Apelin-13 Administration Protects Against LPS-Induced Acute Lung Injury by Inhibiting NF-κB Pathway and NLRP3 Inflammasome Activation

Background/Aims: Acute lung injury (ALI) is induced by a variety of external and internal factors and leads to acute progressive respiratory failure. Previous studies have shown that apelin-13 can decrease the acute lung injury induced by LPS, but the specific mechanism is unclear. Therefore, a mouse lung injury model and a cell model were designed to explore the mechanism of how apelin-13 alleviates the acute lung injury caused by LPS. Methods: The effect of apelin-13 on LPS-induced structural damage was determined by H&E staining and by the wet/dry weight ratio. The related inflammatory factors in BALF were examined by ELISA. The apoptotic pathway and the NF-κB and NLRP3 inflammasome pathways were evaluated by using Western blotting and immunofluorescence staining. Results: LPS induced the structural damage and the production of inflammatory cytokines in the lung tissues of mice. These deleterious effects were attenuated by apelin-13 administration. The protective effects of apelin-13 were associated with decreased reactive oxygen species (ROS) formation and the inhibition of the activation of the NF-κB and NLRP3 inflammasome pathways in mice and in Raw264.7 cells. Conclusion: Taken together, these data suggest that apelin-13 administration ameliorates LPS-induced acute lung injury by suppressing ROS formation, as well as by inhibiting the NF-κB pathway and the activation of the NLRP3 inflammasome in the lungs

Antifungal Activity of Isolated Bacillus amyloliquefaciens SYBC H47 for the Biocontrol of Peach Gummosis.

The gummosis disease is caused by Botryosphaeria dothidea (Moug. ex. Fr) Ces. et de Not., and it is one of the most important diseases of stone fruits worldwide. The use of biocontrol as an alternative approach to synthetic chemical fungicides has aroused general concern about how to control plant diseases that are caused by phytopathogens. The aim of this study is to isolate Bacillus strains from raw honeys with the capacity to inhibit B. dothidea and to explore the mechanisms by which they could be used in the biocontrol of peach gummosis. Bacillus amyloliquefaciens SYBC H47 was isolated and identified on the basis of its physiological and biochemical characteristics and its 16S rRNA and gyrB gene sequences. The cell suspension and the cell-free supernatant of its culture showed significant antifungal activity against Aspergillus niger, Mucor racemosus, Fusarium oxysporum, Penicillium citrinum, and Candida albicans by agar-diffusion assays. The primary antifungal substances were bacillomycin L, fengycin, and surfactin, which were analyzed by HPLC LC/ESI-MS/MS. Bacillomycin L showed the best inhibitory effect against conidial germination of B. dothidea, followed by fengycin and surfactin. Surfactin had limited effects on mycelial growth, contrary to those of bacillomycin L and fengycin. However, a mixture of the three lipopeptides had a synergistic effect that disrupted the structure of the conidia and mycelia. In order to reduce the production cost, the use of waste frying peanut oil and soy oil as the sole carbon source increased the lipopeptide yield levels by approximately 17% (2.42 g/L) and 110% (4.35 g/L), respectively. In a field trial, the decreases in the infected gummosis rate (IGR) and the disease severity index (DSI) through cell suspension treatments were 20% and 57.5% (in 2014), respectively, and 40% and 57.5% (in 2015), respectively, in comparison with the control. In conclusion, B. amyloliquefaciens SYBC H47 could inhibit the germination of conidia and the growth of mycelia from B. dothidea; therefore, this strain behaves as a potential biocontrol agent against the gummosis disease

Hydrogen Peroxide-Resistant CotA and YjqC of Bacillus altitudinis Spores Are a Promising Biocatalyst for Catalyzing Reduction of Sinapic Acid and Sinapine in Rapeseed Meal.

For the more efficient detoxification of phenolic compounds, a promising avenue would be to develop a multi-enzyme biocatalyst comprising peroxidase, laccase and other oxidases. However, the development of this multi-enzyme biocatalyst is limited by the vulnerability of fungal laccases and peroxidases to hydrogen peroxide (H2O2)-induced inactivation. Therefore, H2O2-resistant peroxidase and laccase should be exploited. In this study, H2O2-stable CotA and YjqC were isolated from the outer coat of Bacillus altitudinis SYBC hb4 spores. In addition to the thermal and alkali stability of catalytic activity, CotA also exhibited a much higher H2O2 tolerance than fungal laccases from Trametes versicolor and Trametes trogii. YjqC is a sporulation-related manganese (Mn) catalase with striking peroxidase activity for sinapic acid (SA) and sinapine (SNP). In contrast to the typical heme-containing peroxidases, the peroxidase activity of YjqC was also highly resistant to inhibition by H2O2 and heat. CotA could also catalyze the oxidation of SA and SNP. CotA had a much higher affinity for SA than B. subtilis CotA. CotA and YjqC rendered from B. altitudinis spores had promising laccase and peroxidase activities for SA and SNP. Specifically, the B. altitudinis spores could be regarded as a multi-enzyme biocatalyst composed of CotA and YjqC. The B. altitudinis spores were efficient for catalyzing the degradation of SA and SNP in rapeseed meal. Moreover, efficiency of the spore-catalyzed degradation of SA and SNP was greatly improved by the presence of 15 mM H2O2. This effect was largely attributed to synergistic biocatalysis of the H2O2-resistant CotA and YjqC toward SA and SNP

Identification of proteins extracted from spore coat fraction of <i>B</i>. <i>altitudinis</i> SYBC hb4.

<p>Identification of proteins extracted from spore coat fraction of <i>B</i>. <i>altitudinis</i> SYBC hb4.</p

Primary peaks detected by a UV-MALDI TOF MS analysis of the lipopeptides produced by strain SYBC H47.

<p>Primary peaks detected by a UV-MALDI TOF MS analysis of the lipopeptides produced by strain SYBC H47.</p

Purification of YjqC and CotA from <i>B</i>. <i>altitudinis</i> SYBC hb4 spores.

<p>Purification of YjqC and CotA from <i>B</i>. <i>altitudinis</i> SYBC hb4 spores.</p

Effects of H₂O₂ concentrations on activity of YjqC and CotA from <i>B</i>. <i>altitudinis</i> hb4.

<p>(A) Variable H₂O₂ effects on peroxidase activity from the free and spore YjqC. (B) Inhibition by H₂O₂ of CotA activity toward ABTS, SA and SNP. (C) Stability of CotA incubated with different concentrations of H₂O₂ for 0–180 min. (D) Effects of H₂O₂ concentrations on enzymatic activity of spore enzymes toward SA and SNP.</p

GIR of cell suspension and cell-free supernatant against six indicator fungi.

<p>1: <i>B</i>. <i>dothidea</i>; 2: <i>A</i>. <i>niger</i>; 3: <i>M</i>. <i>racemosus</i>; 4: <i>F</i>. <i>oxysporum</i>; 5: <i>P</i>. <i>citrinum</i>; and 6: <i>C</i>. <i>albicans</i>. Gray columns represent cell suspension, and white columns represent cell-free supernatant.</p

Characteristics of YjqC and CotA purified from <i>B</i>. <i>altitudinis</i> SYBC hb4 spores.

<p>Characteristics of YjqC and CotA purified from <i>B</i>. <i>altitudinis</i> SYBC hb4 spores.</p