Figure 4.

Inhibition of GJ suppresses TXNIP. (A) Effects of GJ inhibitors on TXNIP. NRK cells were incubated with 7.5 μM α-GA for the indicated time intervals. Cellular lysates were subjected to Western blot analysis for TXNIP and Cx43. (B and C) Effects of structural analogue of α-GA and different GJ inhibitors on TXNIP expression. NRK cells were incubated with 7.5 μM α-GA, 7.5 μM ß-GA, 10 μM CA, 15 μM GZA (B), 50 μM FFA, 100 μM lindane (Lin) and 2 mM heptanol (Hep) (C) for 6 hrs. Cellular lysates were subjected to Western blot analysis for TXNIP. (D and E) Downregulation of Cx43 with siRNA on TXNIP expression. NRK cells were transfected with either Cx43 siRNA or control siRNA for 48 hrs. Cellular lysates were subjected to Western blot analysis for TXNIP and Cx43. Equal loading of protein per lane was verified by probing the blots with an anti-β-tubulin antibody. Results are representatives of 3 separate experiments. Densitometric analyses of TXNIP in D was done by using ImageJ software and are expressed as percentage of the control (mean ± SE, n = 3; *P < 0.05 compared with the siRNA control). (F) Effect of TXNIP siRNA on G418-induced cell injury. NRK cells were transfected with either TXNIP siRNA or control siRNA for 48 hrs. The cellular viability was evaluated through CCK-8 assay. Data are expressed as percentage of living cells, compared with the siRNA control (mean ± SD, n = 4; *P < 0.05 versus siRNA control).