Relationship between Nrf2 and ferroptosis during lung ischemia-reperfusion in rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the relationship between nuclear factor E2-related factor 2 (Nrf2) and ferroptosis during lung ischemia-reperfusion (I/R) in rats.Methods:Fifty-four healthy male Sprague-Dawley rats, weighing 220-250 g, were divided into 3 groups ( n=18 each) using a random number table method: sham operation group (Sham group), lung I/R group (IR group), and lung I/R+ Nrf2 agonist sulforaphane group (IR+ SFP group). Lung I/R model was developed by clamping the left pulmonary hilum for 60 min followed by 120 min of reperfusion.In IR+ SFP group, SFP 500 μg/kg was intraperitoneally injected at 3 days before lung ischemia once a day for 3 consecutive days, and the model was developed at 2 h after the end of administration.The rats were sacrificed at the end of reperfusion, and the bronchoalveolar lavage fluid (BALF) was collected to determine the protein concentration (using bicinchoninic acid method), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations (by enzyme-linked immunosorbent assay). The animals were then sacrificed, and lung tissue specimens were harvested for microscopic examination of the pathological changes (with a transmission electron microscope) and for determination of wet/dry weight (W/D) ratio, contents of iron, malondialdehyde (MDA) and glutathione (GSH) (by chemical colorimetric) and expression of nuclear Nrf2, glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long-chain family member 4 (ACSL4) (by Western blot). Results:Compared with Sham group, the concentrations of protein, IL-6 and TNF-α in BALF, W/D ratio, and contents of Fe 2+ and MDA were significantly increased, GSH content was decreased, GPX4 expression was down-regulated, the expression of nuclear Nrf2and ACSL4 was up-regulated ( P<0.05), and the mitochondrial morphology of type Ⅱalveolar epithelial cells showed the characteristic changes of ferroptosis, including the presence of smaller mitochondria and reduced cristae in IR group.Compared with IR group, the concentrations of protein, IL-6 and TNF-α in BALF, W/D ratio, and contents of Fe 2+ and MDA were significantly decreased, GSH content was increased, the expression of nuclear Nrf2 and GPX4 expression was up-regulated, ACSL4 expression was down-regulated ( P<0.05), and the pathological changes of lung tissues were significantly attenuated in IR+ SFP group. Conclusions:Nrf2 can inhibit ferroptosis during lung I/R and is involved in the endogenous protective mechanism in rats.