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1
Wagstaff, Marcus James Dermot. "The neuroprotective effect of the heat shock proteins". Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267150.
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Aron, Badin Romina. "Neuroprotective effects of heat shock proteins in experimental ischaemia : an MRI study". Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1444501/.
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Heat shock proteins (HSPs) are molecular chaperones with essential roles in cellular function such as modulating the proteolytic machinery and accelerating cell repair. HSP overexpression has been observed in vitro and in vivo under stresses including heat, nutrient deprivation and ischaemia. Experiments in in vivo models of stroke indicate that transgenically overexpressed or virally delivered HSPs can enhance cell survival but cannot always reduce lesion size. This study aims to assess the protective effects of HSPs in a rat model of reversible focal cerebral ischaemia using magnetic resonance imaging (MRI) techniques to measure cerebral blood flow and lesion size. The experiments described used three different herpes simplex virus (HSV) constructs: two potentially therapeutic vectors, HSV-HSP27 and HSV-HSP70, and an HSV-LacZ control vector. Initially, the localization and duration of expression from the viral vector used to deliver the HSP genes into the rat brain was assessed. Subsequently, the effect of pre-ischaemic intra-striatal microinjections of HSV-HSP27 and HSV-HSP70 was evaluated in a middle cerebral artery occlusion (MCAO) model of stroke. Finally, the effect of delivering the same HSPs 30 minutes after ischaemia was assessed. Behavioural tests were carried out in the latter study up to a month after MCAO in order to determine whether HSP treatment induced functional recovery as well as reduction in lesion size. Results suggest that intracerebral microinjections with HSV-HSP27 have a neuroprotective effect pre- and [?] ischaemia. Multislice T2-weighted images show that HSP27 treatment results in a significant reduction in lesion size after MCAO, whereas HSP70 treatment does not affect lesion size compared to controls. Western blots confirm that virally-induced overexpression of both HSP27 and HSP70 is achieved in treated animals. For the first time, non-invasive MRI techniques were used to demonstrate the neuroprotective effect of HSP27 and not HSP70 in a rat model of reversible focal cerebral ischaemia.
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Avery, Michelle A. "Axon Death Prevented: Wlds and Other Neuroprotective Molecules: A Dissertation". eScholarship@UMMS, 2010. https://escholarship.umassmed.edu/gsbs_diss/520.
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A common feature of many neuropathies is axon degeneration. While the reasons for degeneration differ greatly, the process of degeneration itself is similar in most cases. Axon degeneration after axotomy is termed ‘Wallerian degeneration,’ whereby injured axons rapidly fragment and disappear after a short period of latency (Waller, 1850). Wallerian degeneration was thought to be a passive process until the discovery of the Wallerian degeneration slow (Wlds) mouse mutant. In these mice, axons survive and function for weeks after nerve transection. Furthermore, when the full-length protein is inserted into mouse models of disease with an axon degeneration phenotype (such as progressive motor neuronopathy), Wlds is able to delay disease onset (for a review, see Coleman, 2005). Wlds has been cloned and was found to be a fusion event of two neighboring genes: Ube4b, which encodes an ubiquitinating enzyme, and NMNAT-1 (nicotinamide mononucleotide adenylyltransferase-1), which encodes a key factor in NAD (nicotinamide adenine dinucleotide) biosynthesis, joined by a 54 nucleotide linker span (Mack et al., 2001).
To address the role of Wlds domains in axon protection and to characterize the subcellular localization of Wlds in neurons, our lab developed a novel method to study Wallerian degeneration in Drosophila in vivo (MacDonald et al., 2006). Using this method, we have discovered that mouse Wlds can also protect Drosophila axons for weeks after acute injury, indicating that the molecular mechanisms of Wallerian degeneration are well conserved between mouse and Drosophila. This observation allows us to use an easily manipulated genetic model to move the Wlds field forward; we can readily identify what Wlds domains give the greatest protection after injury and where in the neuron protection occurs. In chapter two of this thesis, I identify the minimal domains of Wlds that are needed for protection of severed Drosophila axons: the first 16 amino acids of Ube4b fused to Nmnat1. Although Nmnat1 and Wlds are nuclear proteins, we find evidence of a non-nuclear role in axonal protection in that a mitochondrial protein, Nmnat3, protects axons as well as Wlds.
In chapter 3, I further explore a role for mitochondria in Wlds-mediated severed axon protection and find the first cell biological changes seen in a Wlds-expressing neuron. The mitochondria of Wlds- and Nmnat3-expressing neurons are more motile before injury. We find this motility is necessary for protection as suppressing the motility with miro heterozygous alleles suppresses Wldsmediated axon protection. We also find that Wlds- and Nmnat3- expressing neurons show a decrease in calcium fluorescent reporter, gCaMP3, signal after axotomy. We propose a model whereby Wlds, through production of NAD in the mitochondria, leads to an increase in calcium buffering capacity, which would decrease the amount of calcium in the cytosol, allowing for more motile mitochondria. In the case of injury, the high calcium signal is buffered more quickly and so cannot signal for the axon to die.
Finally, in chapter 4 of my thesis, I identify a gene in an EMS-based forward genetic screen which can suppress Wallerian degeneration. This mutant is a loss of function, which, for the first time, definitively demonstrates that Wallerian degeneration is an active process. The mammalian homologue of the gene encodes a mitochondrial protein, which in light of the rest of the work in this thesis, highlights the importance of mitochondria in neuronal health and disease.
In conclusion, the work presented in this thesis highlights a role for mitochondria in both Wlds-mediated axon protection and Wallerian degeneration itself. I identified the first cell biological changes seen in Wlds-expressing neurons and show that at least one of these is necessary for its protection of severed axons. I also helped find the first Wallerian degeneration loss-of-function mutant, showing Wallerian degeneration is an active process, mediated by a molecularly distinct axonal degeneration pathway. The future of the axon degeneration field should focus on the mitochondria as a potential therapeutic target.
4
Boulos, Sherif. "Identification and characterisation of potential neuroprotective proteins induced by erythropoietin (EPO) preconditioning of cortical neuronal cultures". University of Western Australia. School of Biomedical and Chemical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0128.
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[Truncated abstract] Clinical therapeutic agents to directly inhibit ischaemic neuronal death are presently unavailable. One approach to developing therapeutics is based upon the identification of proteins up-regulated by 'preconditioning', a natural adaptive response utilised by the neural cells to counter damaging insults, such as ischaemia. Thus, my project aimed to firstly identify proteins differentially expressed following erythropoietin (EPO) mediated neuronal preconditioning and secondly to assess whether any of these proteins possessed neuroprotective activity using in vitro ischaemia like models. To achieve the first aim, it was shown that in vitro neuronal EPO preconditioning could: (i) induce cell signal changes in neuronal cultures, (ii) protect neurons against in vitro ischaemia and (iii) induce differential protein expression. Overall, 40 differentially expressed proteins were identified in cortical neuronal cultures following EPO preconditioning. In order to investigate the neuroprotective or neurodamaging activity of proteins induced by EPO preconditioning I developed an adenoviral expression system for use in neuronal cultures. To this end, I assessed the suitability of four promoters (cytomegalovirus [CMV], rous sarcoma virus [RSV], human synapsin 1 [hSYN1], rat synapsin 1 [rSYN1]) previously used to express proteins in neuronal cultures and demonstrated the superiority of the RSV promoter for this purpose. ... Finally, in order to validate this adenoviral expression system, I over-expressed the anti-apoptotic protein Bcl-XL in neuronal cultures and subsequently confirmed its neuroprotective activity in the in vitro ischaemia and oxidative stress models used in my project. Using this adenoviral vector system and the in vitro oxidative stress model I assessed a number of proteins up-regulated by EPO preconditioning. The results of this preliminary study indicated that cyclophilin A (CyPA), peroxiredoxin 2 (PRDX2) and superoxide dismutase 1 (SOD1) over-expression were neuroprotective. It was subsequently verified that adenoviral mediated over-expression of CyPA and PRDX2, v but not SOD1 in cortical neuronal cultures could protect neurons from in vitro ischaemia. I also confirmed that CyPA mRNA increased in the rat hippocampus in response to 3 minutes of global cerebral ischaemia. Interestingly, an increase in CyPA, PRDX2 or SOD1 protein was not observed in the same experimental paradigm. To investigate CyPA's mode of action I confirmed that cultured neurons, but not astrocytes, express the CyPA receptor, CD147. It was also demonstrated that administration of exogenous CyPA protein to neuronal cultures could protect neurons against oxidative and ischaemic injury. I further demonstrated that exogenous administration of CyPA induces a rapid and transient activation of the extracellular signal-regulated kinase (ERK) 1/2 pathway in neuronal cultures. From this observation, I have proposed that the extracellular mediated neuroprotective activity of CyPA occurs via CD147 receptor signalling and activation of ERK1/2 pro-survival pathways. Based on the findings reported in this thesis, the neuroprotective activities of PRDX2 and CyPA warrant further investigation as targets for the development of new therapies to treat cerebral ischaemia.
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Lee, Christopher James. "Neuroprotective effects of overexpression of the inhibitor of apoptosis proteins in the quinolinic acid model of excitotoxic injury". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0020/MQ48164.pdf.
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Aboonq, Moutasem Salih. "Activity dependent neuroprotective protein (ADNP) expression and functions". Thesis, University of Liverpool, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540017.
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Lin, Tse-Shen. "Prion protein topologies and the effect on its neuroprotective function". Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18773.
