Pathological Hallmark (pathological + hallmark)

Distribution by Scientific Domains


Selected Abstracts


,-Amyloid immunization approaches for Alzheimer's disease

DRUG DEVELOPMENT RESEARCH, Issue 2 2002
Bruno P. Imbimbo
Abstract Alzheimer's disease (AD) represents the third leading cause of death in the U.S. and the leading cause of dementia in the elderly population. Until recently, there was little hope of efficiently combating this devastating disease. The deposition of ,-amyloid (A,) is the major pathological hallmark of AD brains. Genetic, biochemical, and pharmacological evidence support the hypothesis that A, plays a key role in the development of the disease. Thus, in the last 5 years a number of pharmacological strategies have been developed to interfere with the A, cascade. The most revolutionary of these approaches was proposed in 1999 by scientists at Elan Pharmaceuticals, which immunized against A, transgenic mice with spontaneously developing A, pathology. The immunization was achieved by subcutaneous injections of a preaggregated form of the synthetic human 42-amino acid A, emulsified with Freund's adjuvant, an immune stimulant. The vaccination caused a near complete inhibition of A, plaque formation in younger animals and a marked reduction of the A, burden in older animals. The effects on A, plaques were accompanied by a reduction of A,-associated astrogliosis and neuritic dystrophy. These results were later confirmed by other groups with similar vaccination protocols, which also demonstrated that the A, immunization of transgenic animals normalize or reduce the cognitive impairment associated with A, pathology. Interestingly, effective removal of brain A, plaques was also obtained by peripherally administering A, antibodies. The mechanism with which the vaccine increases A, clearance is not fully understood. Centrally, the vaccine appears to activate A, phagocytosis by microglial monocytes. Peripherally, serum A, antibodies bind and sequester A,, thus altering its equilibrium between CNS and plasma. The dramatic results obtained in animal models of AD raised unprecedented hopes for both a preventive and a curative intervention for this devastating disorder. A vaccine preparation for human use (AN-1792) composed of preaggregated human A,42 peptide and a highly purified saponin derivative (QS-21) was developed by Elan Pharmaceuticals and Wyeth Ayerst and tested in AD patients. Unfortunately, a Phase IIa study aimed at evaluating the safety and immunological activity of AN-1792 in 360 AD patients was discontinued because 15 subjects receiving the vaccine developed serious signs of CNS inflammation. Both central activation of cytotoxic T cells and autoimmune reactions were proposed as potential mechanisms of toxicity. Other therapeutic A, vaccination strategies are being pursued, including immuno-conjugates and monoclonal antibodies. The future of these and other A, immunization approaches depend on a clear understanding of the mechanism of A, clearance and additional insight into the role of inflammation in the AD brain. Drug Dev. Res. 56:150,162, 2002. © 2002 Wiley-Liss, Inc. [source]


Co-expression of C-terminal truncated alpha-synuclein enhances full-length alpha-synuclein-induced pathology

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2010
Ayse Ulusoy
Abstract Lewy bodies, which are a pathological hallmark of Parkinson's disease, contain insoluble polymers of alpha-synuclein (,syn). Among the different modifications that can promote the formation of toxic ,syn species, C-terminal truncation is among the most abundant alterations in patients with Parkinson's disease. In vitro, C-terminal truncated ,syn aggregates faster and sub-stoichiometric amounts of C-terminal truncated ,syn promote aggregation of the full-length ,syn (,synFL) and induce neuronal toxicity. To address in vivo the putative stimulation of ,syn-induced pathology by the presence of truncated ,syn, we used recombinant adeno-associated virus to express either ,synFL or a C-terminal truncated ,syn (1-110) in rats. We adjusted the recombinant adeno-associated virus vector concentrations so that either protein alone led to only mild to moderate axonal pathology in the terminals of nigrostriatal dopamine neurons without frank cell loss. When these two forms of ,syn were co-expressed at these pre-determined levels, it resulted in a more aggressive pathology in fiber terminals as well as dopaminergic cell loss in the substantia nigra. Using an antibody that did not detect the C-terminal truncated ,syn (1-110) but only ,synFL, we demonstrated that the co-expressed truncated protein promoted the progressive accumulation of ,synFL and formation of larger pathological accumulations. Moreover, in the co-expression group, three of the eight animals showed apomorphine-induced turning, suggesting prominent post-synaptic alterations due to impairments in the dopamine release, whereas the mild pathology induced by either form alone did not cause motor abnormalities. Taken together these data suggest that C-terminal truncated ,syn can interact with and exacerbate the formation of pathological accumulations containing ,synFL in vivo. [source]


