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Rapid accumulation of repair factors at DNA double-strand breaks (DSBs) is essential for DSB repair. Several factors involved in DSB repair have been found undergoing liquid-liquid phase separation (LLPS) at DSB sites to facilitate DNA repair. RNF168, a RING-type E3 ubiquitin ligase, catalyzes H2A.X ubiquitination for recruiting DNA repair factors. Yet, whether RNF168 undergoes LLPS at DSB sites remains unclear. Here, we identified K63-linked polyubiquitin-triggered RNF168 condensation which further promoted RNF168-mediated DSB repair. RNF168 formed liquid-like condensates upon irradiation in the nucleus while purified RNF168 protein also condensed in vitro. An intrinsically disordered region containing amino acids 460-550 was identified as the essential domain for RNF168 condensation. Interestingly, LLPS of RNF168 was significantly enhanced by K63-linked polyubiquitin chains, and LLPS largely enhanced the RNF168-mediated H2A.X ubiquitination, suggesting a positive feedback loop to facilitate RNF168 rapid accumulation and its catalytic activity. Functionally, LLPS deficiency of RNF168 resulted in delayed recruitment of 53BP1 and BRCA1 and subsequent impairment in DSB repair. Taken together, our finding demonstrates the pivotal effect of LLPS in RNF168-mediated DSB repair.
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Reparo do DNA , Ubiquitina-Proteína Ligases , Humanos , Quebras de DNA de Cadeia Dupla , Histonas/metabolismo , Histonas/genética , Poliubiquitina/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , UbiquitinaçãoRESUMO
RAP80 has been characterized as a component of the BRCA1-A complex and is responsible for the recruitment of BRCA1 to DNA double-strand breaks (DSBs). However, we and others found that the recruitment of RAP80 and BRCA1 were not absolutely temporally synchronized, indicating that other mechanisms, apart from physical interaction, might be implicated. Recently, liquid-liquid phase separation (LLPS) has been characterized as a novel mechanism for the organization of key signaling molecules to drive their particular cellular functions. Here, we characterized that RAP80 LLPS at DSB was required for RAP80-mediated BRCA1 recruitment. Both cellular and in vitro experiments showed that RAP80 phase separated at DSB, which was ascribed to a highly disordered region (IDR) at its N-terminal. Meanwhile, the Lys63-linked poly-ubiquitin chains that quickly formed after DSBs occur, strongly enhanced RAP80 phase separation and were responsible for the induction of RAP80 condensation at the DSB site. Most importantly, abolishing the condensation of RAP80 significantly suppressed the formation of BRCA1 foci, encovering a pivotal role of RAP80 condensates in BRCA1 recruitment and radiosensitivity. Together, our study disclosed a new mechanism underlying RAP80-mediated BRCA1 recruitment, which provided new insight into the role of phase separation in DSB repair.
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Piezoelectric dynamic therapy (PzDT) is an effective method of tumor treatment by using piezoelectric polarization to generate reactive oxygen species. In this paper, two-dimensional Cu-doped BiOCl nanosheets with surface vacancies are produced by the photoetching strategy. Under ultrasound, a built-in electric field is generated to promote the electron and hole separation. The separated carriers achieve O2 reduction and GSH oxidation, inducing oxidative stress. The bandgap of BiOCl is narrowed by introducing surface oxygen vacancies, which act as charge traps and facilitate the electron and hole separation. Meanwhile, Cu doping induces chemodynamic therapy and depletes GSH via the transformation from Cu(II) to Cu(I). Both in vivo and in vitro results confirmed that oxidative stress can be enhanced by exogenous ultrasound stimulation, which can cause severe damage to tumor cells. This work emphasizes the efficient strategy of doping engineering and defect engineering for US-activated PzDT under exogenous stimulation.
