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1.
Animals (Basel) ; 13(24)2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38136814

RESUMEN

Biodiversity collections are important vehicles for protecting endangered wildlife in situations of adverse anthropogenic influence. In Russia, there are currently a number of institution- and museum-based biological collections, but there are no nation-wide centres of biodiversity collections. In this paper, we report on the results of our survey of 324 bioconservation, big-data, and ecology specialists from different regions of Russia in regard to the necessity to create several large national biodiversity centres of wildlife protection. The survey revealed specific goals that have to be fulfilled during the development of these centres for the protection and restoration of endangered wildlife species. The top three problems/tasks (topics) are the following: (1) the necessity to create large national centres for different types of specimens; (2) the full sequencing and creation of different "omic" (genomic, proteomic, transcriptomic, etc.) databases; (3) full digitisation of a biodiversity collection/centre. These goals may constitute a guideline for the future of biodiversity collections in Russia that would be targeted at protecting and restoring endangered species. With the due network service level, the translation of the website into English, and permission from the regulator (Ministry of Science and Higher Education of Russian Federation), it can also become an international project.

2.
Artículo en Inglés | MEDLINE | ID: mdl-36498366

RESUMEN

Few analytical or research works claim that the negative impact of improper use of ASEs may be comparable with that of hydrocarbons and sometimes even greater. It has become a common view that "green" energy (ASE) is clean, safe and environmentally friendly (eco-friendly) in contrast with "black" energy (hydrocarbons). We analyzed 144 works on systemic and/or comparative research of the modern and prospective ASE: biofuels, hydrogen, hydropower, nuclear power, wind power, solar power, geothermal power, oceanic thermal power, tidal power, wind wave power and nuclear fusion power. We performed our analysis within the Spaceship Earth paradigm. We conclude that there is no perfect ASE that is always eco-friendly. All ASEs may be dangerous to the planet considered as a closed and isolated unit ("spaceship") if they are used in an inconsistent manner. This is not in the least a reason to deny them as prospective sources of energy. Using all ASEs in different proportions in various regions of the planet, where their harm to the planet and humanity can be minimized and, on the contrary, their efficiency maximized, would give humanity the opportunity to decarbonize the Earth, and make the energy transition in the most effective way.


Asunto(s)
Energía Solar , Viento , Estudios Prospectivos , Fuentes Generadoras de Energía , Biocombustibles
3.
Artículo en Inglés | MEDLINE | ID: mdl-36554799

RESUMEN

This review paper discusses the Stockholm Paradigm (SP) as a theoretical framework and practical computational instrument for studying and assessing the risk of emerging infectious diseases (EIDs) as a result of climate change. The SP resolves the long-standing parasite paradox and explains how carbon emissions in the atmosphere increase parasites' generalization and intensify host switches from animals to humans. The SP argues that the growing rate of novel EID occurrence caused by mutated zoonotic pathogens is related to the following factors brought together as a unified issue of humanity: (a) carbon emissions and consequent climate change; (b) resettlement/migration of people with hyper-urbanization; (c) overpopulation; and (d) human-induced distortion of the biosphere. The SP demonstrates that, in an evolutionary way, humans now play a role migratory birds once played in spreading parasite pathogens between the three Earth megabiotopes (northern coniferous forest belt; tropical/equatorial rainforest areas; and hot/cold deserts), i.e., the role of "super-spreaders" of parasitic viruses, bacteria, fungi and protozoa. This makes humans extremely vulnerable to the EID threat. The SP sees the +1.0-+1.2 °C limit as the optimal target for the slow, yet feasible curbing of the EID hazard to public health (150-200 years). Reaching merely the +2.0 °C level will obviously be an EID catastrophe, as it may cause two or three pandemics each year. We think it useful and advisable to include the SP-based research in the scientific repository of the Intergovernmental Panel on Climate Change, since EID appearance and spread are indirect but extremely dangerous consequences of climate change.


