Lipopolisakkarid enterositlerdeki ara baǧlanti proteini konneksin-43′ü etkileyerek hücreler arasi iletişimi bozmaktadir

Aim: Communication between enterocytes is likely to be essential for the maintenance of gut barrier integrity. In many cells such as neurons, intercellular communication occurs through the gap junction (GJ) protein connexin-43 (Cx43), and phosphorylation ofCx43 (pCx43) disrupts GJ function. However, the in vivo effects of LPS on GJ expression and phosphorylation in enterocytes are undefined. We hypothesized that LPS modulates connexin-43 expression and phosphorylation in enterocytes in-vitro. Methods: Inter-enterocyte communication was measured by microinjecting intestinal epithelial cells (IEC-6) with lucifer-yellow (LY) and a larger molecule "rhodamine-dextrane (Rd-D). The specificity of GJ function was assessed by pretreatment of cells with "oleamide", a specific inhibitor of GJ function. Images were obtained by laser confocal microscopy. The expression and distribution of Cx-43 and its phosphorylation (pCx-43) were assessed in IEC-6 cells following treatment with LPS (50 μg/ml 24h) by Western blot and confocal microscopy. Results: Enterocyte injections allowed passage of LY but not Rd-dextran to adjoining cells, suggesting GJ function. Oleamide treatment inhibited the passage of LY to the adjacent cells. LPS significantly increased enterocyte pCx-43 (density rel to actin ctrl: 0.3±0.1 vs LPS 0.9±0.2, p<0.05) but not total Cx-43. LPS significantly increased accumulation of pCX-43 between cells. Conclusion: LPS impairs the function of GJ by increasing the phosphorilation of Cx-43. This may provide insights into maintanence of barrier function by interenterocyte function.