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1.
Proc Natl Acad Sci U S A ; 120(44): e2306177120, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37871210

RESUMO

Lepidopterans affect crop production worldwide. The use of transgenes encoding insecticidal proteins from Bacillus thuringiensis (Bt) in crop plants is a well-established technology that enhances protection against lepidopteran larvae. Concern about widespread field-evolved resistance to Bt proteins has highlighted an urgent need for new insecticidal proteins with different modes or sites of action. We discovered a new family of insecticidal proteins from ferns. The prototype protein from Pteris species (Order Polypodiales) and variants from two other orders of ferns, Schizaeales and Ophioglossales, were effective against important lepidopteran pests of maize and soybean in diet-based assays. Transgenic maize and soybean plants producing these proteins were more resistant to insect damage than controls. We report here the crystal structure of a variant of the prototype protein to 1.98 Å resolution. Remarkably, despite being derived from plants, the structure resembles the 3-domain Cry proteins from Bt but has only two out of three of their characteristic domains, lacking the C-terminal domain which is typically required for their activities. Two of the fern proteins were effective against strains of fall armyworm that were resistant to Bt 3-domain Cry proteins Cry1Fa or Cry2A.127. This therefore represents a novel family of insecticidal proteins that have the potential to provide future tools for pest control.


Assuntos
Bacillus thuringiensis , Gleiquênias , Inseticidas , Traqueófitas , Animais , Inseticidas/metabolismo , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Controle Biológico de Vetores , Endotoxinas/genética , Endotoxinas/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Traqueófitas/metabolismo , Zea mays/metabolismo
2.
Lab Invest ; 104(9): 102107, 2024 09.
Artigo em Inglês | MEDLINE | ID: mdl-38964504

RESUMO

DNA mismatch repair gene MutL homolog-1 (MLH1) has divergent effects in many cancers; however, its impact on the metastasis of pancreatic ductal adenocarcinoma (PDAC) remains unclear. In this study, MLH1 stably overexpressed (OE) and knockdowned (KD) sublines were established. Wound healing and transwell assays were used to evaluate cell migration/invasion. In vivo metastasis was investigated in orthotopic implantation models (severe combined immunodeficiency mice). RT-qPCR and western blotting were adopted to show gene/protein expression. MLH1 downstream genes were screened by transcriptome sequencing. Tissue microarray-based immunohistochemistry was applied to determine protein expression in human specimens. In successfully generated sublines, OE cells presented weaker migration/invasion abilities, compared with controls, whereas in KD cells, these abilities were significantly stronger. The metastasis-inhibitory effect of MLH1 was also observed in mice. Mechanistically, G protein-coupled receptor, family C, group 5, member C (GPRC5C) was a key downstream gene of MLH1 in PDAC cells. Subsequently, transient GPRC5C silencing effectively inhibited cell migration/invasion and remarkably reversed the proinvasive effect of MLH1 knockdown in KD cells. In animal models and human PDAC tissues, tumoral GPRC5C expression, negatively associated with MLH1 expressions, was positively correlated with histologic grade, vessel invasion, and poor cancer-specific survival. In conclusion, MLH1 inhibits the metastatic potential of PDAC via downregulation of GPRC5C.


Assuntos
Carcinoma Ductal Pancreático , Regulação para Baixo , Proteína 1 Homóloga a MutL , Neoplasias Pancreáticas , Receptores Acoplados a Proteínas G , Proteína 1 Homóloga a MutL/metabolismo , Proteína 1 Homóloga a MutL/genética , Humanos , Animais , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Linhagem Celular Tumoral , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Camundongos , Masculino , Feminino , Movimento Celular , Camundongos SCID , Regulação Neoplásica da Expressão Gênica , Pessoa de Meia-Idade , Metástase Neoplásica
3.
Pharmacol Res ; 200: 107079, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38272334