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Cobre , Nanoestruturas , Oxigênio , Oxigênio/química , Cobre/química , Humanos , Nanoestruturas/química , Nanoestruturas/uso terapêutico , Animais , Camundongos , Neoplasias/terapia , Estresse Oxidativo/efeitos dos fármacos , Linhagem Celular Tumoral , Bismuto/química , Espécies Reativas de Oxigênio/metabolismo , Glutationa/químicaRESUMO
Chemodynamic therapy (CDT) is a non-invasive strategy for generating reactive oxygen species (ROS) and is promising for cancer treatment. However, increasing ROS in tumor therapy remains challenging. Therefore, exogenous excitation and inhibition of electron-hole pair recombination are attractive for modulating ROS storms in tumors. Herein, a Ce-doped BiFeO3 (CBFO) piezoelectric sonosensitizer to modulate ROS generation and realize a synergistic mechanism of CDT/sonodynamic therapy and piezodynamic therapy (PzDT) is proposed. The mixed Fe2+ and Ce3+ can implement a circular Fenton/Fenton-like reaction in the tumor microenvironment. Abundant ·OH can be generated by ultrasound (US) stimulation to enhance CDT efficacy. As a typical piezoelectric sonosensitizer, CBFO can produce O2 - owing to the enhanced polarization by the US, resulting in the motion of charge carriers. In addition, CBFO can produce a piezoresponse irradiated upon US, which accelerates the migration rate of electrons/holes in opposite directions and results in energy band bending, further achieving toxic ROS production and realizing PzDT. Density functional theory calculations confirmed that Ce doping shortens the diffusion of electrons and improves the conductivity and catalytic activity of CBFO. This distinct US-enhanced strategy emphasizes the effects of doping engineering and piezoelectric-optimized therapy and shows great potential for the treatment of malignant tumors.
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BACKGROUND: Multiple neural structures involved in maintaining wakefulness have been found to promote arousal from general anesthesia. The medial septum is a critical region that modulates arousal behavior. This study hypothesized that glutamatergic neurons in the medial septum play a crucial role in regulating states of consciousness during sevoflurane general anesthesia. METHODS: Adult male mice were used in this study. The effects of sevoflurane anesthesia on neuronal activity were determined by fiber photometry. Lesions and chemogenetic manipulations were used to study the effects of the altered activity of medial septal glutamatergic neurons on anesthesia induction, emergence, and sensitivity to sevoflurane. Optogenetic stimulation was used to observe the role of acute activation of medial septal glutamatergic neurons on cortical activity and behavioral changes during sevoflurane-induced continuous steady state of general anesthesia and burst suppression state. RESULTS: The authors found that medial septal glutamatergic neuronal activity decreased during sevoflurane anesthesia induction and recovered in the early period of emergence. Chemogenetic activation of medial septal glutamatergic neurons prolonged the induction time (mean ± SD, hM3Dq-clozapine N-oxide vs. hM3Dq-saline, 297.5 ± 60.1 s vs. 229.4 ± 29.9 s, P < 0.001, n = 11) and decreased the emergence time (53.2 ± 11.8 s vs. 77.5 ± 33.5 s, P = 0.025, n = 11). Lesions or chemogenetic inhibition of these neurons produced the opposite effects. During steady state of general anesthesia and deep anesthesia-induced burst suppression state, acute optogenetic activation of medial septal glutamatergic neurons induced cortical activation and behavioral emergence. CONCLUSIONS: The study findings reveal that activation of medial septal glutamatergic neurons has arousal-promoting effects during sevoflurane anesthesia in male mice. The activation of these neurons prolongs the induction and accelerates the emergence of anesthesia.
