LACRIMAL GLAND BIOINFORMATICS: A NEURAL CONNECTION OF DRY EYE AND AGING

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。泪腺（LG）和眼表通过中枢神经系统通过感觉和外周自主神经系统紧密相连。神经活动控制LG分泌反应，从眼表到LG的持续副交感神经输入是维持眼表稳态所必需的。衰老与角膜感觉下降有关，因此，与LG的反应和敏感性下降有关。通过消除副交感神经对分泌物的输入，消除角膜和LG之间的相互作用，导致LG的结构和功能改变。实验侧还出现了干眼症和角膜溃疡。在LG中，与内质网（ER）活性相关的基因表达下调，表明蛋白质质量控制不足；相反，促炎细胞因子和趋化因子的上调表达表明免疫稳态的改变。这一提议的假设是，随着年龄的增长，神经分泌活性的逐渐下降与对毒蕈碱的敏感性丧失有关，毒蕈碱是维持LG内质网完整性和基因表达的关键副交感刺激。该提议的第二个假设是，在对刺激的反应中，LG表现出内质网应激反应的缺陷。年龄相关基因和基因表达模式的鉴定将阐明所观察到的形态学和功能改变的潜在机制，以及可能与老年人干眼症诊断和治疗相关的标记基因。为了更好地了解衰老对这一系统的分子效应，并确定这些基因表达的年龄相关变化，我们提出：具体目的一：确定大鼠泪腺组织中年龄相关基因的表达。特定目的二：研究已知转录因子在调节年龄特异性基因表达中的作用。功能相关基因在其启动子中具有共同的转录调控元件。基因表达模式将揭示有限数量的转录因子(ATF6、XBP-1、NF- y、CHOP、NF？B)在年老的时候可能会改变。使用生物信息学方法可以更好地可视化基因表达模式对共同调控的分析。特异性目的III：探讨副交感神经介导的细胞内信号通路在老龄LG细胞内质网应激和促炎反应中的调节作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The lacrimal gland (LG) and the ocular surface are intimately linked through the central nervous system by sensory and peripheral autonomic neural systems. Nerve activity controls LG secretory response, and a constant parasympathetic input from the ocular surface to the LG is required for maintenance of the ocular surface homeostasis. Aging is associated with decreased corneal sensation and, therefore, with a decrease in response and sensitivity by the LG. Removal of the interaction between the cornea and LG, by eliminating the parasympathetic input to secretion, resulted both in structural and functional alteration in the LG. Dry eye and corneal ulcer also developed on the experimental side. In the LG, the expression of genes associated with the endoplasmic reticulum (ER) activity was down-regulated, suggesting a deficiency in protein quality control; conversely, the upregulated expressions of proinflammatory cytokines and chemokines suggest an alteration in the immune homeostasis. It is the hypothesis of this proposal that the progressive decline in neural activation of secretion that occurs with age is associated with loss of sensitivity to muscarinic, parasympathetic stimulation critical for the maintenance of LG ER integrity and gene expression. The second hypothesis of this proposal is that in response to stimulation, the LG demonstrates deficiency in the ER-stress response. The identification of age-related genes and patterns of gene expression will elucidate the underlying mechanisms responsible for the observed morphologic and functional alterations, as well as marker genes that may be relevant for diagnostic and therapeutic treatment of dry eye in the elderly. To gain a better understanding of the molecular effects of aging on this system, and to identify age-related changes in expression of these classes of genes, we propose: Specific Aim I: To determine age-associated gene expression in rat lacrimal gland tissues. Specific Aim II: To investigate the role of known transcriptional factors in the regulation of age-specific gene expression. Functional related genes share common transcriptional regulatory elements in their promoters. Patterns of gene expression will reveal a limited numbers of transcription factors (ATF6, XBP-1, NF-Y, CHOP, NF?B) that may be altered in the aged LG. Analysis of gene expression patterns to co-regulations is better visualized using bioinformatics approaches. Specific Aim III: To investigate the parasympathetic-mediated intracellular signaling pathways in the modulation of ER-stress and proinflammatory responses in aged LG acini.