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The N7-methylguanosine (m7G) methyltransferase Mettl1 has been recently implicated in cardiac repair and fibrosis. In this study we investigated the role of Mettl1 in mouse cardiomyocytes injury and the underlying mechanisms. Cardiac ischemia/reperfusion (I/R) I/R model was established in mice by ligation of the left anterior descending coronary artery (LAD) for 45 min followed by reperfusion for 24 h. We showed the mRNA and protein levels of Mettl1 were significantly upregulated in mouse I/R hearts and H2O2-treated neonatal mouse cardiomyocytes (NMCMs). Mettl1 knockdown markedly ameliorated cardiac I/R injury, evidenced by decreased infarct size, apoptosis, and improved cardiac function. Overexpression of Mettl1 triggered cardiomyocytes apoptosis in vivo and in vitro. By performing RNA sequencing combined with m7G methylated RNA sequencing in Mettl1-overexpressing mouse hearts, we revealed that Mettl1 catalyzed m7G modification of the deubiquitinase cylindromatosis (CYLD) mRNA to increase the expression of CYLD, which enhanced the stability of P53 via abrogating its ubiquitination degradation. Vice versa, P53 served as a transcriptional factor to positively regulate Mettl1 expression during I/R injury. Knockdown of CYLD mitigated cardiomyocytes apoptosis induced by Mettl1 overexpression or oxidative stress. From the available drug-targets databases and literature, we identified 4 small molecule inhibitors of m7G modification. Sinefungin, one of the Mettl1 inhibitors exerted profound protection against cardiac I/R injury in vivo and in vitro. Collectively, this study has identified Mettl1 as a key regulator of cardiomyocyte apoptosis, and targeting the Mettl1-CYLD-P53 positive feedback circuit may represent a novel therapeutic avenue for alleviating cardiac I/R injury.
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Dicentrinone (Di), liriodenine (Li) and lysicamine (Ly) are three natural oxoaporphine alkaloids (OAs), which revealed significant biological activity such as anticancer, anti-inflammatory and antimicrobial activities and were considered as potential lead compounds for the development of new clinical chemicals. In the present study, confocal laser scanning fluorescence microscopy observation demonstrated these three natural OAs could traverse inside of the nucleus and get an opportunity to interact with DNA. Their interaction properties with DNA were then investigated simultaneously by two spectral fluorescent probes of ethidium bromide (EB) and methyl green (MG), as well as UV-vis absorption and cyclic voltammetry measurements, and further verified by the molecular docking analysis. Results indicated Di and Li were distinctly classified as the intercalative molecules to DNA, however, Ly was confirmed with a mixed-mode binding of partial intercalation and groove affinity. Their binding ability was revealed as the follows: Di ≥ Li > Ly, which was correlated with their structural changes. Thermodynamic studies revealed the binding process of Li and Ly with ctDNA was all spontaneous, the hydrophobic interaction was the major binding force for Li-ctDNA complex, however, the interaction between Ly and ctDNA relied on both hydrophobic and hydrogen binding force. Molecular docking provided detailed computational interaction of Di, Li and Ly with DNA, which proved the intercalation binding of Li-DNA complex and Di-DNA complex stabilizing mainly by the π-π binding force, however, apart from a small quantity of π-π interaction, another binding force in the Ly-DNA complex mainly was supplied from the weaker Pi-Alkyl, hydrogen bond and Pi-Anion interactions.
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Vibrio vulnificus (Vv) is known to cause life-threatening infections, particularly septicemia. These patients often exhibit elevated levels of pro-inflammatory cytokines. While it is established that mitogen-activated protein kinase (MAPK)-interacting kinase (MNK) contributes to the production of pro-inflammatory cytokines, the role of MNK in macrophages during Vv infection remains unclear. In this study, we investigate the impact of MNK on macrophages. We demonstrate that the inhibition of MNK in J774A.1 cells, when treated with lipopolysaccharide or Vv, resulted in decreased production of tumor necrosis factor alpha and interleukin-6, without affecting their transcription. Interestingly, treatment with MNK inhibitor CGP57380 led to enhanced phosphorylation of MNK1 but decreased phosphorylation of eIF4E. Moreover, MNK1 knockout cells exhibited an increased capacity for phagocytosis and clearance of Vv, with more acidic phagosomes than the parental cells. Notably, CGP57380 did not impact phagocytosis, bacterial clearance, or phagosome acidification in Vv-infected J774A.1 cells. Considering the reported association between MNK and mammalian target of rapamycin complex 1 (mTORC1) activation, we investigated the mTORC1 signaling in MNK1 knockout cells infected with Vv. Our results revealed that attenuation of the mTORC1 signaling in these cells and treatment with the mTORC1 inhibitor rapamycin significantly enhanced bacterial clearance in J774A.1 cells following Vv infection. In summary, our findings suggest that MNK promotes the Vv-induced cytokine production in J774A.1 cells without affecting their transcription levels. MNK1 appears to impair the phagocytosis, bacterial clearance, and phagosome acidification in Vv-infected J774A.1 cells through the MNK1-mTORC1 signaling pathway rather than the MNK1-eIF4E signaling pathway. Our findings highlight the importance of the MNK1-mTORC1 pathway in modulating macrophage responses to Vv infection. IMPORTANCE: Mitogen-activated protein kinase (MAPK)-interacting kinase (MNK) plays a role in promoting the production of tumor necrosis factor alpha and interleukin-6 in macrophages during Vibrio vulnificus (Vv) infection. Inhibition or knockout of MNK1 in J774A.1 cells resulted in reduced cytokine production without affecting their transcription levels. MNK1 also impairs phagocytosis, bacterial clearance, and phagosome acidification in Vv-infected cells through the MNK1-mammalian target of rapamycin complex 1 (mTORC1) signaling pathway. The findings highlight the importance of the MNK1-mTORC1 pathway in modulating macrophage responses to Vv infection.