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Estado de Consciência , Neurônios , Camundongos , Animais , Masculino , Sevoflurano/farmacologia , Vigília/fisiologia , Anestesia GeralRESUMO
Hemodialysis is an important part of nosocomial infection prevention and control (IPC). This study aimed to identify the key potential risk areas and failure modes in hemodialysis rooms in hospitals and put forward a series of improvement measures to prevent and control the spread of the coronavirus disease 2019 (COVID-19). Hemodialysis patients are highly susceptible to COVID-19 and usually have a high incidence of severe illness and mortality after infection with COVID-19. Therefore, IPC in hemodialysis patients is of crucial strategic significance. Based on 30 domain experts' interviews and careful analysis of prevention and control documents, we constructed a comprehensive failure system for a model that identifies the potential risks for nosocomial COVID-19 infection in the hemodialysis room. Subsequently, a thorough risk assessment of the potential failure factors identified in our model was conducted. The failure key factors corresponding to the human element in medical waste (garbage) disposal (C2) are verified to be the highest risk factors. They are as follows: The cleaning staff did not dispose of different types of medical waste (garbage) (C21), did not wear masks according to the regulations (C22), and lacked knowledge and norms of nosocomial IPC (C23). This study provides valuable insights for hospital decision-makers on the potential failure factors related to COVID-19 infections in hemodialysis rooms. By working with hospital infection specialists, the suggested improvement measures can help reduce the risk of virus exposure among hospital medical staff, patients, and cleaning staff.
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Electromagnetic indices play a potential role in the forecast of short-term to imminent M ≥ 5.5 earthquakes and have good application prospects. However, despite possible progress in earthquake forecasting, concerns remain because it is difficult to obtain accurate epicenter forecasts based on different forecast indices, and the forecast time span is as large as months in areas with multiple earthquakes. In this study, based on the actual demand for short-term earthquake forecasts in the Gansu-Qinghai-Sichuan region of western China, we refined the construction of earthquake forecast indicators in view of the abundant electromagnetic anomalies before moderate and strong earthquakes. We revealed the advantageous forecast indicators of each method for the three primary earthquake elements (time, epicenter, magnitude) and the spatiotemporal evolution characteristics of the anomalies. The correlations between the magnitude, time, intensity, and electromagnetic anomalies of different M ≥ 5.5 earthquakes indicate that the combination of short-term electromagnetic indices is pivotal in earthquake forecasting.
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Geomagnetic vertical intensity polarization is a method with a clear mechanism, mature processing methods, and a strong ability to extract anomalous information in the quantitative analysis of seismogenic geomagnetic disturbances. The existing analyses of geomagnetic vertical intensity polarization are all based on the 5~100 s frequency band without refinement of the partitioning process. Although many successful results have been obtained, there are still two problems in the process of extracting anomalies: the geomagnetic anomalies that satisfy the determination criteria are still high in occurrence frequency; and the anomalies are distributed over too large an area in space, which leads to difficulties in determining the location of the epicenter. In this study, based on observations from western China, where fluxgate observation points are positioned in areas with frequent, densely distributed medium-strength earthquakes, we refined the frequency bands of geomagnetic vertical intensity polarization, recalculated the spatial and temporal evolution characteristics of geomagnetic disturbances before earthquakes, and improved the crossover frequency anomaly prediction index while promoting the application of the method in earthquake forecasting.
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Compelling evidence has shown that geomagnetic disturbances in vertical intensity polarization before great earthquakes are promising precursors across diverse rupture conditions. However, the geomagnetic vertical intensity polarization method uses the spectrum of smooth signals, and the anomalous waveforms of seismic electromagnetic radiation, which are basically nonstationary, have not been adequately considered. By combining pulse amplitude analysis and an experimental study of the cumulative frequency of anomalies, we found that the pulse amplitudes before the 2022 Luding M6.8 earthquake show characteristics of multiple synchronous anomalies, with the highest (or higher) values occurring during the analyzed period. Similar synchronous anomalies were observed before the 2021 Yangbi M6.4 earthquake, the 2022 Lushan M6.1 earthquake and the 2022 Malcolm M6.0 earthquake, and these anomalies indicate migration from the periphery toward the epicenters over time. The synchronous changes are in line with the recognition of previous geomagnetic anomalies with characteristics of high values before an earthquake and gradual recovery after the earthquake. Our study suggests that the pulse amplitude is effective for extracting anomalies in geomagnetic vertical intensity polarization, especially in the presence of nonstationary signals when utilizing observations from multiple station arrays. Our findings highlight the importance of incorporating pulse amplitude analysis into earthquake prediction research on geomagnetic disturbances.
