Involvement of CRF2 signaling in enterocyte differentiation

Figure 3 Corticotropin releasing factor receptor 2 signaling alters intercellular junction organization and increases para-cellular permeability in early-differentiated HT-29 cells. A: Early-differentiated HT-29 cells were pre-incubated with or without A2b (1 μmol/L) overnight before addition or not of Ucn3 (100 nmol/L). Intercellular junction integrity was evaluated by measuring transepithelial electrical resistance (TEER). Values are means of 5 different experiments ± SEM. ^a,dP < 0.05 vs the three other groups, ^bP < 0.01 vs the three other groups and ^cP < 0.001 vs the three other groups; B: Early differentiated HT-29 cells were treated or not with 100 nmol/L Ucn3 before immunostaining for E-cadherin (left panels) and p120ctn (right panels). Bar is 5 μm. Images were acquired by confocal microscopy on a LEICA TCS/SPE (objective × 100). Ucn3 treatment induces a time-dependent alteration of AJ protein localization; C: AJ proteins are associated with Flotillin-1 enriched LR during HT-29 cell differentiation. Lysates from undifferentiated or early-differentiated HT-29 cells (10 d, D10) exposed or not to 100 nmol/L Ucn3 were fractionated using a sucrose gradient. The presence of LR was assessed by western blot against Flotillin-1. Western blot analysis of Flotillin-1, E-cadherin and p120ctn protein levels in LR under previously described conditions.