Asunto(s)
Dióxido de Carbono , Carbono , Animales , Humanos , Efecto Invernadero , Cambio Climático
5.
Artículo en Inglés | MEDLINE | ID: mdl-35329076

RESUMEN

The total vaccination rate remains relatively low in Russia as of March 2022 (around 55%, with around 20% in some regions). In the paper, we study the reasons for it. We communicate the results of our survey aimed at detecting reasons for the relatively low anti-SARS-CoV-2 vaccination rate in Russia (47.1% as of mid-January 2022) and suggest potential measures to increase the level of confidence in the Russian vaccination campaign. A total of 14,310 users exhibited interest to participate in the research (16.84% of the total number of invitations sent in the Russian social network VKontakte). After the sample set repair, only 5822 (40.68% of those who agreed to participate) responses were suitable for the research, and they composed the final set. The age range of the respondents was 16-51 years old (y.o.) with a mean of 29.1 ± 10.6 y.o. The proportion of the female gender in responses was 44.23%. A total of 2454 persons (42.15%) expressed their hesitant, cautious, or negative attitude towards vaccine uptake. Of the 2454 persons with cautious attitude towards vaccination, only 928 (37.82%) were concerned about the quality of the Russian vaccines. A total of 1323 individuals (53.91%) supported one or more conspiracy beliefs. A total of 5064 (86.98% of the whole set) showed cautious or negative attitude towards the planned introduction of a nationwide system of vaccination certification/verification based on QR codes. The main social factors that hinder the Russian vaccination campaign are: vexation over the lack of desire of officials to receive feedback from the general population regarding vaccination, wide support for conspiracy beliefs, and controversy over the QR code-based digital system. To elevate the vaccination rate in Russia, the following steps may be taken: social encouragement of those who support vaccination, increase in transparency of the vaccination campaign, acceptance of both digital and paper vaccination certificates, increase in participation of society in vaccination-related discussions, public disclosure of vaccine composition, and avoidance of excessive digitalization of data in the vaccination campaign.


Asunto(s)
COVID-19 , Vacunas , Adolescente , Adulto , COVID-19/prevención & control , Femenino , Humanos , Programas de Inmunización , Persona de Mediana Edad , Política Pública , Vacunación , Adulto Joven
6.
Cancers (Basel) ; 13(5)2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33807574

RESUMEN

A special problem in the surgery of rectal cancer is connected with a need for appropriate removal of intestine parts, along with the tumor, including the fragment close to the sphincter. To determine the length of fragments to remove, it is necessary to reveal areas without changes in molecule functioning, specific for tumor. The purpose of the present study was to investigate functioning the proteasomes, the main actors in protein hydrolysis, in patient rectal adenocarcinoma and different intestine locations. Chymotrypsin-like and caspase-like activities, open to complex influence of different factors, were analyzed in 43-54 samples by Suc-LLVY-AMC- and Z-LLE-AMC-hydrolysis correspondingly. Both activities may be arranged by the decrease in the location row: cancer→adjacent tissue→proximal (8-20 cm from tumor) and distal (2 and 4 cm from tumor) sides. These activities did not differ noticeably in proximal and distal locations. Similar patterns were detected for the activities and expression of immune subunits LMP2 and LMP7 and expression of 19S and PA28αß activators. The largest changes in tumor were related to proteasome subtype containing LMP2 and PA28αß that was demonstrated by native electrophoresis. Thus, the results indicate a significance of subtype LMP2-PA28αß for tumor and absence of changes in proteasome pool in distal fragments of 2-4 cm from tumor.

7.
Biomolecules ; 10(4)2020 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-32224970

RESUMEN

This review provides information on the structure of estrogen receptors (ERs), their localization and functions in mammalian cells. Additionally, the structure of proteasomes and mechanisms of protein ubiquitination and cleavage are described. According to the modern concept, the ubiquitin proteasome system (UPS) is involved in the regulation of the activity of ERs in several ways. First, UPS performs the ubiquitination of ERs with a change in their functional activity. Second, UPS degrades ERs and their transcriptional regulators. Third, UPS affects the expression of ER genes. In addition, the opportunity of the regulation of proteasome functioning by ERs-in particular, the expression of immune proteasomes-is discussed. Understanding the complex mechanisms underlying the regulation of ERs and proteasomes has great prospects for the development of new therapeutic agents that can make a significant contribution to the treatment of diseases associated with the impaired function of these biomolecules.