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Arming activatable mild-photothermal therapy (PTT) with the property of relieving tumor thermotolerance holds great promise for overcoming traditional mild PTT limitations such as thermoresistance, insufficient therapeutic effect, and off-target heating. Herein, a mitochondria-targeting, defect-engineered AFCT nanozyme with enhanced multi-enzymatic activity was elaborately designed as a tumor microenvironment (TME)-activatable phototheranostic agent to achieve remarkable anti-tumor therapy via "electron transport chain (ETC) interference and synergistic adjuvant therapy". Density functional theory calculations revealed that the synergistic effect among multi-enzyme active centers endows the AFCT nanozymes with excellent catalytic activity. In TME, open sources of H2O2 can be achieved by superoxide dismutase-mimicking AFCT nanozymes. In response to the dual stimuli of H2O2 and mild acidity, the peroxidase-mimicking activity of AFCT nanozymes not only catalyzes the accumulation of H2O2 to generate ·OH but also converts the loaded 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) into its oxidized form with strong near-infrared absorption, specifically unlocking its photothermal and photoacoustic imaging properties. Intriguingly, the undesired thermoresistance of tumor cells can be greatly alleviated owing to the reduced expression of heat shock proteins enabled by NADH POD-mimicking AFCT-mediated NADH depletion and consequent restriction of ATP supply. Meanwhile, the accumulated ·OH can facilitate both apoptosis and ferroptosis in tumor cells, resulting in synergistic therapeutic outcomes in combination with TME-activated mild PTT.
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Nanopartículas , Neoplasias , Humanos , Terapia Fototérmica , Fototerapia/métodos , Peróxido de Hidrogênio , Transporte de Elétrons , NAD , Nanopartículas/uso terapêutico , Neoplasias/terapia , Linhagem Celular Tumoral , Microambiente TumoralRESUMO
BACKGROUND: Accurately assessing the risk of recurrence in patients with locally advanced rectal cancer (LARC) before treatment is important for the development of treatment strategies. The purpose of this study is to develop an MRI-based scoring system to predict the risk of recurrence in patients with LARC. METHODS: This was a multicenter observational study that enrolled participants who underwent neoadjuvant chemoradiotherapy. To evaluate the risk of recurrence in these patients, we developed the mrDEC scoring system and assessed inter-reader agreement. Additionally, we plotted Kaplan-Meier curves to compare the 3-year disease-free survival (DFS) and 5-year overall survival (OS) rates among patients with different mrDEC scores. RESULTS: A total of 1287 patients with LARC were included in this study. We observed substantial inter-reader agreement for mrDEC. Based on the mrDEC scores ranging from 0 to 3, the patients were categorized into four groups. The 3-year DFS rates for the groups were 91.0%, 79.5%, 65.5%, and 44.0% (P < 0.0001), respectively, and the 5-year OS rates were 92.9%, 87.1%, 74.8%, and 44.5%, respectively (P < 0.0001). CONCLUSIONS: The mrDEC scoring system proved to be an effective tool for predicting the prognosis of patients with LARC and can assist clinicians in clinical decision-making.
