401
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Sievertzon M, Wirta V, Mercer A, Frisén J, Lundeberg J. Epidermal growth factor (EGF) withdrawal masks gene expression differences in the study of pituitary adenylate cyclase-activating polypeptide (PACAP) activation of primary neural stem cell proliferation. BMC Neurosci 2005; 6:55. [PMID: 16124881 PMCID: PMC1208901 DOI: 10.1186/1471-2202-6-55] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Accepted: 08/28/2005] [Indexed: 11/23/2022] Open
Abstract
Background The recently discovered adult neural stem cells, which maintain continuous generation of new neuronal and glial cells throughout adulthood, are a promising and expandable source of cells for use in cell replacement therapies within the central nervous system. These cells could either be induced to proliferate and differentiate endogenously, or expanded and differentiated in culture before being transplanted into the damaged site of the brain. In order to achieve these goals effective strategies to isolate, expand and differentiate neural stem cells into the desired specific phenotypes must be developed. However, little is known as yet about the factors and mechanisms influencing these processes. It has recently been reported that pituitary adenylate cyclase-activating polypeptide (PACAP) promotes neural stem cell proliferation both in vivo and in vitro. Results We used cDNA microarrays with the aim of analysing the transcriptional changes underlying PACAP induced proliferation of neural stem cells. The primary neural stem/progenitor cells used were neurospheres, generated from the lateral ventricle wall of the adult mouse brain. The results were compared to both differentiation and proliferation controls, which revealed an unexpected and significant differential expression relating to withdrawal of epidermal growth factor (EGF) from the neurosphere growth medium. The effect of EGF removal was so pronounced that it masked the changes in gene expression patterns produced by the addition of PACAP. Conclusion Experimental models aiming at transcriptional analysis of induced proliferation in primary neural stem cells need to take into consideration the significant effect on transcription caused by removal of EGF. Alternatively, EGF-free culture conditions need to be developed.
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Affiliation(s)
- Maria Sievertzon
- Royal Institute of Technology, AlbaNova University Center, KTH Genome Center, Dept. of Biotechnology, S-106 91 Stockholm, Sweden
| | - Valtteri Wirta
- Royal Institute of Technology, AlbaNova University Center, KTH Genome Center, Dept. of Biotechnology, S-106 91 Stockholm, Sweden
| | | | - Jonas Frisén
- Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institute, S-171 77 Stockholm, Sweden
| | - Joakim Lundeberg
- Royal Institute of Technology, AlbaNova University Center, KTH Genome Center, Dept. of Biotechnology, S-106 91 Stockholm, Sweden
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402
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Slevin M, Krupinski J, Kumar P, Gaffney J, Kumar S. Gene activation and protein expression following ischaemic stroke: strategies towards neuroprotection. J Cell Mol Med 2005; 9:85-102. [PMID: 15784167 PMCID: PMC6741338 DOI: 10.1111/j.1582-4934.2005.tb00339.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Current understanding of the patho-physiological events that follow acute ischaemic stroke suggests that treatment regimens could be improved by manipulation of gene transcription and protein activation, especially in the penumbra region adjacent to the infarct. An immediate reduction in excitotoxicity in response to hypoxia, as well as the subsequent inflammatory response, and beneficial control of reperfusion via collateral revascularization near the ischaemic border, together with greater control over apoptotic cell death, could improve neuronal survival and ultimately patient recovery. Highly significant differences in gene activation between animal models for stroke by middle cerebral artery occlusion, and stroke in patients, may explain why current treatment strategies based on animal models of stroke often fail. We have highlighted the complexities of cellular regulation and demonstrated a requirement for detailed studies examining cell specific protective mechanisms after stroke in humans.
