Abstract:
UNLABELLED:The aggregates of amyloid beta peptides (Aβs) are regarded as one of the main pathological hallmarks of Alzheimer's disease (AD). An imbalance between the rates of synthesis and clearance of Aβs is considered to be a possible cause for the onset of AD. Dipeptidyl peptidases II and IV (DPPII and DPPIV) are serine proteases removing N-terminal dipeptides from polypeptides and proteins with proline or alanine on the penultimate position. Alanine is an N-terminal penultimate residue in Аβs, and we presumed that DPPII and DPPIV could cleave them. The results of present in vitro research demonstrate for the first time the ability of DPPIV to truncate the commercial Aβ40 and Aβ42 peptides, to hinder the fibril formation by them and to participate in the disaggregation of preformed fibrils of these peptides. The increase of absorbance at 334 nm due to complex formation between primary amines with o-phtalaldehyde was used to show cleaving of Aβ40 and Aβ42. The time-dependent increase of the quantity of primary amines during incubation of peptides in the presence of DPPIV suggested their truncation by DPPIV, but not by DPPII. The parameters of the enzymatic breakdown by DPPIV were determined for Aβ40 (Km=37.5 μM, kcat/Km=1.7×10(3)M(-1)sec(-1)) and Aβ42 (Km=138.4 μM, kcat/Km=1.90×10(2)M(-1)sec(-1)). The aggregation-disaggregation of peptides was controlled by visualization on transmission electron microscope and by Thioflavin-T fluorescence on spectrofluorimeter and fluorescent microscope. DPPIV hindered the peptide aggregation/fibrillation during 3-4 days incubation in 20mM phosphate buffer, pH 7.4, 37°C by 50-80%. Ovalbumin, BSA and DPPII did not show this effect. In the presence of DPPIV, the preformed fibrils were disaggregated by 30-40%. CONCLUSION:for the first time it was shown that the Aβ40 and Aβ42 are substrates of DPPIV. DPPIV prohibits the fibrillation of peptides and promotes disaggregation of their preformed aggregates.
journal_name
Neurochem Intjournal_title
Neurochemistry internationalauthors
Sharoyan S,Antonyan A,Mardanyan S,Harutyunyan H,Movsisyan N,Hovnanyan N,Hovnanyan Kdoi
10.1016/j.neuint.2013.03.017subject
Has Abstractpub_date
2013-06-01 00:00:00pages
1048-54issue
8eissn
0197-0186issn
1872-9754pii
S0197-0186(13)00116-2journal_volume
62pub_type
杂志文章abstract::Excessive glucocorticoid levels in depressed patients have been associated with atrophic changes in some brain regions, but only few studies suggest that some antidepressants can interfere with deleterious effect of glucocorticoids on neuronal cells. The aim of the present study was to examine the effect of dexamethas...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2013.07.007
更新日期:2013-11-01 00:00:00
abstract::25INBOMe ("25-I", "N-Bomb"), one of new psychoactive substances (NPSs), is being abused for recreational purpose. However, the liability for abuse or dependence has not been systematically studied yet. The objective of the present study was to evaluate rewarding and reinforcing effects of 25INBOMe using conditioned pl...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2019.02.007
更新日期:2019-05-01 00:00:00
abstract::To clarify molecular mechanism for sustained activation of gamma protein kinase C (gammaPKC), a neuron-specific subtype, we investigated the involvement of phospholipase A2 (PLA2) products in the membrane association of gammaPKC upon activation of G protein coupled purinoceptors in CHO-K1 and NG 108-15 cells. In addit...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2003.12.006
更新日期:2004-07-01 00:00:00
abstract::Na+-dependent uptake of excitatory neurotransmitter glutamate in astrocytes increases cell energy demands primarily due to the elevated ATP consumption by glutamine synthetase and Na+, K+-ATPase. The major pool of GLAST/EAAT1, the only glutamate transporter subtype expressed by human fetal astrocytes in undifferentiat...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2006.12.015
更新日期:2007-06-01 00:00:00
abstract::Outer (OHC) and inner (IHC) hair cells in the organ of Corti of the mammalian cochlea process sound. OHC and their efferent synapse are part of a feedback system assumed to control and modulate information carried by afferent neurons passing from IHC to the brain. Underlying mechanisms are not well understood. This pa...
