Prostaglandin E receptor subtype 4 (EP4) is widely distributed in the heart, but its role in hepatic
ischemia/reperfusion (I/R), particularly in
mitochondrial permeability transition pore (MPTP) modulation, is yet to be elucidated. In the present study, an EP4 agonist (
CAY10598) was used in a rat model to evaluate the effects of EP4 activation on liver I/R and the mechanisms underlying this. I/R insult upregulated hepatic EP4 expression during early reperfusion. In addition, subcutaneous
CAY10598 injection prior to the onset of reperfusion significantly increased hepatocyte cAMP concentrations and decreased serum ALT and AST levels and necrotic and apoptotic cell percentages, after 6 h of reperfusion. Moreover,
CAY10598 protected mitochondrial morphology, markedly inhibited
mitochondrial permeability transition pore (MPTP) opening and decreased liver
reactive oxygen species levels. This occurred via activation of the ERK1/2‑GSK3β pathway rather than the
janus kinase (JAK)2‑signal transducers and activators of transcription (STAT)3 pathway, and resulted in prevention of mitochondria‑associated cell injury. The
MPTP opener
carboxyatractyloside (CATR) and the ERK1/2 inhibitor
PD98059 also partially reversed the protective effects of
CAY10598 on the liver and mitochondria. The current findings indicate that EP4 activation induces ERK1/2‑GSK3β signaling and subsequent
MPTP inhibition to provide hepatoprotection, and these observations are informative for developing new molecular targets and preventative
therapies for I/R in a clinical setting.