33412Novartis Institutes of Biomedical Research, East Hanover, NJ, USA.
Toxicol Pathol. 2021 Apr;49(3):521-527. doi: 10.1177/0192623320954124. Epub 2020 Oct 12.
Ultrastructural pathology is critical in the morphologic evaluation and characterization of subcellular structures in nonclinical toxicity and efficacy studies. In murine models of ophthalmologic disease, clinical examination is typically paired with other techniques like electroretinography (ERG) and/or optical coherence tomography (OCT) to more fully characterize a finding. High-quality transmission electron microscopy (TEM) can provide a critical, image-based link between these approaches, providing greater confidence in interpretation of ERG or OCT results. In addition to characterization of disease models, TEM can provide detailed visualization of retinal changes identified by clinical examination or light microscopy in nonclinical toxicity studies. The spherical shape of the eye presents unique challenges for trimming, orientation, imaging, and evaluation by TEM. The varied components of the eye require specialized approaches for embedding to facilitate successful sectioning. Controlling for the orientation of the retina is critical to consistent evaluation, driving the need for an improved method of embedding this unique and complex organ. The authors describe a method of sample preparation resulting in optimal orientation of the posterior aspect of murine eyes (rat and mouse) for TEM of the neural retina, Bruch's membrane and/or choroid, with examples from mouse ophthalmic disease models.
超微结构病理学在非临床毒性和功效研究中对细胞内亚结构的形态评估和特征描述至关重要。在眼科疾病的鼠模型中，临床检查通常与其他技术（如视网膜电图（ERG）和/或光学相干断层扫描（OCT））相结合，以更全面地描述发现。高质量的透射电子显微镜（TEM）可以在这些方法之间提供关键的基于图像的联系，从而更有信心解释 ERG 或 OCT 结果。除了疾病模型的特征描述外，TEM 还可以详细观察到临床检查或非临床毒性研究中的光镜识别的视网膜变化。球形眼睛在切割、定向、成像和 TEM 评估方面带来了独特的挑战。眼睛的各种成分需要特殊的包埋方法来促进成功切片。控制视网膜的方向对于一致的评估至关重要，这促使人们需要一种改进的方法来包埋这个独特而复杂的器官。作者描述了一种样本制备方法，可使鼠眼（大鼠和小鼠）的后段（神经视网膜、Bruch 膜和/或脉络膜）在 TEM 中得到最佳定向，并展示了来自鼠眼科疾病模型的示例。
