Targeting P2 Receptors to Restore Salivary and Lacrimal Gland Function in Sjogren's Syndrome

总结 干燥综合征（SS）是一种唾液腺和泪腺的自身免疫性外分泌病， 美国有100万人，其中90%是女性。SS的特征是涎腺炎和泪腺炎， 唾液减少（即，口干症）和泪液产生（即，干眼症）和血清中的存在 抗Ro/SSA和La/SSB的自身抗体。干燥综合征患者的口干和干眼症可导致 牙周炎，酵母菌和细菌感染，消化系统疾病和视力下降，严重减少 患者的生活质量。最终，SS中的慢性炎症导致继发性自身免疫性疾病， 组织纤维化和淋巴瘤。SS的治疗仅限于通过外部水合作用进行症状管理， 人工唾液和泪液以及毒蕈碱受体激动剂，其诱导液体从残余外分泌分泌 腺泡细胞这种补救办法被普遍认为是不够的，因此，发展更有效的 SS治疗是必要的。我们的研究主要集中在细胞表面P2X7和P2Y2受体的细胞外 ATP，细胞内的化学形式的能量，当从受损的唾液腺释放时， 炎症反应。我们的研究表明，P2X7R和P2Y2R拮抗剂可增强唾液分泌， 减少两种不同SS小鼠模型唾液腺中的淋巴细胞灶。P2X7R的拮抗作用也 减少泪腺中的淋巴细胞积聚并增加泪液分泌。这些拮抗剂具有 P2X7R在SS患者的唾液腺中上调， 非SS控制。唾液腺中的P2X7R激活也诱导IL-1 β的成熟和释放， 在免疫和上皮细胞中上调P2Y2R的相关细胞因子，表明P2X7R和P2Y2R 为SS的发展做出贡献。本项目将研究P2X7R和/或P2Y2R的能力 在小鼠中增加唾液和/或泪液分泌并减轻涎腺炎和/或泪腺炎的拮抗剂 SS模型这些发现将通过评估存档的人类中P2X7R和P2Y2R的表达来验证。 SS和对照小唾液腺活组织检查，并评估P2X7R和/或P2Y2R拮抗作用在 新鲜分离的人唾液腺和泪腺细胞。具体目标1将研究假设， P2X7R和P2Y2R在SS小鼠模型慢性涎腺炎和腺体功能障碍中的顺序作用 并且可以拮抗以在体内治疗SS。具体目标2将研究P2X7R和 泪腺上皮细胞中的P2Y2R活化促进SS小鼠模型中的干眼症。具体 目的3研究P2X7R和P2Y2R介导的人原发性唾液腺炎症反应， 泪腺细胞和人SS小唾液腺活检。成功完成此提案将 代表实现靶向P2X7R和/或P2Y2R以治疗的最终目标的关键一步。 SS在人类

Summary Sjögren’s syndrome (SS), an autoimmune exocrinopathy of the salivary and lacrimal glands, affects ~ 4 million Americans, 90% of whom are women. SS is characterized by sialadenitis and dacryoadenitis, decreased saliva (i.e., xerostomia) and tear production (i.e., xerophthalmia) and the presence in blood serum of autoantibodies against Ro/SSA and La/SSB. Xerostomia and xerophthalmia in SS patients can lead to periodontitis, yeast and bacterial infections, digestive disorders and vision deterioration that severely reduce the quality of life for patients. Ultimately, chronic inflammation in SS leads to secondary autoimmune diseases, tissue fibrosis and lymphoma. Therapy for SS is limited to symptom management through external hydration, artificial saliva and tears and muscarinic receptor agonists that induce fluid secretion from residual exocrine acinar cells. Such remedies are universally judged to be inadequate and thus, development of more effective SS treatments is essential. Our research focuses on cell surface P2X7 and P2Y2 receptors for extracellular ATP, the intracellular chemical form of energy that when released from damaged salivary glands initiate inflammatory responses. Our studies show that P2X7R and P2Y2R antagonists enhance saliva secretion and reduce lymphocytic foci in salivary glands of two different mouse models of SS. Antagonism of the P2X7R also reduces lymphocytic accumulation in the lacrimal glands and increases tear secretion. These antagonists have not been used to treat human SS, although P2X7R is upregulated in salivary glands of SS patients compared to non-SS controls. P2X7R activation in salivary glands also induces maturation and release of IL-1β, an SS- related cytokine that upregulates P2Y2R in immune and epithelial cells, suggesting that P2X7R and P2Y2R contribute together to SS development. This project will investigate the ability of P2X7R and/or P2Y2R antagonists to increase saliva and/or tear secretion and reduce sialadenitis and/or dacryoadenitis in mouse models of SS. These findings will be validated by assessing P2X7R and P2Y2R expression in archived human SS and control minor salivary gland biopsies and evaluating effects of P2X7R and/or P2Y2R antagonism in freshly isolated human salivary and lacrimal gland cells. Specific Aim 1 will investigate the hypothesis that P2X7R and P2Y2R play sequential roles in chronic sialadenitis and glandular dysfunction in SS mouse models and can be antagonized to treat SS in vivo. Specific Aim 2 will investigate the hypothesis that P2X7R and P2Y2R activation in lacrimal gland epithelial cells promotes dry eye disease in mouse models of SS. Specific Aim 3 will investigate P2X7R and P2Y2R-mediated proinflammatory responses in human primary salivary and lacrimal gland cells and human SS minor salivary gland biopsies. Successful completion of this proposal will represent a critical step towards realization of the ultimate goal of targeting the P2X7R and/or P2Y2R to treat SS in humans.