Asunto(s)
Complejo de la Endopetidasa Proteasomal/metabolismo , Receptores de Estrógenos/metabolismo , Ubiquitina/metabolismo , Animales , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/metabolismo , Regulación de la Expresión Génica , Humanos , Complejo de la Endopetidasa Proteasomal/química , Receptores de Estrógenos/genética , Complejos de Ubiquitina-Proteína Ligasa/metabolismo
8.
mBio ; 10(1)2019 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-30808702

RESUMEN

The HIV-1 accessory protein Vif, which counteracts the antiviral action of the DNA-editing cytidine deaminase APOBEC3G (A3G), is an attractive and yet unexploited therapeutic target. Vif reduces the virion incorporation of A3G by targeting the restriction factor for proteasomal degradation in the virus-producing cell. Compounds that inhibit Vif-mediated degradation of A3G in cells targeted by HIV-1 would represent a novel antiviral therapeutic. We previously described small molecules with activity consistent with Vif antagonism. In this study, we derived inhibitor escape HIV-1 variants to characterize the mechanism by which these novel agents inhibit virus replication. Here we show that resistance to these agents is dependent on an amino acid substitution in Vif (V142I) and on a point mutation that likely upregulates transcription by modifying the lymphocyte enhancing factor 1 (LEF-1) binding site. Molecular modeling demonstrated a docking site in the Vif-Elongin C complex that is disrupted by these inhibitors. This docking site is lost when Vif acquires the V142I mutation that leads to inhibitor resistance. Competitive fitness experiments indicated that the V142I Vif and LEF-1 binding site mutations created a virus that is better adapted to growing in the presence of A3G than the wild-type virus.IMPORTANCE Although antiretroviral therapy can suppress HIV-1 replication effectively, virus reservoirs persist in infected individuals and virus replication rapidly rebounds if therapy is interrupted. Currently, there is a need for therapeutic approaches that eliminate, reduce, or control persistent viral reservoirs if a cure is to be realized. This work focuses on the preclinical development of novel, small-molecule inhibitors of the HIV-1 Vif protein. Vif inhibitors represent a new class of antiretroviral drugs that may expand treatment options to more effectively suppress virus replication or to drive HIV-1 reservoirs to a nonfunctional state by harnessing the activity of the DNA-editing cytidine deaminase A3G, a potent, intrinsic restriction factor expressed in macrophage and CD4+ T cells. In this study, we derived inhibitor escape variants to characterize the mechanism by which these novel agents inhibit virus replication and to provide evidence for target validation.


Asunto(s)
Antivirales/farmacología , Farmacorresistencia Viral , VIH-1/efectos de los fármacos , Mutación Missense , Replicación Viral/efectos de los fármacos , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/antagonistas & inhibidores , Desaminasa APOBEC-3G/metabolismo , Sustitución de Aminoácidos , Sitios de Unión , Línea Celular , VIH-1/genética , Humanos , Factor de Unión 1 al Potenciador Linfoide/metabolismo , Simulación del Acoplamiento Molecular , Mutación Puntual , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/química , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/genética
9.
Cancers (Basel) ; 10(10)2018 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-30257462

