scholarly journals New Insights on NETosis Induced by Entamoeba histolytica: Dependence on ROS from Amoebas and Extracellular MPO Activity

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 974
Author(s):  
César Díaz-Godínez ◽  
Joshue Fabián Jorge-Rosas ◽  
Mario Néquiz ◽  
Santiago Martínez-Calvillo ◽  
Juan P. Laclette ◽  
...  
Keyword(s):  
Cell Surface ◽  
Nadph Oxidase ◽  
Entamoeba Histolytica ◽  
Pathogen Detection ◽  
Dependent Manner ◽  
Antimicrobial Proteins ◽  
Nadph Oxidase Activity ◽  
Mitochondrial Ros ◽  
Pre Treatment ◽  
Dose Dependent

NETosis is a neutrophil process involving sequential steps from pathogen detection to the release of DNA harboring antimicrobial proteins, including the central generation of NADPH oxidase dependent or independent ROS. Previously, we reported that NETosis triggered by Entamoeba histolytica trophozoites is independent of NADPH oxidase activity in neutrophils, but dependent on the viability of the parasites and no ROS source was identified. Here, we explored the possibility that E. histolytica trophozoites serve as the ROS source for NETosis. NET quantitation was performed using SYTOX® Green assay in the presence of selective inhibitors and scavengers. We observed that respiratory burst in neutrophils was inhibited by trophozoites in a dose dependent manner. Mitochondrial ROS was not also necessary, as the mitochondrial scavenger mitoTEMPO did not affect the process. Surprisingly, ROS-deficient amoebas obtained by pre-treatment with pyrocatechol were less likely to induce NETs. Additionally, we detected the presence of MPO on the cell surface of trophozoites after the interaction with neutrophils and found that luminol and isoluminol, intracellular and extracellular scavengers for MPO derived ROS reduced the amount of NET triggered by amoebas. These data suggest that ROS generated by trophozoites and processed by the extracellular MPO during the contact with neutrophils are required for E. histolytica induced NETosis.

scholarly journals Dectin-1-Mediated Production of Pro-Inflammatory Cytokines Induced by Yeast β-Glucans in Bovine Monocytes

2021 ◽  
Vol 12 ◽  
Author(s):  
Ana R. V. Pedro ◽  
Tânia Lima ◽  
Ricardo Fróis-Martins ◽  
Bárbara Leal ◽  
Isabel C. Ramos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Surface ◽  
Inflammatory Cytokines ◽  
Surface Expression ◽  
Cell Surface Receptor ◽  
Dependent Manner ◽  
Feed Supplements ◽  
Surface Receptor ◽  
Dose Dependent ◽  
Pro Inflammatory Cytokines

Yeast-derived products containing β-glucans have long been used as feed supplements in domesticated animals in an attempt to increase immunity. β-glucans are mainly recognized by the cell surface receptor CLEC7A, also designated Dectin-1. Although the immune mechanisms elicited through Dectin-1 activation have been studied in detail in mice and humans, they are poorly understood in other species. Here, we evaluated the response of bovine monocytes to soluble and particulate purified β-glucans, and also to Zymosan. Our results show that particulate, but not soluble β-glucans, can upregulate the surface expression of costimulatory molecules CD80 and CD86 on bovine monocytes. In addition, stimulated cells increased production of IL-8 and of TNF, IL1B, and IL6 mRNA expression, in a dose-dependent manner, which correlated positively with CLEC7A gene expression. Production of IL-8 and TNF expression decreased significantly after CLEC7A knockdown using two different pairs of siRNAs. Overall, we demonstrated here that bovine monocytes respond to particulate β-glucans, through Dectin-1, by increasing the expression of pro-inflammatory cytokines. Our data support further studies in cattle on the induction of trained immunity using dietary β-glucans.

scholarly journals DJC Suppresses Advanced Glycation End Products-Induced JAK-STAT Signaling and ROS in Mesangial Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Min Sun ◽  
Yan Li ◽  
Wenjie Bu ◽  
Jindong Zhao ◽  
Jianliang Zhu ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Advanced Glycation End Products ◽  
Oxidase Activity ◽  
Mesangial Cells ◽  
Dependent Manner ◽  
Advanced Glycation ◽  
Nadph Oxidase Activity ◽  
Glycation End Products ◽  
End Products ◽  
Anti Inflammatory

