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1.
Plant Cell ; 35(6): 2095-2113, 2023 05 29.
Article in English | MEDLINE | ID: mdl-36883592

ABSTRACT

Flowering is critical for sexual reproduction and fruit production. Several pear (Pyrus sp.) varieties produce few flower buds, but the underlying mechanisms are unknown. The circadian clock regulator EARLY FLOWERING3 (ELF3) serves as a scaffold protein in the evening complex that controls flowering. Here, we report that the absence of a 58-bp sequence in the 2nd intron of PbELF3 is genetically associated with the production of fewer flower buds in pear. From rapid amplification of cDNA ends sequencing results, we identified a short, previously unknown transcript from the PbELF3 locus, which we termed PbELF3ß, whose transcript level was significantly lower in pear cultivars that lacked the 58-bp region. The heterologous expression of PbELF3ß in Arabidopsis (Arabidopsis thaliana) accelerated flowering, whereas the heterologous expression of the full-length transcript PbELF3α caused late flowering. Notably, ELF3ß was functionally conserved in other plants. Deletion of the 2nd intron reduced AtELF3ß expression and caused delayed flowering time in Arabidopsis. AtELF3ß physically interacted with AtELF3α, disrupting the formation of the evening complex and consequently releasing its repression of flower induction genes such as GIGANTEA (GI). AtELF3ß had no effect in the absence of AtELF3α, supporting the idea that AtELF3ß promotes flower induction by blocking AtELF3α function. Our findings show that alternative promoter usage at the ELF3 locus allows plants to fine-tune flower induction.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Circadian Clocks , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Circadian Clocks/physiology , Plants/metabolism , Flowers/metabolism
2.
Plant Biotechnol J ; 21(12): 2597-2610, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37571976

ABSTRACT

CRISPR-based directed evolution is an effective breeding biotechnology to improve agronomic traits in plants. However, its gene diversification is still limited using individual single guide RNA. We described here a multiplexed orthogonal base editor (MoBE), and a randomly multiplexed sgRNAs assembly strategy to maximize gene diversification. MoBE could induce efficiently orthogonal ABE (<36.6%), CBE (<36.0%), and A&CBE (<37.6%) on different targets, while the sgRNA assembling strategy randomized base editing events on various targets. With respective 130 and 84 targets from each strand of the 34th exon of rice acetyl-coenzyme A carboxylase (OsACC), we observed the target-scaffold combination types up to 27 294 in randomly dual and randomly triple sgRNA libraries. We further performed directed evolution of OsACC using MoBE and randomly dual sgRNA libraries in rice, and obtained single or linked mutations of stronger herbicide resistance. These strategies are useful for in situ directed evolution of functional genes and may accelerate trait improvement in rice.


Subject(s)
Gene Editing , Oryza , CRISPR-Cas Systems/genetics , RNA, Guide, CRISPR-Cas Systems , Oryza/genetics , Plant Breeding
3.
BMC Microbiol ; 23(1): 100, 2023 04 13.
Article in English | MEDLINE | ID: mdl-37055727

ABSTRACT

Mosquitoes of many species are key disease vectors, killing millions of people each year. Bacillus thuringiensis-based insecticide formulations are largely recognized as among the most effective, ecologically safe, and long-lasting methods of managing insect pests. New B. thuringiensis strains with high mosquito control effectiveness were isolated, identified, genetically defined, and physiologically characterized. Eight B. thuringiensis strains were identified and shown to carry endotoxin-producing genes. Using a scanning electron microscope, results revealed typical crystal forms of various shapes in B. thuringiensis strains. Fourteen cry and cyt genes were found in the strains examined. Although the genome of the B. thuringiensis A4 strain had twelve cry and cyt genes, not all of them were expressed, and only a few protein profiles were observed. The larvicidal activity of the eight B. thuringiensis strains was found to be positive (LC50: 1.4-28.5 g/ml and LC95: 15.3-130.3 g/ml). Bioassays in a laboratory environment demonstrated that preparations containing B. thuringiensis spores and crystals were particularly active to mosquito larvae and adults. These new findings show that the novel preparation containing B. thuringiensis A4 spores and crystals mixture might be used to control larval and adult mosquitoes in a sustainable and ecologically friendly manner.


