Neuroprotective effects of transcription factor Brn3b in an ocular hypertension rat model of glaucoma.
Neuroprotective effects of transcription factor Brn3b in an ocular hypertension rat model of glaucoma.
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DOI：
10.1167/iovs.14-15008
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发表时间：
2015-01
影响因子：
4.4
通讯作者：
Dorota L. Stankowska;Alena Z. Minton;Margaret Rutledge;B. Mueller;Nitasha R Phatak;Shaoqing He;Hai-ying Ma-Ha
中科院分区：
文献类型：
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作者：
Dorota L. Stankowska;Alena Z. Minton;Margaret Rutledge;B. Mueller;Nitasha R Phatak;Shaoqing He;Hai-ying Ma-Ha
目的青光眼是一种常见的眼内压（intraocular pressure，IOP）升高的视神经病变，可导致视神经乳头（optic nerve head，ONH）杯状突起、轴突缺失和视网膜神经节细胞（retinal ganglion cells，RGC）凋亡，最终导致失明。Brn 3b是一种4类POU结构域转录因子，在RGC发育、轴突生长和寻路中起关键作用。先前的研究表明，Brn 3b水平的降低发生在青光眼的动物模型中。本研究的目的是确定腺相关病毒（AAV）介导的Brn 3b蛋白过表达是否可以在IOP介导的神经变性升高后具有神经保护作用。方法在Brown Norway大鼠（Rattus norvegicus）的一只眼中升高眼内压，随后玻璃体内注射编码GFP（rAAV-CMV-GFP和rAAV-hsyn-GFP）或Brn 3b（rAAV-CMV-Brn 3b和rAAV-hsyn-Brn 3b）的AAV构建体。通过ONH的视网膜切片进行突触可塑性标记物染色，并通过RGC计数和视力测试评估神经保护。结果腺相关病毒介导的Brn 3b蛋白在眼压升高的大鼠眼中的表达促进了ONH后和RGCs中生长相关蛋白43（GAP-43）、肌动蛋白结合LIM蛋白（abLIM）和乙酰化α-微管蛋白（ac-Tuba）的上调。与IOP升高的rAAV-hsyn-GFP注射大鼠相比，IOP升高的rAAV-hsyn-Brn 3b注射大鼠的RGC存活以及轴突完整性评分显著改善。此外，玻璃体内rAAV-hsyn-Brn 3b给药显著恢复了IOP升高的大鼠眼中的视觉视动反应。结论腺相关病毒介导的Brn 3b蛋白表达可能是一种促进青光眼动物模型神经保护的合适方法。
PURPOSE Glaucoma is an optic neuropathy commonly associated with elevated intraocular pressure (IOP), leading to optic nerve head (ONH) cupping, axon loss, and apoptosis of retinal ganglion cells (RGCs), which could ultimately result in blindness. Brn3b is a class-4 POU domain transcription factor that plays a key role in RGC development, axon outgrowth, and pathfinding. Previous studies suggest that a decrease in Brn3b levels occurs in animal models of glaucoma. The goal of this study was to determine if adeno-associated virus (AAV)-directed overexpression of the Brn3b protein could have neuroprotective effects following elevated IOP-mediated neurodegeneration. METHODS Intraocular pressure was elevated in one eye of Brown Norway rats (Rattus norvegicus), following which the IOP-elevated eyes were intravitreally injected with AAV constructs encoding either the GFP (rAAV-CMV-GFP and rAAV-hsyn-GFP) or Brn3b (rAAV-CMV-Brn3b and rAAV-hsyn-Brn3b). Retina sections through the ONH were stained for synaptic plasticity markers and neuroprotection was assessed by RGC counts and visual acuity tests. RESULTS Adeno-associated virus-mediated expression of the Brn3b protein in IOP-elevated rat eyes promoted an upregulation of growth associated protein-43 (GAP-43), actin binding LIM protein (abLIM) and acetylated α-tubulin (ac-Tuba) both posterior to the ONH and in RGCs. The RGC survival as well as axon integrity score were significantly improved in IOP-elevated rAAV-hsyn-Brn3b-injected rats compared with those of the IOP-elevated rAAV-hsyn-GFP- injected rats. Additionally, intravitreal rAAV-hsyn-Brn3b administration significantly restored the visual optomotor response in IOP-elevated rat eyes. CONCLUSIONS Adeno-associated virus-mediated Brn3b protein expression may be a suitable approach for promoting neuroprotection in animal models of glaucoma.