RESUMEN
Implementing dissipative assembly in living systems is meaningful for creation of living materials or even artificial life. However, intracellular dissipative assembly remains scarce and is significantly impeded by the challenges lying in precisely operating chemical reaction cycles under complex physiological conditions. Here, we develop organelle-mediated dissipative self-assembly of peptides in living cells fueled by GSH, via the design of a mitochondrion-targeting and redox-responsive hexapeptide. While the hexapeptide undergoes efficient redox-responsive self-assembly, the addition of GSH into the peptide solution in the presence of mitochondrion-biomimetic liposomes containing hydrogen peroxide allows for transient assembly of peptides. Internalization of the peptide by LPS-stimulated macrophages leads to the self-assembly of the peptide driven by GSH reduction and the association of the peptide assemblies with mitochondria. The association facilitates reversible oxidation of the reduced peptide by mitochondrion-residing ROS and thereby dissociates the peptide from mitochondria to re-enter the cytoplasm for GSH reduction. The metastable peptide-mitochondrion complexes prevent the thermodynamically equilibrated self-assembly, thus establishing dissipative assembly of peptides in stimulated macrophages. The entire dissipative self-assembling process allows for elimination of elevated ROS and decrease of pro-inflammatory cytokine expression. Creating dissipative self-assembling systems assisted by internal structures provides new avenues for the development of living materials or medical agents in the future.
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Mitocondrias , Péptidos , Especies Reactivas de Oxígeno , Péptidos/químicaRESUMEN
Proteolysis targeting chimera (PROTAC) technology is an innovative strategy for cancer therapy, which, however, suffers from poor targeting delivery and limited capability for protein of interest (POI) degradation. Here, we report a strategy for the in situ formulation of antineoplastic Supra-PROTACs via intracellular sulfatase-responsive assembly of peptides. Coassembling a sulfated peptide with two ligands binding to ubiquitin VHL and Bcl-xL leads to the formation of a pro-Supra-PROTAC, in which the ratio of the two ligands is rationally optimized based on their protein binding affinity. The resulting pro-Supra-PROTAC precisely undergoes enzyme-responsive assembly into nanofibrous Supra-PROTACs in cancer cells overexpressing sulfatase. Mechanistic studies reveal that the pro-Supra-PROTACs selectively cause apparent cytotoxicity to cancer cells through the degradation of Bcl-xL and the activation of caspase-dependent apoptosis, during which the rationally optimized ligand ratio improves the bioactivity for POI degradation and cell death. In vivo studies show that in situ formulation enhanced the tumor accumulation and retention of the pro-Supra-PROTACs, as well as the capability for inhibiting tumor growth with excellent biosafety when coadministrating with chemodrugs. Our findings provide a new approach for enzyme-regulated assembly of peptides in living cells and the development of PROTACs with high targeting delivering and POI degradation efficiency.
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Antineoplásicos , Neoplasias , Humanos , Quimera Dirigida a la Proteólisis , Antineoplásicos/farmacología , Sulfatasas , Proteolisis , Péptidos , Ubiquitina-Proteína LigasasRESUMEN
Despite significant progress achieved in artificial self-sorting in solution, operating self-sorting in the body remains a considerable challenge. Here, we report an in vivo self-sorting peptide system via an in situ assembly evolution for combined cancer therapy. The peptide E3C16-SS-EIY consists of two disulfide-connected segments, E3C16SH and SHEIY, capable of independent assembly into twisted or flat nanoribbons. While E3C16-SS-EIY assembles into nanorods, exposure to glutathione (GSH) leads to the conversion of the peptide into E3C16SH and SHEIY, thus promoting in situ evolution from the nanorods into self-sorted nanoribbons. Furthermore, incorporation of two ligand moieties targeting antiapoptotic protein XIAP and organellar endoplasmic reticulum (ER) into the self-sorted nanoribbons allows for simultaneous inhibition of XIAP and accumulation surrounding ER. This leads to the cytotoxicity toward the cancer cells with elevated GSH levels, through activating caspase-dependent apoptosis and inducing ER dysfunction. In vivo self-sorting of E3C16-SS-EIY decorated with ligand moieties is thoroughly validated by tissue studies. Tumor-bearing mouse experiments confirm the therapeutic efficacy of the self-sorted assemblies for inhibiting tumor growth, with excellent biosafety. Our findings demonstrate an efficient approach to develop in vivo self-sorting systems and thereby facilitating in situ formulation of biomedical agents.
