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1.
Bull Exp Biol Med ; 175(1): 144-149, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37336810

RESUMO

Regulation of alternative splicing is carried out by RNA-binding proteins. Each alternative splicing event is controlled by several RNA-binding proteins, which in combination create the distribution of alternative splicing products in a given cell type. Transmembrane protein CD44 plays an important role at various stages of the metastatic cascade and is considered as a promising molecule for the therapy of tumor diseases and the construction of prognostic classifiers. However, the functions of specific isoforms of this protein may differ significantly. In this work, we performed a bioinformatic search of RNA-binding proteins that can determine the expression of clinically significant isoforms 3 and 4 of CD44 protein. The analysis revealed five RNA-binding proteins, three of which (OAS1, ZFP36L2, and DHX58) are shown for the first time as potential regulators of the studied process.


Assuntos
Processamento Alternativo , Neoplasias Colorretais , Humanos , Processamento Alternativo/genética , Receptores de Hialuronatos/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Neoplasias Colorretais/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/genética , 2',5'-Oligoadenilato Sintetase/genética , RNA Helicases/genética , RNA Helicases/metabolismo
2.
Bull Exp Biol Med ; 173(1): 155-159, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35618971

RESUMO

Detection of colorectal cancer biomarkers (CRC) remains an urgent task for the diagnosis and prediction of the disease course. A promising approach is the study of cancer stem cell markers. The cell surface glycoprotein CD44 is very important for CRC and its stem cells. Alternative splicing of 9 variable exons of CD44 mRNA leads to the formation of various isoforms of the protein with different roles in the progression of cancer. Studies of the functions of CD44 isoforms require adequate models considering the distribution of CD44 isoforms in real tumor samples. In the present study, the expression profile of CD44 isoforms in CRC was assessed based on the publicly available mRNA sequencing data of patient tumors from the TCGA-COAD database. It was shown that normal tissues predominantly expressed isoforms 3 and 4 at nearly equal levels, whereas tumors mainly expressed isoforms 2, 3, and 4; isoform 3 was expressed at the highest level. Further, the most relevant cell lines for studying the role of CD44 in CRC were identified based on the analysis of mRNA sequencing data of 55 CRC cell lines form CCLE database.


Assuntos
Neoplasias Colorretais , Receptores de Hialuronatos , Processamento Alternativo , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Humanos , Receptores de Hialuronatos/biossíntese , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/metabolismo , Isoformas de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
3.
Dokl Biochem Biophys ; 494(1): 219-221, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33119820

RESUMO

In the present study, we assessed the role of annexin 13 membrane-binding protein (ANXA13) in the intracellular transport of vesicles containing type II ribosome-inactivating proteins (RIP-IIs). A modified human intestinal epithelial cell line HT29 was used, in which the expression of ANXA13 was significantly reduced. The cytotoxic effect of ricin and viscumin was evaluated by modification of 28S ribosome RNA. The observed differences in the activity of toxins on the parental and modified HT29 lines indicate that ANXA13 plays a different role in the intracellular transport of vesicles containing the RIP-IIs.


Assuntos
Anexinas/metabolismo , Substâncias para a Guerra Química/farmacologia , Neoplasias do Colo/patologia , Proteínas Inativadoras de Ribossomos Tipo 2/farmacologia , Proteínas Inativadoras de Ribossomos/metabolismo , Ribossomos/efeitos dos fármacos , Ricina/farmacologia , Toxinas Biológicas/farmacologia , Transporte Biológico , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Células HT29 , Humanos
4.
Dokl Biochem Biophys ; 493(1): 198-200, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32894464

