was highly expressed in basal breast cancer. Furthermore, high SRPK1 expression correlated with poor breast cancer disease outcome and preferential metastasis to the lungs and brain. In 2 independent murine models of breast tumor metastasis, stable shRNA-based SRPK1 knockdown suppressed metastasis to distant organs, including lung, liver, and spleen, and inhibited focal adhesion reorganization. Our study provides comprehensive information on the molecular determinants of tumor cell migration and suggests that SRPK1 has potential as a drug target for limiting breast cancer metastasis. PMID:25774502

EFFECT OF METHYL MERCURY CHLORIDE EXPOSURE ON PC12 CELL INTEGRIN EXPRESSION AND FUNCTION.

EPA Science Inventory

Integrins are heterodimeric transmembrane cell adhesion proteins composed of a and b protein subunits. They are important during brain development in a number of critical functions, including cell migration (Georges-Labouesse, et al., 1998), axonal elongation (Murase and Hayashi...

Effector CD8^+ T cells migrate via chemokine-enhanced generalized L'evy walks

NASA Astrophysics Data System (ADS)

Banigan, Edward; Harris, Tajie; Christian, David; Liu, Andrea; Hunter, Christopher

2012-02-01

Chemokines play a central role in regulating processes essential to the immune function of T cells, such as their migration within lymphoid tissues and targeting of pathogens in sites of inflammation. In order to understand the role of the chemokine CXCL10 during chronic infection by the parasite T. gondii, we analyze tracks of migrating CD8^+ T cells in brain tissue. Surprisingly, we find that T cell motility is not described by a Brownian walk, but instead is consistent with a generalized L'evy walk consisting of L'evy-distributed runs alternating with pauses of L'evy-distributed durations. According to our model, this enables T cells to find rare targets more than an order of magnitude more efficiently than Brownian random walkers. The chemokine CXCL10 increases the migration speed without changing the character of the walk statistics. Thus, CD8^+ T cells use an efficient search strategy to facilitate an effective immune response, and CXCL10 aids them in shortening the average time to find rare targets.

In vitro modulation of microglia motility by glioma cells is mediated by hepatocyte growth factor/scatter factor.

PubMed

Badie, B; Schartner, J; Klaver, J; Vorpahl, J

1999-05-01

Considered as immune effector cells of the central nervous system, microglia represent a major component of the inflammatory cells found in malignant gliomas. Although their role in brain tumor biology is unclear, accumulation of microglia in malignant brain tumors may be mediated through active secretion of cytokines by glioma cells. Because hepatocyte growth factor/scatter factor (HGF/SF) has been shown to modulate glioma motility through an autocrine mechanism, and because microglia have been reported to express the HGF/SF receptor Met, we hypothesized that microglia recruitment by gliomas may also occur through the secretion of HGF/SF. The effect of glioma cells in augmenting BV-2 murine microglia motility was studied by using an in vitro Boyden chamber migration assay. To determine the chemokines involved in microglia migration, neutralizing monoclonal antibodies against monocyte chemotactic protein-1 and HGF/SF were tested. Immunoblotting was used to check for the expression of HGF/SF by glioma cells, and the expression of Met by BV-2 cells was examined by flow cytometry. BV-2 migration was noted within 7 hours of incubation with both human (U251 MG and U373 MG) and murine (GL261) glioma cell lines. This migration corresponded to HGF/SF secretion by glioma cells and was completely inhibited by neutralizing monoclonal antibody against HGF/SF, but not monocyte chemotactic protein-1. Exposure of BV-2 cells to recombinant HGF/SF, but not monocyte chemotactic protein-1, resulted in their migration and down-regulation of Met in a dose-dependent fashion. HGF/SF, which plays a role in glioma motility and mitogenesis, may also act as a chemokine for microglia and may be responsible for the microglia infiltration in malignant gliomas. This active recruitment of microglia may play an important role in glioma biology.

Parecoxib inhibits glioblastoma cell proliferation, migration and invasion by upregulating miRNA-29c.

PubMed

Li, Lin-Yong; Xiao, Jie; Liu, Qiang; Xia, Kun

2017-03-15

Glioblastoma (GBM) is one of the most lethal brain cancers worldwide, and there is an urgent need for development of novel therapeutic approaches. Parecoxib is a well-known cyclooxygenase-2 (COX-2) inhibitor, and had already been developed for postoperative analgesia with high efficacy and low adverse reaction. A recent study has suggested that parecoxib potently enhances immunotherapeutic efficacy of GBM, but its effects on GBM growth, migration and invasion have not previously been studied. In the present study, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and BrdU (5-bromo-2-deoxyuridine) incorporation assays were used to evaluate the cell proliferation of GBM cells. Wound-healing and transwell assays were preformed to analyze GBM cell migration and invasion, respectively. The results suggested that parecoxib inhibits cell proliferation, migration and invasion of GBM cells in a dose-dependent manner. RT-qPCR (real-time quantitative PCR) analysis demonstrated that miRNA-29c can be significantly induced by parecoxib. Furthermore, our data suggests that a miRNA-29c inhibitor can significantly attenuate parecoxib's effect on proliferation, migration and invasion of GBM. In conclusion, the present study suggests that parecoxib inhibits GBM cell proliferation, migration and invasion by upregulating miRNA-29c. © 2017. Published by The Company of Biologists Ltd.

Parecoxib inhibits glioblastoma cell proliferation, migration and invasion by upregulating miRNA-29c

PubMed Central

Li, Lin-Yong; Xiao, Jie; Liu, Qiang

2017-01-01

ABSTRACT Glioblastoma (GBM) is one of the most lethal brain cancers worldwide, and there is an urgent need for development of novel therapeutic approaches. Parecoxib is a well-known cyclooxygenase-2 (COX-2) inhibitor, and had already been developed for postoperative analgesia with high efficacy and low adverse reaction. A recent study has suggested that parecoxib potently enhances immunotherapeutic efficacy of GBM, but its effects on GBM growth, migration and invasion have not previously been studied. In the present study, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and BrdU (5-bromo-2-deoxyuridine) incorporation assays were used to evaluate the cell proliferation of GBM cells. Wound-healing and transwell assays were preformed to analyze GBM cell migration and invasion, respectively. The results suggested that parecoxib inhibits cell proliferation, migration and invasion of GBM cells in a dose-dependent manner. RT-qPCR (real-time quantitative PCR) analysis demonstrated that miRNA-29c can be significantly induced by parecoxib. Furthermore, our data suggests that a miRNA-29c inhibitor can significantly attenuate parecoxib's effect on proliferation, migration and invasion of GBM. In conclusion, the present study suggests that parecoxib inhibits GBM cell proliferation, migration and invasion by upregulating miRNA-29c. PMID:27895048

CXCL12 Gene Therapy Ameliorates Ischemia-Induced White Matter Injury in Mouse Brain.

PubMed

Li, Yaning; Tang, Guanghui; Liu, Yanqun; He, Xiaosong; Huang, Jun; Lin, Xiaojie; Zhang, Zhijun; Yang, Guo-Yuan; Wang, Yongting

2015-10-01

Remyelination is an important repair process after ischemic stroke-induced white matter injury. It often fails because of the insufficient recruitment of oligodendrocyte progenitor cells (OPCs) to the demyelinated site or the inefficient differentiation of OPCs to oligodendrocytes. We investigated whether CXCL12 gene therapy promoted remyelination after middle cerebral artery occlusion in adult mice. The results showed that CXCL12 gene therapy at 1 week after ischemia could protect myelin sheath integrity in the perifocal region, increase the number of platelet-derived growth factor receptor-α (PDGFRα)-positive and PDGFRα/bromodeoxyuridine-double positive OPCs in the subventricular zone, and further enhance their migration to the ischemic lesion area. Coadministration of AMD3100, the antagonist for CXCL12 receptor CXCR4, eliminated the beneficial effect of CXCL12 on myelin sheath integrity and negatively influenced OPC proliferation and migration. At 5 weeks after ischemia, CXCR4 was found on the PDGFRα- and/or neuron/glia type 2 (NG2)-positive OPCs but not on the myelin basic protein-positive mature myelin sheaths, and CXCR7 was only expressed on the mature myelin sheath in the ischemic mouse brain. Our data indicated that CXCL12 gene therapy effectively protected white matter and promoted its repair after ischemic injury. The treatment at 1 week after ischemia is effective, suggesting that this strategy has a longer therapeutic time window than the treatments currently available. This study has demonstrated for the first time that CXCL12 gene therapy significantly ameliorates brain ischemia-induced white matter injury and promotes oligodendrocyte progenitor cell proliferation in the subventricular zone and migration to the perifocal area in the ischemic mouse brain. Additional data showed that CXCR4 receptor plays an important role during the proliferation and migration of oligodendrocyte progenitor cells, and CXCR7 might play a role during maturation. In contrast to many experimental studies that provide treatment before ischemic insult, CXCL12 gene therapy was performed 1 week after brain ischemia, which significantly prolonged the therapeutic time window of brain ischemia. ©AlphaMed Press.

RasGRP3 regulates the migration of glioma cells via interaction with Arp3

PubMed Central

Lee, Hae Kyung; Finniss, Susan; Cazacu, Simona; Xiang, Cunli; Poisson, Laila M.; Blumberg, Peter M.; Brodie, Chaya

2015-01-01

Glioblastoma (GBM), the most aggressive primary brain tumors, are highly infiltrative. Although GBM express high Ras activity and Ras proteins have been implicated in gliomagenesis, Ras-activating mutations are not frequent in these tumors. RasGRP3, an important signaling protein responsive to diacylglycerol (DAG), increases Ras activation. Here, we examined the expression and functions of RasGRP3 in GBM and glioma cells. RasGRP3 expression was upregulated in GBM specimens and glioma stem cells compared with normal brains and neural stem cells, respectively. RasGRP3 activated Ras and Rap1 in glioma cells and increased cell migration and invasion partially via Ras activation. Using pull-down assay and mass spectroscopy we identified the actin-related protein, Arp3, as a novel interacting protein of RasGRP3. The interaction of RasGRP3 and Arp3 was validated by immunofluorescence staining and co-immunoprecipitation, and PMA, which activates RasGRP3 and induces its translocation to the peri-nuclear region, increased the association of Arp3 and RasGRP3. Arp3 was upregulated in GBM, regulated cell spreading and migration and its silencing partially decreased these effects of RasGRP3 in glioma cells. In summary, RasGRP3 acts as an important integrating signaling protein of the DAG and Ras signaling pathways and actin polymerization and represents an important therapeutic target in GBM. PMID:25682201

Seasonal variation in cell proliferation and cell migration in the brain of adult red-sided garter snakes (Thamnophis sirtalis parietalis).

PubMed

Maine, Ashley R; Powers, Sean D; Lutterschmidt, Deborah I

2014-01-01

Plasticity in the adult central nervous system has been described in all vertebrate classes as well as in some invertebrate groups. However, the limited taxonomic diversity represented in the current neurogenesis literature limits our ability to assess the functional significance of adult neurogenesis for natural behaviors as well as the evolution of its regulatory mechanisms. In the present study, we used free-ranging red-sided garter snakes (Thamnophis sirtalis parietalis) to test the hypothesis that seasonal shifts in physiology and behavior are associated with seasonal variation in postembryonic neurogenesis. Specifically, we used the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) to determine if the rates of cell proliferation in the adult brain vary between male snakes collected during spring and fall at 1, 5, and 10 days post-BrdU treatment. To assess rates of cell migration within the brain, we further categorized BrdU-labeled cells according to their location within the ventricular zone or parenchymal region. BrdU-labeled cells were localized mainly within the lateral, dorsal, and medial cortex, septal nucleus, nucleus sphericus, preoptic area, and hypothalamus. In all regions, the number of BrdU-labeled cells in the ventricular zone was higher in the fall compared to spring. In the parenchymal region, a significantly higher number of labeled cells was also observed during the fall, but only within the nucleus sphericus and the combined preoptic area/hypothalamus. The immunoreactive cell number did not vary significantly with days post-BrdU treatment in either season or in any brain region. While it is possible that the higher rates of cell proliferation in the fall simply reflect increased growth of all body tissues, including the brain, our data show that seasonal changes in cell migration into the parenchyma are region specific. In red-sided garter snakes and other reptiles, the dorsal and medial cortex is important for spatial navigation and memory, whereas the nucleus sphericus, septal nucleus, and preoptic area/hypothalamus are central to reproductive regulation. Thus, our results provide support for the hypothesis that adult neurogenesis plays a role in mediating seasonal rhythms in migratory and reproductive behaviors. © 2014 S. Karger AG, Basel.

Brain metastatic cancer cells release microRNA-181c-containing extracellular vesicles capable of destructing blood–brain barrier

PubMed Central

Tominaga, Naoomi; Kosaka, Nobuyoshi; Ono, Makiko; Katsuda, Takeshi; Yoshioka, Yusuke; Tamura, Kenji; Lötvall, Jan; Nakagama, Hitoshi; Ochiya, Takahiro

2015-01-01

Brain metastasis is an important cause of mortality in breast cancer patients. A key event during brain metastasis is the migration of cancer cells through blood–brain barrier (BBB). However, the molecular mechanism behind the passage through this natural barrier remains unclear. Here we show that cancer-derived extracellular vesicles (EVs), mediators of cell–cell communication via delivery of proteins and microRNAs (miRNAs), trigger the breakdown of BBB. Importantly, miR-181c promotes the destruction of BBB through the abnormal localization of actin via the downregulation of its target gene, PDPK1. PDPK1 degradation by miR-181c leads to the downregulation of phosphorylated cofilin and the resultant activated cofilin-induced modulation of actin dynamics. Furthermore, we demonstrate that systemic injection of brain metastatic cancer cell-derived EVs promoted brain metastasis of breast cancer cell lines and are preferentially incorporated into the brain in vivo. Taken together, these results indicate a novel mechanism of brain metastasis mediated by EVs that triggers the destruction of BBB. PMID:25828099

A dynamic in vivo-like organotypic blood-brain barrier model to probe metastatic brain tumors

NASA Astrophysics Data System (ADS)

Xu, Hui; Li, Zhongyu; Yu, Yue; Sizdahkhani, Saman; Ho, Winson S.; Yin, Fangchao; Wang, Li; Zhu, Guoli; Zhang, Min; Jiang, Lei; Zhuang, Zhengping; Qin, Jianhua

2016-11-01

The blood-brain barrier (BBB) restricts the uptake of many neuro-therapeutic molecules, presenting a formidable hurdle to drug development in brain diseases. We proposed a new and dynamic in vivo-like three-dimensional microfluidic system that replicates the key structural, functional and mechanical properties of the blood-brain barrier in vivo. Multiple factors in this system work synergistically to accentuate BBB-specific attributes-permitting the analysis of complex organ-level responses in both normal and pathological microenvironments in brain tumors. The complex BBB microenvironment is reproduced in this system via physical cell-cell interaction, vascular mechanical cues and cell migration. This model possesses the unique capability to examine brain metastasis of human lung, breast and melanoma cells and their therapeutic responses to chemotherapy. The results suggest that the interactions between cancer cells and astrocytes in BBB microenvironment might affect the ability of malignant brain tumors to traverse between brain and vascular compartments. Furthermore, quantification of spatially resolved barrier functions exists within a single assay, providing a versatile and valuable platform for pharmaceutical development, drug testing and neuroscientific research.

In vitro-microenvironment directs preconditioning of human chorion derived MSC promoting differentiation of OPC-like cells.

PubMed

Periasamy, Ramesh; Surbek, Daniel V; Schoeberlein, Andreina

2018-06-01

The loss of oligodendrocyte progenitor cells (OPC) is a hallmark of perinatal brain injury. Our aim was to develop an in vitro culture condition for human chorion-derived mesenchymal stem cells (MSC) that enhances their stem cell properties and their capability to differentiate towards OPC-like cells. MSC were grown either in serum replacement medium (SRM) or serum-containing medium (SM) and tested for their morphology, proliferation, secretome, migration, protein expression and differentiation into OPC-like cells. MSC cultured in SRM condition have distinct morphology/protein expression profile, increased cell proliferation/migration and capacity to differentiate into OPC-like cells. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of Chinese medicinal herbs on expression of brain-derived Neurotrophic factor (BDNF) and its interaction with human breast cancer MDA-MB-231 cells and endothelial HUVECs.

PubMed

Chiu, Jen-Hwey; Chen, Fang-Pey; Tsai, Yi-Fang; Lin, Man-Ting; Tseng, Ling-Ming; Shyr, Yi-Ming

2017-08-12

Our previous study demonstrated that an up-regulation of the Brain-Derived Neurotrophic Factor (BDNF) signaling pathway is involved the mechanism causing the recurrence of triple negative breast cancer. The aim of this study is to investigate the effects of commonly used Chinese medicinal herbs on MDA-MB-231 and HUVEC cells and how they interact with BDNF. Human TNBC MDA-MB-231 cells and human endothelial HUVEC cells were used to explore the effect of commonly used Chinese herbal medicines on cancer cells alone, on endothelial cells alone and on cancer cell/endothelial cell interactions; this was done via functional studies, including migration and invasion assays. Furthermore, Western blot analysis and real-time PCR investigations were also used to investigate migration signal transduction, invasion signal transduction, and angiogenic signal transduction in these systems. Finally, the effect of the Chinese medicinal herbs on cancer cell/endothelial cell interactions was assessed using co-culture and ELISA. In terms of autoregulation, BDNF up-regulated TrkB gene expression in both MDA-MB-231 and HUVEC cells. Furthermore, BDNF enhanced migration by MDA-MB-231 cells via Rac, Cdc42 and MMP, while also increasing the migration of HUVEC cells via MMP and COX-2 expression. As measured by ELISA, the Chinese herbal medicinal herbs A. membranaceus, P. lactiflora, L. chuanxiong, P. suffruticosa and L. lucidum increased BDNF secretion by MDA-MB-231 cells. Similarly, using a co-culture system with MDA-MB-231 cells, A. membranaceus and L. lucidum modulated BDNF-TrkB signaling by HUVEC cells. We conclude that BDNF plays an important role in the metastatic interaction between MDA-MB-231 and HUVEC cells. Some Chinese medicinal herbs are able to enhance the BDNF-related metastatic potential of the interaction between cancer cells and endothelial cells. These findings provide important information that should help with the development of integrated medical therapies for breast cancer patients.

[Study of migration and distribution of bone marrow cells transplanted animals with B16 melanoma ].

PubMed

Poveshchenko, A F; Solovieva, A O; Zubareva, K E; Strunkin, D N; Gricyk, O B; Poveshchenko, O V; Shurlygina, A V; Konenkov, V I

2017-01-01

Purpose. Reveal features migration and distribution of syngeneic bone marrow cells (BMC) and subpopulations (MSC) after transplantation into the recipient carrier B16 melanoma bodies. Methods. We used mouse male and female C57BL/6 mice. Induction of Tumor Growth: B16 melanoma cells implanted subcutaneously into right hind paw of female C57BL/6 mice at a dose of 2.5 x 105 cells / mouse. migration study in vivo distribution and BMC and MSC was performed using genetic markers - Y-chromosome specific sequence line male C57Bl/6 syngeneic intravenous transplantation in females using the polymerase chain reaction (PCR) in real time on Authorized Termal Cycler - Light Cycler 480 II / 96 (Roche). Introduction suspension of unseparated bone marrow cells, mesenchymal stem cells from donor to recipient male mice (syngeneic recipient female C57BL/6), followed by isolation of recipients of organs was performed at regular intervals, then of organ recipients isolated DNA. Results. It was shown that bone marrow cells positive for Y-chromosome in migrate lymphoid (lymph nodes, spleen, bone marrow) or in non-lymphoid organs (liver, heart, brain, skin) syngeneic recipients. In addition to the migration of cells from the bone marrow to other organs, there is a way back migration of cells from the circulation to the bone marrow. B16 melanoma stimulates the migration of transplanted MSCs and BMC in bone marrow. It is found that tumor growth enhanced migration of transplanted bone marrow cells, including populations of MSCs in the bone marrow. In the early stages of tumor formation MSC migration activity higher than the BMC. In the later stages of tumor formation undivided population of bone marrow cells migrate to the intense swelling compared with a population of MSCs. Conclusion. The possibility of using bone marrow MSCs for targeted therapy of tumor diseases, because migration of MSCs in tumor tissue can be used to effectively deliver anticancer drugs.

Magnolol Inhibits Human Glioblastoma Cell Migration by Regulating N-Cadherin.

PubMed

Cheng, Yu-Chen; Tsao, Min-Jen; Chiu, Chen-Yang; Kan, Po-Chieh; Chen, Ying

2018-06-01

Glioblastoma is a primary malignant brain tumor with a poor prognosis. An effective treatment for glioblastoma is needed. Magnolol is a natural compound from Magnolia officinalis suggested to have antiproliferative activity. The aim of this research was to investigate the anticancer effects of magnolol in glioma, with an emphasis on migration and the underlying mechanism. Magnolol decreased the expression of focal adhesion-related proteins and inhibited LN229 and U87MG glioma cell migration. The levels of phosphorylated myosin light chain (p-MLC), phosphorylated myosin light chain kinase and myosin phosphatase target subunit 1 were reduced in response to magnolol treatment. In addition, immunostaining and membrane fractionation showed that the distribution of N-cadherin at the glioma cell membrane was decreased by magnolol. In an orthotropic xenograft animal model, magnolol treatment not only inhibited tumor progression but also reduced p-MLC and N-cadherin protein expression. In conclusion, magnolol reduces cell migration, potentially through regulating focal adhesions and N-cadherin in glioma cells. Magnolol is a potential candidate for glioma treatment.

Postarrest stalling rather than crawling favors CD8+ over CD4+ T‐cell migration across the blood–brain barrier under flow in vitro

PubMed Central

Rudolph, Henriette; Klopstein, Armelle; Gruber, Isabelle; Blatti, Claudia; Lyck, Ruth

2016-01-01

Although CD8+ T cells have been implied in the pathogenesis of multiple sclerosis (MS), the molecular mechanisms mediating CD8+ T‐cell migration across the blood–brain barrier (BBB) into the central nervous system (CNS) are ill defined. Using in vitro live cell imaging, we directly compared the multistep extravasation of activated CD4+ and CD8+ T cells across primary mouse brain microvascular endothelial cells (pMBMECs) as a model for the BBB under physiological flow. Significantly higher numbers of CD8+ than CD4+ T cells arrested on pMBMECs under noninflammatory and inflammatory conditions. While CD4+ T cells polarized and crawled prior to their diapedesis, the majority of CD8+ T cells stalled and readily crossed the pMBMEC monolayer preferentially via a transcellular route. T‐cell arrest and crawling were independent of G‐protein‐coupled receptor signaling. Rather, absence of endothelial ICAM‐1 and ICAM‐2 abolished increased arrest of CD8+ over CD4+ T cells and abrogated T‐cell crawling, leading to the efficient reduction of CD4+, but to a lesser degree of CD8+, T‐cell diapedesis across ICAM‐1null/ICAM‐2−/− pMBMECs. Thus, cellular and molecular mechanisms mediating the multistep extravasation of activated CD8+ T cells across the BBB are distinguishable from those involved for CD4+ T cells. PMID:27338806

A Brain-Machine-Brain Interface for Rewiring of Cortical Circuitry after Traumatic Brain Injury

DTIC Science & Technology

2014-09-01

810. 22. Plow EB, Carey JR, Nudo RJ, Pascual-Leone A (2009) Invasive cortical stimulation to promote recovery of function after stroke: A critical...stimulation of the motor cortex enhances pro- genitor cell migration in the adult rat brain. Exp Brain Res 231(2):165–177. 28. Edwardson MA, Lucas TH, Carey ...The screws and rod were further secured with dental acrylic (all animals). In both the ADS and OLS groups, a hybrid, 16-channel, single-shank, chronic

Identification of ATP Citrate Lyase as a Positive Regulator of Glycolytic Function in Glioblastomas

PubMed Central

Beckner, Marie E.; Fellows-Mayle, Wendy; Zhang, Zhe; Agostino, Naomi R.; Kant, Jeffrey A.; Day, Billy W.; Pollack, Ian F.

2009-01-01

Glioblastomas, the most malignant type of glioma, are more glycolytic than normal brain tissue. Robust migration of glioblastoma cells has been previously demonstrated under glycolytic conditions and their pseudopodia contain increased glycolytic and decreased mitochondrial enzymes. Glycolysis is suppressed by metabolic acids, including citric acid which is excluded from mitochondria during hypoxia. We postulated that glioma cells maintain glycolysis by regulating metabolic acids, especially in their pseudopodia. The enzyme that breaks down cytosolic citric acid is ATP citrate lyase (ACLY). Our identification of increased ACLY in pseudopodia of U87 glioblastoma cells on 1D gels and immunoblots prompted investigation of ACLY gene expression in gliomas for survival data and correlation with expression of ENO1, that encodes enolase 1. Queries of the NIH’s REMBRANDT brain tumor database based on Affymetrix data indicated that decreased survival correlated with increased gene expression of ACLY in gliomas. Queries of gliomas and glioblastomas found an association of upregulated ACLY and ENO1 expression by chi square for all probe sets (reporters) combined and correlation for numbers of probe sets indicating shared upregulation of these genes. Real-time quantitative PCR confirmed correlation between ACLY and ENO1 in 21 glioblastomas (p < 0.001). Inhibition of ACLY with hydroxycitrate suppressed (p < 0.05) in vitro glioblastoma cell migration, clonogenicity and brain invasion under glycolytic conditions and enhanced the suppressive effects of a Met inhibitor on cell migration. In summary, gene expression data, proteomics and functional assays support ACLY as a positive regulator of glycolysis in glioblastomas. PMID:19795461

Involvement of Receptor-like Protein Tyrosine Phosphatase ζ/RPTPβ and Its Ligand Pleiotrophin/Heparin-binding Growth-associated Molecule (HB-GAM) in Neuronal Migration

PubMed Central

Maeda, Nobuaki; Noda, Masaharu

1998-01-01

Pleiotrophin/heparin-binding growth-associated molecule (HB-GAM) is a specific ligand of protein tyrosine phosphatase ζ (PTPζ)/receptor-like protein tyrosine phosphatase β (RPTPβ) expressed in the brain as a chondroitin sulfate proteoglycan. Pleiotrophin and PTPζ isoforms are localized along the radial glial fibers, a scaffold for neuronal migration, suggesting that these molecules are involved in migratory processes of neurons during brain development. In this study, we examined the roles of pleiotrophin-PTPζ interaction in the neuronal migration using cell migration assay systems with glass fibers and Boyden chambers. Pleiotrophin and poly-l-lysine coated on the substratums stimulated cell migration of cortical neurons, while laminin, fibronectin, and tenascin exerted almost no effect. Pleiotrophin-induced and poly-l-lysine–induced neuronal migrations showed significant differences in sensitivity to various molecules and reagents. Polyclonal antibodies against the extracellular domain of PTPζ, PTPζ-S, an extracellular secreted form of PTPζ, and sodium vanadate, a protein tyrosine phosphatase inhibitor, added into the culture medium strongly suppressed specifically the pleiotrophin-induced neuronal migration. Furthermore, chondroitin sulfate C but not chondroitin sulfate A inhibited pleiotrophin-induced neuronal migration, in good accordance with our previous findings that chondroitin sulfate constitutes a part of the pleiotrophin-binding site of PTPζ, and PTPζ-pleiotrophin binding is inhibited by chondroitin sulfate C but not by chondroitin sulfate A. Immunocytochemical analysis indicated that the transmembrane forms of PTPζ are expressed on the migrating neurons especially at the lamellipodia along the leading processes. These results suggest that PTPζ is involved in the neuronal migration as a neuronal receptor of pleiotrophin distributed along radial glial fibers. PMID:9660874

APLP2 regulates neuronal stem cell differentiation during cortical development.

PubMed

Shariati, S Ali M; Lau, Pierre; Hassan, Bassem A; Müller, Ulrike; Dotti, Carlos G; De Strooper, Bart; Gärtner, Annette

2013-03-01

Expression of amyloid precursor protein (APP) and its two paralogues, APLP1 and APLP2 during brain development coincides with key cellular events such as neuronal differentiation and migration. However, genetic knockout and shRNA studies have led to contradictory conclusions about their role during embryonic brain development. To address this issue, we analysed in depth the role of APLP2 during neurogenesis by silencing APLP2 in vivo in an APP/APLP1 double knockout mouse background. We find that under these conditions cortical progenitors remain in their undifferentiated state much longer, displaying a higher number of mitotic cells. In addition, we show that neuron-specific APLP2 downregulation does not impact the speed or position of migrating excitatory cortical neurons. In summary, our data reveal that APLP2 is specifically required for proper cell cycle exit of neuronal progenitors, and thus has a distinct role in priming cortical progenitors for neuronal differentiation.

Training stem cells for treatment of malignant brain tumors

PubMed Central

Li, Shengwen Calvin; Kabeer, Mustafa H; Vu, Long T; Keschrumrus, Vic; Yin, Hong Zhen; Dethlefs, Brent A; Zhong, Jiang F; Weiss, John H; Loudon, William G

2014-01-01

The treatment of malignant brain tumors remains a challenge. Stem cell technology has been applied in the treatment of brain tumors largely because of the ability of some stem cells to infiltrate into regions within the brain where tumor cells migrate as shown in preclinical studies. However, not all of these efforts can translate in the effective treatment that improves the quality of life for patients. Here, we perform a literature review to identify the problems in the field. Given the lack of efficacy of most stem cell-based agents used in the treatment of malignant brain tumors, we found that stem cell distribution (i.e., only a fraction of stem cells applied capable of targeting tumors) are among the limiting factors. We provide guidelines for potential improvements in stem cell distribution. Specifically, we use an engineered tissue graft platform that replicates the in vivo microenvironment, and provide our data to validate that this culture platform is viable for producing stem cells that have better stem cell distribution than with the Petri dish culture system. PMID:25258664

Soluble TNF receptor 1-secreting ex vivo-derived dendritic cells reduce injury after stroke.

PubMed

Works, Melissa G; Koenig, Jenny B; Sapolsky, Robert M

2013-09-01

Inflammation is a major factor in the progression of damage after stroke and in the clinic, current therapies treat the clot, not the resulting damage. We have developed a novel method of protein delivery that exploits the migration ability of leukocytes after ischemic stroke (transient middle cerebral artery occlusion; tMCAO). In our studies, ex vivo-derived dendritic cells (exDCs) migrate to the inflamed rat brain soon after tMCAO onset and the number of cells that remain in the brain after injection is significantly correlated with the amount of local inflammation at the injury site. In addition, exDCs transduced to overexpress soluble tumor necrosis factor (TNF) receptor1 (sTNFR1) produce functional cargo that is secreted and that blocks TNF-α bioavailability in vitro. When delivered at 6 hours post-tMCAO reperfusion, sTNFR1-exDC-treated rats show significantly smaller infarct size and decreased inflammation compared with animals treated with exDCs transduced with GFP lentivirus. These studies indicate that cell-mediated delivery of proteins may be a promising new approach to reduce brain damage after acute neurologic insult.

Imaging transplanted stem cells in real time using an MRI dual-contrast method

PubMed Central

Ngen, Ethel J.; Wang, Lee; Kato, Yoshinori; Krishnamachary, Balaji; Zhu, Wenlian; Gandhi, Nishant; Smith, Barbara; Armour, Michael; Wong, John; Gabrielson, Kathleen; Artemov, Dmitri

2015-01-01

Stem cell therapies are currently being investigated for the repair of brain injuries. Although exogenous stem cell labelling with superparamagnetic iron oxide nanoparticles (SPIONs) prior to transplantation provides a means to noninvasively monitor stem cell transplantation by magnetic resonance imaging (MRI), monitoring cell death is still a challenge. Here, we investigate the feasibility of using an MRI dual-contrast technique to detect cell delivery, cell migration and cell death after stem cell transplantation. Human mesenchymal stem cells were dual labelled with SPIONs and gadolinium-based chelates (GdDTPA). The viability, proliferation rate, and differentiation potential of the labelled cells were then evaluated. The feasibility of this MRI technique to distinguish between live and dead cells was next evaluated using MRI phantoms, and in vivo using both immune-competent and immune-deficient mice, following the induction of brain injury in the mice. All results were validated with bioluminescence imaging. In live cells, a negative (T2/T2*) MRI contrast predominates, and is used to track cell delivery and cell migration. Upon cell death, a diffused positive (T1) MRI contrast is generated in the vicinity of the dead cells, and serves as an imaging marker for cell death. Ultimately, this technique could be used to manage stem cell therapies. PMID:26330231

Imaging transplanted stem cells in real time using an MRI dual-contrast method.

PubMed

Ngen, Ethel J; Wang, Lee; Kato, Yoshinori; Krishnamachary, Balaji; Zhu, Wenlian; Gandhi, Nishant; Smith, Barbara; Armour, Michael; Wong, John; Gabrielson, Kathleen; Artemov, Dmitri

2015-09-02

Stem cell therapies are currently being investigated for the repair of brain injuries. Although exogenous stem cell labelling with superparamagnetic iron oxide nanoparticles (SPIONs) prior to transplantation provides a means to noninvasively monitor stem cell transplantation by magnetic resonance imaging (MRI), monitoring cell death is still a challenge. Here, we investigate the feasibility of using an MRI dual-contrast technique to detect cell delivery, cell migration and cell death after stem cell transplantation. Human mesenchymal stem cells were dual labelled with SPIONs and gadolinium-based chelates (GdDTPA). The viability, proliferation rate, and differentiation potential of the labelled cells were then evaluated. The feasibility of this MRI technique to distinguish between live and dead cells was next evaluated using MRI phantoms, and in vivo using both immune-competent and immune-deficient mice, following the induction of brain injury in the mice. All results were validated with bioluminescence imaging. In live cells, a negative (T2/T2*) MRI contrast predominates, and is used to track cell delivery and cell migration. Upon cell death, a diffused positive (T1) MRI contrast is generated in the vicinity of the dead cells, and serves as an imaging marker for cell death. Ultimately, this technique could be used to manage stem cell therapies.

The secretome of endothelial progenitor cells promotes brain endothelial cell activity through PI3-kinase and MAP-kinase.

PubMed

Di Santo, Stefano; Seiler, Stefanie; Fuchs, Anna-Lena; Staudigl, Jennifer; Widmer, Hans Rudolf

2014-01-01

Angiogenesis and vascular remodelling are crucial events in tissue repair mechanisms promoted by cell transplantation. Current evidence underscores the importance of the soluble factors secreted by stem cells in tissue regeneration. In the present study we investigated the effects of paracrine factors derived from cultured endothelial progenitor cells (EPC) on rat brain endothelial cell properties and addressed the signaling pathways involved. Endothelial cells derived from rat brain (rBCEC4) were incubated with EPC-derived conditioned medium (EPC-CM). The angiogenic response of rBCEC4 to EPC-CM was assessed as effect on cell number, migration and tubular network formation. In addition, we have compared the outcome of the in vitro experiments with the effects on capillary sprouting from rat aortic rings. The specific PI3K/AKT inhibitor LY294002 and the MEK/ERK inhibitor PD98059 were used to study the involvement of these two signaling pathways in the transduction of the angiogenic effects of EPC-CM. Viable cell number, migration and tubule network formation were significantly augmented upon incubation with EPC-CM. Similar findings were observed for aortic ring outgrowth with significantly longer sprouts. The EPC-CM-induced activities were significantly reduced by the blockage of the PI3K/AKT and MEK/ERK signaling pathways. Similarly to the outcome of the rBCEC4 experiments, inhibition of the PI3K/AKT and MEK/ERK pathways significantly interfered with capillary sprouting induced by EPC-CM. The present study demonstrates that EPC-derived paracrine factors substantially promote the angiogenic response of brain microvascular endothelial cells. In addition, our findings identified the PI3K/AKT and MEK/ERK pathways to play a central role in mediating these effects.

Optimising parameters for the differentiation of SH-SY5Y cells to study cell adhesion and cell migration.

PubMed

Dwane, Susan; Durack, Edel; Kiely, Patrick A

2013-09-11

Cell migration is a fundamental biological process and has an important role in the developing brain by regulating a highly specific pattern of connections between nerve cells. Cell migration is required for axonal guidance and neurite outgrowth and involves a series of highly co-ordinated and overlapping signalling pathways. The non-receptor tyrosine kinase, Focal Adhesion Kinase (FAK) has an essential role in development and is the most highly expressed kinase in the developing CNS. FAK activity is essential for neuronal cell adhesion and migration. The objective of this study was to optimise a protocol for the differentiation of the neuroblastoma cell line, SH-SY5Y. We determined the optimal extracellular matrix proteins and growth factor combinations required for the optimal differentiation of SH-SY5Y cells into neuronal-like cells and determined those conditions that induce the expression of FAK. It was confirmed that the cells were morphologically and biochemically differentiated when compared to undifferentiated cells. This is in direct contrast to commonly used differentiation methods that induce morphological differentiation but not biochemical differentiation. We conclude that we have optimised a protocol for the differentiation of SH-SY5Y cells that results in a cell population that is both morphologically and biochemically distinct from undifferentiated SH-SY5Y cells and has a distinct adhesion and spreading pattern and display extensive neurite outgrowth. This protocol will provide a neuronal model system for studying FAK activity during cell adhesion and migration events.

Gpx 4 is involved in the proliferation, migration and apoptosis of glioma cells.

PubMed

Zhao, Hongyu; Ji, Bin; Chen, Jianguo; Huang, Qingfeng; Lu, Xueguan

2017-06-01

Glioma is one of the most common and aggressive types of human brain tumor, it is important to explore novel glioma-associated genes. In this report, we defined Gpx4 as a therapeutic target for glioma. Western blot and immunohistochemistry(IHC) analysis revealed that the protein level of Gpx4 was higher in glioma tissues and cell lines. In addition, IHC stain revealed that there was statistical significance between the expression of Gpx4 and the WHO grade (P=0.004) and Ki-67(P=0.000) expression. Kaplan-Meier curve showed that high expression of Gpx4 was associated with poor prognosis of glioma patients (P<0.01). To determine whether Gpx4 could regulate the proliferation and migration of glioma cells, we transfected glioma cells with Gpx4-siRNA and then investigated cell proliferation with cell counting kit (CCK) -8, flow cytometry assay and colony formation analyses, and we used wound-healing and transwell assays to investigate cell migration. Our results indicated that knockdown of Gpx4 would inhibit the proliferation and migration of glioma cells. Besides, silencing of Gpx4 could induce the apoptosis of glioma cells. This research indicated that Gpx4 might be thought of as a new prognostic factor in glioma and be closely correlated with glioma cell proliferation, migration and apoptosis. Copyright © 2017 Elsevier GmbH. All rights reserved.

Targeted deletion of RIC8A in mouse neural precursor cells interferes with the development of the brain, eyes, and muscles.

PubMed

Kask, Keiu; Tikker, Laura; Ruisu, Katrin; Lulla, Sirje; Oja, Eva-Maria; Meier, Riho; Raid, Raivo; Velling, Teet; Tõnissoo, Tambet; Pooga, Margus

2018-04-01

Autosomal recessive disorders such as Fukuyama congenital muscular dystrophy, Walker-Warburg syndrome, and the muscle-eye-brain disease are characterized by defects in the development of patient's brain, eyes, and skeletal muscles. These syndromes are accompanied by brain malformations like type II lissencephaly in the cerebral cortex with characteristic overmigrations of neurons through the breaches of the pial basement membrane. The signaling pathways activated by laminin receptors, dystroglycan and integrins, control the integrity of the basement membrane, and their malfunctioning may underlie the pathologies found in the rise of defects reminiscent of these syndromes. Similar defects in corticogenesis and neuromuscular disorders were found in mice when RIC8A was specifically removed from neural precursor cells. RIC8A regulates a subset of G-protein α subunits and in several model organisms, it has been reported to participate in the control of cell division, signaling, and migration. Here, we studied the role of RIC8A in the development of the brain, muscles, and eyes of the neural precursor-specific conditional Ric8a knockout mice. The absence of RIC8A severely affected the attachment and positioning of radial glial processes, Cajal-Retzius' cells, and the arachnoid trabeculae, and these mice displayed additional defects in the lens, skeletal muscles, and heart development. All the discovered defects might be linked to aberrancies in cell adhesion and migration, suggesting that RIC8A has a crucial role in the regulation of cell-extracellular matrix interactions and that its removal leads to the phenotype characteristic to type II lissencephaly-associated diseases. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 374-390, 2018. © 2018 Wiley Periodicals, Inc.

Cdk1 Activates Pre-mitotic Nuclear Envelope Dynein Recruitment and Apical Nuclear Migration in Neural Stem Cells.

PubMed

Baffet, Alexandre D; Hu, Daniel J; Vallee, Richard B

2015-06-22

Dynein recruitment to the nuclear envelope is required for pre-mitotic nucleus-centrosome interactions in nonneuronal cells and for apical nuclear migration in neural stem cells. In each case, dynein is recruited to the nuclear envelope (NE) specifically during G2 via two nuclear pore-mediated mechanisms involving RanBP2-BicD2 and Nup133-CENP-F. The mechanisms responsible for cell-cycle control of this behavior are unknown. We now find that Cdk1 serves as a direct master controller for NE dynein recruitment in neural stem cells and HeLa cells. Cdk1 phosphorylates conserved sites within RanBP2 and activates BicD2 binding and early dynein recruitment. Late recruitment is triggered by a Cdk1-induced export of CENP-F from the nucleus. Forced NE targeting of BicD2 overrides Cdk1 inhibition, fully rescuing dynein recruitment and nuclear migration in neural stem cells. These results reveal how NE dynein recruitment is cell-cycle regulated and identify the trigger mechanism for apical nuclear migration in the brain. Copyright © 2015 Elsevier Inc. All rights reserved.

Inhibition of type I insulin-like growth factor receptor signaling attenuates the development of breast cancer brain metastasis.

PubMed

Saldana, Sandra M; Lee, Heng-Huan; Lowery, Frank J; Khotskaya, Yekaterina B; Xia, Weiya; Zhang, Chenyu; Chang, Shih-Shin; Chou, Chao-Kai; Steeg, Patricia S; Yu, Dihua; Hung, Mien-Chie

2013-01-01

Brain metastasis is a common cause of mortality in cancer patients, yet potential therapeutic targets remain largely unknown. The type I insulin-like growth factor receptor (IGF-IR) is known to play a role in the progression of breast cancer and is currently being investigated in the clinical setting for various types of cancer. The present study demonstrates that IGF-IR is constitutively autophosphorylated in brain-seeking breast cancer sublines. Knockdown of IGF-IR results in a decrease of phospho-AKT and phospho-p70s6k, as well as decreased migration and invasion of MDA-MB-231Br brain-seeking cells. In addition, transient ablation of IGFBP3, which is overexpressed in brain-seeking cells, blocks IGF-IR activation. Using an in vivo experimental brain metastasis model, we show that IGF-IR knockdown brain-seeking cells have reduced potential to establish brain metastases. Finally, we demonstrate that the malignancy of brain-seeking cells is attenuated by pharmacological inhibition with picropodophyllin, an IGF-IR-specific tyrosine kinase inhibitor. Together, our data suggest that the IGF-IR is an important mediator of brain metastasis and its ablation delays the onset of brain metastases in our model system.

Surface topography during neural stem cell differentiation regulates cell migration and cell morphology.

PubMed

Czeisler, Catherine; Short, Aaron; Nelson, Tyler; Gygli, Patrick; Ortiz, Cristina; Catacutan, Fay Patsy; Stocker, Ben; Cronin, James; Lannutti, John; Winter, Jessica; Otero, José Javier

2016-12-01

We sought to determine the contribution of scaffold topography to the migration and morphology of neural stem cells by mimicking anatomical features of scaffolds found in vivo. We mimicked two types of central nervous system scaffolds encountered by neural stem cells during development in vitro by constructing different diameter electrospun polycaprolactone (PCL) fiber mats, a substrate that we have shown to be topographically similar to brain scaffolds. We compared the effects of large fibers (made to mimic blood vessel topography) with those of small-diameter fibers (made to mimic radial glial process topography) on the migration and differentiation of neural stem cells. Neural stem cells showed differential migratory and morphological reactions with laminin in different topographical contexts. We demonstrate, for the first time, that neural stem cell biological responses to laminin are dependent on topographical context. Large-fiber topography without laminin prevented cell migration, which was partially reversed by treatment with rock inhibitor. Cell morphology complexity assayed by fractal dimension was inhibited in nocodazole- and cytochalasin-D-treated neural precursor cells in large-fiber topography, but was not changed in small-fiber topography with these inhibitors. These data indicate that cell morphology has different requirements on cytoskeletal proteins dependent on the topographical environment encountered by the cell. We propose that the physical structure of distinct scaffolds induces unique signaling cascades that regulate migration and morphology in embryonic neural precursor cells. J. Comp. Neurol. 524:3485-3502, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Advanced Microscopic Imaging Methods to Investigate Cortical Development and the Etiology of Mental Retardation

ERIC Educational Resources Information Center

Haydar, Tarik F.

2005-01-01

Studies on human patients and animal models of disease have shown that disruptions in prenatal and early postnatal brain development are a root cause of mental retardation. Since proper brain development is achieved by a strict spatiotemporal control of neurogenesis, cell migration, and patterning of synapses, abnormalities in one or more of these…

Silencing of Urothelial Carcinoma Associated 1 Inhibits the Proliferation and Migration of Medulloblastoma Cells.

PubMed

Zhengyuan, Xie; Hu, Xiao; Qiang, Wang; Nanxiang, Li; Junbin, Cai; Wangming, Zhang

2017-09-16

BACKGROUND UCA1 is a long non-coding RNA that has been found to be aberrantly upregulated in various cancers. The aim of this study was to determine the expression level and function of UCA1 in medulloblastoma, the most common malignant brain tumor during childhood. MATERIAL AND METHODS Real-time PCR was used to detect the expression of UCA1 in medulloblastoma specimens and cell lines. Lentiviral-mediated expression of a short hairpin RNA (shRNA) targeting UCA1 or a negative control shRNA was also achieved with the medulloblastoma cell line, Daoy. Cell proliferation and cell cycle progression were subsequently characterized with cell counting kit (CCK)-8 and flow cytometry. Cell migration was examined in wound healing and Transwell migration assays. RESULTS Levels of UCA1 mRNA were higher in the medulloblastoma specimens (p<0.05) and cell lines (p<0.05) compared to the corresponding nontumor adjacent tissue specimens and a glioblastoma cell line, respectively. For the Daoy cells with silenced UCA1, their proliferation was reduced by 30% compared to the Daoy cells expressing a negative control shRNA (p=0.017). Cell cycle arrest in the G0/G1 phase, resulting in a decreased number of cells in the S phase, as well as reduced cell migration in both wound scratch healing (p=0.001) and Transwell migration assays (p=0.021) were also observed for the Daoy cells with silenced UCA1. CONCLUSIONS UCA1 was highly expressed in part of medulloblastoma specimens and cell lines examined. In addition, knockdown of UCA1 significantly inhibited the proliferation and migration of medulloblastoma cells in vitro.

Cdc42 and the Guanine Nucleotide Exchange Factors Ect2 and Trio Mediate Fn14-Induced Migration and Invasion of Glioblastoma Cells

PubMed Central

Fortin, Shannon P.; Ennis, Matthew J.; Schumacher, Cassie A.; Zylstra-Diegel, Cassandra R.; Williams, Bart O.; Ross, Julianna T.D.; Winkles, Jeffrey A.; Loftus, Joseph C.; Symons, Marc H.; Tran, Nhan L.

2012-01-01

Malignant glioblastomas are characterized by their ability to infiltrate into normal brain. We previously reported that binding of the multifunctional cytokine TNF-like weak inducer of apoptosis (TWEAK) to its receptor fibroblast growth factor–inducible 14 (Fn14) induces glioblastoma cell invasion via Rac1 activation. Here, we show that Cdc42 plays an essential role in Fn14-mediated activation of Rac1. TWEAK-treated glioma cells display an increased activation of Cdc42, and depletion of Cdc42 using siRNA abolishes TWEAK-induced Rac1 activation and abrogates glioma cell migration and invasion. In contrast, Rac1 depletion does not affect Cdc42 activation by Fn14, showing that Cdc42 mediates TWEAK-stimulated Rac1 activation. Furthermore, we identified two guanine nucleotide exchange factors (GEF), Ect2 and Trio, involved in TWEAK-induced activation of Cdc42 and Rac1, respectively. Depletion of Ect2 abrogates both TWEAK-induced Cdc42 and Rac1 activation, as well as subsequent TWEAK-Fn14–directed glioma cell migration and invasion. In contrast, Trio depletion inhibits TWEAK-induced Rac1 activation but not TWEAK-induced Cdc42 activation. Finally, inappropriate expression of Fn14 or Ect2 in mouse astrocytes in vivo using an RCAS vector system for glial-specific gene transfer in G-tva transgenic mice induces astrocyte migration within the brain, corroborating the in vitro importance of the TWEAK-Fn14 signaling cascade in glioblastoma invasion. Our results suggest that the TWEAK-Fn14 signaling axis stimulates glioma cell migration and invasion through two GEF-GTPase signaling units, Ect2-Cdc42 and Trio-Rac1. Components of the Fn14-Rho GEF-Rho GTPase signaling pathway present innovative drug targets for glioma therapy. PMID:22571869

BAG3 is involved in neuronal differentiation and migration.

PubMed

Santoro, Antonietta; Nicolin, Vanessa; Florenzano, Fulvio; Rosati, Alessandra; Capunzo, Mario; Nori, Stefania L

2017-05-01

Bcl2-associated athanogene 3 (BAG3) protein belongs to the family of co-chaperones interacting with several heat shock proteins. It plays a key role in protein quality control and mediates the clearance of misfolded proteins. Little is known about the expression and cellular localization of BAG3 during nervous system development and differentiation. Therefore, we analyze the subcellular distribution and expression of BAG3 in nerve-growth-factor-induced neurite outgrowth in PC12 cells and in developing and adult cortex of mouse brain. In differentiated PC12 cells, BAG3 was localized mainly in the neuritic domain rather than the cell body, whereas in control cells, it appeared to be confined to the cytoplasm near the nuclear membrane. Interestingly, the change of BAG3 localization during neuronal differentiation was associated only with a slight increase in total BAG3 expression. These data were coroborated by transmission electron microscopy showing that BAG3 was confined mainly within large dense-core vesicles of the axon in differentiated PC12 cells. In mouse developing cortex, BAG3 appeared to be intensely expressed in cellular processes of migrating cells, whereas in adult brain, a diffuse expression of low to medium intensity was detected in neuronal cell bodies. These findings suggest that BAG3 expression is required for neuronal differentiation and migration and that its role is linked to a change in its distribution pattern rather than to an increase in its protein expression levels.

Chemokine Receptor Ccr7 Restricts Fatal West Nile Virus Encephalitis.

PubMed

Bardina, Susana V; Brown, Julia A; Michlmayr, Daniela; Hoffman, Kevin W; Sum, Janet; Pletnev, Alexander G; Lira, Sergio A; Lim, Jean K

2017-05-15

West Nile virus (WNV) is a mosquito-transmitted flavivirus that can cause debilitating encephalitis. To delineate the mechanisms behind this pathology, we studied Ccr7-deficient mice, which afforded us the capacity to study infection in mice with disrupted peripheral cellular trafficking events. The loss of Ccr7 resulted in an immediate pan-leukocytosis that remained elevated throughout the infection. This leukocytosis resulted in a significant enhancement of leukocyte accumulation within the central nervous system (CNS). Despite an excess of virus-specific T cells in the CNS, Ccr7-deficient mice had significantly higher CNS viral loads and mortality rates than wild-type animals. Mechanistically, the elevated trafficking of infected myeloid cells into the brain in Ccr7-deficient mice resulted in increased levels of WNV in the CNS, thereby effectively contributing to neuroinflammation and lowering viral clearance. Combined, our experiments suggest that during WNV infection, Ccr7 is a gatekeeper for nonspecific viral transference to the brain. IMPORTANCE In this study, we show that Ccr7 is required for the sufficient migration of dendritic cells and T cells into the draining lymph node immediately following infection and for the restriction of leukocyte migration into the brain. Further, the severe loss of dendritic cells in the draining lymph node had no impact on viral replication in this organ, suggesting that WNV may migrate from the skin into the lymph node through another mechanism. Most importantly, we found that the loss of Ccr7 results in a significant leukocytosis, leading to hypercellularity within the CNS, where monocytes/macrophages contribute to CNS viremia, neuroinflammation, and increased mortality. Together, our data point to Ccr7 as a critical host defense restriction factor limiting neuroinflammation during acute viral infection. Copyright © 2017 American Society for Microbiology.

The role of drebrin in glioma migration and invasion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terakawa, Yuzo; Department of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka; Agnihotri, Sameer

Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite current advances in therapy consisting of surgery followed by chemotherapy and radiation, the overall survival rate still remains poor. Therapeutic failures are partly attributable to the highly infiltrative nature of tumor adjacent to normal brain parenchyma. Recently, evidence is mounting to suggest that actin cytoskeleton dynamics are critical components of the cell invasion process. Drebrin is an actin-binding protein involved in the regulation of actin filament organization, and plays a significant role in cell motility; however, the role of drebrin in glioma cell invasiveness has not yet beenmore » fully elucidated. Therefore, this study was aimed to clarify the role of drebrin in glioma cell morphology and cell motility. Here we show that drebrin is expressed in glioma cell lines and in operative specimens of GBM. We demonstrate that stable overexpression of drebrin in U87 cells leads to alterations in cell morphology, and induces increased invasiveness in vitro while knockdown of drebrin in U87 cells by small interfering RNA (siRNA) decreases invasion and migration. In addition, we show that depletion of drebrin by siRNA alters glioma cell morphology in A172 GBM cell line. Our results suggest that drebrin contributes to the maintenance of cell shape, and may play an important role in glioma cell motility. - Highlights: ► Drebrin is an actin-binding protein aberrantly expressed in several cancers. ► Role of drebrin in glioma cell morphology and motility is previously unknown. ► We demonstrate that drebrin is expressed in 40% of glioblastoma specimens. ► Drebrin plays a significant role in modulating glioma cell migration and invasion.« less

Stem cell-based therapies for tumors in the brain: are we there yet?

PubMed

Shah, Khalid

2016-08-01

Advances in understanding adult stem cell biology have facilitated the development of novel cell-based therapies for cancer. Recent developments in conventional therapies (eg, tumor resection techniques, chemotherapy strategies, and radiation therapy) for treating both metastatic and primary tumors in the brain, particularly glioblastoma have not resulted in a marked increase in patient survival. Preclinical studies have shown that multiple stem cell types exhibit inherent tropism and migrate to the sites of malignancy. Recent studies have validated the feasibility potential of using engineered stem cells as therapeutic agents to target and eliminate malignant tumor cells in the brain. This review will discuss the recent progress in the therapeutic potential of stem cells for tumors in the brain and also provide perspectives for future preclinical studies and clinical translation. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Potential involvement of kinesin-1 in the regulation of subcellular localization of Girdin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muramatsu, Aya; Enomoto, Atsushi, E-mail: enomoto@iar.nagoya-u.ac.jp; Kato, Takuya

Girdin is an actin-binding protein that has multiple functions in postnatal neural development and cancer progression. We previously showed that Girdin is a regulator of migration for neuroblasts born from neural stem cells in the subventricular zone (SVZ) and the dentate gyrus of the hippocampus in the postnatal brain. Despite a growing list of Girdin-interacting proteins, the mechanism of Girdin-mediated migration has not been fully elucidated. Girdin interacts with Disrupted-In-Schizophrenia 1 and partitioning-defective 3, both of which have been shown to interact with the kinesin microtubule motor proteins. Based on this, we have identified that Girdin also interacts with kinesin-1,more » a member of neuronal kinesin proteins. Although a direct interaction of Girdin and kinesin-1 has not been determined, it is of interest to find that Girdin loss-of-function mutant mice with the mutation of a basic amino acid residue-rich region (Basic mut mice) exhibit limited interaction with kinesin-1. Furthermore, expression of a kinesin-1 mutant with motor defects, leads to Girdin mislocalization. Finally, consistent with previous studies on the role of kinesin proteins in trafficking a cell–cell adhesion molecule N-cadherin, Basic mut mice showed an aberrant expression pattern of N-cadherin in migrating SVZ neuroblasts. These findings suggest a potential role of Girdin/kinesin-1 interaction in the regulation of neuroblast migration in the postnatal brain. - Highlights: • Girdin is a regulator of migration for neuroblasts in the postnatal brain. • Girdin interacts with kinesin-1, a member of neuronal kinesin proteins. • Girdin mutant mice showed an aberrant expression of N-cadherin in neuroblasts.« less

Reciprocal Activation of Transcription Factors Underlies the Dichotomy between Proliferation and Invasion of Glioma Cells

PubMed Central

Dhruv, Harshil D.; McDonough Winslow, Wendy S.; Armstrong, Brock; Tuncali, Serdar; Eschbacher, Jenny; Kislin, Kerri; Loftus, Joseph C.; Tran, Nhan L.; Berens, Michael E.

2013-01-01

Histology of malignant glioma depicts dense proliferative areas rich in angiogenesis as well as dissemination of neoplastic cells into adjacent brain tissue. Although the mechanisms that trigger transition from proliferative to invasive phenotypes are complex, the dichotomy of cell proliferation and migration, the “Go or Grow” hypothesis, argues for specific and coordinated regulation of these phenotypes. We investigated transcriptional elements that accompany the phenotypes of migration and proliferation, and consider the therapeutic significance of the “Go or Grow” hypothesis. Interrogation of matched core and rim regions from human glioblastoma biopsy specimens in situ (n = 44) revealed higher proliferation (Ki67 labeling index) in cells residing at the core compared to the rim. Profiling activated transcription factors in a panel of migration-activated versus migration-restricted GBM cells portrayed strong NF-κB activity in the migratory cell population. In contrast, increased c-Myc activity was found in migration-restricted proliferative cells. Validation of transcriptional activity by NF-κB- or c-Myc-driven GFP or RFP, respectively, showed an increased NF-κB activity in the active migrating cells, whereas the proliferative, migration restricted cells displayed increased c-Myc activity. Immunohistochemistry on clinical specimens validated a robust phosphorylated c-Myc staining in tumor cells at the core, whereas increased phosphorylated NF-κB staining was detected in the invasive tumor cells at the rim. Functional genomics revealed that depletion of c-Myc expression by siRNA oligonucleotides reduced cell proliferation in vitro, but surprisingly, cell migration was enhanced significantly. Conversely, inhibition of NF-κB by pharmacological inhibitors, SN50 or BAY-11, decreased both cell migration in vitro and invasion ex vivo. Notably, inhibition of NF-κB was found to have no effect on the proliferation rate of glioma cells. These findings suggest that the reciprocal and coordinated suppression/activation of transcription factors, such as c-Myc and NF-κB may underlie the shift of glioma cells from a “growing-to-going” phenotype. PMID:23967279

Brain perivascular macrophages: characterization and functional roles in health and disease.

PubMed

Faraco, Giuseppe; Park, Laibaik; Anrather, Josef; Iadecola, Costantino

2017-11-01

Perivascular macrophages (PVM) are a distinct population of resident brain macrophages characterized by a close association with the cerebral vasculature. PVM migrate from the yolk sac into the brain early in development and, like microglia, are likely to be a self-renewing cell population that, in the normal state, is not replenished by circulating monocytes. Increasing evidence implicates PVM in several disease processes, ranging from brain infections and immune activation to regulation of the hypothalamic-adrenal axis and neurovascular-neurocognitive dysfunction in the setting of hypertension, Alzheimer disease pathology, or obesity. These effects involve crosstalk between PVM and cerebral endothelial cells, interaction with circulating immune cells, and/or production of reactive oxygen species. Overall, the available evidence supports the idea that PVM are a key component of the brain-resident immune system with broad implications for the pathogenesis of major brain diseases. A better understanding of the biology and pathobiology of PVM may lead to new insights and therapeutic strategies for a wide variety of brain diseases.

RTVP-1 regulates glioma cell migration and invasion via interaction with N-WASP and hnRNPK

PubMed Central

Ziv-Av, Amotz; Giladi, Nissim David; Lee, Hae Kyung; Cazacu, Simona; Finniss, Susan; Xiang, Cunli; Pauker, Maor H.; Barda-Saad, Mira; Poisson, Laila; Brodie, Chaya

2015-01-01

Glioblastoma (GBM) are characterized by increased invasion into the surrounding normal brain tissue. RTVP-1 is highly expressed in GBM and regulates the migration and invasion of glioma cells. To further study RTVP-1 effects we performed a pull-down assay using His-tagged RTVP-1 followed by mass spectrometry and found that RTVP-1 was associated with the actin polymerization regulator, N-WASP. This association was further validated by co-immunoprecipitation and FRET analysis. We found that RTVP-1 increased cell spreading, migration and invasion and these effects were at least partly mediated by N-WASP. Another protein which was found by the pull-down assay to interact with RTVP-1 is hnRNPK. This protein has been recently reported to associate with and to inhibit the effect of N-WASP on cell spreading. hnRNPK decreased cell migration, spreading and invasion in glioma cells. Using co-immunoprecipitation we validated the interactions of hnRNPK with N-WASP and RTVP-1 in glioma cells. In addition, we found that overexpression of RTVP-1 decreased the association of N-WASP and hnRNPK. In summary, we report that RTVP-1 regulates glioma cell spreading, migration and invasion and that these effects are mediated via interaction with N-WASP and by interfering with the inhibitory effect of hnRNPK on the function of this protein. PMID:26305187

Presence of stromal cells in a bioengineered tumor microenvironment alters glioblastoma migration and response to STAT3 inhibition

PubMed Central

Voytik-Harbin, Sherry L.; Sarkaria, Jann N.; Pollok, Karen E.; Fishel, Melissa L.; Rickus, Jenna L.

2018-01-01

Despite the increasingly recognized importance of the tumor microenvironment (TME) as a regulator of tumor progression, only few in vitro models have been developed to systematically study the effects of TME on tumor behavior in a controlled manner. Here we developed a three-dimensional (3D) in vitro model that recapitulates the physical and compositional characteristics of Glioblastoma (GBM) extracellular matrix (ECM) and incorporates brain stromal cells such as astrocytes and endothelial cell precursors. The model was used to evaluate the effect of TME components on migration and survival of various patient-derived GBM cell lines (GBM10, GBM43 and GBAM1) in the context of STAT3 inhibition. Migration analysis of GBM within the 3D in vitro model demonstrated that the presence of astrocytes significantly increases the migration of GBM, while presence of endothelial precursors has varied effects on the migration of different GBM cell lines. Given the role of the tumor microenvironment as a regulator of STAT3 activity, we tested the effect of the STAT3 inhibitor SH-4-54 on GBM migration and survival. SH-4-54 inhibited STAT3 activity and reduced 3D migration and survival of GBM43 but had no effect on GBM10. SH-4-54 treatment drastically reduced the viability of the stem-like line GBAM1 in liquid culture, but its effect lessened in presence of a 3D ECM and stromal cells. Our results highlight the interplay between the ECM and stromal cells in the microenvironment with the cancer cells and indicate that the impact of these relationships may differ for GBM cells of varying genetic and clinical histories. PMID:29566069

The blood-brain barrier internalises Cryptococcus neoformans via the EphA2-tyrosine kinase receptor.

PubMed

Aaron, Phylicia A; Jamklang, Mantana; Uhrig, John P; Gelli, Angie

2018-03-01

Cryptococcus neoformans is an opportunistic fungal pathogen that causes life-threatening meningitis most commonly in populations with impaired immunity. Here, we resolved the transcriptome of the human brain endothelium challenged with C. neoformans to establish whether C. neoformans invades the CNS by co-opting particular signalling pathways as a means to promote its own entry. Among the 5 major pathways targeted by C. neoformans, the EPH-EphrinA1 (EphA2) tyrosine kinase receptor-signalling pathway was examined further. Silencing the EphA2 receptor transcript in a human brain endothelial cell line or blocking EphA2 activity with an antibody or chemical inhibitor prevented transmigration of C. neoformans in an in vitro model of the blood-brain barrier (BBB). In contrast, treating brain endothelial cells with an EphA2 chemical agonist or an EphA2 ligand promoted greater migration of fungal cells across the BBB. C. neoformans activated the EPH-tyrosine kinase pathway through a CD44-dependent phosphorylation of EphA2, promoting clustering and internalisation of EphA2 receptors. Moreover, HEK293T cells expressing EphA2 revealed an association between EphA2 and C. neoformans that boosted internalisation of C. neoformans. Collectively, the results suggest that C. neoformans promotes EphA2 activity via CD44, and this in turn creates a permeable barrier that facilitates the migration of C. neoformans across the BBB. © 2017 John Wiley & Sons Ltd.

Microglia During Development and Aging

PubMed Central

Harry, G. Jean

2013-01-01

Microglia are critical nervous system-specific cells influencing brain development, maintenance of the neural environment, response to injury, and repair. They contribute to neuronal proliferation and differentiation, pruning of dying neurons, synaptic remodeling and clearance of debris and aberrant proteins. Colonization of the brain occurs during gestation with an expansion following birth with localization stimulated by programmed neuronal death, synaptic pruning, andaxonal degeneration. Changes inmicroglia phenotype relate to cellular processes including specific neurotransmitter, pattern recognition, or immune-related receptor activation. Upon activation, microglia cells have the capacity to release a number of substances, e.g., cytokines, chemokines, nitric oxide, and reactive oxygen species, which could be detrimental or beneficial to the surrounding cells. With aging, microglia shift their morphology and may display diminished capacity for normal functions related to migration, clearance, and the ability to shift from a pro-inflammatory to an anti-inflammatory state to regulate injury and repair. This shift in microgliapotentially contributes to increased susceptibility and neurodegeneration as a function of age. In the current review, information is provided on the colonization of the brain by microglia, the expression of various pattern recognition receptors to regulate migration and phagocytosis, and the shift in related functions that occur in normal aging. PMID:23644076

Glioma cell dispersion is driven by α5 integrin-mediated cell-matrix and cell-cell interactions.

PubMed

Blandin, Anne-Florence; Noulet, Fanny; Renner, Guillaume; Mercier, Marie-Cécile; Choulier, Laurence; Vauchelles, Romain; Ronde, Philippe; Carreiras, Franck; Etienne-Selloum, Nelly; Vereb, Gyorgy; Lelong-Rebel, Isabelle; Martin, Sophie; Dontenwill, Monique; Lehmann, Maxime

2016-07-01

Glioblastoma multiform (GBM) is the most common and most aggressive primary brain tumor. The fibronectin receptor, α5 integrin is a pertinent novel therapeutic target. Despite numerous data showing that α5 integrin support tumor cell migration and invasion, it has been reported that α5 integrin can also limit cell dispersion by increasing cell-cell interaction. In this study, we showed that α5 integrin was involved in cell-cell interaction and gliomasphere formation. α5-mediated cell-cell cohesion limited cell dispersion from spheroids in fibronectin-poor microenvironment. However, in fibronectin-rich microenvironment, α5 integrin promoted cell dispersion. Ligand-occupied α5 integrin and fibronectin were distributed in fibril-like pattern at cell-cell junction of evading cells, forming cell-cell fibrillar adhesions. Activated focal adhesion kinase was not present in these adhesions but was progressively relocalized with α5 integrin as cell migrates away from the spheroids. α5 integrin function in GBM appears to be more complex than previously suspected. As GBM overexpressed fibronectin, it is most likely that in vivo, α5-mediated dissemination from the tumor mass overrides α5-mediated tumor cell cohesion. In this respect, α5-integrin antagonists may be useful to limit GBM invasion in brain parenchyma. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Leading-process actomyosin coordinates organelle positioning and adhesion receptor dynamics in radially migrating cerebellar granule neurons

DOE PAGES

Trivedi, Niraj; Ramahi, Joseph S.; Karakaya, Mahmut; ...

2014-12-02

During brain development, neurons migrate from germinal zones to their final positions to assemble neural circuits. A unique saltatory cadence involving cyclical organelle movement (e.g., centrosome motility) and leading-process actomyosin enrichment prior to nucleokinesis organizes neuronal migration. While functional evidence suggests that leading-process actomyosin is essential for centrosome motility, the role of the actin-enriched leading process in globally organizing organelle transport or traction forces remains unexplored. Our results show that myosin ii motors and F-actin dynamics are required for Golgi apparatus positioning before nucleokinesis in cerebellar granule neurons (CGNs) migrating along glial fibers. Moreover, we show that primary cilia aremore » motile organelles, localized to the leading-process F-actin-rich domain and immobilized by pharmacological inhibition of myosin ii and F-actin dynamics. Finally, leading process adhesion dynamics are dependent on myosin ii and F-actin. In conclusion, we propose that actomyosin coordinates the overall polarity of migrating CGNs by controlling asymmetric organelle positioning and cell-cell contacts as these cells move along their glial guides.« less

Leading-process actomyosin coordinates organelle positioning and adhesion receptor dynamics in radially migrating cerebellar granule neurons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trivedi, Niraj; Ramahi, Joseph S.; Karakaya, Mahmut

During brain development, neurons migrate from germinal zones to their final positions to assemble neural circuits. A unique saltatory cadence involving cyclical organelle movement (e.g., centrosome motility) and leading-process actomyosin enrichment prior to nucleokinesis organizes neuronal migration. While functional evidence suggests that leading-process actomyosin is essential for centrosome motility, the role of the actin-enriched leading process in globally organizing organelle transport or traction forces remains unexplored. Our results show that myosin ii motors and F-actin dynamics are required for Golgi apparatus positioning before nucleokinesis in cerebellar granule neurons (CGNs) migrating along glial fibers. Moreover, we show that primary cilia aremore » motile organelles, localized to the leading-process F-actin-rich domain and immobilized by pharmacological inhibition of myosin ii and F-actin dynamics. Finally, leading process adhesion dynamics are dependent on myosin ii and F-actin. In conclusion, we propose that actomyosin coordinates the overall polarity of migrating CGNs by controlling asymmetric organelle positioning and cell-cell contacts as these cells move along their glial guides.« less

Optimising parameters for the differentiation of SH-SY5Y cells to study cell adhesion and cell migration

PubMed Central

2013-01-01

Background Cell migration is a fundamental biological process and has an important role in the developing brain by regulating a highly specific pattern of connections between nerve cells. Cell migration is required for axonal guidance and neurite outgrowth and involves a series of highly co-ordinated and overlapping signalling pathways. The non-receptor tyrosine kinase, Focal Adhesion Kinase (FAK) has an essential role in development and is the most highly expressed kinase in the developing CNS. FAK activity is essential for neuronal cell adhesion and migration. Results The objective of this study was to optimise a protocol for the differentiation of the neuroblastoma cell line, SH-SY5Y. We determined the optimal extracellular matrix proteins and growth factor combinations required for the optimal differentiation of SH-SY5Y cells into neuronal-like cells and determined those conditions that induce the expression of FAK. It was confirmed that the cells were morphologically and biochemically differentiated when compared to undifferentiated cells. This is in direct contrast to commonly used differentiation methods that induce morphological differentiation but not biochemical differentiation. Conclusions We conclude that we have optimised a protocol for the differentiation of SH-SY5Y cells that results in a cell population that is both morphologically and biochemically distinct from undifferentiated SH-SY5Y cells and has a distinct adhesion and spreading pattern and display extensive neurite outgrowth. This protocol will provide a neuronal model system for studying FAK activity during cell adhesion and migration events. PMID:24025096

Effect of lapatinib on the outgrowth of metastatic breast cancer cells to the brain.

PubMed

Gril, Brunilde; Palmieri, Diane; Bronder, Julie L; Herring, Jeanne M; Vega-Valle, Eleazar; Feigenbaum, Lionel; Liewehr, David J; Steinberg, Seth M; Merino, Maria J; Rubin, Stephen D; Steeg, Patricia S

2008-08-06

The brain is increasingly being recognized as a sanctuary site for metastatic tumor cells in women with HER2-overexpressing breast cancer who receive trastuzumab therapy. There are no approved or widely accepted treatments for brain metastases other than steroids, cranial radiotherapy, and surgical resection. We examined the efficacy of lapatinib, an inhibitor of the epidermal growth factor receptor (EGFR) and HER2 kinases, for preventing the outgrowth of breast cancer cells in the brain in a mouse xenograft model of brain metastasis. EGFR-overexpressing MDA-MB-231-BR (231-BR) brain-seeking breast cancer cells were transfected with an expression vector that contained or lacked the HER2 cDNA and used to examine the effect of lapatinib on the activation (ie, phosphorylation) of cell signaling proteins by immunoblotting, on cell growth by the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, and on cell migration using a Boyden chamber assay. The outgrowth of large (ie, >50 microm(2)) and micrometastases was counted in brain sections from nude mice that had been injected into the left cardiac ventricle with 231-BR cells and, beginning 5 days later, treated by oral gavage with lapatinib or vehicle (n = 22-26 mice per treatment group). All statistical tests were two-sided. In vitro, lapatinib inhibited the phosphorylation of EGFR, HER2, and downstream signaling proteins; cell proliferation; and migration in 231-BR cells (both with and without HER2). Among mice injected with 231-BR-vector cells, those treated with 100 mg lapatinib/kg body weight had 54% fewer large metastases 24 days after starting treatment than those treated with vehicle (mean number of large metastases per brain section: 1.56 vs 3.36, difference = 1.80, 95% confidence interval [CI] = 0.92 to 2.68, P < .001), whereas treatment with 30 mg lapatinib/kg body weight had no effect. Among mice injected with 231-BR-HER2 cells, those treated with either dose of lapatinib had 50%-53% fewer large metastases than those treated with vehicle (mean number of large metastases per brain section, 30 mg/kg vs vehicle: 3.21 vs 6.83, difference = 3.62, 95% CI = 2.30 to 4.94, P < .001; 100 mg/kg vs vehicle: 3.44 vs 6.83, difference = 3.39, 95% CI = 2.08 to 4.70, P < .001). Immunohistochemical analysis revealed reduced phosphorylation of HER2 in 231-BR-HER2 cell-derived brain metastases from mice treated with the higher dose of lapatinib compared with 231-BR-HER2 cell-derived brain metastases from vehicle-treated mice (P < .001). Lapatinib is the first HER2-directed drug to be validated in a preclinical model for activity against brain metastases of breast cancer.

