Neurodegenerative Disorders (neurodegenerative + disorders)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Neurodegenerative Disorders

  • age-related neurodegenerative disorders
  • many neurodegenerative disorders
  • other neurodegenerative disorders

  • Selected Abstracts

    The Impact of Neurodegenerative Disorders on Ageing: an Overview of the Sydney Older Persons Study

    H. Creasey
    This paper reviews the Sydney Older Persons Study, a longitudinal study following an initial cohort of 630 subjects aged 75 and over, community living in the inner west region of Sydney, carried out over seven years in four waves from 1991. We discuss the epidemiology of neurodegenerative disorders (NDDs) in relation to: each other, systemic disorders, death, lifestyle, risk factors and their impact on quality of life, service use and carers. [source]

    Protective effects of endomorphins, endogenous opioid peptides in the brain, on human low density lipoprotein oxidation

    FEBS JOURNAL, Issue 6 2006
    Xin Lin
    Neurodegenerative disorders are associated with oxidative stress. Low density lipoprotein (LDL) exists in the brain and is especially sensitive to oxidative damage. Oxidative modification of LDL has been implicated in the pathogenesis of neurodegenerative diseases. Therefore, protecting LDL from oxidation may be essential in the brain. The antioxidative effects of endomorphin 1 (EM1) and endomorphin 2 (EM2), endogenous opioid peptides in the brain, on LDL oxidation has been investigated in vitro. The peroxidation was initiated by either copper ions or a water-soluble initiator 2,2,-azobis(2-amidinopropane hydrochloride) (AAPH). Oxidation of the LDL lipid moiety was monitored by measuring conjugated dienes, thiobarbituric acid reactive substances, and the relative electrophoretic mobility. Low density lipoprotein oxidative modifications were assessed by evaluating apoB carbonylation and fragmentation. Endomorphins markedly and in a concentration-dependent manner inhibited Cu2+ and AAPH induced the oxidation of LDL, due to the free radical scavenging effects of endomorphins. In all assay systems, EM1 was more potent than EM2 and l -glutathione, a major intracellular water-soluble antioxidant. We propose that endomorphins provide protection against free radical-induced neurodegenerative disorders. [source]

    Overlap between neurodegenerative disorders

    NEUROPATHOLOGY, Issue 2 2005
    Richard A. Armstrong
    Neurodegenerative disorders are characterized by the formation of distinct pathological changes in the brain, including extracellular protein deposits, cellular inclusions, and changes in cell morphology. Since the earliest published descriptions of these disorders, diagnosis has been based on clinicopathological features, namely, the coexistence of a specific clinical profile together with the presence or absence of particular types of lesion. In addition, the molecular profile of lesions has become an increasingly important feature both in the diagnosis of existing disorders and in the description of new disease entities. Recent studies, however, have reported considerable overlap between the clinicopathological features of many disorders leading to difficulties in the diagnosis of individual cases and to calls for a new classification of neurodegenerative disease. This article discusses: (i) the nature and degree of the overlap between different neurodegenerative disorders and includes a discussion of Alzheimer's disease, dementia with Lewy bodies, the fronto-temporal dementias, and prion disease; (ii) the factors that contribute to disease overlap, including historical factors, the presence of disease heterogeneity, age-related changes, the problem of apolipoprotein genotype, and the co-occurrence of common diseases; and (iii) whether the current nosological status of disorders should be reconsidered. [source]

    Neurodegenerative disorders in schizophrenia

    No abstract is available for this article. [source]

    The crucial role of metal ions in neurodegeneration: the basis for a promising therapeutic strategy

    Alessandra Gaeta
    The variety of factors and events involved in neurodegeneration renders the subject a major challenge. Neurodegenerative disorders include a number of different pathological conditions, which share similar critical metabolic processes, such as protein aggregation and oxidative stress, both of which are associated with the involvement of metal ions. In this review, Alzheimer's disease, Parkinson's disease and prion disease are discussed, with the aim of identifying common trends underlying these devastating neurological conditions. Chelation therapy could be a valuable therapeutic approach, since metals are considered to be a pharmacological target for the rationale design of new therapeutic agents directed towards the treatment of neurodegeneration. British Journal of Pharmacology (2005) 146, 1041,1059. doi:10.1038/sj.bjp.0706416 [source]

    Progress in the development of new treatments for combined Alzheimer's and Parkinson's diseases