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Neoplasias Retais , Humanos , Resultado do Tratamento , Neoplasias Retais/terapia , Neoplasias Retais/tratamento farmacológico , Quimiorradioterapia , Prognóstico , Intervalo Livre de Doença , Terapia Neoadjuvante , Imageamento por Ressonância Magnética , Medição de Risco , Estudos Retrospectivos , Estadiamento de NeoplasiasRESUMO
Increasing the yield of reactive oxygen species (ROS) to enhance oxidative stress in cells is an eternal goal in cancer therapy. In this study, BiVO4 artificial nanozyme is developed with adjustable vanadium vacancy for ultrasound (US) enhanced piezoelectric/sonodynamic therapy. Under US excitation, the vanadium vacancy-rich BiVO4 nanosheets (abbreviated Vv -r BiVO4 NSs) facilitate the generation of a large number of electrons to improve the ROS yield. Meanwhile, the mechanical strain imposed by US irradiation makes the Vv -r BiVO4 NSs display a typical piezoelectric response, which tilts the conduction band to be more negative and the valance band more positive than the redox potentials of O2 /O2 â¢- and H2 O/·OH, boosting the efficiency of ROS generation. Both density functional theory calculations and experiments confirm that the introduction of cationic vacancy can improve the sonodynamic effect. As expected, Vv -r BiVO4 NSs have better peroxidase enzyme catalytic and glutathione depletion activities, resulting in increased intracellular oxidative stress. This triple amplification strategy of oxidative stress induced by US substantially inhibits the growth of cancer cells. The work may open an avenue to achieve a synergetic therapy by introducing cationic vacancy, broadening the biomedical use of piezoelectric materials.
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Corantes , Vanádio , Espécies Reativas de Oxigênio , Ultrassonografia , CatáliseRESUMO
This work aims at developing a strategy to activate the antigen-presenting cells to enhance the effect of immunotherapy in triple-negative breast cancer (TNBC) through the dissolving microneedle patch (DMNP). In present study, mannosylated chitosan (MCS) nanoparticles (NPs) were designed to target dendritic cells (DCs), and the immunotherapy effect was enhanced by the adjuvant Bacillus Calmette-Guerin polysaccharide (BCG-PSN), achieving the purpose of transdermal immunotherapy for TNBC. Vaccination studies with mice demonstrated that MCS NPs effectively induce DCs maturation in the tumor-draining lymph nodes to stimulate strong immune responses in TNBC. Overall, chitosan-based DMNPs with complex adjuvant constituted a new potent transdermal vaccine delivery platform capable of exploiting more DCs in the skin for effective immunization.
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Vacinas Anticâncer , Quitosana , Nanopartículas , Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Células Dendríticas , Neoplasias de Mama Triplo Negativas/terapia , Vacinas Anticâncer/farmacologia , Imunoterapia , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) has received extensive attention for its utility in tubeless anesthesia. Still, the effects of its carbon dioxide accumulation on emergence from anesthesia have not been reported. This randomized controlled trial aimed at exploring the impact of THRIVE combined with laryngeal mask (LM) on the quality of emergence in patients undergoing microlaryngeal surgery. METHODS: After research ethics board approval, 40 eligible patients receiving elective microlaryngeal vocal cord polypectomy were randomly allocated 1:1 to two groups, THRIVE + LM group: intraoperative apneic oxygenation using THRIVE followed by mechanical ventilation through a laryngeal mask in the post-anesthesia care unit (PACU), or MV + ETT group: mechanically ventilated through an endotracheal tube for both intraoperative and post-anesthesia periods. The primary outcome was duration of PACU stay. Other parameters reflecting quality of emergence and carbon dioxide accumulation were also recorded. RESULTS: Duration of PACU stay (22.4 ± 6.4 vs. 28.9 ± 8.8 min, p = 0.011) was shorter in the THRIVE + LM group. The incidence of cough (2/20, 10% vs. 19/20, 95%, P < 0.001) was significantly lower in the THRIVE + LM group. Peripheral arterial oxygen saturation and mean arterial pressure during intraoperative and PACU stay, Quality of Recovery Item 40 total score at one day after surgery and Voice Handicap Index-10 score at seven days after surgery were of no difference between two groups. CONCLUSIONS: The THRIVE + LM strategy could accelerate emergence from anesthesia and reduce the incidence of cough without compromising oxygenation. However, these benefits did not convert to the QoR-40 and VHI-10 scores improvement. TRIAL REGISTRATION: ChiCTR2000038652.
