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Iron homeostasis is critical for cellular and organismal function and is tightly regulated to prevent toxicity or anemia due to iron excess or deficiency, respectively. However, subcellular regulatory mechanisms of iron remain largely unexplored. Here, we report that SEL1L-HRD1 protein complex of endoplasmic reticulum (ER)-associated degradation (ERAD) in hepatocytes controls systemic iron homeostasis in a ceruloplasmin (CP)-dependent, and ER stress-independent, manner. Mice with hepatocyte-specific Sel1L deficiency exhibit altered basal iron homeostasis and are sensitized to iron deficiency while resistant to iron overload. Proteomics screening for a factor linking ERAD deficiency to altered iron homeostasis identifies CP, a key ferroxidase involved in systemic iron distribution by catalyzing iron oxidation and efflux from tissues. Indeed, CP is highly unstable and a bona fide substrate of SEL1L-HRD1 ERAD. In the absence of ERAD, CP protein accumulates in the ER and is shunted to refolding, leading to elevated secretion. Providing clinical relevance of these findings, SEL1L-HRD1 ERAD is responsible for the degradation of a subset of disease-causing CP mutants, thereby attenuating their pathogenicity. Together, this study uncovers the role of SEL1L-HRD1 ERAD in systemic iron homeostasis and provides insights into protein misfolding-associated proteotoxicity.
Assuntos
Ceruloplasmina , Degradação Associada com o Retículo Endoplasmático , Camundongos , Animais , Ceruloplasmina/genética , Ubiquitina-Proteína Ligases/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas/metabolismo , Homeostase , Ferro/metabolismoRESUMO
Human antigen R (HuR) is a universally expressed RNA-binding protein that plays an essential role in governing the fate of mRNA transcripts. Accumulating evidence indicated that HuR is involved in the development and functions of several cell types. However, its role in cerebral ischemia/reperfusion injury (CIRI) remains unclear. In this study, we found that HuR was significantly upregulated after CIRI. Moreover, we found that silencing HuR could inhibit the inflammatory response of microglia and reduce the damage to neurons caused by oxygen-glucose deprivation/reperfusion treatment. In vivo, we found that microglial HuR deficiency significantly ameliorated CIRI and reduced NLRP3-mediated inflammasome activation. Mechanistically, we found that HuR could regulate NLRP3 mRNA stability by binding to the AU-rich element (ARE) region within the 3' untranslated region (UTR) of NLRP3 mRNA. In addition, we found that the upregulation of HuR was dependent on the upregulation of NADPH oxidase-mediated ROS accumulation. Collectively, our studies revealed that HuR could regulate NLRP3 expression and that HuR deficiency abrogated the enhanced NLRP3 signaling in experimental ischemic stroke. Targeting HuR may be a novel therapeutic strategy for cerebral ischemic stroke treatment.
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Isquemia Encefálica , AVC Isquêmico , Traumatismo por Reperfusão , Isquemia Encefálica/metabolismo , Inflamassomos/metabolismo , AVC Isquêmico/genética , AVC Isquêmico/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo , RNA Mensageiro , Transdução de Sinais , AnimaisRESUMO
BACKGROUND: RabGEF1 is a guanine-nucleotide exchange factor for RAB-5, which plays an oncogenic role in certain human cancers. However, the function of RabGEF1 in glioma has not been studied. Here, we report that the down-regulation of RabGEF1 inhibits the proliferation and metastasis, and induces autophagy of U251 glioblastoma cells. METHODS: The expression of RabGEF1 in glioma and normal tissues were measured by immunohistochemistry. Four siRNAs targeting different sites of RabGEF1 were conducted and the interference efficiencies were verified by qRT-PCR assay. Western blot was used to detect the expression of interest proteins. Cell proliferation was detected using CCK-8 and clone formation assay. Cell migration and invasion were analyzed by scratch assay and transwell assay, respectively. Flow cytometry was used to detect cell cycle distribution and apoptosis. RESULTS: RabGEF1 was significantly up-regulated in human glioma tissues. RabGEF1 knockdown reduced cell viability, induced cell cycle arrest and apoptosis in U251 cells. Cell migration and invasion were also inhibited when RabGEF1 silencing. Mechanism studies showed that Cyclin D1 and CDK4/6 were significantly down-regulated when RabGEF1 silencing. p53 and caspase mediated apoptotic pathway was activated by down-regulation of RabGEF1. Moreover, RabGEF1 knockdown also induced autophagy in glioma cells. The investigation of AKT and Erk pathways suggested that phosphorylated AKT, p70S6K and phosphorylated Erk were all decreased when RabGEF1 silencing. CONCLUSION: In conclusion, our data suggest that RabGEF1 is up-regulated in human glioma and down-regulation of RabGEF1 inhibited cell proliferation and metastasis, and induced autophagy of U251 glioblastoma cells, which might be mediated by inactivation of AKT and Erk signaling pathways.