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Péptidos , Humanos , Animales , Péptidos/química , Péptidos/farmacología , Ratones , Antineoplásicos/farmacología , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Proteína Inhibidora de la Apoptosis Ligada a X/antagonistas & inhibidores , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismo , Glutatión/química , Glutatión/metabolismo , Línea Celular Tumoral , Nanotubos/químicaRESUMEN
Morphology-transformational self-assembly of peptides allows for manipulation of the performance of nanostructures and thereby advancing the development of biomaterials. Acceleration of the morphological transformation process under a biological microenvironment is important to efficiently implement the tailored functions in living systems. Herein, we report redox-regulated in situ seed-induced assembly of peptides via design of two co-assembled bola-amphiphiles serving as a redox-resistant seed and a redox-responsive assembly monomer, respectively. Both of the peptides are able to independently assemble into nanoribbons, while the seed monomer exhibits stronger assembling propensity. The redox-responsive monomer undergoes morphological transformation from well-defined nanoribbons to nanoparticles. Kinetics studies validate the role of the assembled inert monomer as the seeds in accelerating the assembly of the redox-responsive monomer. Alternative addition of oxidants and reductants into the co-assembled monomers promotes the redox-regulated assembly of the peptides facilitated by the in situ-formed seeds. The reduction-induced assembly of the peptide could also be accelerated by in situ-formed seeds in cancer cells with a high level of reductants. Our findings demonstrate that through precisely manipulating the assembling propensity of co-assembled monomers, the in situ seed-induced assembly of peptides could be achieved. Combining the rapid assembly kinetics of the seed-induced assembly with the common presence of redox agents in a biological microenvironment, this strategy potentially offers a new method for developing biomedical materials in living systems.
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Nanoestructuras , Nanotubos de Carbono , Sustancias Reductoras , Péptidos/química , Nanoestructuras/química , Materiales Biocompatibles , Oxidación-ReducciónRESUMEN
INTRODUCTION: Cough is a major complication after lung cancer surgery, potentially impacting lung function and quality of life. However, effective treatments for managing long-term persistent postoperative cough remain elusive. In this study, we investigated the potential of a pulmonary rehabilitation training program to effectively address this issue. METHODS: Between January 2019 and December 2022, a retrospective review was conducted on patients with non-small cell lung cancer (NSCLC) who underwent lobectomy and lymph node dissection via video-assisted thoracoscopic surgery (VATS) at Daping hospital. Based on their postoperative rehabilitation methods, the patients were categorized into 2 groups: the traditional rehabilitation group and the pulmonary rehabilitation group. All patients underwent assessment using the Leicester cough questionnaire (LCQ) on the third postoperative day. Additionally, at the 6-month follow-up, patients' LCQ scores and lung function were re-evaluated to assess the long-term effects of the pulmonary rehabilitation training programs. RESULTS: Among the 276 patients meeting the inclusion criteria, 195 (70.7%) were in the traditional rehabilitation group, while 81 (29.3%) participated in the pulmonary rehabilitation group. The pulmonary rehabilitation group showed a significantly lower incidence of cough on the third postoperative day (16.0% vs 29.7%, P = .018) and higher LCQ scores in the somatic dimension (5.09 ± .81 vs 4.15 ± 1.22, P = .007) as well as in the total score (16.44 ± 2.86 vs 15.11 ± 2.51, P = .018, whereas there were no significant differences in psychiatric and sociological dimensions. At the 6-month follow-up, the pulmonary rehabilitation group continued to have a lower cough incidence (3.7% vs 12.8%, P = .022) and higher LCQ scores across all dimensions: somatic (6.19 ± .11 vs 5.75 ± 1.20, P = .035), mental (6.37 ± 1.19 vs 5.85 ± 1.22, P = .002), sociological (6.76 ± 1.22 vs 5.62 ± 1.08, P < .001), and total (18.22 ± 2.37 vs 16.21 ± 2.53, P < .001). Additionally, lung function parameters including FVC, FVC%, FEV1, FEV1%, MVV, MVV%, DLCO SB, and DLCO% were all significantly higher in the pulmonary rehabilitation group compared to the traditional group. CONCLUSION: Pulmonary rehabilitation exercises significantly reduced the incidence of postoperative cough and improved cough-related quality of life in patients undergoing lobectomy, with sustained benefits observed at the 6-month follow-up. Additionally, these exercises demonstrated superior lung function outcomes compared to traditional rehabilitation methods.
