RESUMEN
The development of potential-resolved electrochemiluminescence (ECL) systems with dual emitting signals holds great promise for accurate and reliable determination in complex samples. However, the practical application of such systems is hindered by the inevitable mutual interaction and mismatch between different luminophores or coreactants. In this work, for the first time, by precisely tuning the oxygen reduction performance of M-N-C single-atom catalysts (SACs), we present a dual potential-resolved luminol ECL system employing endogenous dissolved O2 as a coreactant. Using advanced in situ monitoring and theoretical calculations, we elucidate the intricate mechanism involving the selective and efficient activation of dissolved O2 through central metal species modulation. This modulation leads to the controlled generation of hydroxyl radical (·OH) and superoxide radical (O2·-), which subsequently trigger cathodic and anodic luminol ECL emission, respectively. The well-designed Cu-N-C SACs, with their moderate oxophilicity, enable the simultaneous generation of ·OH and O2·-, thereby facilitating dual potential-resolved ECL. As a proof of concept, we employed the principal component analysis statistical method to differentiate antibiotics based on the output of the dual-potential ECL signals. This work establishes a new avenue for constructing a potential-resolved ECL platform based on a single luminophore and coreactant through precise regulation of active intermediates.
RESUMEN
BACKGROUND: In heart failure (HF), mitochondrial dysfunction and metabolic remodeling lead to a reduction in energy productivity and aggravate cardiomyocyte injury. Supplementation with α-ketoglutarate (AKG) alleviated myocardial hypertrophy and fibrosis in mice with HF and improved cardiac insufficiency. However, the myocardial protective mechanism of AKG remains unclear. We verified the hypothesis that AKG improves mitochondrial function by upregulating NAD+ levels and activating silent information regulator 2 homolog 1 (SIRT1) in cardiomyocytes. METHODS: In vivo, 2% AKG was added to the drinking water of mice undergoing transverse aortic constriction (TAC) surgery. Echocardiography and biopsy were performed to evaluate cardiac function and pathological changes. Myocardial metabolomics was analyzed by liquid chromatographyâmass spectrometry (LCâMS/MS) at 8 weeks after surgery. In vitro, the expression of SIRT1 or PINK1 proteins was inhibited by selective inhibitors and siRNA in cardiomyocytes stimulated with angiotensin II (AngII) and AKG. NAD+ levels were detected using an NAD test kit. Mitophagy and ferroptosis levels were evaluated by Western blotting, qPCR, JC-1 staining and lipid peroxidation analysis. RESULTS: AKG supplementation after TAC surgery could alleviate myocardial hypertrophy and fibrosis and improve cardiac function in mice. Metabolites of the malate-aspartate shuttle (MAS) were increased, but the TCA cycle and fatty acid metabolism pathway could be inhibited in the myocardium of TAC mice after AKG supplementation. Decreased NAD+ levels and SIRT1 protein expression were observed in heart of mice and AngII-treated cardiomyocytes. After AKG treatment, these changes were reversed, and increased mitophagy, inhibited ferroptosis, and alleviated damage in cardiomyocytes were observed. When the expression of SIRT1 was inhibited by a selective inhibitor and siRNA, the protective effect of AKG was suppressed. CONCLUSION: Supplementation with AKG can improve myocardial hypertrophy, fibrosis and chronic cardiac insufficiency caused by pressure overload. By increasing the level of NAD+, the SIRT-PINK1 and SIRT1-GPX4 signaling pathways are activated to promote mitophagy and inhibit ferroptosis in cardiomyocytes, which ultimately alleviates cardiomyocyte damage.
Asunto(s)
Estenosis de la Válvula Aórtica , Ferroptosis , Insuficiencia Cardíaca , Ácidos Cetoglutáricos , Mitofagia , Angiotensina II , Cromatografía Liquida , Ferroptosis/efectos de los fármacos , Fibrosis , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/metabolismo , Hipertrofia , Ácidos Cetoglutáricos/farmacología , Ácidos Cetoglutáricos/uso terapéutico , Mitofagia/efectos de los fármacos , Miocitos Cardíacos , NAD , Proteínas Quinasas , ARN Interferente Pequeño , Sirtuina 1 , Espectrometría de Masas en Tándem , Animales , RatonesRESUMEN
A highly reversible zinc anode is crucial for the commercialization of zinc-ion batteries. However, the change in the microstructure of the electric double layer originated from the dynamic change in charge density on the electrode greatly impacts anode reversibility during charge/discharge, which is rarely considered in previous research. Herein, the zwitterion additive is employed to create an adaptive interface by coupling the transient zwitterion dynamics upon the change of interfacial charge density. Ab initio molecular dynamics simulations suggest the molecular orientation and adsorption groups of zwitterions will be determined by the charging state of the electrode. ZnSO4 electrolyte with zwitterion fulfills a highly reversible Zn anode with an average Coulombic efficiency of up to 99.85%. Zn/Zn symmetric cells achieve greatly enhanced cycling stability for 700 h with extremely small voltage hysteresis of 29 mV under 5 mA cm-2 with 5 mAh cm-2 . This study validates the adaptive interface based on transient dynamics of zwitterions, which sheds new light on developing highly reversible metal anodes with a high utilization rate.