C-terminal 37 residues of LRP promote the amyloidogenic processing of APP independent of FE65

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 6b 2008
Madepalli K. Lakshmana
Abstract The major defining pathological hallmark of Alzheimer's disease (AD) is the accumulation of amyloid , protein (A,), a small peptide derived from ,- and ,-secretase cleavages of the amyloid precursor protein (APP). Recent studies have shown that the Low-density lipoprotein receptor-related protein (LRP) plays a pivotal role in the trafficking of APP and generation of A,. In particular, we recently showed that the soluble cytoplasmic tail of LRP (LRP-ST) without a membrane tether was sufficient to promote A, generation. In this study, we demonstrate that the last 37 residues of LRP cytoplasmic tail (LRP-C37) lacking the NPxY motifs and FE65 binding mediate the core pro-amyloidogenic activity of LRP-ST. Moreover, we show that the conserved dileucine motif within the LRP-C37 region is a key determinant of its A, promoting activity. Finally, results from a yeast two-hybrid screen using LRP-C37 region as bait reveal four new LRP-binding proteins implicated in intracellular signalling and membrane protein trafficking. Our findings indicate that the LRP-C37 sequence represents a new protein-binding domain that may be useful as a therapeutic target and tool to lower A, generation in AD. [source]


Cell death mechanisms in neurodegeneration

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1 2001
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]


TorsinA and heat shock proteins act as molecular chaperones: suppression of ,-synuclein aggregation

JOURNAL OF NEUROCHEMISTRY, Issue 4 2002
Pamela J. McLean
Abstract TorsinA, a protein with homology to yeast heat shock protein104, has previously been demonstrated to colocalize with ,-synuclein in Lewy bodies, the pathological hallmark of Parkinson's disease. Heat shock proteins are a family of chaperones that are both constitutively expressed and induced by stressors, and that serve essential functions for protein refolding and/or degradation. Here, we demonstrate that, like torsinA, specific molecular chaperone heat shock proteins colocalize with ,-synuclein in Lewy bodies. In addition, using a cellular model of ,-synuclein aggregation, we demonstrate that torsinA and specific heat shock protein molecular chaperones colocalize with ,-synuclein immunopositive inclusions. Further, overexpression of torsinA and specific heat shock proteins suppress ,-synuclein aggregation in this cellular model, whereas mutant torsinA has no effect. These data suggest that torsinA has chaperone-like activity and that the disease-associated GAG deletion mutant has a loss-of-function phenotype. Moreover, these data support a role for chaperone proteins, including torsinA and heat shock proteins, in cellular responses to neurodegenerative inclusions. [source]


Lack of neprilysin suffices to generate murine amyloid-like deposits in the brain and behavioral deficit in vivo

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2006
Rime Madani
Abstract Accumulation of the ,-amyloid peptide (A,) in the brain is a major pathological hallmark of Alzheimer's disease (AD), leading to synaptic dysfunction, neuronal death, and memory impairment. The levels of neprilysin, a major A,-degrading enzyme, are decreased in AD brains and during aging. Because neprilysin cleaves A, in vivo, its down-regulation may contribute to the pathophysiology of AD. The aim of this study was to assess the consequences of neprilysin deficiency on accumulation of murine A, in brains and associated pathologies in vivo by investigating neprilysin-deficient mice on biochemical, morphological, and behavioral levels. Aged neprilysin-deficient mice expressed physiological amyloid precursor protein (APP) levels and exhibited elevated brain A, concentrations and amyloid-like deposits in addition to signs of neuronal degeneration in their brains. Behaviorally, neprilysin-deficient mice acquired a significantly weaker conditioned taste aversion that extinguished faster than the aversion of age-matched controls. Our data establish that, under physiological APP expression levels, neprilysin deficiency is associated with increased A, accumulation in the brain and leads to deposition of amyloid-like structures in vivo as well as with signs of AD-like pathology and with behavioral deficits. © 2006 Wiley-Liss, Inc. [source]


