Knockdown of SHP2 attenuated LPS-induced ferroptosis via downregulating ACSL4 expression in acute lung injury

Acute lung injury (ALI) is a complex disease with a high mortality. Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2) is a protein tyrosine phosphatase that participates in pathogenesis of multiple diseases. Nevertheless, the role of SHP2 in ALI remains unknown.

The in vivo and in vitro lipopolysaccharide (LPS)-induced ALI models were successfully established. The histopathological changes were evaluated by hematoxylin and eosin staining. The vascular permeability of lungs was assessed by Evans blue assay. The expression of ACSL4 and SHP2 was detected by western blot and qRT-PCR assay. The lactate dehydrogenase (LDH) activity, malondialdehyde (MDA), iron, and glutathione (GSH) levels were measured by commercial kits.

The SHP2 was upregulated in LPS-induced ALI mice and LPS-stimulated MLE-12 cells. In loss-of function experiment, the knockdown of SHP2 attenuated LPS-induced lung injury, microvessels damage, pulmonary edema, and increase of lung vascular permeability in vivo. Mechanically, shSHP2-rescued LPS induced increase in LDH activity, MDA, and iron levels, and decrease in GSH levels, as well as the accumulation of reactive oxygen species in vivo and in vitro, leading to an alleviation of LPS-induced ferroptosis. Notably, shSHP2 reduced the expression of Acyl-CoA synthetase long-chain 4 (ACSL4). In the rescued experiments, overexpression of ACSL4 abolished the shSHP2-induced reduction of LDH activity, MDA, and iron levels, and increase in GSH levels, thereby aggravating the LPS-induced ferroptosis.

These findings concluded that the knockdown of SHP2 attenuated LPS-induced ferroptosis via downregulation of ACSL4 expression in ALI, providing a novel sight for ALI treatment.