scholarly journals Regulation of Na+/H+ Exchanger in Dendritic Cells by Akt1

2015 ◽  
Vol 36 (3) ◽  
pp. 1237-1249 ◽  
Author(s):  
Yuetao Zhou ◽  
Venkanna Pasham ◽  
Soumya Chatterjee ◽  
Anand Rotte ◽  
Wenting Yang ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Primary Immune Response ◽  
Cytosolic Ph ◽  
Forward Scatter ◽  
Akt Phosphorylation ◽  
Tert Butylhydroperoxide ◽  
Ros Formation ◽  
Bacterial Lipopolysaccharides ◽  
And Migration ◽  
Stimulation Of

Background/Aims: Dendritic cells (DCs), antigen-presenting cells critically important for primary immune response and establishment of immunological memory, are activated by bacterial lipopolysaccharides (LPS) resulting in stimulation of Na+/H+ exchanger, ROS formation and migration. The effects are dependent on phosphoinositide 3 (PI3) kinase and paralleled by Akt phosphorylation. The present study explored the contribution of the Akt isoform Akt1. Methods: Cytosolic pH (pHi) (2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein [BCECF] fluorescence), Na+/H+ exchanger activity (Na+ dependent realkalinization after an ammonium pulse), cell volume (forward scatter in FACS analysis), and ROS production (2′,7′-dichlorodihydrofluorescein diacetate [DCFDA] fluorescence) were determined in DCs isolated from bone marrow of mice lacking functional Akt1/PKBα (akt1-/-) and their wild type littermates (akt1+/+). Results: Forward scatter was lower in akt1-/- than in akt1+/+ DCs, whereas pHi, Na+/H+ exchanger activity and ROS formation were less in untreated akt1-/- and akt1+/+ DCs. Exposure of DCs to LPS was followed by increase of forward scatter and ROS formation to a similar extent in akt1-/- and in akt1+/+ DCs. A 4 hours treatment with either LPS (1µg/ml) or tert-butylhydroperoxide (tBOOH, 5 µM) significantly stimulated Na+/H+ exchanger activity in both genotypes, effects, however, significantly blunted in akt1-/- DCs. Conclusion: The present observations demonstrate that Akt1 is required for the full stimulation of Na+/H+ exchanger activity by LPS or oxidative stress in dendritic cells.

scholarly journals Stimulation of Erythrocyte Cell Membrane Scrambling by Adarotene

2017 ◽  
Vol 41 (2) ◽  
pp. 519-529 ◽  
Author(s):  
Morena Mischitelli ◽  
Mohamed Jemaàa ◽  
MyriamFezai Fezai ◽  
Mustafa Almasry ◽  
Florian Lang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Membrane ◽  
Annexin V ◽  
Forward Scatter ◽  
Erythrocyte Surface ◽  
Suicidal Death ◽  
Phosphatidylserine Translocation ◽  
Surface Signaling ◽  
Ros Formation ◽  
Stimulation Of

Background/Aims: The atypical retinoid E23-(40-hydroxyl-30-adamantylbiphenyl-4-yl) acrylic acid (ST1926, adarotene) is used in the treatment of malignancy. The effect of ST1926 is at least in part due to stimulation of apoptosis. Similar to apoptosis of nucleated cells, erythrocytes may enter eryptosis, the suicidal death of erythrocytes. Hallmarks of eryptosis include cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Signaling involved in the stimulation of eryptosis includes increase of cytosolic Ca2+ activity [Ca2+]<Sub>i</Sub>, oxidative stress and ceramide. The present study explored, whether adarotene induces eryptosis and, if so, to test for the involvement of Ca2+ entry, oxidative stress and ceramide. Methods: Flow cytometry was employed to estimate phosphatidylserine exposure at the cell surface from annexin-V-binding, cell volume from forward scatter, [Ca2+]<Sub>i</Sub> from Fluo3-fluorescence, reactive oxygen species (ROS) formation from DCFDA dependent fluorescence, and ceramide abundance utilizing specific antibodies. Results: A 48 hours exposure of human erythrocytes to adarotene (9 µM) significantly increased the percentage of annexin-V-binding cells, an effect paralleled by significant decrease of forward scatter, as well as significant increase of Fluo3-fluorescence, DCFDA fluorescence, and ceramide abundance. The effect of adarotene (9 µM) on annexin-V-binding was significantly blunted but not abolished by removal of extracellular Ca2+. Conclusions: Adarotene stimulates phospholipid scrambling of the erythrocyte cell membrane, an effect paralleled by and at least in part due to Ca2+ entry, oxidative stress and ceramide.

