顶膜上皮细胞是位于Bowman囊上的一群异质细胞。这些细胞被认为通过一种尚未确定的机制内化白蛋白，尽管已经证明白蛋白能够诱导顶膜上皮细胞的表型变化。近曲小管细胞是通过ClC-5、megalin和cubilin组成的高分子复合物来处理白蛋白的主要参与者。本研究调查了ClC-5、megalin和cubilin在蛋白尿性狼疮性肾炎患者和对照组患者的肾活检标本中对顶膜上皮细胞的作用，并确定了发生在病理环境中的表型改变。对Lupus Nephritis患者的23例肾活检标本和9例对照活检标本（从肾癌切除术中获得）进行了ClC-5、megalin、cubilin、ANXA3、podocalyxin、CD24、CD44、HSA和LTA标记的免疫组化和免疫荧光分析。我们鉴定并描述了两个亚群的肥大顶膜上皮细胞，即ANXA3+/Podocalyxin-/CD44-，都表达ClC-5、megalin和cubilin，并位于近曲小管极：第一个亚群，CD24+/HSA-/LTA-，具有人类成年顶膜上皮多能祖细胞的特征；第二个亚群，CD24-/LTA+/HSA+，有成为表型上皮细胞的近曲小管细胞的承诺。在狼疮性肾炎患者中，ClC-5、megalin和cubilin阳性的肥大顶膜上皮细胞的肾小球数量明显高于对照组。我们的结果可能进一步揭示了位于近曲小管极位置的肥大顶膜上皮细胞在狼疮性肾炎患者蛋白内吞作用中的作用。这些数据还表明，在Bowman囊中存在的肥大顶膜上皮细胞可能是对其他肾小球肾炎中观察到的蛋白负荷做出反应的潜在资源。© 2023. 作者（们）。

Parietal epithelial cells are a heterogeneous population of cells located on Bowman's capsule. These cells are known to internalize albumin with a still undetermined mechanism, although albumin has been shown to induce phenotypic changes in parietal epithelial cells. Proximal tubular cells are the main actors in albumin handling via the macromolecular complex composed by ClC-5, megalin, and cubilin. This study investigated the role of ClC-5, megalin, and cubilin in the parietal epithelial cells of kidney biopsies from proteinuric lupus nephritis patients and control subjects and identified phenotypical changes occurring in the pathological milieu.Immunohistochemistry and immunofluorescence analyses for ClC-5, megalin, cubilin, ANXA3, podocalyxin, CD24, CD44, HSA, and LTA marker were performed on 23 kidney biopsies from patients with Lupus Nephritis and 9 control biopsies (obtained from nephrectomies for renal cancer).Two sub-populations of hypertrophic parietal epithelial cells ANXA3+/Podocalyxin-/CD44-, both expressing ClC-5, megalin, and cubilin and located at the tubular pole, were identified and characterized: the first one, CD24+/HSA-/LTA- had characteristics of human adult parietal epithelial multipotent progenitors, the second one, CD24-/LTA+/HSA+ committed to become phenotypically proximal tubular cells. The number of glomeruli presenting hypertrophic parietal epithelial cells positive for ClC-5, megalin, and cubilin were significantly higher in lupus nephritis patients than in controls.Our results may provide further insight into the role of hypertrophic parietal epithelial cells located at the tubular pole and their possible involvement in protein endocytosis in lupus nephritis patients. These data also suggest that the presence of hypertrophic parietal epithelial cells in Bowman's capsule represents a potential resource for responding to protein overload observed in other glomerulonephritis.© 2023. The Author(s).