scholarly journals A C21-Steroidal Glycoside from Cynanchum atratum Attenuates Concanavalin A-Induced Liver Injury in Mice

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1087 ◽  
Author(s):  
Jian Yang ◽  
Bin Wang ◽  
Chao-feng Zhang ◽  
Xiang-hong Xu ◽  
Mian Zhang
Keyword(s):  
T Lymphocytes ◽  
Concanavalin A ◽  
Underlying Mechanism ◽  
Dependent Manner ◽  
Histopathological Changes ◽  
Con A ◽  
Concentration Dependent Manner ◽  
Steroidal Glycoside ◽  
First Time

Cynatratoside A (CyA) is a C21 Steroidal glycoside with pregnane skeleton isolated from the root of Cynanchum atratum Bunge (Asclepiadaceae). This study aimed to investigate the effects of CyA on concanavalin A (Con A)-induced autoimmune hepatitis (AIH) and the underlying mechanism. CyA was orally administered to mice at 10 and 40 mg/kg 8 h before and 1 h after Con A treatment. The effects of CyA on Con A-induced spleen and liver in mice were assessed via histopathological changes, T lymphocyte amounts and the expressions of IL-1β and ICAM-1. Con A-induced L-02 hepatocytes were used to evaluate whether CyA (0.1–10 μM) can directly protect hepatocytes from cytotoxicity and the possible mechanism. The results revealed that CyA treatment could significantly improve the histopathological changes of spleen and liver, reduce the proliferation of splenic T lymphocytes, and decrease the expressions of IL-1β and ICAM-1 in liver. The experiment in vitro showed that CyA inhibited Con A-induced hepatotoxicity in a concentration-dependent manner. CyA (10 μM) significantly increased/decreased the expression of Bcl-2/Bax and reduced the levels of cleaved caspases-9 and -3. Our study demonstrated for the first time that CyA has a significant protective effect on Con A-induced AIH by inhibiting the activation and adhesion of T lymphocytes and blocking hepatocyte apoptosis.

scholarly journals IFN-γ down-regulates the PD-1 expression and assist nivolumab in PD-1-blockade effect on CD8+ T-lymphocytes in pancreatic cancer

BMC Cancer ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Guoping Ding ◽  
Tao Shen ◽  
Chen Yan ◽  
Mingjie Zhang ◽  
Zhengrong Wu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
T Lymphocytes ◽  
Ductal Adenocarcinoma ◽  
Cytotoxic Activities ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cd8 T Lymphocytes ◽  
Ifn Γ

Abstract Background Pancreatic cancer is characterized by a highly immunosuppressive tumor microenvironment and evasion of immune surveillance. Although programmed cell death 1 receptor (PD-1) blockade has achieved certain success in immunogenic cancers, the responses to the PD-1 antibody are not effective or sustained in patients with pancreatic cancer. Methods Firstly, PD-1 expressions on peripheral CD8+ T-lymphocytes of patients with pancreatic cancer and healthy donors were measured. In in vitro study, peripheral T-lymphocytes were isolated and treated with nivolumab and/or interferon-γ, and next, PD-1-blockade effects, proliferations, cytokine secretions and cytotoxic activities were tested after different treatments. In in vivo study, mice bearing subcutaneous pancreatic cancer cell lines were treated with induced T-lymphocytes and tumor sizes were measured. Results PD-1 protein expression is increased on peripheral CD8+ T cells in patients with pancreatic ductal adenocarcinoma compared with that in health donor. PD-1 expression on CD8+ T-lymphocytes was decreased by nivolumab in a concentration-dependent manner in vitro. IFN-γ could directly down-regulate expression of PD-1 in vitro. Furthermore, the combination therapy of nivolumab and IFN-γ resulted in greatest effect of PD-1-blockde (1.73 ± 0.78), compared with IFN-γ along (18.63 ± 0.82) and nivolumab along (13.65 ± 1.22). Moreover, the effects of nivolumab plus IFN-γ largest promoted the T-lymphocytes function of proliferations, cytokine secretions and cytotoxic activities. Most importantly, T-lymphocytes induced by nivolumab plus IFN-γ presented the best repression of tumor growth. Conclusions IFN-γ plus a PD-1-blockading agent could enhance the immunologic function and might play a crucial role in effective adoptive transfer treatments of pancreatic cancer.

scholarly journals Poly-L-Arginine Induces Apoptosis of NCI-H292 Cells via ERK1/2 Signaling Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Ya-Ni Wang ◽  
Ling-Ling Zhang ◽  
Xiao-Yun Fan ◽  
Sha-Sha Wu ◽  
Sheng-Quan Zhang
Keyword(s):  
Epithelial Cells ◽  
Caspase 3 ◽  
Underlying Mechanism ◽  
Mitochondrial Pathway ◽  
Airway Epithelial Cells ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Cationic Protein ◽  
Concentration Dependent Manner