Involvement of aquaporin‐7 in the cutaneous primary immune response through modulation of antigen uptake and migration in dendritic cells

2011 ◽  
Vol 26 (1) ◽  
pp. 211-218 ◽  
Author(s):  
Mariko Hara‐Chikuma ◽  
Yoshinori Sugiyama ◽  
Kenji Kabashima ◽  
Eisei Sohara ◽  
Shinichi Uchida ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Primary Immune Response ◽  
Antigen Uptake ◽  
Aquaporin 7 ◽  
And Migration

scholarly journals Stimulation of Suicidal Erythrocyte Death by Garcinol

2015 ◽  
Vol 37 (2) ◽  
pp. 805-815 ◽  
Author(s):  
Antonella Fazio ◽  
Marilena Briglia ◽  
Caterina Faggio ◽  
Kousi Alzoubi ◽  
Florian Lang
Keyword(s):  
Gene Expression ◽  
Cell Membrane ◽  
Annexin V ◽  
Cell Shrinkage ◽  
Forward Scatter ◽  
Energy Depletion ◽  
Garcinia Indica ◽  
Atp Levels ◽  
Ros Formation ◽  
Stimulation Of

Background/Aims: The benzophenone garcinol from dried fruit rind of Garcinia indica counteracts malignancy, an effect at least in part due to stimulation of apoptosis. The proapototic effect of garcinol is attributed in part to inhibition of histone acetyltransferases and thus modification of gene expression. Moreover, garcinol triggers mitochondrial depolarisation. Erythrocytes lack gene expression and mitochondria but are nevertheless able to enter apoptosis-like suicidal death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include oxidative stress, energy depletion and Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i). The present study explored, whether and how garcinol induces eryptosis. Methods: To this end, phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, hemolysis from hemoglobin release, [Ca2+]i from Fluo3-fluorescence, ROS formation from DCFDA dependent fluorescence and cytosolic ATP levels utilizing a luciferin-luciferase-based assay. Results: A 24 hours exposure of human erythrocytes to garcinol (2.5 or 5 µM) significantly increased the percentage of annexin-V-binding cells. Garcinol decreased (at 1 µM and 2.5 µM) or increased (at 5 µM) forward scatter. Garcinol (5 µM) further increased Fluo3-fluorescence, increased DCFDA fluorescence, and decreased cytosolic ATP levels. The effect of garcinol on annexin-V-binding was significantly blunted, but not abolished by removal of extracellular Ca2+. Conclusions: Garcinol triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part due to stimulation of ROS formation, energy depletion and Ca2+ entry.

OSR1-sensitive regulation of Na+/H+ exchanger activity in dendritic cells

2012 ◽  
Vol 303 (4) ◽  
pp. C416-C426 ◽  
Author(s):  
Venkanna Pasham ◽  
Anand Rotte ◽  
Wenting Yang ◽  
Christine Zelenak ◽  
Madhuri Bhandaru ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dendritic Cells ◽  
Cell Volume ◽  
Cell Volume Regulation ◽  
Cell Swelling ◽  
Ros Production ◽  
Ros Formation ◽  
The Difference ◽  
And Migration ◽  
The Impact