Subject(s)
Bacillus thuringiensis , Culex , Insecticides , Humans , Animals , Insecticides/pharmacology , Insecticides/metabolism , Bacillus thuringiensis/genetics , Culex/metabolism , Larva/metabolism , Bacillus thuringiensis Toxins/metabolism , Mosquito Vectors , Endotoxins/genetics , Endotoxins/pharmacology , Hemolysin Proteins/genetics , Hemolysin Proteins/pharmacology , Hemolysin Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Proteins/pharmacology , Bacterial Proteins/chemistry
4.
Hepatobiliary Pancreat Dis Int ; 19(5): 467-472, 2020 Oct.
Article in English | MEDLINE | ID: mdl-31983673

ABSTRACT

BACKGROUND: Hemorrhage is one of the most serious complications of endoscopic sphincterotomy (EST). The risk factors for delayed hemorrhage are not clear. This study aimed to explore the risk factors for post-EST delayed hemorrhage and suggest some precautionary measures. METHODS: This study analyzed 8477 patients who successfully underwent endoscopic retrograde cholangiopancreatography (ERCP) and EST between January 2007 and June 2015 in the First Affiliated Hospital of Nanchang University. Univariate and multivariate analyses were performed to find the risk factors for delayed hemorrhage after EST. RESULTS: Of the 8477 patients screened, 137 (1.62%) experienced delayed hemorrhage. Univariate analysis showed that male, the severity of jaundice, duodenal papillary adenoma and carcinoma, diabetes, intraoperative bleeding, moderate and large incisions, and directional deviation of incision were risk factors for post-EST delayed hemorrhage (P < 0.05). Multivariate analysis showed that intraoperative bleeding [odds ratio (OR) = 3.326; 95% CI: 1.785-6.196; P < 0.001] and directional deviation of incision (OR = 2.184; 95% CI: 1.266-3.767; P = 0.005) were independent risk factors for post-EST delayed hemorrhage. CONCLUSIONS: Delayed hemorrhage is the most common and dangerous complication of EST. Intraoperative bleeding and directional deviation of incision are independent risk factors for post-EST delayed hemorrhage.


Subject(s)
Cholangiopancreatography, Endoscopic Retrograde/adverse effects , Postoperative Hemorrhage/etiology , Sphincterotomy, Endoscopic/adverse effects , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome , Young Adult
5.
Fish Shellfish Immunol ; 84: 290-298, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30304710

ABSTRACT

As an important economical shellfish in coastal area of China, abalone is susceptible to bacterial infection, especially Vibiro parahemolyticus (V. parahemolyticus). Matrix metalloproteinases (MMPs) have been extensively investigated in the immune response of mammals. However, little is known about the involvement of MMP in abalone innate immune system against pathogen infection. In this study, the role of MMP-1 in the immune response of Pacific abalone (Haliotis discus hannai) was explored. The results showed that V. parahemolyticus infection induced significantly elevated expression of MMP-1 as well as immune related genes including allograft inflammatory factor 1 (AIF-1), macrophage expressed gene 1 (MPEG-1) and TPA-inducible sequence 11 family protein (Tis11FP). Notably, silencing of MMP-1 reduced the expression of these genes, suggesting that MMP-1 was an upstream regulatory factor in V. parahemolyticus infection. Further analysis showed that MMP-1 was engaged in the regulation of cellular (phagocytosis, apoptosis) and humoral [superoxide dismutase (SOD), alkaline phosphatase (ALP), acid phosphatase (ACP)] immunity. Interestingly, the extracellularly distributed MMP-1 could be translocated to the nuclei of hemocytes, thereby functioning as a transcriptional regulator or by selectively activating or inactivating other components through proteolysis. Hence, our study established an important role of MMP-1 in abalone innate immunity against V. parahemolyticus infection and it represented the first report on the investigation of MMP in abalone.