Protective effect of Toki-shakuyaku-san on amyloid ,25,35 -induced neuronal damage in cultured rat cortical neurons

PHYTOTHERAPY RESEARCH, Issue 5 2005
Nobuaki Egashira
Abstract Amyloid , protein (A,) is the major component of senile plaques, the pathological hallmark of the neurodegeneration associated with Alzheimer's disease (AD). This study investigated the effect of Toki-shakuyaku-san (TSS), a traditional medicine, on A,25,35 -induced neuronal death and lipid peroxidation assessed by measuring lactate dehydrogenase (LDH) and malondialdehyde (MDA), respectively. A,25,35 at 10 µM induced neuronal damage and increased the LDH and MDA. TSS at concentrations of 100 and 300 µg/mL significantly reduced the A,25,35 -induced neuronal death and the lipid peroxidation. These results suggest that TSS has a protective effect against A,25,35 -induced neuronal damage. TSS may be beneficial for the treatment of AD. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Oxidation of specific methionine and tryptophan residues of apolipoprotein A-I in hepatocarcinogenesis

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 18 2005
Jokin Fernández-Irigoyen
Abstract Hepatocellular carcinoma (HCC) is the fifth most common neoplasm with more than 500,000 new cases diagnosed yearly. Although major risk factors of HCC are currently known, the identification of biological targets leading to an early diagnosis of the disease is considered one of the priorities of clinical hepatology. In this work we have used a proteomic approach to identify markers of hepatocarcinogenesis in the serum of a knockout mice deficient in hepatic AdoMet synthesis (MAT1A,/,), as well as in patients with HCC. Three isoforms of apolipoprotein A-I (Apo A-I) with different pI were identified in murine serum. Isoform 1 is up-regulated in the serum of MAT1A,/, mice much earlier than any histological manifestation of liver disease. Further characterization of the differential isoform by electrospray MS/MS revealed specific oxidation of methionine 85 and 216 to methionine sulfoxide while the sequence of the analogous peptides on isoforms 2 and 3 showed the nonoxidized methionine residues. Enrichment of an acidic isoform of Apo A-I was also assessed in the serum of hepatitis B virus patients who developed HCC. Specific oxidation of methionine 112 to methionine sulfoxide and tryptophans 50 and 108 to formylkinurenine were identified selectively in the up-regulated isoform. Although it is not clear at present whether the occurrence of these modifications has a causal role or simply reflects secondary epiphenomena, this selectively oxidized Apo A-I isoform may be considered as a pathological hallmark that may help to the understanding of the molecular pathogenesis of HCC. [source]


Involvement of apoptosis and cholinergic dysfunction in Alzheimer's disease

PSYCHOGERIATRICS, Issue 2006
Shinji TAGAMI
Abstract As Alzheimer's disease (AD) progresses, brain atrophy becomes conspicuous, and histologically there is neuronal loss, primarily with a deficit of cholinergic neurons observed. Hitherto, the view has been that cell death, apoptosis, plays a role in this neuronal loss. Apoptosis is characterized by the morphological changes of nuclear fragmentation, chromatin condensation and cell shrinkage, with activation of caspases, members of the cysteine protease family, resulting in considerable substrate cleavage. TUNEL positive neurons have in fact been detected in AD brain, indicating increased caspase activity and resulting substrate cleavage. In AD brain, amyloid beta peptides (A,), the main constituent of senile plaque, are a specific pathological hallmark observed in extracellular spaces. In contrast, the main constituent of intracellularly observed neurofibrillary tangles (NFT) is hyperphosphorylated tau, which is observed in various neurodegenerative disorders other than AD. The viewpoint of many studies is that the A, and NFT that cause these neuropathological changes probably participate in neuronal death. However, up until now it has been thought that there was no hypothesis offering a comprehensive explanation of how the accumulation of extracellular A, and intracellular NFT leads to neuronal death. This report first covers the mechanism of apoptosis as clarified by molecular biological methods, and provides an explanation of how apoptosis could be involved in AD pathology. The subject of autophagic cell death, a type of cell death morphology that has recently been the focus of attention, is also addressed. [source]


Behçet's disease and vitiligo in two brothers: coincidence or association?