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Affiliation(s)
- M Slevin
- Biological Sciences Department, Manchester Metropolitan University, Chester St, Manchester, UK
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403
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Chen J, Zhang C, Jiang H, Li Y, Zhang L, Robin A, Katakowski M, Lu M, Chopp M. Atorvastatin induction of VEGF and BDNF promotes brain plasticity after stroke in mice. J Cereb Blood Flow Metab 2005; 25:281-90. [PMID: 15678129 PMCID: PMC2804085 DOI: 10.1038/sj.jcbfm.9600034] [Citation(s) in RCA: 340] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Molecular mechanisms underlying the role of statins in the induction of brain plasticity and subsequent improvement of neurologic outcome after treatment of stroke have not been adequately investigated. Here, we use both in vivo and in vitro studies to investigate the potential roles of two prominent factors, vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF), in mediating brain plasticity after treatment of stroke with atorvastatin. Treatment of stroke in adult mice with atorvastatin daily for 14 days, starting at 24 hours after MCAO, shows significant improvement in functional recovery compared with control animals. Atorvastatin increases VEGF, VEGFR2 and BDNF expression in the ischemic border. Numbers of migrating neurons, developmental neurons and synaptophysin-positive cells as well as indices of angiogenesis were significantly increased in the atorvastatin treatment group, compared with controls. In addition, atorvastatin significantly increased brain subventricular zone (SVZ) explant cell migration in vitro. Anti-BDNF antibody significantly inhibited atorvastatin-induced SVZ explant cell migration, indicating a prominent role for BDNF in progenitor cell migration. Mouse brain endothelial cell culture expression of BDNF and VEGFR2 was significantly increased in atorvastatin-treated cells compared with control cells. Inhibition of VEGFR2 significantly decreased expression of BDNF in brain endothelial cells. These data indicate that atorvastatin promotes angiogenesis, brain plasticity and enhances functional recovery after stroke. In addition, VEGF, VEGFR2 and BDNF likely contribute to these restorative processes.
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Affiliation(s)
- Jieli Chen
- Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
| | - Chunling Zhang
- Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
| | - Hao Jiang
- Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
| | - Yi Li
- Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
| | - Lijie Zhang
- Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
| | - Adam Robin
- Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
| | - Mark Katakowski
- Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
| | - Mei Lu
- Department of Biostatistics and Research Epidemiology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
| | - Michael Chopp
- Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA
- Department of Physics, Oakland University, Rochester, Michigan, USA
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404
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Schänzer A, Wachs F, Wilhelm D, Acker T, Cooper‐Kuhn C, Beck H, Winkler J, Aigner L, Plate KH, Kuhn HG. Direct stimulation of adult neural stem cells in vitro and neurogenesis in vivo by vascular endothelial growth factor. Brain Pathol 2004; 14:237-48. [PMID: 15446578 PMCID: PMC8096047 DOI: 10.1111/j.1750-3639.2004.tb00060.x] [Citation(s) in RCA: 280] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Hypoxia as well as global and focal ischemia are strong activators of neurogenesis in the adult mammalian central nervous system. Here we show that the hypoxia-inducible vascular endothelial growth factor (VEGF) and its receptor VEGFR-2/Flk-1 are expressed in clonally-derived adult rat neural stem cells in vitro. VEGF stimulated the expansion of neural stem cells whereas blockade of VEGFR-2/Flk-1-kinase activity reduced neural stem cell expansion. VEGF was also infused into the lateral ventricle to study changes in neurogenesis in the ventricle wall, olfactory bulb and hippocampus. Using a low dose (2.4 ng/d) to avoid endothelial proliferation and changes in vascular permeability, VEGF stimulated adult neurogenesis in vivo. After VEGF infusion, we observed reduced apoptosis but unaltered proliferation suggesting a survival promoting effect of VEGF in neural progenitor cells. Strong expression of VEGFR-2/Flk-1 was detected in the ventricle wall adjacent to the choroid plexus, a site of significant VEGF production, which suggests a paracrine function of endogenous VEGF on neural stem cells in vivo. We propose that VEGF acts as a trophic factor for neural stem cells in vitro and for sustained neurogenesis in the adult nervous system. These findings may have implications for the pathogenesis and therapy of neurodegenerative diseases.