RESUMO

The role of proteasome proteins and proteins of the ERAD system in the cytotoxicity of type II ribosome-inactivating proteins ricin and viscumin was investigated. For this, the cell line of colorectal adenocarcinoma HT29, as well as the HT29-sh002 line obtained on its basis, were used. On the basis on the proteome analysis of these lines and the estimation of the proportion of inactivated ribosomes, it was shown that the contribution of the proteasome to the degradation of the catalytic subunits of toxins is different. The role of the Cdc37 co-chaperone in maintaining the stability of A subunit of viscumin in the cytoplasm is shown.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Chaperoninas/metabolismo , Neoplasias Colorretais/tratamento farmacológico , Complexo de Endopeptidases do Proteassoma/biossíntese , Proteínas Inativadoras de Ribossomos Tipo 2/farmacologia , Ricina/farmacologia , Toxinas Biológicas/farmacologia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Proteínas de Ciclo Celular/genética , Chaperoninas/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Citoplasma/metabolismo , Humanos , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Ribossomos/metabolismo , Células Tumorais Cultivadas
5.
Dokl Biochem Biophys ; 493(1): 208-210, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32894467

RESUMO

Human colorectal adenocarcinoma cell line Caco-2 is often used as a model of healthy intestinal epithelium, in particular, in miRNA studies. The work of the enzymes Drosha and Dicer is an integral part of the process of miRNA formation. Inaccuracies in the work of these enzymes lead to a change in the nucleotide sequences of miRNAs with the formation of new isoforms, which, in turn, can change intracellular regulatory mechanisms. In the framework of this study, it was shown that the quantitative estimates of inaccuracies in Drosha and Dicer activity significantly differ between the specimens of normal colon tissue and malignant colorectal tumors.


Assuntos
Adenocarcinoma/metabolismo , Colo/metabolismo , Neoplasias Colorretais/metabolismo , RNA Helicases DEAD-box/metabolismo , MicroRNAs/metabolismo , Ribonuclease III/metabolismo , Adenocarcinoma/enzimologia , Adenocarcinoma/genética , Adenocarcinoma/patologia , Estudos de Casos e Controles , Colo/enzimologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Biologia Computacional , RNA Helicases DEAD-box/genética , Bases de Dados Genéticas , Humanos , MicroRNAs/genética , Ribonuclease III/genética
6.
Mol Biol (Mosk) ; 53(2): 330-338, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31099783

RESUMO

Received August 28, 2018; revised October 10, 2018; accepted November 6, 2018 The loss of apical-basal cell polarity is a necessary stage of the epithelial-mesenchymal transition (EMT). Polarized epithelial cells interact with the basement membrane (BM) and, in particular, with laminins, the major components of BM. Here, we examined the effect of the transition of colon cancer cells from 2D polarized state to non-polarized 3D state on the expression of EMT associated genes, as well as the role of laminins 332 and 411 (LM-332 and LM-411) in this process. The three studied cell lines, HT-29, HCT-116 and RKO, were found to have different sensitivity to cultivation conditions (2D to 3D changes) and to addition of laminins. One of the possible reasons for this maybe a difference in the initial 2D state of the cells. In particular, it was shown that the cell lines were at different EMT stages. HT-29 exhibited more epithelial expression profile, RKO was more mesenchymal, and HCT-116 was in an intermediate state. The most laminin-sensitive cell line was HCT-116. The magnitude and the specificity of cell response to LM-332 and LM-411 depended on the expression pattern of laminins' receptors. EMT gene expression profile was not substantially changed neither during the transition from 2D to 3D state, nor the presence of laminins' isoforms. However, we detected changes in expression of SNAI1 and ZEB1 genes encoding transcription factors that control the EMT process. Notably, in all three studied cell lines, the expression of SNAI1 was enhanced in response to laminin treatment.


