Kegg Pathway: Neurodegenerative Disorders

Neurosci Lett. 2009 Nov 16;
Gaweda-Walerych K, Safranow K, Maruszak A, Bialecka M, Klodowska-Duda G, Czyzewski K, Slawek J, Rudzinska M, Styczynska M, Opala G, Drozdzik M, Kurzawski M, Szczudlik A, Canter JA, Barcikowska M, Zekanowski C

The mitochondrial transcription factor A (TFAM) has been recently shown to decrease reactive oxygen species (ROS) generation. It is also known that mitochondrial DNA (mtDNA) haplogroups might confer different coupling properties, resulting in different ROS levels. We hypothesized that potentially functional TFAM variants could influence PD risk depending on haplogroup background. To test this we assessed the role of six TFAM variants on PD risk in 326 PD patients and 316 controls, and correlated it with mtDNA haplogroup clusters (HV, JTKU and a putative functionally different group U4U5a1KJ1cJ2, connected previously with partial uncoupling of oxidative phosphorylation). Both genotype and haplotype analysis showed that intronic variant rs2306604 modifies PD risk. Multivariate logistic regression analysis confirmed that rs2306604 G/G genotype is an independent risk factor for PD (OR 1.789, 95% CI 1.162-2.755, p=0.008). There was a borderline interaction between G/G genotype and HV haplogroup (p=0.075). Haplotype analysis showed that all three haplotypes containing rs2306604 allele A occurred at higher frequencies in controls, but only one of them reached statistical significance (Chi Square 4,523, p=0,0334). Conversely, four of five haplotypes containing allele G had higher frequencies in PD group, with no statistical significance.

Life Sci. 2009 Nov 16;
Awasthi H, Tota S, Hanif K, Nath C, Shukla R

AIMS: The aim of the present study is to investigate the effect of curcumin on cerebral blood flow (CBF), memory impairment, oxidative stress and cholinergic dysfunction in intracerebral (IC) streptozotocin (STZ) induced memory impairment in mice. MAIN METHODS: Memory impairment was induced by STZ (0.5mg/kg, IC) administered twice with an interval of 48 hours in mice. Memory function was assessed by Morris water maze and passive avoidance test. CBF was measured by Laser Doppler Flowmetry (LDF). To study the preventive effect, curcumin (10, 20 and 50mg/kg, PO) was administered for 21days starting from the first dose of STZ. In another set of experiment, curcumin was administered for 7days from 19th day after confirming STZ induced dementia to observe its therapeutic effect. Biochemical parameters of oxidative stress and cholinergic function were estimated in brain on 21st day. KEY FINDINGS: The major finding of this study is that STZ (IC) caused a significant reduction in CBF alongwith memory impairment, cholinergic dysfunction and enhanced oxidative stress. Curcumin dose dependently improved CBF in STZ treated mice together with amelioration of memory impairment both in preventive and therapeutic manner. SIGNIFICANCE: The present study clearly demonstrates the beneficial effects of curcumin, the dietary staple of India, on CBF, memory and oxidative stress which can be exploited for dementia associated with age related vascular and Neurodegenerative Disorders.

Nutr Neurosci. 2009 Dec; 12(6): 249-259
Zárate J, Goicoechea E, Pascual J, Echevarría E, Guillén MD

Sunflower oil at a specific oxidation stage (when several oxygenated alpha,beta-unsaturated aldehydes are generated, mainly 4-hydroperoxy-trans-2-alkenals and 4-hydroxy-trans-2-alkenals), caused at 70 degrees C with aeration for 7 days, was administered intraperitoneally to rats. This oil was studied by means of solid phase micro-extraction followed by gas chromatography/mass spectrometry (SPME-GC/MS) and by proton nuclear magnetic resonance ((1)H-NMR). Oxidized sunflower oil (3 ml/kg/day) was administered to male Sprague-Dawley rats for 21 days. The control group was administered non-oxidized sunflower oil in the same volume and for the same duration as the experimental group. A significant decrease in the number of neural cells positively immunostained for TrkA receptor was detected in the frontal cortex of the experimental group, with respect to controls, suggesting both neuronal damage as well as a deficit in neuronal survival signalling at this level. This could lead to apoptosis of cholinergic neurons, which play a key role in memory and attention function. These results indicate that toxic substances present in the oxidized sunflower oil, among them 4-hydroxy-trans-2-nonenal (HNE) and 4-hydroperoxy-trans-2-nonenal (HPNE), could disrupt survival signalling of frontal cortex cholinergic neurons, which could lead to apoptosis and Neurodegenerative diseases. In the case of humans, this fact reinforces the necessity of avoiding the re-utilization of oxidized sunflower oil, in order to contribute to long-term Neurodegenerative diseases prevention.

