PDF(Pubmed)
Abstract：
The main characteristic of polycystic kidney disease is the development of multiple fluid-filled renal cysts. The discovery of mislocalized sodium-potassium pump (Na,K-ATPase) in the apical membrane of cyst-lining epithelia alluded to reversal of polarity as a possible explanation for the fluid secretion. The topic of apical Na,K-ATPase in cysts remains controversial. We investigated the localization of the Na,K-ATPase and assessed the apical-basolateral polarization of cyst-lining epithelia by means of immunohistochemistry in kidney tissue from six polycystic kidney disease patients undergoing nephrectomy. The Na,K-ATPase α1 subunit was conventionally situated in the basolateral membrane of all immunoreactive cysts. Proteins of the Crumbs and partitioning defective (Par) complexes were localized to the apical membrane domain in cyst epithelial cells. The apical targeting protein Syntaxin-3 also immunolocalized to the apical domain of cyst-lining epithelial cells. Proteins of the basolateral Scribble complex immunolocalized to the basolateral domain of cysts. Thus, no deviations from the typical epithelial distribution of basic cell polarity proteins were observed in the cysts from the six patients. Furthermore, we confirmed that cysts can originate from virtually any tubular segment with preserved polarity. In conclusion, we find no evidence of a reversal in apical-basolateral polarity in cyst-lining epithelia in polycystic kidney disease.
摘要：
多囊肾病的主要特征是多个充满液体的肾囊肿的发展。发现错位的钠钾泵（Na，K-ATPase）在囊肿衬里上皮的顶端膜中，暗示极性逆转是对液体分泌的可能解释。根尖Na的主题，囊肿中的K-ATP酶仍存在争议。我们调查了Na的定位，K-ATPase并通过免疫组织化学在6例接受肾切除术的多囊肾病患者的肾组织中评估了囊肿衬里上皮的顶端-基底外侧极化。Na,K-ATPaseα1亚基通常位于所有免疫反应性囊肿的基底外侧膜中。面包屑和分配缺陷（Par）复合物的蛋白质定位于囊肿上皮细胞的顶端膜结构域。顶端靶向蛋白Syntaxin-3也免疫定位到囊肿衬里上皮细胞的顶端结构域。基底外侧涂鸦复合物的蛋白质免疫定位到囊肿的基底外侧域。因此，在6例患者的囊肿中未观察到碱性细胞极性蛋白的典型上皮分布的偏差.此外，我们证实，囊肿可以起源于几乎任何保留极性的肾小管段。总之,我们没有发现多囊肾病囊肿衬里上皮根尖-基底外侧极性逆转的证据.
