Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Trends Cell Biol ; 30(5): 354-369, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32302548

RESUMO

Apoptosis is a form of programmed cell death, deregulation of which occurs in multiple disorders, including neurodegenerative and autoimmune diseases as well as cancer. The formation of a death-inducing signaling complex (DISC) and death effector domain (DED) filaments are critical for initiation of the extrinsic apoptotic pathway. Post-translational modifications (PTMs) of DED-containing DISC components such as FADD, procaspase-8, and c-FLIP comprise an additional level of apoptosis regulation, which is necessary to overcome the threshold for apoptosis induction. In this review we discuss the influence of PTMs of FADD, procaspase-8, and c-FLIP on DED filament assembly and cell death induction, with a focus on the 3D organization of the DED filament.

2.
Cell Death Differ ; 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31959913

RESUMO

Pharmacological targeting via small molecule-based chemical probes has recently acquired an emerging importance as a valuable tool to delineate molecular mechanisms. Induction of apoptosis via CD95/Fas and TRAIL-R1/2 is triggered by the formation of the death-inducing signaling complex (DISC). Caspase-8 activation at the DISC is largely controlled by c-FLIP proteins. However molecular mechanisms of this control have just started to be uncovered. In this study we report the first-in-class chemical probe targeting c-FLIPL in the heterodimer caspase-8/c-FLIPL. This rationally designed small molecule was aimed to imitate the closed conformation of the caspase-8 L2' loop and thereby increase caspase-8 activity after initial processing of the heterodimer. In accordance with in silico predictions, this small molecule enhanced caspase-8 activity at the DISC, CD95L/TRAIL-induced caspase activation, and subsequent apoptosis. The generated computational model provided further evidence for the proposed effects of the small molecule on the heterodimer caspase-8/c-FLIPL. In particular, the model has demonstrated that boosting caspase-8 activity by the small molecule at the early time points after DISC assembly is crucial for promoting apoptosis induction. Taken together, our study allowed to target the heterodimer caspase-8/c-FLIPL and get new insights into molecular mechanisms of its activation.

3.
Oncogene ; 39(8): 1756-1772, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31740779

RESUMO

The assembly of the death-inducing signaling complex (DISC) and death effector domain (DED) filaments at CD95/Fas initiates extrinsic apoptosis. Procaspase-8 activation at the DED filaments is controlled by short and long c-FLIP isoforms. Despite apparent progress in understanding the assembly of CD95-activated platforms and DED filaments, the detailed molecular mechanism of c-FLIP action remains elusive. Here, we further addressed the mechanisms of c-FLIP action at the DISC using biochemical assays, quantitative mass spectrometry, and structural modeling. Our data strongly indicate that c-FLIP can bind to both FADD and procaspase-8 at the DED filament. Moreover, the constructed in silico model shows that c-FLIP proteins can lead to the formation of the DISCs comprising short DED filaments as well as serve as bridging motifs for building a cooperative DISC network, in which adjacent CD95 DISCs are connected by DED filaments. This network is based on selective interactions of FADD with both c-FLIP and procaspase-8. Hence, c-FLIP proteins at the DISC control initiation, elongation, and composition of DED filaments, playing the role of control checkpoints. These findings provide new insights into DISC and DED filament regulation and open innovative possibilities for targeting the extrinsic apoptosis pathway.

4.
BMC Genomics ; 20(Suppl 3): 293, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-31815628

RESUMO

BACKGROUND: Structural homology modeling supported by bioinformatics analysis plays a key role in uncovering new molecular interactions within gene regulatory networks. Here, we have applied this powerful approach to analyze the molecular interactions orchestrating death receptor signaling networks. In particular, we focused on the molecular mechanisms of CD95-mediated NF-κB activation and the role of c-FLIP/NEMO interaction in the induction of this pathway. RESULTS: To this end, we have created the homology model of the c-FLIP/NEMO complex using the reported structure of the v-FLIP/NEMO complex, and rationally designed peptides targeting this complex. The designed peptides were based on the NEMO structure. Strikingly, the experimental in vitro validation demonstrated that the best inhibitory effects on CD95-mediated NF-κB activation are exhibited by the NEMO-derived peptides with the substitution D242Y of NEMO. Furthermore, we have assumed that the c-FLIP/NEMO complex is recruited to the DED filaments formed upon CD95 activation and validated this assumption in silico. Further insight into the function of c-FLIP/NEMO complex was provided by the analysis of evolutionary conservation of interacting regions which demonstrated that this interaction is common in distinct mammalian species. CONCLUSIONS: Taken together, using a combination of bioinformatics and experimental approaches we obtained new insights into CD95-mediated NF-κB activation, providing manifold possibilities for targeting the death receptor network.


Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Quinase I-kappa B/metabolismo , Sondas Moleculares , NF-kappa B/metabolismo , Receptor fas/metabolismo , Sequência de Aminoácidos , Biologia Computacional , Humanos , Domínios e Motivos de Interação entre Proteínas , Estrutura Quaternária de Proteína , Alinhamento de Sequência , Transdução de Sinais
5.
Biomed Res Int ; 2019: 4087160, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31317028

RESUMO

Autophagy is a degradative process in which cellular organelles and proteins are recycled to restore homeostasis and cellular metabolism. Autophagy can be either a prosurvival or a prodeath process and remains one of the most fundamental processes for cell vitality. Thus autophagy modulation is an important approach for reinforcement anticancer therapeutics. Earlier we have demonstrated that recombinant analog of human milk protein lactaptin (RL2) induced apoptosis of various cultured cancer cells and activated lipidation of microtubule-associated protein 1 light chain 3 (LC3). In this study we investigated whether autophagy inhibitors-chloroquine (CQ), Ku55933 (Ku), and 3-methyladenine (3MA)-or inducer-rapamycin (Rap)-can enhance cytotoxic activity of lactaptin analog in cancer cells and its anticancer activity in the mice model. Western Blot analysis revealed that RL2 induced short-term autophagy in MDA-MB-231 and MCF-7 cells at early stages of incubation and that these data were confirmed by the transmission electron microscopy of autophagosome/autophagolysosome formation. RL2 stimulates reactive oxygen species (ROS) production, autophagosomes accumulation, upregulation of ATG5 with processing of LC3I to LC3II, and downregulation of p62/sequestosome 1 (p62). We have shown that autophagy modulators, CQ, Ku, and Rap, synergistically increased cytotoxicity of RL2, and RL2 with CQ induced autophagic cell death. In addition, CQ, Ku, and Rap in combination with RL2 decreased activity of lysosomal protease Cathepsin D. More importantly, combining RL2 with CQ, we improved antitumor effect in mice. Detected synergistic cytotoxic effects of both types of autophagy regulators, inhibitors, and inducers with RL2 against cancer cells allow us to believe that these combinations can be a basis for the new anticancer approach. Finally, we suppose that CQ and Rap promoting of short-term RL2-induced autophagy interlinks with final autophagic cell death.


Assuntos
Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Caseínas/farmacologia , Neoplasias/tratamento farmacológico , Adenina/análogos & derivados , Adenina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Autofagia/genética , Caseínas/genética , Catepsina D/genética , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cloroquina/farmacologia , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/genética , Células MCF-7 , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Morfolinas/farmacologia , Neoplasias/genética , Pironas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Proteína Sequestossoma-1/genética
6.
Apoptosis ; 24(5-6): 385-394, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31069559

RESUMO

CD95 is a member of the death receptor family and is well-known to promote apoptosis. However, accumulating evidence indicates that in some context CD95 has not only the potential to induce apoptosis but also can trigger non-apoptotic signal leading to cell survival, proliferation, cancer growth and metastasis. Despite extensive investigations focused on alterations in the expression level of CD95 and associated signal molecules, very few studies, however, have investigated the effects of post-translational modifications such as glycosylation, phosphorylation, palmitoylation, nitrosylation and glutathionylation on CD95 function. Post-translational modifications of CD95 in mammalian systems are likely to play a more prominent role than anticipated in CD95 induced cell death. In this review we will focus on the alterations in CD95-mediated signaling caused by post-translational modifications of CD95.