ADAM13 function is required in the 3 dimensional context of the embryo during cranial neural crest cell migration in Xenopus laevis

PubMed Central

Cousin, Hélène; Abbruzzese, Genevieve; McCusker, Catherine; Alfandari, Dominique

2012-01-01

The cranial neural crest (CNC) is a population of cells that arises from the lateral part of the developing brain, migrates ventrally and coordinates the entire craniofacial development of vertebrates. Many molecules are involved in CNC migration including the transmembrane metalloproteases ADAM13 and 19. We have previously shown that these ADAMs cleave a number of extracellular proteins and modify the transcription of a number of genes, and that both of these activities are important for cell migration. Here we show that the knock down of ADAM13 inhibits CNC migration in vivo but not in vitro, indicating that ADAM13 function is required in the 3-dimentional context of the embryo. We further show that the migration of CNC that do not express ADAM13 and ADAM19 can be rescued in vivo by co-grafting wild type CNC. Furthermore, the migration of CNC lacking ADAM13 can be rescued by mechanically separating the CNC from the surrounding ectoderm and mesoderm. Finally, we show that ADAM13 function is autonomous to CNC tissue, as the migration of morphant CNC can only be rescued by ADAM13 expression in the CNC and not the surrounding tissues. Together our results suggest that ADAM13 changes CNC interaction with the extracellular environment and that this change is necessary for their migration in vivo. PMID:22683825

Magneto-optical labeling of fetal neural stem cells for in vivo MRI tracking.

PubMed

Flexman, J A; Minoshima, S; Kim, Y; Cross, D J

2006-01-01

Neural stem cell therapy for neurological pathologies, such as Alzheimer's and Parkinson's disease, may delay the onset of symptoms, replace damaged neurons and/or support the survival of endogenous cells. Magnetic resonance imaging (MRI) can be used to track magnetically labeled cells in vivo to observe migration. Prior to transplantation, labeled cells must be characterized to show that they retain their intrinsic properties, such as cell proliferation into neurospheres in a supplemented environment. In vivo images must also be correlated to sensitive, histological markers. In this study, we show that fetus-derived neural stem cells can be co-labeled with superparamagnetic iron oxide and PKH26, a fluorescent dye. Labeled cells retain the ability to proliferate into neurospheres in culture, but labeling prevents neurospheres from merging in a non-adherent culture environment. After labeled NSCs were transplantation into the rat brain, their location and subsequent migration along the corpus callosum was detected using MRI. This study demonstrates an imaging paradigm with which to develop an in vivo assay for quantitatively evaluating fetal neural stem cell migration.

Cytotoxic T Lymphocyte Trafficking and Survival in an Augmented Fibrin Matrix Carrier

PubMed Central

Zou, Zhaoxia; Denny, Erin; Brown, Christine E.; Jensen, Michael C.; Li, Gang; Fujii, Tatsuhiro; Neman, Josh; Jandial, Rahul; Chen, Mike

2012-01-01

Cell-based therapies have intriguing potential for the treatment of a variety of neurological disorders. One such example is genetically engineered cytotoxic T lymphocytes (CTLs) that are being investigated in brain tumor clinical trials. The development of methods for CTL delivery is critical to their use in the laboratory and clinical setting. In our study, we determined whether CTLs can migrate through fibrin matrices and if their migration, survival, and function could be modulated by adding chemokines to the matrix. Our results indicated that CTLs can freely migrate through fibrin matrices. As expected, the addition of the monocyte chemotactic protein-1 (MCP-1), also known as chemokine C-C motif ligand 2 (CCL2), to the surrounding media increased egress of the CTLs out of the fibrin clot. Interleukin (IL) -2 and/or IL-15 embedded in the matrix enhanced T cell survival and further promoted T cell migration. The interleukin-13 receptor alpha 2 specific (IL-13R alpha2) T cells that traveled out of the fibrin clot retained the capacity to kill U251 glioma cells. In summary, CTLs can survive and migrate robustly in fibrin matrices. These processes can be influenced by modification of matrix constituents. We conclude that fibrin matrices may be suitable T cell carriers and can be used to facilitate understanding of T cell interaction with the surrounding microenvironment. PMID:22496835

Cytotoxic T lymphocyte trafficking and survival in an augmented fibrin matrix carrier.

PubMed

Zou, Zhaoxia; Denny, Erin; Brown, Christine E; Jensen, Michael C; Li, Gang; Fujii, Tatsuhiro; Neman, Josh; Jandial, Rahul; Chen, Mike

2012-01-01

Cell-based therapies have intriguing potential for the treatment of a variety of neurological disorders. One such example is genetically engineered cytotoxic T lymphocytes (CTLs) that are being investigated in brain tumor clinical trials. The development of methods for CTL delivery is critical to their use in the laboratory and clinical setting. In our study, we determined whether CTLs can migrate through fibrin matrices and if their migration, survival, and function could be modulated by adding chemokines to the matrix. Our results indicated that CTLs can freely migrate through fibrin matrices. As expected, the addition of the monocyte chemotactic protein-1 (MCP-1), also known as chemokine C-C motif ligand 2 (CCL2), to the surrounding media increased egress of the CTLs out of the fibrin clot. Interleukin (IL) -2 and/or IL-15 embedded in the matrix enhanced T cell survival and further promoted T cell migration. The interleukin-13 receptor alpha 2 specific (IL-13R alpha2) T cells that traveled out of the fibrin clot retained the capacity to kill U251 glioma cells. In summary, CTLs can survive and migrate robustly in fibrin matrices. These processes can be influenced by modification of matrix constituents. We conclude that fibrin matrices may be suitable T cell carriers and can be used to facilitate understanding of T cell interaction with the surrounding microenvironment.

The Innate Immune Receptor CD14 Mediates Lymphocyte Migration in EAE.

PubMed

Halmer, Ramona; Davies, Laura; Liu, Yang; Fassbender, Klaus; Walter, Silke

2015-01-01

Multiple sclerosis is the most common autoimmune disease of the central nervous system in young adults and histopathologically characterized by inflammation, demyelination and gliosis. It is considered as a CD4+ T cell-mediated disease, but also a disease-promoting role of the innate immune system has been proposed, based e.g. on the observation that innate immune receptors modulate disease severity of experimental autoimmune encephalomyelitis. Recent studies of our group provided first evidence for a key role of the innate immune LPS receptor (CD14) in pathophysiology of experimental autoimmune encephalomyelitis. CD14-deficient experimental autoimmune encephalomyelitis mice showed increased clinical symptoms and enhanced infiltration of monocytes and neutrophils in brain and spinal cord. In the current study, we further investigated the causes of the disease aggravation by CD14-deficiency and examined T cell activation, also focusing on the costimulatory molecules CTLA-4 and CD28, and T cell migration capacity over the blood brain barrier by FACS analysis, in vitro adhesion and transmigration assays. In the results, we observed a significantly increased migration of CD14-deficient lymphocytes across an endothelial monolayer. In contrast, we did not see any differences in expression levels of TCR/CTLA-4 or TCR/CD28 and lymphocyte adhesion to endothelial cells from CD14-deficient compared to wildtype mice. The results demonstrate an important role of CD14 in migration of lymphocytes, and strengthen the importance of innate immune receptors in adaptive immune disorders, such as multiple sclerosis. © 2015 The Author(s) Published by S. Karger AG, Basel.

Pcdh19 Loss-of-Function Increases Neuronal Migration In Vitro but is Dispensable for Brain Development in Mice

PubMed Central

Pederick, Daniel T.; Homan, Claire C.; Jaehne, Emily J.; Piltz, Sandra G.; Haines, Bryan P.; Baune, Bernhard T.; Jolly, Lachlan A.; Hughes, James N.; Gecz, Jozef; Thomas, Paul Q.

2016-01-01

Protocadherin 19 (Pcdh19) is an X-linked gene belonging to the protocadherin superfamily, whose members are predominantly expressed in the central nervous system and have been implicated in cell-cell adhesion, axon guidance and dendrite self-avoidance. Heterozygous loss-of-function mutations in humans result in the childhood epilepsy disorder PCDH19 Girls Clustering Epilepsy (PCDH19 GCE) indicating that PCDH19 is required for brain development. However, understanding PCDH19 function in vivo has proven challenging and has not been studied in mammalian models. Here, we validate a murine Pcdh19 null allele in which a β-Geo reporter cassette is expressed under the control of the endogenous promoter. Analysis of β-Geo reporter activity revealed widespread but restricted expression of PCDH19 in embryonic, postnatal and adult brains. No gross morphological defects were identified in Pcdh19+/β-Geo and Pcdh19Y/β-Geo brains and the location of Pcdh19 null cells was normal. However, in vitro migration assays revealed that the motility of Pcdh19 null neurons was significantly elevated, potentially contributing to pathogenesis in patients with PCDH19 mutations. Overall our initial characterization of Pcdh19+/β-Geo, Pcdh19β-Geo/β-Geo and Pcdh19Y/β-Geomice reveals that despite widespread expression of Pcdh19 in the CNS, and its role in human epilepsy, its function in mice is not essential for brain development. PMID:27240640

Nitric oxide donor up-regulation of SDF1/CXCR4 and Ang1/Tie2 promotes neuroblast cell migration after stroke.

PubMed

Cui, Xu; Chen, Jieli; Zacharek, Alex; Roberts, Cynthia; Yang, Yuping; Chopp, Michael

2009-01-01

We tested the hypothesis that a nitric oxide donor, DETA-NONOate, up-regulates stromal cell-derived factor-1 (SDF1) and angiopoietin 1 (Ang1) in the ischemic brain and their respective receptors chemokine CXC motif receptor 4 (CXCR4) and Tie2 in the subventricular zone (SVZ) and thereby promote SVZ neuroblast cell migration after stroke. C57BL/6J mice were subjected to middle cerebral artery occlusion (MCAo), and 24 hr later DETA-NONOate (0.4 mg/kg) or phosphate-buffered solution was intravenously administered. Mice were sacrificed at 14 days for histological assessment or sacrificed at 3 days for analysis by real-time polymerase chain reaction and migration after MCAo. To elucidate whether SDF1/CXCR4 and Ang1/Tie2 pathways mediate DETA-NONOate-induced SVZ migration after stroke, SDF1alpha, Ang1 peptide, a specific antagonist of CXCR4 (AMD3100), and a neutralizing antibody of Tie2 (anti-Tie2) were used in vitro. DETA-NONOate significantly increased the percentage area of doublecortin (DCX, a marker of migrating neuroblasts)-immunoreactive cells in the SVZ and ischemic boundary zone. DETA-NONOate significantly increased the expression of SDF1 and Ang1 in the ischemic border and up-regulated CXCR4 and Tie2 in the SVZ compared with MCAo control. DCX-positive cell migration from SVZ explants was significantly increased in the DETA-NONOate treatment group compared with MCAo-alone animals. In vitro, SDF1alpha and Ang1 significantly increased SVZ explants cell migration. In addition, inhibition of CXCR4 or Tie2 significantly attenuated DETA-NONOate-induced SVZ cell migration. Our data indicate that treatment of stroke with a nitric oxide donor up-regulates SDF1/CXCR4 and Ang1/Tie2 pathways and thereby likely increases SVZ neuroblast cell migration. 2008 Wiley-Liss, Inc.

Nitric Oxide Donor Upregulation of SDF1/CXCR4 and Ang1/Tie2 Promotes Neuroblast Cell Migration After Stroke

PubMed Central

Cui, Xu; Chen, Jieli; Zacharek, Alex; Roberts, Cynthia; Yang, Yuping; Chopp, Michael

2008-01-01

We tested the hypothesis that a nitric oxide donor, DETA-NONOate upregulates Stromal cell-Derived Factor-1 (SDF1) and Angiopoietin 1 (Ang1) in the ischemic brain and their, respective, receptors chemokine CXC motif receptor 4 (CXCR4) and Tie2 in the subventricular zone (SVZ) and thereby promote SVZ neuroblast cell migration after stroke. C57BL/6J mice were subjected to middle cerebral artery occlusion (MCAo) and 24 hours later DETA-NONOate (0.4 mg/kg) or phosphate buffered solution were intravenously administered. Mice were sacrificed at 14 days for histological assessment or sacrificed at 3 days for analysis real-time polymerase chain reaction and migration after MCAo. To elucidate whether SDF1/CXCR4 and Ang1/Tie2 pathways mediate DETA-NONOate induced SVZ migration after stroke, SDF1α, Ang1 peptide and a specific antagonist of CXCR4 (AMD3100) and a neutralizing antibody of Tie2 (anti-Tie2) were used in vitro. DETA-NONOate significantly increased the percent area of doublecortin (a marker of migrating neuroblasts) immunoreactive-cells in the SVZ and ischemic boundary zone. DETA-NONOate significantly increased the expression of SDF1 and Ang1 in the ischemic border and upregulated CXCR4 and Tie2 in the SVZ compared with MCAo control. DCX-positive cell migration from SVZ explants was significantly increased in the DETA-NONOate treatment group compared with MCAo alone animals. In vitro, SDF1α and Ang1 significantly increased SVZ explants cell migration. In addition, inhibition of CXCR4 or Tie2 significantly attenuated DETA-NONOate induced SVZ cell migration. Our data indicated that treatment of stroke with a nitric oxide donor upregulates SDF1/CXCR4 and Ang1/Tie2 pathways and thereby likely increases SVZ neuroblast cell migration. PMID:18711749

Transspinal direct current stimulation modulates migration and proliferation of adult newly born spinal cells in mice.

PubMed

Samaddar, Sreyashi; Vazquez, Kizzy; Ponkia, Dipen; Toruno, Pedro; Sahbani, Karim; Begum, Sultana; Abouelela, Ahmed; Mekhael, Wagdy; Ahmed, Zaghloul

2017-02-01

Direct current electrical fields have been shown to be a major factor in the regulation of cell proliferation, differentiation, migration, and survival, as well as in the maturation of dividing cells during development. During adulthood, spinal cord cells are continuously produced in both animals and humans, and they hold great potential for neural restoration following spinal cord injury. While the effects of direct current electrical fields on adult-born spinal cells cultured ex vivo have recently been reported, the effects of direct current electrical fields on adult-born spinal cells in vivo have not been characterized. Here, we provide convincing findings that a therapeutic form of transspinal direct current stimulation (tsDCS) affects the migration and proliferation of adult-born spinal cells in mice. Specifically, cathodal tsDCS attracted the adult-born spinal cells, while anodal tsDCS repulsed them. In addition, both tsDCS polarities caused a significant increase in cell number. Regarding the potential mechanisms involved, both cathodal and anodal tsDCS caused significant increases in expression of brain-derived neurotrophic factor, while expression of nerve growth factor increased and decreased, respectively. In the spinal cord, both anodal and cathodal tsDCS increased blood flow. Since blood flow and angiogenesis are associated with the proliferation of neural stem cells, increased blood flow may represent a major factor in the modulation of newly born spinal cells by tsDCS. Consequently, we propose that the method and novel findings presented in the current study have the potential to facilitate cellular, molecular, and/or bioengineering strategies to repair injured spinal cords. NEW & NOTEWORTHY Our results indicate that transspinal direct current stimulation (tsDCS) affects the migratory pattern and proliferation of adult newly born spinal cells, a cell population which has been implicated in learning and memory. In addition, our results suggest a potential mechanism of action regarding the functional effects of applying direct current. Thus tsDCS may represent a novel method by which to manipulate the migration and cell number of adult newly born cells and restore functions following brain or spinal cord injury. Copyright © 2017 the American Physiological Society.

Secoisolariciresinol diglucoside is a blood-brain barrier protective and anti-inflammatory agent: implications for neuroinflammation.

PubMed

Rom, Slava; Zuluaga-Ramirez, Viviana; Reichenbach, Nancy L; Erickson, Michelle A; Winfield, Malika; Gajghate, Sachin; Christofidou-Solomidou, Melpo; Jordan-Sciutto, Kelly L; Persidsky, Yuri

2018-01-27

Secoisolariciresinol diglucoside (SDG), the main lignan in flaxseed, is known for its beneficial effects in inflammation, oxidative stress, heart disease, tumor progression, atherosclerosis, and diabetes. SDG might be an attractive natural compound that protects against neuroinflammation. Yet, there are no comprehensive studies to date investigating the effects of SDG on brain endothelium using relevant in vivo and in vitro models. We evaluated the effects of orally administered SDG on neuroinflammatory responses using in vivo imaging of the brain microvasculature during systemic inflammation and aseptic encephalitis. In parallel, the anti-inflammatory actions of SDG on brain endothelium and monocytes were evaluated in vitro blood-brain barrier (BBB) model. Multiple group comparisons were performed by one-way analysis of variance with Dunnet's post hoc tests. We found that SDG diminished leukocyte adhesion to and migration across the BBB in vivo in the setting of aseptic encephalitis (intracerebral TNFα injection) and prevented enhanced BBB permeability during systemic inflammatory response (LPS injection). In vitro SDG pretreatment of primary human brain microvascular endothelial cells (BMVEC) or human monocytes diminished adhesion and migration of monocytes across brain endothelial monolayers in conditions mimicking CNS inflammatory responses. Consistent with our in vivo observations, SDG decreased expression of the adhesion molecule, VCAM1, induced by TNFα, or IL-1β in BMVEC. SDG diminished expression of the active form of VLA-4 integrin (promoting leukocyte adhesion and migration) and prevented the cytoskeleton changes in primary human monocytes activated by relevant inflammatory stimuli. This study indicates that SDG directly inhibits BBB interactions with inflammatory cells and reduces the inflammatory state of leukocytes. Though more work is needed to determine the mechanism by which SDG mediates these effects, the ability of SDG to exert a multi-functional response reducing oxidative stress, inflammation, and BBB permeability makes it an exciting potential therapeutic for neuroinflammatory diseases. SDG can serve as an anti-inflammatory and barrier-protective agent in neuroinflammation.

Genetic mapping of Foxb1-cell lineage shows migration from caudal diencephalon to telencephalon and lateral hypothalamus

PubMed Central

Zhao, Tianyu; Szabó, Nora; Ma, Jun; Luo, Lingfei; Zhou, Xunlei; Alvarez-Bolado, Gonzalo

2008-01-01

The hypothalamus is a brain region with vital functions, and alterations in its development can cause human disease. However, we still do not have a complete description of how this complex structure is put together during embryonic and early postnatal stages. Radially oriented, outside-in migration of cells is prevalent in the developing hypothalamus. In spite of this, cell contingents from outside the hypothalamus as well as tangential hypothalamic migrations also have an important role. Here we study migrations in the hypothalamic primordium by genetically labeling the Foxb1 diencephalic lineage. Foxb1 is a transcription factor gene expressed in the neuroepithelium of the developing neural tube with a rostral expression boundary between caudal and rostral diencephalon, and therefore appropriate for marking migrations from caudal levels into the hypothalamus. We have found a large, longitudinally oriented migration stream apparently originating in the thalamic region and following an axonal bundle to end in the anterior portion of the lateral hypothalamic area. Additionally, we have mapped a specific expansion of the neuroepithelium into the rostral diencephalon. The expanded neuroepithelium generates abundant neurons for the medial hypothalamus at the tuberal level. Finally, we have uncovered novel diencephalon-to-telencephalon migrations into septum, piriform cortex and amygdala. PMID:19046377

Precursor N-cadherin mediates glial cell line-derived neurotrophic factor-promoted human malignant glioma

PubMed Central

Zhu, Shuang; Zhang, Baole; Qin, Yuxia; Yao, Ruiqin; Zhou, Hao; Gao, Dian Shuai

2017-01-01

As the most prevalent primary brain tumor, gliomas are highly metastatic, invasive and are characteristic of high levels of glial cell-line derived neurotrophic factor (GDNF). GDNF is an important factor for invasive glioma cell growth; however, the underlying mechanism involved is unclear. In this study, we affirm a significantly higher expression of the precursor of N-cadherin (proN-cadherin) in most gliomas compared with normal brain tissues. Our findings reveal that GDNF interacts with the extracellular domain of proN-cadherin, which suggests that proN-cadherin mediates GDNF-induced glioma cell migration and invasion. We hypothesize that proN-cadherin might cause homotypic adhesion loss within neighboring cells and at the same time promote heterotypic adhesion within the extracellular matrix (ECM) through a certain mechanism. This study also demonstrates that the interaction between GDNF and proN-cadherin activates specific intracellular signaling pathways; furthermore, GDNF promoted the secretion of matrix metalloproteinase-9 (MMP-9), which degrades the ECM via proN-cadherin. To reach the future goal of developing novel therapies of glioma, this study, reveals a unique mechanism of glioma cell migration and invasion. PMID:28212546

Precursor N-cadherin mediates glial cell line-derived neurotrophic factor-promoted human malignant glioma.

PubMed

Xiong, Ye; Liu, Liyun; Zhu, Shuang; Zhang, Baole; Qin, Yuxia; Yao, Ruiqin; Zhou, Hao; Gao, Dian Shuai

2017-04-11

As the most prevalent primary brain tumor, gliomas are highly metastatic, invasive and are characteristic of high levels of glial cell-line derived neurotrophic factor (GDNF). GDNF is an important factor for invasive glioma cell growth; however, the underlying mechanism involved is unclear. In this study, we affirm a significantly higher expression of the precursor of N-cadherin (proN-cadherin) in most gliomas compared with normal brain tissues. Our findings reveal that GDNF interacts with the extracellular domain of proN-cadherin, which suggests that proN-cadherin mediates GDNF-induced glioma cell migration and invasion. We hypothesize that proN-cadherin might cause homotypic adhesion loss within neighboring cells and at the same time promote heterotypic adhesion within the extracellular matrix (ECM) through a certain mechanism. This study also demonstrates that the interaction between GDNF and proN-cadherin activates specific intracellular signaling pathways; furthermore, GDNF promoted the secretion of matrix metalloproteinase-9 (MMP-9), which degrades the ECM via proN-cadherin. To reach the future goal of developing novel therapies of glioma, this study, reveals a unique mechanism of glioma cell migration and invasion.

Evidence of a Cell Surface Role for Hsp90 Complex Proteins Mediating Neuroblast Migration in the Subventricular Zone.

PubMed

Miyakoshi, Leo M; Marques-Coelho, Diego; De Souza, Luiz E R; Lima, Flavia R S; Martins, Vilma R; Zanata, Silvio M; Hedin-Pereira, Cecilia

2017-01-01

In most mammalian brains, the subventricular zone (SVZ) is a germinative layer that maintains neurogenic activity throughout adulthood. Neuronal precursors arising from this region migrate through the rostral migratory stream (RMS) and reach the olfactory bulbs where they differentiate and integrate into the local circuitry. Recently, studies have shown that heat shock proteins have an important role in cancer cell migration and blocking Hsp90 function was shown to hinder cell migration in the developing cerebellum. In this work, we hypothesize that chaperone complexes may have an important function regulating migration of neuronal precursors from the subventricular zone. Proteins from the Hsp90 complex are present in the postnatal SVZ as well as in the RMS. Using an in vitro SVZ explant model, we have demonstrated the expression of Hsp90 and Hop/STI1 by migrating neuroblasts. Treatment with antibodies against Hsp90 and co-chaperone Hop/STI1, as well as Hsp90 and Hsp70 inhibitors hinder neuroblast chain migration. Time-lapse videomicroscopy analysis revealed that cell motility and average migratory speed was decreased after exposure to both antibodies and inhibitors. Antibodies recognizing Hsp90, Hsp70, and Hop/STI1 were found bound to the membranes of cells from primary SVZ cultures and biotinylation assays demonstrated that Hsp70 and Hop/STI1 could be found on the external leaflet of neuroblast membranes. The latter could also be detected in conditioned medium samples obtained from cultivated SVZ cells. Our results suggest that chaperones Hsp90, Hsp70, and co-chaperone Hop/STI1, components of the Hsp90 complex, regulate SVZ neuroblast migration in a concerted manner through an extracellular mechanism.

Direct contact with perivascular tumor cells enhances integrin αvβ3 signaling and migration of endothelial cells

PubMed Central

Burgett, Monica E.; Lathia, Justin D.; Roth, Patrick; Nowacki, Amy S.; Galileo, Deni S.; Pugacheva, Elena; Huang, Ping; Vasanji, Amit; Li, Meizhang; Byzova, Tatiana; Mikkelsen, Tom; Bao, Shideng; Rich, Jeremy N.; Weller, Michael; Gladson, Candece L.

2016-01-01

The secretion of soluble pro-angiogenic factors by tumor cells and stromal cells in the perivascular niche promotes the aggressive angiogenesis that is typical of glioblastoma (GBM). Here, we show that angiogenesis also can be promoted by a direct interaction between brain tumor cells, including tumor cells with cancer stem-like properties (CSCs), and endothelial cells (ECs). As shown in vitro, this direct interaction is mediated by binding of integrin αvβ3 expressed on ECs to the RGD-peptide in L1CAM expressed on CSCs. It promotes both EC network formation and enhances directed migration toward basic fibroblast growth factor. Activation of αvβ3 and bone marrow tyrosine kinase on chromosome X (BMX) is required for migration stimulated by direct binding but not for migration stimulated by soluble factors. RGD-peptide treatment of mice with established intracerebral GBM xenografts significantly reduced the percentage of Sox2-positive tumor cells and CSCs in close proximity to ECs, decreased integrin αvβ3 and BMX activation and p130CAS phosphorylation in the ECs, and reduced the vessel surface area. These results reveal a previously unrecognized aspect of the regulation of angiogenesis in GBM that can impact therapeutic anti-angiogenic targeting. PMID:27270311

Oligodendroglial p130Cas Is a Target of Fyn Kinase Involved in Process Formation, Cell Migration and Survival

PubMed Central

Gonsior, Constantin; Binamé, Fabien; Frühbeis, Carsten; Bauer, Nina M.; Hoch-Kraft, Peter; Luhmann, Heiko J.; Trotter, Jacqueline; White, Robin

2014-01-01

Oligodendrocytes are the myelinating glial cells of the central nervous system. In the course of brain development, oligodendrocyte precursor cells migrate, scan the environment and differentiate into mature oligodendrocytes with multiple cellular processes which recognize and ensheath neuronal axons. During differentiation, oligodendrocytes undergo dramatic morphological changes requiring cytoskeletal rearrangements which need to be tightly regulated. The non-receptor tyrosine kinase Fyn plays a central role in oligodendrocyte differentiation and myelination. In order to improve our understanding of the role of oligodendroglial Fyn kinase, we have identified Fyn targets in these cells. Purification and mass-spectrometric analysis of tyrosine-phosphorylated proteins in response to overexpressed active Fyn in the oligodendrocyte precursor cell line Oli-neu, yielded the adaptor molecule p130Cas. We analyzed the function of this Fyn target in oligodendroglial cells and observed that reduction of p130Cas levels by siRNA affects process outgrowth, the thickness of cellular processes and migration behavior of Oli-neu cells. Furthermore, long term p130Cas reduction results in decreased cell numbers as a result of increased apoptosis in cultured primary oligodendrocytes. Our data contribute to understanding the molecular events taking place during oligodendrocyte migration and morphological differentiation and have implications for myelin formation. PMID:24586768

Endothelial cell-derived GABA signaling modulates neuronal migration and postnatal behavior

PubMed Central

Li, Suyan; Kumar T, Peeyush; Joshee, Sampada; Kirschstein, Timo; Subburaju, Sivan; Khalili, Jahan S; Kloepper, Jonas; Du, Chuang; Elkhal, Abdallah; Szabó, Gábor; Jain, Rakesh K; Köhling, Rüdiger; Vasudevan, Anju

2018-01-01

The cerebral cortex is essential for integration and processing of information that is required for most behaviors. The exquisitely precise laminar organization of the cerebral cortex arises during embryonic development when neurons migrate successively from ventricular zones to coalesce into specific cortical layers. While radial glia act as guide rails for projection neuron migration, pre-formed vascular networks provide support and guidance cues for GABAergic interneuron migration. This study provides novel conceptual and mechanistic insights into this paradigm of vascular-neuronal interactions, revealing new mechanisms of GABA and its receptor-mediated signaling via embryonic forebrain endothelial cells. With the use of two new endothelial cell specific conditional mouse models of the GABA pathway (Gabrb3ΔTie2-Cre and VgatΔTie2-Cre), we show that partial or complete loss of GABA release from endothelial cells during embryogenesis results in vascular defects and impairs long-distance migration and positioning of cortical interneurons. The downstream effects of perturbed endothelial cell-derived GABA signaling are critical, leading to lasting changes to cortical circuits and persistent behavioral deficits. Furthermore, we illustrate new mechanisms of activation of GABA signaling in forebrain endothelial cells that promotes their migration, angiogenesis and acquisition of blood-brain barrier properties. Our findings uncover and elucidate a novel endothelial GABA signaling pathway in the CNS that is distinct from the classical neuronal GABA signaling pathway and shed new light on the etiology and pathophysiology of neuropsychiatric diseases, such as autism spectrum disorders, epilepsy, anxiety, depression and schizophrenia. PMID:29086765

Expression and role of the cell surface protease seprase/fibroblast activation protein-α (FAP-α) in astroglial tumors.

PubMed

Mentlein, Rolf; Hattermann, Kirsten; Hemion, Charles; Jungbluth, Achim A; Held-Feindt, Janka

2011-03-01

Seprase or fibroblast activation protein-α (FAP-α) is a cell-surface serine protease that was previously described nearly exclusively on reactive and tumor stromal fibroblasts and thought to be involved in tissue remodeling. We investigated the expression and significance of FAP-α in astrocytomas/glioblastomas. As shown by quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, FAP-α was elevated in whole glioblastoma tissues and in particular in most glioma cells in situ and in vitro. In glioma stem-like cells (gliospheres), FAP-α was detected at low levels; however, FAP-α was considerably induced upon differentiation with 10% fetal calf serum. To explore its functional role, FAP-α was silenced by siRNA transfection. In Boyden chamber assays, FAP-α silenced cells migrated similar as control cells through non-coated or Matrigel (basal lamina)-coated porous membranes, but significantly slower through membranes coated with gelatin or brevican, a major component of brain extracellular matrix. Furthermore, FAP-α-silenced glioma cells migrated through murine brain slices much slower under the conditions tested than differentially fluorescent-labeled control cells. Thus, FAP-α is highly expressed on the surface of glioma cells and contributes to diffuse glioma invasion through extracellular matrix components.

Circular RNA hsa_circ_0008344 regulates glioblastoma cell proliferation, migration, invasion, and apoptosis.

PubMed

Zhou, Jinxu; Wang, Hongxiang; Chu, Junsheng; Huang, Qilin; Li, Guangxu; Yan, Yong; Xu, Tao; Chen, Juxiang; Wang, Yuhai

2018-04-24

Recent studies have found circular RNAs (circRNAs) involved in the biological process of cancers. However, little is known about their functional roles in glioblastoma. Human circRNA microarray analysis was performed to screen the expression profile of circRNAs in IDH1 wild-type glioblastoma tissue. The expression of hsa_circ_0008344 in glioblastoma and normal brain samples was quantified by qRT-PCR. Functional experiments were performed to investigate the biological functions of hsa_circ_0008344, including MTT assay, colony formation assay, transwell assay, and cell apoptosis assay. CircRNA microarray revealed a total of 417 abnormally expressed circRNAs (>1.5-fold, P < .05) in glioblastoma tissue compared with the adjacent normal brain. Hsa_circ_0008344, among the top differentially expressed circRNAs, was significantly upregulated in IDH1 wild-type glioblastoma. Further in vitro studies showed that knockdown of hsa_circ_0008344 suppressed glioblastoma cell proliferation, colony formation, migration, and invasion, but increased cell apoptotic rate. Hsa_circ_0008344 is upregulated in glioblastoma and may contribute to the progression of this malignancy. © 2018 Wiley Periodicals, Inc.

PAMAM Dendrimers Cross the Blood-Brain Barrier When Administered through the Carotid Artery in C57BL/6J Mice.

PubMed

Srinageshwar, Bhairavi; Peruzzaro, Sarah; Andrews, Melissa; Johnson, Kayla; Hietpas, Allison; Clark, Brittany; McGuire, Crystal; Petersen, Eric; Kippe, Jordyn; Stewart, Andrew; Lossia, Olivia; Al-Gharaibeh, Abeer; Antcliff, Aaron; Culver, Rebecca; Swanson, Douglas; Dunbar, Gary; Sharma, Ajit; Rossignol, Julien

2017-03-14

Drug delivery into the central nervous system (CNS) is challenging due to the blood-brain barrier (BBB) and drug delivery into the brain overcoming the BBB can be achieved using nanoparticles such as dendrimers. The conventional cationic dendrimers used are highly toxic. Therefore, the present study investigates the role of novel mixed surface dendrimers, which have potentially less toxicity and can cross the BBB when administered through the carotid artery in mice. In vitro experiments investigated the uptake of amine dendrimers (G1-NH₂ and G4-NH₂) and novel dendrimers (G1-90/10 and G4-90/10) by primary cortical cultures. In vivo experiments involved transplantation of G4-90/10 into mice through (1) invasive intracranial injections into the striatum; and (2) less invasive carotid injections. The animals were sacrificed 24-h and 1-week post-transplantations and their brains were analyzed. In vivo experiments proved that the G4-90/10 can cross the BBB when injected through the carotid artery and localize within neurons and glial cells. The dendrimers were found to migrate through the corpus callosum 1-week post intracranial injection. Immunohistochemistry showed that the migrating cells are the dendrimer-infected glial cells. Overall, our results suggest that poly-amidoamine (PAMAM) dendrimers may be used as a minimally invasive means to deliver biomolecules for treating neurological diseases or disorders.

Developing a Novel Embryo-Larval Zebrafish Xenograft Assay to Prioritize Human Glioblastoma Therapeutics.

PubMed

Wehmas, Leah Christine; Tanguay, Robert L; Punnoose, Alex; Greenwood, Juliet A

2016-08-01

Glioblastoma is an aggressive brain cancer requiring improved treatments. Existing methods of drug discovery and development require years before new therapeutics become available to patients. Zebrafish xenograft models hold promise for prioritizing drug development. We have developed an embryo-larval zebrafish xenograft assay in which cancer cells are implanted in a brain microenvironment to discover and prioritize compounds that impact glioblastoma proliferation, migration, and invasion. We illustrate the utility of our assay by evaluating the well-studied, phosphatidylinositide 3-kinase inhibitor LY294002 and zinc oxide nanoparticles (ZnO NPs), which demonstrate selective cancer cytotoxicity in cell culture, but the in vivo effectiveness has not been established. Exposures of 3.125-6.25 μM LY294002 significantly decreased proliferation up to 34% with concentration-dependent trends. Exposure to 6.25 μM LY294002 significantly inhibited migration/invasion by ∼27% within the glioblastoma cell mass (0-80 μm) and by ∼32% in the next distance region (81-160 μm). Unexpectedly, ZnO enhanced glioblastoma proliferation by ∼19% and migration/invasion by ∼35% at the periphery of the cell mass (161+ μm); however, dissolution of these NPs make it difficult to discern whether this was a nano or ionic effect. These results demonstrate that we have a short, relevant, and sensitive zebrafish-based assay to aid glioblastoma therapeutic development.

Cell fusion in the brain: two cells forward, one cell back.

PubMed

Kemp, Kevin; Wilkins, Alastair; Scolding, Neil

2014-11-01

Adult stem cell populations, notably those which reside in the bone marrow, have been shown to contribute to several neuronal cell types in the rodent and human brain. The observation that circulating bone marrow cells can migrate into the central nervous system and fuse with, in particular, cerebellar Purkinje cells has suggested, at least in part, a potential mechanism behind this process. Experimentally, the incidence of cell fusion in the brain is enhanced with age, radiation exposure, inflammation, chemotherapeutic drugs and even selective damage to the neurons themselves. The presence of cell fusion, shown by detection of increased bi-nucleated neurons, has also been described in a variety of human central nervous system diseases, including both multiple sclerosis and Alzheimer's disease. Accumulating evidence is therefore raising new questions into the biological significance of cell fusion, with the possibility that it represents an important means of cell-mediated neuroprotection or rescue of highly complex neurons that cannot be replaced in adult life. Here, we discuss the evidence behind this phenomenon in the rodent and human brain, with a focus on the subsequent research investigating the physiological mechanisms of cell fusion underlying this process. We also highlight how these studies offer new insights into endogenous neuronal repair, opening new exciting avenues for potential therapeutic interventions against neurodegeneration and brain injury.

Activating Endogenous Neural Precursor Cells Using Metformin Leads to Neural Repair and Functional Recovery in a Model of Childhood Brain Injury.

PubMed

Dadwal, Parvati; Mahmud, Neemat; Sinai, Laleh; Azimi, Ashkan; Fatt, Michael; Wondisford, Fredric E; Miller, Freda D; Morshead, Cindi M

2015-08-11

The development of cell replacement strategies to repair the injured brain has gained considerable attention, with a particular interest in mobilizing endogenous neural stem and progenitor cells (known as neural precursor cells [NPCs]) to promote brain repair. Recent work demonstrated metformin, a drug used to manage type II diabetes, promotes neurogenesis. We sought to determine its role in neural repair following brain injury. We find that metformin administration activates endogenous NPCs, expanding the size of the NPC pool and promoting NPC migration and differentiation in the injured neonatal brain in a hypoxia-ischemia (H/I) injury model. Importantly, metformin treatment following H/I restores sensory-motor function. Lineage tracking reveals that metformin treatment following H/I causes an increase in the absolute number of subependyma-derived NPCs relative to untreated H/I controls in areas associated with sensory-motor function. Hence, activation of endogenous NPCs is a promising target for therapeutic intervention in childhood brain injury models. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Clinically viable magnetic poly(lactide-co-glycolide) (PLGA) particles for MRI-based cell tracking

PubMed Central

Granot, Dorit; Nkansah, Michael K.; Bennewitz, Margaret F.; Tang, Kevin S.; Markakis, Eleni A.; Shapiro, Erik M.

2013-01-01

Purpose To design, fabricate, characterize and in vivo assay clinically viable magnetic particles for MRI-based cell tracking. Methods PLGA encapsulated magnetic nano- and microparticles were fabricated. Multiple biologically relevant experiments were performed to assess cell viability, cellular performance and stem cell differentiation. In vivo MRI experiments were performed to separately test cell transplantation and cell migration paradigms, as well as in vivo biodegradation. Results Highly magnetic nano- (~100 nm) and microparticles (~1–2 μm) were fabricated. Magnetic cell labeling in culture occurred rapidly achieving 3–50 pg Fe/cell at 3 hrs for different particles types, and >100 pg Fe/cell after 10 hours, without the requirement of a transfection agent, and with no effect on cell viability. The capability of magnetically labeled mesenchymal or neural stem cells to differentiate down multiple lineages, or for magnetically labeled immune cells to release cytokines following stimulation, was uncompromised. An in vivo biodegradation study revealed that NPs degraded ~80% over the course of 12 weeks. MRI detected as few as 10 magnetically labeled cells, transplanted into the brains of rats. Also, these particles enabled the in vivo monitoring of endogenous neural progenitor cell migration in rat brains over 2 weeks. Conclusion The robust MRI properties and benign safety profile of these particles make them promising candidates for clinical translation for MRI-based cell tracking. PMID:23568825

ROLE OF ENDOTHELIAL NITRIC OXIDE SYNTHETASE IN ARTERIOGENESIS AFTER STROKE IN MICE

PubMed Central

CUI, X.; CHOPP, M.; ZACHAREK, A.; ZHANG, C.; ROBERTS, C.; CHEN, J.

2009-01-01

Arteriogenesis supports restored perfusion in the ischemic brain and improves long-term functional outcome after stroke. We investigate the role of endothelial nitric oxide synthetase (eNOS) and an NO donor, [(Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) aminio] diazen-1-ium-1, 2-diolate (DETA-NONOate), in promoting arteriogenesis after stroke. Adult wild-type (WT, n=18) and eNOS-knockout (eNOS-/-, n=36) mice were subjected to transient (2.5 hours) right middle cerebral artery occlusion (MCAo) and were treated with or without DETA-NONOate (0.4 mg/kg) 24 hours after MCAo. Functional evaluation was performed. Animals were sacrificed 3 days after MCAo for arterial cell culture studies, or 14 days for immunohistochemical analysis. Consistent with previous studies, eNOS-/- mice exhibited a higher mortality rate (p<0.05, n=18/group) and more severe neurological functional deficit after MCAo than WT mice (p<0.05, n=12/group). Decreased arteriogenesis, was evident in eNOS-/- mice compared with WT mice, as demonstrated by reduced vascular smooth muscle cell (VSMC) proliferation, arterial density and diameter in the ischemic brain. eNOS-/- mice treated with DETA-NONOate had a significantly decreased mortality rate and improved functional recovery, and exhibited enhanced arteriogenesis identified by increased VSMC proliferation, and upregulated arterial density and diameter compared to eNOS-/- mice after stroke (p<0.05, n=12/group). To elucidate the mechanisms underlying eNOS/NO mediated arteriogenesis, VSMC migration was measured in vitro. Arterial cell migration significantly decreased in the cultured common carotid artery (CCA) derived from eNOS-/- mice 3 days after MCAo compared to WT arterial cells. DETA-NONOate-treatment significantly attenuated eNOS-/--induced decrease of arterial cell migration compared to eNOS-/- control artery (p<0.05. n=6/group). Using VSMC culture, DETA-NONOate significantly increased VSMC migration, while inhibition of NOS significantly decreased VSMC migration (p<0.05. n=6/group). Our data indicated that eNOS not only promotes vascular dilation but also increases VSMC proliferation and migration, and thereby enhances arteriogenesis after stroke. Therefore, increase eNOS may play an important role in regulating of arteriogenesis after stroke. PMID:19154781

Role of endothelial nitric oxide synthetase in arteriogenesis after stroke in mice.

PubMed

Cui, X; Chopp, M; Zacharek, A; Zhang, C; Roberts, C; Chen, J

2009-03-17

Arteriogenesis supports restored perfusion in the ischemic brain and improves long-term functional outcome after stroke. We investigate the role of endothelial nitric oxide synthetase (eNOS) and a nitric oxide (NO) donor, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1, 2-diolate (DETA-NONOate), in promoting arteriogenesis after stroke. Adult wild-type (WT, n=18) and eNOS-knockout (eNOS(-/-), n=36) mice were subjected to transient (2.5 h) right middle cerebral artery occlusion (MCAo) and were treated with or without DETA-NONOate (0.4 mg/kg) 24 h after MCAo. Functional evaluation was performed. Animals were sacrificed 3 days after MCAo for arterial cell culture studies, or 14 days for immunohistochemical analysis. Consistent with previous studies, eNOS(-/-) mice exhibited a higher mortality rate (P<0.05, n=18/group) and more severe neurological functional deficit after MCAo than WT mice (P<0.05, n=12/group). Decreased arteriogenesis, was evident in eNOS(-/-) mice compared with WT mice, as demonstrated by reduced vascular smooth muscle cell (VSMC) proliferation, arterial density and diameter in the ischemic brain. eNOS(-/-) mice treated with DETA-NONOate had a significantly decreased mortality rate and improved functional recovery, and exhibited enhanced arteriogenesis identified by increased VSMC proliferation, and upregulated arterial density and diameter compared to eNOS(-/-) mice after stroke (P<0.05, n=12/group). To elucidate the mechanisms underlying eNOS/NO mediated arteriogenesis, VSMC migration was measured in vitro. Arterial cell migration significantly decreased in the cultured common carotid artery (CCA) derived from eNOS(-/-) mice 3 days after MCAo compared to WT arterial cells. DETA-NONOate-treatment significantly attenuated eNOS(-/-)-induced decrease of arterial cell migration compared to eNOS(-/-) control artery (P<0.05; n=6/group). Using VSMC culture, DETA-NONOate significantly increased VSMC migration, while inhibition of NOS significantly decreased VSMC migration (P<0.05; n=6/group). Our data indicated that eNOS not only promotes vascular dilation but also increases VSMC proliferation and migration, and thereby enhances arteriogenesis after stroke. Therefore, increase eNOS may play an important role in regulating of arteriogenesis after stroke.

Effect of Lapatinib on the Outgrowth of Metastatic Breast Cancer Cells to the Brain

PubMed Central

Gril, Brunilde; Palmieri, Diane; Bronder, Julie L.; Herring, Jeanne M.; Vega-Valle, Eleazar; Feigenbaum, Lionel; Liewehr, David J.; Steinberg, Seth M.; Merino, Maria J.; Rubin, Stephen D.

2008-01-01

Background The brain is increasingly being recognized as a sanctuary site for metastatic tumor cells in women with HER2-overexpressing breast cancer who receive trastuzumab therapy. There are no approved or widely accepted treatments for brain metastases other than steroids, cranial radiotherapy, and surgical resection. We examined the efficacy of lapatinib, an inhibitor of the epidermal growth factor receptor (EGFR) and HER2 kinases, for preventing the outgrowth of breast cancer cells in the brain in a mouse xenograft model of brain metastasis. Methods EGFR-overexpressing MDA-MB-231-BR (231-BR) brain-seeking breast cancer cells were transfected with an expression vector that contained or lacked the HER2 cDNA and used to examine the effect of lapatinib on the activation (ie, phosphorylation) of cell signaling proteins by immunoblotting, on cell growth by the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, and on cell migration using a Boyden chamber assay. The outgrowth of large (ie, >50 μm2) and micrometastases was counted in brain sections from nude mice that had been injected into the left cardiac ventricle with 231-BR cells and, beginning 5 days later, treated by oral gavage with lapatinib or vehicle (n = 22–26 mice per treatment group). All statistical tests were two-sided. Results In vitro, lapatinib inhibited the phosphorylation of EGFR, HER2, and downstream signaling proteins; cell proliferation; and migration in 231-BR cells (both with and without HER2). Among mice injected with 231-BR-vector cells, those treated with 100 mg lapatinib/kg body weight had 54% fewer large metastases 24 days after starting treatment than those treated with vehicle (mean number of large metastases per brain section: 1.56 vs 3.36, difference = 1.80, 95% confidence interval [CI] = 0.92 to 2.68, P < .001), whereas treatment with 30 mg lapatinib/kg body weight had no effect. Among mice injected with 231-BR-HER2 cells, those treated with either dose of lapatinib had 50%–53% fewer large metastases than those treated with vehicle (mean number of large metastases per brain section, 30 mg/kg vs vehicle: 3.21 vs 6.83, difference = 3.62, 95% CI = 2.30 to 4.94, P < .001; 100 mg/kg vs vehicle: 3.44 vs 6.83, difference = 3.39, 95% CI = 2.08 to 4.70, P < .001). Immunohistochemical analysis revealed reduced phosphorylation of HER2 in 231-BR-HER2 cell–derived brain metastases from mice treated with the higher dose of lapatinib compared with 231-BR-HER2 cell–derived brain metastases from vehicle-treated mice (P < .001). Conclusions Lapatinib is the first HER2-directed drug to be validated in a preclinical model for activity against brain metastases of breast cancer. PMID:18664652

Seeing the forest and trees: whole-body and whole-brain imaging for circadian biology.

PubMed

Ode, K L; Ueda, H R

2015-09-01

Recent advances in methods for making mammalian organs translucent have made possible whole-body fluorescent imaging with single-cell resolution. Because organ-clearing methods can be used to image the heterogeneous nature of cell populations, they are powerful tools to investigate the hierarchical organization of the cellular circadian clock, and how the clock synchronizes a variety of physiological activities. In particular, methods compatible with genetically encoded fluorescent reporters have the potential to detect circadian activity in different brain regions and the circadian-phase distribution across the whole body. In this review, we summarize the current methods and strategy for making organs translucent (removal of lipids, decolourization of haemoglobin and adjusting the refractive index of the specimen). We then discuss possible applications to circadian biology. For example, the coupling of circadian rhythms among different brain regions, brain activity in sleep-wake cycles and the role of migrating cells such as immune cells and cancer cells in chronopharmacology. © 2015 John Wiley & Sons Ltd.

What is CAR doing in the middle of the adult neurogenic road?

PubMed Central

Junyent, Felix; Coré, Nathalie; Cremer, Harold

2017-01-01

ABSTRACT The molecular and cellular basis of adult neurogenesis has attracted considerable attention for fundamental and clinical applications because neural stem cells and newborn neurons may, one day, be harnessed to replace neurons and allow cognitive improvement in the diseased brain. In rodents, neural progenitors are located in the dentate gyrus and the sub/periventricular zone. In the dentate gyrus the generation of newborn neurons is associated with plasticity, including regulation of memory. The role of subventricular zone neural precursors that migrate to the olfactory bulb is less characterized. Identifying factors that impact neural stem cell proliferation, migration and differentiation is therefore sine qua non before we can harness their potential. Here, we expand upon our recent results showing that CAR, the coxsackievirus and adenovirus receptor, is among the developing list of key players when it comes to the complex process of integrating newborn neurons into existing circuits in the mature brain. PMID:28516108

ApoER2 Controls Not Only Neuronal Migration in the Intermediate Zone But Also Termination of Migration in the Developing Cerebral Cortex.

PubMed

Hirota, Yuki; Kubo, Ken-Ichiro; Fujino, Takahiro; Yamamoto, Tokuo T; Nakajima, Kazunori

2018-01-01

Neuronal migration contributes to the establishment of mammalian brain. The extracellular protein Reelin sends signals to various downstream molecules by binding to its receptors, the apolipoprotein E receptor 2 (ApoER2) and very low-density lipoprotein receptor and exerts essential roles in the neuronal migration and formation of the layered neocortex. However, the cellular and molecular functions of Reelin signaling in the cortical development are not yet fully understood. Here, to gain insight into the role of Reelin signaling during cortical development, we examined the migratory behavior of Apoer2-deficient neurons in the developing brain. Stage-specific labeling of newborn neurons revealed that the neurons ectopically invaded the marginal zone (MZ) and that neuronal migration of both early- and late-born neurons was disrupted in the intermediate zone (IZ) in the Apoer2 KO mice. Rescue experiments showed that ApoER2 functions both in cell-autonomous and noncell-autonomous manners, that Rap1, integrin, and Akt are involved in the termination of migration beneath the MZ, and that Akt also controls neuronal migration in the IZ downstream of ApoER2. These data indicate that ApoER2 controls multiple processes in neuronal migration, including the early stage of radial migration and termination of migration beneath the MZ in the developing neocortex. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Influence of the CCR-5/MIP-1 α Axis in the Pathogenesis of Rocio Virus Encephalitis in a Mouse Model

PubMed Central

Chávez, Juliana H.; França, Rafael F. O.; Oliveira, Carlo J. F.; de Aquino, Maria T. P.; Farias, Kleber J. S.; Machado, Paula R. L.; de Oliveira, Thelma F. M.; Yokosawa, Jonny; Soares, Edson G.; da Silva, João S.; da Fonseca, Benedito A. L.; Figueiredo, Luiz T. M.

2013-01-01

Rocio virus (ROCV) caused an outbreak of human encephalitis during the 1970s in Brazil and its immunopathogenesis remains poorly understood. CC-chemokine receptor 5 (CCR5) is a chemokine receptor that binds to macrophage inflammatory protein (MIP-1 α). Both molecules are associated with inflammatory cells migration during infections. In this study, we demonstrated the importance of the CCR5 and MIP-1 α, in the outcome of viral encephalitis of ROCV-infected mice. CCR5 and MIP-1 α knockout mice survived longer than wild-type (WT) ROCV-infected animals. In addition, knockout mice had reduced inflammation in the brain. Assessment of brain viral load showed mice virus detection five days post-infection in wild-type and CCR5−/− mice, while MIP-1 α−/− mice had lower viral loads seven days post-infection. Knockout mice required a higher lethal dose than wild-type mice as well. The CCR5/MIP-1 α axis may contribute to migration of infected cells to the brain and consequently affect the pathogenesis during ROCV infection. PMID:24080631

Functionalized iron oxide nanoparticles for controlling the movement of immune cells

NASA Astrophysics Data System (ADS)

White, Ethan E.; Pai, Alex; Weng, Yiming; Suresh, Anil K.; van Haute, Desiree; Pailevanian, Torkom; Alizadeh, Darya; Hajimiri, Ali; Badie, Behnam; Berlin, Jacob M.

2015-04-01

Immunotherapy is currently being investigated for the treatment of many diseases, including cancer. The ability to control the location of immune cells during or following activation would represent a powerful new technique for this field. Targeted magnetic delivery is emerging as a technique for controlling cell movement and localization. Here we show that this technique can be extended to microglia, the primary phagocytic immune cells in the central nervous system. The magnetized microglia were generated by loading the cells with iron oxide nanoparticles functionalized with CpG oligonucleotides, serving as a proof of principle that nanoparticles can be used to both deliver an immunostimulatory cargo to cells and to control the movement of the cells. The nanoparticle-oligonucleotide conjugates are efficiently internalized, non-toxic, and immunostimulatory. We demonstrate that the in vitro migration of the adherent, loaded microglia can be controlled by an external magnetic field and that magnetically-induced migration is non-cytotoxic. In order to capture video of this magnetically-induced migration of loaded cells, a novel 3D-printed ``cell box'' was designed to facilitate our imaging application. Analysis of cell movement velocities clearly demonstrate increased cell velocities toward the magnet. These studies represent the initial step towards our final goal of using nanoparticles to both activate immune cells and to control their trafficking within the diseased brain.Immunotherapy is currently being investigated for the treatment of many diseases, including cancer. The ability to control the location of immune cells during or following activation would represent a powerful new technique for this field. Targeted magnetic delivery is emerging as a technique for controlling cell movement and localization. Here we show that this technique can be extended to microglia, the primary phagocytic immune cells in the central nervous system. The magnetized microglia were generated by loading the cells with iron oxide nanoparticles functionalized with CpG oligonucleotides, serving as a proof of principle that nanoparticles can be used to both deliver an immunostimulatory cargo to cells and to control the movement of the cells. The nanoparticle-oligonucleotide conjugates are efficiently internalized, non-toxic, and immunostimulatory. We demonstrate that the in vitro migration of the adherent, loaded microglia can be controlled by an external magnetic field and that magnetically-induced migration is non-cytotoxic. In order to capture video of this magnetically-induced migration of loaded cells, a novel 3D-printed ``cell box'' was designed to facilitate our imaging application. Analysis of cell movement velocities clearly demonstrate increased cell velocities toward the magnet. These studies represent the initial step towards our final goal of using nanoparticles to both activate immune cells and to control their trafficking within the diseased brain. Electronic supplementary information (ESI) available: Transmission electron microscopy images of the particles, additional independent experiments for the NFκB activity and exocytosis assays, TEM images for the SPION untreated cells, bright field microscopy images of the cells alone in the presence and absence of magnet, images of the magnetic movement experiments at higher doses of SPION, full uncropped images of the post-migration LIVE/DEAD assay, and a video file of cell movement. See DOI: 10.1039/c3nr04421a

Evaluation of the effects of swainsonine, captopril, tangeretin and nobiletin on the biological behaviour of brain tumour cells in vitro.

PubMed

Rooprai, H K; Kandanearatchi, A; Maidment, S L; Christidou, M; Trillo-Pazos, G; Dexter, D T; Rucklidge, G J; Widmer, W; Pilkington, G J

2001-02-01

Although intrinsic tumours of the brain seldom metastasize to distant sites, their diffuse, infiltrative-invasive growth within the brain generally precludes successful surgical and adjuvant therapy. Hence, attention has now focused on novel therapeutic approaches to combat brain tumours that include the use of anti-invasive and anti-proliferative agents. The effect of four anti-invasive agents, swainsonine (a locoweed alkaloid), captopril (an anti-hypertensive drug), tangeretin and nobiletin (both citrus flavonoids), were investigated on various parameters of brain tumour invasion such as matrix metalloproteinase (MMP) secretion, migration, invasion and adhesion. A standard cytotoxicity assay was used to optimize working concentrations of the drugs on seven human brain tumour-derived cell lines of various histological type and grade of malignancy. A qualitative assessment by gelatin zymography revealed that the effect of these agents varied between the seven cell lines such that the low grade pilocytic astrocytoma was unaffected by three of the agents. In contrast, downregulation of the two gelatinases, MMP-2 and MMP-9 was seen in the grade 3 astrocytoma irrespective of which agent was used. Generally, swainsonine was the least effective whereas the citrus flavonoids, particularly nobiletin, showed the greatest downregulation of secretion of the MMPs. Furthermore, captopril and nobiletin were most efficient at inhibiting invasion, migration and adhesion in four representative cell lines (an ependymoma, a grade II oligoastrocytoma, an anaplastic astrocytoma and a glioblastoma multiforme). Yet again, the effects of the four agents varied between the four cell lines. Nobiletin was, nevertheless, the most effective agent used in these assays. In conclusion, the differential effects seen on the various parameters studied by these putative anti-invasive agents may be the result of interference with MMPs and other mechanisms underlying the invasive phenotype. From these pilot studies, it is possible that these agents, especially the citrus flavonoids, could be of future therapeutic value. However, further work is needed to validate this in a larger study.

β1 integrin signaling promotes neuronal migration along vascular scaffolds in the post-stroke brain.

PubMed

Fujioka, Teppei; Kaneko, Naoko; Ajioka, Itsuki; Nakaguchi, Kanako; Omata, Taichi; Ohba, Honoka; Fässler, Reinhard; García-Verdugo, José Manuel; Sekiguchi, Kiyotoshi; Matsukawa, Noriyuki; Sawamoto, Kazunobu

2017-02-01

Cerebral ischemic stroke is a main cause of chronic disability. However, there is currently no effective treatment to promote recovery from stroke-induced neurological symptoms. Recent studies suggest that after stroke, immature neurons, referred to as neuroblasts, generated in a neurogenic niche, the ventricular-subventricular zone, migrate toward the injured area, where they differentiate into mature neurons. Interventions that increase the number of neuroblasts distributed at and around the lesion facilitate neuronal repair in rodent models for ischemic stroke, suggesting that promoting neuroblast migration in the post-stroke brain could improve efficient neuronal regeneration. To move toward the lesion, neuroblasts form chain-like aggregates and migrate along blood vessels, which are thought to increase their migration efficiency. However, the molecular mechanisms regulating these migration processes are largely unknown. Here we studied the role of β1-class integrins, transmembrane receptors for extracellular matrix proteins, in these migrating neuroblasts. We found that the neuroblast chain formation and blood vessel-guided migration critically depend on β1 integrin signaling. β1 integrin facilitated the adhesion of neuroblasts to laminin and the efficient translocation of their soma during migration. Moreover, artificial laminin-containing scaffolds promoted neuroblast chain formation and migration toward the injured area. These data suggest that laminin signaling via β1 integrin supports vasculature-guided neuronal migration to efficiently supply neuroblasts to injured areas. This study also highlights the importance of vascular scaffolds for cell migration in development and regeneration. Copyright © 2017 3-V Biosciences. Published by Elsevier B.V. All rights reserved.

The Role of Astrocytes in the Generation, Migration, and Integration of New Neurons in the Adult Olfactory Bulb

PubMed Central

Gengatharan, Archana; Bammann, Rodrigo R.; Saghatelyan, Armen

2016-01-01

In mammals, new neurons in the adult olfactory bulb originate from a pool of neural stem cells in the subventricular zone of the lateral ventricles. Adult-born cells play an important role in odor information processing by adjusting the neuronal network to changing environmental conditions. Olfactory bulb neurogenesis is supported by several non-neuronal cells. In this review, we focus on the role of astroglial cells in the generation, migration, integration, and survival of new neurons in the adult forebrain. In the subventricular zone, neural stem cells with astrocytic properties display regional and temporal specificity when generating different neuronal subtypes. Non-neurogenic astrocytes contribute to the establishment and maintenance of the neurogenic niche. Neuroblast chains migrate through the rostral migratory stream ensheathed by astrocytic processes. Astrocytes play an important regulatory role in neuroblast migration and also assist in the development of a vasculature scaffold in the migratory stream that is essential for neuroblast migration in the postnatal brain. In the olfactory bulb, astrocytes help to modulate the network through a complex release of cytokines, regulate blood flow, and provide metabolic support, which may promote the integration and survival of new neurons. Astrocytes thus play a pivotal role in various processes of adult olfactory bulb neurogenesis, and it is likely that many other functions of these glial cells will emerge in the near future. PMID:27092050

Adult subependymal neural precursors, but not differentiated cells, undergo rapid cathodal migration in the presence of direct current electric fields.

PubMed

Babona-Pilipos, Robart; Droujinine, Ilia A; Popovic, Milos R; Morshead, Cindi M

2011-01-01

The existence of neural stem and progenitor cells (together termed neural precursor cells) in the adult mammalian brain has sparked great interest in utilizing these cells for regenerative medicine strategies. Endogenous neural precursors within the adult forebrain subependyma can be activated following injury, resulting in their proliferation and migration toward lesion sites where they differentiate into neural cells. The administration of growth factors and immunomodulatory agents following injury augments this activation and has been shown to result in behavioural functional recovery following stroke. With the goal of enhancing neural precursor migration to facilitate the repair process we report that externally applied direct current electric fields induce rapid and directed cathodal migration of pure populations of undifferentiated adult subependyma-derived neural precursors. Using time-lapse imaging microscopy in vitro we performed an extensive single-cell kinematic analysis demonstrating that this galvanotactic phenomenon is a feature of undifferentiated precursors, and not differentiated phenotypes. Moreover, we have shown that the migratory response of the neural precursors is a direct effect of the electric field and not due to chemotactic gradients. We also identified that epidermal growth factor receptor (EGFR) signaling plays a role in the galvanotactic response as blocking EGFR significantly attenuates the migratory behaviour. These findings suggest direct current electric fields may be implemented in endogenous repair paradigms to promote migration and tissue repair following neurotrauma.

Innate (inherent) control of brain infection, brain inflammation and brain repair: the role of microglia, astrocytes, "protective" glial stem cells and stromal ependymal cells.

PubMed

Hauwel, Mathieu; Furon, Emeline; Canova, Cecile; Griffiths, Mark; Neal, Jim; Gasque, Philippe

2005-04-01

In invertebrates and primitive vertebrates, the brain contains large numbers of "professional" macrophages associated with neurones, ependymal tanycytes and radial glia to promote robust regenerative capacity. In higher vertebrates, hematogenous cells are largely excluded from the brain, and innate immune molecules and receptors produced by the resident "amateur" macrophages (microglia, astrocytes and ependymal cells) control pathogen infiltration and clearance of toxic cell debris. However, there is minimal capacity for regeneration. The transfer of function from hematogenous cells to macroglia and microglia is associated with the sophistication of a yet poorly-characterized neurone-glia network. This evolutionary pattern may have been necessary to reduce the risk of autoimmune attack while preserving the neuronal web but the ability to repair central nervous system damage may have been sacrificed in the process. We herein argue that it may be possible to re-educate and stimulate the resident phagocytes to promote clearance of pathogens (e.g., Prion), toxic cell debris (e.g., amyloid fibrils and myelin) and apoptotic cells. Moreover, as part of this greater division of labour between cell types in vertebrate brains, it may be possible to harness the newly described properties of glial stem cells in neuronal protection (revitalization) rather than replacement, and to control brain inflammation. We will also highlight the emerging roles of stromal ependymal cells in controlling stem cell production and migration into areas of brain damage. Understanding the mechanisms involved in the nurturing of damaged neurons by protective glial stem cells with the safe clearance of cell debris could lead to remedial strategies for chronic brain diseases.

The effect of pulsed electric fields on the electrotactic migration of human neural progenitor cells through the involvement of intracellular calcium signaling.

PubMed

Hayashi, Hisamitsu; Edin, Fredrik; Li, Hao; Liu, Wei; Rask-Andersen, Helge

2016-12-01

Endogenous electric fields (EFs) are required for the physiological control of the central nervous system development. Application of the direct current EFs to neural stem cells has been studied for the possibility of stem cell transplantation as one of the therapies for brain injury. EFs generated within the nervous system are often associated with action potentials and synaptic activity, apparently resulting in a pulsed current in nature. The aim of this study is to investigate the effect of pulsed EF, which can reduce the cytotoxicity, on the migration of human neural progenitor cells (hNPCs). We applied the mono-directional pulsed EF with a strength of 250mV/mm to hNPCs for 6h. The migration distance of the hNPCs exposed to pulsed EF was significantly greater compared with the control not exposed to the EF. Pulsed EFs, however, had less of an effect on the migration of the differentiated hNPCs. There was no significant change in the survival of hNPCs after exposure to the pulsed EF. To investigate the role of Ca 2+ signaling in electrotactic migration of hNPCs, pharmacological inhibition of Ca 2+ channels in the EF-exposed cells revealed that the electrotactic migration of hNPCs exposed to Ca 2+ channel blockers was significantly lower compared to the control group. The findings suggest that the pulsed EF induced migration of hNPCs is partly influenced by intracellular Ca 2+ signaling. Copyright © 2016 Elsevier B.V. All rights reserved.

Cellular Composition and Organization of the Subventricular Zone and Rostral Migratory Stream in the Adult and Neonatal Common Marmoset Brain

PubMed Central

Sawamoto, Kazunobu; Hirota, Yuki; Alfaro-Cervello, Clara; Soriano-Navarro, Mario; He, Xiaoping; Hayakawa-Yano, Yoshika; Yamada, Masayuki; Hikishima, Keigo; Tabata, Hidenori; Iwanami, Akio; Nakajima, Kazunori; Toyama, Yoshiaki; Itoh, Toshio; Alvarez-Buylla, Arturo; Garcia-Verdugo, Jose Manuel; Okano, Hideyuki

2014-01-01

The adult subventricular zone (SVZ) of the lateral ventricle contains neural stem cells. In rodents, these cells generate neuroblasts that migrate as chains toward the olfactory bulb along the rostral migratory stream (RMS). The neural-stem-cell niche at the ventricular wall is conserved in various animal species, including primates. However, it is unclear how the SVZ and RMS organization in nonhuman primates relates to that of rodents and humans. Here we studied the SVZ and RMS of the adult and neonatal common marmoset (Callithrix jacchus), a New World primate used widely in neuroscience, by electron microscopy, and immunohistochemical detection of cell-type-specific markers. The marmoset SVZ contained cells similar to type B, C, and A cells of the rodent SVZ in their marker expression and morphology. The adult marmoset SVZ had a three-layer organization, as in the human brain, with ependymal, hypocellular, and astro-cyte-ribbon layers. However, the hypocellular layer was very thin or absent in the adult-anterior and neonatal SVZ. Anti-PSA-NCAM staining of the anterior SVZ in whole-mount ventricular wall preparations of adult marmosets revealed an extensive network of elongated cell aggregates similar to the neuroblast chains in rodents. Time-lapse recordings of marmoset SVZ explants cultured in Matrigel showed the neuroblasts migrating in chains, like rodent type A cells. These results suggest that some features of neurogenesis and neuronal migration in the SVZ are common to marmosets, humans, and rodents. This basic description of the adult and neonatal marmoset SVZ will be useful for future studies on adult neurogenesis in primates. PMID:21246550

Neural stem cell-based dual suicide gene delivery for metastatic brain tumors.

PubMed

Wang, C; Natsume, A; Lee, H J; Motomura, K; Nishimira, Y; Ohno, M; Ito, M; Kinjo, S; Momota, H; Iwami, K; Ohka, F; Wakabayashi, T; Kim, S U

2012-11-01

In our previous works, we demonstrated that human neural stem cells (NSCs) transduced with the cytosine deaminase (CD) gene showed remarkable 'bystander killer effect' on glioma and medulloblastoma cells after administration of the prodrug 5-fluorocytosine (5-FC). In addition, herpes simplex virus thymidine kinase (TK) is a widely studied enzyme used for suicide gene strategies, for which the prodrug is ganciclovir (GCV). To apply this strategy to brain metastasis treatment, we established here a human NSC line (F3.CD-TK) expressing the dual suicide genes CD and TK. We examined whether F3.CD-TK cells intensified the antitumor effect on lung cancer brain metastases. In vitro studies showed that F3.CD-TK cells exerted a marked bystander effect on human lung cancer cells after treatment with 5-FC and GCV. In a novel experimental brain metastases model, intravenously administered F3 cells migrated near lung cancer metastatic lesions, which were induced by the injection of lung cancer cells via the intracarotid artery. More importantly, F3.CD-TK cells in the presence of prodrugs 5-FC and GCV decreased tumor size and considerably prolonged animal survival. The results of the present study indicate that the dual suicide gene-engineered, NSC-based treatment strategy might offer a new promising therapeutic modality for brain metastases.

Podoplanin increases migration and angiogenesis in malignant glioma

PubMed Central

Grau, Stefan J; Trillsch, Fabian; Tonn, Joerg-Christian; Goldbrunner, Roland H; Noessner, Elfriede; Nelson, Peter J; von Luettichau, Irene

2015-01-01

Expression of podoplanin in glial brain tumors is grade dependent. While serving as a marker for tumor progression and modulating invasion in various neoplasms, little is known about podoplanin function in gliomas. Therefore we stably transfected two human glioma cell lines (U373MG and U87MG) with expression plasmids encoding podoplanin. The efficacy of transfection was confirmed by FACS analysis, PCR and immunocytochemistry. Cells were then sorted for highly podoplanin expressing cells (U373Phigh/U87Phigh). Transfection did not influence the production of pro-angiogenic factors including VEGF, VEGF-C and D. Also, expression of VEGF receptors (VEGFR) remained unchanged except for U87Phigh, where a VEGFR3 expression was induced. U373Phigh showed significantly reduced proliferation as compared to mock transfected group. By contrast, podoplanin significantly increased migration and invasion into collagen matrix. Furthermore, conditioned media from Phigh glioma cells strongly induced tube formation on matrigel. In conclusion, podoplanin increased migration of tumor cells and enhanced tube formation activity in endothelial cells independent from VEGF. Thus, podoplanin expression may be an important step in tumor progression. PMID:26339454

Small-molecule agonists of mammalian Diaphanous-related (mDia) formins reveal an effective glioblastoma anti-invasion strategy.

PubMed

Arden, Jessica D; Lavik, Kari I; Rubinic, Kaitlin A; Chiaia, Nicolas; Khuder, Sadik A; Howard, Marthe J; Nestor-Kalinoski, Andrea L; Alberts, Arthur S; Eisenmann, Kathryn M

2015-11-01

The extensive invasive capacity of glioblastoma (GBM) makes it resistant to surgery, radiotherapy, and chemotherapy and thus makes it lethal. In vivo, GBM invasion is mediated by Rho GTPases through unidentified downstream effectors. Mammalian Diaphanous (mDia) family formins are Rho-directed effectors that regulate the F-actin cytoskeleton to support tumor cell motility. Historically, anti-invasion strategies focused upon mDia inhibition, whereas activation remained unexplored. The recent development of small molecules directly inhibiting or activating mDia-driven F-actin assembly that supports motility allows for exploration of their role in GBM. We used the formin inhibitor SMIFH2 and mDia agonists IMM-01/-02 and mDia2-DAD peptides, which disrupt autoinhibition, to examine the roles of mDia inactivation versus activation in GBM cell migration and invasion in vitro and in an ex vivo brain slice invasion model. Inhibiting mDia suppressed directional migration and spheroid invasion while preserving intrinsic random migration. mDia agonism abrogated both random intrinsic and directional migration and halted U87 spheroid invasion in ex vivo brain slices. Thus mDia agonism is a superior GBM anti-invasion strategy. We conclude that formin agonism impedes the most dangerous GBM component-tumor spread into surrounding healthy tissue. Formin activation impairs novel aspects of transformed cells and informs the development of anti-GBM invasion strategies. © 2015 Arden et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Attenuated migration by green tea extract (-)-epigallocatechin gallate (EGCG): involvement of 67 kDa laminin receptor internalization in macrophagic cells.

PubMed

Ren, Xuezhi; Guo, Xingzhi; Chen, Li; Guo, Minxia; Peng, Ning; Li, Rui

2014-08-01

Excessive activation of the microglia in the brain is involved in the development of several neurodegenerative diseases. Previous studies have indicated that (-)-epigallocatechin gallate (EGCG), a major active constituent of green tea, exhibits potent suppressive effects on the activation of microglia. As the 67 kDa laminin receptor (67LR) is a key element in cellular activation and migration, we investigated the effect of EGCG on cell migration and 67LR in lipopolysaccharide (LPS)-activated macrophagic RAW264.7 cells. The presence of EGCG (1-25 μM) markedly attenuated LPS-induced cell migration in a dose-dependent manner. However, the total amount of 67LR protein in the RAW264.7 cells was unaffected by EGCG, as revealed by Western blot analysis. In addition, confocal immunofluorescence microscopy indicated that EGCG caused a marked membrane translocation of 67LR from the membrane surface towards the cytoplasm. Cell-surface biotinylation analysis confirmed that EGCG induced a significant internalization of 67LR by 24-68% in a dose-dependent manner. This study helps to explain the pharmacological action of EGCG on 67LR, suggesting its potential use in the treatment of diseases associated with macrophage/microglia activation, such as neurodegenerative diseases and cancer.

Brain aging phenomena in migrating sockeye salmon Oncorhynchus nerka nerka.

