Abstract
Endogenous adenosine A2B receptors (A2BAR) mediate cAMP accumulation in HEK 293 cells. Here we have used a biosensor to investigate the mechanism of action of the A2BAR antagonist PSB 603 in HEK 293 cells. The A2A agonist CGS 21680 elicited a small response in these cells (circa 20% of that obtained with NECA), suggesting that they also contain a small population of A2A receptors. The responses to NECA and adenosine were antagonised by PSB 603, but not by the selective A2AAR antagonist SCH 58261. In contrast, CGS 21680 responses were not antagonised by high concentrations of PSB 603, but were sensitive to inhibition by SCH 58261. Analysis of the effect of increasing concentrations of PSB 603 on the response to NECA indicated a non-competitive mode of action yielding a marked reduction in the NECA EMAX with no significant effect on EC50 values. Kinetics analysis of the effect of PSB 603 on the A2BAR-mediated NECA responses confirmed a saturable effect that was consistent with an allosteric mode of antagonism. The possibility that PSB 603 acts as a negative allosteric modulator of A2BAR suggests new approaches to the development of therapeutic agents to treat conditions where adenosine levels are high.
| Original language | English |
|---|---|
| Pages (from-to) | 55-66 |
| Number of pages | 12 |
| Journal | Biochemical Pharmacology |
| Volume | 147 |
| DOIs | |
| Publication status | Published - 1 Jan 2018 |
| Externally published | Yes |
Keywords
- A receptor
- Adenosine receptor
- Allosterism
- Cyclic AMP
- Kinetics
- PSB 603
Cite this
}
Characterisation of endogenous A2A and A2B receptor-mediated cyclic AMP responses in HEK 293 cells using the GloSensor™ biosensor : Evidence for an allosteric mechanism of action for the A2B-selective antagonist PSB 603. / Goulding, Joelle; May, Lauren T.; Hill, Stephen J.
In: Biochemical Pharmacology, Vol. 147, 01.01.2018, p. 55-66.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Characterisation of endogenous A2A and A2B receptor-mediated cyclic AMP responses in HEK 293 cells using the GloSensor™ biosensor
T2 - Evidence for an allosteric mechanism of action for the A2B-selective antagonist PSB 603
AU - Goulding, Joelle
AU - May, Lauren T.
AU - Hill, Stephen J.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Endogenous adenosine A2B receptors (A2BAR) mediate cAMP accumulation in HEK 293 cells. Here we have used a biosensor to investigate the mechanism of action of the A2BAR antagonist PSB 603 in HEK 293 cells. The A2A agonist CGS 21680 elicited a small response in these cells (circa 20% of that obtained with NECA), suggesting that they also contain a small population of A2A receptors. The responses to NECA and adenosine were antagonised by PSB 603, but not by the selective A2AAR antagonist SCH 58261. In contrast, CGS 21680 responses were not antagonised by high concentrations of PSB 603, but were sensitive to inhibition by SCH 58261. Analysis of the effect of increasing concentrations of PSB 603 on the response to NECA indicated a non-competitive mode of action yielding a marked reduction in the NECA EMAX with no significant effect on EC50 values. Kinetics analysis of the effect of PSB 603 on the A2BAR-mediated NECA responses confirmed a saturable effect that was consistent with an allosteric mode of antagonism. The possibility that PSB 603 acts as a negative allosteric modulator of A2BAR suggests new approaches to the development of therapeutic agents to treat conditions where adenosine levels are high.
AB - Endogenous adenosine A2B receptors (A2BAR) mediate cAMP accumulation in HEK 293 cells. Here we have used a biosensor to investigate the mechanism of action of the A2BAR antagonist PSB 603 in HEK 293 cells. The A2A agonist CGS 21680 elicited a small response in these cells (circa 20% of that obtained with NECA), suggesting that they also contain a small population of A2A receptors. The responses to NECA and adenosine were antagonised by PSB 603, but not by the selective A2AAR antagonist SCH 58261. In contrast, CGS 21680 responses were not antagonised by high concentrations of PSB 603, but were sensitive to inhibition by SCH 58261. Analysis of the effect of increasing concentrations of PSB 603 on the response to NECA indicated a non-competitive mode of action yielding a marked reduction in the NECA EMAX with no significant effect on EC50 values. Kinetics analysis of the effect of PSB 603 on the A2BAR-mediated NECA responses confirmed a saturable effect that was consistent with an allosteric mode of antagonism. The possibility that PSB 603 acts as a negative allosteric modulator of A2BAR suggests new approaches to the development of therapeutic agents to treat conditions where adenosine levels are high.
KW - A receptor
KW - Adenosine receptor
KW - Allosterism
KW - Cyclic AMP
KW - Kinetics
KW - PSB 603
UR - http://www.scopus.com/inward/record.url?scp=85035035008&partnerID=8YFLogxK
U2 - 10.1016/j.bcp.2017.10.013
DO - 10.1016/j.bcp.2017.10.013
M3 - Article
VL - 147
SP - 55
EP - 66
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
SN - 0006-2952
ER -