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Macrófagos , Alvo Mecanístico do Complexo 1 de Rapamicina , Fagocitose , Proteínas Serina-Treonina Quinases , Vibrio vulnificus , Vibrio vulnificus/metabolismo , Vibrio vulnificus/genética , Macrófagos/microbiologia , Macrófagos/imunologia , Macrófagos/metabolismo , Animais , Camundongos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Linhagem Celular , Vibrioses/imunologia , Vibrioses/microbiologia , Transdução de Sinais , Citocinas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fosforilação , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Humanos , Compostos de Anilina , PurinasRESUMO
Current evidence suggests that porcine circovirus type 2 (PCV2) infection induces immunosuppression in piglets. Sophora subprostrate polysaccharide (SSP) exhibits various pharmacological activities, including immunoregulatory, anti-inflammatory, antiviral, and antioxidant properties. However, the acts of lncRNAs in regulating the therapeutic effects of SSP on PCV2-infected RAW264.7 cells remains poorly understood. This study aimed to investigate the molecular mechanisms by which lncRNAs regulate PCV2-induced immunosuppression during SSP treatment. Our findings revealed that 1699 mRNAs, 373 lncRNAs, and 129 miRNAs were differentially expressed in PCV2-infected RAW264.7 cells. Additionally, 359 mRNAs, 271 lncRNAs, and 79 miRNAs exhibited differential expression in SSP-treated PCV2-infected RAW264.7 cells. GO and KEGG analyses indicated that the candidate genes were enriched in the TNF/NF-κB signaling pathway. Furthermore, based on GO and KEGG pathway analysis, a ceRNA network involving chemokine (C-X-C motif) ligand 2 (CXCL2), miR-217-x, and MSTRG.5823.1 was constructed. We demonstrated that lncRNA MSTRG.5823.1 localized to the cytoplasm. Moreover, we found that silencing or overexpressing lncRNA MSTRG.5823.1 significantly modulated PCV2-induced immunosuppression by regulating the activation of the TNF/NF-κB signaling pathway. Specifically, lncRNA MSTRG.5823.1 overexpression increased the expression of TNF/NF-κB signaling pathway-related genes and proteins in PCV2-infected RAW264.7 cells. Conversely, silencing lncRNA MSTRG.5823.1 decreased their expression. Rescue assays further revealed that the suppressive effects of miR-217-x overexpression on TNF/NF-κB signaling pathway-related genes and proteins could be reversed by MSTRG.5823.1 overexpression. These findings highlight the critical role of lncRNA MSTRG.5823.1 in PCV2 infection progression and suggest a new strategy for the prevention and treatment of PCV2 infection.