    Eliezer Masliah
    Abstract Misfolding of synaptic molecules such as amyloid , peptide and ,-synuclein has been proposed to play a key role in the mechanisms of neurodegeneration in Alzheimer's and Parkinson's disease, respectively. Notably, the majority of patients with Alzheimer's disease also have ,-synuclein-immunoreactive Lewy bodies, and a substantial proportion of them develop a form of parkinsonism also known as Lewy body disease, that defies conventional therapies. Thus, factors involved in the pathogenesis of Alzheimer's disease might promote the development of particularly recalcitrant forms of Lewy body disease. We have shown that the amyloid , peptide 1-42, of Alzheimer's disease, promotes the toxic conversion of ,-synuclein and accelerates ,-synuclein-dependent deficits in transgenic mice. Understanding the mechanisms promoting the toxic conversion of ,-synuclein is of critical importance for the design of rationale treatments for Lewy body disease and transgenic models hold the promise for the development of such novel therapies. In this context therapies aimed at: (1) reducing amyloid , peptide 1-42 production, (2) blocking toxic ,-synuclein oligomerization (e.g., ,-synuclein, antioxidants), (3) promoting ,-synuclein protofibril degradation, and (4) protecting neurons (e.g., anti-oxidants, neurotrophic agents) against toxic ,-synuclein aggregates might prove to be significantly useful in the treatment of Lewy body disease. We characterized ,-synuclein, the non-amyloidogenic homologue of ,-synuclein, as an inhibitor of aggregation of ,-synuclein. Our results raise the intriguing possibility that ,-synuclein might be a natural negative regulator of ,-synuclein aggregation, and that a similar class of endogenous factors might modulate the toxic conversion of other molecules involved in neurodegeneration. Such an anti-amyloidogenic property of ,-synuclein in combination with other treatments might also provide a novel strategy for the treatment of neurodegenerative disorders. Drug Dev. Res. 56:282,292, 2002. © 2002 Wiley-Liss, Inc. [source]

    Prospects for therapeutic vaccination with glatiramer acetate for neurodegenerative diseases such as Alzheimer's disease

    Michal Schwartz
    Abstract Neurodegenerative diseases, whatever their primary causes, are characterized by certain common features, one of which is their self-perpetuating nature. The ongoing progression of the disorder is due to the effects of destructive self-compounds, whose presence in the tissues is an outcome of the early phase of the disease and which gradually destroy remaining functional neurons. Studies in our laboratory have led to the recent formulation of a novel concept of protective autoimmunity as the body's mechanism of defense against these destructive self-compounds. This autoimmune response to central nervous system (CNS) insults is mediated by T-cells and presumably operates by activating and regulating local microglia and infiltrating macrophages (inflammatory response) to carry out their function of clearing destructive material from the tissue at risk. We suggest that a well-controlled autoimmunity counteracts and overcomes the destructive effects of the potentially harmful self-compounds, at the cost of some loss of tissue. An additional risk to the individual is the induction of an autoimmune disease, which is likely to occur if the autoimmune response is malfunctioning. An optimal balance of the various factors will lead to an outcome of maximal benefit at minimal cost to the tissue. A procedure for safely boosting the autoimmune response, by vaccination with a weak self-crossreactive antigen such as glatiramer acetate (also known as Cop-1) was found to protect rats from glutamate toxicity, a major mediator of the spread of damage and a well-known causative factor in neurodegenerative disorders. Cop-1, when administered according to a different regimen, is an FDA-approved drug for the treatment of multiple sclerosis. Different formulations of the same drug can therefore be used to treat two extreme manifestations of chronic degenerative diseases of the CNS. Drug Dev. Res. 56:143,149, 2002. © 2002 Wiley-Liss, Inc. [source]

    Sensitive Electrochemical Detection of Native and Aggregated ,-Synuclein Protein Involved in Parkinson's Disease

    ELECTROANALYSIS, Issue 13-14 2004
    Michal Masa
    Abstract The aggregation of ,-synuclein, a 14,kDa protein, is involved in several human neurodegenerative disorders, including Parkinson's disease. We studied native and in vitro aggregated ,-synuclein by circular dichroism (CD), atomic force microscopy (AFM) and electrochemical methods. We used constant current chronopotentiometric stripping analysis (CPSA) to measure hydrogen evolution catalyzed by ,-synuclein (peak H) at hanging mercury drop electrodes (HMDE) and square-wave stripping voltammetry (SWSV) to monitor tyrosine oxidation at carbon paste electrodes (CPE). To decrease the volume of the analyte, most of the electrochemical measurements were performed by adsorptive transfer (medium exchange) from 3,6,,L drops of ,-synuclein samples. With both CPE and HMDE we observed changes in electrochemical responses of ,-synuclein corresponding to protein fibrillization detectable by CD, fluorescence and AFM. Aggregation-induced changes in peak H at HMDE were relatively large in strongly aggregated samples, suggesting that this electrochemical signal may find use in the analysis of early stages of ,-synuclein aggregation. This assumption was documented by marked changes in the peak H potential and height in samples withdrawn at the end of the lag and the beginning of the elongation phase. Native ,-synuclein can be detected down to subnanomolar concentrations by CPSA. [source]

    Decreased hippocampal volume on MRI is associated with increased extracellular glutamate in epilepsy patients

    EPILEPSIA, Issue 8 2008
    Idil Cavus
    Summary Purpose: Temporal lobe epilepsy (TLE) is associated with smaller hippocampal volume and with elevated extracellular (EC) glutamate levels. We investigated the relationship between the hippocampal volume and glutamate in refractory TLE patients. Methods: We used quantitative MRI volumetrics to measure the hippocampal volume and zero-flow microdialysis to measure the interictal glutamate, glutamine, and GABA levels in the epileptogenic hippocampus of 17 patients with medication-resistant epilepsy undergoing intracranial EEG evaluation. The relationships between hippocampal volume, neurochemical levels, and relevant clinical factors were examined. Results: Increased EC glutamate in the epileptogenic hippocampus was significantly related to smaller ipsilateral (R2= 0.75, p < 0.0001), but not contralateral hippocampal volume when controlled for glutamine and GABA levels, and for clinical factors known to influence hippocampal volume. Glutamate in the atrophic hippocampus was significantly higher (p = 0.008, n = 9), with the threshold for hippocampal atrophy estimated as 5 ,M. GABA and glutamine levels in the atrophic and nonatrophic hippocampus were comparable. Decreased hippocampal volume was related to higher seizure frequency (p = 0.008), but not to disease duration or febrile seizure history. None of these clinical factors were related to the neurochemical levels. Conclusions: We provide evidence for a significant association between increased EC glutamate and decreased ipsilateral epileptogenic hippocampal volume in TLE. Future work will be needed to determine whether the increase in glutamate has a causal relationship with hippocampal atrophy, or whether another, yet unknown factor results in both. This work has implications for the understanding and treatment of epilepsy as well as other neurodegenerative disorders associated with hippocampal atrophy. [source]

