scholarly journals Comparative Study of the Effect of Baicalin and Its Natural Analogs on Neurons with Oxygen and Glucose Deprivation Involving Innate Immune Reaction of TLR2/TNFα

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hui-Ying Li ◽  
Jun Hu ◽  
Shuang Zhao ◽  
Zhi-Yi Yuan ◽  
Hong-Jiao Wan ◽  
...  
Keyword(s):  
Protective Effect ◽  
Immune Reaction ◽  
Glucose Deprivation ◽  
Innate Immune ◽  
Oxygen Glucose Deprivation ◽  
Toll Like Receptor ◽  
Tlr2 Expression ◽  
Oxygen And Glucose Deprivation ◽  
Toll Like Receptor 2 ◽  
Anti Inflammation

This work is to study the baicalin and its three analogs, baicalin, wogonoside, and wogonin, on the protective effect of neuron from oxygen-glucose deprivation (OGD) and toll-like receptor 2 (TLR2) expression in OGD damage. The results showed that baicalin and its three analogs did protect neurons from OGD damage and downregulated protein level of TLR2. D-Glucopyranosiduronic acid on site 7 in the structure played a core of cytotoxicity of these flavonoid analogs. The methoxyl group on carbon 8 of the structure had the relation with TLR2 protein expression, as well as the anti-inflammation. In addition, we detected caspase3 and antioxidation capability, to investigate the effect of four analogs on cell apoptosis and total antioxidation competence in OGD model.

Protective effect of nicotinamide on neuronal cells under oxygen and glucose deprivation and hypoxia/reoxygenation

2004 ◽  
Vol 11 (4) ◽  
pp. 472-481 ◽  
Author(s):  
Chiung-Chyi Shen ◽  
Hsueh-Meei Huang ◽  
Hsiu-Chung Ou ◽  
Huan-Lian Chen ◽  
Wen-Chi Chen ◽  
...  
Keyword(s):  
Protective Effect ◽  
Neuronal Cells ◽  
Glucose Deprivation ◽  
Oxygen And Glucose Deprivation ◽  
Hypoxia Reoxygenation

scholarly journals Copper-Induced Expression of a Transmissible Lipoprotein Intramolecular Transacylase Alters Lipoprotein Acylation and the Toll-Like Receptor 2 Response to Listeria monocytogenes

2019 ◽  
Vol 201 (13) ◽  
Author(s):  
Krista M. Armbruster ◽  
Gloria Komazin ◽  
Timothy C. Meredith
Keyword(s):  
Listeria Monocytogenes ◽  
Bacterial Species ◽  
Acyl Chain ◽  
Constitutive Expression ◽  
Innate Immune ◽  
Copper Resistance ◽  
Toll Like Receptor ◽  
General Role ◽  
Content Type ◽  
Toll Like Receptor 2

ABSTRACT Bacterial lipoproteins are globular proteins anchored to the extracytoplasmic surfaces of cell membranes through lipidation at a conserved N-terminal cysteine. Lipoproteins contribute to an array of important cellular functions for bacteria, as well as being a focal point for innate immune system recognition through binding to Toll-like receptor 2 (TLR2) heterodimer complexes. Although lipoproteins are conserved among nearly all classes of bacteria, the presence and type of α-amino-linked acyl chain are highly variable and even strain specific within a given bacterial species. The reason for lyso-lipoprotein formation and N-acylation variability in general is presently not fully understood. In Enterococcus faecalis, lipoproteins are anchored by an N-acyl-S-monoacyl-glyceryl cysteine (lyso form) moiety installed by a chromosomally encoded lipoprotein intramolecular transacylase (Lit). Here, we describe a mobile genetic element common to environmental isolates of Listeria monocytogenes and Enterococcus spp. encoding a functional Lit ortholog (Lit2) that is cotranscribed with several well-established copper resistance determinants. Expression of Lit2 is tightly regulated, and induction by copper converts lipoproteins from the diacylglycerol-modified form characteristic of L. monocytogenes type strains to the α-amino-modified lyso form observed in E. faecalis. Conversion to the lyso form through either copper addition to media or constitutive expression of lit2 decreases TLR2 recognition when using an activated NF-κB secreted embryonic alkaline phosphatase reporter assay. While lyso formation significantly diminishes TLR2 recognition, lyso-modified lipoprotein is still predominantly recognized by the TLR2/TLR6 heterodimer. IMPORTANCE The induction of lipoprotein N-terminal remodeling in response to environmental copper in Gram-positive bacteria suggests a more general role in bacterial cell envelope physiology. N-terminal modification by lyso formation, in particular, simultaneously modulates the TLR2 response in direct comparison to their diacylglycerol-modified precursors. Thus, use of copper as a frontline antimicrobial control agent and ensuing selection raises the potential of diminished innate immune sensing and enhanced bacterial virulence.

