Inhibition of metabotropic glutamate receptor-5 alleviates hepatic steatosis by enhancing autophagy via activation of the AMPK signaling pathway

Figure 1 Inhibition of metabotropic glutamate receptor type 5 attenuates hepatocyte steatosis in vitro. A: Protein expression of metabotropic glutamate receptor type 5 (mGluR5) in HepG2 cells treated with different concentrations of free fatty acids (FFAs) for 24 hours; B: Protein expression of mGluR5 in HepG2 cells treated with 0.5 mmol/L FFAs for different Durations; C: CCK-8 assays revealed the effects of MPEP (2.5, 5, 10, 20, and 50 μM) on HepG2 cell viability; D: CCK-8 assays revealed the effects of CHPG (50, 100, 200, 500, and 1000 μM) on HepG2 cell viability; E and F: HepG2 cells were stimulated with 0.5 mmol/L FFAs for 24 hours and then treated with MPEP (10 μM) or CHPG (500 μM) for another 24 hours. The cells were stained with Oil Red O, and the intracellular triglyceride concentration was quantitatively determined. ^aP < 0.05 vs free fatty acids, ^bP < 0.01 vs free fatty acids, ^cP < 0.001 vs free fatty acids; ^dP < 0.001 vs bovine serum albumin. The data are presented as the mean ± SE. All cell experiments were repeated three times. mGluR5: Metabotropic glutamate receptor type 5; FFAs: Free fatty acids; BSA: Bovine serum albumin.