Infection and Drug Resistance
·
2018
·
IF 3.443
Yufeng Du,Li Liu,Chunping Zhang,Yani Zhang
Staphylococcus aureus is becoming increasingly intractable because of its ability to acquire antimicrobial resistance and secrete numerous virulence factors that can exacerbate inflammation. Alpha-hemolysin (Hla) is a pore-forming virulence factor produced by S. aureus that can self-assemble into heptameric mushroom-structured pores in target cell membranes, leading to cell lysis and death. In the present study, we sought to better understand the mechanism underlying hemolysis and the oligomerization of Hla by creating nine mutants with single amino acid changes in different positions of the Hla protein: N17C, T18C, P103C, N105C, M113C, T117C, N121C, D128C, and T129C. The results showed that the P103C and N105C mutations, which are located in the triangle region, significantly diminished hemolysis and heptamer formation when compared with the wild-type Hla protein. This suggests that the P103 and N105 residues play key roles in the assembly of the Hla pore. These results improve our understanding of the mechanism underlying the pore-forming ability of Hla.
研究领域:
微生物学
·
分子生物学
·
感染与免疫
✓ 已验证
产品关联
DOI
PubMed
高影响因子
REPRODUCTION
·
2023
·
IF 3.8
Min Chen,Jia-Lu Shi,Zi-Meng Zheng,Zhi Lin,Ming-Qing Li,Jun Shao
The autophagy of trophoblasts is necessary for developing and maintaining of a healthy pregnancy. Autophagy dysfunction in trophoblast cells is linked to recurrent spontaneous abortion (RSA). However, the mechanism underlying trophoblast autophagy is unknown. In this study, we investigated the expression of autophagy-related genes in both normal and RSA villi. We also examined the production of lysophosphatidic acid (LPA) and lysophosphatidic acid receptor1 (LPAR1) in trophoblast cells during early pregnancy. We found that the activation of the LPA-LPAR1 axis triggered the autophagy of trophoblast cells and increased the expression of sodium/hydrogen exchanger 1 (NHE1). Inhibition of NHE1 suppressed the autophagy in trophoblast cells and we confirmed that NHE1 regulates LPA production in trophoblast cells. Additionally, we found decreased expression of autophagy-related genes and LPAR1 in villi from RSA patients. These observations indicate that the LPA/LPAR1-NHE1 axis regulates the autophagy of trophoblast cells during pregnancy. Insufficient autophagy and poor expression of LPAR1 in trophoblast cells may result in dysfunction of the trophoblasts and increased risk of spontaneous abortion. Overall, our research elucidated that a positive LPA/LPAR1-NHE1 axis can promote the autophagy of trophoblast cells and the abnormal axis leads to the autophagy deficiency of trophoblast cells in recurrent spontaneous abortion.
研究领域:
妇产科学
·
分子生物学
·
生殖医学
✓ 已验证
DOI
PubMed
高影响因子
FEMS MICROBIOLOGY LETTERS
·
2018
·Vol. 365
·期 7
·
IF 1.735
Qian Bingjun,Yin Lirong,Yao Xiaomin,Zhong Yaoguang,Gui Juan,Lu Feifeng,Zhang Fuming,Zhang Jianhua
The saponins, as components of tea seed meal, are undesirable hemolytic components and should be degraded for reducing their hemolytic activity in order to be used in animal feed. In this study, β-glucuronidase was verified to be a potent hydrolase of tea seed saponins to reduce their hemolytic activity and a β-glucuronidase-producing Lactobacillus crustorum strain was screened from raw bovine milk. Next, solid-state fermentation with the isolated L. crustorum and a Bacillus subtilis natto strain, which can produce cellulase and hence improve the fermentation performance of tea seed meal, was carried out for detoxification of tea seed meal. The 50% hemolytic dosage (HD50) value of tea seed saponins was increased from 6.69 to 27.43 μg mL−1. The results of LC–MS analysis showed that the percentage of saponin aglycones increased from 30.95 to 84.25% after the fermentation. According to the roles of sugar moieties in hemolytic activity, and the enzymatic hydrolysis characteristics of β-glucuronidase, the degradation of tea seed saponins from glucosides to aglycones may contribute to the reduction of hemolytic activity. Therefore, tea seed meal may be used as animal feed after fermentation with the tested saponin-degrading microbial strains.
