Publications by authors named "Zakian S"

Frontotemporal dementia with parkinsonism-17 is a neurodegenerative disease characterised by pathological aggregation of the tau protein with the formation of neurofibrillary tangles and subsequent neuronal death. The inherited form of frontotemporal dementia can be caused by mutations in several genes, including the MAPT gene on chromosome 17, which encodes the tau protein. As there are currently no medically approved treatments for frontotemporal dementia, there is an urgent need for research using in vitro cell models to understand the molecular genetic mechanisms that lead to the development of the disease, to identify targets for therapeutic intervention and to test potential drugs to prevent neuronal death.

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The clinical significance of numerous cardiovascular gene variants remains to be determined. CRISPR/Cas9 allows for the introduction and/or correction of a certain variant in induced pluripotent stem cells (iPSCs). The resulting isogenic iPSC lines can be differentiated into cardiomyocytes and used as a platform to assess the pathogenicity of the variant.

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  • * The study utilized CRISPR/Cas9 to create a specific mutation in induced pluripotent stem cells (iPSCs) from a healthy donor, allowing the researchers to analyze the effects of a variant found in an HCM patient.
  • * Cardiomyocytes developed from the mutated iPSCs displayed characteristic HCM traits, including enlarged size and altered gene expression, confirming the pathogenicity of the p.M659I variant.
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Familial Mediterranean fever (FMF) is a systemic autoinflammatory disorder caused by inherited mutations in the (Mediterranean FeVer) gene, located on chromosome 16 (16p13.3) and encoding the pyrin protein. Despite the existing data on mutations, the exact mechanism of their effect on the development of the pathological processes leading to the spontaneous and recurrent autoinflammatory attacks observed in FMF, remains unclear.

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  • - Endoplasmic reticulum (ER) stress is linked to various diseases, especially Parkinson’s disease (PD), which currently has no cure, highlighting the need to understand its underlying mechanisms.
  • - Genetically encoded biosensors, particularly those utilizing fluorescent proteins, enable real-time study of molecular events in living cells, enhancing research on diseases.
  • - By using CRISPR technology to create a specific cell model from induced pluripotent stem cells (iPSCs) expressing a biosensor for the UPR system, researchers can investigate how ER stress activates certain pathways and develop potential treatment strategies.
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Base excision repair (BER) is the predominant pathway for the removal of most forms of hydrolytic, oxidative, and alkylative DNA lesions. The precise functioning of BER is achieved via the regulation of each step by regulatory/accessory proteins, with the most important of them being poly(ADP-ribose) polymerase 1 (PARP1). PARP1's regulatory functions extend to many cellular processes including the regulation of mRNA stability and decay.

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Defects in the low-density lipoprotein receptor (LDLR) are associated with familial hypercholesterolemia (FH), manifested by atherosclerosis and cardiovascular disease. LDLR deficiency in hepatocytes leads to elevated blood cholesterol levels, which damage vascular cells, especially endothelial cells, through oxidative stress and inflammation. However, the distinctions between endothelial cells from individuals with normal and defective LDLR are not yet fully understood.

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  • * Understanding PD mechanisms remains challenging, and recent findings highlight the role of both dopaminergic neurons and astrocytes in its pathogenesis.
  • * Researchers created two induced pluripotent stem cell (iPSC) lines from a patient with a specific genetic mutation to study astrocyte involvement in GBA-associated PD, demonstrating the potential of iPSCs in disease modeling.
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The spectrum of neurodegenerative diseases known today is quite extensive. The complexities of their research and treatment lie not only in their diversity. Even many years of struggle and narrowly focused research on common pathologies such as Alzheimer's, Parkinson's, and other brain diseases have not brought cures for these illnesses.

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Tyrosyl-DNA phosphodiesterase 1 and 2 (Tdp1 and Tdp2) are DNA repair enzymes that repair DNA damage caused by various agents, including anticancer drugs. Thus, these enzymes resist anticancer therapy and could be the reason for resistance to such widely used drugs such as topotecan and etoposide. In the present work, we found compounds capable of inhibiting both enzymes among derivatives of (-)-usnic acid.

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The study of pathological processes in cells carrying mutations should be carried out in comparison with a healthy control group. Familial Mediterranean fever (FMF), which is caused by a mutation in the MEFV gene, is predominantly found in people of Armenian nationality with the prevalence of 14-100 per 10000. We have obtained induced pluripotent stem cells (iPSCs) from Armenian healthy patient, which will be included as a control group in the study of this disease.

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Article Synopsis
  • Topoisomerase 1 (TOP1) is crucial for DNA functions like replication and is targeted by anticancer drugs such as topotecan, which can cause cell death by stabilizing the TOP1 cleavage complex.
  • Tyrosyl-DNA phosphodiesterase 1 (TDP1) can remove this complex, thereby reducing the effectiveness of topotecan.
  • A study comparing wild type and PARP1 knockout HEK293A cells revealed that PARP1 deficiency led to significantly more changes in gene expression when treated with topotecan and a TDP1 inhibitor, affecting pathways related to cancer development and DNA repair.
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The locus has clinical significance for lipid metabolism, Mendelian familial hypercholesterolemia (FH), and common lipid metabolism-related diseases (coronary artery disease and Alzheimer's disease), but its intronic and structural variants are underinvestigated. The aim of this study was to design and validate a method for nearly complete sequencing of the gene using long-read Oxford Nanopore sequencing technology (ONT). Five PCR amplicons from of three patients with compound heterozygous FH were analyzed.