RESUMO

The AIM2 inflammasome represents a multifaceted oligomeric protein complex within the innate immune system, with the capacity to perceive double-stranded DNA (dsDNA) and engage in diverse physiological reactions and disease contexts, including cancer. While originally conceived as a discerning DNA sensor, AIM2 has demonstrated its capability to discern various nucleic acid variations, encompassing RNA and DNA-RNA hybrids. Through its interaction with nucleic acids, AIM2 orchestrates the assembly of a complex involving multiple proteins, aptly named the AIM2 inflammasome, which facilitates the enzymatic cleavage of proinflammatory cytokines, namely pro-IL-1ß and pro-IL-18. This process, in turn, underpins its pivotal biological role. In this review, we provide a systematic summary and discussion of the latest advancements in AIM2 sensing various types of nucleic acids. Additionally, we discuss the modulation of AIM2 activation, which can cause cell death, including pyroptosis, apoptosis, and autophagic cell death. Finally, we fully illustrate the evidence for the dual role of AIM2 in different cancer types, including both anti-tumorigenic and pro-tumorigenic functions. Considering the above information, we uncover the therapeutic promise of modulating the AIM2 inflammasome in cancer treatment.


Assuntos
Neoplasias , Ácidos Nucleicos , Humanos , Inflamassomos/metabolismo , Ácidos Nucleicos/uso terapêutico , Neoplasias/tratamento farmacológico , DNA , RNA , Proteínas de Ligação a DNA/metabolismo
4.
J Mol Cell Cardiol ; 166: 91-106, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35235835

RESUMO

Adult mammals have limited potential for cardiac regeneration after injury. In contrast, neonatal mouse heart, up to 7 days post birth, can completely regenerate after injury. Therefore, identifying the key factors promoting the proliferation of endogenous cardiomyocytes (CMs) is a critical step in the development of cardiac regeneration therapies. In our previous study, we predicted that mitogen-activated protein kinase (MAPK) interacting serine/threonine-protein kinase 2 (MNK2) has the potential of promoting regeneration by using phosphoproteomics and iGPS algorithm. Here, we aimed to clarify the role of MNK2 in cardiac regeneration and explore the underlying mechanism. In vitro, MNK2 overexpression promoted, and MNK2 knockdown suppressed cardiomyocyte proliferation. In vivo, inhibition of MNK2 in CMs impaired myocardial regeneration in neonatal mice. In adult myocardial infarcted mice, MNK2 overexpression in CMs in the infarct border zone activated cardiomyocyte proliferation and improved cardiac repair. In CMs, MNK2 binded to eIF4E and regulated its phosphorylation level. Knockdown of eukaryotic translation initiation factor (eIF4E) impaired the proliferation-promoting effect of MNK2 in CMs. MNK2-eIF4E axis stimulated CMs proliferation by activating cyclin D1. Our study demonstrated that MNK2 kinase played a critical role in cardiac regeneration. Over-expression of MNK2 promoted cardiomyocyte proliferation in vitro and in vivo, at least partly, by activating the eIF4E-cyclin D1 axis. This investigation identified a novel target for heart regenerative therapy.


Assuntos
Fator de Iniciação 4E em Eucariotos , Infarto do Miocárdio , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Ciclina D1/metabolismo , Fator de Iniciação 4E em Eucariotos/metabolismo , Mamíferos/metabolismo , Camundongos , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Fosforilação
5.
J Cell Mol Med ; 26(10): 2895-2907, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35373434

RESUMO

Pyroptosis is associated with various cardiovascular diseases. Increasing evidence suggests that long noncoding RNAs (lncRNAs) have been implicated in gene regulation, but how lncRNAs participate in the regulation of pyroptosis in the heart remains largely unknown. In this study, we aimed to explore the antipyroptotic effects of lncRNA FGF9-associated factor (FAF) in acute myocardial infarction (AMI). The expression patterns of lncRNA FAF, miR-185-5p and P21 activated kinase 2 (PAK2) were detected in hypoxia/ischaemia-induced cardiomyocytes. Hoechst 33342/PI staining, lactate dehydrogenase (LDH) release assay, immunofluorescence and Western blotting were conducted to assay cell pyroptosis. The interaction between lncRNA FAF, miR-185-5p and PAK2 was verified by bioinformatics analysis, small RNA sequencing luciferase reporter assay and qRT-PCR. The expression of LncRNA FAF was downregulated in hypoxic cardiomyocytes and myocardial tissues. Overexpression of lncRNA FAF could attenuate cardiomyocyte pyroptosis, improve cell viability and reduce infarct size during the procession of AMI. Moreover, lncRNA FAF was confirmed as a sponge of miR-185-5p and promoted PAK2 expression in cardiomyocytes. Collectively, our findings reveal a novel lncRNA FAF/miR-185-5p/PAK2 axis as a crucial regulator in cardiomyocyte pyroptosis, which might be a potential therapeutic target of AMI.