Cationic protein is a cytotoxic protein secreted by eosinophils and takes part in the damage of airway epithelium in asthma. Poly-L-arginine (PLA), a synthetic cationic protein, is widely used to mimic the biological function of the natural cationic protein in vitro. Previous studies demonstrated the damage of the airway epithelial cells by cationic protein, but the molecular mechanism is unclear. The purpose of this study aimed at exploring whether PLA could induce apoptosis of human airway epithelial cells (NCI-H292) and the underlying mechanism. Methods. The morphology of apoptotic cells was observed by transmission electron microscopy. The rate of apoptosis was analyzed by flow cytometry (FCM). The expressions of the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), Bcl-2/Bax, and cleaved caspase-3 were assessed by western blot. Results. PLA can induce apoptosis in NCI-H292 cells in a concentration-dependent manner. Moreover, the phosphorylation of the ERK1/2 and the unbalance of Bcl2/Bax, as well as the activation of caspase-3, were involved in the PLA-induced apoptosis. Conclusions. PLA can induce the apoptosis in NCI-H292 cells, and this process at least involved the ERK1/2 and mitochondrial pathway. The results could have some indications in revealing the apoptotic damage of the airway epithelial cells. Besides, inhibition of cationic protein-induced apoptotic death in airway epithelial cells could be considered as a potential target of anti-injury or antiremodeling in asthmatics.

Role of CYP27A1 in progesterone metabolism in vitro and in vivo

2009 ◽  
Vol 297 (4) ◽  
pp. E949-E955 ◽  
Author(s):  
Geneviève Escher ◽  
Isabelle Vögeli ◽  
Robert Escher ◽  
Robert C. Tuckey ◽  
Sandra Erickson ◽  
...  
Keyword(s):  
Gene Knockout ◽  
Human Kidney ◽  
Underlying Mechanism ◽  
Expression Cloning ◽  
Dependent Manner ◽  
Expression Library ◽  
Concentration Dependent Manner ◽  
Adrenodoxin Reductase

In the kidney, progesterone is inactivated to 20α-dihydro-progesterone (20α-DH-progesterone) to protect the mineralocorticoid receptor from progesterone excess. In an attempt to clone the enzyme with 20α-hydroxysteroid activity using expression cloning in CHOP cells and a human kidney expression library, serendipitously cDNA encoding CYP27A1 was isolated. Overexpression of CYP27A1 in CHOP cells decreased progesterone conversion to 20α-DH-progesterone in a dose-dependent manner, an effect enhanced by cotransfection with adrenodoxin and adrenodoxin reductase. Incubation of CHOP cells with 27-hydroxycholesterol, a product of CYP27A1, increased the ratio of progesterone to 20α-DH-progesterone in a concentration-dependent manner, indicating that the effect of CYP27A1 overexpression was mediated by 27-hydroxycholesterol. To analyze whether these observations are relevant in vivo, progesterone and 20α-DH-progesterone were measured by gas chromatography-mass spectometry in 24-h urine of CYP27A1 gene knockout (ko) mice and their control wild-type and heterozygote littermates. In CYP27A1 ko mice, urinary progesterone concentrations were decreased, 20α-DH-progesterone increased, and the progesterone-to-20α-DH-progesterone ratio decreased threefold ( P < 0.001). Thus CYP27A1 modulates progesterone concentrations. The underlying mechanism is inhibition of 20α-hydroxysteroid dehydrogenase by 27-hydroxycholesterol.

scholarly journals Two distinct mechanisms regulate the in vivo generation of cytotoxic T cells.

1982 ◽  
Vol 156 (3) ◽  
pp. 918-923 ◽  
Author(s):  
M S Sy ◽  
S H Lee ◽  
M Tsurufuji ◽  
K L Rock ◽  
B Benacerraf ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Concanavalin A ◽  
Cytotoxic T Cells ◽  
Cytolytic T Lymphocytes ◽  
Spleen Cells ◽  
Suppressor T Cells ◽  
Con A

Treatment of responder cells with monoclonal anti-Ly-1,2 antibodies plus complement in vitro completely eliminated their ability to generate azobenzenearsonate (ABA)-specific cytolytic T lymphocytes (CTL). However, addition of the concanavalin A-stimulated supernatants of rat spleen cells (Con A-Sup) can fully reconstitute the response. Therefore, Lyt-1,2-bearing T cells are required for the generation of ABA-specific CTL, and such requirement can be replaced by factors present in the Con A- sup. Suppressor T cells (Ts), when adoptively transferred into naive recipients, will inhibit the in vivo priming of CTL. This inhibition can also be reversed by in vitro addition of Con A-Sup. furthermore, mice serving as donors of Ts also show profound unresponsiveness when primed and restimulated in vitro. In contrast to the Ts-mediated inhibition, in vitro addition of Con A-Sup was unable to abolish the unresponsiveness observed in these cultures. Thus, we identified two unresponsive states in a hapten-specific killing system that differ in their ability to be reconstituted by Con A-Sup.

scholarly journals Modulation of human lymphocyte function by C3a and C3a(70-77).

