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

• Published in: Biomedicine & pharmacotherapy Vol. 92; pp. 544 - 553
• Main Authors: Li, Yin, Lu, Ling, Luo, Ning, Wang, Yong-Qiang, Gao, Hong-Mei
• Format: Journal Article
• Language: English
• Published: France 01.08.2017
• Subjects: Animals; Autophagy - drug effects; Autophagy - physiology; Female; Galactosamine - toxicity; Internal Medicine; Lipopolysaccharides - toxicity; Liver Failure, Acute - chemically induced; Liver Failure, Acute - drug therapy; Liver Failure, Acute - metabolism; Male; Medical Education; Molecular Chaperones - antagonists & inhibitors; Molecular Chaperones - metabolism; Phosphatidylinositol 3-Kinases - metabolism; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt - antagonists & inhibitors; Proto-Oncogene Proteins c-akt - metabolism; Rats; Rats, Sprague-Dawley; Signal Transduction - drug effects; Signal Transduction - physiology; TOR Serine-Threonine Kinases - antagonists & inhibitors; TOR Serine-Threonine Kinases - metabolism; Acute liver failure; Chaperone-mediated autophagy; d-Galactosamine/lipopolysaccharide; PI3K/AKt/mTOR signaling pathway
• ISSN: 0753-3322; 1950-6007
• DOI: 10.1016/j.biopha.2017.05.037

Abstract 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.