Subject(s)
Gastropoda/genetics , Gastropoda/immunology , Gene Expression Regulation/immunology , Immunity, Innate/genetics , Matrix Metalloproteinase 1/genetics , Vibrio parahaemolyticus/physiology , Animals , Cell Nucleus/genetics , Immunity, Cellular/genetics , Immunity, Humoral/genetics
6.
Microb Pathog ; 119: 86-92, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29604422

ABSTRACT

The aim of this study was to investigate the protective effects and mechanism of isovitexin, a glycosylflavonoid isolated from rice hulls of Oryza sativa, on Lipopolysaccharide (LPS)/d-galactosamine (D-Gal)-induced acute liver injury. The mice were randomly divided into five groups: control group, LPS/D-Gal group, and LPS/D-Gal + isovitexin groups. The mice of LPS/D-Gal group were received of LPS (50 µg/kg) and D-gal (800 mg/kg) intraperitoneal. The mice of LPS/D-Gal + isovitexin groups were received isovitexin (25, 50, 100 mg/kg) 1 h before LPS/D-Gal treatment. The results showed that the severity of liver injury was attenuated by treatment of isovitexin, as confirmed by the decreased liver histopathologic changes, as well as serum AST and ALT levels. Furthermore, the levels of TNF-α in serum and liver tissues, MPO activity and MDA content were significantly inhibited by isovitexin. In addition, isovitexin significantly attenuated NF-κB phosphorylation induced by LPS/D-Gal. The expression of Nrf2 and HO-1 were significantly up-regulated by isovitexin. In conclusion, isovitexin could protect against LPS/D-Gal-induced liver injury by inhibiting inflammatory and oxidative responses. Isovitexin also had protective effects against carbon tetrachloride (CCl4)-induced liver injury. Isovitexin may used as a potential agent for the treatment of liver injury.


Subject(s)
Apigenin/pharmacology , Chemical and Drug Induced Liver Injury/drug therapy , Galactosamine/adverse effects , Lipopolysaccharides/adverse effects , Liver/drug effects , NF-E2-Related Factor 2/metabolism , NF-kappa B/drug effects , Animals , Apigenin/administration & dosage , Carbon Tetrachloride/adverse effects , Galactosamine/administration & dosage , Gene Expression Regulation/drug effects , Heme Oxygenase-1/metabolism , Lipopolysaccharides/administration & dosage , Liver Function Tests , Male , Membrane Proteins/metabolism , Mice , Mice, Inbred BALB C , NF-kappa B/metabolism , Oryza/chemistry , Phosphorylation , Plant Extracts/pharmacology , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/blood , Up-Regulation
7.
Fish Shellfish Immunol ; 72: 210-219, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29108972

ABSTRACT

Vibrio parahemolyticus (V. parahemolyticus) is a major pathogen for abalone, an important economical shellfish in coastal area of China. There is little known about the abalone innate immune system against pathogen infection. Clip-domain serine proteases (cSPs) are increasingly recognized to play important roles in host immune defense in invertebrates. In this study, we cloned a cSP (Hdh-cSP) from abalone (Haliotis discus hannai). We found out that Hdh-cSP was widely expressed in multiple tissues of abalone, with highest level in the immune-like organ, hepatopancreas. V. parahemolyticus infection induced significantly elevated expression of Hdh-cSP in addition to better-characterized innate immune component genes including Rel/NF-κB, allograft inflammatory factor (ALInFa), macrophage expressed protein (MEP) and caspase-8. Importantly, the silencing of Hdh-cSP reduced the expression of these genes, suggesting that Hdh-cSP was an upstream regulatory factor in V. parahemolyticus infection. Further analysis showed that apoptosis of hemocytes was inhibited when the transcription of Hdh-cSP was knocked down, suggesting that Hdh-cSP participated in cell apoptosis by regulation of caspase 8 expression in V. parahemolyticus infection. Therefore, our study established an important role of cSP in the innate immunity against V. parahemolyticus infection in abalone.


