82 research outputs found

    Role of pyroptosis in hemostasis activation in sepsis

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    Sepsis is frequently associated with hemostasis activation and thrombus formation, and systematic hemostatic changes are associated with a higher risk of mortality. The key events underlying hemostasis activation during sepsis are the strong activation of innate immune pathways and the excessive inflammatory response triggered by invading pathogens. Pyroptosis is a proinflammatory form of programmed cell death, that defends against pathogens during sepsis. However, excessive pyroptosis can lead to a dysregulation of host immune responses and organ dysfunction. Recently, pyroptosis has been demonstrated to play a prominent role in hemostasis activation in sepsis. Several studies have demonstrated that pyroptosis participates in the release and coagulation activity of tissue factors. In addition, pyroptosis activates leukocytes, endothelial cells, platelets, which cooperate with the coagulation cascade, leading to hemostasis activation in sepsis. This review article attempts to interpret the molecular and cellular mechanisms of the hemostatic imbalance induced by pyroptosis during sepsis and discusses potential therapeutic strategies

    Improving Iturin A Production of Bacillus amyloliquefaciens by Genome Shuffling and Its Inhibition Against Saccharomyces cerevisiae in Orange Juice

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    Genome shuffling is an effective method for the rapid improvement of the production of secondary metabolites. This study used the principle of gene shuffling to enhance the yield of iturin A produced by Bacillus amyloliquefaciens LZ-5. Improvements in lipopeptide yield were evident among four strains subjected to recursive protoplast fusion. The four strains were obtained through mutagenesis processes: nitrosoguanidine, ultraviolet irradiation, and atmospheric and room temperature plasma. A high yield strain with 179.22 mg/l of iturin A was obtained after two rounds of genome shuffling, which was a 2.03-fold increase compared with the wild strain. To evaluate the efficacy of iturin A for control of spoilage yeast in food, the anti-yeast efficacy of iturin A was evaluated in orange juice incubated with Saccharomyces cerevisiae. The juice treated with 0.76 mg/ml iturin A showed a significant (p < 0.05) control on yeast population during the storage, similar to that of the 0.30 mg/ml natamycin. In addition, iturin A showed a tiny effect on chemical-physical characteristics of orange juice. Our results provide a basis for the application of antimicrobial lipopeptide in juice products

    Enhanced Expression of Pullulanase in Bacillus subtilis by New Strong Promoters Mined From Transcriptome Data, Both Alone and in Combination

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    Pullulanase plays an important role as a starch hydrolysis enzyme in the production of bio-fuels and animal feed, and in the food industry. Compared to the methods currently used for pullulanase production, synthesis by Bacillus subtilis would be safer and easier. However, the current yield of pullulanase from B. subtilis is low to meet industrial requirements. Therefore, it is necessary to improve the yield of pullulanase by B. subtilis. In this study, we mined 10 highly active promoters from B. subtilis based on transcriptome and bioinformatic data. Individual promoters and combinations of promoters were used to improve the yield of pullulanase in B. subtilis BS001. Four recombinant strains with new promoters (Phag, PtufA, PsodA, and PfusA) had higher enzyme activity than the control (PamyE). The strain containing PsodA+fusA (163 U/mL) and the strain containing PsodA+fusA+amyE (336 U/mL) had the highest activity among the analyzed dual- and triple-promoter construct stains in shake flask, which were 2.29 and 4.73 times higher than that of the strain with PamyE, respectively. Moreover, the activity of the strain containing PsodA+fusA+amyE showed a maximum activity of 1,555 U/mL, which was 21.9 times higher than that of the flask-grown PamyE strain in a 50-liter fermenter. Our work showed that these four strong promoters mined from transcriptome data and their combinations could reliably increase the yield of pullulanase in quantities suitable for industrial applications

    Acetate and auto-inducing peptide are independent triggers of quorum sensing in Lactobacillus plantarum