RESUMEN

Tumor growth is associated with elevated proteasome expression and activity. This makes proteasomes a promising target for antitumor drugs. Current antitumor drugs such as bortezomib that inhibit proteasome activity have significant side effects. The purpose of the present study was to develop effective low-toxic antitumor compositions with combined effects on proteasomes. For compositions, we used bortezomib in amounts four and ten times lower than its clinical dose, and chose menadione sodium bisulfite (MSB) as the second component. MSB is known to promote oxidation of NADH, generate superoxide radicals, and as a result damage proteasome function in cells that ensure the relevance of MSB use for the composition development. The proteasome pool was investigated by the original native gel electrophoresis method, proteasome chymotrypsin-like activity-by Suc-LLVY-AMC-hydrolysis. For the compositions, we detected 10 and 20 µM MSB doses showing stronger proteasome-suppressing and cytotoxic in cellulo effects on malignant cells than on normal ones. MSB indirectly suppressed 26S-proteasome activity in cellulo, but not in vitro. At the same time, MSB together with bortezomib displayed synergetic action on the activity of all proteasome forms in vitro as well as synergetic antitumor effects in cellulo. These findings determine the properties of the developed compositions in vivo: antitumor efficiency, higher (against hepatocellular carcinoma and mammary adenocarcinoma) or comparable to bortezomib (against Lewis lung carcinoma), and drastically reduced toxicity (LD50) relative to bortezomib. Thus, the developed compositions represent a novel generation of bortezomib-based anticancer drugs combining high efficiency, low general toxicity, and a potentially expanded range of target tumors.

10.
Oncotarget ; 8(41): 70941-70957, 2017 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-29050334

RESUMEN

The aim of this work was to detect changes in proteasome pools of brain parts of August rats with monoamine metabolism violations in comparison with that of control Wistar rats. To reveal active proteasome structures, a method of native electrophoresis for the analysis of crude tissue fractions was developed. By means of this method and following Western blotting, the most pronounced changes in reorganization of proteasome structures were detected in proteasome pool of the brain cortex of August rats. Main findings are the enhanced expression of immune proteasome subtypes containing proteolytic subunit LMP2 and activator PA28αß as well as immune proteasome subtypes containing proteolytic subunit LMP7 and activator PA700 and simultaneously decreased expression of subtypes with subunit LMP2 and activator PA700 in the brain cortex of August rats compared to that of Wistar rats. These results were indirectly confirmed by SDS PAGE method followed by Western blotting, which showed the increased quantities of immune subunits and proteasome activators in the brain cortex of August rats compared to that of Wistar rats. Immune proteasomes were revealed by immunohistochemistry in neurons, but not in glial cells of August and Wistar rat cortex. The detected reorganization of proteasome pools is likely to be important for production of special peptides to provide the steady interaction between neurons and adaptation of central nervous system to conditions caused by monoamine metabolism deviations.

11.
J Med Chem ; 59(16): 7677-82, 2016 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-27509004

RESUMEN

RN-18 based viral infectivity factor (Vif), Vif antagonists reduce viral infectivity by rescuing APOBEC3G (A3G) expression and enhancing A3G-dependent Vif degradation. Replacement of amide functionality in RN-18 (IC50 = 6 µM) by isosteric heterocycles resulted in the discovery of a 1,2,3-trizole, 1d (IC50 = 1.2 µM). We identified several potent HIV-1 inhibitors from a 1d based library including 5ax (IC50 = 0.01 µM), 5bx (0.2 µM), 2ey (0.4 µM), 5ey (0.6 µM), and 6bx (0.2 µM).


Asunto(s)
Fármacos Anti-VIH/farmacología , Descubrimiento de Drogas , VIH-1/efectos de los fármacos , Triazoles/farmacología , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/antagonistas & inhibidores , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/química , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Relación Estructura-Actividad , Triazoles/síntesis química , Triazoles/química
12.
J Alzheimers Dis ; 54(2): 763-76, 2016 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-27567864

RESUMEN

Accumulation of amyloid-ß (Aß) in neurons accompanies Alzheimer's disease progression. In the cytoplasm Aß influences activity of proteasomes, the multisubunit protein complexes that hydrolyze the majority of intracellular proteins. However, the manner in which Aß affects the proteolytic activity of proteasomes has not been established. In this study the effect of Aß42 and Aß42 with isomerized Asp7 on activity of different forms of proteasomes has been analyzed. It has been shown that Aß peptides efficiently reduce activity of the 20S proteasomes, but increase activity of the 20S proteasomes capped with the 19S and/or 11S regulators. Modulation of proteasome activity is mainly determined by the C-terminal segment of Aß (amino acids 17-42). This study demonstrated an important role of proteasome regulators in the interplay between Aß and the proteasomes.


