Ciliary Neurotrophic Factor (CNTF) Protects Myocardial Cells from Oxygen Glucose Deprivation (OGD)/Re-Oxygenation via Activation of Akt-Nrf2 Signaling.

BACKGROUND/AIMS: Oxygen glucose deprivation (OGD)/re-oxygenation (OGDR) exposure to myocardial cells mimics ischemia-reperfusion injuries. We studied the potential activity of ciliary neurotrophic factor (CNTF) on OGDR-treated myocardial cells.

METHODS

CNTF and CNTFR expression were tested by RT-PCR assay and Western blotting assay. Cell viability and death were tested by MTT assay and LDH release assay, respectively. Akt-Nrf2 signalings were tested by Western blotting assay and qPCR assay.

RESULTS

CNTF and its receptor CNTFR were functionally expressed in established H9c2 myocardial cells and primary murine myocardiocytes. Pretreatment of CNTF significantly attenuated OGDR-induced viability reduction and death in myocardial cells. Further studies show that in the myocardial cells CNTF activated NF-E2-related factor 2 (Nrf2) signaling to inhibit OGDR-induced reactive oxygen species (ROS) production and programmed necrosis, preventing adenine nucleotide translocator 1 (ANT-1)-p53-cyclophilin D (Cyp-D) mitochondrial association and mitochondrial depolarization. Nrf2 silencing or knockout almost abolished CNTF-induced H9c2 cytoprotection against OGDR. CNTF activated Akt in H9c2 cells and primary murine myocardiocytes. Conversely, Akt blockage by the pharmacological inhibitors not only blocked CNTF-induced Nrf2 Ser-40 phosphorylation and activation, but also nullified anti-OGDR actions by CNTF in myocardial cells.

CONCLUSION

CNTF activates Akt-Nrf2 signaling to protect myocardial cells from OGDR.