RESUMEN
Gemcitabine (GEM) resistance affects chemotherapy efficacy of pancreatic cancer (PC). Cancer-associated fibroblasts (CAFs) possess the ability of regulating chemoresistance. This study probed the mechanism of hypoxia-treated CAFs regulating cell stemness and GEM resistance in PC. Miapaca-2/SW1990 were co-cultured with PC-derived CAFs under normoxic/hypoxic conditions. Cell viability/self-renewal ability was determined by MTT/sphere formation assays, respectively. Protein levels of CD44, CD133, Oct4, and Sox2 were determined by western blot. GEM tumoricidal assay was performed. PC cell GEM resistance was evaluated by MTT assay. CAFs were cultured at normoxia/hypoxia. HIF-1α and miR-21 expression levels were assessed by RT-qPCR and western blot, with their binding sites and binding relationship predicted and verified. CAF-extracellular vesicles (EVs) were incubated with Miapaca-2 cells. The RAS/AKT/ERK pathway activation was detected by western blot. PC xenograft models were established and treated with hypoxic CAF-EVs and GEM. CAFs and PC cell co-culture increased cell stemness maintenance, GEM resistance, cell viability, stem cell sphere number, and protein levels of CD44, CD133, Oct4, and Sox2, and weakened GEM tumoricidal ability to PC cells, with the effects further enhanced by hypoxia. Hypoxia induced HIF-1α and miR-21 overexpression in CAFs. Hypoxia promoted CAFs to secrete high-level miR-21 EVs via the HIF-1α/miR-21 axis, and activated the miR-21/RAS/AKT/ERK pathway. CAF-EVs promoted GEM resistance in PC via the miR-21/RAS/ATK/ERK pathway in vivo. Hypoxia promoted CAFs to secrete high-level miR-21 EVs through the HIF-1α/miR-21 axis, and activated the miR-21/RAS/AKT/ERK pathway via EVs to trigger stemness maintenance and GEM resistance in PC.
Asunto(s)
Fibroblastos Asociados al Cáncer , MicroARNs , Neoplasias Pancreáticas , Humanos , Gemcitabina , Fibroblastos Asociados al Cáncer/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Línea Celular Tumoral , Hipoxia/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/metabolismoRESUMEN
A-kinase anchoring protein 95 (AKAP95) functions as a scaffold for protein kinase A. Prior work by our group has shown that AKAP95, in coordination with Connexin 43 (Cx43), modulates the expression of cyclin D and E proteins, thus affecting the cell cycle progression in lung cancer cells. In the current study, we confirmed that AKAP95 forms a complex with Cx43. Moreover, it associates with cyclins D1 and E1 during the G1 phase, leading to the formation of protein complexes that subsequently translocate to the nucleus. These findings indicate that AKAP95 might facilitate the nuclear transport of cyclins D1 and E1. Throughout this process, AKAP95 and Cx43 collectively regulate the expression of cyclin D, phosphorylate cyclin E1 proteins, and target their specific ubiquitin ligases, ultimately impacting cell cycle progression.