Subject(s)
Gastropoda/genetics , Gastropoda/immunology , Gene Expression Regulation/immunology , Immunity, Innate/genetics , Serine Proteases/genetics , Serine Proteases/immunology , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , Gastropoda/chemistry , Gastropoda/enzymology , Gene Expression Profiling , Phylogeny , Sequence Alignment , Serine Proteases/chemistry , Vibrio
8.
Tumour Biol ; 37(1): 331-9, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26219890

ABSTRACT

Acquisition of cisplatin resistance is the common and critical limitation for hepatocellular carcinoma (HCC) therapy. Our study was aimed to determine whether there were conditions under which the addition of imperatorin would reverse the resistance of HCC cells to cisplatin-based therapy. In this study, we found that addition of imperatorin significantly enhanced the cytotoxicity of cisplatin to HCC cells. Since the Mcl-1 was overexpressed in HCC cell lines (HepG2, HepG3B, PLC, Huh7) compared with normal liver cell line (L-O2), we found that the Mcl-1 expression was downregulated by imperatorin but not influenced by cisplatin in HCC cells. In addition, our results showed the combination of imperatorin and cisplatin induced apoptosis and ∆Ψm collapse more significantly compared with treatment of imperatorin or cisplatin alone. Furthermore, the imperatorin-induced sensitization for cisplatin-cytotoxicity to HCC cells was abolished by the transfection of Mcl-1 expression plasmid. Finally, we found that the addition of imperatorin significantly reversed the resistance to cisplatin in cisplatin-resistant HCC cells, which was Mcl-1 dependent. In summary, our study revealed that combination with imperatorin could enhance the antitumor activity of cisplatin via targeting Mcl-1 and reverse the resistance to cisplatin in HCC.


Subject(s)
Carcinoma, Hepatocellular/metabolism , Cisplatin/chemistry , Furocoumarins/chemistry , Liver Neoplasms/metabolism , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Apoptosis , Cell Line, Tumor/drug effects , Cell Survival , Dose-Response Relationship, Drug , Down-Regulation , Drug Resistance, Neoplasm , Drug Synergism , Hep G2 Cells/drug effects , Humans , Membrane Potential, Mitochondrial , Plasmids/metabolism , Polymerase Chain Reaction
9.
J Vasc Surg ; 59(2): 492-9, 2014 Feb.
Article in English | MEDLINE | ID: mdl-23676189

ABSTRACT

OBJECTIVE: This study examined the influence of 3,4-benzopyrene (BaP), a compound found in cigarette smoke, on the formation of angiotensin II (Ang II)-induced abdominal aortic aneurysm (AAA) formation in mice and the underlying mechanisms. METHODS: C57/B6n mice were divided into four groups. The control group received a weekly intraperitoneal injection of medium-chain triglycerides. The Ang II group received a daily Ang II infusion (0.72 mg/kg) and a weekly intraperitoneal injection of medium-chain triglycerides. The Ang II/BaP group received a daily Ang II infusion (0.72 mg/kg) and a weekly intraperitoneal BaP injection (10 mg/kg, dissolved in medium-chain triglycerides). The BaP group received a weekly intraperitoneal BaP injection (10 mg/kg). After 5 weeks, abdominal aortic diameter was determined. Aortic tissues underwent hematoxylin and eosin, Masson, and immunochemistry staining for evaluation of vascular wall structure, collagen, macrophage infiltration, matrix metalloproteinases (MMPs), and apoptosis. RESULTS: The Ang II infusion and BaP injection induced AAAs in 41.67% of mice vs 25% in the Ang II group (P < .05). The average aortic diameter increased in the Ang II/BaP group compared with the Ang II group (1.40 ± 0.25 vs 1.2 ± 0.23 mm; P < .05). Average aortic muscular cell apoptosis was higher in the Ang II/BaP group (31% ± 12%) than in the Ang II (19% ± 5%; P < .05) or BaP groups (23% ± 4%; P < .05). Aortic macrophage infiltration and expression of MMP-2, MMP-9, MMP-12, and nuclear factor-κB increased (0.56 ± 0.12, 0.47 ± 0.13, 0.49 ± 0.14, 0.49 ± 0.11, and 0.42 ± 0.12, respectively) in the Ang II/BaP group compared with the Ang II group (0.27 ± 0.08, 0.25 ± 0.06, 0.24 ± 0.09, 0.24 ± 0.09, and 0.23 ± 0.06, respectively; P < .05 for all). CONCLUSIONS: BaP promotes Ang II-induced AAA formation in mice via elevating infiltration of macrophages, activating nuclear factor-κB, upregulating the expression of MMP-2, MMP-9, and MMP-12, and increasing the apoptosis of vascular muscle cells in its synergistic effect with Ang II in aortic wall.