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Anestesiologia , Insuflação , Humanos , Dióxido de Carbono , Tosse , Anestesia GeralRESUMO
Context: Surgery for early-stage lung carcinoma (LC) is invasive and most patients will experience psychological disorders, such as depression and anxiety. Accumulating evidence has shown that a nursing intervention can exert significant improvements in clinical efficacy for perioperative patients. Objective: The study intended to investigate the clinical value during the perioperative period of a nursing service based on Roy's Adaptation Model (RAM), for patients undergoing radical resection for early-stage LC, to provide accurate guidance and reference for a future clinical nursing intervention for LC patients. Design: The research team designed a retrospective analysis, controlled study. Setting: The study took place at Jiangsu Cancer Hospital in Nanjing, Jiangsu, China. Participants: Participants were 69 patients with early-stage LC who had been admitted to the hospital between March 2018 and March 2020. Intervention: The research team assigned participants to an intervention or a control group, with 42 participants in the intervention group receiving RAM nursing during hospitalization, and 27 participants in the control group receiving routine nursing care. Outcome Measures: The study measured the alterations in pulmonary function (PF) pre- and postoperatively and assessed the incidence of complications postintervention. At baseline and postintervention, the research team also assessed participants' psychological states using the Self-rating Anxiety Scale (SAS) and the Self-rating Depression Scale (SDS) and their pain levels using a visual analogue scale (VAS). Postintervention, participants competed a nursing satisfaction survey. At baseline and postintervention, the participants completed the Karnofsky Performance Status (KPS) scale for functional status, the Self-Perceived Burden Scale in Cancer Patients (SPBS-CP), the Pittsburgh Sleep Quality Index (PSQI) for sleep quality, and the WHO-QOL-BREF questionnaire. Results: Postoperatively, the PF indexes had decreased significantly for both groups, but the intervention group's value were significantly higher postoperatively than those in the control group (P < .05). No differences existed in the incidence of adverse reactions between the groups (P > .05). The intervention group had significantly lower SAS and SDS scores, pain scores, and SPBS-CP scores than the control group postintervention but had significantly higher KPS scores (all P < .05). The intervention group significantly higher nursing satisfaction, sleep quality, and quality of life than the control group did (P < .05). Conclusions: RAM nursing can significantly protect the PF of patients with early-stage LC who are undergoing a radical resection and can effectively improve patients' psychological states, sleep quality, and nursing satisfaction, which makes it worthy of clinical reference and popularization.
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Neoplasias Pulmonares , Enfermagem Perioperatória , Humanos , Qualidade de Vida , Estudos Retrospectivos , DorRESUMO
Tectonic extrusion bypassing the eastern Himalayan syntaxis results in a significant increase in regional stress instability and the associated frequent occurrence of earthquakes in southern Yunnan, China. However, the stress field, and the relationship between the focal mechanism of earthquakes and stress evolution in southern Yunnan, remain enigmatic. In this paper, using a modified grid point test method, we calculated the focal mechanism of ML ≥ 2.5 earthquakes in southern Yunnan (22-25° N, 100-104° E) from January 2009 to June 2023. Utilizing the solutions of historical earthquake focal mechanisms, we obtained the present-day regional tectonic stress field in southern Yunnan via inversion. The results indicate complex and diverse seismic focal mechanisms, and the main types of earthquakes are strike-slip events, followed by normal fault and reverse fault events. The orientations of the maximum and minimum principal stress axes rotate in a clockwise direction from northeast to southwest. The internal stress orientation distribution of the rhombic Sichuan-Yunnan block in the study area is consistent, and the block boundary zone is the site where stress deflection occurs, and the regional tectonic stress field is influenced by the interaction among different blocks. The distribution of R-value in the Lamping-Simao block gradually increases from north to south, indicating that the compressive stress required for material transport becomes relatively small. Combined with the geological and tectonic background of the study area, our results suggest that the speed of block movement gradually decreases from north to south; the distribution of R-value in the South China block is significantly smaller than that of the interior of the Sichuan-Yunnan rhombus, and the proportion of compressive stresses is larger, indicating a stronger extrusion in this region, which may be related to the fact that the Sichuan-Yunnan rhombus is strongly resisted by the South China block in the east.