RESUMEN
Lung cancer, a prevalent and aggressive disease, is characterized by recurrence and drug resistance. It is essential to comprehend the fundamental processes and discover novel therapeutic objectives for augmenting treatment results. Based on our research findings, we have identified a correlation between methylation of cg09897064 and decreased expression of ZBP1, indicating a link to unfavorable prognosis in patients with lung cancer. Furthermore, these factors play a role in macrophage polarization, with ZBP1 upregulated in M1 macrophages compared to both M0 and M2 polarized macrophages. We observed cg09897064 methylation in M2 polarization, but not in M0 and M1 polarized macrophages. ATACseq analysis revealed closed chromatin accessibility of ZBP1 in M0 polarized macrophages, while open accessibility was observed in both M1 and M2 polarized macrophages. Our findings suggest that ZBP1 is downregulated in M0 polarized macrophages due to closed chromatin accessibility and downregulated in M2 polarized macrophages due to cg09897064 methylation. Further investigations manipulating cg09897064 methylation and ZBP1 expression through overexpression plasmids and shRNAs provided evidence for their role in modulating macrophage polarization and tumor growth. ZBP1 inhibits M2 polarization and suppresses tumor growth, while cg09897064 methylation promotes M2 polarization and macrophage-induced tumor growth. In mechanism investigations, we found that cg09897064 methylation impairs CEBPA binding to the ZBP1 promoter, leading to decreased ZBP1 expression. Clinical experiments were conducted to validate the correlation between methylation at cg09897064, ZBP1 expression, and macrophage M2 polarization. Targeting these factors may hold promise as a strategy for developing innovative checkpoint inhibitors in lung cancer treatment.
Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Proteínas de Unión al ARN , Humanos , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Cromatina/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Macrófagos/metabolismo , Metilación , Proteínas de Unión al ARN/genéticaRESUMEN
Soil salinity is often heterogeneous in saline fields. Nonuniform root salinity increases nitrate uptake into cotton (Gossypium hirsutum) root portions exposed to low salinity, which may be regulated by root portions exposed to high salinity through a systemic long-distance signaling mechanism. However, the signals transmitted between shoots and roots and their precise molecular mechanisms for regulating nitrate uptake remain unknown. Here, we showed that nonuniform root salinity treatment using split-root systems increases the expression of C-TERMINALLY ENCODED PEPTIDE (GhCEP) genes in high-saline-treated root portions. GhCEP peptides originating in high-saline-treated root portions act as ascending long-distance mobile signals transported to the shoots to promote the expression of CEP DOWNSTREAM (GhCEPD) genes by inducing the expression of CEP receptor (GhCEPR) genes. The shoot-derived GhCEPD polypeptides act as descending mobile signals transported to the roots through the phloem, increasing the expression of nitrate transport genes NITRATE TRANSPORTER 1.1 (GhNRT1.1), GhNRT2.1, and GhNRT1.5 in nonsaline-treated root portions, thereby increasing nitrate uptake in the nonsaline-treated root portions. This study indicates that GhCEP and GhCEPD signals are transported between roots and shoots to increase nitrate uptake in cotton, and the transport from the nonsaline root side is in response to nonuniform root salinity distribution.
Asunto(s)
Gossypium , Nitratos , Gossypium/metabolismo , Nitratos/metabolismo , Salinidad , Transporte Iónico , Estrés Salino , Raíces de Plantas/metabolismoRESUMEN
BACKGROUND: Weaning usually causes low feed intake and weight loss in piglets, which mobilizes lipid to energize. The microbe-derived antioxidants (MAs) exhibit great potential in antioxidation, anti-inflammation, and metabolic regulation. OBJECTIVES: We aimed to investigate the changes of lipid metabolism postweaning and effects of MA on growth performance and hepatic lipid metabolism in weanling piglets. METHODS: In the first experiment, piglets weaned at 21 d of age were slaughtered on weaning day (d0), 4 (d4), and 14 (d14) postweaning (6 piglets per day). In the second experiment, piglets were divided into 2 groups, receiving MA (MA) and saline gavage (CON), respectively. All piglets were weaned at 21 d of age and 6 piglets from each group were slaughtered at 25 d of age. RESULTS: In experiment 1, the serum triglyceride, total cholesterol (TC), and LDL cholesterol on d4 and d14 declined significantly compared with d0 (P < 0.05). The serum leptin on d0 was higher than that on d4 and d14 (P < 0.05). The serum ghrelin kept increasing from d0 to d14 (P < 0.05). The hepatic hormone-sensitive lipase and adipose triglyceride lipase first increased from d0 to d4 and then decreased from d4 to d14 (P < 0.05). In experiment 2, the average daily gain and average daily feed intake from 21 to 25 d of age increased in the MA group compared with the CON group (P < 0.05). The serum TC, hepatic TC, and glucose of MA group showed a significant increase than that of the CON group (P < 0.05). The expression of SCD1, ACAT2, and PPARγ were upregulated in the MA group (P < 0.05). Contrary to the decreased expression of phosphorylation of adenosine 5'-monophosphate-activated protein kinase alfa subunit (Thr172), the nuclear sterol regulatory element-binding protein 1c, fatty acid synthase, and peroxisome proliferator-activated receptor gamma of MA group increased than that of CON group (P < 0.05). CONCLUSIONS: Weaning promoted hepatic lipolysis and MA could enhance lipid synthesis by regulating adenosine 5'-monophosphate-activated protein kinase alfa subunit-sterol regulatory element-binding protein 1c pathway, thus improving growth performance of weanling piglets.