PubMed

Götz, M E; Malz, C R; Dirr, A; Blum, D; Gsell, W; Schmidt, S; Burger, R; Pohli, S; Riederer, P

2005-09-01

Aging, a process occurring in all vertebrates, is closely related to a loss in physical and functional abilities. There is widespread interest in clarifying the relevance of environmental, metabolic, and genetic factors for vertebrate aging. In the Pacific salmon a dramatic example of aging is known. Looking for changes in the salmon brain, perhaps even in the role of initiating the aging processes, we investigated several biochemical parameters that should reflect brain functional activity and stress response such as the neurotransmitters dopamine, and serotonin, and two of their respective metabolites 3,4-dihydroxyphenylacetic acid, and 5-hydroxyindole acetic acid, as well as glutathione, glutathione disulfide, and the extent of terminal deoxynucleotidyltransferase-mediated dUTP nick end-labelling. The aging of migrating sockeye salmon (Oncorhynchus nerka nerka) is accompanied by gradual increase in dopamine and serotonin turnover and a gradual decrease of brain total protein and glutathione levels. There appears to be an increased need for detoxification of reactive biological intermediates since activities of superoxide dismutase and catalase increase with age. However, our data do not support a major increase in apoptotic cell death during late aging but rather implicate an age related downward regulation of protein and glutathione synthesis and proteolysis increasing the need for autophagocytosis or heterophagocytosis in the course of cell death.

The Long and Winding Road: From the High-Affinity Choline Uptake Site to Clinical Trials for Malignant Brain Tumors.

PubMed

Lowenstein, P R; Castro, M G

2016-01-01

Malignant brain tumors are one of the most lethal cancers. They originate from glial cells which infiltrate throughout the brain. Current standard of care involves surgical resection, radiotherapy, and chemotherapy; median survival is currently ~14-20 months postdiagnosis. Given that the brain immune system is deficient in priming systemic immune responses to glioma antigens, we proposed to reconstitute the brain immune system to achieve immunological priming from within the brain. Two adenoviral vectors are injected into the resection cavity or remaining tumor. One adenoviral vector expresses the HSV-1-derived thymidine kinase which converts ganciclovir into a compound only cytotoxic to dividing glioma cells. The second adenovirus expresses the cytokine fms-like tyrosine kinase 3 ligand (Flt3L). Flt3L differentiates precursors into dendritic cells and acts as a chemokine that attracts dendritic cells to the brain. HSV-1/ganciclovir killing of tumor cells releases tumor antigens that are taken up by dendritic cells within the brain tumor microenvironment. Tumor killing also releases HMGB1, an endogenous TLR2 agonist that activates dendritic cells. HMGB1-activated dendritic cells, loaded with glioma antigens, migrate to cervical lymph nodes to stimulate a systemic CD8+ T cells cytotoxic immune response against glioma. This immune response is specific to glioma tumors, induces immunological memory, and does neither cause brain toxicity nor autoimmune responses. An IND was granted by the FDA on 4/7/2011. A Phase I, first in person trial, to test whether reengineering the brain immune system is potentially therapeutic is ongoing. © 2016 Elsevier Inc. All rights reserved.

L1 stimulation of human glioma cell motility correlates with FAK activation

PubMed Central

Yang, Muhua; Li, Yupei; Chilukuri, Kalyani; Brady, Owen A.; Boulos, Magdy I.; Kappes, John C.

2011-01-01

The neural adhesion/recognition protein L1 (L1CAM; CD171) has been shown or implicated to function in stimulation of cell motility in several cancer types, including high-grade gliomas. Our previous work demonstrated the expression and function of L1 protein in stimulation of cell motility in rat glioma cells. However, the mechanism of this stimulation is still unclear. This study further investigated the function of L1 and L1 proteolysis in human glioblastoma multiforme (GBM) cell migration and invasion, as well as the mechanism of this stimulation. L1 mRNA was found to be present in human T98G GBM cell line but not in U-118 MG grade III human glioma cell line. L1 protein expression, proteolysis, and release were found in T98G cells and human surgical GBM cells by Western blotting. Exosome-like vesicles released by T98G cells were purified and contained full-length L1. In a scratch assay, T98G cells that migrated into the denuded scratch area exhibited upregulation of ADAM10 protease expression coincident with loss of surface L1. GBM surgical specimen cells exhibited a similar loss of cell surface L1 when xenografted into the chick embryo brain. When lentivirally introduced shRNA was used to attenuate L1 expression, such T98G/shL1 cells exhibited significantly decreased cell motility by time lapse microscopy in our quantitative Super Scratch assay. These cells also showed a decrease in FAK activity and exhibited increased focal complexes. L1 binding integrins which activate FAK were found in T98G and U-118 MG cells. Addition of L1 ectodomain-containing media (1) rescued the decreased cell motility of T98G/shL1 cells and (2) increased cell motility of U-118 MG cells but (3) did not further increase T98G cell motility. Injection of L1-attenuated T98G/shL1 cells into embryonic chick brains resulted in the absence of detectable invasion compared to control cells which invaded brain tissue. These studies support a mechanism where glioma cells at the edge of a cell mass upregulate ADAM10 to proteolyze surface L1 and the resultant ectodomain increases human glioma cell migration and invasion by binding to integrin receptors, activating FAK, and increasing turnover of focal complexes. PMID:21373966

L1 stimulation of human glioma cell motility correlates with FAK activation.

PubMed

Yang, Muhua; Li, Yupei; Chilukuri, Kalyani; Brady, Owen A; Boulos, Magdy I; Kappes, John C; Galileo, Deni S

2011-10-01

The neural adhesion/recognition protein L1 (L1CAM; CD171) has been shown or implicated to function in stimulation of cell motility in several cancer types, including high-grade gliomas. Our previous work demonstrated the expression and function of L1 protein in stimulation of cell motility in rat glioma cells. However, the mechanism of this stimulation is still unclear. This study further investigated the function of L1 and L1 proteolysis in human glioblastoma multiforme (GBM) cell migration and invasion, as well as the mechanism of this stimulation. L1 mRNA was found to be present in human T98G GBM cell line but not in U-118 MG grade III human glioma cell line. L1 protein expression, proteolysis, and release were found in T98G cells and human surgical GBM cells by Western blotting. Exosome-like vesicles released by T98G cells were purified and contained full-length L1. In a scratch assay, T98G cells that migrated into the denuded scratch area exhibited upregulation of ADAM10 protease expression coincident with loss of surface L1. GBM surgical specimen cells exhibited a similar loss of cell surface L1 when xenografted into the chick embryo brain. When lentivirally introduced shRNA was used to attenuate L1 expression, such T98G/shL1 cells exhibited significantly decreased cell motility by time lapse microscopy in our quantitative Super Scratch assay. These cells also showed a decrease in FAK activity and exhibited increased focal complexes. L1 binding integrins which activate FAK were found in T98G and U-118 MG cells. Addition of L1 ectodomain-containing media (1) rescued the decreased cell motility of T98G/shL1 cells and (2) increased cell motility of U-118 MG cells but (3) did not further increase T98G cell motility. Injection of L1-attenuated T98G/shL1 cells into embryonic chick brains resulted in the absence of detectable invasion compared to control cells which invaded brain tissue. These studies support a mechanism where glioma cells at the edge of a cell mass upregulate ADAM10 to proteolyze surface L1 and the resultant ectodomain increases human glioma cell migration and invasion by binding to integrin receptors, activating FAK, and increasing turnover of focal complexes.

Estrogen promotes the brain metastatic colonization of triple negative breast cancer cells via an astrocyte-mediated paracrine mechanism.

PubMed

Sartorius, C A; Hanna, C T; Gril, B; Cruz, H; Serkova, N J; Huber, K M; Kabos, P; Schedin, T B; Borges, V F; Steeg, P S; Cittelly, D M

2016-06-02

Brain metastases (BM) are a devastating consequence of breast cancer. BM occur more frequently in patients with estrogen receptor-negative (ER-) breast cancer subtypes; HER2 overexpressing (HER2+) tumors and triple-negative (TN) (ER-, progesterone receptor-negative (PR-) and normal HER2) tumors. Young age is an independent risk factor for the development of BM, thus we speculated that higher circulating estrogens in young, pre-menopausal women could exert paracrine effects through the highly estrogen-responsive brain microenvironment. Using a TN experimental metastases model, we demonstrate that ovariectomy decreased the frequency of magnetic resonance imaging-detectable lesions by 56% as compared with estrogen supplementation, and that the combination of ovariectomy and letrozole further reduced the frequency of large lesions to 14.4% of the estrogen control. Human BM expressed 4.2-48.4% ER+ stromal area, particularly ER+ astrocytes. In vitro, E2-treated astrocytes increased proliferation, migration and invasion of 231BR-EGFP cells in an ER-dependent manner. E2 upregulated epidermal growth factor receptor (EGFR) ligands Egf, Ereg and Tgfa mRNA and protein levels in astrocytes, and activated EGFR in brain metastatic cells. Co-culture of 231BR-EGFP cells with E2-treated astrocytes led to the upregulation of the metastatic mediator S100 Calcium-binding protein A4 (S100A4) (1.78-fold, P<0.05). Exogenous EGF increased S100A4 mRNA levels in 231BR-EGFP cells (1.40±0.02-fold, P<0.01 compared with vehicle control) and an EGFR/HER2 inhibitor blocked this effect, suggesting that S100A4 is a downstream effector of EGFR activation. Short hairpin RNA-mediated S100A4 silencing in 231BR-EGFP cells decreased their migration and invasion in response to E2-CM, abolished their increased proliferation in co-cultures with E2-treated astrocytes and decreased brain metastatic colonization. Thus, S100A4 is one effector of the paracrine action of E2 in brain metastatic cells. These studies provide a novel mechanism by which estrogens, acting through ER+ astrocytes in the brain microenvironment, can promote BM of TN breast cancers, and suggests existing endocrine agents may provide some clinical benefit towards reducing and managing BM.

Estrogen promotes the brain metastatic colonization of triple negative breast cancer cells via an astrocyte-mediated paracrine mechanism

PubMed Central

Sartorius, Carol A.; Hanna, Colton T.; Gril, Brunilde; Cruz, Hazel; Serkova, Natalie J.; Huber, Kendra M.; Kabos, Peter; Schedin, Troy B.; Borges, Virginia F.; Steeg, Patricia S.; Cittelly, Diana M.

2015-01-01

Brain metastases (BM) are a devastating consequence of breast cancer. BM occur more frequently in patients with estrogen receptor-negative (ER−) breast cancer subtypes; HER2 overexpressing (HER2+) tumors and triple-negative (TN) (ER−, progesterone receptor-negative (PR−) and normal HER2) tumors. Young age is an independent risk factor for development of BM, thus we speculated that higher circulating estrogens in young, pre-menopausal women could exert paracrine effects through the highly estrogen-responsive brain microenvironment. Using a TN experimental metastases model, we demonstrate that ovariectomy decreased the frequency of MRI detectable lesions by 56% as compared to estrogen supplementation, and that the combination of ovariectomy and letrozole further reduced the frequency of large lesions to 14.4% of the estrogen control. Human BM expressed 4.2-48.4% ER+ stromal area, particularly ER+ astrocytes. In vitro, E2-treated astrocytes increased proliferation, migration and invasion of 231BR-EGFP cells in an ER-dependent manner. E2 upregulated EGFR ligands Egf, Ereg, and Tgfa mRNA and protein levels in astrocytes, and activated EGFR in brain metastatic cells. Co-culture of 231BR-EGFP cells with E2-treated astrocytes led to upregulation of the metastatic mediator S100 Calcium-binding protein A4 (S100A4) (1.78-fold, P<0.05). Exogenous EGF increased S100A4 mRNA levels in 231BR-EGFP cells (1.40±0.02 fold, P<0.01 compared to vehicle-control) and an EGFR/HER2 inhibitor blocked this effect, suggesting that S100A4 is a downstream effector of EGFR activation. ShRNA-mediated S100A4 silencing in 231BR-EGFP cells decreased their migration and invasion in response to E2-CM, abolished their increased proliferation in co-cultures with E2-treated astrocytes, and decreased brain metastatic colonization. Thus, S100A4 is one effector of the paracrine action of E2 in brain metastatic cells. These studies provide a novel mechanism by which estrogens, acting through ER+ astrocytes in the brain microenvironment, can promote BM of TN breast cancers, and suggests existing endocrine agents may provide some clinical benefit towards reducing and managing BM. PMID:26411365

A dangerous liaison: Leptin and sPLA2-IIA join forces to induce proliferation and migration of astrocytoma cells.

PubMed

Martín, Rubén; Cordova, Claudia; Gutiérrez, Beatriz; Hernández, Marita; Nieto, María L

2017-01-01

Glioblastoma, the most aggressive type of primary brain tumour, shows worse prognosis linked to diabetes or obesity persistence. These pathologies are chronic inflammatory conditions characterized by altered profiles of inflammatory mediators, including leptin and secreted phospholipase A2-IIA (sPLA2-IIA). Both proteins, in turn, display diverse pro-cancer properties in different cell types, including astrocytes. Herein, to understand the underlying relationship between obesity and brain tumors, we investigated the effect of leptin, alone or in combination with sPLA2-IIA on astrocytoma cell functions. sPLA2-IIA induced up-regulation of leptin receptors in 1321N1 human astrocytoma cells. Leptin, as well as sPLA2-IIA, increased growth and migration in these cells, through activation/phosphorylation of key proteins of survival cascades. Leptin, at concentrations with minimal or no activating effects on astrocytoma cells, enhanced growth and migration promoted by low doses of sPLA2-IIA. sPLA2-IIA alone induced a transient phosphorylation pattern in the Src/ERK/Akt/mTOR/p70S6K/rS6 pathway through EGFR transactivation, and co-addition of leptin resulted in a sustained phosphorylation of these signaling regulators. Mechanistically, EGFR transactivation and tyrosine- and serine/threonine-protein phosphatases revealed a key role in this leptin-sPLA2-IIA cross-talk. This cooperative partnership between both proteins was also found in primary astrocytes. These findings thus indicate that the adipokine leptin, by increasing the susceptibility of cells to inflammatory mediators, could contribute to worsen the prognosis of tumoral and neurodegenerative processes, being a potential mediator of some obesity-related medical complications.

Biological characteristics of human-urine-derived stem cells: potential for cell-based therapy in neurology.

PubMed

Guan, Jun-Jie; Niu, Xin; Gong, Fei-Xiang; Hu, Bin; Guo, Shang-Chun; Lou, Yuan-Lei; Zhang, Chang-Qing; Deng, Zhi-Feng; Wang, Yang

2014-07-01

Stem cells in human urine have gained attention in recent years; however, urine-derived stem cells (USCs) are far from being well elucidated. In this study, we compared the biological characteristics of USCs with adipose-derived stem cells (ASCs) and investigated whether USCs could serve as a potential cell source for neural tissue engineering. USCs were isolated from voided urine with a modified culture medium. Through a series of experiments, we examined the growth rate, surface antigens, and differentiation potential of USCs, and compared them with ASCs. USCs showed robust proliferation ability. After serial propagation, USCs retained normal karyotypes. Cell surface antigen expression of USCs was similar to ASCs. With lineage-specific induction factors, USCs could differentiate toward the osteogenic, chondrogenic, adipogenic, and neurogenic lineages. To assess the ability of USCs to survive, differentiate, and migrate, they were seeded onto hydrogel scaffold and transplanted into rat brain. The results showed that USCs were able to survive in the lesion site, migrate to other areas, and express proteins that were associated with neural phenotypes. The results of our study demonstrate that USCs possess similar biological characteristics with ASCs and have multilineage differentiation potential. Moreover USCs can differentiate to neuron-like cells in rat brain. The present study shows that USCs are a promising cell source for tissue engineering and regenerative medicine.

The ROCK/GGTase Pathway Are Essential to the Proliferation and Differentiation of Neural Stem Cells Mediated by Simvastatin.

PubMed

Zhang, Chan; Wu, Jian-Min; Liao, Min; Wang, Jun-Ling; Xu, Chao-Jin

2016-12-01

Simvastatin, a lipophilic and fermentation-derived natural statin, is reported to treat neurological disorders, such as traumatic brain injury, Parkinson's disease (PD), Alzheimer disease (AD), etc. Recently, research also indicated that simvastatin could promote regeneration in the dentate gyrus of adult mice by Wnt/β-catenin signaling (Robin et al. in Stem Cell Reports 2:9-17, 2014). However, the effect and mechanisms by which simvastatin may affect the neural stem cells (NSCs; from the embryonic day 14.5 (E14.5) SD rat brain) are not fully understood. Here, we investigated the effects of different doses of simvastatin on the survival, proliferation, differentiation, migration, and cell cycle of NSCs as well as underlying intracellular signaling pathways. The results showed that simvastatin not only inhibits the proliferation of NSCs but also enhances the βIII-tubulin + neuron differentiation rate. Additionally, we find that simvastatin could also promote NSC migration and induce cell cycle arrest at M2 phrase. All these effects of simvastatin on NSCs were mimicked with an inhibitor of Rho kinase (ROCK) and a specific inhibitor of geranylgeranyl transferase (GGTase). In conclusion, these data indicate that simvastatin could promote neurogenesis of neural stem cells, and these effects were mediated through the ROCK/GGTase pathway.

The Src substrate SKAP2 regulates actin assembly by interacting with WAVE2 and cortactin proteins.

PubMed

Shimamura, Shintaro; Sasaki, Kazuki; Tanaka, Masamitsu

2013-01-11

In our attempt to screen for substrates of Src family kinases in glioblastoma, Src kinase-associated phosphoprotein 2 (SKAP2) was identified. Although SKAP2 has been suggested to be associated with integrin-mediated adhesion of hematopoietic cells, little is known about its molecular function and the effects in other types of cells and tumors. Here, we demonstrate that SKAP2 physically associates with actin assembly factors WAVE2 and cortactin and inhibits their interaction. Cortactin is required for the membrane localization of WAVE2, and SKAP2 suppresses actin polymerization mediated by WAVE2 and cortactin in vitro. Knockdown of SKAP2 in NIH3T3 accelerated cell migration and enhanced translocation of WAVE2 to the cell membrane, and those effects of SKAP2 depend on the binding activity of SKAP2 to WAVE2. Furthermore, reduction of SKAP2 in the glioblastoma promoted tumor invasion both in ex vivo organotypic rat brain slices and immune-deficient mouse brains. These results suggest that SKAP2 negatively regulates cell migration and tumor invasion in fibroblasts and glioblastoma cells by suppressing actin assembly induced by the WAVE2-cortactin complex, indicating that SKAP2 may be a novel candidate for the suppressor of tumor progression.

The Src Substrate SKAP2 Regulates Actin Assembly by Interacting with WAVE2 and Cortactin Proteins*

PubMed Central

Shimamura, Shintaro; Sasaki, Kazuki; Tanaka, Masamitsu

2013-01-01

In our attempt to screen for substrates of Src family kinases in glioblastoma, Src kinase-associated phosphoprotein 2 (SKAP2) was identified. Although SKAP2 has been suggested to be associated with integrin-mediated adhesion of hematopoietic cells, little is known about its molecular function and the effects in other types of cells and tumors. Here, we demonstrate that SKAP2 physically associates with actin assembly factors WAVE2 and cortactin and inhibits their interaction. Cortactin is required for the membrane localization of WAVE2, and SKAP2 suppresses actin polymerization mediated by WAVE2 and cortactin in vitro. Knockdown of SKAP2 in NIH3T3 accelerated cell migration and enhanced translocation of WAVE2 to the cell membrane, and those effects of SKAP2 depend on the binding activity of SKAP2 to WAVE2. Furthermore, reduction of SKAP2 in the glioblastoma promoted tumor invasion both in ex vivo organotypic rat brain slices and immune-deficient mouse brains. These results suggest that SKAP2 negatively regulates cell migration and tumor invasion in fibroblasts and glioblastoma cells by suppressing actin assembly induced by the WAVE2-cortactin complex, indicating that SKAP2 may be a novel candidate for the suppressor of tumor progression. PMID:23161539

PAMAM Dendrimers Cross the Blood–Brain Barrier When Administered through the Carotid Artery in C57BL/6J Mice

PubMed Central

Srinageshwar, Bhairavi; Peruzzaro, Sarah; Andrews, Melissa; Johnson, Kayla; Hietpas, Allison; Clark, Brittany; McGuire, Crystal; Petersen, Eric; Kippe, Jordyn; Stewart, Andrew; Lossia, Olivia; Al-Gharaibeh, Abeer; Antcliff, Aaron; Culver, Rebecca; Swanson, Douglas; Dunbar, Gary; Sharma, Ajit; Rossignol, Julien

2017-01-01

Drug delivery into the central nervous system (CNS) is challenging due to the blood–brain barrier (BBB) and drug delivery into the brain overcoming the BBB can be achieved using nanoparticles such as dendrimers. The conventional cationic dendrimers used are highly toxic. Therefore, the present study investigates the role of novel mixed surface dendrimers, which have potentially less toxicity and can cross the BBB when administered through the carotid artery in mice. In vitro experiments investigated the uptake of amine dendrimers (G1-NH2 and G4-NH2) and novel dendrimers (G1-90/10 and G4-90/10) by primary cortical cultures. In vivo experiments involved transplantation of G4-90/10 into mice through (1) invasive intracranial injections into the striatum; and (2) less invasive carotid injections. The animals were sacrificed 24-h and 1-week post-transplantations and their brains were analyzed. In vivo experiments proved that the G4-90/10 can cross the BBB when injected through the carotid artery and localize within neurons and glial cells. The dendrimers were found to migrate through the corpus callosum 1-week post intracranial injection. Immunohistochemistry showed that the migrating cells are the dendrimer-infected glial cells. Overall, our results suggest that poly-amidoamine (PAMAM) dendrimers may be used as a minimally invasive means to deliver biomolecules for treating neurological diseases or disorders PMID:28335421

Molecular dialogues between the ischemic brain and the peripheral immune system: Dualistic roles in injury and repair

PubMed Central

An, Chengrui; Shi, Yejie; Li, Peiying; Hu, Xiaoming; Gan, Yu; Stetler, Ruth A.; Leak, Rehana K.; Gao, Yanqin; Sun, Bao-Liang; Zheng, Ping; Chen, Jun

2014-01-01

Immune and inflammatory responses actively modulate the pathophysiological processes of acute brain injuries such as stroke. Soon after the onset of stroke, signals such as brain-derived antigens, danger-associated molecular patterns (DAMPs), cytokines, and chemokines are released from the injured brain into the systemic circulation. The injured brain also communicates with peripheral organs through the parasympathetic and sympathetic branches of the autonomic nervous system. Many of these diverse signals not only activate resident immune cells in the brain, but also trigger robust immune responses in the periphery. Peripheral immune cells then migrate toward the site of injury and release additional cytokines, chemokines, and other molecules, causing further disruptive or protective effects in the ischemic brain. Bidirectional communication between the injured brain and the peripheral immune system is now known to regulate the progression of stroke pathology as well as tissue repair. In the end, this exquisitely coordinated crosstalk helps determine the fate of animals after stroke. This article reviews the literature on ischemic brain-derived signals through which peripheral immune responses are triggered, and the potential impact of these peripheral responses on brain injury and repair. Pharmacological strategies and cell-based therapies that target the dialogue between the brain and peripheral immune system show promise as potential novel treatments for stroke. PMID:24374228

Developing a Novel Embryo–Larval Zebrafish Xenograft Assay to Prioritize Human Glioblastoma Therapeutics

PubMed Central

Wehmas, Leah Christine; Tanguay, Robert L.; Punnoose, Alex

2016-01-01

Abstract Glioblastoma is an aggressive brain cancer requiring improved treatments. Existing methods of drug discovery and development require years before new therapeutics become available to patients. Zebrafish xenograft models hold promise for prioritizing drug development. We have developed an embryo–larval zebrafish xenograft assay in which cancer cells are implanted in a brain microenvironment to discover and prioritize compounds that impact glioblastoma proliferation, migration, and invasion. We illustrate the utility of our assay by evaluating the well-studied, phosphatidylinositide 3-kinase inhibitor LY294002 and zinc oxide nanoparticles (ZnO NPs), which demonstrate selective cancer cytotoxicity in cell culture, but the in vivo effectiveness has not been established. Exposures of 3.125–6.25 μM LY294002 significantly decreased proliferation up to 34% with concentration-dependent trends. Exposure to 6.25 μM LY294002 significantly inhibited migration/invasion by ∼27% within the glioblastoma cell mass (0–80 μm) and by ∼32% in the next distance region (81–160 μm). Unexpectedly, ZnO enhanced glioblastoma proliferation by ∼19% and migration/invasion by ∼35% at the periphery of the cell mass (161+ μm); however, dissolution of these NPs make it difficult to discern whether this was a nano or ionic effect. These results demonstrate that we have a short, relevant, and sensitive zebrafish-based assay to aid glioblastoma therapeutic development. PMID:27158859

A galvanotaxis assay for analysis of neural precursor cell migration kinetics in an externally applied direct current electric field.

PubMed

Babona-Pilipos, Robart; Popovic, Milos R; Morshead, Cindi M

2012-10-13

The discovery of neural stem and progenitor cells (collectively termed neural precursor cells) (NPCs) in the adult mammalian brain has led to a body of research aimed at utilizing the multipotent and proliferative properties of these cells for the development of neuroregenerative strategies. A critical step for the success of such strategies is the mobilization of NPCs toward a lesion site following exogenous transplantation or to enhance the response of the endogenous precursors that are found in the periventricular region of the CNS. Accordingly, it is essential to understand the mechanisms that promote, guide, and enhance NPC migration. Our work focuses on the utilization of direct current electric fields (dcEFs) to promote and direct NPC migration - a phenomenon known as galvanotaxis. Endogenous physiological electric fields function as critical cues for cell migration during normal development and wound repair. Pharmacological disruption of the trans-neural tube potential in axolotl embryos causes severe developmental malformations(1). In the context of wound healing, the rate of repair of wounded cornea is directly correlated with the magnitude of the epithelial wound potential that arises after injury, as shown by pharmacological enhancement or disruption of this dcEF(2-3). We have demonstrated that adult subependymal NPCs undergo rapid and directed cathodal migration in vitro when exposed to an externally applied dcEF. In this protocol we describe our lab's techniques for creating a simple and effective galvanotaxis assay for high-resolution, long-term observation of directed cell body translocation (migration) on a single-cell level. This assay would be suitable for investigating the mechanisms that regulate dcEF transduction into cellular motility through the use of transgenic or knockout mice, short interfering RNA, or specific receptor agonists/antagonists.

CNS angiogenesis and barriergenesis occur simultaneously.

PubMed

Umans, Robyn A; Henson, Hannah E; Mu, Fangzhou; Parupalli, Chaithanyarani; Ju, Bensheng; Peters, Jennifer L; Lanham, Kevin A; Plavicki, Jessica S; Taylor, Michael R

2017-05-15

The blood-brain barrier (BBB) plays a vital role in the central nervous system (CNS). A comprehensive understanding of BBB development has been hampered by difficulties in observing the differentiation of brain endothelial cells (BECs) in real-time. Here, we generated two transgenic zebrafish line, Tg(glut1b:mCherry) and Tg(plvap:EGFP), to serve as in vivo reporters of BBB development. We showed that barriergenesis (i.e. the induction of BEC differentiation) occurs immediately as endothelial tips cells migrate into the brain parenchyma. Using the Tg(glut1b:mCherry) transgenic line, we performed a genetic screen and identified a zebrafish mutant with a nonsense mutation in gpr124, a gene known to play a role in CNS angiogenesis and BBB development. We also showed that our transgenic plvap:EGFP line, a reporter of immature brain endothelium, is initially expressed in newly formed brain endothelial cells, but subsides during BBB maturation. Our results demonstrate the ability to visualize the in vivo differentiation of brain endothelial cells into the BBB phenotype and establish that CNS angiogenesis and barriergenesis occur simultaneously. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Swelling-induced chloride current in glioblastoma proliferation, migration, and invasion.

PubMed

Wong, Raymond; Chen, Wenliang; Zhong, Xiao; Rutka, James T; Feng, Zhong-Ping; Sun, Hong-Shuo

2018-01-01

Glioblastoma (GBM) remains as the most common and aggressive brain tumor. The survival of GBM has been linked to the aberrant activation of swelling-induced chloride current I Cl,swell . In this study, we investigated the effects of I Cl,swell on cell viability, proliferation, and migration in the human GBM cell lines, U251 and U87, using a combination of patch clamp electrophysiology, MTT, colony formation, wound healing assays and Western immunoblotting. First, we showed that the specific inhibitor of I Cl,swell , DCPIB, potently reduced the I Cl,swell in U87 cells. Next, in both U87 and U251 cells, we found that DCPIB reduced GBM viability, proliferation, colony formation, migration, and invasion. In addition, our Western immunoblot assay showed that DCPIB-treated U251 cells had a reduction in JAK2, STAT3, and Akt phosphorylation, thus, suggesting that DCPIB potentially suppresses GBM functions through inhibition of the JAK2/STAT3 and PI3K/Akt signaling pathways. Therefore, the I Cl,swell may be a potential drug target for GBM. © 2017 Wiley Periodicals, Inc.

Transplanted Dental Pulp Stem Cells Migrate to Injured Area and Express Neural Markers in a Rat Model of Cerebral Ischemia.

PubMed

Zhang, Xuemei; Zhou, Yinglian; Li, Hulun; Wang, Rui; Yang, Dan; Li, Bing; Cao, Xiaofang; Fu, Jin

2018-01-01

Ischemic stroke is a major cause of disability and mortality worldwide, while effective restorative treatments are limited at present. Stem cell transplantation holds therapeutic potential for ischemic vascular diseases and may provide an opportunity for neural regeneration. Dental pulp stem cells (DPSCs) origin from neural crest and have neuro-ectodermal features including proliferation and multilineage differentiation potentials. The rat model of middle cerebral artery occlusion (MCAO) was used to evaluate whether intravenous administration of DPSCs can reduce infarct size and to estimate the migration and trans-differentiation into neuron-like cells in focal cerebral ischemia models. Brain tissues were collected at 4 weeks following cell transplantation and analyzed with immunofluorescence, immunohistochemistry and real-time polymerase chain reaction (RT-PCR) methods. Intravenously administration of rat-derived DPSCs were found to migrate into the boundary of ischemic areas and expressed neural specific markers, reducing infarct volume and cerebral edema. These results suggest that DPSCs treatment may serve as a potential therapy for clinical stroke patients in the future. © 2018 The Author(s). Published by S. Karger AG, Basel.

hiPSC-derived neural stem cells from patients with schizophrenia induce an impaired angiogenesis.

PubMed

Casas, Bárbara S; Vitória, Gabriela; do Costa, Marcelo N; Madeiro da Costa, Rodrigo; Trindade, Pablo; Maciel, Renata; Navarrete, Nelson; Rehen, Stevens K; Palma, Verónica

2018-02-22

Schizophrenia is a neurodevelopmental disease characterized by cerebral connectivity impairment and loss of gray matter. It was described in adult schizophrenia patients (SZP) that concentration of VEGFA, a master angiogenic factor, is decreased. Recent evidence suggests cerebral hypoperfusion related to a dysfunctional Blood Brain Barrier (BBB) in SZP. Since neurogenesis and blood-vessel formation occur in a coincident and coordinated fashion, a defect in neurovascular development could result in increased vascular permeability and, therefore, in poor functionality of the SZP's neurons. Here, we characterized the conditioned media (CM) of human induced Pluripotent Stem Cells (hiPSC)-derived Neural Stem Cells of SZP (SZP NSC) versus healthy subjects (Ctrl NSC), and its impact on angiogenesis. Our results reveal that SZP NSC have an imbalance in the secretion and expression of several angiogenic factors, among them non-canonical neuro-angiogenic guidance factors. SZP NSC migrated less and their CM was less effective in inducing migration and angiogenesis both in vitro and in vivo. Since SZP originates during embryonic brain development, our findings suggest a defective crosstalk between NSC and endothelial cells (EC) during the formation of the neuro-angiogenic niche.

Gelatinized Copper–Capillary Alginate Gel Functions as an Injectable Tissue Scaffolding System for Stem Cell Transplants

PubMed Central

Willenberg, Bradley Jay; Zheng, Tong; Meng, Fan-Wei; Meneses, Juan Carlos; Rossignol, Candace; Batich, Christopher D.; Terada, Naohiro; Steindler, Dennis A.; Weiss, Michael D.

2013-01-01

In severe hypoxic–ischemic brain injury, cellular components such as neurons and astrocytes are injured or destroyed along with the supporting extracellular matrix. This presents a challenge to the field of regenerative medicine since the lack of extracellular matrix and supporting structures makes the transplant milieu inhospitable to the transplanted cells. A potential solution to this problem is the use of a biomaterial to provide the extracellular components needed to keep cells localized in cystic brain regions, allowing the cells to form connections and repair lost brain tissue. Ideally, this biomaterial would be combined with stem cells, which have been proven to have therapeutic potentials, and could be delivered via an injection. To study this approach, we derived a hydrogel biomaterial tissue scaffold from oligomeric gelatin and copper–capillary alginate gel (GCCAG). We then demonstrated that our multipotent astrocytic stem cells (MASCs) could be maintained in GCCAG scaffolds for up to 2 weeks in vitro and that the cells retained their multipotency. We next performed a pilot transplant study in which GCCAG was mixed with MASCs and injected into the brain of a neonatal rat pup. After a week in vivo, our results showed that: the GCCAG biomaterial did not cause a significant reactive gliosis; viable cells were retained within the injected scaffolds; and some delivered cells migrated into the surrounding brain tissue. Therefore, GCCAG tissue scaffolds are a promising, novel injectable system for transplantation of stem cells to the brain. PMID:20699061

Native Mutant Huntingtin in Human Brain

PubMed Central

Sapp, Ellen; Valencia, Antonio; Li, Xueyi; Aronin, Neil; Kegel, Kimberly B.; Vonsattel, Jean-Paul; Young, Anne B.; Wexler, Nancy; DiFiglia, Marian

2012-01-01

Huntington disease (HD) is caused by polyglutamine expansion in the N terminus of huntingtin (htt). Analysis of human postmortem brain lysates by SDS-PAGE and Western blot reveals htt as full-length and fragmented. Here we used Blue Native PAGE (BNP) and Western blots to study native htt in human postmortem brain. Antisera against htt detected a single band broadly migrating at 575–850 kDa in control brain and at 650–885 kDa in heterozygous and Venezuelan homozygous HD brains. Anti-polyglutamine antisera detected full-length mutant htt in HD brain. There was little htt cleavage even if lysates were pretreated with trypsin, indicating a property of native htt to resist protease cleavage. A soluble mutant htt fragment of about 180 kDa was detected with anti-htt antibody Ab1 (htt-(1–17)) and increased when lysates were treated with denaturants (SDS, 8 m urea, DTT, or trypsin) before BNP. Wild-type htt was more resistant to denaturants. Based on migration of in vitro translated htt fragments, the 180-kDa segment terminated ≈htt 670–880 amino acids. If second dimension SDS-PAGE followed BNP, the 180-kDa mutant htt was absent, and 43–50 kDa htt fragments appeared. Brain lysates from two HD mouse models expressed native full-length htt; a mutant fragment formed if lysates were pretreated with 8 m urea + DTT. Native full-length mutant htt in embryonic HD140Q/140Q mouse primary neurons was intact during cell death and when cell lysates were exposed to denaturants before BNP. Thus, native mutant htt occurs in brain and primary neurons as a soluble full-length monomer. PMID:22375012

Brain Tumor Genetic Modification Yields Increased Resistance to Paclitaxel in Physical Confinement

PubMed Central

Bui, Loan; Hendricks, Alissa; Wright, Jamie; Chuong, Cheng-Jen; Davé, Digant; Bachoo, Robert; Kim, Young-tae

2016-01-01

Brain tumor cells remain highly resistant to radiation and chemotherapy, particularly malignant and secondary cancers. In this study, we utilized microchannel devices to examine the effect of a confined environment on the viability and drug resistance of the following brain cancer cell lines: primary cancers (glioblastoma multiforme and neuroblastoma), human brain cancer cell lines (D54 and D54-EGFRvIII), and genetically modified mouse astrocytes (wild type, p53−/−, p53−/− PTEN−/−, p53−/− Braf, and p53−/− PTEN−/− Braf). We found that loss of PTEN combined with Braf activation resulted in higher viability in narrow microchannels. In addition, Braf conferred increased resistance to the microtubule-stabilizing drug Taxol in narrow confinement. Similarly, survival of D54-EGFRvIII cells was unaffected following treatment with Taxol, whereas the viability of D54 cells was reduced by 75% under these conditions. Taken together, our data suggests key targets for anticancer drugs based on cellular genotypes and their specific survival phenotypes during confined migration. PMID:27184621

Immunostimulatory CpG on Carbon Nanotubes Selectively Inhibits Migration of Brain Tumor Cells.

PubMed

Alizadeh, Darya; White, Ethan E; Sanchez, Teresa C; Liu, Shunan; Zhang, Leying; Badie, Behnam; Berlin, Jacob M

2018-05-16

Even when treated with aggressive current therapies, patients with glioblastoma usually survive less than two years and exhibit a high rate of recurrence. CpG is an oligonucleotide that activates the innate immune system via Toll-like receptor 9 (TLR9) activation. Injection of CpG into glioblastoma tumors showed promise as an immunotherapy in mouse models but proved disappointing in human trials. One aspect of glioma that is not addressed by CpG therapy alone is the highly invasive nature of glioma cells, which is associated with resistance to radiation and chemotherapy. Here, we demonstrate that single-walled carbon nanotubes noncovalently functionalized with CpG (SWNT/CpG), which retain the immunostimulatory property of the CpG, selectively inhibit the migration of glioma cells and not macrophages without affecting cell viability or proliferation. SWNT/CpG also selectively decreased NF-κB activation in glioma cells, while activating macrophages by induction of the TLR9/NF-κB pathway, as we have previously reported. The migration inhibition of glioma cells was correlated with selective reduction of intracellular levels of reactive oxygen species (ROS), suggesting that an antioxidant-based mechanism mediates the observed effects. To the best of our knowledge, SWNT/CpG is the first nanomaterial that inhibits the migration of cancer cells while stimulating the immune system.

Control of adult neurogenesis by programmed cell death in the mammalian brain.

PubMed

Ryu, Jae Ryun; Hong, Caroline Jeeyeon; Kim, Joo Yeon; Kim, Eun-Kyoung; Sun, Woong; Yu, Seong-Woon

2016-04-21

The presence of neural stem cells (NSCs) and the production of new neurons in the adult brain have received great attention from scientists and the public because of implications to brain plasticity and their potential use for treating currently incurable brain diseases. Adult neurogenesis is controlled at multiple levels, including proliferation, differentiation, migration, and programmed cell death (PCD). Among these, PCD is the last and most prominent process for regulating the final number of mature neurons integrated into neural circuits. PCD can be classified into apoptosis, necrosis, and autophagic cell death and emerging evidence suggests that all three may be important modes of cell death in neural stem/progenitor cells. However, the molecular mechanisms that regulate PCD and thereby impact the intricate balance between self-renewal, proliferation, and differentiation during adult neurogenesis are not well understood. In this comprehensive review, we focus on the extent, mechanism, and biological significance of PCD for the control of adult neurogenesis in the mammalian brain. The role of intrinsic and extrinsic factors in the regulation of PCD at the molecular and systems levels is also discussed. Adult neurogenesis is a dynamic process, and the signals for differentiation, proliferation, and death of neural progenitor/stem cells are closely interrelated. A better understanding of how adult neurogenesis is influenced by PCD will help lead to important insights relevant to brain health and diseases.

Engraftment of enteric neural progenitor cells into the injured adult brain.

PubMed

Belkind-Gerson, Jaime; Hotta, Ryo; Whalen, Michael; Nayyar, Naema; Nagy, Nandor; Cheng, Lily; Zuckerman, Aaron; Goldstein, Allan M; Dietrich, Jorg

2016-01-25

A major area of unmet need is the development of strategies to restore neuronal network systems and to recover brain function in patients with neurological disease. The use of cell-based therapies remains an attractive approach, but its application has been challenging due to the lack of suitable cell sources, ethical concerns, and immune-mediated tissue rejection. We propose an innovative approach that utilizes gut-derived neural tissue for cell-based therapies following focal or diffuse central nervous system injury. Enteric neuronal stem and progenitor cells, able to differentiate into neuronal and glial lineages, were isolated from the postnatal enteric nervous system and propagated in vitro. Gut-derived neural progenitors, genetically engineered to express fluorescent proteins, were transplanted into the injured brain of adult mice. Using different models of brain injury in combination with either local or systemic cell delivery, we show that transplanted enteric neuronal progenitor cells survive, proliferate, and differentiate into neuronal and glial lineages in vivo. Moreover, transplanted cells migrate extensively along neuronal pathways and appear to modulate the local microenvironment to stimulate endogenous neurogenesis. Our findings suggest that enteric nervous system derived cells represent a potential source for tissue regeneration in the central nervous system. Further studies are needed to validate these findings and to explore whether autologous gut-derived cell transplantation into the injured brain can result in functional neurologic recovery.

Brain-derived neurotrophic factor (BDNF) -TrKB signaling modulates cancer-endothelial cells interaction and affects the outcomes of triple negative breast cancer

PubMed Central

Tsai, Yi-Fang; Hsu, Chih-Yi; Yang, Muh-Hwa; Shyr, Yi-Ming

2017-01-01

Aims There is good evidence that the tumor microenvironment plays an important role in cancer metastasis and progression. Our previous studies have shown that brain-derived neurotrophic factor (BDNF) participates in the process of metastasis and in the migration of cancer cells. The aim of this study was to investigate the role of BDNF on the tumor cell microenvironment, namely, the cancer cell-endothelial cell interaction of TNBC cells. Methods We conducted oligoneucleotide microarray analysis of potential biomarkers that are able to differentiate recurrent TNBC from non-recurrent TNBC. The MDA-MB-231 and human endothelial HUVEC lines were used for this study and our approaches included functional studies, such as migration assay, as well as Western blot and real-time PCR analysis of migration and angiogenic signaling. In addition, we analyzed the survival outcome of TNBC breast cancer patients according to their expression level of BDNF using clinical samples. Results The results demonstrated that BDNF was able to bring about autocrinal (MDA-MB-231) and paracrinal (HUVECs) regulation of BDNF-TrkB gene expression and this affected cell migratory activity. The BDNF-induced migratory activity was blocked by inhibitors of ERK, PI3K and TrkB when MDA-MB-231 cells were examined, but only an inhibitor of ERK blocked this activity when HUVEC cells were used. Furthermore, decreased migratory activity was found for △BDNF and △TrkB cell lines. Ingenuity pathway analysis (IPA) of MDA-MB-231 cells showed that BDNF is a key factor that is able to regulate a network made up of metalloproteases and calmodulin. Protein expression levels in a tissue array of tumor slices were found to be correlated with patient prognosis and the results showed that there was significant correlation of TrkB expression, but not of BDNF. expressionwith patient DFS and OS. Conclusion Our study demonstrates that up-regulation of the BDNF signaling pathway seems tobe involved in the mechanism associated with early recurrence in triple negative breast cancer cell. In addition, BDNF can function in either an autocrine or a paracrine manner to increase the migration ability of both MDA-MB-231 cells and HUVEC cells. Finally, overexpression of TrkB, but not of BDNF, is significantly associated with a poor survival outcome for TNBC patients. PMID:28604807

Brain-derived neurotrophic factor (BDNF) -TrKB signaling modulates cancer-endothelial cells interaction and affects the outcomes of triple negative breast cancer.

PubMed

Tsai, Yi-Fang; Tseng, Ling-Ming; Hsu, Chih-Yi; Yang, Muh-Hwa; Chiu, Jen-Hwey; Shyr, Yi-Ming

2017-01-01

There is good evidence that the tumor microenvironment plays an important role in cancer metastasis and progression. Our previous studies have shown that brain-derived neurotrophic factor (BDNF) participates in the process of metastasis and in the migration of cancer cells. The aim of this study was to investigate the role of BDNF on the tumor cell microenvironment, namely, the cancer cell-endothelial cell interaction of TNBC cells. We conducted oligoneucleotide microarray analysis of potential biomarkers that are able to differentiate recurrent TNBC from non-recurrent TNBC. The MDA-MB-231 and human endothelial HUVEC lines were used for this study and our approaches included functional studies, such as migration assay, as well as Western blot and real-time PCR analysis of migration and angiogenic signaling. In addition, we analyzed the survival outcome of TNBC breast cancer patients according to their expression level of BDNF using clinical samples. The results demonstrated that BDNF was able to bring about autocrinal (MDA-MB-231) and paracrinal (HUVECs) regulation of BDNF-TrkB gene expression and this affected cell migratory activity. The BDNF-induced migratory activity was blocked by inhibitors of ERK, PI3K and TrkB when MDA-MB-231 cells were examined, but only an inhibitor of ERK blocked this activity when HUVEC cells were used. Furthermore, decreased migratory activity was found for △BDNF and △TrkB cell lines. Ingenuity pathway analysis (IPA) of MDA-MB-231 cells showed that BDNF is a key factor that is able to regulate a network made up of metalloproteases and calmodulin. Protein expression levels in a tissue array of tumor slices were found to be correlated with patient prognosis and the results showed that there was significant correlation of TrkB expression, but not of BDNF. expressionwith patient DFS and OS. Our study demonstrates that up-regulation of the BDNF signaling pathway seems tobe involved in the mechanism associated with early recurrence in triple negative breast cancer cell. In addition, BDNF can function in either an autocrine or a paracrine manner to increase the migration ability of both MDA-MB-231 cells and HUVEC cells. Finally, overexpression of TrkB, but not of BDNF, is significantly associated with a poor survival outcome for TNBC patients.

Asymmetry of Radial and Symmetry of Tangential Neuronal Migration Pathways in Developing Human Fetal Brains

PubMed Central

Miyazaki, Yuta; Song, Jae W.; Takahashi, Emi

2016-01-01

The radial and tangential neural migration pathways are two major neuronal migration streams in humans that are critical during corticogenesis. Corticogenesis is a complex process of neuronal proliferation that is followed by neuronal migration and the formation of axonal connections. Existing histological assessments of these two neuronal migration pathways have limitations inherent to microscopic studies and are confined to small anatomic regions of interest (ROIs). Thus, little evidence is available about their three-dimensional (3-D) fiber pathways and development throughout the entire brain. In this study, we imaged and analyzed radial and tangential migration pathways in the whole human brain using high-angular resolution diffusion MR imaging (HARDI) tractography. We imaged ten fixed, postmortem fetal (17 gestational weeks (GW), 18 GW, 19 GW, three 20 GW, three 21 GW and 22 GW) and eight in vivo newborn (two 30 GW, 34 GW, 35 GW and four 40 GW) brains with no neurological/pathological conditions. We statistically compared the volume of the left and right radial and tangential migration pathways, and the volume of the radial migration pathways of the anterior and posterior regions of the brain. In specimens 22 GW or younger, the volume of radial migration pathways of the left hemisphere was significantly larger than that of the right hemisphere. The volume of posterior radial migration pathways was also larger when compared to the anterior pathways in specimens 22 GW or younger. In contrast, no significant differences were observed in the radial migration pathways of brains older than 22 GW. Moreover, our study did not identify any significant differences in volumetric laterality in the tangential migration pathways. These results suggest that these two neuronal migration pathways develop and regress differently, and radial neuronal migration varies regionally based on hemispheric and anterior-posterior laterality, potentially explaining regional differences in the amount of excitatory neurons that migrate along the radial scaffold. PMID:26834572

Cadherin 2/4 signaling via PTP1B and catenins is crucial for nucleokinesis during radial neuronal migration in the neocortex

PubMed Central

Martinez-Garay, Isabel; Gil-Sanz, Cristina; Franco, Santos J.; Espinosa, Ana; Molnár, Zoltán

2016-01-01

Cadherins are crucial for the radial migration of excitatory projection neurons into the developing neocortical wall. However, the specific cadherins and the signaling pathways that regulate radial migration are not well understood. Here, we show that cadherin 2 (CDH2) and CDH4 cooperate to regulate radial migration in mouse brain via the protein tyrosine phosphatase 1B (PTP1B) and α- and β-catenins. Surprisingly, perturbation of cadherin-mediated signaling does not affect the formation and extension of leading processes of migrating neocortical neurons. Instead, movement of the cell body and nucleus (nucleokinesis) is disrupted. This defect is partially rescued by overexpression of LIS1, a microtubule-associated protein that has previously been shown to regulate nucleokinesis. Taken together, our findings indicate that cadherin-mediated signaling to the cytoskeleton is crucial for nucleokinesis of neocortical projection neurons during their radial migration. PMID:27151949

Selective matrix metalloproteinase inhibitor, N-biphenyl sulfonyl phenylalanine hydroxamic acid, inhibits the migration of CD4+ T lymphocytes in patients with HTLV-I-associated myelopathy.

PubMed

Ikegami, Mayumi; Umehara, Fujio; Ikegami, Naohito; Maekawa, Ryuji; Osame, Mitsuhiro

2002-06-01

Matrix metalloproteinases (MMPs) have been reported to be involved in various inflammatory disorders. Previous studies revealed that MMP-2 and MMP-9 might play important roles in the breakdown of the blood-brain barrier (BBB) in the central nervous system (CNS) of patients with HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). N-Biphenyl sulfonyl-phenylalanine hydroxamic acid (BPHA) selectively inhibits MMP-2, -9 and -14, but not MMP-1, -3 and -7. In the present study, we examined whether or not the selective MMP inhibitor BPHA could inhibit the heightened migrating activity of CD4+ T cells in HAM/TSP patients. The migration assay using an invasion chamber showed that migration of CD4+ T cells in HAM/TSP patients was inhibited by 25 microM BPHA. In addition, the inhibitory ratio of migrating CD4+ lymphocytes was higher in HAM patients compared to normal controls. These results suggest that the selective MMP inhibitor BPHA has therapeutic potential for HAM/TSP.

Endothelial-Mesenchymal Transition of Brain Endothelial Cells: Possible Role during Metastatic Extravasation

PubMed Central

Krizbai, István A.; Gasparics, Ákos; Nagyőszi, Péter; Fazakas, Csilla; Molnár, Judit; Wilhelm, Imola; Bencs, Rita; Rosivall, László; Sebe, Attila

2015-01-01

Cancer progression towards metastasis follows a defined sequence of events described as the metastatic cascade. For extravasation and transendothelial migration metastatic cells interact first with endothelial cells. Yet the role of endothelial cells during the process of metastasis formation and extravasation is still unclear, and the interaction between metastatic and endothelial cells during transendothelial migration is poorly understood. Since tumor cells are well known to express TGF-β, and the compact endothelial layer undergoes a series of changes during metastatic extravasation (cell contact disruption, cytoskeletal reorganization, enhanced contractility), we hypothesized that an EndMT may be necessary for metastatic extravasation. We demonstrate that primary cultured rat brain endothelial cells (BEC) undergo EndMT upon TGF-β1 treatment, characterized by the loss of tight and adherens junction proteins, expression of fibronectin, β1-integrin, calponin and α-smooth muscle actin (SMA). B16/F10 cell line conditioned and activated medium (ACM) had similar effects: claudin-5 down-regulation, fibronectin and SMA expression. Inhibition of TGF-β signaling during B16/F10 ACM stimulation using SB-431542 maintained claudin-5 levels and mitigated fibronectin and SMA expression. B16/F10 ACM stimulation of BECs led to phosphorylation of Smad2 and Smad3. SB-431542 prevented SMA up-regulation upon stimulation of BECs with A2058, MCF-7 and MDA-MB231 ACM as well. Moreover, B16/F10 ACM caused a reduction in transendothelial electrical resistance, enhanced the number of melanoma cells adhering to and transmigrating through the endothelial layer, in a TGF-β-dependent manner. These effects were not confined to BECs: HUVECs showed TGF-β-dependent SMA expression when stimulated with breast cancer cell line ACM. Our results indicate that an EndMT may be necessary for metastatic transendothelial migration, and this transition may be one of the potential mechanisms occurring during the complex phenomenon known as metastatic extravasation. PMID:25742314

Defective neuronal migration and inhibition of bipolar to multipolar transition of migrating neural cells by Mesoderm-Specific Transcript, Mest, in the developing mouse neocortex.

PubMed

Ji, Liting; Bishayee, Kausik; Sadra, Ali; Choi, Seunghyuk; Choi, Wooyul; Moon, Sungho; Jho, Eek-Hoon; Huh, Sung-Oh

2017-07-04

Brain developmental disorders such as lissencephaly can result from faulty neuronal migration and differentiation during the formation of the mammalian neocortex. The cerebral cortex is a modular structure, where developmentally, newborn neurons are generated as a neuro-epithelial sheet and subsequently differentiate, migrate and organize into their final positions in the cerebral cortical plate via a process involving both tangential and radial migration. The specific role of Mest, an imprinted gene, in neuronal migration has not been previously studied. In this work, we reduced expression of Mest with in utero electroporation of neuronal progenitors in the developing embryonic mouse neocortex. Reduction of Mest levels by shRNA significantly reduced the number of neurons migrating to the cortical plate. Also, Mest-knockdown disrupted the transition of bipolar neurons into multipolar neurons migrating out of the sub-ventricular zone region. The migrating neurons also adopted a more tangential migration pattern upon knockdown of the Mest message, losing their potential to attach to radial glia cells, required for radial migration. The differentiation and migration properties of neurons via Wnt-Akt signaling were affected by Mest changes. In addition, miR-335, encoded in a Mest gene intron, was identified as being responsible for blocking the default tangential migration of the neurons. Our results suggest that Mest and its intron product, miR-335, play important roles in neuronal migration with Mest regulating the morphological transition of primary neurons required in the formation of the mammalian neocortex. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Protein kinase D2 regulates migration and invasion of U87MG glioblastoma cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernhart, Eva; Damm, Sabine; Wintersperger, Andrea

Glioblastoma multiforme (GBM) is the most common malignant brain tumor, which, despite combined modality treatment, reoccurs and is invariably fatal for affected patients. Recently, a member of the serine/threonine protein kinase D (PRKD) family, PRKD2, was shown to be a potent mediator of glioblastoma growth. Here we studied the role of PRKD2 in U87MG glioblastoma cell migration and invasion in response to sphingosine-1-phosphate (S1P), an activator of PRKD2 and a GBM mitogen. Time-lapse microscopy demonstrated that random cell migration was significantly diminished in response to PRKD2 silencing. The pharmacological PRKD family inhibitor CRT0066101 decreased chemotactic migration and invasion across uncoatedmore » or matrigel-coated Transwell inserts. Silencing of PRKD2 attenuated migration and invasion of U87MG cells even more effectively. In terms of downstream signaling, CRT0066101 prevented PRKD2 autophosphorylation and inhibited p44/42 MAPK and to a smaller extent p54/46 JNK and p38 MAPK activation. PRKD2 silencing impaired activation of p44/42 MAPK and p54/46 JNK, downregulated nuclear c-Jun protein levels and decreased c-Jun{sup S73} phosphorylation without affecting the NFκB pathway. Finally, qPCR array analyses revealed that silencing of PRKD2 downregulates mRNA levels of integrin alpha-2 and -4 (ITGA2 and -4), plasminogen activator urokinase (PLAU), plasminogen activator urokinase receptor (PLAUR), and matrix metallopeptidase 1 (MMP1). Findings of the present study identify PRKD2 as a potential target to interfere with glioblastoma cell migration and invasion, two major determinants contributing to recurrence of glioblastoma after multimodality treatment. Highlights: • Sphingosine-1-phosphate induces glioma cell migration and invasion. • Part of the effects is mediated by protein kinase D2 (PRKD2) activation. • Inactivation of PRKD2 attenuates glioblastoma cell migration and invasion. • Both, RNAi and pharmacological inhibition of PRKD2 inhibits MAPK signaling. • PRKD2 regulates transcription of gene products implicated in migration and invasion.« less

Tangential migration of corridor guidepost neurons contributes to anxiety circuits.

PubMed

Tinterri, Andrea; Deck, Marie; Keita, Maryama; Mailhes, Caroline; Rubin, Anna Noren; Kessaris, Nicoletta; Lokmane, Ludmilla; Bielle, Franck; Garel, Sonia

2018-02-15

In mammals, thalamic axons are guided internally toward their neocortical target by corridor (Co) neurons that act as axonal guideposts. The existence of Co-like neurons in non-mammalian species, in which thalamic axons do not grow internally, raised the possibility that Co cells might have an ancestral role. Here, we investigated the contribution of corridor (Co) cells to mature brain circuits using a combination of genetic fate-mapping and assays in mice. We unexpectedly found that Co neurons contribute to striatal-like projection neurons in the central extended amygdala. In particular, Co-like neurons participate in specific nuclei of the bed nucleus of the stria terminalis, which plays essential roles in anxiety circuits. Our study shows that Co neurons possess an evolutionary conserved role in anxiety circuits independently from an acquired guidepost function. It furthermore highlights that neurons can have multiple sequential functions during brain wiring and supports a general role of tangential migration in the building of subpallial circuits. © 2017 Wiley Periodicals, Inc.

Di-Ethylhexylphthalate (DEHP) Modulates Cell Invasion, Migration and Anchorage Independent Growth through Targeting S100P in LN-229 Glioblastoma Cells

PubMed Central

Sims, Jennifer Nicole; Graham, Barbara; Pacurari, Maricica; Leggett, Sophia S.; Tchounwou, Paul B.; Ndebele, Kenneth

2014-01-01

Glioblastoma multiforme (GBM) is the most aggressive brain cancer with a median survival of 1–2 years. The treatment of GBM includes surgical resection, radiation and chemotherapy, which minimally extends survival. This poor prognosis necessitates the identification of novel molecular targets associated with glioblastoma. S100P is associated with drug resistance, metastasis, and poor clinical outcomes in many malignancies. The functional role of S100P in glioblastoma has not been fully investigated. In this study, we examined the role of S100P mediating the effects of the environmental contaminant, DEHP, in glioblastoma cells (LN-229) by assessing cell proliferation, apoptosis, anchorage independent growth, cell migration and invasion following DEHP exposure. Silencing S100P and DEHP treatment inhibited LN-229 glioblastoma cell proliferation and induced apoptosis. Anchorage independent growth study revealed significantly decreased colony formation in shS100P cells. We also observed reduced cell migration in cells treated with DEHP following S100P knockdown. Similar results were observed in spheroid formation and expansion. This study is the first to demonstrate the effects of DEHP on glioblastoma cells, and implicates S100P as a potential therapeutic target that may be useful as a drug response biomarker. PMID:24821384

Concise review: Patient-derived olfactory stem cells: new models for brain diseases.

PubMed

Mackay-Sim, Alan

2012-11-01

Traditional models of brain diseases have had limited success in driving candidate drugs into successful clinical translation. This has resulted in large international pharmaceutical companies moving out of neuroscience research. Cells are not brains, obviously, but new patient-derived stem models have the potential to elucidate cell biological aspects of brain diseases that are not present in worm, fly, or rodent models, the work horses of disease investigations and drug discovery. Neural stem cells are present in the olfactory mucosa, the organ of smell in the nose. Patient-derived olfactory mucosa has demonstrated disease-associated differences in a variety of brain diseases and recently olfactory mucosa stem cells have been generated from patients with schizophrenia, Parkinson's disease, and familial dysautonomia. By comparison with cells from healthy controls, patient-derived olfactory mucosa stem cells show disease-specific alterations in gene expression and cell functions including: a shorter cell cycle and faster proliferation in schizophrenia, oxidative stress in Parkinson's disease, and altered cell migration in familial dysautonomia. Olfactory stem cell cultures thus reveal patient-control differences, even in complex genetic diseases such as schizophrenia and Parkinson's disease, indicating that multiple genes of small effect can converge on shared cell signaling pathways to present as a disease-specific cellular phenotype. Olfactory mucosa stem cells can be maintained in homogeneous cultures that allow robust and repeatable multiwell assays suitable for screening libraries of drug candidate molecules. Copyright © 2012 AlphaMed Press.

A role for adult TLX-positive neural stem cells in learning and behaviour.

PubMed

Zhang, Chun-Li; Zou, Yuhua; He, Weimin; Gage, Fred H; Evans, Ronald M

2008-02-21

Neurogenesis persists in the adult brain and can be regulated by a plethora of external stimuli, such as learning, memory, exercise, environment and stress. Although newly generated neurons are able to migrate and preferentially incorporate into the neural network, how these cells are molecularly regulated and whether they are required for any normal brain function are unresolved questions. The adult neural stem cell pool is composed of orphan nuclear receptor TLX-positive cells. Here, using genetic approaches in mice, we demonstrate that TLX (also called NR2E1) regulates adult neural stem cell proliferation in a cell-autonomous manner by controlling a defined genetic network implicated in cell proliferation and growth. Consequently, specific removal of TLX from the adult mouse brain through inducible recombination results in a significant reduction of stem cell proliferation and a marked decrement in spatial learning. In contrast, the resulting suppression of adult neurogenesis does not affect contextual fear conditioning, locomotion or diurnal rhythmic activities, indicating a more selective contribution of newly generated neurons to specific cognitive functions.

LncRNA-TP53TG1 Participated in the Stress Response Under Glucose Deprivation in Glioma.

PubMed

Chen, Xin; Gao, Yang; Li, Deheng; Cao, Yiqun; Hao, Bin

2017-12-01

Gliomas are the most common brain tumors of the center nervous system. And long non-coding RNAs (lncRNAs) are non-protein coding transcripts, which have been considered as one type of gene expression regulator for cancer development. In this study, we investigated the role of lncRNA-TP53TG1 in response to glucose deprivation in human gliomas. The expression levels of TP53TG1 in glioma tissues and cells were analyzed by qRT-PCR. In addition, the influence of TP53TG1 on glucose metabolism related genes at the mRNA level during both high and low glucose treatment was detected by qRT-PCR. MTT, clonogenicity assays, and flow cytometry were performed to detect the cell proliferation and cell apoptosis. Furthermore, the migration of glioma cells was examined by Transwell assays. The expression of TP53TG1 was significantly higher in human glioma tissues or cell lines compared with normal brain tissue or NHA. Moreover, TP53TG1 and some tumor glucose metabolism related genes, such as GRP78, LDHA, and IDH1 were up-regulated significantly in U87 and LN18 cells under glucose deprivation. In addition, knockdown of TP53TG1 decreased cell proliferation and migration and down-regulated GRP78 and IDH1 expression levels and up-regulated PKM2 levels in U87 cells under glucose deprivation. However, over-expression of TP53TG1 showed the opposite tendency. Moreover, the effects of TP53TG1 were more remarkable in low glucose than that in high glucose. Our data showed that TP53TG1 under glucose deprivation may promote cell proliferation and migration by influencing the expression of glucose metabolism related genes in glioma. J. Cell. Biochem. 118: 4897-4904, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Proteoglycans and neuronal migration in the cerebral cortex during development and disease

PubMed Central

Maeda, Nobuaki

2015-01-01

Chondroitin sulfate proteoglycans and heparan sulfate proteoglycans are major constituents of the extracellular matrix and the cell surface in the brain. Proteoglycans bind with many proteins including growth factors, chemokines, axon guidance molecules, and cell adhesion molecules through both the glycosaminoglycan and the core protein portions. The functions of proteoglycans are flexibly regulated due to the structural variability of glycosaminoglycans, which are generated by multiple glycosaminoglycan synthesis and modifying enzymes. Neuronal cell surface proteoglycans such as PTPζ, neuroglycan C and syndecan-3 function as direct receptors for heparin-binding growth factors that induce neuronal migration. The lectican family, secreted chondroitin sulfate proteoglycans, forms large aggregates with hyaluronic acid and tenascins, in which many signaling molecules and enzymes including matrix proteases are preserved. In the developing cerebrum, secreted chondroitin sulfate proteoglycans such as neurocan, versican and phosphacan are richly expressed in the areas that are strategically important for neuronal migration such as the striatum, marginal zone, subplate and subventricular zone in the neocortex. These proteoglycans may anchor various attractive and/or repulsive cues, regulating the migration routes of inhibitory neurons. Recent studies demonstrated that the genes encoding proteoglycan core proteins and glycosaminoglycan synthesis and modifying enzymes are associated with various psychiatric and intellectual disorders, which may be related to the defects of neuronal migration. PMID:25852466

Behavior of Xeno-Transplanted Undifferentiated Human Induced Pluripotent Stem Cells Is Impacted by Microenvironment Without Evidence of Tumors.

PubMed

Martínez-Cerdeño, Veronica; Barrilleaux, Bonnie L; McDonough, Ashley; Ariza, Jeanelle; Yuen, Benjamin T K; Somanath, Priyanka; Le, Catherine T; Steward, Craig; Horton-Sparks, Kayla; Knoepfler, Paul S

2017-10-01

Human pluripotent stem cells (hPSC) have great clinical potential through the use of their differentiated progeny, a population in which there is some concern over risks of tumorigenicity or other unwanted cellular behavior due to residual hPSC. Preclinical studies using human stem cells are most often performed within a xenotransplant context. In this study, we sought to measure how undifferentiated hPSC behave following xenotransplant. We directly transplanted undifferentiated human induced pluripotent stem cells (hIPSC) and human embryonic stem cells (hESC) into the adult mouse brain ventricle and analyzed their fates. No tumors or precancerous lesions were present at more than one year after transplantation. This result differed with the tumorigenic capacity we observed after allotransplantation of mouse ESC into the mouse brain. A substantial population of cellular derivatives of undifferentiated hESC and hIPSC engrafted, survived, and migrated within the mouse brain parenchyma. Within brain structures, transplanted cell distribution followed a very specific pattern, suggesting the existence of distinct microenvironments that offer different degrees of permissibility for engraftment. Most of the transplanted hESC and hIPSC that developed into brain cells were NeuN+ neuronal cells, and no astrocytes were detected. Substantial cell and nuclear fusion occurred between host and transplanted cells, a phenomenon influenced by microenvironment. Overall, hIPSC appear to be largely functionally equivalent to hESC in vivo. Altogether, these data bring new insights into the behavior of stem cells without prior differentiation following xenotransplantation into the adult brain.

Short-term sPECAM-Fc treatment ameliorates EAE while chronic use hastens onset of symptoms

PubMed Central

Reinke, Emily K.; Lee, JangEun; Zozulya, Alla; Karman, Jozsef; Muller, William A.; Sandor, Matyas; Fabry, Zsuzsanna

2007-01-01

The homotypic cell adhesion molecule PECAM-1 is a major participant in the migration of leukocytes across endothelium. We examined the ability of a chimeric soluble sPECAM-1 fused to human IgG-Fc to impair leukocyte entry through the blood-brain barrier and reduce CNS autoimmunity. sPECAM-Fc impaired migration of lymphocytes across brain endothelial monolayers and diminished the severity of EAE, an experimental model of MS, when administered at the onset of symptoms. However, in mice transgenic for sPECAM-Fc, the chronically elevated levels of sPECAM-Fc hastened onset of EAE disease without significantly changing clinical score severity. Our data suggests that short-term treatment of diseases like MS with sPECAM-Fc has therapeutic potential. PMID:17467062

WIF1 re-expression in glioblastoma inhibits migration through attenuation of non-canonical WNT signaling by downregulating the lncRNA MALAT1.

PubMed

Vassallo, I; Zinn, P; Lai, M; Rajakannu, P; Hamou, M-F; Hegi, M E

2016-01-07

Glioblastoma is the most aggressive primary brain tumor in adults and due to the invasive nature cannot be completely removed. The WNT inhibitory factor 1 (WIF1), a secreted inhibitor of WNTs, is systematically downregulated in glioblastoma and acts as strong tumor suppressor. The aim of this study was the dissection of WIF1-associated tumor-suppressing effects mediated by canonical and non-canonical WNT signaling. We found that WIF1 besides inhibiting the canonical WNT pathway selectively downregulates the WNT/calcium pathway associated with significant reduction of p38-MAPK (p38-mitogen-activated protein kinase) phosphorylation. Knockdown of WNT5A, the only WNT ligand overexpressed in glioblastoma, phenocopied this inhibitory effect. WIF1 expression inhibited cell migration in vitro and in an orthotopic brain tumor model, in accordance with the known regulatory function of the WNT/Ca(2+) pathway on migration and invasion. In search of a mediator for this function differential gene expression profiles of WIF1-expressing cells were performed. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA and key positive regulator of invasion, emerged as the top downregulated gene. Indeed, knockdown of MALAT1 reduced migration in glioblastoma cells, without effect on proliferation. Hence, loss of WIF1 enhances the migratory potential of glioblastoma through WNT5A that activates the WNT/Ca(2+) pathway and MALAT1. These data suggest the involvement of canonical and non-canonical WNT pathways in glioblastoma promoting key features associated with this deadly disease, proliferation on one hand and invasion on the other. Successful targeting will require a dual strategy affecting both canonical and non-canonical WNT pathways.

The Fat-like Cadherin CDH-4 Acts Cell-Non-Autonomously in Anterior-Posterior Neuroblast Migration

PubMed Central

Sundararajan, Lakshmi; Norris, Megan L.; Schöneich, Sebastian; Ackley, Brian D.; Lundquist, Erik A.

2014-01-01

Directed migration of neurons is critical in the normal and pathological development of the brain and central nervous system. In C. elegans, the bilateral Q neuroblasts, QR on the right and QL on the left, migrate anteriorly and posteriorly, respectively. Initial protrusion and migration of the Q neuroblasts is autonomously controlled by the transmembrane proteins UNC-40/DCC, PTP-3/LAR, and MIG-21. As QL migrates posteriorly, it encounters and EGL-20/Wnt signal that induces MAB-5/Hox expression that drives QL descendant posterior migration. QR migrates anteriorly away from EGL-20/Wnt and does not activate MAB-5/Hox, resulting in anterior QR descendant migration. A forward genetic screen for new mutations affecting initial Q migrations identified alleles of cdh-4, which caused defects in both QL and QR directional migration similar to unc-40, ptp-3, and mig-21. Previous studies showed that in QL, PTP-3/LAR and MIG-21 act in a pathway in parallel to UNC-40/DCC to drive posterior QL migration. Here we show genetic evidence that CDH-4 acts in the PTP-3/MIG-21 pathway in parallel to UNC-40/DCC to direct posterior QL migration. In QR, the PTP-3/MIG-21 and UNC-40/DCC pathways mutually inhibit each other, allowing anterior QR migration. We report here that CDH-4 acts in both the PTP-3/MIG-21 and UNC-40/DCC pathways in mutual inhibition in QR, and that CDH-4 acts cell-non-autonomously. Interaction of CDH-4 with UNC-40/DCC in QR but not QL represents an inherent left-right asymmetry in the Q cells, the nature of which is not understood. We conclude that CDH-4 might act as a permissive signal for each Q neuroblast to respond differently to anterior-posterior guidance information based upon inherent left-right asymmetries in the Q neuroblasts. PMID:24954154

Glucose-Coated Gold Nanoparticles Transfer across Human Brain Endothelium and Enter Astrocytes In Vitro

PubMed Central

Gromnicova, Radka; Davies, Heather A.; Sreekanthreddy, Peddagangannagari; Romero, Ignacio A.; Lund, Torben; Roitt, Ivan M.; Phillips, James B.; Male, David K.

2013-01-01

The blood-brain barrier prevents the entry of many therapeutic agents into the brain. Various nanocarriers have been developed to help agents to cross this barrier, but they all have limitations, with regard to tissue-selectivity and their ability to cross the endothelium. This study investigated the potential for 4 nm coated gold nanoparticles to act as selective carriers across human brain endothelium and subsequently to enter astrocytes. The transfer rate of glucose-coated gold nanoparticles across primary human brain endothelium was at least three times faster than across non-brain endothelia. Movement of these nanoparticles occurred across the apical and basal plasma membranes via the cytosol with relatively little vesicular or paracellular migration; antibiotics that interfere with vesicular transport did not block migration. The transfer rate was also dependent on the surface coating of the nanoparticle and incubation temperature. Using a novel 3-dimensional co-culture system, which includes primary human astrocytes and a brain endothelial cell line hCMEC/D3, we demonstrated that the glucose-coated nanoparticles traverse the endothelium, move through the extracellular matrix and localize in astrocytes. The movement of the nanoparticles through the matrix was >10 µm/hour and they appeared in the nuclei of the astrocytes in considerable numbers. These nanoparticles have the correct properties for efficient and selective carriers of therapeutic agents across the blood-brain barrier. PMID:24339894

Molecular dialogs between the ischemic brain and the peripheral immune system: dualistic roles in injury and repair.

PubMed

An, Chengrui; Shi, Yejie; Li, Peiying; Hu, Xiaoming; Gan, Yu; Stetler, Ruth A; Leak, Rehana K; Gao, Yanqin; Sun, Bao-Liang; Zheng, Ping; Chen, Jun

2014-04-01

Immune and inflammatory responses actively modulate the pathophysiological processes of acute brain injuries such as stroke. Soon after the onset of stroke, signals such as brain-derived antigens, danger-associated molecular patterns (DAMPs), cytokines, and chemokines are released from the injured brain into the systemic circulation. The injured brain also communicates with peripheral organs through the parasympathetic and sympathetic branches of the autonomic nervous system. Many of these diverse signals not only activate resident immune cells in the brain, but also trigger robust immune responses in the periphery. Peripheral immune cells then migrate toward the site of injury and release additional cytokines, chemokines, and other molecules, causing further disruptive or protective effects in the ischemic brain. Bidirectional communication between the injured brain and the peripheral immune system is now known to regulate the progression of stroke pathology as well as tissue repair. In the end, this exquisitely coordinated crosstalk helps determine the fate of animals after stroke. This article reviews the literature on ischemic brain-derived signals through which peripheral immune responses are triggered, and the potential impact of these peripheral responses on brain injury and repair. Pharmacological strategies and cell-based therapies that target the dialog between the brain and peripheral immune system show promise as potential novel treatments for stroke. Published by Elsevier Ltd.

