N-nitrosodimethylamine (NDMA) induced apoptosis dependent on Fas/FasL complex in human leukocytes

2019 ◽  
Vol 38 (5) ◽  
pp. 578-587
Author(s):  
A Iwaniuk ◽  
K Grubczak ◽  
W Ratajczak-Wrona ◽  
M Garley ◽  
K Nowak ◽  
...  

Objective: To investigate the mechanism of apoptosis dependent on the Fas/FasL (Fas ligand) complex in the presence of N-nitrosodimethylamine (NDMA) in human leukocytes. Methods: Polymorphonuclear neutrophils (PMNs) and peripheral blood mononuclear cells (PBMCs) were isolated form whole blood by density centrifugation. The concentration of NDMA was assessed by cellular toxicity assay. Apoptotic cells were assessed with flow cytometry and the expression of pro- and antiapoptotic proteins was investigated by Western blotting in PMNs and PBMCs treated with NDMA and/or FasL. Results: PMNs showed a higher ratio of apoptotic cells than PBMCs after exposure to NDMA and/or FasL. Enhanced apoptosis was related to the increased expression of proapoptotic proteins in neutrophils following exposure to either NDMA or FasL. In PBMCs, the relation was observed after exposure to FasL only. PMNs and PBMCs incubated with NDMA and FasL simultaneously demonstrated the highest increase in protein expression. Conclusions: NDMA shows a stronger proapoptotic effect with PMNs than with PBMCs. The Fas/FasL complex, along with other proapoptotic proteins of the receptor (Fas, FADD) and mitochondrial pathway (Noxa, Puma, Bim), plays a key role in the induction of neutrophil apoptosis. Synergic effects of NDMA and FasL which lead to higher induction of apoptosis in PMNs than in PBMCs indicates a multistage and varied regulation of apoptosis in different populations of leukocytes.

Blood ◽  
1998 ◽  
Vol 91 (7) ◽  
pp. 2360-2368 ◽  
Author(s):  
Laurent Genestier ◽  
Sylvie Fournel ◽  
Monique Flacher ◽  
Olga Assossou ◽  
Jean-Pierre Revillard ◽  
...  

Polyclonal horse antilymphocyte and rabbit antithymocyte globulins (ATGs) are currently used in severe aplastic anemia and for the treatment of organ allograft acute rejection and graft-versus-host disease. ATG treatment induces a major depletion of peripheral blood lymphocytes, which contributes to its overall immunosuppressive effects. Several mechanisms that may account for lymphocyte lysis were investigated in vitro. At high concentrations (.1 to 1 mg/mL) ATGs activate the human classic complement pathway and induce lysis of both resting and phytohemagglutinin (PHA)-activated peripheral blood mononuclear cells. At low, submitogenic, concentration ATGs induce antibody-dependent cell cytotoxicity of PHA-activated cells, but not resting cells. They also trigger surface Fas (Apo-1, CD95) expression in naive T cells and Fas-ligand gene and protein expression in both naive and primed T cells, resulting in Fas/Fas-L interaction-mediated cell death. ATG-induced apoptosis and Fas-L expression were not observed with an ATG preparation lacking CD2 and CD3 antibodies. Susceptibility to ATG-induced apoptosis was restricted to activated cells, dependent on IL-2, and prevented by Cyclosporin A, FK506, and rapamycin. The data suggest that low doses of ATGs could be clinically evaluated in treatments aiming at the selective deletion of in vivo activated T cells in order to avoid massive lymphocyte depletion and subsequent immunodeficiency.


Blood ◽  
1998 ◽  
Vol 91 (7) ◽  
pp. 2360-2368 ◽  
Author(s):  
Laurent Genestier ◽  
Sylvie Fournel ◽  
Monique Flacher ◽  
Olga Assossou ◽  
Jean-Pierre Revillard ◽  
...  