Assuntos
MicroRNAs , Infarto do Miocárdio , Miócitos Cardíacos , RNA Longo não Codificante , Quinases Ativadas por p21 , Apoptose , Humanos , Hipóxia/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Piroptose/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
6.
Ecotoxicol Environ Saf ; 230: 113105, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34954678

RESUMO

Simazine is a triazine pesticides that typically detected in ground water and soil, and can reportedly affect reproductive health in humans and animals. However, the effect of simazine on female germ cell development remains unclear. In the present study, we observed that simazine exposure decreased oocyte maturation competence and embryonic developmental capacity. Importantly, simazine exposure disrupted microtubule stability and actin polymerization, resulting in failure of spindle assembly and migration. In addition, simazine exposure impaired mitochondrial function and cytosolic Ca2+ homeostasis in both oocyte and 2-cell embryos, thus increasing the levels of reactive oxygen species (ROS). Moreover, simazine exposure induced DNA damage and early apoptosis during oocyte maturation. Collectively, our results demonstrate that simazine exposure-induced mitochondrial dysfunction and apoptosis are major causes of poor oocytes quality.

7.
Pak J Med Sci ; 38(5): 1292-1297, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35799762

RESUMO

Objective: To observe the clinical efficacy of external ventricular drain combined with intraventricular urokinase injection and intravenous piracetam in the treatment of intraventricular hemorrhage. Methods: A randomized controlled trial was used in this study conducted at Baoding First Central Hospital, China from January 2017 to December 2019. Sixty patients with intraventricular hemorrhage were randomly divided into two groups. Patients in the control group were treated with external ventricular drain, while patients in the experimental group were given intraventricular urokinase injection and intravenous piracetam on the basis of the control group. The incidence of adverse drug reactions, hospitalization time, hematoma elimination time, and drainage tube removal time in two groups were compared and analyzed including the cerebrospinal fluid protein content, changes in GCS score, neurological function recovery (ADL score), and Glasgow outcome scale (GOS) of the two groups after treatment. Results: The hematoma elimination time, drainage tube removal time and hospitalization time of the experimental group were shorter than those of the control group, with a statistically significant difference (P<0.05). After treatment, compared with the control group, the protein content of cerebrospinal fluid in the experimental group decreased more significantly (P=0.00), the GCS score was higher (P=0.00), the overall good rate of neurological function was higher (P=0.04), while the rate of good prognosis was higher (P=0.03). Within one month of treatment, the incidence of surgical complications in experimental group was significantly lower than that in control group (P=0.04). Conclusions: External ventricular drain combined with intraventricular urokinase injection and intravenous piracetam is an effective method for the treatment of intraventricular hemorrhage, which is worthy of clinical promotion.

8.
Pak J Med Sci ; 37(2): 320-324, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33679906

RESUMO

OBJECTIVE: To examine the clinical efficacy of combining Riluzole with mannitol and hyperbaric oxygen therapy in treating thoracolumbar vertebral fracture-induced acute spinal cord injury (ASCI). METHODS: From June 2015 to May 2018, 80 patients with thoracolumbar fractures and ASCI who were treated at Baoding First Central Hospital were selected. All patients underwent posterior laminectomy and screw fixation, and they were randomly divided into two groups using a random number table method. The control group received conventional postoperative treatment, while the experimental group was treated with riluzole combined with mannitol and hyperbaric oxygen on the basis of conventional treatment. The recovery of nerve function which included motor function and sensory function, and the changes of serum IL-6, CRP, BDNF, BFGF and other factors before treatment and four weeks after treatment of the two groups of patients were observed and evaluated. RESULTS: After treatment, the motor function scores and sensory function scores of the two groups of patients were improved compared with those before treatment (p<0.05). Compared with the control group, the experimental group improved significantly, and the difference was statistically significant (p<0.05). The levels of IL-6, BDNF and NFGF in the experimental group were significantly lower than those in the control group (p<0.05). CONCLUSIONS: For patients with thoracolumbar fractures and ASCI undergoing laminar decompression and fixation, the comprehensive treatment plan of riluzole combined with mannitol and hyperbaric oxygen has certain advantages. Compared with the conventional therapy, it may significantly improve the movement and sensory functions of patients, relieve the inflammatory response of spinal cord, and promote recovery from the injury.