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Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/patologia , Regulação Neoplásica da Expressão Gênica , Glioblastoma/patologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Sistema de Sinalização das MAP Quinases , Proteínas Proto-Oncogênicas c-akt/metabolismo , Apoptose , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Estudos de Casos e Controles , Ciclo Celular , Movimento Celular , Proliferação de Células , Feminino , Glioblastoma/genética , Glioblastoma/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Células Tumorais CultivadasRESUMO
With the development of the Internet-of-Things (IoT) technology, the applications of gas sensors in the fields of smart homes, wearable devices, and smart mobile terminals have developed by leaps and bounds. In such complex sensing scenarios, the gas sensor shows the defects of cross sensitivity and low selectivity. Therefore, smart gas sensing methods have been proposed to address these issues by adding sensor arrays, signal processing, and machine learning techniques to traditional gas sensing technologies. This review introduces the reader to the overall framework of smart gas sensing technology, including three key points; gas sensor arrays made of different materials, signal processing for drift compensation and feature extraction, and gas pattern recognition including Support Vector Machine (SVM), Artificial Neural Network (ANN), and other techniques. The implementation, evaluation, and comparison of the proposed solutions in each step have been summarized covering most of the relevant recently published studies. This review also highlights the challenges facing smart gas sensing technology represented by repeatability and reusability, circuit integration and miniaturization, and real-time sensing. Besides, the proposed solutions, which show the future directions of smart gas sensing, are explored. Finally, the recommendations for smart gas sensing based on brain-like sensing are provided in this paper.
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Background: Methamphetamine is an illegal drug that poses serious public health concerns worldwide. Previous studies have demonstrated a strong association between methamphetamine abuse and non-lethal haemorrhagic stroke. Ischaemic stroke after methamphetamine intake is less common than haemorrhagic stroke. The present study investigated the clinical features and potential pathogenesis in a young methylamphetamine addict that presented with acute ischaemic stroke and reversible middle cerebral artery (MCA) occlusion. Methods: A retrospective data analysis was performed for the young methylamphetamine addict admitted to a hospital for acute ischaemic stroke followed by a literature review to explore the possible pathogenesis. Results: The patient had been receiving methamphetamine for past 2 years. His recurrent headache occurred half an hour after each consumption and was relieved within a few hours. The patient was admitted for acute ischaemic stroke. Urine toxicology screening was positive for methamphetamine. Magnetic resonance angiography revealed occlusion of the right MCA. After discontinuing medication and routine treatment, digital subtraction angiography revealed normal blood flow in the right MCA, indicating reversible MCA occlusion. Conclusion: For young patients with a stroke, a thorough investigation of the history of illicit drug use and toxicological screening of urine and serum samples should be performed. Young methamphetamine users need to be aware of the elevated risk of stroke as well as early signs and symptoms. Transient headaches in young methamphetamine users may be caused by cerebral vasospasms, suggesting the possibility of future catastrophic stroke events.