    Structural disorder in amyloid fibrils: its implication in dynamic interactions of proteins

    FEBS JOURNAL, Issue 19 2009
    P. Tompa
    Proteins are occasionally converted from their normal soluble state to highly ordered fibrillar aggregates (amyloids), which give rise to pathological conditions that range from neurodegenerative disorders to systemic amyloidoses. Recent methodological advances in solid-state NMR and EPR spectroscopy have enabled determination of the 3D structure of several amyloids at residue-level resolution. The general picture that emerges is that amyloids constitute parallel , sheets, in which individual polypeptide chains run roughly perpendicular to the major axis of the fibril and are stacked in-register. Thus, the unifying theme of amyloid formation is the structural transition from an initial globular or intrinsically disordered state to a highly ordered regular form. In this minireview, we show that this description is somewhat oversimplified, because part of the polypeptide chain in the amyloid remains intrinsically disordered and does not become part of the ordered core. As demonstrated through examples such as the amyloids of ,-synuclein and A, peptide and the yeast prions HET-s and Ure2p, these disordered segments are depleted in amino acids NQFYV and are enriched in DEKP. They are also significantly more charged and have a higher predicted disordered value than segments in the cross-, core. We suggest that structural disorder in amyloid is a special case of ,fuzziness', i.e. disorder in the bound state that may serve different functions, such as the accommodation of destabilizing residues and the mediation of secondary interactions between protofibrils. [source]

    Protective effects of endomorphins, endogenous opioid peptides in the brain, on human low density lipoprotein oxidation

    FEBS JOURNAL, Issue 6 2006
    Xin Lin
    Neurodegenerative disorders are associated with oxidative stress. Low density lipoprotein (LDL) exists in the brain and is especially sensitive to oxidative damage. Oxidative modification of LDL has been implicated in the pathogenesis of neurodegenerative diseases. Therefore, protecting LDL from oxidation may be essential in the brain. The antioxidative effects of endomorphin 1 (EM1) and endomorphin 2 (EM2), endogenous opioid peptides in the brain, on LDL oxidation has been investigated in vitro. The peroxidation was initiated by either copper ions or a water-soluble initiator 2,2,-azobis(2-amidinopropane hydrochloride) (AAPH). Oxidation of the LDL lipid moiety was monitored by measuring conjugated dienes, thiobarbituric acid reactive substances, and the relative electrophoretic mobility. Low density lipoprotein oxidative modifications were assessed by evaluating apoB carbonylation and fragmentation. Endomorphins markedly and in a concentration-dependent manner inhibited Cu2+ and AAPH induced the oxidation of LDL, due to the free radical scavenging effects of endomorphins. In all assay systems, EM1 was more potent than EM2 and l -glutathione, a major intracellular water-soluble antioxidant. We propose that endomorphins provide protection against free radical-induced neurodegenerative disorders. [source]

    Glutathione depletion in hippocampal cells increases levels of H and L ferritin and glutathione S-transferase mRNAs

    GENES TO CELLS, Issue 5 2007
    Nadya Morozova
    Glutathione plays an essential role in maintaining cellular redox balance, protecting cells from oxidative stress and detoxifying xenobiotic compounds. Glutathione depletion has been implicated in neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. Cells of neuronal origin are acutely sensitive to glutathione depletion, providing an avenue for studying the mechanisms invoked for neuronal survival in response to oxidant challenge. We investigated the changes in mRNA profile in HT22 hippocampal cells following administration of homocysteic acid (HCA), a glutathione-depleting drug. We report that HCA treatment of HT22 murine hippocampal cells increases the levels of the mRNAs encoding at least three proteins involved in protection from oxidant injury, the mRNAs encoding heavy (H) and light (L) ferritin and glutathione S-transferase (GST). [source]

    Aversive phototaxic suppression: evaluation of a short-term memory assay in Drosophila melanogaster