1982 ◽  
Vol 156 (3) ◽  
pp. 756-765 ◽  
Author(s):  
D G Payan ◽  
D E Trentham ◽  
E J Goetzl
Keyword(s):  
T Lymphocytes ◽  
Mononuclear Cells ◽  
Interaction Analysis ◽  
Direct Interaction ◽  
Mononuclear Leukocytes ◽  
Lymphocyte Function ◽  
Dependent Manner ◽  
Con A ◽  
Concentration Dependent Manner ◽  
Human Mononuclear Cells

Human C3a and the synthetic octapeptide C3a (70-77), which retains the activities of an anaphylatoxin, inhibit in a concentration-dependent manner the generation of leukocyte inhibitory factor (LIF) activity by human mononuclear leukocytes and T lymphocytes cultured with the mitogens phytohemagglutinin (PHA) or concanavalin A (Con A) or the antigen streptokinase-streptodornase (SK-SD). The generation of LIF activity was inhibited by 50% by 10(-8) M C3a or C3a(70-77) with PHA or Con A as the stimulus, whereas a more than 10-fold higher concentration of C3a(70-77) than C3a was required to achieve the same level of suppression with SK-SD as the stimulus. Similar concentrations of C3a(70-77) inhibited to the same extent the migration of T lymphocytes stimulated by alpha-thioglycerol of Con A. Neither C3a nor C3a(70-77) altered significantly the uptake of [3H]thymidine by human mononuclear cells exposed to PHA, Con A, or SK-SD. The capacity of C3a(70-77)-Sepharose,m but not Sepharose alone, to adsorb or inactivate mononuclear leukocytes required for the generation of LIF activity established a direct interaction. Analysis of the lymphocytes in the effluent from C3a(70-77)-Sepharose columns, using monoclonal antibodies to surface antigens, showed a selective depletion of the helper/inducer population of lymphocytes. C3a might represent an important mediator of the functionally selective regulation of human T lymphocyte activities by the complement system.

scholarly journals The Characterisation and Quantification of Immobilised Concanavalin A on Quartz Surfaces Based on The Competitive Binding to Glucose and Fluorescent Labelled Dextran

2019 ◽  
Vol 9 (2) ◽  
pp. 318 ◽  
Author(s):  
Trinh Hoang ◽  
Bjørn Stokke ◽  
Ulrik Hanke ◽  
Agne Johannessen ◽  
Erik Johannessen
Keyword(s):  
Concanavalin A ◽  
Binding Property ◽  
Dependent Manner ◽  
Con A ◽  
Concentration Dependent Manner ◽  
Specific Element ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dominant Structure ◽  
Fluorescent Molecules

The competition between various carbohydrates in the binding to Concanavalin A (Con A) can be exploited in gravimetric microsensors that detect changes in mass or viscoelasticity as a function of glucose concentration. Such sensors are based on the immobilisation of Con A as the ligand specific element, and a successful application requires that the binding property of Con A is retained. This paper presents a simplified immobilisation procedure of Con A on a quartz surface, a common material for gravimetric microsensors. Structural assessment with atomic force microscopy confirmed that the surface was covered with a layer of macromolecules. This layer shows the presence of entities of various sizes, presumably monomers, dimers and tetramers among which dimers of the Con A are the most dominant structure. Functional assessment using fluorescent labelled dextran (FITC and Alexa 488) suggests a surface coverage ranging from 1.8 × 1011 to 2.1 × 1012 immobilised fluorescent molecules per cm2. The assay was responsive to glucose over a concentration range from 0–40 mM, but became gradually saturated above 20 mM. Hence, the immobilised Con A is able to bind dextran, which is displaced by glucose in a concentration dependent manner, thus triggering a mass change proportional to the MW of dextran.

scholarly journals In-VitroCarbofuran Induced Genotoxicity in Human Lymphocytes and Its Mitigation by Vitamins C and E

