Mast cells express connexins on their cytoplasmic membrane.

Background: Because of the close association between mast cells and fibroblasts in the microenvironment and the importance of connexins (Cxs) in fibroblast communication with other cells, we hypothesized that mast cells also express Cxs, allowing them to similarly communicate with other cells through gap junctions.

Objectives: We sought to identify the expression of Cxs (particularly Cx43, Cx32, and Cx26) by murine mast cells.

Methods: The expression of Cxs was studied by RT-PCR, Northern blot analysis, Western blot analysis, flow cytometry, and confocal laser scanning microscopy.

Results: In this report we demonstrate that murine bone marrow cultured mast cells and the growth factor-independent murine mast cell line C57, express Cx43 and Cx32 as assessed by RT-PCR, Northern blot analysis, Western blot analysis, and flow cytometry, but do not express Cx26. We also show, by confocal laser scanning microscopy, that Cx43 localizes to the cytoplasmic membrane of mast cells in a pattern similar to that seen in fibroblasts.

Conclusions: Mast cells express Cx43 and Cx32, and Cx43 is associated with the cytoplasmic membrane, suggesting that mast cells have the potential to communicate with other cells in their microenvironment in part through gap junctions.