Pulmonary rehabilitation exercises significantly reduced the incidence of postoperative cough and improved cough-related quality of life in patients undergoing lobectomy, with sustained benefits observed at the 6-month follow-up. Additionally, these exercises demonstrated superior lung function outcomes compared to traditional rehabilitation methods.
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Carcinoma de Pulmón de Células no Pequeñas , Tos Crónica , Terapia por Ejercicio , Neoplasias Pulmonares , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Carcinoma de Pulmón de Células no Pequeñas/rehabilitación , Tos Crónica/terapia , Enfermedad Crónica , Terapia por Ejercicio/métodos , Neoplasias Pulmonares/cirugía , Neoplasias Pulmonares/rehabilitación , Neumonectomía/efectos adversos , Neumonectomía/rehabilitación , Complicaciones Posoperatorias/prevención & control , Calidad de Vida , Estudios Retrospectivos , Cirugía Torácica Asistida por VideoRESUMEN
Atrial fibrillation (AF) can increase thrombosis, especially arterial thrombosis, and some studies show that AF patients have a higher risk of developing pulmonary embolism (PE). The objective of our study is to investigate whether there is a direct causal effect of AF on PE. A two-sample Mendelian randomization (MR) approach was utilized to determine whether there is a causal relationship between AF and PE. European population-based consortia provided statistical data on the associations between Single Nucleotide Polymorphisms (SNPs) and relevant traits. The AF dataset was obtained from genome-wide association studies (GWAS) comprising 60,620 cases and 970,216 controls, while a GWAS of 1846 cases and 461,164 controls identified genetic variations associated with PE. Estimation of the causal effect was mainly performed using the random effects inverse-variance weighted method (IVW). Additionally, other tests such as MR-Egger intercept, MR-PRESSO, Cochran's Q test, "Leave-one-out," and funnel plots were conducted to assess the extent of pleiotropy and heterogeneity. Using 70 SNPs, there was no evidence to suggest an association between genetically predicted AF and risk of PE with multiplicative random-effects IVW MR analysis (odds ratio = 1.0003, 95% confidence interval: 0.9998-1.0008, P = 0.20). A null association was also observed in other methods. MR-Egger regression and MR-PRESSO respectively showed no evidence of directional (intercept, - 2.25; P = 0.94) and horizontal(P-value in the global heterogeneity test = 0.99) pleiotropic effect across the genetic variants. No substantial evidence was found to support the causal role of AF in the development of PE.
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Fibrilación Atrial , Embolia Pulmonar , Trombosis , Humanos , Fibrilación Atrial/genética , Estudio de Asociación del Genoma Completo , Análisis de la Aleatorización Mendeliana , Nonoxinol , Embolia Pulmonar/genéticaRESUMEN
OBJECTIVE: Early diagnosis of laryngeal cancer (LC) is crucial, particularly in rural areas. Despite existing studies on deep learning models for LC identification, challenges remain in selecting suitable models for rural areas with shortages of laryngologists and limited computer resources. We present the intelligent laryngeal cancer detection system (ILCDS), a deep learning-based solution tailored for effective LC screening in resource-constrained rural areas. METHODS: We compiled a dataset comprised of 2023 laryngoscopic images and applied data augmentation techniques for dataset expansion. Subsequently, we utilized eight deep learning models-AlexNet, VGG, ResNet, DenseNet, MobileNet, ShuffleNet, Vision Transformer, and Swin Transformer-for LC identification. A comprehensive evaluation of their performances and efficiencies was conducted, and the most suitable model was selected to assemble the ILCDS. RESULTS: Regarding performance, all models attained an average accuracy exceeding 90 % on the test set. Particularly noteworthy are VGG, DenseNet, and MobileNet, which exceeded an accuracy of 95 %, with scores of 95.32 %, 95.75 %, and 95.99 %, respectively. Regarding efficiency, MobileNet excels owing to its compact size and fast inference speed, making it an ideal model for integration into ILCDS. CONCLUSION: The ILCDS demonstrated promising accuracy in LC detection while maintaining modest computational resource requirements, indicating its potential to enhance LC screening accuracy and alleviate the workload on otolaryngologists in rural areas.
