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

摘要 干燥综合征(SS)是一种涎腺和泪腺的自身免疫性外分泌病，影响~4 百万美国人，其中90%是女性。SS的特征是涎腺炎和泪囊炎， 唾液减少(即口干症)和泪液分泌减少(即干眼症)，血清中出现 抗Ro/SSA和La/SSB自身抗体。SS患者的口干症和干眼症可导致 牙周炎，酵母菌和细菌感染，消化障碍和视力下降，严重减少 患者的生活质量。最终，SS的慢性炎症会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化的症状管理， 人工唾液、泪液和毒扁豆碱受体激动剂可诱导残余外分泌物分泌液体 腺泡细胞。这种补救措施被普遍认为是不充分的，因此，制定更有效的 SS处理是必不可少的。我们的研究主要集中在细胞表面的胞外P2X7和P2Y2受体 三磷酸腺苷，细胞内能量的化学形式，当从受损的唾液腺释放出来时 炎症反应。我们的研究表明，P2X7R和P2Y2R拮抗剂促进唾液分泌和 减少两种不同SS模型小鼠唾液腺中的淋巴细胞灶。P2X7R的拮抗性也 减少泪腺中的淋巴细胞堆积，增加泪液分泌。这些对手已经 虽然P2X7R在SS患者的唾液腺中表达上调，但未用于治疗SS 给非党卫军控制中心。唾液腺中P2X7R的激活也可以诱导IL-1β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，提示P2X7R和P2Y2R 共同为党卫军的发展贡献力量。本项目将调查P2X7R和/或P2Y2R的能力 拮抗剂增加唾液和/或泪液分泌并减轻小鼠涎腺炎和/或泪囊炎 SS的模型。这些发现将通过评估P2X7R和P2Y2R在归档人类中的表达来验证 SS和对照小涎腺活检及P2X7R和/或P2Y2R拮抗作用的评价 新鲜分离的人唾液和泪腺细胞。具体目标1将调查以下假设 P2X7R和P2Y2R在SS小鼠慢性涎腺炎和腺体功能障碍模型中的序贯作用 并可拮抗体内治疗SS。《特定目标2》将调查这样一种假设，即P2X7R和 泪腺上皮细胞中的P2Y2R激活促进了SS模型小鼠的干眼病。特定的 AIM 3将研究人类原发唾液中的P2X7R和P2Y2R介导的促炎反应 泪腺细胞和人SS小涎腺活检。成功完成这项提案将 代表着朝着实现以P2X7R和/或P2Y2R为治疗目标的最终目标迈出的关键一步 人类中的SS。

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.