Tissue mechanics regulate brain development, homeostasis and disease

PubMed Central

Barnes, J. Matthew

2017-01-01

ABSTRACT All cells sense and integrate mechanical and biochemical cues from their environment to orchestrate organismal development and maintain tissue homeostasis. Mechanotransduction is the evolutionarily conserved process whereby mechanical force is translated into biochemical signals that can influence cell differentiation, survival, proliferation and migration to change tissue behavior. Not surprisingly, disease develops if these mechanical cues are abnormal or are misinterpreted by the cells – for example, when interstitial pressure or compression force aberrantly increases, or the extracellular matrix (ECM) abnormally stiffens. Disease might also develop if the ability of cells to regulate their contractility becomes corrupted. Consistently, disease states, such as cardiovascular disease, fibrosis and cancer, are characterized by dramatic changes in cell and tissue mechanics, and dysregulation of forces at the cell and tissue level can activate mechanosignaling to compromise tissue integrity and function, and promote disease progression. In this Commentary, we discuss the impact of cell and tissue mechanics on tissue homeostasis and disease, focusing on their role in brain development, homeostasis and neural degeneration, as well as in brain cancer. PMID:28043968

Characterization of cell proliferation throughout the brain of the African cichlid fish Astatotilapia burtoni and its regulation by social status.

PubMed

Maruska, Karen P; Carpenter, Russ E; Fernald, Russell D

2012-10-15

New cells are added in the brains of all adult vertebrates, but fishes have some of the greatest potential for neurogenesis and gliogenesis among all taxa, partly due to their indeterminate growth. Little is known, however, about how social interactions influence cell proliferation in the brain of these fishes that comprise the largest group of vertebrates. We used 5-bromo-2'-deoxyuridine (BrdU) to identify and localize proliferation zones in the telencephalon, diencephalon, mesencephalon, and rhombencephalon that were primarily associated with ventricular surfaces in the brain of the African cichlid fish Astatotilapia burtoni. Cell migration was evident in some regions by 1 day post injection, and many newborn cells coexpressed the neuronal marker HuC/D at 30 days, suggesting they had differentiated into neurons. To test the hypothesis that social status and perception of an opportunity to rise in rank influenced cell proliferation, we compared numbers of BrdU-labeled cells in multiple brain nuclei among fish of different social status. Socially suppressed subordinate males had the lowest numbers of proliferating cells in all brain regions examined, but males that were given an opportunity to rise in status had higher cell proliferation rates within 1 day, suggesting rapid upregulation of brain mitotic activity associated with this social transition. Furthermore, socially isolated dominant males had similar numbers of BrdU-labeled cells compared with dominant males that were housed in a socially rich environment, suggesting that isolation has little effect on proliferation and that reduced proliferation in subordinates is a result of the social subordination. These results suggest that A. burtoni will be a useful model to analyze the mechanisms of socially induced neurogenesis in vertebrates. Copyright © 2012 Wiley Periodicals, Inc.

Systemic treatment of focal brain injury in the rat by human umbilical cord blood cells being at different level of neural commitment.

PubMed

Gornicka-Pawlak, El Bieta; Janowski, Miroslaw; Habich, Aleksandra; Jablonska, Anna; Drela, Katarzyna; Kozlowska, Hanna; Lukomska, Barbara; Sypecka, Joanna; Domanska-Janik, Krystyna

2011-01-01

The aim of the study was to evaluate therapeutic effectiveness of intra-arterial infusion of human umbilical cord blood (HUCB) derived cells at different stages of their neural conversion. Freshly isolated mononuclear cells (D-0), neurally directed progenitors (D-3) and neural-like stem cells derived from umbilical cord blood (NSC) were compared. Focal brain damage was induced in rats by stereotactic injection of ouabain into dorsolateral striatum Three days later 10(7) of different subsets of HUCB cells were infused into the right internal carotid artery. Following surgery rats were housed in enriched environment for 30 days. Behavioral assessment consisted of tests for sensorimotor deficits (walking beam, rotarod, vibrissae elicited forelimb placing, apomorphine induced rotations), cognitive impairments (habit learning and object recognition) and exploratory behavior (open field). Thirty days after surgery the lesion volume was measured and the presence of donor cells was detected in the brain at mRNA level. At the same time immunohistochemical analysis of brain tissue was performed to estimate the local tissue response of ouabain injured rats and its modulation after HUCB cells systemic treatment. Functional effects of different subsets of cord blood cells shared substantial diversity in various behavioral tests. An additional analysis showed that D-0 HUCB cells were the most effective in functional restoration and reduction of brain lesion volume. None of transplanted cord blood derived cell fractions were detected in rat's brains at 30(th) day after treatment. This may suggest that the mechanism(s) underlying positive effects of HUCB derived cell may concern the other than direct neural cell supplementation. In addition increased immunoreactivity of markers indicating local cells proliferation and migration suggests stimulation of endogenous reparative processes by HUCB D-0 cell interarterial infusion.

Possible linkage between neuronal recruitment and flight distance in migratory birds

PubMed Central

Barkan, Shay; Roll, Uri; Yom-Tov, Yoram; Wassenaar, Leonard I.; Barnea, Anat

2016-01-01

New neuronal recruitment in an adult animal’s brain is presumed to contribute to brain plasticity and increase the animal’s ability to contend with new and changing environments. During long-distance migration, birds migrating greater distances are exposed to more diverse spatial information. Thus, we hypothesized that greater migration distance in birds would correlate with the recruitment of new neurons into the brain regions involved with migratory navigation. We tested this hypothesis on two Palearctic migrants - reed warblers (Acrocephalus scirpaceus) and turtle doves (Streptopelia turtur), caught in Israel while returning from Africa in spring and summer. Birds were injected with a neuronal birth marker and later inspected for new neurons in brain regions known to play a role in navigation - the hippocampus and nidopallium caudolateral. We calculated the migration distance of each individual by matching feather isotopic values (δ2H and δ13C) to winter base-maps of these isotopes in Africa. Our findings suggest a positive correlation between migration distance and new neuronal recruitment in two brain regions - the hippocampus in reed warblers and nidopallium caudolateral in turtle doves. This multidisciplinary approach provides new insights into the ability of the avian brain to adapt to different migration challenges. PMID:26905978

Brain Migration Revisited

ERIC Educational Resources Information Center

Vinokur, Annie

2006-01-01

The "brain drain/brain gain" debate has been going on for the past 40 years, with irresolvable theoretical disputes and unenforceable policy recommendations that economists commonly ascribe to the lack of reliable empirical data. The recent report of the World Bank, "International migration, remittances and the brain drain", documents the…

Involvement of nitric oxide synthase in matrix metalloproteinase-9- and/or urokinase plasminogen activator receptor-mediated glioma cell migration

PubMed Central

2013-01-01

Background Src tyrosine kinase activates inducible nitric oxide synthase (iNOS) and, in turn, nitric oxide production as a means to transduce cell migration. Src tyrosine kinase plays a key proximal role to control α9β1 signaling. Our recent studies have clearly demonstrated the role of α9β1 integrin in matrix metalloproteinase-9 (MMP-9) and/or urokinase plasminogen activator receptor (uPAR)-mediated glioma cell migration. In the present study, we evaluated the involvement of α9β1 integrin-iNOS pathway in MMP-9- and/or uPAR-mediated glioma cell migration. Methods MMP-9 and uPAR shRNAs and overexpressing plasmids were used to downregulate and upregulate these molecules, respectively in U251 glioma cells and 5310 glioma xenograft cells. The effect of treatments on migration and invasion potential of these glioma cells were assessed by spheroid migration, wound healing, and Matrigel invasion assays. In order to attain the other objectives we also performed immunocytochemical, immunohistochemical, RT-PCR, Western blot and fluorescence-activated cell sorting (FACS) analysis. Results Immunohistochemical analysis revealed the prominent association of iNOS with glioblastoma multiforme (GBM). Immunofluorescence analysis showed prominent expression of iNOS in glioma cells. MMP-9 and/or uPAR knockdown by respective shRNAs reduced iNOS expression in these glioma cells. RT-PCR analysis revealed elevated iNOS mRNA expression in either MMP-9 or uPAR overexpressed glioma cells. The migration potential of MMP-9- and/or uPAR-overexpressed U251 glioma cells was significantly inhibited after treatment with L-NAME, an inhibitor of iNOS. Similarly, a significant inhibition of the invasion potential of the control or MMP-9/uPAR-overexpressed glioma cells was noticed after L-NAME treatment. A prominent reduction of iNOS expression was observed in the tumor regions of nude mice brains, which were injected with 5310 glioma cells, after MMP-9 and/or uPAR knockdown. Protein expressions of cSrc, phosphoSrc and p130Cas were reduced with simultaneous knockdown of both MMP-9 and uPAR. Conclusions Taken together, our results from the present and earlier studies clearly demonstrate that α9β1 integrin-mediated cell migration utilizes the iNOS pathway, and inhibition of the migratory potential of glioma cells by simultaneous knockdown of MMP-9 and uPAR could be attributed to the reduced α9β1 integrin and iNOS levels. PMID:24325546

Functionalized Iron Oxide Nanoparticles for Controlling the Movement of Immune Cells

PubMed Central

White, Ethan E; Pai, Alex; Weng, Yiming; Suresh, Anil K.; Van Haute, Desiree; Pailevanian, Torkom; Alizadeh, Darya; Hajimiri, Ali; Badie, Behnam; Berlin, Jacob M.

2015-01-01

Immunotherapy is currently being investigated for the treatment of many diseases, including cancer. The ability to control the location of immune cells during or following activation would represent a powerful new technique for this field. Targeted magnetic delivery is emerging as a technique for controlling cell movement and localization. Here we show that this technique can be extended to microglia, the primary phagocytic immune cells in the central nervous system. The magnetized microglia were generated by loading the cells with iron oxide nanoparticles functionalized with CpG oligonucleotides, serving as a proof of principle that nanoparticles can be used to both deliver an immunostimulatory cargo to cells and to control the movement of the cells. The nanoparticle-oligonucleotide conjugates are efficiently internalized, non-toxic, and immunostimulatory. We demonstrate that the in vitro migration of the adherent, loaded microglia can be controlled by an external magnetic field and that magnetically-induced migration is non-cytotoxic. In order to capture video of this magnetically-induced migration of loaded cells, a novel 3D-printed “cell box” was designed to facilitate our imaging application. Analysis of cell movement velocities clearly demonstrate increased cell velocities toward the magnet. These studies represent the initial step towards our final goal of using nanoparticles to both activate immune cells and to control their trafficking within the diseased brain. PMID:25848983

Functionalized iron oxide nanoparticles for controlling the movement of immune cells.

PubMed

White, Ethan E; Pai, Alex; Weng, Yiming; Suresh, Anil K; Van Haute, Desiree; Pailevanian, Torkom; Alizadeh, Darya; Hajimiri, Ali; Badie, Behnam; Berlin, Jacob M

2015-05-07

Immunotherapy is currently being investigated for the treatment of many diseases, including cancer. The ability to control the location of immune cells during or following activation would represent a powerful new technique for this field. Targeted magnetic delivery is emerging as a technique for controlling cell movement and localization. Here we show that this technique can be extended to microglia, the primary phagocytic immune cells in the central nervous system. The magnetized microglia were generated by loading the cells with iron oxide nanoparticles functionalized with CpG oligonucleotides, serving as a proof of principle that nanoparticles can be used to both deliver an immunostimulatory cargo to cells and to control the movement of the cells. The nanoparticle-oligonucleotide conjugates are efficiently internalized, non-toxic, and immunostimulatory. We demonstrate that the in vitro migration of the adherent, loaded microglia can be controlled by an external magnetic field and that magnetically-induced migration is non-cytotoxic. In order to capture video of this magnetically-induced migration of loaded cells, a novel 3D-printed "cell box" was designed to facilitate our imaging application. Analysis of cell movement velocities clearly demonstrate increased cell velocities toward the magnet. These studies represent the initial step towards our final goal of using nanoparticles to both activate immune cells and to control their trafficking within the diseased brain.

Human mesenchymal stem cells target adhesion molecules and receptors involved in T cell extravasation.

PubMed

Benvenuto, Federica; Voci, Adriana; Carminati, Enrico; Gualandi, Francesca; Mancardi, Gianluigi; Uccelli, Antonio; Vergani, Laura

2015-12-10

Systemic delivery of bone marrow-derived mesenchymal stem cells (MSC) seems to be of benefit in the treatment of multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS) sustained by migration of T cells across the brain blood barrier (BBB) and subsequent induction of inflammatory lesions into CNS. MSC have been found to modulate several effector functions of T cells. In this study, we investigated the effects of MSC on adhesion molecules and receptors on T cell surface that sustain their transendothelial migration. We used different co-culture methods combined with real-time PCR and flow cytometry to evaluate the expression both at the mRNA and at the plasma-membrane level of α4 integrin, β2 integrin, ICAM-1 and CXCR3. In parallel, we assessed if MSC are able to modulate expression of adhesion molecules on the endothelial cells that interact with T cells during their transendothelial migration. Our in vitro analyses revealed that MSC: (i) inhibit proliferation and activation of both peripheral blood mononuclear cells (PBMC) and CD3(+)-selected lymphocytes through the release of soluble factors; (ii) exert suppressive effects on those surface molecules highly expressed by activated lymphocytes and involved in transendothelial migration; (iii) inhibit CXCL10-driven chemotaxis of CD3(+) cells; (iv) down-regulated expression of adhesion molecules on endothelial cells. Taken together, these data demonstrate that the immunosuppressive effect of MSC does not exclusively depends on their anti-proliferative activity on T cells, but also on the impairment of leukocyte migratory potential through the inhibition of the adhesion molecules and receptors that are responsible for T cell trafficking across BBB. This could suggest a new mechanism through which MSC modulate T cell responses.

Environmental enrichment brings a beneficial effect on beam walking and enhances the migration of doublecortin-positive cells following striatal lesions in rats.

PubMed

Urakawa, S; Hida, H; Masuda, T; Misumi, S; Kim, T-S; Nishino, H

2007-02-09

Rats raised in an enriched environment (enriched rats) have been reported to show less motor dysfunction following brain lesions, but the neuronal correlates of this improvement have not been well clarified. The present study aimed to elucidate the effect of chemical brain lesions and environmental enrichment on motor function and lesion-induced neurogenesis. Three week-old, recently weaned rats were divided into two groups: one group was raised in an enriched environment and the other group was raised in a standard cage for 5 weeks. Striatal damage was induced at an age of 8 weeks by injection of the neuro-toxins 6-hydroxydopamine (6-OHDA) or quinolinic acid (QA) into the striatum, or by injection of 6-OHDA into the substantia nigra (SN), which depleted nigrostriatal dopaminergic innervation. Enriched rats showed better performance on beam walking compared with those raised in standard conditions, but both groups showed similar forelimb use asymmetry in a cylinder test. The number of bromodeoxyuridine-labeled proliferating cells in the subventricular zone was increased by a severe striatal lesion induced by QA injection 1 week after the lesion, but decreased by injection of 6-OHDA into the SN. Following induction of lesions by striatal injection of 6-OHDA or QA, the number of cells positive for doublecortin (DCX) was strongly increased in the striatum; however, there was no change in the number of DCX-positive cells following 6-OHDA injection into the SN. Environmental enrichment enhanced the increase of DCX-positive cells with migrating morphology in the dorsal striatum. In enriched rats, DCX-positive cells traversed the striatal parenchyma far from the corpus callosum and lateral ventricle. DCX-positive cells co-expressed an immature neuronal marker, polysialylated neural cell adhesion molecule, but were negative for a glial marker. These data suggest that environmental enrichment improves motor performance on beam walking and enhances neuronal migration toward a lesion area in the striatum.

Estrogen-induced cell signaling in the sexually dimorphic nucleus of the rat preoptic area: potential involvement of cofilin in actin dynamics for cell migration.

PubMed

Wada-Kiyama, Yuko; Suzuki, Chiaki; Hamada, Tomohiro; Rai, Dilip; Kiyama, Ryoiti; Kaneda, Makoto; Sakuma, Yasuo

2013-05-03

Estrogen is a key factor to induce the sexually dimorphic nucleus (SDN) in the preoptic area (POA) of the rat brain. Identification of estrogen-dependent signaling pathways at SDN in POA during the critical period is a prerequisite for elucidating the mechanism. In the present study, we treated female rats with/without 17β-estradiol (E2) at birth, designated as postnatal day 1 (P1), and prepared total RNA from brain slices containing SDN for DNA microarray analysis. Among the estrogen-responsive genes identified, protein kinase C-delta (PKC-δ) was significantly up-regulated by E2 at P5. We examined the downstream effectors of PKC-δ protein by Western blotting and found an E2-induced PKC-δ/Rac1/PAK1/LIMK1/cofilin pathway. In the pathway, E2 suppressed the phosphorylation (inactive form) of cofilin. This result was supported by immunohistochemistry, where the phosphorylation/dephosphorylation of cofilin occurred at SDN, which suggests that cell migration is a cue to create sexual dimorphism in POA. Copyright © 2013 Elsevier Inc. All rights reserved.

Up-regulation of plakophilin-2 is correlated with the progression of glioma.

PubMed

Zhang, Degeng; Qian, Yuxia; Liu, Xiaoxing; Yu, Hong; Zhao, Niangao; Wu, Zhengdong

2017-06-01

Glioma is the most common type of primary brain tumor in the CNS. Due to its poor prognosis and high mortality rates, it is urgent to find out more effective therapies. Plakophilin-2 (PKP2) is a widespread desmosomal plaque protein. Recently, the important roles of PKP2 in the proliferation and migration of cancer cells and tumor progression has been shown. However, the expression and potential function of PKP2 in glioma was still unclear. In this study, we demonstrated that PKP2 protein expression level was increased in glioma tissues compared with normal brain tissues, and its level was significantly associated with the Ki-67 expression and WHO grade by Western blot analysis and immunohistochemistry. Clinically, high PKP2 expression was tightly related to poor prognosis of glioma patients. Interestingly, we found that down-regulated PKP2 expression was shown to inhibit the migration of cells in glioma. Moreover, cell counting kit (CCK)-8 and colony formation analyses proved that reduced expression of PKP2 could weaken glioma cell proliferation. Taken together, these data uncover a potential role for PKP2 in the pathogenic process of glioma, suggesting that PKP2 may be a promising therapeutic target of glioma. © 2017 Japanese Society of Neuropathology.

Developmental and perinatal brain diseases.

PubMed

Adle-Biassette, Homa; Golden, Jeffery A; Harding, Brian

2017-01-01

This chapter briefly describes the normal development of the nervous system, the neuropathology and pathophysiology of acquired and secondary disorders affecting the embryo, fetus, and child. They include CNS manifestations of chromosomal change; forebrain patterning defects; disorders of the brain size; cell migration and specification disorders; cerebellum, hindbrain and spinal patterning defects; hydrocephalus; secondary malformations and destructive pathologies; vascular malformations; arachnoid cysts and infectious diseases. The distinction between malformations and disruptions is important for pathogenesis and genetic counseling. Copyright © 2017 Elsevier B.V. All rights reserved.

Differentiation of Drosophila glial cells.

PubMed

Sasse, Sofia; Neuert, Helen; Klämbt, Christian

2015-01-01

Glial cells are important constituents of the nervous system and a hallmark of these cells are their pronounced migratory abilities. In Drosophila, glial lineages have been well described and some of the molecular mechanisms necessary to guide migrating glial cells to their final target sites have been identified. With the onset of migration, glial cells are already specified into one of five main glial cell types. The perineurial and subperineurial glial cells are eventually located at the outer surface of the Drosophila nervous system and constitute the blood-brain barrier. The cortex glial cells ensheath all neuroblasts and their progeny and reside within the central nervous system. Astrocyte-like cells invade the neuropil to control synaptic function and ensheathing glial cells encase the entire neuropil. Within the peripheral nervous system, wrapping glial cells ensheath individual axons or axon fascicles. Here, we summarize the current knowledge on how differentiation of glial cells into the specific subtypes is orchestrated. Furthermore, we discuss sequencing data that will facilitate further analyses of glial differentiation in the fly nervous system. © 2015 Wiley Periodicals, Inc.

Computer Vision Evidence Supporting Craniometric Alignment of Rat Brain Atlases to Streamline Expert-Guided, First-Order Migration of Hypothalamic Spatial Datasets Related to Behavioral Control

PubMed Central

Khan, Arshad M.; Perez, Jose G.; Wells, Claire E.; Fuentes, Olac

2018-01-01

The rat has arguably the most widely studied brain among all animals, with numerous reference atlases for rat brain having been published since 1946. For example, many neuroscientists have used the atlases of Paxinos and Watson (PW, first published in 1982) or Swanson (S, first published in 1992) as guides to probe or map specific rat brain structures and their connections. Despite nearly three decades of contemporaneous publication, no independent attempt has been made to establish a basic framework that allows data mapped in PW to be placed in register with S, or vice versa. Such data migration would allow scientists to accurately contextualize neuroanatomical data mapped exclusively in only one atlas with data mapped in the other. Here, we provide a tool that allows levels from any of the seven published editions of atlases comprising three distinct PW reference spaces to be aligned to atlas levels from any of the four published editions representing S reference space. This alignment is based on registration of the anteroposterior stereotaxic coordinate (z) measured from the skull landmark, Bregma (β). Atlas level alignments performed along the z axis using one-dimensional Cleveland dot plots were in general agreement with alignments obtained independently using a custom-made computer vision application that utilized the scale-invariant feature transform (SIFT) and Random Sample Consensus (RANSAC) operation to compare regions of interest in photomicrographs of Nissl-stained tissue sections from the PW and S reference spaces. We show that z-aligned point source data (unpublished hypothalamic microinjection sites) can be migrated from PW to S space to a first-order approximation in the mediolateral and dorsoventral dimensions using anisotropic scaling of the vector-formatted atlas templates, together with expert-guided relocation of obvious outliers in the migrated datasets. The migrated data can be contextualized with other datasets mapped in S space, including neuronal cell bodies, axons, and chemoarchitecture; to generate data-constrained hypotheses difficult to formulate otherwise. The alignment strategies provided in this study constitute a basic starting point for first-order, user-guided data migration between PW and S reference spaces along three dimensions that is potentially extensible to other spatial reference systems for the rat brain. PMID:29765309

Nociceptin/orphanin FQ antagonizes lipopolysaccharide-stimulated proliferation, migration and inflammatory signaling in human glioblastoma U87 cells.

PubMed

Bedini, Andrea; Baiula, Monica; Vincelli, Gabriele; Formaggio, Francesco; Lombardi, Sara; Caprini, Marco; Spampinato, Santi

2017-09-15

Glioblastoma is among the most aggressive brain tumors and has an exceedingly poor prognosis. Recently, the importance of the tumor microenvironment in glioblastoma cell growth and progression has been emphasized. Toll-like receptor 4 (TLR4) recognizes bacterial lipopolysaccharide (LPS) and endogenous ligands originating from dying cells or the extracellular matrix involved in host defense and in inflammation. G-protein coupled receptors (GPCRs) have gained interest in anti-tumor drug discovery due to the role that they directly or indirectly play by transactivating other receptors, causing cell migration and proliferation. A proteomic analysis showed that the nociceptin receptor (NOPr) is among the GPCRs significantly expressed in glioblastoma cells, including U87 cells. We describe a novel role of the peptide nociceptin (N/OFQ), the endogenous ligand of the NOPr that counteracts cell migration, proliferation and increase in IL-1β mRNA elicited by LPS via TLR4 in U87 glioblastoma cells. Signaling pathways through which N/OFQ inhibits LPS-mediated cell migration and elevation of [Ca 2+ ] i require β-arrestin 2 and are sensitive to TNFR-associated factor 6, c-Src and protein kinase C (PKC). LPS-induced cell proliferation and increase in IL-1β mRNA are counteracted by N/OFQ via β-arrestin 2, PKC and extracellular signal-regulated kinase 1/2; furthermore, the contributions of the transcription factors NF-kB and AP-1 were investigated. Independent of LPS, N/OFQ induces a significant increase in cell apoptosis. Contrary to what was observed in other cell models, a prolonged exposure to this endotoxin did not promote any tolerance of the cellular effects above described, including NOPr down-regulation while N/OFQ loses its inhibitory role. Copyright © 2017 Elsevier Inc. All rights reserved.

MeCP2 overexpression inhibits proliferation, migration and invasion of C6 glioma by modulating ERK signaling and gene expression.

PubMed

Sharma, Kedarlal; Singh, Juhi; Frost, Emma E; Pillai, Prakash P

2018-05-01

MethylCpG binding protein-2 (MeCP2) is an epigenetic regulator and essential for brain development. MeCP2 mutations are associated with a spectrum of neuro-developmental disorders that vary depending on the patient gender, most notably Rett Syndrome. MeCP2 is essential for normal neuronal maturation, and glial cell function in the brain. Besides, its role in neurodevelopmental disorders, MeCP2 is involved in many cancers such as breast, colorectal, lung, liver, and prostate cancer. Glioma is the most lethal form of brain cancer. Studies have shown that dysfunctional epigenetic regulation plays a crucial role in glioma progression. Further, previous studies have suggested a role for MeCP2 in glioma pathogenesis. In this study, we show that MeCP2 may play a critical role in the suppression of glioma progression. Stable overexpression of MeCP2in C6 glioma cells inhibits proliferation, migration, invasion, and adhesion. Moreover, MeCP2 overexpression inhibits pERKand BDNF expression while inducing GFAP expression in C6 glioma. These findings suggest that MeCP2 may play a crucial role in suppression of glioma progression. Copyright © 2018 Elsevier B.V. All rights reserved.

Integrative Mechanisms of Oriented Neuronal Migration in the Developing Brain

PubMed Central

Evsyukova, Irina; Plestant, Charlotte; Anton, E.S.

2014-01-01

The emergence of functional neuronal connectivity in the developing cerebral cortex depends on neuronal migration. This process enables appropriate positioning of neurons and the emergence of neuronal identity so that the correct patterns of functional synaptic connectivity between the right types and numbers of neurons can emerge. Delineating the complexities of neuronal migration is critical to our understanding of normal cerebral cortical formation and neurodevelopmental disorders resulting from neuronal migration defects. For the most part, the integrated cell biological basis of the complex behavior of oriented neuronal migration within the developing mammalian cerebral cortex remains an enigma. This review aims to analyze the integrative mechanisms that enable neurons to sense environmental guidance cues and translate them into oriented patterns of migration toward defined areas of the cerebral cortex. We discuss how signals emanating from different domains of neurons get integrated to control distinct aspects of migratory behavior and how different types of cortical neurons coordinate their migratory activities within the developing cerebral cortex to produce functionally critical laminar organization. PMID:23937349

Cadherin 2/4 signaling via PTP1B and catenins is crucial for nucleokinesis during radial neuronal migration in the neocortex.

PubMed

Martinez-Garay, Isabel; Gil-Sanz, Cristina; Franco, Santos J; Espinosa, Ana; Molnár, Zoltán; Mueller, Ulrich

2016-06-15

Cadherins are crucial for the radial migration of excitatory projection neurons into the developing neocortical wall. However, the specific cadherins and the signaling pathways that regulate radial migration are not well understood. Here, we show that cadherin 2 (CDH2) and CDH4 cooperate to regulate radial migration in mouse brain via the protein tyrosine phosphatase 1B (PTP1B) and α- and β-catenins. Surprisingly, perturbation of cadherin-mediated signaling does not affect the formation and extension of leading processes of migrating neocortical neurons. Instead, movement of the cell body and nucleus (nucleokinesis) is disrupted. This defect is partially rescued by overexpression of LIS1, a microtubule-associated protein that has previously been shown to regulate nucleokinesis. Taken together, our findings indicate that cadherin-mediated signaling to the cytoskeleton is crucial for nucleokinesis of neocortical projection neurons during their radial migration. © 2016. Published by The Company of Biologists Ltd.

Preconditioning of bone marrow-derived mesenchymal stromal cells by tetramethylpyrazine enhances cell migration and improves functional recovery after focal cerebral ischemia in rats.

PubMed

Li, Lin; Chu, Lisheng; Fang, Yan; Yang, Yan; Qu, Tiebing; Zhang, Jianping; Yin, Yuanjun; Gu, Jingjing

2017-05-12

Transplantation of bone marrow-derived mesenchymal stem cells (BMSCs) is one of the new therapeutic strategies for treating ischemic stroke. However, the relatively poor migratory capacity of BMSCs toward infarcted regions limited the therapeutic potential of this approach. Pharmacological preconditioning can increase the expression of CXC chemokine receptor 4 (CXCR4) in BMSCs and enhance cell migration toward the injury site. In the present study, we investigated whether tetramethylpyrazine (TMP) preconditioning could enhance BMSCs migration to the ischemic brain and improve functional recovery through upregulating CXCR4 expression. BMSCs were identified by flow cytometry analysis. BMSCs migration was evaluated in vitro by transwell migration assay, and CXCR4 expression was measured by quantitative reverse transcription-polymerase chain reaction and western blot analysis. In rats with focal cerebral ischemia, the neurological function was evaluated by the modified neurological severity score, the adhesive removal test and the corner test. The homing BMSCs and angiogenesis were detected by immunofluorescence, and expression of stromal cell-derived factor-1 (SDF-1) and CXCR4 was measured by western blot analysis. Flow cytometry analysis demonstrated that BMSCs expressed CD29 and CD90, but not CD34 and CD45. TMP pretreatment dose-dependently induced BMSCs migration and CXCR4 expression in vitro, which was significantly inhibited by AMD3100, a CXCR4 antagonist. In rat stroke models, we found more TMP-preconditioned BMSCs homing toward the infarcted regions than nonpreconditioned cells, leading to improved neurological performance and enhanced angiogenesis. Moreover, TMP-preconditioned BMSCs significantly upregulated the protein expression of SDF-1 and CXCR4 in the ischemic boundary regions. These beneficial effects of TMP preconditioning were blocked by AMD3100. TMP preconditioning enhances the migration and homing ability of BMSCs, increases CXCR4 expression, promotes angiogenesis, and improves neurological performance. Therefore, TMP preconditioning may be an effective strategy to improve the therapeutic potency of BMSCs for ischemic stroke due to enhanced BMSCs migration to ischemic regions.

In vivo transcriptional profile analysis reveals RNA splicing and chromatin remodeling as prominent processes for adult neurogenesis.

PubMed

Lim, Daniel A; Suárez-Fariñas, Mayte; Naef, Felix; Hacker, Coleen R; Menn, Benedicte; Takebayashi, Hirohide; Magnasco, Marcelo; Patil, Nila; Alvarez-Buylla, Arturo

2006-01-01

Neural stem cells and neurogenesis persist in the adult mammalian brain subventricular zone (SVZ). Cells born in the rodent SVZ migrate to the olfactory bulb (Ob) where they differentiate into interneurons. To determine the gene expression and functional profile of SVZ neurogenesis, we performed three complementary sets of transcriptional analysis experiments using Affymetrix GeneChips: (1) comparison of adult mouse SVZ and Ob gene expression profiles with those of the striatum, cerebral cortex, and hippocampus; (2) profiling of SVZ stem cells and ependyma isolated by fluorescent-activated cell sorting (FACS); and (3) analysis of gene expression changes during in vivo SVZ regeneration after anti-mitotic treatment. Gene Ontology (GO) analysis of data from these three separate approaches showed that in adult SVZ neurogenesis, RNA splicing and chromatin remodeling are biological processes as statistically significant as cell proliferation, transcription, and neurogenesis. In non-neurogenic brain regions, RNA splicing and chromatin remodeling were not prominent processes. Fourteen mRNA splicing factors including Sf3b1, Sfrs2, Lsm4, and Khdrbs1/Sam68 were detected along with 9 chromatin remodeling genes including Mll, Bmi1, Smarcad1, Baf53a, and Hat1. We validated the transcriptional profile data with Northern blot analysis and in situ hybridization. The data greatly expand the catalogue of cell cycle components, transcription factors, and migration genes for adult SVZ neurogenesis and reveal RNA splicing and chromatin remodeling as prominent biological processes for these germinal cells.

Breaking ignorance: the case of the brain.

PubMed

Wekerle, H

2006-01-01

Immunological self-tolerance is maintained through diverse mechanisms, including deletion of autoreactive immune cells following confrontation with autoantigen in the thymus or in the periphery and active suppression by regulatory cells. A third way to prevent autoimmunity is by hiding self tissues behind a tissue barrier impermeable for circulating immune cells. The latter mechanism has been held responsible for self-tolerance within the nervous tissue. Indeed, the nervous tissues enjoy a conditionally privileged immune status: they are normally unreachable for self-reactive T and B cells, they lack lymphatic drainage, and they are deficient in local antigen-presenting cells. Yet the immune system is by no means fully ignorant of the nervous structures. An ever-growing number of brain specific autoantigens is expressed within the thymus, which ensures an early confrontation with the unfolding T cell repertoire, and there is evidence that B cells also contact CNS-like structures outside of the brain. Then pathological processes such as neurodegeneration commonly lift the brain's immune privilege, shifting the local milieus from immune-hostile to immune-friendly. Finally, brain-reactive T cells, which abound in the healthy immune repertoire, but remain innocuous throughout life, can be activated and gain access to their target tissues. On their way, they take an ordered migration through peripheral lymphoid tissues and blood circulation, and undergo a profound reprogramming of their gene expression profile, which renders them fit to enter the nervous system and to interact with local cellule elements.

Activation of matrix metalloproteinase-9 (MMP-9) by neurotensin promotes cell invasion and migration through ERK pathway in gastric cancer.

PubMed

Akter, Hafeza; Park, Min; Kwon, Oh-Seung; Song, Eun Joo; Park, Won-Sang; Kang, Min-Jung

2015-08-01

Neurotensin (NT) is distributed throughout the brain and gastrointestinal tract. Although the relationship between NT and matrix metalloproteinase-9 (MMP-9) activity in gastric cancer has not been reported, the elevation of MMP-9 and NT is reported in the breast, lung, prostate, and gastric cancer. The aim of our study is to investigate the relationship between NT and MMP-9 activity and the underlying signaling mechanism in gastric cancer cell lines. Commercial ELISA kits were used for estimation of NT and MMP-9 expression, and fluorescence resonance energy transfer (FRET) assay was used for measurement of MMP-9 activity. Cell migration and invasion were determined by wound healing and transwell assay. The expression of signaling proteins was measured by Western blotting. Our study reveals a positive correlation between increased plasma NT and MMP-9 activity in both of patient's serum and gastric cancer cell lines. A dose-dependent elevation of MMP-9 activity was observed by NT treatment in gastric cancer cells (MKN-1 and MKN-45) compared to untreated gastric cancer and normal epithelial cell (HFE-145). Moreover, NT-mediated migration and invasion were observed in gastric cancer cells unlike in normal cell. The signaling mechanism of NT in gastric cancer cells was confirmed in protein kinase C (PKC), extracellular-signal regulated kinase (ERK), and phosphatidylinositol 3-kinase (PI3K) pathway. In addition, pretreatment of gastric cancer cells with NTR1 inhibitor SR48692 was shown to significantly inhibit the NT-mediated MMP-9 activity, cell invasion, and migration. Our finding illustrated NTR1 could be a possible therapeutic target for gastric cancer.

Developmental Patterns of Doublecortin Expression and White Matter Neuron Density in the Postnatal Primate Prefrontal Cortex and Schizophrenia

PubMed Central

Fung, Samantha J.; Joshi, Dipesh; Allen, Katherine M.; Sivagnanasundaram, Sinthuja; Rothmond, Debora A.; Saunders, Richard; Noble, Pamela L.; Webster, Maree J.; Shannon Weickert, Cynthia

2011-01-01

Postnatal neurogenesis occurs in the subventricular zone and dentate gyrus, and evidence suggests that new neurons may be present in additional regions of the mature primate brain, including the prefrontal cortex (PFC). Addition of new neurons to the PFC implies local generation of neurons or migration from areas such as the subventricular zone. We examined the putative contribution of new, migrating neurons to postnatal cortical development by determining the density of neurons in white matter subjacent to the cortex and measuring expression of doublecortin (DCX), a microtubule-associated protein involved in neuronal migration, in humans and rhesus macaques. We found a striking decline in DCX expression (human and macaque) and density of white matter neurons (humans) during infancy, consistent with the arrival of new neurons in the early postnatal cortex. Considering the expansion of the brain during this time, the decline in white matter neuron density does not necessarily indicate reduced total numbers of white matter neurons in early postnatal life. Furthermore, numerous cells in the white matter and deep grey matter were positive for the migration-associated glycoprotein polysialiated-neuronal cell adhesion molecule and GAD65/67, suggesting that immature migrating neurons in the adult may be GABAergic. We also examined DCX mRNA in the PFC of adult schizophrenia patients (n = 37) and matched controls (n = 37) and did not find any difference in DCX mRNA expression. However, we report a negative correlation between DCX mRNA expression and white matter neuron density in adult schizophrenia patients, in contrast to a positive correlation in human development where DCX mRNA and white matter neuron density are higher earlier in life. Accumulation of neurons in the white matter in schizophrenia would be congruent with a negative correlation between DCX mRNA and white matter neuron density and support the hypothesis of a migration deficit in schizophrenia. PMID:21966452

Anti-proliferative and anti-migration effects of Polish propolis combined with Hypericum perforatum L. on glioblastoma multiforme cell line U87MG.

PubMed

Borawska, Maria H; Naliwajko, Sylwia K; Moskwa, Justyna; Markiewicz-Żukowska, Renata; Puścion-Jakubik, Anna; Soroczyńska, Jolanta

2016-09-20

Propolis and Hypericum perforatum L. are natural products which contain many active compounds and have numerous beneficial effects, including an antitumor effect. Gliobmastoma multiforme (GBM) is a common primary brain tumor with poor prognosis and limited treatment options. In this study, the effect of propolis (EEP) combined with H. perforatum L. (HPE) on glioblastoma cell line U87MG was investigated for the first time. Anti-proliferative activity of EEP, HPE and their combination (EEP + HPE) was determined by a cytotoxicity test, DNA binding by [(3)H]-thymidine incorporation and cell migration assay. Anti-metastatic properties in U87MG treated with EEP, HPE and EEP + HPE were estimated on cells migration test (scratch assay) and metalloproteinases (MMP2 and MMP9) secretion (gelatin zymography). Combination of HPE and EEP extracts was found to have a time- and dose-dependent inhibitory effect on the viability of U87MG cells. This effect was significantly higher (p < 0.05) when compared to these two extracts applied separately, which was confirmed by the significant reduction of DNA synthesis and significantly higher mitochondrial membrane permeabilization. A significant decreasing in migration cells and in pro-MMP9 and pro-MMP2 secretion in U87MG cells were demonstrated after exposure to combination of EEP (30 μg/ml) with HPE (6.25 μg/ml). In this study, the combination of ethanolic extract from propolis and ethanolic extract of fresh-cut H. perforatum L. was proved the ability to reduce invasiveness of glioma cells through the inhibition of MMP2 and MMP9 secretion and suppression of cell migration. It has a more potent anti-proliferative effect on U87MG glioma cell line compared to using propolis and H. perforatum L. separately. Further studies are required to verify whether the examined extracts can activate apoptotic pathways.

Thirteen is the lucky number for doublecortin.

PubMed

Akhmanova, Anna; Severin, Fedor

2004-07-01

Doublecortin is a microtubule-associated protein that is essential for normal brain development. A recent report published in Molecular Cell shows that doublecortin associates preferentially with microtubules made of 13 protofilaments, by recognizing a novel site between the protofilaments. These findings explain how doublecortin stabilizes microtubules and provide clues about its function during neuronal migration.

The Chemokine Receptor CXCR6 Evokes Reverse Signaling via the Transmembrane Chemokine CXCL16

PubMed Central

Adamski, Vivian; Mentlein, Rolf; Lucius, Ralph; Synowitz, Michael; Held-Feindt, Janka; Hattermann, Kirsten

2017-01-01

Reverse signaling is a signaling mechanism where transmembrane or membrane-bound ligands transduce signals and exert biological effects upon binding of their specific receptors, enabling a bidirectional signaling between ligand and receptor-expressing cells. In this study, we address the question of whether the transmembrane chemokine (C-X-C motif) ligand 16, CXCL16 is able to transduce reverse signaling and investigate the biological consequences. For this, we used human glioblastoma cell lines and a melanoma cell line as in vitro models to show that stimulation with recombinant C-X-C chemokine receptor 6 (CXCR6) or CXCR6-containing membrane preparations induces intracellular (reverse) signaling. Specificity was verified by RNAi experiments and by transfection with expression vectors for the intact CXCL16 and an intracellularly-truncated form of CXCL16. We showed that reverse signaling via CXCL16 promotes migration in CXCL16-expressing melanoma and glioblastoma cells, but does not affect proliferation or protection from chemically-induced apoptosis. Additionally, fast migrating cells isolated from freshly surgically-resected gliomas show a differential expression pattern for CXCL16 in comparison to slowly-migrating cells, enabling a possible functional role of the reverse signaling of the CXCL16/CXCR6 pair in human brain tumor progression in vivo. PMID:28698473

The Chemokine Receptor CXCR6 Evokes Reverse Signaling via the Transmembrane Chemokine CXCL16.

PubMed

Adamski, Vivian; Mentlein, Rolf; Lucius, Ralph; Synowitz, Michael; Held-Feindt, Janka; Hattermann, Kirsten

2017-07-08

Reverse signaling is a signaling mechanism where transmembrane or membrane-bound ligands transduce signals and exert biological effects upon binding of their specific receptors, enabling a bidirectional signaling between ligand and receptor-expressing cells. In this study, we address the question of whether the transmembrane chemokine (C-X-C motif) ligand 16, CXCL16 is able to transduce reverse signaling and investigate the biological consequences. For this, we used human glioblastoma cell lines and a melanoma cell line as in vitro models to show that stimulation with recombinant C-X-C chemokine receptor 6 (CXCR6) or CXCR6-containing membrane preparations induces intracellular (reverse) signaling. Specificity was verified by RNAi experiments and by transfection with expression vectors for the intact CXCL16 and an intracellularly-truncated form of CXCL16. We showed that reverse signaling via CXCL16 promotes migration in CXCL16-expressing melanoma and glioblastoma cells, but does not affect proliferation or protection from chemically-induced apoptosis. Additionally, fast migrating cells isolated from freshly surgically-resected gliomas show a differential expression pattern for CXCL16 in comparison to slowly-migrating cells, enabling a possible functional role of the reverse signaling of the CXCL16/CXCR6 pair in human brain tumor progression in vivo.

Post-transcriptional regulation in corticogenesis: how RNA-binding proteins help build the brain

PubMed Central

Pilaz, Louis-Jan; Silver, Debra L.

2015-01-01

The cerebral cortex, the brain structure responsible for our higher cognitive functions, is built during embryonic development in a process called corticogenesis. During corticogenesis, neural stem cells generate distinct populations of progenitors and excitatory neurons. These new neurons migrate radially in the cortex, eventually forming neuronal layers and establishing synaptic connections with other neurons both within and outside the cortex. Perturbations to corticogenesis can result in severe neurodevelopmental disorders, thus emphasizing the need to better understand molecular regulation of brain development. Recent studies in both model organisms and humans have collectively highlighted roles for post-transcriptional regulation in virtually all steps of corticogenesis. Genomic approaches have revealed global RNA changes associated with spatial and temporal regulation of cortical development. Additionally, genetic studies have uncovered RNA-binding proteins (RBPs) critical for cell proliferation, differentiation, and migration within the developing neocortex. Many of these same RBPs play causal roles in neurodevelopmental pathologies. In the developing neocortex, RBPs influence diverse steps of mRNA metabolism, including splicing, stability, translation, and localization. With the advent of new technologies, researchers have begun to uncover key transcripts regulated by these RBPs. Given the complexity of the developing mammalian cortex, a major challenge for the future will be to understand how dynamic RNA regulation occurs within heterogeneous cell populations, across space and time. In sum, post-transcriptional regulation has emerged as a critical mechanism for driving corticogenesis and exciting direction of future research. PMID:26088328

Sleep loss and acute drug abuse can induce DNA damage in multiple organs of mice.

PubMed

Alvarenga, T A; Ribeiro, D A; Araujo, P; Hirotsu, C; Mazaro-Costa, R; Costa, J L; Battisti, M C; Tufik, S; Andersen, M L

2011-09-01

The purpose of the present study was to characterize the genetic damage induced by paradoxical sleep deprivation (PSD) in combination with cocaine or ecstasy (3,4-methylenedioxymethamphetamine; MDMA) in multiple organs of male mice using the single cell gel (comet) assay. C57BL/6J mice were submitted to PSD by the platform technique for 72 hours, followed by drug administration and evaluation of DNA damage in peripheral blood, liver and brain tissues. Cocaine was able to induce genetic damage in the blood, brain and liver cells of sleep-deprived mice at the majority of the doses evaluated. Ecstasy also induced increased DNA migration in peripheral blood cells for all concentrations tested. Analysis of damaged cells by the tail moment data suggests that ecstasy is a genotoxic chemical at the highest concentrations tested, inducing damage in liver or brain cells after sleep deprivation in mice. Taken together, our results suggest that cocaine and ecstasy/MDMA act as potent genotoxins in multiple organs of mice when associated with sleep loss.

Migrating Interneurons Secrete Fractalkine to Promote Oligodendrocyte Formation in the Developing Mammalian Brain.

PubMed

Voronova, Anastassia; Yuzwa, Scott A; Wang, Beatrix S; Zahr, Siraj; Syal, Charvi; Wang, Jing; Kaplan, David R; Miller, Freda D

2017-05-03

During development, newborn interneurons migrate throughout the embryonic brain. Here, we provide evidence that these interneurons act in a paracrine fashion to regulate developmental oligodendrocyte formation. Specifically, we show that medial ganglionic eminence (MGE) interneurons secrete factors that promote genesis of oligodendrocytes from glially biased cortical precursors in culture. Moreover, when MGE interneurons are genetically ablated in vivo prior to their migration, this causes a deficit in cortical oligodendrogenesis. Modeling of the interneuron-precursor paracrine interaction using transcriptome data identifies the cytokine fractalkine as responsible for the pro-oligodendrocyte effect in culture. This paracrine interaction is important in vivo, since knockdown of the fractalkine receptor CX3CR1 in embryonic cortical precursors, or constitutive knockout of CX3CR1, causes decreased numbers of oligodendrocyte progenitor cells (OPCs) and oligodendrocytes in the postnatal cortex. Thus, in addition to their role in regulating neuronal excitability, interneurons act in a paracrine fashion to promote the developmental genesis of oligodendrocytes. Copyright © 2017 Elsevier Inc. All rights reserved.

Radiotherapy planning for glioblastoma based on a tumor growth model: improving target volume delineation.

PubMed

Unkelbach, Jan; Menze, Bjoern H; Konukoglu, Ender; Dittmann, Florian; Le, Matthieu; Ayache, Nicholas; Shih, Helen A

2014-02-07

Glioblastoma differ from many other tumors in the sense that they grow infiltratively into the brain tissue instead of forming a solid tumor mass with a defined boundary. Only the part of the tumor with high tumor cell density can be localized through imaging directly. In contrast, brain tissue infiltrated by tumor cells at low density appears normal on current imaging modalities. In current clinical practice, a uniform margin, typically two centimeters, is applied to account for microscopic spread of disease that is not directly assessable through imaging. The current treatment planning procedure can potentially be improved by accounting for the anisotropy of tumor growth, which arises from different factors: anatomical barriers such as the falx cerebri represent boundaries for migrating tumor cells. In addition, tumor cells primarily spread in white matter and infiltrate gray matter at lower rate. We investigate the use of a phenomenological tumor growth model for treatment planning. The model is based on the Fisher-Kolmogorov equation, which formalizes these growth characteristics and estimates the spatial distribution of tumor cells in normal appearing regions of the brain. The target volume for radiotherapy planning can be defined as an isoline of the simulated tumor cell density. This paper analyzes the model with respect to implications for target volume definition and identifies its most critical components. A retrospective study involving ten glioblastoma patients treated at our institution has been performed. To illustrate the main findings of the study, a detailed case study is presented for a glioblastoma located close to the falx. In this situation, the falx represents a boundary for migrating tumor cells, whereas the corpus callosum provides a route for the tumor to spread to the contralateral hemisphere. We further discuss the sensitivity of the model with respect to the input parameters. Correct segmentation of the brain appears to be the most crucial model input. We conclude that the tumor growth model provides a method to account for anisotropic growth patterns of glioma, and may therefore provide a tool to make target delineation more objective and automated.

Radiotherapy planning for glioblastoma based on a tumor growth model: improving target volume delineation

NASA Astrophysics Data System (ADS)

Unkelbach, Jan; Menze, Bjoern H.; Konukoglu, Ender; Dittmann, Florian; Le, Matthieu; Ayache, Nicholas; Shih, Helen A.

2014-02-01

Glioblastoma differ from many other tumors in the sense that they grow infiltratively into the brain tissue instead of forming a solid tumor mass with a defined boundary. Only the part of the tumor with high tumor cell density can be localized through imaging directly. In contrast, brain tissue infiltrated by tumor cells at low density appears normal on current imaging modalities. In current clinical practice, a uniform margin, typically two centimeters, is applied to account for microscopic spread of disease that is not directly assessable through imaging. The current treatment planning procedure can potentially be improved by accounting for the anisotropy of tumor growth, which arises from different factors: anatomical barriers such as the falx cerebri represent boundaries for migrating tumor cells. In addition, tumor cells primarily spread in white matter and infiltrate gray matter at lower rate. We investigate the use of a phenomenological tumor growth model for treatment planning. The model is based on the Fisher-Kolmogorov equation, which formalizes these growth characteristics and estimates the spatial distribution of tumor cells in normal appearing regions of the brain. The target volume for radiotherapy planning can be defined as an isoline of the simulated tumor cell density. This paper analyzes the model with respect to implications for target volume definition and identifies its most critical components. A retrospective study involving ten glioblastoma patients treated at our institution has been performed. To illustrate the main findings of the study, a detailed case study is presented for a glioblastoma located close to the falx. In this situation, the falx represents a boundary for migrating tumor cells, whereas the corpus callosum provides a route for the tumor to spread to the contralateral hemisphere. We further discuss the sensitivity of the model with respect to the input parameters. Correct segmentation of the brain appears to be the most crucial model input. We conclude that the tumor growth model provides a method to account for anisotropic growth patterns of glioma, and may therefore provide a tool to make target delineation more objective and automated.

Isolation and Characterization of Ischemia-Derived Astrocytes (IDAs) with Ability to Transactivate Quiescent Astrocytes

PubMed Central

Villarreal, Alejandro; Rosciszewski, Gerardo; Murta, Veronica; Cadena, Vanesa; Usach, Vanina; Dodes-Traian, Martin M.; Setton-Avruj, Patricia; Barbeito, Luis H.; Ramos, Alberto J.

2016-01-01

Reactive gliosis involving activation and proliferation of astrocytes and microglia, is a widespread but largely complex and graded glial response to brain injury. Astroglial population has a previously underestimated high heterogeneity with cells differing in their morphology, gene expression profile, and response to injury. Here, we identified a subset of reactive astrocytes isolated from brain focal ischemic lesions that show several atypical characteristics. Ischemia-derived astrocytes (IDAs) were isolated from early ischemic penumbra and core. IDA did not originate from myeloid precursors, but rather from pre-existing local progenitors. Isolated IDA markedly differ from primary astrocytes, as they proliferate in vitro with high cell division rate, show increased migratory ability, have reduced replicative senescence and grow in the presence of macrophages within the limits imposed by the glial scar. Remarkably, IDA produce a conditioned medium that strongly induced activation on quiescent primary astrocytes and potentiated the neuronal death triggered by oxygen-glucose deprivation. When re-implanted into normal rat brains, eGFP-IDA migrated around the injection site and induced focal reactive gliosis. Inhibition of gamma secretases or culture on quiescent primary astrocytes monolayers facilitated IDA differentiation to astrocytes. We propose that IDA represent an undifferentiated, pro-inflammatory, highly replicative and migratory astroglial subtype emerging from the ischemic microenvironment that may contribute to the expansion of reactive gliosis. Main Points: Ischemia-derived astrocytes (IDA) were isolated from brain ischemic tissue IDA show reduced replicative senescence, increased cell division and spontaneous migration IDA potentiate death of oxygen-glucose deprived cortical neurons IDA propagate reactive gliosis on quiescent astrocytes in vitro and in vivo Inhibition of gamma secretases facilitates IDA differentiation to astrocytes PMID:27313509

FGF-2 and Anosmin-1 are selectively expressed in different types of multiple sclerosis lesions.

PubMed

Clemente, Diego; Ortega, María Cristina; Arenzana, Francisco Javier; de Castro, Fernando

2011-10-19

Multiple sclerosis is a demyelinating disease that affects ≈ 2,000,000 people worldwide. In the advanced stages of the disease, endogenous oligodendrocyte precursors cannot colonize the lesions or differentiate into myelinating oligodendrocytes. During development, both FGF-2 and Anosmin-1 participate in oligodendrocyte precursor cell migration, acting via the FGF receptor 1 (FGFR1). Hence, we performed a histopathological and molecular analysis of these developmental modulators in postmortem tissue blocks from multiple sclerosis patients. Accordingly, we demonstrate that the distribution of FGF-2 and Anosmin-1 varies between the different types of multiple sclerosis lesions: FGF-2 is expressed only within active lesions and in the periplaque of chronic lesions, whereas Anosmin-1 is upregulated within chronic lesions and is totally absent in active lesions. We show that the endogenous oligodendrocyte precursor cells recruited toward chronic-active lesions express FGFR1, possibly in response to the FGF-2 produced by microglial cells in the periplaque. Also in human tissue, FGF-2 is upregulated in perivascular astrocytes in regions of the normal-appearing gray matter, where the integrity of the blood-brain barrier is compromised. In culture, FGF-2 and Anosmin-1 influence adult mouse oligodendrocyte precursor cell migration in the same manner as at embryonic stages, providing an explanation for the histopathological observations: FGF-2 attracts/enhances its migration, which is hindered by Anosmin-1. We propose that FGF-2 and Anosmin-1 are markers for the histopathological type and the level of inflammation of multiple sclerosis lesions, and that they may serve as novel pharmacogenetic targets to design future therapies that favor effective remyelination and protect the blood-brain barrier.

Human umbilical cord blood stem cells show PDGF-D–dependent glioma cell tropism in vitro and in vivo

PubMed Central

Gondi, Christopher S.; Veeravalli, Krishna Kumar; Gorantla, Bharathi; Dinh, Dzung H.; Fassett, Dan; Klopfenstein, Jeffrey D.; Gujrati, Meena; Rao, Jasti S.

2010-01-01

Despite advances in clinical therapies and technologies, the prognosis for patients with malignant glioma is poor. Neural stem cells (NSCs) have a chemotactic tropism toward glioma cells. The use of NSCs as carriers of therapeutic agents for gliomas is currently being explored. Here, we demonstrate that cells isolated from the umbilical cord blood show mesenchymal characteristics and can differentiate to adipocytes, osteocytes, and neural cells and show tropism toward cancer cells. We also show that these stem cells derived from the human umbilical cord blood (hUCB) induce apoptosis-like cell death in the glioma cell line SNB19 via Fas-mediated caspase-8 activation. From our glioma tropism studies, we have observed that hUCB cells show tropism toward glioma cells in vitro, in vivo, and ex vivo. We determined that this migration is partially dependent on the expression levels of platelet-derived growth factor (PDGF)-D from glioma cells and have observed that local concentration gradient of PDGF-D is sufficient to cause migration of hUCB cells toward the gradient as seen from our brain slice cultures. In our animal experiment studies, we observed that intracranially implanted SNB19 green fluorescent protein cells induced tropism of the hUCB cells toward themselves. In addition, the ability of these hUCBs to inhibit established intracranial tumors was also observed. We also determined that the migration of stem cells toward glioma cells was partially dependent on PDGF secreted by glioma cells and that the presence of PDGF-receptor (PDGFR) on hUCB is required for migration. Our results demonstrate that hUCB are capable of inducing apoptosis in human glioma cells and also show that glioma tropism and hUCB tropism toward glioma cells are partially dependent on the PDGF/PGGFR system. PMID:20406896

Alternative Splicing in Neurogenesis and Brain Development.

PubMed

Su, Chun-Hao; D, Dhananjaya; Tarn, Woan-Yuh

2018-01-01

Alternative splicing of precursor mRNA is an important mechanism that increases transcriptomic and proteomic diversity and also post-transcriptionally regulates mRNA levels. Alternative splicing occurs at high frequency in brain tissues and contributes to every step of nervous system development, including cell-fate decisions, neuronal migration, axon guidance, and synaptogenesis. Genetic manipulation and RNA sequencing have provided insights into the molecular mechanisms underlying the effects of alternative splicing in stem cell self-renewal and neuronal fate specification. Timely expression and perhaps post-translational modification of neuron-specific splicing regulators play important roles in neuronal development. Alternative splicing of many key transcription regulators or epigenetic factors reprograms the transcriptome and hence contributes to stem cell fate determination. During neuronal differentiation, alternative splicing also modulates signaling activity, centriolar dynamics, and metabolic pathways. Moreover, alternative splicing impacts cortical lamination and neuronal development and function. In this review, we focus on recent progress toward understanding the contributions of alternative splicing to neurogenesis and brain development, which has shed light on how splicing defects may cause brain disorders and diseases.

The Sodium Pump α1 Subunit as a Potential Target to Combat Apoptosis-Resistant Glioblastomas1

PubMed Central

Lefranc, Florence; Kiss, Robert

2008-01-01

Purpose To review the involvement of the ion transporter Na+/K+-ATPase (NaK) in the migration and proliferation of glioma cells. Preliminary studies indicate that NaK α1 subunits seem to be upregulated in a proportion of glioblastomas but not in normal brain tissues. Design The present review focuses on (1) the natural resistance of migrating malignant glioma cells to apoptosis, (2) autophagic cell death as an alternative to combat malignant gliomas, (3) the fact that reducing the levels of malignant glioma cell motility can restore proapoptotic drug sensitivity, and (4) on the observation that inhibiting the NaK activity reduces both glioma cell proliferation and migration. Results The natural ligands of the NaK are the cardiotonic steroids. A hemisynthetic derivative of 2″-oxovoruscharin (UNBS1450), a novel cardenolide, displays unique structural features, making its binding affinity to NaK α subunits (including α1) 10 to 100 times higher than that of other cardenolides. UNBS1450 markedly decreases intracellular ATP concentration in glioma cells, disorganizes the actin cytoskeleton, and leads to autophagic cell death in NaK α1 over-expressing glioma cells. Conclusions Glioblastoma patients who do not respond to chemotherapy and whose tumors over-express NaK α1 subunits could benefit from a treatment using ligands with marked binding affinity for the NaK α1 subunit. PMID:18323016

The sodium pump alpha1 subunit as a potential target to combat apoptosis-resistant glioblastomas.

PubMed

Lefranc, Florence; Kiss, Robert

2008-03-01

To review the involvement of the ion transporter Na+/K+-ATPase (NaK) in the migration and proliferation of glioma cells. Preliminary studies indicate that NaK alpha1 subunits seem to be upregulated in a proportion of glioblastomas but not in normal brain tissues. The present review focuses on (1) the natural resistance of migrating malignant glioma cells to apoptosis, (2) autophagic cell death as an alternative to combat malignant gliomas, (3) the fact that reducing the levels of malignant glioma cell motility can restore proapoptotic drug sensitivity,and (4) on the observation that inhibiting the NaK activity reduces both glioma cell proliferation and migration. The natural ligands of the NaK are the cardiotonic steroids. A hemisynthetic derivative of 2"-oxovoruscharin (UNBS1450), a novel cardenolide, displays unique structural features, making its binding affinity to NaK alpha subunits (including alpha1) 10 to 100 times higher than that of other cardenolides. UNBS1450 markedly decreases intracellular ATP concentration in glioma cells, disorganizes the actin cytoskeleton, and leads to autophagic cell death in NaK alpha1 over-expressing glioma cells. Glioblastoma patients who do not respond to chemotherapy and whose tumors over-express NaK alpha1 subunits could benefit from a treatment using ligands with marked binding affinity for the NaK alpha1 subunit.

Is Polysialylated NCAM Not Only a Regulator during Brain Development But also during the Formation of Other Organs?

PubMed Central

Galuska, Christina E.; Lütteke, Thomas; Galuska, Sebastian P.

2017-01-01

In mammals several cell adhesion molecules are involved during the pre- and postnatal development of all organ systems. A very prominent member of this family is the neural cell adhesion molecule (NCAM). Interestingly, NCAM can be a target for a special form of posttranslational modification: polysialylation. Whereas nearly all extracellular proteins bear mono-sialic acid residues, only a very small group can be polysialylated. Polysialic acid is a highly negatively-charged sugar polymer and can comprise more than 90 sialic acid residues in postnatal mouse brains increasing dramatically the hydrodynamic radius of their carriers. Thus, adhesion and communication processes on cell surfaces are strongly influenced allowing, e.g., the migration of neuronal progenitor cells. In the developing brain the essential role of polysialylated NCAM has been demonstrated in many studies. In comparison to the neuronal system, however, during the formation of other organs the impact of the polysialylated form of NCAM is not well characterized and the number of studies is limited so far. This review summarizes these observations and discusses possible roles of polysialylated NCAM during the development of organs other than the brain. PMID:28448440

Interleukin‑6 induces an epithelial‑mesenchymal transition phenotype in human adamantinomatous craniopharyngioma cells and promotes tumor cell migration.

PubMed

Zhou, Jie; Zhang, Chao; Pan, Jun; Chen, Ligang; Qi, Song-Tao

2017-06-01

Total resection of adamantinomatous craniopharyngioma (ACP) is complex and often leads to postoperative recurrence. This is due to the tendency of the tumor to invade the surrounding brain tissue and the generation of a local inflammatory state between the tumor cells and parenchyma. While there is evidence to suggest that interleukin‑6 (IL‑6) induces craniopharyngioma (CP)‑associated inflammation, particularly in ACP, the role of IL‑6 in the progression of ACP remains unclear. The results of the present study demonstrated that CP inflammation was associated with pathological classification, extent of surgery, degree of calcification and postoperative hypothalamic status scale. Cytokine antibody arrays were conducted to measure the expression of IL‑6 and other inflammatory factors in tumor tissues in response to various levels of inflammatory exposure. IL‑6, IL‑6 receptor (IL‑6R) and glycoprotein 130 expression was detected by immunohistochemistry. In addition, an ELISA was performed to quantify the levels of soluble IL‑6R (sIL‑6R) in the cystic fluid and supernatants of ACP cells and tumor‑associated fibroblasts. These measurements demonstrated that ACP cells produce IL‑6 and its associated proteins. In addition, the results revealed that while the viability of ACP cells was not affected, the migration of ACP cells was promoted by IL‑6 treatment in a concentration‑dependent manner. Conversely, treatment with an IL‑6‑blocking monoclonal antibody significantly decreased the migration of ACP cells. In addition, IL‑6 treatment increased the expression of vimentin and decreased the expression of E‑cadherin in a dose‑dependent manner. The findings of the present study demonstrate that IL‑6 may promote migration in vitro via the classic‑ and trans‑signaling pathways by inducing epithelial‑mesenchymal transition in ACP cell cultures.

Interleukin-6 induces an epithelial-mesenchymal transition phenotype in human adamantinomatous craniopharyngioma cells and promotes tumor cell migration

PubMed Central

Zhou, Jie; Zhang, Chao; Pan, Jun; Chen, Ligang; Qi, Song-Tao

2017-01-01

Total resection of adamantinomatous craniopharyngioma (ACP) is complex and often leads to postoperative recurrence. This is due to the tendency of the tumor to invade the surrounding brain tissue and the generation of a local inflammatory state between the tumor cells and parenchyma. While there is evidence to suggest that interleukin-6 (IL-6) induces craniopharyngioma (CP)-associated inflammation, particularly in ACP, the role of IL-6 in the progression of ACP remains unclear. The results of the present study demonstrated that CP inflammation was associated with pathological classification, extent of surgery, degree of calcification and postoperative hypothalamic status scale. Cytokine antibody arrays were conducted to measure the expression of IL-6 and other inflammatory factors in tumor tissues in response to various levels of inflammatory exposure. IL-6, IL-6 receptor (IL-6R) and glycoprotein 130 expression was detected by immunohistochemistry. In addition, an ELISA was performed to quantify the levels of soluble IL-6R (sIL-6R) in the cystic fluid and supernatants of ACP cells and tumor-associated fibroblasts. These measurements demonstrated that ACP cells produce IL-6 and its associated proteins. In addition, the results revealed that while the viability of ACP cells was not affected, the migration of ACP cells was promoted by IL-6 treatment in a concentration-dependent manner. Conversely, treatment with an IL-6-blocking monoclonal antibody significantly decreased the migration of ACP cells. In addition, IL-6 treatment increased the expression of vimentin and decreased the expression of E-cadherin in a dose-dependent manner. The findings of the present study demonstrate that IL-6 may promote migration in vitro via the classic- and trans-signaling pathways by inducing epithelial-mesenchymal transition in ACP cell cultures. PMID:28487953

Erythropoietin Augments Survival of Glioma Cells After Radiation and Temozolomide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hassouna, Imam; Sperling, Swetlana; Kim, Ella

2008-11-01

Purpose: Despite beneficial effects of irradiation/chemotherapy on survival of glioblastoma (GBM) patients, collateral damage to intact neural tissue leads to 'radiochemobrain' and reduced quality of life in survivors. For prophylactic neuroprotection, erythropoietin (EPO) is a promising candidate, provided that concerns regarding potential tumor promoting effects are alleviated. Methods and Materials: Human GBM-derived cell lines U87, G44, G112, and the gliosarcoma-derived line G28 were treated with EPO, with and without combinations of irradiation or temozolomide (TMZ). Responsiveness of glioma cells to EPO was measured by cell migration from spheroids, cell proliferation, and clonogenic survival. Implantation of U87 cells into brains ofmore » nude mice, followed 5 days later by EPO treatment (5,000 U/kg intraperitoneal every other day for 2 weeks) should reveal effects of EPO on tumor growth in vivo. Reverse transcriptase-polymerase chain reaction was performed for EPOR, HIF-1{alpha}, and epidermal growth factor receptor (EGFR)vIII in cell lines and 22 human GBM specimens. Results: EPO did not modulate basal glioma cell migration and stimulated proliferation in only one of four cell lines. Importantly, EPO did not enhance tumor growth in mouse brains. Preincubation of glioma cells with EPO for 3 h, followed by irradiation and TMZ for another 24 h, resulted in protection against chemoradiation-induced cytotoxicity in three cell lines. Conversely, EPO induced a dose-dependent decrease in survival of G28 gliosarcoma cells. In GBM specimens, expression of HIF-1{alpha} correlated positively with expression of EPOR and EGFRvIII. EPOR and EGFRvIII expression did not correlate. Conclusions: EPO is unlikely to appreciably influence basal glioma growth. However, concomitant use of EPO with irradiation/chemotherapy in GBM patients is not advisable.« less

miR-139-5p suppresses cancer cell migration and invasion through targeting ZEB1 and ZEB2 in GBM.

PubMed

Yue, Sihai; Wang, Lihua; Zhang, Hui; Min, Youhui; Lou, Yongli; Sun, Hongshan; Jiang, Yu; Zhang, Wenjin; Liang, Aming; Guo, Yongkun; Chen, Ping; Lv, Guowei; Wang, Liuxiang; Zong, Qinghua; Li, Yong

2015-09-01

Invasion and migration of glioblastoma multiforme (GBM) is a multistep process and an important phenotype that causes this disease to invade surrounding tissues in the brain. Recent studies have highlighted that miRNAs play a pivotal role in controlling GBM cell plasticity. In this report, we used wound healing and transwell assays to identify a novel role of miR-139-5p in inhibition of GBM cell migration and invasion. Bioinformatics coupled with luciferase and Western blot assays also revealed that miR-139-5p inhibited expression of ZEB1 and ZEB2, which are master regulators of tumor metastasis. MiR-139-5p specifically interacts with the 3'-UTR regions of ZEB1 and ZEB2, attenuating their expression in GBM cells. To corroborate this finding, we rescued ZEB1 and ZEB2 expression and found partial but significant increases in miR-139-5p-suppressed invasion of GBM cells. The biological relevance of our study was validated by analyzing levels of miR-139-5p in GBM tissue. We found that its expression significantly downregulated compared to normal tissue and shorter overall survival rates in patients with lower miR-139-5p expression. These results confirm that miR-139-5p suppresses GBM migration and invasion and highlight its potential as a biomarker and therapeutic target for treating GBM.

Controlling micro- and nano-environment of tumor and stem cells for novel research and therapy of brain cancer

NASA Astrophysics Data System (ADS)

Smith, Christopher Lloyd

The use of modern technologies in cancer research has engendered a great deal of excitement. Many of these advanced approaches involve in-depth mathematical analyses of the inner working of cells, via genomic and proteomic analyses. However these techniques may not be ideal for the study of complex cell phenotypes and behaviors. This dissertation explores cancer and potential therapies through phenotypic analysis of cell behaviors, an alternative approach. We employ this experimental framework to study brain cancer (glioma), a particularly formidable example of this diverse ailment. Through the application of micro- and nanotechnology, we carefully control the surrounding environments of cells to understand their responses to various cues and to manipulate their behaviors. Subsequently we obtain clinically relevant information that allows better understanding of glioma, and enhancement of potential therapies. We first aim to address brain tumor dispersal, through analysis of cell migration. Utilizing nanometer-scale topographic models of the extracellular matrix, we study the migratory response of glioma cells to various stimuli in vitro. Second, we implement knowledge gained from these investigations to define characteristics of tumor progression in patients, and to develop treatments inhibiting cell migration. Next we use microfluidic and nanotopographic models to study the behaviors of stem cells in vitro. Here we attempt to improve their abilities to deliver therapeutic proteins to cancer, an innovative treatment approach. We analyze the multi-step process by which adipose-derived stem cells naturally home to tumor sites, and identify numerous environmental perturbations to enhance this behavior. Finally, we attempt to demonstrate that these cell culture-based manipulations can enhance the localization of adipose stem cells to glioma in vivo using animal models. Throughout this work we utilize environmental cues to analyze and induce particular behaviors in cells. We further demonstrate that this general technique can be used to determine clinically relevant tumor characteristics, to identify potential drug targets, and to enhance potential therapies. Therefore this thesis illuminates a novel framework for experimentation into cancer, and specifically advances two treatment approaches. We anticipate that the methodologies described in this study will prove useful to various branches of medicine and biological research.

Intranasally administered mesenchymal stem cells promote a regenerative niche for repair of neonatal ischemic brain injury.

PubMed

Donega, Vanessa; Nijboer, Cora H; van Tilborg, Geralda; Dijkhuizen, Rick M; Kavelaars, Annemieke; Heijnen, Cobi J

2014-11-01

Previous work from our group has shown that intranasal MSC-treatment decreases lesion volume and improves motor and cognitive behavior after hypoxic-ischemic (HI) brain damage in neonatal mice. Our aim was to determine the kinetics of MSC migration after intranasal administration, and the early effects of MSCs on neurogenic processes and gliosis at the lesion site. HI brain injury was induced in 9-day-old mice and MSCs were administered intranasally at 10days post-HI. The kinetics of MSC migration were investigated by immunofluorescence and MRI analysis. BDNF and NGF gene expression was determined by qPCR analysis following MSC co-culture with HI brain extract. Nestin, Doublecortin, NeuN, GFAP, Iba-1 and M1/M2 phenotypic expression was assessed over time. MRI and immunohistochemistry analyses showed that MSCs reach the lesion site already within 2h after intranasal administration. At 12h after administration the number of MSCs at the lesion site peaks and decreases significantly at 72h. The number of DCX(+) cells increased 1 to 3days after MSC administration in the SVZ. At the lesion, GFAP(+)/nestin(+) and DCX(+) expression increased 3 to 5days after MSC-treatment. The number of NeuN(+) cells increased within 5days, leading to a dramatic regeneration of the somatosensory cortex and hippocampus at 18days after intranasal MSC administration. Interestingly, MSCs expressed significantly more BDNF gene when exposed to HI brain extract in vitro. Furthermore, MSC-treatment resulted in the resolution of the glial scar surrounding the lesion, represented by a decrease in reactive astrocytes and microglia and polarization of microglia towards the M2 phenotype. In view of the current lack of therapeutic strategies, we propose that intranasal MSC administration is a powerful therapeutic option through its functional repair of the lesion represented by regeneration of the cortical and hippocampal structure and decrease of gliosis. Copyright © 2014. Published by Elsevier Inc.

Coadministration of the Human Umbilical Cord Matrix-Derived Mesenchymal Cells and Aspirin Alters Postischemic Brain Injury in Rats.