RESUMEN
Bio-inspired design of peptides represents one facile strategy for development of supramolecular monomers for self-assembly into well-defined nanostructures. Inspired by methylation of arginine during post-translational modification for manipulating protein functions, herein, the controllable self-assembly of peptides via rational incorporation of methylated arginine residues into bola-amphiphilic peptides is reported. A series of bola-amphiphilic peptides are designed and synthesized either containing natural arginine or methylated arginine and investigate the influence of arginine methylation on peptide assembly. This study finds that incorporation of symmetrically di-methylated arginine into oppositely charged hexapeptide hex-SDMAE leads to distinct assembling performance compare to natural peptide hex-RE. The findings demonstrate that the methylation of rationally designed peptide sequences allows for regulation of self-assembly of peptides, thus implying the great potential of arginine methylation in establishing controllable peptide assembling systems and creating in situ formulation of biomedical materials in the future.
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Arginina , Péptidos , Arginina/química , Péptidos/química , Proteínas , Procesamiento Proteico-Postraduccional , MetilaciónRESUMEN
Starch and cellulose are the fundamental components of tobacco, while their excessive content will affect the quality of tobacco. Enzymatic treatment with different enzymes is a promising method to modulate the chemical composition and improve the sensory quality of tobacco leaves. In this study, enzymatic treatments, such as amylase, cellulase, and their mixed enzymes, were used to improve tobacco quality, which could alter the content of total sugar, reducing sugar, starch, and cellulose in tobacco leaves. The amylase treatment changed surface structure of tobacco leaves, increased the content of neophytadiene in tobacco by 16.48%, and improved the total smoking score of heat-not-burn (HnB) cigarette products by 5.0 points compared with the control. The Bacillus, Rubrobacter, Brevundimonas, Methylobacterium, Stenotrophomonas, Acinetobacter, Pseudosagedia-chlorotica, and Sclerophora-peronella were found to be significant biomarkers in the fermentation process by LEfSe analysis. The Basidiomycota and Agaricomycetes were significantly correlated with aroma and flavor, taste, and total score of HnB. The results showed that microbial community succession occurred due to amylase treatment, which promoted the formation of aroma compounds, and regulated the chemical composition of tobacco, and improved tobacco quality during tobacco fermentation. This study provides a method for enzymatic treatment to upgrade the quality of tobacco raw materials, thereby improving the quality of HnB cigarettes, and the potential mechanism is also revealed by chemical composition and microbial community analysis. KEY POINTS: Enzymatic treatment can change the chemical composition of tobacco leaves. The microbial community was significantly affected by enzymatic treatment. The quality of HnB cigarettes was significantly improved by amylase treatment.