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The normal prion protein (PrP) is ubiquitously expressed and is especially abundant in the brain. However, the major physiological function of PrP has remained elusive. Recently, it was demonstrated that PrP prevents Bcl-2 associated protein X (Bax)-mediated cell death by inhibiting the initial Bax conformational change that converts cytosolic Bax into a pro-apoptotic protein (Roucou et al., 2005). To further determine the form and subcellular location of PrP with anti-Bax function, we co-expressed various Syrian hamster PrP (SHaPrP) mutants that favor specific PrP topologies and subcellular localization with N-terminally green fluorescent protein tagged pro-apoptotic Bax (EGFP-Bax) in MCF-7 cells and primary human neurons. The PrP mutants that synthesize transmembrane PrP lose their anti-Bax function, whereas those that exclusively synthesize secreted or cytosolic PrP (CyPrP) retain protection comparable to that of wild type PrP in both cell types. Furthermore, co-expression of CyPrP with these mutants rescues the anti-Bax function. Addition of extracellular PrP supports only minimally the anti-Bax function. Therefore, the results indicate that the CyPrP is the predominant form of PrP with anti-Bax function. We have previously excluded the need for other Bcl-2 family members in the anti-Bax function of PrP. Here, we also fail to co-immunoprecipitate PrP and Bax indicating that PrP's anti-Bax function is not through a direct PrP-Bax interaction in the cytosol. We conclude that there must exist a cytosolic Bax interactor through which PrP exerts its effect.La forme normale du prion (PrP) est exprimée de façon omniprésente mais elle est particulièrement abondante dans le cerveau. Cependant, la fonction physiologique principale du PrP reste indéfinie. Récemment, il a été démontré que PrP empêche la mort cellulaire causée par Bax (Bcl-2-associated protein X) en inhibant le changement de conformation initial de Bax, à partir duquel le Bax cytosolique est converti en protéine pro-apoptotique (Roucou et al., 2005). Afin de mieux déterminer la forme et la localisation sous-cellulaire de PrP ayant une fonction anti-Bax, nous avons co-exprimé divers mutants de PrP du hamster syrien (SHaPrP), lesquels favorisent des topologies et des localisations sous-cellulaires spécifiques de PrP, avec la construction pro-apoptotique Bax marquée à son bout N-terminal par la protéine fluorescente verte (EGFP-Bax), et ce, dans la lignée cellulaire MCF-7 et dans les neurones humaines primaires. Les mutants PrP qui favorisent les formes transmembranaire de PrP perdent leur fonction anti-Bax, tandis que ceux qui produisent exclusivement du PrP sécrété ou cytosolique (CyPrP) retiennent une protection comparable à celle du PrP sauvage retrouvée dans les deux types de cellules. De plus, la co-expression de CyPrP avec ces mutants récupère la fonction anti-Bax. L'ajout du PrP extracellulaire ne soutient que de façon minimale la fonction anti-Bax. Par conséquent, ces résultats indiquent que le CyPrP est la forme prédominante de PrP possédant une fonction anti-Bax. Nous avons exclut précédemment la nécessité de présence de d'autres membres de la famille Bcl-2 dans la fonction anti-Bax. Ici, nous n'avons pas pu co-immunoprécipiter PrP et Bax, ce qui indique que la fonction anti-Bax du PrP ne peut être pas attribuée à une interaction directe entre PrP et Bax, dans le cytosol. Nous concluons donc que PrP exercerait son effet sur Bax via un interagisseur cytosolique.
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Johnson, Erik Andrew. "Survivin expression after traumatic brain injury potential roles in neuroprotection /". [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008337.
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Thesis (Ph.D.)--University of Florida, 2004.Typescript. Title from title page of source document. Document formatted into pages; contains 87 pages. Includes Vita. Includes bibliographical references.
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Gustafsson, Helena. "Uncoupling Proteins : Regulation by IGF-1 and Neuroprotection during Hyperglycemia in Vitro". Doctoral thesis, Stockholm : Institutionen för neurokemi och neurotoxikologi, Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-121.
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Sakthivelu, Vignesh. "Functional characterization of Shadoo, a PrP-like protein with neuroprotective activity". Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-144326.
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Gains, Malcolm J. "The in vivo neuroprotective role of the normal cellular prion protein /". Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103158.
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The role of prion protein (PrPC) as a crucial factor in the pathogenesis of the Transmissible Spongiform Encephalopathies (TSE's) is well known. However, the physiologic role of this highly conserved protein in vivo is thus far, largely unknown. In vitro evidence shows that PrPC may have a neuroprotective role, inhibiting Bax-mediated apoptosis, by preventing the conformational change of Bax, which is one of the early steps leading to Bax activation and subsequently, apoptosis. In vivo evidence indicates that in some transgenic mouse models overexpressing a mutant prion protein that result in neuronal death, the simultaneous expression of PrP protects against this neuronal death. The pathogenesis of the neuronal death in these in vivo models is unknown. Our objective was to determine if PrPC could protect against Bax-mediated cell death in vivo. We used two experimental paradigms to investigate this neuroprotective role of PrPC in vivo.The first paradigm involved an external insult (ethanol injection) to 7 day old mice, which induces massive Bax-mediated neuronal death. We then quantified the number of active caspase 3 positive cells, as a downstream marker of Bax activation, induced in mice on various genetic backgrounds, PrP overexpressors (PrpOexp), PrP wild-type (PrP+/+ ) and PrP knockout (PrP0/0). We also examined Bax activation by immunoprecipitation of subcellular fractions, as well as total Bax activation and cytochrome c release directly in ex-vivo mouse brains. In addition, we examined the insertion of active Bax into the mitochondrial membrane, also using subcellular fractionation.
The second paradigm involves an internal insult (physiological Bax-mediated neuronal death during embryonic development). This insult results in massive Bax-mediated cell death in embryonic mice that do not express the natural antagonist of Bax i.e. BClxL. We have therefore created 3 lines of transgenic mice expressing Syrian Hamster PrP (SHaPrP) under the control of the Bclx promoter, to cross with Bclx+/- mice to see if the SHaPrP can assume the role of Bclx in Bclx knockout mice and rescue the neuronal cell death.
In the first paradigm, greater numbers of neurons undergoing apoptosis following ethanol insult were seen in PrP0/0 than in PrP +/+ mice, although the differences were not statistically significant. The ex-vivo examination of mouse brains did not provide definitive results.
In the second paradigm, 3 lines of transgenic mice have been created and are in various stages of breeding to obtain the required genotypes to test our hypothesis. The level of expression of SHaPrP in these mice is below the level of detection via western blot or immunoprecipitation.
The trend shown in our results suggests that in vivo, PrPC may provide some protection for neurons from Bax-mediated cell death as a result of an external insult. Research is ongoing to see if PrPC can protect neurons in vivo against developmental Bax-mediated cell death. The work presented here highlights the variability and technical difficulty inherent with in vivo studies, particularly when the available knowledge of the biochemical pathways involved is incomplete.
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Piorkowska-Stanco, Katarzyna. "DJ-1 as a neuroprotective protein in models of Parkinson's disease /". [S.l.] : [s.n.], 2007. http://library.epfl.ch/theses/?nr=3926.
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Gennet, Nicole. "Activity dependent neuroprotective protein : initial characterisation of its role in physiology". Thesis, University of Liverpool, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423968.
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Yang, Guang. "Palmitoyl-proteins : regulators of neuronal functions and potential targets for neuroprotection". Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/38155.
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Protein palmitoylation is an important post-translational lipid modification. While hundreds of palmitoyl proteins have been identified in neurons, little is known about how palmitoylation regulates these neuronal proteins and how it contributes to neuronal development and function. A special group of palmitoyl proteins, 23 mammalian zinc-finger DHHC-type containing (zD) proteins are potent palmitoyl acyltransferases (PATs) that catalyze protein palmitoylation. However, the physiopathological roles of these PATs in brain function are largely elusive. AMPA receptor (AMPAR) subunit GluR1 and GluR2 are palmitoyl proteins. In this thesis, I have found that GluR1 and GluR2 show different palmitoylation properties in neurons. Palmitoylation regulate AMPAR stability in a subunit-selective manner in response to synaptic stimulations. In addition, c-jun N-terminal kinase 3 (JNK3), but not other JNK isoforms, has been identified in this thesis as a novel palmitoyl protein. Without palmitoylation, JNK3 is associated more strongly with the cytoskeleton and promotes axonal branching. This suggests a potential role of palmitoylation in modulating axonal development via isoform-specific regulation of JNK3. I have further revealed that zD17 mediates neuronal responses in acute ischemic brain injury via a mechanism independent of its PAT activity. ZD17 directly interacts with JNK to form a signaling module for JNK activation. Pathological stressors induce the zD17-JNK interaction which promotes downstream neuronal cell death signals. I have developed novel peptides targeting the JNK-interacting motif on zD17 to selectively block the enhancement of the zD17-JNK interaction and the activation of JNK isoforms 2 and 3. Application of these peptides successfully blocks JNK activation and neuronal cell death pathways, protects cultured neurons from excitotoxicity, and dramatically reduces brain damage and behavioural deficits in a rat model of focal ischemic stroke. These findings indicate PAT zD17 as a key player in ischemic stroke, and suggest the potential therapeutic value of targeting palmitoyl proteins for neuroprotection.
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Rahim, Titissa. "Investigating the regulation of ARNT2, a neuroprotective protein, in models of multiple sclerosis". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58253.