Abstract Polyclonal horse antilymphocyte and rabbit antithymocyte globulins (ATGs) are currently used in severe aplastic anemia and for the treatment of organ allograft acute rejection and graft-versus-host disease. ATG treatment induces a major depletion of peripheral blood lymphocytes, which contributes to its overall immunosuppressive effects. Several mechanisms that may account for lymphocyte lysis were investigated in vitro. At high concentrations (.1 to 1 mg/mL) ATGs activate the human classic complement pathway and induce lysis of both resting and phytohemagglutinin (PHA)-activated peripheral blood mononuclear cells. At low, submitogenic, concentration ATGs induce antibody-dependent cell cytotoxicity of PHA-activated cells, but not resting cells. They also trigger surface Fas (Apo-1, CD95) expression in naive T cells and Fas-ligand gene and protein expression in both naive and primed T cells, resulting in Fas/Fas-L interaction-mediated cell death. ATG-induced apoptosis and Fas-L expression were not observed with an ATG preparation lacking CD2 and CD3 antibodies. Susceptibility to ATG-induced apoptosis was restricted to activated cells, dependent on IL-2, and prevented by Cyclosporin A, FK506, and rapamycin. The data suggest that low doses of ATGs could be clinically evaluated in treatments aiming at the selective deletion of in vivo activated T cells in order to avoid massive lymphocyte depletion and subsequent immunodeficiency.


Medicines ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 101 ◽  
Author(s):  
Cholet ◽  
Decombat ◽  
Vareille-Delarbre ◽  
Gainche ◽  
Berry ◽  
...  

Background: Some Bupleurum species, such as the Bupleurum chinense DC. or the Bupleurum scorzonerifolium Willd have been extensively studied (especially their roots) for the treatment of inflammation. In contrast, only compounds extracted from the aerial parts of Bupleurum rotundifolium have been studied and showed anti-inflammatory or antiproliferative activities. This study was conducted to investigate the antioxidant, anti-inflammatory, and immunomodulatory effects of Bupleurum rotundifolium roots. Methods: To tackle the various aspects of inflammation, we studied in vitro a methanolic extract from the roots of Bupleurum rotundifolium on peripheral blood mononuclear cells (PBMCs), polymorphonuclear neutrophils (PMNs), and the monocytic cells THP-1. Its antioxidant capacities and iron-chelating activity were assessed. The extract was tested on THP-1 differentiation, reactive oxygen species (ROS) production by leukocytes, neutrophils chemotaxis, cytokines, PGE2 production, and NF-κB activation in PBMCs. Results: The extract showed a decreased ROS production in stimulated cells. It increased PBMC chemokine secretion and up-regulated the differentiation of THP-1 monocytes into macrophage-like cells, indicating a potential interest of the extract in the resolution of acute inflammation. In addition, the analysis of cytokine production suggests that Bupleurum rotundifolium has immunomodulatory properties. Conclusions: Cytokines secretion, especially IL-1β and IL-12p70, provided us with a set of indicators suggesting that the extract might be able to drive the polarization of macrophages and lymphocytes toward a Th2 anti-inflammatory profile in excessive inflammation.


Blood ◽  
2008 ◽  
Vol 112 (3) ◽  
pp. 770-781 ◽  
Author(s):  
Mithun Vinod Shah ◽  
Ranran Zhang ◽  
Rosalyn Irby ◽  
Ravi Kothapalli ◽  
Xin Liu ◽  
...  