7.
Cell Death Differ ; 26(6): 981-993, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30903104

RESUMO

Glycosylation and glycan-binding proteins such as galectins play an important role in the control of cell death signaling. Strikingly, very little attention has been given so far to the understanding of the molecular details behind this key regulatory network. Glycans attached to the death receptors such as CD95 and TRAIL-Rs, either alone or in a complex with galectins, might promote or inhibit apoptotic signals. However, we have just started to decode the functions of galectins in the modulation of extrinsic and intrinsic apoptosis. In this work, we have discussed the current understanding of the glycosylation-galectin regulatory network in CD95- as well as TRAIL-R-induced apoptosis and therapeutic strategies based on targeting galectins in cancer.

8.
BMC Med Genomics ; 12(Suppl 2): 47, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30871556

RESUMO

BACKGROUND: Currently, more than 150 million people worldwide suffer from lymphedema. It is a chronic progressive disease characterized by high-protein edema of various parts of the body due to defects in lymphatic drainage. Molecular-genetic mechanisms of the disease are still poorly understood. Beginning of a clinical manifestation of primary lymphedema in middle age and the development of secondary lymphedema after treatment of breast cancer can be genetically determined. Disruption of endothelial cell apoptosis can be considered as one of the factors contributing to the development of lymphedema. However, a study of the relationship between genes associated with lymphedema and genes involved in endothelial apoptosis, in the associative gene network was not previously conducted. METHODS: In the current work, we used well-known methods (ToppGene and Endeavour), as well as methods previously developed by us, to prioritize genes involved in endothelial apoptosis and to find potential participants of molecular-genetic mechanisms of lymphedema among them. Original methods of prioritization took into account the overrepresented Gene Ontology biological processes, the centrality of vertices in the associative gene network, describing the interactions of endothelial apoptosis genes with genes associated with lymphedema, and the association of the analyzed genes with diseases that are comorbid to lymphedema. RESULTS: An assessment of the quality of prioritization was performed using criteria, which involved an analysis of the enrichment of the top-most priority genes by genes, which are known to have simultaneous interactions with lymphedema and endothelial cell apoptosis, as well as by genes differentially expressed in murine model of lymphedema. In particular, among genes involved in endothelial apoptosis, KDR, TNF, TEK, BMPR2, SERPINE1, IL10, CD40LG, CCL2, FASLG and ABL1 had the highest priority. The identified priority genes can be considered as candidates for genotyping in the studies involving the search for associations with lymphedema. CONCLUSIONS: Analysis of interactions of these genes in the associative gene network of lymphedema can improve understanding of mechanisms of interaction between endothelial apoptosis and lymphangiogenesis, and shed light on the role of disturbance of these processes in the development of edema, chronic inflammation and connective tissue transformation during the progression of the disease.

9.
Int J Cancer ; 145(6): 1558-1569, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30828789

RESUMO

Mutations of fms-like tyrosine kinase 3 (FLT3) are the most frequent mutations in acute myeloid leukemia (AML). Furthermore, the internal tandem duplication (ITD) represents the most common mutation of FLT3 in AML. To explore therapeutic strategies for AML patients carrying FLT3-ITD, we analyzed death receptor (DR) signaling networks in AML cells comprising FLT3-ITD. We have started with murine myeloid progenitor 32D cells that ectopically express human FLT3-ITD (32D- FLT3-ITD) and found that RIPK1 is strongly upregulated in these cells. Subsequently, we have shown that combinatorial treatment of 32D-FLT3-ITD cells with the SMAC mimetic BV6 and CD95L sensitizes these cells toward apoptosis and necroptosis. Moreover, combinatorial treatment with death ligands (DLs), for example, CD95L or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and BV6 enhanced cell death in primary AML blasts from patients carrying FLT3-ITD mutation. Finally, pharmacological and genetic targeting of RIPK1 inhibited DL/BV6-mediated cell death in cells with FLT3-ITD mutations. Taken together, our study suggests a promising therapeutic opportunity for AML cancer cells harboring FLT3-ITD mutation via targeting RIPK1 pathways.


