Glucocorticoids, ocular hypertension and glaucoma

糖皮质激素(GCs)是一种常用的抗炎和免疫抑制治疗药物。 过多的疾病和状况。每年有超过1%的人口接受GC处方。尽管 非常广泛和强大的抗炎作用，长时间的GC治疗会引起严重的副作用， 包括对眼睛的伤害。在接受长期GC治疗的人中，有30%-75%的人会患上GC- 诱导性高眼压(OHT)，如果不被发现，可能会导致医源性开角型青光眼和 永久性视力丧失。尽管认识到这一重大GC副作用已有60多年，但我们仍然 不了解GC诱导的OHT易感性差异的原因或机制(S) 负责GC-OHT的行动。我们之前已经证明了选择性剪接显性负值 糖皮质激素受体(GRB)的异构体抑制培养的人TM细胞的GC活性。分离的TM细胞 来自青光眼的供眼(GTM)的GRB水平较低，因此对GCs更敏感。尽管一个 许多研究已经检测了地塞米松诱导的TM细胞和组织中的转录组，没有 提示哪些差异表达的基因或分子途径参与了GC-OHT。几个 研究表明，发生GC-OHT的易感性是遗传的，但没有基因被遗传 肯定与GC-OHT有关。我们的总体假设是，GC-OHT是：(A)由 内源性Gra to GRb在TM中的表达；(B)由特定的分子途径介导，可 与GC响应者和无响应者的眼睛区分；以及(C)经基因决定，GC-OHT 基因可以被绘制和识别。这一总体假设将在3个具体目标上进行检验。具体目标1： 确定内源性GRB在人眼前段体外灌流中对GC-OHT的调节作用 在小鼠体内和体外培养。特定目标2：确定GC-OHT耐药和Tm转录组 敏感品系小鼠及在眼前段灌流培养的人眼以鉴定 负责GC-OHT的分子途径。具体目标3：绘制和识别基因图谱 负责利用BXD重组近交系小鼠的QTL进行GC-OHT。本研究具有创新性。 因此，我们将评估内源性GRB在小鼠品系中的作用(使用我们的新的GC-OHT小鼠模型) 在对GC-OHT敏感性不同的人眼前节体外灌流培养中，用小鼠 对GC-OHT有不同反应的菌株和人类灌流培养的前节段 从分子水平剖析GC-OHT的致病途径，并利用BXD重组体定位GC-OHT基因 近亲繁殖的小鼠。这项工作非常重要，因为我们的实验结果将有助于确定 内源性GRB在调节GC-OHT反应中的作用及其分子机制 GC-OHT，以及预测类固醇应答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 临床需要作为GC-OHT正变得越来越普遍。

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.