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Sistemas Electrónicos de Liberación de Nicotina , Productos de Tabaco , Productos de Tabaco/análisis , Fermentación , CalorRESUMEN
Astaxanthin is widely used in food, aquaculture, cosmetics, and pharmaceuticals due to its strong antioxidant activity and coloring ability, but its production from Phaffia rhodozyma remains the main challenge due to the high fermentation cost and low content of carotenoid. In this study, the production of carotenoids from food waste (FW) by a P. rhodozyma mutant was investigated. P. rhodozyma mutant screened by UV mutagenesis and flow cytometry could stably produce high carotenoids at 25°C, with carotenoid production (32.9 mg/L) and content (6.7 mg/g), respectively, increasing by 31.6% and 32.3% compared with 25 mg/L and 5.1 mg/g of wild strain. Interestingly, the carotenoid production reached 192.6 mg/L by feeding wet FW, which was 21% higher than batch culture. The 373 g vacuum freeze-dried products were obtained from the fermentation of 1 kg FW by P. rhodozyma, which contained 784 mg carotenoids and 111 mg astaxanthin. The protein, total amino acids, and essential amino acids content of the fermentation products were 36.6%, 40.5%, and 18.2% (w/w), respectively, and lysine-added fermentation products had the potential of high-quality protein feed source. This study provides insights for the high-throughput screening of mutants, astaxanthin production, and the development of the feed potential of FW.
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Basidiomycota , Eliminación de Residuos , Citometría de Flujo , Alimento Perdido y Desperdiciado , Alimentos , Carotenoides/metabolismo , Basidiomycota/genética , Basidiomycota/metabolismoRESUMEN
Self-sorting is a common phenomenon in eukaryotic cells and represents one of the versatile strategies for the formation of advanced functional materials; however, developing artificial self-sorting assemblies within living cells remains challenging. Here, we report on the GSH-responsive in situ self-sorting peptide assemblies within cancer cells for simultaneous organelle targeting to promote combinatorial organelle dysfunction and thereby cell death. The self-sorting system was created via the design of two peptides E3C16E6 and EVMSeO derived from lipid-inspired peptide interdigitating amphiphiles and peptide bola-amphiphiles, respectively. The distinct organization patterns of the two peptides facilitate their GSH-induced self-sorting into isolated nanofibrils as a result of cleavage of disulfide-connected hydrophilic domains or reduction of selenoxide groups. The GSH-responsive in situ self-sorting in the peptide assemblies within HeLa cells was directly characterized by super-resolution structured illumination microscopy. Incorporation of the thiol and ER-targeting groups into the self-sorted assemblies endows their simultaneous targeting of endoplasmic reticulum and Golgi apparatus, thus leading to combinatorial organelle dysfunction and cell death. Our results demonstrate the establishment of the in situ self-sorting peptide assemblies within living cells, thus providing a unique platform for drug targeting delivery and an alternative strategy for modulating biological processes in the future.
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Aparato de Golgi , Péptidos , Retículo Endoplásmico/metabolismo , Aparato de Golgi/metabolismo , Células HeLa , Humanos , Péptidos/química , Transporte de ProteínasRESUMEN
Purpose: This study aimed to investigate the relationship of partial pressure of carbon dioxide (PaCO2) with BODE and GOLD in stable COPD subjects and to explore the predictive value of PaCO2 for severe COPD (BODE index score ≥5 or GOLD index score ≥3). Patients and Methods. In total, 80 participants with COPD and free from other conditions affecting PaCO2 were recruited. Arterial blood gases, BODE, GOLD, SGRQ, lung function, and other data were collected. The BODE index was calculated, and patients were divided into two groups according to the BODE index and PaCO2 median, respectively. We used Pearson's correlation test and the receiver operating characteristic curves to evaluate the utility of PaCO2. Besides, the univariate and multivariate logistic regression analyses were conducted to verify whether PaCO2 was an independent factor associated with BODE grades. Results: COPD subjects with BODE ≥5 and GOLD ≥3 had significantly higher levels of PaCO2 (p = 0.004, p = 0.001, respectively). In the high PaCO2 group, patients underwent poorer outcomes than the low PaCO2 group. PaCO2 was negatively correlated with forced expiratory volume in 1 second in percent of the predicted value (FEV1%) (r = -0.612, p < 0.001). The performance of PaCO2 levels in predicting BODE ≥5 and GOLD ≥3 was 0.748 and 0.755, respectively. The logistic regression analyses proved that PaCO2 was associated with BODE ≥5 in COPD patients (odds ratio = 1.160, 95% CI: 1.025-1.313, p = 0.019). Conclusions: A higher level of PaCO2 was associated with a higher index for BODE or GOLD in COPD and had the predictive value for severe COPD.
