Figure 5
Effect of Cana on the expression of SIRT1 and its downstream signaling components. Confluent growth-arrested LLC-PK1 cell monolayers were stimulated with HG medium on the basolateral side for up to 24 h with or without pretreatment with Cana in the apical side. Immunofluorescence analysis (A) and immunoblotting (B) for SGLT2 expression in LLC-PK1 cells. The relative quantification of the SGLT2 immunofluorescence was measured and is indicated in the bar graphs. Scale bar, 50 µm. *P < 0.05 vs. NG group, n = 4 independent experiments. (C) The effect of SGLT2 inhibitors on cellular glucose entry in LLC-PK1 cells. LLC-PK1 cells were incubated in Dulbecco’s modified minimal essential medium containing 100 μM 2-NBDG for 15 min from the apical side of the cell. Cellular glucose entry was assessed as 2-NBDG entry into the cell, as described in the Methods section. Scale bar = 20 µm. *P < 0.05 vs. NG group and §P < 0.05 vs. HG without Cana, n = 4 independent experiments. NG, normal glucose (5.5 mM); HG, high glucose (22.5 mM); HG + Cana, HG with Cana treatment. (D) Immunoblotting analysis of SIRT1 expression in LLC-PK1 cell monolayers stimulated with HG medium on the basolateral side for up to 24 h with or without pretreatment with low or high doses of Cana. Quantification of immunoblotting images was normalized to α-tubulin. *P < 0.05 vs. NG group and §P < 0.05 vs. HG without Cana, n = 4 independent experiments.