The antidiabetic properties and anti-inflammatory effects of Danzhi Jiangtang Capsules (DJC) have been demonstrated in clinical and laboratory experiments. In this study, we explored whether DJC can ameliorate advanced glycation end products- (AGEs-) mediated cell injury and the precise mechanisms of DJC in treating diabetic nephropathy (DN). Western blot analysis was employed to assess the expressions of iNOS, COX2, and SOCS and the phosphorylation of JAK2, STAT1, and STAT3 in glomerular mesangial cells (GMCs) after treatment with DJC. TNF-α, IL-6, and MCP-1 were determined using double-antibody sandwich ELISA. ROS and NADPH oxidase activity were measured by DCFH-DA assay and lucigenin-enhanced chemiluminescence, respectively. DJC significantly reversed the AGEs-induced expression of COX2 and iNOS. Moreover, DJC inhibited the AGEs-induced JAK2-STAT1/STAT3 activation, resulting in the inhibition of inflammatory cytokines such as IL-6, MCP-1, and TNF-αin a concentration-dependent manner. The ability of DJC to suppress STAT activation was also verified by the observation that DJC significantly increased the SOCS3 protein level. DJC reversed the AGEs-induced accumulation of ROS and NADPH oxidase activity, thus confirming that DJC possesses antioxidant activity. The results suggest that the anti-inflammatory effects of DJC in GMCs may be due to its ability to suppress the JAK2-STAT1/STAT3 cascades and reduce ROS production.

scholarly journals Ethnopharmacological basis for antispasmodic, antidiarrheal and antiemetic activities of Ceratonia siliqua pods

2017 ◽  
Vol 12 (4) ◽  
pp. 384
Author(s):  
Irfan Hamid ◽  
Khalid Hussain Janbaz
Keyword(s):  
Crude Extract ◽  
Video Clip ◽  
Dependent Manner ◽  
Ceratonia Siliqua ◽  
Spasmolytic Activity ◽  
Rabbit Jejunum ◽  
Pre Treatment ◽  
Dose Dependent

<p class="Abstract">The study was conducted to provide the ethnopharmacological bases of the crude extract of seed pods of <em>Ceratonia siliqua</em> in the gastrointestinal spasm, diarrhea and emesis. In segregated rabbit jejunum, it showed dose-dependent (0.01-10 mg/mL) relaxation of spontaneous as well as carbachol (1 µM)-induced contraction. Pre-treatment of segregated rat ileum with <em>C. siliqua</em>, significantly (p&lt;0.0001) suppressed the carbachol (1 µM)-induced contraction similar to atropine (1 µM). These results indicated that <em>C. siliqua</em> possesses spasmolytic activity through possible blockage of muscarinic receptor in jejunum preparations. Furthermore, the crude extract inhibited the castor oil-induced diarrhea, charcoal meal propulsion in mice and copper sulfate-induced retches in chicks in a dose-dependent manner (100, 200, 300 mg/kg). These in vitro and in vivo results indicate that <em>C. siliqua</em> possesses the spasmolytic and antidiarrheal activities mediated possibly through blockage of muscarinic receptors. Thus, this study provides a rationale for its folkloric use.</p><p><strong>Video Clip of Methodology</strong>:</p><p>12 min 42 sec   <a href="https://www.youtube.com/v/BQGWdIZqpsY">Full Screen</a>   <a href="https://www.youtube.com/watch?v=BQGWdIZqpsY">Alternate</a></p>

scholarly journals Interaction of C4-binding protein with cell-bound C4b. A quantitative analysis of binding and the role of C4-binding protein in proteolysis of cell-bound C4b.

1983 ◽  
Vol 157 (4) ◽  
pp. 1239-1251 ◽  
Author(s):  
T Fujita ◽  
N Tamura
Keyword(s):  
Cell Surface ◽  
Binding Protein ◽  
Fluid Phase ◽  
Radioactive Tracer ◽  
Scatchard Analysis ◽  
Dependent Manner ◽  
Alpha Chain ◽  
Tracer Techniques ◽  
Dose Dependent

