Pigmentiphaga kullae CHJ604 improved the growth of tobacco by degrading allelochemicals and xenobiotics in continuous cropping obstacles.

Plant autotoxicity is considered to be one of the important causes of continuous cropping obstacles in modern agriculture, which accumulates a lot of allelochemicals and xenobiotics and is difficult to solve effectively. To overcome tobacco continuous obstacles, a strain Pigmentiphaga kullae CHJ604 isolated from the environment can effectively degrade these compounds in this study. CHJ604 strain can degrade 11 types of autotoxicity allelochemicals and xenobiotics (1646.22 µg/kg) accumulated in the soil of ten-years continuous cropping of tobacco. The 11 allelochemicals and xenobiotics significantly reduced Germination Percentage (GP), Germination Index (GI), and Mean Germination Time (MGT) of tobacco seeds, and inhibited the development of leaves, stems, and roots. These negative disturbances can be eliminated by CHJ604 strain. The degradation pathways of 11 allelochemicals and xenobiotics were obtained by whole genome sequence and annotation of CHJ604 strain. The heterologous expression of a terephthalate 1,2-dioxygenase can catalyze 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 4-hydroxybenzaldehyde, and 4-hydroxy-3-methoxy-benzaldehyde, respectively. The phthalate 4,5-dioxygenase can catalyze phthalic acid, diisobutyl phthalate, and dibutyl phthalate. These two enzymes are conducive to the simultaneous degradation of multiple allelochemicals and xenobiotics by strain CHJ604. This study provides new insights into the biodegradation of autotoxicity allelochemicals and xenobiotics as it is the first to describe a degrading bacterium of 11 types of allelochemicals and xenobiotics and their great potential in improving tobacco continuous obstacles.

Bacteriostatic effect of Ag@TiO2-Poly(p-dioxanone)-coated gauzes in vitro and in vivo on otitis media pathogens.

The application of packing agents affects the final surgical outcomes in treating otitis media (OM) and introduces the risk of infection. To decrease the infectious risks of packing agents and even introduce positive bacteriostatic functions, a kind of PPDO-grafted Ag-incorporated TiO2 nanoparticles (Ag@TiO2-PPDO NP)-coated gauzes were prepared by a solution immersion method. Morphologies and in vitro Ag+ releasing of Ag@TiO2-PPDO NP coated gauzes were determined by scanning electron microscope (SEM) and inductively coupled plasma-mass spectrum (ICP-Ms). Ag@TiO2-PPDO NP could respond to visible light, which might make Ag@TiO2-PPDO NP inhibit the proliferation of bacteria continually and positively with irradiation of visible light. Then the bacteriostatic effects of these gauzes on OM pathogens were investigated in vitro and in vivo. These gauzes could inhibit the proliferation of pathogenic Staphylococcus aureus (S. aureus) and Streptococcus pneumoniae (S. pneumoniae) in vitro and rat subcutaneous infection models. Specifically, the bacteriostatic effect of these gauzes on S. aureus and S. pneumoniae could be enhanced with irradiation by visible light in vitro. Further, the rat external auditory canal infection model verified the enhanced bacteriostatic effect of Ag@TiO2-PPDO-coated gauzes on S. aureus with irradiation by visible light. The Ag@TiO2-PPDO-coated gauzes are promising for packing materials after OM surgery and could reduce postoperative antibiotic requirements.

Botrytis cinerea BcCDI1 protein triggers both plant cell death and immune response.

Cell death-inducing proteins (CDIPs) play important roles in the infection of Botrytis cinerea, a broad host-range necrotrophic phytopathogen. Here, we show that the secreted protein BcCDI1 (Cell Death Inducing 1) can cause necrosis in tobacco leaves and at the same time elicit plant defense. The transcription of Bccdi1 was induced at the infection stage. Deletion or overexpression of Bccdi1 resulted in no notable change in disease lesion on bean, tobacco, and Arabidopsis leaves, indicating that Bccdi1 has no effect on the final outcome of B. cinerea infection. Furthermore, the plant receptor-like kinases BAK1 and SOBIR1 are required to transduce the cell death-promoting signal induced by BcCDI1. These findings suggest that BcCDI1 is possibly recognized by plant receptors and then induces plant cell death.

The auto-inhibition mechanism of transcription factor Ets-1 induced by phosphorylation on the intrinsically disordered region.