Asunto(s)
Péptidos beta-Amiloides/farmacología , Fragmentos de Péptidos/farmacología , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Secuencia de Aminoácidos , Línea Celular Tumoral , Activación Enzimática/efectos de los fármacos , Activación Enzimática/fisiología , Humanos , Complejo de la Endopetidasa Proteasomal/química
13.
FASEB J ; 30(3): 1234-46, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26601824

RESUMEN

HIV invades the brain early after infection; however, its interactions with the cells of the blood-brain barrier (BBB) remain poorly understood. Our goal was to evaluate the role of occludin, one of the tight junction proteins that regulate BBB functions in HIV infection of BBB pericytes. We provide evidence that occludin levels largely control the metabolic responses of human pericytes to HIV. Occludin in BBB pericytes decreased by 10% during the first 48 h after HIV infection, correlating with increased nuclear translocation of the gene repressor C-terminal-binding protein (CtBP)-1 and NFκB-p65 activation. These changes were associated with decreased expression and activation of the class III histone deacetylase sirtuin (SIRT)-1. Occludin levels recovered 96 h after infection, restoring SIRT-1 and reducing HIV transcription to 20% of its highest values. We characterized occludin biochemically as a novel NADH oxidase that controls the expression and activation of SIRT-1. The inverse correlation between occludin and HIV transcription was then replicated in human primary macrophages and differentiated monocytic U937 cells, in which occludin silencing resulted in 75 and 250% increased viral transcription, respectively. Our work shows that occludin has previously unsuspected metabolic properties and is a target of HIV infection, opening the possibility of designing novel pharmacological approaches to control HIV transcription.


Asunto(s)
Barrera Hematoencefálica/virología , Infecciones por VIH/virología , VIH/genética , Ocludina/metabolismo , Oxidorreductasas de Alcohol/metabolismo , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Encéfalo/virología , Células Cultivadas , Proteínas de Unión al ADN/metabolismo , VIH/metabolismo , Infecciones por VIH/metabolismo , Humanos , FN-kappa B/metabolismo , Pericitos/metabolismo , Pericitos/virología , Sirtuina 1/metabolismo , Uniones Estrechas/metabolismo , Uniones Estrechas/virología , Transcripción Genética/genética
14.
FASEB J ; 29(5): 1901-13, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25634956

RESUMEN

Recent findings indicate that the ubiquitin-proteasome system is involved in the pathogenesis of cancer as well as autoimmune and several neurodegenerative diseases, and is thus a target for novel therapeutics. One disease that is related to aberrant protein degradation is multiple sclerosis, an autoimmune disorder involving the processing and presentation of myelin autoantigens that leads to the destruction of axons. Here, we show that brain-derived proteasomes from SJL mice with experimental autoimmune encephalomyelitis (EAE) in an ubiquitin-independent manner generate significantly increased amounts of myelin basic protein peptides that induces cytotoxic lymphocytes to target mature oligodendrocytes ex vivo. Ten times enhanced release of immunogenic peptides by cerebral proteasomes from EAE-SJL mice is caused by a dramatic shift in the balance between constitutive and ß1i(high) immunoproteasomes in the CNS of SJL mice with EAE. We found that during EAE, ß1i is increased in resident CNS cells, whereas ß5i is imported by infiltrating lymphocytes through the blood-brain barrier. Peptidyl epoxyketone specifically inhibits brain-derived ß1i(high) immunoproteasomes in vitro (kobs/[I] = 240 M(-1)s(-1)), and at a dose of 0.5 mg/kg, it ameliorates ongoing EAE in vivo. Therefore, our findings provide novel insights into myelin metabolism in pathophysiologic conditions and reveal that the ß1i subunit of the immunoproteasome is a potential target to treat autoimmune neurologic diseases.