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Infecções por Circoviridae , Circovirus , NF-kappa B , Polissacarídeos , RNA Longo não Codificante , Transdução de Sinais , Sophora , Animais , Camundongos , Circovirus/imunologia , NF-kappa B/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos , Infecções por Circoviridae/imunologia , Polissacarídeos/farmacologia , Suínos , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Tolerância Imunológica/efeitos dos fármacosRESUMO
PANoptosis is manifested with simultaneous activation of biomarkers for both pyroptotic, apoptotic and necroptotic signaling via the molecular platform PANoptosome and it is involved in pathologies of various inflammatory diseases including hemophagocytic lymphohistiocytosis (HLH). Scutellarin is a flavonoid isolated from herbal Erigeron breviscapus (Vant.) Hand.-Mazz. and has been shown to possess multiple pharmacological effects, but it is unknown whether scutellarin has any effects on PANoptosis and related inflammatory diseases. In this study, we found that scutellarin inhibited cell death in bone marrow-derived macrophages (BMDMs) and J774A.1 cells treated with TGF-ß-activated kinase 1 (TAK1) inhibitor 5Z-7-oxozeaenol (OXO) plus lipopolysaccharide (LPS), which has been commonly used to induce PANoptosis. Western blotting showed that scutellarin dose-dependently inhibited the activation biomarkers for pyroptotic (Caspase-1p10 and GSDMD-NT), apoptotic (cleaved Casp3/8/9 and GSDME-NT), and necroptotic (phosphorylated MLKL) signaling. The inhibitory effect of scutellarin was unaffected by NLRP3 or Caspase-1 deletion. Interestingly, scutellarin blocked the assembly of PANoptosome that encompasses ASC, RIPK3, Caspase-8 and ZBP1, suggesting its action on upstream signaling. Consistent with this, scutellarin inhibited mitochondrial damage and mitochondrial reactive oxygen species (mtROS) generation in cells treated with OXO+LPS. Further, mito-TEMPO that can scavenge mtROS significantly inhibited OXO+LPS-induced PANoptotic cell death. In line with the in vitro results, scutellarin markedly alleviated systemic inflammation, multiple organ injury, and activation of PANoptotic biomarkers in mice with HLH. Collectively, our data suggest that scutellarin can inhibit PANoptosis by suppressing mitochondrial damage and mtROS generation and thereby mitigating multiple organ injury in mice with inflammatory disorders.
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Apigenina , Glucuronatos , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Mitocôndrias , Espécies Reativas de Oxigênio , Apigenina/farmacologia , Apigenina/uso terapêutico , Glucuronatos/farmacologia , Glucuronatos/uso terapêutico , Animais , Espécies Reativas de Oxigênio/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Camundongos , Linhagem Celular , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/imunologia , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Necroptose/efeitos dos fármacos , Masculino , MAP Quinase Quinase Quinases/metabolismo , Inflamação/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Zearalenona/administração & dosagem , Lactonas , ResorcinóisRESUMO
Stem cell therapy requires massive-scale homogeneous stem cells under strict qualification control. However, Prolonged ex vivo expansion impairs the biological functions and results in senescence of mesenchymal stem cells (MSCs). We investigated the function of CTDSPL in the premature senescence process of MSCs and clarified that miR-18a-5p played a prominent role in preventing senescence of long-term cultured MSCs and promoting the self-renewal ability of MSCs. Over-expression of CTDSPL resulted in an enlarged morphology, up-regulation of p16 and accumulation of SA-ß-gal of MSCs. The reduced phosphorylated RB suggested cell cycle arrest of MSCs. All these results implied that CTDSPL induced premature senescence of MSCs. We further demonstrated that miR-18a-5p was a putative regulator of CTDSPL by luciferase reporter assay. Inhibition of miR-18a-5p promoted the expression of CTDSPL and induced premature senescence of MSCs. Continuous overexpression of miR-18a-5p improved self-renewal of MSCs by reducing ROS level, increased expression of Oct4 and Nanog, and promoted growth rate and differentiation capability. We reported for the first time that the dynamic interaction of miR-18a-5p and CTDSPL is crucial for stem cell senescence.
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Células-Tronco Mesenquimais , MicroRNAs , MicroRNAs/genética , MicroRNAs/metabolismo , Diferenciação Celular/genética , Senescência Celular/genética , Regulação para Cima , Células-Tronco Mesenquimais/metabolismoRESUMO
OBJECTIVE: PANoptosis, a new form of regulated cell death, concomitantly manifests hallmarks for pyroptosis, apoptosis, and necroptosis. It has been usually observed in macrophages, a class of widely distributed innate immune cells in various tissues, upon pathogenic infections. The second-generation curaxin, CBL0137, can trigger necroptosis and apoptosis in cancer-associated fibroblasts. This study aimed to explore whether CBL0137 induces PANoptosis in macrophages in vitro and in mouse tissues in vivo. METHODS: Bone marrow-derived macrophages and J774A.1 cells were treated with CBL0137 or its combination with LPS for indicated time periods. Cell death was assayed by propidium iodide staining and immunoblotting. Immunofluorescence microscopy was used to detect cellular protein distribution. Mice were administered with CBL0137 plus LPS and their serum and tissues were collected for biochemical and histopathological analyses, respectively. RESULTS: The results showed that CBL0137 alone or in combination with LPS induced time- and dose-dependent cell death in macrophages, which was inhibited by a combination of multiple forms of cell death inhibitors but not each alone. This cell death was independent of NLRP3 expression. CBL0137 or CBL0137 + LPS-induced cell death was characterized by simultaneously increased hallmarks for pyroptosis, apoptosis and necroptosis, indicating that this is PANoptosis. Induction of PANoptosis was associated with Z-DNA formation in the nucleus and likely assembly of PANoptosome. ZBP1 was critical in mediating CBL0137 + LPS-induced cell death likely by sensing Z-DNA. Moreover, intraperitoneal administration of CBL0137 plus LPS induced systemic inflammatory responses and caused multi-organ (including the liver, kidney and lung) injury in mice due to induction of PANoptosis in these organs. CONCLUSIONS: CBL0137 alone or plus inflammatory stimulation induces PANoptosis both in vitro and in vivo, which is associated with systemic inflammatory responses in mice.