As the most abundant post-translation modifications (PTMs), the phosphorylation usually occurred on the intrinsically disordered regions (IDRs). The regulation on the structures and interactions of IDRs induced by phosphorylation is critical to the function performing. The eukaryotic transcription factor 1 (Ets-1) is a member of transcription factor family, which participates in many important biological processes. The DNA-binding ability of Ets-1 is auto-inhibited by a disordered serine-rich region (SRR) on the Ets-1. The inhibition ability of SRR is greatly enhanced by the phosphorylation of the serine on the SRR. Nevertheless, the molecular mechanisms of the phosphorylation regulation on the structure and activity of Ets-1 are still unclear and under debates. By using both of the molecular simulations and biochemical experiments, we studied the molecule mechanism of phosphorylation regulation on the auto-inhibition of the Ets-1. The reasons of stabilization of Ets-1 core by phosphorylation on SRR region were elucidated. More important, the free energy landscapes (FEL) show that both of the steric hindrance and allosteric regulation are responsible for the DNA-binding inhibitory induced by phosphorylation, but the steric effects contribute greater than the allosteric regulation. The phosphorylation not only enhances the electrostatic interactions to facilitate the steric impedance, but also promotes the formation of hydrophobic residue clusters, which provide major driven force for the allosteric regulation. The structural basis of auto-inhibition of Ets-1 induced by the phosphorylation revealed in this study would great help the developing of inhibitor for the cancer therapy.

The cyclase-associated protein ChCAP is important for regulation of hyphal growth, appressorial development, penetration, pathogenicity, conidiation, intracellular cAMP level, and stress tolerance in Colletotrichum higginsianum.

Colletotrichum higginsianum causes anthracnose disease in a wide range of cruciferous crops and has been used as a model system to study plant-pathogen interactions and pathogenicity of hemibiotrophic plant pathogens. Conidiation, hyphae growth, appressorial development and appressorial penetration are significant steps during the infection process of C. higginsianum. However, the mechanisms of these important steps during infection remain incompletely understood. To further investigate the mechanisms of the plant-C. higginsianum interactions during infection progress, we characterized Cyclase-Associated Protein (ChCAP) gene. Deletion of the ChCAP gene resulted in reduction in conidiation and hyphal growth rate. The pathogenicity of ΔChCAP mutants was significantly reduced with much smaller lesion on the infected leaves compared to that of wild type strain with typically water-soaked and dark necrotic lesions on Arabidopsis leaves. Further study demonstrated that the appressorial formation rate, turgor pressure, penetration ability and switch from biotrophic to necrotrophic phases decreased obviously in ΔChCAP mutants, indicating that the attenuated pathogenicity of ΔChCAP mutants was due to these defective phenotypes. In addition, the ΔChCAP mutants sectored on PDA with abnormal, dark color, vesicle-like colony morphology and hyphae tip. Moreover, the ΔChCAP mutants had a reduced intracellular cAMP levels and exogenous cAMP can partially rescue the defects of ΔChCAP mutants in appressorial formation and penetration rate, but not in colony morphology, conidial shape and virulence, indicating that ChCAP is a key component in cAMP signaling pathway and likely play other roles in biology of C. higginsianum. In summary, our findings support the role of ChCAP in regulating conidiation, intracellular cAMP level, hyphal growth, appressorial formation, penetration ability and pathogenicity of this hemibiotrophic fungus.

Curcumol attenuates epithelial-mesenchymal transition of nasopharyngeal carcinoma cells via TGF-ß1.

The current study aimed to identify the effect and primary mechanism of Curcumol on the migration of nasopharyngeal carcinoma (NPC) cells in vitro and in vivo. Curcumol was dissolved in absolute ethyl alcohol and the experiment was performed in NPC 5­8F cells in vitro and in vivo. The effect of different concentrations of Curcumol on cell migration was determined using wound healing and Transwell assays. A cell counting kit­8 (CCK­8) assay was also performed in order to determine cell viability. Flow cytometry was used to detect the effect of Curcumol on apoptosis. The expression of epithelial­mesenchymal transition (EMT)­associated proteins and genes was evaluated by western blotting, reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and ELISA. In addition, the antitumor activity of Curcumol was investigated in female BALB/C nude mice with orthotopic tumor implants. The results indicated that cell apoptosis was increased and the viability of NPC 5­8F cells was decreased following treatment with Curcumol at doses of 0.1, 0.2 and 0.4 µM/ml. The results of in vivo experiments indicated that tumor growth and weight were decreased following Curcumol administration. Furthermore, the results of western blotting and RT­qPCR demonstrated that Curcumol altered the level of E­cadherin and N­cadherin in a dose­dependent manner in vivo. Curcumol also regulated the secretion of protein markers in the serum that were associated with EMT and TGF­ß1 in the 5­8F xenograft mouse model. Thus, the results indicated that Curcumol induced TGF­ß1­mediated EMT arrest by regulating E­cadherin and N­cadherin, which may prevent further development of NPC.

