Complement activation in glaucoma

描述（由申请人提供）：我们已经证明在青光眼视网膜中表达改变的主要基因之一是补体成分C1q。在DBA/2型青光眼小鼠模型、激光诱导的猴青光眼和人青光眼中，视网膜C1q在发病早期表达上调。我们还在产生DBA/2背景下的C1q基因敲除（KO）菌株方面取得了重大进展，我们将在未来的研究中使用该菌株来了解C1q在青光眼中的作用。C1q和其他补体基因表达的变化表明，在青光眼视网膜神经节细胞（RGC）病理中，神经炎症过程是可操作的。事实上，我们提供的初步证据表明，炎症反应对DBA/2小鼠RGC丢失的发展至关重要。基于以上以及补体在调节适应性免疫中的作用，我们就补体激活如何参与青光眼的发病机制提出以下假设：补体激活的中间组分引起RGC轴突和体细胞损伤。[这种损害是否直接或间接发生（通过对支持细胞、视网膜胶质细胞或免疫细胞和细胞外基质的影响）超出了本项目的范围]。为了验证这一假设，我们必须首先了解哪些效应补体分子参与了这一过程。因此，我们提出以下具体目标：从诱导的和自发的（DBA/2）小鼠青光眼模型，以及激光诱导的灵长类青光眼和青光眼患者的标本中，测试视网膜中中间补体成分的表达水平和/或数量发生改变的推论。SA2。通过表征我们在上一个资助期产生的基因DBA/2 C1q -/-动物的表型，确定通过经典途径激活的补体是否参与疾病的病理生理。SA3。确定青光眼病理发展是否需要C4和C3补体成分。这将通过评估基因DBA/2 C4 -/和C3-/动物的RGC和轴突损失以及胶质细胞激活来实现，以及C4和C3 KO和野生型动物受到激光诱导IOP升高。SA4。确定C5在青光眼的发病机制中是否具有保护作用。这将通过评估基因DBA/2 C5充足的动物、C5 KOs和野生型小鼠在激光诱导IOP升高下的RGC和轴突损失以及胶质细胞激活来实现。SA5。体外测定压力对Muller细胞及RGC补体成分表达的影响。本提案将剖析各种补体成分，以便精确确定它们在青光眼发病机制中的作用。研究结果将对其他神经退行性疾病产生更广泛的影响。公共卫生相关性：C1q和其他补体基因表达的变化表明，在青光眼视网膜神经节细胞（RGC）病理中，神经炎症过程是可操作的。虽然一旦确定了与神经退行性疾病相关的新途径（在本例中为抗补体疗法），尝试引入新疗法是很有诱惑力的，但重要的是首先要充分了解任何干预措施的所有含义，以避免浪费宝贵的资源，甚至可能伤害患者。这一建议将剖析各种补体成分，以便精确确定每种补体在青光眼发病机制中的作用，并使我们能够合理设计新的治疗方法。

DESCRIPTION (provided by applicant): We have shown that one of the major genes with altered expression in the glaucomatous retina is complement component C1q. Retinal C1q is up-regulated early in the disease process in the DBA/2 mouse model of glaucoma, in laser induced monkey glaucoma and in human glaucoma. We have also made significant progress towards generating a congenic C1q knockout (KO) strain on the DBA/2 background which we will employ in future studies to understand the role of C1q in glaucoma. The changes in expression of C1q and other complement genes, suggest that a neuro-inflammatory process is operational in glaucomatous retinal ganglion cell (RGC) pathology. In fact we present preliminary evidence that an inflammatory reaction is critical for the development of RGC loss in the DBA/2 mouse. Based on the above and the role that complement plays in modulating adaptive immunity we propose the following hypothesis on how complement activation participates in the pathogenesis of glaucoma: Intermediate components of complement activation cause RGC axon and soma damage. [Whether this damage occurs directly or indirectly (through effects on supportive cells, retinal glia or immune cells and extracellular matrix) is beyond the scope of the present project]. To test this hypothesis we must first understand which of the many effector complement molecules are involved in this process. We thus propose the following specific aims: SA1.Test the corollaries that expression levels and/or amounts of intermediate complement components are altered in the retinas from induced and spontaneous (DBA/2) mouse models of glaucoma, as well as in laser induced primate glaucoma and in specimens from patients with glaucoma. SA2. Determine whether complement activation through the classical pathway is involved in the pathophysiology of the disease by characterizing phenotypically the congenic DBA/2 C1q -/- animals we have generated in the previous funding period. SA3. Determine whether the C4 and C3 complement components are required for development of the glaucomatous pathology. This will be achieved by assessing RGC and axonal loss as well as glial activation in congenic DBA/2 C4 -/-and C3-/- animals, as well as in C4 and C3 KO and wild type animals subjected to laser- induced IOP elevation. SA4. Determine whether C5 has a protective role in the pathogenesis of glaucoma. This will be achieved by assessing RGC and axonal loss as well as glial activation in congenic DBA/2 C5 sufficient animals as well as in C5 KOs and wild type mice subjected to laser-induced IOP elevation. SA5. Determine the effect of pressure on Muller cell and RGC complement component expression in vitro. This proposal will dissect the various complement components to allow precise determination of their role in the pathogenesis of glaucoma. Findings will have wider implications for other neurodegenerative disease. PUBLIC HEALTH RELEVANCE: Changes in expression of C1q and other complement genes, suggest that a neuro- inflammatory process is operational in glaucomatous retinal ganglion cell (RGC) pathology. Although it is tempting to try to introduce new therapies once a new pathway involved in neurodegeneration has been identified (in this case anti-complement therapies), it is important to first fully understand all the implications of any intervention in order to avoid wasting valuable resources and potentially even harming patients. This proposal will dissect the various complement components to allow precise determination of the role of each one in the pathogenesis of glaucoma and allow us to rationally design new therapeutic approaches.