Download MendeleyEfficacy and Mode of Action of a Direct Inhibitor of Mycobacterium abscessus InhA.
Alcaraz, M., Roquet-Baneres, F., Leon-Icaza, S.A., Abendroth, J., Boudehen, Y.M., Cougoule, C., Edwards, T.E., Kremer, L.(2022) ACS Infect Dis 8: 2171-2186
- PubMed: 36107992
- DOI: https://doi.org/10.1021/acsinfecdis.2c00314
- Primary Citation of Related Structures:
7KLI, 7L6C, 7U0M - PubMed Abstract:
There is an unmet medical need for effective treatments against Mycobacterium abscessus pulmonary infections, to which cystic fibrosis (CF) patients are particularly vulnerable. Recent studies showed that the antitubercular drug isoniazid is inactive against M. abscessus due to the incapacity of the catalase-peroxidase to convert the pro-drug into a reactive metabolite that inhibits the enoyl-ACP reductase InhA. To validate InhA MAB as a druggable target in M. abscessus , we assayed the activity of NITD-916, a 4-hydroxy-2-pyridone lead candidate initially described as a direct inhibitor of InhA that bypasses KatG bioactivation in Mycobacterium tuberculosis . The compound displayed low MIC values against rough and smooth clinical isolates in vitro and significantly reduced the bacterial burden inside human macrophages. Moreover, treatment with NITD-916 reduced the number and size of intracellular mycobacterial cords, regarded as markers of the severity of the infection. Importantly, NITD-916 significantly lowered the M. abscessus burden in CF-derived lung airway organoids. From a mechanistic perspective, NITD-916 abrogated de novo synthesis of mycolic acids and NITD-916-resistant spontaneous mutants harbored point mutations in InhA MAB at residue 96. That NITD-916 targets InhA MAB directly without activation requirements was confirmed genetically and by resolving the crystal structure of the protein in complex with NADH and NITD-916. These findings collectively indicate that InhA MAB is an attractive target to be exploited for future chemotherapeutic developments against this difficult-to-treat mycobacterium and highlight the potential of NITD-916 derivatives for further evaluation in preclinical settings.
Organizational Affiliation:
Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France.