J Pineal Res. 2009 Nov 17;
Jou MJ, Peng TI, Hsu LF, Jou SB, Reiter RJ, Yang CM, Chiao CC, Lin YF, Chen CC

Melatonin protects cells against various types of oxidative stress-induced apoptosis due primarily to its ability to effectively scavenge pathological and disease condition-augmented generation of mitochondrial reactive oxygen species (mROS). Once produced, mROS indiscriminately damage mitochondrial components and more importantly they crucially activate directly the mitochondrial permeability transition (MPT), one of the critical mechanisms for initiating post mitochondrial apoptotic signaling. Whether or not melatonin targets directly the MPT, however, remains inconclusive, particularly during oxidative stress. This study, thus, investigated this possibility of an 'oxidation free Ca(2+) stress' in the presence of vitamin E after ionomycin exposure as a sole Ca(2+)-mediated MPT in order to exclude melatonin's primary antioxidative effects as well as Ca(2+)-mediated oxidative stress. The studies were carried out using cultured rat brain astrocytes RBA-1. With the application of laser scanning multiple fluorescence imaging microscopy, we visualized for the first time multiple mitochondrial protective effects provided by melatonin during Ca(2+) stress. First, melatonin, due to its primary antioxidative actions, completely prevented mCa(2+)-induced mROS formation during ionomycin exposure. Secondly, when melatonin(')s antioxidative effects were prevented due to the addition of vitamin E, melatonin significantly prevented mCa(2+)-mediated MPT and apoptosis suggesting its direct targeting of the MPT. Surprisingly, in the presence of cyclosporin A, a MPT inhibitor, melatonin reduced further mCa(2+)-mediated apoptosis during ionomycin exposure also suggesting its targeting beyond the MPT. As astrocytes are actively involve in regulating synaptic transmission and neurovascular coupling in the CNS, these multiple mitochondrial layers of protection provided by melatonin against mCa(2+)-and/or mROS-mediated apoptosis in astrocytes may be crucial for future therapeutic prevention and treatment of astrocyte-mediated Neurodegenerative diseases in the CNS.

Anticancer Agents Med Chem. 2009 Dec; 9(10): 1114-1122
Miyashita K, Nakada M, Shakoori A, Ishigaki Y, Shimasaki T, Motoo Y, Kawakami K

Improvement in the outcome of cancer patients who are refractory to currently available treatments relies on the development of target-directed therapies. One group of molecular targets with potential clinical relevance is a set of protein tyrosine kinases encoded mostly by proto-oncogenes and that are frequently deregulated in cancer. Glycogen synthase kinase 3beta (GSK3beta), a serine/threonine protein kinase, has emerged as a therapeutic target for common chronic diseases including type 2 diabetes mellitus, Neurodegenerative Disorders, inflammation and osteoporosis. This is based on its currently known functions and primary pathologic causalities. GSK3beta has well characterized roles in the regulation of gene transcription and in oncogenic signaling. We have shown that deregulated GSK3beta promotes gastrointestinal, pancreatic and liver cancers and glioblastomas. Furthermore, we have demonstrated that inhibition of GSK3beta attenuates cell survival and proliferation, induces cell senescence and apoptosis and sensitizes tumor cells to chemotherapeutic agents and ionizing radiation. This has led us to propose GSK3beta as a potential therapeutic target in cancer. The anti-tumor effects of GSK3beta inhibition are mediated by changes in the expression and phosphorylation of molecules critical to the regulation of cell cycling, proliferation and apoptosis and underlie the pathological role for GSK3beta in cancer. Investigation of the mechanisms responsible for deregulation of GSK3beta and the consequent downstream pathologic effects in cancer cells has shed light on the molecular pathways leading to tumorigenesis. This will allow exploration of novel therapeutic strategies for cancer that target aberrant GSK3beta.