Asunto(s)
Antioxidantes , Metabolismo de los Lípidos , Animales , Antioxidantes/metabolismo , Proteínas Quinasas/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Porcinos , DesteteRESUMEN
Herein we report an additive-free protocol for the facile synthesis of α,α-dichloroketones and α-chlorohydrins from various aryl terminal, diaryl internal, and aliphatic terminal alkynes and alkenes, respectively. The commercially available tert-butyl hypochlorite (tBuOCl) was employed as a suitable chlorinating reagent, being accompanied by the less harmful tBuOH as the by-product. In addition, the oxygen atoms in the products came from water rather than molecular oxygen, based on the 18O-labelling experiments. Meanwhile, the diastereoselectivity of the Z- and the corresponding E-alkenes has been compared and rationalized. Using a group of control experiments, the possible mechanisms have been proposed as the initial electrophilic chlorination of unsaturated C-C bonds in a Markovnikov-addition manner in general followed by a nucleophilic addition with water. This work simplified the oxychlorination method with a mild chlorine source and a green oxygen source under ambient conditions.
RESUMEN
Amyotrophic lateral sclerosis (ALS) is a uniformly lethal neurodegenerative disease characterized by progressive deterioration of motor neurons and neuromuscular denervation. Adeno-associated virus (AAV)-mediated delivery of trophic factors is being considered as a potential disease-modifying therapeutic avenue. Here we show a marked effect of AAV-mediated over-expression of neuron-derived neurotrophic factor (NDNF) on SOD1G93A ALS model mice. First, we adopt AAV-PHP.eB capsid to enable widespread expression of target proteins in the brain and spinal cord when delivered intrathecally. Then we tested the effects of AAV-NDNF on SOD1G93A mice at different stages of disease. Interestingly, AAV-NDNF markedly improved motor performance and alleviated weight loss when delivered at early post-symptomatic stage. Injection in the middle post-symptomatic stages still improved the locomotion ability, although it did not alleviate the loss of body weight. Injection in the late stage also extended the life span of SOD1G93A mice. Furthermore, NDNF expression promoted the survival of spinal motoneurons, reduced abnormal protein aggregation, and preserved the innervated neuromuscular functions. We further analyzed the signaling pathways of NDNF expression and found that it activates cell survival and growth-associated mammalian target of rapamycin signaling pathway and downregulates apoptosis-related pathways. Thus, intrathecally AAV-NDNF delivery has provided a potential strategy for the treatment of ALS.
Asunto(s)
Esclerosis Amiotrófica Lateral , Enfermedades Neurodegenerativas , Animales , Ratones , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/terapia , Dependovirus/genética , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Ratones Transgénicos , Neuronas Motoras/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Médula Espinal/metabolismo , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismoRESUMEN
Haloferax and Halobellus are the representatives of the family Haloferacaceae and they are dominant in hypersaline ecosystems. Some Haloferax and Halobellus species exhibit a close evolutionary relationship. Genomic, phylogenetic (based on 16S rRNA gene sequence), and phylogenomic analysis were performed to evaluate the taxonomic positions of the genera Haloferax and Halobellus. Based on the results we propose to reclassify Halobellus ramosii as a later heterotypic synonym of Halobellus inordinatus; Haloferax lucentense and Haloferax alexandrinum as later heterotypic synonyms of Haloferax volcanii.
