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result(s) for
"Chailyan, S. G."
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Thermostable enzyme isoforms, continuously producing monocomponent superoxide radicals, from human postoperative serous fluids: isolation and properties
by
Yekmalyan, H. H.
,
Sarkavagyan, H. K.
,
Babayan, M. A.
in
Antineoplastic drugs
,
Apoptosis
,
Biomedical and Life Sciences
2025
Free radicals are generated in the body through endogenous and exogenous systems, with their overproduction linked to chronic diseases such as cancer. Interestingly, chemotherapeutic drugs utilize free radicals to induce apoptosis in cancer cells, highlighting their dual nature. This study explores the therapeutic potential of free-radical-generating compounds in solid tumor treatment. Using a patented universal method, superoxide (O
2
−
)-producing enzymatic systems were isolated for the first time from serous fluids of patients with breast cancer, gastric cancer, and liver cirrhosis. These enzymes were qualitatively and quantitatively characterized and found to continuously produce monocomponent O
2
−
under aerobic in vitro conditions. The enzyme complexes consist of flavin adenine dinucleotide (FAD), a reduced nicotinamide adenine dinucleotide phosphate (NADPH)-containing protein component (NPC), and Fe(III) ions. Their stable O
2
−
production mechanism was elucidated, and characteristic optical absorption and fluorescence excitation spectra were recorded. The concentrations of monocomponent O
2
−
were quantified in moles (mol/ml) for each serous fluid type. These findings suggest that liquid-phase O
2
−
could be used to selectively destroy cancer cells by predetermining effective concentrations. Furthermore, since O
2
−
-producing enzymes can oxidize adrenaline, they may help reduce elevated adrenaline levels in tumor cells. Future animal studies will assess their efficacy in eliminating metastatic cells, particularly in the postoperative period. This novel approach may offer a promising adjunct therapy in oncology.
Journal Article
Morpho-functional study of the hypothalamic proline-rich polypeptide apoptotic activity against mouse Ehrlich ascites carcinoma
2020
A new type of bioactive polypeptides of the neurosecretory hypothalamus called proline-rich peptides (PRPs), which are isolated from bovine neurosecretory granules of the neurohypophysis, are synthesized in the form of a common precursor protein (neurophysin vasopressin-associated glycoprotein). Proline-rich polypetide 1 (PRP-1; also known as galarmin) is comprised of 15 amino acids residues, and has been suggested to possess anti-neurodegenerative, immunoregulatory, hematopoietic, antimicrobial and antitumor properties. The cytostatic, antiproliferative effect of PRP-1 was demonstrated in the human chondrosarcoma JJ012 and triple negative breast carcinoma MDA MB 231 cell lines. PRP-1 action is disease and tissue specific. To further explore the antitumorigenic and possible cytotoxic effects of PRP-1, a morpho-functional study on the effect of PRP-1 on a mouse Ehrlich ascites carcinoma (EAC) model was conducted. The PRP-1-induced morphological features of EAC cells confirmed the apoptotic nature of PRP-1, as manifested by cell shrinkage, membrane blebbing, chromosome condensation (pyknosis) and nuclear fragmentation (karyorrhexis). The effect of PRP-1 on the number of tumor cells incubated for 24 h and their viability in trypan blue-stained samples lead to a 44% reduction in the number of viable cells on day 11 post-inoculation vs. 22% inhibition of viable cells after PRP-1 treatment (0.1 µg/ml) on day 7 post-inoculation. Apoptosis experiments using an Annexin V-cyanine 3 apoptosis detection kit indicated that 24 h incubation with 0.1 µg/ml PRP-1 caused a significant increase in the number of apoptotic cells, reaching 50.33%, compared to 8.33% in the sample control on day 7 post-inoculation.