9.
Phys Rev Lett ; 125(5): 056402, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32794859

RESUMO

We propose a universal practical approach to realize magnetic second-order topological insulator (SOTI) materials, based on properly breaking the time reversal symmetry in conventional (first-order) topological insulators. The approach works for both three dimensions (3D) and two dimensions (2D), and is particularly suitable for 2D, where it can be achieved by coupling a quantum spin Hall insulator with a magnetic substrate. Using first-principles calculations, we predict bismuthene on EuO(111) surface as the first realistic system for a two-dimensional magnetic SOTI. We explicitly demonstrate the existence of the protected corner states. Benefitting from the large spin-orbit coupling and sizable magnetic proximity effect, these corner states are located in a boundary gap ∼83 meV, and hence can be readily probed in experiment. By controlling the magnetic phase transition, a topological phase transition between a first-order TI and a SOTI can be simultaneously achieved in the system. The effect of symmetry breaking, the connection with filling anomaly, and the experimental detection are discussed.

10.
Ren Fail ; 42(1): 1004-1014, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32985309

RESUMO

BACKGROUND: Trimethylamine-N-Oxide (TMAO) is a proatherogenic and prothrombotic metabolite. Our study examined the association of plasma TMAO level with cardiovascular and all-cause mortality in hemodialysis (HD) patients. METHODS: Patients who were at least 18 years-old and received HD for at least 6 months were enrolled within 6 months. Patients with coronary heart disease, congestive heart failure, arrhythmia, or stroke within 3 months before study onset were excluded. The primary endpoints were cardiovascular and all-cause death, and the secondary endpoint was cerebrovascular death. RESULTS: We recruited 252 patients and divided them into a high-TMAO group (>4.73 µg/mL) and a low-TMAO group (≤4.73 µg/mL). The median follow-up time was 73.4 months (interquartile range: 42.9, 108). A total of 123 patients died, 39 from cardiovascular disease, 19 from cerebrovascular disease, and 65 from other causes. Kaplan-Meier analysis indicated that the high-TMAO group had a greater incidence of cardiovascular death (Log-Rank: p = 0.006) and all-cause death (Log-Rank: p < 0.001). Cox regression analysis showed that high TMAO level was significantly associated with cardiovascular and all-cause mortality. After adjustment for confounding, this association remained significant for cardiovascular mortality (TMAO as a continuous variable: HR: 1.18, 95%CI: 1.07, 1.294, p < 0.001; TMAO as a dichotomous variable: HR: 3.44, 95%CI: 1.68, 7.08, p < 0.001) and all-cause mortality (TMAO as a continuous variable: HR: 1.14, 95%CI: 1.08, 1.21, p < 0.001; TMAO as a dichotomous variable: HR: 2.54, 95%CI: 1.71, 3.76, p < 0.001). CONCLUSIONS: High plasma TMAO level is significantly and independently associated with cardiovascular and all-cause mortality in HD patients.


Assuntos
Doenças Cardiovasculares/mortalidade , Falência Renal Crônica/terapia , Metilaminas/sangue , Diálise Renal , Adulto , Idoso , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Causas de Morte , China , Comorbidade , Feminino , Humanos , Incidência , Estimativa de Kaplan-Meier , Falência Renal Crônica/sangue , Falência Renal Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco
11.
J Med Virol ; 91(1): 22-30, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30133803

RESUMO

To analyze the effects of phenol red at various pH values on the Sabin type 2 inactivated polio vaccine (sIPV2), several biophysical techniques were used to evaluate the particle size and capsid protein for conformation. sIPV2's size was assessed via transmission electron microscopy and dynamic light scattering. The effects of various pH values (from 4.0 to 7.0) on the biophysical characters of sIPV2 particles in solution were determined by dynamic light scattering and zeta potential. The results clearly indicated that aggregation and instability occurred in the solution of sIPV2 particles at a pH of 6.0. Under similar conditions, by dynamic light scattering and zeta potential, the virus particles in solution showed more dispersion and were stable with the addition of 0.05 mM phenol red. According to circular dichroism and intrinsic tryptophan fluorescence data, it was observed that the secondary and tertiary structures of the sIPV2 particles were more stable with the protection of phenol red. At a pH below 6.0, the sIPV2 solution with phenol red had more D-antigen content, which was confirmed by enzyme-linked immunosorbent assay and rat experiments. These results strongly suggested that phenol red improved the pH stability of the sIPV2. The study indicated the potential of phenol red in preserving vaccine potency of the sIPV2 at various pH values.


