Abstract：
Connexins (Cxs) are transmembrane proteins involved in the formation of hemichannels and gap junctions (GJs). GJs are involved in various physiological functions, including secretion in glandular tissue. It has been demonstrated that Cx26, Cx32, and Cx43 are mainly expressed in glands, but no data are available in human salivary glands to date. The aim of our study was to investigate the presence and the localization of Cxs in human minor labial salivary glands. Immunofluorescence and immunoelectron microscopy were employed to evaluate the Cx26, Cx32, and Cx43 protein in human labial salivary gland biopsies (hLSGBs). RT-PCR was also used to detect their mRNA expression. Cx expression was found at both the mRNA and protein levels in all hLSGBs analysed. Cxs were observed at the level of the duct and acinar cells, as well as in myoepithelial cells. The localization of the three Cx types was very similar, suggesting colocalization of these Cxs in the same connexons. These results demonstrated the presence of Cxs in human salivary glands for the first time. Moreover, the few samples with primary Sjögren\'s Syndrome analysed only by immunofluorescence showed an alteration of the Cx expression, indicating that these proteins could be involved in salivary gland dysfunctions.
摘要：
连接蛋白(Cxs)是参与半通道和间隙连接(GJs)形成的跨膜蛋白。GJ参与各种生理功能，包括腺体组织的分泌物。已经证明Cx26，Cx32和Cx43主要在腺体中表达，但迄今为止没有人类唾液腺的数据。我们研究的目的是研究Cxs在人类小唇唾液腺中的存在和定位。免疫荧光和免疫电子显微镜用于评估人唇腺活检（hLSGB）中的Cx26，Cx32和Cx43蛋白。RT-PCR也用于检测它们的mRNA表达。在所有分析的hLSGB中,在mRNA和蛋白质水平都发现了Cx表达。在导管和腺泡细胞的水平观察到Cxs，以及肌上皮细胞。三种Cx类型的定位非常相似，表明这些Cxs在同一连接子中的共定位。这些结果首次证明了Cxs在人唾液腺中的存在。此外，仅通过免疫荧光分析的少数原发性干燥综合征样本显示Cx表达改变，这表明这些蛋白质可能与唾液腺功能障碍有关。
