RESUMO
Inflammasomes are intracellular, multiprotein supercomplexes that mediate a post-translational inflammatory response to both pathogen and endogenous danger signals. They consist of a sensor, the adapter ASC, and the protease caspase 1 and, following their activation, lead to cl1ß, as well as lytic cell death. Due to this potent inflammatory capacity, understanding inflammasome biology is important in many pathological conditions. It is increasingly clear that inflammasomes are particularly relevant in macrophages, which express a diverse range of inflammasome sensors. In these two chapters, we detail methods to isolate and differentiate human macrophages, murine bone marrow-derived macrophages, and murine microglia and stimulate the inflammasomes known to be expressed in macrophages, including the AIM2, NLRP3, NLRC4, NLRP1, and non-canonical inflammasomes. Furthermore, we describe the methodology required to measure the various results of inflammasome activation including ASC speck formation, monitoring lytic cell death and cytokine release, as well as caspase-1 activation.
Assuntos
Inflamassomos , Microglia , Humanos , Animais , Camundongos , Macrófagos , Caspase 1 , Morte CelularRESUMO
Many animal- and plant-pathogenic bacteria use a type III secretion system to deliver effector proteins into host cells1,2. Elucidation of how these effector proteins function in host cells is critical for understanding infectious diseases in animals and plants3-5. The widely conserved AvrE-family effectors, including DspE in Erwinia amylovora and AvrE in Pseudomonas syringae, have a central role in the pathogenesis of diverse phytopathogenic bacteria6. These conserved effectors are involved in the induction of 'water soaking' and host cell death that are conducive to bacterial multiplication in infected tissues. However, the exact biochemical functions of AvrE-family effectors have been recalcitrant to mechanistic understanding for three decades. Here we show that AvrE-family effectors fold into a ß-barrel structure that resembles bacterial porins. Expression of AvrE and DspE in Xenopus oocytes results in inward and outward currents, permeability to water and osmolarity-dependent oocyte swelling and bursting. Liposome reconstitution confirmed that the DspE channel alone is sufficient to allow the passage of small molecules such as fluorescein dye. Targeted screening of chemical blockers based on the predicted pore size (15-20 Å) of the DspE channel identified polyamidoamine dendrimers as inhibitors of the DspE/AvrE channels. Notably, polyamidoamines broadly inhibit AvrE and DspE virulence activities in Xenopus oocytes and during E. amylovora and P. syringae infections. Thus, we have unravelled the biochemical function of a centrally important family of bacterial effectors with broad conceptual and practical implications in the study of bacterial pathogenesis.
Assuntos
Proteínas de Bactérias , Células Vegetais , Doenças das Plantas , Porinas , Água , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Morte Celular , Fluoresceína/metabolismo , Lipossomos/metabolismo , Oócitos/metabolismo , Oócitos/microbiologia , Células Vegetais/metabolismo , Células Vegetais/microbiologia , Doenças das Plantas/microbiologia , Porinas/química , Porinas/metabolismo , Dobramento de Proteína , Soluções/metabolismo , Água/metabolismo , Xenopus laevis , Concentração OsmolarRESUMO
Oxidative stress has been shown to induce cell death in a wide range of human diseases including cardiac ischemia/reperfusion injury, drug induced cardiotoxicity, and heart failure. However, the mechanism of cell death induced by oxidative stress remains incompletely understood. Here we provide new evidence that oxidative stress primarily induces ferroptosis, but not apoptosis, necroptosis, or mitochondria-mediated necrosis, in cardiomyocytes. Intriguingly, oxidative stress induced by organic oxidants such as tert-butyl hydroperoxide (tBHP) and cumene hydroperoxide (CHP), but not hydrogen peroxide (H2O2), promoted glutathione depletion and glutathione peroxidase 4 (GPX4) degradation in cardiomyocytes, leading to increased lipid peroxidation. Moreover, elevated oxidative stress is also linked to labile iron overload through downregulation of the transcription suppressor BTB and CNC homology 1 (Bach1), upregulation of heme oxygenase 1 (HO-1) expression, and enhanced iron release via heme degradation. Strikingly, oxidative stress also promoted HO-1 translocation to mitochondria, leading to mitochondrial iron overload and lipid reactive oxygen species (ROS) accumulation. Targeted inhibition of mitochondrial iron overload or ROS accumulation, by overexpressing mitochondrial ferritin (FTMT) or mitochondrial catalase (mCAT), respectively, markedly inhibited oxidative stress-induced ferroptosis. The levels of mitochondrial iron and lipid peroxides were also markedly increased in cardiomyocytes subjected to simulated ischemia and reperfusion (sI/R) or the chemotherapeutic agent doxorubicin (DOX). Overexpressing FTMT or mCAT effectively prevented cardiomyocyte death induced by sI/R or DOX. Taken together, oxidative stress induced by organic oxidants but not H2O2 primarily triggers ferroptotic cell death in cardiomyocyte through GPX4 and Bach1/HO-1 dependent mechanisms. Our results also reveal mitochondrial iron overload via HO-1 mitochondrial translocation as a key mechanism as well as a potential molecular target for oxidative stress-induced ferroptosis in cardiomyocytes.
