Fig. 5

The expression of human and mouse STRA6 in vitro and in vivo. a HepG2 cells were treated with 1 μM retinol in DMSO for 1 day, and the expression levels of the human STRA6 mRNA and protein were determined. The expression level of GAPDH was detected as an endogenous control. The experiments were performed in triplicate. The quantification of western blot data was performed using Image J and unpaired Student’s t-tests were performed in Prism8. *P < 0.05. b The distributions of STRA6 and αSMA in normal (n = 3) and TAA-induced fibrotic mouse liver tissues (n = 3). STRA6 is shown in green, and αSMA is shown in red. The nuclei were stained with DAPI (blue). Scale bar: 25 μm. c The distributions of STRA6 and αSMA in normal (n = 3) and cirrhotic human liver tissues (n = 4). STRA6 is shown in green, and αSMA is shown in red. The nuclei were stained with DAPI (blue). Four samples in the cirrhosis group were analyzed independently, and representative data are shown in each panel. Scale bar of lower magnification: 25 μm; scale bar of higher magnification: 5 μm. d The accumulation of triglyceride in HepG2 cells treated with or without 1 μM retinol in DMSO for 24 h following transfection with a siRNA targeting human STRA6. Retinol autofluorescence is shown in blue, and triglyceride was stained using BODIPY (red). Retinol or triglyceride-positive area % per 0.03 mm² were quantified five images using Image J program. Reproducible result from three independent experiments was shown. *P < 0.05, **P < 0.01, ***P < 0.001. Scale bar: 10 μm. e The expression levels of the mRNAs encoding human STRA6, FASN, and SREBP1 in HepG2 cells transfected with or without a siRNA targeting STRA6, and treated with or without retinol as described in a. The experiments were performed in triplicate. Unpaired Student’s t-tests were performed in Prism8. **P < 0.01, ***P < 0.001