EIF2AK3 and hydrops fetalis: In summary, we have shown that PERK is vital for the cardioprotective effects of sildenafil in PO-induced HF, suppressing the maturation of PO-induced miRNAs, such as miR 23a-3p and 24-3p, and upregulating NRF2-mediated oxidative stress response and mitochondrial biogenesis.