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Sobrecarga de Ferro , Estresse Oxidativo , Humanos , Espécies Reativas de Oxigênio , Morte Celular , Ferro , Miócitos CardíacosRESUMO
Despite the accumulating evidence linking the development of Alzheimer's disease (AD) to the aggregation of Aß peptides and the emergence of Aß oligomers, the FDA has approved very few anti-aggregation-based therapies over the past several decades. Here, we report the discovery of an Aß peptide aggregation inhibitor: an ultra-small nanodot called C3N. C3N nanodots alleviate aggregation-induced neuron cytotoxicity, rescue neuronal death, and prevent neurite damage in vitro. Importantly, they reduce the global cerebral Aß peptides levels, particularly in fibrillar amyloid plaques, and restore synaptic loss in AD mice. Consequently, these C3N nanodots significantly ameliorate behavioral deficits of APP/PS1 double transgenic male AD mice. Moreover, analysis of critical tissues (e.g., heart, liver, spleen, lung, and kidney) display no obvious pathological damage, suggesting C3N nanodots are biologically safe. Finally, molecular dynamics simulations also reveal the inhibitory mechanisms of C3N nanodots in Aß peptides aggregation and its potential application against AD.
Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Nanopartículas , Animais , Masculino , Camundongos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Morte Celular , Citoesqueleto , Camundongos Transgênicos , Peptídeos , Nanopartículas/uso terapêutico , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Agregados Proteicos/efeitos dos fármacosRESUMO
AIMS: Idiopathic pulmonary fibrosis (IPF) is a severe pulmonary interstitial pneumonia. Our study focuses on the role of PLA2 enzyme in the IPF to explore a more effective diagnosis and treatment mechanism of IPF. MAIN METHODS: Transcriptome data of IPF from GEO database and bleomycin-induced pulmonary fibrosis mice were analyzed to identify PLA2 enzyme and their metabolite, lysophosphatidylcholines 18:0, in IPF. Based on PLA2G2A and PLA2G2D / PLA2G2A-associated cell death genes (PCDs), the consensus clustering analysis was used to identify the subtypes of IPF and the correlation between PLA2G2A and prognosis was analyzed. The machine learning (ML) models and artificial neural network (ANN) model was used to validate the diagnostic accuracy of PLA2s and PCDs in diagnosing IPF. The gene and protein expression of NLRP3, GSDMD, and CASP-1 was estimated in recombinant PLA2G2A protein induced MLE-12 cells. KEY FINDINGS: The expression of PLA2G2D, PLA2G2A, and LPC18 significantly changed in IPF. Furtherly, PLA2G2A has a significant correlation with poor patient prognosis, which could predict the 2 or 3-years mortality rates of IPF. Two subtypes of IPF patients, identified based on PCDs, showed significant different immunoinfiltration. Recombinant PLA2G2A protein could induce the pyrotosis in the MLE-12 cell. The generalized linear model and ANN model of PLA2s or PCDs accurate diagnosis IPF. SIGNIFICANCE: PLA2G2A is the most robustly associated gene with IPF among the PLA2s, which demonstrates a potential in diagnosing and prognostic value in IPF, and provides a foundation for further understanding and breakthroughs in IPF diagnosis and treatment.
