Fig. 6.

Effect of E-cadherin silencing on basal levels of paracellular permeability. A: representative immunoblots for E-cadherin, β-catenin, and zonula occludens-1 (ZO-1) proteins. Cells were transfected with specific small interfering RNA (siRNA) targeting the coding region of E-cadherin mRNA (siE-cad) or control siRNA (C-siRNA) for 48 h, and levels of E-cadherin, β-catenin, and ZO-1 proteins were measured by Western blot analysis. B: paracellular permeability in cells described in A. After cells were transfected with siE-cad or C-siRNA, they were plated at confluent density on the insert and maintained for an additional 48 h. Levels of paracellular permeability were measured 2 h after addition of [¹⁴C]mannitol or [³H]inulin. Values are means ± SE of data from 6 samples. *P < 0.05 compared with controls and cells transfected with C-siRNA. C: changes in levels of paracellular permeability after challenge with H₂O₂ in E-cadherin knockdown cells described in A. Cells were transfected with siE-cad or C-siRNA for 48 h, and levels of paracellular permeability were measured 2 h after addition of [¹⁴C]mannitol or [³H]inulin. Values are means ± SE of data from 6 samples. *P < 0.05 compared with cells transfected with C-siRNA.