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Background: The process of axonal degeneration and neuronal loss has been described as the major cause of irreversible clinical disability in multiple sclerosis (MS). An ideal neuroprotective strategy would be to focus on inhibition of axonal degeneration and on protection against neuronal cell death in addition to immunomodulation. The aryl-hydrocarbon receptor nuclear translocator 2 (ARNT2) is a protein with neuroprotective properties previously described in ischemic insults and oxidative damage. We hypothesize that alterations in ARNT2 expression are associated with changes in cell viability in in vitro and in vivo models of multiple sclerosis. Methods: Following exposure to various compounds mimicking MS disease processes, ARNT2 protein and mRNA levels were observed in primary cortical neuron-enriched cultures using western blotting, quantitative polymerase chain reaction (qPCR) and immunocytochemistry, alongside cytotoxicity measurements, using a lactate dehydrogenase (LDH) release assay/Live/Dead® Viability/Cytotoxicity assay. ARNT2 protein levels were also evaluated in primary cortical astrocytes using immunocytochemistry. Analyses in an animal model of MS, experimental autoimmune encephalomyelitis (EAE) were conducted, with tissue collected at various stages of the disease course, to examine ARNT2 expression patterns in vivo. Results: Examination of individual neurons reveals that most cells demonstrate low-medium ARNT2 expression under steady-state conditions. Exposing cells to both low and higher concentrations of hydrogen peroxide (H₂O₂) to mimic mild to more severe oxidative stress significantly increases ARNT2 protein levels early, as measured via western blotting and immunocytochemistry. At the mRNA level, oxidative stress fails to drive Arnt2. This increased detection of ARNT2 protein is observed in both neurons and reactive astrocytes specifically within the neuronal-enriched mixed populations. Non-reactive astrocytes also express ARNT2 at baseline conditions. Finally, ARNT2 is differentially expressed in healthy versus EAE tissue at peak disease. Conclusions: This work demonstrates for the first time that ARNT2 can follow altered expression patterns in vitro in neurons depending on the severity/duration of the stimulus involved in MS disease progression. This lays a foundation for understanding the link between ARNT2 expression and neuronal health in vitro.Medicine, Faculty of
Pathology and Laboratory Medicine, Department of
Graduate
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Davis, Stephanie. "Leukemia Inhibitory Factor as a Neuroprotective Agent against Focal Cerebral Ischemia". Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6218.
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Previous publications from this laboratory demonstrated that administration of leukemia inhibitory factor (LIF) (125 µg/kg) to young, male Sprague-Dawley rats at 6, 24, and 48 h after middle cerebral artery occlusion (MCAO) reduced infract volume, improved sensimotor skills, and alleviated damage to white matter at 72 h after the injury. In vitro studies using cultured oligodendrocytes (OLs) showed that LIF (200 ng/ml) also protects against 24 h of oxygen-glucose deprivation through activation of Akt signaling and upregulation of the antioxidant enzymes peroxiredoxin IV and metallothionein III. Other groups have demonstrated that LIF reduces neurodegeneration in animal models of disease, but the neuroprotective mechanisms of LIF during permanent ischemia have not yet been examined. The overall hypothesis to be tested in this project is whether LIF exerts similar protective mechanisms against neurons during ischemia through increased antioxidant enzyme expression in neurons.
In the first set of experiments, superoxide dismutase (SOD) activity was significantly increased in the ipsilateral hemisphere of LIF-treated rats compared to rats that received PBS treatment at 72 h after MCAO. Western blot and immunohistochemical analysis revealed that SOD3 was upregulated in brain tissue and induced specifically in cortical neurons tissue at this time point. Neurons that expressed high levels of SOD3 at 72 h after MCAO also showed high levels of phosphorylated Akt (Ser473). LIF (200 ng/ml) reduced necrotic and apoptotic cell death against 24 h of OGD as measured by lactate dehydrogenase (LDH) release and caspase-3 activation. Quantitative real-time PCR analysis showed that LIF treatment upregulated SOD3 gene expression in vitro during OGD. Treatment with 10 µM Akt Inhibitor IV and transfection with SOD3 siRNA counteracted the neuroprotective effects of LIF in vitro, showing that upregulation of SOD3 and activation of Akt signaling are necessary for LIF-mediated neuroprotection.
Several transcription factors that regulated Akt-inducible genes were previously identified by this lab, including myeloid zinc finger-1 (MZF-1) and specificity protein-1 (Sp1). The goal of the second set of experiments was to determine whether LIF exerted protective actions through MZF-1 and Sp1. According to analysis with Genomatix, MZF-1 and Sp1 have multiple binding sites in the promoter for the rat SOD3 gene. Western blot analysis showed that there was a trend towards increased MZF-1 protein expression in the brains of LIF-treated rats that approached significance. Immunohistochemical analysis and quantitative real-time PCR showed a significant in vitro upregulation in MZF-1 expression among LIF-treated neurons compared to PBS-treated neurons. Sp1 gene expression was not changed by LIF treatment, but there was a trend towards increased protein expression. In addition, there was a significant correlation between Sp1 and MZF-1 among brain samples from LIF-treated rats but not PBS-treated or sham rats at 72 h after MCAO. Immunohistochemical analysis revealed that Sp1 and MZF-1 co-localized with neuronal nuclei and SOD3 at 72 h after MCAO. Neurons that were transfected with MZF-1 or Sp1 siRNA following isolation did not show a significant decrease in LDH release after 24 h OGD that was observed among neurons transfected with scrambled siRNA. These data demonstrate that Sp1 and MZF-1 are involved with the neuroprotective signaling of LIF under ischemia.
This laboratory has demonstrated that LIF activates transcription of protective genes and increases the activity of transcription factors through modulation of intracellular signaling. However, the upstream signaling mechanisms of LIF during ischemia had not previously been investigated. Previous investigators found that the LIF-specific subunit of the heterodimeric LIF receptor (LIFR) is induced by CNS injury. Western blot analysis was used to determine whether LIFR was induced in the brain and the spleen, which plays a role in the peripheral immune response, after MCAO. According to these results, LIF treatment significantly upregulates LIF in the brain compared to PBS treatment or sham injury at 72 h after MCAO. Genomatix analysis of the LIFR promoter region revealed a binding site for Sp1, which is one of the transcription factors responsible for neuroprotection by LIF. At this same time point, splenic LIFR expression is significantly reduced after MCAO compared to sham injury. LIF treatment did not significantly increase LIFR expression, but did significantly increase spleen size compared to PBS treatment at 72 h after MCAO. Although there was a trend towards increased LIFR expression in the spleen from 24 h to 72 h after MCAO, this increase was not statistically significant. However, there was a significant positive correlation between spleen weight and LIFR expression among rats euthanized 24-72 h after MCAO/sham injury. In addition, there was a significant negative correlation between LIFR expression in the brain and the spleen weight, thus showing that LIFR is upregulated following the splenic response.
According to findings from other groups, JAK1 has been shown to associate with the heterodimeric LIF receptor (LIFR/gp130) and directly activate PI3K/Akt signaling. To test whether JAK1 contributes neuroprotection during ischemia, cultured neurons were treated with several concentrations (2.5-50 nM) of GLPG0634, a JAK1-specific inhibitor prior to 24 h of OGD. With the exception of the 2.5 nM concentration, all concentrations of GLPG0634 significantly decreased LDH release compared to DMSO treatment, with the 5 nM concentration having the most potent effect on reducing cytotoxicity. However, the 5 nM concentration had no significant did not significantly reduce LDH release compared to DMSO treatment under 24 h of normoxic conditions. These results indicate that JAK1 activity is primarily detrimental to neurons during ischemia. Although it is possible that LIF signaling activates JAK1, it is unlikely that JAK1 is responsible for LIF-mediated neuroprotection during ischemia.
The results of these experiments allowed us to determine several molecular mechanisms for LIF-mediated neuroprotection. LIF, which binds to its heterodimeric receptor, activates Akt signaling during ischemia. The transcription factors Sp1 and MZF-1, which are located downstream of Akt, bind to the promoter of the SOD3 gene. In addition, Sp1 also regulates the LIFR gene. SOD3 upregulation increases total SOD activity, which decreases apoptotic and necrotic cell death during apoptosis. Due to its ability to promote antioxidant expression and survival signaling in multiple neural cell types, LIF shows promise as a novel treatment for permanent focal cerebral ischemia.
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Maezawa, Izumi. "Glia-regulated, apolipoprotein E specific mechanisms of neuroprotection and neurodegeneration /". Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/6340.
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Benn, Susanna Clare. "Neuroprotection by heat shock protein 27 in sensory and motor neurons". Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271424.
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Kelly, Stephen. "Neuroprotection and functional alterations in mice over-expressing heat shock protein 70i". Thesis, University of Glasgow, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327580.
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Ali, Yousuf O. "The Mechanism of Neuroprotection Mediated By Nicotinamide Mononucleotide Adenylyl Transferase (NMNAT)". Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/633.
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Neurons need to be maintained to persist throughout adulthood for proper brain function. However neuronal activity, injury and aging exert physical stress on the nervous system, which compromise nervous system function. Healthy neurons are able to maintain their integrity throughout the lifespan of the animal, suggesting the existence of a maintenance mechanism that allows neurons to sustain or even repair damage. A forward genetic screening in Drosophila identified mutations in a gene called nmnat that cause a rapid and severe neurodegeneration immediately post neuronal differentiation and development. NMNAT protein was required to maintain neuronal integrity in an activity-dependent manner. When probing for the exact role of NMNAT in neuronal maintenance, a novel stress responsive chaperone function was identified, in addition to its essential housekeeping NAD synthase role. In this work, the mechanism of NMNAT-mediated neuroprotection is investigated. First, the transcriptional regulation of Drosophila NMNAT during acute stress is analyzed. Here, both stress transcription factors heat shock factor (HSF) and hypoxia inducible factor alpha (HIF1-α) have been shown to upregulate NMNAT during stress through a heat shock element in the nmnat promoter. In addition, the role of NMNAT for stress tolerance in Drosophila is revealed. Second, to elucidate the neuroprotective capacity of NMNAT in neurodegenerative disease, mouse models of tauopathy have been used. In the P301L Tau-transgenic mouse model, the levels of endogenous NMNAT2 have been studied at various ages to link a reduction in NMNAT2 as a precursor for neurodegeneration. The underlying mechanism of NMNAT2 downregulation is further studied in this model. Third, using Drosophila model of Tauopathy, the protective capacity of both wild type and enzyme-inactive NMNAT in ameliorating the pathological and behavioral impairments from Tau-induced neurodegeneration were studied extensively. The possible protective mechanism of NMNAT is uncovered by identifying novel interactions of NMNAT with hyperphosphorylated and ubiquitinated Tau in regulating the levels of toxic Tau species. Finally, this study also identified endogenous proteins that NMNAT interacts with to provide insight into a neuroprotective chaperone role of NMNAT. Together, these studies improve our understanding of the mechanisms of neuronal maintenance, by providing a comprehensive investigation of the stress-responsive regulation of NMNAT in both Drosophila and mammalian models, and its role as a chaperone both in protein foldopathies and in healthy neurons.