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Carbazóis , DNA Forma Z , Neoplasias , Camundongos , Animais , Lipopolissacarídeos/farmacologia , Apoptose , PiroptoseRESUMO
Fulminant hepatitis (FH) is a severe clinical syndrome leading to hepatic failure and even mortality. D-galactosamine (D-GalN) plus lipopolysaccharide (LPS) challenge is commonly used to establish an FH mouse model, but the mechanism underlying D-GalN/LPS-induced liver injury is incompletely understood. Previously, it has been reported that extracellular ATP that can be released under cytotoxic and inflammatory stresses serves as a damage signal to induce potassium ion efflux and trigger the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome activation through binding to P2X7 receptor. In this study, we tried to investigate whether it contributed to the fulminant hepatitis (FH) induced by D-GalN plus LPS. In an in vitro cellular model, D-GalN plus extracellular ATP, instead of D-GalN alone, induced pyroptosis and apoptosis, accompanied by mitochondrial reactive oxygen species (ROS) burst, and the oligomerization of Drp1, Bcl-2, and Bak, as well as the loss of mitochondrial membrane potential in LPS-primed macrophages, well reproducing the events induced by D-GalN and LPS in vivo. Moreover, these events in the cellular model were markedly suppressed by both A-804598 (an ATP receptor P2X7R inhibitor) and glibenclamide (an ATP-sensitive potassium ion channel inhibitor); in the FH mouse model, administration of A-804598 significantly mitigated D-GalN/LPS-induced hepatic injury, mitochondrial damage, and the activation of apoptosis and pyroptosis signaling, corroborating the contribution of extracellular ATP to the cell death. Collectively, our data suggest that extracellular ATP acts as an autologous damage-associated molecular pattern to augment mitochondrial damage, hepatic cell death, and liver injury in D-GalN/LPS-induced FH mouse model.
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Guanidinas , Lipopolissacarídeos , Necrose Hepática Massiva , Quinolinas , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Lipopolissacarídeos/farmacologia , Galactosamina/farmacologia , Fígado/metabolismo , Apoptose , Trifosfato de Adenosina/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
BACKGROUND: The transcriptional repressor B-cell lymphoma 6 (BCL6) has been reported to inhibit inflammation. So far, experimental evidence for the role of BCL6 in bronchopulmonary dysplasia (BPD) is lacking. Our study investigated the roles of BCL6 in the progression of BPD and its downstream mechanisms. METHODS: Hyperoxia or lipopolysaccharide (LPS) was used to mimic the BPD mouse model. To investigate the effects of BCL6 on BPD, recombination adeno-associated virus serotype 9 expressing BCL6 (rAAV9-BCL6) and BCL6 inhibitor FX1 were administered in mice. The pulmonary pathological changes, inflammatory chemokines and NLRP3-related protein were observed. Meanwhile, BCL6 overexpression plasmid was used in human pulmonary microvascular endothelial cells (HPMECs). Cell proliferation, apoptosis, and NLRP3-related protein were detected. RESULTS: Either hyperoxia or LPS suppressed pulmonary BCL6 mRNA expression. rAAV9-BCL6 administration significantly inhibited hyperoxia-induced NLRP3 upregulation and inflammation, attenuated alveolar simplification and dysregulated angiogenesis in BPD mice, which were characterized by decreased mean linear intercept, increased radical alveolar count and alveoli numbers, and the upregulated CD31 expression. Meanwhile, BCL6 overexpression promoted proliferation and angiogenesis, inhibited apoptosis and inflammation in hyperoxia-stimulated HPMECs. Moreover, administration of BCL6 inhibitor FX1 arrested growth and development. FX1-treated BPD mice exhibited exacerbation of alveolar pathological changes and pulmonary vessel permeability, with upregulated mRNA levels of pro-inflammatory cytokines and pro-fibrogenic factors. Furthermore, both rAAV9-BCL6 and FX1 administration exerted a long-lasting effect on hyperoxia-induced lung injury (≥4 wk). CONCLUSIONS: BCL6 inhibits NLRP3-mediated inflammation, attenuates alveolar simplification and dysregulated pulmonary vessel development in hyperoxia-induced BPD mice. Hence, BCL6 may be a target in treating BPD and neonatal diseases.
