Expression of dual nucleotides/cysteinyl-leukotrienes receptor GPR17 in early trafficking of cardiac stromal cells after myocardial infarction.
Bottom Line: Before induction of ischaemia, results indicated the presence of the receptor in a population of stromal cells expressing the stem-cell antigen-1 (Sca-1).These experiments showed a migratory function of the receptor by treatment with UDP-glucose and leukotriene LTD4, two GPR17 pharmacological agonists.These findings suggest a regulation of heart-resident mesenchymal cells and blood-borne cellular species recruitment following myocardial infarction, orchestrated by GPR17.
Affiliation: Laboratorio di Biologia e Biochimica dell'Aterotrombosi, Centro Cardiologico Monzino, IRCCS, Milan, Italy.Show MeSH
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Mentions: The presence of Adenosine receptor A2B has been recently reported in Sca-1+/CD31− cardiac cells, implying purinergic signalling in the regulation of these cells . We therefore hypothesized that GPR17 may be expressed, before and after ischaemia, in stromal cells with mesenchymal characteristics . To this aim, an IF analysis was performed to assess the expression of Sca-1 marker in GPR17+ cells. The results showed that before MI induction the vast majority of GPR17+ cells expressed Sca-1 (Fig. 2A). Because of their paucity, cells expressing Sca-1 in the non-ischaemic ventricular tissue could not be quantified. At 24 and 48 hrs after ischaemia, there was a dramatic increase in the number of cells expressing both markers (Fig. 2B, Fig. S2) and the appearance of GPR17+ cells, which did not express Sca-1. Irrespectively of Sca-1 expression, GPR17+ cells appeared located in groups apparently migrating just beneath the living myocardial cells. Membrane expression of GPR17 was confirmed by Z-stack reconstruction of confocal images (Fig. S3).
Affiliation: Laboratorio di Biologia e Biochimica dell'Aterotrombosi, Centro Cardiologico Monzino, IRCCS, Milan, Italy.