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Dióxido de Carbono , Enfermedad Pulmonar Obstructiva Crónica , Volumen Espiratorio Forzado , Humanos , Presión Parcial , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Índice de Severidad de la EnfermedadRESUMEN
Design of endogenous stimuli-responsive amino acids allows for precisely modulating proteins or peptides under a biological microenvironment and thereby regulating their performance. Herein we report a noncanonical amino acid 2-nitroimidazol-1-yl alanine and explore its functions in creation of the nitroreductase (NTR)-responsive peptide-based supramolecular probes for efficient hypoxia imaging. On the basis of the reduction potential of the nitroimidazole unit, the amino acid was synthesized via the Mitsunobu reaction between 2-nitroimidazole and a serine derivate. We elucidated the relationship between the NTR-responsiveness of the amino acid and the structural feature of peptides involving a series of peptides. This eventually facilitates development of aromatic peptides undergoing NTR-responsive self-assembly by rationally optimizing the sequences. Due to the intrinsic role of 2-nitroimidazole in the fluorescence quench, we created a morphology-transformable supramolecular probe for imaging hypoxic tumor cells based on NTR reduction. We found that the resulting supramolecular probes penetrated into solid tumors, thus allowing for efficient fluorescence imaging of tumor cells in hypoxic regions. Our findings demonstrate development of a readily synthesized and versatile amino acid with exemplified properties in creating fluorescent peptide nanostructures responsive to a biological microenvironment, thus providing a powerful toolkit for synthetic biology and development of novel biomaterials.
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Aminoácidos/metabolismo , Péptidos/metabolismo , Alanina/química , Alanina/metabolismo , Aminoácidos/química , Animales , Neoplasias de la Mama/patología , Línea Celular Tumoral , Femenino , Colorantes Fluorescentes/química , Ratones , Microscopía Confocal , Nitroimidazoles/química , Nitrorreductasas/metabolismo , Imagen Óptica , Péptidos/química , Trasplante HomólogoRESUMEN
Parkinson disease (PD) is a neurodegenerative disease characterized by selective loss of dopaminergic (DA) neurons in the midbrain. The regulatory role of a variety of microRNAs in PD has been confirmed, and our study is the first to demonstrate that miR-3473b is involved in the regulation of PD. In vitro, an miR-3473b inhibitor can inhibit the secretion of inflammatory factors (TNF-α and IL-1ß) in moues microglia cell line (BV2) cells induced by lipopolysaccharide (LPS) and promote autophagy in BV2 cells. In vivo, miR-3473b antagomir can inhibit the activation of substantia nigra pars compacta (SNpc) microglia of C57BL/6 mice induced by 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and promote autophagy. Deletion of TREM2, one of the most highly expressed receptors in microglia, leads to the occurrence and development of PD. ULK1 is a component of the Atg1 complex. Deletion of ULK1 aggravates the pathological reaction of PD. TREM2 and ULK1 are predicted potential targets of miR-3473b by Targetscan. Then, the results of our experiments indicate that transfection with a miR-3473b mimic can inhibit the expression of TREM2 and ULK1. Data from a double luciferase experiment indicate that the 3'-UTR of TREM2, but not ULK1, is the direct target of miR-3473b. Then we aim to investigate the regulation of TREM2 and ULK1 in PD. We found that the expression of p-ULK1 was significantly increased via up-regulation of TREM2. The increased expression of p-ULK1 can promote autophagy and inhibit the expression of inflammatory factors. The regulation of ULK1 by miR-3473b may be accomplished indirectly through TREM2. Thus, miR-3473b may regulate the secretion of proinflammatory mediators by targeting TREM2/ULK1 expression to regulate the role of autophagy in the pathogenesis of inflammation in Parkinson's disease, suggesting that mir-3473b may be a potential therapeutic target to regulate the inflammatory response in PD.