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Displasia Broncopulmonar , Hiperóxia , Lesão Pulmonar , Animais , Humanos , Recém-Nascido , Camundongos , Animais Recém-Nascidos , Displasia Broncopulmonar/etiologia , Displasia Broncopulmonar/metabolismo , Modelos Animais de Doenças , Células Endoteliais/patologia , Hiperóxia/metabolismo , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Pulmão/metabolismo , Lesão Pulmonar/tratamento farmacológico , Lesão Pulmonar/etiologia , Lesão Pulmonar/prevenção & controle , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , RNA Mensageiro/metabolismoRESUMO
Materials showing second-order nonlinear transport under time reversal symmetry can be used for Radio Frequency (RF) rectification, but practical application demands room temperature operation and sensitivity to microwatts level RF signals in the ambient. In this study, we demonstrate that BiTeBr exhibits a giant nonlinear response which persists up to 350 K. Through scaling and symmetry analysis, we show that skew scattering is the dominant mechanism. Additionally, the sign of the nonlinear response can be electrically switched by tuning the Fermi energy. Theoretical analysis suggests that the large Rashba spin-orbit interactions (SOI), which gives rise to the chirality of the Bloch electrons, provide the microscopic origin of the observed nonlinear response. Our BiTeBr rectifier is capable of rectifying radiation within the frequency range of 0.2 to 6 gigahertz at room temperature, even at extremely low power levels of -15 dBm, and without the need for external biasing. Our work highlights that materials exhibiting large Rashba SOI have the potential to exhibit nonlinear responses at room temperature, making them promising candidates for harvesting high-frequency and low-power ambient electromagnetic energy.
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OBJECTIVES: Chronic hyperglycemia is considered as an important factor to promote the neurodegenerative process of brain, and the synaptic plasticity as well as heterogeneity of hippocampal cells are thought to be associated with cognitive dysfunction in the early process of neurodegeneration. To date, fibronectin type III domain-containing protein 5 (FNDC5) has been highlighted its protective role in multiple neurodegenerative diseases. However, the potential molecular and cellular mechanisms of FNDC5 on synaptic plasticity regulation in cognitive impairment (CI) induced by diabetics are still need to known. METHODS/DESIGN: To investigate the heterogeneity and synaptic plasticity of hippocampus in animals with CI state induced by hyperglycemia, and explore the potential role of FNDC5 involved in this process. Firstly, the single cell sequencing was performed based on the hippocampal tissue from db diabetic mice induced CI and normal health control mice by ex vivo experiments; and then the integrated analysis and observations validation using Quantitative Real-time PCR, western blot as well as other in vitro studies. RESULTS: We observed and clarified the sub-cluster of type IC spiral ganglion neurons expressed marker genes as Trmp3 and sub-cluster of astrocytes with marker gene as Atp1a2 in hippocampal cells from diabetic animals induced CI and the effect of those on neuron-glial communication. We also found that FNDC5\BDNF-Trk axis was involved in the synaptic plasticity regulation of hippocampus. In high glucose induced brain injury model in vitro, we investigated that FNDC5 significantly regulates BDNF expression and that over-expression of FNDC5 up-regulated BDNF expression (p < 0.05) and can also significantly increase the expression of synapsin-1 (p < 0.05), which is related to synaptic plasticity, In addition, the unbalanced methylation level between H3K4 and H3K9 in Fndc5 gene promoter correlated with significantly down-regulated expression of FNDC5 (p < 0.05) in the hyperglycemia state. CONCLUSION: The current study revealed that the synaptic plasticity of hippocampal cells in hyperglycemia might be regulated by FNDC5\BDNF-Trk axis, playing the protective role in the process of CI induced by hyperglycemia and providing a target for the early treatment of hyperglycemia induced cognitive dysfunction in clinic.
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Disfunção Cognitiva , Diabetes Mellitus Experimental , Fibronectinas , Hiperglicemia , Animais , Humanos , Camundongos , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cognição , Disfunção Cognitiva/genética , Disfunção Cognitiva/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Fibronectinas/genética , Fibronectinas/metabolismo , Hipocampo , Hiperglicemia/metabolismo , Plasticidade Neuronal/fisiologia , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
Cell senescence has been implicated in the pathology of Parkinson's disease (PD). Both abnormal α-synuclein aggregation and iron deposition are suggested to be the triggers, facilitators, and aggravators during the development of PD. In this study, we investigated the involvement of α-synuclein and iron in the process of cell senescence in a mouse model of PD. In order to overexpress α-syn-A53T in the substantia nigra pars compacta (SNpc), human α-syn-A53T was microinjected into both sides of the SNpc in mice. We found that overexpression of α-syn-A53T for one week induced significant pro-inflammatory senescence-associated secretory phenotype (SASP), increased cell senescence-related proteins (ß-gal, p16, p21, H2A.X and γ-H2A.X), mitochondrial dysfunction accompanied by dysregulation of iron-related proteins (L-ferritin, H-ferritin, DMT1, IRP1 and IRP2) in the SNpc. In contrast, significant loss of nigral dopaminergic neurons and motor dysfunction were only observed after overexpression of α-syn-A53T for 4 weeks. In PC12 cells stably overexpressing α-syn-A53T, iron overload (ferric ammonium citrate, FAC, 100 µM) not only increased the level of reactive oxygen species (ROS), p16 and p21, but also exacerbated the processes of oxidative stress and cell senescence signalling induced by α-syn-A53T overexpression. Interestingly, reducing the iron level with deferoxamine (DFO) or knockdown of transferrin receptor 1 (TfR1) significantly improved both the phenotypes and dysregulated proteins of cell senescence induced by α-syn-A53T overexpression. All these evidence highlights the toxic interaction between iron and α-synuclein inducing cell senescence, which precedes nigral dopaminergic neuronal loss in PD. Further investigation on cell senescence may yield new therapeutic agents for the prevention or treatment of PD.
