E-cadherin overexpression in kidney PTC abolishes β-catenin redistribution, decreases proliferation and protects against Cd2+-induced epithelial barrier disruption and cytotoxicity. (A)β-catenin immunoblots of WKPT-0293 Cl.2 cells transiently transfected with full length E-cadherin expression plasmid (E-cadherin) or empty vector (vector) and incubated for 6 h ± 25 μM Cd2+. β-catenin signals were normalized to loading markers and the ratio of β-catenin in Cd2+ and respective control samples was determined. Means ± SEM (n = 7) are shown. Student's unpaired t-test compares Cd2+ treated cells to respective controls. (B) Vector or E-cadherin PTC were reseeded in SCM in ECIS 8WE10 arrays. C40 kHz reflects cell attachment, spreading and proliferation (see Methods). Initial values of the cell-free electrode were set to 100% (vector, 63.5 ± 1.9 nF; E-cadherin, 65.2 ± 3.3 nF; means ± SEM of 3 experiments). Data show means ± SEM of 3 experiments. (C) At confluence PTC were exposed to SFM ± 20 μM Cd2+. Values of the confluent cell-covered electrode were set to 100% (vector, 3670 ± 83 ohm; E-cadherin, 2994 ± 300 ohm; means ± SEM of 3 different experiments). A drop in R400 Hz indicates disruption of epithelial barrier and cell detachment. (D) Vector or E-cadherin cells were exposed to 25 μM Cd2+ for 6 h and cell viability was determined by MTT assay. Graph depicts means ± SEM of 9-10 experiments. Student's unpaired t-test compares Cd2+ treated cells to respective controls as well as Cd2+-exposed vector to Cd2+-exposed E-cadherin cells.