Comparative in vitro and ex vivo activities of selected inhibitors of transthyretin aggregation: relevance in drug design

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Isabel Cardoso (Author) Other; Maria Rosario Almeida (Author) ICBAS; Nelson Ferreira (Author) Other; Gemma Arsequell (Author) Other; Gregorio Valencia (Author) Other; Maria Joao Saraiva (Author) ICBAS

Journal

Title: Biochemical Journal

Vol. 408

Pages: 131-138

ISSN: 0264-6021

Publisher: PORTLAND PRESS LTD

Indexing

ISI Web of Knowledge - 24 Citations

Scopus - 29 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-004-69G

DOI: 10.1042/bj20070689

Abstract (EN): Destabilization of the tetrameric fold of TTR (transthyretin) is important for aggregation of the protein which culminates in amyloid fibril formation. Many TTR mutations interfere with tetramer stability, increasing the amyloidogenic potential of the protein. The vast majority of proposed TTR fibrillogenesis inhibitors are based on in vitro assays with isolated protein, limiting their future use in clinical assays. In the present study we investigated TTR fibrillogenesis inhibitors using a cellular system that produces TTR intermediates/aggregates in the medium. Plasmids carrying wild-type TTR, V30M or L55P cDNA were transfected into a rat Schwannoma cell line and TTR aggregates were investigated in the medium using a dot-blot filter assay followed by immunodetection. Results showed that, in 24 h, TTR L55P forms aggregates in the medium, whereas, up to 72 h, wildtype TTR and V30M do not. A series of 12 different compounds, described in the literature as in vitro TTR fibrillogenesis inhibitors, were tested for their ability to inhibit L55P aggregate formation; in this system, 2-[(3,5-dichlorophenyl) amino] benzoic acid, benzoxazole, 4-(3,5-difluorophenyl) benzoic acid and tri-iodophenol were the most effective inhibitors, as compared with the reference iododiflunisal, previously shown by ex vivo and in vitro procedures to stabilize TTR and inhibit fibrillogenesis. Among these drugs, 2-[(3,5-dichlorophenyl) amino] benzoic acid and tri-iodophenol stabilized TTR from heterozygotic carriers of V30M in the same ex vivo conditions as those used previously for iododiflunisal. The novel cellular-based test herein proposed for TTR fibrillogenesis inhibitor screens avoids not only lengthy and cumbersome large-scale protein isolation steps but also artefacts associated with most current in vitro first-line screening methods, such as those associated with acidic conditions and the absence of serum proteins.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8