Assuntos
Imunogenicidade da Vacina/efeitos dos fármacos , Fenolsulfonaftaleína/metabolismo , Vacina Antipólio de Vírus Inativado/imunologia , Poliovirus/efeitos dos fármacos , Vírion/efeitos dos fármacos , Animais , Fenômenos Biofísicos , Dicroísmo Circular , Estabilidade de Medicamentos , Difusão Dinâmica da Luz , Feminino , Concentração de Íons de Hidrogênio , Masculino , Microscopia Eletrônica , Vacina Antipólio de Vírus Inativado/química , Ratos Wistar
12.
Cell Physiol Biochem ; 48(3): 1019-1029, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30041247

RESUMO

BACKGROUND/AIMS: High mobility group B-1 (HMGB-1)-induced endoplasmic reticulum stress (ERS) has been implicated in inflammation and dendritic cell maturation. C/EBP-homologous protein (CHOP) is a vital component of ERS and apoptosis and plays a critical role in atherosclerosis. However, only a little information is available about the role of HMGB-1 in foam cell formation. Thus, the role of HMGB-1-induced ERS/CHOP pathway in apoptosis and formation of macrophage-derived foam cells is investigated. METHODS: RAW264.7 cells were treated with oxidized low-density lipoprotein (oxLDL) in the absence and/or presence of HMGB-1, N-acetylcysteine (NAC, an antioxidant), glycyrrhizin (Gly, an HMGB-1 inhibitor), tunicamycin (TM, an ERS inducer), and 4-phenylbutyrate (4-PBA, an ERS inhibitor). Reactive oxygen species (ROS) production was examined by dihydroethidium (DHE) staining. Oil Red O staining, intracellular total cholesterol assay, and Dil-oxLDL uptake assay evaluated the accumulation of lipids in macrophages. Cell apoptosis was measured by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Western blot detected the expression of HMGB-1/ERS/CHOP pathway. RESULTS: oxLDL induced HMGB-1 translocation and secretion in a dose- and time-dependent manner, which was inhibited by NAC. oxLDL-induced lipid accumulation in macrophages was promoted synergistically by HMGB-1 that was attenuated by Gly. Moreover, TM synergized with oxLDL induced lipid accumulation and apoptosis of macrophages; however, 4-PBA alleviated the oxLDL-induced apoptotic foam cells. Additionally, the inhibition of ERS with 4-PBA suppressed the expression of HMGB-1-induced CHOP. CONCLUSIONS: OxLDL triggered HMGB-1 secretion in macrophages via oxidative stress. Furthermore, HMGB-1 promoted the formation and apoptosis of macrophage-derived foam cells via activation of ERS/CHOP pathway.


Assuntos
Apoptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Proteína HMGB1/farmacologia , Animais , Chaperona BiP do Retículo Endoplasmático , Células Espumosas/citologia , Células Espumosas/metabolismo , Proteína HMGB1/metabolismo , Proteínas de Choque Térmico/metabolismo , Lipoproteínas LDL/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição CHOP/metabolismo
13.
Plant Biotechnol J ; 16(2): 649-659, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28796437

RESUMO

The coleopteran insect western corn rootworm (WCR, Diabrotica virgifera virgifera) is an economically important pest in North America and Europe. Transgenic corn plants producing Bacillus thuringiensis (Bt) insecticidal proteins have been useful against this devastating pest, but evolution of resistance has reduced their efficacy. Here, we report the discovery of a novel insecticidal protein, PIP-47Aa, from an isolate of Pseudomonas mosselii. PIP-47Aa sequence shows no shared motifs, domains or signatures with other known proteins. Recombinant PIP-47Aa kills WCR, two other corn rootworm pests (Diabrotica barberi and Diabrotica undecimpunctata howardi) and two other beetle species (Diabrotica speciosa and Phyllotreta cruciferae), but it was not toxic to the spotted lady beetle (Coleomegilla maculata) or seven species of Lepidoptera and Hemiptera. Transgenic corn plants expressing PIP-47Aa show significant protection from root damage by WCR. PIP-47Aa kills a WCR strain resistant to mCry3A and does not share rootworm midgut binding sites with mCry3A or AfIP-1A/1B from Alcaligenes that acts like Cry34Ab1/Cry35Ab1. Our results indicate that PIP-47Aa is a novel insecticidal protein for controlling the corn rootworm pests.