Subject(s)
Angiotensin II , Aorta, Abdominal/drug effects , Aortic Aneurysm, Abdominal/chemically induced , Benzo(a)pyrene/toxicity , Animals , Aorta, Abdominal/metabolism , Aorta, Abdominal/pathology , Aortic Aneurysm, Abdominal/metabolism , Aortic Aneurysm, Abdominal/pathology , Apoptosis/drug effects , Benzo(a)pyrene/administration & dosage , Disease Models, Animal , Drug Administration Schedule , Injections, Intraperitoneal , Macrophages/drug effects , Macrophages/metabolism , Male , Matrix Metalloproteinase 12/metabolism , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Mice , Mice, Inbred C57BL , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/pathology , NF-kappa B/metabolism , Smoking/adverse effects , Time Factors
10.
Environ Technol ; : 1-11, 2023 Jun 11.
Article in English | MEDLINE | ID: mdl-37272148

ABSTRACT

Enzymatic catalysis is a promising approach for the degradation of organic pollutants and peroxidases (PODs) are one of the most common enzyme classes used to degrade organic pollutants. Proso millet peroxidase (PmPOD) is a peroxidase extracted and purified from proso millet bran which is the by-product of proso millet processing. In this study, we investigated the effects of PmPOD on the degradation of typical organic pollutants (Rhodamine B (RhB), bisphenol A, sulfadiazine) for the first time. Moreover, we screened RhB as the substrate with the best degradation effect. The degradation rate of RhB catalyzed by PmPOD (10 nM) reached 99.46% in 30 min under the optimal conditions (pH 5, 30°C, and molar ratio of RhB, H2O2 and HOBT of 1:9.58:1.94 × 10-3). The reaction kinetics parameters of PmPOD-mediated RhB degradation Km, Vmax and kcat were 62.2, 935.7 and 9.357 × 104, respectively. High-performance liquid chromatography analyses confirmed that PmPOD transformed RhB into two new products. Furthermore, toxicological evaluation in Caenorhabditis elegans demonstrated that 10 µg/mL RhB significantly reduced the lifespan by 8.3%, reduced the motility and pharynx-pumping rate compared with the control group, while the 10 µg/mL RhB product had no significant effect on these indexes. These data indicated that the toxicity of RhB disappeared after catalytic degradation by PmPOD. Taken together, these data suggest that catalysis of PmPOD is an effective method for degradation and detoxification of RhB. This study provides a potential candidate method for the biological treatment of RhB, and improves the added value of proso millet bran.

11.
J Cheminform ; 15(1): 65, 2023 Jul 19.
Article in English | MEDLINE | ID: mdl-37468954

ABSTRACT

Machine learning has great potential in predicting chemical information with greater precision than traditional methods. Graph neural networks (GNNs) have become increasingly popular in recent years, as they can automatically learn the features of the molecule from the graph, significantly reducing the time needed to find and build molecular descriptors. However, the application of machine learning to energetic materials property prediction is still in the initial stage due to insufficient data. In this work, we first curated a dataset of 12,072 compounds containing CHON elements, which are traditionally regarded as main composition elements of energetic materials, from the Cambridge Structural Database, then we implemented a refinement to our force field-inspired neural network (FFiNet), through the adoption of a Transformer encoder, resulting in force field-inspired Transformer network (FFiTrNet). After the improvement, our model outperforms other machine learning-based and GNNs-based models and shows its powerful predictive capabilities especially for high-density materials. Our model also shows its capability in predicting the crystal density of potential energetic materials dataset (i.e. Huang & Massa dataset), which will be helpful in practical high-throughput screening of energetic materials.

