Histochemical study for apolipoprotein abnormalities in lipoprotein glomerulopathy

我们阐明了使用免疫电镜和系列观察与电子显微镜和脂质染色以及常规组织学，特定的载脂蛋白（apo）E变异体参与形成肾小球内脂蛋白血栓的脂蛋白肾小球病（LPG）的情况下，其实验模型。此外，我们还研究了脂蛋白血栓中颗粒大小与血浆中脂蛋白谱之间的关系。我们分别使用了apoE-仙台（Arg 145 Pro），apoE与18个氨基酸缺失和apoE-东京与3个氨基酸缺失的LPG病例的活检标本。我们还研究了apoE基因缺陷小鼠注射apoE-仙台病毒诱导的LPG模型的组织化学。我们应用抗人apoE抗体对活检标本和小鼠肾脏部分的速冻切片进行免疫过氧化物酶研究，并通过倒立包埋法将切片包埋在Epon 812中进行电镜观察。在人和实验性LPG的肾小球内脂蛋白血栓中，脂颗粒周围均可见apoE阳性染色.为了确定脂蛋白血栓中颗粒的特征，用电子显微镜和Sudan-IV染色观察Epon包埋块的连续切片。结果表明，脂蛋白血栓主要包括甘油三酯，它是由不饱和脂肪酸组成。Epon包埋过程中对苯二胺的孵育增强了实验性LPG的发现。我们在电子显微镜下检查肾小球内脂质颗粒的平均直径，并与血浆中的脂蛋白谱进行比较。结果表明，肾动脉直径与血浆和HDL中的甘油三酯/胆固醇比值呈显著正相关（r=-0.80，p <0.01），而与VLDL和LDL中的甘油三酯/胆固醇比值无显著相关性（r=-0.80，p = 0.01）。

We clarified using immunoelectron microscopy and serial observations with electron microscopy and lipid stain as well as routine histology that specific apolipoprotein (apo) E variants are involved in the formation of intraglomerular lipoprotein thrombi in cases of lipoprotein glomerulopathy (LPG) and its experimental model. In addition, we investigated the relationship between sizes of particles in lipoprotein thrombi and lipoprotein profile in plasma.1. We use biopsy specimens from cases of LPG having apoE-Sendai(Arg145Pro), apoE with 18 amino acid deletion and apoE-Tokyo with 3 amino acid deletion, respectively. We also investigated histochemistry of a LPG model induced by the injection of apoE-Sendai virus into apoE-deficient mice.2. We applied immunoperoxidase study with anti-human apoE antibody to snap-frozen sections of biopsy specimens and mouse kidney portions, and embedded the sections in Epon 812 by the handstand-embedding method for electron microscopic observation. Positive stain of apoE were seen around lipid granules in the intraglomerular lipoprotein thrombi of both human and experimental LPG.3. To define the characteristics of particles in lipoprotein thrombi, serial sections of Epon-embedded blocks were observed with electron microscopy and Sudan-IV stain. The results showed that lipoprotein thrombi mainly included triglycerides, which were composed of unsaturated fatty acids. The findings in experimental LPG were enhanced by incubation in p-phenylenediamine during Epon-embedding.4. We examined the mean diameters of intraglomerular lipid particles under electron microscopy and compared with lipoprotein profile in plasma. The diameters were significantly correlated with triglycerides/cholesterol ratios in whole plasma and in HDL fraction (r=-0.80, p<0.01) but not in VLDL or LDL.In addition, the cases showing smaller lipid granules and higher TG/Chol ratios in plasma and in HDL were nephrotic or became nephrotic within 6 months.