The altered glomerular filtration slits seen in puromycin aminonucleoside nephrosis and protamine sulfate-treated rats contain the tight junction protein ZO-1.
The altered glomerular filtration slits seen in puromycin aminonucleoside nephrosis and protamine sulfate-treated rats contain the tight junction protein ZO-1.
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发表时间：
1992-10
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通讯作者：
H. Kurihara;James M. Anderson;D. Kerjaschki;M. Farquhar
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作者：
H. Kurihara;James M. Anderson;D. Kerjaschki;M. Farquhar
嘌呤霉素氨基糖苷治疗（PAN）诱导的大鼠肾病导致肾小球滤过狭缝膜由新形成的细胞间闭塞型连接顶端移位。硫酸鱼精蛋白（PS）急性肾灌注也可引起类似的变化。我们已经调查了这些改变路口使用ZO-1，一种蛋白质的抗体分子的性质，发现专门在紧密连接。免疫印迹显示ZO-1，一个225 kd的带，在肾小球提取物的正常，PAN，和PS处理的大鼠。通过免疫荧光法，ZO-1定位于足细胞的底部，勾勒出所有三个实验组的肾小球毛细血管袢。在电子显微镜水平，使用免疫过氧化物酶或免疫金标记，ZO-1集中沿着细胞质表面的正常大鼠的狭缝隔膜。在PAN或PS大鼠中，它沿着新形成的闭塞型连接和剩余的狭缝隔膜集中。当podocalyxin（足细胞的主要膜唾液蛋白）也同样定位，它被发现完全顶端的位移狭缝膜。基于形态学和ZO-1的存在，在PAN和PS大鼠中观察到的改变的连接似乎代表真正的紧密连接。它们在PS处理的大鼠中的快速（15分钟）诱导表明，在通过聚阳离子灌注中和细胞表面电荷时，从预先存在的连接蛋白池形成不连续的紧密连接。这些研究结果提出了肾小球水力传导率可能部分通过调节局部紧密连接组装的相对通畅性和过滤缝隙宽度来调节的可能性。
Nephrosis induced in rats by puromycin aminonucleoside treatment (PAN) results in the apical displacement of the glomerular filtration slit membrane by newly formed, intercellular occluding-type junctions. Similar changes can also be induced by acute kidney perfusion with protamine sulfate (PS). We have investigated the molecular nature of these altered junctions using an antibody to ZO-1, a protein found exclusively in tight junctions. Immunoblotting demonstrates ZO-1, a 225-kd band, in glomerular extracts of normal, PAN-, and PS-treated rats. By immunofluorescence, ZO-1 was localized at the base of podocytes outlining the capillary loops of glomeruli from all three experimental groups. At the electron microscope level, using immunoperoxidase or immunogold labeling, ZO-1 was concentrated along the cytoplasmic surfaces of the slit diaphragms of normal rats. In PAN or PS rats, it was concentrated along both the newly formed occluding-type junctions and the remaining slit diaphragms. When podocalyxin (the major membrane sialoprotein of the podocyte) was similarly localized, it was found exclusively apical to the displaced slit membrane. Based on morphology and the presence of ZO-1, the altered junctions seen in PAN and PS rats appear to represent bona fide tight junctions. Their rapid (15-minute) induction in PS-treated rats suggests that on neutralization of the cell surface charge by polycation perfusion, discontinuous tight junctions form from a preexisting pool of junctional proteins. These findings raise the possibility that glomerular hydraulic conductivity may be regulated in part by regulating the relative patency and width of the filtration slits through focal tight junction assembly.