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BACKGROUND: Brain metastasis (BM) is a major pathological subtype of lung adenocarcinoma (LAD), but the pathogenic mechanisms of BM remain unclear. The potential prognostic biomarkers and therapeutic targets for BM of LAD urgently need to be identified. AC122108.1 is a recently discovered new long non-coding ribonucleic acid (RNA). METHODS: AC122108 was found to be overexpressed in a LAD BM cell model, and upregulated in 64.52% of LAD BM tissues. AC122108 is an independent factor of BM during LAD development; however, the molecular mechanisms and clinical significance of AC122108.1 in LAD have not yet been established. Additionally, in vitro and in vivo experiments showed that the direct binding of AC122108.1 with aldolase A (ALDOA) enhanced the proliferation, apoptosis, invasiveness, migration, and metastasis of LAD cells. RESULTS: This RNA-protein complex decreased the stability of the ß-catenin destruction complex, leading to the accumulation of ß-catenin in the cytoplasm and ultimately its translocation into the nucleus to activate Wnt(wingless/integrated)/ß-catenin signaling. CONCLUSIONS: Overall, AC122108.1 promotes LAD BM and its progression through the Wnt/ß-catenin pathway by directly binding to ALDOA. This study provides insights into the regulatory mechanism of the LAD BM. AC122108.1 may serve as a potential therapeutic target and prognostic biomarker of LAD.
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Abnormal levels of autophagy have been implicated in the pathogenesis of multiple diseases, including cancer. However, little is known about the role of autophagy-related genes (ARGs) in low-grade gliomas (LGG). Accordingly, the aims of this study were to assess the prognostic values of ARGs and to establish a genetic signature for LGG prognosis. Expression profile data from patients with and without primary LGG were obtained from The Cancer Genome Atlas (TCGA) and Genome Tissue Expression databases, respectively, and consensus clustering was used to identify clusters of patients with distinct prognoses. Nineteen differentially expressed ARGs were selected with threshold values of FDR < 0.05 and |log2 fold change (FC)| ≥ 2, and functional analysis revealed that these genes were associated with autophagy processes as expected. An autophagy-related signature was established using a Cox regression model of six ARGs that separated patients from TCGA training cohort into high- and low-risk groups. Univariate and multivariate Cox regression analysis indicated that the signature-based risk score was an independent prognostic factor. The signature was successfully validated using the TCGA testing, TCGA entire, and Chinese Glioma Genome Atlas cohorts. Stratified analyses demonstrated that the signature was associated with clinical features and prognosis, and gene set enrichment analysis revealed that autophagy- and cancer-related pathways were more enriched in high-risk patients than in low-risk patients. The prognostic value and expression of the six signature-related genes were also investigated. Thus, the present study constructed and validated an autophagy-related prognostic signature that could optimize individualized survival prediction in LGG patients.
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Autofagia/genética , Bases de Dados de Ácidos Nucleicos , Regulação Neoplásica da Expressão Gênica , Glioma , Intervalo Livre de Doença , Feminino , Glioma/genética , Glioma/metabolismo , Glioma/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Taxa de SobrevidaRESUMO
α-synuclein is a predominantly expressing neuronal protein for understanding the neurodegenerative disorders. A diagnosing system with aggregated α-synuclein encoded by SNCA gene is necessary to make the precautionary treatment against Parkinson's disease (PD). Herein, gold-nanourchin conjugated anti-α-synuclein antibody was desired as the probe and seeded on single-walled carbon nanotube (SWCN) integrated interdigitated electrode (IDE). The surface morphology of SWCN-modified IDE and gold urchin-antibody conjugates were observed under FESEM, FETEM and AFM, the existing elements were confirmed. Voltammetry analysis revealed that the limit of fibril-formed α-synuclein detection was improved by 1000 folds (1â¯fM) with gold-nanourchin-antibody modified surface, compared to the surface with only antibody (1 pM). Validating the interaction of α-synuclein by Enzyme-linked Immunosorbent Assay was displayed the detection limit as 10 pM. IDE has a good reproducibility and a higher selectivity on α-synuclein as evidenced by the interactive analysis with the control proteins, PARK1 and DJ-1.