Asunto(s)
Filogenia , ARN Ribosómico 16S , ARN Ribosómico 16S/genética , Haloferax/genética , Haloferax/clasificación , Análisis de Secuencia de ADN , ADN de Archaea/genética , ADN de Archaea/químicaRESUMEN
BACKGROUND: Effective teaching methods are needed to improve students' abilities in hand-eye coordination and understanding of cardiac anatomy in echocardiography education. Simulation devices have emerged as innovative teaching tools and exhibited distinctive advantages due to their ability to provide vivid and visual learning experiences. This study aimed to investigate the effect of simulation of sectional human anatomy using ultrasound on students' learning outcomes and satisfaction in echocardiography education. METHODS: The study included 18 first-year clinical medical students with no prior echocardiography training. After randomization, they underwent a pre-test to assess basic knowledge. Following this, the students were divided into two groups: traditional teaching (traditional group) and simulation of sectional human anatomy using ultrasound (digital group). Each group received 60 min of instruction. Post-tests were assigned to students at two different time points: immediately after the lecture, and one week later (referred to as post-tests 1, and 2). In addition, anonymous questionnaires were distributed to students after class to investigate their satisfaction with teaching. RESULTS: Both groups showed significant improvement in their scores on post-test 1 compared to pre-test (traditional group: from 33.1 ± 8.8 to 48.1 ± 13.1, P = 0.034 vs. digital group: from 35.0 ± 6.7 to 58.0 ± 13.2, P = 0.008). However, there were no significant differences between the two groups in several post-test comparisons. Student satisfaction ratings revealed that the digital group experienced significantly greater satisfaction in areas such as subject interest, teaching style, course alignment, and interaction compared to the traditional group. Additionally, 80% of the digital group strongly endorsed the use of simulation of sectional human anatomy using ultrasound for echocardiography teaching, highlighting its effectiveness. CONCLUSIONS: Simulation of sectional human anatomy using ultrasound may improve students' understanding of echocardiography and satisfaction with the course. Our study provides evidence supporting the use of simulation teaching devices in medical education. Further research is needed to explore the long-term impact of this teaching method on students' learning outcomes and its integration into the medical curriculum. TRIAL REGISTRATION: http://www.chictr.org.cn (registration number: ChiCTR2300074015, 27/07/2023).
Asunto(s)
Ecocardiografía , Educación de Pregrado en Medicina , Evaluación Educacional , Satisfacción Personal , Estudiantes de Medicina , Humanos , Proyectos Piloto , Femenino , Masculino , Educación de Pregrado en Medicina/métodos , Adulto Joven , Entrenamiento Simulado , Anatomía/educación , CurriculumRESUMEN
Great efforts have been made to expand the application fields of nanozymes, which puts forward requirements for nanozymes with both superior catalytic activity and specificity. Herein, we reported the high-indexed intermetallic Pt3Sn (H-Pt3Sn) with high peroxidase-like activity and specificity. The resultant H-Pt3Sn exhibits a specific activity of 345.3 U/mg, which is 1.82 times higher than Pt. Moreover, H-Pt3Sn possesses negligible oxidase-like and catalase-like activities, achieving superior catalytic specificity toward H2O2 activation. Experimental and theoretical calculations reveal both the splitting energy for adsorbed H2O2 and the energy barrier for the rate-determining step of H-Pt3Sn are significantly decreased compared with Pt3Sn and Pt. Finally, a nanozyme-linked immunosorbent assay is successfully developed, achieving the sensitive and accurate colorimetric detection for carcinoembryonic antigen with a low detection limit of 0.49 pg/mL and showing practical feasibility in serum sample detection.
Asunto(s)
Peróxido de Hidrógeno , Peroxidasa , Peroxidasas , Inmunoensayo , ColorimetríaRESUMEN
The tris(bipyridine)ruthenium(II) (Ru(bpy)32+)-tripropylamine anodic electrochemiluminescence (ECL) system has been widely applied in commercial bioanalysis. However, the presence of amine compounds in the biological environment results in unavoidable anodic interference signals, which hinder further extensive use of the system. In contrast, the cathodic Ru(bpy)32+ ECL system can overcome these limitations. The Ru(bpy)32+/peroxydisulfate (S2O82-, PDS) ECL system has been extensively employed due to its ability to produce a sulfate radical anion (SO4â¢-) with strong oxidation ability, which enhances the ECL signal. However, the symmetrical molecular structure of PDS makes it challenging to be activated and causes low luminescence efficiency. To address this issue, we propose an efficient Ru(bpy)32+-based ternary ECL system that uses the iron-nitrogen-carbon single-atom catalyst (Fe-N-C SAC) as an advanced accelerator. Fe-N-C SAC can efficiently activate PDS into reactive oxygen species at a lower voltage, which significantly boosts the cathodic ECL emission of Ru(bpy)32+. Benefiting from the outstanding catalytic activity of Fe-N-C SAC, we successfully established an ECL biosensor that detects alkaline phosphatase activity with high sensitivity, demonstrating the feasibility of practical application.