12.
Commun Biol ; 6(1): 59, 2023 01 17.
Article in English | MEDLINE | ID: mdl-36650277

ABSTRACT

Tumor suppressor p53 prevents tumorigenesis by promoting cell cycle arrest and apoptosis through transcriptional regulation. Dysfunction of p53 occurs frequently in human cancers. Thus, p53 becomes one of the most promising targets for anticancer treatment. A bacterial effector protein azurin triggers tumor suppression by stabilizing p53 and elevating its basal level. However, the structural and mechanistic basis of azurin-mediated tumor suppression remains elusive. Here we report the atomic details of azurin-mediated p53 stabilization by combining X-ray crystallography with nuclear magnetic resonance. Structural and mutagenic analysis reveals that the p28 region of azurin, which corresponds to a therapeutic peptide, significantly contributes to p53 binding. This binding stabilizes p53 by disrupting COP1-mediated p53 ubiquitination and degradation. Using the structure-based design, we obtain several affinity-enhancing mutants that enable amplifying the effect of azurin-induced apoptosis. Our findings highlight how the structure of the azurin-p53 complex can be leveraged to design azurin derivatives for cancer therapy.


Subject(s)
Azurin , Tumor Suppressor Protein p53 , Ubiquitination , Humans , Azurin/chemistry , Bacterial Proteins/chemistry , Peptides/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
13.
Nat Commun ; 14(1): 718, 2023 02 09.
Article in English | MEDLINE | ID: mdl-36759618

ABSTRACT

Inorganic polyphosphate (polyP) is an ancient energy metabolite and phosphate store that occurs ubiquitously in all organisms. The vacuolar transporter chaperone (VTC) complex integrates cytosolic polyP synthesis from ATP and polyP membrane translocation into the vacuolar lumen. In yeast and in other eukaryotes, polyP synthesis is regulated by inositol pyrophosphate (PP-InsP) nutrient messengers, directly sensed by the VTC complex. Here, we report the cryo-electron microscopy structure of signal-activated VTC complex at 3.0 Å resolution. Baker's yeast VTC subunits Vtc1, Vtc3, and Vtc4 assemble into a 3:1:1 complex. Fifteen trans-membrane helices form a novel membrane channel enabling the transport of newly synthesized polyP into the vacuolar lumen. PP-InsP binding orients the catalytic polymerase domain at the entrance of the trans-membrane channel, both activating the enzyme and coupling polyP synthesis and membrane translocation. Together with biochemical and cellular studies, our work provides mechanistic insights into the biogenesis of an ancient energy metabolite.


Subject(s)
Polyphosphates , Saccharomyces cerevisiae , Polyphosphates/metabolism , Cryoelectron Microscopy , Saccharomyces cerevisiae/metabolism , Cytosol/metabolism , Ion Channels/metabolism
14.
Food Chem ; 333: 127452, 2020 Dec 15.
Article in English | MEDLINE | ID: mdl-32673951

ABSTRACT

Aimed to study the characteristics of prolyl endopeptidase (PEP, EC 3.4.21.26) and its possible role in the degradation of collagen, we cloned the full-length cDNA sequence of PEP from abalone (Haliotis discus hannai) (Hdh-PEP). Recombinant Hdh-PEP (rHdh-PEP) was expressed in vitro, its enzymatic properties were detected, and its secondary structure was analyzed by Circular Dichroism (CD). We for the first time determined the 1.5 Å crystal structure of rHdh-PEP. The decomposition effect of rHdh-PEP on collagen peptides was analyzed. Our data revealed that the molecular weight of rHdh-PEP is 85 kDa, consisting of a catalytic domain and a ß-propeller domain. The optimal pH and temperature of rHdh-PEP were pH 6.0 and 20 °C, respectively. Using small collagen peptides as substrates, HPLC-ESI-MS analysis confirmed that rHdh-PEP specifically cleaved at the carboxyl side of proline residues, suggesting its role in the degradation of collagen peptides during autolysis.


