Nonsense codons suppression. An acute toxicity study of three optimized TRIDs in murine model, safety and tolerability evaluation.

Stop mutations cause 11% of the genetic diseases, due to the introduction of a premature termination codon (PTC) in the mRNA, followed by the production of a truncated protein. A promising therapeutic approach is the suppression therapy by Translational Readthrough Inducing Drugs (TRIDs), restoring the expression of the protein. Recently, three new TRIDs (NV848, NV914, NV930) have been proposed, and validated by several in vitro assays, for the rescue of the CFTR protein, involved in Cystic Fibrosis disease. In this work, an acute toxicological study for the three TRIDs was conducted in vivo on mice, according to the OECD No.420 guidelines. Animals were divided into groups and treated with …

RESCUE OF LRBA GENE EXPRESSION IN PRIMARY HUMAN FIBROBLASTS CHARACTERISED BY NONSENSE MUTATION c. 5047 (C>T).

Primary immunodeficiencies (PIDs) are rare genetic diseases characterized by susceptibility to infections, increased risk of autoimmunity, hypogammaglobulinemia, and lymphoproliferative syndromes. PIDs are associated to genetic alterations in about 400 known genes, among which, mutations of the LRBA gene. LRBA gene encodes a widely expressed multi-domain protein with highly conserved BEACH domain, involved in regulation of endosomal trafficking, particularly endocytosis of ligand-activated receptors. It was reported that stop mutations affect this gene leading to the loss of the protein expression. Recently, we identified three Translational Readthrough Inducing Drug (TRID), that showed hig…

The innovative role of the readthrough inducing drugs in the translation rescue of mRNAs characterized by premature stop codon (PTCs).

Translational readthrough inducing drugs: a study of toxicity in mice models and in vitro safety validation of the specific readthrough process.

Objective Nonsense mutations are responsible for 15% of Cystic Fibrosis (CF) patients due to the introduction of a premature stop codon (PTC) in the mRNA and the production of a truncated CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) protein1. A promising therapeutic approach for stop mutations is the suppression therapy by Translational Readthrough Inducing Drugs (TRIDs) to restore the expression of the protein2,3. Recently three new TRIDS (NV848, NV914, NV930) have been proposed and validated by several assays. Our work was focused on TRIDs NV848, NV914, NV930. Important aspects of TRIDs to be evaluated are their specificity towards PTC, to demonstrate that TRIDs do not inter…

Pharmacophore-Based Design of New Chemical Scaffolds as Translational Readthrough-Inducing Drugs (TRIDs)

[Image: see text] Translational readthrough-inducing drugs (TRIDs) rescue the functional full-length protein expression in genetic diseases, such as cystic fibrosis, caused by premature termination codons (PTCs). Small molecules have been developed as TRIDs to trick the ribosomal machinery during recognition of the PTC. Herein we report a computational study to identify new TRID scaffolds. A pharmacophore approach was carried out on compounds that showed readthrough activity. The pharmacophore model applied to screen different libraries containing more than 87000 compounds identified four hit-compounds presenting scaffolds with diversity from the oxadiazole lead. These compounds have been s…

Inhibition of FTSJ1, a tryptophan tRNA-specific 2’-O-methyltransferase as possible mechanism to readthrough premature termination codons (UGAs) of the CFTR mRNA

Cystic Fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene, coding for the CFTR chloride channel. About 10 % of the mutations affecting the CFTR gene are "stop" mutations, which generate a Premature Termination Codon (PTC), thus resulting in the synthesis of a truncated CFTR protein. A way to bypass PTC relies on ribosome readthrough, that is the capacity of the ribosome to skip a PTC, thus generating a full-length protein. “TRIDs” are molecules exerting ribosome readthrough and for some of them the mechanism of action is still under debate. By in silico analysis as well as in vitro studies, we investigate a possible mechanism of action (MOA) by whic…

STUDY OF SMALL MOLECULES IN THE FIGHT AGAINST NONSENSE AND SPLICING MUTATIONS THAT CAUSE CYSTIC FIBROSIS.

Readthrough Inducing Drugs (TRIDs) in human fibroblasts harboring the c.5047 C>T (R1683*) nonsense mutation