    L. Seugnet
    Drosophila melanogaster is increasingly being used to model human conditions that are associated with cognitive deficits including fragile-X syndrome, Alzheimer's disease, Parkinson's disease, sleep loss, etc. With few exceptions, cognitive abilities that are known to be modified in these conditions in humans have not been evaluated in fly models. One reason is the absence of a simple, inexpensive and reliable behavioral assay that can be used by laboratories that are not expert in learning and memory. Aversive phototaxic suppression (APS) is a simple assay in which flies learn to avoid light that is paired with an aversive stimulus (quinine/humidity). However, questions remain about whether the change in the fly's behavior reflects learning an association between light and quinine/humidity or whether the change in behavior is because of nonassociative effects of habituation and/or sensitization. We evaluated potential effects of sensitization and habituation on behavior in the T-maze and conducted a series of yoked control experiments to further exclude nonassociative effects and determine whether this task evaluates operant learning. Together these experiments indicate that a fly must associate the light with quinine/humidity to successfully complete the task. Next, we show that five classic memory mutants are deficient in this assay. Finally, we evaluate performance in a fly model of neurodegenerative disorders associated with the accumulation of Tau. These data indicate that APS is a simple and effective assay that can be used to evaluate fly models of human conditions associated with cognitive deficits. [source]

    Glaucomatous optic nerve injury involves early astrocyte reactivity and late oligodendrocyte loss

    GLIA, Issue 7 2010
    Janice L. Son
    Abstract Glaucoma, a neurodegenerative disease affecting retinal ganglion cells (RGC), is a leading cause of blindness. Since gliosis is common in neurodegenerative disorders, it is important to describe the changes occurring in various glial populations in glaucoma animal models in relation to axon loss, as only changes that occur early are likely to be useful therapeutic targets. Here, we describe changes occurring in glia within the myelinated portion of the optic nerve (ON) in both DBA/2J mice and in a rat ocular hypertension model. In both glaucoma animal models, we found only a modest loss of oligodendrocytes that occurred after axons had already degenerated. In DBA/2J mice there was proliferation of oligodendrocyte precursor cells (OPCs) and new oligodendrocyte generation. Activation of microglia was detected only in highly degenerated DBA/2J ONs. In contrast, a large increase in astrocyte reactivity occurred early in both animal models. These results are consistent with astrocytes playing a prominent role in regulating axon loss in glaucoma. © 2010 Wiley-Liss, Inc. [source]

    Enhancement of neuronal outward delayed rectifier K+ current by human monocyte-derived macrophages

    GLIA, Issue 14 2009
    Dehui Hu
    Abstract Macrophages are critical cells in mediating the pathology of neurodegenerative disorders and enhancement of neuronal outward potassium (K+) current has implicated in neuronal apoptosis. To understand how activated macrophages induce neuronal dysfunction and injury, we studied the effects of lipopolysaccharide (LPS)-stimulated human monocytes-derived macrophage (MDM) on neuronal outward delayed rectifier K+ current (IK) and resultant change on neuronal viability in primary rat hippocampal neuronal culture. Bath application of LPS-stimulated MDM-conditioned media (MCM) enhanced neuronal IK in a concentration-dependentmanner, whereas non-stimulated MCM failed to alter neuronal IK. The enhancement of neuronal IK was repeated in a macrophage-neuronal co-culture system. The link of stimulated MCM (MCM(+))-associated enhancement of IK to MCM(+)-induced neuronal injury, as detected by PI/DAPI (propidium iodide/4,,6-diamidino-2-phenylindol) staining and MTT assay, was demonstrated by experimental results showing that addition of IK blocker tetraethylammonium to the culture protected hippocampal neurons from MCM(+)-associated challenge. Further investigation revealed elevated levels of Kv 1.3 and Kv 1.5 channel expression in hippocampal neurons after addition of MCM(+) to the culture. These results suggest that during brain inflammation macrophages, through their capacity of releasing bioactive molecules, induce neuronal injury by enhancing neuronal IK and that modulation of Kv channels is a new approach to neuroprotection. © 2009 Wiley-Liss, Inc. [source]

    Cannabinoid CB2 receptor agonists protect the striatum against malonate toxicity: Relevance for Huntington's disease

    GLIA, Issue 11 2009
    Onintza Sagredo
    Abstract Cannabinoid agonists might serve as neuroprotective agents in neurodegenerative disorders. Here, we examined this hypothesis in a rat model of Huntington's disease (HD) generated by intrastriatal injection of the mitochondrial complex II inhibitor malonate. Our results showed that only compounds able to activate CB2 receptors were capable of protecting striatal projection neurons from malonate-induced death. That CB2 receptor agonists are neuroprotective was confirmed by using the selective CB2 receptor antagonist, SR144528, and by the observation that mice deficient in CB2 receptor were more sensitive to malonate than wild-type animals. CB2 receptors are scarce in the striatum in healthy conditions, but they are markedly upregulated after the lesion with malonate. Studies of double immunostaining revealed a significant presence of CB2 receptors in cells labeled with the marker of reactive microglia OX-42, and also in cells labeled with GFAP (a marker of astrocytes). We further showed that the activation of CB2 receptors significantly reduced the levels of tumor necrosis factor-, (TNF-,) that had been increased by the lesion with malonate. In summary, our results demonstrate that stimulation of CB2 receptors protect the striatum against malonate toxicity, likely through a mechanism involving glial cells, in particular reactive microglial cells in which CB2 receptors would be upregulated in response to the lesion. Activation of these receptors would reduce the generation of proinflammatory molecules like TNF-,. Altogether, our results support the hypothesis that CB2 receptors could constitute a therapeutic target to slowdown neurodegeneration in HD. © 2008 Wiley-Liss, Inc. [source]

    Modulation of astrocyte P2Y1 receptors by the carboxyl terminal domain of the gap junction protein Cx43