J Med Chem. 2009 Nov 19;
Colabufo NA, Berardi F, Cantore M, Contino M, Inglese C, Niso M, Perrone R

Anal Chem. 2009 Nov 19;
Shi T, Weerasekera R, Yan C, Reginold W, Ball H, Kislinger T, Schmitt-Ulms G

The low resolution structure of a protein can sometimes be inferred from information about existing disulfide bridges or experimentally introduced chemical crosslinks. Frequently, this task involves enzymatic digestion of a protein followed by mass spectrometry-based identification of covalently linked peptides. To facilitate this task, we developed a method for the enrichment of covalently linked peptides following the chemical cleavage of a protein. The method capitalizes on the availability of homoserine lactone moieties at the C-termini of cyanogen bromide cleavage products which support selective conjugation of affinity tags. The availability of two C-termini within covalently linked peptides allows for the conjugation of two distinct affinity tags and thereby enables subsequent removal of unmodified peptides by tandem affinity chromatography. Here, we demonstrate the stepwise implementation of this method using a polyhistidine tag and a biotin tag for the selective two-step purification of covalently linked cyanogen bromide fragments from increasingly complex protein samples. The method is independent of the nature of the covalent bond, is adaptable to fully denaturing conditions, and requires only low picomole quantities of starting material.

PLoS One. 2009; 4(11): e7900
Giliberto L, Matsuda S, Vidal R, D'Adamio L

BACKGROUND: Mutations in the integral membrane protein 2B [1], also known as BRI(2)[2], a type II trans-membrane domain protein cause two autosomal dominant Neurodegenerative diseases, Familial British and Danish Dementia [3]. In these conditions, accumulation of a C-terminal peptide (ABri and ADan) cleaved off from the mutated precursor protein by the pro-protein convertase furin [4], leads to amyloid deposition in the walls of blood vessels and parenchyma of the brain. Recent advances in the understanding of the generation of amyloid in Alzheimer's disease has lead to the finding that BRI(2) interacts with the Amyloid Precursor Protein (APP), decreasing the efficiency of APP processing to generate Abeta [5], [6], [7]. The interaction between the two precursors, APP and BRI(2), and possibly between Abeta and ABri or ADan, could be important in influencing the rate of amyloid production or the tendency of these peptides to aggregate. METHODOLOGY/PRINCIPAL FINDINGS: We have generated the first BRI(2) Danish Knock-In (FDD(KI)) murine model of FDD, expressing the pathogenic decamer duplication in exon 6 of the BRI(2) gene. FDD(KI) mice do not show any evident abnormal phenotype, with normal brain histology and no detectable amyloid deposition in blood vessel walls or parenchyma. CONCLUSIONS/SIGNIFICANCE: This new murine mouse model will be important to further understand the interaction between APP and BRI(2), and to provide insights into the molecular basis of FDD.

PLoS One. 2009; 4(11): e7893
Uemura K, Lill CM, Li X, Peters JA, Ivanov A, Fan Z, Destrooper B, Bacskai BJ, Hyman BT, Berezovska O

BACKGROUND: Presenilin 1(PS1) is the catalytic subunit of gamma-secretase, the enzyme responsible for the Abeta C-terminal cleavage site, which results in the production of Abeta peptides of various lengths. Production of longer forms of the Abeta peptide occur in patients with autosomal dominant Alzheimer disease (AD) due to mutations in presenilin. Many modulators of gamma-secretase function have been described. We hypothesize that these modulators act by a common mechanism by allosterically modifying the structure of presenilin. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis we generated a genetically encoded GFP-PS1-RFP (G-PS1-R) FRET probe that allows monitoring of the conformation of the PS1 molecule in its native environment in live cells. We show that G-PS1-R can be incorporated into the gamma-secretase complex, reconstituting its activity in PS1/2 deficient cells. Using Förster resonance energy transfer (FRET)-based approaches we show that various pharmacological and genetic manipulations that target either gamma-secretase components (PS1, Pen2, Aph1) or gamma-secretase substrate (amyloid precursor protein, APP) and are known to change Abeta(42) production are associated with a consistent conformational change in PS1. CONCLUSIONS/SIGNIFICANCE: These results strongly support the hypothesis that allosteric changes in PS1 conformation underlie changes in the Abeta(42/40) ratio. Direct measurement of physiological and pathological changes in the conformation of PS1/gamma-secretase may provide insight into molecular mechanism of Abeta(42) generation, which could be exploited therapeutically.