The oxidative stress-responsive kinase 1 (OSR1) is activated by WNK (with no K kinases) and in turn stimulates the thiazide-sensitive Na-Cl cotransporter (NCC) and the furosemide-sensitive Na-K-2Cl cotransporter (NKCC), thus contributing to transport and cell volume regulation. Little is known about extrarenal functions of OSR1. The present study analyzed the impact of decreased OSR1 activity on the function of dendritic cells (DCs), antigen-presenting cells linking innate and adaptive immunity. DCs were cultured from bone marrow of heterozygous WNK-resistant OSR1 knockin mice ( osr KI) and wild-type mice ( osr WT). Cell volume was estimated from forward scatter in FACS analysis, ROS production from 2′,7′-dichlorodihydrofluorescein-diacetate fluorescence, cytosolic pH (pHi) from 2′,7′- bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein fluorescence, and Na+/H+ exchanger activity from Na+-dependent realkalinization following ammonium pulse and migration utilizing transwell chambers. DCs expressed WNK1, WNK3, NCC, NKCC1, and OSR1. Phosphorylated NKCC1 was reduced in osr KI DCs. Cell volume and pHi were similar in osr KI and osr WT DCs, but Na+/H+ exchanger activity and ROS production were higher in osr KI than in osr WT DCs. Before LPS treatment, migration was similar in osr KI and osr WT DCs. LPS (1 μg/ml), however, increased migration of osr WT DCs but not of osr KI DCs. Na+/H+ exchanger 1 inhibitor cariporide (10 μM) decreased cell volume, intracellular reactive oxygen species (ROS) formation, Na+/H+ exchanger activity, and pHi to a greater extent in osr KI than in osr WT DCs. LPS increased cell volume, Na+/H+ exchanger activity, and ROS formation in osr WT DCs but not in osr KI DCs and blunted the difference between osr KI and osr WT DCs. Na+/H+ exchanger activity in osr WT DCs was increased by the NKCC1 inhibitor furosemide (100 nM) to values similar to those in osr KI DCs. Oxidative stress (10 μM tert-butyl-hydroperoxide) increased Na+/H+ exchanger activity in osr WT DCs but not in osr KI DCs and reversed the difference between genotypes. Cariporide virtually abrogated Na+/H+ exchanger activity in both genotypes and blunted LPS-induced cell swelling and ROS formation in osr WT mice. In conclusion, partial OSR1 deficiency influences Na+/H+ exchanger activity, ROS formation, and migration of dendritic cells.

The paracaspase MALT1 in psoriasis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Stephan Hailfinger ◽  
Klaus Schulze-Osthoff
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Transcription Factors ◽  
Skin Disease ◽  
Cell Types ◽  
Cytokine Receptors ◽  
Molecular Scaffold ◽  
Therapeutic Implications ◽  
Stimulation Of

Abstract Psoriasis is a frequent autoimmune-related skin disease, which involves various cell types such as T cells, keratinocytes and dendritic cells. Genetic variations, such as mutations of CARD14, can promote the development of the disease. CARD14 mutations as well as the stimulation of immune and cytokine receptors activate the paracaspase MALT1, a potent activator of the transcription factors NF-κB and AP-1. The disease-promoting role of MALT1 for psoriasis is mediated by both its protease activity as well as its molecular scaffold function. Here, we review the importance of MALT1-mediated signaling and its therapeutic implications in psoriasis.

Stimulation of autologous proliferative and cytotoxic T-cell responses by “leukemic dendritic cells” derived from blast cells in acute myeloid leukemia

Blood ◽  
2001 ◽  
Vol 97 (9) ◽  
pp. 2764-2771 ◽  
Author(s):  
Beth D. Harrison ◽  
Julie A. Adams ◽  
Mark Briggs ◽  
Michelle L. Brereton ◽  
John A. Liu Yin
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
Dendritic Cells ◽  
T Cell ◽  
Myeloid Leukemia ◽  
T Cell Responses ◽  
Cell Responses ◽  
Antigen Presenting ◽  
Acute Myeloid ◽  
Stimulation Of