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    The synthesis of plantaricin in Lactobacillus plantarum is regulated by quorum sensing. However, the nature of the extra-cytoplasmic (EC) sensing domain of the histidine kinase (PlnB1) and the ability to recognize the auto-inducing peptide PlnA1 is not known. We demonstrate the key motif Ile-Ser-Met-Leu of auto-inducing peptide PlnA1 binds to the hydrophobic region Phe-Ala-Ser-Gln-Phe of EC loop 2 of PlnB1 via hydrophobic interactions and hydrogen bonding. Moreover, we identify a new inducer, acetate, that regulates the synthesis of plantaricin by binding to a positively charged region (Arg-Arg-Tyr-Ser-His-Lys) in loop 4 of PlnB1 via electrostatic interaction. The side chain of Phe143 on loop 4 determined the specificity and affinity of PlnB1 to recognize acetate. PlnA1 activates quorum sensing in log phase growth and acetate in stationary phase to maintain the synthesis of plantaricin under conditions of reduced growth. Acetate activation of PlnB was also evident in four types of PlnB present in different Lb. plantarum strains. Finally, we proposed a model to explain the developmental regulation of plantaricin synthesis by PlnA and acetate. These results have potential applications in improving food fermentation and bacteriocin production

    Template Attack of LWE/LWR-Based Schemes with Cyclic Message Rotation

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    The side-channel security of lattice-based post-quantum cryptography has gained extensive attention since the standardization of post-quantum cryptography. Based on the leakage mechanism in the decapsulation stage of LWE/LWR-based post-quantum cryptography, a message recovery method, with templates and cyclic message rotation targeting the message decoding operation, was proposed. The templates were constructed for the intermediate state based on the Hamming weight model and cyclic message rotation was used to construct special ciphertexts. Using the power leakage during operation, secret messages in the LWE/LWR-based schemes were recovered. The proposed method was verified on CRYSTAL-Kyber. The experimental results demonstrated that this method could successfully recover the secret messages used in the encapsulation stage, thereby recovering the shared key. Compared with existing methods, the power traces required for templates and attack were both reduced. The success rate was significantly increased under the low SNR, indicating a better performance with lower recovery cost. The message recovery success rate could reach 99.6% with sufficient SNR

    Urothelial Differentiation of Human Umbilical Cord-Derived Mesenchymal Stromal Cells In Vitro

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    Human umbilical cord-derived mesenchymal stromal cells (hUCMSCs) are the most primitive of those isolated from other post-natal tissue source. The hUCMSCs possess the capability of differentiating along multi-lineage. This study aimed to investigate whether hUCMSCs can differentiate into urothelium-like cells. The hUCMSCs were isolated from fresh human umbilical cord postpartum and expanded at least to passage 3 in vitro. Subsequently, they were cultured with conditioned medium from urothelial cells (UC-CM) supplemented with 20 ng/ml exogenous epidermal growth factor (EGF). Urothelial cell specific marker uroplakin II (UPII) and cytokeratins were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunofluorescence technology. During culture, hUCMSCs started to express UPII and cytokeratins weakly at 7 days and were significantly up-regulated at 2 weeks post-induction. Additionally, morphology of hUCMSCs changed from spindle-shape to a polygonal epithelial-shape similar to that of urothelial cells after 7 days. The study results indicated that hUCMSCs can differentiate into urothelium-like cells in a defined micro-environment in vitro constituted by UC-CM and exogenous EGF

    Mesenchymal Stromal Cells Derived Extracellular Vesicles Ameliorate Acute Renal Ischemia Reperfusion Injury by Inhibition of Mitochondrial Fission through miR-30

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    Background. The immoderation of mitochondrial fission is one of the main contributors in ischemia reperfusion injury (IRI) and mesenchymal stromal cells (MSCs) derived extracellular vesicles have been regarded as a potential therapy method. Here, we hypothesized that extracellular vesicles (EVs) derived from human Wharton Jelly mesenchymal stromal cells (hWJMSCs) ameliorate acute renal IRI by inhibiting mitochondrial fission through miR-30b/c/d. Methods. EVs isolated from the condition medium of MCS were injected intravenously in rats immediately after monolateral nephrectomy and renal pedicle occlusion for 45 minutes. Animals were sacrificed at 24 h after reperfusion and samples were collected. MitoTracker Red staining was used to see the morphology of the mitochondria. The expression of DRP1 was measured by western blot. miR-30 in EVs and rat tubular epithelial cells was assessed by qRT-PCR. Apoptosis pathway was identified by immunostaining. Results. We found that the expression of miR-30 in injured kidney tissues was declined and mitochondrial dynamics turned to fission. But they were both restored in EVs group in parallel with reduced cell apoptosis. What is more, when the miR-30 antagomirs were used to reduce the miRNA levels, all the related effects of EVs reduced remarkably. Conclusion. A single administration of hWJMSC-EVs could protect the kidney from IRI by inhibition of mitochondrial fission via miR-30
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