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Lee, Bo Young. "Signaling events in activity dependent neuroprotection, neurodegeneration, and synaptic plasticity". Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1180458484.
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Ho, Wing-Lok Philip. "The role of neuronal mitochondrial uncoupling proteins in MPP+ -Induced toxicity : a potential for neuroprotection in Parkinsonism". Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31498966.
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Ho, Wing-Lok Philip, i 何永樂. "The role of neuronal mitochondrial uncoupling proteins in MPP+ -Induced toxicity: a potential for neuroprotection in Parkinsonism". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31498966.
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Sakthivelu, Vignesh [Verfasser], i Jörg [Akademischer Betreuer] Tatzelt. "Functional characterization of Shadoo, a PrP-like protein with neuroprotective activity / Vignesh Sakthivelu. Betreuer: Jörg Tatzelt". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2012. http://d-nb.info/1023661055/34.
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Lorente, Picon Marina. "Neuroprotective effect of stomatin-like protein 2 overexpression in A53T-a-synuclein parkinson disease mice model". Master's thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/66338.
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Yau, Suk-yu. "Neuroprotective effects of physical exercise on stressed brain : its relationship to hippocampal neurogenesis and dendritic remodeling /". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B4322376X.
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Campelo, Marcio Wilker Soares. "Preconditioning with nitrosyl ruthenium promotes neuroprotection involving protein kinase in rat brain in vivo". Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16083.
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FundaÃÃo de Amparo à Pesquisa do Estado do CearÃBackground and purpose - The NO donors can decrease neuronal injury during cerebral ischemia and reperfusion (I/R) by increasing the blood flow to the brain. The objective of this study is to study whether a new nitrosyl ruthenium complex makes some effect during I/R and if involves protein kinases. Methods - Used 180 male rats, Wistar rats, with an average weight of 290.27 g, distributed 6 groups: Sham 1h, saline + ischemia/reperfusion 1h, Ru-bpy ischemia/reperfusion 1h, Sham 24h, saline + ischemia/reperfusion 24h, Ru-bpy ischemia/reperfusion 24h. Used global cerebral ischemia model incomplete, with occlusion of bilateral common carotid artery and administration of SF or Rut-bpy in their respective groups by intraperitoneal way. At the end of the experiment, the animals were decapitated and the brain removed to be evaluated to the area of injury by histology with H&E, immunohistochemistry, quantification of brain swelling, nitrite, immunoassay for kinases. During the experiment (phase of ischemia and first hour of reperfusion) PAM of animals was monitored. Results: Decreased number of neurons reds and edema in brain tissue in animals preconditioned with nitrosyl ruthenium. PAM variation was lower in animals treated with Ru-bpy the end of ischemia and early reperfusion. Inhibition of NF-kB. Activates the kinase protein Akt, Erk 1/2, p70S6 and CREB, with inhibition of JNK protein.Conclusion: The Rut-bpy has protective effect during neuronal event of I/R supported by 24h and keeping PAM more stable during the beginning of reperfusion. Involving the protein kinase.
IntroduÃÃo e objetivo: Doadores de NO (Ãxido nÃtrico) podem diminuir a lesÃo neuronal durante a isquemia/reperfusÃo (I/R) cerebral experimental por aumento do fluxo sanguÃneo cerebral. O objetivo deste estudo foi avaliar se um novo doador de NO complexo nitrosil rutÃnio (Ru-bpy) apresenta algum efeito durante I/R e se envolve proteÃnas quinases. MÃtodo: Foram utilizados 180 ratos machos, da linhagem Wistar, com peso mÃdio de 290.27 g, distribuÃdos 6 grupos: Sham 1h, soluÃÃo salina + isquemia/reperfusÃo 1h, Ru-bpy + isquemia/reperfusÃo 1h, Sham 24h, soluÃÃo salina + isquemia/reperfusÃo 24h, Ru-bpy + isquemia/reperfusÃo 24h. Utilizado o modelo de isquemia cerebral global incompleta, com oclusÃo da artÃria carÃtida comum bilateral e administraÃÃo do SF ou Rut-bpy em seus respectivos grupos via intraperitoneal 30 minutos antes do inicio do pinÃamento das carÃtidas comuns. ApÃs 30 minutos de isquemia. No final do experimento os animais foram decapitados e o cÃrebro retirado para ser avaliado à Ãrea de lesÃo por histologia com H&E, imunohistoquÃmica, quantificaÃÃo de edema cerebral, nitrito, imunoensaio para quinases. Durante o experimento (fase de isquemia e primeira hora de reperfusÃo) a pressÃo artÃrial mÃdia (PAM) dos animais foi monitorizada. Resultados: DiminuiÃÃo do nÃmero de neurÃnios eosinofÃlicos e do edema no tecido cerebral nos animais prÃ-condicionados com nitrosil rutÃnio. A variaÃÃo da PAM foi menor nos animais tratados com Ru-bpy ao final da isquemia e inÃcio da reperfusÃo. InibiÃÃo do NF-kB. AtivaÃÃo das proteÃnas quinase AKT, P70S6, ERK 1/2 e CREB, com inibiÃÃo da proteÃna JNK. ConclusÃo: O Rut-bpy tem efeito protetor neuronal durante evento de I/R sustentado por 24h mantendo a PAM mais estÃvel durante o inÃcio da reperfusÃo. Envolvendo a via das proteÃnas quinases.
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Yau, Suk-yu, i 邱淑瑜. "Neuroprotective effects of physical exercise on stressed brain : its relationship to hippocampal neurogenesis and dendritic remodeling". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hdl.handle.net/10722/210329.
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Kundu, Arpita [Verfasser], Donat [Gutachter] Kögel i Jochen [Gutachter] Klein. "The role of the amyloid precursor protein (APP) in protein homeostasis and neuroprotection / Arpita Kundu ; Gutachter: Donat Kögel, Jochen Klein". Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2017. http://d-nb.info/114052576X/34.
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Descamps, Elodie Vamecq Joseph. "La protéine disulfide isomérase et l'ischémie cérébrale une voie de neuroprotection ? /". [S.l.] : [s.n.], 2009. http://tel.archives-ouvertes.fr/tel-00399737/fr.
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Davis, Laurie Michelle Helene. "THE UNDERLYING MECHANISM(S) OF FASTING INDUCED NEUROPROTECTION AFTER MODERATE TRAUMATIC BRAIN INJURY". UKnowledge, 2008. http://uknowledge.uky.edu/gradschool_diss/673.
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Traumatic brain injury (TBI) is becoming a national epidemic, as it accounts for 1.5 million cases each year. This disorder affects primarily the young population and elderly. Currently, there is no treatment for TBI, which means that ~2% of the U.S. population is currently living with prolonged neurological damage and dysfunction. Recently, there have been many studies showing that TBI negatively impacts mitochondrial function. It has been proposed that in order to save the cell from destruction mitochondrial function must be preserved. The ketogenic diet, originally designed to mimic fasting physiology, is effective in treating epilepsy. Therefore, we have used fasting as a post injury treatment and attempted to elucidate its underlying mechanism. 24 hours of fasting after a moderate TBI increased tissue sparing, cognitive recovery, improved mitochondrial function, and decreased mitochondrial biomarkers of injury. Fasting results in hypoglycemia, the production of ketones, and the upregulation of free fatty acids (FFA). As such, we investigated the neuroprotective effect of hypoglycemia in the absence of fasting through insulin administration. Insulin administration was not neuroprotective and increased mortality in some treatment groups. However, ketone administration resulted in increased tissue sparing. Also, reduced reactive oxygen species (ROS) production, increased the efficiency of NADH utilization, and increased respiratory function. FFAs and uncoupling proteins (UCP) have been implicated in an endogenously regulated anti-ROS mechanism. FFAs of various chain lengths and saturation were screened for their ability to activate UCP mediated mitochondrial respiration and attenuate ROS production. We also measured FFA levels in serum, brain, and CSF after a 24 hour fast. We also used UCP2 transgenic overexpressing and knockout mice in our CCI injury model, which showed UCP2 overexpression increased tissue sparing, however UCP2 deficient mice did not show a decrease in tissue sparing, compared with their wild type littermates. Together our results indicate that post injury initiated fasting is neuroprotective and that this treatment is able to preserve mitochondrial function. Our work also indicates ketones and UCPs may be working together to preserve mitochondrial and cellular function in a concerted mechanism, and that this cooperative system is the underlying mechanism of fasting induced neuroprotection.
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Welin, Dag. "Neuroprotection and axonal regeneration after peripheral nerve injury". Doctoral thesis, Umeå : Umeå university, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-32819.
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Sousa, Rafael Augusto Teixeira de. "Fisiopatologia do Transtorno de Humor Bipolar e efeito do tratamento com lítio: enfoque em neuroproteção e função mitocondrial". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/5/5142/tde-05052014-142705/.