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Doença de Parkinson , Ratos , Camundongos , Animais , Humanos , Doença de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Neurônios Dopaminérgicos/metabolismo , Ferro/metabolismo , Substância Negra/metabolismo , Substância Negra/patologia , Dopamina/metabolismo , Senescência Celular , Modelos Animais de DoençasRESUMO
Malignant ventricular arrhythmia (VA) after myocardial infarction (MI) is mainly caused by myocardial electrophysiological remodeling. Brahma-related gene 1 (BRG1) is an ATPase catalytic subunit that belongs to a family of chromatin remodeling complexes called Switch/Sucrose Non-Fermentable Chromatin (SWI/SNF). BRG1 has been reported as a molecular chaperone, interacting with various transcription factors or proteins to regulate transcription in cardiac diseases. In this study, we investigated the potential role of BRG1 in ion channel remodeling and VA after ischemic infarction. Myocardial infarction (MI) mice were established by ligating the left anterior descending (LAD) coronary artery, and electrocardiogram (ECG) was monitored. Epicardial conduction of MI mouse heart was characterized in Langendorff-perfused hearts using epicardial optical voltage mapping. Patch-clamping analysis was conducted in single ventricular cardiomyocytes isolated from the mice. We showed that BRG1 expression in the border zone was progressively increased in the first week following MI. Cardiac-specific deletion of BRG1 by tail vein injection of AAV9-BRG1-shRNA significantly ameliorated susceptibility to electrical-induced VA and shortened QTc intervals in MI mice. BRG1 knockdown significantly enhanced conduction velocity (CV) and reversed the prolonged action potential duration in MI mouse heart. Moreover, BRG1 knockdown improved the decreased densities of Na+ current (INa) and transient outward potassium current (Ito), as well as the expression of Nav1.5 and Kv4.3 in the border zone of MI mouse hearts and in hypoxia-treated neonatal mouse ventricular cardiomyocytes. We revealed that MI increased the binding among BRG1, T-cell factor 4 (TCF4) and ß-catenin, forming a transcription complex, which suppressed the transcription activity of SCN5A and KCND3, thereby influencing the incidence of VA post-MI.
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Infarto do Miocárdio , Camundongos , Animais , Infarto do Miocárdio/metabolismo , Arritmias Cardíacas/genética , Miocárdio/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Miócitos Cardíacos/metabolismoRESUMO
BACKGROUND: Increasing evidence suggests that long noncoding RNAs play significant roles in vascular biology and disease development. One such long noncoding RNA, PSMB8-AS1, has been implicated in the development of tumors. Nevertheless, the precise role of PSMB8-AS1 in cardiovascular diseases, particularly atherosclerosis, has not been thoroughly elucidated. Thus, the primary aim of this investigation is to assess the influence of PSMB8-AS1 on vascular inflammation and the initiation of atherosclerosis. METHODS: We generated PSMB8-AS1 knockin and Apoe (Apolipoprotein E) knockout mice (Apoe-/-PSMB8-AS1KI) and global Apoe and proteasome subunit-ß type-9 (Psmb9) double knockout mice (Apoe-/-Psmb9-/-). To explore the roles of PSMB8-AS1 and Psmb9 in atherosclerosis, we fed the mice with a Western diet for 12 weeks. RESULTS: Long noncoding RNA PSMB8-AS1 is significantly elevated in human atherosclerotic plaques. Strikingly, Apoe-/-PSMB8-AS1KI mice exhibited increased atherosclerosis development, plaque vulnerability, and vascular inflammation compared with Apoe-/- mice. Moreover, the levels of VCAM1 (vascular adhesion molecule 1) and ICAM1 (intracellular adhesion molecule 1) were significantly upregulated in atherosclerotic lesions and serum of Apoe-/-PSMB8-AS1KI mice. Consistently, in vitro gain- and loss-of-function studies demonstrated that PSMB8-AS1 induced monocyte/macrophage adhesion to endothelial cells and increased VCAM1 and ICAM1 levels in a PSMB9-dependent manner. Mechanistic studies revealed that PSMB8-AS1 induced PSMB9 transcription by recruiting the transcription factor NONO (non-POU domain-containing octamer-binding protein) and binding to the PSMB9 promoter. PSMB9 (proteasome subunit-ß type-9) elevated VCAM1 and ICAM1 expression via the upregulation of ZEB1 (zinc finger E-box-binding homeobox 1). Psmb9 deficiency decreased atherosclerotic lesion size, plaque vulnerability, and vascular inflammation in Apoe-/- mice in vivo. Importantly, endothelial overexpression of PSMB8-AS1-increased atherosclerosis and vascular inflammation were attenuated by Psmb9 knockout. CONCLUSIONS: PSMB8-AS1 promotes vascular inflammation and atherosclerosis via the NONO/PSMB9/ZEB1 axis. Our findings support the development of new long noncoding RNA-based strategies to counteract atherosclerotic cardiovascular disease.