PubMed

Shams ara, Ali; Sheibani, Vahid; Esmaeilpour, Khadije; Eslaminejad, Touba; Nematollahi-Mahani, Seyed N

2015-09-01

Ischemic stroke is an acute brain insult that induces dramatic changes in the neurons. Treatment of brain stroke is one of the main therapeutic targets of neuroprotective therapies. The aim of this study was to evaluate the protective potential of implanted human umbilical cord mesenchymal stem (hUCMs) cells with/without aspirin (ASA) against focal cerebral ischemia. We assessed the migration and distribution of PKH26-labeled cells after transplantation. After day 10 of transient occlusion, we evaluated the effect of ASA and hUCMs on the recovery of learning and memory in rats by Morris water maze. Afterward, animals were sacrificed, and the infarct area in the brain was evaluated using 2, 3, 5-triphenyltetrazolium chloride staining and also by hematoxylin and eosin. The recovery of learning and memory in ischemic animals that received ASA and hUCM cells improved significantly compared with the untreated ischemic animals. Coadministration of ASA and hUCM cells did not improve the outcome at a comparable rate with ASA and hUCM cells alone. PKH26-labeled cells were detectable in the ischemic area of the brain tissue sections. 2,3,5-Triphenyltetrazolium chloride staining and histologic examinations showed that treatment with ASA and hUCM cells could significantly alter the ischemic area. The results of the present study suggest that ASA and hUCM cells can withstand degenerative changes induced by artificial stroke in the rat. Also the learning and memory disturbance in the ASA and cell-treated animals is less pronounced than ischemic animals. Coadministration of ASA and hUCM cells did not raise the outcome higher than administration of ASA and hUCM cells alone. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Thrombin/Matrix Metalloproteinase-9-Dependent SK-N-SH Cell Migration is Mediated Through a PLC/PKC/MAPKs/NF-κB Cascade.

PubMed

Yang, Chien-Chung; Lin, Chih-Chung; Chien, Peter Tzu-Yu; Hsiao, Li-Der; Yang, Chuen-Mao

2016-11-01

Thrombin has been known to activate inflammatory genes including matrix metalloproteinases (MMPs). The elevated expression of MMP-9 has been observed in patients with neuroinflammatory diseases and may contribute to the pathology of brain diseases. However, the mechanisms underlying thrombin-induced MMP-9 expression in SK-N-SH cells remain unknown. The effects of thrombin on MMP-9 expression were examined in SK-N-SH cells by gelatin zymography, Western blot, real-time PCR, promoter activity assay, and cell migration assay. The detailed mechanisms were analyzed by using pharmacological inhibitors and small intefering RNA (siRNA) transfection. Here, we demonstrated that thrombin induced the expression of proform MMP-9 and migration of SK-N-SH cells, which were attenuated by pretreatment with the inhibitor of thrombin (PPACK), Gq (GPA2A), PC-PLC (D609), PI-PLC (ET-18-OCH 3 ), nonselective protien kinase C (PKC, GF109203X), PKCα/βII (Gö6983), PKCδ (Rottlerin), p38 mitogen-activated protein kinases (MAPK) (SB202190), JNK1/2 (SP600125), or NF-κB (Bay11-7082 or Helenalin) and transfection with siRNA of Gq, PKCα, PKCβ, PKCδ, p38, JNK1/2, IKKα, IKKβ, or p65. Moreover, thrombin-stimulated PKCα/βII, PKCδ, p38 MAPK, JNK1/2, or p65 phosphorylation was abrogated by their respective inhibitor of PPACK, GPA2A, D609, ET-18-OCH 3 , Gö6983, Rottlerin, SB202190, SP600125, Bay11-7082, or Helenalin. Pretreatment with these inhibitors or transfection with MMP-9 siRNA also blocked thrombin-induced SK-N-SH cell migration. Our results show that thrombin stimulates a Gq/PLC/PKCs/p38 MAPK and JNK1/2 cascade, which in turn triggers NF-κB activation and ultimately induces MMP-9 expression and cell migration in SK-N-SH cells.

Putative adult neurogenesis in two domestic pigeon breeds (Columba livia domestica): racing homer versus utility carneau pigeons

PubMed Central

Mazengenya, Pedzisai; Bhagwandin, Adhil; Nkomozepi, Pilani; Manger, Paul R.; Ihunwo, Amadi O.

2017-01-01

Generation of neurons in the brains of adult birds has been studied extensively in the telencephalon of song birds and few studies are reported on the distribution of PCNA and DCX in the telencephalon of adult non-song learning birds. We report here on adult neurogenesis throughout the brains of two breeds of adult domestic pigeons (Columba livia domestica), the racing homer and utility carneau using endogenous immunohistochemical markers proliferating cell nuclear antigen (PCNA) for proliferating cells and doublecortin (DCX) for immature and migrating neurons. The distribution of PCNA and DCX immunoreactivity was very similar in both pigeon breeds with only a few minor differences. In both pigeons, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, walls of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and cerebellum. Generally, the olfactory bulbs and telencephalon had more PCNA and DCX cells than other regions. Two proliferative hotspots were evident in the dorsal and ventral poles of the lateral ventricles. PCNA- and DCX-immunoreactive cells migrated radially from the walls of the lateral ventricle into the parenchyma. In most telencephalic regions, the density of PCNA- and DCX-immunoreactive cells increased from rostral to caudal, except in the mesopallium where the density decreased from rostral to middle levels and then increased caudally. DCX immunoreactivity was more intense in fibres than in cell bodies and DCX-immunoreactive cells included small granular cells, fusiform bipolar cells, large round and or polygonal multipolar cells. The similarity in the distribution of proliferating cells and new neurons in the telencephalon of the two breeds of pigeons may suggest that adult neurogenesis is a conserved trait as an ecological adaptation irrespective of body size. PMID:28852390

Putative adult neurogenesis in two domestic pigeon breeds (Columba livia domestica): racing homer versus utility carneau pigeons.

PubMed

Mazengenya, Pedzisai; Bhagwandin, Adhil; Nkomozepi, Pilani; Manger, Paul R; Ihunwo, Amadi O

2017-07-01

Generation of neurons in the brains of adult birds has been studied extensively in the telencephalon of song birds and few studies are reported on the distribution of PCNA and DCX in the telencephalon of adult non-song learning birds. We report here on adult neurogenesis throughout the brains of two breeds of adult domestic pigeons (Columba livia domestica), the racing homer and utility carneau using endogenous immunohistochemical markers proliferating cell nuclear antigen (PCNA) for proliferating cells and doublecortin (DCX) for immature and migrating neurons. The distribution of PCNA and DCX immunoreactivity was very similar in both pigeon breeds with only a few minor differences. In both pigeons, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, walls of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and cerebellum. Generally, the olfactory bulbs and telencephalon had more PCNA and DCX cells than other regions. Two proliferative hotspots were evident in the dorsal and ventral poles of the lateral ventricles. PCNA- and DCX-immunoreactive cells migrated radially from the walls of the lateral ventricle into the parenchyma. In most telencephalic regions, the density of PCNA- and DCX-immunoreactive cells increased from rostral to caudal, except in the mesopallium where the density decreased from rostral to middle levels and then increased caudally. DCX immunoreactivity was more intense in fibres than in cell bodies and DCX-immunoreactive cells included small granular cells, fusiform bipolar cells, large round and or polygonal multipolar cells. The similarity in the distribution of proliferating cells and new neurons in the telencephalon of the two breeds of pigeons may suggest that adult neurogenesis is a conserved trait as an ecological adaptation irrespective of body size.

Lack of a p21waf1/cip -dependent G1/S checkpoint in neural stem and progenitor cells after DNA damage in vivo.

PubMed

Roque, Telma; Haton, Céline; Etienne, Olivier; Chicheportiche, Alexandra; Rousseau, Laure; Martin, Ludovic; Mouthon, Marc-André; Boussin, François D

2012-03-01

The cyclin-dependent kinase inhibitor p21(waf1/cip) mediates the p53-dependent G1/S checkpoint, which is generally considered to be a critical requirement to maintain genomic stability after DNA damage. We used staggered 5-ethynyl-2'deoxyuridine/5-bromo-2'-deoxyuridine double-labeling in vivo to investigate the cell cycle progression and the role of p21(waf1/cip) in the DNA damage response of neural stem and progenitor cells (NSPCs) after exposure of the developing mouse cortex to ionizing radiation. We observed a radiation-induced p21-dependent apoptotic response in migrating postmitotic cortical cells. However, neural stem and progenitor cells (NSPCs) did not initiate a p21(waf1/cip1) -dependent G1/S block and continued to enter S-phase at a similar rate to the non-irradiated controls. The G1/S checkpoint is not involved in the mechanisms underlying the faithful transmission of the NSPC genome and/or the elimination of critically damaged cells. These processes typically involve intra-S and G2/M checkpoints that are rapidly activated after irradiation. p21 is normally repressed in neural cells during brain development except at the G1 to G0 transition. Lack of activation of a G1/S checkpoint and apoptosis of postmitotic migrating cells after DNA damage appear to depend on the expression of p21 in neural cells, since substantial cell-to-cell variations are found in the irradiated cortex. This suggests that repression of p21 during brain development prevents the induction of the G1/S checkpoint after DNA damage. Copyright © 2011 AlphaMed Press.

Macrophage Migration Inhibitory Factor is subjected to glucose modification and oxidation in Alzheimer’s Disease

PubMed Central

Kassaar, Omar; Pereira Morais, Marta; Xu, Suying; Adam, Emily L.; Chamberlain, Rosemary C.; Jenkins, Bryony; James, Tony; Francis, Paul T.; Ward, Stephen; Williams, Robert J.; van den Elsen, Jean

2017-01-01

Glucose and glucose metabolites are able to adversely modify proteins through a non-enzymatic reaction called glycation, which is associated with the pathology of Alzheimer’s Disease (AD) and is a characteristic of the hyperglycaemia induced by diabetes. However, the precise protein glycation profile that characterises AD is poorly defined and the molecular link between hyperglycaemia and AD is unknown. In this study, we define an early glycation profile of human brain using fluorescent phenylboronate gel electrophoresis and identify early glycation and oxidation of macrophage migration inhibitory factor (MIF) in AD brain. This modification inhibits MIF enzyme activity and ability to stimulate glial cells. MIF is involved in immune response and insulin regulation, hyperglycaemia, oxidative stress and glycation are all implicated in AD. Our study indicates that glucose modified and oxidised MIF could be a molecular link between hyperglycaemia and the dysregulation of the innate immune system in AD. PMID:28230058

[Effect of weightlessness on the indices of brain development (the results of pregnant rats being on the Kosmos-1514 biosatellite and research on the subsequent development of their progeny on Earth)].

PubMed

Olenev, S N; Danilov, A R; Kriuchkova, T A; Sorokina, L M; Krasnov, I B

1987-09-01

Beginning from the 13th day of pregnancy the rats were under conditions of weightlessness of spaceflight for 6 days. After landing in 18-day-old fetuses the state of their brain development is investigated comparing to that in control animals, that are on the Earth. As demonstrates analysis of a number of morphological processes: reproduction, migration, neuronal differentiation, growth of processes, establishment of nervous connections, neuroglial interconnections and vascularization--all they under conditions of weightlessness develop rather fully. Certain deviations in vascularization (as examples the medulla oblongata and the striated tuber are taken) are observed--the amount of vessels is greater and they are thinner--and changes in migration rate of cells is demonstrated by the example of the cortical plate formation. These changes are quickly levelled during their subsequent development on the Earth.

To the Brain and Back: Migratory Paths of Dendritic Cells in Multiple Sclerosis.

PubMed

De Laere, Maxime; Berneman, Zwi N; Cools, Nathalie

2018-03-01

Migration of dendritic cells (DC) to the central nervous system (CNS) is a critical event in the pathogenesis of multiple sclerosis (MS). While up until now, research has mainly focused on the transmigration of DC through the blood-brain barrier, experimental evidence points out that also the choroid plexus and meningeal vessels represent important gateways to the CNS, especially in early disease stages. On the other hand, DC can exit the CNS to maintain immunological tolerance to patterns expressed in the CNS, a process that is perturbed in MS. Targeting trafficking of immune cells, including DC, to the CNS has demonstrated to be a successful strategy to treat MS. However, this approach is known to compromise protective immune surveillance of the brain. Unravelling the migratory paths of regulatory and pathogenic DC within the CNS may ultimately lead to the design of new therapeutic strategies able to selectively interfere with the recruitment of pathogenic DC to the CNS, while leaving host protective mechanisms intact. © 2018 American Association of Neuropathologists, Inc.

Molecular crosstalk between tumour and brain parenchyma instructs histopathological features in glioblastoma.

PubMed

Bougnaud, Sébastien; Golebiewska, Anna; Oudin, Anaïs; Keunen, Olivier; Harter, Patrick N; Mäder, Lisa; Azuaje, Francisco; Fritah, Sabrina; Stieber, Daniel; Kaoma, Tony; Vallar, Laurent; Brons, Nicolaas H C; Daubon, Thomas; Miletic, Hrvoje; Sundstrøm, Terje; Herold-Mende, Christel; Mittelbronn, Michel; Bjerkvig, Rolf; Niclou, Simone P

2016-05-31

The histopathological and molecular heterogeneity of glioblastomas represents a major obstacle for effective therapies. Glioblastomas do not develop autonomously, but evolve in a unique environment that adapts to the growing tumour mass and contributes to the malignancy of these neoplasms. Here, we show that patient-derived glioblastoma xenografts generated in the mouse brain from organotypic spheroids reproducibly give rise to three different histological phenotypes: (i) a highly invasive phenotype with an apparent normal brain vasculature, (ii) a highly angiogenic phenotype displaying microvascular proliferation and necrosis and (iii) an intermediate phenotype combining features of invasion and vessel abnormalities. These phenotypic differences were visible during early phases of tumour development suggesting an early instructive role of tumour cells on the brain parenchyma. Conversely, we found that tumour-instructed stromal cells differentially influenced tumour cell proliferation and migration in vitro, indicating a reciprocal crosstalk between neoplastic and non-neoplastic cells. We did not detect any transdifferentiation of tumour cells into endothelial cells. Cell type-specific transcriptomic analysis of tumour and endothelial cells revealed a strong phenotype-specific molecular conversion between the two cell types, suggesting co-evolution of tumour and endothelial cells. Integrative bioinformatic analysis confirmed the reciprocal crosstalk between tumour and microenvironment and suggested a key role for TGFβ1 and extracellular matrix proteins as major interaction modules that shape glioblastoma progression. These data provide novel insight into tumour-host interactions and identify novel stroma-specific targets that may play a role in combinatorial treatment strategies against glioblastoma.

Molecular crosstalk between tumour and brain parenchyma instructs histopathological features in glioblastoma

PubMed Central

Bougnaud, Sébastien; Golebiewska, Anna; Oudin, Anaïs; Keunen, Olivier; Harter, Patrick N.; Mäder, Lisa; Azuaje, Francisco; Fritah, Sabrina; Stieber, Daniel; Kaoma, Tony; Vallar, Laurent; Brons, Nicolaas H.C.; Daubon, Thomas; Miletic, Hrvoje; Sundstrøm, Terje; Herold-Mende, Christel; Mittelbronn, Michel; Bjerkvig, Rolf; Niclou, Simone P.

2016-01-01

The histopathological and molecular heterogeneity of glioblastomas represents a major obstacle for effective therapies. Glioblastomas do not develop autonomously, but evolve in a unique environment that adapts to the growing tumour mass and contributes to the malignancy of these neoplasms. Here, we show that patient-derived glioblastoma xenografts generated in the mouse brain from organotypic spheroids reproducibly give rise to three different histological phenotypes: (i) a highly invasive phenotype with an apparent normal brain vasculature, (ii) a highly angiogenic phenotype displaying microvascular proliferation and necrosis and (iii) an intermediate phenotype combining features of invasion and vessel abnormalities. These phenotypic differences were visible during early phases of tumour development suggesting an early instructive role of tumour cells on the brain parenchyma. Conversely, we found that tumour-instructed stromal cells differentially influenced tumour cell proliferation and migration in vitro, indicating a reciprocal crosstalk between neoplastic and non-neoplastic cells. We did not detect any transdifferentiation of tumour cells into endothelial cells. Cell type-specific transcriptomic analysis of tumour and endothelial cells revealed a strong phenotype-specific molecular conversion between the two cell types, suggesting co-evolution of tumour and endothelial cells. Integrative bioinformatic analysis confirmed the reciprocal crosstalk between tumour and microenvironment and suggested a key role for TGFβ1 and extracellular matrix proteins as major interaction modules that shape glioblastoma progression. These data provide novel insight into tumour-host interactions and identify novel stroma-specific targets that may play a role in combinatorial treatment strategies against glioblastoma. PMID:27049916

Blockade of the SNARE Protein Syntaxin 1 Inhibits Glioblastoma Tumor Growth

PubMed Central

Ulloa, Fausto; Gonzàlez-Juncà, Alba; Meffre, Delphine; Barrecheguren, Pablo José; Martínez-Mármol, Ramón; Pazos, Irene; Olivé, Núria; Cotrufo, Tiziana; Seoane, Joan; Soriano, Eduardo

2015-01-01

Glioblastoma (GBM) is the most prevalent adult brain tumor, with virtually no cure, and with a median overall survival of 15 months from diagnosis despite of the treatment. SNARE proteins mediate membrane fusion events in cells and are essential for many cellular processes including exocytosis and neurotransmission, intracellular trafficking and cell migration. Here we show that the blockade of the SNARE protein Syntaxin 1 (Stx1) function impairs GBM cell proliferation. We show that Stx1 loss-of-function in GBM cells, through ShRNA lentiviral transduction, a Stx1 dominant negative and botulinum toxins, dramatically reduces the growth of GBM after grafting U373 cells into the brain of immune compromised mice. Interestingly, Stx1 role on GBM progression may not be restricted just to cell proliferation since the blockade of Stx1 also reduces in vitro GBM cell invasiveness suggesting a role in several processes relevant for tumor progression. Altogether, our findings indicate that the blockade of SNARE proteins may represent a novel therapeutic tool against GBM. PMID:25803850

A feedback regulatory loop involving microRNA-9 and nuclear receptor TLX in neural stem cell fate determination.

PubMed

Zhao, Chunnian; Sun, GuoQiang; Li, Shengxiu; Shi, Yanhong

2009-04-01

MicroRNAs have been implicated as having important roles in stem cell biology. MicroRNA-9 (miR-9) is expressed specifically in neurogenic areas of the brain and may be involved in neural stem cell self-renewal and differentiation. We showed previously that the nuclear receptor TLX is an essential regulator of neural stem cell self-renewal. Here we show that miR-9 suppresses TLX expression to negatively regulate neural stem cell proliferation and accelerate neural differentiation. Introducing a TLX expression vector that is not prone to miR-9 regulation rescued miR-9-induced proliferation deficiency and inhibited precocious differentiation. In utero electroporation of miR-9 in embryonic brains led to premature differentiation and outward migration of the transfected neural stem cells. Moreover, TLX represses expression of the miR-9 pri-miRNA. By forming a negative regulatory loop with TLX, miR-9 provides a model for controlling the balance between neural stem cell proliferation and differentiation.

A feedback regulatory loop involving microRNA-9 and nuclear receptor TLX in neural stem cell fate determination

PubMed Central

Zhao, Chunnian; Sun, GuoQiang; Li, Shengxiu; Shi, Yanhong

2009-01-01

Summary MicroRNAs are important players in stem cell biology. Among them, microRNA-9 (miR-9) is expressed specifically in neurogenic areas of the brain. Whether miR-9 plays a role in neural stem cell self-renewal and differentiation is unknown. We showed previously that nuclear receptor TLX is an essential regulator of neural stem cell self-renewal. Here we show that miR-9 suppresses TLX expression to negatively regulate neural stem cell proliferation and accelerate neural differentiation. Introducing a TLX expression vector lacking the miR-9 recognition site rescued miR-9-induced proliferation deficiency and inhibited precocious differentiation. In utero electroporation of miR-9 in embryonic brains led to premature differentiation and outward migration of the transfected neural stem cells. Moreover, TLX represses miR-9 pri-miRNA expression. MiR-9, by forming a negative regulatory loop with TLX, establishes a model for controlling the balance between neural stem cell proliferation and differentiation. PMID:19330006

Immunovirotherapy with measles virus strains in combination with anti-PD-1 antibody blockade enhances antitumor activity in glioblastoma treatment.

PubMed

Hardcastle, Jayson; Mills, Lisa; Malo, Courtney S; Jin, Fang; Kurokawa, Cheyne; Geekiyanage, Hirosha; Schroeder, Mark; Sarkaria, Jann; Johnson, Aaron J; Galanis, Evanthia

2017-04-01

Glioblastoma (GBM) is the most common primary malignant brain tumor and has a dismal prognosis. Measles virus (MV) therapy of GBM is a promising strategy due to preclinical efficacy, excellent clinical safety, and its ability to evoke antitumor pro-inflammatory responses. We hypothesized that combining anti- programmed cell death protein 1 (anti-PD-1) blockade and MV therapy can overcome immunosuppression and enhance immune effector cell responses against GBM, thus improving therapeutic outcome. In vitro assays of MV infection of glioma cells and infected glioma cells with mouse microglia ± aPD-1 blockade were established to assess damage associated molecular pattern (DAMP) molecule production, migration, and pro-inflammatory effects. C57BL/6 or athymic mice bearing syngeneic orthotopic GL261 gliomas were treated with MV, aPD-1, and combination treatment. T2* weighted immune cell-specific MRI and fluorescence activated cell sorting (FACS) analysis of treated mouse brains was used to examine adaptive immune responses following therapy. In vitro, MV infection induced human GBM cell secretion of DAMP (high-mobility group protein 1, heat shock protein 90) and upregulated programmed cell death ligand 1 (PD-L1). MV infection of GL261 murine glioma cells resulted in a pro-inflammatory response and increased migration of BV2 microglia. In vivo, MV+aPD-1 therapy synergistically enhanced survival of C57BL/6 mice bearing syngeneic orthotopic GL261 gliomas. MRI showed increased inflammatory cell influx into the brains of mice treated with MV+aPD-1; FACS analysis confirmed increased T-cell influx predominantly consisting of activated CD8+ T cells. This report demonstrates that oncolytic measles virotherapy in combination with aPD-1 blockade significantly improves survival outcome in a syngeneic GBM model and supports the potential of clinical/translational strategies combining MV with αPD-1 therapy in GBM treatment. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

A centrosomal protein FOR20 regulates microtubule assembly dynamics and plays a role in cell migration.

PubMed

Srivastava, Shalini; Panda, Dulal

2017-08-10

Here, we report that a centrosomal protein FOR20 [FOP (FGFR1 (fibroblast growth factor receptor 1) oncogene protein)-like protein of molecular mass of 20 kDa; also named as C16orf63, FLJ31153 or PHSECRG2] can regulate the assembly and stability of microtubules. Both FOR20 IgG antibody and GST (glutathione S -transferase)-tagged FOR20 could precipitate tubulin from the HeLa cell extract, indicating a possible interaction between FOR20 and tubulin. FOR20 was also detected in goat brain tissue extract and it cycled with microtubule-associated proteins. Furthermore, FOR20 bound to purified tubulin and inhibited the assembly of tubulin in vitro. The overexpression of FOR20 depolymerized interphase microtubules and the depletion of FOR20 prevented nocodazole-induced depolymerization of microtubules in HeLa cells. In addition, the depletion of FOR20 suppressed the dynamics of individual microtubules in live HeLa cells. FOR20-depleted MDA-MB-231 cells displayed zigzag motion and migrated at a slower rate than the control cells, indicating that FOR20 plays a role in directed cell migration. The results suggested that the centrosomal protein FOR20 is a new member of the microtubule-associated protein family and that it regulates the assembly and dynamics of microtubules. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Rac regulates vascular endothelial growth factor stimulated motility.

PubMed

Soga, N; Connolly, J O; Chellaiah, M; Kawamura, J; Hruska, K A

2001-01-01

During angiogenesis endothelial cells migrate towards a chemotactic stimulus. Understanding the mechanism of endothelial cell migration is critical to the therapeutic manipulation of angiogenesis and ultimately cancer prevention. Vascular endothelial growth factor (VEGF) is a potent chemotactic stimulus of endothelial cells during angiogenesis. The endothelial cell signal transduction pathway of VEGF represents a potential target for cancer therapy, but the mechanisms of post-receptor signal transduction including the roles of rho family GTPases in regulating the cytoskeletal effects of VEGF in endothelial cells are not understood. Here we analyze the mechanisms of cell migration in the mouse brain endothelial cell line (bEND3). Stable transfectants containing a tetracycline repressible expression vector were used to induce expression of Rac mutants. Endothelial cell haptotaxis was stimulated by constitutively active V12Rac on collagen and vitronectin coated supports, and chemotaxis was further stimulated by VEGF. Osteopontin coated supports were the most stimulatory to bEND3 haptotaxis, but VEGF was not effective in further increasing migration on osteopontin coated supports. Haptotaxis on support coated with collagen, vitronectin, and to a lesser degree osteopontin was inhibited by N17 Rac. N17 Rac expression blocked stimulation of endothelial cell chemotaxis by VEGF. As part of the chemotactic stimulation, VEGF caused a loss of actin organization at areas of cell-cell contact and increased stress fiber expression in endothelial cells which were directed towards pores in the transwell membrane. N17 Rac prevented the stimulation of cell-cell contact disruption and the stress fiber stimulation by VEGF. These data demonstrate two pathways of regulating endothelial cell motility, one in which Rac is activated by matrix/integrin stimulation and is a crucial modulator of endothelial cell haptotaxis. The other pathway, in the presence of osteopontin, is Rac independent. VEGF stimulated chemotaxis, is critically dependent on Rac activation. Osteopontin was a potent matrix activator of motility, and perhaps one explanation for the absence of a VEGF plus osteopontin effect is that osteopontin stimulated motility was inhibitory to the Rac pathway.

Regional and stage-specific effects of prospectively purified vascular cells on the adult V-SVZ neural stem cell lineage.

PubMed

Crouch, Elizabeth E; Liu, Chang; Silva-Vargas, Violeta; Doetsch, Fiona

2015-03-18

Adult neural stem cells reside in specialized niches. In the ventricular-subventricular zone (V-SVZ), quiescent neural stem cells (qNSCs) become activated (aNSCs), and generate transit amplifying cells (TACs), which give rise to neuroblasts that migrate to the olfactory bulb. The vasculature is an important component of the adult neural stem cell niche, but whether vascular cells in neurogenic areas are intrinsically different from those elsewhere in the brain is unknown. Moreover, the contribution of pericytes to the neural stem cell niche has not been defined. Here, we describe a rapid FACS purification strategy to simultaneously isolate primary endothelial cells and pericytes from brain microregions of nontransgenic mice using CD31 and CD13 as surface markers. We compared the effect of purified vascular cells from a neurogenic (V-SVZ) and non-neurogenic brain region (cortex) on the V-SVZ stem cell lineage in vitro. Endothelial and pericyte diffusible signals from both regions differentially promote the proliferation and neuronal differentiation of qNSCs, aNSCs, and TACs. Unexpectedly, diffusible cortical signals had the most potent effects on V-SVZ proliferation and neurogenesis, highlighting the intrinsic capacity of non-neurogenic vasculature to support stem cell behavior. Finally, we identify PlGF-2 as an endothelial-derived mitogen that promotes V-SVZ cell proliferation. This purification strategy provides a platform to define the functional and molecular contribution of vascular cells to stem cell niches and other brain regions under different physiological and pathological states. Copyright © 2015 the authors 0270-6474/15/354528-12$15.00/0.

Expanding Concepts in Mental Retardation; Scientific Symposium of the Joseph P. Kennedy, Jr., Foundation (3rd, Boston, Massachusetts, 1966).

ERIC Educational Resources Information Center

Jervis, George A., Ed.

The genetics of mental retardation are discussed in terms of geographical isolates, prospects for prevention of trisomic conditions, population genetics, and cytogenetics of Down's syndrome; problems of neurogenesis described are anabolic pathways of galactose and glucose metabolism, abnormal cell migrations in developing brains, and genetic…

SDF-1 promotes endochondral bone repair during fracture healing at the traumatic brain injury condition.

PubMed

Liu, Xiaoqi; Zhou, Changlong; Li, Yanjing; Ji, Ye; Xu, Gongping; Wang, Xintao; Yan, Jinglong

2013-01-01

The objective of this study was to investigate the role of stromal cell-derived factor-1 (SDF-1) and its receptor, CXCR4, on bone healing and whether SDF-1 contributes to accelerating bone repair in traumatic brain injury (TBI)/fracture model. Real-time polymerase chain reaction and immunohistochemical analysis were used to detect the expression of SDF-1 during the repair of femoral bone in TBI/fracture model. The TBI/fracture model was treated with anti-SDF-1 neutralizing antibody or AMD3100, an antagonist for CXCR4, and evaluated by histomorphometry. In vitro and in vivo migration assays were used to evaluate the functional effect of SDF-1 on primary mesenchymal stem cells. The expression of SDF1 and CXCR4 messenger RNA was increased during the bone healing in TBI/fracture model but was less increased in fracture only model. High expression of SDF-1 protein was observed in the surrounding tissue of the damaged bone. Treated with anti-SDF-1 antibody or AMD3100 could inhibit new bone formation. SDF-1 increased mesenchymal stem cell chemotaxis in vitro in a dose-dependent manner. The in vivo migration study demonstrated that mesenchymal stem cells recruited by SDF-1 participate in endochondral bone repair. The SDF-1/CXCR4 axis plays a crucial role in the accelerating fracture healing under the condition of TBI and contributes to endochondral bone repair.

More than just water channels: unexpected cellular roles of aquaporins.

PubMed

Verkman, A S

2005-08-01

Aquaporins (AQPs) are membrane proteins that transport water and, in some cases, also small solutes such as glycerol. AQPs are expressed in many fluid-transporting tissues, such as kidney tubules and glandular epithelia, as well as in non-fluid-transporting tissues, such as epidermis, adipose tissue and astroglia. Their classical role in facilitating trans-epithelial fluid transport is well understood, as in the urinary concentrating mechanism and gland fluid secretion. AQPs are also involved in swelling of tissues under stress, as in the injured cornea and the brain in stroke, tumor and infection. Recent analysis of AQP-knockout mice has revealed unexpected cellular roles of AQPs. AQPs facilitate cell migration, as manifested by reduced tumor angiogenesis in AQP1-knockout mice, by a mechanism that might involve facilitated water transport in lamellipodia of migrating cells. AQPs that transport both glycerol and water regulate glycerol content in epidermis and fat, and consequently skin hydration/biosynthesis and fat metabolism. AQPs might also be involved in neural signal transduction, cell volume regulation and organellar physiology. The many roles of AQPs could be exploited for clinical benefit; for example, treatments that modulate AQP expression/function could be used as diuretics, and in the treatment of brain swelling, glaucoma, epilepsy, obesity and cancer.

Simultaneously targeting inflammatory response and parasite sequestration in brain to treat Experimental Cerebral Malaria

PubMed Central

Dende, Chaitanya; Meena, Jairam; Nagarajan, Perumal; Panda, Amulya K.; Rangarajan, Pundi N.; Padmanaban, Govindarajan

2015-01-01

Malaria afflicts around 200 million people annually, with a mortality number close to 600,000. The mortality rate in Human Cerebral Malaria (HCM) is unacceptably high (15–20%), despite the availability of artemisinin-based therapy. An effective adjunct therapy is urgently needed. Experimental Cerebral Malaria (ECM) in mice manifests many of the neurological features of HCM. Migration of T cells and parasite-infected RBCs (pRBCs) into the brain are both necessary to precipitate the disease. We have been able to simultaneously target both these parameters of ECM. Curcumin alone was able to reverse all the parameters investigated in this study that govern inflammatory responses, CD8+ T cell and pRBC sequestration into the brain and blood brain barrier (BBB) breakdown. But the animals eventually died of anemia due to parasite build-up in blood. However, arteether-curcumin (AC) combination therapy even after the onset of symptoms provided complete cure. AC treatment is a promising therapeutic option for HCM. PMID:26227888

Expression of CXCL4 in microglia in vitro and in vivo and its possible signaling through CXCR3.

PubMed

de Jong, Eiko K; de Haas, Alexander H; Brouwer, Nieske; van Weering, Hilmar R J; Hensens, Marjolein; Bechmann, Ingo; Pratley, Pierre; Wesseling, Evelyn; Boddeke, Hendrikus W G M; Biber, Knut

2008-06-01

Signaling through chemokine receptor CXCR3 in the brain has been implicated in various brain diseases, as CXCR3 and its ligands are found under these conditions. Recently, a new chemokine ligand for CXCR3 was reported. In humans, an alternatively spliced variant of CXCR3 expressed on microvascular endothelial cells, named CXCR3b, was shown to bind CXCL4. In the periphery, the cellular expression and functions of CXCL4 are well described but in the brain its expression and function are unknown. Here, we show that brain microglia are a cellular source of CXCL4 in vitro and in vivo under neurodegenerating conditions. Microglial migration induced by CXCL4 is absent in CXCR3-deficient microglia, indicating a role of CXCR3. CXCL4 furthermore attenuates lipopolysaccharide-induced microglial phagocytosis and nitric oxide production in microglia and BV-2 cells. Based on these findings, it is proposed that locally released CXCL4 may control microglia responses.

Transcranial low-level laser therapy increases memory, learning, neuroprogenitor cells, BDNF and synaptogenesis in mice with traumatic brain injury

NASA Astrophysics Data System (ADS)

Xuan, Weijun; Huang, Liyi; Vatansever, Fatma; Agrawal, Tanupriya; Hamblin, Michael R.

2015-03-01

Increasing concern is evident over the epidemic of traumatic brain injury in both civilian and military medicine, and the lack of approved treatments. Transcranial low level laser therapy tLLLT) is a new approach in which near infrared laser is delivered to the head, penetrates the scalp and skull to reach the brain. We asked whether tLLLT at 810-nm could improve memory and learning in mice with controlled cortical impact traumatic brain injury. We investigated the mechanism of action by immunofluorescence studies in sections from brains of mice sacrificed at different times. Mice with TBI treated with 1 or 3 daily laser applications performed better on Morris Water Maze test at 28 days. Laser treated mice had increased BrdU incorporation into NeuN positive cells in the dentate gyrus and subventricular zone indicating formation of neuroprogenitor cells at 7 days and less at 28 days. Markers of neuron migration (DCX and Tuj1) were also increased, as was the neurotrophin, brain derived neurotrophic factor (BDNF) at 7 days. Markers of synaptogenesis (formation of new connections between existing neurons) were increased in the perilesional cortex at 28 days. tLLLT is proposed to be able to induce the brain to repair itself after injury. However its ability to induce neurogenesis and synaptogenesis suggests that tLLLT may have much wider applications to neurodegenerative and psychiatric disorders.

Impact of mesenchymal stem cells' secretome on glioblastoma pathophysiology.

PubMed

Vieira de Castro, Joana; Gomes, Eduardo D; Granja, Sara; Anjo, Sandra I; Baltazar, Fátima; Manadas, Bruno; Salgado, António J; Costa, Bruno M

2017-10-02

Glioblastoma (GBM) is a highly aggressive primary brain cancer, for which curative therapies are not available. An emerging therapeutic approach suggested to have potential to target malignant gliomas has been based on the use of multipotent mesenchymal stem cells (MSCs), either unmodified or engineered to deliver anticancer therapeutic agents, as these cells present an intrinsic capacity to migrate towards malignant tumors. Nevertheless, it is still controversial whether this innate tropism of MSCs towards the tumor area is associated with cancer promotion or suppression. Considering that one of the major mechanisms by which MSCs interact with and modulate tumor cells is via secreted factors, we studied how the secretome of MSCs modulates critical hallmark features of GBM cells. The effect of conditioned media (CM) from human umbilical cord perivascular cells (HUCPVCs, a MSC population present in the Wharton's jelly of the umbilical cord) on GBM cell viability, migration, proliferation and sensitivity to temozolomide treatment of U251 and SNB-19 GBM cells was evaluated. The in vivo chicken chorioallantoic membrane (CAM) assay was used to evaluate the effect of HUCPVCs CM on tumor growth and angiogenesis. The secretome of HUCPVCs was characterized by proteomic analyses. We found that both tested GBM cell lines exposed to HUCPVCs CM presented significantly higher cellular viability, proliferation and migration. In contrast, resistance of GBM cells to temozolomide chemotherapy was not significantly affected by HUCPVCs CM. In the in vivo CAM assay, CM from HUCPVCs promoted U251 and SNB-19 tumor cells growth. Proteomic analysis to characterize the secretome of HUCPVCs identified several proteins involved in promotion of cell survival, proliferation and migration, revealing novel putative molecular mediators for the effects observed in GBM cells exposed to HUCPVCs CM. These findings provide novel insights to better understand the interplay between GBM cells and MSCs, raising awareness to potential safety issues regarding the use of MSCs as stem-cell based therapies for GBM.

Mutations in IRX5 impair craniofacial development and germ cell migration via SDF1.

PubMed

Bonnard, Carine; Strobl, Anna C; Shboul, Mohammad; Lee, Hane; Merriman, Barry; Nelson, Stanley F; Ababneh, Osama H; Uz, Elif; Güran, Tülay; Kayserili, Hülya; Hamamy, Hanan; Reversade, Bruno

2012-05-13

Using homozygosity mapping and locus resequencing, we found that alterations in the homeodomain of the IRX5 transcription factor cause a recessive congenital disorder affecting face, brain, blood, heart, bone and gonad development. We found through in vivo modeling in Xenopus laevis embryos that Irx5 modulates the migration of progenitor cell populations in branchial arches and gonads by repressing Sdf1. We further found that transcriptional control by Irx5 is modulated by direct protein-protein interaction with two GATA zinc-finger proteins, GATA3 and TRPS1; disruptions of these proteins also cause craniofacial dysmorphisms. Our findings suggest that IRX proteins integrate combinatorial transcriptional inputs to regulate key signaling molecules involved in the ontogeny of multiple organs during embryogenesis and homeostasis.

Anti-GD2-ch14.18/CHO coated nanoparticles mediate glioblastoma (GBM)-specific delivery of the aromatase inhibitor, Letrozole, reducing proliferation, migration and chemoresistance in patient-derived GBM tumor cells.

PubMed

Tivnan, Amanda; Heilinger, Tatjana; Ramsey, Joanne M; O'Connor, Gemma; Pokorny, Jenny L; Sarkaria, Jann N; Stringer, Brett W; Day, Bryan W; Boyd, Andrew W; Kim, Ella L; Lode, Holger N; Cryan, Sally-Ann; Prehn, Jochen H M

2017-03-07

Aromatase is a critical enzyme in the irreversible conversion of androgens to oestrogens, with inhibition used clinically in hormone-dependent malignancies. We tested the hypothesis that targeted aromatase inhibition in an aggressive brain cancer called glioblastoma (GBM) may represent a new treatment strategy. In this study, aromatase inhibition was achieved using third generation inhibitor, Letrozole, encapsulated within the core of biodegradable poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs). PLGA-NPs were conjugated to human/mouse chimeric anti-GD2 antibody ch14.18/CHO, enabling specific targeting of GD2-positive GBM cells. Treatment of primary and recurrent patient-derived GBM cells with free-Letrozole (0.1 μM) led to significant decrease in cell proliferation and migration; in addition to reduced spheroid formation. Anti-GD2-ch14.18/CHO-NPs displayed specific targeting of GBM cells in colorectal-glioblastoma co-culture, with subsequent reduction in GBM cell numbers when treated with anti-GD2-ch14.18-PLGA-Let-NPs in combination with temozolomide. As miR-191 is an estrogen responsive microRNA, its expression, fluctuation and role in Letrozole treated GBM cells was evaluated, where treatment with premiR-191 was capable of rescuing the reduced proliferative phenotype induced by aromatase inhibitor. The repurposing and targeted delivery of Letrozole for the treatment of GBM, with the potential role of miR-191 identified, provides novel avenues for target assessment in this aggressive brain cancer.

Anti-GD2-ch14.18/CHO coated nanoparticles mediate glioblastoma (GBM)-specific delivery of the aromatase inhibitor, Letrozole, reducing proliferation, migration and chemoresistance in patient-derived GBM tumor cells

PubMed Central

Tivnan, Amanda; Heilinger, Tatjana; Ramsey, Joanne M; O’Connor, Gemma; Pokorny, Jenny L; Sarkaria, Jann N; Stringer, Brett W; Day, Bryan W; Boyd, Andrew W; Kim, Ella L; Lode, Holger N; Cryan, Sally-Ann; Prehn, Jochen H.M

2017-01-01

Aromatase is a critical enzyme in the irreversible conversion of androgens to oestrogens, with inhibition used clinically in hormone-dependent malignancies. We tested the hypothesis that targeted aromatase inhibition in an aggressive brain cancer called glioblastoma (GBM) may represent a new treatment strategy. In this study, aromatase inhibition was achieved using third generation inhibitor, Letrozole, encapsulated within the core of biodegradable poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs). PLGA-NPs were conjugated to human/mouse chimeric anti-GD2 antibody ch14.18/CHO, enabling specific targeting of GD2-positive GBM cells. Treatment of primary and recurrent patient-derived GBM cells with free-Letrozole (0.1 μM) led to significant decrease in cell proliferation and migration; in addition to reduced spheroid formation. Anti-GD2-ch14.18/CHO-NPs displayed specific targeting of GBM cells in colorectal-glioblastoma co-culture, with subsequent reduction in GBM cell numbers when treated with anti-GD2-ch14.18-PLGA-Let-NPs in combination with temozolomide. As miR-191 is an estrogen responsive microRNA, its expression, fluctuation and role in Letrozole treated GBM cells was evaluated, where treatment with premiR-191 was capable of rescuing the reduced proliferative phenotype induced by aromatase inhibitor. The repurposing and targeted delivery of Letrozole for the treatment of GBM, with the potential role of miR-191 identified, provides novel avenues for target assessment in this aggressive brain cancer. PMID:28178667

FOXP2 drives neuronal differentiation by interacting with retinoic acid signaling pathways.

PubMed

Devanna, Paolo; Middelbeek, Jeroen; Vernes, Sonja C

2014-01-01

FOXP2 was the first gene shown to cause a Mendelian form of speech and language disorder. Although developmentally expressed in many organs, loss of a single copy of FOXP2 leads to a phenotype that is largely restricted to orofacial impairment during articulation and linguistic processing deficits. Why perturbed FOXP2 function affects specific aspects of the developing brain remains elusive. We investigated the role of FOXP2 in neuronal differentiation and found that FOXP2 drives molecular changes consistent with neuronal differentiation in a human model system. We identified a network of FOXP2 regulated genes related to retinoic acid signaling and neuronal differentiation. FOXP2 also produced phenotypic changes associated with neuronal differentiation including increased neurite outgrowth and reduced migration. Crucially, cells expressing FOXP2 displayed increased sensitivity to retinoic acid exposure. This suggests a mechanism by which FOXP2 may be able to increase the cellular differentiation response to environmental retinoic acid cues for specific subsets of neurons in the brain. These data demonstrate that FOXP2 promotes neuronal differentiation by interacting with the retinoic acid signaling pathway and regulates key processes required for normal circuit formation such as neuronal migration and neurite outgrowth. In this way, FOXP2, which is found only in specific subpopulations of neurons in the brain, may drive precise neuronal differentiation patterns and/or control localization and connectivity of these FOXP2 positive cells.

FOXP2 drives neuronal differentiation by interacting with retinoic acid signaling pathways

PubMed Central

Devanna, Paolo; Middelbeek, Jeroen; Vernes, Sonja C.

2014-01-01

FOXP2 was the first gene shown to cause a Mendelian form of speech and language disorder. Although developmentally expressed in many organs, loss of a single copy of FOXP2 leads to a phenotype that is largely restricted to orofacial impairment during articulation and linguistic processing deficits. Why perturbed FOXP2 function affects specific aspects of the developing brain remains elusive. We investigated the role of FOXP2 in neuronal differentiation and found that FOXP2 drives molecular changes consistent with neuronal differentiation in a human model system. We identified a network of FOXP2 regulated genes related to retinoic acid signaling and neuronal differentiation. FOXP2 also produced phenotypic changes associated with neuronal differentiation including increased neurite outgrowth and reduced migration. Crucially, cells expressing FOXP2 displayed increased sensitivity to retinoic acid exposure. This suggests a mechanism by which FOXP2 may be able to increase the cellular differentiation response to environmental retinoic acid cues for specific subsets of neurons in the brain. These data demonstrate that FOXP2 promotes neuronal differentiation by interacting with the retinoic acid signaling pathway and regulates key processes required for normal circuit formation such as neuronal migration and neurite outgrowth. In this way, FOXP2, which is found only in specific subpopulations of neurons in the brain, may drive precise neuronal differentiation patterns and/or control localization and connectivity of these FOXP2 positive cells. PMID:25309332

Production and characterization of immortal human neural stem cell line with multipotent differentiation property.

PubMed

Kim, Seung U; Nagai, Atsushi; Nakagawa, Eiji; Choi, Hyun B; Bang, Jung H; Lee, Hong J; Lee, Myung A; Lee, Yong B; Park, In H

2008-01-01

We document the protocols and methods for the production of immortalized cell lines of human neural stem cells from the human fetal central nervous system (CNS) cells by using a retroviral vector encoding v-myc oncogene. One of the human neural stem cell lines (HB1.F3) was found to express nestin and other specific markers for human neural stem cells, giving rise to three fundamental cell types of the CNS: neurons, astrocytes, and oligodendrocytes. After transplantation into the brain of mouse model of stroke, implanted human neural stem cells were observed to migrate extensively from the site of implantation into other anatomical sites and to differentiate into neurons and glial cells.

Cadherins in cerebellar development: translation of embryonic patterning into mature functional compartmentalization.

PubMed

Redies, Christoph; Neudert, Franziska; Lin, Juntang

2011-09-01

Cadherins are cell adhesion molecules with multiple morphogenic functions in brain development, for example, in neuroblast migration and aggregation, axon navigation, neural circuit formation, and synaptogenesis. More than 100 members of the cadherin superfamily are expressed in the developing and mature brain. Most of the cadherins investigated, in particular classic cadherins and δ-protocadherins, are expressed in the cerebellum. For several cadherin subtypes, expression begins at early embryonic stages and persists until mature stages of cerebellar development. At intermediate stages, distinct Purkinje cell clusters exhibit unique rostrocaudal and mediolateral expression profiles for each cadherin. In the chicken, mouse, and other species, the Purkinje cell clusters are separated by intervening raphes of migrating granule cells. This pattern of Purkinje cell clusters/raphes is, at least in part, continuous with the parasagittal striping pattern that is apparent in the mature cerebellar cortex, for example, for zebrin II/aldolase C. Moreover, subregions of the deep cerebellar nuclei, vestibular nuclei and the olivary complex also express cadherins differentially. Neuroanatomical evidence suggests that the nuclear subregions and cortical domains that express the same cadherin subtype are connected to each other, to form neural subcircuits of the cerebellar system. Cadherins thus provide a molecular code that specifies not only embryonic structures but also functional cerebellar compartmentalization. By following the implementation of this code, it can be revealed how mature functional architecture emerges from embryonic patterning during cerebellar development. Dysfunction of some cadherins is associated with psychiatric diseases and developmental impairments and may also affect cerebellar function.

Some glial progenitors in the neonatal subventricular zone migrate through the corpus callosum to the contralateral cerebral hemisphere.

PubMed

Kakita, Akiyoshi; Zerlin, Marielba; Takahashi, Hitoshi; Goldman, James E

2003-04-14

The great majority of glial cells of the mammalian forebrain are generated in the perinatal period from progenitors in the subventricular zone (SVZ). We investigated the migration of progenitors from the neonatal (postnatal day 0, P0) rat forebrain SVZ by labeling them in vivo with a green fluorescence protein (GFP) retrovirus and monitoring their movements by time-lapse video microscopy in P3 slices. We identified a small number of progenitors that migrated tangentially within the corpus callosum (CC) and crossed the midline. These cells retained a relatively uniform morphology: the leading process was extended toward the contralateral side but showed no process branching or turning away from the migratory direction. Net migration requires the elongation of the leading process and nuclear translocation, and the migrating cells in the CC showed both modes. We confirmed the presence of unmyelinated axon bundles within the P3 CC, but failed to detect any radially directed glial processes (vimentin- or GLAST-immunolabeled fibers) spanning through the CC. Confocal images showed a close proximity between neurofilament-immunolabeled axons and the leading process of the GFP-expressing progenitors in the CC. The destination of the callosal fibers was examined by applying DiI to the right cingulum; the labeled fibers ran throughout the CC and reached the left cingulate and motor areas. The distribution and final fates of the retrovirus-labeled cells were examined in P28 brains. A small proportion of the labeled cells were found in the contralateral hemisphere, where, as oligodendrocytes and astrocytes, they colonized predominantly the cortex and the underlying white matter of the cingulate and secondary motor areas. The distribution pattern appears to coincide well with the projection direction of the callosal fibers. Thus, glial progenitors migrate across the CC, presumably in conjunction with unmyelinated axons, to colonize the contralateral hemisphere. Copyright 2003 Wiley-Liss, Inc.

Investigation of adhesion and mechanical properties of human glioma cells by single cell force spectroscopy and atomic force microscopy.

PubMed

Andolfi, Laura; Bourkoula, Eugenia; Migliorini, Elisa; Palma, Anita; Pucer, Anja; Skrap, Miran; Scoles, Giacinto; Beltrami, Antonio Paolo; Cesselli, Daniela; Lazzarino, Marco

2014-01-01

Active cell migration and invasion is a peculiar feature of glioma that makes this tumor able to rapidly infiltrate into the surrounding brain tissue. In our recent work, we identified a novel class of glioma-associated-stem cells (defined as GASC for high-grade glioma--HG--and Gasc for low-grade glioma--LG) that, although not tumorigenic, act supporting the biological aggressiveness of glioma-initiating stem cells (defined as GSC for HG and Gsc for LG) favoring also their motility. Migrating cancer cells undergo considerable molecular and cellular changes by remodeling their cytoskeleton and cell interactions with surrounding environment. To get a better understanding about the role of the glioma-associated-stem cells in tumor progression, cell deformability and interactions between glioma-initiating stem cells and glioma-associated-stem cells were investigated. Adhesion of HG/LG-cancer cells on HG/LG-glioma-associated stem cells was studied by time-lapse microscopy, while cell deformability and cell-cell adhesion strengths were quantified by indentation measurements by atomic force microscopy and single cell force spectroscopy. Our results demonstrate that for both HG and LG glioma, cancer-initiating-stem cells are softer than glioma-associated-stem cells, in agreement with their neoplastic features. The adhesion strength of GSC on GASC appears to be significantly lower than that observed for Gsc on Gasc. Whereas, GSC spread and firmly adhere on Gasc with an adhesion strength increased as compared to that obtained on GASC. These findings highlight that the grade of glioma-associated-stem cells plays an important role in modulating cancer cell adhesion, which could affect glioma cell migration, invasion and thus cancer aggressiveness. Moreover this work provides evidence about the importance of investigating cell adhesion and elasticity for new developments in disease diagnostics and therapeutics.

Elasticity-based boosting of neuroepithelial nucleokinesis via indirect energy transfer from mother to daughter.

PubMed

Shinoda, Tomoyasu; Nagasaka, Arata; Inoue, Yasuhiro; Higuchi, Ryo; Minami, Yoshiaki; Kato, Kagayaki; Suzuki, Makoto; Kondo, Takefumi; Kawaue, Takumi; Saito, Kanako; Ueno, Naoto; Fukazawa, Yugo; Nagayama, Masaharu; Miura, Takashi; Adachi, Taiji; Miyata, Takaki

2018-04-01

Neural progenitor cells (NPCs), which are apicobasally elongated and densely packed in the developing brain, systematically move their nuclei/somata in a cell cycle-dependent manner, called interkinetic nuclear migration (IKNM): apical during G2 and basal during G1. Although intracellular molecular mechanisms of individual IKNM have been explored, how heterogeneous IKNMs are collectively coordinated is unknown. Our quantitative cell-biological and in silico analyses revealed that tissue elasticity mechanically assists an initial step of basalward IKNM. When the soma of an M-phase progenitor cell rounds up using actomyosin within the subapical space, a microzone within 10 μm from the surface, which is compressed and elastic because of the apical surface's contractility, laterally pushes the densely neighboring processes of non-M-phase cells. The pressed processes then recoil centripetally and basally to propel the nuclei/somata of the progenitor's daughter cells. Thus, indirect neighbor-assisted transfer of mechanical energy from mother to daughter helps efficient brain development.

Elasticity-based boosting of neuroepithelial nucleokinesis via indirect energy transfer from mother to daughter

PubMed Central

Shinoda, Tomoyasu; Nagasaka, Arata; Inoue, Yasuhiro; Higuchi, Ryo; Minami, Yoshiaki; Kato, Kagayaki; Suzuki, Makoto; Kondo, Takefumi; Kawaue, Takumi; Saito, Kanako; Ueno, Naoto; Fukazawa, Yugo; Nagayama, Masaharu; Miura, Takashi; Adachi, Taiji

2018-01-01

Neural progenitor cells (NPCs), which are apicobasally elongated and densely packed in the developing brain, systematically move their nuclei/somata in a cell cycle–dependent manner, called interkinetic nuclear migration (IKNM): apical during G2 and basal during G1. Although intracellular molecular mechanisms of individual IKNM have been explored, how heterogeneous IKNMs are collectively coordinated is unknown. Our quantitative cell-biological and in silico analyses revealed that tissue elasticity mechanically assists an initial step of basalward IKNM. When the soma of an M-phase progenitor cell rounds up using actomyosin within the subapical space, a microzone within 10 μm from the surface, which is compressed and elastic because of the apical surface’s contractility, laterally pushes the densely neighboring processes of non–M-phase cells. The pressed processes then recoil centripetally and basally to propel the nuclei/somata of the progenitor’s daughter cells. Thus, indirect neighbor-assisted transfer of mechanical energy from mother to daughter helps efficient brain development. PMID:29677184

Signaling mechanisms regulating adult neural stem cells and neurogenesis

PubMed Central

Faigle, Roland; Song, Hongjun

2012-01-01

Background Adult neurogenesis occurs throughout life in discrete regions of the mammalian brain and is tightly regulated via both extrinsic environmental influences and intrinsic genetic factors. In recent years, several crucial signaling pathways have been identified in regulating self-renewal, proliferation, and differentiation of neural stem cells, as well as migration and functional integration of developing neurons in the adult brain. Scope of review Here we review our current understanding of signaling mechanisms, including Wnt, notch, sonic hedgehog, growth and neurotrophic factors, bone morphogenetic proteins, neurotransmitters, transcription factors, and epigenetic modulators, and crosstalk between these signaling pathways in the regulation of adult neurogenesis. We also highlight emerging principles in the vastly growing field of adult neural stem cell biology and neural plasticity. Major conclusions Recent methodological advances have enabled the field to identify signaling mechanisms that fine-tune and coordinate neurogenesis in the adult brain, leading to a better characterization of both cell-intrinsic and environmental cues defining the neurogenic niche. Significant questions related to niche cell identity and underlying regulatory mechanisms remain to be fully addressed and will be the focus of future studies. General significance A full understanding of the role and function of individual signaling pathways in regulating neural stem cells and generation and integration of newborn neurons in the adult brain may lead to targeted new therapies for neurological diseases in humans. PMID:22982587

Tissue plasminogen activator followed by antioxidant-loaded nanoparticle delivery promotes activation/mobilization of progenitor cells in infarcted rat brain.

PubMed

Petro, Marianne; Jaffer, Hayder; Yang, Jun; Kabu, Shushi; Morris, Viola B; Labhasetwar, Vinod

2016-03-01

Inherent neuronal and circulating progenitor cells play important roles in facilitating neuronal and functional recovery post stroke. However, this endogenous repair process is rather limited, primarily due to unfavorable conditions in the infarcted brain involving reactive oxygen species (ROS)-mediated oxidative stress and inflammation following ischemia/reperfusion injury. We hypothesized that during reperfusion, effective delivery of antioxidants to ischemic brain would create an environment without such oxidative stress and inflammation, thus promoting activation and mobilization of progenitor cells in the infarcted brain. We administered recombinant human tissue-type plasminogen activator (tPA) via carotid artery at 3 h post stroke in a thromboembolic rat model, followed by sequential administration of the antioxidants catalase (CAT) and superoxide dismutase (SOD), encapsulated in biodegradable nanoparticles (nano-CAT/SOD). Brains were harvested at 48 h post stroke for immunohistochemical analysis. Ipsilateral brain slices from animals that had received tPA + nano-CAT/SOD showed a widespread distribution of glial fibrillary acidic protein-positive cells (with morphology resembling radial glia-like neural precursor cells) and nestin-positive cells (indicating the presence of immature neurons); such cells were considerably fewer in untreated animals or those treated with tPA alone. Brain sections from animals receiving tPA + nano-CAT/SOD also showed much greater numbers of SOX2- and nestin-positive progenitor cells migrating from subventricular zone of the lateral ventricle and entering the rostral migratory stream than in t-PA alone treated group or untreated control. Further, animals treated with tPA + nano-CAT/SOD showed far fewer caspase-positive cells and fewer neutrophils than did other groups, as well as an inhibition of hippocampal swelling. These results suggest that the antioxidants mitigated the inflammatory response, protected neuronal cells from undergoing apoptosis, and inhibited edema formation by protecting the blood-brain barrier from ROS-mediated reperfusion injury. A longer-term study would enable us to determine if our approach would assist progenitor cells to undergo neurogenesis and to facilitate neurological and functional recovery following stroke and reperfusion injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

RTVP-1 promotes mesenchymal transformation of glioma via a STAT-3/IL-6-dependent positive feedback loop

PubMed Central

Giladi, Nis David; Ziv-Av, Amotz; Lee, Hae Kyung; Finniss, Susan; Cazacu, Simona; Xiang, Cunli; Ben-Asher, Hiba Waldman; deCarvalho, Ana; Mikkelsen, Tom; Poisson, Laila; Brodie, Chaya

2015-01-01

Glioblastomas (GBMs), the most aggressive primary brain tumors, exhibit increased invasiveness and resistance to anti-tumor treatments. We explored the role of RTVP-1, a glioma-associated protein that promotes glioma cell migration, in the mesenchymal transformation of GBM. Analysis of The Cancer Genome Atlas (TCGA) demonstrated that RTVP-1 expression was higher in mesenchymal GBM and predicted tumor recurrence and poor clinical outcome. ChiP analysis revealed that the RTVP-1 promoter binds STAT3 and C/EBPβ, two master transcription factors that regulate mesenchymal transformation of GBM. In addition, IL-6 induced RTVP-1 expression in a STAT3-dependent manner. RTVP-1 increased the migration and mesenchymal transformation of glioma cells. Similarly, overexpression of RTVP-1 in human neural stem cells induced mesenchymal differentiation, whereas silencing of RTVP-1 in glioma stem cells (GSCs) decreased the mesenchymal transformation and stemness of these cells. Silencing of RTVP-1 also increased the survival of mice bearing GSC-derived xenografts. Using gene array analysis of RTVP-1 silenced glioma cells we identified IL-6 as a mediator of RTVP-1 effects on the mesenchymal transformation and migration of GSCs, therefore acting in a positive feedback loop by upregulating RTVP-1 expression via the STAT3 pathway. Collectively, these results implicate RTVP-1 as a novel prognostic marker and therapeutic target in GBM. PMID:26267319

The mRNA-edited form of GABRA3 suppresses GABRA3-mediated Akt activation and breast cancer metastasis

PubMed Central

Gumireddy, Kiranmai; Li, Anping; Kossenkov, Andrew V.; Sakurai, Masayuki; Yan, Jinchun; Li, Yan; Xu, Hua; Wang, Jian; Zhang, Paul J.; Zhang, Lin; Showe, Louise C.; Nishikura, Kazuko; Huang, Qihong

2016-01-01

Metastasis is a critical event affecting breast cancer patient survival. To identify molecules contributing to the metastatic process, we analysed The Cancer Genome Atlas (TCGA) breast cancer data and identified 41 genes whose expression is inversely correlated with survival. Here we show that GABAA receptor alpha3 (Gabra3), normally exclusively expressed in adult brain, is also expressed in breast cancer, with high expression of Gabra3 being inversely correlated with breast cancer survival. We demonstrate that Gabra3 activates the AKT pathway to promote breast cancer cell migration, invasion and metastasis. Importantly, we find an A-to-I RNA-edited form of Gabra3 only in non-invasive breast cancers and show that edited Gabra3 suppresses breast cancer cell invasion and metastasis. A-to-I-edited Gabra3 has reduced cell surface expression and suppresses the activation of AKT required for cell migration and invasion. Our study demonstrates a significant role for mRNA-edited Gabra3 in breast cancer metastasis. PMID:26869349

The mRNA-edited form of GABRA3 suppresses GABRA3-mediated Akt activation and breast cancer metastasis.

PubMed

Gumireddy, Kiranmai; Li, Anping; Kossenkov, Andrew V; Sakurai, Masayuki; Yan, Jinchun; Li, Yan; Xu, Hua; Wang, Jian; Zhang, Paul J; Zhang, Lin; Showe, Louise C; Nishikura, Kazuko; Huang, Qihong

2016-02-12

Metastasis is a critical event affecting breast cancer patient survival. To identify molecules contributing to the metastatic process, we analysed The Cancer Genome Atlas (TCGA) breast cancer data and identified 41 genes whose expression is inversely correlated with survival. Here we show that GABAA receptor alpha3 (Gabra3), normally exclusively expressed in adult brain, is also expressed in breast cancer, with high expression of Gabra3 being inversely correlated with breast cancer survival. We demonstrate that Gabra3 activates the AKT pathway to promote breast cancer cell migration, invasion and metastasis. Importantly, we find an A-to-I RNA-edited form of Gabra3 only in non-invasive breast cancers and show that edited Gabra3 suppresses breast cancer cell invasion and metastasis. A-to-I-edited Gabra3 has reduced cell surface expression and suppresses the activation of AKT required for cell migration and invasion. Our study demonstrates a significant role for mRNA-edited Gabra3 in breast cancer metastasis.

Methods for assisting recovery of damaged brain and spinal cord using arrays of X-Ray microplanar beams

DOEpatents

Dilmanian, F. Avraham; McDonald, III, John W.

2007-12-04

A method of assisting recovery of an injury site of brain or spinal cord injury includes providing a therapeutic dose of X-ray radiation to the injury site through an array of parallel microplanar beams. The dose at least temporarily removes regeneration inhibitors from the irradiated regions. Substantially unirradiated cells surviving between the microplanar beams migrate to the in-beam irradiated portion and assist in recovery. The dose may be administered in dose fractions over several sessions, separated in time, using angle-variable intersecting microbeam arrays (AVIMA). Additional doses may be administered by varying the orientation of the microplanar beams. The method may be enhanced by injecting stem cells into the injury site.

Methods for assisting recovery of damaged brain and spinal cord using arrays of X-ray microplanar beams

DOEpatents

Dilmanian, F. Avraham; McDonald, III, John W.

2007-01-02

A method of assisting recovery of an injury site of brain or spinal cord injury includes providing a therapeutic dose of X-ray radiation to the injury site through an array of parallel microplanar beams. The dose at least temporarily removes regeneration inhibitors from the irradiated regions. Substantially unirradiated cells surviving between the microplanar beams migrate to the in-beam irradiated portion and assist in recovery. The dose may be administered in dose fractions over several sessions, separated in time, using angle-variable intersecting microbeam arrays (AVIMA). Additional doses may be administered by varying the orientation of the microplanar beams. The method may be enhanced by injecting stem cells into the injury site.

YAP/TAZ enhance mammalian embryonic neural stem cell characteristics in a Tead-dependent manner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Dasol; Byun, Sung-Hyun; Park, Soojeong

Mammalian brain development is regulated by multiple signaling pathways controlling cell proliferation, migration and differentiation. Here we show that YAP/TAZ enhance embryonic neural stem cell characteristics in a cell autonomous fashion using diverse experimental approaches. Introduction of retroviral vectors expressing YAP or TAZ into the mouse embryonic brain induced cell localization in the ventricular zone (VZ), which is the embryonic neural stem cell niche. This change in cell distribution in the cortical layer is due to the increased stemness of infected cells; YAP-expressing cells were colabeled with Sox2, a neural stem cell marker, and YAP/TAZ increased the frequency and sizemore » of neurospheres, indicating enhanced self-renewal- and proliferative ability of neural stem cells. These effects appear to be TEA domain family transcription factor (Tead)–dependent; a Tead binding-defective YAP mutant lost the ability to promote neural stem cell characteristics. Consistently, in utero gene transfer of a constitutively active form of Tead2 (Tead2-VP16) recapitulated all the features of YAP/TAZ overexpression, and dominant negative Tead2-EnR resulted in marked cell exit from the VZ toward outer cortical layers. Taken together, these results indicate that the Tead-dependent YAP/TAZ signaling pathway plays important roles in neural stem cell maintenance by enhancing stemness of neural stem cells during mammalian brain development. - Highlights: • Roles of YAP and Tead in vivo during mammalian brain development are clarified. • Expression of YAP promotes embryonic neural stem cell characteristics in vivo in a cell autonomous fashion. • Enhancement of neural stem cell characteristics by YAP depends on Tead. • Transcriptionally active form of Tead alone can recapitulate the effects of YAP. • Transcriptionally repressive form of Tead severely reduces stem cell characteristics.« less

Toxoplasma Modulates Signature Pathways of Human Epilepsy, Neurodegeneration & Cancer.

PubMed

Ngô, Huân M; Zhou, Ying; Lorenzi, Hernan; Wang, Kai; Kim, Taek-Kyun; Zhou, Yong; El Bissati, Kamal; Mui, Ernest; Fraczek, Laura; Rajagopala, Seesandra V; Roberts, Craig W; Henriquez, Fiona L; Montpetit, Alexandre; Blackwell, Jenefer M; Jamieson, Sarra E; Wheeler, Kelsey; Begeman, Ian J; Naranjo-Galvis, Carlos; Alliey-Rodriguez, Ney; Davis, Roderick G; Soroceanu, Liliana; Cobbs, Charles; Steindler, Dennis A; Boyer, Kenneth; Noble, A Gwendolyn; Swisher, Charles N; Heydemann, Peter T; Rabiah, Peter; Withers, Shawn; Soteropoulos, Patricia; Hood, Leroy; McLeod, Rima

2017-09-13

One third of humans are infected lifelong with the brain-dwelling, protozoan parasite, Toxoplasma gondii. Approximately fifteen million of these have congenital toxoplasmosis. Although neurobehavioral disease is associated with seropositivity, causality is unproven. To better understand what this parasite does to human brains, we performed a comprehensive systems analysis of the infected brain: We identified susceptibility genes for congenital toxoplasmosis in our cohort of infected humans and found these genes are expressed in human brain. Transcriptomic and quantitative proteomic analyses of infected human, primary, neuronal stem and monocytic cells revealed effects on neurodevelopment and plasticity in neural, immune, and endocrine networks. These findings were supported by identification of protein and miRNA biomarkers in sera of ill children reflecting brain damage and T. gondii infection. These data were deconvoluted using three systems biology approaches: "Orbital-deconvolution" elucidated upstream, regulatory pathways interconnecting human susceptibility genes, biomarkers, proteomes, and transcriptomes. "Cluster-deconvolution" revealed visual protein-protein interaction clusters involved in processes affecting brain functions and circuitry, including lipid metabolism, leukocyte migration and olfaction. Finally, "disease-deconvolution" identified associations between the parasite-brain interactions and epilepsy, movement disorders, Alzheimer's disease, and cancer. This "reconstruction-deconvolution" logic provides templates of progenitor cells' potentiating effects, and components affecting human brain parasitism and diseases.

MACF1 Controls Migration and Positioning of Cortical GABAergic Interneurons in Mice.

PubMed

Ka, Minhan; Moffat, Jeffrey J; Kim, Woo-Yang

2017-12-01

GABAergic interneurons develop in the ganglionic eminence in the ventral telencephalon and tangentially migrate into the cortical plate during development. However, key molecules controlling interneuron migration remain poorly identified. Here, we show that microtubule-actin cross-linking factor 1 (MACF1) regulates GABAergic interneuron migration and positioning in the developing mouse brain. To investigate the role of MACF1 in developing interneurons, we conditionally deleted the MACF1 gene in mouse interneuron progenitors and their progeny using Dlx5/6-Cre-IRES-EGFP and Nkx2.1-Cre drivers. We found that MACF1 deletion results in a marked reduction and defective positioning of interneurons in the mouse cerebral cortex and hippocampus, suggesting abnormal interneuron migration. Indeed, the speed and mode of interneuron migration were abnormal in the MACF1-mutant brain, compared with controls. Additionally, MACF1-deleted interneurons showed a significant reduction in the length of their leading processes and dendrites in the mouse brain. Finally, loss of MACF1 decreased microtubule stability in cortical interneurons. Our findings suggest that MACF1 plays a critical role in cortical interneuron migration and positioning in the developing mouse brain. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Embryonic Cerebrospinal Fluid Increases Neurogenic Activity in the Brain Ventricular-Subventricular Zone of Adult Mice.

PubMed

Alonso, Maria I; Lamus, Francisco; Carnicero, Estela; Moro, Jose A; de la Mano, Anibal; Fernández, Jose M F; Desmond, Mary E; Gato, Angel

2017-01-01

Neurogenesis is a very intensive process during early embryonic brain development, becoming dramatically restricted in the adult brain in terms of extension and intensity. We have previously demonstrated the key role of embryonic cerebrospinal fluid (CSF) in developing brain neurogenic activity. We also showed that cultured adult brain neural stem cells (NSCs) remain competent when responding to the neurogenic influence of embryonic CSF. However, adult CSF loses its neurogenic inductive properties. Here, by means of an organotypic culture of adult mouse brain sections, we show that local administration of embryonic CSF in the subventricular zone (SVZ) niche is able to trigger a neurogenic program in NSCs. This leads to a significant increase in the number of non-differentiated NSCs, and also in the number of new neurons which show normal migration, differentiation and maturation. These new data reveal that embryonic CSF activates adult brain NSCs, supporting the previous idea that it contains key instructive components which could be useful in adult brain neuroregenerative strategies.

Embryonic Cerebrospinal Fluid Increases Neurogenic Activity in the Brain Ventricular-Subventricular Zone of Adult Mice

PubMed Central

Alonso, Maria I.; Lamus, Francisco; Carnicero, Estela; Moro, Jose A.; de la Mano, Anibal; Fernández, Jose M. F.; Desmond, Mary E.; Gato, Angel

2017-01-01

Neurogenesis is a very intensive process during early embryonic brain development, becoming dramatically restricted in the adult brain in terms of extension and intensity. We have previously demonstrated the key role of embryonic cerebrospinal fluid (CSF) in developing brain neurogenic activity. We also showed that cultured adult brain neural stem cells (NSCs) remain competent when responding to the neurogenic influence of embryonic CSF. However, adult CSF loses its neurogenic inductive properties. Here, by means of an organotypic culture of adult mouse brain sections, we show that local administration of embryonic CSF in the subventricular zone (SVZ) niche is able to trigger a neurogenic program in NSCs. This leads to a significant increase in the number of non-differentiated NSCs, and also in the number of new neurons which show normal migration, differentiation and maturation. These new data reveal that embryonic CSF activates adult brain NSCs, supporting the previous idea that it contains key instructive components which could be useful in adult brain neuroregenerative strategies. PMID:29311854

Human Brain Organoids on a Chip Reveal the Physics of Folding.

PubMed

Karzbrun, Eyal; Kshirsagar, Aditya; Cohen, Sidney R; Hanna, Jacob H; Reiner, Orly

2018-05-01

Human brain wrinkling has been implicated in neurodevelopmental disorders and yet its origins remain unknown. Polymer gel models suggest that wrinkling emerges spontaneously due to compression forces arising during differential swelling, but these ideas have not been tested in a living system. Here, we report the appearance of surface wrinkles during the in vitro development and self-organization of human brain organoids in a micro-fabricated compartment that supports in situ imaging over a timescale of weeks. We observe the emergence of convolutions at a critical cell density and maximal nuclear strain, which are indicative of a mechanical instability. We identify two opposing forces contributing to differential growth: cytoskeletal contraction at the organoid core and cell-cycle-dependent nuclear expansion at the organoid perimeter. The wrinkling wavelength exhibits linear scaling with tissue thickness, consistent with balanced bending and stretching energies. Lissencephalic (smooth brain) organoids display reduced convolutions, modified scaling and a reduced elastic modulus. Although the mechanism here does not include the neuronal migration seen in in vivo , it models the physics of the folding brain remarkably well. Our on-chip approach offers a means for studying the emergent properties of organoid development, with implications for the embryonic human brain.

Human brain organoids on a chip reveal the physics of folding

NASA Astrophysics Data System (ADS)

Karzbrun, Eyal; Kshirsagar, Aditya; Cohen, Sidney R.; Hanna, Jacob H.; Reiner, Orly

2018-05-01

Human brain wrinkling has been implicated in neurodevelopmental disorders and yet its origins remain unknown. Polymer gel models suggest that wrinkling emerges spontaneously due to compression forces arising during differential swelling, but these ideas have not been tested in a living system. Here, we report the appearance of surface wrinkles during the in vitro development and self-organization of human brain organoids in a microfabricated compartment that supports in situ imaging over a timescale of weeks. We observe the emergence of convolutions at a critical cell density and maximal nuclear strain, which are indicative of a mechanical instability. We identify two opposing forces contributing to differential growth: cytoskeletal contraction at the organoid core and cell-cycle-dependent nuclear expansion at the organoid perimeter. The wrinkling wavelength exhibits linear scaling with tissue thickness, consistent with balanced bending and stretching energies. Lissencephalic (smooth brain) organoids display reduced convolutions, modified scaling and a reduced elastic modulus. Although the mechanism here does not include the neuronal migration seen in vivo, it models the physics of the folding brain remarkably well. Our on-chip approach offers a means for studying the emergent properties of organoid development, with implications for the embryonic human brain.