Taraxerol Induces Cell Apoptosis through A Mitochondria-Mediated Pathway in HeLa Cells.

OBJECTIVES: Taraxerol acetate has potent anti-cancer effects via the induction of apoptosis, autophagy, cell cycle arrest, and inhibition of cell migration. However, whether taraxerol induced apoptosis and its underlying mechanisms of action is not clear. In the present study, we assess the effects of taraxerol on the mitochondrial apoptotic pathway and determine the release of cytochrome c to the cytosol and activation of caspases. MATERIALS AND METHODS: In this experimental study, we mainly investigated the effect of taraxerol on HeLa cells. We tested cell viability by the MTT assay and morphologic changes, analyzed apoptosis by DAPI staining and flow cytometry. We also determined reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) using a Microplate Reader. In addition, the apoptotic proteins were tested by Western blot. RESULTS: Taraxerol enhanced ROS levels and attenuated the MMP (Δψm) in HeLa cells. Taraxerol induced apoptosis mainly via the mitochondrial pathway including the release of cytochrome c to the cytosol and activation of caspases 9 and 3, and anti-poly (ADPribose) polymerase (PARP). Taraxerol could induce the down-regulation of the anti-apoptotic protein Bcl-2 and up-regulation of pro-apoptotic protein Bax. It suppressed the PI3K/ Akt signaling pathway. CONCLUSIONS: These results demonstrated that taraxerol induced cell apoptosis through a mitochondria-mediated pathway in HeLa cells. Thus, taraxerol might be a potential anticervical cancer candidate.

Solanesol induces the expression of heme oxygenase-1 via p38 and Akt and suppresses the production of proinflammatory cytokines in RAW264.7 cells.

The aim of the present study was to examine the anti-inflammatory effect of solanesol and to elucidate the underlying mechanisms. Heme oxygenase-1 (HO-1) plays an important role in cytoprotection against oxidative stress and inflammation. Solanesol induced HO-1 expression both at the level of mRNA and proteins, resulting in increased HO-1 activity. Solanesol treatment enhanced the level of the phosphorylated form, nuclear translocation, ARE-binding, and transcriptional activity of Nrf2. p38 and Akt contributed to ARE-driven HO-1 expression. Solanesol activated both p38 and Akt, and treatments with SB203580 (a p38 kinase inhibitor), LY294002 (an Akt inhibitor), specific p38 siRNA and Akt siRNA suppressed the solanesol-induced activation of Nrf2, resulting in a decrease in HO-1 expression. Solanesol also elevated the autophagic protein LC3B-II level. SnPP (a HO-1 inhibitor) and HO-1 siRNA markedly abolished the anti-inflammatory effect of solanesol against LPS-induced cell damage. Likewise, SB203580, LY294002, 3-MA and Baf-A1 inhibited the solanesol-induced anti-inflammatory effect. These studies demonstrate that solanesol attenuates inflammation by HO-1 induction via p38 and Akt signaling. Thus, it is quite plausible that HO-1 induction by solanesol could trigger anti-inflammatory pathways including limiting LPS-stimulated cytokine production through autophagic signaling via p38 and Akt.

Over-expression of genes and proteins of ubiquitin specific peptidases (USPs) and proteasome subunits (PSs) in breast cancer tissue observed by the methods of RFDD-PCR and proteomics.

The ubiquitin-proteasome system facilitates the degradation of damaged proteins and regulators of growth and stress response. Alterations in this proteolytic system are associated with a variety of human pathologies. By restriction fragment differential display polymerase chain reaction (RFDD-PCR) and matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF-TOF MS) based on two-dimensional polyacrylamide gel electrophoresis (2-DE), differentially expressed genes and proteins of ubiquitin specific proteases (USPs), proteasome subuinits (PSs) and ubiquitin protein ligase E3A (UBE3A) were analyzed between breast cancer and adjacent normal tissues. Some of them were further verified as over-expression by immunohistochemical stain. Five genes of proteasome subunits (PSs), including PSMB5, PSMD1, PSMD2, PSMD8 and PSMD11, four genes of USPs, including USP9X, USP9Y, USP10 and USP25, and ubiquitin protein ligase E3A (UBE3A) were over-expressed (>3-fold) in breast cancer tissue compared to adjacent normal tissue, and over-expression (>4-fold) of proteins of PSMA1 and SMT3A were observed in breast cancer tissue. PSMD8, PSMD11 and UBE3A were further verified as over-expression by immunohistochemical stain. The action of ubiquitin-proteasome system were obviously enhanced in breast cancer, and selectively intervention in action of ubiquitin-proteasome system may be a useful method of treating human breast cancer.