Bifunctional carbazole derivatives for simultaneous therapy and fluorescence imaging in prion disease murine cell models

• Published in: European journal of medicinal chemistry Vol. 245; no. Pt 1; pp. 114923 - 114936
• Main Authors: Staderini, Matteo, Vanni, Silvia, Baldeschi, Arianna Colini, Giachin, Gabriele, Zattoni, Marco, Celauro, Luigi, Ferracin, Chiara, Bistaffa, Edoardo, Moda, Fabio, Pérez, Daniel I., Martínez, Ana, Martín, M. Antonia, Martín-Cámara, Olmo, Cores, Ángel, Bianchini, Giulia, Kammerer, Robert, Menéndez, J. Carlos, Legname, Giuseppe, Bolognesi, Maria Laura
• Format: Journal Article
• Language: English
• Published: ISSY-LES-MOULINEAUX Elsevier Masson SAS 05.01.2023; Elsevier
• Subjects: Animals; Carbazoles; Carbazoles - chemistry; Carbazoles - pharmacology; Carbazoles - therapeutic use; Cell Line; Chemistry, Medicinal; GN8; Life Sciences & Biomedicine; Mice; Optical Imaging; Pharmacology & Pharmacy; Prion Diseases - diagnosis; Prion Diseases - drug therapy; Prion protein; Prions; Protein Aggregates - drug effects; PrPC Proteins - antagonists & inhibitors; PrPC Proteins - chemistry; Science & Technology; Theranostics; GN8; Carbazoles; Prion protein; Theranostics; Prions; PROTEIN; REPLICATION; INHIBITION; MISFOLDING CYCLIC AMPLIFICATION; ALZHEIMERS; AGGREGATION
• ISSN: 0223-5234; 1768-3254
• DOI: 10.1016/j.ejmech.2022.114923

Prion diseases are characterized by the self-assembly of pathogenic misfolded scrapie isoforms (PrPSc) of the cellular prion protein (PrPC). In an effort to achieve a theranostic profile, symmetrical bifunctional carbazole derivatives were designed as fluorescent rigid analogues of GN8, a pharmacological chaperone that stabilizes the native PrPC conformation and prevents its pathogenic conversion. A focused library was synthesized via a four-step route, and a representative member was confirmed to have native fluorescence, including a band in the near-infrared region. After a cytotoxicity study, compounds were tested on the RML-infected ScGT1 neuronal cell line, by monitoring the levels of protease-resistant PrPSc. Small dialkylamino groups at the ends of the molecule were found to be optimal in terms of therapeutic index, and the bis-(dimethylaminoacetamido)carbazole derivative 2b was selected for further characterization. It showed activity in two cell lines infected with the mouse-adapted RML strain (ScGT1 and ScN2a). Unlike GN8, 2b did not affect PrPC levels, which represents a potential advantage in terms of toxicity. Amyloid Seeding Assay (ASA) experiments showed the capacity of 2b to delay the aggregation of recombinant mouse PrP. Its ability to interfere with the amplification of the scrapie RML strain by Protein Misfolding Cyclic Amplification (PMCA) was shown to be higher than that of GN8, although 2b did not inhibit the amplification of human vCJD prion. Fluorescent staining of PrPSc aggregates by 2b was confirmed in living cells. 2b emerges as an initial hit compound for further medicinal chemistry optimization towards strain-independent anti-prion compounds. [Display omitted] •Synthesis of a new generation of carbazole derivatives for concomitant treatment and diagnosis of prion diseases.•The carbazole derivatives were designed as fluorescent rigid analogues of GN8, an antiprion compound.•Many of the compounds showed antiprion activity in two infected cell lines.•The best-performing compound was able to reduce and stain at the same time prion aggregates in cell models.