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There is increasing evidence indicating that the production of heat-labile enterotoxin (LT) enhances bacterial adherence within in vitro and in vivo models. However, which subunit plays the main role, and the precise regulatory mechanisms remain unclear. To further elucidate the contribution of the A subunit of LT (LTA) and the B subunit of LT (LTB) in LT-enhanced bacterial adherence, we generated several LT mutants where their ADP-ribosylation activity or GM1 binding ability was impaired and evaluated their abilities to enhance the two LT-deficient E. coli strains (1836-2 and EcNc) adherence. Our results showed that the two LT-deficient strains, expressing either the native LT or LT derivatives, had a significantly greater number of adhesions to host cells than the parent strains. The adherence abilities of strains expressing the LT mutants were significantly reduced compared with the strains expressing the native LT. Moreover, E. coli 1836-2 and EcNc strains when exogenously supplied with cyclic AMP (cAMP) highly up-regulated the adhesion molecules expression and improved their adherence abilities. Ganglioside GM1, the receptor for LTB subunit, is enriched in lipid rafts. The results showed that deletion of cholesterol from cells also significantly decreased the ability of LT to enhance bacterial adherence. Overall, our data indicated that both subunits are equally responsible for LT-enhanced bacterial adherence, the LTA subunit contributes to this process mainly by increasing bacterial adhesion molecules expression, while LTB subunit mainly by mediating the initial interaction with the GM1 receptors of host cells.
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Toxinas Bacterianas , Proteínas de Escherichia coli , Enterotoxinas/genética , Enterotoxinas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Temperatura Alta , Gangliosídeo G(M1) , Proteínas de Escherichia coli/genéticaRESUMO
Myocardial infarction (MI)-induced heart failure (HF) is commonly accompanied with profound effects on skeletal muscle. With the process of MI-induced HF, perturbations in skeletal muscle contribute to muscle atrophy. Exercise is viewed as a feasible strategy to prevent muscle atrophy. The aims of this study were to investigate whether exercise could alleviate MI-induced skeletal muscle atrophy via insulin-like growth factor 1 (IGF-1) pathway in mice. Male C57/BL6 mice were used to establish the MI model and were divided into three groups: sedentary MI group (MI), MI with aerobic exercise group, and MI with resistance exercise group; sham-operated group was used as control. Exercise-trained animals were subjected to 4 wk of aerobic exercise (AE) or resistance exercise (RE). Cardiac function, muscle weight, myofiber size, levels of IGF-1 signaling and proteins related to myogenesis, protein synthesis, and degradation and apoptosis in gastrocnemius muscle were detected. H2O2-treated C2C12 cells were intervened with recombinant human IGF-1, IGF-1 receptor (IGF-1R) inhibitor NVP-AEW541, and PI3K inhibitor LY294002 to explore the mechanism. Exercises upregulated the IGF-1/IGF-1R-phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling; increased the expressions of Pax7, myogenic regulatory factors (MRFs), and protein synthesis; and reduced protein degradation and cell apoptosis in MI mice. In vitro, IGF-1 upregulated the levels of Pax7, MRFs, mTOR, and P70S6K; reduced MuRF1 and MAFbx; and inhibited cell apoptosis via IGF-1R-PI3K/Akt pathway. AE and RE, safely and effectively, alleviate skeletal muscle atrophy by regulating the levels of myogenesis, protein degradation, and cell apoptosis in mice with MI via activating IGF-1/IGF-1R-PI3K/Akt signaling pathway.
