Fig. 2.

Cx43 hemichannels contribute to Ca²⁺ depletion-elicited disruption of epithelia barrier. (A–C) Effect of Cx43 inhibitors on junctional protein expression and function. NRK-E52 cells were pre-treated with 3 mM heptanol and 100 μM lindane for 20 min before exposed to Ca²⁺-free medium for an additional 1 h (A) or 30 min (B, C). Cells were subjected to immunofluorescence for ZO-1 (A), Western blot analysis for pan-cadherin (B) and measurement for TER (C). Data shown in C are mean ± SE (n=3; # P<0.05 vs. control). (D, E) Downregulation of Cx43 with siRNA on junctional protein expression and function. Cells were transfected with control siRNA (siControl) or siRNA against Cx43 for 48 h before exposing to Ca²⁺-free medium for the indicated time (D) or 30 min (E). Cellular lysates were subjected to western blot analysis for cadherin or Cx43 (D). Epithelial barrier function was analyzed through measurement of TER (E). Data are mean ± SE (n=4; # P<0.05 vs. siControl). (F) Effect of suramin on Pan-cadherin expression. NRK-E52 cells were pre-treated with 200 μM suramin or 100 μM lindane for 20 min before exposed to Ca²⁺-free medium for an additional 30 min. Cellular lysates were subjected to Western blot analysis for pan-cadherin.