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Fibrose Pulmonar Idiopática , Animais , Humanos , Camundongos , Bleomicina , Caspase 1 , Morte Celular , Análise por Conglomerados , Fosfolipases A2 do Grupo II , Fibrose Pulmonar Idiopática/genéticaRESUMO
Mitochondrial transplantation is a promising therapeutic approach for the treatment of mitochondrial diseases caused by mutations in mitochondrial DNA, as well as several metabolic and neurological disorders. Animal studies have shown that mitochondrial transplantation can improve cellular energy metabolism, restore mitochondrial function, and prevent cell death. However, challenges need to be addressed, such as the delivery of functional mitochondria to the correct cells in the body, and the long-term stability and function of the transplanted mitochondria. Researchers are exploring new methods for mitochondrial transplantation, including the use of nanoparticles or CRISPR gene editing. Mechanisms underlying the integration and function of transplanted mitochondria are complex and not fully understood, but research has revealed some key factors that play a role. While the safety and efficacy of mitochondrial transplantation have been investigated in animal models and human trials, more research is needed to optimize delivery methods and evaluate long-term safety and efficacy. Clinical trials using mitochondrial transplantation have shown mixed results, highlighting the need for further research in this area. In conclusion, although mitochondrial transplantation holds significant potential for the treatment of various diseases, more work is needed to overcome challenges and evaluate its safety and efficacy in human trials. [BMB Reports 2023; 56(9): 488-495].
Assuntos
DNA Mitocondrial , Mitocôndrias , Animais , Humanos , DNA Mitocondrial/genética , Morte Celular , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Metabolismo EnergéticoRESUMO
A high temperature-adapted bacteriophage, vB_PtoS_NIIg3.2 (NIIg3.2), was isolated in Lithuania from compost heaps using Parageobacillus toebii strain NIIg-3 as a host for phage propagation. Furthermore, NIIg3.2 was active against four strains of Geobacillus thermodenitrificans, and it infected the host cells from 50 to 80 °C. Transmission electron microscopy analysis revealed siphovirus morphology characterized by an isometric head (~59 nm in diameter) and a noncontractile tail (~226 nm in length). The double-stranded DNA genome of NIIg3.2 (38,970 bp) contained 71 probable protein-encoding genes and no genes for tRNA. In total, 29 NIIg3.2 ORFs were given a putative functional annotation, including those coding for the proteins responsible for DNA packaging, virion structure/morphogenesis, phage-host interactions, lysis/lysogeny, replication/regulation, and nucleotide metabolism. Based on comparative phylogenetic and bioinformatic analysis, NIIg3.2 cannot be assigned to any genus currently recognized by ICTV and potentially represents a new one within siphoviruses. The results of this study not only extend our knowledge about poorly explored thermophilic bacteriophages but also provide new insights for further investigation and understanding the evolution of Bacilllus-group bacteria-infecting viruses.
Assuntos
Bacteriófagos , Bacteriófagos/genética , Filogenia , Lisogenia , Técnicas de Tipagem Bacteriana , Morte CelularRESUMO
Parkinson's disease (PD) and Alzheimer's disease (AD) are the most common rapidly developing neurodegenerative diseases that lead to serious health and socio-economic consequences. Ferroptosis is a non-apoptotic form of cell death; there is growing evidence to support the notion that ferroptosis is involved in a variety of pathophysiological contexts, and there is increasing interest in the role of ferroptosis in PD and AD. Simultaneously, cells may have evolved four defense systems to counteract the toxic effects of ferroptosis occasioned by lipid peroxidation. This review, which focuses on the analysis of ferroptosis in the PD and AD context, outlines four cellular defense systems against ferroptosis and how each of them is involved in PD and AD.