Assuntos
Biomarcadores Tumorais/metabolismo , Moléculas de Adesão Celular/farmacologia , Técnicas de Cultura de Células/métodos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Laminina/farmacologia , Linhagem Celular Tumoral , Humanos , Calinina
7.
Obes Rev ; 20(1): 108-118, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30248223

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is the most common liver pathology. Here we propose tissue-cooperative, homeostatic model of NAFLD. During early stages of NAFLD the intrahepatic production of miR-122 falls, while the secretion of miRNA-containing exosomes by adipose increases. Bloodstream carries exosome to the liver, where their miRNA cargo is released to regulate their intrahepatic targets. When the deterioration of adipose catches up with the failing hepatic parenchyma, the external supply of liver-supporting miRNAs gradually tapers off, leading to the fibrotic decompensation of the liver and an increase in hepatic carcinogenesis. This model may explain paradoxical observations of the disease-associated decrease in intrahepatic production of certain miRNAs with an increase in their levels in serum. Infusions of miR-122 and, possibly, some other miRNAs may be efficient for preventing NAFLD-associated hepatocellular carcinoma. The best candidates for exosome-wrapped miRNA producer are adipose tissue-derived mesenchymal stem cells (MSCs), known for their capacity to shed large amounts of exosomes into the media. Notably, MSC-derived exosomes with no specific loading are already tested in patients with liver fibrosis. Carrier exosomes may be co-manufactured along with their cargo. Exosome-delivered miRNA cocktails may augment functioning of human organs suffering from a variety of chronic diseases.


Assuntos
Tecido Adiposo/metabolismo , MicroRNAs/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Adiposidade , Progressão da Doença , Humanos
8.
Mol Biol (Mosk) ; 52(5): 810-816, 2018.
Artigo em Russo | MEDLINE | ID: mdl-30363056

RESUMO

The architecture of stroma is crucial for normal lymph node functioning, as well as for the systemic and local immune response. Data from previous studies in metastatic lymph nodes suggest that changes in the composition of extracellular matrix proteins may occur, not only around the lesion site, but throughout the lymph node stroma. In the present study, the extracellular matrix status was compared between the affected and metastasis-free lymph nodes in prostate cancer. It was found that the presence of tumor cells was associated with significant changes in the expression of genes encoding extracellular matrix components, including α4, ß1 and γl laminin chains, osteonectin, and collagen, as well as with decrease in the expression of lymphatic endothelial cell biomarkers LYVE1 and NRP2. This result suggests that the normal stromal architecture is significantly disrupted in metastatic lymph nodes and may indicate the development of immune tolerance to the tumor cells.


Assuntos
Linfonodos/patologia , Metástase Linfática/patologia , Neoplasias da Próstata/patologia , Proteínas da Matriz Extracelular/química , Humanos , Masculino
9.
Mol Biol (Mosk) ; 52(4): 675-682, 2018.
Artigo em Russo | MEDLINE | ID: mdl-30113033

RESUMO

The mistletoe lectin viscumin (MLI) is a ribosome-inactivating protein from Viscum album widely used in cancer therapy. Its antitumor properties are due to its immunomodulating action, previously demonstrated in experiments involving intravenous, subcutaneous, and oral administration of viscumin. To investigate whether viscumin has a cytotoxic effect on the intestinal epithelium, its safety was assessed using (i) impedance spectroscopy to measure the integrity of the colorectal adenocarcinoma Caco-2 cell monolayer after exposure to viscumin and (ii) a novel technique of determining the portion of viscumin-inactivated ribosomes. It was shown that inactivation of at least 20% of the ribosomes within 6 h did not lead to disruption of the Caco-2 cell monolayer or alter the physicochemical parameters of enterocyte membranes.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Mucosa Intestinal/efeitos dos fármacos , Proteínas Inativadoras de Ribossomos Tipo 2/farmacologia , Ribossomos/efeitos dos fármacos , Toxinas Biológicas/farmacologia , Células CACO-2 , Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/patologia , Impedância Elétrica , Enterócitos/efeitos dos fármacos , Humanos , Ribossomos/genética
10.
Mol Biol (Mosk) ; 52(3): 411-434, 2018.
Artigo em Russo | MEDLINE | ID: mdl-29989574