Abstract T-cell large granular lymphocyte (LGL) leukemia is characterized by clonal expansion of CD3+CD8+ cells. Leukemic LGLs correspond to terminally differentiated effector-memory cytotoxic T lymphocytes (CTLs) that escape Fas-mediated activation-induced cell death (AICD) in vivo. The gene expression signature of peripheral blood mononuclear cells from 30 LGL leukemia patients showed profound dysregulation of expression of apoptotic genes and suggested uncoupling of activation and apoptotic pathways as a mechanism for failure of AICD in leukemic LGLs. Pathway-based microarray analysis indicated that balance of proapoptotic and antiapoptotic sphingolipid-mediated signaling was deregulated in leukemic LGLs. We further investigated sphingolipid pathways and found that acid ceramidase was constitutively overexpressed in leukemic LGLs and that its inhibition induced apoptosis of leukemic LGLs. We also showed that S1P5 is the predominant S1P receptor in leukemic LGLs, whereas S1P1 is down-regulated. FTY720, a functional antagonist of S1P-mediated signaling, induced apoptosis in leukemic LGLs and also sensitized leukemic LGLs to Fas-mediated death. Collectively, these results show a role for sphingolipid-mediated signaling as a mechanism for long-term survival of CTLs. Therapeutic targeting of this pathway, such as use of FTY720, may have efficacy in LGL leukemia.


2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Selin Yildirim ◽  
Noushin Zibandeh ◽  
Deniz Genc ◽  
Elif Merve Ozcan ◽  
Kamil Goker ◽  
...  

Aim. To compare the effects of various mesenchymal stem cells, those isolated from human exfoliated deciduous teeth (SHEDs), dental pulp stem cells (DPSCs), and dental follicle stem cells (DFSCs), on human peripheral blood mononuclear cells (PBMCs).Method. Mesenchymal stem cells were isolated from three sources in the orofacial region. Characterization and PCR analyses were performed. Lymphocytes were isolated from healthy peripheral venous blood. Lymphocytes were cocultured with stem cells in the presence and absence of IFN-γand stimulated with anti-CD2, anti-CD3, and anti-CD28 for 3 days. Then, lymphocyte proliferation, the number of CD4+FoxP3+T regulatory cells, and the levels of Fas/Fas ligand, IL-4, IL-10, and IFN-γin the culture supernatant were measured.Results. The DFSCs exhibited an enhanced differentiation capacity and an increased number of CD4+FoxP3+T lymphocytes and suppressed the proliferation and apoptosis of PBMCs compared with SHEDs and DPSCs. The addition of IFN-γaugmented the proliferation of DFSCs. Furthermore, the DFSCs suppressed IL-4 and IFN-γcytokine levels and enhanced IL-10 levels compared with the other cell sources.Conclusion. These results suggest that IFN-γstimulates DFSCs by inducing an immunomodulatory effect on the PBMCs of healthy donors while suppressing apoptosis and proliferation and increasing the number of CD4+FoxP3+cells.


2019 ◽  
Vol 12 (2) ◽  
pp. 152-162 ◽  
Author(s):  
Min He ◽  
Nan Wu ◽  
Man Cheong Leong ◽  
Weiwei Zhang ◽  
Zi Ye ◽  
...  

Abstract Chronic inflammation plays a pivotal role in insulin resistance and type 2 diabetes, yet the mechanisms are not completely understood. Here, we demonstrated that serum LPS levels were significantly higher in newly diagnosed diabetic patients than in normal control. miR-145 level in peripheral blood mononuclear cells decreased in type 2 diabetics. LPS repressed the transcription of miR-143/145 cluster and decreased miR-145 levels. Attenuation of miR-145 activity by anti-miR-145 triggered liver inflammation and increased serum chemokines in C57BL/6 J mice. Conversely, lentivirus-mediated miR-145 overexpression inhibited macrophage infiltration, reduced body weight, and improved glucose metabolism in db/db mice. And miR-145 overexpression markedly reduced plaque size in the aorta in ApoE−/− mice. Both OPG and KLF5 were targets of miR-145. miR-145 repressed cell proliferation and induced apoptosis partially by targeting OPG and KLF5. miR-145 also suppressed NF-κB activation by targeting OPG and KLF5. Our findings provide an association of the environment with the progress of metabolic disorders. Increasing miR-145 may be a new potential therapeutic strategy in preventing and treating metabolic diseases such as type 2 diabetes and atherosclerosis.


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