RESUMEN
Self-powered sensing system (SPSS) integrating the enzymatic biofuel cell and biosensing platform has attracted tremendous interest. However, natural enzymes suffer from the intrinsic drawbacks of enzymes and enzymatic proteins. Nanozymes with enzyme-like activities are the ideal alternatives to enzymes, and it is greatly challenging to explore high-performance nanozymatic biofuel cell for SPSS. Herein, the advanced nanozymatic biofuel cell-enabled SPSS is developed for the sensitive detection of the prostate-specific antigen (PSA), where Ir single atoms supported by nitrogen-doped carbon and Au nanozymes serve as the cathode and anode, respectively. Based on the excellent electrochemical activity and stability, the resultant nanozymatic biofuel cell exhibits a higher power output and open-circuit potential than the Pt/C-based counterpart, which is beneficial for the application of SPSS. As a proof of concept, the nanozymatic biofuel cell-enabled SPSS shows a wide detection range of 0.2-500 ng mL-1 with a detection limit of 62 pg mL-1 for PSA, which provides new insight into broadening the application scenarios of nanozymes.
Asunto(s)
Fuentes de Energía Bioeléctrica , Inmunoensayo , Inmunoensayo/métodos , Técnicas Biosensibles , Límite de Detección , Electrodos , Antígeno Prostático Específico/análisisRESUMEN
Cortex development is controlled by temporal patterning of neural progenitor (NP) competence with sequential generation of deep and superficial layer neurons, but underlying mechanisms remain elusive. Here, we report a role for heterogeneous nuclear ribonucleoprotein A3 (HNRNPA3) in regulating the division of early cortical NPs that mainly give rise to deep-layer neurons via direct neurogenesis. HNRNPA3 is expressed at high levels in NPs of mouse and human cortex at early stages, with a unique peri-chromosome pattern. Intriguingly, downregulation of HNRNPA3 caused chromosome disarrangement, which hindered normal separation of chromosomes during NP division, leading to mitotic delay. Furthermore, HNRNPA3 is associated with the cohesin-core subunit SMC1A and controls its association with chromosomes, implicating a mechanism for the role of HNRNPA3 in regulating chromosome segregation in dividing NPs. Hnrnpa3-deficient mice exhibited reduced cortical thickness, especially of deep layers. Moreover, downregulation of HNRNPA3 in cultured human cerebral organoids led to marked reduction in NPs and deep-layer neurons. Thus, this study has identified a crucial role for HNRNPA3 in NP division and highlighted the relationship between mitosis progression and early neurogenesis.
Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Ribonucleoproteína Heterogénea-Nuclear Grupo A-B/metabolismo , Mitosis/genética , Células-Madre Neurales/metabolismo , Neurogénesis/genética , Animales , Línea Celular , Proliferación Celular/genética , Corteza Cerebral/embriología , Segregación Cromosómica/genética , Femenino , Ribonucleoproteína Heterogénea-Nuclear Grupo A-B/genética , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neuronas/metabolismo , Transfección , CohesinasRESUMEN
BACKGROUND: Broussonetia papyrifera (L.) L'Hér. ex Vent. has the characteristics of strong stress resistance, high crude protein content, and pruning tolerance. It is an ecological, economic, and medicinal plant. Polyploid plants usually perform better than their corresponding diploid plants in terms of nutrients, active substances, and stress resistance. RESULTS: In this study, the leaves, calli, and seeds of diploid B. papyrifera were used for tetraploid induction by colchicine. The induction effect of colchicine on B. papyrifera was summarized through the early morphology, chromosome count and flow cytometry. It was concluded that the best induction effect (18.6%) was obtained when the leaves of B. papyrifera were treated in liquid MS (Murashige and Skoog) medium containing 450 mg·L-1 colchicine for 3 d. The comparative analysis of the growth characteristics of diploid and tetraploid B. papyrifera showed that tetraploid B. papyrifera has larger ground diameter, larger stomata, thicker palisade tissue and thicker sponge tissue than diploid B. papyrifera. In addition, the measurement of photosynthetic features also showed that tetraploids had higher chlorophyll content and higher photosynthetic rates. CONCLUSION: This study showed that tetraploid B. papyrifera could be obtained by treating leaves, callus and seeds with liquid and solid colchicine, but the induction efficiency was different. Moreover, there were differences in stomata, leaf cell structure and photosynthetic features between tetraploid B. papyrifera and its corresponding diploid. The induced tetraploid B. papyrifera can provide a technical basis and breeding material for the creation of B. papyrifera germplasm resources in the future.
