Double expressions of connexin 43 and 32 in human periodontal ligament fibroblasts

Abstract The expressions of connexin 43 and 32 in cultured and intact human periodontal ligament fibroblasts (PDLFs) were examined using immunohistochemical methods, and western blot analysis was conducted with anti-connexin 43 and 32 in cultured PDLFs. The PDLFs both in cultured cells and tissue sections reacted with anti-connexin 43 and 32, and western blot analysis showed bands of approximately 43 kD and 27 kD reacted with anti-connexin 43 and 32 respectively, suggesting the existence of gap junctions in human PDLFs. In cultured PDLFs there were no reaction products of connexin 43 when the cells were not in contact with adjacent cells, but reaction products were increasingly observed with increases in cell–cell contacts. Different from connexin 43, the reaction products of connexin 32 were found in the cytoplasm, regardless of whether the cells were or were not in contact with adjacent cells. Further, the reaction activity of connexin 32 varied among PDLFs; some were strong, some moderate, and some weak. The expressions of connexin 43 and 32 in human PDLFs are suggested to be related to the regulation of two different functions of the PDLFs.