Adenosine Receptors Regulate Gap Junction Coupling Of The Human Cerebral Microvascular Endothelial Cells Hcmec/D3 By Ca2+ Influx Through Cyclic Nucleotide-Gated Channels
JOURNAL OF PHYSIOLOGY-LONDON(2017)
摘要
The human cerebral microvascular endothelial cell line hCMEC/D3 was used to characterize the physiological link between adenosine receptors and the gap junction coupling in endothelial cells of the blood-brain barrier. Expressed adenosine receptor subtypes and connexin (Cx) isoforms were identified by RT-PCR. Scrape loading/dye transfer was used to evaluate the impact of the A(2A) and A(2B) adenosine receptor subtype agonist 2-phenylaminoadenosine (2-PAA) on the gap junction coupling. We found that 2-PAA stimulated cAMP synthesis and enhanced gap junction coupling in a concentration-dependent manner. This enhancement was accompanied by an increase in gap junction plaques formed by Cx43. Inhibition of protein kinase A did not affect the 2-PAA-related enhancement of gap junction coupling. In contrast, the cyclic nucleotide-gated (CNG) channel inhibitor l-cis-diltiazem, as well as the chelation of intracellular Ca2+ with BAPTA, or the absence of external Ca2+, suppressed the 2-PAA-related enhancement of gap junction coupling. Moreover, we observed a 2-PAA-dependent activation of CNG channels by a combination of electrophysiology and pharmacology. In conclusion, the stimulation of adenosine receptors in hCMEC/D3 cells induces a Ca2+ influx by opening CNG channels in a cAMP-dependent manner. Ca2+ in turn induces the formation of new gap junction plaques and a consecutive sustained enhancement of gap junction coupling. The report identifies CNG channels as a physiological link that integrates gap junction coupling into the adenosine receptor-dependent signalling of endothelial cells of the blood-brain barrier.
更多查看译文
关键词
CNG channel,Ca2+ influx,adenosine receptor,blood-brain barrier,cyclic adenosine monophosphate (cAMP),endothelial cell,gap junction
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络