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Fator de Crescimento Insulin-Like I/biossíntese , Atrofia Muscular/metabolismo , Infarto do Miocárdio/metabolismo , Condicionamento Físico Animal/fisiologia , Receptor IGF Tipo 1/biossíntese , Treinamento Resistido , Animais , Linhagem Celular , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Atrofia Muscular/diagnóstico por imagem , Atrofia Muscular/terapia , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/terapia , Fosfatidilinositol 3-Quinase/biossíntese , Condicionamento Físico Animal/métodos , Proteínas Proto-Oncogênicas c-akt/biossíntese , Treinamento Resistido/métodos , Transdução de Sinais/fisiologiaRESUMO
Tailoring the morphology of nanocrystals is a promising way to enhance their catalytic performance. In most previous shape-controlled synthesis strategies, surfactants are inevitable due to their capability to stabilize different facets. However, the adsorbed surfactants block the intrinsic active sites of the nanocrystals, reducing their catalytic performance. For now, strategies to control the morphology without surfactants are still limited but necessary. Herein, a facile surfactant-free synthesis method is developed to regulate the morphology of Cu2O nanocrystals (e.g., solid nanocube, concave nanocube, cubic framework, branching nanocube, branching concave nanocube, and branching cubic framework) to enhance the electrocatalytic performance for the conversion of CO to n-propanol. Specifically, the Cu2O branching cubic framework (BCF-Cu2O), which is difficult to fabricate using previous surfactant-free methods, is fabricated by combining the concentration depletion effect and the oxidation etching process. More significantly, the BCF-Cu2O-derived catalyst (BCF) presents the highest n-propanol current density (-0.85 mA cm-2) at -0.45 V versus the reversible hydrogen electrode (VRHE), which is fivefold higher than that of the surfactant-coated Cu2O nanocube-derived catalyst (SFC, -0.17 mA cm-2). In terms of the n-propanol Faradaic efficiency in CO electroreduction, that of the BCF exhibits a 41% increase at -0.45 VRHE as compared with SFC. The high catalytic activity of the BCF that results from the clean surface and the coexistence of Cu(100) and Cu(110) in the lattice is well-supported by density functional theory calculations. Thus, this work presents an important paradigm for the facile fabrication of surface-clean nanocrystals with an enhanced application performance.
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Mild photothermal therapy (PTT, <45 °C) can prevent tumor metastasis and heat damage to normal tissue, compared with traditional PTT (>50 °C). However, its therapeutic efficacy is limited owing to the hypoxic tumor environment and tumor thermoresistance owing to the overproduction of heat shock proteins (HSPs). Herein, a near-infrared (NIR)-triggered theranostic nanoplatform (GA-PB@MONs@LA) is designed for synergistic mild PTT and enhanced Fenton nanocatalytic therapy against hypoxic tumors. The nanoplatform is fabricated by the confined formation of Prussian blue (PB) nanoparticles in mesoporous organosilica nanoparticles (MONs), followed by the loading of gambogic acid (GA), an HSP90 inhibitor, and coating with thermo-sensitive lauric acid (LA). Upon NIR irradiation, the photothermal effect (44 °C) of PB not only induces apoptosis of tumor cells but also triggers the on-demand release of GA, inhibiting the production of HSP90. Moreover, the delivered heat simultaneously enhances the catalase-like and Fenton activity of PB@MONs@LA in an acidic tumor microenvironment, relieving the tumor hypoxia and promoting the generation of highly toxic â¢OH. In addition, the nanoplatform enables magnetic resonance/photoacoustic dual-modal imaging. Thus, this study describes a distinctive paradigm for the development of NIR-triggered theranostic nanoplatforms for enhanced cancer therapy.