Asunto(s)
Autoinmunidad/inmunología , Barrera Hematoencefálica/metabolismo , Encéfalo/inmunología , Encefalomielitis Autoinmune Experimental/inmunología , Activación de Linfocitos/inmunología , Proteína Básica de Mielina/metabolismo , Complejo de la Endopetidasa Proteasomal/inmunología , Animales , Western Blotting , Encéfalo/metabolismo , Encéfalo/patología , Células Cultivadas , Cromatografía Liquida , Encefalomielitis Autoinmune Experimental/metabolismo , Encefalomielitis Autoinmune Experimental/patología , Femenino , Técnicas para Inmunoenzimas , Ratones , Ratones Endogámicos BALB C , Proteína Básica de Mielina/inmunología , Vaina de Mielina/metabolismo , Subunidades de Proteína , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectrometría de Masas en Tándem , Ubiquitina/metabolismo
15.
PLoS One ; 9(10): e109933, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25329802

RESUMEN

Breast cancer is one of four oncology diseases that are most widespread in the world. Moreover, breast cancer is one of leading causes of cancer-related deaths in female population within economically developed regions of the world. So far, detection of new mechanisms of breast cancer development is very important for discovery of novel areas in which therapy approaches may be elaborated. The objective of the present study is to investigate involvement of proteasomes, which cleave up to 90% of cellular proteins and regulate numerous cellular processes, in mechanisms of breast cancer development. Proteasome characteristics in 106 patient breast carcinomas and adjacent tissues, as well as relationships of detected proteasome parameters with clinical-pathological factors, were investigated. Proteasome chymotrypsin-like activity was evaluated by hydrolysis of fluorogenic peptide Suc-LLVY-AMC. The expression of proteasome subunits was studied by Western-blotting and immunohistochemistry. The wide range of chymotrypsin-like activity in tumors was detected. Activity in tumors was higher if compared to adjacent tissues in 76 from 106 patients. Multiple analysis of generalized linear models discovered that in estrogen α-receptor absence, tumor growth was connected with the enhanced expression of proteasome immune subunit LMP2 and proteasome activator PA700 in tumor (at 95% confidence interval). Besides, by this analysis we detected some phenomena in adjacent tissue, which are important for tumor growth and progression of lymph node metastasis in estrogen α-receptor absence. These phenomena are related to the enhanced expression of activator PA700 and immune subunit LMP7. Thus, breast cancer development is connected with functioning of immune proteasome forms and activator PA700 in patients without estrogen α-receptors in tumor cells. These results could indicate a field for search of new therapy approaches for this category of patients, which has the worst prognosis of health recovery.


Asunto(s)
Neoplasias de la Mama/enzimología , Carcinoma/enzimología , Cisteína Endopeptidasas/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Carcinoma/patología , Receptor alfa de Estrógeno/metabolismo , Femenino , Humanos , Persona de Mediana Edad
16.
mBio ; 4(2): e000193, 2013 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-23592263

