Visfatin Plays a Significant Role in Alleviating Lipopolysaccharide-Induced Apoptosis and Autophagy Through PI3K/AKT Signaling Pathway During Acute Lung Injury in Mice.

ABSTRACT

Visfatin is involved in the body's inflammation and immune response. Inflammation could promote, while visfatin may directly or indirectly mitigate the effects of apoptosis and autophagy. Whether visfatin lessens the detrimental effects of lipopolysaccharide (LPS)-induced mouse acute lung injury (ALI) is poorly understood yet. Therefore, in the current study, the regulation mechanism of visfatin on apoptosis and autophagy was explored in Kunming mice by replicating LPS-induced inflammatory ALI model. Based on the mouse model of ALI, HE staining, TUNEL, transmission electron microscopy, immunohistochemical staining, real-time fluorescence quantitative PCR and western blot were used and the results showed that the alveolar septum was thinner than that of the LPS group, slight lung interstitial and alveolar exudation appeared, and a small number of inflammatory cell infiltration was found in the visfatin intervention group, indicating reduced tissue damage in lungs. After visfatin treatment, the expression of pro-apoptotic genes Bax, Bik, and p53 decreased and the expression of anti-apoptotic genes Bcl-2 and Bcl-xl increased, and expression of autophagy factors LC3 and Beclin1 decreased, indicating that visfatin inhibits apoptosis and reduces autophagy. The expression of PI3K and p-AKT was upregulated in the visfatin intervention group, the expression of AKT was downregulated, and the PI3K/AKT signaling pathway was activated. Hence, visfatin could activate the PI3K/AKT signaling pathway, reduce the apoptotic rate in alveolar epithelial cells and the level of autophagy in ALI by regulating the expression of autophagy factors, ultimately causing a protective effect on lung tissue.