Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center (OUHSC), Oklahoma City, Oklahoma, United States.
Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Munich, Germany.
Invest Ophthalmol Vis Sci. 2020 Oct 1;61(12):19. doi: 10.1167/iovs.61.12.19.
The immune-privileged environment and complex organization of retinal tissue support the retina's essential role in visual function, yet confound inquiries into cell-specific inflammatory effects that lead to dysfunction and degeneration. Caveolin-1 (Cav1) is an integral membrane protein expressed in several retinal cell types and is implicated in immune regulation. However, whether Cav1 promotes or inhibits inflammatory processes in the retina (as well as in other tissues) remains unclear. Previously, we showed that global-Cav1 depletion resulted in reduced retinal inflammatory cytokine production but paradoxically elevated retinal immune cell infiltration. We hypothesized that these disparate responses are the result of differential cell-specific Cav1 functions in the retina.
We used Cre/lox technology to deplete Cav1 specifically in the neural retinal (NR) compartment to clarify the role NR-specific Cav1 (NR-Cav1) in the retinal immune response to intravitreal inflammatory challenge induced by activation of Toll-like receptor-4 (TLR4). We used multiplex protein suspension array and flow cytometry to evaluate innate immune activation. Additionally, we used bioinformatics assessment of differentially expressed membrane-associated proteins to infer relationships between NR-Cav1 and immune response pathways.
NR-Cav1 depletion, which primarily affects Müller glia Cav1 expression, significantly altered immune response pathway regulators, decreased retinal inflammatory cytokine production, and reduced retinal immune cell infiltration in response to LPS-stimulated inflammatory induction.
Cav1 expression in the NR compartment promotes the innate TLR4-mediated retinal tissue immune response. Additionally, we have identified novel potential immune modulators differentially expressed with NR-Cav1 depletion. This study further clarifies the role of NR-Cav1 in retinal inflammation.
视网膜组织的免疫特权环境和复杂结构支持其在视觉功能中的重要作用，但也阻碍了对导致功能障碍和变性的细胞特异性炎症反应的研究。窖蛋白-1（Cav1）是一种在多种视网膜细胞类型中表达的完整膜蛋白，与免疫调节有关。然而，Cav1 是否促进或抑制视网膜（以及其他组织）中的炎症过程仍不清楚。此前，我们发现全身性 Cav1 耗竭导致视网膜炎症细胞因子产生减少，但出人意料的是，视网膜免疫细胞浸润增加。我们假设这些不同的反应是 Cav1 在视网膜中的细胞特异性功能差异的结果。
我们使用 Cre/lox 技术特异性耗竭神经视网膜（NR）隔室中的 Cav1，以阐明 NR 特异性 Cav1（NR-Cav1）在 TLR4 激活诱导的眼内炎症挑战对视网膜免疫反应中的作用。我们使用多重蛋白质悬浮阵列和流式细胞术评估固有免疫激活。此外，我们还使用差异表达膜相关蛋白的生物信息学评估来推断 NR-Cav1 与免疫反应途径之间的关系。
NR-Cav1 耗竭主要影响 Müller 胶质细胞 Cav1 的表达，显著改变了免疫反应途径调节剂，减少了 LPS 刺激诱导的炎症反应中视网膜炎症细胞因子的产生，并减少了视网膜免疫细胞浸润。
NR 隔室中 Cav1 的表达促进了 TLR4 介导的固有视网膜组织免疫反应。此外，我们还鉴定出与 NR-Cav1 耗竭相关的新型潜在免疫调节剂。本研究进一步阐明了 NR-Cav1 在视网膜炎症中的作用。
