Implication of P2Y₁₂ receptor in uc.48+-mediated abnormal sympathoexcitatory reflex via superior cervical ganglia in myocardial ischemic rats

Purinergic 2Y₁₂ (P2Y₁₂₎ receptor antagonists are used as platelet aggregation inhibitors. Long non-coding RNAs (lncRNAs) play an important role in neuropathological events. Satellite glial cells (SGCs) in the superior cervical ganglia (SCGs) encircle the somata of neurons. This study explored if the upregulated P2Y₁₂ receptor in SCGs was relevant to lncRNA uc.48+ during myocardial ischemia (MI). The results showed that upregulation of P2Y₁₂ receptor was accompanied by increased expression of uc.48+ in the SCGs of MI rats which displayed abnormal changes in cervical sympathetic nerve activity, blood pressure, heart rate, electrocardiograms and cardiac tissue structure. The P2Y₁₂ antagonist clopidogrel improved abnormal alterations in cardiac function and tissue structure in MI rats. Short hairpin RNA (shRNA) against uc.48+ significantly inhibited P2Y₁₂ receptor upregulation and its co-expression with glial fibrillary acidic protein (GFAP) in SCGs, and ameliorated the cardiac dysfunction in MI rats. By contrast, overexpression of uc.48+ increased the expression of P2Y₁₂ in SCGs and enhanced cervical sympathetic nerve activity in control rats. Direct interaction between uc.48+ and the P2Y₁₂ receptor was predicted using the bioinformatic tool CatRAPID and confirmed by RNA immunoprecipitation. Moreover, overexpression of the P2Y₁₂ receptor reversed the protective effect of uc.48+ shRNA on cardiac dysfunction in MI rats. Uc.48 shRNA treatment also inhibited the enhanced rise of intracellular free Ca²⁺ level ([Ca²⁺]_i) evoked by the P2Y₁₂ agonist 2-methylthio-adenosine-5′-diphosphate (2-MeSADP) in SGCs of SCGs after oxygen-glucose deprivation (OGD) treatment. These data demonstrated that uc.48+ shRNA could counteract the P2Y₁₂ upregulation and improve P2Y₁₂-implicated cardiac dysfunction due to MI.