Glucocorticoids, ocular hypertension and glaucoma

糖皮质激素（GC）是治疗慢性炎症的常用抗炎和免疫抑制治疗剂。 各种疾病和条件。我们每年有超过1%的人口接受GC处方。尽管 非常广泛和有效的抗炎作用，延长GC治疗可引起严重的副作用， 包括对眼睛的伤害接受长期GC治疗的个体中有30-75%发生GC- 诱导性高眼压（OHT），如果未被识别，可导致医源性开角型青光眼， 永久性视力丧失尽管认识到这一重大的GC副作用超过六十年，我们仍然 不了解对GC诱导的OHT敏感性差异的原因或 负责GC-OHT的行动。我们以前已经证明，选择性剪接显性负性 糖皮质激素受体（GRb）的同种型抑制培养的人TM细胞中的GC活性。分离的TM细胞 来自青光眼供体眼（GTM）的GTM具有低的GRb水平，因此对GC更敏感。虽然 许多研究已经检查了TM细胞和组织中的DEX诱导的转录组，但没有 表明哪些差异表达的基因或分子途径参与GC-OHT。几 研究表明，GC-OHT的易感性是遗传的，但没有基因被遗传。 与GC-OHT明确相关。我们的总体假设是GC-OHT：（a）由以下比值决定： TM中的内源性GR a至GR B表达;（B）由特异性分子途径介导， 与GC-应答者和非应答者眼区分;和（c）遗传决定，使得GC-OHT 基因可以被定位和识别。这一总体假设将在3个具体目标中进行检验。具体目标1： 确定人眼前节离体灌注中内源性GRb在调节GC-OHT中的作用 培养和小鼠体内。具体目标#2：确定GC-OHT抗性和GC-OHT抗性中的TM转录组 敏感品系的小鼠和眼前节灌注培养的人眼，以鉴定 负责GC-OHT的分子途径。具体目标#3：映射和识别基因 负责使用BXD重组近交系小鼠系的QTL的GC-OHT。这项研究具有创新性 我们将评估内源性GRb在小鼠品系中的作用（使用我们新的GC-OHT小鼠模型） 以及在离体灌注培养的对GC-OHT敏感性不同的人眼前节中，使用小鼠 菌株和人灌注培养的眼前节，其对GC-OHT的响应差异， 从分子水平剖析了GC-OHT的通路，并利用BXD重组体定位了GC-OHT基因 近交系小鼠这项工作是必要的和有意义的，因为我们的实验结果将有助于确定 内源性GRb在调节GC-OHT反应性中的作用， GC-OHT是预测类固醇反应者的最佳和最有效的方法，这仍然是一个重要的未满足的问题。 临床需要，因为GC-OHT变得越来越普遍。

Glucocorticoids (GCs) are commonly used anti-inflammatory and immunosuppressive therapeutic agents for a plethora of diseases and conditions. Over 1% of our population receives GC prescriptions annually. Despite the very broad and potent anti-inflammatory effects, prolonged GC therapy can cause serious side effects, including damage to the eye. Between 30-75% of individuals receiving prolonged GC therapy develop GC- induced ocular hypertension (OHT), which if unrecognized can lead to iatrogenic open-angle glaucoma and permanent vision loss. Despite recognition of this significant GC side effect for more than six decades, we still do not understand the reason for differences in susceptibility to GC-induced OHT or the mechanism(s) of action responsible for GC-OHT. We have previously shown that the alternative spliced dominant negative isoform of the glucocorticoid receptor (GRb) inhibits GC activity in cultured human TM cells. TM cells isolated from glaucoma donor eyes (GTM) have low GRb levels and are therefore more sensitive to GCs. Although a number of studies have examined the DEX-induced transcriptome in TM cells and tissues, there is no indication which of the differentially expressed genes or molecular pathways are involved in GC-OHT. Several studies have shown that susceptibility to develop GC-OHT is genetically inherited, but no genes have been definitively linked to GC-OHT. Our overall hypothesis is that GC-OHT is: (a) determined by the ratio of endogenous GRa to GRb expression in the TM; (b) mediated by specific molecular pathways that can be differentiated from GC-responder and non-responder eyes; and (c) genetically determined so that GC-OHT genes can be mapped and identified. This overall hypothesis will be tested in 3 specific aims. Specific Aim #1: Determine the role of endogenous GRb in regulating GC-OHT in human anterior segment ex vivo perfusion culture and in vivo in mice. Specific Aim #2: Determine the TM transcriptome in GC-OHT resistant and sensitive strains of mice and in anterior segment perfusion cultured human eyes in order to identify the molecular pathways that are responsible for GC-OHT. Specific Aim #3: Map and identify the genes responsible for GC-OHT using QTL of the BXD recombinant inbred mouse lines. This research is innovative in that we will evaluate the role of endogenous GRb in mouse strains (with our new mouse model of GC-OHT) and in ex vivo perfusion cultured human anterior segments that differ in sensitivity to GC-OHT, use mouse strains and human perfusion cultured anterior segments that are differentially responsive to GC-OHT to molecularly dissect the pathway responsible for GC-OHT, and map GC-OHT genes using BXD recombinant inbred mice. This work is essential and significant because our experimental results will help determine the role of endogenous GRb in regulating responsiveness to GC-OHT, the molecular mechanisms responsible for GC-OHT, and the best and most effective way to predict steroid responders, which still is an important unmet clinical need as GC-OHT is becoming increasingly prevalent.