Assuntos
Bacillus thuringiensis/metabolismo , Zea mays/metabolismo , Zea mays/microbiologia , Animais , Controle Biológico de Vetores , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/microbiologia
14.
Phys Chem Chem Phys ; 20(17): 12138-12148, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29682637

RESUMO

The quantum anomalous Hall (QAH) effect is superior to the quantum spin Hall (QSH) effect, which can avoid the inelastic scattering of two edge electrons located on one side of a topological nontrivial material, and thus it has attracted both theoretical and experimental interest. Here, we systematically investigate the lattice structures, and electronic and magnetic properties of hydrogenated arsenene decorated with certain transition metals (Cr, Mo and Cu) based on density-functional theory. A unique QAH effect in Mo@AsH is predicted, whose Chern number (C = 1) indicates only one chiral edge channel located on its one side. Then, we prove that this QAH effect realization is closely related with band inversion, which is the competitive result between its spin-orbit coupling (SOC) strength and exchange field. The quantum state of Mo@AsH can also be tuned by an external strain, similar to SOC, and it is noted that its increased topological gap of about 35 meV under 5.0% tensile strain, is large enough to realize the QAH effect at room-temperature. Additionally, the quantum valley Hall effect in Cu@AsH contributed by the inequality of AB sublattices is also found. Our results reveal the physical mechanism to realize the QAH effect in TM@AsH and provide a platform for electrically controllable topological states, which are highly desirable for nanoelectronics and spintronics.

15.
Nanotechnology ; 28(8): 085705, 2017 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-28102176

RESUMO

Molecularly imprinted polymer nanoparticles incorporating magnetic nanoparticles (MNPs) have been investigated for their selective adsorption properties. Here we describe the synthesis and characterization of magnetic cytosine-imprinted chitosan nanoparticles (CIPs) for gene delivery. In particular, CIPs carrying the mammalian expression plasmid of enhanced green fluorescent protein were prepared by the co-precipitation of MNPs, chitosan and a template nucleobase (cytosine). The results show that the selective reabsorption of cytosine to magnetic CIPs was at least double that of non-imprinted polymers and other nucleobases (such as adenine and thymine). The gene carrier CIPs were used for the transfection of human embryonic kidney 293 cells showing dramatic increase their efficiency with that of conventional chitosan nanoparticles. Furthermore, the gene carrier magnetic CIPs also exhibit low toxicity compared to that of commercially available cationic lipids.

16.
Water Sci Technol ; 75(10): 2291-2298, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28541936

RESUMO

Substrate adsorption is one of the main processes by which redundant phosphorus is removed from wastewater in surface flow constructed wetlands (SFCWs). The physical properties of the substrate, such as depth and particle size, will influence the amount of phosphorus adsorption. This study was carried out in a long-running intermittent inflow constructed wetland that covered a total area of 940.4 m2 in the Shunyi District of Beijing, China. We investigated how the concentrations of four phosphorus fractions, namely calcium phosphate (CaP), iron phosphate (FeP), adsorbed phosphorus (AdsP), and organic phosphorus (OP), varied between the surface (0-10 cm) and subsurface (10-20 cm) substrate and among the different substrate particle sizes. The total phosphorus concentrations in the substrate ranged from 154.97 to 194.69 mg/kg; CaP accounted for more than 80% of the total phosphorus content. The concentrations of OP were significantly higher in the surface layer than in the subsurface layer, but the concentrations of inorganic phosphorus were not significantly different between the two layers. The CaP, AdsP, and OP adsorption capacities were greater for small-sized substrate particles than for large-sized substrate particles. The results from this study provide a theoretical basis for the construction of constructed wetlands.


