Program in Craniofacial Biology, Department of Cell & Tissue Biology, University of California San Francisco, San Francisco, CA, 94143, USA.
Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California San Francisco, San Francisco, CA, 94143, USA.
J Autoimmun. 2020 Nov;114:102500. doi: 10.1016/j.jaut.2020.102500. Epub 2020 Jun 18.
Autoimmune-mediated dry eye disease is a pathological feature of multiple disorders including Sjögren's syndrome, lupus and rheumatoid arthritis that has a life-long, detrimental impact on vision and overall quality of life. Although late stage disease outcomes such as epithelial barrier dysfunction, reduced corneal innervation and chronic inflammation have been well characterized in both human patients and mouse models, there is little to no understanding of early pathological processes. Moreover, the mechanisms underlying the loss of cornea homeostasis and disease progression are unknown. Here, we utilize the autoimmune regulatory (Aire)-deficient mouse model of autoimmune-mediated dry eye disease in combination with genome wide transcriptomics, high-resolution imaging and atomic force microscopy to reveal a potential extracellular matrix (ECM)-biomechanical-based mechanism driving cellular and morphological changes at early disease onset. Early disease in the Aire-deficient mouse model is associated with a mild reduction in tear production and moderate immune cell infiltration, allowing for interrogation of cellular, molecular and biomechanical changes largely independent of chronic inflammation. Using these tools, we demonstrate for the first time that the emergence of autoimmune-mediated dry eye disease is associated with an alteration in the biomechanical properties of the cornea. We reveal a dramatic disruption of the synthesis and organization of the extracellular matrix as well as degradation of the epithelial basement membrane during early disease. Notably, we provide evidence that the nerve supply to the cornea is severely reduced at early disease stages and that this is independent of basement membrane destruction or significant immune cell infiltration. Furthermore, diseased corneas display spatial heterogeneity in mechanical, structural and compositional changes, with the limbal compartment often exhibiting the opposite response compared to the central cornea. Despite these differences, however, epithelial hyperplasia is apparent in both compartments, possibly driven by increased activation of IL-1R1 and YAP signaling pathways. Thus, we reveal novel perturbations in corneal biomechanics, matrix organization and cell behavior during the early phase of dry eye that may underlie disease development and progression, presenting new potential targets for therapeutic intervention.
自身免疫性干眼症是包括干燥综合征、狼疮和类风湿关节炎在内的多种疾病的病理特征，它对视力和整体生活质量造成终身的、有害的影响。尽管在人类患者和小鼠模型中已经很好地描述了晚期疾病结果，如上皮屏障功能障碍、角膜神经支配减少和慢性炎症，但对早期病理过程知之甚少。此外，角膜稳态丧失和疾病进展的机制尚不清楚。在这里，我们利用自身免疫调节（Aire）缺陷型小鼠模型自身免疫性干眼症，结合全基因组转录组学、高分辨率成像和原子力显微镜，揭示了一个潜在的细胞外基质（ECM）-力学基础机制，该机制驱动疾病早期发病时的细胞和形态变化。Aire 缺陷型小鼠模型的早期疾病与泪液产生轻度减少和中度免疫细胞浸润有关，这使得可以在很大程度上不受慢性炎症影响来研究细胞、分子和力学变化。使用这些工具，我们首次证明自身免疫性干眼症的发生与角膜生物力学特性的改变有关。我们发现，在疾病早期，细胞外基质的合成和组织以及上皮基底膜的降解发生了显著破坏。值得注意的是，我们提供的证据表明，角膜的神经供应在早期疾病阶段严重减少，这与基底膜破坏或显著的免疫细胞浸润无关。此外，患病角膜在机械、结构和成分变化方面表现出空间异质性，角膜缘区通常与中央角膜的反应相反。然而，尽管存在这些差异，上皮过度增生在两个区域都很明显，可能是由 IL-1R1 和 YAP 信号通路的激活增加所驱动。因此，我们揭示了干眼症早期阶段角膜生物力学、基质组织和细胞行为的新的扰动，这些扰动可能是疾病发展和进展的基础，为治疗干预提供了新的潜在靶点。
