Weiand Matthias, Sandfort Vanessa, Nadzemova Oksana, Schierwagen Robert, Trebicka Jonel, Schlevogt Bernhard, Kabar Iyad, Schmidt Hartmut, Zibert Andree
Medizinische Klinik B, Universitätsklinikum Münster, Münster, Germany.
Department of Gastroenterology, Medical Center Osnabrück, Osnabrück, Germany.
Sci Rep. 2024 Apr 25;14(1):9506. doi: 10.1038/s41598-024-59033-3.
SEC61A1 encodes a central protein of the mammalian translocon and dysfunction results in severe disease. Recently, mutation R236C was identified in patients having autosomal dominant polycystic liver disease (ADPLD). The molecular phenotype of R236C was assessed in two cellular platforms. Cells were immortalized by retroviral transduction of an oncogene (UCi) or reprogrammed to induced pluripotent stem cells (iPSC) that were differentiated to cholangiocyte progenitor-like cells (CPLC). UCi and CPLC were subjected to analyses of molecular pathways that were associated with development of disease. UCi displayed markers of epithelial cells, while CPLCs expressed typical markers of both cholangiocytes and hepatocytes. Cells encoding R236C showed a stable, continuous proliferation in both platforms, however growth rates were reduced as compared to wildtype control. Autophagy, cAMP synthesis, and secretion of important marker proteins were reduced in R236C-expressing cells. In addition, R236C induced increased calcium leakiness from the ER to the cytoplasm. Upon oxidative stress, R236C led to a high induction of apoptosis and necrosis. Although the grade of aberrant cellular functions differed between the two platforms, the molecular phenotype of R236C was shared suggesting that the mutation, regardless of the cell type, has a dominant impact on disease-associated pathways.
SEC61A1编码哺乳动物转位子的一种核心蛋白，其功能障碍会导致严重疾病。最近，在患有常染色体显性多囊肝病（ADPLD）的患者中发现了R236C突变。在两个细胞平台上评估了R236C的分子表型。通过癌基因（UCi）的逆转录病毒转导使细胞永生化，或将其重编程为诱导多能干细胞（iPSC），再将其分化为胆管细胞祖细胞样细胞（CPLC）。对UCi和CPLC进行了与疾病发展相关的分子途径分析。UCi显示出上皮细胞的标志物，而CPLC则表达胆管细胞和肝细胞的典型标志物。编码R236C的细胞在两个平台上均显示出稳定、持续的增殖，然而与野生型对照相比，生长速率降低。在表达R236C的细胞中，自噬、cAMP合成以及重要标志物蛋白的分泌均减少。此外，R236C导致从内质网到细胞质的钙泄漏增加。在氧化应激下，R236C导致细胞凋亡和坏死的高度诱导。尽管两个平台之间异常细胞功能的程度有所不同，但R236C的分子表型是相同的，这表明该突变无论细胞类型如何，对疾病相关途径都有主要影响。