RESUMO

Laminins are a family of extracellular heterotrimeric glycoproteins that are the main structural component of basement membranes (BMs), perform a barrier function, and are important for adhesion, differentiation, migration, and resistance to apoptosis of various cells, including cancer cells. The review summarizes the current knowledge of how laminins produced by cancer and normal cells influence the key stages of carcinogenesis. Laminin 332 (LN-332) and LN-111 enhance proliferation of certain cancer cells and increase the tumour growth. LN-111 increases resistance to apoptosis, induces differentiation, and inhibits the epithelial-mesenchymal transition (EMT) of cancer cells. LN-332 is associated with higher adhesion and higher migration potential of cancer cells. LN-411 and LN-421 significantly increase motility of cancer cells. LN-332 and LN-511 facilitate cell-cell adhesion and affect the efficacy of cell-cell interactions. The laminin chains α4 and α5 are important for the development and function of blood and lymphatic vessels. The expression ratio of the α4 and α5 laminin chains defines the BM permeability to leukocytes and, presumably, cancer cells in blood and lymphatic vessels. Interactions between LN-511 and α2-containing laminins enhance self-renewal and survival of circulating cancer stem cells. Moreover, laminins are involved in the formation of premetastatic niches and new colonies. Endogenous expression of the α4 laminin chain stimulates proliferation of individualised circulating cancer cells in vitro and in vivo and facilitates micrometastasis.


Assuntos
Movimento Celular , Laminina/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Células Neoplásicas Circulantes/metabolismo , Animais , Humanos , Laminina/genética , Proteínas de Neoplasias/genética , Neoplasias/genética , Neoplasias/patologia , Células Neoplásicas Circulantes/patologia
11.
Artigo em Russo | MEDLINE | ID: mdl-29119956

RESUMO

BACKGRAUND: The objective of the present study was to estimate the expectations about psychotherapy in terms of social and medical rehabilitation among the employees of hazardous occupations suffering from the consequences of a psychological trauma. MATERIAL AND METHODS: A total of 100 subjects employed by various departments of the Russian Ministry of Internal Affairs (MIA) were recruited to participate in the study. Their age varied from 19 to 35 (mean 25.8±3.6) years. The mean age of the 56 men and the 44 women was 25.8±3.7 years and 25.9±3.5 years respectively. The methods of research included a questionnaire study for the elucidation of psychotherapeutic expectations and psychotherapeutic experience, the diagnostic test for the assessment of the interpersonal relationships, and the NEO five-factor personality inventory (NEO-FFI). RESULTS: The results of the questionnaire studies designed to obtain the profile of expectations about psychotherapy among the entire sample suggested the positive attitude of the responders toward the therapeutic interventions with no significant preferences given to their specific type providing that they proved efficient. However, the averaged estimates for the subscales that implied self-exploration (e.g. inward orientation and catharsis) for the general sample proved somewhat lower than those for such subscales as outward orientation including advice, defensiveness, support, the development and practicing of concrete specific skills and techniques needed to facilitate dealing with particular problems and symptoms. Generally speaking, the participants of the present study positively evaluated the effectiveness of psychological aid designed to resolve the problems associated with psychic traumatization based on the relevant personal experience dictating the necessity to avoid factors and situations either reminiscent of those that had resulted in the psychotraumatic event or symbolizing it. Moreover, the patients exhibiting the signs of post-traumatic stress disorders (PTSD) suffere a number of abnormal changes in the cognitive and emotional spheres in the combination with enhanced physiological responsiveness. CONCLUSION: The results of the present study give evidence of the importance of taking into consideration the expectations of the patients suffering from the consequences of a psychological trauma as regards the results of psychotherapy as well as the mode of their personal interactions with the attending physicians which in its turn depend on the specific dynamics features of the disease and its overall clinical picture. In order to maintain a 'working alliance' between the patient of the given group and the psychotherapist, the latter should follow a certain pattern of interpersonal relationships with the patient which can be described by octants 2, 4-7 of the Interpersonal Relationship Diagnostics questionnaire. Also, the results obtained in the study can be used for the elaboration and implementation of the comprehensive psychotherapeutic and rehabilitative programs within the framework of health resort-based treatment programs for the employees of hazardous occupations who experience problems arising from the consequences of psychic trauma.