Abstract Effective presentation of tumor antigens is fundamental to strategies aimed at enrolling the immune system in eradication of residual disease after conventional treatments. Myeloid malignancies provide a unique opportunity to derive dendritic cells (DCs), functioning antigen-presenting cells, from the malignant cells themselves. These may then co-express leukemic antigens together with appropriate secondary signals and be used to generate a specific, antileukemic immune response. In this study, blasts from 40 patients with acute myeloid leukemia (AML) were cultured with combinations of granulocyte-macrophage colony-stimulating factor, interleukin 4, and tumor necrosis factor α, and development to DCs was assessed. After culture, cells from 24 samples exhibited morphological and immunophenotypic features of DCs, including expression of major histocompatibility complex class II, CD1a, CD83, and CD86, and were potent stimulators in an allogeneic mixed lymphocyte reaction (MLR). Stimulation of autologous T-cell responses was assessed by the proliferative response of autologous T cells to the leukemic DCs and by demonstration of the induction of specific, autologous, antileukemic cytotoxicity. Of 17 samples, 11 were effective stimulators in the autologous MLR, and low, but consistent, autologous, antileukemic cytotoxicity was induced in 8 of 11 cases (mean, 27%; range, 17%-37%). This study indicates that cells with enhanced antigen-presenting ability can be generated from AML blasts, that these cells can effectively prime autologous cytotoxic T cells in vitro, and that they may be used as potential vaccines in the immunotherapy of AML.

scholarly journals Survival and Migration of Human Dendritic Cells Are Regulated by an IFN-α-Inducible Axl/Gas6 Pathway

2009 ◽  
Vol 183 (5) ◽  
pp. 3004-3013 ◽  
Author(s):  
Sara Scutera ◽  
Tiziana Fraone ◽  
Tiziana Musso ◽  
Paola Cappello ◽  
Silvia Rossi ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
And Migration ◽  
Human Dendritic Cells

Kappa-opioid peptide receptor stimulation increases cytosolic pH and myofilament responsiveness to Ca2+ in cardiac myocytes

1991 ◽  
Vol 261 (5) ◽  
pp. H1671-H1674 ◽  
Author(s):  
C. Ventura ◽  
M. C. Capogrossi ◽  
H. A. Spurgeon ◽  
E. G. Lakatta
Keyword(s):  
Cardiac Myocytes ◽  
Opioid Receptor ◽  
Kappa Opioid Receptor ◽  
Kappa Opioid ◽  
Methane Sulfonate ◽  
Receptor Stimulation ◽  
Cytosolic Ph ◽  
Prolonged Incubation ◽  
Ventricular Cells ◽  
Stimulation Of

Although kappa- and delta-opioid receptors on mammalian cardiac myocytes have been discovered recently, the intracellular effects that result from stimulation of these receptors remain unknown. We examine the effects of a rapid and brief exposure to a kappa-opioid receptor agonist on intracellular Ca2+, pH, and cell length in individual isolated rat ventricular cells. The specific kappa-agonist trans-dl-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]- benzene-acetamide (U-50488H) (methane sulfonate salt) caused a transient increase in cytosolic pH (pHi) measured from the change in SNARF-1 fluorescence and an increase in cytosolic [Ca2+] (Cai), indexed by a change in indo-1 fluorescence. The initial Cai increase often was followed by Cai oscillations. Both pHi and Cai effects were blocked by the specific antagonist kappa-opioid receptor l-(N-furylmethyl)-alpha-normetazocine methane-sulfonate (Mr 1452). The amplitude of contraction that accompanied the Cai increase elicited by U-50488H was greater than that associated with a similar increase in Cai elicited by electrical stimulation or by the rapid exposure of cells to caffeine. Thus an acute and brief kappa-opioid receptor stimulation of cardiac cells leads to an increase in Cai and pHi. The pHi increase was abolished by 1) blockade of the Na(+)-H+ exchanger by ethyl isopropyl amiloride and 2) inhibition of protein kinase C (PKC) activity via pretreatment with staurosporine or prolonged incubation with 4 beta-phorbol 12-myristate 13-acetate. These maneuvers did not abolish the U-50488H-induced increase in Ca.(ABSTRACT TRUNCATED AT 250 WORDS)

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