Stimulus-Secretion Coupling in Diseased Lacrimal Gland

干燥综合征是一种几乎只发生于女性的全身炎症性自身免疫性疾病，是导致水性泪液缺乏性干眼的主要原因。到目前为止，还没有治愈这种疾病的方法，导致泪液分泌减少的确切机制在很大程度上是未知的。该实验室的研究指出，促炎细胞因子，白细胞介素-1 α (IL-1a), il -1 β (IL-lb)和肿瘤坏死α (TNFa)在干燥综合征相关泪腺功能受损中的潜在关键作用。具体来说，我们发现这些细胞因子在泪腺中具有双重靶点：神经末梢（即抑制神经递质释放）和上皮细胞（即抑制泪腺蛋白分泌）。然而，这些细胞因子干扰泪腺神经末梢和泪腺腺泡上皮细胞功能的机制仍有待阐明。因此，本研究的长期目标是确定促炎刺激激活的细胞内信号通路，以抑制泪腺分泌。第二个目的是使用干燥综合征小鼠模型测试这些途径的选择性抑制剂对泪腺分泌的影响。为了实现这些目标，我们提出了以下具体目标：(1)明确炎症刺激激活的信号通路，抑制神经递质释放和泪腺分泌；(2)确定JNK、ERK和iNOS是否参与干燥综合征相关泪腺分泌受损；(3)确定炎症诱导的神经递质释放和泪腺分泌抑制是否需要ICE活性。将从患病和正常的雌性小鼠身上制备泪腺切片。JNK、ERK和iNOS的激活将通过免疫印迹法测定。用分光光度法测定泪腺神经末梢神经递质的释放和蛋白质的分泌。将JNK、ERK和/或iNOS的选择性抑制剂皮下注射到患病和对照雌性小鼠。

DESCRIPTION (provided by applicant): Sjogren's syndrome, a systemic inflammatory autoimmune disease which occurs almost exclusively in females, is the leading cause of aqueous tear deficient dry eye. To date there is no cure for this disease and the precise mechanisms responsible for the decreased tear secretion are largely unknown. Studies from this laboratory point to a potentially pivotal role of the proinflammatory cytokines, interleukin-1alpha (IL-1a), IL-1beta (IL-lb), and tumor necrosis alpha (TNFa), in the impaired function of the lacrimal gland associated with Sjogren's syndrome. Specifically, we found that these cytokines have a dual target in the lacrimal gland: the nerve endings (i.e., inhibition of neurotransmitter release) and the epithelial cells (i.e., inhibition of lacrimal gland protein secretion). However, the mechanism(s) by which these cytokines interfere with lacrimal gland nerve endings and lacrimal gland acinar epithelial cell functions remain to be elucidated. Thus, the long term objective of the present proposal is to define the intracellular signaling pathways activated by proinflammatory stimuli to inhibit lacrimal gland secretion. A second objective is to test the effects of selective inhibitors of these pathways on lacrimal gland secretion using a murine model of Sjogren's syndrome. To obtain these goals, the following specific aims have been proposed: (1) define the signaling pathways activated by inflammatory stimuli to inhibit neurotransmitter release and lacrimal gland secretion; (2) determine if JNK, ERK, and iNOS are involved in the impaired lacrimal gland secretion associated with Sjogren's syndrome; and (3) determine if ICE activity is necessary for inflammation-induced inhibition of neurotransmitter release and lacrimal gland secretion. Lacrimal gland slices will be prepared from diseased and control female mice. Activation of JNK, ERK, and iNOS will be measured by western blotting. The release of neurotransmitter from lacrimal gland nerve endings and protein secretion will be measured spetrophotometrically. Selective inhibitors of JNK, ERK, and/or iNOS will be given subcutaneously to diseased and control female mice.