Mechanism of anti-atherosclerosis of astragaloside IV based on regulation of macrophage autophagy by PI3K/Akt/mTOR signaling pathway / 中草药

ABSTRACT

Objective To study the mechanism of anti-atherosclerosis of astragaloside IV by observing the regulation of PI3K/Akt/mTOR signaling pathway. Methods In the in vitro experiments, macrophages were randomly divided into control group, astragaloside IV group, Kangshide group, rapamycin group and siRNA group. The changes of autophagy of macrophages were observed by transmission electron microscopy (TEM) after 48 h of mouse RAW264.7 macrophages in vitro treated by astragaloside IV-containing serum, Akt inhibitor Kangshide, mTOR inhibitor rapamycin and mTOR-siRNA. The expression of Akt, mTOR and autophagy-associated protein Beclin 1 was detected by real-time quantitative RT-PCR and Western blotting. The expression of Beclin 1 was detected by immunofluorescence and Western blotting. IL-4, IL-10, IL-2, and IFN-γ in RAW264.7 cells were detected by ELISA. In the in vivo experiments, the pathological changes of aorta were detected by HE staining. The expression of Akt, mTOR mRNA and protein in aorta of mice was detected by qRT-PCR and Western blotting, respectively. Results In vitro experimental results showed that compared with control group, the autophagus of astragaloside IV-containing serum group and each inhibitor group was significantly increased under the TEM (P < 0.05). The expression levels of LC3-II and Beclin1 were significantly up-regulated (P < 0.05). The expression of Akt and mTOR mRNA and protein was significantly decreased (P < 0.05). The secretion of IL-10 was significantly decreased and the secretion of IFN-γ was significantly increased (P < 0.05). HE staining results showed that, compared with the model group, the blood vessels of astragalus membranaceus group were normal, arranged neatly, with small focal calcification of the granules. The lesions were mild, the patches were small, the foam cells and the lipids were reduced, the elastic plates were basically complete, The degree of lesion was significantly lighter and lighter than that of the inhibitor groups. The expression of Akt, mTOR mRNA and protein were significantly lower in the aorta of astragaloside IV group (P < 0.05). Conclusion Astragaloside IV inhibition of atherosclerotic plaque formation mechanism and regulation of PI3K/Akt/mTOR signaling pathway, inhibition of inflammatory response.