Purified C4-binding protein (C4-bp) was shown to bind to cell-bound C4b by radioactive tracer techniques. With EAC4 bearing greater than 3,000 C4b-molecules/cell, the number of C4-bp molecules bound was directly proportional to the number of C4b molecule on the cell surface; EAC4 bearing less than 3,000 C4b-molecules/cell bound a very small amount of C4-bp. Scatchard analysis of binding of C4-bp indicated an equilibrium constant of 4.6 X 10(8) L/M and a maximum of 0.43 C4-bp molecules bound per C4b molecule, equivalent to an average of one molecule of C4-bp per two or three molecules of C4b. Fluid-phase C4b inhibited the binding of C4-bp to cell-bound C4b in a dose-dependent manner, whereas native C4 had little effect. C2 inhibited this binding and also released C4-bp from EAC4,C4-bp. However, C2 was 27 times less effective than unlabeled C4-bp on a molar basis and a considerable amount of C4-bp remained bound to C4b on the cell surface even in the presence of a large excess of C2. We also examined the cofactor activity of C4-bp in the cleavage of cell-bound C4b by C3b/C4b inactivator (I). Cleavage of the alpha' chain of C4b on the cell surface by I alone was incomplete and an intermediate cleavage product, alpha-75, was observed. When C4-bp bound to C4b on the cell surface, the alpha' chain of the C4b cleaved into three fragments, alpha 2, alpha 3, and alpha 4. The alpha 3, alpha 4, beta, and gamma peptides (C4c) were released into the fluid phase, and the alpha 2 fragment (C4d) remained linked covalently to the cell membrane via an ester bond. In some situations, therefore, C4-bp enhances the proteolytic activity of I on cell-bound C4b.

scholarly journals Lipopolysaccharide biosynthesis-related genes are required for colony pigmentation of Porphyromonas gingivalis

Microbiology ◽  
2009 ◽  
Vol 155 (4) ◽  
pp. 1282-1293 ◽  
Author(s):  
Keiko Sato ◽  
Nobuo Kido ◽  
Yukitaka Murakami ◽  
Charles I. Hoover ◽  
Koji Nakayama ◽  
...  
Keyword(s):  
Cell Surface ◽  
Porphyromonas Gingivalis ◽  
Dependent Manner ◽  
Wild Type ◽  
Gene Encoding ◽  
Lipopolysaccharide Biosynthesis ◽  
Ladder Pattern ◽  
Surface Polysaccharides ◽  
Culture Supernatants ◽  
Dose Dependent

The periodontopathic bacterium Porphyromonas gingivalis forms pigmented colonies when incubated on blood agar plates as a result of accumulation of μ-oxo haem dimer on the cell surface. Gingipain–adhesin complexes are responsible for production of μ-oxo haem dimer from haemoglobin. Non-pigmented mutants (Tn6-5, Tn7-1, Tn7-3 and Tn10-4) were isolated from P. gingivalis by Tn4351 transposon mutagenesis [Hoover & Yoshimura (1994), FEMS Microbiol Lett 124, 43–48]. In this study, we found that the Tn6-5, Tn7-1 and Tn7-3 mutants carried Tn4351 DNA in a gene homologous to the ugdA gene encoding UDP-glucose 6-dehydrogenase, a gene encoding a putative group 1 family glycosyltransferase and a gene homologous to the rfa gene encoding ADP heptose-LPS heptosyltransferase, respectively. The Tn10-4 mutant carried Tn4351 DNA at the same position as that for Tn7-1. Gingipain activities associated with cells of the Tn7-3 mutant (rfa) were very weak, whereas gingipain activities were detected in the culture supernatants. Immunoblot and mass spectrometry analyses also revealed that gingipains, including their precursor forms, were present in the culture supernatants. A lipopolysaccharide (LPS) fraction of the rfa deletion mutant did not show the ladder pattern that was usually seen for the LPS of the wild-type P. gingivalis. A recombinant chimera gingipain was able to bind to an LPS fraction of the wild-type P. gingivalis in a dose-dependent manner. These results suggest that the rfa gene product is associated with biosynthesis of LPS and/or cell-surface polysaccharides that can function as an anchorage for gingipain–adhesin complexes.