Assuntos
Leucemia Mieloide Aguda/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Tirosina Quinase 3 Semelhante a fms/metabolismo , Animais , Morte Celular , Linhagem Celular Tumoral , Duplicação Gênica , Humanos , Leucemia Mieloide Aguda/patologia , Camundongos , Mutação , Regulação para Cima , Tirosina Quinase 3 Semelhante a fms/genética
10.
PLoS Comput Biol ; 14(9): e1006368, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30256782

RESUMO

CD95/Fas/APO-1 is a member of the death receptor family that triggers apoptotic and anti-apoptotic responses in particular, NF-κB. These responses are characterized by a strong heterogeneity within a population of cells. To determine how the cell decides between life and death we developed a computational model supported by imaging flow cytometry analysis of CD95 signaling. Here we show that CD95 stimulation leads to the induction of caspase and NF-κB pathways simultaneously in one cell. The related life/death decision strictly depends on cell-to-cell variability in the formation of the death-inducing complex (DISC) on one side (extrinsic noise) vs. stochastic gene expression of the NF-κB pathway on the other side (intrinsic noise). Moreover, our analysis has uncovered that the stochasticity in apoptosis and NF-kB pathways leads not only to survival or death of a cell, but also causes a third type of response to CD95 stimulation that we termed ambivalent response. Cells in the ambivalent state can undergo cell death or survive which was subsequently validated by experiments. Taken together, we have uncovered how these two competing pathways control the fate of a cell, which in turn plays an important role for development of anti-cancer therapies.


Assuntos
Análise de Célula Única/métodos , Receptor fas/fisiologia , Apoptose , Caspase 3/metabolismo , Caspases/metabolismo , Linhagem da Célula , Simulação por Computador , Citometria de Fluxo , Células HeLa , Humanos , Modelos Teóricos , NF-kappa B/metabolismo , Transdução de Sinais
11.
Sci Rep ; 8(1): 12199, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-30111833

RESUMO

The cleavage of nuclear proteins by caspases promotes nuclear breakdown and, therefore, plays a key role in apoptosis execution. However, the detailed molecular mechanisms of these events remain unclear. To get more insights into the mechanisms of nuclear events during apoptosis we set up a rapid fractionation protocol for the separation of the cytoplasmic and nuclear fractions of cells undergoing cisplatin-induced apoptosis. Importantly, nuclear accumulation of effector caspase-3 as well as initiator caspase-2, -8 and -9 was observed using the developed protocol and immunofluorescence microscopy. The detection of caspases and their cleavage products in the nucleus occurred within the same time interval after cisplatin treatment and took place shortly before nuclear fragmentation. The entry of initiator caspases to the nucleus was independent of caspase-3. Given that all three initiator caspases had catalytic activity in the nuclei, our findings indicate that initiator caspases might participate in the proteolysis of nuclear components during apoptosis, promoting its disintegration and apoptotic cell death.


Assuntos
Apoptose/fisiologia , Caspases/metabolismo , Caspases/fisiologia , Caspase 2/metabolismo , Caspase 3/metabolismo , Caspase 8/metabolismo , Fracionamento Celular/métodos , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Cisplatino/farmacologia , Cisteína Endopeptidases/metabolismo , Citoplasma/metabolismo , Fragmentação do DNA , Células HeLa , Humanos , Células MCF-7 , Proteínas Nucleares/metabolismo , Frações Subcelulares/fisiologia
12.
Int J Biochem Cell Biol ; 102: 101-108, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30025878

RESUMO

The role of caspase-2 in cell death regulation remains largely unknown. In this study we have analyzed the involvement of caspase-2 in RIPK1-regulated necrosis (necroptosis) in human ovarian carcinoma cells. We show that these cells undergo necroptosis upon treatment with the DNA damaging drug cisplatin in combination with the pan-caspase inhibitor zVAD-fmk. Downregulation of caspase-2 leads to an increase of necroptosis in CAOV-4 cells. Interestingly, an association of caspase-2 to the necrosome complex was not detected. Importantly, downregulation of caspase-2 with shRNA or CRISPR/Cas9 system led to an enhanced phosphorylation of RIPK1 and MLKL. Taken together, our data strongly indicate that caspase-2 negatively regulates necroptotic cell death, which might play an important role in further therapeutic applications.