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Homólogo de la Proteína 1 Relacionada con la Autofagia/biosíntesis , Autofagia/genética , Regulación de la Expresión Génica/genética , Inflamación/genética , Glicoproteínas de Membrana/biosíntesis , MicroARNs/genética , Enfermedad de Parkinson Secundaria/genética , Receptores Inmunológicos/biosíntesis , Animales , Homólogo de la Proteína 1 Relacionada con la Autofagia/genética , Inflamación/patología , Lipopolisacáridos , Intoxicación por MPTP , Masculino , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos C57BL , Enfermedad de Parkinson Secundaria/inducido químicamente , Enfermedad de Parkinson Secundaria/patología , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores Inmunológicos/genética , Regulación hacia Arriba/efectos de los fármacosRESUMEN
BACKGROUND: Weather change in high-altitude areas subjects mature tobacco (Nicotiana tabacum L.) to cold stress, which damages tobacco leaf yield and quality. A brupt diurnal temperature differences (the daily temperature dropping more than 20 °C) along with rainfall in tobacco-growing areas at an altitude above 2450 m, caused cold stress to field-grown tobacco. RESULTS: After the flue-cured tobacco suffered cold stress in the field, the surface color of tobacco leaves changed and obvious large browning areas were appeared, and the curing availability was extremely poor. Further research found the quality of fresh tobacco leaves, the content of key chemical components, and the production quality were greatly reduced by cold stress. We hypothesize that cold stress in high altitude environments destroyed the antioxidant enzyme system of mature flue-cured tobacco. Therefore, the quality of fresh tobacco leaves, the content of key chemical components, and the production quality were greatly reduced by cold stress. CONCLUSION: This study confirmed that cold stress in high-altitude tobacco areas was the main reason for the browning of tobacco leaves during the tobacco curing process. This adverse environment seriously damaged the quality of tobacco leaves, but can be mitigated by pay attention to the weather forecast and pick tobacco leaves in advance.
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Respuesta al Choque por Frío/fisiología , Factores de Transcripción del Choque Térmico/fisiología , Nicotiana/química , Nicotiana/crecimiento & desarrollo , Hojas de la Planta/química , Hojas de la Planta/crecimiento & desarrollo , China , Productos Agrícolas/química , Productos Agrícolas/crecimiento & desarrolloRESUMEN
Self-propelled directional liquid transport (SDLT) has been observed on many natural substrates, serving as an efficient strategy to utilize surrounding liquids for a better habitat to the local environment. Drawing inspiration, various artificial materials capable of SDLT have been developed. However, the liquid transport velocity is normally very low (ca. 3-30 µm/s), which limits its practical applications. Herein, we developed novel pyramid-structured fibers with concave curved surfaces (P-concave curved-fiber, PCCF), which enable the ultrafast SDLT. Specifically, the liquid transport velocity can be up to â¼28.79 mm/s on a dry tri-PCCF, over 50 times faster than that on the surface of Sarracenia trichome (â¼520 µm/s). The velocity is even faster on a wet fiber by two times (â¼47.34 mm/s). Here, the Laplace pressure difference (FL) induced by the tapered structure determines the liquid transport direction. It is proposed that both the capillary rises imparted by the concave curved surfaces and the oriented microridges/valleys and the enhanced FL aroused by the reduced cross-sectional area accelerate the SDLT on surfaces of the PCCFs. Consequently, the PCCF takes a different liquid transport strategy with a convex-shaped advancing meniscus, differing from that on traditional conical fibers. Moreover, the as-developed PCCF is also applicable for underwater ultrafast SDLT of oil. We envision that the result will open a new perspective for fabricating a fibrous system for microfluidic and liquid manipulation.
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Analogous to DNA methylation and histone modification, RNA modification, as another epigenetic layer, plays an important role in many diseases, especially in tumours. As the most common form of RNA modification, m6A methylation has attracted increasing research interest in recent years. m6A is catalysed by RNA methyltransferases METTL3, METTL14 and WTAP (writers), m6A is removed by the demethylases FTO and ALKBH5 (erasers) and interacts with m6A-binding proteins, such as YT521-B homology (YTH) domain-containing proteins. This article reviews recent studies on methylation modification of m6A in gastrointestinal tract cancers.
