Research On The Mechanism Of Sj(o|")gren's Syndrome Treatment By Zengye Decoction Via Regulating The Expression Of Vasoactive Intestinal Peptide

ObjectiveTo discuss the Traditional Chinese Medicine (TCM) theoretical basis on the mechanism of Sjogren's syndrome (SS) treated by Zengye decoction. To investigate whether the readjustment of Zengye decoction for the imbalance between Thl/Th2, Thl7/Treg and abnormal expression of AQP5 in SS was done via up-regulating the vasoactive intestinal peptide (VIP) expression.MethodTheoretical research is divided into two parts to analyze the pertinent literatures for investigating the etiology and pathogenesis of SS, respectively. Experimental study is divided into four parts. Part one is designed to observe the protective effects of Zengye decoction on NOD mice submandibular gland by measuring the salivary flow rate of NOD mice, detecting the IFN-? and IL-10 expression in serum of model mice by ELISA, evaluating the histological features from one side of submandibular glands in NOD mice, and detecting the mRNA expression of IFN-y and IL-10 by RT-PCR from the other side of submandibular glands, and to verify whether it can up-regulate the VIP mRNA expression Part two is designed to observe the salivary flow rate, biopsy of submadibular gland, and the expression of IFN-?, IL-10, IL-17A, and AQP5 in submadjbular gland by peritoneal injection with VIP on NOD mice. Part three is to culture the submadibular gland of SD mice in vitro and introduce the VIP and related inhibitors into the culture medium. Detect the expression of AQP5 in submadibular gland of SD rats by immunofluorescence staining and Western blotting, and investigate whether this regulation was done via the VIP/cAMP/PKA/AQP5 signal pathway. Part four is to investigate whether the readjustment of Zengye decoction for the imbalance between Thl/Th2, Thl7/Treg, and abnormal expression of AQP5 in SS was done via up-regulating the VIP expression by introducing both Zengye decoction and VIP receptor antagonist into NOD mice, detecting the cytokines, IFN-?, IL-10, and IL-17A, in serum of model mice by ELISA, evaluating the histological grade from one side of submandibular glands in NOD mice, and detecting the mRNA expression of IFN-?, IL-10, IL-17A, and VIP by RT-PCR from the other side of submandibular glands.Results:Theoretical research results:It is hard to find out the direct causes of the SS, however, second pathological factors can be found by the method of syndrome differentiation. The second pathological factors of SS include dryness toxin and blood stasis, etc., might relate to abnormal immunity response in modern medicine. Clearing away second pathogenic factors is the key point to treat SS. Therefore, removing second pathogenic factors is significant for treating SS. Besides, the dysfunction of metabolism of body fluid is the key pathogenesis in SS, and this dysfunction influences the structure and function of internal organs, while normal function of internal organs is beneficial to the production and distribution of body fluids. It is essential and possible to treat SS by improving the metabolism of body fluid via adjusting the function of internal organs. Moreover, the dysfunction of metabolism may relate to abnormal expression of the AQPs. The theoretical basis for Zengye decoction in treating SS lies in its capacity of not only dispelling the second pathogenic factors but also improving the function of internal organs.Experimental study results:Zengye decoction is beneficial to improve the salivary flow, protect the histological feature of submandibular gland, remedy the imbalance of IFN-?/IL-10 in serum and in submandibular gland, and up-regulate VIP mRNA expression in NOD mice.VIP can improve the salivary flow and histological features of submandibular gland, reduce the ratio imbalance of IFN-y/IL-10 and IL-17A/IL-10, and up-regulate AQP5 mRNA expression in submandibular gland of NOD mice.VIP can up-regulate the expression of AQP5 in submandibular gland of SD rats, and this process can be antagonized by cAMP or PKA inhibitor. Therefore, this implies that the signal path of VIP/cAMP/PKA/AQP5 may exist in the submandibular gland of SD rats.Zengye decoction failed neither to improve the histological features of submandibular gland, to readjust the imbalance between IFN-y/IL-10, IL-17A/IL-10, nor to up-regulate the expression of AQP5 after the VIP receptor of NOD mice was antagonized.Conclusion:On the theoretical side, dryness toxin, blood stasis, etc. are the major second pathological factors of SS. The dysfunction of metabolism of body fluid and the dysfunction of internal organs are the key pathogeneses of SS. Zengye decoction possesses multiplicity efficacy, including detoxinfying, moistening dryness, tonifying yin, and promoting the production of body fluid. The consistency of principle and method is the theoretical basis of the superior efficacy of Zengye decoction. On the experimental side, Zengye decoction can protect the function of submandibular gland, readjust the imbalance between Th1/Th2, Th17/Treg, and abnormal expression of AQP5 on submandibular gland in SS model mice, and this improving process may relate to its capacity of up-reglulating the expression of VIP.