Assuntos
Caspase 2/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Terapia de Alvo Molecular , Necrose/enzimologia , Transporte Proteico
13.
Cell Prolif ; 51(5): e12467, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29947118

RESUMO

Apoptosis is a mode of regulated cell death that is indispensable for the morphogenesis, development and homeostasis of multicellular organisms. Caspases are cysteine-dependent aspartate-specific proteases, which function as initiators and executors of apoptosis. Caspases are cytosolic proteins that can cleave substrates located in different intracellular compartments during apoptosis. Many years ago, the involvement of caspases in the regulation of nuclear changes, a hallmark of apoptosis, was documented. Accumulated data suggest that apoptosis-associated alterations in nucleocytoplasmic transport are also linked to caspase activity. Here, we aim to discuss the current state of knowledge regarding this process. Particular attention will be focused on caspase nuclear entry and their functions in the demolition of the nucleus upon apoptotic stimuli.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Apoptose/fisiologia , Caspases/metabolismo , Núcleo Celular/metabolismo , Núcleo Celular/fisiologia , Citoplasma/metabolismo , Citoplasma/fisiologia , Animais , Humanos
14.
PLoS One ; 13(5): e0197208, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29768460

RESUMO

Imaging flow cytometry is a powerful experimental technique combining the strength of microscopy and flow cytometry to enable high-throughput characterization of cell populations on a detailed microscopic scale. This approach has an increasing importance for distinguishing between different cellular phenotypes such as proliferation, cell division and cell death. In the course of undergoing these different pathways, each cell is characterized by a high amount of properties. This makes it hard to filter the most relevant information for cell state discrimination. The traditional methods for cell state discrimination rely on dye based two-dimensional gating strategies ignoring information that is hidden in the high-dimensional property space. In order to make use of the information ignored by the traditional methods, we present a simple and efficient approach to distinguish biological states within a cell population based on machine learning techniques. We demonstrate the advantages and drawbacks of filter techniques combined with different classification schemes. These techniques are illustrated with two case studies of apoptosis detection in HeLa cells. Thereby we highlight (i) the aptitude of imaging flow cytometry regarding automated, label-free cell state discrimination and (ii) pitfalls that are frequently encountered. Additionally a MATLAB script is provided, which gives further insight regarding the computational work presented in this study.


Assuntos
Apoptose , Citometria de Fluxo/métodos , Animais , Citometria de Fluxo/instrumentação , Células HeLa , Humanos
15.
BMC Med Genomics ; 11(Suppl 1): 15, 2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29504915

RESUMO

BACKGROUND: Hypertension and bronchial asthma are a major issue for people's health. As of 2014, approximately one billion adults, or ~ 22% of the world population, have had hypertension. As of 2011, 235-330 million people globally have been affected by asthma and approximately 250,000-345,000 people have died each year from the disease. The development of the effective treatment therapies against these diseases is complicated by their comorbidity features. This is often a major problem in diagnosis and their treatment. Hence, in this study the bioinformatical methodology for the analysis of the comorbidity of these two diseases have been developed. As such, the search for candidate genes related to the comorbid conditions of asthma and hypertension can help in elucidating the molecular mechanisms underlying the comorbid condition of these two diseases, and can also be useful for genotyping and identifying new drug targets. RESULTS: Using ANDSystem, the reconstruction and analysis of gene networks associated with asthma and hypertension was carried out. The gene network of asthma included 755 genes/proteins and 62,603 interactions, while the gene network of hypertension - 713 genes/proteins and 45,479 interactions. Two hundred and five genes/proteins and 9638 interactions were shared between asthma and hypertension. An approach for ranking genes implicated in the comorbid condition of two diseases was proposed. The approach is based on nine criteria for ranking genes by their importance, including standard methods of gene prioritization (Endeavor, ToppGene) as well as original criteria that take into account the characteristics of an associative gene network and the presence of known polymorphisms in the analysed genes. According to the proposed approach, the genes IL10, TLR4, and CAT had the highest priority in the development of comorbidity of these two diseases. Additionally, it was revealed that the list of top genes is enriched with apoptotic genes and genes involved in biological processes related to the functioning of central nervous system. CONCLUSIONS: The application of methods of reconstruction and analysis of gene networks is a productive tool for studying the molecular mechanisms of comorbid conditions. The method put forth to rank genes by their importance to the comorbid condition of asthma and hypertension was employed that resulted in prediction of 10 genes, playing the key role in the development of the comorbid condition. The results can be utilised to plan experiments for identification of novel candidate genes along with searching for novel pharmacological targets.


