Inhibition of PI3K/AKt/mTOR signaling pathway protects against d-galactosamine/lipopolysaccharide-induced acute liver failure by chaperone-mediated autophagy in rats.

Objective: This study aims to investigate the effects of PI3K/AKt/mTOR signaling pathway on the proliferation and apoptosis in acute liver failure (ALF) by chaperone mediated autophagy (CMA).

Methods: The hepatocytes extracted from both normal rats and rats with ALF were assigned to control, acute injury, P13K agonist, and P13K inhibitor groups. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used as part of this investigation to detect the expression of PI3K/AKt/mTOR signaling pathway related-proteins (PI3K, AKt, mTOR), apoptosis related-proteins (Fas, Bax, Bcl-2), chaperone-mediated autophagy (CMA) marker proteins (LAMP-2A, HSC 70), p-PI3K, p-AKt, p-4E-BPI, and p-S6K. An MTT assay was used for analysis of cell proliferation after transfection. Flow cytometry is performed to detect the cell apoptosis.

Results: In comparison to the normal group, the model group showed enhanced positive rate of PI3K, AKt, mTOR, increased expression levels of PI3K, AKt, mTOR, Fas, Bax, p-PI3K, p-AKt, p-4E-BPI and p-S6K, reduced expression levels of Bcl-2, LAMP-2A and HSC 70. The results in vitro experiment: compared with the acute injury group, the PI3K agonist group showed elevated expression levels of PI3K, AKt, mTOR, Fas, Bax, p-PI3K, p-AKt, p-4E-BPI and p-S6K, decreased expression levels of Bcl-2, LAMP-2A and HSC 70, inhibited cell proliferation, more arrested cells in G1 stage, and promoted cell apoptosis. Opposing this, the P13K inhibitor group exhibited an opposite trend.

Conclusion: In conclusion, inhibition of the PI3K/AKt/mTOR signaling pathway plays a protective role in ALF by promoting CMA expression, which could arrest cell proliferation and promote cell apoptosis.