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Doença de Alzheimer , Ferroptose , Doença de Parkinson , Humanos , Morte Celular , Peroxidação de LipídeosRESUMO
Mat cells (MCs) are located in the skin and mucous membranes at points where the body meets the environment. When activated, MCs release inflammatory cytokines, which help the immune system to fight viruses. MCs produce, and have receptors for interferons (IFNs), which belong to a family of cytokines recognized for their antiviral properties. Previously, we reported that MCs produced proinflammatory cytokines in response to a recombinant vesicular stomatitis virus (rVSVΔm51) and that IFNAR signaling was required to down-modulate these responses. Here, we have demonstrated that UV-irradiated rVSVΔm51 did not cause any inflammatory cytokines in either in vitro cultured mouse IFNAR-intact (IFNAR+/+), or in IFNAR-knockout (IFNAR-/-) MCs. However, the non-irradiated virus was able to replicate more effectively in IFNAR-/- MCs and produced a higher level of inflammatory cytokines compared with the IFNAR+/+ MCs. Interestingly, MCs lacking IFNAR expression displayed reduced levels of reactive oxygen species (ROS) compared with IFNAR+/+ MCs. Additionally, upon the viral infection, these IFNAR-/- MCs were found to coexist with many dying cells within the cell population. Based on our findings, IFNAR-intact MCs exhibit a lower rate of rVSVΔm51 infectivity and lower levels of cytokines while demonstrating higher levels of ROS. This suggests that MCs with intact IFNAR signaling may survive viral infections by producing cell-protective ROS mechanisms and are less likely to die than IFNAR-/- cells.
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Citocinas , Viroses , Animais , Camundongos , Espécies Reativas de Oxigênio , Mastócitos , Fatores Imunológicos , Viroses/genética , Morte CelularRESUMO
The discovery of protein-protein interactions can provide crucial information on protein function by linking proteins into known pathways or complexes within the cell. Mass spectrometry (MS)-based methods, such as affinity purification (AP)-MS and proximity-dependent biotin identification (BioID), allowed for a vast increase in the number of reported protein complexes. As a more recent addition to the arsenal of MS-based methods, Virotrap represents a unique technology that benefits from the specific properties of the human immunodeficiency virus-1 (HIV-1) Gag polyprotein. More specifically, Virotrap captures protein complexes in virus-like particles budded from human embryonic kidney (HEK293T) cells, bypassing the need for cell lysis and thus supporting identification of their content using MS. Being intrinsically different to its two main predecessors, affinity purification MS (AP-MS) and biotin-dependent identification (BioID), Virotrap was shown to complement data obtained with the existing MS-based toolkit. The proven complementarity of these MS-based strategies underlines the importance of using different techniques to enable comprehensive mapping of protein-protein interactions (PPIs). In this chapter, we provide a detailed overview of the Virotrap protocol to screen for PPIs using a bait protein of interest.
Assuntos
Biotina , Caça , Humanos , Morte Celular , Cromatografia de Afinidade , Células HEK293RESUMO
The immune isolation of cells within devices has the potential to enable long-term protein replacement and functional cures for a range of diseases, without requiring immune suppressive therapy. However, a lack of vasculature and the formation of fibrotic capsules around cell immune-isolating devices limits oxygen availability, leading to hypoxia and cell death in vivo. This is particularly problematic for pancreatic islet cells that have high O2 requirements. Here, we combine bioelectronics with encapsulated cell therapies to develop the first wireless, battery-free oxygen-generating immune-isolating device (O2-Macrodevice) for the oxygenation and immune isolation of cells in vivo. The system relies on electrochemical water splitting based on a water-vapor reactant feed, sustained by wireless power harvesting based on a flexible resonant inductive coupling circuit. As such, the device does not require pumping, refilling, or ports for recharging and does not generate potentially toxic side products. Through systematic in vitro studies with primary cell lines and cell lines engineered to secrete protein, we demonstrate device performance in preventing hypoxia in ambient oxygen concentrations as low as 0.5%. Importantly, this device has shown the potential to enable subcutaneous (SC) survival of encapsulated islet cells, in vivo in awake, freely moving, immune-competent animals. Islet transplantation in Type I Diabetes represents an important application space, and 1-mo studies in immune-competent animals with SC implants show that the O2-Macrodevice allows for survival and function of islets at high densities (~1,000 islets/cm2) in vivo without immune suppression and induces normoglycemia in diabetic animals.
