INHIBITION OF FERROPTOSIS BY LIPROXSTATIN‐1 COMPOUND PROTECTS THE MYOCARDIUM AGAINST ISCHEMIA/REPERFUSION INJURY BY DECREASING VDAC1 LEVELS AND INCREASING IN GPX4 ACTIVITY

Abstract

Ferroptosis is a non‐apoptotic form of cell death characterized by iron‐dependent accumulation of lethal lipid reactive oxygen species (ROS) and liproxstatin‐1 is a potent inhibitor of ferroptosis. We investigated whether Liproxstatin‐1 can protect heart against ischemia/reperfusion (I/R) injury and determine the mechanism underlying cardioprotection. Isolated C57BL/6J mice hearts were subjected to 35 min ischemia followed 120 min reperfusion and treated with Liproxstatin‐1 (200nM). Myocardial infarct size was assessed at the end of the reperfusion, mitochondrial integrity was measured by analyzing cristae morphology and ROS production was assessed using amplex red method. The calcium retention capacity (CRC) required to induce mitochondrial permeability transition pore (mPTP) opening was measured using calcium green dye. The levels of mitochondrial proteins cyclophilin D (CypD), Glutathione peroxidase 4 (GPX4), VDAC1, 2 and 3 were assessed by Western blot; and GPX4 activity was measured using a kit. We found that liproxstatin‐1 treatment decreased myocardial infarction size, ROS production, and VDAC1 expression as well as preserved mitochondrial structural integrity by protecting cristae from damage. These mitochondrial effects of liproxstatin‐1 were associated with the increase in the GPX4 levels and activity. But, liproxstatin‐1 did not affect the CypD, VDAC2, and VDAC3 expression as well as mitochondrial CRC. Together, these result indicate that liproxstatin‐1 treatment protects myocardium against I/R injury by increasing GPX4 activity resulting in the decrease in mitochondrial ROS production; preserving mitochondrial structure as well as decrease in VDAC1 (but not VDAC 2 and 3) expression. Liproxstain‐1 cardioprotective action does not involve the regulation of the mPTP opening. These results point to the cardioprotective role of anti‐ferroptosis compound after I/R.Support or Funding Information[NIH RO1 grant HL138093 (JCB)]