Role of Adenosine Receptor A2A in Traumatic Optic Neuropathies

2013 ◽  
Author(s):  
Gregory I. Liou ◽  
Saif Ahmad ◽  
Ahmed Elsherbini
Keyword(s):  
Adenosine Receptor ◽  
Adenosine Receptor A2a

scholarly journals Role of Adenosine Receptor A2A in Traumatic Optic Neuropathies

2012 ◽  
Author(s):  
Gregory I. Liou ◽  
Saif Ahmad ◽  
Mohammad Naime ◽  
Nadeem Fatteh ◽  
Sohail Khan
Keyword(s):  
Adenosine Receptor ◽  
Adenosine Receptor A2a

Acute adenosine preconditioning is mediated by p38 MAPK activation in discrete subcellular compartments

2005 ◽  
Vol 288 (3) ◽  
pp. H1359-H1366 ◽  
Author(s):  
Cherry Ballard-Croft ◽  
Gentian Kristo ◽  
Yukihiro Yoshimura ◽  
Easton Reid ◽  
Byron J. Keith ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Adenosine Receptor ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fraction ◽  
Control Group ◽  
Mapk Activation ◽  
Subcellular Compartments ◽  
Sb 203580

Although acute adenosine preconditioning (PC) is well established, the signaling pathways mediating this cardioprotection remain unclear. Because adenosine receptor agonists activate p38 MAPK and this kinase has been implicated in ischemic and pharmacological PC, the purpose of this study was to determine the role of p38 MAPK in acute adenosine receptor PC. The role of p38 MAPK activation in discrete subcellular compartments during ischemia-reperfusion was also determined. The following groups were used in an in vivo rat ischemia-reperfusion model: 1) control (10% DMSO iv), 2) the A1/A2a adenosine receptor AMP-579 (50 μg/kg iv), 3) AMP-579 + the A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 100 μg/kg iv), 4) AMP-579 + the p38 MAPK inhibitor SB-203580 (1 mg/kg iv), and 5) SB-203580 alone. p38 MAPK activation was measured by Western blot analysis in cytosolic, mitochondrial, membrane, and nuclear/myofilament fractions obtained from hearts at preischemic, ischemic, and reperfusion time points. A significant reduction in infarct size was observed with AMP-579 PC, an effect blocked by DPCPX or SB-203580 pretreatment. AMP-579 treatment was associated with a significant increase in p38 MAPK activation in the nuclear/myofilament fraction before ischemia, whereas no activation of this kinase occurred during ischemia or reperfusion. In contrast, p38 MAPK was activated in the mitochondrial fraction by ischemia and in the cytosolic, mitochondrial, and membrane fractions by reperfusion in the control group. SB-203580 blocked the AMP-579-induced increase in phosphorylation of the downstream p38 substrate activating transcription factor-2. These results suggest a role for p38 MAPK activation in discrete subcellular compartments in acute adenosine A1 receptor PC.

Sa1746 A1 and A2A Adenosine Receptor Subtype Selective Agonists Activate Splanchnic Colonic Afferents With a Clear Modulatory Role of Nav1.9

2013 ◽  
Vol 144 (5) ◽  
pp. S-297
Author(s):  
Vincent Cibert-Goton ◽  
James R. Hockley ◽  
Michael Tranter ◽  
George Boundouki ◽  
Mark D. Baker ◽  
...  
Keyword(s):  
Adenosine Receptor ◽  
Receptor Subtype ◽  
A2a Adenosine Receptor ◽  
Selective Agonists ◽  
Subtype Selective

Agonist-induced polarized trafficking and surface expression of the adenosine 2b receptor in intestinal epithelial cells: role of SNARE proteins

2004 ◽  
Vol 287 (5) ◽  
pp. G1100-G1107 ◽  
Author(s):  
Lixin Wang ◽  
Vasantha Kolachala ◽  
Baljit Walia ◽  
Srividya Balasubramanian ◽  
Randy A. Hall ◽  
...  
Keyword(s):  
Adenosine Receptor ◽  
Intestinal Inflammation ◽  
Apical Membrane ◽  
Snare Proteins ◽  
Cell Fractionation ◽  
Camp Synthesis ◽  
Agonist Stimulation ◽  
A2b Receptor ◽  
In Cells