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Affiliation(s)
- Anne Schänzer
- Institute of Neurology (Edinger‐Institute), Johann Wolfgang Goethe‐University, Frankfurt/Main, Germany
| | - Frank‐Peter Wachs
- Department of Neurology, University of Regensburg, Regensburg, Germany
| | - Daniel Wilhelm
- Institute of Neurology (Edinger‐Institute), Johann Wolfgang Goethe‐University, Frankfurt/Main, Germany
| | - Till Acker
- Institute of Neurology (Edinger‐Institute), Johann Wolfgang Goethe‐University, Frankfurt/Main, Germany
| | | | - Heike Beck
- Institute of Neurology (Edinger‐Institute), Johann Wolfgang Goethe‐University, Frankfurt/Main, Germany
| | - Jürgen Winkler
- Department of Neurology, University of Regensburg, Regensburg, Germany
| | - Ludwig Aigner
- Department of Neurology, University of Regensburg, Regensburg, Germany
| | - Karl H. Plate
- Institute of Neurology (Edinger‐Institute), Johann Wolfgang Goethe‐University, Frankfurt/Main, Germany
| | - H. Georg Kuhn
- Department of Neurology, University of Regensburg, Regensburg, Germany
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405
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Jin K, Galvan V, Xie L, Mao XO, Gorostiza OF, Bredesen DE, Greenberg DA. Enhanced neurogenesis in Alzheimer's disease transgenic (PDGF-APPSw,Ind) mice. Proc Natl Acad Sci U S A 2004; 101:13363-7. [PMID: 15340159 PMCID: PMC516572 DOI: 10.1073/pnas.0403678101] [Citation(s) in RCA: 316] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Neurogenesis continues in the adult brain and is increased in certain pathological states. We reported recently that neurogenesis is enhanced in hippocampus of patients with Alzheimer's disease (AD). We now report that the effect of AD on neurogenesis can be reproduced in a transgenic mouse model. PDGF-APP(Sw,Ind) mice, which express the Swedish and Indiana amyloid precursor protein mutations, show increased incorporation of BrdUrd and expression of immature neuronal markers in two neuroproliferative regions: the dentate gyrus and subventricular zone. These changes, consisting of approximately 2-fold increases in the number of BrdUrd-labeled cells, were observed at age 3 months, when neuronal loss and amyloid deposition are not detected. Because enhanced neurogenesis occurs in both AD and an animal model of AD, it seems to be caused by the disease itself and not by confounding clinical factors. As neurogenesis is increased in PDGF-APP(Sw,Ind) mice in the absence of neuronal loss, it must be triggered by more subtle disease manifestations, such as impaired neurotransmission. Enhanced neurogenesis in AD and animal models of AD suggests that neurogenesis may be a compensatory response and that measures to enhance neurogenesis further could have therapeutic potential.
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Affiliation(s)
- Kunlin Jin
- Buck Institute for Age Research, Novato, CA 94945, USA
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406
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Abstract
VEGF is a prototype angiogenic factor, but recent evidence indicates that this growth factor also has direct effects on neural cells. Abnormal regulation of VEGF expression has now been implicated in several neurodegenerative disorders, including motoneuron degeneration. This has stimulated an increasing interest in assessing the therapeutic potential of VEGF as a neuroprotective agent for such neurodegenerative disorders.
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Affiliation(s)
- Erik Storkebaum
- Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology, University of Leuven, Leuven, Belgium
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407
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Zhang H, Vutskits L, Pepper MS, Kiss JZ. VEGF is a chemoattractant for FGF-2-stimulated neural progenitors. ACTA ACUST UNITED AC 2004; 163:1375-84. [PMID: 14691144 PMCID: PMC2173724 DOI: 10.1083/jcb.200308040] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Mmigration of undifferentiated neural progenitors is critical for the development and repair of the nervous system. However, the mechanisms and factors that regulate migration are not well understood. Here, we show that vascular endothelial growth factor (VEGF)-A, a major angiogenic factor, guides the directed migration of neural progenitors that do not display antigenic markers for neuron- or glia-restricted precursor cells. We demonstrate that progenitor cells express both VEGF receptor (VEGFR) 1 and VEGFR2, but signaling through VEGFR2 specifically mediates the chemotactic effect of VEGF. The expression of VEGFRs and the chemotaxis of progenitors in response to VEGF require the presence of fibroblast growth factor 2. These results demonstrate that VEGF is an attractive guidance cue for the migration of undifferentiated neural progenitors and offer a mechanistic link between neurogenesis and angiogenesis in the nervous system.
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Affiliation(s)
- Huanxiang Zhang
- Department of Morphology, University Medical Center, University of Geneva Medical School, 1 rue Michel Servet, CH-1211 Geneva 4, Switzerland
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