scholarly journals Adenosine receptor expression in rheumatoid synovium: a basis for methotrexate action

2012 ◽  
Vol 14 (3) ◽  
pp. R138 ◽  
Author(s):  
Lisa K Stamp ◽  
Jody Hazlett ◽  
Rebecca L Roberts ◽  
Christopher Frampton ◽  
John Highton ◽  
...  
Keyword(s):  
Adenosine Receptor ◽  
Receptor Expression ◽  
Rheumatoid Synovium

Adenosine receptor expression and function in bladder uroepithelium

2006 ◽  
Vol 291 (2) ◽  
pp. C254-C265 ◽  
Author(s):  
Weiqun Yu ◽  
Lefteris C. Zacharia ◽  
Edwin K. Jackson ◽  
Gerard Apodaca
Keyword(s):  
Adenosine Receptor ◽  
Adenosine Receptors ◽  
Cell Layer ◽  
Basolateral Membrane ◽  
Membrane Capacitance ◽  
Receptor Expression ◽  
Membrane Turnover ◽  
Impermeable Barrier ◽  
Umbrella Cell ◽  
Umbrella Cells

The uroepithelium of the bladder forms an impermeable barrier that is maintained in part by regulated membrane turnover in the outermost umbrella cell layer. Other than bladder filling, few physiological regulators of this process are known. Western blot analysis established that all four adenosine receptors (A1, A2a, A2b, and A3) are expressed in the uroepithelium. A1 receptors were prominently localized to the apical membrane of the umbrella cell layer, whereas A2a, A2b, and A3 receptors were localized intracellularly or on the basolateral membrane of umbrella cells and the plasma membrane of the underlying cell layers. Adenosine was released from the uroepithelium, which was potentiated 10-fold by stretching the tissue. Administration of adenosine to the serosal or mucosal surface of the uroepithelium led to increases in membrane capacitance (where 1 μF ≈ 1 cm2 tissue area) of ∼30% or ∼24%, respectively, after 5 h. Although A1, A2a, and A3 selective agonists all stimulated membrane capacitance after being administrated serosally, only the A1 agonist caused large increases in capacitance after being administered mucosally. Adenosine receptor antagonists as well as adenosine deaminase had no effect on stretch-induced capacitance increases, but adenosine potentiated the effects of stretch. Treatment with U-73122, 2-aminoethoxydiphenylborate, or xestospongin C or incubation in calcium-free Krebs solution inhibited adenosine-induced increases in capacitance. These data indicate that the uroepithelium is a site of adenosine biosynthesis, that adenosine receptors are expressed in the uroepithelium, and that one function of these receptors may be to modulate exocytosis in umbrella cells.

scholarly journals Lipopolysaccharide rapidly modifies adenosine receptor transcripts in murine and human macrophages: role of NF-κB in A2A adenosine receptor induction

2005 ◽  
Vol 391 (3) ◽  
pp. 575-580 ◽  
Author(s):  
Lauren J. Murphree ◽  
Gail W. Sullivan ◽  
Melissa A. Marshall ◽  
Joel Linden
Keyword(s):  
Adenosine Receptor ◽  
Acid Methyl Ester ◽  
Fold Increase ◽  
Nuclear Factor Κb ◽  
Receptor Expression ◽  
A2a Adenosine Receptor ◽  
Monocytic Cell ◽  
Human Macrophages ◽  
Primary Mouse ◽  
Receptor Number

The A2A adenosine receptor (A2AAR) mediates anti-inflammatory actions of adenosine in a variety of cell types. LPS (lipopolysaccharide) was reported to induce a small (<2-fold) increase in the expression of A2AAR mRNA in human monocytes and monocytic cell lines. We investigated the effects of LPS on the expression of adenosine receptor mRNAs in primary mouse IPMΦ (intraperitoneal macrophages), human macrophages and Wehi-3 cells. Treatment with 10 ng/ml LPS for 4 h produced a >100-fold increase in A2AAR mRNA. LPS-induced increases in mRNA for A2AAR and TNFα (tumour necrosis factor α) are reduced by 90% in IPMΦ pretreated with the NF-κB (nuclear factor κB) inhibitor, BAY 11-7082 {(E)3-[(4-methylphenyl)sulphonyl]-2-propenenitrile; 10 μM}. In Wehi-3 cells exposed to LPS, A2AAR and A2BAR transcripts are elevated by 290- and 10-fold respectively, the A1AR transcript is unchanged and the A3AR transcript is decreased by 67%. The induction of A2AAR mRNA by LPS is detectable after 1 h, reaches a peak at 6 h at 600 times control and remains elevated beyond 24 h. The ED50 (effective dose) of LPS is 2.3 ng/ml. A2AAR receptor number, measured by 125I-ZM241385 binding to whole cells, is undetectable in naïve cells and increases linearly at a rate of 23 receptors·cell−1·min−1 to a Bmax of 348 fmol/mg (28000 receptors/cell) in 20 h. The increase in receptor number is correlated with an increase in the potency of an A2A agonist (4-{3-[6-amino-9-(5-ethylcarbamoyl-3,4-dihydroxy-tetrahydro-furan-2-yl)-9H-purin-2-yl]-prop-2-ynyl}-cyclohexanecarboxylic acid methyl ester; referred to as ATL146e) to stimulate cAMP in these cells. After LPS pretreatment, the potency of the A2A agonist, ATL146e, to reduce TNFα release from IPMΦ was increased by 200-fold. The results support the hypothesis that regulation of adenosine receptor expression, especially up-regulation of the A2AAR, is part of a delayed feedback mechanism initiated through NF-κB to terminate the activation of human and mouse macrophages.