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Introdução: Diversas evidências apontam para um papel da disfunção mitocondrial no Transtorno de Humor Bipolar (THB), mas pouco se sabe sobre isso no THB de início recente. Na mitocôndria a atividade da cadeia transportadora de elétrons (CTE) atua juntamente com o ciclo do ácido cítrico na produção de energia, mas não está claro se estão alteradas no THB. O DNA mitocondrial (DNAmt) codifica diversas proteínas da CTE e está associado ao estresse oxidativo, mas nunca foi avaliado em pacientes no THB in vivo. O estresse oxidativo está associado ao THB e à disfunção mitocondrial, mas não se sabe muito das atividades das enzimas antioxidantes no THB de início recente. O óxido nítrico (NO) é uma molécula com efeitos neuromoduladores, mas com um papel no THB ainda não elucidado. O lítio é um tratamento padrão-ouro no THB, tendo mostrado efeitos neuroprotetores. Apesar disso, pouco se conhece do efeito do lítio na CTE, nas enzimas do ciclo do ácido cítrico, no conteúdo de DNAmt e na regulação de NO em humanos. Também não está claro o papel antioxidante do lítio no THB. Metódos: Pacientes com THB em depressão (n=31), não medicados em sua maioria (84%), foram tratados por 6 semanas com lítio. Antes e depois do tratamento, verificaram-se em leucócitos as atividades dos complexos I-IV da CTE, atividades das enzimas citrato sintase, succinato desidrogenase e malato desidrogenase e também o conteúdo de DNAmt; em plasma foram analisados os níveis de NO, substâncias reativas ao ácido tiobarbitúrico (TBARS) e as atividades de catalase (CAT), glutationa peroxidase (GPx), superóxido dismutase (SOD) e razão de SOD/CAT. Os pacientes com depressão bipolar foram comparados com 28 controles saudáveis. Resultados: Em comparação com controles, os pacientes com THB tiveram um aumento de GPx (p < 0,001) e CAT (p=0,005) e uma diminuição de SOD/CAT (p=0,001), sem outras diferenças nos demais biomarcadores. Pacientes com THB I mostraram uma diminuição de citrato sintase (p=0,02) e uma discreta diminuição do conteúdo de DNAmt (p=0,05) em comparação com o THB II; o conteúdo de DNAmt esteve ligeiramente diminuído no THB I comparado com controles (p=0,05). Do início ao fim do tratamento com lítio houve aumento da atividade do complexo I da CTE (p=0,02), diminuição de TBARS (p=0,02) e SOD (p=0,03) e aumento de NO (p=0,02), sem haver alteração de outros parâmetros. Depois do tratamento, o TBARS se mostrou diminuído em respondedores comparados a não respondedores (p=0,02) e diminuído no THB II em comparação com o THB I (p=0,04). Discussão: No THB de início recente, houve poucas alterações em biomarcadores. Os achados sugerem aumento de CAT e GPx na depressão bipolar de início recente e uma diminuição de conteúdo mitocondrial no THB I comparado com o THB II, que devem ser confirmadas por outros estudos. Os resultados reforçam um papel neuroprotetor do lítio, sugerindo que a droga aumente a atividade do complexo I da CTE mitocondrial e aumente os níveis de NO na depressão bipolar. Além disso, o lítio reforçou o seu papel antioxidante e modulador das enzimas antioxidantes no THBBackground: Several evidences point to a role for mitochondrial dysfunction in Bipolar Disorder (BD), but few is known about it on short-term BD. In mitochondria the electron transport chain (ETC) acts jointly with citric acid cycle to produce energy, but it is not clear if they are altered in BD. Mitochondrial DNA (mtDNA) encodes several ETC proteins and is associated with oxidative stress, but it was never evaluated in BD in vivo. Oxidative stress is associated with BD and with mitochondrial dysfunction, but few is known about the activities of antioxidant enzymes in short-term BD. Nitric oxide (NO) is a molecule with neuromodulatory effects, but with an unclear role in BD. Lithium is a gold-standard treatment for BD, which has shown neuroprotective effects. However, few is known about lithium effect on ETC, citric acid cycle, mtDNA content, and NO regulation in humans. Also, lithium\'s antioxidant role in BD is unclear. Methods: Patients with BD depression (n=31) unmedicated in majority (84%) received lithium treatment for 6 weeks. Before and after treatment, in leukocytes the activities of ETC complex I-IV, citrate synthase, succinate dehydrogenase, and malate dehydrogenase, and mtDNA content were evaluated; in plasma, NO levels, thiobarbituric acid reactive substances (TBARS), the activities of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD), and SOD/CAT ratio were evaluated. Bipolar depression patients were compared with 28 healthy controls. Results: When compared with controls, BD patients showed an increase in GPx (p < 0.001) and CAT (p=0.005) and a decrease in SOD/CAT (p=0.001), but showed no difference for other biomarkers. Patients with BD I showed a decrease in citrate synthase (p=0.02) and a slight decrease in mtDNA content (p=0.05) when compared to BD II; mtDNA content was slightly decreased in BD I compared to controls (p=0.05). From baseline to endpoint, there was an increase in ETC complex I activity (p=0.02), a decrease in TBARS (p=0.02) and SOD (p=0.03) and an increase in NO (p=0.02), without change in other parameters. After treatment, TBARS was decreased in responders compared to non-responders (p=0.02) and decreased in BD II compared to BD I (p=0.04). Discussion: In short-term BD few alterations were observed on biomarkers. The findings suggest increase on CAT and GPX in short-term bipolar depression and mitochondrial content decrease in BD I when compared to BD II, which deserve other studies for confirmation. The results reinforce a lithium\'s neuroprotective role and suggest that lithium increases ETC complex I activity and NO levels in bipolar depression. Moreover, lithium reinforced its role as antioxidant and as a modulator of antioxidant enzymes in BD
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Choi, Christopher J. "Interaction of prion protein with divalent metals possible role in neuroprotection and neurodegeneration in prion disease model /". [Ames, Iowa : Iowa State University], 2007.
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Lai, Sau-wan. "Investigating beta-amyloid peptide neurotoxicity from neuronal apoptosis to endoplasmic reticulum collapse translational research back to basic science research /". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B41633702.
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Descamps, Elodie. "La protéine disulfide isomérase et l'ischémie cérébrale : une voie de neuroprotection ?" Phd thesis, Lille 2, 2009. http://www.theses.fr/2009LIL2S009.
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Es accidents vasculaires cérébraux (AVC) représentent, dans nos contrées, une cause importante de handicap et de mortalité. Les approches thérapeutiques restent toutefois relativement impuissantes face à ce problème de santé publique. Elles reposent essentiellement sur la prévention ou la suppression de facteurs de risques tels que le tabagisme, l'hypertension ou encore l'hypercholestérolémie. L'AVC peut être hémorragique, mais dans 80% des cas son origine vasculaire est obstructive. Son traitement aigu peut dans ce cas bénéficier d'agents thrombolytiques dont l'administration est cependant soumise à une fenêtre d'intervention immédiate relativement étroite. L'efficacité d'agents neuroprotecteurs, dont la finalité est de protéger le cerveau des conséquences délétères de l'ischémie/reperfusion cérébrale inhérente à l'AVC (lésions irréversibles et handicap), reste aujourd'hui assez décevante. La recherche de nouvelles cibles thérapeutiques s'impose dès lors plus que jamais dans ce domaine. S'intéressant aux protéines dont la concentration peut varier au cours du temps, une étude protéomique préliminaire a mis en évidence l'augmentation de la protéine disulfure isomérase (PDI) au cours de l'ischémie reperfusion cérébrale (IRC), un résultat en accord avec les données de la littérature (Tanaka, S. , Uehara, T. , Nomura, Y. , 2000, J. Biol. Chem. 275, 10388-10393). La PDI est une protéine chaperonne dotée d'une activité oxydoréductase/isomérase et est principalement localisée dans le réticulum endoplasmique. Elle assiste le repliement des protéines par la formation ou le déplacement de ponts disulfures. Les agents modulateurs de la PDI incluent l'alcool 4-hydroxybenzylique (4-HBA) et la bacitracine, respectivement inducteur et inhibiteur de cette protéine. Pour déterminer le rôle potentiellement bénéfique ou délétère de la PDI dans l'IRC, l'impact cérébral des modulateurs précités a été étudié dans un modèle murin d'IRC basé sur l'occlusion unilatérale et transitoire de l'artère cérébrale moyenne chez la souris. Dans ce modèle expérimental, le 4-HBA réduit significativement (respectivement de 22 et 55%). La taille de l'infarctus cérébral touchant le cortex et le striatum. L'implication de la PDI dans cette protection cérébrale est confirmée par la suppression de l'effet protecteur du 4-HBA par la bacitracine, le 4-HBA ne manifestant par ailleurs aucune propriété anti-oedémateuse dans le modèle expérimental d'IRC. L'induction de la PDI par le 4-HBA a elle été démontrée sur le cerveau sain de souris, la protéine étant quantifiée par immuno-chemiluminescence après migration électrophorétique (Western blots). Différents isomères de position (alcool 2-hydroxybenzylique et alcool 3-hydroxybenzylique) ainsi que des analogues aliphatiques (1,4-butanediol et 1,5-pentanediol) du 4-HBA se sont avérés, à l'inverse du dernier, incapables de réduire la taille des lésions cérébrales dans le modèle expérimental d'IRC et d'induire la PDI cérébrale. Le potentiel neuroprotecteur du 4-HBA a été étudié dans un autre modèle d'évaluation, à savoir celui des crises audiogènes chez la souris déficiente en magnésium, connu pour sa réponse aux agents anticonvulsivants mais aussi aux composés antioxydants (Vamecq, J. , Maurois, P. , Bac, P. , Bailly, F. , Bernier, J. L. , Stables, J. P. , Husson, I. ,Gressens, P. , 2003, Eur. J. Neurosci. 18, 1110-1120). La dose de 4-HBA protégeant 50% des animaux vis-à-vis de la crise audiogène était de 25 mg/kg contre 35mg/kg pour la 6-hydroxyflavanone (6-HFN), une flavone de référence active dans ce test. Ces résultats suggérant un potentiel antioxydant similaire des deux composés ont conduit à une étude comparative de leurs effets protecteurs dans le modèle murin d'IRC. Cette étude tout en confirmant la protection offerte par le 4-HBA dans l'IRC expérimentale a révélé l'incapacité du 6-HFN d'induire une protection significative dans ce modèle. A l'inverse du 4-HBA, le 6-HFN n'induisait pas la PDI cérébrale murine, confortant ici l'hypothèse que la protection du 4-HBA vis-à-vis de l'IRC résulte plus de sa capacité à induire la PDI que d'autres de ses propriétés parmi lesquelles son potentiel antioxydant. Finalement, le 4-HBA, à des doses atteignant 200 mg/kg, s'est avéré dénué de toxicité dans le test de la barre tournante. En conclusion, le 4-HBA représente un agent neuroprotecteur actif dans plusieurs modèles d'évaluation. Son efficacité vis-à-vis des lésions induites par l'IRC semble étroitement liée à sa capacité à induire la PDI cérébrale, faisant dès lors de cette protéine une cible pharmacologique prometteuse pour le développement pharmacologique de composés actifs dans l'AVC
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Gupte, Raeesa Prashant. "Phosphoregulation of somatodendritic voltage-gated potassium channels by pituitary adenylate cyclase-activating polypeptide". Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/5766.