Journal Article
Novel Vaccine against Pathological Pyroglutamate-Modified Amyloid Beta for Prevention of Alzheimer’s Disease
by
Chadarevian, Jean Paul
,
Antonyan, Tatevik
,
Ghazaryan, Manush
in
Advertising executives
,
Alzheimer Disease - pathology
,
Alzheimer Disease - prevention & control
2023
Post-translationally modified N-terminally truncated amyloid beta peptide with a cyclized form of glutamate at position 3 (pE3Aβ) is a highly pathogenic molecule with increased neurotoxicity and propensity for aggregation. In the brains of Alzheimer’s Disease (AD) cases, pE3Aβ represents a major constituent of the amyloid plaque. The data show that pE3Aβ formation is increased at early pre-symptomatic disease stages, while tau phosphorylation and aggregation mostly occur at later stages of the disease. This suggests that pE3Aβ accumulation may be an early event in the disease pathogenesis and can be prophylactically targeted to prevent the onset of AD. The vaccine (AV-1986R/A) was generated by chemically conjugating the pE3Aβ3-11 fragment to our universal immunogenic vaccine platform MultiTEP, then formulated in AdvaxCpG adjuvant. AV-1986R/A showed high immunogenicity and selectivity, with endpoint titers in the range of 105–106 against pE3Aβ and 103–104 against the full-sized peptide in the 5XFAD AD mouse model. The vaccination showed efficient clearance of the pathology, including non-pyroglutamate-modified plaques, from the mice brains. AV-1986R/A is a novel promising candidate for the immunoprevention of AD. It is the first late preclinical candidate which selectively targets a pathology-specific form of amyloid with minimal immunoreactivity against the full-size peptide. Successful translation into clinic may offer a new avenue for the prevention of AD via vaccination of cognitively unimpaired individuals at risk of disease.
Journal Article
Experimental Clarification of PRPS-1 Structural Essentials
by
Chailyan, Samvel G
,
Grabski, Hovakim V
,
Ginosyan, Siranuysh V
in
Amino acids
,
Antibiotics
,
Biosynthesis
2022
Phosphoribosyl pyrophosphate synthetase-1 (PRPS-1; EC 2.7.6.1.) catalyzes the binding of phosphate-group to ribose 5-phosphate, forming the 5-phosphoribosyl-1-pyrophosphate, which is necessary for the salvage pathways of purine and pyrimidine, pyridine nucleotide cofactors - NAD and NADP, the amino acids histidine and tryptophan biosynthesis. We aimed to investigate the impact of the different effectors on the activity of PRPS-1, to check the activity of the enzyme in vitro in a wide range of pHs and investigate some structural essentials of the enzyme, isolated from brain and liver. Molecular docking analyses were used to delineate the essentials of PRPS-1 structure, to find out the existence of enzyme effectors. Previously created by us kit was used for determination of the activity of PRPS-1 based on the formation of the inorganic phosphates (λ = 700 nm, Cary 60, Agilent, USA). Effectors impact on the activity of PRPS-1 was evaluated. In silico results of the effectors were later proven by in vitro experiments. For the first time biochemical essentials, including the existence of the multiple pockets, involvement of the amino acids into the processes of interactions with the effectors, evolutional of the sequence conservation, tissue depended Vmax differences were identified.
Journal Article
A chromosome conformation capture ordered sequence of the barley genome
2017
Cereal grasses of the Triticeae tribe have been the major food source in temperate regions since the dawn of agriculture. Their large genomes are characterized by a high content of repetitive elements and large pericentromeric regions that are virtually devoid of meiotic recombination. Here we present a high-quality reference genome assembly for barley (
Hordeum vulgare
L.). We use chromosome conformation capture mapping to derive the linear order of sequences across the pericentromeric space and to investigate the spatial organization of chromatin in the nucleus at megabase resolution. The composition of genes and repetitive elements differs between distal and proximal regions. Gene family analyses reveal lineage-specific duplications of genes involved in the transport of nutrients to developing seeds and the mobilization of carbohydrates in grains. We demonstrate the importance of the barley reference sequence for breeding by inspecting the genomic partitioning of sequence variation in modern elite germplasm, highlighting regions vulnerable to genetic erosion.
The International Barley Genome Sequencing Consortium reports sequencing and assembly of a reference genome for barley,
Hordeum vulgare
.
