Uma abordagem multi-alvo sustentável para desligar o metabolismo energético do Mycobacterium tuberculosis

The ShutdownTB project will address the needs of modern antimycobacterial drug discovery targeting the mycobacterial energy metabolism as an underexploited but highly promising TB therapy. The rationale for this approach stems from the fact that M.tb relies on ATP for optimal growth, persistence, and pathogenicity. Production of ATP utilizes the energy stored through a transmembrane electrochemical potential difference generated by the respiratory electron transport chain (ETC). The synthesis of ATP occurs even in low oxygen conditions, as those commonly found in remote parts of human lungs or inside phagosomes of human macrophages. Thus, targeting the ETC with small molecules to disrupt ATP production is a valuable strategy to kill both replicant and latent mycobacteria and prevent resistance. The focus of ShutdownTB is to identify viable lead candidates capable of targeting the ETC, leading to disruption of ATP production and killing latent M.tb. This project leverages on a set of unique hit compounds containing the unique pyrroloquinolone chemotype, that emerged from the screening of iMed chemical library against M.tb, (Fig. 1). ShutdownTB will provide an insight on how these hits bind to mycobacterial cyt-bcc, and this information will then be used to progress them to validated lead candidates with capability of inhibiting bacterial growth. Multi-targeting energy metabolism in M.tb will also be explored by enabling site-specific release of NO radical to interfere with ETC and ATP production. The specific research objectives are: Objective 1. Generative AI-driven optimization of a series of pyrroloquinolones, leading to candidates with improved affinity toward cyt-bcc and capable of inhibiting bacterial growth, including in MDR and XDR strains; Objective 2. Development of hybrid compounds for dual-targeting the mycobacterial energy metabolism, combining cyt-bcc inhibitors with a NO-releasing warhead, capable to interfere with ETC components, shutdown the ATP production, and active against replicant and latent forms of M.tb; Objective 3. Deliver a pre-clinical candidate, with validated mechanism of action, adequate physicochemical properties, and evidence of oral exposure in an in vivo pharmacokinetic (PK) model. To accomplish these specific goals, we propose two different approaches. First, multimodal generative AI will be used to design pyrroloquinolones conditioned by the putative cyt-bcc binding pocket architecture. The most promising compounds, which comply with an appropriate predicted ADME profile, will be synthesised and tested in our in vitro screening platform. The second approach consists in designing resistance evasive multi-targeting hybrid molecules, capable of inhibiting cyt bcc and releasing NO upon selective activation in mycobacteria, to shut down energy metabolism. SAR data from the AI-driven optimisation will guide the selection of the cyt-bcc inhibitors to be ligated to NO generating moieties. The most potent compounds identified from both approaches will then be subject to in vivo PK studies. Uncovering new chemical entities with innovative or underexploited mechanisms of mycobacterial killing is aligned with the WHO agenda. Targeting the mycobacterial energy metabolism is an emerging attractive approach to deliver major breakthroughs for new and shorter TB treatments, and successful completion of ShutdownTB will contribute to narrow the gap on translational application of novel therapeutics to treat TB.