Human T-Lymphotropic Virus Type 1-Induced Overexpression of Activated Leukocyte Cell Adhesion Molecule (ALCAM) Facilitates Trafficking of Infected Lymphocytes through the Blood-Brain Barrier

PubMed Central

Curis, Céline; Percher, Florent; Jeannin, Patricia; Montange, Thomas; Chevalier, Sébastien A.; Seilhean, Danielle; Cartier, Luis; Couraud, Pierre-Olivier; Gout, Olivier; Gessain, Antoine; Ceccaldi, Pierre-Emmanuel

2016-01-01

ABSTRACT Human T-lymphotropic virus type 1 (HTLV-1) is the etiological agent of a slowly progressive neurodegenerative disease, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). This disease develops upon infiltration of HTLV-1-infected lymphocytes into the central nervous system, mostly the thoracic spinal cord. The central nervous system is normally protected by a physiological structure called the blood-brain barrier (BBB), which consists primarily of a continuous endothelium with tight junctions. In this study, we investigated the role of activated leukocyte cell adhesion molecule (ALCAM/CD166), a member of the immunoglobulin superfamily, in the crossing of the BBB by HTLV-1-infected lymphocytes. We demonstrated that ALCAM is overexpressed on the surface of HTLV-1-infected lymphocytes, both in chronically infected cell lines and in primary infected CD4+ T lymphocytes. ALCAM overexpression results from the activation of the canonical NF-κB pathway by the viral transactivator Tax. In contrast, staining of spinal cord sections of HAM/TSP patients showed that ALCAM expression is not altered on the BBB endothelium in the context of HTLV-1 infection. ALCAM blockade or downregulation of ALCAM levels significantly reduced the migration of HTLV-1-infected lymphocytes across a monolayer of human BBB endothelial cells. This study suggests a potential role for ALCAM in HAM/TSP pathogenesis. IMPORTANCE Human T-lymphotropic virus type 1 (HTLV-1) is the etiological agent of a slowly progressive neurodegenerative disease, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). This disease is the consequence of the infiltration of HTLV-1-infected lymphocytes into the central nervous system (CNS), mostly the thoracic spinal cord. The CNS is normally protected by a physiological structure called the blood-brain barrier (BBB), which consists primarily of a continuous endothelium with tight junctions. The mechanism of migration of lymphocytes into the CNS is unclear. Here, we show that the viral transactivator Tax increases activated leukocyte cell adhesion molecule (ALCAM/CD166) expression. This molecule facilitates the migration of lymphocytes across the BBB endothelium. Targeting this molecule could be of interest in preventing or reducing the development of HAM/TSP. PMID:27252538

Human T-Lymphotropic Virus Type 1-Induced Overexpression of Activated Leukocyte Cell Adhesion Molecule (ALCAM) Facilitates Trafficking of Infected Lymphocytes through the Blood-Brain Barrier.

PubMed

Curis, Céline; Percher, Florent; Jeannin, Patricia; Montange, Thomas; Chevalier, Sébastien A; Seilhean, Danielle; Cartier, Luis; Couraud, Pierre-Olivier; Gout, Olivier; Gessain, Antoine; Ceccaldi, Pierre-Emmanuel; Afonso, Philippe V

2016-08-15

Human T-lymphotropic virus type 1 (HTLV-1) is the etiological agent of a slowly progressive neurodegenerative disease, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). This disease develops upon infiltration of HTLV-1-infected lymphocytes into the central nervous system, mostly the thoracic spinal cord. The central nervous system is normally protected by a physiological structure called the blood-brain barrier (BBB), which consists primarily of a continuous endothelium with tight junctions. In this study, we investigated the role of activated leukocyte cell adhesion molecule (ALCAM/CD166), a member of the immunoglobulin superfamily, in the crossing of the BBB by HTLV-1-infected lymphocytes. We demonstrated that ALCAM is overexpressed on the surface of HTLV-1-infected lymphocytes, both in chronically infected cell lines and in primary infected CD4(+) T lymphocytes. ALCAM overexpression results from the activation of the canonical NF-κB pathway by the viral transactivator Tax. In contrast, staining of spinal cord sections of HAM/TSP patients showed that ALCAM expression is not altered on the BBB endothelium in the context of HTLV-1 infection. ALCAM blockade or downregulation of ALCAM levels significantly reduced the migration of HTLV-1-infected lymphocytes across a monolayer of human BBB endothelial cells. This study suggests a potential role for ALCAM in HAM/TSP pathogenesis. Human T-lymphotropic virus type 1 (HTLV-1) is the etiological agent of a slowly progressive neurodegenerative disease, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). This disease is the consequence of the infiltration of HTLV-1-infected lymphocytes into the central nervous system (CNS), mostly the thoracic spinal cord. The CNS is normally protected by a physiological structure called the blood-brain barrier (BBB), which consists primarily of a continuous endothelium with tight junctions. The mechanism of migration of lymphocytes into the CNS is unclear. Here, we show that the viral transactivator Tax increases activated leukocyte cell adhesion molecule (ALCAM/CD166) expression. This molecule facilitates the migration of lymphocytes across the BBB endothelium. Targeting this molecule could be of interest in preventing or reducing the development of HAM/TSP. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Transport Characteristics of Aquaporins.

PubMed

Geng, Xiaoqiang; Yang, Baoxue

2017-01-01

Aquaporins (AQPs ) are a class of the integral membrane proteins, which are permeable to water , some small neutral solutes and certain gases across biological membranes. AQPs are considered as critical transport mediators that are involved in many physiological functions and pathological processes such as transepithelial fluid transport , cell migration, brain edema , neuro excitation and carcinoma. This chapter will provide information about the transport characteristics of AQPs .

The 15-LO-1/15-HETE system promotes angiogenesis by upregulating VEGF in ischemic brains.

PubMed

Chen, Li; Zhu, Yan-Mei; Li, Yu-Nong; Li, Peng-Yan; Wang, Di; Liu, Yu; Qu, You-Yang; Zhu, Da-Ling; Zhu, Yu-Lan

2017-09-01

Angiogenesis promotes neurobehavioral recovery after cerebral ischemic stroke. 15(S)-hydroxyeicosatetraenoic acid (15-HETE) is one of the major metabolites of arachidonic acid by 15-lipoxygenase (15-LO) and stimulates the production of vascular endothelial growth factor (VEGF), thus, inducing autocrine-mediated angiogenesis. The present study aimed to investigate the role of 15-LO/15-HETE system on VEGF expression and angiogenesis in brain ischemia. Rat cerebral arterial vascular endothelial cells were used to set up a cell injury model of oxygen-glucose deprivation and reoxygenation (OGD/R), mimicking a condition of brain ischemia. A mouse model of middle cerebral artery occlusion (MCAO) was established. Oxygen-glucose deprivation increased cellular expression of 15-LO-1 and VEGF. Transfection of 15-LO-1 siRNA depleted cells of 15-LO-1, and sequentially induced downregulation of VEGF expression; while, incubation of 15-HETE increased the expression of VEGF. Incubation of 15-HETE attenuated the reduction in cell viability induced by oxygen-glucose deprivation, and promoted cell migration, while transfection of 15-LO-1 siRNA showed an opposite effect. In animal experiments, the density of microvessels in hypoxic regions of brains was significantly increased after MCAO, while intracerebroventricular delivery of 15-LO-1 siRNA significantly reduced the density of microvessels, and downregulates VEGF expression. The results indicate that the 15-LO-1/15-HETE system promotes angiogenesis in ischemic brains by upregulation of VEGF, representing a potential target for improving neurobehavioral recovery after cerebral ischemic stroke.

RhoE deficiency alters postnatal subventricular zone development and the number of calbindin-expressing neurons in the olfactory bulb of mouse.

PubMed

Ballester-Lurbe, Begoña; González-Granero, Susana; Mocholí, Enric; Poch, Enric; García-Manzanares, María; Dierssen, Mara; Pérez-Roger, Ignacio; García-Verdugo, José M; Guasch, Rosa M; Terrado, José

2015-11-01

The subventricular zone represents an important reservoir of progenitor cells in the adult brain. Cells from the subventricular zone migrate along the rostral migratory stream and reach the olfactory bulb, where they originate different types of interneurons. In this work, we have analyzed the role of the small GTPase RhoE/Rnd3 in subventricular zone cell development using mice-lacking RhoE expression. Our results show that RhoE null mice display a remarkable postnatal broadening of the subventricular zone and caudal rostral migratory stream. This broadening was caused by an increase in progenitor proliferation, observed in the second postnatal week but not before, and by an altered migration of the cells, which appeared in disorganized cell arrangements that impaired the appropriate contact between cells in the rostral migratory stream. In addition, the thickness of the granule cell layer in the olfactory bulb was reduced, although the density of granule cells did not differ between wild-type and RhoE null mice. Finally, the lack of RhoE expression affected the olfactory glomeruli inducing a severe reduction of calbindin-expressing interneurons in the periglomerular layer. This was already evident in the newborns and even more pronounced 15 days later when RhoE null mice displayed 89% less cells than control mice. Our results indicate that RhoE has pleiotropic functions on subventricular cells because of its role in proliferation and tangential migration, affecting mainly the development of calbindin-expressing cells in the olfactory bulb.

Are endogenous sex hormones related to DNA damage in paradoxically sleep-deprived female rats?

PubMed

Andersen, Monica L; Ribeiro, Daniel A; Alvarenga, Tathiana A; Silva, Andressa; Araujo, Paula; Zager, Adriano; Tenorio, Neuli M; Tufik, Sergio

2010-02-01

The aim of this investigation was to evaluate overall DNA damage induced by experimental paradoxical sleep deprivation (PSD) in estrous-cycling and ovariectomized female rats to examine possible hormonal involvement during DNA damage. Intact rats in different phases of the estrous cycle (proestrus, estrus, and diestrus) or ovariectomized female Wistar rats were subjected to PSD by the single platform technique for 96 h or were maintained for the equivalent period as controls in home-cages. After this period, peripheral blood and tissues (brain, liver, and heart) were collected to evaluate genetic damage using the single cell gel (comet) assay. The results showed that PSD caused extensive genotoxic effects in brain cells, as evident by increased DNA migration rates in rats exposed to PSD for 96 h when compared to negative control. This was observed for all phases of the estrous cycle indistinctly. In ovariectomized rats, PSD also led to DNA damage in brain cells. No significant statistically differences were detected in peripheral blood, the liver or heart for all groups analyzed. In conclusion, our data are consistent with the notion that genetic damage in the form of DNA breakage in brain cells induced by sleep deprivation overrides the effects related to endogenous female sex hormones. Copyright 2009 Elsevier Inc. All rights reserved.

Flt3L controls the development of radiosensitive dendritic cells in the meninges and choroid plexus of the steady-state mouse brain

PubMed Central

Anandasabapathy, Niroshana; Victora, Gabriel D.; Meredith, Matthew; Feder, Rachel; Dong, Baojun; Kluger, Courtney; Yao, Kaihui; Dustin, Michael L.; Nussenzweig, Michel C.; Steinman, Ralph M.

2011-01-01

Antigen-presenting cells in the disease-free brain have been identified primarily by expression of antigens such as CD11b, CD11c, and MHC II, which can be shared by dendritic cells (DCs), microglia, and monocytes. In this study, starting with the criterion of Flt3 (FMS-like receptor tyrosine kinase 3)-dependent development, we characterize the features of authentic DCs within the meninges and choroid plexus in healthy mouse brains. Analyses of morphology, gene expression, and antigen-presenting function established a close relationship between meningeal and choroid plexus DCs (m/chDCs) and spleen DCs. DCs in both sites shared an intrinsic requirement for Flt3 ligand. Microarrays revealed differences in expression of transcripts encoding surface molecules, transcription factors, pattern recognition receptors, and other genes in m/chDCs compared with monocytes and microglia. Migrating pre-DC progenitors from bone marrow gave rise to m/chDCs that had a 5–7-d half-life. In contrast to microglia, DCs actively present self-antigens and stimulate T cells. Therefore, the meninges and choroid plexus of a steady-state brain contain DCs that derive from local precursors and exhibit a differentiation and antigen-presenting program similar to spleen DCs and distinct from microglia. PMID:21788405

Flt3L controls the development of radiosensitive dendritic cells in the meninges and choroid plexus of the steady-state mouse brain.

PubMed

Anandasabapathy, Niroshana; Victora, Gabriel D; Meredith, Matthew; Feder, Rachel; Dong, Baojun; Kluger, Courtney; Yao, Kaihui; Dustin, Michael L; Nussenzweig, Michel C; Steinman, Ralph M; Liu, Kang

2011-08-01

Antigen-presenting cells in the disease-free brain have been identified primarily by expression of antigens such as CD11b, CD11c, and MHC II, which can be shared by dendritic cells (DCs), microglia, and monocytes. In this study, starting with the criterion of Flt3 (FMS-like receptor tyrosine kinase 3)-dependent development, we characterize the features of authentic DCs within the meninges and choroid plexus in healthy mouse brains. Analyses of morphology, gene expression, and antigen-presenting function established a close relationship between meningeal and choroid plexus DCs (m/chDCs) and spleen DCs. DCs in both sites shared an intrinsic requirement for Flt3 ligand. Microarrays revealed differences in expression of transcripts encoding surface molecules, transcription factors, pattern recognition receptors, and other genes in m/chDCs compared with monocytes and microglia. Migrating pre-DC progenitors from bone marrow gave rise to m/chDCs that had a 5-7-d half-life. In contrast to microglia, DCs actively present self-antigens and stimulate T cells. Therefore, the meninges and choroid plexus of a steady-state brain contain DCs that derive from local precursors and exhibit a differentiation and antigen-presenting program similar to spleen DCs and distinct from microglia.

From migration to settlement: the pathways, migration modes and dynamics of neurons in the developing brain

PubMed Central

HATANAKA, Yumiko; ZHU, Yan; TORIGOE, Makio; KITA, Yoshiaki; MURAKAMI, Fujio

2016-01-01

Neuronal migration is crucial for the construction of the nervous system. To reach their correct destination, migrating neurons choose pathways using physical substrates and chemical cues of either diffusible or non-diffusible nature. Migrating neurons extend a leading and a trailing process. The leading process, which extends in the direction of migration, determines navigation, in particular when a neuron changes its direction of migration. While most neurons simply migrate radially, certain neurons switch their mode of migration between radial and tangential, with the latter allowing migration to destinations far from the neurons’ site of generation. Consequently, neurons with distinct origins are intermingled, which results in intricate neuronal architectures and connectivities and provides an important basis for higher brain function. The trailing process, in contrast, contributes to the late stage of development by turning into the axon, thus contributing to the formation of neuronal circuits. PMID:26755396

Managing health worker migration: a qualitative study of the Philippine response to nurse brain drain

PubMed Central

2012-01-01

Background The emigration of skilled nurses from the Philippines is an ongoing phenomenon that has impacted the quality and quantity of the nursing workforce, while strengthening the domestic economy through remittances. This study examines how the development of brain drain-responsive policies is driven by the effects of nurse migration and how such efforts aim to achieve mind-shifts among nurses, governing and regulatory bodies, and public and private institutions in the Philippines and worldwide. Methods Interviews and focus group discussions were conducted to elicit exploratory perspectives on the policy response to nurse brain drain. Interviews with key informants from the nursing, labour and immigration sectors explored key themes behind the development of policies and programmes that respond to nurse migration. Focus group discussions were held with practising nurses to understand policy recipients’ perspectives on nurse migration and policy. Results Using the qualitative data, a thematic framework was created to conceptualize participants’ perceptions of how nurse migration has driven the policy development process. The framework demonstrates that policymakers have recognised the complexity of the brain drain phenomenon and are crafting dynamic policies and programmes that work to shift domestic and global mindsets on nurse training, employment and recruitment. Conclusions Development of responsive policy to Filipino nurse brain drain offers a glimpse into a domestic response to an increasingly prominent global issue. As a major source of professionals migrating abroad for employment, the Philippines has formalised efforts to manage nurse migration. Accordingly, the Philippine paradigm, summarised by the thematic framework presented in this paper, may act as an example for other countries that are experiencing similar shifts in healthcare worker employment due to migration. PMID:23249411

Why do primordial germ cells migrate through an embryo and what does it mean for biological evolution?

PubMed

Olovnikov, A M

2013-10-01

An explanation of the role of primordial germ cell (PGC) migration during embryogenesis is proposed. According to the hypothesis, various PGCs during their migrations through an early embryo are contacting with anlagen of organs and acquiring nonidentical organ specificities. An individual PGC gets such an organ specificity, which corresponds to specificity of the first anlage with which this PGC has the first contact. As a result, the cellular descendants of PGCs (oocytes or spermatocytes) will express nonidentical organ-specific receptors, hence becoming functionally heterogeneous. Therefore, each clone of germ cells becomes capable of recognizing specifically the molecular signals that correspond only to "its" organ of the body. Such signals are produced by the body's organ when it functions in an extreme mode. Signals from the "exercising" organ of the body are delivered to the gonad only via the brain retransmitter, which is composed of neurons grouped as virtual organs of a homunculus. Homunculi are so-called somatotopic maps of the skeletomotor and other parts of the body represented in the brain. Signals, as complexes of regulatory RNAs and proteins, are transported from the "exercising" organ of the body to the corresponding virtual organ of the homunculus where they are processed and then forwarded to the gonad. The organ-specific signal will be selectively recognized by certain gametocytes according to their organ specificity, and then it will initiate the directed epimutation in the gametocyte genome. The nonrandomness of the gene order in chromosomes, that is the synteny and genetic map, is controlled by the so-called creatron that consolidates the soma and germline into a united system, providing the possibility of evolutionary responses of an organism to environmental influences.

Hypoxia-induced expression of VE-cadherin and filamin B in glioma cell cultures and pseudopalisade structures.

PubMed

Nissou, Marie-France; El Atifi, Michèle; Guttin, Audrey; Godfraind, Catherine; Salon, Caroline; Garcion, Emmanuel; van der Sanden, Boudewijn; Issartel, Jean-Paul; Berger, François; Wion, Didier

2013-06-01

Most of our knowledge regarding glioma cell biology comes from cell culture experiments. For many years the standards for glioma cell culture were the use of cell lines cultured in the presence of serum and 20 % O2. However, in vivo, normoxia in many brain areas is in close to 3 % O2. Hence, in cell culture, the experimental value referred as the norm is hyperoxic compared to any brain physiological value. Likewise, cells in vivo are not usually exposed to serum, and low-passaged glioma neurosphere cultures maintained in serum-free medium is emerging as a new standard. A consequence of changing the experimental normoxic standard from 20 % O2 to the more brain physiological value of 3 % O2, is that a 3 % O2 normoxic reference point enabled a more rigorous characterization of the level of regulation of genes by hypoxia. Among the glioma hypoxia-regulated genes characterized using this approach we found VE-cadherin that is required for blood vessel formation, and filamin B a gene involved in endothelial cell motility. Both VE-cadherin and filamin B were found expressed in pseudopalisades, a glioblastoma pathognomonic structure made of hypoxic migrating cancer cells. These results provide additional clues on the role played by hypoxia in the acquisition of endothelial traits by glioma cells and on the functional links existing between pseudopalisades, hypoxia, and tumor progression.

Gold nanoparticle-cell labeling methodology for tracking stem cells within the brain

NASA Astrophysics Data System (ADS)

Betzer, Oshra; Meir, Rinat; Motiei, Menachem; Yadid, Gal; Popovtzer, Rachela

2017-02-01

Cell therapy provides a promising approach for diseases and injuries that conventional therapies cannot cure effectively. Mesenchymal stem cells (MSCs) can be used as effective targeted therapy, as they exhibit homing capabilities to sites of injury and inflammation, exert anti-inflammatory effects, and can differentiate in order to regenerate damaged tissue. Despite the potential efficacy of cell therapy, applying cell-based therapy in clinical practice is very challenging; there is a need to uncover the mystery regarding the fate of the transplanted cells. Therefore, in this study, we developed a method for longitudinal and quantitative in vivo cell tracking, based on the superior visualization abilities of classical X-ray computed tomography (CT), and combined with gold nanoparticles as labeling agents. We applied this technique for non-invasive imaging of MSCs transplanted in a rat model for depression, a highly prevalent and disabling neuropsychiatric disorder lacking effective treatment. Our results, which demonstrate that cell migration could be detected as early as 24 hours and up to one month post-transplantation, revealed that MSCs specifically navigated and homed to distinct depression related brain regions. This research further reveals that cell therapy is a beneficial approach for treating neuropsychiatric disorders; Behavioral manifestations of core symptoms of depressive behavior, were significantly attenuated following treatment. We expect This CT-based technique to lead to a significant enhancement in cellular therapy both for basic research and clinical applications of brain pathologies.

Ex Utero Electroporation and Organotypic Slice Cultures of Embryonic Mouse Brains for Live-Imaging of Migrating GABAergic Interneurons.

PubMed

Eid, Lara; Lachance, Mathieu; Hickson, Gilles; Rossignol, Elsa

2018-04-20

GABAergic interneurons (INs) are critical components of neuronal networks that drive cognition and behavior. INs destined to populate the cortex migrate tangentially from their place of origin in the ventral telencephalon (including from the medial and caudal ganglionic eminences (MGE, CGE)) to the dorsal cortical plate in response to a variety of intrinsic and extrinsic cues. Different methodologies have been developed over the years to genetically manipulate specific pathways and investigate how they regulate the dynamic cytoskeletal changes required for proper IN migration. In utero electroporation has been extensively used to study the effect of gene repression or overexpression in specific IN subtypes while assessing the impact on morphology and final position. However, while this approach is readily used to modify radially migrating pyramidal cells, it is more technically challenging when targeting INs. In utero electroporation generates a low yield given the decreased survival rates of pups when electroporation is conducted before e14.5, as is customary when studying MGE-derived INs. In an alternative approach, MGE explants provide easy access to the MGE and facilitate the imaging of genetically modified INs. However, in these explants, INs migrate into an artificial matrix, devoid of endogenous guidance cues and thalamic inputs. This prompted us to optimize a method where INs can migrate in a more naturalistic environment, while circumventing the technical challenges of in utero approaches. In this paper, we describe the combination of ex utero electroporation of embryonic mouse brains followed by organotypic slice cultures to readily track, image and reconstruct genetically modified INs migrating along their natural paths in response to endogenous cues. This approach allows for both the quantification of the dynamic aspects of IN migration with time-lapse confocal imaging, as well as the detailed analysis of various morphological parameters using neuronal reconstructions on fixed immunolabeled tissue.

Cryo-image Analysis of Tumor Cell Migration, Invasion, and Dispersal in a Mouse Xenograft Model of Human Glioblastoma Multiforme

PubMed Central

Qutaish, Mohammed Q.; Sullivant, Kristin E.; Burden-Gulley, Susan M.; Lu, Hong; Roy, Debashish; Wang, Jing; Basilion, James P.; Brady-Kalnay, Susann M.; Wilson, David L.

2012-01-01

Purpose The goals of this study were to create cryo-imaging methods to quantify characteristics (size, dispersal, and blood vessel density) of mouse orthotopic models of glioblastoma multiforme (GBM) and to enable studies of tumor biology, targeted imaging agents, and theranostic nanoparticles. Procedures Green fluorescent protein-labeled, human glioma LN-229 cells were implanted into mouse brain. At 20–38 days, cryo-imaging gave whole brain, 4-GB, 3D microscopic images of bright field anatomy, including vasculature, and fluorescent tumor. Image analysis/visualization methods were developed. Results Vessel visualization and segmentation methods successfully enabled analyses. The main tumor mass volume, the number of dispersed clusters, the number of cells/cluster, and the percent dispersed volume all increase with age of the tumor. Histograms of dispersal distance give a mean and median of 63 and 56 μm, respectively, averaged over all brains. Dispersal distance tends to increase with age of the tumors. Dispersal tends to occur along blood vessels. Blood vessel density did not appear to increase in and around the tumor with this cell line. Conclusion Cryo-imaging and software allow, for the first time, 3D, whole brain, microscopic characterization of a tumor from a particular cell line. LN-229 exhibits considerable dispersal along blood vessels, a characteristic of human tumors that limits treatment success. PMID:22125093

Group A Streptococcus intranasal infection promotes CNS infiltration by streptococcal-specific Th17 cells.

PubMed

Dileepan, Thamotharampillai; Smith, Erica D; Knowland, Daniel; Hsu, Martin; Platt, Maryann; Bittner-Eddy, Peter; Cohen, Brenda; Southern, Peter; Latimer, Elizabeth; Harley, Earl; Agalliu, Dritan; Cleary, P Patrick

2016-01-01

Group A streptococcal (GAS) infection induces the production of Abs that cross-react with host neuronal proteins, and these anti-GAS mimetic Abs are associated with autoimmune diseases of the CNS. However, the mechanisms that allow these Abs to cross the blood-brain barrier (BBB) and induce neuropathology remain unresolved. We have previously shown that GAS infection in mouse models induces a robust Th17 response in nasal-associated lymphoid tissue (NALT). Here, we identified GAS-specific Th17 cells in tonsils of humans naturally exposed to GAS, prompting us to explore whether GAS-specific CD4+ T cells home to mouse brains following i.n. infection. Intranasal challenge of repeatedly GAS-inoculated mice promoted migration of GAS-specific Th17 cells from NALT into the brain, BBB breakdown, serum IgG deposition, microglial activation, and loss of excitatory synaptic proteins under conditions in which no viable bacteria were detected in CNS tissue. CD4+ T cells were predominantly located in the olfactory bulb (OB) and in other brain regions that receive direct input from the OB. Together, these findings provide insight into the immunopathology of neuropsychiatric complications that are associated with GAS infections and suggest that crosstalk between the CNS and cellular immunity may be a general mechanism by which infectious agents exacerbate symptoms associated with other CNS autoimmune disorders.

Corridors of migrating neurons in the human brain and their decline during infancy.

PubMed

Sanai, Nader; Nguyen, Thuhien; Ihrie, Rebecca A; Mirzadeh, Zaman; Tsai, Hui-Hsin; Wong, Michael; Gupta, Nalin; Berger, Mitchel S; Huang, Eric; Garcia-Verdugo, Jose-Manuel; Rowitch, David H; Alvarez-Buylla, Arturo

2011-09-28

The subventricular zone of many adult non-human mammals generates large numbers of new neurons destined for the olfactory bulb. Along the walls of the lateral ventricles, immature neuronal progeny migrate in tangentially oriented chains that coalesce into a rostral migratory stream (RMS) connecting the subventricular zone to the olfactory bulb. The adult human subventricular zone, in contrast, contains a hypocellular gap layer separating the ependymal lining from a periventricular ribbon of astrocytes. Some of these subventricular zone astrocytes can function as neural stem cells in vitro, but their function in vivo remains controversial. An initial report found few subventricular zone proliferating cells and rare migrating immature neurons in the RMS of adult humans. In contrast, a subsequent study indicated robust proliferation and migration in the human subventricular zone and RMS. Here we find that the infant human subventricular zone and RMS contain an extensive corridor of migrating immature neurons before 18 months of age but, contrary to previous reports, this germinal activity subsides in older children and is nearly extinct by adulthood. Surprisingly, during this limited window of neurogenesis, not all new neurons in the human subventricular zone are destined for the olfactory bulb--we describe a major migratory pathway that targets the prefrontal cortex in humans. Together, these findings reveal robust streams of tangentially migrating immature neurons in human early postnatal subventricular zone and cortex. These pathways represent potential targets of neurological injuries affecting neonates.

Microglia in CNS development: Shaping the brain for the future.

PubMed

Mosser, Coralie-Anne; Baptista, Sofia; Arnoux, Isabelle; Audinat, Etienne

Microglial cells are the resident macrophages of the central nervous system (CNS) and are mainly known for their roles in neuropathologies. However, major recent developments have revealed that these immune cells actively interact with neurons in physiological conditions and can modulate the fate and functions of synapses. Originating from myeloid precursors born in the yolk sac, microglial cells invade the CNS during early embryonic development. As a consequence they can potentially influence neuronal proliferation, migration and differentiation as well as the formation and maturation of neuronal networks, thereby contributing to the entire shaping of the CNS. We review here recent evidence indicating that microglial cells are indeed involved in crucial steps of the CNS development, including neuronal survival and apoptosis, axonal growth, migration of neurons, pruning of supernumerary synapses and functional maturation of developing synapses. We also discuss current hypotheses proposing that diverting microglial cells of their physiological functions, by promoting the expression of an immune phenotype during development, may be central to neurodevelopmental disorders such as autism, schizophrenia and epilepsy. Copyright © 2017 Elsevier Ltd. All rights reserved.

The neural stem cell fate determinant TLX promotes tumorigenesis and genesis of cells resembling glioma stem cells.

PubMed

Park, Hyo-Jung; Kim, Jun-Kyum; Jeon, Hye-Min; Oh, Se-Yeong; Kim, Sung-Hak; Nam, Do-Hyun; Kim, Hyunggee

2010-11-01

A growing body of evidence indicates that deregulation of stem cell fate determinants is a hallmark of many types of malignancies. The neural stem cell fate determinant TLX plays a pivotal role in neurogenesis in the adult brain by maintaining neural stem cells. Here, we report a tumorigenic role of TLX in brain tumor initiation and progression. Increased TLX expression was observed in a number of glioma cells and glioma stem cells, and correlated with poor survival of patients with gliomas. Ectopic expression of TLX in the U87MG glioma cell line and Ink4a/Arf-deficient mouse astrocytes (Ink4a/Arf(-/-) astrocytes) induced cell proliferation with a concomitant increase in cyclin D expression, and accelerated foci formation in soft agar and tumor formation in in vivo transplantation assays. Furthermore, overexpression of TLX in Ink4a/Arf(-/-) astrocytes inhibited cell migration and invasion and promoted neurosphere formation and Nestin expression, which are hallmark characteristics of glioma stem cells, under stem cell culture conditions. Our results indicate that TLX is involved in glioma stem cell genesis and represents a potential therapeutic target for this type of malignancy.

A small-molecule antagonist of CXCR4 inhibits intracranial growth of primary brain tumors

NASA Astrophysics Data System (ADS)

Rubin, Joshua B.; Kung, Andrew L.; Klein, Robyn S.; Chan, Jennifer A.; Sun, Yanping; Schmidt, Karl; Kieran, Mark W.; Luster, Andrew D.; Segal, Rosalind A.

2003-11-01

The vast majority of brain tumors in adults exhibit glial characteristics. Brain tumors in children are diverse: Many have neuronal characteristics, whereas others have glial features. Here we show that activation of the Gi protein-coupled receptor CXCR4 is critical for the growth of both malignant neuronal and glial tumors. Systemic administration of CXCR4 antagonist AMD 3100 inhibits growth of intracranial glioblastoma and medulloblastoma xenografts by increasing apoptosis and decreasing the proliferation of tumor cells. This reflects the ability of AMD 3100 to reduce the activation of extracellular signal-regulated kinases 1 and 2 and Akt, all of which are pathways downstream of CXCR4 that promote survival, proliferation, and migration. These studies (i) demonstrate that CXCR4 is critical to the progression of diverse brain malignances and (ii) provide a scientific rationale for clinical evaluation of AMD 3100 in treating both adults and children with malignant brain tumors.

Amelioration of cerebellar dysfunction in rats following postnatal ethanol exposure using low-intensity pulsed ultrasound.

PubMed

Bolbanabad, Hiva Mohammadi; Anvari, Enayat; Rezai, Mohammad Jafar; Moayeri, Ardashir; Kaffashian, Mohammad Reza

2017-04-01

The neonatal development stage of the cerebellum in rats is equivalent to a human foetus in the third trimester of pregnancy. In this stage, cell proliferation, migration, differentiation, and synaptogenesis occur. Clinical and experimental findings have shown that ethanol exposure during brain development causes a variety of disruptions to the brain, including neurogenesis depression, delayed neuronal migration, changes in neurotransmitter synthesis, and neuronal depletion.During postnatal cerebellar development, neurons are more vulnerable to the destructive effects of ethanol. The effects of low-intensity pulsed ultrasound (LIPUS) on the number of cells and thickness of the cell layers within the cerebellar cortex were examined during the first two postnatal weeks in rats following postnatal ethanol exposure. Postpartum rats were distributed randomly into six groups. Normal saline was injected intraperitoneally into control animals and ethanol (20%) was injected into the intervention groups for three consecutive days. Intervention groups received LIPUS at different frequencies (3 or 5MHz), after administration of ethanol. After transcardial perfusion, the rat's brain was removed, and a complete series of sagittal cerebellum sections were obtained by systematic random manner. Photomicrographs were made with Motic digital cameras and analysed using Nikon digital software. The numbers of granular cells decreased in ethanol-treated rats compared to the control group. LIPUS, administered at (3 or 5MHz), combined with ethanol administration resulted in a reduction of ethanol's effects. Using 5MHz LIPUS resulted in significantly higher numbers of granular cells in the internal layer compared to the control rats. Using 3 or 5MHz LIPUS alone resulted in a significant enhancement in the granular cells of the molecular layer. A significant reduction was seen in the thickness of the external granular layer in ethanol-treated rats. This study showed that exposure to LIPUS can affect the number of granular cells and thickness of the cell layer within the cerebellar cortex in neonatal rats. LIPUS also could attenuate ethanol toxicity effects on the cerebellum. Copyright © 2017 Elsevier B.V. All rights reserved.

In vitro cyto-biocompatibility study of thin-film transistors substrates using an organotypic culture method.

PubMed

Leclerc, Eric; Duval, Jean-Luc; Egles, Christophe; Ihida, Satoshi; Toshiyoshi, Hiroshi; Tixier-Mita, Agnès

2017-01-01

Thin-Film-Transistors Liquid-Crystal Display has become a standard in the field of displays. However, the structure of these devices presents interest not only in that field, but also for biomedical applications. One of the key components, called here TFT substrate, is a glass substrate with a dense and large array of thousands of transparent micro-electrodes that can be considered as a large scale multi-electrode array(s). Multi-electrode array(s) are widely used for in vitro electrical investigations on neurons and brain, allowing excitation, registration, and recording of their activity. However, the range of application of conventional multi-electrode array(s) is usually limited to some tens of cells in a homogeneous cell culture, because of a small area, small number and a low density of the micro-electrodes. TFT substrates do not have these limitations and the authors are currently studying the possibility to use TFT substrates as new tools for in vitro electrical investigation on tissues and organoids. In this respect, experiments to determine the cyto-biocompatibility of TFT substrates with tissues were conducted and are presented in this study. The investigation was performed using an organotypic culture method with explants of brain and liver tissues of chick embryos. The results in term of morphology, cell migration, cell density and adhesion were compared with the results from Thermanox ® , a conventional plastic for cell culture, and with polydimethylsiloxane, a hydrophobic silicone. The results with TFT substrates showed similar results as for the Thermanox ® , despite the TFT hydrophobicity. TFT substrates have a weak cell adhesion and promote cell migration similarly to Thermanox ® . It could be concluded that the TFT substrates are cyto-biocompatible with the two studied organs.

Restructuring brain drain: strengthening governance and financing for health worker migration.

PubMed

Mackey, Tim K; Liang, Bryan A

2013-01-15

Health worker migration from resource-poor countries to developed countries, also known as ''brain drain'', represents a serious global health crisis and a significant barrier to achieving global health equity. Resource-poor countries are unable to recruit and retain health workers for domestic health systems, resulting in inadequate health infrastructure and millions of dollars in healthcare investment losses. Using acceptable methods of policy analysis, we first assess current strategies aimed at alleviating brain drain and then propose our own global health policy based solution to address current policy limitations. Although governments and private organizations have tried to address this policy challenge, brain drain continues to destabilise public health systems and their populations globally. Most importantly, lack of adequate financing and binding governance solutions continue to fail to prevent health worker brain drain. In response to these challenges, the establishment of a Global Health Resource Fund in conjunction with an international framework for health worker migration could create global governance for stable funding mechanisms encourage equitable migration pathways, and provide data collection that is desperately needed.

Restructuring brain drain: strengthening governance and financing for health worker migration

PubMed Central

Mackey, Tim K.; Liang, Bryan A.

2013-01-01

Background Health worker migration from resource-poor countries to developed countries, also known as ‘‘brain drain’’, represents a serious global health crisis and a significant barrier to achieving global health equity. Resource-poor countries are unable to recruit and retain health workers for domestic health systems, resulting in inadequate health infrastructure and millions of dollars in healthcare investment losses. Methods Using acceptable methods of policy analysis, we first assess current strategies aimed at alleviating brain drain and then propose our own global health policy based solution to address current policy limitations. Results Although governments and private organizations have tried to address this policy challenge, brain drain continues to destabilise public health systems and their populations globally. Most importantly, lack of adequate financing and binding governance solutions continue to fail to prevent health worker brain drain. Conclusions In response to these challenges, the establishment of a Global Health Resource Fund in conjunction with an international framework for health worker migration could create global governance for stable funding mechanisms encourage equitable migration pathways, and provide data collection that is desperately needed. PMID:23336617

Induced neural stem cells achieve long-term survival and functional integration in the adult mouse brain.

PubMed

Hemmer, Kathrin; Zhang, Mingyue; van Wüllen, Thea; Sakalem, Marna; Tapia, Natalia; Baumuratov, Aidos; Kaltschmidt, Christian; Kaltschmidt, Barbara; Schöler, Hans R; Zhang, Weiqi; Schwamborn, Jens C

2014-09-09

Differentiated cells can be converted directly into multipotent neural stem cells (i.e., induced neural stem cells [iNSCs]). iNSCs offer an attractive alternative to induced pluripotent stem cell (iPSC) technology with regard to regenerative therapies. Here, we show an in vivo long-term analysis of transplanted iNSCs in the adult mouse brain. iNSCs showed sound in vivo long-term survival rates without graft overgrowths. The cells displayed a neural multilineage potential with a clear bias toward astrocytes and a permanent downregulation of progenitor and cell-cycle markers, indicating that iNSCs are not predisposed to tumor formation. Furthermore, the formation of synaptic connections as well as neuronal and glial electrophysiological properties demonstrated that differentiated iNSCs migrated, functionally integrated, and interacted with the existing neuronal circuitry. We conclude that iNSC long-term transplantation is a safe procedure; moreover, it might represent an interesting tool for future personalized regenerative applications. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

miR-137 forms a regulatory loop with nuclear receptor TLX and LSD1 in neural stem cells

PubMed Central

Sun, GuoQiang; Ye, Peng; Murai, Kiyohito; Lang, Ming-Fei; Li, Shengxiu; Zhang, Heying; Li, Wendong; Fu, Chelsea; Yin, Jason; Wang, Allen; Ma, Xiaoxiao; Shi, Yanhong

2012-01-01

miR-137 is a brain-enriched microRNA. Its role in neural development remains unknown. Here we show that miR-137 plays an essential role in controlling embryonic neural stem cell fate determination. miR-137 negatively regulates cell proliferation and accelerates neural differentiation of embryonic neural stem cells. In addition, we show that histone demethylase LSD1, a transcriptional co-repressor of nuclear receptor TLX, is a downstream target of miR-137. In utero electroporation of miR-137 in embryonic mouse brains led to premature differentiation and outward migration of the transfected cells. Introducing a LSD1 expression vector lacking the miR-137 recognition site rescued miR-137-induced precocious differentiation. Furthermore, we demonstrate that TLX, an essential regulator of neural stem cell self-renewal, represses the expression of miR-137 by recruiting LSD1 to the genomic regions of miR-137. Thus, miR-137 forms a feedback regulatory loop with TLX and LSD1 to control the dynamics between neural stem cell proliferation and differentiation during neural development. PMID:22068596

The Nedd4 binding protein 3 is required for anterior neural development in Xenopus laevis.

PubMed

Kiem, Lena-Maria; Dietmann, Petra; Linnemann, Alexander; Schmeisser, Michael J; Kühl, Susanne J

2017-03-01

The Fezzin family member Nedd4-binding protein 3 (N4BP3) is known to regulate axonal and dendritic branching. Here, we show that n4bp3 is expressed in the neural tissue of the early Xenopus laevis embryo including the eye, the brain and neural crest cells. Knockdown of N4bp3 in the Xenopus anterior neural tissue results in severe developmental impairment of the eye, the brain and neural crest derived cranial cartilage structures. Moreover, we demonstrate that N4bp3 depletion leads to a significant reduction of both eye and brain specific marker genes and reduced neural crest cell migration. Finally, we demonstrate an impact of N4bp3 deficiency on cell apoptosis and proliferation. Our studies indicate that N4bp3 is required for early anterior neural development of vertebrates. This is in line with a study implicating that genetic disruption of N4BP3 in humans might be related to neurodevelopmental disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Moving messages in the developing brain—emerging roles for mRNA transport and local translation in neural stem cells

PubMed Central

Pilaz, Louis-Jan; Silver, Debra L.

2017-01-01

The mammalian cerebral cortex is a complex brain structure integral to our higher cognition. During embryonic cortical development, radial glial progenitors (RGCs) produce neurons and serve as physical structures for migrating neurons. Recent discoveries highlight new roles for RNA localization and local translation in RGCs, both at the cell body and at distal structures called basal endfeet. By implementing technologies from the field of RNA research to brain development, investigators can manipulate RNA-binding proteins as well as visualize single-molecule RNAs, live movement of mRNAs and their binding proteins, and translation. Going forward, these studies establish a framework for investigating how post-transcriptional RNA regulation helps shape RGC function and triggers neurodevelopmental diseases. PMID:28304078

Aquaporins: important but elusive drug targets

PubMed Central

Verkman, Alan S.; Anderson, Marc O.; Papadopoulos, Marios C.

2014-01-01

The aquaporins (AQPs) are a family of small, integral membrane proteins that facilitate water transport across the plasma membranes of cells in response to osmotic gradients. Data from knockout mice support the involvement of AQPs in epithelial fluid secretion, cell migration, brain oedema and adipocyte metabolism, which suggests that modulation of AQP function or expression could have therapeutic potential in oedema, cancer, obesity, brain injury, glaucoma and several other conditions. Moreover, loss-of-function mutations in human AQPs cause congenital cataracts (AQP0) and nephrogenic diabetes insipidus (AQP2), and autoantibodies against AQP4 cause the autoimmune demyelinating disease neuromyelitis optica. Although some potential AQP modulators have been identified, challenges associated with the development of better modulators include the druggability of the target and the suitability of the assay methods used to identify modulators. PMID:24625825

Galectin-3 enhances angiogenic and migratory potential of microglial cells via modulation of integrin linked kinase signaling

PubMed Central

Wesley, Umadevi V.; Vemuganti, Raghu; Ayvaci, Rabia; Dempsey, Robert J.

2013-01-01

Focal cerebral ischemia initiates self-repair mechanisms that include the production of neurotrophic factors and cytokines. Galectin-3 is an important angiogenic cytokine. We have previously demonstrated that expression of galectin 3 (Gal-3), a carbohydrate binding protein is significantly upregulated in activated microglia in the brains of rats subjected to focal ischemia. Further blocking of Gal-3 function with Gal-3 neutralizing antibody decreased the microvessel density in ischemic brain. We currently show that Gal-3 significantly increases the viability of microglia BV2 cells subjected to oxygen glucose deprivation (OGD) and re-oxygenation. Exogenous Gal-3 promoted the formation of pro-angiogenic structures in an in vitro human umbilical vein endothelial (HUVEC) and BV2 cell co-culture model. Gal-3 induced angiogenesis was associated with increased expression of vascular endothelial growth factor. The conditioned medium of BV2 cells exposed to OGD contained increased Gal-3 levels, and promoted the formation of pro-angiogenic structures in an in vitro HUVEC culture model. Gal-3 also augmented the in vitro migratory potential of BV2 microglia. Gal-3 mediated functions were associated with increased levels of integrin-linked kinase (ILK) signaling as demonstrated by the impaired angiogenesis and migration of BV2 cells following targeted silencing of ILK expression by SiRNA. Furthermore, we show that ILK levels correlate with the levels of phos-AKT and ERK1/2 that are downstream effectors of ILK pathway. Taken together, our studies indicate that Gal-3 contributes to angiogenesis and microglia migration that may have implications in post stroke repair. PMID:23246924

miR-135b suppresses tumorigenesis in glioblastoma stem-like cells impairing proliferation, migration and self-renewal.

PubMed

Lulli, Valentina; Buccarelli, Mariachiara; Martini, Maurizio; Signore, Michele; Biffoni, Mauro; Giannetti, Stefano; Morgante, Liliana; Marziali, Giovanna; Ilari, Ramona; Pagliuca, Alfredo; Larocca, Luigi Maria; De Maria, Ruggero; Pallini, Roberto; Ricci-Vitiani, Lucia

2015-11-10

Glioblastoma multiforme (GBM) is the most common and fatal malignant adult primary brain tumor. Currently, the overall prognosis for GBM patients remains poor despite advances in neurosurgery and adjuvant treatments. MicroRNAs (miRNAs) contribute to the pathogenesis of various types of tumor, including GBM. In this study we analyzed the expression of a panel of miRNAs, which are known to be differentially expressed by the brain and GBM tumor, in a collection of patient-derived GBM stem-like cells (GSCs). Notably, the average expression level of miR-135b, was the most downregulated compared to its normal counterpart, suggesting a potential role as anti-oncogene.Restoration of miR-135b in GSCs significantly decreased proliferation, migration and clonogenic abilities. More importantly, miR-135b restoration was able to significantly reduce brain infiltration in mouse models of GBM obtained by intracerebral injection of GSC lines. We identified ADAM12 and confirmed SMAD5 and GSK3β as miR-135b targets and potential mediators of its effects. The whole transcriptome analysis ascertained that the expression of miR-135b downmodulated additional genes driving key pathways in GBM survival and infiltration capabilities.Our results identify a critical role of miR-135b in the regulation of GBM development, suggesting that miR-135b might act as a tumor-suppressor factor and thus providing a potential candidate for the treatment of GBM patients.

Evolution and development of the mammalian cerebral cortex.

PubMed

Molnár, Zoltán; Kaas, Jon H; de Carlos, Juan A; Hevner, Robert F; Lein, Ed; Němec, Pavel

2014-01-01

Comparative developmental studies of the mammalian brain can identify key changes that can generate the diverse structures and functions of the brain. We have studied how the neocortex of early mammals became organized into functionally distinct areas, and how the current level of cortical cellular and laminar specialization arose from the simpler premammalian cortex. We demonstrate the neocortical organization in early mammals, which helps to elucidate how the large, complex human brain evolved from a long line of ancestors. The radial and tangential enlargement of the cortex was driven by changes in the patterns of cortical neurogenesis, including alterations in the proportions of distinct progenitor types. Some cortical cell populations travel to the cortex through tangential migration whereas others migrate radially. A number of recent studies have begun to characterize the chick, mouse and human and nonhuman primate cortical transcriptome to help us understand how gene expression relates to the development and anatomical and functional organization of the adult neocortex. Although all mammalian forms share the basic layout of cortical areas, the areal proportions and distributions are driven by distinct evolutionary pressures acting on sensory and motor experiences during the individual ontogenies. © 2014 S. Karger AG, Basel.

Progranulin Is a Chemoattractant for Microglia and Stimulates Their Endocytic Activity

PubMed Central

Pickford, Fiona; Marcus, Jacob; Camargo, Luiz Miguel; Xiao, Qiurong; Graham, Danielle; Mo, Jan-Rung; Burkhardt, Matthew; Kulkarni, Vinayak; Crispino, Jamie; Hering, Heike; Hutton, Michael

2011-01-01

Mutations resulting in progranulin haploinsufficiency cause disease in patients with a subset of frontotemporal lobar degeneration; however, the biological functions of progranulin in the brain remain unknown. To address this subject, the present study initially assessed changes in gene expression and cytokine secretion in rat primary cortical neurons treated with progranulin. Molecular pathways enriched in the progranulin gene set included cell adhesion and cell motility pathways and pathways involved in growth and development. Secretion of cytokines and several chemokines linked to chemoattraction but not inflammation were also increased from progranulin-treated primary neurons. Therefore, whether progranulin is involved in recruitment of immune cells in the brain was investigated. Localized lentiviral expression of progranulin in C57BL/6 mice resulted in an increase of Iba1-positive microglia around the injection site. Moreover, progranulin alone was sufficient to promote migration of primary mouse microglia in vitro. Primary microglia and C4B8 cells demonstrated more endocytosis of amyloid β1-42 when treated with progranulin. These data demonstrate that progranulin acts as a chemoattractant in the brain to recruit or activate microglia and can increase endocytosis of extracellular peptides such as amyloid β. PMID:21224065

PCDH10 is required for the tumorigenicity of glioblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Echizen, Kanae; Nakada, Mitsutoshi, E-mail: mnakada@med.kanazawa-u.ac.jp; Hayashi, Tomoatsu

Highlights: • PCDH10 is required for the proliferation, survival and self-renewal of glioblastoma cells. • PCDH10 is required for glioblastoma cell migration and invasion. • PCDH10 is required for the tumorigenicity of glioblastoma cells. • PCDH10 may be a promising target for the therapy of glioblastoma. - Abstract: Protocadherin10 (PCDH10)/OL-protocadherin is a cadherin-related transmembrane protein that has multiple roles in the brain, including facilitating specific cell–cell connections, cell migration and axon guidance. It has recently been reported that PCDH10 functions as a tumor suppressor and that its overexpression inhibits proliferation or invasion of multiple tumor cells. However, the function ofmore » PCDH10 in glioblastoma cells has not been elucidated. In contrast to previous reports on other tumors, we show here that suppression of the expression of PCDH10 by RNA interference (RNAi) induces the growth arrest and apoptosis of glioblastoma cells in vitro. Furthermore, we demonstrate that knockdown of PCDH10 inhibits the growth of glioblastoma cells xenografted into immunocompromised mice. These results suggest that PCDH10 is required for the proliferation and tumorigenicity of glioblastoma cells. We speculate that PCDH10 may be a promising target for the therapy of glioblastoma.« less

Expression of membrane progesterone receptors (mPRs) in rat peripheral glial cell membranes and their potential role in the modulation of cell migration and protein expression.

PubMed

Castelnovo, Luca F; Magnaghi, Valerio; Thomas, Peter

2017-09-28

The role played by progestogens in modulating Schwann cell pathophysiology is well established. Progestogens exert their effects in these cells through both classical genomic and non-genomic mechanisms, the latter mediated by the GABA-A receptor. However, there is evidence that other receptors may be involved. Membrane progesterone receptors (mPRs) are novel 7-transmembrane receptors coupled to G proteins that have been characterized in different tissues and cells, including the central nervous system (CNS). The mPRs were shown to mediate some of progestogens' neuroprotective effects in the CNS, and to be upregulated in glial cells after traumatic brain injury. Based on this evidence, this paper investigated the possible involvement of mPRs in mediating progestogen actions in S42 Schwann cells. All five mPR isoforms and progesterone receptor membrane component 1 (PGRMC1) were detected in Schwann cells, and were present on the cell membrane. Progesterone and the mPR-specific agonist, Org-OD-02-0 (02) bound to these membranes, indicating the presence of functional mPRs. The mPR agonist 02 rapidly increased cell migration in an in vitro assay, suggesting a putative role of mPRs in the nerve regeneration process. Treatment with pertussis toxin and 8-Br-cAMP blocked 02-induced cell migration, suggesting this progestogen action is mediated by activation of an inhibitory G protein, leading to a decrease in intracellular cAMP levels. In contrast, long-term mPR activation led to increased expression levels of myelin associated glycoprotein (MAG). Taken together, these findings show that mPRs are present and active in Schwann cells and have a role in modulating their physiological processes. Copyright © 2017 Elsevier Inc. All rights reserved.

miR-221/222 overexpession in human glioblastoma increases invasiveness by targeting the protein phosphate PTPμ

PubMed Central

Quintavalle, C; Garofalo, M; Zanca, C; Romano, G; Iaboni, M; De Caro, M del Basso; Martinez-Montero, JC; Incoronato, M; Nuovo, G; Croce, CM; Condorelli, G

2015-01-01

Glioblastoma is the most frequent brain tumor in adults and is the most lethal form of human cancer. Despite the improvements in treatments, survival of patients remains poor. In order to identify microRNAs (miRs) involved in glioma tumorigenesis, we evaluated, by a miRarray, differential expression of miRs in the tumorigenic glioma LN-18, LN-229 and U87MG cells compared with the non-tumorigenic T98G cells. Among different miRs we focused our attention on miR-221 and -222. We demonstrated the presence of a binding site for these two miRs in the 3′ untranslated region of the protein tyrosine phosphatase μ (PTPμ). Previous studies indicated that PTPμ suppresses cell migration and is downregulated in glioblastoma. Significantly, we found that miR-221 and -222 over-expression induced a downregulation of PTPμ as analyzed by both western blot and real-time PCR. Furthermore, miR-222 and -221 induced an increase in cell migration and growth in soft agar in glioma cells. Interestingly, the re-expression of PTPμ gene was able to revert the miR-222 and -221 effects on cell migration. Furthermore, we found an inverse correlation between miR-221 and -222 and PTPμ in human glioma cancer samples. In conclusion, our results suggest that miR-221 and -222 regulate glioma tumorigenesis at least in part through the control of PTPμ protein expression. PMID:21743492

Neuroinflammation Induced by Intracerebroventricular Injection of Microbial Neuraminidase

PubMed Central

Granados-Durán, Pablo; López-Ávalos, María D.; Grondona, Jesús M.; Gómez-Roldán, María del Carmen; Cifuentes, Manuel; Pérez-Martín, Margarita; Alvarez, Martina; Rodríguez de Fonseca, Fernando; Fernández-Llebrez, Pedro

2015-01-01

In the present paper, we describe the facts that took place in the rat brain after a single injection of the enzyme neuraminidase from Clostridium perfringens into the right lateral ventricle. After injection, it diffused through the cerebrospinal fluid of the ipsilateral ventricle and the third ventricle, and about 400 μm into the periventricular brain parenchyma. The expression of ICAM1 in the endothelial cells of the periventricular vessels, IBA1 in microglia, and GFAP in astrocytes notably increased in the regions reached by the injected neuraminidase. The subependymal microglia and the ventricular macrophages begun to express IL1β and some appeared to cross the ependymal layer. After about 4 h of the injection, leukocytes migrated from large venules of the affected choroid plexus, the meninges and the local subependyma, and infiltrated the brain. The invading cells arrived orderly: first neutrophils, then macrophage-monocytes, and last CD8α-positive T-lymphocytes and B-lymphocytes. Leukocytes in the ventricles and the perivascular zones penetrated the brain parenchyma passing through the ependyma and the glia limitans. Thus, it is likely that a great part of the damage produced by microorganism invading the brain may be due to their neuraminidase content. PMID:25853134

Neuroinflammation induced by intracerebroventricular injection of microbial neuraminidase.

PubMed

Granados-Durán, Pablo; López-Ávalos, María D; Grondona, Jesús M; Gómez-Roldán, María Del Carmen; Cifuentes, Manuel; Pérez-Martín, Margarita; Alvarez, Martina; Rodríguez de Fonseca, Fernando; Fernández-Llebrez, Pedro

2015-01-01

In the present paper, we describe the facts that took place in the rat brain after a single injection of the enzyme neuraminidase from Clostridium perfringens into the right lateral ventricle. After injection, it diffused through the cerebrospinal fluid of the ipsilateral ventricle and the third ventricle, and about 400 μm into the periventricular brain parenchyma. The expression of ICAM1 in the endothelial cells of the periventricular vessels, IBA1 in microglia, and GFAP in astrocytes notably increased in the regions reached by the injected neuraminidase. The subependymal microglia and the ventricular macrophages begun to express IL1β and some appeared to cross the ependymal layer. After about 4 h of the injection, leukocytes migrated from large venules of the affected choroid plexus, the meninges and the local subependyma, and infiltrated the brain. The invading cells arrived orderly: first neutrophils, then macrophage-monocytes, and last CD8α-positive T-lymphocytes and B-lymphocytes. Leukocytes in the ventricles and the perivascular zones penetrated the brain parenchyma passing through the ependyma and the glia limitans. Thus, it is likely that a great part of the damage produced by microorganism invading the brain may be due to their neuraminidase content.

Myosin II Motors and F-Actin Dynamics Drive the Coordinated Movement of the Centrosome and Soma during CNS Glial-Guided Neuronal Migration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solecki, Dr. David; Trivedi, Dr. Niraj; Govek, Eve-Ellen

2009-01-01

Lamination of cortical regions of the vertebrate brain depends on glial-guided neuronal migration. The conserved polarity protein Par6{alpha} localizes to the centrosome and coordinates forward movement of the centrosome and soma in migrating neurons. The cytoskeletal components that produce this unique form of cell polarity and their relationship to polarity signaling cascades are unknown. We show that F-actin and Myosin II motors are enriched in the neuronal leading process and that Myosin II activity is necessary for leading process actin dynamics. Inhibition of Myosin II decreased the speed of centrosome and somal movement, whereas Myosin II activation increased coordinated movement.more » Ectopic expression or silencing of Par6{alpha} inhibited Myosin II motors by decreasing Myosin light-chain phosphorylation. These findings suggest leading-process Myosin II may function to 'pull' the centrosome and soma forward during glial-guided migration by a mechanism involving the conserved polarity protein Par6{alpha}.« less

Toward a 3D model of human brain development for studying gene/environment interactions

PubMed Central

2013-01-01

This project aims to establish and characterize an in vitro model of the developing human brain for the purpose of testing drugs and chemicals. To accurately assess risk, a model needs to recapitulate the complex interactions between different types of glial cells and neurons in a three-dimensional platform. Moreover, human cells are preferred over cells from rodents to eliminate cross-species differences in sensitivity to chemicals. Previously, we established conditions to culture rat primary cells as three-dimensional aggregates, which will be humanized and evaluated here with induced pluripotent stem cells (iPSCs). The use of iPSCs allows us to address gene/environment interactions as well as the potential of chemicals to interfere with epigenetic mechanisms. Additionally, iPSCs afford us the opportunity to study the effect of chemicals during very early stages of brain development. It is well recognized that assays for testing toxicity in the developing brain must consider differences in sensitivity and susceptibility that arise depending on the time of exposure. This model will reflect critical developmental processes such as proliferation, differentiation, lineage specification, migration, axonal growth, dendritic arborization and synaptogenesis, which will probably display differences in sensitivity to different types of chemicals. Functional endpoints will evaluate the complex cell-to-cell interactions that are affected in neurodevelopment through chemical perturbation, and the efficacy of drug intervention to prevent or reverse phenotypes. The model described is designed to assess developmental neurotoxicity effects on unique processes occurring during human brain development by leveraging human iPSCs from diverse genetic backgrounds, which can be differentiated into different cell types of the central nervous system. Our goal is to demonstrate the feasibility of the personalized model using iPSCs derived from individuals with neurodevelopmental disorders caused by known mutations and chromosomal aberrations. Notably, such a human brain model will be a versatile tool for more complex testing platforms and strategies as well as research into central nervous system physiology and pathology. PMID:24564953

Identification of a novel synaptic protein, TMTC3, involved in periventricular nodular heterotopia with intellectual disability and epilepsy

PubMed Central

Farhan, Sali M K; Nixon, Kevin C J; Everest, Michelle; Edwards, Tara N; Long, Shirley; Segal, Dmitri; Knip, Maria J; Arts, Heleen H; Chakrabarti, Rana; Wang, Jian; Robinson, John F; Lee, Donald; Mirsattari, Seyed M; Rupar, C Anthony; Siu, Victoria M; Poulter, Michael O; Hegele, Robert A; Kramer, Jamie M

2017-01-01

Abstract Defects in neuronal migration cause brain malformations, which are associated with intellectual disability (ID) and epilepsy. Using exome sequencing, we identified compound heterozygous variants (p.Arg71His and p. Leu729ThrfsTer6) in TMTC3, encoding transmembrane and tetratricopeptide repeat containing 3, in four siblings with nocturnal seizures and ID. Three of the four siblings have periventricular nodular heterotopia (PVNH), a common brain malformation caused by failure of neurons to migrate from the ventricular zone to the cortex. Expression analysis using patient-derived cells confirmed reduced TMTC3 transcript levels and loss of the TMTC3 protein compared to parental and control cells. As TMTC3 function is currently unexplored in the brain, we gathered support for a neurobiological role for TMTC3 by generating flies with post-mitotic neuron-specific knockdown of the highly conserved Drosophila melanogaster TMTC3 ortholog, CG4050/tmtc3. Neuron-specific knockdown of tmtc3 in flies resulted in increased susceptibility to induced seizures. Importantly, this phenotype was rescued by neuron-specific expression of human TMTC3, suggesting a role for TMTC3 in seizure biology. In addition, we observed co-localization of TMTC3 in the rat brain with vesicular GABA transporter (VGAT), a presynaptic marker for inhibitory synapses. TMTC3 is localized at VGAT positive pre-synaptic terminals and boutons in the rat hypothalamus and piriform cortex, suggesting a role for TMTC3 in the regulation of GABAergic inhibitory synapses. TMTC3 did not co-localize with Vglut2, a presynaptic marker for excitatory neurons. Our data identified TMTC3 as a synaptic protein that is involved in PVNH with ID and epilepsy, in addition to its previously described association with cobblestone lissencephaly. PMID:28973161

Identification of a novel synaptic protein, TMTC3, involved in periventricular nodular heterotopia with intellectual disability and epilepsy.

PubMed

Farhan, Sali M K; Nixon, Kevin C J; Everest, Michelle; Edwards, Tara N; Long, Shirley; Segal, Dmitri; Knip, Maria J; Arts, Heleen H; Chakrabarti, Rana; Wang, Jian; Robinson, John F; Lee, Donald; Mirsattari, Seyed M; Rupar, C Anthony; Siu, Victoria M; Poulter, Michael O; Hegele, Robert A; Kramer, Jamie M

2017-11-01

Defects in neuronal migration cause brain malformations, which are associated with intellectual disability (ID) and epilepsy. Using exome sequencing, we identified compound heterozygous variants (p.Arg71His and p. Leu729ThrfsTer6) in TMTC3, encoding transmembrane and tetratricopeptide repeat containing 3, in four siblings with nocturnal seizures and ID. Three of the four siblings have periventricular nodular heterotopia (PVNH), a common brain malformation caused by failure of neurons to migrate from the ventricular zone to the cortex. Expression analysis using patient-derived cells confirmed reduced TMTC3 transcript levels and loss of the TMTC3 protein compared to parental and control cells. As TMTC3 function is currently unexplored in the brain, we gathered support for a neurobiological role for TMTC3 by generating flies with post-mitotic neuron-specific knockdown of the highly conserved Drosophila melanogaster TMTC3 ortholog, CG4050/tmtc3. Neuron-specific knockdown of tmtc3 in flies resulted in increased susceptibility to induced seizures. Importantly, this phenotype was rescued by neuron-specific expression of human TMTC3, suggesting a role for TMTC3 in seizure biology. In addition, we observed co-localization of TMTC3 in the rat brain with vesicular GABA transporter (VGAT), a presynaptic marker for inhibitory synapses. TMTC3 is localized at VGAT positive pre-synaptic terminals and boutons in the rat hypothalamus and piriform cortex, suggesting a role for TMTC3 in the regulation of GABAergic inhibitory synapses. TMTC3 did not co-localize with Vglut2, a presynaptic marker for excitatory neurons. Our data identified TMTC3 as a synaptic protein that is involved in PVNH with ID and epilepsy, in addition to its previously described association with cobblestone lissencephaly. © The Author 2017. Published by Oxford University Press.

The LHRH-astroglial network of signals as a model to study neuroimmune interactions: assessment of messenger systems and transduction mechanisms at cellular and molecular levels.

PubMed

Marchetti, B

1996-01-01

Neurons and astrocytes have a close anatomic and functional relationship that plays a crucial role during development and in the adult brain. Astrocytes in the central nervous system (CNS) express receptors for a variety of growth factors (GFs), neurotransmitters and/or neuromodulators; in turn, neuronal cells can respond to astrocyte-derived GFs and control astrocyte function via a common set of signaling molecules and intracellular transducing pathways. There is also increasing evidence that soluble factors from lymphoid/mononuclear cells are able to modulate the growth and function of cells found in the CNS, specifically macroglial and microglial cells. Furthermore, glial cells can secrete immunoregulatory molecules that influence immune cells as well as the glial cells themselves. As neuronal and immune cells share common signaling systems, the potential exists for bidirectional communication not only between lymphoid and glial cells, but also between neuronal cells and immune and glial cells. In the present work, interactions of luteinizing-hormone-releasing hormone (LHRH) and the astroglial cell are proposed as a prototype for the study of neuroimmune communication within the CNS in the light of (1) the commonality of signal molecules (hormones, neurotransmitters and cytokines) and transduction mechanisms shared by glia LHRH neurons and lymphoid cells; (2) the central role of glia in the developmental organization and pattern of LHRH neuronal migration during embryogenesis, and (3) the strong modulatory role played by sex steroids in mechanisms involved in synaptic and interneuronal organization, as well as in the sexual dimorphisms of neuroendocrine-immune functions. During their maturation and differentiation in vitro, astroglial cells release factors able to accelerate markedly the LHRH neuronal phenotypic differentiation as well as the acquisition of mature LHRH secretory potential, with a potency depending on both the 'age' and the specific brain localization of the astroglia, as well as the degree of LHRH neuronal differentiation in vitro. Regional differences in astroglial sensitivity to estrogens were also measured. Different experimental paradigms such as coculture and mixed-culture models between the immortalized LHRH (GT1-1) neuronal cell line and astroglial cells in primary culture, disclosed the presence of a bidirectional flow of informational molecules regulating both proliferative and secretory capacities of each cell type. The importance of adhesive mechanisms in such cross-talk is underscored by the complete abolition of GT1-1 LHRH production and cell proliferation following the counteraction of neuronal-neuronal/neuronal-glial interactions through addition of neural-cell adhesion molecule antiserum. Other information came from pharmacological experiments manipulating the astroglia-derived cytokines and/or nitric oxide, which revealed cross-talk between the neuronal and astroglial compartments. From the bulk of this information, it seems likely that interactions between astroglia and LHRH neurons play a major role in the integration of the multiplicity of brain signals converging on the LHRH neurons that govern reproduction. Another important facet of neuronal-glial interactions is that concerning neuron-guided migration, and unraveling astroglial/LHRH-neuronal networks might then constitute an additional effort in the comprehension of defective LHRH-neuronal migration in Kallman's syndrome.

Pathophysiological analyses of leptomeningeal heterotopia using gyrencephalic mammals.

PubMed

Matsumoto, Naoyuki; Kobayashi, Naoki; Uda, Natsu; Hirota, Miwako; Kawasaki, Hiroshi

2018-03-15

Leptomeningeal glioneuronal heterotopia (LGH) is a focal malformation of the cerebral cortex and frequently found in patients with thanatophoric dysplasia (TD). The pathophysiological mechanisms underlying LGH formation are still largely unclear because of difficulties in obtaining brain samples from human TD patients. Recently, we established a new animal model for analysing cortical malformations of human TD by utilizing our genetic manipulation technique for gyrencephalic carnivore ferrets. Here we investigated the pathophysiological mechanisms underlying the formation of LGH using our TD ferrets. We found that LGH was formed during corticogenesis in TD ferrets. Interestingly, we rarely found Ki-67-positive and phospho-histone H3-positive cells in LGH, suggesting that LGH formation does not involve cell proliferation. We uncovered that vimentin-positive radial glial fibers and doublecortin-positive migrating neurons were accumulated in LGH. This result may indicate that preferential cell migration into LGH underlies LGH formation. Our findings provide novel mechanistic insights into the pathogenesis of LGH in TD.

Topical Therapy with Mesenchymal Stem Cells Following an Acute Experimental Head Injury Has Benefits in Motor-Behavioral Tests for Rodents.

PubMed

Lam, P K; Wang, Kevin K W; Ip, Anthony W I; Ching, Don W C; Tong, Cindy S W; Lau, Henry C H; Kong, Themis H C S; Lai, Paul B S; Wong, George K C; Poon, W S

2016-01-01

The neuroprotective effects of mesenchymal stem cells (MSCs) have been reported in rodent and in preliminary clinical studies. MSCs are usually transplanted to patients by systemic infusion. However, only a few of the infused MSCs are delivered to the brain because of pulmonary trapping and the blood-brain barrier. In this study, MSCs were topically applied to the site of traumatic brain injury (TBI) and the neuroprotective effects were assessed. TBI was induced in Sprague-Dawley (SD) rats with an electromagnetically controlled cortical impact device after craniotomy was performed between the bregma and lambda, 1 mm lateral to the midline. We applied 1.5 million MSCs, derived from the adipose tissue of transgenic green fluorescent protein (GFP)-SD rats, to the exposed cerebral cortex at the injured site. The MSCs were held in position by a thin layer of fibrin. Neurological function in the test (n = 10) and control (n = 10) animals was evaluated using the rotarod test, the water maze test, and gait analysis at different time points. Within 5 days following topical application, GFP-positive cells were found in the brain parenchyma. These cells co-expressed with markers of Glial fibrillary acidic protein (GFAP), nestin, and NeuN. There was less neuronal death in CA1 and CA3 of the hippocampus in the test animals. Neurological functional recovery was significantly improved. Topically applied MSCs can migrate to the injured brain parenchyma and offer neuroprotective effects.

Longitudinal Tracking of Human Fetal Cells Labeled with Super Paramagnetic Iron Oxide Nanoparticles in the Brain of Mice with Motor Neuron Disease

PubMed Central

Bigini, Paolo; Diana, Valentina; Barbera, Sara; Fumagalli, Elena; Micotti, Edoardo; Sitia, Leopoldo; Paladini, Alessandra; Bisighini, Cinzia; De Grada, Laura; Coloca, Laura; Colombo, Laura; Manca, Pina; Bossolasco, Patrizia; Malvestiti, Francesca; Fiordaliso, Fabio; Forloni, Gianluigi; Morbidelli, Massimo; Salmona, Mario; Giardino, Daniela; Mennini, Tiziana; Moscatelli, Davide; Silani, Vincenzo; Cova, Lidia

2012-01-01

Stem Cell (SC) therapy is one of the most promising approaches for the treatment of Amyotrophic Lateral Sclerosis (ALS). Here we employed Super Paramagnetic Iron Oxide nanoparticles (SPIOn) and Hoechst 33258 to track human Amniotic Fluid Cells (hAFCs) after transplantation in the lateral ventricles of wobbler (a murine model of ALS) and healthy mice. By in vitro, in vivo and ex vivo approaches we found that: 1) the main physical parameters of SPIOn were maintained over time; 2) hAFCs efficiently internalized SPIOn into the cytoplasm while Hoechst 33258 labeled nuclei; 3) SPIOn internalization did not alter survival, cell cycle, proliferation, metabolism and phenotype of hAFCs; 4) after transplantation hAFCs rapidly spread to the whole ventricular system, but did not migrate into the brain parenchyma; 5) hAFCs survived for a long time in the ventricles of both wobbler and healthy mice; 6) the transplantation of double-labeled hAFCs did not influence mice survival. PMID:22384217

Enriched environment reduces glioma growth through immune and non-immune mechanisms in mice

PubMed Central

Garofalo, Stefano; D’Alessandro, Giuseppina; Chece, Giuseppina; Brau, Frederic; Maggi, Laura; Rosa, Alessandro; Porzia, Alessandra; Mainiero, Fabrizio; Esposito, Vincenzo; Lauro, Clotilde; Benigni, Giorgia; Bernardini, Giovanni; Santoni, Angela; Limatola, Cristina

2015-01-01

Mice exposed to standard (SE) or enriched environment (EE) were transplanted with murine or human glioma cells and differences in tumour development were evaluated. We report that EE exposure affects: (i) tumour size, increasing mice survival; (ii) glioma establishment, proliferation and invasion; (iii) microglia/macrophage (M/Mφ) activation; (iv) natural killer (NK) cell infiltration and activation; and (v) cerebral levels of IL-15 and BDNF. Direct infusion of IL-15 or BDNF in the brain of mice transplanted with glioma significantly reduces tumour growth. We demonstrate that brain infusion of IL-15 increases the frequency of NK cell infiltrating the tumour and that NK cell depletion reduces the efficacy of EE and IL-15 on tumour size and of EE on mice survival. BDNF infusion reduces M/Mφ infiltration and CD68 immunoreactivity in tumour mass and reduces glioma migration inhibiting the small G protein RhoA through the truncated TrkB.T1 receptor. These results suggest alternative approaches for glioma treatment. PMID:25818172

Epidermal Growth Factor Treatment of the Adult Brain Subventricular Zone Leads to Focal Microglia/Macrophage Accumulation and Angiogenesis

PubMed Central

Lindberg, Olle R.; Brederlau, Anke; Kuhn, H. Georg

2014-01-01

Summary One of the major components of the subventricular zone (SVZ) neurogenic niche is the specialized vasculature. The SVZ vasculature is thought to be important in regulating progenitor cell proliferation and migration. Epidermal growth factor (EGF) is a mitogen with a wide range of effects. When stem and progenitor cells in the rat SVZ are treated with EGF, using intracerebroventricular infusion, dysplastic polyps are formed. Upon extended infusion, blood vessels are recruited into the polyps. In the current study we demonstrate how polyps develop through distinct stages leading up to angiogenesis. As polyps progress, microglia/macrophages accumulate in the polyp core concurrent with increasing cell death. Both microglia/macrophage accumulation and cell death peak during angiogenesis and subsequently decline following polyp vascularization. This model of inducible angiogenesis in the SVZ neurogenic niche suggests involvement of microglia/macrophages in acquired angiogenesis and can be used in detail to study angiogenesis in the adult brain. PMID:24749069

Splicing factors PTBP1 and PTBP2 promote proliferation and migration of glioma cell lines

PubMed Central

Cheung, Hannah C.; Hai, Tao; Zhu, Wen; Baggerly, Keith A.; Tsavachidis, Spiridon; Krahe, Ralf

2009-01-01

Polypyrimidine tract-binding protein 1 (PTBP1) is a multi-functional RNA-binding protein that is aberrantly overexpressed in glioma. PTBP1 and its brain-specific homologue polypyrimidine tract-binding protein 2 (PTBP2) regulate neural precursor cell differentiation. However, the overlapping and non-overlapping target transcripts involved in this process are still unclear. To determine why PTBP1 and not PTBP2 would promote glial cell-derived tumours, both PTBP1 and PTBP2 were knocked down in the human glioma cell lines U251 and LN229 to determine the role of these proteins in cell proliferation, migration, and adhesion. Surprisingly, removal of both PTBP1 and PTBP2 slowed cell proliferation, with the double knockdown having no additive effects. Decreased expression of both proteins individually and in combination inhibited cell migration and increased adhesion of cells to fibronectin and vitronectin. A global survey of differential exon expression was performed following PTBP1 knockdown in U251 cells using the Affymetrix Exon Array to identify PTBP1-specific splicing targets that enhance gliomagenesis. In the PTBP1 knockdown, previously determined targets were unaltered in their splicing patterns. A single gene, RTN4 (Nogo) had significantly enhanced inclusion of exon 3 when PTBP1 was removed. Overexpression of the splice isoform containing exon 3 decreased cell proliferation to a similar degree as the removal of PTBP1. These results provide the first evidence that RNA-binding proteins affect the invasive and rapid growth characteristics of glioma cell lines. Its actions on proliferation appear to be mediated, in part, through alternative splicing of RTN4. PMID:19506066

Malformations of cortical development: 3T magnetic resonance imaging features

PubMed Central

Battal, Bilal; Ince, Selami; Akgun, Veysel; Kocaoglu, Murat; Ozcan, Emrah; Tasar, Mustafa

2015-01-01

Malformation of cortical development (MCD) is a term representing an inhomogeneous group of central nervous system abnormalities, referring particularly to embriyological aspect as a consequence of any of the three developmental stages, i.e., cell proliferation, cell migration and cortical organization. These include cotical dysgenesis, microcephaly, polymicrogyria, schizencephaly, lissencephaly, hemimegalencephaly, heterotopia and focal cortical dysplasia. Since magnetic resonance imaging is the modality of choice that best identifies the structural anomalies of the brain cortex, we aimed to provide a mini review of MCD by using 3T magnetic resonance scanner images. PMID:26516429

The alkaloids of Banisteriopsis caapi, the plant source of the Amazonian hallucinogen Ayahuasca, stimulate adult neurogenesis in vitro.