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The endogenous neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) exerts various neuromodulatory functions in mammalian brain. Enhancement of synaptic activity, mediation of chronic inflammatory and neuropathic pain, and neuroprotection in cerebral ischemia reperfusion injury constitute some of the exemplary functions of PACAP. However, it remains unclear whether PACAP signaling can directly influence the function of critical voltage-gated ion channels, which could profoundly alter the excitability of neurons. Voltage-gated K+ (Kv) channels are critical regulators of neuronal excitability. The major Kv channel in the dendrites of mammalian neurons, Kv4.2, contributes most of the fast-activating and rapidly-inactivating K+ currents (IA), and is a key regulator of dendritic excitability, as well as modulation of synaptic inputs. In addition, the major somatic Kv channel Kv2.1 that contributes the bulk of slow-activating and non-inactivating K+ currents (IK), acts as an integrator of neuronal inputs and limits high frequency firing in neurons. As such, it provides homeostatic control of excitability under hyperexcitable and ischemic conditions. Both these Kv channels are known to undergo extensive post-translational modifications mainly by phosphorylation that alters their localization and biophysical properties. PACAP can activate its specific receptor PAC1 that could result in downstream activation of various kinases including protein kinase A (PKA), protein kinase C (PKC), extracellular signal-regulated kinase (ERK1/2). Therefore, I hypothesize that PACAP activation of PAC1 receptor can cause phosphorylation-dependent modulation of somatodendritic Kv4.2 and Kv2.1 channels, resulting in altered neuronal excitability.
First, I identified the various PAC1 receptor isoforms expressed in rat and mouse brain and elucidated that their activation by PACAP caused downstream PKA- and PKC-dependent signaling pathways, ultimately converging on ERK1/2 activation. Further, PACAP caused reduction in IA that was mediated by phosphorylation-dependent internalization of the channel protein from the plasma membrane. These effects were mediated by direct phosphorylation of the channel by ERK1/2 at the cytoplasmic C-terminus of the channel. Although PACAP did not significantly alter the voltage-dependence of Kv4.2 channel activation/inactivation, I observed distinct ERK1/2- and PKA-dependent changes in the extent and kinetics of channel inactivation.
Next, I observed that PACAP induced dephosphorylation of the Kv2.1 channel in CHN that was mediated by protein phosphatase 2A (PP2A), and was dependent on PKC activation but was independent of the effects of PACAP on Kv4.2 currents. Rapid but reversible dephosphorylation of Kv2.1 was also observed following induction of ischemia in neurons by oxygen-glucose deprivation (OGD). PACAP prolonged the dephosphorylation of Kv2.1 following in vitro ischemia-reperfusion and also reduced neuronal death. My results therefore suggest a novel PACAP/PAC1-PKC-PP2A-Kv2.1 signaling axis that provides neuroprotection during ischemia reperfusion injury.
In summary, my results suggest that PACAP can induce direct phosphorylation-dependent modulation of the Kv4.2 and Kv2.1 channel localization and function in mammalian brain neurons. The effect of PACAP on these two critical somatodendritic ion channels occurs via distinct signaling - convergent PKA-PKC-ERK-mediated phosphorylation of Kv4.2 channel, and PKC-PP2A-mediated dephosphorylation of the Kv2.1 channel. Such distinct modulations of these ion channels are presumably responsible for the multifarious roles of PACAP in the central nervous system.
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Hata, Masayuki. "KUS121, a VCP modulator, attenuates ischemic retinal cell death via suppressing endoplasmic reticulum stress". Kyoto University, 2018. http://hdl.handle.net/2433/232075.
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Montecinos, Carla. "AMPA receptor stabilization mediated by non-canonical Wnt signaling protects against Aβ42 oligomers synaptotoxicity". Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0268.
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Les récepteurs AMPAR sont les principaux responsables de la transmission excitatrice rapide dans le système nerveux central, y compris dans les neurones d’hippocampe étudiés ici. Ils sont très dynamiques dans la membrane. Au sein des épines dendritiques, ils peuvent se déplacer par traffic membranaire entre les compartiments intracellulaires et la membrane plasmique. Une fois à la surface, ils se déplacent par diffusion latérale et peuvent s'ancrer réversiblement avec des protéines de la densité postsynaptique ou retourner dans des compartiments endocytaires. Les oligomères Aß augmentent l'endocytose des récepteurs AMPAR, diminuent la densité des épines dendritique et provoquent des défaillances globales dans la transmission synaptique excitatrice. Ces effets, sont englobés dans le terme "synaptotoxicité des oligomères Aß" et sont un domaine principal d'étude de l'étiologie de la maladie d'Alzheimer. Wnt5a un ligand Wnt endogène connu pour activer la voie non-canonique dans les neurones d'hippocampe, génère une augmentation des courants excitateurs et des aggrégats de PSD95 et protége les neurones contre la synaptotoxicité des oligomères Aβ. Compte tenu du fait que Wnt5a semble contrecarrer les effets nocifs causés par les oligomères Aß, nous avons procédé à l'étude du mécanisme par lequel Wnt5a protège de la synaptotoxicité des oligomères Aβ. Cela nous a conduit à évaluer l'effet de Wnt5a sur l'un des facteurs dans la transmission glutamatergique, la dynamique des récepteurs AMPAR. En utilisant la microscopie à super-résolution dans les neurones d'hippocampe vivants et fixés, nous avons trouvé que Wnt5a module la dynamique et la localisation des récepteurs AMPAR. Plus précisément, Wnt5a stabilise les récepteurs AMPAR dans les sites synaptiques et extrasynaptiques. Ceci est corrélé avec une augmentation de la co-localisation et de l'interaction entre GluA2 et PSD95. Ces effets ne sont exercés que par l'activation non-canonique de la signalisation Wnt, à travers le ligand Wnt5a et non par les effets canoniques de Wnt7a. De manière intéressante, la pré-incubation de Wnt5a prévient la toxicité des oligomères Aß et maintient la dynamique basale des récepteurs AMPAR. Nos données suggèrent que Wnt5a empêche les effets des oligomères Aβ en favorisant leur stabilisation dans les sites synaptiquesAMPARs (AMPARs) are responsible for most fast excitatory synaptic transmission in the central nervous system, including hippocampal neurons studied here. AMPARs are highly dynamic in the plasma membrane. Within dendritic spines, they move by membrane trafficking between intracellular compartments and the plasma membrane. Once at the surface, they move through lateral brownian diffusion and can reversibly anchor to postsynaptic density proteins or return to endocytic compartments. Aβ oligomers increase endocytosis of AMPARs, diminish dendritic spine density and cause overall failures in excitatory transmission. These effects, among others, are englobed in the term “Aβ oligomers synaptotoxicity” and are a main focus on the study of Alzheimers disease ethiology. On the contrary, Wnt5a - an endogenous Wnt ligand known to activate the non-canonical pathway in hippocampal neurons - generates an increase in excitatory currents and in clusters of PSD95 and protects neurons against Aβ oligomers synaptotoxicity. Given the fact that Wnt5a seems to counteract the distresses caused by Aβ oligomers, we proceeded to study the mechanism through which Wnt5a protects from Aβ oligomers synaptotoxicity. This led us to evaluate the effect of Wnt5a on one of the important factors in glutamatergic transmission, i.e. AMPAR receptor dynamics. By using super-resolution microscopy in live and fixed hippocampal neurons, we found that Wnt5a modulates the dynamic and localization of AMPARs. Specifically, Wnt5a stabilizes AMPARs in synaptic and extrasynaptic sites. This correlates with an increase in co-localization and interaction between GluA2 and PSD95. These effects are exerted only by non-canonical activation of Wnt signaling, through Wnt5a ligand and not by the canonical effects of Wnt7a. Interestingly, pre-incubation of Wnt5a prevents toxicity of Aβ oligomers and maintains basal AMPARs dynamics. Our data suggest that Wnt5a prevents Aβ oligomers effects by promoting their stabilization in synaptic sites
Los receptores AMPA (AMPARs) son los principales responsables de la respuesta excitatoria rápida en el sistema nervioso central, incluyendo neuronas hipocampales, estudiadas en esta tesis. A diferencia de otros receptores glutamatérgicos, los AMPARs son altamente dinámicos. Dentro de las espinas dendríticas, se pueden mover hacia y desde compartimentos endocíticos y hacia la membrana plasmática. Una vez en la superficie, a través de difusión lateral, se pueden anclar a proteínas de la densidad postsináptica o regresar a compartimentos endocíticos. Por otro lado, los oligómeros Aβ (oAβ) aumentan la endocitosis de AMPARs, disminuyen la densidad de espinas dendríticas y causan una falla generalizada de la transmisión sináptica excitatoria. Estos efectos, entre otros, se engloban en el término “sinaptotoxicidad por oAβ” y es uno de los principales puntos de estudio en la etiología de la enfermedad de Alzheimer. Al contrario, Wnt5a un ligando endógeno conocido por activar la vía no canónica en neuronas hipocampales, genera un aumento en corrientes excitatorias y en los clusters de PSD95 y protege a las neuronas contra la sinaptotoxicidad causada por oAβ. Debido a esto, procedimos a estudiar el mecanismo por el cual Wnt5a protege de la sinaptotoxicidad causada por Aβ. Esto nos llevó a evaluar los efectos de Wnt5a en uno de los principales factores en la transmisión glutamatérgica, la dinámica de los AMPARs. Con el uso de microscopía de super-resolución en neuronas hipocampales vivas, encontramos que Wnt5a modula la dinámica y localización de los AMPARs. Específicamente, Wnt5a estabiliza los AMPARs en espinas y dendritas. Lo cual se correlaciona con un aumento en la co-localización e interacción entre GluA2 y PSD95. Estos efectos son causados únicamente por la activación no-canónica de la vía Wnt, a través del ligando Wnt5a y no por los efectos canónicos de Wnt7a. De manera interesante, la pre-incubación de Wnt5a previene la toxicicidad de los oligómeros Aβ y mantiene la dinámica basal de los AMPARs. Esta data sugiere que Wnt5a promueve la estabilización de AMPARs, previniendo los efectos synaptotóxicos de los oAβ
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Bertling, Frederik [Verfasser], i Ursula [Akademischer Betreuer] Felderhoff-Müser. "Tumor necrosis factor-inducible gene 6 protein : A novel neuroprotective factor against inflammation-induced developmental brain injury / Frederik Bertling ; Betreuer: Ursula Felderhoff-Müser". Duisburg, 2017. http://d-nb.info/1143518705/34.