Assuntos
Aterosclerose , Placa Aterosclerótica , RNA Longo não Codificante , Animais , Humanos , Camundongos , Apolipoproteínas E/genética , Aterosclerose/metabolismo , Células Endoteliais/metabolismo , Inflamação/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Placa Aterosclerótica/patologia , Complexo de Endopeptidases do Proteassoma/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismoRESUMO
BACKGROUND: Despite the usefulness of white light endoscopy (WLE) and non-magnified narrow-band imaging (NBI) for screening for superficial oesophageal squamous cell carcinoma and precancerous lesions, these lesions might be missed due to their subtle features and interpretation variations among endoscopists. Our team has developed an artificial intelligence (AI) system to detect superficial oesophageal squamous cell carcinoma and precancerous lesions using WLE and non-magnified NBI. We aimed to evaluate the auxiliary diagnostic performance of the AI system in a real clinical setting. METHODS: We did a multicentre, tandem, double-blind, randomised controlled trial at 12 hospitals in China. Eligible patients were aged 18 years or older and underwent sedated upper gastrointestinal endoscopy for screening, investigation of gastrointestinal symptoms, or surveillance. Patients were randomly assigned (1:1) to either the AI-first group or the routine-first group using a computerised random number generator. Patients, pathologists, and statistical analysts were masked to group assignment, whereas endoscopists and research assistants were not. The same endoscopist at each centre did tandem upper gastrointestinal endoscopy for each eligible patient on the same day. In the AI-first group, the endoscopist did the first examination with the assistance of the AI system and the second examination without it. In the routine-first group, the order of examinations was reversed. The primary outcome was the miss rate of superficial oesophageal squamous cell carcinoma and precancerous lesions, calculated on a per-lesion and per-patient basis. All analyses were done on a per-protocol basis. This trial is registered with the Chinese Clinical Trial Registry (ChiCTR2100052116) and is completed. FINDINGS: Between Oct 19, 2021, and June 8, 2022, 5934 patients were randomly assigned to the AI-first group and 5912 to the routine-first group, of whom 5865 and 5850 were eligible for analysis. Per-lesion miss rates were 1·7% (2/118; 95% CI 0·0-4·0) in the AI-first group versus 6·7% (6/90; 1·5-11·8) in the routine-first group (risk ratio 0·25, 95% CI 0·06-1·08; p=0·079). Per-patient miss rates were 1·9% (2/106; 0·0-4·5) in AI-first group versus 5·1% (4/79; 0·2-9·9) in the routine-first group (0·37, 0·08-1·71; p=0·40). Bleeding after biopsy of oesophageal lesions was observed in 13 (0·2%) patients in the AI-first group and 11 (0·2%) patients in the routine-first group. No serious adverse events were reported by patients in either group. INTERPRETATION: The observed effect of AI-assisted endoscopy on the per-lesion and per-patient miss rates of superficial oesophageal squamous cell carcinoma and precancerous lesions under WLE and non-magnified NBI was consistent with substantial benefit through to a neutral or small negative effect. The effectiveness and cost-benefit of this AI system in real-world clinical settings remain to be further assessed. FUNDING: National Natural Science Foundation of China, 1·3·5 project for disciplines of excellence, West China Hospital, Sichuan University, and Chengdu Science and Technology Project. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.
Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Lesões Pré-Cancerosas , Humanos , Inteligência Artificial , Endoscopia/métodos , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/diagnóstico por imagem , Lesões Pré-Cancerosas/diagnóstico por imagem , Adolescente , AdultoRESUMO
Long non-coding RNAs (lncRNAs) function as key modulators in mammalian immunity, particularly due to their involvement in lncRNA-mediated competitive endogenous RNA (ceRNA) crosstalk. Despite their recognized significance in mammals, research on lncRNAs in lower vertebrates remains limited. In the present study, we characterized the first immune-related lncRNA (pol-lnc78) in the teleost Japanese flounder ( Paralichthys olivaceus). Results indicated that pol-lnc78 acted as a ceRNA for pol-miR-n199-3p to target the sterile alpha and armadillo motif-containing protein (SARM), the fifth discovered member of the Toll/interleukin 1 (IL-1) receptor (TIR) adaptor family. This ceRNA network regulated the antibacterial responses of flounder via the Toll-like receptor (TLR) signaling pathway. Specifically, SARM acted as a negative regulator and exacerbated bacterial infection by inhibiting the expression of inflammatory cytokines IL-1ß and tumor necrosis factor-α (TNF-α). Pol-miR-n199-3p reduced SARM expression by specifically interacting with the 3' untranslated region (UTR), thereby promoting SARM-dependent inflammatory cytokine expression and protecting the host against bacterial dissemination. Furthermore, pol-lnc78 sponged pol-miR-n199-3p to ameliorate the inhibition of SARM expression. During infection, the negative regulators pol-lnc78 and SARM were significantly down-regulated, while pol-miR-n199-3p was significantly up-regulated, thus favoring host antibacterial defense. These findings provide novel insights into the mechanisms underlying fish immunity and open new horizons to better understand ceRNA crosstalk in lower vertebrates.
Assuntos
Linguado , MicroRNAs , RNA Longo não Codificante , Animais , Citocinas/metabolismo , Regulação para Baixo , Linguado/genética , Linguado/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Endógeno Competitivo , RNA Longo não Codificante/genéticaRESUMO
Damage-associated molecular patterns (DAMPs) such as extracellular ATP and nigericin (a bacterial toxin) not only act as potassium ion (K+) efflux inducers to activate NLRP3 inflammasome, leading to pyroptosis, but also induce cell death independently of NLRP3 expression. However, the roles of energy metabolism in determining NLRP3-dependent pyroptosis and -independent necrosis upon K+ efflux are incompletely understood. Here we established cellular models by pharmacological blockade of energy metabolism, followed by stimulation with a K+ efflux inducer (ATP or nigericin). Two energy metabolic inhibitors, namely CPI-613 that targets α-ketoglutarate dehydrogenase and pyruvate dehydrogenase (a rate-limiting enzyme) and 2-deoxy-d-glucose (2-DG) that targets hexokinase, are recruited in this study, and Nlrp3 gene knockout macrophages were used. Our data showed that CPI-613 and 2-DG dose-dependently inhibited NLRP3 inflammasome activation, but profoundly increased cell death in the presence of ATP or nigericin. The cell death was K+ efflux-induced but NLRP3-independent, which was associated with abrupt reactive oxygen species (ROS) production, reduction of mitochondrial membrane potential, and oligomerization of mitochondrial proteins, all indicating mitochondrial damage. Notably, the cell death induced by K+ efflux and blockade of energy metabolism was distinct from pyroptosis, apoptosis, necroptosis or ferroptosis. Furthermore, fructose 1,6-bisphosphate, a high-energy intermediate of glycolysis, significantly suppressed CPI-613+nigericin-induced mitochondrial damage and cell death. Collectively, our data show that energy deficiency diverts NLRP3 inflammasome activation-dependent pyroptosis to Nlrp3-independent necrosis upon K+ efflux inducers, which can be dampened by high-energy intermediate, highlighting a critical role of energy metabolism in cell survival and death under inflammatory conditions.
Assuntos
Caprilatos , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Sulfetos , Humanos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/genética , Inflamassomos/metabolismo , Nigericina/farmacologia , Potássio/metabolismo , Necrose/genética , Metabolismo Energético/genética , Trifosfato de Adenosina/metabolismo , Interleucina-1beta/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
We present a novel use of femtosecond laser to treat capsular block syndrome (CBS) in a patient with dense opaque capsular block, who presented 16 years postcataract surgery. The extensive posterior capsular distension and densely opaque, milky fluid trapped behind the intraocular lens (IOL) prevented the use of neodymium-doped yttrium aluminum garnet (Nd: YAG) laser posterior capsulotomy as primary treatment. Intra-operative optical coherence tomography enabled visualization of the posterior capsule and iris hooks were used to increase the pupillary diameter to enable femtosecond laser-assisted posterior capsulotomy to be performed in a minimally invasive technique. CBS was relieved successfully and Nd: YAG laser performed subsequently to remove residual posterior capsule opacification safely and with good visual outcomes. This method avoids risks associated with posterior vitrectomies and compromised IOL stability from inadvertent capsular bag damage, and adds to the expanding uses of femtosecond laser technology.