Angiostatin and plasminogen share binding to endothelial cell surface actin

2005 ◽  
Vol 83 (1) ◽  
pp. 28-35 ◽  
Author(s):  
A K Dudani ◽  
M Ben-Tchavtchavadze ◽  
S Porter ◽  
E Tackaberry
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Surface ◽  
Dependent Manner ◽  
Proteolytic Fragment ◽  
Binding Motifs ◽  
Fluorescence Studies ◽  
Endothelial Cell Surface ◽  
Dose Dependent ◽  
Dependent Processes

Previous studies from this laboratory have demonstrated that plasminogen binds to endothelial cell surface-associated actin via its kringles in a dose-dependent and specific manner. The purpose of this study was to determine whether angiostatin, a proteolytic fragment of plasminogen, shares binding properties with plasminogen. Our results indicated that like plasminogen, angiostatin bound to actin in a time-, concentration-, and kringle-dependent manner. Furthermore, this binding was significantly inhibited by excess plasminogen, suggesting that both proteins shared binding motifs on the actin molecule. Fluorescence studies demonstrated that angiostatin bound to intact endothelial cells through its kringles, and this binding was also inhibited by plasminogen but not by unrelated proteins. Ligand blot analyses on endothelial cell lysates indicated that angiostatin interacted with a 42 kDa protein, which was identified as actin. Furthermore, an anti-actin antibody inhibited binding of angiostatin to endothelial cells by approximately 25%. These results suggest that angiostatin and plasminogen share binding to endothelial cell surface actin and, therefore, that angiostatin has the potential to inhibit plasmin-dependent processes such as cell migration–movement.Key words: plasminogen, angiostatin, endothelial cells, actin.

Characterisation of the progesterone receptor on canine spermatozoa

2005 ◽  
Vol 17 (7) ◽  
pp. 733 ◽  
Author(s):  
Jui-Te Wu ◽  
Pei-Shiue Tsai ◽  
Shuang-Lin Lee ◽  
Feng-Pang Cheng
Keyword(s):  
Monoclonal Antibodies ◽  
Plasma Membrane ◽  
Progesterone Receptor ◽  
Seminal Plasma ◽  
High Capacity ◽  
Fluorescein Isothiocyanate ◽  
Dependent Manner ◽  
Sperm Plasma Membrane ◽  
Pre Treatment ◽  
Dose Dependent

The present study was conducted to characterise and localise the progesterone receptor (PR) on canine spermatozoa. Using a progesterone–bovine serum albumin–fluorescein isothiocyanate conjugate (PBF) and different monoclonal antibodies (C262 and NCL-PGR against the steroid binding domain and N-terminus of intracellular PR, respectively, and h151 against the hinge domain of the intracellular oestrogen receptor), the PR was identified on the plasma membrane over the acrosomal region. Two proteins (54 kDa and 65 kDa) were detected by recognition of the three monoclonal antibodies using Western blotting. PBF labelling was observed in the majority of cauda epididymal spermatozoa (63 ± 4%), but this labelling was markedly reduced (33 ± 17%) after the addition of canine seminal plasma. Over a 7-h capacitation, the proportion of ejaculated spermatozoa exhibiting PBF labelling (indicating the presence of the PR) increased from 18 ± 10% (onset) to 59 ± 7% by 5 h, where it plateaued. Progesterone (P4) induced the acrosome reaction (AR) in a dose-dependent manner (0, 0.1, 1 and 10 µg/mL P4 corresponding to 10 ± 5%, 16 ± 9%, 23 ± 7% and 30 ± 7%). Pre-treatment of capacitated spermatozoa with canine seminal plasma reduced the incidence of the P4-induced AR (12 ± 5%). In addition, treatment with the monoclonal antibodies significantly reduced the incidence of the P4-induced AR (10 µg/mL) in capacitated ejaculated spermatozoa from 19 ± 6% to 11 ± 4% (h151, 1 : 10) and 12 ± 6% (C262, 1 : 10), respectively. A typical Scatchard plot revealed one binding with high affinity and low capacity, and another binding with low affinity and high capacity, suggesting at least two different characteristic PR. Taken together, these results demonstrate that P4 induced the AR in a dose-dependent manner via functional transmembranal receptors in the acrosomal region of the canine sperm plasma membrane. The characteristics of this membrane receptor seem similar to those of other mammalian spermatozoa, and it shows structural homology to the intracellular PR.

