High-resolution imaging of pericytes and capillary blood flow in diabetic mice

描述(申请人提供)：据估计，有1700万至3400万人患有不同阶段的糖尿病视网膜病变(DR)1。在美国，它是导致工作年龄成年人失明的主要原因，并且仍然是世界各地的公共卫生问题。DR最早的表现被认为起源于毛细血管闭塞2，导致局部毛细血管的低灌注和高灌注。此外，包被毛细血管内皮细胞的血管相关细胞在3、4期糖尿病视网膜病变中特征性丢失。虽然这些表现已被确认为该病的特征，但这些事件的发病年表仍不清楚。在确定毛细血管梗塞、退化和增殖的原发和相关原因方面的一个主要障碍是缺乏足够的分辨率来识别活体眼睛中的这些微观事件。传统的眼底检查方法缺乏必要的分辨率来分辨亚细胞结构，因为眼睛的光学系统使视网膜图像变得模糊。因此，我们将使用自适应光学扫描激光检眼镜(AOSLO)来矫正眼睛的像差，以达到本研究所需的亚细胞分辨率。由于AOSLO是非侵入性的，这种方法的一个好处是可以在疾病的纵向发展过程中对相同的受试者进行成像；不需要进行尸检分析来获得足够的分辨率。我们将在一个表达荧光周细胞的转基因小鼠模型中同时显示周细胞和毛细血管血流。在这个模型中，我们将通过注射链脲佐菌素来诱导类似于人类1型糖尿病的情况，链脲佐菌素是一种选择性地破坏胰腺中产生胰岛素的细胞的试剂。通过跟踪同一动物在几周内毛细血管血流和周细胞密度的逐渐变化，我们试图更好地了解与人类形式的DR！

DESCRIPTION (provided by applicant): It is estimated that 17-34 million have a varying stage of diabetic retinopathy (DR)1. In the US, it is the leading cause of blindness in working age adults and remains a public health problem throughout the world. The earliest manifestations of DR are believed to originate in capillary occlusion 2 resulting in both hypo- and hyperperfusion of regional capillaries. Additionally, vascular associated cells called pericytes which ensheathe the capillary endothelium, are characteristically lost with DR progression3,4. And while these manifestations have been identified as hallmarks of the disease, the pathogenic chronology of these events remain unclear. A major obstacle in identifying the primary and associated cause of capillary infarction, regression and proliferation has been lack of sufficient resolution to identify these microscopic events in the living eye. Traditional fundoscopy approaches lack necessary resolution to resolve sub-cellular structure because the eye's optics blur the retinal image. Therefore, we will use an adaptive optics scanning laser ophthalmoscope (AOSLO) which corrects for the eyes aberrations to achieve sub-cellular resolution needed for this research. Because AOSLO is non-invasive, a benefit of this approach is that the same subjects can be imaged over longitudinal progression of the disease; not requiring post-mortem analysis to acquire sufficient resolution. We will image both pericytes and capillary blood flow in a transgenic mouse model expressing fluorescent pericytes. In this model, we will induce a condition similar to human type-1 diabetes mellitus by injecting streptozotocin, an agent that selectively destroys insulin producing ¿-cells in the pancreas. By tracking the progressive changes in capillary flow and pericyte density in the same animals over the course of weeks, we seek to better understand the chronology of the earliest events related to the human form of DR!