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 8 2009
M. Borlu
Summary Behçet's disease (BD) and vitiligo are disorders with unknown aetiology. We report on two brothers with ocular Behcet's disease who had advanced unilateral ophthalmic symptoms associated with vitiligo. The two brothers had recurrent oral and genital ulceration, uveitis and white patches on their skin. The most probable hypothesis for the aetiology of BD is that of an autoimmune reaction in genetically predisposed individuals, with vasculitis as the main pathological hallmark. Despite many years of research, the specific causes of vitiligo remain obscure, and the most advanced aetiological hypothesis remains that of autoimmunity. To our knowledge, this is the first reported case within the literature of BD associated with vitiligo. The existence of the two different disorders is noteworthy as they were observed in two brothers during the same period in their lives, with very similar clinical observations. [source]


Cytosolic protein-protein interactions that regulate the amyloid precursor protein

DRUG DEVELOPMENT RESEARCH, Issue 2 2002
Shasta L. Sabo
Abstract Alzheimer disease (AD), a progressive neurodegenerative disease, is the most common cause of dementia in the elderly and is among the leading causes of death in adults. AD is characterized by two major pathological hallmarks, amyloid plaques and neurofibrillary tangles. For a number of reasons, amyloid plaque accumulation is widely thought to be the probable cause of AD. The amyloid plaque core is largely composed of an approximately 4-kDa peptide referred to as A,. A, is derived from its precursor, the Alzheimer amyloid protein precursor (APP), by endoproteolytic processing. APP is a type I integral membrane protein, with a long extracellular domain, one transmembrane domain, and a short (,50 amino acid) cytoplasmic tail. Despite intense efforts to decipher the function of APP, its normal physiological role has remained elusive. The carboxy-terminus of APP contains the sequence YENPTY, which is absolutely conserved across APP homologues and across species. The YENPTY sequence is important for regulation of APP processing and trafficking. Given the importance of the cytoplasmic domain in APP physiology, a number of laboratories have hypothesized that proteins that bind to the YENPTY sequence in the cytoplasmic domain of APP might regulate APP processing, trafficking, and/or function. In this article, we will discuss data revealing which proteins bind to the cytoplasmic domain of APP, how these binding-proteins regulate APP metabolism and function, and why such protein-protein interactions provide an exciting new target for therapeutic intervention in AD. Drug Dev. Res. 56:228,241, 2002. © 2002 Wiley-Liss, Inc. [source]


Proteomic identification of nitrated brain proteins in early Alzheimer's disease inferior parietal lobule

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 8b 2009
Tanea T. Reed
Abstract Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive decline in multiple cognitive domains. Its pathological hallmarks include senile plaques and neurofibrillary tangles. Mild cognitive impairment (MCI) is the earliest detectable stage of AD with limited symptomology and no dementia. The yearly conversion rate of patients from MCI to AD is 10,15%, although conversion back to normal is possible in a small percentage. Early diagnosis of AD is important in an attempt to intervene or slow the advancement of the disease. Early AD (EAD) is a stage following MCI and characterized by full-blown dementia; however, information involving EAD is limited. Oxidative stress is well-established in MCI and AD, including protein oxidation. Protein nitration also is an important oxidative modification observed in MCI and AD, and proteomic analysis from our laboratory identified nitrated proteins in both MCI and AD. Therefore, in the current study, a proteomics approach was used to identify nitrated brain proteins in the inferior parietal lobule from four subjects with EAD. Eight proteins were found to be significantly nitrated in EAD: peroxiredoxin 2, triose phosphate isomerase, glutamate dehydrogenase, neuropolypeptide h3, phosphoglycerate mutase1, H+, transporting ATPase, ,-enolase and fructose-1,6-bisphosphate aldolase. Many of these proteins are also nitrated in MCI and late-stage AD, making this study the first to our knowledge to link nitrated proteins in all stages of AD. These results are discussed in terms of potential involvement in the progression of this dementing disorder. [source]