Sodium Butyrate Pre-Treatment Enhance Differentiation of Bone Marrow Mesenchymal Stem Cells (BM-MSCs) into Hepatocytes and Improve Liver Injury

2021 ◽  
Vol 21 ◽  
Author(s):  
Qiu-Yun Li ◽  
Juan Chen ◽  
Yong-Heng Luo ◽  
Wei Zhang ◽  
En-Hua Xiao
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Dependent Manner ◽  
Hepatic Differentiation ◽  
Marrow Mesenchymal Stem Cells ◽  
Specific Factors ◽  
Pre Treatment ◽  
Dose Dependent

Objective: The treatment of liver failure by stem cell transplantation has attracted growing interest. Herein, we aim to explore the role of sodium butyrate (NaB) in the hepatic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) under liver-specific factors induction in vitro and vivo. Materials & Methods: We isolated BM-MSCs from the mononuclear cell fraction of rabbit bone marrow samples, and identified the cells by Immunophenotypic analysis. We investigated the effects of different concentrations and induction conditions. The histone deacetylase inhibitor NaB induced hepatic differentiation of BM-MSCs under liver-specific factors induction in vitro. Morphological features, liver-specific gene and protein expression, and functional analyses in vitro and vivo were performed to evaluate the hepatic differentiation of BM-MSCs. Results: Our results showed that pre-treated NaB inhibited the expression of liver-specific protein in a dose-dependent manner. The induction efficiency of NaB with 24h pre-treatment was higher than that of NaB continuous intervention. 0.5 mM 24h NaB pre-treated cells can improve liver tissue damage in vivo. And the liver ALB, AAT and the serum TP were significantly increased, while the serum ALT was significantly reduced. Conclusion: Continuous NaB treatment can inhibit BM-MSCs proliferation in a dose-dependent manner at a certain concentration range. 0.5 mM 24h pre-treatment of NaB enhanced differentiation of BM-MSCs into hepatocytes and improves liver injury in vitro and vivo.

Constitutive Expression of CD40L on Bone Marrow Mast Cells Supports the Growth of Lymphoplasmacytic Cells in Patients with Waldenstrom’s Macroglobulinemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2350-2350 ◽  
Author(s):  
Olivier Tournilhac ◽  
Daniel Ditzel Santos ◽  
Lian Xu ◽  
Jeffery Kutok ◽  
Yu Tsu Tai ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Mast Cells ◽  
Cell Surface ◽  
Tumor Cells ◽  
Thymidine Uptake ◽  
Dependent Manner ◽  
Rt Pcr ◽  
Potent Inducer ◽  
Dose Dependent

Abstract CD40 ligand (CD40L) is a potent inducer of normal and malignant B-cell proliferation through interaction with CD40. We and others have observed excess mast cells (MC) in bone marrow (BM) biopsies of WM patients, which are commonly found admixed with tumor aggregates. (Tournilhac et al, JCO 2004, 22:571S). We therefore sought to clarify the role of MC in WM. Co-culture of 0.5% paraformaldehyde fixed, or sublethally irradiated HMC-1, LAD, and KU mast or basophilic cell lines and sorted BM lymphoplasmacytic cells (LPC) from 10 WM patients resulted in MC dose-dependent tumor colony formation and/or proliferation as assessed by 3H-thymidine uptake studies. As demonstrated by immunohistochemical, multicolor flow cytometric (CD117+FceRI+) and/or RT-PCR analysis, CD40L was expressed on BM MC from 29 of 31 (94%), 11 of 13 (85%), and 7 of 9 (78%) of WM patients, respectively. In contrast, cell surface CD40L expression was not detected by immunohistochemistry (p=0.00005) and flow cytometry (p=0.003) in 5 normal donors, and only faint expression for 1 of 5 normal donors by RT-PCR (p=0.09). Moreover, by multicolor flow cytometry, CD40 was expressed on BM tumor cells from 14/17 (83%) patients. CD40 functionality was confirmed either by the G28.5 CD40 agonistic antibody which induced dose dependent proliferation or by the rh-CD40L which partly prevented serum starvation-induced-apoptosis of WM LPC from 4/4 and 3/4 patients respectively. Importantly, expansion of tumor cells from 3 of 4 patients in mixed cultures with paraformaldehyde fixed MC was blocked in a dose dependent manner by use of a CD40L blocking protein (CD40:Fc). These studies demonstrate that CD40L is constitutively expressed on the cell surface of BM MC in WM and support the growth of WM tumor cells, and therefore provide the framework for therapeutic targeting of MC and MC-WM cell interactions in WM.

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