Proteinuria and perinatal lethality in mice lacking NEPH1, a novel protein with homology to NEPHRIN
Proteinuria and perinatal lethality in mice lacking NEPH1, a novel protein with homology to NEPHRIN
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DOI：
10.1128/mcb.21.14.4829-4836.2001
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发表时间：
2001-07-01
影响因子：
5.3
通讯作者：
Powell, DR
中科院分区：
文献类型：
--
作者：
Donoviel, DB;Freed, DD;Powell, DR
采用一种基于胚胎干细胞基因捕获的高通量逆转录病毒介导的突变方法鉴定了一个新的小鼠基因。人直系同源物编码一种含有5个细胞外免疫球蛋白样结构域的跨膜蛋白，该结构域与人NEPHRIN（一种与先天性肾病综合征相关的蛋白质）结构相关。北方分析显示在人类和小鼠中广泛表达，在肾脏中表达最高。基于与NEPHRIN的相似性和在肾脏中的丰富表达，将该蛋白命名为NEPH 1，并且使用在Neph 1基因座中含有逆转录病毒插入的胚胎干细胞来产生突变小鼠。来自Neph 1（-/-）小鼠的肾脏RNA的分析显示逆转录病毒插入破坏了Neph 1转录物的表达，Neph 1（-/-）幼仔在1至3日龄时的预期正常孟德尔比率，但在出生后10至12天仅为预期频率的10%，表明出生后早期致死。存活超过第一周的Neph 1（-/-）动物体弱多病，体型较小，但无水肿，所有动物均在3至8周龄之间死亡。所有Neph 1（-/-）小鼠均出现300 - 2,000 mg/dl的蛋白尿。电镜显示Neph 1（-/-）小鼠肾小球足细胞表达NEPH 1，足细胞足突消失。这些发现表明，NEPH 1和NEPHRIN一样，可能在维持滤过屏障结构中发挥重要作用，该结构可防止蛋白质自由进入肾小球泌尿空间。
A high-throughput, retrovirus-mediated mutagenesis method based on gene trapping in embryonic stem cells was used to identify a novel mouse gene. The human ortholog encodes a transmembrane protein containing five extracellular immunoglobulin-like domains that is structurally related to human NEPHRIN, a protein associated with congenital nephrotic syndrome. Northern analysis revealed wide expression in humans and mice, with highest expression in kidney, Based on similarity to NEPHRIN and abundant expression in kidney, this protein was designated NEPH1 and embryonic stem cells containing the retroviral insertion in the Neph1 locus were used to generate mutant mice, Analysis of kidney RNA from Neph1(-/-) mice showed that the retroviral insertion disrupted expression of Neph1 transcripts, Neph1(-/-) pups were represented at the expected normal Mendelian ratios at 1 to 3 days of age but at only 10% of the expected frequency at 10 to 12 days after birth, suggesting an early postnatal lethality, The Neph1(-/-) animals that survived beyond the first week of life were sickly and small but without edema, and all died between 3 and 8 weeks of age. Proteinuria ranging from 300 to 2,000 mg/dl was present in all Neph1(-/-) mice, Electron microscopy demonstrated NEPH1 expression in glomerular podocytes and revealed effacement of podocyte foot processes in Neph1(-/-) mice. These findings suggest that NEPH1, like NEPHRIN, may play an important role in maintaining the structure of the filtration barrier that prevents proteins from freely entering the glomerular urinary space.