Kakimoto Tetsuhiro, Okada Kinya, Fujitaka Keisuke, Nishio Masashi, Kato Tsuyoshi, Fukunari Atsushi, Utsumi Hiroyuki
Safety Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Toda-shi 335-8505, Saitama, Japan.
Advanced Medical Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Toda-shi 335-8505, Saitama, Japan.
Exp Toxicol Pathol. 2015 Feb;67(2):171-7. doi: 10.1016/j.etp.2014.11.007. Epub 2014 Dec 4.
Podocytes are an essential component of the renal glomerular filtration barrier, their injury playing an early and important role in progressive renal dysfunction. This makes quantification of podocyte marker immunoreactivity important for early detection of glomerular histopathological changes. Here we have specifically applied a state-of-the-art automated computational method of glomerulus recognition, which we have recently developed, to study quantitatively podocyte markers in a model with selective podocyte injury, namely the rat puromycin aminonucleoside (PAN) nephropathy model. We also retrospectively investigated mRNA expression levels of these markers in glomeruli which were isolated from the same formalin-fixed, paraffin-embedded kidney samples by laser microdissection. Among the examined podocyte markers, the immunopositive area and mRNA expression level of both podoplanin and synaptopodin were decreased in PAN glomeruli. The immunopositive area of podocin showed a slight decrease in PAN glomeruli, while its mRNA level showed no change. We have also identified a novel podocyte injury marker β-enolase, which was increased exclusively by podocytes in PAN glomeruli, similarly to another widely used marker, desmin. Thus, we have shown the specific application of a state-of-the-art computational method and retrospective mRNA expression analysis to quantitatively study the changes of various podocyte markers. The proposed methods will open new avenues for quantitative elucidation of renal glomerular histopathology.
足细胞是肾小球滤过屏障的重要组成部分,其损伤在进行性肾功能障碍的早期及发展过程中起重要作用。这使得对足细胞标志物免疫反应性进行定量分析对于早期检测肾小球组织病理学变化具有重要意义。在此,我们专门应用了一种最新的肾小球识别自动化计算方法(这是我们最近开发的),来定量研究选择性足细胞损伤模型(即大鼠嘌呤霉素氨基核苷(PAN)肾病模型)中的足细胞标志物。我们还回顾性研究了通过激光显微切割从相同的福尔马林固定、石蜡包埋肾脏样本中分离出的肾小球中这些标志物的mRNA表达水平。在所检测的足细胞标志物中,PAN肾小球中足板蛋白和突触素的免疫阳性面积及mRNA表达水平均降低。足蛋白的免疫阳性面积在PAN肾小球中略有降低,但其mRNA水平无变化。我们还鉴定出一种新型足细胞损伤标志物β-烯醇化酶,与另一种广泛使用的标志物结蛋白类似(在PAN肾小球中仅由足细胞升高)。因此,我们展示了一种最新计算方法及回顾性mRNA表达分析在定量研究各种足细胞标志物变化方面的具体应用。所提出的方法将为定量阐明肾小球组织病理学开辟新途径。