    GLIA, Issue 2 2008
    Eliana Scemes
    Abstract Gap junction proteins, connexins, provide intercellular channels that allow ions and small signaling molecules to be transmitted to adjacent coupled cells. Besides this function, it is becoming apparent that connexins also exert channel-independent effects, which are likely mediated by processes involving protein,protein interactions. Although a number of connexin interacting proteins have been identified, only little is known about the functional consequences of such interactions. We have previously shown that deletion of the astrocytic gap junction protein, connexin43 (Cx43) causes a right-ward shift in the dose-response curve to P2Y1R agonists and decreased P2Y1R expression levels. To evaluate whether these changes were due to reduced gap junctional communication or to protein,protein interactions, Cx43-null astrocytes were transfected with full-length Cx43 and Cx43 domains, and P2Y1R function and expression levels evaluated. Results indicate that restoration of P2Y1R function is independent of gap junctional communication and that the Cx43 carboxyl terminus spanning the SH3 binding domain (260,280) participates in the rescue of P2Y1R pharmacological behavior (shifting to the left the P2Y1R dose-response curve) without affecting its expression levels. These results suggest that the Cx43 carboxyl-terminus domain provides a binding site for an intracellular molecule, most likely a member of the c-Src tyrosine kinase family, which affects P2Y1R-induced calcium mobilization. It is here proposed that a nonchannel function of Cx43 is to serve as a decoy for such kinases. Such modulation of P2Y1R is expected to influence several neural cell functions, especially under inflammation and neurodegenerative disorders where expression levels of Cx43 are decreased. © 2007 Wiley-Liss, Inc. [source]

    Transplanted astrocytes internalize deposited ,-amyloid peptides in a transgenic mouse model of Alzheimer's disease

    GLIA, Issue 2 2008
    Rea Pihlaja
    Abstract Alzheimer's disease (AD) is one of the most devastating neurodegenerative disorders. The neuropathological hallmarks include extracellular senile plaques consisting of deposited ,-amyloid (A,) peptides and intraneuronal neurofibrillary tangles. Neuroinflammation and activation of astrocytes are also well-established features of AD neuropathology; however, the relationships between astrocytes and A, deposition remain unclear. Previous studies have shown that adult mouse astrocytes internalize and degrade A, deposits in brain sections prepared from human amyloid precursor protein (APP) transgenic mice. In the present study, we demonstrate that cultured adult, but not neonatal mouse astrocytes, respond morphologically and degrade A, deposits present in human AD brain. We also transplanted astrocytes isolated from enhanced green fluorescent protein expressing adult and neonatal mice into the hippocampi of human A, plaque-bearing transgenic APPSwe+PS1dE9 (APdE9) mice and their wild-type littermates and followed the migration and localization of these astrocytes by confocal microscopy upto 7 days after transplantation. Posttransplantation the astrocytes localized as aggregates or thin strings of many cells within the hippocampi of APdE9 and wild-type mice and showed limited migration from the injection site. Interestingly, most of the transplanted astrocytes were found near A, deposits in the hippocampi of APdE9 mice. In contrast to findings in ex vivo degradation assay, confocal microscopy revealed that both adult and neonatal transplanted astrocytes internalized human A, immunoreactive material in vivo. These results support the role of astrocytes as active A, clearing cells in the CNS that may have important implications for future development of therapeutic strategies for AD. © 2007 Wiley-Liss, Inc. [source]

    Hemochromatosis genotypes and risk of 31 disease endpoints: Meta-analyses including 66,000 cases and 226,000 controls,

    HEPATOLOGY, Issue 4 2007
    Christina Ellervik
    Hemochromatosis genotypes have been associated with liver disease, diabetes mellitus, heart disease, arthritis, porphyria cutanea tarda, stroke, neurodegenerative disorders, cancer, and venous disease. We performed meta-analyses including 202 studies with 66,263 cases and 226,515 controls to examine associations between hemochromatosis genotypes C282Y/C282Y, C282Y/H63D, C282Y/wild type, H63D/H63D, and H63D/wild type versus wild type/wild type and 9 overall endpoints and 22 endpoint subgroups. We also explored potential sources of heterogeneity. For liver disease, the odds ratio for C282Y/C282Y versus wild type/wild type was 3.9 (99% confidence interval: 1.9,8.1) overall, 11 (3.7,34) for hepatocellular carcinoma, 4.1 (1.2,14) for hepatitis C, and 10 (2.1,53) for nonalcoholic steatohepatitis. For porphyria cutanea tarda, the odds ratios were 48 (24,95) for C282Y/C282Y, 8.1 (3.9,17) for C282Y/H63D, 3.6 (1.8,7.3) for C282Y/wild type, 3.0 (1.6,5.6) for H63D/H63D, and 1.7 (1.0,3.1) for H63D/wild type versus wild type/wild type. Finally, for amyotrophic lateral sclerosis, the odds ratio was 3.9 (1.2,13) for H63D/H63D versus wild type/wild type. These findings were consistent across individual studies. The hemochromatosis genotypes were not associated with risk for diabetes mellitus, heart disease, arthritis, stroke, cancer, or venous disease in the overall analyses; however, the odds ratio for C282Y/C282Y versus wild type/wild type was 3.4 (1.1,11) for diabetes mellitus among North Europeans. Conclusion: In aggregate, clinically ascertained cases who are homozygous for the C282Y mutation are associated with a 4,11,fold risk of liver disease, whereas all 5 hemochromatosis genotypes are associated with a 2,48,fold risk of porphyria cutanea tarda, and H63D/H63D is associated with a 4-fold risk of amyotrophic lateral sclerosis. These results, mainly from case-control studies, cannot necessarily be extrapolated to the general population. (HEPATOLOGY 2007.) [source]

