Publications by authors named "Sergey P Medvedev"

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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Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a human DNA repair protein. It is a member of the phospholipase D family based on structural similarity. TDP1 is a key enzyme of the repair of stalled topoisomerase 1 (TOP1)-DNA complexes.

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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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  • * 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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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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  • 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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  • * 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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  • 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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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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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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Tyrosyl-DNA phosphodiesterase 1 (TDP1) catalyzes the cleavage of the phosphodiester bond between the tyrosine residue of topoisomerase 1 (TOP1) and the 3' phosphate of DNA in the single-strand break generated by TOP1. TDP1 promotes the cleavage of the stable DNA-TOP1 complexes with the TOP1 inhibitor topotecan, which is a clinically used anticancer drug. This article reports the synthesis and study of usnic acid thioether and sulfoxide derivatives that efficiently suppress TDP1 activity, with IC values in the 1.

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The major human apurinic/apyrimidinic (AP) site endonuclease, APEX1, is a central player in the base excision DNA repair (BER) pathway and has a role in the regulation of DNA binding by transcription factors. In vertebrates, APEX1 knockouts are embryonic lethal, and only a handful of knockout cell lines are known. To facilitate studies of multiple functions of this protein in human cells, we have used the CRISPR/Cas9 system to knock out the APEX1 gene in a widely used non-cancer hypotriploid HEK 293FT cell line.

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The development of cell models of human diseases based on induced pluripotent stem cells (iPSCs) and a cell therapy approach based on differentiated iPSC derivatives has provided a powerful stimulus in modern biomedical research development. Moreover, it led to the creation of personalized regenerative medicine. Due to this, in the last decade, the pathological mechanisms of many monogenic diseases at the cell level have been revealed, and clinical trials of various cell products derived from iPSCs have begun.

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  • * Researchers synthesized ten new UA derivatives, discovering that four of them effectively inhibited TDP1 and showed low toxicity in human cell lines, while also enhancing the effectiveness of the anti-cancer drug topotecan in cancer cells.
  • * The findings suggest a potential for combining UA derivatives with topotecan in cancer treatment, but further research is needed to understand how these compounds affect non-cancerous cells differently.
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Metabolomic profiles of somatic cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) reflect their metabolic phenotypes. The comparative study of metabolomes of these cells is important for understanding the differences in metabolism between somatic and pluripotent cells, and also the possible differences between ESCs and iPSCs. Here, we performed for the first time the metabolomic analysis of rat ESCs, iPSCs, and embryonic fibroblasts (EFs) at both quantitative and semi-quantitative levels using NMR spectroscopy and liquid chromatography with mass spectrometric detection, respectively.

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  • Researchers discovered two new types of TDP1 inhibitors that can effectively inhibit the TDP1 enzyme, crucial for DNA repair, at low concentrations, with the strongest compound showing an IC value of 0.65 μM.
  • The inhibitors were synthesized from monoterpene compounds and they demonstrated a synergistic effect when tested with the cancer drug topotecan in HEK293FT cells with functional TDP1.
  • This synergy suggests that using non-toxic inhibitors alongside existing cancer therapies can improve treatment effectiveness while minimizing harmful side effects.
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  • In voles (Microtus levis), preimplantation embryo and extraembryonic tissue cells experience a process called imprinted X chromosome inactivation (iXCI), which is initiated by the long non-coding RNA known as Xist.
  • The study used vole trophoblast stem (TS) cells to explore the chromatin structure of the inactive X chromosome, noting the presence of certain proteins and histone modifications.
  • Findings revealed that while Xist RNA didn't play a major role in maintaining the inactive state of the X chromosome, it was essential for recruiting an additional histone modification during the differentiation of these cells.
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Pluripotent stem cells have great potential for developmental biology and regenerative medicine. Embryonic stem cells, which are obtained from blastocysts, and induced pluripotent stem cells, which are generated by the reprogramming of somatic cells, are two main types of pluripotent cells. It is important to understand the regulatory network that controls the pluripotency state and reprogramming process.

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MicroRNAs (miRNAs) constitute a class of small noncoding RNAs that plays an important role in the post-transcriptional regulation of gene expression. Much evidence has demonstrated that miRNAs are involved in regulating the human and mouse pluripotency. Nevertheless, to our knowledge, miRNAs in the pluripotent stem cells of one of the most commonly used model organisms - the Rattus norvegicus have not been studied.

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The development of new revolutionary technologies for directed gene editing has made it possible to thoroughly model and study NgAgo human diseases at the cellular and molecular levels. Gene editing tools like ZFN, TALEN, CRISPR-based systems, NgAgo and SGN can introduce different modifications. In gene sequences and regulate gene expression in different types of cells including induced pluripotent stem cells (iPSCs).

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Fundamental studies of molecular and cellular mechanisms of cardiovascular disease pathogenesis are required to create more effective and safer methods of their therapy. The studies can be carried out only when model systems that fully recapitulate pathological phenotype seen in patients are used. Application of laboratory animals for cardiovascular disease modeling is limited because of physiological differences with humans.

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One of the reasons for the death of motor neurons of the brain and spinal cord in patients with amyotrophic lateral sclerosis is known to be formation of subcellular protein aggregates that are caused by mutations in the SOD1 gene. Patient survival time was earlier shown to have limiting correlation with thermostability change of SOD1 mutant forms of patients' carriers. We hypothesized that aggregation of mutant SOD1 may occur not only due to the protein destabilization, but through formation of novel interatomic bonds which stabilize "pathogenic" conformations of the mutant as well.

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  • Rat pluripotent stem cells, including embryonic (ESCs) and induced pluripotent stem cells (iPSCs), show promise for research on early mammalian development, but data on rat pluripotency and differentiation methods are limited.
  • The study utilized RNA-Seq to analyze the transcriptomes of rat ESCs and iPSCs, revealing that they are quite similar and distinct from differentiated cells, along with a notable X-chromosome reactivation during reprogramming.
  • A new monolayer differentiation protocol was developed to better understand X-chromosome inactivation dynamics and facilitate the creation of specific cell types for biomedical applications.
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Induced pluripotent stem (iPS) cells can be derived from a wide range of somatic cells via overexpression of a set of specific genes. With respect to their properties, iPS cells closely resemble embryonic stem cells. Because of their main property, pluripotency, iPS cells have excellent prospects for use in substitutive cell therapy; however, the methods of directed differentiation of iPS cells have not been yet sufficiently elaborated.

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