Assuntos
Exposição Ocupacional/efeitos adversos , Polícia , Estresse Psicológico/psicologia , Estresse Psicológico/terapia , Inquéritos e Questionários , Feminino , Humanos , Masculino
12.
Bull Exp Biol Med ; 163(6): 745-748, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29063321

RESUMO

External magnetic field is characterized by low toxicity and existence of magnetic properties, which contributes to an interest in the development of products from ferromagnetic nanoparticles (FNP) for antitumor therapy. Previously we synthesized a conjugate of ferromagnetic magnetite nanoparticles and viscumin (mistletoe lectin I, MLI), which exhibits the antitumor activity. Studying the pharmacological properties of this conjugate (FNP-MLI) was directed to the evaluation of FNP-MLI elimination after intratumor injection in mice. The elimination rate of FNP-MLI was much lower than that of native plant MLI. The presence of FNP-MLI was not accompanied by undesired changes in the tumor tissue. The use of a FNP-MLI conjugate allowed us to prolong the time of MLI presence in tissues without increasing the dose of exogenous lectin. These features contribute to the prolongation of an immunomodulatory effect of MLI.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos Fitogênicos/farmacocinética , Neoplasias da Mama/tratamento farmacológico , Portadores de Fármacos/administração & dosagem , Nanopartículas de Magnetita/administração & dosagem , Proteínas Inativadoras de Ribossomos Tipo 2/farmacocinética , Toxinas Biológicas/farmacocinética , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Portadores de Fármacos/farmacocinética , Feminino , Humanos , Injeções Intralesionais , Injeções Subcutâneas , Imageamento por Ressonância Magnética , Camundongos , Camundongos SCID , Proteínas Inativadoras de Ribossomos Tipo 2/farmacologia , Toxinas Biológicas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Bull Exp Biol Med ; 163(4): 482-485, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28853065

RESUMO

We studied the possibility of using viscumin lectin (MLI) for targeted delivery of antitumor drugs. Affinity of MLI for more than 600 oligosaccharide structures was determined and the glycosylation profiles of cell surface in various mouse tissues were analyzed. It was found that biodistribution of MLI was determined by not only expression of oligosaccharides specifically recognized by the lectin in tissue cells, but also by the structure of glycan in general.


Assuntos
Lectinas de Plantas/metabolismo , Proteínas Inativadoras de Ribossomos Tipo 2/metabolismo , Toxinas Biológicas/metabolismo , Animais , Feminino , Glicosilação , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oligossacarídeos/metabolismo , Polissacarídeos/metabolismo
15.
Dokl Biochem Biophys ; 469(1): 264-8, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27599508

RESUMO

In this study, we performed transcriptome profiling of oligodendrocyte culture of mice treated with the remyelinating therapeutic agent benztropine in the presence and absence of interferon gamma (IFNγ). The results of this work are important for understanding the expression profile of oligodendrocytes under conditions of systemic inflammation in the central nervous system in multiple sclerosis as well as the mechanisms of cellular response to benztropine in light of its possible use for the treatment of multiple sclerosis.


Assuntos
Oligodendroglia/imunologia , RNA Mensageiro/imunologia , Transcriptoma/imunologia , Animais , Anti-Inflamatórios/farmacologia , Benzotropina/farmacologia , Células Cultivadas , Perfilação da Expressão Gênica , Fatores Imunológicos/farmacologia , Interferon gama/farmacologia , Camundongos Endogâmicos C3H , Oligodendroglia/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/imunologia , Transcriptoma/efeitos dos fármacos
16.
Bull Exp Biol Med ; 161(1): 69-71, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27270938

RESUMO

We studied the effect of ß1i-specific peptidyl aldehyde IPSI-001 on proteasome from mammalian cells. In concentrations <1 µM, this agent effectively suppressed immunoproteasome, but only slightly reduced chymotrypsin-like activity of constitutive proteasome. Intraperitoneal administration of this inhibitor to C3H/He mice in a dose of 100 mg/kg induced no significant physiological or behavioral changes, which attested to its considerable therapeutic potential in the treatment of autoimmune neurodegenerative pathologies.