Pharmacology. 2009 Nov 18; 85(1): 1-17
Tillement JP, Lecanu L, Papadopoulos V

Most Neurodegenerative diseases share several clinical, genetic and pathophysiological features, and an irreversible evolution as well. They are characterized by an endogenous production of abnormal proteins called amyloid proteins (AP), which are not hydrosoluble, form depots, and are only partly cleared by autophagy and the ubiquitin-protease system. Despite their different structures, they are probably generated by a common pathological pathway, a misfolding process. This hypothesis suggests a common pharmacological approach, which can consist of either the blockade of the misfolding process, the elimination of AP or both. The currently validated treatments are mostly palliative ones, trying to supplant the function of destroyed neurons. New trends involve the regulation of the cerebral cholesterol metabolism and the preservation of neuron mitochondrial functions. Special attention is given to already marketed drugs used for other indications, which are also able to act on neurodegeneration.

Neuroimmunomodulation. 2009 Nov 17; 17(2): 67-78
Bombeiro AL, D'Império Lima MR, Chadi G, Alvarez JM

Background/Aim: Chagas' disease is caused by Trypanosoma cruzi and occurs in most Latin American countries. The protozoan may colonize the central nervous system (CNS) of immune-compromised human hosts, thus causing neuronal Disorders. Systemic control of the intracellular forms of the parasite greatly depends on the establishment of a TH1 response and subsequent nitric oxide (NO) release. At the CNS, it is known that low concentrations of NO promote neuronal survival and growth, while high concentrations exert toxic effects and neuron death. Accounting for NO production by astrocytes is the glia-derived factor S100beta, which is overproduced in some Neurodegenerative diseases. In the current work, we studied the expression of NO, interferon (IFN)-gamma and S100beta in the spinal cord tissue of IL-12p40KO mice infected with T. cruzi, a model of Neurodegenerative process. Methods: IL-12p40KO and wild-type (WT) female mice infected with T. cruzi Sylvio X10/4 (10(5) trypomastigotes, intraperitoneally) were euthanized when IL-12p40KO individuals presented limb paralysis. Spinal cord sections were submitted to immunohistochemical procedures for localization of neurofilament, laminin, nitrotyrosine, NO synthases (NOS), IFN-gamma and S100beta. The total number of neurons was estimated by stereological analysis and the area and intensity of immunoreactivities were assessed by microdensitometric/morphometric image analysis. Results: No lesion was found in the spinal cord sections of WT mice, while morphological disarrangements, many inflammatory foci, enlarged vessels, amastigote nests and dying neurons were seen at various levels of IL-12p40KO spinal cord. Compared to WT mice, IL-12p40KO mice presented a decrement on total number of neurons (46.4%, p < 0.05) and showed increased values of immunoreactive area for nitrotyrosine (239%, p < 0.01) and NOS (544%, p < 0.001). Moreover, the intensity of nitrotyrosine (16%, p < 0.01), NOS (38%, p < 0.05) and S100beta (21%, p < 0.001) immunoreactivities were also augmented. No IFN-gamma-labeled cells were seen in WT spinal cord tissue, contrary to IL-12p40KO tissue that displayed inflammatory infiltrating cells and also some parenchymal cells positively labeled. Conclusion: We suggest that overproduction of NO may account for neuronal death at the spinal cord of T. cruzi-infected IL-12p40KO mice and that IFN-gamma and S100beta may contribute to NOS activation in the absence of IL-12.