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Jiang, Lixian. "Interactions of Neurons, Astrocytes and Microglia with HUCB Cell Populations in Stroke Models: Migration, Neuroprotection and Inflammation". [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002552.
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Suttkus, Anne, S. Rohn, Solveig Weigel, P. Glöckner, Thomas Arendt i Markus Morawski. "Aggrecan, link protein and tenascin-R are essential components of the perineuronal net to protect neurons against iron-induced oxidative stress". Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-148326.
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In Alzheimer’s disease (AD), different types of neurons and different brain areas show differential patterns of vulnerability towards neurofibrillary degeneration, which provides the basis for a highly predictive profile of disease progression throughout the brain that now is widely accepted for neuropathological staging. In previous studies we could demonstrate that in AD cortical and subcortical neurons are constantly less frequently affected by neurofibrillary degeneration if they are enwrapped by a specialized form of the hyaluronan-based extracellular matrix (ECM), the so called ‘perineuronal net’ (PN). PNs are basically composed of large aggregating chondroitin sulphate proteoglycans connected to a hyaluronan backbone, stabilized by link proteins and cross-linked via tenascin-R (TN-R). Under experimental conditions in mice, PN-ensheathed neurons are better protected against iron-induced neurodegeneration than neurons without PN. Still, it remains unclear whether these neuroprotective effects are directly mediated by the PNs or are associated with some other mechanism in these neurons unrelated to PNs. To identify molecular components that essentially mediate the neuroprotective aspect on PN-ensheathed neurons, we comparatively analysed neuronal degeneration induced by a single injection of FeCl3 on four different mice knockout strains, each being deficient for a different component of PNs. Aggrecan, link protein and TN-R were identified to be essential for the neuroprotective properties of PN, whereas the contribution of brevican was negligible. Our findings indicate that the protection of PN-ensheathed neurons is directly mediated by the net structure and that both the high negative charge and the correct interaction of net components are essential for their neuroprotective function.
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Leva, Géraldine. "Neuroprotection dans des modèles animaux de la sclérose en plaques : évaluation pluridisciplinaire de la capacité du XBD173, un ligand du translocator protein, à améliorer les symptômes cliniques et les marqueurs neuropathologiques". Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAJ076/document.
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La sclérose en plaques (SEP) est une maladie auto-immune inflammatoire chronique qui détériore la myéline centrale des patients. Des progrès ont été réalisés dans le traitement de la SEP mais il n'existe pas encore de neuroprotecteurs efficaces contre les dommages axonaux entraînant un lourd handicap. Ce travail de thèse a évalué le potentiel du XBD173, un ligand du translocator protein contrôlant la neurostéroïdogenèse et la neuroinflammation, à améliorer les symptômes dans un modèle de SEP induit par la protéolipide-protéine (souris EAE-PLP) qui mime la forme rémittente-récurrente de la SEP (85% des patients). Nos résultats montrent qu'à faible dose, le XBD173, qui diminue les taux sériques d’interleukines pro-inflammatoires et empêche la répression des marqueurs myélinique et axonal, améliore aussi la symptomatologie des souris EAE-PLP. L'effet bénéfique du XBD173 contre les signes cliniques est reproduit chez les souris EAE-MOG mimant la forme progressive de la SEP. La thèse ouvre des perspectives pour l'élaboration de stratégies efficaces contre la SEP sans induire d'effets secondaires majeursMultiple sclerosis (MS) is a chronic inflammatory autoimmune disease affecting the central myelin. Progress has been made for MS treatment, but effective neuroprotective drugs against MS-evoked axonal damages and severe disability are still missing. This thesis assessed the potential of XBD173, a ligand of the translocator protein controlling neurosteroidogenesis and neuroinflammation, to improve symptoms in the proteolipid protein-induced MS model (EAE-PLP mice) that mimics the relapsing-remitting form affecting 85% of MS patients. Our results show that XBD173 at low dose decreases serum levels of pro-inflammatory interleukins, prevents the repression of myelin and axonal markers, and also ameliorates clinical deficits in EAE-PLP mice. The beneficial effect of XBD173 against clinical symptoms was also observed in the EAE-MOG mice mimicking the progressive MS. Promising perspectives are open for the development of effective strategies against MS with little or no serious side effects
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Mohammadi, Behnam [Verfasser], i Christian [Akademischer Betreuer] Lohr. "Investigation of the therapeutic potential of the neuroprotective prion protein N1-fragment in cellular and mouse models of Alzheimers and prion disease / Behnam Mohammadi ; Betreuer: Christian Lohr". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2020. http://d-nb.info/1208394800/34.
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Mohammadi, Behnam Verfasser], i Christian [Akademischer Betreuer] [Lohr. "Investigation of the therapeutic potential of the neuroprotective prion protein N1-fragment in cellular and mouse models of Alzheimers and prion disease / Behnam Mohammadi ; Betreuer: Christian Lohr". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2020. http://nbn-resolving.de/urn:nbn:de:gbv:18-103440.
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Lai, Sau-wan, i 賴秀芸. "Investigating beta-amyloid peptide neurotoxicity from neuronal apoptosis to endoplasmic reticulum collapse: translational research back to basic science research". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B41633702.
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Israelsson, Charlotte. "Molecular Characterization of Experimental Traumatic Brain Injury". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7087.
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Arbo, Bruno Dutra. "Efeitos neuroprotetores do 4'-clorodiazepam em modelos experimentais de Doença de Alzheimer in vitro e sobre o desenvolvimento neuronal". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/147880.