Assuntos
Dipeptídeos/farmacologia , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Linhagem Celular , Humanos , Camundongos , Camundongos Endogâmicos C3H , Proteína Básica da Mielina/metabolismo
17.
Bull Exp Biol Med ; 161(1): 116-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27265127

RESUMO

The behavior of magnetite nanoparticles was studied in the cell chip microcapillaries. No aggregation of magnetite nanoparticles under conditions of long-term circulation was noted. Biodistribution and toxicity of magnetite nanoparticles (14 nm) and aminated magnetite after their intragastric administration to mice were studied in vivo. According to mass spectrometry and microscopy data, accumulation of nanoparticles occurred mainly in the liver cells.


Assuntos
Nanopartículas de Magnetita/química , Animais , Animais não Endogâmicos , Avaliação Pré-Clínica de Medicamentos , Estabilidade de Medicamentos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Nanopartículas de Magnetita/toxicidade , Masculino , Camundongos , Microcirculação , Técnicas Analíticas Microfluídicas , Modelos Biológicos , Soluções , Distribuição Tecidual
18.
Bull Exp Biol Med ; 160(6): 763-6, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27165078

RESUMO

Acetaminophen in a concentration of 5 mM increased the expression of JNK, HIF1A (hypoxiainduced factor), and CASP3, which indicated development of oxidative stress and apoptotic cell death. Acetaminophen in a concentration of 10 mM did not induce expression of HIF1A and CASP3, but reduced expression of chaperone HSP90, which attested to activation of a caspase-3-independent mechanism of cell death. The methods of preventing acetaminophen intoxication are discussed.


Assuntos
Acetaminofen/farmacologia , Analgésicos não Narcóticos/farmacologia , Caspase 3/metabolismo , Neurônios/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Apoptose , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Humanos , Estresse Oxidativo
19.
Bull Exp Biol Med ; 160(6): 831-4, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27160885

RESUMO

We studied the effects of silver nanoparticles (10 nm) on HepaRG cell spheroids simulating liver tissue. The mathematical model was proposed that describes nanoparticle diffusion in a spheroid consisting of 5000 cells depending on the external nanoparticle concentration. It was demonstrated that cells in the 3D model were less sensitive to the toxic effects of nanoparticles in comparison with 2D cultures. Impaired integrity of the cell membrane did not deteriorate cell viability (according to MTT test).


Assuntos
Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Esferoides Celulares/fisiologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/fisiologia , Humanos , Prata/metabolismo , Esferoides Celulares/efeitos dos fármacos
20.
J Chem Phys ; 142(16): 164905, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25933789

RESUMO

We study force-extension curves of a single semiflexible chain consisting of several rigid rods connected by flexible spacers. The atomic force microscopy and laser optical or magnetic tweezers apparatus stretching these rod-coil macromolecules are discussed. In addition, the stretching by external isotropic force is analyzed. The main attention is focused on computer simulation and analytical results. We demonstrate that the force-extension curves for rod-coil chains composed of two or three rods of equal length differ not only quantitatively but also qualitatively in different probe methods. These curves have an anomalous shape for a chain of two rods. End-to-end distributions of rod-coil chains are calculated by Monte Carlo method and compared with analytical equations. The influence of the spacer's length on the force-extension curves in different probe methods is analyzed. The results can be useful for interpreting experiments on the stretching of rod-coil block-copolymers.


Assuntos
Substâncias Macromoleculares/química , Fenômenos Mecânicos , Modelos Moleculares , Fenômenos Magnéticos , Conformação Molecular , Método de Monte Carlo , Probabilidade
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