RESUMEN

UNLABELLED: The question of how HIV-1 interfaces with cellular microRNA (miRNA) biogenesis and effector mechanisms has been highly controversial. Here, we first used deep sequencing of small RNAs present in two different infected cell lines (TZM-bl and C8166) and two types of primary human cells (CD4(+) peripheral blood mononuclear cells [PBMCs] and macrophages) to unequivocally demonstrate that HIV-1 does not encode any viral miRNAs. Perhaps surprisingly, we also observed that infection of T cells by HIV-1 has only a modest effect on the expression of cellular miRNAs at early times after infection. Comprehensive analysis of miRNA binding to the HIV-1 genome using the photoactivatable ribonucleoside-induced cross-linking and immunoprecipitation (PAR-CLIP) technique revealed several binding sites for cellular miRNAs, a subset of which were shown to be capable of mediating miRNA-mediated repression of gene expression. However, the main finding from this analysis is that HIV-1 transcripts are largely refractory to miRNA binding, most probably due to extensive viral RNA secondary structure. Together, these data demonstrate that HIV-1 neither encodes viral miRNAs nor strongly influences cellular miRNA expression, at least early after infection, and imply that HIV-1 transcripts have evolved to avoid inhibition by preexisting cellular miRNAs by adopting extensive RNA secondary structures that occlude most potential miRNA binding sites. IMPORTANCE: MicroRNAs (miRNAs) are a ubiquitous class of small regulatory RNAs that serve as posttranscriptional regulators of gene expression. Previous work has suggested that HIV-1 might subvert the function of the cellular miRNA machinery by expressing viral miRNAs or by dramatically altering the level of cellular miRNA expression. Using very sensitive approaches, we now demonstrate that neither of these ideas is in fact correct. Moreover, HIV-1 transcripts appear to largely avoid regulation by cellular miRNAs by adopting an extensive RNA secondary structure that occludes the ability of cellular miRNAs to interact with viral mRNAs. Together, these data suggest that HIV-1, rather than seeking to control miRNA function in infected cells, has instead evolved a mechanism to become largely invisible to cellular miRNA effector mechanisms.


Asunto(s)
VIH-1/fisiología , Interacciones Huésped-Patógeno , MicroARNs/metabolismo , ARN Viral/metabolismo , Linfocitos T CD4-Positivos/virología , Células Cultivadas , Regulación Viral de la Expresión Génica , VIH-1/patogenicidad , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Macrófagos/virología , MicroARNs/química , MicroARNs/genética , ARN Mensajero/metabolismo
17.
ChemMedChem ; 7(7): 1217-29, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22555953

RESUMEN

The human immunodeficiency virus 1 (HIV-1) virion infectivity factor (Vif) protein, essential for in vivo viral replication, protects the virus from innate antiviral cellular factor apolipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3G (APOBEC3G; A3G) and is an attractive target for the development of novel antiviral therapeutics. We have evaluated the structure-activity relationships of N-(2-methoxyphenyl)-2-((4-nitrophenyl)thio)benzamide (RN-18), a small molecule recently identified as an inhibitor of Vif function that blocks viral replication only in nonpermissive cells expressing A3G, by inhibiting Vif-A3G interactions. Microwave-assisted cross-coupling reactions were developed to prepare a series of RN18 analogues with diverse linkages and substitutions on the phenyl rings. A dual cell-based assay system was used to assess antiviral activity against wild-type HIV-1 in both nonpermissive (H9) and permissive (MT4) cells that also allowed evaluation of specificity. In general, variations of phenyl substitutions were detrimental to antiviral potency and specificity, but isosteric replacements of amide and ether linkages were relatively well tolerated. These structure-activity relationship data define structural requirements for Vif-specific activity, identify new compounds with improved antiviral potency and specificity, and provide leads for further exploration to develop new antiviral therapeutics.


Asunto(s)
Fármacos Anti-VIH/farmacología , VIH-1/efectos de los fármacos , VIH-1/crecimiento & desarrollo , Replicación Viral/efectos de los fármacos , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/antagonistas & inhibidores , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/química , Línea Celular , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Células HeLa , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Estereoisomerismo , Relación Estructura-Actividad , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/metabolismo
18.
ACS Med Chem Lett ; 3(6): 465-469, 2012 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-24533175

RESUMEN

We describe structure-activity relationship and optimization studies of RN-18, an HIV-1 Vif-APOBEC3G axis inhibitor. Targeted modifications of RN-18 ring-C, ring-B, ring-A, bridge A-B, and bridge B-C were performed to identify the crucial structural features, which generated new inhibitors with similar (4g and 4i) and improved (5, 8b, and 11) activities. Two potent water-soluble RN-18 analogues, 17 and 19, are also disclosed, and we describe the results of pharmacological studies with compound 19. The findings described here will be useful in the development of more potent Vif inhibitors and in the design of probes to identify the target protein of RN-18 and its analogues.