2012 ◽  
Vol 32 (3) ◽  
pp. 153-163 ◽  
Author(s):  
Ratnesh Kumar Sharma ◽  
Bechan Sharma
Keyword(s):  
Dna Damage ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Natural Antioxidants ◽  
Underlying Mechanism ◽  
Positive Control ◽  
Peripheral Blood Lymphocytes ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Various efforts have been made in past in order to predict the underlying mechanism of pesticide-induced toxicity usingin vitroand animal models, however, these predictions may or may not be directly correlated with humans. The present study was designed to investigate the carbofuran induced genotoxicity and its amelioration by vitamins C and E by treating human peripheral blood lymphocytes (PBLs) with different concentrations (0, 0.5, 1.25, 2.5, 3.75 and 5.0 μM) of this compound. The treatment of PBLs with carbofuran displayed significant DNA damage in concentration dependent manner. The carbofuran induced genotoxicity could be ameliorated to considerable extent by pretreatment of PBLs with equimolar (10 μM) concentration of each of the vitamins C and E; the magnitude of protection by vitamin E being higher than by vitamin C. Also, it was found that the level of protection by these vitamins was higher when PBLs were treated with lower concentrations of pesticide. The significant DNA damage as observed by H2O2, a positive control in the present study, and its amelioration by natural antioxidants (vitamins C and E) lend an evidence to suggest that carbofuran would have caused genotoxicity via pesticide induced oxidative stress.

scholarly journals A New Immunosuppressive Pregnane Glycoside and Two Known Analogues from Epigynum cochinchinensis

2018 ◽  
Vol 13 (6) ◽  
pp. 1934578X1801300
Author(s):  
Yuting Shao ◽  
Yan Zhao ◽  
Hong Zhang ◽  
Mengjun Jiang ◽  
Afsar Khan ◽  
...  
Keyword(s):  
Concanavalin A ◽  
Soluble Fraction ◽  
Spectroscopic Techniques ◽  
Dependent Manner ◽  
Immunosuppressive Activity ◽  
Con A ◽  
Phytochemical Investigation ◽  
Pregnane Glycoside ◽  
Dose Dependent

Phytochemical investigation of the ethyl acetate soluble fraction from the leaves of Epigynum cochinchinensis led to the isolation of one new C21 pregnane glycoside, epigycoside C (1), along with two known analogues epigycoside A (2) and epigynoside G (3). Their structures were elucidated on the basis of extensive spectroscopic techniques. The in vitro immunosuppressive activity of compound 1 was evaluated against concanavalin A (Con A)- and lipopolysaccharides (LPS)-stimulated proliferation of mice splenocytes. Compound 1 displayed significant immunosuppressive activities in a dose-dependent manner.

Chickpea (Cicer arietinum L.) Lectin Exhibit Inhibition of ACE-I, α-amylase and α-glucosidase Activity

2019 ◽  
Vol 26 (7) ◽  
pp. 494-501 ◽  
Author(s):  
Sameer Suresh Bhagyawant ◽  
Dakshita Tanaji Narvekar ◽  
Neha Gupta ◽  
Amita Bhadkaria ◽  
Ajay Kumar Gautam ◽  
...  
Keyword(s):  
Biological Effects ◽  
Exchange Chromatography ◽  
Health Concern ◽  
Carbohydrate Binding ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ic50 Values ◽  
Chickpea Lectin

Background: Diabetes and hypertension are the major health concern and alleged to be of epidemic proportions. This has made it a numero uno subject at various levels of investigation. Glucosidase inhibitor provides the reasonable option in treatment of Diabetes Mellitus (DM) as it specifically targets post prandial hyperglycemia. The Angiotensin Converting Enzyme (ACE) plays an important role in hypertension. Therefore, inhibition of ACE in treatment of elevated blood pressure attracts special interest of the scientific community. Chickpea is a food legume and seeds contain carbohydrate binding protein- a lectin. Some of the biological properties of this lectin hitherto been elucidated. Methods: Purified by ion exchange chromatography, chickpea lectin was tested for its in vitro antioxidant, ACE-I inhibitory and anti-diabetic characteristic. Results: Lectin shows a characteristic improvement over the synthetic drugs like acarbose (oral anti-diabetic drug) and captopril (standard antihypertensive drug) when, their IC50 values are compared. Lectin significantly inhibited α-glucosidase and α-amylase in a concentration dependent manner with IC50 values of 85.41 ± 1.21 ҝg/ml and 65.05 ± 1.2 µg/ml compared to acarbose having IC50 70.20 ± 0.47 value of µg/ml and 50.52 ± 1.01 µg/ml respectively. β-Carotene bleaching assay showed antioxidant activity of lectin (72.3%) to be as active as Butylated Hydroxylanisole (BHA). In addition, lectin demonstrated inhibition against ACE-I with IC50 value of 57.43 ± 1.20 µg/ml compared to captopril. Conclusion: Lectin demonstrated its antioxidant character, ACE-I inhibition and significantly inhibitory for α-glucosidase and α-amylase seems to qualify as an anti-hyperglycemic therapeutic molecule. The biological effects of chickpea lectin display potential for reducing the parameters of medically debilitating conditions. These characteristics however needs to be established under in vivo systems too viz. animals through to humans.

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