研究领域:
微生物学
·
动物营养学
✓ 已验证
DOI
高影响因子
Food Bioscience
·
2023
·
IF 5.2
Mei Bai,Jinming Dai,Wei Hu,Changzhu Li,Haiying Cui,Lin Lin
This study investigated the use of Litsea cubeba essential oil (LC-EO) as an anti-virulence agent targeting listeriolysin O (LLO) of Listeria monocytogenes ( L. monocytogenes ). The hemolysis assay showed a significant decrease in the hemolytic activity of LLO by 90.7% and 70.2% after exposure to 500 μg mL −1 LC-EO or 700 μg mL −1 citral (the main component of LC-EO), respectively. This suggested that citral plays a major role in the anti-virulence function against LLO. The experiments including UV–visible absorption spectroscopy , fluorescence quenching and three-dimensional fluorescence spectroscopy demonstrated that exposure to citral leads to significant changes in the conformation of LLO, potentially resulting in the unfolding of its structure and the formation of a ground-state complex. Synchronous fluorescence spectra analysis indicated that the binding site of citral could be the undecapeptide region of LLO. Additionally, the results of molecular docking and the acid-base effect experiment of different aldehydes and phenols revealed that the cysteine residue of LLO and the α, β-unsaturated aldehyde of citral are likely to form a covalent bond through Michael addition . This interaction is believed to be the primary reason for the loss of hemolytic activity. As a result, this work provides a new approach for the development of LLO-targeting anti-virulence agents and holds promise for expanding the application of LC-EO in the field of food microbiological safety.
研究领域:
食品科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
MICROBIAL PATHOGENESIS
·
2018
·
IF 2.332
Tengteng Lv,Tongxiang Song,Huijie Liu,Ruibing Peng,Xiamin Jiang,Weiwei Zhang,Qingxi Han
Vibrio alginolyticus is a ubiquitous marine opportunistic pathogen that can infect various hosts in marine environment. In the present study, V. alginolyticus strain Wz11 was isolated from diseased cuttlefish , Sepia pharaonis , with 20% of promoted death and high survival capacity in skin mucus and tissue liquid. Its growth, siderophore production, and expressions of haemolysin and swarming related genes were characterized under iron limited conditions. The minimal inhibitory concentration (MIC) of 2,2′-dipyridyl (DP) to V. alginolyticus strain Wz11 was 640 μM. While growth of V. alginolyticus strain Wz11 was inhibited by DP , production of iron-seizing substances, haemolytic activity and swarming motility were increased. Moreover, expressions of haemolysin related genes tlh , tdh and vah and flagellar related genes flgH , fliC , fliD and fliS were also characterized using real-time reverse transcriptase PCR. Expression of tdh was up-regulated to 7.7-fold, while expressions of tlh and vah were down-regulated to 0.016-fold and 0.03-fold, respectively. The expression of fliC , flgH , fliD and fliS was up-regulated to 4.9-, 3.8-, 8.6- and 4.5-fold, respectively. Concluded from our results suggested that V. alginolyticus strain Wz11 was considered as a potential pathogen of S. pharaonis , and iron level played an important role in the production of iron-seizing substances, and activities of haemolysin and bacterial swarming as well as their related gene expressions.
研究领域:
微生物学
·
海洋生物学
·
水产养殖学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Fang Hao,Xiu-Ping Yan
Understanding the toxicity of metal-organic frameworks (MOFs) is important for improving their biocompatibility in further applications, especially the hematotoxicity of MOFs due to the unavoidable contact of MOFs with blood in biomedical science. Here we report the hematotoxicity and underlying mechanisms of nano-sized zeolite-like MOFs ZIF-8 and ZIF-67 because of their wide applications in biomedical science. ZIF-67 induced significant hemolysis of red blood cell (Rb) through breaking the structure of membrane due to the generation of free radicals, whereas ZIF-8 was hematocompatible. ZIF-67 was thus internalized by Rb and then bound with hemoglobin via hydrogen bond and van der Waals force , which influenced the structure and function of hemoglobin in accompany with heme release. These findings reveal the detailed mechanism of the hematological effects of MOFs on Rb and are helpful to the assessment of the toxicity and potential health risks of MOFs and the design of biosafe MOFs for biomedical applications.
