Figure 7.

SIRT3 regulates cubilin expression and albumin endocytosis. (a) qPCR analysis of SIRT3 siRNA on the expression of SIRT3 mRNA in HK-2 cells. (b) Western blot analysis of SIRT3 in HK-2 cells transfected with SIRT3 siRNA. (c) Quantification of protein expression of SIRT3 in b. (d) qPCR analysis of the effect of SIRT3 siRNA on cubilin mRNA expression in HK-2 cells. (e) Immunofluorescence staining of cubilin in HK-2 cells. (f) Western blot analysis of cubilin in HK-2 cells transfected with SIRT3 siRNA. (g) Quantification of protein expression of cubilin in f. (h, i) Effect on albumin endocytosis in HK-2 cells transfected with SIRT3 siRNA as revealed by confocal microscopy (i) and quantification (h). The scale bar represents 20 μm. Data are expressed as mean ± SD.

In a–c: ^*p < 0.05 compared with the blank control group; ^#p < 0.05 compared with the siRNA control group. In d–i: ^*p < 0.05 compared with 5 ng/ml insulin + siRNA NC group, ^#p < 0.05 compared with 5 ng/ml insulin + SIRT3 siRNA group; ^△p < 0.05 compared with 50 ng/ml insulin + siRNA control group. All data are representative of three independent experiments.

qPCR, quantitative polymerase chain reaction; Ins, Insulin; NC, normal control.