Barley genome sequenced
Triticeae grasses, which include barley, wheat and rye, are widely cultivated plants with particularly complex genomes and evolutionary histories. Sequencing of the barley genome has been particularly challenging owing to its large size and particular genomic features, such as an abundance of repetitive elements. Nils Stein and colleagues of the International Barley Genome Sequencing Consortium report sequencing and assembly of a reference genome for barley (
Hordeumvulgare
L). They use a combined approach of hierarchical shotgun sequencing of bacterial artificial chromosomes, genome mapping on nanochannel arrays and chromosome-scale scaffolding with Hi-C sequencing. This brings the first comprehensive, completely ordered assembly of the pericentromeric regions of a Triticeae genome. The authors also sequenced and examined genetic diversity in the exomes of 96 European elite barley lines with a spring or winter growth habit, and highlight the utility of this resource for cereal genomics and breeding programs.
Journal Article
A MultiTEP platform-based epitope vaccine targeting the phosphatase activating domain (PAD) of tau: therapeutic efficacy in PS19 mice
by
Shabestari, Sepideh Kiani
,
Chadarevian, Jean Paul
,
Antonyan, Tatevik
in
13/106
,
14/19
,
631/250/251
2019
Pathological tau correlates well with cognitive impairments in Alzheimer’s disease (AD) patients and therefore represents a promising target for immunotherapy. Targeting an appropriate B cell epitope in pathological tau could in theory produce an effective reduction of pathology without disrupting the function of normal native tau. Recent data demonstrate that the N-terminal region of tau (aa 2-18), termed the “phosphatase activation domain (PAD)”, is hidden within native Tau in a ‘paperclip’-like conformation. Conversely, PAD is exposed in pathological tau and plays an essential role in the inhibition of fast axonal transport and tau polymerization. Thus, we hypothesized that anti-tau2-18 antibodies may safely and specifically reduce pathological tau and prevent further aggregation, which in turn would neutralize tau toxicity. Therefore, we evaluated the immunogenicity and therapeutic efficacy of our MultiTEP platform-based vaccine targeting tau2-18 formulated with Advax
CpG
adjuvant (AV-1980R/A) in PS19 tau transgenic mice. The AV-1980R/A induced extremely high antibody responses and the resulting sera recognized neurofibrillary tangles and plaque-associated dystrophic neurites in AD brain sections. In addition, under non-denaturing conditions AV-1980R/A sera preferentially recognized AD-associated tau. Importantly, vaccination also prevented age-related motor and cognitive deficits in PS19 mice and significantly reduced insoluble total and phosphorylated tau species. Taken together, these findings suggest that predominantly targeting misfolded tau with AV-1980R/A could represent an effective strategy for AD immunotherapy.
Journal Article
Immunogenicity of MultiTEP-Platform-Based Recombinant Protein Vaccine, PV-1950R, Targeting Three B-Cell Antigenic Determinants of Pathological α-Synuclein
by
Petrushina, Irina
,
Zagorski, Karen
,
Masliah, Eliezer
in
alpha-Synuclein - metabolism
,
Alzheimer's disease
,
Animals
2022
Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) are characterized by the aberrant accumulation of intracytoplasmic misfolded and aggregated α-synuclein (α-Syn), resulting in neurodegeneration associated with inflammation. The propagation of α-Syn aggregates from cell to cell is implicated in the spreading of pathological α-Syn in the brain and disease progression. We and others demonstrated that antibodies generated after active and passive vaccinations could inhibit the propagation of pathological α-Syn in the extracellular space and prevent/inhibit disease/s in the relevant animal models. We recently tested the immunogenicity and efficacy of four DNA vaccines on the basis of the universal MultiTEP platform technology in the DLB/PD mouse model. The antibodies generated by these vaccines efficiently reduced/inhibited the accumulation of pathological α-Syn in the different brain regions and improved the motor deficit of immunized female mice. The most immunogenic and preclinically effective vaccine, PV-1950D, targeting three B-cell epitopes of pathological α-Syn simultaneously, has been selected for future IND-enabling studies. However, to ensure therapeutically potent concentrations of α-Syn antibodies in the periphery of the vaccinated elderly, we developed a recombinant protein-based MultiTEP vaccine, PV-1950R/A, and tested its immunogenicity in young and aged D-line mice. Antibody responses induced by immunizations with the PV-1950R/A vaccine and its homologous DNA counterpart, PV-1950D, in a mouse model of PD/DLB have been compared.