Assuntos
Fósforo/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes da Água/análise , Áreas Alagadas , Pequim , China , Tamanho da Partícula
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 37(1): 166-71, 2017 01.
Artigo em Zh | MEDLINE | ID: mdl-30196004

RESUMO

Poly-L-lysine is an important polycation which has great prospect in the biomedical application. However, there are few reports on the blood compatibility of poly-L-lysine at present, especially the interaction between poly-L-lysine and some important proteins from the blood, which is studied with spectroscopic methods. Therefore, it is of certain innovation to further evaluate the blood compatibility of poly-L-lysine, which is studied by the interaction between poly-L-lysine and fibrinogen with many spectroscopic methods. In this study, the fluorescence, ultraviolet visible and circular dichroism spectroscopy were used to research the effects of poly-L-lysine on the structure of fibrinogen. Briefly, zeta potential experiment showed that positive potential of poly-L-lysine increased with increasing concentration. Complexation experiment showed that 0.01 mg·mL(-1) poly-L-lysine had little effect on the function of fibrinogen, and the interaction strengthened with concentration increasing. Fluorescence spectra showed that the fluorescence of fibrinogen was quenched in a concentration dependent way when the emission wavelength was 341 nm (λem=341 nm). Ultraviolet visible spectra showed that the absorption intensity of fibrinogen at 200~240 and 278 nm, which was less affected by 0.025 mg·mL(-1) poly-L-lysine, reduced with the concentration of poly-L-lysine increasing. Circular dichroism spectra showed when the concentration of poly-L-lysine increased, the effect of poly-L-lysine on the secondary structure of fibrinogen strengthened. Overall, as the concentration of poly-L-lysine increased, the α-helix content of fibrinogen decreased and the ß-fold, ß-turn and random coil content of fibrinogen increased. These results showed that the electrostatic interaction was occurred between poly-L-lysine and fibrinogen, which influenced the structure of fibrinogen by concentration dependence. While the effect of poly-L-lysine (0.01 and 0.025 mg·mL(-1)) on fibrinogen was little, poly-L-lysine of high concentration would damage the physiological function of fibrinogen. Therefore, it is necessary to consider the concentration factor in the development and application of poly-L-lysine. In this study, a simple, convenient and systematic method is utilized to study the interaction between materials and fibrinogen which is helpful to evaluate the blood compatibility of materials sufficiently. Furthermore, the results of this study will provide important guiding information for the biomedical applications of poly-L-lysine.


Assuntos
Polilisina/química , Dicroísmo Circular , Fibrinogênio , Estrutura Secundária de Proteína
18.
Environ Sci Technol ; 50(6): 2931-7, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26894796

RESUMO

Soil organic matter (SOM) is the major factor affecting sequestration of heavy metals in soil. The mean free binding energy and the mean free adsorption energy and speciation of Zn in soil, as affected by SOM, were determined by employing Wien effect measurements. The presence of SOM markedly decreased the Zn binding energy in soils in the following order: Top (5.86 kJ mol(-1)) < Bottom (8.66 kJ mol(-1)) < Top OM-free (9.44 kJ mol(-1)) ≈ Bottom OM-free (9.50 kJ mol(-1)). The SOM also significantly decreased the adsorption energy of Zn on black soil particles by reducing nonspecific adsorption of Zn on their surfaces. The speciation of Zn in soils was elucidated by extended X-ray absorption fine structure spectroscopy and microfocus X-ray fluorescence. The results obtained by linear combination fitting of EXAFS spectra revealed that the main forms of Zn in soil were outer-sphere Zn, Zn-illite, Zn-kaolinite, and HA-Zn. As the SOM content increased, the proportion of HA-Zn among the total immobilized Zn increased, and the proportion of nonspecific adsorbed Zn decreased. The present results implied that SOM is an important controlling factor for the environmental behavior of Zn in soils.


Assuntos
Poluentes do Solo/química , Solo/química , Zinco/química , Adsorção , Espectroscopia por Absorção de Raios X , Raios X
19.
BMC Cardiovasc Disord ; 16: 5, 2016 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-26750922