J Pharmacol Exp Ther. 2009 Nov 18;
Eibl JK, Chapelsky SA, Ross GM

Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are members of the neurotrophin family which normally play a role in the development and maintenance of the nervous system. However, neurotrophin dysregulation has been implicated in several Neurodegenerative diseases and psychiatric Disorders including Alzheimer's disease, Parkinson's disease, neuropathic pain, depression and substance abuse. Despite their central role in the nervous system, neurotrophins have proven to be an elusive pharmacological target. Here we describe a novel multi-potent neurotrophin antagonist, Y1036. Y1036, 3-[(5E)-4-oxo-5-[[5-(4-sulfamoylphenyl)-2-furyl]methylene]-2-thioxo-thiazolidin-3-yl]propanoic acid, binds BDNF (K(D) = 3.5 +/- 0.3 muM) and NGF (K(D) = 3.0 +/- 0.4 muM) preventing either neurotrophin from interacting with their obligate receptor(s). Y1036 prevents both BDNF- and NGF-mediated trk activation, downstream activation of the p44/42 MAPK pathway, and prevents neurotrophin-mediated differentiation of dorsal-root ganglion neurons. Identification of a BDNF- and NGF-specific antagonist is of considerable interest in the study and treatment of diseases where dysregulation of multiple neurotrophins has been implicated.

J Neurosci. 2009 Nov 18; 29(46): 14663-14669
Wang Y, Wu C, Caprariello AV, Somoza E, Zhu W, Wang C, Miller RH

Destruction or changes associated with myelin membranes in the CNS play a key role in the pathogenesis of multiple sclerosis and other related Neurodegenerative Disorders. A long-standing goal has been to detect and quantify myelin content in vivo. For this reason, we have developed a myelin-imaging technique based on positron emission tomography (PET). PET is a quantitative imaging modality that has been widely used in clinical settings for direct assessment of biological processes at the molecular level. However, lack of myelin-imaging probes has hampered the use of PET for imaging of myelination in the CNS. Here, we report a myelin-imaging agent, termed Case Imaging Compound (CIC) that readily penetrates the blood-brain barrier and preferentially localizes to myelinated regions of the brain. After radiolabeling with positron-emitting carbon-11, [(11)C]CIC-PET was conducted in longitudinal studies using a lysolethicin-induced rat model of focal demyelination and subsequent remyelination. Quantitative analysis showed that the retention of [(11)C]CIC correlates with the level of demyelination/remyelination. These studies indicate that, for the first time, [(11)C]CIC-PET can be used as an imaging marker of myelination, which has the potential to be translated into clinical studies in multiple sclerosis and other myelin-related diseases for early diagnosis, subtyping, and efficacy evaluation of therapeutic treatments aimed at myelin repair.

BMC Neurosci. 2009 Nov 18; 10(1): 135
Marques F, Sousa JC, Coppola G, Geschwind DH, Sousa N, Palha JA, Correia-Neves M

ABSTRACT: BACKGROUND: Chronic systemic inflammation triggers alterations in the central nervous system that may relate to the underlying inflammatory component reported in Neurodegenerative Disorders such as multiple sclerosis and Alzheimer's disease. However, it is far from being understood whether and how peripheral inflammation contributes to induce brain inflammatory response in such illnesses. As part of the barriers that separate the blood from the brain, the choroid plexus conveys inflammatory immune signals into the brain, largely through alterations in the composition of the cerebrospinal fluid. RESULTS: In the present study we investigated the mouse choroid plexus gene expression profile, using microarray analyses, in response to a repeated inflammatory stimulus induced by the intraperitoneal administration of lipopolysaccharide every two weeks for a period of three months; mice were sacrificed 3 and 15 days after the last lipopolysaccharide injection. The data show that the choroid plexus displays a sustained response to the repeated inflammatory stimuli by altering the expression profile of several genes. From a total of 24,000 probes, 369 are up-regulated and 167 are down-regulated 3 days after the last lipopolysaccharide injection, while at 15 days the number decreases to 98 and 128, respectively. The pathways displaying the most significant changes include those facilitating entry of cells into the cerebrospinal fluid, and those participating in the innate immune response to infection. CONCLUSIONS: These observations contribute to a better understanding of the brain response to peripheral inflammation and pave the way to study their impact on the progression of several Disorders of the central nervous system in which inflammation is known to be implicated.

