New therapeutic options for GNE Myopathy: in silico and in vitro approaches to accelerate drug discovery pipeline

• Autor(a) principal: Cunha, Joana Sousa
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/161275
• topic: Glycosylation; GNE Myopathy; Sialic acid; Prodrugs; Hepatotoxicity; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Rare Diseases (RDs) pose a significant challenge. Almost 8,000 RDs are known, but only 200 have a treatment. The development of drugs is an extensive and costly process and in silico tools have gained a particular interest in the last decade by giving insights into drug metabolization and interaction with biological targets. Defective glycosylation leads to a family of RDs known as congenital disorders of glycosylation (CDG). GNE Myopathy (GNEM) is an ultra-rare CDG caused by mutations in the GNE gene responsible for encoding the bifunctional enzyme UDP-N-acetylglucosamine 2-epimerase/ N-acetylmannosamine kinase that regulates the sialic acid biosynthesis. To date, there is no approved therapy for GNEM but supplementation approaches with sialic acid and its precursors have been studied. In this work, in silico tools were used to explore the absorption, distribution, metabolism, excretion and toxicity properties, as well as off-target interactions of five novel prodrugs (PGNE 1-5) for treating GNEM. These prodrugs are predicted to have a potential advantage in terms of absorption when compared with N-acetylmannosamine, which is currently in a phase 2 clinical trial. However, PGNE 1-5 display concerning toxicological indicators namely related to hepatotoxicity. These alerts may be attributed to interactions with proteins involved in distribution (P-glycoprotein) and metabolism (cytochrome P450 3A4 and carboxylesterase 1). To evaluate the extension of the hepatotoxicity predictions and the safety of the prodrugs, in vitro studies were conducted by using a hepatic and a GNEM cell model, respectively. The viability assays did not confirm the toxicity alerts and indicate that the prodrugs are safe within the tested concentrations. In conclusion, while in silico assessments raised concerns about potential hepatotoxicity, our in vitro studies promised the safety of the tested prodrugs, emphasizing the urgency of investigating their efficacy as prospective treatments for GNEM.