Assuntos
Asma/genética , Biomarcadores/análise , Doenças do Sistema Nervoso Central/etiologia , Biologia Computacional/métodos , Mineração de Dados/métodos , Redes Reguladoras de Genes , Hipertensão/genética , Asma/epidemiologia , Catalase/genética , Comorbidade , Perfilação da Expressão Gênica , Humanos , Hipertensão/epidemiologia , Interleucina-10/genética , Software , Receptor 4 Toll-Like/genética
16.
Biochim Biophys Acta Gen Subj ; 1862(3): 557-566, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29203282

RESUMO

BACKGROUND: The development of approaches that increase therapeutic effects of anti-cancer drugs is one of the most important tasks of oncology. Caloric restriction in vivo or serum deprivation (SD) in vitro has been shown to be an effective tool for sensitizing cancer cells to chemotherapeutic drugs. However, the detailed mechanisms underlying the enhancement of apoptosis in cancer cells by SD remain to be elucidated. METHODS: Flow cytometry, caspase activity assay and western blotting were used for cell death rate evaluation. Western blotting, gel-filtration, siRNA approach and qRT-PCR were used to elucidate the mechanism underlying cell death potentiation upon SD. RESULTS: We demonstrated that SD sensitizes cancer cells to treatment with chemotherapeutic agent cisplatin. This effect is independent on activation of caspases-2 and -8, apical caspases triggering apoptosis in response to genotoxic stress. SD potentiates cell death via downregulation of the anti-apoptotic protein Mcl-1. In fact, SD reduces the Mcl-1 mRNA level, which consequently decreases the Mcl-1 protein level and renders cells more susceptible to apoptosis induction via the formation of apoptosome. CONCLUSIONS: Mcl-1 protein is an important regulator of sensitivity of cancer cells to apoptotic stimuli upon SD. GENERAL SIGNIFICANCE: This study identifies Mcl-1 as a new target for the sensitization of human cancer cells to cell death by SD, which is of great significance for the development of efficient anti-cancer therapies.


Assuntos
Antineoplásicos Alquilantes/farmacologia , Apoptose/efeitos dos fármacos , Cisplatino/farmacologia , Meios de Cultura Livres de Soro/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteína de Sequência 1 de Leucemia de Células Mieloides/biossíntese , Proteínas de Neoplasias/biossíntese , Apoptose/fisiologia , Apoptossomas/fisiologia , Caspase 2/fisiologia , Caspase 8/fisiologia , Linhagem Celular Tumoral , Cisteína Endopeptidases/fisiologia , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/fisiologia , Células HeLa , Humanos , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/fisiologia , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiologia , Interferência de RNA , RNA Interferente Pequeno/genética
17.
Cell Death Differ ; 24(9): 1621-1631, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28574503

RESUMO

The human pathogen Helicobacter pylori infects more than half of the world's population and is a paradigm for persistent yet asymptomatic infection but increases the risk for chronic gastritis and gastric adenocarcinoma. For successful colonization, H. pylori needs to subvert the host cell death response, which serves to confine pathogen infection by killing infected cells and preventing malignant transformation. Infection of gastric epithelial cells by H. pylori provokes direct and fast activation of the proinflammatory and survival factor NF-κB, which regulates target genes, such as CXCL8, BIRC3 and TNFAIP3. However, it is not known how H. pylori exploits NF-κB activation and suppresses the inflammatory response and host apoptotic cell death, in order to avert the innate immune response and avoid cell loss, and thereby enhance colonization to establish long-term infection. Here we assign for the first time that H. pylori and also Campylobacter jejuni-induced ubiquitin-editing enzyme A20 bifunctionally terminates NF-κB activity and negatively regulates apoptotic cell death. Mechanistically, we show that the deubiquitinylase activity of A20 counteracts cullin3-mediated K63-linked ubiquitinylation of procaspase-8, therefore restricting the activity of caspase-8. Interestingly, another inducible NF-κB target gene, the scaffold protein p62, ameliorates the interaction of A20 with procaspase-8. In conclusion, pathogen-induced de novo synthesis of A20 regulates the shut-off of the survival factor NF-κB but, on the other hand, also impedes caspase-8-dependent apoptotic cell death so as to promote the persistence of pathogens.


