The self-assembly of short peptides is a promising route to the creation of smart biomaterials. To combine peptide self-assembly with enzymatic catalysis, we design an amphiphilic short peptide I3QGK that can self-assemble into long nanoribbons in aqueous solution. Upon addition of transglutaminase (TGase), the peptide solution undergoes a distinct sol-gel transition to form a rigid hydrogel, which shows strong shear-thinning and immediate recovery properties. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) measurements indicate the occurrence of considerable nanofibers in addition to the original nanoribbons. Liquid chromatography and mass spectrometry analyses reveal the enzymatic formation of peptide dimers from monomers through intermolecular ε-(γ-glutamyl)lysine isopeptide bonding. The dimers rapidly self-assemble into flexible and entangled nanofibers, and the coexistence of the original nanoribbons and the newly created nanofibers is responsible for hydrogelation. Factor XIII in blood is converted by thrombin to an active TGase (Factor XIIIa) during bleeding, so the peptide solution shows a more rapid and effective hemostasis via a combination of gelling blood and promoting platelet adhesion, relative to other hemostasis methods or materials. These features of I3QGK, together with its low cytotoxicity against normal mammalian cells and noninduction of nonspecific immunogenic responses, endow it with great potential for future clinical hemostasis applications.
Aim: To investigate the anti-inflammatory mechanism of the polysaccharides of Ginkgo biloba leaves (PGBL) by inhibiting leucocyte adhesion. Methods: The rough PGBL were isolated and purified. The anti-inflammatory effects of purified PGBL (p-PGBL) were assayed by ear edema induced by xylol and the acute peritonitis model in mice. The effect of p-PGBL on inhibiting the interaction between Pselectin and its ligands was investigated by flow cytometry and flow chamber. Results: p-PGBL could effectively inhibit the acute inflammation in mice and interfere with the adhesion of HL-60 cells, a human leukaemia cell line, or neutrophils to P-selectin in static conditions, as well as the adhesion of neutrophils to Chinese hamster ovary cells expressing human P-selectin and human umbilical vein endothelial cells in flow conditions in a dose-dependant manner. Conclusions: p-PGBL can inhibit the inflammatory process through interfering with the interaction between P-selectin and its ligands. Key wordspolysaccharides of Ginkgo biloba leaves; cell a dhesi on i nhi bit i on; infla mma t i on; Pselectin
Serine protease inhibitors (serpins) are native inhibitors of serine proteases, constituting a large protein family with members spread over eukaryotes and prokaryotes. However, only very few prokaryotic serpins, especially from extremophiles, have been characterized to date. In this study, Pnserpin, a putative serine protease inhibitor from the thermophile Pyrobaculum neutrophilum, was overexpressed in Escherichia coli for purification and characterization. It irreversibly inhibits chymotrypsin-, trypsin-, elastase-, and subtilisin-like proteases in a temperature range from 20 to 100 °C in a concentration-dependent manner. The stoichiometry of inhibition (SI) of Pnserpin for proteases decreases as the temperature increases, indicating that the inhibitory activity of Pnserpin increases with the temperature. SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) showed that Pnserpin inhibits proteases by forming a SDS-resistant covalent complex. Homology modeling and molecular dynamic simulations predicted that Pnserpin can form a stable common serpin fold. Results of the present work will help in understanding the structural and functional characteristics of thermophilic serpin and will broaden the current knowledge about serpins from extremophiles.
BACKGROUND: Atrial fibrillation (AF) is one of the most common types of arrhythmia diagnosed in clinical practice. Due to its negative effects on people's physical and mental health, it is necessary to prevent and treat AF. Recently, scholars have found that acupuncture can be used to treat AF, but some scholars have questioned its therapeutic efficacy. AIM: Therefore, this study was performed to assess the efficacy and safety of acupuncture treatment for AF patients. METHODS: Previously published research articles were retrieved from six databases, and the data was analysed using RevMan5.3 software with a statistically significant difference defined as P < 0.05. RESULTS: A total of 8 relevant kinds of literature were retrieved containing 633 AF patients (323 in the treatment group and 310 in the control group). Acupuncture treatment increased the total efficacy and the rate of AF cardioversion to sinus rhythm (RR: 1.38; 95% CI: 1.25 to 1.53 vs RR: 1.40;95% CI: 1.16 to 1.69; each P < 0.05), and decreased the time of AF cardioversion to sinus rhythm, the heart rate and incidence of adverse effects (RR: -3.95; 95% CI: -4.98 to -2.91 vs RR: -14.54; 95% CI: -24.09 to -5.00 vs RR: 0.48; 95% CI: 0.21 to 1.11, each P < 0.05). There was difference between retention time more and less than 30 minutes (I2 = 74.9%, P = 0.05). The funnel plot displayed a symmetrical and funnel-form shape, indicating low bias. CONCLUSION: Acupuncture has a good therapeutic effect and safety profile on patients with AF, and its application in clinical practice should be considered.
Serine protease inhibitors (serpins) are a superfamily of proteins involved in many important biological processes, including inflammation. Serpins dysfunction-related diseases are mainly treated by augmentation therapy using serpins purified from human plasma. Pnserpin from hyperthermophilic archaeon Pyrobaculum neutrophilum showed protease inhibition activity and high stability. In this study, we examined the anti-inflammatory activity of Pnserpin using xyleneinduced acute inflammatory model of mouse ear swelling and lipopolysaccharide (LPS)-induced murine RAW 264.7 macrophages cellular model. The inhibition of mouse ear swelling and the production of pro-inflammatory cytokines in mouse serum or in macrophages cell were used to evaluate the anti-inflammatory effect of Pnserpin. Our results showed that Pnserpin could inhibit the xylene-induced mouse ear swelling and suppress the production of pro-inflammatory cytokines in mouse serum and in LPS-induced RAW264.7 cells. This study indicated that Pnserpin might have antiinflammatory effect in vivo and in vitro.
Abstract. Polysaccharides derived from Ginkgo biloba leaf (PGBL) is a kind of active ingredient came out from ginkgo biloba leaf extractions. Previous studies have shown that PGBL has a good anti-inflammatory effect. However, the mechanism is not clear. This study is to investigate the modulated immunity effect of PGBL on RAW264.7 cells. Here we showed that lipopolysaccharide (LPS) induces the expression of tumor necrosis factor-Į (TNF-Į) and interleukin-6 (IL-6), and this induction can be repressed by PGBL treatment both in protein level and mRNA level, and PGBL strongly reduced the translocation of nuclear factor (NF)-țB to the cell nucleus. These findings demonstrate that PGBL can decrease the sensitivity of monocytes to LPS, and PGBL has applications in systemic inflammation and immune diseases.
Porcine pleuropneumonia is a common infectious disease of pigs caused by Actinobacillus pleuropneumoniae (APP). IFN-γ expression increases in the lung of pigs after APP infection, but the role of IFN-γ during the infection is still obscure. In this study, an IFN-γ-/- mouse infection model was established, and bacterial load, the levels of inflammatory cytokines and the types of neutrophils in the lungs were studied at different times post APP infection. We found that wild-type (WT) mice were more susceptible to APP than IFN-γ-/- mice. At 6 h post infection (hpi), the expression of IL-18 and IL-1β in the lungs of IFN-γ-/- mice were significantly increased compared to WT mice. The bacterial load and levels of inflammatory cytokines (IL-1β and IL-6) of IFN-γ-/- mice were significantly reduced at 12 hpi compared to WT mice. After an initial loss, the numbers of lung polymorphonuclear (PMN)-I cells dramatically increased in the lungs of IFN-γ-/- but not WT mice, whereas PMN-II cells continually decreased. Finally, in vivo administration of IL-18 significantly reduced clinical scores and bacterial load in the lungs of APP-infected mice. This study identifies IFN-γ as a target for regulating the inflammatory response in the lung, and provides a basis for understanding the course of clinical bacterial pneumonia and for the formulation of treatment protocols.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.