| Objective:To investigate the mechanism of liraglutide (Lira) intervention on oxidative stress, mitochondrial function and autophagy damage in human neuroblastoma (SH-SY5Y) cells.Methods:SH-SY5Y cells were divided into control group (normal culture), high glucose (HG) group [50 mM glucose (Glu) medium], HG+LI-L group (100 nM Lira+50 mM Glu medium), HG+LI-H group (500 nM Lira+50 mM Glu medium), HG+LI-H+3-methyladenine (3MA) group (500 nM Lira+5 mM 3-MA+50 mM Glu medium). The cell proliferation ability was detected by cell counting kit (CCK)-8 method. The levels of Glu, malondialdehyde (MDA), adenosine triphosphate (ATP) and superoxide dismutase (SOD) were detected by enzyme-linked immunosorbent assay. Cell apoptosis, reactive oxygen species (ROS) level and mitochondrial membrane potential were detected by flow cytometry. The expression and localization of microtubule-associated protein 1 light chain 3 (LC3B) and p62 were detected by immunofluorescence. The expression of phosphatidylinositol 3-kinase (PI3K), p-PI3K, mammalian rapamycin target protein (mTOR) p-mTOR , protein kinase B (Akt) and p-Akt protein were detected by Western blot. Results:Compared with HG group, the cell proliferation activity in HG+LI (500 nM) group was the most significant (P<0.05). Compared with control group, Glu, MDA, apoptosis rate, ROS fluorescence intensity, Glu, MDA, JC-1, P-mTOR and p62 protein expression in HG group increased, while SOD, ATP, cell survival rate, p-PI3K、p-Akt and LC3B protein expression decreased (P<0.05). Compared with HG group, Glu and MDA decreased and SOD increased in HG+LI (500 nM) group (P<0.05). Compared with HG group, the cell viability, ATP and SOD were increased, and the apoptosis rate, ROS fluorescence intensity, Glu, MDA and JC-1 were decreased in HG+LI-L group and HG+LI-H group, and the cell viability, ATP and SOD in HG+LI-H group were higher than those in HG+LI-L group, and the apoptosis rate, ROS fluorescence intensity, Glu, MDA and JC-1 were lower than those in HG+LI-L group (P<0.05). Compared with HG group, p-mTOR and p62 proteins expression were decreased, p-PI3K, p-Akt and LC3B proteins expression were increased in the HG+LI-H group (P<0.05). Compared with HG+LI-H group, the cell viability, ATP, SOD, p-PI3K、p-Akt and LC3B protein expression were decreased, and the apoptosis rate, ROS fluorescence intensity, Glu, MDA JC-1, p-mTOR and p62 protein expression were increased in HG+LI-H+3MA group (P<0.05).Conclusion:Lira may reduce oxidative stress in SH-SY5Y cells in a dose-dependent manner, increase cell membrane potential, improve mitochondrial function and PI3K/AKT/mTOR autophagy pathway, resist apoptosis and protect nerve cells, while 3MA weakens the protective effect of Lira on neuronal cells. |
