Vasoactive Intestinal Peptide Protects Salivary Glands against Structural Injury and Secretory Dysfunction via IL-17A and AQP5 Regulation in a Model of Sjögren Syndrome.

Objective: Sjogren syndrome (SS) is an autoimmune disease involving exocrine glands. Currently, drugs that can improve both abnormal immunity and exocrine gland function are needed. The study aimed to investigate the effect and mechanism of vasoactive intestinal peptide (VIP) on the immune response and exocrine gland function in SS. Methods: We investigated the effects of VIP on the immune response and secretory function of submandibular glands using NOD mice, and analyzed the expression of IL-17A and AQP5 (aquaporin 5). The submandibular gland cells from healthy 8-day-old Sprague-Dawley rats were used to observe the influence of VIP on AQP5 expression. Results: Our study shows that treatment with VIP in an SS mouse model could not only reduce the immune injury to exocrine glands but also improve the secretory function of these glands. Furthermore, VIP was shown to improve the abnormal immune status by down-regulating IL-17A expression in the exocrine glands. It also enhanced the secretory function of exocrine glands by up-regulating AQP5 expression. Conclusions: Using a model of SS, we found that VIP could not only modulate the immune response but also affect exocrine gland function, and that these therapeutic effects were associated with IL-17A and AQP5 regulation. (C) 2018 S. Karger AG, Basel