Activation of adenosine A2a receptor accelerates and A2a receptor antagonist reduces intermittent hypoxia induced PC12 cell injury via PKC-KATP pathway

Abstract

Obstructive sleep apnea hypopnea syndrome (OSAHS) is associated with multiple system diseases. Neurocognitive dysfunction resulting from central nervous system complications has been reported, especially in children with OSAHS. Chronic intermittent hypoxia is accepted to be the major pathophysiological mechanism of OSAHS. Adenosine plays an important role in cellular function via interactions with its receptors. A2a receptor has been recognized as a factor involved in neuroprotection. However, the role of adenosine A2a receptor in intermittent hypoxia induced cellular injury is not completely understood. In this study, we aim to investigate the underlying mechanisms of A2a receptor mediated cellular damage caused by intermittent hypoxia in PC12 cells. We found that activated A2a receptor by CGS21680 decreased cellular viability, increased PKC as well as ATP-sensitive potassium channel (KATP) subunits expression Kir6.2 and SUR1. Inhibition of A2a receptor by SCH58261 increased cellular viability, suppressed PKC and SUR1 expression level, ultimately showing a protective role in PC12 cells. Moreover, we observed that CHE, which is an antagonist of PKC, downregulated Kir6.2 and SUR1 expression and increased cellular viability. Additionally, we found that A2a receptor activation induced cell injury was associated with increased Cleaved-Caspase 3 expression, which can be decreased by inhibition of A2a receptor or PKC. In conclusion, our findings indicate that A2a receptor induced KATP expression by PKC activation and plays a role in accelerating PC12 cells injury induced by intermittent hypoxia exposure via A2a-PKC-KATP signal pathway mediated apoptosis.