| Backgroud:Sj?gren's Syndrome (SS)is a common inflammatory disease characterized by lymphocytic infiltration of salivary and lacrimal glands leading to glandular hypofunction and dry mouth and eyes. salivary gland biopsies show lymphocytic infiltrates with a maximal 50% decrease in acini number, and Metalloprotenases have been implicated in acinar destruction. However, in addition to loss of gland elements, gland dysfunction plays an important role in the clinical expression of the disease. Several factors may contribute to impaired salivary flow including proinflammatory cytokines, such as IL-1 and TNF-a, that can inhibit both basal and stimulated secretion. Decreased protein kinase C levels in salivary gland acilar cells of SS Patients, along with the presence of antibodies against muscarinic M3 receptor in primary SS patients could prevent normal gland response to neuronal simulation, In a normal salivary gland, the acini secrete a primary isotonic fluid from which considerable NaCl is resorbed during the passage through the ducts. Ductal cell possess a sodium channel, a chloride channel, and a sodium-proton exchanger, which are likely to be involved in NaCl reabsorption. Recent discovery of a family of water-specific membrane channel proteins, the aquaporins, provided in sight into the molecular mechanism of membrane water permeability in a variety of tissues, AQP1 provides the molecular patheway for water reasorption in the renal proximal tubule and vasa recta, participates in lung water homeostasis, and in the secretion of cerebrospinal fluid and bile, It was also confirmed to distributing in salivary gland tissues; AQP5 was cloned from rat submandbular glands and is present in the lacrimal gland and lung, suggesting roles in generation of saliva, tears and pulmonary secretions. Among the aquaporins identified to date, only AQP1, AQP2 and AQP5 have been immunohistochemically localized to human salivary glands.Abjective: To develope a mouse model for non-bacterial sialoadenitis similar to Sj?gren's Syndrome and examine the distribution of various subtypes of water channel protein (aquaporin,AQP1,2,5)in various structures of submandibular salivary glands, try to find out the changes of water channel protein expressed in SS mice and a theory clue provided for gene therapy to SS patients.Methods: 60 BALb/C mice were divided into three groups(2w,4w,6w),in each group 10 were injected by homologous antigen of submandibular gland tissues mixed with completely freund's adjuvant(CFA), pertussis vaccaine injected to enhence immuological reaction. another 10 mice were injected only by the same volume saline as control experiment, submandbular glands were analyzed histologically at different time points. submandibular gland, were excised and sectioned by ultra cryotomy. The sections were labled with antibody by immunohistochemical method and western blot analysis. Computer-assisted image analysis system was performed to quantitatively evaluate AQP1,2,5 distribution in the immunoreactive acini and duct of both SS and control group.Results: (1)According to our study,the constant and clear reaction could be observed in mice submandibular gland tissues with the first antibody concentration of 1:200 for AQP5 and 1:100 for AQP1.and AQP2. AQP1 was labeled in the basement membrane, blood capillary endothelium and ductal basementmembrane; AQP5 was strongly labeled not only in the mucous alvoli apical membrane but also in basolateral membrane. It also could clearly be observed in secretary duct. Unexpectedly, the reaction of AQP2, which has been confirmed to express in human salivary gland, was not be found in the mouse salivary gland with the concentration of 1:100, even 1:50ï¼› (2) Computer-assisted image analysis data show that 2w and 4w group has no significant difference vs control group(P> 0.05), but 6w-group sharply dicrease(P< 0.01).As far as the remaining acinus are concerned, stain in acinus basal membrane is much stronger than that in the apical membraneï¼›(3) Expression of AQP1 decrease slightly in... |
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