Subject(s)
Collagen/metabolism , Gastropoda/enzymology , Serine Endopeptidases/chemistry , Serine Endopeptidases/metabolism , Animals , Circular Dichroism , Crystallography, X-Ray , DNA, Complementary/genetics , Hydrogen-Ion Concentration , Proline/metabolism , Prolyl Oligopeptidases , Protein Structure, Secondary , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Serine Endopeptidases/genetics , Spectrometry, Mass, Electrospray Ionization , Temperature
15.
Front Chem ; 7: 672, 2019.
Article in English | MEDLINE | ID: mdl-31681726

ABSTRACT

In this study, a series of novel 1,5-di(nitramino)tetrazole (DNAT)-based bimetallic energetic coordination polymers, MK2(DNAT)2·4H2O [M = Fe, Cu, Ni, Co, and Zn], were designed and synthesized in a simple and convenient self-assembly synthetic process. The obtained compounds were fully characterized by IR spectroscopy, multinuclear NMR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). Additionally, the structures of target compounds were confirmed by single-crystal X-ray diffraction. Based on the room-temperature X-ray densities (2.095-2.138 g cm-3) and the calculated (CBS-QB3) heats of formation (-41.3 to 170.5 kJ mol-1), the detonation properties such as detonation velocities (8,147.0-8,478.4 m s-1) and detonation pressures (29.7-32.8 GPa) were computed using the EXPLO5 v6.04 program. Their excellent energetic properties indicated that they could serve as promising "green" primary explosives for replacement of lead azide (LA).

16.
Dalton Trans ; 48(4): 1524-1529, 2019 Jan 22.
Article in English | MEDLINE | ID: mdl-30637424

ABSTRACT

A new family of C-trinitromethyl-substituted pyrazoles was designed and obtained in good yields by the reaction of N2O4 with the pyrazolecarbaldehyde oxime followed by further N-nitration and C-nitration. All of the new compounds were fully characterized by IR and NMR spectroscopy, elemental analysis and differential scanning calorimetry (DSC). Compounds 2 and 3 were further confirmed by X-ray crystallography. These pyrazole derivatives have good densities, positive enthalpies of formation and acceptable sensitivity values. Theoretical calculations carried out using Gaussian 03 and EXPLO5 program demonstrate good to excellent detonation velocities and pressures in the range of ADN and HMX. Compound 3 exhibiting a positive oxygen balance, high specific impulse and moderate thermal stability is a promising high energy density oxidizer.

18.
RSC Adv ; 8(25): 13755-13763, 2018 Apr 11.
Article in English | MEDLINE | ID: mdl-35539301

ABSTRACT

1-Amino-3,5-dinitro-1,2,4-triazole (ADNT) was prepared using an efficient N-amination process. Three novel catenated N6 energetic derivatives of ADNT, which contain 1,1'-azobis(3,5-dinitro-1,2,4-triazole) (ABDNT), 1,1'-azobis(3-chloro-5-nitro-1,2,4-triazole) (ABCNT) and 1,1'-azobis(3,5-diazido-1,2,4-triazole) (ABDAT), were synthesized from N-amino oxidative-coupling reactions of ADNT. All compounds were fully characterized by 1H and 13C nuclear magnetic resonance spectroscopies, infrared spectroscopy, elemental analysis, mass spectrum, as well as differential scanning calorimetry (DSC). The crystal structure of compound ABCNT was confirmed by single-crystal X-ray diffraction showing an extensive conjugated structure. The densities of energetic derivatives ranged from 1.71 to 1.93 g cm-3, and all compounds have positive heats of formation in the range of 774.8 to 2150.8 kJ mol-1. Based on the measured densities and calculated heats of formation, theoretical performance calculations, including detonation pressures (29.6-42.4 GPa) and detonation velocities (8.22-9.49 km s-1) were carried out using the Gaussian 09 program and Kamlet-Jacobs equations, and they compared favorably with those of TNT and RDX. These properties make them potentially competitive as new high energy-density compounds.