RESUMO

BACKGROUND: Myocardial fibrosis is an essential hallmark of diabetic cardiomyopathy (DCM) contributing to cardiac dysfunctions. Resveratrol, an antioxidant, exerts its anti-fibrotic effect via inhibition of oxidative stress, while the underlying molecular mechanism remains largely elusive. Periostin, a fibrogenesis matricellular protein, has been shown to be associated with oxidative stress. In the present study, we investigated the role of periostin in anti-fibrotic effect of resveratrol in streptozocin (STZ)-induced diabetic heart and the underlying mechanisms. METHODS: Diabetic mice were induced by STZ injection. After treatment with resveratrol (5 or 25 mg/kg/day i.g) or Saline containing 0.5% carboxymethyl cellulose (CMC) for 2 months, the hearts were detected for oxidative stress and cardiac fibrosis using western blot, Masson's trichrome staining and Dihydroethidium (DHE) staining. In in vitro experiments, proliferation and differentiation of fibroblasts under different conditions were investigated through western blot, 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay and immunofluorescence staining. RESULTS: Administration of resveratrol significantly mitigated oxidative level, interstitial fibrosis and expressions of related proteins in STZ-induced diabetic hearts. In in vitro experiments, resveratrol exhibited anti-proliferative effect on primary mouse cardiac fibroblasts via inhibiting reactive oxygen species (ROS)/extracellular regulated kinase (ERK) pathway and ameliorated myofibroblast differentiation via suppressing ROS/ERK/ transforming growth factor ß (TGF-ß)/periostin pathway. CONCLUSION: Increased ROS production, activation of ERK/TGF-ß/periostin pathway and myocardial fibrosis are important events in DCM. Alleviated ROS genesis by resveratrol prevents myocardial fibrosis by regulating periostin related signaling pathway. Thus, inhibition of ROS/periostin may represent a novel approach for resveratrol to reverse fibrosis in DCM.


Assuntos
Antioxidantes/farmacologia , Diabetes Mellitus Experimental/metabolismo , Cardiomiopatias Diabéticas/patologia , Coração/efeitos dos fármacos , Miocárdio/patologia , Estilbenos/farmacologia , Animais , Moléculas de Adesão Celular/efeitos dos fármacos , Moléculas de Adesão Celular/metabolismo , Diabetes Mellitus Experimental/complicações , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/metabolismo , Fibrose , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Miocárdio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Resveratrol , Transdução de Sinais , Fator de Crescimento Transformador beta/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo
20.
Nephrology (Carlton) ; 21(10): 828-34, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26609639

RESUMO

AIM: Renal ischaemia/reperfusion injury (IRI) is a complication of major surgeries. Regulatory T cells (Tregs) can suppress immunologic damage in the renal IR. Previous studies indicated that delayed ischaemic preconditioning (IPC) partially attenuates IR by inducing Treg expansion. Galectin-9 also attenuates inflammation-related organ injury by expanding Tregs, but it was not used in renal IR yet. Our aim was to test whether IPC combined with galectin-9 has an increased renoprotective effect. METHODS: Mice were divided into five treatment groups (n = 6 per group): (i) IR group: renal ischaemia/reperfusion group; (ii) IPC-IR group: IPC followed by renal IR; (iii) IPC-Gal9-IR group: Gal-9 injections during the time between IPC and IR; (iv) IPC-Gal9-PC61-IR group: anti-CD25 antibody administration apart from IPC, Gal-9 and IR; (v) sham-sham group. We assessed the renal function, histopathological scores, and percentages of Tregs and interferon-γ (IFN-γ) cells in peripheral bood, spleen, and kidney and compared these values among the different groups. RESULTS: Serum creatinine measured was significantly lower after IPC and even lower in combination with Gal-9 injection. The histopathological scores for tubulo-interstitial injury were decreased following IPC and markedly lower after the addition of Gal-9. The number of kidney infiltrating neutrophils and IFN-γ secreting CD4+ T cells was diminished in the IPC/Gal9 combination group, while the percentage of Treg cells in the peripheral blood, spleen, and kidney of animals from the IPC-Gal9-IR group was also markedly increased. CONCLUSION: The renoprotective effect of delayed IPC combined with galectin-9 was superior to IPC alone, through a mechanism related to expansion of regulatory T cells.


Assuntos
Injúria Renal Aguda/prevenção & controle , Galectinas , Precondicionamento Isquêmico/métodos , Traumatismo por Reperfusão , Linfócitos T Reguladores/imunologia , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/imunologia , Animais , Creatinina/sangue , Modelos Animais de Doenças , Galectinas/metabolismo , Galectinas/farmacologia , Inflamação/imunologia , Inflamação/prevenção & controle , Rim/imunologia , Rim/patologia , Testes de Função Renal/métodos , Masculino , Camundongos , Substâncias Protetoras/metabolismo , Substâncias Protetoras/farmacologia , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/prevenção & controle , Resultado do Tratamento
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