Assuntos
Caspase 8/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/fisiologia , Apoptose/genética , Apoptose/fisiologia , Proteína 3 com Repetições IAP de Baculovírus/genética , Proteína 3 com Repetições IAP de Baculovírus/metabolismo , Campylobacter jejuni/patogenicidade , Linhagem Celular , Eletroforese em Gel de Poliacrilamida , Helicobacter pylori/patogenicidade , Humanos , Interleucina-8/genética , Interleucina-8/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo , Ubiquitina
18.
Trends Cell Biol ; 27(5): 322-339, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28188028

RESUMO

Apoptosis is a crucial program of cell death that controls development and homeostasis of multicellular organisms. The main initiators and executors of this process are the Cysteine-dependent ASPartate proteASES - caspases. A number of regulatory circuits tightly control caspase processing and activity. One of the most important, yet, at the same time still poorly understood control mechanisms of activation of caspases involves their post-translational modifications. The addition and/or removal of chemical groups drastically alters the catalytic activity of caspases or stimulates their nonapoptotic functions. In this review, we will describe and discuss the roles of key caspase modifications such as phosphorylation, ubiquitination, nitrosylation, glutathionylation, SUMOylation, and acetylation in the regulation of apoptotic cell death and cell survival.


Assuntos
Apoptose , Caspases/metabolismo , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Animais , Ativação Enzimática , Humanos , Fosforilação , Ubiquitinação
19.
J Bioinform Comput Biol ; 15(2): 1650045, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28152643

RESUMO

Gene network modeling is one of the widely used approaches in systems biology. It allows for the study of complex genetic systems function, including so-called mosaic gene networks, which consist of functionally interacting subnetworks. We conducted a study of a mosaic gene networks modeling method based on integration of models of gene subnetworks by linear control functionals. An automatic modeling of 10,000 synthetic mosaic gene regulatory networks was carried out using computer experiments on gene knockdowns/knockouts. Structural analysis of graphs of generated mosaic gene regulatory networks has revealed that the most important factor for building accurate integrated mathematical models, among those analyzed in the study, is data on expression of genes corresponding to the vertices with high properties of centrality.


Assuntos
Redes Reguladoras de Genes , Modelos Teóricos , Simulação por Computador , Técnicas de Silenciamento de Genes , Técnicas de Inativação de Genes , Modelos Genéticos , Biologia de Sistemas/métodos
20.
Virus Res ; 218: 79-85, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-27109913

RESUMO

Molecular genetic processes generally involve proteins from distinct intracellular localisations. Reactions that follow the same process are distributed among various compartments within the cell. In this regard, the reaction rate and the efficiency of biological processes can depend on the subcellular localisation of proteins. Previously, the authors proposed a method of evaluating the efficiency of biological processes based on the analysis of the distribution of protein subcellular localisation (Popik et al., 2014). Here, NACE is presented, which is an open access web-oriented program that implements this method and allows the user to evaluate the intercompartmental efficiency of human molecular genetic networks. The method has been extended by a new feature that provides the evaluation of the tissue-specific efficiency of networks for more than 2800 anatomical structures. Such assessments are important in cases when molecular genetic pathways in different tissues proceed with the participation of various proteins with a number of intracellular localisations. For example, an analysis of KEGG pathways, conducted using the developed program, showed that the efficiencies of many KEGG pathways are tissue-specific. Analysis of efficiencies of regulatory pathways in the liver, linking proteins of the hepatitis C virus with human proteins involved in the KEGG apoptosis pathway, showed that intercompartmental efficiency might play an important role in host-pathogen interactions. Thus, the developed tool can be useful in the study of the effectiveness of functioning of various molecular genetic networks, including metabolic, regulatory, host-pathogen interactions and others taking into account tissue-specific gene expression. The tool is available via the following link: http://www-bionet.sscc.ru/nace/.


Assuntos
Redes Reguladoras de Genes , Hepacivirus/genética , Hepatite C/genética , NF-kappa B/genética , Software , Proteínas não Estruturais Virais/genética , Apoptose/genética , Compartimento Celular , Quinase do Ponto de Checagem 2/genética , Quinase do Ponto de Checagem 2/metabolismo , Regulação da Expressão Gênica , Hepacivirus/metabolismo , Hepatite C/metabolismo , Hepatite C/virologia , Hepatócitos/metabolismo , Hepatócitos/virologia , Interações Hospedeiro-Patógeno , Humanos , Redes e Vias Metabólicas/genética , NF-kappa B/metabolismo , Especificidade de Órgãos , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Proteínas não Estruturais Virais/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA