"Good basement membrane" will inhibit diabetic retinopathy

糖尿病视网膜病变的特征是血管生成增加以及血管渗漏导致异常出血。本研究的目的是明确基底膜在糖尿病视网膜病变中的作用。我们假设基底膜的破坏或异常组织化是糖尿病视网膜病变导致血管脆弱性的病理变化的初始步骤，我们重点研究了基底膜的两种成分，层粘连蛋白和IV型胶原。糖尿病视网膜病变的血管渗漏通过腹腔注射链脲佐菌素（STZ）（180mg/kg）制备糖尿病大鼠模型。测量血糖水平。所有大鼠均表现出持续的高血糖水平（> 250mg/dl）。我们用伊文思蓝染色法观察糖尿病大鼠视网膜。尽管处于糖尿病状态，我们的大鼠没有显示出血管渗漏的特殊证据。糖尿病视网膜病变中基底膜成分的分布我们观察了基底膜的主要成分层粘连蛋白和IV型胶原的分布。用抗Ⅳ型胶原α 1~α 6链和层粘连蛋白α 4、α 5链的特异性抗体进行免疫荧光染色分析，在视网膜血管基底膜可见Ⅳ型胶原α 1、α 2链，内界膜可见Ⅳ型胶原α 5、α 6链和Ⅳ型胶原α 1、α 2链的阳性信号。基底膜成分的改变与糖尿病视网膜病变的发生我们认为建立合适的糖尿病视网膜病变模型至关重要。基底膜的转基因动物可能是感兴趣的。

Diabetic retinopathy is characterized as increased angiogenesis as well as leaky vessels resulted in abnormal bleeding. The aim of our study was to define the role of basement membrane for diabetic retinopathy. We hypothesized that a breakdown or an abnormal organization of basement membrane was the initial step of the pathological change in the diabetic retinopathy that leads to the vulnerability of the vessels.We focused on the two components of basement membrane, laminin and type IV collagen.1. Leaky vessels in diabetic retinopathyDiabetic rat model was made by administration of streptozotocin (STZ) (180mg/kg, i.p.). The blood glucose level was measured. All the rats demonstrated continued high blood glucose level (>250mg/dl). We examined the retina of the diabetic rat by using Evans blue staining. Despite the diabetic state, our rats did not show particular evidence of leaky vessels.2. Distribution of basement membrane components in diabetic retinopathyWe examined the distribution of the major components of basement membrane, laminin and type IV collagen. We used specific antibody against from α1 to α6 chains of type IV collagen and α4 and α5 chain of laminin for the immunofluorescent staining analysis.In the vascular basement membrane of the retina, α1 and α2 chains of type IV collagen was observed, while internal limiting membrane (ILM) showed positive signals for α5 and α6 chains of collagen IV as well as α1 and α2 chains of collagen IV.3. The change of basement membrane components and the diabetic retinopathyWe concluded that the establishment of proper model for diabetic retinopathy is crucial. The transgenic animal of basement membrane may be of interest.