PubMed

Morales-García, Jose A; de la Fuente Revenga, Mario; Alonso-Gil, Sandra; Rodríguez-Franco, María Isabel; Feilding, Amanda; Perez-Castillo, Ana; Riba, Jordi

2017-07-13

Banisteriopsis caapi is the basic ingredient of ayahuasca, a psychotropic plant tea used in the Amazon for ritual and medicinal purposes, and by interested individuals worldwide. Animal studies and recent clinical research suggests that B. caapi preparations show antidepressant activity, a therapeutic effect that has been linked to hippocampal neurogenesis. Here we report that harmine, tetrahydroharmine and harmaline, the three main alkaloids present in B. caapi, and the harmine metabolite harmol, stimulate adult neurogenesis in vitro. In neurospheres prepared from progenitor cells obtained from the subventricular and the subgranular zones of adult mice brains, all compounds stimulated neural stem cell proliferation, migration, and differentiation into adult neurons. These findings suggest that modulation of brain plasticity could be a major contribution to the antidepressant effects of ayahuasca. They also expand the potential application of B. caapi alkaloids to other brain disorders that may benefit from stimulation of endogenous neural precursor niches.

Pathogenic role for macrophage migration inhibitory factor in glioblastoma and its targeting with specific inhibitors as novel tailored therapeutic approach

PubMed Central

Mangano, Katia; Mazzon, Emanuela; Basile, Maria Sofia; Di Marco, Roberto; Bramanti, Placido; Mammana, Santa; Petralia, Maria Cristina; Fagone, Paolo; Nicoletti, Ferdinando

2018-01-01

Macrophage Migration Inhibitory Factor (MIF) is a pro-inflammatory cytokine expressed by a variety of cell types. Although MIF has been primarily studied for its role in the pathogenesis of autoimmune diseases, it has also been shown to promote tumorigenesis and it is over expressed in various malignant tumors. MIF is able to induce angiogenesis, cell cycle progression, and to block apoptosis. As tailored therapeutic approaches for the inhibition of endogenous MIF are being developed, it is important to evaluate the role of MIF in individual neoplastic conditions that may benefit from specific MIF inhibitors. Along with this line, in this paper, we have reviewed the evidence of the involvement of MIF in the etiopathogenesis and progression of glioblastoma and the preclinical data suggesting the possible use of specific MIF inhibition as a potential novel therapeutic strategy for brain tumors. PMID:29707160

Fractional kinetics of glioma treatment by a radio-frequency electric field

NASA Astrophysics Data System (ADS)

Iomin, A.

2013-09-01

A realistic model for estimation of the medical effect of brain cancer (glioma) treatment by a radio-frequency (RF) electric field is suggested. This low intensity, intermediate-frequency alternating electric field is known as the tumor-treating field (TTF). The model is based on a construction of 3D comb model for a description of the cancer cells dynamics, where the migration-proliferation dichotomy becomes naturally apparent, and the outer-invasive region of glioma cancer is considered as a fractal composite embedded in the 3D space. In the framework of this model, the interplay between the TTF and the migration-proliferation dichotomy of cancer cells is considered, and the efficiency of this TTF is estimated. It is shown that the efficiency of the medical treatment by the TTF depends essentially on the mass fractal dimension of the cancer in the outer-invasive region.

Neuronal cell reconstruction with umbilical cord blood cells in the brain hypoxia-ischemia.

PubMed

Ghaffaripour, Hossein Ali; Jalali, Mehdi; Nikravesh, Mohammad Reza; Seghatoleslam, Masoumeh; Sanchooli, Javad

2015-01-01

Brain hypoxia-ischemia is a human neonatal injury that is considered a candidate for stem cell therapy. The possible therapeutic potential of human umbilical cord blood (HUCB) stem cells was evaluated in 14-day-old rats subjected to the right common carotid occlusion, a model of neonatal brain hypoxia-ischemia. Seven days after hypoxia-ischemia, rats received either saline solution or 4 × 105 HUCB cells i.v. Rats in control group did not receive any injection. After two weeks, rats were assessed using two motor tests. Subsequently, rats were scarified for histological and immunohistochemical analyses. Our immunohistochemical findings demonstrated selective migration of the injected HUCB cells to the ischemic area as well as reduction in infarct volume. Seven days after surgery, we found significant recovery in the behavioral performance in the test group (12.7 +/- 0.3) compared to the sham group (10.0 +/-0.05), a trend which continued to day 14 (15.3 ± 0.3 vs. 11.9 ± 0.5, P<0.05). Postural and motor asymmetries at days 7 and 14 in the test group showed a significant decrease in the percentage of right turns in comparison to the sham group (75% and 59% vs. 97% and 96%, P<0.05). The results show the potential of HUCB stem cells in reduction of neurologic deficits associated with neonatal hypoxia-ischemia.

Clustering of brain tumor cells: a first step for understanding tumor recurrence

NASA Astrophysics Data System (ADS)

Khain, Evgeniy; Nowicki, M. O.; Chiocca, E. A.; Lawler, S. E.; Schneider-Mizell, C. M.; Sander, L. M.

2012-02-01

Glioblastoma tumors are highly invasive; therefore the overall prognosis of patients remains poor, despite major improvements in treatment techniques. Cancer cells detach from the inner tumor core and actively migrate away [1]; eventually these invasive cells might form clusters, which can develop to recurrent tumors. In vitro experiments in collagen gel [1] followed the clustering dynamics of different glioma cell lines. Based on the experimental data, we formulated a stochastic model for cell dynamics, which identified two mechanisms of clustering. First, there is a critical value of the strength of adhesion; above the threshold, large clusters grow from a homogeneous suspension of cells; below it, the system remains homogeneous, similarly to the ordinary phase separation. Second, when cells form a cluster, there is evidence that their proliferation rate increases. We confirmed the theoretical predictions in a separate cell migration experiment on a substrate and found that both mechanisms are crucial for cluster formation and growth [2]. In addition to their medical importance, these phenomena present exciting examples of pattern formation and collective cell behavior in intrinsically non-equilibrium systems [3]. [4pt] [1] A. M. Stein et al, Biophys. J., 92, 356 (2007). [0pt] [2] E. Khain et al, EPL 88, 28006 (2009). [0pt] [3] E. Khain et al, Phys. Rev. E. 83, 031920 (2011).

Stimulation of cell-surface urokinase-type plasminogen activator activity and cell migration in vascular endothelial cells by a novel hexapeptide analogue of neurotensin.

PubMed

Ushiro, S; Mizoguchi, K; Yoshida, S; Jimi, S; Fujiwara, T; Yoshida, M; Wei, E T; Kitabgi, P; Amagaya, S; Ono, M; Kuwano, M

1997-12-01

To investigate if neurotensin (NT) could induce activation of urokinase-type plasminogen activator (uPA) in vascular endothelial cells, we utilized the acetyl-NT (8-13) analogue, TJN-950, in which the C-terminal leucine is reduced to leucinol. TJN-950 inhibited the binding of 125I-NT to membranes of newborn rat brains and of COS-7 cells transfected with rat NT receptor cDNA, but at 10(4) higher doses than NT (8-13). However, TJN-950 was as effective as NT in inducing the fibrinolytic activity in bovine vascular aortic and human umbilical vein endothelial cells, and enhanced the migration of vascular endothelial cells. Moreover, administration of TJN-950 induced neovascularization in the rat cornea in vivo. TJN-950 had no effect on expression of uPA, plasminogen activator inhibitor-1 or uPA receptor mRNA. The binding of 125I-TJN-950 to cell membranes was blocked by unlabeled uPA and TJN-950, but not the amino-terminal or 12-32 fragment of uPA. TJN-950 may enhance uPA activity in vascular endothelial cells by interacting with the uPA receptor, resulting in induction of angiogenesis.

Neuronal Tracing with Magnetic Labels: NMR Imaging Methods, Preliminary Results, and New Optimized Coils.

NASA Astrophysics Data System (ADS)

Ghosh, Pratik

1992-01-01

The investigations focussed on in vivo NMR imaging studies of magnetic particles with and within neural cells. NMR imaging methods, both Fourier transform and projection reconstruction, were implemented and new protocols were developed to perform "Neuronal Tracing with Magnetic Labels" on small animal brains. Having performed the preliminary experiments with neuronal tracing, new optimized coils and experimental set-up were devised. A novel gradient coil technology along with new rf-coils were implemented, and optimized for future use with small animals in them. A new magnetic labelling procedure was developed that allowed labelling of billions of cells with ultra -small magnetite particles in a short time. The relationships among the viability of such cells, the amount of label and the contrast in the images were studied as quantitatively as possible. Intracerebral grafting of magnetite labelled fetal rat brain cells made it possible for the first time to attempt monitoring in vivo the survival, differentiation, and possible migration of both host and grafted cells in the host rat brain. This constituted the early steps toward future experiments that may lead to the monitoring of human brain grafts of fetal brain cells. Preliminary experiments with direct injection of horse radish peroxidase-conjugated magnetite particles into neurons, followed by NMR imaging, revealed a possible non-invasive alternative, allowing serial study of the dynamic transport pattern of tracers in single living animals. New gradient coils were built by using parallel solid-conductor ribbon cables that could be wrapped easily and quickly. Rapid rise times provided by these coils allowed implementation of fast imaging methods. Optimized rf-coil circuit development made it possible to understand better the sample-coil properties and the associated trade -offs in cases of small but conducting samples.

Cell-autonomous inactivation of the Reelin pathway impairs adult neurogenesis in the hippocampus

PubMed Central

Teixeira, Catia M.; Kron, Michelle M.; Masachs, Nuria; Zhang, Helen; Lagace, Diane C.; Martinez, Albert; Reillo, Isabel; Duan, Xin; Bosch, Carles; Pujadas, Lluis; Brunso, Lucas; Song, Hongjun; Eisch, Amelia J.; Borrell, Victor; Howell, Brian W.; Parent, Jack M.; Soriano, Eduardo

2012-01-01

Adult hippocampal neurogenesis is thought to be essential for learning and memory and has been implicated in the pathogenesis of several disorders. Although recent studies have identified key factors regulating neuroprogenitor proliferation in the adult hippocampus, the mechanisms that control the migration and integration of adult-born neurons into circuits are largely unknown. Reelin is an extracellular matrix protein that is vital for neuronal development. Activation of the Reelin cascade leads to phosphorylation of disabled-1 (Dab1), an adaptor protein required for Reelin signaling. Here we used transgenic mouse and retroviral reporters along with Reelin signaling gain- and loss-of-function studies to show that the Reelin pathway regulates migration and dendritic development of adult-generated hippocampal neurons. Whereas overexpression of Reelin accelerated dendritic maturation, inactivation of the Reelin signaling pathway specifically in adult neuroprogenitor cells resulted in aberrant migration, decreased dendrite development, formation of ectopic dendrites in the hilus and the establishment of aberrant circuits. Our findings support a cell-autonomous and critical role for the Reelin pathway in regulating dendritic development and the integration of adult-generated granule cells and point to this pathway as a key regulator of adult neurogenesis. Moreover, our data reveal a novel role of the Reelin cascade in adult brain function with potential implications for the pathogenesis of several neurological and psychiatric disorders. PMID:22933789

West Nile virus-induced cell adhesion molecules on human brain microvascular endothelial cells regulate leukocyte adhesion and modulate permeability of the in vitro blood-brain barrier model.

PubMed

Roe, Kelsey; Orillo, Beverly; Verma, Saguna

2014-01-01

Characterizing the mechanisms by which West Nile virus (WNV) causes blood-brain barrier (BBB) disruption, leukocyte infiltration into the brain and neuroinflammation is important to understand the pathogenesis of WNV encephalitis. Here, we examined the role of endothelial cell adhesion molecules (CAMs) in mediating the adhesion and transendothelial migration of leukocytes across human brain microvascular endothelial cells (HBMVE). Infection with WNV (NY99 strain) significantly induced ICAM-1, VCAM-1, and E-selectin in human endothelial cells and infected mice brain, although the levels of their ligands on leukocytes (VLA-4, LFA-1and MAC-1) did not alter. The permeability of the in vitro BBB model increased dramatically following the transmigration of monocytes and lymphocytes across the models infected with WNV, which was reversed in the presence of a cocktail of blocking antibodies against ICAM-1, VCAM-1, and E-selectin. Further, WNV infection of HBMVE significantly increased leukocyte adhesion to the HBMVE monolayer and transmigration across the infected BBB model. The blockade of these CAMs reduced the adhesion and transmigration of leukocytes across the infected BBB model. Further, comparison of infection with highly neuroinvasive NY99 and non-lethal (Eg101) strain of WNV demonstrated similar level of virus replication and fold-increase of CAMs in HBMVE cells suggesting that the non-neuropathogenic response of Eg101 is not because of its inability to infect HBMVE cells. Collectively, these results suggest that increased expression of specific CAMs is a pathological event associated with WNV infection and may contribute to leukocyte infiltration and BBB disruption in vivo. Our data further implicate that strategies to block CAMs to reduce BBB disruption may limit neuroinflammation and virus-CNS entry via 'Trojan horse' route, and improve WNV disease outcome.

Influence of Post-Traumatic Stress Disorder on Neuroinflammation and Cell Proliferation in a Rat Model of Traumatic Brain Injury

PubMed Central

Diamond, David M.; Shinozuka, Kazutaka; Ishikawa, Hiroto; Hernandez, Diana G.; Sanberg, Paul R.; Kaneko, Yuji; Borlongan, Cesar V.

2013-01-01

Long-term consequences of traumatic brain injury (TBI) are closely associated with the development of severe psychiatric disorders, such as post-traumatic stress disorder (PTSD), yet preclinical studies on pathological changes after combined TBI with PTSD are lacking. In the present in vivo study, we assessed chronic neuroinflammation, neuronal cell loss, cell proliferation and neuronal differentiation in specific brain regions of adult Sprague-Dawley male rats following controlled cortical impact model of moderate TBI with or without exposure to PTSD. Eight weeks post-TBI, stereology-based histological analyses revealed no significant differences between sham and PTSD alone treatment across all brain regions examined, whereas significant exacerbation of OX6-positive activated microglial cells in the striatum, thalamus, and cerebral peduncle, but not cerebellum, in animals that received TBI alone and combined TBI-PTSD compared with PTSD alone and sham treatment. Additional immunohistochemical results revealed a significant loss of CA3 pyramidal neurons in the hippocampus of TBI alone and TBI-PTSD compared to PTSD alone and sham treatment. Further examination of neurogenic niches revealed a significant downregulation of Ki67-positive proliferating cells, but not DCX-positive neuronally migrating cells in the neurogenic subgranular zone and subventricular zone for both TBI alone and TBI-PTSD compared to PTSD alone and sham treatment. Comparisons of levels of neuroinflammation and neurogenesis between TBI alone and TBI+PTSD revealed that PTSD did not exacerbate the neuropathological hallmarks of TBI. These results indicate a progressive deterioration of the TBI brain, which, under the conditions of the present approach, was not intensified by PTSD, at least within our time window and within the examined areas of the brain. Although the PTSD manipulation employed here did not exacerbate the pathological effects of TBI, the observed long-term inflammation and suppressed cell proliferation may evolve into more severe neurodegenerative diseases and psychiatric disorders currently being recognized in traumatized TBI patients. PMID:24349091

Müller glia: Stem cells for generation and regeneration of retinal neurons in teleost fish

PubMed Central

Lenkowski, Jenny R.; Raymond, Pamela A.

2014-01-01

Adult zebrafish generate new neurons in the brain and retina throughout life. Growth-related neurogenesis allows a vigorous regenerative response to damage, and fish can regenerate retinal neurons, including photoreceptors, and restore functional vision following photic, chemical, or mechanical destruction of the retina. Müller glial cells in fish function as radial-glial-like neural stem cells. During adult growth, Müller glial nuclei undergo sporadic, asymmetric, self-renewing mitotic divisions in the inner nuclear layer to generate a rod progenitor that migrates along the radial fiber of the Müller glia into the outer nuclear layer, proliferates, and differentiates exclusively into rod photoreceptors. When retinal neurons are destroyed, Müller glia in the immediate vicinity of the damage partially and transiently dedifferentiate, re-express retinal progenitor and stem cell markers, re-enter the cell cycle, undergo interkinetic nuclear migration (characteristic of neuroepithelial cells), and divide once in an asymmetric, self-renewing division to generate a retinal progenitor. This daughter cell proliferates rapidly to form a compact neurogenic cluster surrounding the Müller glia; these multipotent retinal progenitors then migrate along the radial fiber to the appropriate lamina to replace missing retinal neurons. Some aspects of the injury-response in fish Müller glia resemble gliosis as observed in mammals, and mammalian Müller glia exhibit some neurogenic properties, indicative of a latent ability to regenerate retinal neurons. Understanding the specific properties of fish Müller glia that facilitate their robust capacity to generate retinal neurons will inform and inspire new clinical approaches for treating blindness and visual loss with regenerative medicine. PMID:24412518

Genetic Approaches to Reveal the Connectivity of Adult-Born Neurons

PubMed Central

Arenkiel, Benjamin R.

2011-01-01

Much has been learned about the environmental and molecular factors that influence the division, migration, and programmed cell death of adult-born neurons in the mammalian brain. However, detailed knowledge of the mechanisms that govern the formation and maintenance of functional circuit connectivity via adult neurogenesis remains elusive. Recent advances in genetic technologies now afford the ability to precisely target discrete brain tissues, neuronal subtypes, and even single neurons for vital reporter expression and controlled activity manipulations. Here, I review current viral tracing methods, heterologous receptor expression systems, and optogenetic technologies that hold promise toward elucidating the wiring diagrams and circuit properties of adult-born neurons. PMID:21519388

Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis

PubMed Central

Tosetti, Valentina; Sassone, Jenny; Ferri, Anna L. M.; Taiana, Michela; Bedini, Gloria; Nava, Sara; Brenna, Greta; Di Resta, Chiara; Pareyson, Davide; Di Giulio, Anna Maria; Carelli, Stephana

2017-01-01

The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT. PMID:28704421

Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis.

PubMed

Tosetti, Valentina; Sassone, Jenny; Ferri, Anna L M; Taiana, Michela; Bedini, Gloria; Nava, Sara; Brenna, Greta; Di Resta, Chiara; Pareyson, Davide; Di Giulio, Anna Maria; Carelli, Stephana; Parati, Eugenio A; Gorio, Alfredo

2017-01-01

The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT.

Role of the Immune System in HIV-associated Neuroinflammation and Neurocognitive Implications

PubMed Central

Hong, Suzi; Banks, William A.

2014-01-01

Individuals living with HIV who are optimally treated with combination antiretroviral therapy (cART) can now lead an extended life. In spite of this remarkable survival benefit from viral suppression achieved by cART in peripheral blood, the rate of mild to moderate cognitive impairment remains high. A cognitive decline that includes impairments in attention, learning and executive function is accompanied by increased rates of mood disorders that together adversely impact the daily life of those with chronic HIV infection. The evidence is clear that cells in the brain are infected with HIV that has crossed the blood-brain barrier both as cell-free virus and within infected monocytes and T cells. Viral proteins that circulate in blood can induce brain endothelial cells to release cytokines, invoking another source of neuroinflammation. The difficulty of efficient delivery of cART to the central nervous system (CNS) contributes to elevated viral load in the CNS, resulting in a persistent HIV-associated neurocognitive disorders (HAND). The pathogenesis of HAND is multifaceted, and mounting evidence indicates that immune cells play a major role. HIV-infected monocytes and T cells not only infect brain resident cells upon migration into the CNS but also produce proinflammatory cytokines such as TNF and IL-1β, which in turn, further activate microglia and astrocytes. These activated brain resident cells, along with perivascular macrophages, are the main contributors to neuroinflammation in HIV infection and release neurotoxic factors such as excitatory amino acids and inflammatory mediators, resulting in neuronal dysfunction and death. Cytokines, which are elevated in the blood of patients with HIV infection, may also contribute to brain inflammation by entering the brain from the blood. Host factors such as aging and co-morbid conditions such as cytomegalovirus co-infection and vascular pathology are important factors that affect the HIV-host immune interactions in HAND pathogenesis. By these diverse mechanisms, HIV-1 induces a neuroinflammatory response that is likely to be a major contributor to the cognitive and behavior changes seen in HIV infection. PMID:25449672

Naringin inhibits the invasion and migration of human glioblastoma cell via downregulation of MMP-2 and MMP-9 expression and inactivation of p38 signaling pathway.

PubMed

Aroui, Sonia; Najlaoui, Feten; Chtourou, Yassine; Meunier, Annie-Claire; Laajimi, Amel; Kenani, Abderraouf; Fetoui, Hamadi

2016-03-01

Gliomas are the most common and malignant primary brain tumors. They are associated with a poor prognosis despite the availability of multiple therapeutic options. Naringin, a common dietary flavonoid abundantly present in fruits and vegetables, is believed to possess strong anti-proliferative and anti-cancer properties. However, there are no reports describing its effects on the invasion and migration of glioblastoma cell lines. Our results showed that the treatment of U251 glioma cell lines with different concentrations of naringin inhibited the invasion and migration of these cells. In addition, we revealed a decrease in the levels of matrix metalloproteinases (MMP-2) and (MMP-9) expression as well as proteinase activity in U251 glioma cells. In contrast, the expression of tissue inhibitor of metalloproteinases (TIMP-1) and (TIMP-2) was increased. Furthermore, naringin treatment decreased significantly the phosphorylated level of p38. Combined treatment with a p38 inhibitor (SB203580) resulted in the synergistic reduction of MMP-2 and MMP-9 expressions correlated with an increase of TIMP-1 and TIMP-2 expressions and the anti-invasive properties. However, p38 chemical activator (anisomycin) could block these effects produced by naringin, suggesting a direct downregulation of the p38 signaling pathway. These data suggest that naringin may have therapeutic potential for controlling invasiveness of malignant gliomas by inhibiting of p38 signal transduction pathways.

MicroRNA 203 Modulates Glioma Cell Migration via Robo1/ERK/MMP-9 Signaling

PubMed Central

Dontula, Ranadheer; Dinasarapu, Ashok; Chetty, Chandramu; Pannuru, Padmavathi; Herbert, Engelhard; Ozer, Howard

2013-01-01

Glioblastoma (GBM) is the most common and malignant primary adult brain cancer. Allelic deletion on chromosome 14q plays an important role in the pathogenesis of GBM, and this site was thought to harbor multiple tumor suppressor genes associated with GBM, a region that also encodes microRNA-203 (miR-203). In this study, we sought to identify the role of miR-203 as a tumor suppressor in the pathogenesis of GBM. We analyzed the miR-203 expression data of GBM patients in 10 normal and 495 tumor tissue samples derived from The Cancer Genome Atlas data set. Quantitative real-time PCR and in situ hybridization in 10 high-grade GBM and 10 low-grade anaplastic astrocytoma tumor samples showed decreased levels of miR-203 expression in anaplastic astrocytoma and GBM tissues and cell lines. Exogenous expression of miR-203 using a plasmid expressing miR-203 precursor (pmiR-203) suppressed glioma cell proliferation, migration, and invasion. We determined that one relevant target of miR-203 was Robo1, given that miR-203 expression decreased mRNA and protein levels as determined by RT-PCR and Western blot analysis. Moreover, cotransfection experiments using a luciferase-based transcription reporter assay have shown direct regulation of Robo1 by miR-203. We also show that Robo1 mediates miR-203 mediated antimigratory functions as up-regulation of Robo1 abrogates miR-203 mediated antimigratory effects. We also show that miR-203 expression suppressed ERK phosphorylation and MMP-9 expression in glioma cells. Furthermore, we demonstrate that miR-203 inhibits migration of the glioma cells by disrupting the Robo1/ERK/MMP-9 signaling axis. Taken together, these studies demonstrate that up-regulation of Robo1 in response to the decrease in miR-203 in glioma cells is responsible for glioma tumor cell migration and invasion. PMID:24167656

Preconditioning mesenchymal stem cells with the mood stabilizers lithium and valproic acid enhances therapeutic efficacy in a mouse model of Huntington's disease.

PubMed

Linares, Gabriel R; Chiu, Chi-Tso; Scheuing, Lisa; Leng, Yan; Liao, Hsiao-Mei; Maric, Dragan; Chuang, De-Maw

2016-07-01

Huntington's disease (HD) is a fatal neurodegenerative disorder caused by CAG repeat expansions in the huntingtin gene. Although, stem cell-based therapy has emerged as a potential treatment for neurodegenerative diseases, limitations remain, including optimizing delivery to the brain and donor cell loss after transplantation. One strategy to boost cell survival and efficacy is to precondition cells before transplantation. Because the neuroprotective actions of the mood stabilizers lithium and valproic acid (VPA) induce multiple pro-survival signaling pathways, we hypothesized that preconditioning bone marrow-derived mesenchymal stem cells (MSCs) with lithium and VPA prior to intranasal delivery to the brain would enhance their therapeutic efficacy, and thereby facilitate functional recovery in N171-82Q HD transgenic mice. MSCs were treated in the presence or absence of combined lithium and VPA, and were then delivered by brain-targeted single intranasal administration to eight-week old HD mice. Histological analysis confirmed the presence of MSCs in the brain. Open-field test revealed that ambulatory distance and mean velocity were significantly improved in HD mice that received preconditioned MSCs, compared to HD vehicle-control and HD mice transplanted with non-preconditioned MSCs. Greater benefits on motor function were observed in HD mice given preconditioned MSCs, while HD mice treated with non-preconditioned MSCs showed no functional benefits. Moreover, preconditioned MSCs reduced striatal neuronal loss and huntingtin aggregates in HD mice. Gene expression profiling of preconditioned MSCs revealed a robust increase in expression of genes involved in trophic effects, antioxidant, anti-apoptosis, cytokine/chemokine receptor, migration, mitochondrial energy metabolism, and stress response signaling pathways. Consistent with this finding, preconditioned MSCs demonstrated increased survival after transplantation into the brain compared to non-preconditioned cells. Our results suggest that preconditioning stem cells with the mood stabilizers lithium and VPA before transplantation may serve as an effective strategy for enhancing the therapeutic efficacy of stem cell-based therapies. Copyright © 2016. Published by Elsevier Inc.

Mutations in α-Tubulin Cause Abnormal Neuronal Migration in Mice and Lissencephaly in Humans

PubMed Central

Keays, David A.; Tian, Guoling; Poirier, Karine; Huang, Guo-Jen; Siebold, Christian; Cleak, James; Oliver, Peter L.; Fray, Martin; Harvey, Robert J.; Molnár, Zoltán; Piñon, Maria C.; Dear, Neil; Valdar, William; Brown, Steve D.M.; Davies, Kay E.; Rawlins, J. Nicholas P.; Cowan, Nicholas J.; Nolan, Patrick; Chelly, Jamel; Flint, Jonathan

2007-01-01

Summary The development of the mammalian brain is dependent on extensive neuronal migration. Mutations in mice and humans that affect neuronal migration result in abnormal lamination of brain structures with associated behavioral deficits. Here, we report the identification of a hyperactive N-ethyl-N-nitrosourea (ENU)-induced mouse mutant with abnormalities in the laminar architecture of the hippocampus and cortex, accompanied by impaired neuronal migration. We show that the causative mutation lies in the guanosine triphosphate (GTP) binding pocket of α-1 tubulin (Tuba1) and affects tubulin heterodimer formation. Phenotypic similarity with existing mouse models of lissencephaly led us to screen a cohort of patients with developmental brain anomalies. We identified two patients with de novo mutations in TUBA3, the human homolog of Tuba1. This study demonstrates the utility of ENU mutagenesis in the mouse as a means to discover the basis of human neurodevelopmental disorders. PMID:17218254

Cerebral Developmental Abnormalities in a Mouse with Systemic Pyruvate Dehydrogenase Deficiency

PubMed Central

Pliss, Lioudmila; Hausknecht, Kathryn A.; Stachowiak, Michal K.; Dlugos, Cynthia A.; Richards, Jerry B.; Patel, Mulchand S.

2013-01-01

Pyruvate dehydrogenase (PDH) complex (PDC) deficiency is an inborn error of pyruvate metabolism causing a variety of neurologic manifestations. Systematic analyses of development of affected brain structures and the cellular processes responsible for their impairment have not been performed due to the lack of an animal model for PDC deficiency. METHODS: In the present study we investigated a murine model of systemic PDC deficiency by interrupting the X-linked Pdha1 gene encoding the α subunit of PDH to study its role on brain development and behavioral studies. RESULTS: Male embryos died prenatally but heterozygous females were born. PDC activity was reduced in the brain and other tissues in female progeny compared to age-matched control females. Immunohistochemical analysis of several brain regions showed that approximately 40% of cells were PDH−. The oxidation of glucose to CO2 and incorporation of glucose-carbon into fatty acids were reduced in brain slices from 15 day-old PDC-deficient females. Histological analyses showed alterations in several structures in white and gray matters in 35 day-old PDC-deficient females. Reduction in total cell number and reduced dendritic arbors in Purkinje neurons were observed in PDC-deficient females. Furthermore, cell proliferation, migration and differentiation into neurons by newly generated cells were reduced in the affected females during pre- and postnatal periods. PDC-deficient mice had normal locomotor activity in a novel environment but displayed decreased startle responses to loud noises and there was evidence of abnormal pre-pulse inhibition of the startle reflex. CONCLUSIONS: The results show that a reduction in glucose metabolism resulting in deficit in energy production and fatty acid biosynthesis impairs cellular differentiation and brain development in PDC-deficient mice. PMID:23840713

Arginyltransferase ATE1 is targeted to the neuronal growth cones and regulates neurite outgrowth during brain development.

PubMed

Wang, Junling; Pavlyk, Iuliia; Vedula, Pavan; Sterling, Stephanie; Leu, N Adrian; Dong, Dawei W; Kashina, Anna

2017-10-01

Arginylation is an emerging protein modification mediated by arginyltransferase ATE1, shown to regulate embryogenesis and actin cytoskeleton, however its functions in different physiological systems are not well understood. Here we analyzed the role of ATE1 in brain development and neuronal growth by producing a conditional mouse knockout with Ate1 deletion in the nervous system driven by Nestin promoter (Nes-Ate1 mice). These mice were weaker than wild type, resulting in low postnatal survival rates, and had abnormalities in the brain that suggested defects in neuronal migration. Cultured Ate1 knockout neurons showed a reduction in the neurite outgrowth and the levels of doublecortin and F-actin in the growth cones. In wild type, ATE1 prominently localized to the growth cones, in addition to the cell bodies. Examination of the Ate1 mRNA sequence reveals the existence of putative zipcode-binding sequences involved in mRNA targeting to the cell periphery and local translation at the growth cones. Fluorescence in situ hybridization showed that Ate1 mRNA localized to the tips of the growth cones, likely due to zipcode-mediated targeting, and this localization coincided with spots of localization of arginylated β-actin, which disappeared in the presence of protein synthesis inhibitors. We propose that zipcode-mediated co-targeting of Ate1 and β-actin mRNA leads to localized co-translational arginylation of β-actin that drives the growth cone migration and neurite outgrowth. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Epidermal growth factor receptor expression is related to post-mitotic events in cerebellar development: regulation by thyroid hormone.

PubMed

Carrasco, Emilce; Blum, Mariann; Weickert, Cynthia Shannon; Casper, Diana

2003-01-10

It has been established that thyroid hormone and neurotrophic factors both orchestrate developmental events in the brain. However, it is not clear how these two influences are related. In this study, we investigated the effects of thyroid hormone on cerebellar development and the coincident expression of transforming growth factor-alpha (TGF-alpha), a ligand in the epidermal growth factor (EGF) family, and the epidermal growth factor receptor (EGFR). Profiles of thyroid hormone expression were measured in postnatal animals and were found to peak at postnatal day 15 (P15). These levels dropped below detectable levels when mice were made hypothyroid with propylthiouracil (PTU). TGF-alpha and EGFR expression, as determined by RNAse protection assay, was maximal at P6 in normal animals, but remained low in hypothyroid animals, suggesting that thyroid hormone was responsible for their induction. In situ hybridization and immunohistochemical analysis of EGFR expression revealed that this receptor was present on granule cells within the inner zone of the external granule cell layer (EGL), suggesting that EGFR-ligands were not inducing granule cell proliferation. The persistence of EGFR expression on migrating granule cells and subsequent down-regulation of expression in the internal granule cell layer (IGL) implicates a role for EGFR-ligands in differentiation and/or migration. In hypothyroid animals, we observed a delayed progression of granule cell migration, consistent with the persistence of EGFR labeling in the EGL, and in the 'pile-up' of labeled cells at the interface between the molecular layer and the Purkinje cell layer. Taken together, these results implicate thyroid hormone in the coordinated expression of TGF-alpha and EGFR, which are positioned to play a role in post-mitotic developmental events in the cerebellum.

Innovative Therapeutic Strategies in the Treatment of Brain Metastases

PubMed Central

Caffo, Maria; Barresi, Valeria; Caruso, Gerardo; Cutugno, Mariano; La Fata, Giuseppe; Venza, Mario; Alafaci, Concetta; Tomasello, Francesco

2013-01-01

Brain metastases (BM) are the most common intracranial tumors and their incidence is increasing. Untreated brain metastases are associated with a poor prognosis and a poor performance status. Metastasis development involves the migration of a cancer cell from the bulk tumor into the surrounding tissue, extravasation from the blood into tissue elsewhere in the body, and formation of a secondary tumor. In the recent past, important results have been obtained in the management of patients affected by BM, using surgery, radiation therapy, or both. Conventional chemotherapies have generally produced disappointing results, possibly due to their limited ability to penetrate the blood–brain barrier. The advent of new technologies has led to the discovery of novel molecules and pathways that have better depicted the metastatic process. Targeted therapies such as bevacizumab, erlotinib, gefitinib, sunitinib and sorafenib, are all licensed and have demonstrated improved survival in patients with metastatic disease. In this review, we will report current data on targeted therapies. A brief review about brain metastatic process will be also presented. PMID:23340652

miR-137 forms a regulatory loop with nuclear receptor TLX and LSD1 in neural stem cells.

PubMed

Sun, GuoQiang; Ye, Peng; Murai, Kiyohito; Lang, Ming-Fei; Li, Shengxiu; Zhang, Heying; Li, Wendong; Fu, Chelsea; Yin, Jason; Wang, Allen; Ma, Xiaoxiao; Shi, Yanhong

2011-11-08

miR-137 is a brain-enriched microRNA. Its role in neural development remains unknown. Here we show that miR-137 has an essential role in controlling embryonic neural stem cell fate determination. miR-137 negatively regulates cell proliferation and accelerates neural differentiation of embryonic neural stem cells. In addition, we show that the histone lysine-specific demethylase 1 (LSD1), a transcriptional co-repressor of nuclear receptor TLX, is a downstream target of miR-137. In utero electroporation of miR-137 in embryonic mouse brains led to premature differentiation and outward migration of the transfected cells. Introducing a LSD1 expression vector lacking the miR-137 recognition site rescued miR-137-induced precocious differentiation. Furthermore, we demonstrate that TLX, an essential regulator of neural stem cell self-renewal, represses the expression of miR-137 by recruiting LSD1 to the genomic regions of miR-137. Thus, miR-137 forms a feedback regulatory loop with TLX and LSD1 to control the dynamics between neural stem cell proliferation and differentiation during neural development.

Aging increases microglial proliferation, delays cell migration, and decreases cortical neurogenesis after focal cerebral ischemia.

PubMed

Moraga, Ana; Pradillo, Jesús M; García-Culebras, Alicia; Palma-Tortosa, Sara; Ballesteros, Ivan; Hernández-Jiménez, Macarena; Moro, María A; Lizasoain, Ignacio

2015-05-10

Aging is not just a risk factor of stroke, but it has also been associated with poor recovery. It is known that stroke-induced neurogenesis is reduced but maintained in the aged brain. However, there is no consensus on how neurogenesis is affected after stroke in aged animals. Our objective is to determine the role of aging on the process of neurogenesis after stroke. We have studied neurogenesis by analyzing proliferation, migration, and formation of new neurons, as well as inflammatory parameters, in a model of cerebral ischemia induced by permanent occlusion of the middle cerebral artery in young- (2 to 3 months) and middle-aged mice (13 to 14 months). Aging increased both microglial proliferation, as shown by a higher number of BrdU(+) cells and BrdU/Iba1(+) cells in the ischemic boundary and neutrophil infiltration. Interestingly, aging increased the number of M1 monocytes and N1 neutrophils, consistent with pro-inflammatory phenotypes when compared with the alternative M2 and N2 phenotypes. Aging also inhibited (subventricular zone) SVZ cell proliferation by decreasing both the number of astrocyte-like type-B (prominin-1(+)/epidermal growth factor receptor (EGFR)(+)/nestin(+)/glial fibrillary acidic protein (GFAP)(+) cells) and type-C cells (prominin-1(+)/EGFR(+)/nestin(-)/Mash1(+) cells), and not affecting apoptosis, 1 day after stroke. Aging also inhibited migration of neuroblasts (DCX(+) cells), as indicated by an accumulation of neuroblasts at migratory zones 14 days after injury; consistently, aged mice presented a smaller number of differentiated interneurons (NeuN(+)/BrdU(+) and GAD67(+) cells) in the peri-infarct cortical area 14 days after stroke. Our data confirm that stroke-induced neurogenesis is maintained but reduced in aged animals. Importantly, we now demonstrate that aging not only inhibits proliferation of specific SVZ cell subtypes but also blocks migration of neuroblasts to the damaged area and decreases the number of new interneurons in the cortical peri-infarct area. Thus, our results highlight the importance of using aged animals for translation to clinical studies.

In vivo studies of low level laser (light) therapy for traumatic brain injury

NASA Astrophysics Data System (ADS)

Xuan, Weijun; Wu, Qiuhe; Huang, Ying-Ying; Ando, Takahiro; Huang, Liyi; Hamblin, Michael R.

2012-03-01

Low-level laser (or light) therapy (LLLT) is attracting growing interest to treat both stroke and traumatic brain injury (TBI). The fact that near-infrared light can penetrate into the brain allows non-invasive treatment to be carried out with a low likelihood of treatment-related adverse events. It is proposed that red and NIR light is absorbed by chromophores in the mitochondria of cells leading to changes in gene transcription and upregulation of proteins involved in cell survival, antioxidant production, collagen synthesis, reduction of chronic inflammation and cell migration and proliferation. We developed a mouse model of controlled cortical impact (CCI) TBI and examined the effect of 0, 1, 3, and 14 daily 810-nm CW laser treatments in the CCI model as measured by neurological severity score and wire grip and motion test. 1 laser Tx gave a significant improvement while 3 laser Tx was even better. Surprisingly 14 laser Tx was no better than no treatment. Histological studies at necropsy suggested that the neurodegeneration was reduced at 14 days and that the cortical lesion was repaired by BrdU+ve neural progenitor (stem) cells at 28 days. Transcranial laser therapy is a promising treatment for acute (and chronic TBI) and the lack of side-effects and paucity of alternative treatments encourages early clinical trials.

The role of cannabinoids in adult neurogenesis

PubMed Central

Prenderville, Jack A; Kelly, Áine M; Downer, Eric J

2015-01-01

The processes underpinning post-developmental neurogenesis in the mammalian brain continue to be defined. Such processes involve the proliferation of neural stem cells and neural progenitor cells (NPCs), neuronal migration, differentiation and integration into a network of functional synapses within the brain. Both intrinsic (cell signalling cascades) and extrinsic (neurotrophins, neurotransmitters, cytokines, hormones) signalling molecules are intimately associated with adult neurogenesis and largely dictate the proliferative activity and differentiation capacity of neural cells. Cannabinoids are a unique class of chemical compounds incorporating plant-derived cannabinoids (the active components of Cannabis sativa), the endogenous cannabinoids and synthetic cannabinoid ligands, and these compounds are becoming increasingly recognized for their roles in neural developmental processes. Indeed, cannabinoids have clear modulatory roles in adult neurogenesis, probably through activation of both CB1 and CB2 receptors. In recent years, a large body of literature has deciphered the signalling networks involved in cannabinoid-mediated regulation of neurogenesis. This timely review summarizes the evidence that the cannabinoid system is intricately associated with neuronal differentiation and maturation of NPCs and highlights intrinsic/extrinsic signalling mechanisms that are cannabinoid targets. Overall, these findings identify the central role of the cannabinoid system in adult neurogenesis in the hippocampus and the lateral ventricles and hence provide insight into the processes underlying post-developmental neurogenesis in the mammalian brain. PMID:25951750

Brain-derived neurotrophic factor promotes VEGF-C-dependent lymphangiogenesis by suppressing miR-624-3p in human chondrosarcoma cells.

PubMed

Lin, Chih-Yang; Wang, Shih-Wei; Chen, Yen-Ling; Chou, Wen-Yi; Lin, Ting-Yi; Chen, Wei-Cheng; Yang, Chen-Yu; Liu, Shih-Chia; Hsieh, Chia-Chu; Fong, Yi-Chin; Wang, Po-Chuan; Tang, Chih-Hsin

2017-08-03

Chondrosarcoma is the second most common primary malignancy of bone, and one of the most difficult bone tumors to diagnose and treat. It is well known that increased levels of vascular endothelial growth factor-C (VEGF-C) promote active tumor lymphangiogenesis and lymphatic tumor spread to regional lymph nodes. Brain-derived neurotrophic factor (BDNF) is known to promote metastasis in human chondrosarcoma cells. Knowing more about the mechanism of BDNF in VEGF-C expression and lymphangiogenesis in human chondrosarcoma would improve our understanding as how to prevent chondrosarcoma angiogenesis and metastasis, which currently lacks effective adjuvant treatment. Here, we found that BDNF expression was at least 2.5-fold higher in the highly migratory JJ012(S10) cell line as compared with the primordial cell line (JJ012). In addition, VEGF-C expression and secretion was markedly increased in JJ012(S10) cells. Conditioned medium from JJ012(S10) cells significantly promoted migration and tube formation of human lymphatic endothelial cells (LECs), whereas knockdown of BDNF attenuated LEC migration and tube formation by suppressing VEGF-C production in JJ012(S10) cells. Mechanistic investigations indicated that BDNF facilitated VEGF-C-dependent lymphangiogenesis through the MEK/ERK/mTOR signaling pathway. We also showed that microRNA (miR)-624-3p expression was negatively regulated by BDNF via the MEK/ERK/mTOR cascade. Importantly, BDNF knockdown profoundly inhibited tumor-associated lymphangiogenesis in vivo. Further analyses identified that BDNF promoted tumor lymphangiogenesis by downregulating miR-624-3p in human chondrosarcoma tissues. In conclusion, this study is the first to reveal the mechanism underlying BDNF-induced lymphangiogenesis. We suggest that BDNF may serve as a promising therapeutic target for the restriction of VEGF-C-mediated tumor lymphangiogenesis and lymphatic metastasis.

Brain-derived neurotrophic factor promotes VEGF-C-dependent lymphangiogenesis by suppressing miR-624-3p in human chondrosarcoma cells

PubMed Central

Lin, Chih-Yang; Wang, Shih-Wei; Chen, Yen-Ling; Chou, Wen-Yi; Lin, Ting-Yi; Chen, Wei-Cheng; Yang, Chen-Yu; Liu, Shih-Chia; Hsieh, Chia-Chu; Fong, Yi-Chin; Wang, Po-Chuan; Tang, Chih-Hsin

2017-01-01

Chondrosarcoma is the second most common primary malignancy of bone, and one of the most difficult bone tumors to diagnose and treat. It is well known that increased levels of vascular endothelial growth factor-C (VEGF-C) promote active tumor lymphangiogenesis and lymphatic tumor spread to regional lymph nodes. Brain-derived neurotrophic factor (BDNF) is known to promote metastasis in human chondrosarcoma cells. Knowing more about the mechanism of BDNF in VEGF-C expression and lymphangiogenesis in human chondrosarcoma would improve our understanding as how to prevent chondrosarcoma angiogenesis and metastasis, which currently lacks effective adjuvant treatment. Here, we found that BDNF expression was at least 2.5-fold higher in the highly migratory JJ012(S10) cell line as compared with the primordial cell line (JJ012). In addition, VEGF-C expression and secretion was markedly increased in JJ012(S10) cells. Conditioned medium from JJ012(S10) cells significantly promoted migration and tube formation of human lymphatic endothelial cells (LECs), whereas knockdown of BDNF attenuated LEC migration and tube formation by suppressing VEGF-C production in JJ012(S10) cells. Mechanistic investigations indicated that BDNF facilitated VEGF-C-dependent lymphangiogenesis through the MEK/ERK/mTOR signaling pathway. We also showed that microRNA (miR)-624-3p expression was negatively regulated by BDNF via the MEK/ERK/mTOR cascade. Importantly, BDNF knockdown profoundly inhibited tumor-associated lymphangiogenesis in vivo. Further analyses identified that BDNF promoted tumor lymphangiogenesis by downregulating miR-624-3p in human chondrosarcoma tissues. In conclusion, this study is the first to reveal the mechanism underlying BDNF-induced lymphangiogenesis. We suggest that BDNF may serve as a promising therapeutic target for the restriction of VEGF-C-mediated tumor lymphangiogenesis and lymphatic metastasis. PMID:28771226

Human endogenous retrovirus W env increases nitric oxide production and enhances the migration ability of microglia by regulating the expression of inducible nitric oxide synthase.

PubMed

Xiao, Ran; Li, Shan; Cao, Qian; Wang, Xiuling; Yan, Qiujin; Tu, Xiaoning; Zhu, Ying; Zhu, Fan

2017-06-01

Human endogenous retrovirus W env (HERV-W env) plays a critical role in many neuropsychological diseases such as schizophrenia and multiple sclerosis (MS). These diseases are accompanied by immunological reactions in the central nervous system (CNS). Microglia are important immunocytes in brain inflammation that can produce a gasotransmitter-nitric oxide (NO). NO not only plays a role in the function of neuronal cells but also participates in the pathogenesis of various neuropsychological diseases. In this study, we reported increased NO production in CHME-5 microglia cells after they were transfected with HERV-W env. Moreover, HERV-W env increased the expression and function of human inducible nitric oxide synthase (hiNOS) and enhanced the promoter activity of hiNOS. Microglial migration was also enhanced. These data revealed that HERV-W env might contribute to increase NO production and microglial migration ability in neuropsychological disorders by regulating the expression of inducible NOS. Results from this study might lead to the identification of novel targets for the treatment of neuropsychological diseases, including neuroinflammatory diseases, stroke, and neurodegenerative diseases.

Sex differences in the phagocytic and migratory activity of microglia and their impairment by palmitic acid.

PubMed

Yanguas-Casás, Natalia; Crespo-Castrillo, Andrea; de Ceballos, Maria L; Chowen, Julie A; Azcoitia, Iñigo; Arevalo, Maria Angeles; Garcia-Segura, Luis M

2018-03-01

Sex differences in the incidence, clinical manifestation, disease course, and prognosis of neurological diseases, such as autism spectrum disorders or Alzheimer's disease, have been reported. Obesity has been postulated as a risk factor for cognitive decline and Alzheimer's disease and, during pregnancy, increases the risk of autism spectrum disorders in the offspring. Obesity is associated with increased serum and brain levels of free fatty acids, such as palmitic acid, which activate microglial cells triggering a potent inflammatory cascade. In this study, we have determined the effect of palmitic acid in the inflammatory profile, motility, and phagocytosis of primary male and female microglia, both in basal conditions and in the presence of a pro-inflammatory stimulus (interferon-γ). Male microglia in vitro showed higher migration than female microglia under basal and stimulated conditions. In contrast, female microglia had higher basal and stimulated phagocytic activity than male microglia. Palmitic acid did not affect basal migration or phagocytosis, but abolished the migration and phagocytic activity of male and female microglia in response to interferon-γ. These findings extend previous observations of sex differences in microglia and suggest that palmitic acid impairs the protective responses of these cells. © 2017 Wiley Periodicals, Inc.

Myelin Proteolipid Protein Complexes with αv Integrin and AMPA Receptors In Vivo and Regulates AMPA-Dependent Oligodendrocyte Progenitor Cell Migration through the Modulation of Cell-Surface GluR2 Expression

PubMed Central

Harlow, Danielle E.; Saul, Katherine E.; Komuro, Hitoshi

2015-01-01

In previous studies, stimulation of ionotropic AMPA/kainate glutamate receptors on cultured oligodendrocyte cells induced the formation of a signaling complex that includes the AMPA receptor, integrins, calcium-binding proteins, and, surprisingly, the myelin proteolipid protein (PLP). AMPA stimulation of cultured oligodendrocyte progenitor cells (OPCs) also caused an increase in OPC migration. The current studies focused primarily on the formation of the PLP–αv integrin–AMPA receptor complex in vivo and whether complex formation impacts OPC migration in the brain. We found that in wild-type cerebellum, PLP associates with αv integrin and the calcium-impermeable GluR2 subunit of the AMPA receptor, but in mice lacking PLP, αv integrin did not associate with GluR2. Live imaging studies of OPC migration in ex vivo cerebellar slices demonstrated altered OPC migratory responses to neurotransmitter stimulation in the absence of PLP and GluR2 or when αv integrin levels were reduced. Chemotaxis assays of purified OPCs revealed that AMPA stimulation was neither attractive nor repulsive but clearly increased the migration rate of wild-type but not PLP null OPCs. AMPA receptor stimulation of wild-type OPCs caused decreased cell-surface expression of the GluR2 AMPA receptor subunit and increased intracellular Ca2+ signaling, whereas PLP null OPCs did not reduce GluR2 at the cell surface or increase Ca2+ signaling in response to AMPA treatment. Together, these studies demonstrate that PLP is critical for OPC responses to glutamate signaling and has important implications for OPC responses when levels of glutamate are high in the extracellular space, such as following demyelination. SIGNIFICANCE STATEMENT After demyelination, such as occurs in multiple sclerosis, remyelination of axons is often incomplete, leading to loss of neuronal function and clinical disability. Remyelination may fail because oligodendrocyte precursor cells (OPCs) do not completely migrate into demyelinated areas or OPCs in lesions may not mature into myelinating oligodendrocytes. We have found that the myelin proteolipid protein is critical to regulating OPC migratory responses to the neurotransmitter glutamate through modulation of cell-surface expression of the calcium-impermeable GluR2 subunit of the AMPA glutamate receptor and increased intercellular Ca2+ signaling. Altered glutamate homeostasis has been reported in demyelinated lesions. Therefore, understanding how OPCs respond to glutamate has important implications for treatment after white matter injury and disease. PMID:26311781

Fetal Alcohol Spectrum Disorders: An Overview from the Glia Perspective.

PubMed

Wilhelm, Clare J; Guizzetti, Marina

2015-01-01

Alcohol consumption during pregnancy can produce a variety of central nervous system (CNS) abnormalities in the offspring resulting in a broad spectrum of cognitive and behavioral impairments that constitute the most severe and long-lasting effects observed in fetal alcohol spectrum disorders (FASD). Alcohol-induced abnormalities in glial cells have been suspected of contributing to the adverse effects of alcohol on the developing brain for several years, although much research still needs to be done to causally link the effects of alcohol on specific brain structures and behavior to alterations in glial cell development and function. Damage to radial glia due to prenatal alcohol exposure may underlie observations of abnormal neuronal and glial migration in humans with Fetal Alcohol Syndrome (FAS), as well as primate and rodent models of FAS. A reduction in cell number and altered development has been reported for several glial cell types in animal models of FAS. In utero alcohol exposure can cause microencephaly when alcohol exposure occurs during the brain growth spurt a period characterized by rapid astrocyte proliferation and maturation; since astrocytes are the most abundant cells in the brain, microenchephaly may be caused by reduced astrocyte proliferation or survival, as observed in in vitro and in vivo studies. Delayed oligodendrocyte development and increased oligodendrocyte precursor apoptosis has also been reported in experimental models of FASD, which may be linked to altered myelination/white matter integrity found in FASD children. Children with FAS exhibit hypoplasia of the corpus callosum and anterior commissure, two areas requiring guidance from glial cells and proper maturation of oligodendrocytes. Finally, developmental alcohol exposure disrupts microglial function and induces microglial apoptosis; given the role of microglia in synaptic pruning during brain development, the effects of alcohol on microglia may be involved in the abnormal brain plasticity reported in FASD. The consequences of prenatal alcohol exposure on glial cells, including radial glia and other transient glial structures present in the developing brain, astrocytes, oligodendrocytes and their precursors, and microglia contributes to abnormal neuronal development, reduced neuron survival and disrupted brain architecture and connectivity. This review highlights the CNS structural abnormalities caused by in utero alcohol exposure and outlines which abnormalities are likely mediated by alcohol effects on glial cell development and function.

Enriched Environment Increases PCNA and PARP1 Levels in Octopus vulgaris Central Nervous System: First Evidence of Adult Neurogenesis in Lophotrochozoa.

PubMed

Bertapelle, Carla; Polese, Gianluca; Di Cosmo, Anna

2017-06-01

Organisms showing a complex and centralized nervous system, such as teleosts, amphibians, reptiles, birds and mammals, and among invertebrates, crustaceans and insects, can adjust their behavior according to the environmental challenges. Proliferation, differentiation, migration, and axonal and dendritic development of newborn neurons take place in brain areas where structural plasticity, involved in learning, memory, and sensory stimuli integration, occurs. Octopus vulgaris has a complex and centralized nervous system, located between the eyes, with a hierarchical organization. It is considered the most "intelligent" invertebrate for its advanced cognitive capabilities, as learning and memory, and its sophisticated behaviors. The experimental data obtained by immunohistochemistry and western blot assay using proliferating cell nuclear antigen and poli (ADP-ribose) polymerase 1 as marker of cell proliferation and synaptogenesis, respectively, reviled cell proliferation in areas of brain involved in learning, memory, and sensory stimuli integration. Furthermore, we showed how enriched environmental conditions affect adult neurogenesis. © 2017 Wiley Periodicals, Inc.

Angiotensin II receptor type 1--a novel target for preventing neonatal meningitis in mice by Escherichia coli K1.

PubMed

Krishnan, Subramanian; Shanmuganathan, Muthusamy V; Behenna, Douglas; Stoltz, Brian M; Prasadarao, Nemani V

2014-02-01

The increasing incidence of Escherichia coli K1 meningitis due to escalating antibiotic resistance warrants alternate treatment options to prevent this deadly disease. We screened a library of small molecules from the National Institutes of Health clinical collection and identified telmisartan, an angiotensin II receptor type 1 (AT1R) blocker, as a potent inhibitor of E. coli invasion into human brain microvascular endothelial cells (HBMECs). Immunoprecipitation studies revealed that AT1R associates with endothelial cell gp96, the receptor in HBMECs for E. coli outer membrane protein A. HBMECs pretreated with telmisartan or transfected with AT1R small interfering RNA were resistant to E. coli invasion because of downregulation of protein kinase C-α phosphorylation. Administration of a soluble derivative of telmisartan to newborn mice before infection with E. coli prevented the onset of meningitis and suppressed neutrophil infiltration and glial cell migration in the brain. Therefore, telmisartan has potential as an alternate treatment option for preventing E. coli meningitis.

[P21-activated kinases and their role in the nervous system].

PubMed

Qin, Yuan; Ding, Yue-Min; Xia, Qiang

2012-12-25

P21-activated kinases (PAK) participate in a variety of important cellular activities, such as cytoskeleton remodeling, cell migration, cell cycle regulation, and apoptosis or survival. PAK also has an important impact on brain development, neuronal differentiation, and regulation of synaptic plasticity in the nervous system. PAK abnormalities result in diseases including cancer, Parkinson's disease (PD), Alzheimer's disease (AD) and neural retardation. Therefore, it is of vital physiological significance to investigate the neuronal function of PAK. In this paper we review the advancement of research on the neuronal biological function and the underlying mechanisms of PAK.

Rethinking International Migration of Human Capital and Brain Circulation: The Case of Chinese-Canadian Academics

ERIC Educational Resources Information Center

Blachford, Dongyan Ru; Zhang, Bailing

2014-01-01

This article examines the dynamics of brain circulation through a historical review of the debates over international migration of human capital and a case study on Chinese-Canadian academics. Interviews with 22 Chinese-Canadian professors who originally came from China provide rich data regarding the possibilities and problems of the contemporary…

Non-invasive neural stem cells become invasive in vitro by combined FGF2 and BMP4 signaling.

PubMed

Sailer, Martin H M; Gerber, Alexandra; Tostado, Cristóbal; Hutter, Gregor; Cordier, Dominik; Mariani, Luigi; Ritz, Marie-Françoise

2013-08-15

Neural stem cells (NSCs) typically show efficient self-renewal and selective differentiation. Their invasion potential, however, is not well studied. In this study, Sox2-positive NSCs from the E14.5 rat cortex were found to be non-invasive and showed only limited migration in vitro. By contrast, FGF2-expanded NSCs showed a strong migratory and invasive phenotype in response to the combination of FGF2 and BMP4. Invasive NSCs expressed Podoplanin (PDPN) and p75NGFR (Ngfr) at the plasma membrane after exposure to FGF2 and BMP4. FGF2 and BMP4 together upregulated the expression of Msx1, Snail1, Snail2, Ngfr, which are all found in neural crest (NC) cells during or after epithelial-mesenchymal transition (EMT), but not in forebrain stem cells. Invasive cells downregulated the expression of Olig2, Sox10, Egfr, Pdgfra, Gsh1/Gsx1 and Gsh2/Gsx2. Migrating and invasive NSCs had elevated expression of mRNA encoding Pax6, Tenascin C (TNC), PDPN, Hey1, SPARC, p75NGFR and Gli3. On the basis of the strongest upregulation in invasion-induced NSCs, we defined a group of five key invasion-related genes: Ngfr, Sparc, Snail1, Pdpn and Tnc. These genes were co-expressed and upregulated in seven samples of glioblastoma multiforme (GBM) compared with normal human brain controls. Induction of invasion and migration led to low expression of differentiation markers and repressed proliferation in NSCs. Our results indicate that normal forebrain stem cells have the inherent ability to adopt a glioma-like invasiveness. The results provide a novel in vitro system to study stem cell invasion and a novel glioma invasion model: tumoral abuse of the developmental dorsoventral identity regulation.

Tumor associated CD70 expression is involved in promoting tumor migration and macrophage infiltration in GBM.

PubMed

Ge, Haitao; Mu, Luyan; Jin, Linchun; Yang, Changlin; Chang, Yifan Emily; Long, Yu; DeLeon, Gabriel; Deleyrolle, Loic; Mitchell, Duane A; Kubilis, Paul S; Lu, Dunyue; Qi, Jiping; Gu, Yunhe; Lin, Zhiguo; Huang, Jianping

2017-10-01

Tumor migration/metastasis and immunosuppression are major obstacles in effective cancer therapy. Incidentally, these 2 hurdles usually coexist inside tumors, therefore making therapy significantly more complicated, as both oncogenic mechanisms must be addressed for successful therapeutic intervention. Our recent report highlights that the tumor expression of a TNF family member, CD70, is correlated with poor survival for primary gliomas. In this study, we investigated how CD70 expression by GBM affects the characteristics of tumor cells and the tumor microenvironment. We found that the ablation of CD70 in primary GBM decreased CD44 and SOX2 gene expression, and inhibited tumor migration, growth and the ability to attract monocyte-derived M2 macrophages in vitro. In the tumor microenvironment, CD70 was associated with immune cell infiltrates, such as T cells; myeloid-derived suppressor cells; and monocytes/macrophages based on the RNA-sequencing profile. The CD163+ macrophages were far more abundant than T cells were. This overwhelming level of macrophages was identified only in GBM and not in low-grade gliomas and normal brain specimens, implying their tumor association. CD70 was detected only on tumor cells, not on macrophages, and was highly correlated with CD163 gene expression in primary GBM. Additionally, the co-expression of the CD70 and CD163 genes was found to correlate with decreased survival for patients with primary GBM. Together, these data suggest that CD70 expression is involved in promoting tumor aggressiveness and immunosuppression via tumor-associated macrophage recruitment/activation. Our current efforts to target this molecule using chimeric antigen receptor T cells hold great potential for treating patients with GBM. © 2017 UICC.

Omnisphero: a high-content image analysis (HCA) approach for phenotypic developmental neurotoxicity (DNT) screenings of organoid neurosphere cultures in vitro.

PubMed

Schmuck, Martin R; Temme, Thomas; Dach, Katharina; de Boer, Denise; Barenys, Marta; Bendt, Farina; Mosig, Axel; Fritsche, Ellen

2017-04-01

Current developmental neurotoxicity (DNT) testing in animals faces major limitations, such as high cost and time demands as well as uncertainties in their methodology, evaluation and regulation. Therefore, the use of human-based 3D in vitro systems in combination with high-content image analysis (HCA) might contribute to DNT testing with lower costs, increased throughput and enhanced predictivity for human hazard identification. Human neural progenitor cells (hNPCs) grown as 3D neurospheres mimic basic processes of brain development including hNPC migration and differentiation and are therefore useful for DNT hazard identification. HCA of migrated neurospheres creates new challenges for automated evaluations because it encompasses variable cell densities, inconsistent z-layers and heterogeneous cell populations. We tackle those challenges with our Omnisphero software, which assesses multiple endpoints of the 'Neurosphere Assay.' For neuronal identification, Omnisphero reaches a true positive rate (TPR) of 83.8 % and a false discovery rate (FDR) of 11.4 %, thus being comparable to the interindividual difference among two researchers (TPR = 94.3, FDR = 11.0 %) and largely improving the results obtained by an existing HCA approach, whose TPR does not exceed 50 % at a FDR above 50 %. The high FDR of existing methods results in incorrect measurements of neuronal morphological features accompanied by an overestimation of compound effects. Omnisphero additionally includes novel algorithms to assess 'neurosphere-specific' endpoints like radial migration and neuronal density distribution within the migration area. Furthermore, a user-assisted parameter optimization procedure makes Omnisphero accessible to non-expert end users.

Microtubule actin cross-linking factor 1, a novel target in glioblastoma.

PubMed

Afghani, Najlaa; Mehta, Toral; Wang, Jialiang; Tang, Nan; Skalli, Omar; Quick, Quincy A

2017-01-01

Genetic heterogeneity is recognized as a major contributing factor of glioblastoma resistance to clinical treatment modalities and consequently low overall survival rates. This genetic diversity results in variations in protein expression, both intratumorally and between individual glioblastoma patients. In this regard, the spectraplakin protein, microtubule actin cross-linking factor 1 (MACF1), was examined in glioblastoma. An expression analysis of MACF1 in various types of brain tumor tissue revealed that MACF1 was predominately present in grade III-IV astroctyomas and grade IV glioblastoma, but not in normal brain tissue, normal human astrocytes and lower grade brain tumors. Subsequent genetic inhibition experiments showed that suppression of MACF1 selectively inhibited glioblastoma cell proliferation and migration in cell lines established from patient derived xenograft mouse models and immortalized glioblastoma cell lines that were associated with downregulation of the Wnt-signaling mediators, Axin1 and β-catenin. Additionally, concomitant MACF1 silencing with the chemotherapeutic agent temozolomide (TMZ) used for the clinical treatment of glioblastomas cooperatively reduced the proliferative capacity of glioblastoma cells. In conclusion, the present study represents the first investigation on the functional role of MACF1 in tumor cell biology, as well as demonstrates its potential as a unique biomarker that can be targeted synergistically with TMZ as part of a combinatorial therapeutic approach for the treatment of genetically multifarious glioblastomas.

Nanoparticle engineered TRAIL-overexpressing adipose-derived stem cells target and eradicate glioblastoma via intracranial delivery

PubMed Central

Jiang, Xinyi; Fitch, Sergio; Wang, Christine; Wilson, Christy; Li, Jianfeng; Grant, Gerald A.; Yang, Fan

2016-01-01

Glioblastoma multiforme (GBM) is one of the most intractable of human cancers, principally because of the highly infiltrative nature of these neoplasms. Tracking and eradicating infiltrating GBM cells and tumor microsatellites is of utmost importance for the treatment of this devastating disease, yet effective strategies remain elusive. Here we report polymeric nanoparticle-engineered human adipose-derived stem cells (hADSCs) overexpressing tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as drug-delivery vehicles for targeting and eradicating GBM cells in vivo. Our results showed that polymeric nanoparticle-mediated transfection led to robust up-regulation of TRAIL in hADSCs, and that TRAIL-expressing hADSCs induced tumor-specific apoptosis. When transplanted in a mouse intracranial xenograft model of patient-derived glioblastoma cells, hADSCs exhibited long-range directional migration and infiltration toward GBM tumor. Importantly, TRAIL-overexpressing hADSCs inhibited GBM growth, extended survival, and reduced the occurrence of microsatellites. Repetitive injection of TRAIL-overexpressing hADSCs significantly prolonged animal survival compared with single injection of these cells. Taken together, our data suggest that nanoparticle-engineered TRAIL-expressing hADSCs exhibit the therapeutically relevant behavior of “seek-and-destroy” tumortropic migration and could be a promising therapeutic approach to improve the treatment outcomes of patients with malignant brain tumors. PMID:27849590

Hypoxia-induced PLOD2 promotes proliferation, migration and invasion via PI3K/Akt signaling in glioma.

PubMed

Song, Ye; Zheng, Shihao; Wang, Jizhou; Long, Hao; Fang, Luxiong; Wang, Gang; Li, Zhiyong; Que, Tianshi; Liu, Yi; Li, Yilei; Zhang, Xi'an; Fang, Weiyi; Qi, Songtao

2017-06-27

Gliomas are the most common form of malignant primary brain tumors with poor 5-year survival rate. Dysregulation of procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) was observed in gliomas, but the specific role and molecular mechanism of PLOD2 in glioma have not been reported yet. In this study, PLOD2 was found to be frequently up-regulated in glioma and could serve as an independent prognostic marker to identify patients with poor clinical outcome. Knockdown of PLOD2 inhibited proliferation, migration and invasion of glioma cells in vitro and in vivo. Mechanistically, inhibition of PLOD2 inactivated PI3K/AKT signaling pathway and thus regulated the expression of its downstream epithelial-mesenchymal transition (EMT)-associated regulators, including E-cadherin, vimentin, N-cadherin, β-catenin, snail and slug in glioma cells. Moreover, PLOD2 could be induced by hypoxia-inducible factor-1α (HIF-1α) via hypoxia, thereby promoting hypoxia-induced EMT in glioma cells. Our data suggests that PLOD2 may be a potential therapeutic target for patients with glioma.

Riding the glial monorail: a common mechanism for glial-guided neuronal migration in different regions of the developing mammalian brain.

PubMed

Hatten, M E

1990-05-01

In vitro studies from our laboratory indicate that granule neurons, purified from early postnatal mouse cerebellum, migrate on astroglial fibers by forming a 'migration junction' with the glial fiber along the length of the neuronal soma and extending a motile 'leading process' in the direction of migration. Similar dynamics are seen for hippocampal neurons migrating along hippocampal astroglial fibers in vitro. In heterotypic recombinations of neurons and glia from mouse cerebellum and rat hippocampus, neurons migrate on astroglial processes with a cytology and neuron-glia relationship identical to that of homotypic neuronal migration in vitro. In all four cases, the migrating neuron presents a stereotyped posture, speed and mode of movement, suggesting that glial fibers provide a generic pathway for neuronal migration in developing brain. Studies on the molecular basis of glial-guided migration suggest that astrotactin, a neuronal antigen that functions as a neuron-glia ligand, is likely to play a crucial role in the locomotion of the neuron along glial fibers. The navigation of neurons from glial fibers into cortical layers, in turn, is likely to involve neuron-neuron adhesion ligands.

Effects of dynamic matrix remodelling on en masse migration of fibroblasts on collagen matrices.

PubMed

Ozcelikkale, Altug; Dutton, J Craig; Grinnell, Frederick; Han, Bumsoo

2017-10-01

Fibroblast migration plays a key role during various physiological and pathological processes. Although migration of individual fibroblasts has been well studied, migration in vivo often involves simultaneous locomotion of fibroblasts sited in close proximity, so-called ' en masse migration', during which intensive cell-cell interactions occur. This study aims to understand the effects of matrix mechanical environments on the cell-matrix and cell-cell interactions during en masse migration of fibroblasts on collagen matrices. Specifically, we hypothesized that a group of migrating cells can significantly deform the matrix, whose mechanical microenvironment dramatically changes compared with the undeformed state, and the alteration of the matrix microenvironment reciprocally affects cell migration. This hypothesis was tested by time-resolved measurements of cell and extracellular matrix movement during en masse migration on collagen hydrogels with varying concentrations. The results illustrated that a group of cells generates significant spatio-temporal deformation of the matrix before and during the migration. Cells on soft collagen hydrogels migrate along tortuous paths, but, as the matrix stiffness increases, cell migration patterns become aligned with each other and show coordinated migration paths. As cells migrate, the matrix is locally compressed, resulting in a locally stiffened and dense matrix across the collagen concentration range studied. © 2017 The Author(s).

Embryonic cell-cell adhesion: a key player in collective neural crest migration.

PubMed

Barriga, Elias H; Mayor, Roberto

2015-01-01

Cell migration is essential for morphogenesis, adult tissue remodeling, wound healing, and cancer cell migration. Cells can migrate as individuals or groups. When cells migrate in groups, cell-cell interactions are crucial in order to promote the coordinated behavior, essential for collective migration. Interestingly, recent evidence has shown that cell-cell interactions are also important for establishing and maintaining the directionality of these migratory events. We focus on neural crest cells, as they possess extraordinary migratory capabilities that allow them to migrate and colonize tissues all over the embryo. Neural crest cells undergo an epithelial-to-mesenchymal transition at the same time than perform directional collective migration. Cell-cell adhesion has been shown to be an important source of planar cell polarity and cell coordination during collective movement. We also review molecular mechanisms underlying cadherin turnover, showing how the modulation and dynamics of cell-cell adhesions are crucial in order to maintain tissue integrity and collective migration in vivo. We conclude that cell-cell adhesion during embryo development cannot be considered as simple passive resistance to force, but rather participates in signaling events that determine important cell behaviors required for cell migration. © 2015 Elsevier Inc. All rights reserved.

Putative Adult Neurogenesis in Old World Parrots: The Congo African Grey Parrot (Psittacus erithacus) and Timneh Grey Parrot (Psittacus timneh).

PubMed

Mazengenya, Pedzisai; Bhagwandin, Adhil; Manger, Paul R; Ihunwo, Amadi O

2018-01-01

In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey parrot ( Psittacus erithacus ) and Timneh grey parrot ( Psittacus timneh ) using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA), which labels proliferating cells, and doublecortin (DCX), which stains immature and migrating neurons. A similar distribution of PCNA and DCX immunoreactivity was found throughout the brain of the Congo African grey and Timneh grey parrots, but minor differences were also observed. In both species of parrots, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, subventricular zone of the lateral wall of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and the rhombencephalon. The olfactory bulb and telencephalic subdivisions exhibited a higher density of both PCNA and DCX immunoreactive cells than any other brain region. DCX immunoreactive staining was stronger in the telencephalon than in the subtelencephalic structures. There was evidence of proliferative hot spots in the dorsal and ventral poles of the lateral ventricle in the Congo African grey parrots at rostral levels, whereas only the dorsal accumulation of proliferating cells was observed in the Timneh grey parrot. In most pallial regions the density of PCNA and DCX stained cells increased from rostral to caudal levels with the densest staining in the nidopallium caudolaterale (NCL). The widespread distribution of PCNA and DCX in the brains of both parrot species suggest the importance of adult neurogenesis and neuronal plasticity during learning and adaptation to external environmental variations.