scholarly journals Toll-Like Receptor 2 Expression as a New Hallmark of Advanced Endometriosis

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1813 ◽  
Author(s):  
Małgorzata Sobstyl ◽  
Paulina Niedźwiedzka-Rystwej ◽  
Ewelina Grywalska ◽  
Izabela Korona-Głowniak ◽  
Anna Sobstyl ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
B Lymphocytes ◽  
Characteristic Curve ◽  
Cost Effective ◽  
Peripheral Blood Lymphocytes ◽  
Toll Like Receptor ◽  
Myeloid Dendritic Cells ◽  
Tlr2 Expression ◽  
Toll Like Receptor 2 ◽  
Effective Diagnosis

Recent evidence suggests that immunological aspects play a pivotal role in this disorder. Toll-like receptor 2 (TLR2) is crucial in recognizing microbial infections and mediating innate immune response. The objective of our study was to rate with flow cytometry the levels of several subsets of dendritic cells, monocytes, and basic peripheral blood lymphocytes expressing TLR2, aiming at the determination of a possible correlation between the expression of TLR2 and the clinical outcomes of endometriosis in 40 patients and 40 age-matched healthy women. Our study showed the importance of TLR2 expression, mainly on myeloid dendritic cells (mDCs) and B cells in patients with endometriosis. Both mDCs BDCA1+CD19-TLR2+ and B lymphocytes CD19+TLR-2+ proved useful in the differentiation of affected individuals with stages 3–4 of the disease (area under the receiver operating characteristic curve /AUC/ = 0.96, p < 0.0001 for mDCs; AUC = 0.78, p = 0.0001 for B lymphocytes), and those presenting adhesion (AUC = 0.92, p < 0.0001 for mDCs; AUC = 0.82, p < 0.0001 for B lymphocytes) or infertility (AUC = 0.83, p < 0.0001 for mDCs; AUC = 0.73, p = 0.006 for B lymphocytes). Our findings suggest that the levels of TLR2-expressing cells, particularly mDCs and B lymphocytes, may be an effective biomarker of endometriosis, because the disease currently lacks clinically useful noninvasive biomarkers enabling early and cost-effective diagnosis.

scholarly journals Influence of dietary zinc on growth, zinc bioaccumulation and expression of genes involved in antioxidant and innate immune in juvenile mud crabs (Scylla paramamosain)

2020 ◽  
Vol 124 (7) ◽  
pp. 681-692
Author(s):  
Jiaxiang Luo ◽  
Tingting Zhu ◽  
Min Jin ◽  
Xin Cheng ◽  
Ye Yuan ◽  
...  
Keyword(s):  
Innate Immune ◽  
Scylla Paramamosain ◽  
Toll Like Receptor ◽  
Expression Of Genes ◽  
Total Antioxidant ◽  
Percentage Weight ◽  
Toll Like Receptor 2 ◽  
Lower Expression ◽  
Total Superoxide Dismutase ◽  
Mud Crabs