19.
Oncotarget ; 8(59): 100524-100532, 2017 Nov 21.
Article in English | MEDLINE | ID: mdl-29245998

ABSTRACT

OBJECT: Several studies have investigated a survival benefit for levosimendan treatment in patients with septic shock. However, data are conflicting. We conducted a meta-analysis to evaluate the effect of levosimendan treatment on mortality in patients with septic shock. MATERIALS AND METHODS: We searched PubMed, EMBASE and Cochrane Library Databases up to March 27, 2017, without language restrictions. We searched for terms related to septic shock, levosimendan, randomized clinical trial. Randomized controlled trials reported the effect of levosimendan on mortality were included. Moreover, we constructed the trial sequential analysis (TSA) to determine the reliability of the outcomes. Furthermore, secondary outcomes were cardiac index(CI), mean arterial pressure (MAP), blood lactate, norepinephrine dose and length of ICU stay. RESULTS: Ten studies with a total of 816 patients were included in this meta-analysis. There was no significant difference in the mortality between the levosimendan group and the standard inotropic therapy group [RR = 0.96, 95% CI (0.81-1.12), I2 = 0]. However, methods adapted from formal interim monitoring boundaries applied to TSA indicated that the cumulative evidence was unreliable and inconclusive. Blood lactate was significantly reduced in the levosimendan group while there was no difference in MAP, CI, norepinephrine dose and length of ICU stay. CONCLUSIONS: Findings from this meta-analysis demonstrated that levosimendan treatment may not reduce mortality in patients with septic shock. The result remains inclusive and further randomized controlled trials were needed to confirm these conclusions.

20.
Eur J Pharmacol ; 770: 85-91, 2016 Jan 05.
Article in English | MEDLINE | ID: mdl-26668000

ABSTRACT

Mangiferin, a glucosylxanthone from Mangifera indica, has been reported to have anti-inflammatory effects. However, the protective effects and mechanisms of mangiferin on liver injury remain unclear. This study aimed to determine the protective effects and mechanisms of mangiferin on lipopolysaccharide (LPS) and D-galactosamine (D-GalN)-induced acute liver injury. Mangiferin was given 1h after LPS and D-GalN treatment. The results showed that mangiferin inhibited the levels of serum ALT, AST, IL-1ß, TNF-α, MCP-1, and RANTES, as well as hepatic malondialdehyde (MDA) and ROS levels. Moreover, mangiferin significantly inhibited IL-1ß and TNF-α production in LPS-stimulated primary hepatocytes. Mangiferin was found to up-regulate the expression of Nrf2 and HO-1 in a dose-dependent manner. Furthermore, mangiferin inhibited LPS/d-GalN-induced hepatic NLRP3, ASC, caspase-1, IL-1ß and TNF-α expression. In conclusion, mangiferin protected against LPS/GalN-induced liver injury by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation.


Subject(s)
Carrier Proteins/metabolism , Chemical and Drug Induced Liver Injury/metabolism , Chemical and Drug Induced Liver Injury/pathology , Galactosamine/pharmacology , Inflammasomes/metabolism , Lipopolysaccharides/pharmacology , Xanthones/pharmacology , Acute Disease , Alanine Transaminase/blood , Animals , Apoptosis/drug effects , Aspartate Aminotransferases/blood , Chemical and Drug Induced Liver Injury/drug therapy , Cytoprotection/drug effects , Gene Expression Regulation, Enzymologic/drug effects , Liver/drug effects , Liver/metabolism , Liver/pathology , Male , Malondialdehyde/metabolism , Mice , Mice, Inbred C57BL , NF-E2-Related Factor 2/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Xanthones/therapeutic use
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