Chronophin is a glial tumor modifier involved in the regulation of glioblastoma growth and invasiveness.

PubMed

Schulze, M; Fedorchenko, O; Zink, T G; Knobbe-Thomsen, C B; Kraus, S; Schwinn, S; Beilhack, A; Reifenberger, G; Monoranu, C M; Sirén, A-L; Jeanclos, E; Gohla, A

2016-06-16

Glioblastoma is the most aggressive primary brain tumor in adults. Although the rapid recurrence of glioblastomas after treatment is a major clinical challenge, the relationships between tumor growth and intracerebral spread remain poorly understood. We have identified the cofilin phosphatase chronophin (gene name: pyridoxal phosphatase, PDXP) as a glial tumor modifier. Monoallelic PDXP loss was frequent in four independent human astrocytic tumor cohorts and increased with tumor grade. We found that aberrant PDXP promoter methylation can be a mechanism leading to further chronophin downregulation in glioblastomas, which correlated with shorter glioblastoma patient survival. Moreover, we observed an inverse association between chronophin protein expression and cofilin phosphorylation levels in glioma tissue samples. Chronophin-deficient glioblastoma cells showed elevated cofilin phosphorylation, an increase in polymerized actin, a higher directionality of cell migration, and elevated in vitro invasiveness. Tumor growth of chronophin-depleted glioblastoma cells xenografted into the immunodeficient mouse brain was strongly impaired. Our study suggests a mechanism whereby the genetic and epigenetic alterations of PDXP resulting in altered chronophin expression may regulate the interplay between glioma cell proliferation and invasion.

Long non-coding RNA SNHG6 promotes glioma tumorigenesis by sponging miR-101-3p.

PubMed

Meng, Qiang; Yang, Bao-Ying; Liu, Bei; Yang, Ji-Xue; Sun, Yang

2018-05-01

Glioma is the most common primary brain tumor. The small nucleolar RNA host gene (SNHG) SNHG6 is a potential oncogene in the development of several types of cancers. In this study, we investigated the functional role of long non-coding RNA (lncRNA) SNHG6 in the malignancy of glioma in cell lines and transplanted nude mice. We found that the expression of lncRNA SNHG6 was higher in glioma tissues and cells than in normal brain tissues and cells. The expression of lncRNA SNHG6 was positively correlated with the malignancy and poor prognosis of glioma patients. microRNA (miR)-101-3p expression was decreased in glioma tissues and cells and was negatively correlated with the malignancy and poor prognosis of glioma patients. In glioma tissues, the expression of lncRNA SNHG6 was negatively correlated with the expression of miR-101-3p. SNHG6 contained a binding site of miR-101-3p. Knockdown of SNHG6 expression resulted in a significant increase of miR-101-3p expression. miR-101-3p mimic markedly decreased the luciferase activity of SNHG6. Knockdown of SNHG6 inhibited glioma cell proliferation, migration, and epithelial-mesenchymal transition (EMT), and increased apoptosis. miR-101-3p mimic enhanced knockdown of SNHG6-induced inhibition of cell proliferation, migration, and EMT, and an increase of apoptosis. Anti-miR-101-3p reversed the the effects of si-SNHG6 on cell malignancy. Knockdown of SNHG6 remarkably reduced the increase of tumor volumes in xenograft mouse models. In tumor tissues, knockdown of SNHG6 increased the expression of miR-101-3p and reduced EMT biomarker expression. Our study provides novel insights into the functions of lncRNA SNHG6/miR-101-3p axis in the tumorigenesis of glioma.

The role of microglia and macrophages in glioma maintenance and progression

PubMed Central

Hambardzumyan, Dolores; Gutmann, David H; Kettenmann, Helmut

2016-01-01

There is a growing recognition that gliomas are complex tumors composed of neoplastic and non-neoplastic cells, which each individually contribute to cancer formation, progression and response to treatment. The majority of the non-neoplastic cells are tumor-associated macrophages (TAMs), either of peripheral origin or representing brain-intrinsic microglia, that create a supportive stroma for neoplastic cell expansion and invasion. TAMs are recruited to the glioma environment, have immune functions, and can release a wide array of growth factors and cytokines in response to those factors produced by cancer cells. In this manner, TAMs facilitate tumor proliferation, survival and migration. Through such iterative interactions, a unique tumor ecosystem is established, which offers new opportunities for therapeutic targeting. PMID:26713745

Neurodegeneration and adaptation in response to low-dose photon irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Limoli, Charles L.

2014-10-27

Neural stem and precursor cells (i.e. multipotent neural cells) are concentrated in the neurogenic regions of the brain (hippocampal dentate gyrus, subventricular zones), and considerable evidence suggests that these cells are important in mediating the stress response of the CNS after damage from ionizing radiation. The capability of these cells to proliferate, migrate and differentiate (i.e. to undergo neurogenesis) suggests they can participate in the repair and maintenance of CNS functions by replacing brain cells damaged or depleted due to irradiation. Importantly, we have shown that multipotent neural cells are markedly sensitive to irradiation and oxidative stress, insults that compromisemore » neurogenesis and hasten the onset and progression of degenerative processes that are likely to have an adverse impact on cognition. Our past and current work has demonstrated that relatively low doses of radiation cause a persistent (weeks-months) oxidative stress in multipotent neural cells that can elicit a range of degenerative sequelae in the CNS. Therefore, our project is focused on determining the extent that endogenous and redox sensitive multipotent neural cells represent important radioresponsive targets for low dose radiation effects. We hypothesize that the activation of redox sensitive signaling can trigger radioadaptive changes in these cells that can be either harmful or beneficial to overall cognitive health.« less

Ablation of the 14-3-3gamma Protein Results in Neuronal Migration Delay and Morphological Defects in the Developing Cerebral Cortex.

PubMed

Wachi, Tomoka; Cornell, Brett; Marshall, Courtney; Zhukarev, Vladimir; Baas, Peter W; Toyo-oka, Kazuhito

2016-06-01

14-3-3 proteins are ubiquitously-expressed and multifunctional proteins. There are seven isoforms in mammals with a high level of homology, suggesting potential functional redundancy. We previously found that two of seven isoforms, 14-3-3epsilon and 14-3-3zeta, are important for brain development, in particular, radial migration of pyramidal neurons in the developing cerebral cortex. In this work, we analyzed the function of another isoform, the protein 14-3-3gamma, with respect to neuronal migration in the developing cortex. We found that in utero 14-3-3gamma-deficiency resulted in delays in neuronal migration as well as morphological defects. Migrating neurons deficient in 14-3-3gamma displayed a thicker leading process stem, and the basal ends of neurons were not able to reach the boundary between the cortical plate and the marginal zone. Consistent with the results obtained from in utero electroporation, time-lapse live imaging of brain slices revealed that the ablation of the 14-3-3gamma proteins in pyramidal neurons slowed down their migration. In addition, the 14-3-3gamma deficient neurons showed morphological abnormalities, including increased multipolar neurons with a thicker leading processes stem during migration. These results indicate that the 14-3-3gamma proteins play an important role in radial migration by regulating the morphology of migrating neurons in the cerebral cortex. The findings underscore the pathological phenotypes of brain development associated with the disruption of different 14-3-3 proteins and will advance the preclinical data regarding disorders caused by neuronal migration defects. © 2015 Wiley Periodicals, Inc.

Abnormal electroretinogram associated with developmental brain anomalies.

PubMed Central

Cibis, G W; Fitzgerald, K M

1995-01-01

PURPOSE: We have encountered abnormal ERGs associated with optic nerve hypoplasia, macular, optic nerve and chorioretinal colobomata and developmental brain anomalies. Brain anomalies include cortical dysgenesis, lissencephaly, porencephaly, cerebellar and corpus callosum hypoplasia. We describe six exemplar cases. METHODS: Scotopic and photopic ERGs adherent to international standards were performed as well as photopic ERGs to long-duration stimuli. CT or MRI studies were also done. The ERGs were compared to age-matched normal control subjects. RESULTS: ERG changes include reduced amplitude b-waves to blue and red stimuli under scotopic testing conditions. Implicit times were often delayed. The photopic responses also showed reduced amplitude a- and b-waves with implicit time delays. The long-duration photopic ERG done in one case shows attenuation of both ON- and OFF-responses. CONCLUSIONS: Common underlying developmental genetic or environmental unifying casualties are speculated to be at fault in causing these cases of associated retinal and brain abnormalities. No single etiology is expected. Multiple potential causes acting early in embryogenesis effecting neuronal induction, migration and differentiation are theorized. These occur at a time when brain and retinal cells are sufficiently undifferentiated to be similarly effected. We call these cases examples of Brain Retina Neuroembryodysgenesis (BRNED). Homeobox and PAX genes with global neuronal developmental influences are gene candidates to unify the observed disruption of brain and retinal cell development. The ERG can provide a valuable clinical addition in understanding and ultimately classifying these disorders. Images FIGURE 1 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 PMID:8719676

Dopamine Increases CD14+CD16+ Monocyte Migration and Adhesion in the Context of Substance Abuse and HIV Neuropathogenesis

PubMed Central

Coley, Jacqueline S.; Calderon, Tina M.; Gaskill, Peter J.; Eugenin, Eliseo A.; Berman, Joan W.

2015-01-01

Drug abuse is a major comorbidity of HIV infection and cognitive disorders are often more severe in the drug abusing HIV infected population. CD14+CD16+ monocytes, a mature subpopulation of peripheral blood monocytes, are key mediators of HIV neuropathogenesis. Infected CD14+CD16+ monocyte transmigration across the blood brain barrier mediates HIV entry into the brain and establishes a viral reservoir within the CNS. Despite successful antiretroviral therapy, continued influx of CD14+CD16+ monocytes, both infected and uninfected, contributes to chronic neuroinflammation and the development of HIV associated neurocognitive disorders (HAND). Drug abuse increases extracellular dopamine in the CNS. Once in the brain, CD14+CD16+ monocytes can be exposed to extracellular dopamine due to drug abuse. The direct effects of dopamine on CD14+CD16+ monocytes and their contribution to HIV neuropathogenesis are not known. In this study, we showed that CD14+CD16+ monocytes express mRNA for all five dopamine receptors by qRT-PCR and D1R, D5R and D4R surface protein by flow cytometry. Dopamine and the D1-like dopamine receptor agonist, SKF38393, increased CD14+CD16+ monocyte migration that was characterized as chemokinesis. To determine whether dopamine affected cell motility and adhesion, live cell imaging was used to monitor the accumulation of CD14+CD16+ monocytes on the surface of a tissue culture dish. Dopamine increased the number and the rate at which CD14+CD16+ monocytes in suspension settled to the dish surface. In a spreading assay, dopamine increased the area of CD14+CD16+ monocytes during the early stages of cell adhesion. In addition, adhesion assays showed that the overall total number of adherent CD14+CD16+ monocytes increased in the presence of dopamine. These data suggest that elevated extracellular dopamine in the CNS of HIV infected drug abusers contributes to HIV neuropathogenesis by increasing the accumulation of CD14+CD16+ monocytes in dopamine rich brain regions. PMID:25647501

Protocadherin-7 induces bone metastasis of breast cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Ai-Min; Tian, Ai-Xian; Zhang, Rui-Xue

2013-07-05

Highlights: •PCDH7 is overexpression in high bone metastatic MDA-MB-231 cells. •PCDH7 is up-regulation in bone metastatic breast cancer tissues. •Suppression of PCDH7 inhibits cell proliferation, migration, and invasion in vitro. •PCDH7 induces breast cancer bone metastasis in vivo. -- Abstract: Breast cancer had a propensity to metastasize to bone, resulting in serious skeletal complications associated with poor outcome. Previous study showed that Protocadherin-7 (PCDH7) play an important role in brain metastatic breast cancer, however, the role of PCDH7 in bone metastatic breast cancer has never been explored. In the present study, we found that PCDH7 expression was up-regulation in bonemore » metastatic breast cancer tissues by real-time PCR and immunohistochemistry assays. Furthermore, suppression of PCDH7 inhibits breast cancer cell proliferation, migration, and invasion in vitro by MTT, scratch, and transwell assays. Most importantly, overexpression of PCDH7 promotes breast cancer cell proliferation and invasion in vitro, and formation of bone metastasis in vivo. These data provide an important insight into the role of PCDH7 in bone metastasis of breast cancer.« less

JIP3 regulates neuronal radial migration by mediating TrkB axonal anterograde transport in the developing cerebral cortex.

PubMed

Ma, Huixian; Yu, Hui; Li, Ting; Zhao, Yan; Hou, Ming; Chen, Zheyu; Wang, Yue; Sun, Tao

2017-04-15

Radial migration is essential for the precise lamination and the coordinated function of the cerebral cortex. However, the molecular mechanisms for neuronal radial migration are not clear. Here, we report that c-Jun NH2-terminal kinase (JNK)-interacting protein-3 (JIP3) is highly expressed in the brain of embryonic mice and essential for radial migration. Knocking down JIP3 by in utero electroporation specifically perturbs the radial migration of cortical neurons but has no effect on neurogenesis and neuronal differentiation. Furthermore, we illustrate that JIP3 knockdown delays but does not block the migration of cortical neurons by investigating the distribution of neurons with JIP3 knocked down in the embryo and postnatal mouse. Finally, we find that JIP3 regulates cortical neuronal migration by mediating TrkB axonal anterograde transport during brain development. These findings deepen our understanding of the regulation of neuronal development by JIP3 and provide us a novel view on the regulating mechanisms of neuronal radial migration. Copyright © 2017 Elsevier Inc. All rights reserved.

Quantitative analysis of random migration of cells using time-lapse video microscopy.

PubMed

Jain, Prachi; Worthylake, Rebecca A; Alahari, Suresh K

2012-05-13

Cell migration is a dynamic process, which is important for embryonic development, tissue repair, immune system function, and tumor invasion (1, 2). During directional migration, cells move rapidly in response to an extracellular chemotactic signal, or in response to intrinsic cues (3) provided by the basic motility machinery. Random migration occurs when a cell possesses low intrinsic directionality, allowing the cells to explore their local environment. Cell migration is a complex process, in the initial response cell undergoes polarization and extends protrusions in the direction of migration (2). Traditional methods to measure migration such as the Boyden chamber migration assay is an easy method to measure chemotaxis in vitro, which allows measuring migration as an end point result. However, this approach neither allows measurement of individual migration parameters, nor does it allow to visualization of morphological changes that cell undergoes during migration. Here, we present a method that allows us to monitor migrating cells in real time using video - time lapse microscopy. Since cell migration and invasion are hallmarks of cancer, this method will be applicable in studying cancer cell migration and invasion in vitro. Random migration of platelets has been considered as one of the parameters of platelet function (4), hence this method could also be helpful in studying platelet functions. This assay has the advantage of being rapid, reliable, reproducible, and does not require optimization of cell numbers. In order to maintain physiologically suitable conditions for cells, the microscope is equipped with CO(2) supply and temperature thermostat. Cell movement is monitored by taking pictures using a camera fitted to the microscope at regular intervals. Cell migration can be calculated by measuring average speed and average displacement, which is calculated by Slidebook software.

Treatment of hypoxic-ischemic encephalopathy in mouse by transplantation of embryonic stem cell-derived cells.

PubMed

Ma, Jie; Wang, Yu; Yang, Jianhua; Yang, Min; Chang, Keun-A; Zhang, Linhua; Jiang, Feng; Li, Yi; Zhang, Zhonggong; Heo, Chaejeong; Suh, Yoo-Hun

2007-07-01

A 7-day-old hypoxic-ischemic encephalopathy (HIE) mouse model was used to study the effect of transplantation of embryonic stem (ES) cell-derived cells on the HIE. After the inducement in vitro, the ES cell-derived cells expressed Nestin and MAP-2, rather than GFAP mRNA. After transplantation, ES cell-derived cells can survive, migrate into the injury site, and specifically differentiate into neurons, showing improvement of the learning ability and memory of the HIE mouse at 8 months post-transplantation. The non-grafted HIE mouse brain showed typical pathological changes in the hippocampus and cerebral cortex, where the number of neurons was reduced, while in the cell graft group, number of the neurons increased in the same regions. Although further study is necessary to elucidate the precise mechanisms responsible for this functional recovery, we believe that ES cells have advantages for use as a donor source in HIE.

Migration and site selection of Ornithodiplostomum ptychocheilus (Trematoda: Digenea) metacercariae in the brain of fathead minnows ( Pimephales promelas).

PubMed

Matisz, Chelsea E; Goater, Cameron P; Bray, Douglas

2010-04-01

The migration of subadult parasites to preferred sites within final hosts is well characterized. In contrast, the migration of larval stages of trematodes to specific sites within their second intermediate hosts is poorly understood. We used a serial necropsy approach to characterize the migration of Ornithodiplostomum ptychocheilus diplostomules from the point of cercarial penetration, to encystment within the outermost tissues of the brain of fathead minnows. Diplostomules utilized peripheral nerves to access the central nerve cord, or they used specific cranial nerves to directly access the brain. Within 3 h of exposure to cercariae, 46% of all diplostomules were observed within the medulla of the brain. Diplostomules subsequently utilized specific neural tracts to reach lateral regions of the outermost tissue layer of the optic lobes, the stratum marginale. Diplostomules remained in this layer during their 4-week growth phase, then shifted site to the adjacent meninges for encystment. Characterization of a habitat shift for developing versus encysted metacercariae helps explain the results of previous ecological studies that document transient changes in the effects of metacercariae on the surivival, behaviour, and anti-parasite defences of infected fish.

Modular control of endothelial sheet migration

PubMed Central

Vitorino, Philip; Meyer, Tobias

2008-01-01

Growth factor-induced migration of endothelial cell monolayers enables embryonic development, wound healing, and angiogenesis. Although collective migration is widespread and therapeutically relevant, the underlying mechanism by which cell monolayers respond to growth factor, sense directional signals, induce motility, and coordinate individual cell movements is only partially understood. Here we used RNAi to identify 100 regulatory proteins that enhance or suppress endothelial sheet migration into cell-free space. We measured multiple live-cell migration parameters for all siRNA perturbations and found that each targeted protein primarily regulates one of four functional outputs: cell motility, directed migration, cell–cell coordination, or cell density. We demonstrate that cell motility regulators drive random, growth factor-independent motility in the presence or absence of open space. In contrast, directed migration regulators selectively transduce growth factor signals to direct cells along the monolayer boundary toward open space. Lastly, we found that regulators of cell–cell coordination are growth factor-independent and reorient randomly migrating cells inside the sheet when boundary cells begin to migrate. Thus, cells transition from random to collective migration through a modular control system, whereby growth factor signals convert boundary cells into pioneers, while cells inside the monolayer reorient and follow pioneers through growth factor-independent migration and cell–cell coordination. PMID:19056882

The effects of chronic alcoholism on cell proliferation in the human brain.

PubMed

Sutherland, G T; Sheahan, P J; Matthews, J; Dennis, C V P; Sheedy, D S; McCrossin, T; Curtis, M A; Kril, J J

2013-09-01

Neurogenesis continues in the human subventricular zone and to a lesser extent in the hippocampal subgranular zone throughout life. Subventricular zone-derived neuroblasts migrate to the olfactory bulb where survivors become integrated as interneurons and are postulated to contribute to odor discrimination. Adult neurogenesis is dysregulated in many neurological, neurovascular and neurodegenerative diseases. Alcohol abuse can result in a neurodegenerative condition called alcohol-related brain damage. Alcohol-related brain damage manifests clinically as cognitive dysfunction and the loss of smell sensation (hyposmia) and pathologically as generalized white matter atrophy and focal neuronal loss. The exact mechanism linking chronic alcohol intoxication with alcohol-related brain damage remains largely unknown but rodent models suggest that decreased neurogenesis is an important component. We investigated this idea by comparing proliferative events in the subventricular zone and olfactory bulb of a well-characterized cohort of 15 chronic alcoholics and 16 age-matched controls. In contrast to the findings in animal models there was no difference in the number of proliferative cell nuclear antigen-positive cells in the subventricular zone of alcoholics (mean±SD=28.7±20.0) and controls (27.6±18.9, p=1.0). There were also no differences in either the total (p=0.89) or proliferative cells (p=0.98) in the granular cell layer of the olfactory bulb. Our findings show that chronic alcohol consumption does not affect cell proliferation in the human SVZ or olfactory bulb. In fact only microglial proliferation could be demonstrated in the latter. Therefore neurogenic deficits are unlikely to contribute to hyposmia in chronic alcoholics. Copyright © 2013 Elsevier Inc. All rights reserved.

Functional expression of calcium-permeable canonical transient receptor potential 4-containing channels promotes migration of medulloblastoma cells.

PubMed

Wei, Wei-Chun; Huang, Wan-Chen; Lin, Yu-Ping; Becker, Esther B E; Ansorge, Olaf; Flockerzi, Veit; Conti, Daniele; Cenacchi, Giovanna; Glitsch, Maike D

2017-08-15

The proton sensing ovarian cancer G protein coupled receptor 1 (OGR1, aka GPR68) promotes expression of the canonical transient receptor potential channel subunit TRPC4 in normal and transformed cerebellar granule precursor (DAOY) cells. OGR1 and TRPC4 are prominently expressed in healthy cerebellar tissue throughout postnatal development and in primary cerebellar medulloblastoma tissues. Activation of TRPC4-containing channels in DAOY cells, but not non-transformed granule precursor cells, results in prominent increases in [Ca 2+ ] i and promotes cell motility in wound healing and transwell migration assays. Medulloblastoma cells not arising from granule precursor cells show neither prominent rises in [Ca 2+ ] i nor enhanced motility in response to TRPC4 activation unless they overexpressTRPC4. Our results suggest that OGR1 enhances expression of TRPC4-containing channels that contribute to enhanced invasion and metastasis of granule precursor-derived human medulloblastoma. Aberrant intracellular Ca 2+ signalling contributes to the formation and progression of a range of distinct pathologies including cancers. Rises in intracellular Ca 2+ concentration occur in response to Ca 2+ influx through plasma membrane channels and Ca 2+ release from intracellular Ca 2+ stores, which can be mobilized in response to activation of cell surface receptors. Ovarian cancer G protein coupled receptor 1 (OGR1, aka GPR68) is a proton-sensing G q -coupled receptor that is most highly expressed in cerebellum. Medulloblastoma (MB) is the most common paediatric brain tumour that arises from cerebellar precursor cells. We found that nine distinct human MB samples all expressed OGR1. In both normal granule cells and the transformed human cerebellar granule cell line DAOY, OGR1 promoted expression of the proton-potentiated member of the canonical transient receptor potential (TRPC) channel family, TRPC4. Consistent with a role for TRPC4 in MB, we found that all MB samples also expressed TRPC4. In DAOY cells, activation of TRPC4-containing channels resulted in large Ca 2+ influx and enhanced migration, while in normal cerebellar granule (precursor) cells and MB cells not derived from granule precursors, only small levels of Ca 2+ influx and no enhanced migration were observed. Our results suggest that OGR1-dependent increases in TRPC4 expression may favour formation of highly Ca 2+ -permeable TRPC4-containing channels that promote transformed granule cell migration. Increased motility of cancer cells is a prerequisite for cancer invasion and metastasis, and our findings may point towards a key role for TRPC4 in progression of certain types of MB. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Preparative electrophoresis of cultured human cells: Effect of cell cycle phase

NASA Technical Reports Server (NTRS)

Kunze, M. E.; Todd, P. W.; Goolsby, C. L.; Walker, J. T.

1985-01-01

Human epithelioid T-1E cells were cultured in suspension and subjected to density gradient electrophoresis upward in a vertical column. It is indicated that the most rapidly migrating cells were at the beginning of the cell cycle and the most slowly migrating cells were at the end of the cell cycle. The fastest migrating cells divided 24 hr later than the slowest migrating cells. Colonies developing from slowly migrating cells had twice as many cells during exponential growth as did the most rapidly migrating cells, and the numbers of cells per colony at any time was inversely related to the electrophoretic migration rate. The DNA measurements by fluorescence flow cytometry indicates that the slowest migrating cell populations are enriched in cells that have twice as much DNA as the fastest migrating cells. It is concluded that electrophoretic mobility of these cultured human cells declines steadily through the cell cycle and that the mobility is lowest at the end of G sub 2 phase and highest at the beginning of G sub 1 phase.

Transmigration of Neural Stem Cells across the Blood Brain Barrier Induced by Glioma Cells

PubMed Central

Díaz-Coránguez, Mónica; Segovia, José; López-Ornelas, Adolfo; Puerta-Guardo, Henry; Ludert, Juan; Chávez, Bibiana; Meraz-Cruz, Noemi; González-Mariscal, Lorenza

2013-01-01

Transit of human neural stem cells, ReNcell CX, through the blood brain barrier (BBB) was evaluated in an in vitro model of BBB and in nude mice. The BBB model was based on rat brain microvascular endothelial cells (RBMECs) cultured on Millicell inserts bathed from the basolateral side with conditioned media (CM) from astrocytes or glioma C6 cells. Glioma C6 CM induced a significant transendothelial migration of ReNcells CX in comparison to astrocyte CM. The presence in glioma C6 CM of high amounts of HGF, VEGF, zonulin and PGE2, together with the low abundance of EGF, promoted ReNcells CX transmigration. In contrast cytokines IFN-α, TNF-α, IL-12p70, IL-1β, IL-6, IL-8 and IL-10, as well as metalloproteinases -2 and -9 were present in equal amounts in glioma C6 and astrocyte CMs. ReNcells expressed the tight junction proteins occludin and claudins 1, 3 and 4, and the cell adhesion molecule CRTAM, while RBMECs expressed occludin, claudins 1 and 5 and CRTAM. Competing CRTAM mediated adhesion with soluble CRTAM, inhibited ReNcells CX transmigration, and at the sites of transmigration, the expression of occludin and claudin-5 diminished in RBMECs. In nude mice we found that ReNcells CX injected into systemic circulation passed the BBB and reached intracranial gliomas, which overexpressed HGF, VEGF and zonulin/prehaptoglobin 2. PMID:23637756

Increased Transendothelial Transport of CCL3 Is Insufficient to Drive Immune Cell Transmigration through the Blood-Brain Barrier under Inflammatory Conditions In Vitro.

PubMed

De Laere, Maxime; Sousa, Carmelita; Meena, Megha; Buckinx, Roeland; Timmermans, Jean-Pierre; Berneman, Zwi; Cools, Nathalie

2017-01-01

Many neuroinflammatory diseases are characterized by massive immune cell infiltration into the central nervous system. Identifying the underlying mechanisms could aid in the development of therapeutic strategies specifically interfering with inflammatory cell trafficking. To achieve this, we implemented and validated a blood-brain barrier (BBB) model to study chemokine secretion, chemokine transport, and leukocyte trafficking in vitro. In a coculture model consisting of a human cerebral microvascular endothelial cell line and human astrocytes, proinflammatory stimulation downregulated the expression of tight junction proteins, while the expression of adhesion molecules and chemokines was upregulated. Moreover, chemokine transport across BBB cocultures was upregulated, as evidenced by a significantly increased concentration of the inflammatory chemokine CCL3 at the luminal side following proinflammatory stimulation. CCL3 transport occurred independently of the chemokine receptors CCR1 and CCR5, albeit that migrated cells displayed increased expression of CCR1 and CCR5. However, overall leukocyte transmigration was reduced in inflammatory conditions, although higher numbers of leukocytes adhered to activated endothelial cells. Altogether, our findings demonstrate that prominent barrier activation following proinflammatory stimulation is insufficient to drive immune cell recruitment, suggesting that additional traffic cues are crucial to mediate the increased immune cell infiltration seen in vivo during neuroinflammation.

Adult neural stem cell cycling in vivo requires thyroid hormone and its alpha receptor.

PubMed

Lemkine, G F; Raj, A; Alfama, G; Turque, N; Hassani, Z; Alegria-Prévot, O; Samarut, J; Levi, G; Demeneix, B A

2005-05-01

Thyroid hormones (TH) are essential for brain development. However, information on if and how this key endocrine factor affects adult neurogenesis is fragmentary. We thus investigated the effects of TH on proliferation and apoptosis of stem cells in the subventricular zone (SVZ), as well as on migration of transgene-tagged neuroblasts out of the stem cell niche. Hypothyroidism significantly reduced all three of these processes, inhibiting generation of new cells. To determine the mechanisms relaying TH action in the SVZ, we analyzed which receptor was implicated and whether the effects were played out directly at the level of the stem cell population. The alpha TH receptor (TRalpha), but not TRbeta, was found to be expressed in nestin positive progenitor cells of the SVZ. Further, use of TRalpha mutant mice showed TRalpha to be required to maintain full proliferative activity. Finally, a direct TH transcriptional effect, not mediated through other cell populations, was revealed by targeted gene transfer to stem cells in vivo. Indeed, TH directly modulated transcription from the c-myc promoter reporter construct containing a functional TH response element containing TRE but not from a mutated TRE sequence. We conclude that liganded-TRalpha is critical for neurogenesis in the adult mammalian brain.

Seasonal variation in telencephalon cell proliferation in adult female tsinling dwarf skinks (Scincella tsinlingensis).

PubMed

Yang, Chun; Wang, Limin; Xing, Xiangyang; Gao, Yanyan; Guo, Li

2017-05-01

In adult mammals, neurogenesis is limited to specific niches in the brain, but considerable adult neurogenesis occurs in many brain regions in non-mammalian vertebrates. Non-mammalian vertebrates provide invaluable comparative material for understanding the core mechanisms of adult neural stem cell maintenance and fate, but phylogenetic differences in adult neurogenesis remain poorly understood. Here we examine cell proliferation seasonality in the telencephalon of adult female tsinling dwarf skinks (Scincella tsinlingensis) by injecting wild animals caught in summer, autumn and spring, and animals caught in autumn and raised under winter conditions, with 5-Bromo-2'-deoxyuridine (BrdU). Then, 24h, 7d and 28d after BrdU administration we examined brain tissue and quantified BrdU-labeled cells as a marker of neuronal proliferation. The highest number of labeled cells in the telencephalon was found in the 7d group. BrdU-positive cells were widely distributed in the anterior olfactory nucleus (AON), medial cortex (MC), dorsal cortex (DC), lateral cortex (LC), dorsal ventricular ridge (DVR), septum (SP), striatum (STR) and nucleus sphericus (NS). No BrdU-positive cells were detected in olfactory bulbs or elsewhere in the telencephalon. The highest proliferative levels were found in the AON in autumn. The NS exhibited relatively high levels of cell proliferation. The proliferative rate in the AON fluctuated seasonally as autumn>summer>spring>winter. Glial fibrillary acidic protein-positive cells were widely distributed in the telencephalon and their fibrous processes extended into brain parenchyma and anchored in the meninges. Doublecortin-positive newborn neurons of the subventricular zone appeared to migrate into the cerebral cortex via the radial migratory stream. Cell proliferation in the telencephalon of adult female S. tsinlingensis fluctuates seasonally, especially in regions related to olfactory memory. This is the first demonstration of proliferative activity in the telencephalon of a skink. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinicopathologic features and pathogenesis of melanocytic colonization in atypical meningioma.

PubMed

Dehghan Harati, Mitra; Yu, Andrew; Magaki, Shino D; Perez-Rosendahl, Mari; Im, Kyuseok; Park, Young K; Bergsneider, Marvin; Yong, William H

2018-02-01

Only two prior cases of benign dendritic melanocytes colonizing a meningioma have been reported. We add a third case, describe clinicopathologic features shared by the three, and elucidate the risk factors for this very rare phenomenon. A 29 year-old Hispanic woman presented with headache and hydrocephalus. MRI showed a lobulated enhancing pineal region mass measuring 41 mm in greatest dimension. Subtotal resection of the mass demonstrated an atypical meningioma, WHO grade II, and the patient subsequently underwent radiotherapy. She presented 4 years later with diplopia, and MRI showed an enhancing extra-axial mass measuring 47 mm in greatest dimension and centered on the tentorial incisura. Subtotal resection showed a brain-invasive atypical meningioma with melanocytic colonization. The previous two cases in the literature were atypical meningiomas, one of which was also brain invasive. Atypical meningiomas may be at particular risk for melanocytic colonization as they upregulate molecules known to be chemoattractants for melanocytes. We detected c-Kit expression in a minority of the melanocytes as well as stem cell factor and basic fibroblast growth factor in the meningioma cells, suggesting that mechanisms implicated in normal melanocyte migration may be involved. In some cases, brain invasion with disruption of the leptomeningeal barrier may also facilitate migration from the subarachnoid space into the tumor. Whether there is low-level proliferation of the dendritic melanocytes is unclear. Given that all three patients were non-Caucasian, meningiomas in persons and/or brain regions with increased dendritic melanocytes may predispose to colonization. The age range spanned from 6 years old to 70 years old. All three patients were female. The role of gender and estrogen in the pathogenesis of this entity remains to be clarified. Whether melanocytic colonization may also occur in the more common Grade I meningiomas awaits identification of additional cases. © 2017 Japanese Society of Neuropathology.

The Development of a Novel High Throughput Computational Tool for Studying Individual and Collective Cellular Migration

PubMed Central

Chapnick, Douglas A.; Jacobsen, Jeremy; Liu, Xuedong

2013-01-01

Understanding how cells migrate individually and collectively during development and cancer metastasis can be significantly aided by a computation tool to accurately measure not only cellular migration speed, but also migration direction and changes in migration direction in a temporal and spatial manner. We have developed such a tool for cell migration researchers, named Pathfinder, which is capable of simultaneously measuring the migration speed, migration direction, and changes in migration directions of thousands of cells both instantaneously and over long periods of time from fluorescence microscopy data. Additionally, we demonstrate how the Pathfinder software can be used to quantify collective cell migration. The novel capability of the Pathfinder software to measure the changes in migration direction of large populations of cells in a spatiotemporal manner will aid cellular migration research by providing a robust method for determining the mechanisms of cellular guidance during individual and collective cell migration. PMID:24386097

Integrated Genomic and Epigenomic Analysis of Breast Cancer Brain Metastasis

PubMed Central

Salhia, Bodour; Kiefer, Jeff; Ross, Julianna T. D.; Metapally, Raghu; Martinez, Rae Anne; Johnson, Kyle N.; DiPerna, Danielle M.; Paquette, Kimberly M.; Jung, Sungwon; Nasser, Sara; Wallstrom, Garrick; Tembe, Waibhav; Baker, Angela; Carpten, John; Resau, Jim; Ryken, Timothy; Sibenaller, Zita; Petricoin, Emanuel F.; Liotta, Lance A.; Ramanathan, Ramesh K.; Berens, Michael E.; Tran, Nhan L.

2014-01-01

The brain is a common site of metastatic disease in patients with breast cancer, which has few therapeutic options and dismal outcomes. The purpose of our study was to identify common and rare events that underlie breast cancer brain metastasis. We performed deep genomic profiling, which integrated gene copy number, gene expression and DNA methylation datasets on a collection of breast brain metastases. We identified frequent large chromosomal gains in 1q, 5p, 8q, 11q, and 20q and frequent broad-level deletions involving 8p, 17p, 21p and Xq. Frequently amplified and overexpressed genes included ATAD2, BRAF, DERL1, DNMTRB and NEK2A. The ATM, CRYAB and HSPB2 genes were commonly deleted and underexpressed. Knowledge mining revealed enrichment in cell cycle and G2/M transition pathways, which contained AURKA, AURKB and FOXM1. Using the PAM50 breast cancer intrinsic classifier, Luminal B, Her2+/ER negative, and basal-like tumors were identified as the most commonly represented breast cancer subtypes in our brain metastasis cohort. While overall methylation levels were increased in breast cancer brain metastasis, basal-like brain metastases were associated with significantly lower levels of methylation. Integrating DNA methylation data with gene expression revealed defects in cell migration and adhesion due to hypermethylation and downregulation of PENK, EDN3, and ITGAM. Hypomethylation and upregulation of KRT8 likely affects adhesion and permeability. Genomic and epigenomic profiling of breast brain metastasis has provided insight into the somatic events underlying this disease, which have potential in forming the basis of future therapeutic strategies. PMID:24489661

Can mesenchymal cells undergo collective cell migration?

PubMed Central

Theveneau, Eric

2011-01-01

Cell migration is critical for proper development of the embryo and is also used by many cell types to perform their physiological function. For instance, cell migration is essential for immune cells to monitor the body and for epithelial cells to heal a wound whereas, in cancer cells, acquisition of migratory capabilities is a critical step toward malignancy. Migratory cells are often categorized into two groups: (1) mesenchymal cells, produced by an epithelium-to-mesenchyme transition, that undergo solitary migration and (2) epithelial-like cells which migrate collectively. However, on some occasions, mesenchymal cells may travel in large, dense groups and exhibit key features of collectively migrating cells such as coordination and cooperation. Here, using data published on neural crest cells, a highly invasive mesenchymal cell population that extensively migrate throughout the embryo, we explore the idea that mesenchymal cells, including cancer cells, might be able to undergo collective cell migration under certain conditions and discuss how they could do so. PMID:22274714

Regulation of Cell Migration in Breast Cancer

DTIC Science & Technology

2011-04-01

the wound healing, assay by scarring and Oris plate migration assay, transwell migration assay and live - cell imaging studies. Cell migration capacity...evaluated by the use of techniques that include the wound healing assay by scarring and Oris plate migration assay, transwell migration assay and live - cell imaging studies

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) promotes glioblastoma cell chemotaxis via Lyn activation

PubMed Central

Tran, Nhan L.

2014-01-01

The long-term survival of patients with glioblastoma is compromised by the proclivity for local invasion into the surrounding normal brain, escaping surgical resection and contributing to therapeutic resistance. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor superfamily, can stimulate glioma cell invasion via binding to fibroblast growth factor-inducible 14 (Fn14) and subsequent activation of the Rho guanosine triphosphatase family member Rac1. Here, we demonstrate that TWEAK acts as a chemotactic factor for glioma cells, a potential process for driving cell invasion into the surrounding brain tissue. TWEAK exposure induced the activation of Src family kinases (SFKs), and pharmacologic suppression of SFK activity inhibited TWEAK-induced chemotactic migration. We employed a multiplexed Luminex assay and identified Lyn as a candidate SFK activated by TWEAK. Depletion of Lyn suppressed TWEAK-induced chemotaxis and Rac1 activity. Furthermore, Lyn gene expression levels increase with primary glioma tumor grade and inversely correlate with patient survival. These results show that TWEAK-induced glioma cell chemotaxis is dependent upon Lyn kinase function and, thus, provides opportunities for therapeutic targeting of this deadly disease. PMID:23975833

Exosomal miR-9 Released from HIV Tat Stimulated Astrocytes Mediates Microglial Migration.

PubMed

Yang, Lu; Niu, Fang; Yao, Honghong; Liao, Ke; Chen, Xufeng; Kook, Yeonhee; Ma, Rong; Hu, Guoku; Buch, Shilpa

2018-03-01

Chronic neuroinflammation still remains a common underlying feature of HIV-infected patients on combined anti-retroviral therapy (cART). Previous studies have reported that despite near complete suppression of virus replication by cART, cytotoxic viral proteins such as HIV trans-activating regulatory protein (Tat) continue to persist in tissues such as the brain and the lymph nodes, thereby contributing, in part, to chronic glial activation observed in HIV-associated neurological disorders (HAND). Understanding how the glial cells cross talk to mediate neuropathology is thus of paramount importance. MicroRNAs (miR) also known as regulators of gene expression, have emerged as key paracrine signaling mediators that regulate disease pathogenesis and cellular crosstalk, through their transfer via the extracellular vesicles (EV). In the current study we have identified a novel function of miR-9, that of mediating microglial migration. We demonstrate that miR-9 released from Tat-stimulated astrocytes can be taken up by microglia resulting in their migratory phenotype. Exposure of human astrocytoma (A172) cells to HIV Tat resulted in induction and release of miR-9 in the EVs, which, was taken up by microglia, leading in turn, increased migration of the latter cells, a process that could be blocked by both an exosome inhibitor GW4869 or a specific target protector of miR-9. Furthermore, it was also demonstrated that EV miR-9 mediated inhibition of the expression of target PTEN, via its binding to the 3'UTR seed sequence of the PTEN mRNA, was critical for microglial migration. To validate the role of miR-9 in this process, microglial cells were treated with EVs loaded with miR-9, which resulted in significant downregulation of PTEN expression with a concomitant increase in microglial migration. These findings were corroborated by transfecting microglia with a specific target protector of PTEN, that blocked miR-9-mediated downregulation of PTEN as well as microglial migration. In vivo studies wherein the miR-9 precursor-transduced microglia were transplanted into the striatum of mice, followed by assessing their migration in response to a stimulus administered distally, further validated the role of miR-9 in mediating microglial migration. Collectively, our findings provide evidence that glial crosstalk via miRs released from EVs play a vital role in mediating disease pathogenesis and could provide new avenues for development of novel therapeutic strategies aimed at dampening neuropathogenesis.

A Novel c-Jun N-terminal Kinase (JNK) Signaling Complex Involved in Neuronal Migration during Brain Development.

PubMed

Zhang, Feng; Yu, Jingwen; Yang, Tao; Xu, Dan; Chi, Zhixia; Xia, Yanheng; Xu, Zhiheng

2016-05-27

Disturbance of neuronal migration may cause various neurological disorders. Both the transforming growth factor-β (TGF-β) signaling and microcephaly-associated protein WDR62 are important for neuronal migration during brain development; however, the underlying molecular mechanisms involved remain unclear. We show here that knock-out or knockdown of Tak1 (TGFβ-activated kinase 1) and Jnk2 (c-Jun N-terminal kinase 2) perturbs neuronal migration during cortical development and that the migration defects incurred by knock-out and/or knockdown of Tβr2 (type II TGF-β receptor) or Tak1 can be partially rescued by expression of TAK1 and JNK2, respectively. Furthermore, TAK1 forms a protein complex with RAC1 and two scaffold proteins of the JNK pathway, the microcephaly-associated protein WDR62 and the RAC1-interacting protein POSH (plenty of Src homology). Components of the complex coordinate with each other in the regulation of TAK1 as well as JNK activities. We suggest that unique JNK protein complexes are involved in the diversified biological and pathological functions during brain development and pathogenesis of diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Overexpression of miR-29a reduces the oncogenic properties of glioblastoma stem cells by downregulating Quaking gene isoform 6.

PubMed

Xi, Zhuo; Wang, Ping; Xue, Yixue; Shang, Chao; Liu, Xiaobai; Ma, Jun; Li, Zhiqing; Li, Zhen; Bao, Min; Liu, Yunhui

2017-04-11

Glioblastoma is the most common type of malignant primary brain tumor and has high recurrence and lethality rates. Glioblastoma stem cells (GSCs), a subpopulation of glioblastoma cells, may promote rapid tumor recurrence and therapy resistance. Because altered microRNA (miR) expression in GSCs may lead to glioblastoma progression, we assessed the effects of miR-29a expression on the oncogenic behavior of GSCs. MiR-29a expression was lower in GSCs than non-GSCs, and overexpression of miR-29a in GSCs inhibited cell proliferation, migration and invasion, but promoted apoptosis. MiR-29a directly inhibited the expression of Quaking gene isoform 6 (QKI-6) by binding to its 3'-UTR, and thus inhibited GSC malignant behavior. In addition, Wilms' tumor 1-associating protein (WTAP) was identified as a downstream target of QKI-6. Overexpression of miR-29a in GSCs inhibited expression of WTAP and suppressed both phosphoinositide 3-kinase/AKT and extracellular signal-related kinase pathways by downregulating QKI-6, thereby inhibiting cell proliferation, migration, and invasion but promoting apoptosis. We have characterized a novel miR-29a/QKI-6/WTAP axis in GSCs, which may provide theoretical support for the treatment of glioblastoma with miR-29a agomirs.

OTX2 exhibits cell-context-dependent effects on cellular and molecular properties of human embryonic neural precursors and medulloblastoma cells

PubMed Central

Kaur, Ravinder; Aiken, Christopher; Morrison, Ludivine Coudière; Rao, Radhika; Del Bigio, Marc R.; Rampalli, Shravanti; Werbowetski-Ogilvie, Tamra

2015-01-01

ABSTRACT Medulloblastoma (MB) is the most common malignant primary pediatric brain tumor and is currently divided into four subtypes based on different genomic alterations, gene expression profiles and response to treatment: WNT, Sonic Hedgehog (SHH), Group 3 and Group 4. This extensive heterogeneity has made it difficult to assess the functional relevance of genes to malignant progression. For example, expression of the transcription factor Orthodenticle homeobox2 (OTX2) is frequently dysregulated in multiple MB variants; however, its role may be subtype specific. We recently demonstrated that neural precursors derived from transformed human embryonic stem cells (trans-hENs), but not their normal counterparts (hENs), resemble Groups 3 and 4 MB in vitro and in vivo. Here, we tested the utility of this model system as a means of dissecting the role of OTX2 in MB using gain- and loss-of-function studies in hENs and trans-hENs, respectively. Parallel experiments with MB cells revealed that OTX2 exerts inhibitory effects on hEN and SHH MB cells by regulating growth, self-renewal and migration in vitro and tumor growth in vivo. This was accompanied by decreased expression of pluripotent genes, such as SOX2, and was supported by overexpression of SOX2 in OTX2+ SHH MB and hENs that resulted in significant rescue of self-renewal and cell migration. By contrast, OTX2 is oncogenic and promotes self-renewal of trans-hENs and Groups 3 and 4 MB independent of pluripotent gene expression. Our results demonstrate a novel role for OTX2 in self-renewal and migration of hENs and MB cells and reveal a cell-context-dependent link between OTX2 and pluripotent genes. Our study underscores the value of human embryonic stem cell derivatives as alternatives to cell lines and heterogeneous patient samples for investigating the contribution of key developmental regulators to MB progression. PMID:26398939

Thyroid hormone enhanced human hepatoma cell motility involves brain-specific serine protease 4 activation via ERK signaling

PubMed Central

2014-01-01

Background The thyroid hormone, 3, 3′, 5-triiodo-L-thyronine (T3), has been shown to modulate cellular processes via interactions with thyroid hormone receptors (TRs), but the secretory proteins that are regulated to exert these effects remain to be characterized. Brain-specific serine protease 4 (BSSP4), a member of the human serine protease family, participates in extracellular matrix remodeling. However, the physiological role and underlying mechanism of T3-mediated regulation of BSSP4 in hepatocellular carcinogenesis are yet to be established. Methods The thyroid hormone response element was identified by reporter and chromatin immunoprecipitation assays. The cell motility was analyzed via transwell and SCID mice. The BSSP4 expression in clinical specimens was examined by Western blot and quantitative reverse transcription polymerase chain reaction. Results Upregulation of BSSP4 at mRNA and protein levels after T3 stimulation is a time- and dose-dependent manner in hepatoma cell lines. Additionally, the regulatory region of the BSSP4 promoter stimulated by T3 was identified at positions -609/-594. BSSP4 overexpression enhanced tumor cell migration and invasion, both in vitro and in vivo. Subsequently, BSSP4-induced migration occurs through the ERK 1/2-C/EBPβ-VEGF cascade, similar to that observed in HepG2-TRα1 and J7-TRα1 cells. BSSP4 was overexpressed in clinical hepatocellular carcinoma (HCC) patients, compared with normal subjects, and positively associated with TRα1 and VEGF to a significant extent. Importantly, a mild association between BSSP4 expression and distant metastasis was observed. Conclusions Our findings collectively support a potential role of T3 in cancer cell progression through regulation of the BSSP4 protease via the ERK 1/2-C/EBPβ-VEGF cascade. BSSP4 may thus be effectively utilized as a novel marker and anti-cancer therapeutic target in HCC. PMID:24980078

Thyroid hormone enhanced human hepatoma cell motility involves brain-specific serine protease 4 activation via ERK signaling.

PubMed

Chen, Cheng-Yi; Chung, I-Hsiao; Tsai, Ming-Ming; Tseng, Yi-Hsin; Chi, Hsiang-Cheng; Tsai, Chung-Ying; Lin, Yang-Hsiang; Wang, You-Ching; Chen, Chie-Pein; Wu, Tzu-I; Yeh, Chau-Ting; Tai, Dar-In; Lin, Kwang-Huei

2014-07-01

The thyroid hormone, 3, 3', 5-triiodo-L-thyronine (T3), has been shown to modulate cellular processes via interactions with thyroid hormone receptors (TRs), but the secretory proteins that are regulated to exert these effects remain to be characterized. Brain-specific serine protease 4 (BSSP4), a member of the human serine protease family, participates in extracellular matrix remodeling. However, the physiological role and underlying mechanism of T3-mediated regulation of BSSP4 in hepatocellular carcinogenesis are yet to be established. The thyroid hormone response element was identified by reporter and chromatin immunoprecipitation assays. The cell motility was analyzed via transwell and SCID mice. The BSSP4 expression in clinical specimens was examined by Western blot and quantitative reverse transcription polymerase chain reaction. Upregulation of BSSP4 at mRNA and protein levels after T3 stimulation is a time- and dose-dependent manner in hepatoma cell lines. Additionally, the regulatory region of the BSSP4 promoter stimulated by T3 was identified at positions -609/-594. BSSP4 overexpression enhanced tumor cell migration and invasion, both in vitro and in vivo. Subsequently, BSSP4-induced migration occurs through the ERK 1/2-C/EBPβ-VEGF cascade, similar to that observed in HepG2-TRα1 and J7-TRα1 cells. BSSP4 was overexpressed in clinical hepatocellular carcinoma (HCC) patients, compared with normal subjects, and positively associated with TRα1 and VEGF to a significant extent. Importantly, a mild association between BSSP4 expression and distant metastasis was observed. Our findings collectively support a potential role of T3 in cancer cell progression through regulation of the BSSP4 protease via the ERK 1/2-C/EBPβ-VEGF cascade. BSSP4 may thus be effectively utilized as a novel marker and anti-cancer therapeutic target in HCC.

Identification of brain metastasis genes and therapeutic evaluation of histone deacetylase inhibitors in a clinically relevant model of breast cancer brain metastasis.

PubMed

Kim, Soo-Hyun; Redvers, Richard P; Chi, Lap Hing; Ling, Xiawei; Lucke, Andrew J; Reid, Robert C; Fairlie, David P; Baptista Moreno Martin, Ana Carolina; Anderson, Robin L; Denoyer, Delphine; Pouliot, Normand

2018-05-21

Breast cancer brain metastasis remains largely incurable. While several mouse models have been developed to investigate the genes and mechanisms regulating breast cancer brain metastasis, these models often lack clinical relevance since they require the use of immune-compromised mice and/or are poorly metastatic to brain from the mammary gland. We describe the development and characterisation of an aggressive brain metastatic variant of the 4T1 syngeneic model (4T1Br4) that spontaneously metastasises to multiple organs, but is selectively more metastatic to the brain from the mammary gland than parental 4T1 tumours. By immunohistochemistry, 4T1Br4 tumours and brain metastases display a triple negative phenotype, consistent with the high propensity of this breast cancer subtype to spread to brain. In vitro assays indicate that 4T1Br4 cells have an enhanced ability to adhere to or migrate across a brain-derived endothelial monolayer and greater invasive response to brain-derived soluble factors compared to 4T1 cells. These properties are likely to contribute to the brain-selectivity of 4T1Br4 tumours. Expression profiling and gene set enrichment analyses demonstrate the clinical relevance of the 4T1Br4 model at the transcriptomic level. Pathway analyses implicate tumour-intrinsic immune regulation and vascular interactions in successful brain colonisation, revealing potential therapeutic targets. Evaluation of two histone deacetylase inhibitors, SB939 and 1179.4b, shows partial efficacy against 4T1Br4 metastasis to brain and other sites in vivo and potent radio-sensitising properties in vitro The 4T1Br4 model provides a clinically relevant tool for mechanistic studies and to evaluate novel therapies against brain metastasis. © 2018. Published by The Company of Biologists Ltd.

p75 neurotrophin receptor and pro-BDNF promote cell survival and migration in clear cell renal cell carcinoma

PubMed Central

Sánchez-Prieto, Ricardo; Saada, Sofiane; Naves, Thomas; Guillaudeau, Angélique; Perraud, Aurélie; Sindou, Philippe; Lacroix, Aurélie; Descazeaud, Aurélien; Lalloué, Fabrice; Jauberteau, Marie-Odile

2016-01-01

p75NTR, a member of TNF receptor family, is the low affinity receptor common to several mature neurotrophins and the high affinity receptor for pro-neurotrophins. Brain-Derived Neurotrophic Factor (BDNF), a member of neurotrophin family has been described to play an important role in development and progression of several cancers, through its binding to a high affinity tyrosine kinase receptor B (TrkB) and/or p75NTR. However, the functions of these two receptors in renal cell carcinoma (RCC) have never been investigated. An overexpression of p75NTR, pro-BDNF, and to a lesser extent for TrkB and sortilin, was detected by immunohistochemistry in a cohort of 83 clear cell RCC tumors. p75NTR, mainly expressed in tumor tissues, was significantly associated with higher Fuhrman grade in multivariate analysis. In two derived-RCC lines, 786-O and ACHN cells, we demonstrated that pro-BDNF induced cell survival and migration, through p75NTR as provided by p75NTR RNA silencing or blocking anti-p75NTR antibody. This mechanism is independent of TrkB activation as demonstrated by k252a, a tyrosine kinase inhibitor for Trk neurotrophin receptors. Taken together, these data highlight for the first time an important role for p75NTR in renal cancer and indicate a putative novel target therapy in RCC. PMID:27120782

Co-Regulation of Cell Polarization and Migration by Caveolar Proteins PTRF/Cavin-1 and Caveolin-1

PubMed Central

Hill, Michelle M.; Daud, Noor Huda; Aung, Cho Sanda; Loo, Dorothy; Martin, Sally; Murphy, Samantha; Black, Debra M.; Barry, Rachael; Simpson, Fiona; Liu, Libin; Pilch, Paul F.; Hancock, John F.; Parat, Marie-Odile; Parton, Robert G.

2012-01-01

Caveolin-1 and caveolae are differentially polarized in migrating cells in various models, and caveolin-1 expression has been shown to quantitatively modulate cell migration. PTRF/cavin-1 is a cytoplasmic protein now established to be also necessary for caveola formation. Here we tested the effect of PTRF expression on cell migration. Using fluorescence imaging, quantitative proteomics, and cell migration assays we show that PTRF/cavin-1 modulates cellular polarization, and the subcellular localization of Rac1 and caveolin-1 in migrating cells as well as PKCα caveola recruitment. PTRF/cavin-1 quantitatively reduced cell migration, and induced mesenchymal epithelial reversion. Similar to caveolin-1, the polarization of PTRF/cavin-1 was dependent on the migration mode. By selectively manipulating PTRF/cavin-1 and caveolin-1 expression (and therefore caveola formation) in multiple cell systems, we unveil caveola-independent functions for both proteins in cell migration. PMID:22912783

Epithelial-mesenchymal transition transcription factors control pluripotent adult stem cell migration in vivo in planarians

PubMed Central

Abnave, Prasad; Aboukhatwa, Ellen; Kosaka, Nobuyoshi; Thompson, James; Hill, Mark A.

2017-01-01

Migration of stem cells underpins the physiology of metazoan animals. For tissues to be maintained, stem cells and their progeny must migrate and differentiate in the correct positions. This need is even more acute after tissue damage by wounding or pathogenic infection. Inappropriate migration also underpins metastasis. Despite this, few mechanistic studies address stem cell migration during repair or homeostasis in adult tissues. Here, we present a shielded X-ray irradiation assay that allows us to follow stem cell migration in planarians. We demonstrate the use of this system to study the molecular control of stem cell migration and show that snail-1, snail-2 and zeb-1 EMT transcription factor homologs are necessary for cell migration to wound sites and for the establishment of migratory cell morphology. We also observed that stem cells undergo homeostatic migration to anterior regions that lack local stem cells, in the absence of injury, maintaining tissue homeostasis. This requires the polarity determinant notum. Our work establishes planarians as a suitable model for further in-depth study of the processes controlling stem cell migration in vivo. PMID:28893948

Checkpoints to the Brain: Directing Myeloid Cell Migration to the Central Nervous System

PubMed Central

Harrison-Brown, Meredith; Liu, Guo-Jun; Banati, Richard

2016-01-01

Myeloid cells are a unique subset of leukocytes with a diverse array of functions within the central nervous system during health and disease. Advances in understanding of the unique properties of these cells have inspired interest in their use as delivery vehicles for therapeutic genes, proteins, and drugs, or as “assistants” in the clean-up of aggregated proteins and other molecules when existing drainage systems are no longer adequate. The trafficking of myeloid cells from the periphery to the central nervous system is subject to complex cellular and molecular controls with several ‘checkpoints’ from the blood to their destination in the brain parenchyma. As important components of the neurovascular unit, the functional state changes associated with lineage heterogeneity of myeloid cells are increasingly recognized as important for disease progression. In this review, we discuss some of the cellular elements associated with formation and function of the neurovascular unit, and present an update on the impact of myeloid cells on central nervous system (CNS) diseases in the laboratory and the clinic. We then discuss emerging strategies for harnessing the potential of site-directed myeloid cell homing to the CNS, and identify promising avenues for future research, with particular emphasis on the importance of untangling the functional heterogeneity within existing myeloid subsets. PMID:27918464

Vasculostatin inhibits intracranial glioma growth and negatively regulates in vivo angiogenesis through a CD36-dependent mechanism

PubMed Central

Kaur, Balveen; Cork, Sarah M; Sandberg, Eric M; Devi, Narra S; Zhang, Zhaobin; Klenotic, Philip A; Febbraio, Maria; Shim, Hyunsuk; Mao, Hui; Tucker-Burden, Carol; Silverstein, Roy L; Brat, Daniel J; Olson, Jeffrey J; Van Meir, Erwin G

2008-01-01

Angiogenesis is a critical physiological process that is appropriated during tumorigenesis. Little is known about how this process is specifically regulated in the brain. Brain Angiogenesis Inhibitor-1 (BAI1) is a primarily brain specific seven-transmembrane protein that contains five anti-angiogenic thrombospondin type-1 repeats (TSR). We recently showed that BAI1 is cleaved at a conserved proteolytic cleavage site releasing a soluble, 120 kDa anti-angiogenic factor called Vasculostatin (Vstat120). Vstat120 has been shown to inhibit in vitro angiogenesis and suppress subcutaneous tumor growth. Here, we examine its effect on intracranial growth of malignant gliomas and further study the mechanism of its anti-tumor effects. First, we show that expression of Vstat120 strongly suppresses the intracranial growth of malignant gliomas, even in the presence of the strong pro-angiogenic stimulus mediated by the oncoprotein Epidermal Growth Factor Receptor variant III (EGFRvIII). This tumor suppressive effect is accompanied by a decrease in vascular density in the tumors, suggesting a potent anti-angiogenic effect in the brain. Second, and consistent with this interpretation, we find that treatment with Vstat120 reduces the migration of cultured microvascular endothelial cells in vitro and inhibits corneal angiogenesis in vivo. Third, we demonstrate that these anti-vascular effects are critically dependent on the presence of the cell surface receptor CD36 on endothelial cells in vitro and in vivo, supporting a role of the Vstat120 TSRs in mediating these effects. These results advance the understanding of brain-specific angiogenic regulation, and suggest that Vstat120 has therapeutic potential in the treatment of brain tumors and other intra-cerebral vasculopathies. PMID:19176395

CXCL12 modulation of CXCR4 and CXCR7 activity in human glioblastoma stem-like cells and regulation of the tumor microenvironment.

PubMed

Würth, Roberto; Bajetto, Adriana; Harrison, Jeffrey K; Barbieri, Federica; Florio, Tullio

2014-01-01

Chemokines are crucial autocrine and paracrine players in tumor development. In particular, CXCL12, through its receptors CXCR4 and CXCR7, affects tumor progression by controlling cancer cell survival, proliferation and migration, and, indirectly, via angiogenesis or recruiting immune cells. Glioblastoma (GBM) is the most prevalent primary malignant brain tumor in adults and despite current multimodal therapies it remains almost incurable. The aggressive and recurrent phenotype of GBM is ascribed to high growth rate, invasiveness to normal brain, marked angiogenesis, ability to escape the immune system and resistance to standard of care therapies. Tumor molecular and cellular heterogeneity severely hinders GBM therapeutic improvement. In particular, a subpopulation of chemo- and radio-therapy resistant tumorigenic cancer stem-like cells (CSCs) is believed to be the main responsible for tumor cell dissemination to the brain. GBM cells display heterogeneous expression levels of CXCR4 and CXCR7 that are overexpressed in CSCs, representing a molecular correlate for the invasive potential of GBM. The microenvironment contribution in GBM development is increasingly emphasized. An interplay exists between CSCs, differentiated GBM cells, and the microenvironment, mainly through secreted chemokines (e.g., CXCL12) causing recruitment of fibroblasts, endothelial, mesenchymal and inflammatory cells to the tumor, via specific receptors such as CXCR4. This review covers recent developments on the role of CXCL12/CXCR4-CXCR7 networks in GBM progression and the potential translational impact of their targeting. The biological and molecular understanding of the heterogeneous GBM cell behavior, phenotype and signaling is still limited. Progress in the identification of chemokine-dependent mechanisms that affect GBM cell survival, trafficking and chemo-attractive functions, opens new perspectives for development of more specific therapeutic approaches that include chemokine-based drugs.

Exposure to 3G mobile phone signals does not affect the biological features of brain tumor cells.

PubMed

Liu, Yu-xiao; Li, Guo-qing; Fu, Xiang-ping; Xue, Jing-hui; Ji, Shou-ping; Zhang, Zhi-wen; Zhang, Yi; Li, An-ming

2015-08-08

The increase in mobile phone use has generated concerns about possible risks to human health, especially the development of brain tumors. Whether tumor patients should continue to use mobile telephones has remained unclear because of a paucity of information. Herein, we investigated whether electromagnetic fields from mobile phones could alter the biological features of human tumor cells and act as a tumor-promoting agent. Human glioblastoma cell lines, U251-MG and U87-MG, were exposed to 1950-MHz time division-synchronous code division multiple access (TD-SCDMA) at a specific absorption rate (maximum SAR = 5.0 W/kg) for 12, 24, and 48 h. Cell morphologies and ultra-structures were observed by microscopy and the rates of apoptosis and cell cycle progression were monitored by flow cytometry. Additionally, cell growth was determined using the CKK-8 assay, and the expression levels of tumor and apoptosis-related genes and proteins were analyzed by real-time PCR and western blotting, respectively. Tumor formation and invasiveness were measured using a tumorigenicity assay in vivo and migration assays in vitro. No significant differences in either biological features or tumor formation ability were observed between unexposed and exposed glioblastoma cells. Our data showed that exposure to 1950-MHz TD-SCDMA electromagnetic fields for up to 48 h did not act as a cytotoxic or tumor-promoting agent to affect the proliferation or gene expression profile of glioblastoma cells. Our findings implied that exposing brain tumor cells in vitro for up to 48 h to 1950-MHz continuous TD-SCDMA electromagnetic fields did not elicit a general cell stress response.

Pertussis toxin permeabilization enhances the traversal of Escherichia coli K1, macrophages, and monocytes in a cerebral endothelial barrier model in vitro.

PubMed

Seidel, Gabriela; Böcker, Kathrin; Schulte, Jessica; Wewer, Corinna; Greune, Lilo; Humberg, Verena; Schmidt, M Alexander

2011-03-01

The occasionally severe neurological complications following the human respiratory tract infection 'whooping cough' have been attributed to pertussis toxin (PT) expressed by the causative agent Bordetella pertussis. Disruption of the endothelial blood-brain barrier (BBB) by PT might facilitate the translocation of immune cells and of hematogenous microbial pathogens. To test this hypothesis, we investigated whether PT enhances the traversal of bacteria employing human brain microvascular endothelial cells (HBMEC) as an in vitro endothelial barrier model. PT incubation significantly increased the translocation of Escherichia coli K1 across the HBMEC barrier. Only intercellular E. coli K1 bacteria could be identified by electron microscopy suggesting paracellular translocation. In addition, the migration of differentiated HL60-derived macrophages and of human monocytic U937 cells through PT-treated HBMEC barriers was also enhanced. In comparison to E. coli C600, E. coli K1 showed prolonged survival in translocated HL60-derived and J774 macrophages as well as in U937 monocytes which suggested a contribution of the 'Trojan horse' mechanism. In summary, our findings demonstrate that the PT-induced permeabilization of endothelial barriers enhances the paracellular transmigration of microbes and immune cells. In vivo, this activity might lower the threshold of bacteremia facilitating secondary cerebral infections and the subsequent development of brain pathologies. Copyright © 2010 Elsevier GmbH. All rights reserved.

IGF-I: A Key Growth Factor that Regulates Neurogenesis and Synaptogenesis from Embryonic to Adult Stages of the Brain

PubMed Central

Nieto-Estévez, Vanesa; Defterali, Çağla; Vicario-Abejón, Carlos

2016-01-01

The generation of neurons in the adult mammalian brain requires the activation of quiescent neural stem cells (NSCs). This activation and the sequential steps of neuron formation from NSCs are regulated by a number of stimuli, which include growth factors. Insulin-like growth factor-I (IGF-I) exert pleiotropic effects, regulating multiple cellular processes depending on their concentration, cell type, and the developmental stage of the animal. Although IGF-I expression is relatively high in the embryonic brain its levels drop sharply in the adult brain except in neurogenic regions, i.e., the hippocampus (HP) and the subventricular zone-olfactory bulb (SVZ-OB). By contrast, the expression of IGF-IR remains relatively high in the brain irrespective of the age of the animal. Evidence indicates that IGF-I influences NSC proliferation and differentiation into neurons and glia as well as neuronal maturation including synapse formation. Furthermore, recent studies have shown that IGF-I not only promote adult neurogenesis by regulating NSC number and differentiation but also by influencing neuronal positioning and migration as described during SVZ-OB neurogenesis. In this article we will revise and discuss the actions reported for IGF-I signaling in a variety of in vitro and in vivo models, focusing on the maintenance and proliferation of NSCs/progenitors, neurogenesis, and neuron integration in synaptic circuits. PMID:26941597

Role of mTOR Complexes in Neurogenesis.

PubMed

LiCausi, Francesca; Hartman, Nathaniel W

2018-05-22

Dysregulation of neural stem cells (NSCs) is associated with several neurodevelopmental disorders, including epilepsy and autism spectrum disorder. The mammalian target of rapamycin (mTOR) integrates the intracellular signals to control cell growth, nutrient metabolism, and protein translation. mTOR regulates many functions in the development of the brain, such as proliferation, differentiation, migration, and dendrite formation. In addition, mTOR is important in synaptic formation and plasticity. Abnormalities in mTOR activity is linked with severe deficits in nervous system development, including tumors, autism, and seizures. Dissecting the wide-ranging roles of mTOR activity during critical periods in development will greatly expand our understanding of neurogenesis.

Plasticity and Adult Neurogenesis in Amphibians and Reptiles: More Questions than Answers.

PubMed

Powers, Alice Schade

2016-08-24

Studies of the relationship between behavioral plasticity and new cells in the adult brain in amphibians and reptiles are sparse but demonstrate that environmental and hormonal variables do have an effect on the amount of cell proliferation and/or migration. The variables that are reviewed here are: enriched environment, social stimulation, spatial area use, season, photoperiod and temperature, and testosterone. Fewer data are available for amphibians than for reptiles, but for both groups many issues are still to be resolved. It is to be hoped that the questions raised here will generate more answers in future studies. © 2016 S. Karger AG, Basel.

Mib1 contributes to persistent directional cell migration by regulating the Ctnnd1-Rac1 pathway.

PubMed

Mizoguchi, Takamasa; Ikeda, Shoko; Watanabe, Saori; Sugawara, Michiko; Itoh, Motoyuki

2017-10-31

Persistent directional cell migration is involved in animal development and diseases. The small GTPase Rac1 is involved in F-actin and focal adhesion dynamics. Local Rac1 activity is required for persistent directional migration, whereas global, hyperactivated Rac1 enhances random cell migration. Therefore, precise control of Rac1 activity is important for proper directional cell migration. However, the molecular mechanism underlying the regulation of Rac1 activity in persistent directional cell migration is not fully understood. Here, we show that the ubiquitin ligase mind bomb 1 (Mib1) is involved in persistent directional cell migration. We found that knockdown of MIB1 led to an increase in random cell migration in HeLa cells in a wound-closure assay. Furthermore, we explored novel Mib1 substrates for cell migration and found that Mib1 ubiquitinates Ctnnd1. Mib1-mediated ubiquitination of Ctnnd1 K547 attenuated Rac1 activation in cultured cells. In addition, we found that posterior lateral line primordium cells in the zebrafish mib1 ta52b mutant showed increased random migration and loss of directional F-actin-based protrusion formation. Knockdown of Ctnnd1 partially rescued posterior lateral line primordium cell migration defects in the mib1 ta52b mutant. Taken together, our data suggest that Mib1 plays an important role in cell migration and that persistent directional cell migration is regulated, at least in part, by the Mib1-Ctnnd1-Rac1 pathway. Published under the PNAS license.

Photo-activated Cancer Therapy: Potential for Treatment of Brain Tumors

NASA Astrophysics Data System (ADS)

Hirschberg, Henry

The diffuse and infiltrative nature of high grade gliomas, such as glioblastoma multiforme (GBM), makes complete surgical resection virtually impossible. The propensity of glioma cells to migrate along white matter tracts suggests that a cure is possible only if these migratory cells can be eradicated. Approximately 80% of GBMs recur within 2 cm of the resection margin, suggesting that a reasonable approach for improving the prognosis of GBM patients would be the development of improved local therapies capable of eradicating glioma cells in the brain-adjacent-to-tumor (BAT). An additional complicating factor for the development of successful therapies is the presence of the blood-brain barrier (BBB) which is highly variable throughout the BAT—it is intact in some regions, while leaky in others. This variance in BBB patency has significant implications for the delivery of therapeutic agents. The results of a number of studies have shown that experimental light-based therapeutic modalities such as photochemical internalization (PCI) and photothermal therapy (PTT) may be useful in the treatment of gliomas. This chapter summarizes recent findings illustrating the potential of: (1) PCI for the delivery of therapeutic macromolecules such as chemotherapeutic agents and tumor suppressor genes, and (2) nanoshell-mediated PTT, including nanoparticle delivery approaches via macrophages.

A single rapamycin dose protects against late-stage experimental cerebral malaria via modulation of host immunity, endothelial activation and parasite sequestration.

PubMed

Mejia, Pedro; Treviño-Villarreal, J Humberto; Reynolds, Justin S; De Niz, Mariana; Thompson, Andrew; Marti, Matthias; Mitchell, James R

2017-11-09

Maladaptive immune responses during cerebral malaria (CM) result in high mortality despite opportune anti-malarial chemotherapy. Rapamycin, an FDA-approved immunomodulator, protects against experimental cerebral malaria (ECM) in mice through effects on the host. However, the potential for reduced adaptive immunity with chronic use, combined with an incomplete understanding of mechanisms underlying protection, limit translational potential as an adjunctive therapy in CM. The results presented herein demonstrate that a single dose of rapamycin, provided as late as day 4 or 5 post-infection, protected mice from ECM neuropathology and death through modulation of distinct host responses to infection. Rapamycin prevented parasite cytoadherence in peripheral organs, including white adipose tissue, via reduction of CD36 expression. Rapamycin also altered the splenic immune response by reducing the number of activated T cells with migratory phenotype, while increasing local cytotoxic T cell activation. Finally, rapamycin reduced brain endothelial ICAM-1 expression concomitant with reduced brain pathology. Together, these changes potentially contributed to increased parasite elimination while reducing CD8 T cell migration to the brain. Rapamycin exerts pleotropic effects on host immunity, vascular activation and parasite sequestration that rescue mice from ECM, and thus support the potential clinical use of rapamycin as an adjunctive therapy in CM.

Neural stem cell apoptosis after low-methylmercury exposures in postnatal hippocampus produce persistent cell loss and adolescent memory deficits.

PubMed

Sokolowski, Katie; Obiorah, Maryann; Robinson, Kelsey; McCandlish, Elizabeth; Buckley, Brian; DiCicco-Bloom, Emanuel

2013-12-01

The developing brain is particularly sensitive to exposures to environmental contaminants. In contrast to the adult, the developing brain contains large numbers of dividing neuronal precursors, suggesting that they may be vulnerable targets. The postnatal day 7 (P7) rat hippocampus has populations of both mature neurons in the CA1-3 region as well as neural stem cells (NSC) in the dentate gyrus (DG) hilus, which actively produce new neurons that migrate to the granule cell layer (GCL). Using this well-characterized NSC population, we examined the impact of low levels of methylmercury (MeHg) on proliferation, neurogenesis, and subsequent adolescent learning and memory behavior. Assessing a range of exposures, we found that a single subcutaneous injection of 0.6 µg/g MeHg in P7 rats induced caspase activation in proliferating NSC of the hilus and GCL. This acute NSC death had lasting impact on the DG at P21, reducing cell numbers in the hilus by 22% and the GCL by 27%, as well as reductions in neural precursor proliferation by 25%. In contrast, non-proliferative CA1-3 pyramidal neuron cell number was unchanged. Furthermore, animals exposed to P7 MeHg exhibited an adolescent spatial memory deficit as assessed by Morris water maze. These results suggest that environmentally relevant levels of MeHg exposure may decrease NSC populations and, despite ongoing neurogenesis, the brain may not restore the hippocampal cell deficits, which may contribute to hippocampal-dependent memory deficits during adolescence. Copyright © 2013 Wiley Periodicals, Inc.