Int J Neurosci. 2009; 119(8): 1155-1169
Guven A, Yavuz O, Cam M, Comunoglu C, Sevi˙nc O

Diabetes mellitus is a common, potentially serious metabolic disorder. Over the long term, diabetes leads to serious consequences in a number of tissues, especially those that are insulin insensitive (retina, neurons, kidneys). It also causes a variety of functional and structural Disorders in the central and peripheral nervous systems. We investigated whether Neurodegenerative changes were observable in the hippocampus, cortex, and cerebellum after 4 weeks of streptozotocin (STZ)-induced diabetes in rats and the effect(s) of melatonin. Male Wistar rats (n = 32) were divided into four groups (n = 8 each): untreated controls, melatonin-treated controls, untreated diabetics, and melatonin-treated diabetics. Experimental diabetes was induced by a single dose of STZ (60 mg/kg, intraperitoneal (ip)). For 3 days before the administration of STZ, melatonin (200 mug/kg/day, ip) was injected and continued for 4 weeks. Sections of hippocampus, cortex, and cerebellum were stained with hematoxylin and eosin and examined using light microscopy. In addition, brain tissues were examined immunohistochemically for the expression of glial and neuronal markers, including glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), and heat shock protein-70 (HSP-70). No Neurodegenerative changes were observed in the hippocampus, cortex, or cerebellum of the untreated diabetic group after 4 weeks compared with the other groups. We did not observe any change in GFAP, NSE, or HSP-70 immunostaining in the brain tissues of STZ-induced diabetic rats. In summary, after 4 weeks of STZ-induced diabetes in rats, no degenerative or immunohistochemical changes were detected in the hippocampus, cortex, or cerebellum.

Amyotroph Lateral Scler. 2009; 10(5-6): 487-489
Van Rooij FG, Schelhaas HJ, Lammers GJ, Verbeek MM, Overeem S

Hypocretin (orexin) neurotransmission is not only crucially involved in the regulation of sleep and wake, but serves in multiple autonomic and cognitive functions as well. This is reflected in the widespread connections between the hypothalamic hypocretin neurons and the rest of the brain, such as dense projections to the frontal cortex. Both frontal cognitive impairment and autonomic disturbances have been described in ALS. Furthermore, in some ALS patients there may be sleep disturbances other than sleep related breathing Disorders, including REM sleep behaviour disorder. In addition, a role for the hypocretin system in the regulation of motor functions has been suggested. Hypocretin defects have been described in several Neurodegenerative Disorders. We therefore speculated that the hypocretin system is also involved in ALS and measured hypocretin-1 levels in cerebrospinal fluid samples from 20 patients. All results were well within the normal range (>200 pg/ml) and individual values showed no correlation with age, gender and disease duration. We conclude that it is unlikely that the hypocretin system is involved in the degenerative process of ALS.

Hippocampus. 2009 Nov 17;
Fontán-Lozano A, Suárez-Pereira I, Delgado-García JM, Carrión AM

Aging, mental retardation, number of psychiatric and neurological Disorders are all associated with learning and memory impairments. As the underlying causes of such conditions are very heterogeneous, manipulations that can enhance learning and memory in mice under different circumstances might be able to overcome the cognitive deficits in patients. The M-current regulates neuronal excitability and action potential firing, suggesting that its inhibition may increase cognitive capacities. We demonstrate that XE991, a specific M-current blocker, enhances learning and memory in healthy mice. This effect may be achieved by altering basal hippocampal synaptic activity and by diminishing the stimulation threshold for long-term changes in synaptic efficacy and learning-related gene expression. We also show that training sessions regulate the M-current by transiently decreasing the levels of KCNQ/Kv7.3 protein, a pivotal subunit for the M-current. Furthermore, we found that XE991 can revert the cognitive impairment associated with acetylcholine depletion and the neurodegeneration induced by kainic acid. Together, these results show that inhibition of the M-current as a general strategy may be useful to enhance cognitive capacities in healthy and aging individuals, as well as in those with Neurodegenerative diseases. (c) 2009 Wiley-Liss, Inc.