Abnormal distribution of AQP5 in labial salivary glands is associated with poor saliva secretion in patients with Sjogren's syndrome including neuromyelitis optica complicated patients

作者：Yoshimura Shunsuke; Nakamura Hideki^*; Horai Yoshiro; Nakajima Hideki; Shiraishi Hirokazu; Hayashi Tomayoshi; Takahashi Toshiyuki; Kawakami Atsushi

来源：Modern Rheumatology, 2016, 26(3): 384-390.

DOI：10.3109/14397595.2015.1083146

• Aquaporin
• Labial salivary glands
• Neuromyelitis optica
• Sjogren's syndrome

Objective: To investigate whether aquaporins (AQPs) are involved in salivary gland dysfunction in patients with neuromyelitis optica (NMO) complicated with Sjogren's syndrome (SS).
Methods: Eight primary SS (pSS) patients, four NMO spectrum disorder (NMOsd) patients complicated with SS (NMOsd-SS), and three control subjects were enrolled. Immunohistochemistry of labial salivary glands (LSGs) was performed to determine the expressions of AQP4, AQP5, and tumor necrosis factor-alpha (TNF-alpha). In vitro expression of AQP5 was examined by Western blotting in cultured primary salivary gland epithelial cells (SGECs).
Results: No expression of AQP4 was shown in all LSGs. AQP5 was clearly expressed in the all acini, but the predominant localization of AQP5 in the apical side was diminished in the patients with pSS or NMOsd-SS compared with the controls and tended to be even lower in NMOsd-SS than pSS. The abnormal localization of AQP5 was associated with poor saliva secretion. No difference was found in TNF-alpha expression in the LSGs between patients with pSS and NMOsd-SS. AQP5 expression of SGECs in vitro was not changed by TNF-alpha or interleukin-10.
Conclusions: Our results suggest that AQP5 but not AQP4 contributes to salivary secretion in patients with SS including those with NMO complicated with SS.

• 出版日期2016