    An update on the neuropathology of HIV in the HAART era

    HISTOPATHOLOGY, Issue 6 2004
    J E Bell
    This review compares the neuropathology of highly active antiretroviral therapy (HAART)-treated HIV+ individuals with the reported central nervous system (CNS) findings from the pre-HAART era. HAART has had considerable success in combating HIV-related immune collapse and has prevented many of the former end-stage complications of AIDS. However, with increased survival times the prevalence of minor HIV-associated cognitive impairment appears to be rising among treated patients and this may be a particular risk for older individuals. HIV encephalitis (HIVE) is still prevalent in treated patients although attenuated forms of HIVE and CNS opportunistic disorders are also observed. Some subjects show very significant CNS lymphocytic infiltrates in the context of HAART-induced immune reconstitution. HIV-associated cognitive impairment correlates best with the increased presence of activated, though not necessarily infected, microglia and CNS macrophages. This suggests that indirect mechanisms of neuronal injury and loss occur in HIV/AIDS as a basis for dementia since neurones are not themselves productively infected. Research to elucidate the mechanisms of neuronal injury in HIV/AIDS may contribute to the understanding of CNS function not only in HAART-treated subjects but also in other neurodegenerative disorders. [source]

    The neuronal ceroid lipofuscinosis protein CLN5: new insights into cellular maturation, transport, and consequences of mutations,

    HUMAN MUTATION, Issue 3 2010
    Mia-Lisa Schmiedt
    Abstract Neuronal ceroid lipofuscinoses (NCLs) represent a group of children's inherited neurodegenerative disorders caused by mutations in at least eight different genes. Mutations in the CLN5 gene result in the Finnish variant late infantile NCL characterized by gradual loss of vision, epileptic seizures, and mental deterioration. The CLN5 gene encodes a lysosomal glycoprotein of unidentified function. In this study, we have used both transient and stable expression systems for the characterization of CLN5, focusing on the localization, processing, and intracellular trafficking. We show that CLN5 is proteolytically cleaved, and that the mature polypeptide is transported to the lysosomes. Our data provide the first evidence that soluble CLN5 protein can also undergo mannose-6-phosphate receptor-independent trafficking to the lysosomes. We studied the localization and maturation of the CLN5 carrying the previously uncharacterized vLINCL disease causing mutations in HeLa cells. All analyzed disease mutations disturb the lysosomal trafficking of the mutated CLN5 proteins. The level of lysosomal targeting does not correlate, however, to disease onset, indicating that CLN5 may also function outside lysosomes. This study furthers our understanding of the basic properties of the CLN5 protein, necessary for the characterization of the consequences of disease mutations and for the planning of future therapies for vLINCL. Hum Mutat 31:356,365, 2010. © 2010 Wiley-Liss, Inc. [source]

    Kennedy's disease: pathogenesis and clinical approaches

    K. J. Greenland
    Abstract Kennedy's disease, also known as spinal and bulbar muscular atrophy, is a progressive degenerative con­dition affecting lower motor neurons. It is one of nine neurodegenerative disorders caused by a polyglutamine repeat expansion. Affecting only men, Kennedy's disease is the only one of these conditions that follows an X-linked mode of inheritance. The causative protein in Kennedy's disease, with a polyglutamine expansion residing in the first N-terminal domain, is the androgen receptor. Research in this field has made significant advances in recent years, and with the increased understanding of pathogenic mechanisms, feasible approaches to treatments are being investigated. In Kennedy's disease research, the most significant issue to emerge recently is the role of androgens in exacerbating the disease process. On the basis of animal experiments, a viable hypothesis is that higher circulating levels of androgens in men could trigger the degeneration of motor neurons causing this disease, and that lower levels in heterozygous and homozygous women are protective. This is a major issue, as treatment of individuals affected by Kennedy's disease with testosterone has been con­sidered a reasonable therapy by some neurologists. The rationale behind this approach relates to the fact that Kennedy's disease is accompanied by mild androgen insensitivity. It was therefore believed that treatment with high doses of testosterone might compensate for this loss of androgen action, with the added benefit of preventing muscle wasting. The current review provides an overview of recent advances in the field of Kennedy's disease research, including approaches to treatment. (Intern Med J 2004; 34: 279,286) [source]