AbstractThe aim of the present study was to investigate the effects of dietary Zn level on growth performance, Zn bioaccumulation, antioxidant capacity and innate immunity in juvenile mud crabs (Scylla paramamosain). Six semi-purified diets were formulated to contain dietary Zn levels of 44·5, 56·9, 68·5, 97·3, 155·6 or 254·7 mg/kg. Dietary Zn level significantly influenced percentage weight gain (PWG), with the highest observed in crabs fed the diet containing 97·3 mg/kg Zn. Tissue Zn concentrations significantly increased as dietary Zn levels increased from 44·5 to 254·7 mg/kg. Retention of Zn in hepatopancreas increased with dietary Zn levels up to 68·5 mg/kg and then significantly decreased. Moreover, inadequate dietary Zn (44·5 and 56·9 mg/kg) reduced antioxidation markers including total superoxide dismutase (SOD) and Cu/Zn SOD activities and total antioxidant level. Crabs fed the diet with 44·5 mg/kg Zn also showed significantly lower expression of genes involved in antioxidant status, such as Cu/Zn SOD, glutathione peroxidase, catalase and thioredoxin than those fed diets containing 68·5 and 97·3 mg/kg Zn. The highest activities of phenoloxidase and alkaline phosphatase were recorded in crabs fed the diets containing 68·5 and 97·3 mg/kg Zn. Expression levels of prophenoloxidase and toll-like receptor 2 were higher in crabs fed the 97·3 mg/kg Zn diet compared with crabs fed the other diets. Based on PWG alone, the optimal dietary Zn level was estimated to be 82·9 mg/kg, with 68·5 to 97·3 mg/kg recommended for maintaining optimal Zn bioaccumulation, oxidation resistance and innate immune response of juvenile mud crabs.

scholarly journals Staphylococcus aureus Releases Proinflammatory Membrane Vesicles To Resist Antimicrobial Fatty Acids

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Arnaud Kengmo Tchoupa ◽  
Andreas Peschel
Keyword(s):  
Fatty Acids ◽  
Staphylococcus Aureus ◽  
Immune Responses ◽  
Membrane Vesicle ◽  
Membrane Vesicles ◽  
Innate Immune ◽  
Toll Like Receptor ◽  
Content Type ◽  
Healthy Humans ◽  
Toll Like Receptor 2

ABSTRACT Staphylococcus aureus is a major pathogen, which colonizes one in three otherwise healthy humans. This significant spread of S. aureus is largely due to its ability to circumvent innate immune responses, including antimicrobial fatty acids (AFAs) on the skin and in nasal secretions. In response to AFAs, S. aureus swiftly induces resistance mechanisms, which have yet to be completely elucidated. Here, we identify membrane vesicle (MV) release as a resistance strategy used by S. aureus to sequester host-specific AFAs. MVs protect S. aureus against a wide array of AFAs. Strikingly, beside MV production, S. aureus modulates MV composition upon exposure to AFAs. MVs purified from bacteria grown in the presence of linoleic acid display a distinct protein content and are enriched in lipoproteins, which strongly activate Toll-like receptor 2 (TLR2). Cumulatively, our findings reveal the protective capacities of MVs against AFAs, which are counteracted by an increased TLR2-mediated innate immune response. IMPORTANCE The nares of one in three humans are colonized by Staphylococcus aureus. In these environments, and arguably on all mucosal surfaces, bacteria encounter fatty acids with antimicrobial properties. Our study uncovers that S. aureus releases membrane vesicles (MVs) that act as decoys to protect the bacterium against antimicrobial fatty acids (AFAs). The AFA-neutralizing effects of MVs were neither strain specific nor restricted to one particular AFA. Hence, MVs may represent “public goods” playing an overlooked role in shaping bacterial communities in AFA-rich environments such as the skin and nose. Intriguingly, in addition to MV biogenesis, S. aureus modulates MV composition in response to exposure to AFAs, including an increased release of lipoproteins. These MVs strongly stimulate the innate immunity via Toll-like receptor 2 (TLR2). TLR2-mediated inflammation, which helps to fight infections, may exacerbate inflammatory disorders like atopic dermatitis. Our study highlights intricate immune responses preventing infections from colonizing bacteria.

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