Chartier Aymeric, Raz Vered, Sterrenburg Ellen, Verrips C Theo, van der Maarel Silvère M, Simonelig Martine
mRNA Regulation and Development, Institut de Génétique Humaine, CNRS UPR 1142, Montpellier, France.
Hum Mol Genet. 2009 May 15;18(10):1849-59. doi: 10.1093/hmg/ddp101. Epub 2009 Mar 3.
Oculopharyngeal muscular dystrophy (OPMD) is a late onset disorder characterized by progressive weakening of specific muscles. It is caused by short expansions of the N-terminal polyalanine tract in the poly(A) binding protein nuclear 1 (PABPN1), and it belongs to the group of protein aggregation diseases, such as Huntington's, Parkinson's and Alzheimer diseases. Mutant PABPN1 forms nuclear aggregates in diseased muscles in both patients and animal models. Intrabodies are antibodies that are modified to be expressed intracellularly and target specific antigens in subcellular locations. They are commonly generated by artificially linking the variable domains of antibody heavy and light chains. However, natural single-chain antibodies are produced in Camelids and, when engineered, combined the advantages of being single-chain, small sized and very stable. Here, we determine the in vivo efficiency of Llama intrabodies against PABPN1, using the established Drosophila model of OPMD. Among six anti-PABPN1 intrabodies expressed in muscle nuclei, we identify one as a strong suppressor of OPMD muscle degeneration in Drosophila, leading to nearly complete rescue. Expression of this intrabody affects PABPN1 aggregation and restores muscle gene expression. This approach promotes the identification of intrabodies with high therapeutic value and highlights the potential of natural single-chain intrabodies in treating protein aggregation diseases.
眼咽型肌营养不良症（OPMD）是一种迟发性疾病，其特征是特定肌肉逐渐衰弱。它是由聚腺苷酸结合蛋白细胞核1（PABPN1）中N端多聚丙氨酸序列的短片段扩增引起的，属于蛋白质聚集性疾病，如亨廷顿舞蹈症、帕金森病和阿尔茨海默病。在患者和动物模型的患病肌肉中，突变的PABPN1会形成核内聚集体。胞内抗体是经过修饰后可在细胞内表达并靶向亚细胞位置特定抗原的抗体。它们通常通过人工连接抗体重链和轻链的可变结构域产生。然而，天然单链抗体是在骆驼科动物中产生的，经过改造后，兼具单链、体积小和非常稳定的优点。在这里，我们利用已建立的OPMD果蝇模型，确定了羊驼胞内抗体针对PABPN1的体内效率。在肌肉细胞核中表达的六种抗PABPN1胞内抗体中，我们鉴定出一种是果蝇OPMD肌肉退化的强效抑制剂，几乎能完全挽救。这种胞内抗体的表达影响PABPN1聚集并恢复肌肉基因表达。这种方法有助于识别具有高治疗价值的胞内抗体，并突出了天然单链胞内抗体在治疗蛋白质聚集性疾病方面的潜力。