Asunto(s)
Broussonetia , Morus , Tetraploidía , Broussonetia/genética , Colchicina/farmacología , FitomejoramientoRESUMEN
The accurate evaluation of electron correlations is highly necessary for the proper descriptions of the electronic structures in strongly correlated molecules, ranging from bond-dissociating molecules, polyradicals, to large conjugated molecules and transition metal complexes. For this purpose, in this paper, a new ab-initio quantum chemistry program Kylin 1.0 for electron correlation calculations at various quantum many-body levels, including configuration interaction (CI), perturbation theory (PT), and density matrix renormalization group (DMRG), is presented. Furthermore, fundamental quantum chemistry methods such as Hartree-Fock self-consistent field (HF-SCF) and the complete active space SCF (CASSCF) are also implemented. The Kylin 1.0 program possesses the following features: (1) a matrix product operator (MPO) formulation-based efficient DMRG implementation for describing static electron correlation within a large active space composed of more than 100 orbitals, supporting both U 1 n × U 1 S z and U 1 n × SU 2 S symmetries; (2) an efficient second-order DMRG-self-consistent field (SCF) implementation; (3) an externally contracted multi-reference CI (MRCI) and Epstein-Nesbet PT with DMRG reference wave functions for including the remaining dynamic electron correlation outside the large active spaces. In this paper, we introduce the capabilities and numerical benchmark examples of the Kylin 1.0 program.
RESUMEN
Endothelial cells (ECs) angiogenesis is the process of sprouting new vessels from the existing ones, playing critical roles in physiological and pathological processes such as wound healing, placentation, ischemia/reperfusion, cardiovascular diseases and cancer metastasis. Although mitochondria are not the major sites of energy source in ECs, they function as important biosynthetic and signaling hubs to regulate ECs metabolism and adaptations to local environment, thus affecting ECs migration, proliferation and angiogenic process. The understanding of the importance and potential mechanisms of mitochondria in regulating ECs metabolism, function and the process of angiogenesis has developed in the past decades. Thus, in this review, we discuss the current understanding of mitochondrial proteins and signaling molecules in ECs metabolism, function and angiogeneic signaling, to provide new and therapeutic targets for treatment of diverse cardiovascular and angiogenesis-dependent diseases.
Asunto(s)
Células Endoteliales , Transducción de Señal , Células Endoteliales/metabolismo , Transducción de Señal/fisiología , Neovascularización Fisiológica , MitocondriasRESUMEN
Dengue virus (DENV) is a mosquito-borne pathogen that causes a spectrum of diseases including life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Vascular leakage is a common clinical crisis in DHF/DSS patients and highly associated with increased endothelial permeability. The presence of vascular leakage causes hypotension, circulatory failure, and disseminated intravascular coagulation as the disease progresses of DHF/DSS patients, which can lead to the death of patients. However, the mechanisms by which DENV infection caused the vascular leakage are not fully understood. This study reveals a distinct mechanism by which DENV induces endothelial permeability and vascular leakage in human endothelial cells and mice tissues. We initially show that DENV2 promotes the matrix metalloproteinase-9 (MMP-9) expression and secretion in DHF patients' sera, peripheral blood mononuclear cells (PBMCs), and macrophages. This study further reveals that DENV non-structural protein 1 (NS1) induces MMP-9 expression through activating the nuclear factor κB (NF-κB) signaling pathway. Additionally, NS1 facilitates the MMP-9 enzymatic activity, which alters the adhesion and tight junction and vascular leakage in human endothelial cells and mouse tissues. Moreover, NS1 recruits MMP-9 to interact with ß-catenin and Zona occludens protein-1/2 (ZO-1 and ZO-2) and to degrade the important adhesion and tight junction proteins, thereby inducing endothelial hyperpermeability and vascular leakage in human endothelial cells and mouse tissues. Thus, we reveal that DENV NS1 and MMP-9 cooperatively induce vascular leakage by impairing endothelial cell adhesion and tight junction, and suggest that MMP-9 may serve as a potential target for the treatment of hypovolemia in DSS/DHF patients.