    Human prion diseases: biology and transmission by blood

    J. W. Ironside
    Human prion diseases are a group of rare fatal transmissible neurodegenerative disorders that occur in sporadic, acquired and familial forms. In 1996, a new type of human prion disease, variant Creutzfeldt-Jakob disease (vCJD), was first identified and has subsequently been identified in 10 additional countries. vCJD results from human exposure to the bovine spongiform encephalopathy (BSE) agent, most likely through the consumption of BSE-contaminated meat products. Unlike other human prion diseases, both infectivity and the disease-associated form of the prion protein are readily detected in lymphoid tissues in vCJD, suggesting that infectivity may also be present in blood. Three recent cases of apparent iatrogenic vCJD infection by blood transfusion have occurred in the UK, following red blood cell transfusions from asymptomatic donors who subsequently died from vCJD. The first and third cases resulted in a clinical illness identical to vCJD, while the second case was an asymptomatic infection only detected at autopsy. There are no current means of detecting vCJD infection in asymptomatic donors, so continuing surveillance is required in the UK and other countries to monitor the incidence of vCJD and further cases of secondary transmission by blood transfusion. [source]

    Oligomeric alpha-synuclein and its role in neuronal death

    IUBMB LIFE, Issue 5 2010
    David R. Brown
    Abstract Alpha-synuclein is a natively unfolded protein associated with a number of neurodegenerative disorders that include Parkinson's disease. In the past, research has focused on the fibrillar form of the protein. Current research now indicates that oligomeric alpha-synuclein is the form of the protein most likely to causes neuronal death. Recent research has suggested that a unique oligomer associated with the copper binding capacity of the protein is the neurotoxic form of the protein. This review looks at the evidence for this possibility. © 2010 IUBMB IUBMB Life, 62(5): 334,339, 2010 [source]

    The Neuropathological Spectrum of Neurodegenerative Tauopathies

    IUBMB LIFE, Issue 6 2003
    Markus Tolnay
    Abstract Abundant neurofibrillary lesions made of abnormal and hyperphosphorylated microtubule-associated protein tau constitute one of the defining neuropathological features of Alzheimer's disease. However, tau containing filamentous deposits in neurons and/or glial cells also define a heterogeneous group of neurodegenerative disorders clinically characterized by dementia and/or motor syndromes. Thus, all these disorders are collectively grouped under the generic term of tauopathies. In the present review we outline the morphological and biochemical characteristics of some major tauopathies, including Alzheimer's disease, Pick's disease, progressive supranuclear palsy, corticobasal degeneration and argyrophilic grain disease. The second part will deal with the recent discovery of tau gene mutations in frontotemporal dementia and parkinsonism linked to chromosome 17 which demonstrates that tau dysfunction can lead to neurodegeneration. Finally, we will discuss the very recent finding of 'tau-deficient' tauopathy in a subset of frontotemporal dementia cases. IUBMB Life, 55: 299-305, 2003 [source]

    The effect of water on particle size, porosity and the rate of drug release from implanted titania reservoirs

    Tessy Lopez
    Abstract The implantation of controlled drug release devices represents a new strategy in the treatment of neurodegenerative disorders. Sol,gel titania implants filled with valproic acid, have been used for this purpose to treat induced epilepsy in rats. The kinetics of the drug release depend on: (a) porosity, (b) chemical interactions between valproic acid and surface hydroxyl groups of titania, (c) particle size, and (d) particle size agglomerates. The concentration of water used in the hydrolysis reaction is an important variable in the degree of porosity, hydroxylation, and structural defects of the nanostructured titanium oxide reservoir. The titanium n -butoxide/water ratio was systematically varied during the sol,gel synthesis, while maintaining the amount of valproic acid constant. Characterization studies were performed using DTA-TGA, FTIR, Raman, TEM, SEM, BET, and in vitro release kinetic measurements. The particle agglomerate size and porosity were found to depend on the amount of water used in the sol,gel reaction. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010 [source]

    Aging Increases the Interleukin-1,,Induced INOS Gene Expression and Nitric Oxide (NO) Production in Vascular Smooth Muscle Cells

    Gabriel HH Chan
    Objectives: Inducible form of nitric oxide synthase (iNOS) is induced by cytokines (e.g. interleukin-1, (IL-1,)) during pathological conditions, such as sepsis. Excessive NO synthesis in blood vessels during sepsis can result in massive vasodilation and life-threatening hypotension. In addition, chronic expression of iNOS contributes to onset of diabetes, autoimmune diseases, arthritis, renal toxicity, and neurodegenerative disorders. The purpose of the present study was to examine the effect of aging on the levels of expression of iNOS induced by a low concentration (5 ng/ml) of IL-1, in VSMCs. Methods: Gene expression of iNOS was determined by RT-PCR and analysis of the PCR products by both agarose gel electrophoresis and capillary electrophoresis with laser-induced fluorescence detector (CE-LIF). This new CE-LIF technique, just developed in our laboratory, provides greater than 1,000 fold better sensitivity compared to agarose gels. The production of nitrite, the stable metabolite of NO, was measured (by a modified Griess reaction) in the media of cultured VSMCs isolated from young and elderly rats (3-month and 20-months old, respectively) of both genders following the exposure to IL-1, (5 ng/ml). VSMCs were used in their 1st passage to avoid phenotypic changes that typically occur in cultures of VSMCs after 3-10 passages. Results: IL-1, (5 ng/ml) caused a much larger increase in iNOS mRNA in VSMCs of elderly rats as compared to young rats. Furthermore, IL-1, (5 ng/ml) had no significant effect on nitrite levels in VSMCs of young, but significantly increased nitrite levels by 7.9 fold in VSMCs from elderly male rats and by 2.6 fold in VSMCs from elderly female rats, as compared to young rats. A report had previously shown that the neuropeptide CGRP could synergistically enhance the expression of iNOS caused by IL-1, in later passages (10-15 passages) of rat aortic VSMCs (i.e. phenotypically modulated VSMCs). We found that IL-1, and CGRP together did not act synergistically to increase production of nitrite in our phenotypically normal (1st passage) VSMCs. Conclusion: IL-1,, at a low concentration (5 ng/ml), preferentially induces iNOS expression and increases production of NO in VSMCs of elderly rats as compared to young rats. The data suggest that aging enhances the responsiveness of VSMCs to the iNOS-inducing actions of the cytokine IL-1,. This may be a contributing factor in the increased risk of developing severe hypotension in elderly patients with sepsis. (Supported by a Direct Grant for Research). [source]