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Hipóxia , Oxigênio , Animais , Hipóxia/terapia , Morte Celular , Linhagem Celular , Terapia Baseada em Transplante de Células e TecidosRESUMO
Mitophagy, a central process guarding mitochondrial quality, is commonly impaired in human diseases such as Parkinson's disease, but its impact in adaptive immunity remains unclear. The differentiation and survival of memory CD8+ T cells rely on oxidative metabolism, a process that requires robust mitochondrial quality control. Here, we found that Parkinson's disease patients have a reduced frequency of CD8+ memory T cells compared with healthy donors and failed to form memory T cells upon vaccination against COVID-19, highlighting the importance of mitochondrial quality control for memory CD8+ T cell formation. We further uncovered that regulators of mitophagy, including Parkin and NIX, were up-regulated in response to interleukin-15 (IL-15) for supporting memory T cell formation. Mechanistically, Parkin suppressed VDAC1-dependent apoptosis in memory T cells. In contrast, NIX expression in T cells counteracted ferroptosis by preventing metabolic dysfunction resulting from impaired mitophagy. Together, our results indicate that the mitophagy machinery orchestrates survival and metabolic dynamics required for memory T cell formation, as well as highlight a deficit in T cell-mediated antiviral responses in Parkinson's disease patients.
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COVID-19 , Doença de Parkinson , Humanos , Linfócitos T CD8-Positivos , Células T de Memória , Mitofagia , Morte CelularRESUMO
The central dogma of molecular biology was no longer "central" after ground-breaking discoveries conveyed gene expression involves more complex physiological functions in cancer pathogenesis over the last decade. MicroRNAs (miRNAs) are short non-coding RNA that regulate gene expression, affecting key molecular pathways involved in sustaining the proliferative signalling for tumour development, evasion of cellular death, invasion, angiogenesis, as well as metastasis in a plethora of cancer types. MiRNA expression is dysregulated in human cancer through a number of processes, including miRNA gene amplification or deletion, faulty miRNA transcriptional regulation, dysregulated epigenetic alterations, and flaws in the miRNA biogenesis machinery. As a result, the current progress of treatment intervention focuses on modifying the miRNA levels in cancer therapeutics. Nevertheless, the mode of delivery and current management of miRNA therapies remains one of the many questions that need to be addressed. Here, we provided a comprehensive mini-review outlining the role of miRNA in cancer as well as its mode of delivery which includes liposomes, viral vectors, inorganic material-based nanoparticles, and cell-derived membrane vesicles. Likewise, the regulation of miRNA in other diseases and their challenges in translational research was also thoroughly discussed.
Assuntos
MicroRNAs , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/terapia , Morte Celular , Membrana Celular , Lipossomos , MicroRNAs/genéticaRESUMO
The lysis of cancer cells inside a sessile droplet was performed using traveling surface acoustic waves (SAWs) without any chemical reagents. Raman spectrum profiling was then carried out to explore detailed cell-derived data. The Rayleigh waves formed by an interdigital transducer were made to propagate along the surface of an LiNbO3 substrate. Polystyrene microparticles (PSMPs) were used to establish mechanical cell lysis effectively, and gold nanoparticles (AuNPs) were added to enhance the Raman signals from the lysed cells by SAWs. The lysis efficiency was evaluated according to the size and concentration of the PSMPs in experiments where the frequency was varied. Lysis occurred mainly by mechanical collision using PSMPs in a high-frequency domain, and the lysis efficiency was improved by increasing the application time and the energy density of the SAWs. Raman signals from the lysed cells were greatly enhanced by nanogaps formed by the AuNPs, which were evenly distributed irrespective of the SAWs through the frequency-independent behavior of the AuNPs. Finally, detailed Raman spectra of MDA-MB-231, malignant breast cancer cells, were acquired, and various organic matter-derived peaks were observed. The 95% confidence region for cells subjected to lysis was more widely distributed than that of cells not subjected to lysis. The proposed SAW platform is expected to facilitate the detection of small quantities and to be applied in biomedical applications.