研究领域:
生物医学
·
毒理学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Bing Cai,Kebang Hu,Chunming Li,Jing Jin,Yuexin Hu
Graphene oxide (GO) had great potential in various applications especial biomedical materials. In this study, we improved the hemocompatibility especial hemolysis properties of GO nanosheets by grafting bovine serum albumin (BSA). The hemocompatibility of GO-g-BSA was improved. The hemolysis ratio of GO-g-BSA was lower than 0.2% and no visible hemoglobin release was observed. In a flowed condition, the interaction between GO and RBC was monitored real time by quartz crystal microbalance with dissipation (QCM-D) and the hemolysis rates of eluted RBC solution was determined. The balance between the adsorption and degradation of RBC on the surface of GO was a linear process. The GO-g-BSA surface decreased the adhesion of RBC in a flowed condition, maintained the morphology of RBC and reduced the hemolysis rate in the most effective manner. The inert of BSA resisted GO interacting with the lipid bilayers of RBC and the negative charge on the surface of BSA repelled the approach of negative charged RBC. The excellent hemocompatibility of the BSA modified GO might confer its great potentials for various biomedical applications.
研究领域:
生物材料学
·
医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Xiaoxiao Gu,Dongmei Li,Haoyang Yuan,Cailing Li,Dinghua Yu,Guowei Wang,Shuang Li
Baicalin is a flavonoid compound extracted from the Scutellaria baicalensis plant. It possesses strong free radical scavenging ability and has a wide range of medical applications in antibacterial, anti-inflammatory, and anti-tumor fields. However, its limited solubility in water restricts its application. In this study, we prepared SL-DMEA by the amidation of acidic sophorolipids and N, N-dimethylethanolamine, while SL-TMEAI was synthesized via the quaternization of SL-DMEA with iodomethane. The structures of SL-DMEA and SL-TMEAI were confirmed by 1 H NMR, FT-IR, and Mass spectra. Surface tension and micelle microenvironment indicated that SL-DMEA and SL-TMEAI exhibit superior surface activity. Furthermore, the solubility of baicalin in aqueous solutions containing SL-DMEA and SL-TMEAI was approximately 70 mg/L and 75 mg/L, while it was only 18 mg/L in SL-COOH solution, which were significantly higher than the solubility in pure water (4 mg/L). Similarly, SL-DMEA and SL-TMEAI can enhance the antioxidant activity of baicalin. Specifically, in the SL-TMEAI aqueous solution, the free radical scavenging rate of baicalin was increased by 10 %–20 %. Density functional theory calculations revealed that SL-DMEA and SL-TMEAI formed stable hydrogen bonds with baicalin molecules, which can increase the solubility of baicalin in water and expose the groups that react with free radicals in the solution, thereby enhancing the antioxidant activity. These results demonstrated that SL-DMEA and SL-TMEAI could significantly enhance the solubility and antioxidating of baicalin in water through a hydrotropy mechanism.
研究领域:
生物化学
·
药物化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 72
·68322-68334
·
IF 3.289
Yang Wang,Baomei Zhang,Guangxi Zhai
The hemolysis assay is a common method used to evaluate the in vitro biocompatibility of biomaterials, but presently there is inadequate understanding of the interactions between RBCs and biomaterials, especially from the view of the incubation conditions and sample concentration. In this report, we used unmodified graphene oxide (GO) as a biomaterial model and measured the hemolytic properties of GO at a series of concentrations under multiple conditions, including medium type, red blood cell (RBC) species, RBC concentration, storage duration of the RBCs, animal health status, centrifugal speed, exposure time and incubation temperature. Additionally, a calculation method for the hemolytic index was proposed so as to objectively evaluate the hemolysis properties, distinct from frequently used methods. Compared to the hemolytic results under these conditions, we found that the hemolytic properties of GO had huge differences, and false-negative or false-positive errors might be produced by inappropriate incubation conditions. In our opinion, the feasible conditions for unmodified GO are: isotonic glucose solution as the medium type, fresh and healthy rabbit RBCs as the test object, 1% hematocrit as the RBC concentration, 3000 rpm for 5 min as the centrifugation conditions, 6 h as the exposure time and physiological temperature (37 °C) as the incubation temperature.