19.
Cell Immunol ; 271(2): 385-91, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21889127

RESUMEN

Dynamics of the expression of MHC class I, immune proteasomes and proteasome regulators 19S, PA28, total proteasome pool and proteasome chymotrypsin-like activity in Walker 256 tumor after implantation into Brattleboro rats with the hereditary defect of arginine-vasopressin synthesis was studied. The tumor growth and regression in Brattleboro rats were accompanied by changes in the proteasome subunit level unlike the tumor growth in WAG rats with normal expression of arginine-vasopressin gene. In the tumor implanted into Brattleboro rats the immune proteasome level was maximal between days 14 and 17, when the tumor underwent regression. Conversely, the expression of proteasome regulators tended to decrease during this period. Immune proteasomes are known to produce antigen epitopes for MHC class I to be presented to CD8+ T lymphocytes. Enhanced expression of immune proteasomes coincided with the recovery of MHC class I expression, suggesting the efficient presentation of tumor antigens in Brattleboro rats.


Asunto(s)
Arginina Vasopresina/genética , Carcinoma 256 de Walker/genética , Carcinoma 256 de Walker/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Complejo de la Endopetidasa Proteasomal/inmunología , Animales , Presentación de Antígeno , Antígenos de Neoplasias/metabolismo , Arginina Vasopresina/biosíntesis , Carcinoma 256 de Walker/metabolismo , Carcinoma 256 de Walker/patología , Quimotripsina/inmunología , Quimotripsina/metabolismo , Cisteína Endopeptidasas/inmunología , Cisteína Endopeptidasas/metabolismo , Masculino , Regresión Neoplásica Espontánea/genética , Regresión Neoplásica Espontánea/inmunología , Trasplante de Neoplasias , Complejo de la Endopetidasa Proteasomal/metabolismo , Ratas , Ratas Brattleboro
20.
Cell Immunol ; 266(1): 83-9, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20888554

RESUMEN

Immune proteasomes in thymus are involved in processing of self-antigens, which are presented by MHC class I molecules for rejection of autoreactive thymocytes in adults and probably in perinatal rats. The distribution of immune proteasome subunits LMP7 and LMP2 in thymic cells have been investigated during rat perinatal ontogenesis. Double immunofluorescent labeling revealed LMP7 and LMP2 in thymic epithelial and dendritic cells, as well as in CD68 positive cells - macrophages, monocytes - at all developmental stages. LMP2 and LMP7 were also detected by flow cytometry in almost all thymic CD90 lymphocytes through pre- and postnatal ontogenesis. Our results demonstrate that the immune proteasomes are expressed in all types of thymic antigen presenting cells during perinatal ontogenesis, suggesting the establishment of the negative selection in the thymus at the end of fetal life. The observation of the immune proteasome expression in T lymphocytes suggests their role in thymocyte differentiation besides antigen processing in thymus.


Asunto(s)
Sistema Inmunológico/embriología , Sistema Inmunológico/crecimiento & desarrollo , Complejo de la Endopetidasa Proteasomal/metabolismo , Timo/enzimología , Timo/crecimiento & desarrollo , Animales , Animales Recién Nacidos , Células Presentadoras de Antígenos/citología , Células Presentadoras de Antígenos/metabolismo , Antígenos CD/metabolismo , Antígenos de Diferenciación/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Cisteína Endopeptidasas/metabolismo , Células Dendríticas/citología , Células Dendríticas/metabolismo , Células Epiteliales/citología , Células Epiteliales/metabolismo , Queratina-18/metabolismo , Queratina-19/metabolismo , Complejo de la Endopetidasa Proteasomal/inmunología , Subunidades de Proteína/metabolismo , Proteínas/metabolismo , Ratas , Ratas Wistar , Linfocitos T/citología , Linfocitos T/metabolismo , Antígenos Thy-1/metabolismo , Timo/citología , Timo/embriología
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