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O aumento da expectativa de vida da população mundial tem se associado com uma maior prevalência de doenças neurodegenerativas. A Doença de Alzheimer (DA) é a doença neurodegenerativa mais comum e a principal causa de demência em indivíduos com mais de 60 anos, sendo caracterizada por um declínio progressivo na memória e função mental dos pacientes. Esses sintomas são acompanhados por alterações histopatológicas no cérebro desses indivíduos, incluindo a presença de uma grande quantidade de placas senis, formadas pela deposição do peptídeo beta-amiloide (Aβ), e de emaranhados neurofibrilares formados pela hiperfosforilação da proteína Tau. Estudos indicam que a deposição do Aβ é uma das principais responsáveis pelo desenvolvimento da DA, causando dano neuronal através da ativação de várias vias pró-apoptóticas e dando origem aos sintomas de demência típicos dessa doença. Até o momento, não existem tratamentos eficazes para o combate à DA, de forma que a maior parte das intervenções farmacológicas é destinada apenas ao tratamento de alguns de seus sintomas. A proteína translocadora (TSPO) se localiza em pontos de contato entre as membranas mitocondriais interna e externa e está relacionada com o transporte de colesterol para o interior da mitocôndria e com a regulação da esteroidogênese e da apoptose. Estudos mostram que ligantes da TSPO apresentam efeitos neuroprotetores em diferentes modelos experimentais de lesão cerebral e doenças neurodegenerativas. Especificamente em relação à DA, um estudo indicou que o 4’-clorodiazepam (4’-CD), um ligante da TSPO, apresenta efeitos neuroprotetores em um modelo animal dessa doença, sendo um possível candidato para o seu tratamento. Dessa forma, o objetivo desse estudo foi verificar o efeito neuroprotetor do 4’-CD em diferentes modelos in vitro de toxicidade induzida pelo Aβ, além de seus efeitos sobre o desenvolvimento de neurônios hipocampais. Inicialmente, demonstramos que o 4’-CD reduziu a morte celular de células SH-SY5Y expostas a um modelo de toxicidade induzida pela administração de Aβ. Esses efeitos estiveram associados com a redução da expressão da proteína pró-apoptótica Bax e com um aumento da expressão da survivina, uma proteína anti-apoptótica. A expressão das proteínas Bcl-xl e procaspase-3, por outro lado, não foi alterada pelos tratamentos. Posteriormente, estudamos os efeitos neuroprotetores do 4’-CD contra a toxicidade induzida pela administração do Aβ em culturas organotípicas de hipocampo. Nesses experimentos, foi demonstrado que o 4’-CD reduz a morte celular de culturas organotípicas de hipocampo expostas ao Aβ através de um aumento na expressão da enzima SOD, sem alterar, no entanto, a expressão das proteínas Akt e procaspase-3. Por fim, foi avaliado o efeito do 4’-CD sobre o desenvolvimento de culturas primárias de neurônios hipocampais de camundongos machos e fêmeas. Foi observado que as culturas de neurônios hipocampais das fêmeas apresentaram um desenvolvimento mais rápido do que as dos machos. O 4’-CD acelerou a maturação e aumentou a ramificação neurítica dos neurônios hipocampais dos machos, mas não exerceu qualquer efeito sobre os neurônios das fêmeas. Em suma, foi observado que o 4’-CD apresenta efeitos neuroprotetores contra o Aβ em células SH-SY5Y e em culturas organotípicas do hipocampo, apresentando-se como um fármaco em potencial para o tratamento da DA. Além disso, foi observado que o 4’-CD exerceu um efeito dependente do sexo sobre o desenvolvimento de culturas primárias de neurônios hipocampais, estimulando o desenvolvimento e a ramificação neurítica de neurônios hipocampais de machos, mas não de fêmeas.The increase in life expectancy of the world population has been associated with a higher prevalence of neurodegenerative diseases. The Alzheimer’s Disease (AD) is the most common neurodegenerative disorder and the main cause of dementia among people over 60 years, being characterized by a progressive decline in the memory and mental function of the patients. These symptoms are associated with histopathological changes in the brain of these patients, including the presence of senile plaques, formed by the deposition of amyloid-beta (Aβ), and neurofibrillary tangles, which are related to the hyperphosphorylation of Tau protein. Studies indicate that Aβ deposition is a major contributor to AD progression, promoting neuronal damage through the activation of different pro-apoptotic pathways and giving rise to the typical dementia symptoms of this disease. To date, there are no effective treatments for AD, so that most of the pharmacological intervention is intended for the treatment of some of its symptoms. The translocator protein (TSPO) is located in contact sites between the outer and the inner mitochondrial membranes and is involved in the cholesterol transport into the mitochondria and in the regulation of steroidogenesis and apoptosis. Studies show that TSPO ligands present neuroprotective effects in different experimental models of brain injury and neurodegenerative diseases. Specifically regarding AD, a study indicated that 4’-chlorodiazepam (4’-CD), a TSPO ligand, is neuroprotective in an animal model of this disease, being a possible candidate for its treatment. Therefore, the aim of this study was to evaluate the neuroprotective effect of 4’-CD in different experimental models of Aβ- induced neurotoxicity in vitro, as well as its effects on the development of hipocampal neurons. First, it was demonstrated that 4’-CD decreased the cell death of SH-SY5Y cells exposed to the Aβ. This effect was associated with the inhibition of the Aβ-induced upregulation of Bax, a pro-apoptotic protein, and downregulation of survivin, a prosurvival protein. On the other hand, the expression of Bcl-xl and procaspase-3 was not change by the treatments. After, it was studied the neuroprotective effects of 4’-CD against Aβ in organotypic hipocampal cultures. In these experiments, it was shown that 4’-CD decreases the cell death of organotypic hippocampal slices exposed to the Aβ by increasing the protein expression of SOD, but without changing the expression of Akt and procaspase-3. Finally, due to the importance of the processes of neuronal development and maturation in the regeneration of CNS after injury, it was evaluated the effect of 4’-CD on the development of primary hippocampal neurons of male and female mice. It was observed that female primary hippocampal neurons presented an increased rate of development than male neurons. 4’-CD stimulated the development and increased the neuritic branching of male but not from female neurons. In summary, it was observed that 4’-CD presented a neuroprotective effect against Aβ in SH-SY5Y cells and in rat organotypical hippocampal slices, presenting itself as a promising agent for the treatment of AD. Also, it was observed that 4’-CD modulates the development of hippocampal neurons in a sex-dependent manner, stimulating the development of male but not from female cells.
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Loureiro, Liliana Raquel Rodrigues. "DJ-1 mutants binding partners: insights into Parkinson's Disease". Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12583.
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Mestrado em Biotecnologia - Biotecnologia MolecularParkinson´s disease (PD), the second most common progressive neurodegenerative disorder, is a multifactorial disease caused by both genetic and environmental factors. Among the genes associated with PD, DJ-1 is a multifunctional protein involved in oxidative stress response and neuroprotection. DJ-1 mutations, such as L166P, M26I and E163K lead to loss of protein function causing early onset autosomal recessive PD. Moreover, the residue C106 is considered crucial in DJ-1 function as a sensor of oxidative stress. In this study, one missense mutations (E163K) and two engineered mutations in the residue C106 (C106A and C106DD) were produced and characterized in order to evaluate the neuroprotective effect of each mutation and also characterize their dynamic interactome. Structural analysis confirmed the production of all the mutants in the dimeric form, with a molecular weight of approximately 43kDa. Moreover, protein´s thermal stability was assessed by thermal shift and the results showed that the mutant E163K was the less stable and the C106A the most stable. Secondary structure analysis was performed by circular dichroism and revealed similar secondary structures between DJ-1 WT and mutants. In addition, a LC-MS/MS was performed to determine proteins´ contaminants and the majority of the protein contaminants were coming from the expression system and culture medium used in proteins´ production. Moreover, neuroprotection assays revealed that DJ-1 WT did not protect SH-SY5Y cells under oxidative stress conditions. The dynamic interactome of DJ-1 WT and mutants C106DD, E163K and C106A was characterized under oxidative stress conditions. A wide number of binding partners were identified and for some of them quantification in the different conditions was also determined. These interactors have a broad range of functions but the majority are associated with cellular response to oxidative stress. The study of DJ-1 mutations is very important, since it gives elucidations into DJ-1 WT functions and related disease mechanisms. In this way, the putative DJ-1 WT interactors identified still lack validation, but from these characterized dynamic interactomes further elucidations can be obtained into Parkinson’s Disease pathology and potential new targets for PD prevention and therapy, like ATP-dependent RNA helicase DDX3X herein identified as new dynamic interactor of DJ-1.
A Doença de Parkinson, a segunda doença neurodegenerativa progressiva mais comum, é uma doença multifatorial causada conjuntamente por fatores genéticos e fatores ambientais. De entre os inúmeros genes associados à Doença de Parkinson, a DJ-1 é uma proteína multifuncional envolvida na resposta ao stress oxidativo e neuroproteção. Mutações na DJ-1, tais como L166P, M26I e E136K levam à perda de função da proteína causando a forma de Parkinson autossomal recessiva com desenvolvimento precoce. De salientar que o resíduo C106 é considerado crucial na função de sensor de stress oxidativo que a DJ-1 desempenha. Neste estudo, foram produzidas e caracterizadas duas mutações sintéticas no resíduo C106 (C106A e C106DD) e uma mutação natural (E163K) de modo a avaliar o efeito neuroprotetor de cada mutação bem como caracterizar o seu interactoma dinâmico. Análises estruturais confirmaram a produção de todos os mutantes na forma dimérica, apresentando um peso molecular de aproximadamente 43kDa. A estabilidade térmica das proteínas foi ainda avaliada por thermal shift e os resultados revelaram que o mutante E163K foi o menos estável enquanto que o mutante C106A foi o mais estável. Análise da estrutura secundária foi realizada por dicroísmo circular revelando elevada semelhança entre as estruturas secundárias da DJ-1 nativa e mutantes. Por fim, foi realizada uma análise de LC-MS/MS de modo a determinar os contaminantes das proteínas produzidas e verificou-se que a maioria dos contaminantes era proveniente do sistema de expressão e meio de cultura utilizados na produção das proteínas. Seguidamente, ensaios de neuroproteção revelaram que a DJ-1 nativa não exercia um efeito neuroprotetor nas células SH-SY5Y em condições de stress oxidativo. O interactoma dinâmico da DJ-1 nativa e mutantes C106DD, E163K e C106A foi caracterizado sob condições de stress oxidativo. Um elevado número de interactores foram identificados e para alguns deles foi possível obter uma quantificação nas diferentes condições. Os referidos interactores apresentam uma enorme variedade de funções, contudo a grande maioria está associada à resposta celular ao stress oxidativo. O estudo das mutações na DJ-1 é considerado muito relevante visto que fornece importantes elucidações relativamente às funções e mecanismos da DJ-1 nativa associados à doença. Neste sentido, os supostos interactores da DJ-1 nativa identificados ainda carecem de validação, mas da caracterização dos interactomas dinâmicos, elucidações podem ser obtidas sobre a patologia da Doença de Parkinson e identificação de novos potenciais alvos para prevenção e terapia desta doença, tal como a RNA helicase DDX3X dependente de ATP aqui identificada como novo interactor dinâmico da DJ-1.
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Hobbs, Carey Anne. "Structural and functional characterization of bacterial response and neuroprotective proteins". 2009. http://www.lib.ncsu.edu/theses/available/etd-09082009-115433/unrestricted/etd.pdf.
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