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  • * Researchers analyzed dopaminergic neurons derived from induced pluripotent stem cells (iPSCs) of individuals with the mutation (GBA-PD), asymptomatic carriers (GBA-carrier), and healthy controls to assess the activity of lysosomal enzymes.
  • * Findings revealed that GBA-PD neurons exhibit lower glucocerebrosidase (GCase) activity and altered activity in other lysosomal enzymes compared to GBA-carrier and control neurons, indicating the need for further research into the genetic and environmental factors influencing PD development.
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The effect of PARP1 knockout in HEK293 cells on the gene expression of DNA base excision repair (BER) proteins was studied. It was shown that the expression of all differentially expressed genes (DEGs) of BER was reduced by knockout. The expression of the DNA glycosylase gene NEIL1, which is considered to be one of the common "hubs" for binding BER proteins, has changed the most.

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Imprinted X chromosome inactivation (iXCI) balances the expression of X-linked genes in preimplantation embryos and extraembryonic tissues in rodents. Long noncoding Xist RNA drives iXCI, silencing genes and recruiting Xist-dependent chromatin repressors. Some domains on the inactive X chromosome include repressive modifications specific to constitutive heterochromatin, which show no direct link to Xist RNA.

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Huntington's disease (HD) is a hereditary autosomal dominant neurodegenerative disease caused by the polyglutamine stretch expansion in the huntingtin (HTT) protein. In HD, dysregulation of multiple cellular processes occurs, resulting in the death of medium spiny neurons of striatum. A line of induced pluripotent stem cells (iPSCs) ICGi033-A was obtained from peripheral blood mononuclear cells of a patient carrying 77 CAG repeats in the HTT gene.

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  • Oxidative stress is linked to neurodegenerative diseases, contributing to neuron death and disease progression.
  • Genetically encoded biosensors have been created to monitor oxidative stress, but more research is needed on their effectiveness in human cell models, particularly in understanding neurodegenerative disorders.
  • This study developed a method to use these biosensors in live motor neurons with SOD1 mutations related to ALS, showing they can effectively track changes in oxidative states under various conditions, making them a valuable tool for studying neurodegenerative mechanisms.
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In our previous study, we showed that discarded cardiac tissue from the right atrial appendage and right ventricular myocardium is an available source of functional endothelial and smooth muscle cells for regenerative medicine and tissue engineering. In the study, we aimed to find out what benefits are given by vascular cells from cardiac explants used for seeding on vascular patches engrafted to repair vascular defects . Additionally, to make the application of these cells safer in regenerative medicine we tested an approach that arrested mitotic division to avoid the potential tumorigenic effect of dividing cells.

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Familial hypercholesterolemia (FH) is an autosomal dominant disorder increasing premature cardiovascular diseases risk due to atherosclerosis. Pathogenic mutations in the LDLR gene cause most FH cases. Available treatments are effective not for all LDLR mutations.

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The development of cellular models for familial hypercholesterolemia (FH) is an important direction for creating new approaches to atherosclerosis treatment. Pathogenic mutations in the LDLR gene are the main FH source. We generated an iPSC line from peripheral blood mononuclear cells of the patient with compound heterozygous c.

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Mutation in the glucocerebrosidase encoding gene (GBA) is one of the most frequent genetic cause of Parkinson's disease. ICGi034-A induced pluripotent stem cell (iPSC) line obtained by reprogramming peripheral blood mononuclear cells (PBMCs) of a patient with heterozygous c.1226A > G (p.

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Familial hypercholesterolemia (FH) is a monogenic disease, leading to atherosclerosis due to a high level of low-density lipoprotein cholesterol. Most cases of the disease are based on pathological variants in the LDLR gene. Hepatocyte-like and endothelial cells derived from individual iPSCs are a good model for developing new approaches to therapy.

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Spinal muscular atrophy is a progressive motor neuron disorder caused by deletions or point mutations in the SMN1 gene. It is not known why motor neurons are particularly sensitive to a decrease in SMN protein levels and what factors besides SMN2 underlie the high clinical heterogeneity of the disease. Here we studied the methylation patterns of genes on sequential stages of motor neuron differentiation from induced pluripotent stem cells derived from the patients with SMA type I and II.

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One of the challenges of modern biology and medicine is to visualize biomolecules in their natural environment, in real-time and in a non-invasive fashion, so as to gain insight into their physiological behavior and highlight alterations in pathological settings, which will enable to devise appropriate therapeutic strategies. Genetically encoded fluorescent biosensors constitute a class of imaging agents that enable visualization of biological processes and events directly in situ, preserving the native biological context and providing detailed insight into their localization and dynamics in cells. Real-time monitoring of drug action in a specific cellular compartment, organ, or tissue type; the ability to screen at the single-cell resolution; and the elimination of false-positive results caused by low drug bioavailability that is not detected by in vitro testing methods are a few of the obvious benefits of using genetically encoded fluorescent biosensors in drug screening.

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