Unresolved issues relating to the Shaking Palsy on the celebration of James Parkinson's 250th birthday

MOVEMENT DISORDERS, Issue S17 2007
Andrew J. Lees MD
Abstract James Parkinson's Essay on the Shaking Palsy published in 1817 provided the first clear clinical description for the disorder now known throughout the world by his name. His primary reason for publishing his monograph shortly before his retirement from medical practice was to draw the medical profession's attention to a malady, which had not yet been defined as a nosological entity. He also hoped that the eminent anatomists of the day would be stimulated to elucidate the pathological lesion responsible for the clinical picture and that this in turn might lead to a rational cure. The concept of Parkinson's disease remains clinically based and successive generations of neurologists have refined and embellished Parkinson's seminal descriptions. Narrative accounts by affected individuals have also helped physicians understand what it is like to live with Parkinson's disease. For many years, the pathological hallmarks of Parkinson's disease were disputed and there were few clinico-pathological reports with adequate clinical description. However, most neurologists now link severe loss of nigral cells in the ventrolateral tier of the pars compacta of the substantia nigra with bradykinesia and the presence of Lewy bodies in a number of discrete brain stem and cortical regions with Parkinson's disease. There are many unanswered clinical questions relating to Parkinson's disease including the striking heterogeneity and frequent limb asymmetry. It also remains somewhat uncertain whether Parkinson's disease is ever truly unilateral by the time of clinical presentation and whether the hand rather than the foot is the most common site of onset. Hyposmia and visual hallucinations are helpful pointers in distinguishing Parkinson's disease from atypical Parkinsonism and should be specifically enquired about in the history. Simple reliable cultural-specific smell identification batteries are an urgent need and target of clinical research. It remains to be determined whether Alzheimer type dementia as opposed to a dysexecutive syndrome should be considered a part of Parkinson's disease and further detailed clinico-pathological correlative studies are needed. It is also unclear whether autosomal dominant monogenetic Parkinsonism due to synuclein or LRRK-2 mutations will prove to be identical clinically with Parkinson's disease and for the present it is wiser to regard Parkinson's disease as a sporadic disorder. Parkinson was an active political reformer and if alive today would certainly be campaigning to translate more effectively the rich seam of neuroscientific research of the last decade into therapeutic benefits for the rising number of people who are developing the shaking palsy as a result of increasing longevity in the developed world. © 2007 Movement Disorder Society [source]


Specific association of small heat shock proteins with the pathological hallmarks of Alzheimer's disease brains

NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2006
M. M. M. Wilhelmus
The small heat shock protein family (sHsp) comprises molecular chaperones able to interact with incorrectly folded proteins. Alzheimer's disease (AD) is characterized by pathological lesions such as senile plaques (SPs), cerebral amyloid angiopathy (CAA) and neurofibrillary tangles (NFTs), predominantly consisting of the incorrectly folded proteins amyloid-, (A,) and tau respectively. The aim of this study was to investigate the association of the chaperones Hsp20, HspB2, ,B-crystallin and Hsp27 with the pathological lesions of AD brains. For this purpose, a panel of well-characterized antibodies directed against these sHsps was used in immunohistochemistry and immunoblotting. We observed extracellular expression of Hsp20, Hsp27 and HspB2 in classic SPs, and Hsp20 expression in diffuse SPs. In addition, extracellular expression of HspB2 was observed in CAA. Both Hsp27 and ,B-crystallin were also observed in astrocytes associated with both SPs and CAA. Furthermore, none of the sHsps were observed in NFTs in AD brains. We conclude that specific sHsp species may be involved in the pathogenesis of either SPs or CAA in AD. [source]


Ballooned neurones in the limbic lobe are associated with Alzheimer type pathology and lack diagnostic specificity

NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 6 2004
Y. Fujino
Ballooned neurones (BNs) are one of the pathological hallmarks of several neurodegenerative diseases, including Pick's disease, corticobasal degeneration and argyrophilic grain disease (AGD). They have also been described in Alzheimer disease (AD), but the frequency of BNs in AD has not been systematically addressed. In the present study, immunohistochemistry for ,B-crystallin was used as a sensitive method to detect BNs to determine the frequency of BNs in the limbic lobe in AD. At least a few BNs were detected in the limbic lobe of virtually all AD cases, and their density correlated with Braak stage, as well as the density of neurofibrillary tangles and senile plaques in the limbic lobe. The density of BN tended to be greater in AD cases with concurrent AGD than in pure AD. Given the high prevalence of AD in brain banks for neurodegenerative disease and the frequent presence of BNs in these areas with ,B-crystallin immunohistochemistry, the present findings further indicate that BNs confined to the limbic lobe lack specificity in diagnostic neuropathology. [source]


Modern strategies to identify new molecular targets for the treatment of liver diseases: The promising role of Proteomics and Redox Proteomics investigations

PROTEOMICS - CLINICAL APPLICATIONS, Issue 2 2009
Andrea Scaloni Dr.
Abstract Oxidative stress, due to an imbalance between the generation of ROS and the antioxidant defense capacity of the cell, is a major pathogenetic event occurring in several liver diseases, ranging from metabolic to proliferative. Main sources of ROS are represented by mitochondria and cytochrome P450 enzymes in the hepatocytes, Küppfer cells, and neutrophils. Oxidative stress affects major cellular components including lipids, DNA, and proteins. Through modulation of protein structure/function, ROS can influence gene expression profile by affecting intracellular signal transduction pathways. While several enzymatic and nonenzymatic markers of chronic oxidative stress are well known in liver, early protein targets of oxidative injury are yet poorly defined. Identification of these biomarkers will enable early detection of liver diseases and will allow monitoring the degree of liver damage, the response to pharmacological therapies, and the development of new therapeutic approaches. In the era of molecular medicine, new proteomic methodologies promise to establish a relationship between pathological hallmarks of the disease and protein structural/functional modifications, thus allowing a better understanding and a more rational therapy on liver disorders. Purpose of this review is to critically analyze the application of proteomic and redox proteomic approaches to the study of oxidative stress-linked liver diseases. [source]


Proteome analysis of substantia nigra and striatal tissue in the mouse MPTP model of Parkinson's disease

PROTEOMICS - CLINICAL APPLICATIONS, Issue 12 2007
Xin Zhao
Abstract The dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) replicates many of the pathological hallmarks of Parkinson's disease (PD) in mice via selective destruction of dopamine neurons of the substantia nigra and striatum. Although MPTP has been widely used to study downstream effects following the degeneration of dopaminergic neurons, the underlying mechanisms of MPTP action remain poorly understood. To determine the underlying mechanisms of MPTP action at the protein level, a 2-DE-based proteomics approach was used to evaluate the changes in protein expression in substantia nigra and striatal tissue in C57BL/6 mice after MPTP administration. We identified nine proteins that were markedly altered and are likely to be involved in mitochondrial function, heat shock protein activity, and which contribute enzyme activities for energy metabolism and protein degradation. [source]


Rationally designed dehydroalanine (,Ala)-containing peptides inhibit amyloid-, (A,) peptide aggregation

BIOPOLYMERS, Issue 6 2009
Vijayaraghavan Rangachari
Abstract Among the pathological hallmarks of Alzheimer's disease (AD) is the deposition of amyloid-, (A,) peptides, primarily A, (1,40) and A, (1,42), in the brain as senile plaques. A large body of evidence suggests that cognitive decline and dementia in AD patients arise from the formation of various aggregated forms of A,, including oligomers, protofibrils and fibrils. Hence, there is increasing interest in designing molecular agents that can impede the aggregation process and that can lead to the development of therapeutically viable compounds. Here, we demonstrate the ability of the specifically designed ,,,-dehydroalanine (,Ala)-containing peptides P1 (K-L-V-F-,A-I-,A) and P2 (K-F-,A-,A-,A-F) to inhibit A, (1,42) aggregation. The mechanism of interaction of the two peptides with A, (1,42) seemed to be different and distinct. Overall, the data reveal a novel application of ,Ala-containing peptides as tools to disrupt A, aggregation that may lead to the development of anti-amyloid therapies not only for AD but also for many other protein misfolding diseases. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 456,465, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source]