Adenosine, acting through the A2b receptor, induces vectorial chloride and IL-6 secretion in intestinal epithelia and may play an important role in intestinal inflammation. We have previously shown that apical or basolateral adenosine receptor stimulation results in the recruitment of the A2b receptor to the plasma membrane. In this study, we examined domain specificity of recruitment and the role of soluble N-ethylmaleimide (NEM) attachment receptor (SNARE) proteins in the agonist-mediated recruitment of the A2b receptor to the membrane. The colonic epithelial cell line T84 was used because it only expresses the A2b-subtype adenosine receptor. Cell fractionation, biotinylation, and electron microscopic studies showed that the A2b receptor is intracellular at rest and that apical or basolateral adenosine stimulation resulted in the recruitment of the receptor to the apical membrane. Upon agonist stimulation, the A2b receptor is enriched in the vesicle fraction containing vesicle-associated membrane protein (VAMP)-2. Furthermore, in cells stimulated with apical or basolateral adenosine, we demonstrate a complex consisting of VAMP-2, soluble NEM-sensitive factor attachment protein (SNAP)-23, and A2b receptor that is coimmunoprecipitated in cells stimulated with adenosine within 5 min and is no longer detected within 15 min. Inhibition of trafficking with NEM or nocodazole inhibits cAMP synthesis induced by apical or basolateral adenosine by 98 and 90%, respectively. cAMP synthesis induced by foskolin was not affected, suggesting that generalized signaling is not affected under these conditions. Collectively, our data suggest that 1) the A2b receptor is intracellular at rest; 2) apical or basolateral agonist stimulation induces recruitment of the A2b receptor to the apical membrane; 3) the SNARE proteins, VAMP-2 and SNAP-23, participate in the recruitment of the A2b receptor; and 4) the SNARE-mediated recruitment of the A2b receptor may be required for its signaling.

scholarly journals Adenosine Receptor Heteromers and their Integrative Role in Striatal Function

2007 ◽  
Vol 7 ◽  
pp. 74-85 ◽  
Author(s):  
Sergi Ferré ◽  
Francisco Ciruela ◽  
César Quiroz ◽  
Rafael Luján ◽  
Patrizia Popoli ◽  
...  
Keyword(s):  
Adenosine Receptor ◽  
Neurotransmitter Receptors ◽  
Neurotransmitter Receptor ◽  
Binding Characteristics ◽  
New Concepts ◽  
Receptor Heteromers ◽  
The Central Nervous System ◽  
The Individual ◽  
Striatal Function

By analyzing the functional role of adenosine receptor heteromers, we review a series of new concepts that should modify our classical views of neurotransmission in the central nervous system (CNS). Neurotransmitter receptors cannot be considered as single functional units anymore. Heteromerization of neurotransmitter receptors confers functional entities that possess different biochemical characteristics with respect to the individual components of the heteromer. Some of these characteristics can be used as a “biochemical fingerprint” to identify neurotransmitter receptor heteromers in the CNS. This is exemplified by changes in binding characteristics that are dependent on coactivation of the receptor units of different adenosine receptor heteromers. Neurotransmitter receptor heteromers can act as “processors” of computations that modulate cell signaling, sometimes critically involved in the control of pre- and postsynaptic neurotransmission. For instance, the adenosine A1-A2Areceptor heteromer acts as a concentration-dependent switch that controls striatal glutamatergic neurotransmission. Neurotransmitter receptor heteromers play a particularly important integrative role in the “local module” (the minimal portion of one or more neurons and/or one or more glial cells that operates as an independent integrative unit), where they act as processors mediating computations that convey information from diverse volume-transmitted signals. For instance, the adenosine A2A-dopamine D2receptor heteromers work as integrators of two different neurotransmitters in the striatal spine module.

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