journal_title:Neurochemistry international
pub_type: 杂志文章,评审
doi:10.1016/0197-0186(95)00011-v
更新日期:1995-10-01 00:00:00
abstract::Excitotoxicity is the main event during neurological disorders producing drastic morphological and functional changes. Rac-GTPase is involved in cytoskeletal remodeling and survival. However, the role of Rac1 after cerebral ischemia has not been completely understood yet. In this study, we evaluated the activity of Ra...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2010.08.014
更新日期:2010-12-01 00:00:00
abstract::The distribution of substance P in the colon of piebald lethal (s(1)/s(1)) mice was studied by radioimmunoassay and immunohistochemistry. These animals inherit as a Mendelian recessive trait an aganglionic distal colon. In the region proximal to the aganglionic segment, there is an extensive transitional or hypogangli...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/0197-0186(84)90026-3
更新日期:1984-01-01 00:00:00
abstract::G protein-coupled receptors are cell surface receptors that mediate the effects of extracellular signals in the endocrine/paracrine and sensory systems. Experimental evidence is accumulating, which suggest that these receptors form dimers or higher order oligomers. The functional relevance of G protein-coupled recepto...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2007.05.018
更新日期:2007-10-01 00:00:00
abstract::The influence of citalopram on regional 5-hydroxytryptamine (serotonin, 5-HT) synthesis, one of the most important presynaptic parameters of serotonergic neurotransmission, was studied. Sprague-Dawley (SPD) rats were used as the controls, and Flinders Resistant Line (FRL) rats were used as auxiliary controls, to hopef...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2009.01.005
更新日期:2009-05-01 00:00:00
abstract::Previously we reported that gene expression of astrocytic 5-HT2B receptors was decreased in brains of depressed animals exposed to chronic mild stress (CMS) (Li et al., 2012) and of Parkinson's disease (Song et al., 2018). Depression is also one of the psychiatric symptoms in hyperammonemia, and astrocyte is a primary...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2019.104479
更新日期:2019-10-01 00:00:00
abstract::Chemokine-like factor 1 (CKLF1) is a novel C-C chemokine, and plays important roles in immune response and brain development. In previous study, we have found that the expression of CKLF1 increased after focal cerebral ischemia and inhibition of CKLF1 using antagonist C19 peptide protected against cerebral ischemia. H...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2014.07.004
更新日期:2014-10-01 00:00:00
abstract::RBFox proteins are well-known alternative splicing regulators. We have shown previously that during neuronal differentiation of P19 cells induced by all-trans retinoic acid and cell aggregation, RBFox1 shows markedly increased temporal expression. To find its key splicing regulation, we examined the effect of RBFox1 o...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2014.08.001
更新日期:2014-12-01 00:00:00
abstract::Esters of dimethylcarbamic acid are known to be poor substrates of acetylcholinesterase. They carbamylate the active catalytic site of the enzyme and the subsequent decarbamylation is a slow but measurable process. Similarly, acetylcholinesterase can be phosphonylated, and the dephosphonylation is extremely slow. Rapi...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/0197-0186(81)90061-9
更新日期:1981-01-01 00:00:00
abstract::Much attention has been paid to the connection between periodontitis and Alzheimer's disease (AD). We previously showed that infection of P. gingivalis, one of major periodontal pathogen causing periodontitis, induced migration and inflammatory responses in murine microglia through gingipain-induced activation of prot...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2020.104840
更新日期:2020-11-01 00:00:00
abstract::Changes in the level of ornithine decarboxylase mRNA after partial mesodiencephalic hemitransection were evaluated in various regions of the rat brain by means of in situ hybridization histochemistry coupled with computer-assisted image analysis. On days 1 and 2 after the lesion, increased accumulation of ornithine de...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/0197-0186(91)90165-a
更新日期:1991-01-01 00:00:00
abstract::To identify whether the process of apoptosis bears a topographic relationship to selected aspects of Alzheimer's disease (AD) pathology, we used an in situ nick translation method (TUNEL) to map DNA fragmentation in hippocampal sections immunostained for abnormally phosphorylated tau, which exists in the neurofibrilla...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/s0197-0186(96)00158-1
更新日期:1997-08-01 00:00:00
abstract::The expression of 5-hydroxytryptamine-2B (5-HT2B) receptor mRNA has recently been shown in cultured astrocytes. Here the expression of functional 5-HT2B receptors has been studied in cultured astrocytes from rat cerebral cortex, hippocampus, and brain stem. Fluo-3- and fura-2-based microspectrofluorometry was used for...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/s0197-0186(99)00134-5
更新日期:2000-04-01 00:00:00
abstract::Positron-emitting beta-adrenoceptor ligands for the CNS could allow determination of changes in beta-adrenoceptor availability after treatment of patients with norepinephrine reuptake inhibitors or tricyclic antidepressants, and differential diagnosis between multiple sclerosis and other brain disorders in an early st...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2007.09.009
更新日期:2008-03-01 00:00:00
abstract::The effects of cholesterol oxides on regular and neuronal PC12 cells were examined. Among the cholesterol oxides tested, 7-beta-, 22(R)- and 25-OH-cholesterol were very toxic to regular PC12 cells such that approximately 80% of cells were killed after a 3 day incubation with 20 micrograms/ml (50 microM) of these agent...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/s0197-0186(97)00020-x
更新日期:1997-10-01 00:00:00
abstract::Increasing evidences support that glial connexins are involved in the demyelination pathology of multiple sclerosis (MS), a chronic inflammatory demyelinating disorder. Here, we review the data from patients with MS and animal models of MS that implicate connexins in demyelination. Connexins expressed in oligodendrocy...