Journal Article
Testing a MultiTEP-based combination vaccine to reduce Aβ and tau pathology in Tau22/5xFAD bigenic mice
by
Danhash, Emma
,
Antonyan, Tatevik
,
Davtyan, Hayk
in
Adjuvant
,
Alzheimer Disease - metabolism
,
Alzheimer Disease - pathology
2019
Background
Alzheimer disease (AD) is characterized by the accumulation of beta-amyloid (Aβ) plaques and neurofibrillary tangles composed of hyperphosphorylated tau, which together lead to neurodegeneration and cognitive decline. Current therapeutic approaches have primarily aimed to reduce pathological aggregates of either Aβ or tau, yet phase 3 clinical trials of these approaches have thus far failed to delay disease progression in humans. Strong preclinical evidence indicates that these two abnormally aggregated proteins interact synergistically to drive downstream neurodegeneration. Therefore, combinatorial therapies that concurrently target both Aβ and tau might be needed for effective disease modification.
Methods
A combinatorial vaccination approach was designed to concurrently target both Aβ and tau pathologies. Tau22/5xFAD (T5x) bigenic mice that develop both pathological Aβ and tau aggregates were injected intramuscularly with a mixture of two MultiTEP epitope vaccines: AV-1959R and AV-1980R, targeting Aβ and tau, respectively, and formulated in Advax
CpG
, a potent polysaccharide adjuvant. Antibody responses of vaccinated animals were measured by ELISA, and neuropathological changes were determined in brain homogenates of vaccinated and control mice using ELISA and Meso Scale Discovery (MSD) multiplex assays.
Results
T5x mice immunized with a mixture of Aβ- and tau-targeting vaccines generated high Aβ- and tau-specific antibody titers that recognized senile plaques and neurofibrillary tangles/neuropil threads in human AD brain sections. Production of these antibodies in turn led to significant reductions in the levels of soluble and insoluble total tau, and hyperphosphorylated tau as well as insoluble Aβ
42
, within the brains of bigenic T5x mice.
Conclusions
AV-1959R and AV-1980R formulated with Advax
CpG
adjuvant are immunogenic and therapeutically potent vaccines that in combination can effectively reduce both of the hallmark pathologies of AD in bigenic mice. Taken together, these findings warrant further development of this vaccine technology for ultimate testing in human AD.
Journal Article
Proline Rich Peptides of Neurohypophysial Origin: Related Peptides and Possible Functions
by
Hayrapetyan, Hripsime L
,
Chailyan, Samvel G
,
Hambardzumyan, Artur A
in
Amino acids
,
Argipressin
,
C-Terminus
2021
Proline rich polypeptide 1 (PRP-1) was isolated from the neurosecretory granules of bovine neurohypophysis and thoroughly characterized by Professor A. Galoyan and coauthors. BLAST analyses of PRP-1 with proteins of protein data bank indicated, that it is the C-terminus of third constituent of pre-pro-arginine vasopressin – copeptin, for all studied mammal species, as showed Galoyan and coauthors for bovine case. Also, BLAST analyses indicated, that the amino acid motive of PRP-1 is conservative in the course of the evolution, and occurred among enzymes of prokaryotic and eukaryotic origin Obtained to date data indicate multiple functionalities of this polypeptide, through to its diverse modulatory actions on set of different receptors. Using the AutoDock vina software it was shown, that PRP-1 and its homologues strongly interact with receptors, such as: mouse phosphorylated mitogen activated protein kinase 14, mouse toll like receptor 4, human Ca-sensing receptor, human epithelial growth factor receptor and human superoxide dismutase 1. As these receptors play important role in multiple cell signaling processes, the importance of their ligand peptides and homologues is obvious. But it should be stated, that, through docking experiments although are very informative, they should be considered as supplementary to real physical experiments, which should be carried out with the same receptors.
Journal Article