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Adenosina/análogos & derivados , Susceptibilidad a Enfermedades , Neoplasias Gastrointestinales/etiología , Neoplasias Gastrointestinales/metabolismo , ARN/genética , ARN/metabolismo , Adenosina/metabolismo , Animales , Biomarcadores , Neoplasias Gastrointestinales/patología , Regulación Neoplásica de la Expresión Génica , Humanos , MetilaciónRESUMEN
Cerium oxide (CeO x) with a reversible surface Ce3+/Ce4+ redox pair has played an important role in catalytic reactions, whereas catalase mimetics of CeO x have attracted little attention in the field of biotherapy. Herein, a smart photosensitizer-cerium oxide nanoprobe was developed to represent a promising paradigm in high-performance photodynamic therapy. The photosensitizer was linked to CeO x nanoparticles through a substrate peptide (EGPLGVRGK) of matrix metalloproteinase-2 (MMP-2). The smart nanoprobe could be converted from the "silent state" before arriving at the cancer cells to the "activated state" within the cells to turn on the fluorescence and 1O2 generation when the peptide linker (EGPLGVRGK) was cut by the cancer biomarker MMP-2. Moreover, CeO x played the role of an excellent catalase-like compound to decompose endogenous hydrogen peroxide to relieve tumor hypoxia. Via the conventional application of CeO x, our study showed innovatively how a smart nanoprobe could relieve tumor hypoxia and achieve a therapeutic effect for highly selective and efficient personalized treatment.
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Cerio/química , Cerio/metabolismo , Sondas Moleculares/química , Sondas Moleculares/metabolismo , Nanopartículas/química , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/química , Secuencia de Aminoácidos , Transporte Biológico , Clorofila/análogos & derivados , Clorofila/química , Clorofila/farmacología , Células Hep G2 , Humanos , Metaloproteinasa 2 de la Matriz/metabolismo , Modelos Moleculares , Conformación Molecular , Péptidos/química , Fármacos Fotosensibilizantes/farmacologíaRESUMEN
Lignocellulose, one of the most abundant renewable sources of sugar, can be converted into bioenergy through hydrolysis of cellulose and hemicellulose. Due to its renewability and availability in large quantities, bioenergy is considered as a possible alternative to fossil energy and attracts the attention of the world with increased concerns about environmental protection and energy crisis. The depolymerization of cellulosic substrate to monomer is the rate-limiting step in the bioconversion of lignocellulose by cellulolytic microbes. Cellulosome, a multienzyme complex from anaerobic cellulolytic bacteria, can efficiently degrade the cellulosic substrates. Previous studies have shown that the reconstitution of cellulosome in vitro and its heterologous expression or display on the cell surface can help to solve the low yield problem of cellulosome in cellulolytic bacteria. This paper reviews the research progress in the reconstitution of cellulosome as well as its application in biorefinery, including the construction of cellulosome as well as different methods for cellulosome reconstitution and its surface display. This review will promote the understanding of cellulosome and its reconstitution.
Asunto(s)
Celulosomas/metabolismo , Celulosomas/químicaRESUMEN
Fabrication of a high quality quantum dot (QD) film is essentially important for a high-performance QD light emitting diode display (QLED) device. It is normally a high-cost and multiple-step solution-transfer process where large amounts of QDs were needed but with only limited usefulness. Thus, developing a simple, efficient, and low-cost approach to fabricate high-quality micropatterned QD film is urgently needed. Here, we proposed that the Chinese brush enables the controllable transfer of a QD solution directly onto a homogeneous and ultrasmooth micropatterned film in one step. It is proposed that the dynamic balance of QDs was enabled during the entire solution transfer process under the cooperative effect of Marangoni flow aroused by the asymmetric solvent evaporation and the Laplace pressure different by conical fibers. By this approach, QD nanoparticles were homogeneously transferred onto the desired area on the substrate. The as-prepared QLED devices show rather high performances with the current efficiencies of 72.38, 26.03, and 4.26 cd/A and external quantum efficiencies of 17.40, 18.96, and 6.20% for the green, red, and blue QLED devices, respectively. We envision that the result offers a low-cost, facile, and practically applicable solution-processing approach that works even in air for fabricating high-performance QLED devices.