Mast cells express connexins on their cytoplasmic membrane

Background: Because of the close association between mast cells and fibrobl asts in the microenvironment and the importance of connexins (Cxs) in fibro blast communication with other cells, we hypothesized that mast cells also express Cxs, allowing them to similarly communicate with other cells throug h 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 analysi s, Western blot analysis, flow cytometry, and confocal laser scanning micro scopy. Results: In this report we demonstrate that murine bone marrow cultured mas t cells and the growth factor-independent murine mast cell line C57, expres s 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 co nfocal laser scanning microscopy, that Cx43 localizes to the cytoplasmic me mbrane 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.