Allergen inhalation decreases adenosine receptor expression in sputum and blood of asthma patients

Allergy ◽  
2008 ◽  
Vol 63 (9) ◽  
pp. 1186-1194 ◽  
Author(s):  
M. Versluis ◽  
M. van den Berge ◽  
W. Timens ◽  
B. Luijk ◽  
B. Rutgers ◽  
...  
Keyword(s):  
Adenosine Receptor ◽  
Receptor Expression ◽  
Asthma Patients ◽  
Allergen Inhalation

Noise induces A1 adenosine receptor expression in the chinchilla cochlea

2004 ◽  
Vol 188 (1-2) ◽  
pp. 47-56 ◽  
Author(s):  
Vickram Ramkumar ◽  
Craig A. Whitworth ◽  
Sandeep C. Pingle ◽  
Larry F. Hughes ◽  
Leonard P. Rybak
Keyword(s):  
Adenosine Receptor ◽  
Receptor Expression ◽  
A1 Adenosine Receptor

Relationship between A2A Adenosine Receptor Expression and Intradialytic Hypotension during Hemodialysis

2006 ◽  
Vol 54 (8) ◽  
pp. 473-477 ◽  
Author(s):  
Philippe Giaime ◽  
Louis Carrega ◽  
Emmanuel Fenouillet ◽  
Laurence Mercier ◽  
Victoria Gerolami ◽  
...  
Keyword(s):  
Adenosine Receptor ◽  
Receptor Expression ◽  
Intradialytic Hypotension ◽  
A2a Adenosine Receptor

Adenosine Receptor Expression and Modulation of Ca2+Channels in Rat Striatal Cholinergic Interneurons

2000 ◽  
Vol 83 (1) ◽  
pp. 322-332 ◽  
Author(s):  
Wen-Jie Song ◽  
Tatiana Tkatch ◽  
D. James Surmeier
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
G Protein ◽  
Adenosine Receptor ◽  
Acetylcholine Release ◽  
Cell Voltage ◽  
Receptor Expression ◽  
Cholinergic Interneurons ◽  
Receptor Mrna ◽  
Kinase C

Adenosine is a potent regulator of acetylcholine release in the striatum, yet the mechanisms mediating this regulation are largely undefined. To begin to fill this gap, adenosine receptor expression and coupling to voltage-dependent Ca2+ channels were studied in cholinergic interneurons by combined whole cell voltage-clamp recording and single-cell reverse transcription–polymerase chain reaction. Cholinergic interneurons were identified by the presence of choline acetyltransferase mRNA. Nearly all of these interneurons (90%, n = 28) expressed detectable levels of A1 adenosine receptor mRNA. A2a and A2b receptor mRNAs were less frequently detected. A3 receptor mRNA was undetectable. Adenosine rapidly and reversibly reduced N-type Ca2+ currents in cholinergic interneurons. The A1 receptor antagonist 8-cyclopentyl-1,3-dimethylxanthine completely blocked the effect of adenosine. The IC50 of the A1 receptor selective agonist 2-chloro-N6-cyclopentyladenosine was 45 nM, whereas it was near 30 μM for the A2a receptor agonist CGS-21680. Dialysis with GDPβS or brief exposure to the G protein (Gi/o) alkylating agent N-ethylmaleimide also blocked the adenosine modulation. The reduction in N-type currents was partially reversed by depolarizing prepulses. A membrane-delimited pathway mediated the modulation, because it was not seen in cell-attached patches when agonist was applied to the bath. Activation of protein kinase C attenuated the adenosine modulation. Taken together, our results argue that activation of A1 adenosine receptors in cholinergic interneurons reduces N-type Ca2+currents via a membrane-delimited, Gi/o class G-protein pathway that is regulated by protein kinase C. These observations establish a cellular mechanism by which adenosine may serve to reduce acetylcholine release.

