Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul, Brazil.
Programa de Pós-Graduação em Medicina e Ciências da Saúde, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Microbiol Spectr. 2022 Aug 31;10(4):e0072822. doi: 10.1128/spectrum.00728-22. Epub 2022 Jul 14.
Tuberculosis (TB) remains one of the leading causes of death due to a single pathogen. The emergence and proliferation of multidrug-resistant (MDR-TB) and extensively drug-resistant strains (XDR-TB) represent compelling reasons to invest in the pursuit of new anti-TB agents. The shikimate pathway, responsible for chorismate biosynthesis, which is a precursor of important aromatic compounds, is required for Mycobacterium tuberculosis growth. The enzyme 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAHPS) catalyzes the first step in the shikimate pathway and it is an attractive target for anti-tubercular agents. Here, we used a CRISPRi system to evaluate the DAHPS as a vulnerable target in M. tuberculosis. The silencing of significantly reduces the M. tuberculosis growth in both rich medium and, especially, in infected murine macrophages. The supplementation with amino acids was only able to partially rescue the growth of bacilli, whereas the Aro supplement (aromix) was enough to sustain the bacterial growth at lower rates. This study shows that DAHPS protein is vulnerable and, therefore, an attractive target to develop new anti-TB agents. In addition, the study contributes to a better understanding of the biosynthesis of aromatic compounds and the bacillus physiology. Determining the vulnerability of a potential target allows us to assess whether its partial inhibition will impact bacterial growth. Here, we evaluated the vulnerability of the enzyme 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAHPS) from M. tuberculosis by silencing the DAHPS-coding gene in different contexts. These results could lead to the development of novel and potent anti-tubercular agents in the near future.
结核病（TB）仍然是单一病原体导致死亡的主要原因之一。耐多药（MDR-TB）和广泛耐药（XDR-TB）菌株的出现和扩散是投资研发新抗结核药物的重要原因。莽草酸途径负责分支酸的生物合成，分支酸是重要芳香族化合物的前体，是结核分枝杆菌生长所必需的。酶 3-脱氧-D-阿拉伯庚酮糖 7-磷酸合酶（DAHPS）催化莽草酸途径的第一步，是抗结核药物的一个有吸引力的靶标。在这里，我们使用 CRISPRi 系统来评估 DAHPS 在结核分枝杆菌中的脆弱靶标。沉默 显著降低了结核分枝杆菌在丰富培养基中的生长，尤其是在感染的鼠巨噬细胞中。补充氨基酸只能部分挽救细菌的生长，而 Aro 补充剂（aromix）足以维持较低速率的细菌生长。这项研究表明 DAHPS 蛋白是脆弱的，因此是开发新的抗结核药物的有吸引力的靶标。此外，该研究有助于更好地了解芳香族化合物的生物合成和芽孢杆菌的生理学。确定潜在靶标的脆弱性可以评估其部分抑制是否会影响细菌的生长。在这里，我们通过沉默结核分枝杆菌中编码 DAHPS 的 基因，在不同的环境中评估了酶 3-脱氧-D-阿拉伯庚酮糖 7-磷酸合酶（DAHPS）的脆弱性。这些结果可能会导致在不久的将来开发出新型有效的抗结核药物。
