The localization of calcium-activated chloride channel and its contribution on related pathologic conditions

本课题旨在阐明大鼠唾液腺（主要是颌下腺）钙激活氯通道相关分子在生理和病理状态下的分布。rCLCA定位于rER、高尔基体、早期和晚期内体等胞质器官。导管系统的铝。在唾液腺导管系统中，rCLCA在纹状管和颗粒曲管中表达最强，在闰管和排泄管中表达减弱，在浆液性和粘液性腺泡细胞中未检测到rCLCA。上述导管系统中的rCLCA分子与其他氯离子通道分子如CFTR共定位。本研究采用分子生物学、电生理学、药理学、生物化学等方法对rCLCA的功能进行了研究，并与同事沿着进行了功能分析。随后，rCLCA与CFTR的相互作用以及rCLCA对唾液腺导管系统离子转运的影响被部分阐明，并在国际期刊上发表。当给予异丙肾上腺素诱导腺泡细胞增生时，rCLCA表达显著降低，除闰管外，几乎所有的rCLCA蛋白均消失。与不表达rCLCA的细胞株相比，稳定表达rCLCA的细胞株经Staurosporine处理后，增殖活性降低，凋亡增加，rCLCA在生理和病理状态下的其他功能有待进一步研究。

This project clarified how rat calcium-activated chloride channel-related (rCLCA) molecules distribute in the salivary gland (chiefly submandibular gland) both at physiological and pathologic states. rCLCA was localizad throughout the cytoplasmic organellae, namely rER, Golgi apparatus, early and late endosomes, et. Al. of the ductal sytem. Within the salivary ductal system, striated ducts and granular convoluted tubules showed the most intense localization of rCLCA, while the amount of rCLCA weakened in intercalated ducts and excretory ducts, and no rCLCA was detected in the serous and mucinous acinar cells. rCLCA molecules at the above ductal system colocalized with other chloride channel molecules such as CFTR. The function of rCLCA was analyzed with broad methodological approaches as molecular biology (the inhibition of mRNA procuction with siRNA), electro-physiology, pharmacology and biochemistry along with co-workers. Subsequently the interaction of rCLCA and CFTR and the influence of rCLCA on ion transport of salivary ductal system were partially clarified, and these products were published in international journals.rCLCA expression was drastically depressed when the hyperplasia of acinar cells was induced by the isoproterenol administration; almost all rCLCA proteins disappeared except at the intercalated duct. Cell lines with stable rCLCAexpression showed decreased proliferative activity and increased apoptosis after the exposure of Staurosporine, compared with the same cell lines without rCLCAexpression.Further exploration would be required to elucidate the other function of rCLCA both in physiologic and pathlogic states.