Adenosine Signaling Regulates Adult Erythropoiesis.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2171-2171
Author(s):  
Wulin Aerbajinai ◽  
Bhanu V. Natarajan ◽  
Nicole Gantt ◽  
Patricia Oneal ◽  
Sung-Ho Goh ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Adenosine Receptor ◽  
Terminal Differentiation ◽  
S Phase ◽  
Receptor Expression ◽  
Receptor Signaling ◽  
Morphological Examination ◽  
Erythroid Progenitor ◽  
Cell Counts ◽  
Adenosine Signaling

Abstract Adenosine signal transduction in human cells is achieved through four distinct G-protein-coupled receptors named A1, A2A, A2B and A3. Adenosine signaling events affect several physiological processes including growth regulation and cellular responses to hypoxia. Despite extensive studies of native and pharmacologically-targeted adenosine signal transduction, the potential for adenosine to regulate erythropoiesis remains largely unexplored. Here we systematically studied adenosine receptor expression, activation, and inhibition among CD34+ human erythroid progenitor cells cultured in the presence of erythropoietin. This 14 day culture system has been studied extensively in the context of erythroblast commitment and terminal differentiation (BLOOD 99(8):3005–13). Using real-time RT-PCR, we demonstrated that the A2A, A2B and A3 adenosine receptors are expressed in highly regulated patterns. The expression of A2A and A2B were highest early in the culture period and later declined as the cells underwent terminal differentiation. Receptor A3 gene expression gradually increased during the terminal differentiation. Expression of the A1 receptor gene was not detected above background levels at any stage of differentiation (compared with the positive control). Based upon those receptor expression patterns, several adenosine receptor signaling agonists and antagonists were screened for possible effects on erythroblast growth and differentiation. Among those screened molecules, the selective A3 adenosine receptor agonist, CI-IB-MECA, had effects on the proliferation and differentiation of the cells without overt toxicity in the dose range of 10–100uM. CI-IB-MECA significantly inhibited the proliferation of the cells with resulting cell counts being only 10% of those in matched controls after 14 days. Cell cycle analyses demonstrated that the growth inhibitory effects of CI-IB-MECA were largely due to a significant reduction in the percentage of S-phase proerythroblasts (S-phase: 16 ± 5% in CI-IB-MECA versus 51 ± 2% in matched controls; p<0.01). The level of apoptosis increased in CI-IB-MECA, but did not reach statistical significance (sub-G1 population: 8.3 ± 3% in CI-IB-MECA versus 1.5 ± 0.2% in matched controls; p= 0.08). Despite the profound inhibition of cell cycling, CI-IB-MECA did not prevent erythroblast commitment as evidenced by the expression of CD71 and Glycophorin A on the cell surface during the second culture week. However, CI-IB-MECA delayed the expression of those surface markers by 2–4 days when compared with the matched controls. The delayed maturation of the cells was also detected by morphological examination. On day 14, less than 10% of the cells were hemoglobinized erythroblasts in CI-IB-MECA compared with a predominance of those cells (>80%) in the matched controls. Consistent with the morphological examination, HPLC analyses revealed barely detectable levels of hemoglobin in the presence of CI-IB-MECA after 14 days. These finding suggest that selective activation of adenosine A3 receptors permits erythroid commitment, but profoundly inhibits the proliferation of those committed cells and retards their terminal differentiation. As a novel regulator of erythropoiesis, adenosine A3 receptor signaling should be explored in patients with growth-related erythroid diseases.

Oxidative Stress Increases A1 Adenosine Receptor Expression by Activating Nuclear Factor κB

1998 ◽  
Vol 53 (4) ◽  
pp. 663-669 ◽  
Author(s):  
Zhongzhen Nie ◽  
Yun Mei ◽  
Mary Ford ◽  
Leonard Rybak ◽  
Adrianna Marcuzzi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Adenosine Receptor ◽  
Nuclear Factor Κb ◽  
Receptor Expression ◽  
Nuclear Factor ◽  
A1 Adenosine Receptor

scholarly journals Prognostic impact of CD73 and A2A adenosine receptor expression in non-small-cell lung cancer

Oncotarget ◽  
2017 ◽  
Vol 8 (5) ◽  
pp. 8738-8751 ◽  
Author(s):  
Yusuke Inoue ◽  
Katsuhiro Yoshimura ◽  
Nobuya Kurabe ◽  
Tomoaki Kahyo ◽  
Akikazu Kawase ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
Adenosine Receptor ◽  
Small Cell ◽  
Receptor Expression ◽  
Prognostic Impact ◽  
Small Cell Lung ◽  
A2a Adenosine Receptor
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