    Cell death mechanisms in neurodegeneration

    K. A. Jellinger
    Abstract Progressive cell loss in specific neuronal populations often associated with typical cytoskeletal protein aggregations is a pathological hallmark of neurodegenerative disorders, but the nature, time course and molecular causes of cell death and their relation to cytoskeletal pathologies are still unresolved. Apoptosis or alternative pathways of cell death have been discussed in Alzheimer's disease and other neurodegenerative disorders. Apoptotic DNA fragmentation in human brain as a sign of neuronal injury is found too frequent as to account for continous neuron loss in these slowly progressive processes. Morphological studies revealed extremely rare apoptotic neuronal death in Alzheimer's disease but yielded mixed results for Parkinson's disease and other neurodegenerative disorders. Based on recent data in human brain, as well as in animal and cell culture models, a picture is beginning to emerge suggesting that, in addition to apoptosis, other forms of programmed cell death may participate in neurodegeneration. Better understanding of the molecular players will further elucidate the mechanisms of cell death in these disorders and their relations to cytoskeletal abnormalities. Susceptible cell populations in a proapoptotic environment show increased vulnerability towards multiple noxious factors discussed in the pathogenesis of neurodegeneration. In conclusion, although many in vivo and in vitro data are in favor of apoptosis involvement in neurodegenerative processes, there is considerable evidence that very complex events may contribute to neuronal death with possible repair mechanisms, the elucidation of which may prove useful for future prevention and therapy of neurodegenerative disorders. [source]

    Temporal requirements of insulin/IGF-1 signaling for proteotoxicity protection

    AGING CELL, Issue 2 2010
    Ehud Cohen
    Summary Toxic protein aggregation (proteotoxicity) is a unifying feature in the development of late-onset human neurodegenerative disorders. Reduction of insulin/IGF-1 signaling (IIS), a prominent lifespan, developmental and reproductive regulatory pathway, protects worms from proteotoxicity associated with the aggregation of the Alzheimer's disease-linked A, peptide. We utilized transgenic nematodes that express human A, and found that late life IIS reduction efficiently protects from A, toxicity without affecting development, reproduction or lifespan. To alleviate proteotoxic stress in the animal, the IIS requires heat shock factor (HSF)-1 to modulate a protein disaggregase, while DAF-16 regulates a presumptive active aggregase, raising the question of how these opposing activities could be co-regulated. One possibility is that HSF-1 and DAF-16 have distinct temporal requirements for protection from proteotoxicity. Using a conditional RNAi approach, we found an early requirement for HSF-1 that is distinct from the adult functions of DAF-16 for protection from proteotoxicity. Our data also indicate that late life IIS reduction can protect from proteotoxicity when it can no longer promote longevity, strengthening the prospect that IIS reduction might be a promising strategy for the treatment of neurodegenerative disorders caused by proteotoxicity. [source]

    Dysfunction of the unfolded protein response increases neurodegeneration in aged rat hippocampus following proteasome inhibition

    AGING CELL, Issue 6 2009
    María Paz Gavilán
    Summary Dysfunctions of the ubiquitin proteasome system (UPS) have been proposed to be involved in the aetiology and/or progression of several age-related neurodegenerative disorders. However, the mechanisms linking proteasome dysfunction to cell degeneration are poorly understood. We examined in young and aged rat hippocampus the activation of the unfolded protein response (UPR) under cellular stress induced by proteasome inhibition. Lactacystin injection blocked proteasome activity in young and aged animals in a similar extent and increased the amount of ubiquitinated proteins. Young animals activated the three UPR arms, IRE1,, ATF6, and PERK, whereas aged rats failed to induce the IRE1, and ATF6, pathways. In consequence, aged animals did not induce the expression of pro-survival factors (chaperones, Bcl-XL and Bcl-2), displayed a more sustained expression of pro-apoptotic markers (CHOP, Bax, Bak and JKN), an increased caspase-3 processing. At the cellular level, proteasome inhibition induced neuronal damage in young and aged animals as assayed using Fluorojade-B staining. However, degenerating neurons were evident as soon as 24 h postinjection in aged rats, but it was delayed up to 3 days in young animals. Our findings show evidence supporting age-related dysfunctions in the UPR activation as a potential mechanism linking protein accumulation to cell degeneration. An imbalance between pro-survival and pro-apoptotic proteins, because of noncanonical activation of the UPR in aged rats, would increase the susceptibility to cell degeneration. These findings add a new molecular vision that might be relevant in the aetiology of several age-related neurodegenerative disorders. [source]