Apigenin alleviates lung ischemia-reperfusion injury in mice / 中华器官移植杂志

ABSTRACT

Objective:To explore the effects and mechanism of apigenin on lung ischemia-reperfusion (I/R) injury in mice.Methods:A total of 40 male C57/B6 mice were randomized into 4 groups of sham, I/R, low-dose apigenin and high-dose apigenin (n=10 each). Lung I/R injury model was established by clipping left hilum for 1h and reperfusion for 2 h. Low/high-dose apigenin group received a gavage of apigenin (10/50 mg·kg -1·d -1) for 7 days before lung I/R.After 2-hour reperfusion, lung tissue was collected and lung injury status evaluated and scored by hematoxylin-eosin (H&E) stain; mRNA expression levels of interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), high mobility group box 1 (HMGB1), prostaglandin-endoperoxide synthase 2 (PTGS2) and glutathione peroxidase 4 (GPX4) were detected by reverse transcription-polymerase chain reaction (RT-PCR); Western blot was utilized for detecting the protein expressions of Bax, Bcl-2 and HIF-1α.Finally, after morinostat activated Hif-1α, the effect of apigenin (50 μmol/L) on hypoxia-reoxygenation (H/R)-induced ferroptosis was further observed in A549 lung epithelial cells. Results:As compared with sham group, lung injury score spiked markedly in I/R group (7.05±0.6 vs.1.25±0.42), pulmonary edema worsened obviously (8.65±1.12 vs.4.17±0.54), the percentage of Tunel positive cells rose significantly (58.22±4.92 vs.8.23±1.22) and mRNA expression levels of IL-1β, TNF-α and HMGB1 increased (7.82±0.16 vs.1.00±0.14, 4.24±0.12 vs.1.00±0.19, 6.24±0.19 vs.1.00±0.11) ( P<0.05); Compared with I/R group, lung injury score declined markedly in low/high-dose apigenin group (4.88±0.31/2.11±0.29 vs.7.05±0.66)( P<0.05), pulmonary edema lessened markedly (6.42±1.03/4.88±1.62 vs.8.65±1.12)( P<0.05) and the percentage of Tunel positive cells (41.46±6.73/16.02±5.31 vs.58.22±4.92) and the mRNA expression levels of IL-1β, TNF-α and HMGB1 became obviously suppressed (5.88±0.13/3.21±0.19 vs.7.82±0.16, 3.56±0.11/2.12±0.09 vs.4.24±0.12, 4.12±0.14/3.12±0.09 vs.6.24±0.19)( P<0.05); protein expressions of HIF-1α and PTGS2 dropped sharply in low/high-dose apigenin group (2.00±0.10/0.93±0.11 vs.2.99±0.06, 4.12±0.14/2.51±0.18 vs.6.11±0.12) while GPX4 protein rose obviously (0.55±0.02/0.83±0.02 vs.0.38±0.04)( P<0.05). In vitro experiments further showed that apigenin could significantly suppress the H/R-induced protein expression of PTGS2 in A549 lung epithelial cells (1.11±0.0 vs.4.55±0.12)( P<0.05) while up-regulating the protein expression of GPX4 (0.93±0.11 vs.0.32±0.04)( P<0.05). The inhibition of PTGS2 protein (4.01±0.12 vs.1.11±0.05) and the up-regulation of GPX4 were significantly blocked (0.52±0.05 vs.0.93±0.11)( P<0.05). Conclusions:Through an inhibition of HIF-1α/ferroptosis axis, apigenin can alleviate lung injury, apoptosis and inflammatory response associated with lung I/R in mice.