Assuntos
Micropartículas Derivadas de Células , Nanopartículas Metálicas , Neoplasias , Ouro , Morte Celular , PoliestirenosRESUMO
Dihydroorotate dehydrogenase (DHODH) is a central enzyme of the de novo pyrimidine biosynthesis pathway and is a promising drug target for the treatment of cancer and autoimmune diseases. This study presents the identification of a potent DHODH inhibitor by proteomic profiling. Cell-based screening revealed that NPD723, which is reduced to H-006 in cells, strongly induces myeloid differentiation and inhibits cell growth in HL-60 cells. H-006 also suppressed the growth of various cancer cells. Proteomic profiling of NPD723-treated cells in ChemProteoBase showed that NPD723 was clustered with DHODH inhibitors. H-006 potently inhibited human DHODH activity in vitro, whereas NPD723 was approximately 400 times less active than H-006. H-006-induced cell death was rescued by the addition of the DHODH product orotic acid. Moreover, metabolome analysis revealed that H-006 treatment promotes marked accumulation of the DHODH substrate dihydroorotic acid. These results suggest that NPD723 is reduced in cells to its active metabolite H-006, which then targets DHODH and suppresses cancer cell growth. Thus, H-006-related drugs represent a potentially powerful treatment for cancer and other diseases.
Assuntos
Di-Hidro-Orotato Desidrogenase , Proteômica , Humanos , Transformação Celular Neoplásica , Ciclo Celular , Morte CelularRESUMO
Background: Cuprotosis is a newly discovered form of cell death that differs from other types of cell death. The aim of this study was to investigate the functional role and a possible prognostic model for thyroid cancer. Methods: TCGA and GEO were used to investigate the differential expression of CRGs in THCA. KEGG and GO enrichment analyses were applied to investigate the possible molecular functions. The features of CRGs were selected by LASSO regression. 20 pairs of samples were randomly collected from the hospital to compare expression between tumor and normal. Results: Among the 19 CRGs related to thyroid cancer recurrence, 16 genes were differentially expressed in thyroid cancer. KEGG analysis showed that the 19 CRGs were mainly enriched in cell death, cell cycle and ribosomal pathways. K-M survival analysis and subsequent multiple logistic regression revealed that the expression of BUB1 and GINS2 were potential risk factors for disease-free survival (DFS) of thyroid cancer. In addition, further LASSO-regression selected the following three DFS-related CRGs: FDX1, BUB1 and RPL3. A novel prognostic prediction model was constructed by nomogram, and the prediction probability for 1-, 3- and 5-year survival approached the actual time. As for the possible mechanisms, FDX1, BUB1 and RPL3 were associated with immune infiltration. The cell model experiment illustrated that the ATM signaling pathway might be involved in thyroid cancer cell death. Conclusion: Three CRG models (FDX1, BUB1, RPL3) could better predict the prognosis of thyroid cancer. Immune cell infiltration and the ATM pathway were the possible mechanisms.
Assuntos
Neoplasias da Glândula Tireoide , Humanos , Intervalo Livre de Doença , Neoplasias da Glândula Tireoide/genética , Ciclo Celular , Morte Celular , Proteínas Cromossômicas não HistonaRESUMO
Real-time monitoring of early antitumor efficacy is one of the key issues in realizing high-efficiency and more precise tumor treatment. As a highly specific event in the early stage of apoptosis, the release of cytochrome c may act as a key biomarker for monitoring cell apoptosis. However, achieving real-time monitoring of the cytochrome c release in vivo remains a challenge. Herein, we report a novel integrated nanosystem named DFeK nanoparticle (DFeK NP) to achieve a favorable collaboration of inducing tumor cell apoptosis and monitoring early therapeutic efficacy, which combined the cytochrome c-activated DNA nanoprobe cApt-App with pro-apoptotic peptide [KLAKLAK]2 and ferrous ions. [KLAKLAK]2 can target the mitochondria to disrupt the mitochondrial membrane together with reactive oxygen species produced by ferrous ions via the Fenton reaction to promote mitochondrial damage. Then, cytochrome c is released from damaged mitochondria to trigger apoptosis, further activating the cApt-App probe from the fluorescence "off" state to the "on" state. The cytochrome c-specific "off-to-on" transition was successfully applied in fluorescence imaging of cytochrome c in vivo and thus achieved real-time early therapeutic efficacy monitoring. Collectively, this work presents a valuable integrated tool for tumor inhibition and therapeutic efficacy evaluation to realize more precise and more effective tumor treatment.