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Nanopartículas Metálicas/química , Nanotubos de Carbono/química , alfa-Sinucleína/análise , Anticorpos Imobilizados/imunologia , Biomarcadores/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Ouro/química , Imunoensaio/métodos , Limite de Detecção , Doença de Parkinson/diagnóstico , Reprodutibilidade dos Testes , alfa-Sinucleína/imunologiaRESUMO
OBJECTIVE: Glioma is one of the leading causes of death worldwide with high incidence, recurrence, and mortality. Interleukin-10 (IL-10) is a cytokine with dual function in many types of tumors. Although IL-10 is overexpressed and promotes tumor progression in human primary brain tumor, the mechanisms are largely unknown. MATERIALS AND METHODS: Glioma cells were treated with different dosages of IL-10. The cell growth was detected by CCK-8, and the invasion was measured by Transwell. The relative expression of messenger RNAs was detected by quantitative real-time polymerase chain reaction. RESULTS: We found that IL-10 treatment significantly enhanced glioma cell growth and invasion. Moreover, KPNA2 was significantly upregulated after treatment with IL-10. By performing knockdown experiments, we found that the glioma cell growth and invasion were significantly declined. CONCLUSIONS: The results indicated that knockdown of KPNA2 significantly inhibited the growth and invasion of glioma cells. Moreover, IL-10 promotes glioma progression via upregulation of KPNA2. This study will be of important significance and provides a potential target for treatment of patients with glioma.
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Neoplasias Encefálicas/patologia , Movimento Celular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Glioma/patologia , Interleucina-10/metabolismo , alfa Carioferinas/metabolismo , Apoptose , Neoplasias Encefálicas/genética , Glioma/genética , Humanos , Técnicas In Vitro , Interleucina-10/antagonistas & inibidores , Interleucina-10/genética , Invasividade Neoplásica , RNA Interferente Pequeno/genética , Células Tumorais Cultivadas , alfa Carioferinas/genéticaRESUMO
In order to explore the reason for the weak bond intensity between pyro-phosphate copper plating layer and iron substrate, spectrum technology was adopted. The compositions of various elements in the perpendicular interface were analyzed. The effect of surface roughness in the metal substrate on various elements distribution was discussed. According to etching time, the membrane layer was divided into three portions: surface layer with nitrogen and oxygen content decreasing quickly, mesosphere of basic fixed composition, and mix disturbing layer with substrate element appearing and occupying a half thickness. Through analyzing oxygen content in the mix layer, it was concluded that the oxygen layer in the interface of copper layer/iron substrate was the main cause of influencing the bond intensity between the plating layer and substrate.
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OBJECTIVE: To observe the clinical treatment effectiveness of clarithromycin for naso-sinusitis after nasopharyngeal carcinoma radiotherapy. METHOD: Twenty-four cases of naso-sinusitis after one year nasopharyngeal carcinoma radiotherapy were treated with the oral clarithromycin of small dosage (250 mg everyday). The course of treatment were for 12 to 20 weeks. The treatment effectiveness were evaluated with the chronic naso-sinusitis visual analog quality table mark system (VAS) and Lund-Mackay nasal sinuses CT image mark system before and after treatment. RESULT: The VAS mark and CT image mark have significant deviation (P < 0.01) among pretherapy, post-treatment and 6 months after drug withdrawal. No significant deviation was found(P > 0.05) between post treatment and 6 months after drug withdrawal. The treatment effectiveness was judged for very good is 9 cases, for the good is 11 cases and for the bad is 4 cases. CONCLUSION: The clarithromycin of small dosage for long-term treatment of naso-sinusitis after nasopharyngeal carcinoma radiotherapy has positive clinical treatment effectiveness, which is a better treatment method.