journal_title:Neurochemistry international
pub_type: 杂志文章,评审
doi:10.1016/j.neuint.2020.104731
更新日期:2020-06-01 00:00:00
abstract::Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder and is characterized by pathological aggregates of amyloid β-protein (Aβ) and tau protein. On the basis of genetic evidence, biochemical data, and animal models, Aβ has been suggested to be responsible for the pathogenesis of AD (the am...
journal_title:Neurochemistry international
pub_type: 杂志文章,评审
doi:10.1016/j.neuint.2017.08.010
更新日期:2018-10-01 00:00:00
abstract::The present study was designed to investigate the turnover rates of D1 dopamine receptors in the brain and retina of adult and aged rats. To this aim, we monitored the increase in the density of 3H-SCH 23390 binding sites after the administration of the irreversible antagonist N-ethoxycarbonyl-2-ethoxy-1,2 dihydroquin...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/0197-0186(92)90233-h
更新日期:1992-03-01 00:00:00
abstract::Development of tissue structure and three-dimensional microenvironment is crucial for regeneration of axons in the peripheral nerve repair. In this study we aimed to evaluate the efficacy of nerve regeneration by using an acellular nerve allograft (ANA) injected with allogenic skin-derived precursor differentiated Sch...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2016.04.003
更新日期:2016-07-01 00:00:00
abstract::Using a consistent, reproducible and reliable cortical focal ischemia in rat (permanent unilateral occlusion of the left middle cerebral artery & the ipsilateral common carotid artery [MCAo + CCAo] with a 1 h temporary occlusion of the contralateral CCA), the levels of four major membrane fatty acids (palmitic, C16:0;...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/0197-0186(93)90094-l
更新日期:1993-08-01 00:00:00
abstract::Bindings of glutamate receptor agonists and related modulators were investigated in 10 discrete tissues from gerbil brain using a biochemical technique. There appeared considerable discrepancies, in respect of intrahippocampal profiles, from reported data by autoradiography on rat brain. In the gerbil, an almost equiv...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/0197-0186(93)90066-e
更新日期:1993-01-01 00:00:00
abstract::The brain uses long-chain fatty acids (LCFAs) to a negligible extent as fuel for the mitochondrial energy generation, in contrast to other tissues that also demand high energy. Besides this generally accepted view, some studies using cultured neural cells or whole brain indicate a moderately active mitochondrial β-oxi...
journal_title:Neurochemistry international
pub_type: 杂志文章,评审
doi:10.1016/j.neuint.2017.03.018
更新日期:2017-10-01 00:00:00
abstract::High levels of angiotensin converting enzyme (ACE) are found in the caudate-putamen (CPu), globus pallidus, entopeduncular nucleus and substantia nigra pars reticulata; these structures were connected by a continuous band of ACE. In order to investigate whether ACE was associated with dopaminergic projections from the...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/0197-0186(87)90180-x
更新日期:1987-01-01 00:00:00
abstract::Cerebral ischemia is one of leading causes of death and long-term disability worldwide. Stem cell-based therapy is promising some valuable strategies for the structural and functional recovery after ischemic insult. The inhibition of phosphodiesterases (PDEs) has wide spectrum neuroprotective properties by stimulating...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2019.104630
更新日期:2020-02-01 00:00:00
abstract::The N-methyl-D-aspartate (NMDA) receptor is a subtype of ionotropic glutamate receptor that is involved in synaptic mechanisms of learning and memory, and mediates excitotoxic neuronal injury. In this study, we tested the hypothesis that NMDA receptor subunit gene expression is altered in cortex and hippocampus of OKA...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2014.06.012
更新日期:2014-10-01 00:00:00
abstract::Homozygous deletion or mutation in the survival motor neuron (SMN)1 gene causes proximal spinal muscular atrophy (SMA), whereas SMN2 acts as a modifying gene that can influence the severity of SMA. It has been suggested that restoration of the SMN protein level in neuronal cells may prevent cell loss and may be helpfu...
journal_title:Neurochemistry international
pub_type: 杂志文章
doi:10.1016/j.neuint.2004.04.005
更新日期:2004-12-01 00:00:00