Assuntos
Apoptose , Citocromos c , Morte Celular , Ferro , ÍonsRESUMO
Evidence has long suggested that epidermal growth factor receptor (EGFR) may play a prominent role in triple-negative breast cancer (TNBC) pathogenesis, but clinical trials of EGFR inhibitors have yielded disappointing results. Using a candidate drug screen, we identified that inhibition of cyclin-dependent kinases 12 and 13 (CDK12/13) dramatically sensitizes diverse models of TNBC to EGFR blockade. This combination therapy drives cell death through the 4E-BP1-dependent suppression of the translation and translation-linked turnover of driver oncoproteins, including MYC. A genome-wide CRISPR/Cas9 screen identified the CCR4-NOT complex as a major determinant of sensitivity to the combination therapy whose loss renders 4E-BP1 unresponsive to drug-induced dephosphorylation, thereby rescuing MYC translational suppression and promoting MYC stability. The central roles of CCR4-NOT and 4E-BP1 in response to the combination therapy were further underscored by the observation of CNOT1 loss and rescue of 4E-BP1 phosphorylation in TNBC cells that naturally evolved therapy resistance. Thus, pharmacological inhibition of CDK12/13 reveals a long-proposed EGFR dependence in TNBC that functions through the cooperative regulation of translation-coupled oncoprotein stability.
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Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Receptores ErbB/genética , Fosforilação , Morte Celular , Proteínas Oncogênicas , Quinases Ciclina-Dependentes/genética , Fatores de TranscriçãoRESUMO
Glioblastoma (GBM) is a deadly and the most common primary brain tumor in adults. Due to their regulation of a high number of mRNA transcripts, microRNAs (miRNAs) are key molecules in the control of biological processes and are thereby promising therapeutic targets for GBM patients. In this regard, we recently reported miRNAs as strong modulators of GBM aggressiveness. Here, using an integrative and comprehensive analysis of the TCGA database and the transcriptome of GBM biopsies, we identified three critical and clinically relevant miRNAs for GBM, miR-17-3p, miR-222, and miR-340. In addition, we showed that the combinatorial modulation of three of these miRNAs efficiently inhibited several biological processes in patient-derived GBM cells of all these three GBM subtypes (Mesenchymal, Proneural, Classical), induced cell death, and delayed tumor growth in a mouse tumor model. Finally, in a doxycycline-inducible model, we observed a significant inhibition of GBM stem cell viability and a significant delay of orthotopic tumor growth. Collectively, our results reveal, for the first time, the potential of miR-17-3p, miR-222 and miR-340 multi-targeting as a promising therapeutic strategy for GBM patients.
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Glioblastoma , MicroRNAs , Adulto , Humanos , Animais , Camundongos , MicroRNAs/genética , Glioblastoma/genética , Agressão , Biópsia , Morte Celular , Modelos Animais de DoençasRESUMO
Development of oxidative/nitrosative stress associated with the activation of oncogenic pathways results from the increase in the generation of reactive oxygen and nitrogen species (ROS/RNS) in tumor cells, where they can have a dual effect. At high concentrations, ROS/RNS cause cell death and limit tumor growth at certain phases of its development, while their low amounts promote oxidative/nitrosative modifications of key redox-dependent residues in regulatory proteins. The reversibility of such modifications as S-glutathionylation and S-nitrosylation that proceed through the electrophilic attack of ROS/RNS on nucleophilic Cys residues ensures the redox-dependent switch in the activity of signaling proteins, as well as the ability of these compounds to control cell proliferation and programmed cell death. The content of S-glutathionylated and S-nitrosylated proteins is controlled by the balance between S-glutathionylation/deglutathionylation and S-nitrosylation/denitrosylation, respectively, and depends on the cellular redox status. The extent of S-glutathionylation and S-nitrosylation of protein targets and their ratio largely determine the status and direction of signaling pathways in cancer cells. The review discusses the features of S-glutathionylation and S-nitrosylation reactions and systems that control them in cancer cells, as well as their relationship with redox-dependent processes and tumor growth.