研究领域:
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Biosensors-Basel
·
2023
·Vol. 13
·期 1
·111
·
IF 5.4
Tianyi Yang,Yanju Chen,Jinsong He,Jian Wu,Meixia Wang,Xiaoping Zhong
A rapid and intuitive method for detecting Vibrio parahaemolyticus (VP) was established by a designed reaction vessel which coupled CRISPR/Cas12a with loop-mediated isothermal nucleic acid amplification (LAMP). There were two spaces in the vessel-holding LAMP reaction solution and CRISPR reaction solution, respectively, which were separated with a polyvinyl alcohol (PVA) membrane. The PVA membrane could be dissolved with a water solution. The thermolabile hemolysin (TLH) gene of VP was employed as the detection target. After the target sequence of the TLH gene was amplified with LAMP, the PVA membrane would be dissolved and the CRISPR reaction solution mixed with the LAMP reaction solution. In this way, amplicons could be detected with CRISPR/Cas12a in the reaction vessel. The fluorescent signals produced by the positive samples were clearly identified by the naked eye under a UV light, while the negative samples were dark. The whole detection procedure could be finished within 35 min with a detection limit of 100 copies/µL. The designed reaction vessel is easy to produce and can effectively prevent contamination due to the opening of the reaction vessel after the LAMP reaction. Thus, it will have the potential to provide a new solution for rapid detection in the field.Keywords:polyvinyl alcohol;dissolvable membrane;CRISPR/Cas12a;LAMP reaction;Vibrio parahaemolyticus
研究领域:
分子生物学
·
病原体检测
·
生物技术
✓ 已验证
DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2016
·Vol. 101
·期 8
·3371-3378
·
IF 3.376
Zhang Shanshan,Liu Ningning,Liang Weikang,Han Qingxi,Zhang Weiwei,Li Chenghua
In the present study, the effects of an environmental friendly natural reagent coumarin, on the growth and potential virulence factors, as well as its ability to interfere the infection of Vibrio splendidus (Vs), were determined. Coumarin showed no effects on the maximal growth of Vs, and biofilm formation of Vs, while it significantly decreased protease activity and hemolytic activity by 43 and 80%, respectively. Correspondingly, coumarin exhibited an obviously protective effect, with a relative percent survival of 60% upon Apostichopus japonicus from infection by Vs. To preliminarily investigate the mechanism underlining the inhibitory effects, regulation of genes Vsm and Vsh respectively related to protease activity and hemolytic activity by supernatant and supernatant extract containing acyl-homoserine lactones (AHLs) and coumarin was determined. Cell-free supernatant from higher density and its ethyl acetate extract containing AHL signal molecules could respectively upregulate the mRNA level of Vsm by 17.4- and 2.3-fold and Vsh by 7.2- and 5.0-fold, when Vs was at lower cell density. However, coumarin could reduce the stimulatory effects of both the supernatant and its ethyl acetate extract. Combining all the results in our study, it was suggested that coumarin could be considered as an alternative to be used for controlling infection of Vs, downregulating the expression of potential virulence factors through interfering the AHL-mediated pathways.
研究领域:
微生物学
·
海洋生物学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2020
·
IF 3.644
Wu Haitao,Su Manlin,Jin Hui,Li Xinyu,Wang Puyu,Chen Jingxiao,Chen Jinghua
In this paper, we fabricated rutin-loaded silver nanoparticles (Rutin@AgNPs) as the nano-anticoagulant with antithrombotic function. The serum stability, anticoagulation activity, and bleeding risk of Rutin@AgNPs were evaluated. The results showed Rutin@AgNPs had good serum stability, hemocompatibility, and cytocompatibility. The anticoagulation activity of rutin was maintained, and its stability and aqueous solubility were improved. The Rutin@AgNPs could provide a sustained release to prolong the half-life of rutin. The results of the coagulation parameter assay and thrombus formation test in mice model showed that the activated partial thromboplastin time and prothrombin time were prolonged, and Rutin@AgNPs inhibited the thrombosis in the 48 h period. Moreover, the limited bleeding time indicated that the Rutin@AgNPs significantly minimized the hemorrhage risk of rutin. This Rutin@AgNPs is a potential anticoagulant for antithrombotic therapy.
研究领域:
纳米医学
·
药理学
·
生物材料科学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）