Background Mycobacterium tuberculosis infection triggers various forms of host cell death, including ferroptosis in lung epithelial cells; YY1, a critical transcription factor, plays a pivotal role in regulating ferroptosis, however, the underlying mechanisms are not fully understood. Methods To investigate Mycobacterium marinum ( M.marinum )infection in lung epithelial cells A549 and H1299, we utilized flow cytometry to evaluate cell death and measure reactive oxygen species (ROS). Colony-forming unit (CFU) assays determined the intracellular bacterial load. Ferroptosis was analyzed using a specific detection kit to measure malondialdehyde (MDA) and glutathione (GSH) levels. The interaction between the transcription factor YY1 and the iNOS promoter was assessed through a dual-luciferase reporter assay. Results M.marinum induced ferroptosis in lung epithelial cells through invasion. This effect is most pronounced at 8 h of infection and decreases over time but increased with a higher multiplicity of infection (MOI). YY1 knockdown decreases the expression of SLC7A11 and GPX4, attenuates cellular ferroptosis, while YY1 overexpression has the opposite phenomenon, enhancing the expression of bactericidal molecules such as iNOS and MPEG1, thereby markedly reducing the intracellular bacterial load. We identified substantial binding of YY1 to the iNOS promoter region (−655 to −1018 bp), enhancing mycobactericidal activity in YY1-overexpressing cells. Conclusions Our study demonstrates that YY1 inhibits ferroptosis induced by Mycobacterium marinum infection and reduces intracellular bacterial proliferation in lung epithelial cells. These findings provide a crucial basis for developing anti-tuberculosis therapies that target YY1 modulation, potentially offering new clinical avenues for the treatment of tuberculosis.
A highly efficient synthesis of structurally diverse ortho-acylphenol–diindolylmethane hybrids 3 using carboxylic acid-activated chromones as versatile synthetic building blocks is reported here for the first time, through 1,4-nucleophilic addition and followed by a decarboxylation and pyrone ring opening reaction process. The newly synthesized compounds were evaluated for their in vitro anticancer activity, and most of the compounds displayed good anticancer activities against four tested tumor cells (A549, PC-3, NCI-H1299, Caco-2). Among these compounds, compound 3t displayed the most potent and broad-spectrum anti-proliferative inhibition against the tested cell lines, especially A549 cells, and was more potent than arundine and cisplatin drugs, and had selectivity in cancer cells compared to MRC-5 and HK-2 normal cells. Preliminary mechanism studies showed that compound 3t exerted an anti-tumor effect in A549 cells by inhibiting the proliferation, colony formation and migration of A549 cells, and inducing cycle arrest at the G0/G1 phase and apoptosis. Furthermore, treatment of A549 cells with compound 3t caused increased ROS content and induced MMP collapse; western blot analysis showed that the expression level of p53 was significantly increased; Bax/Bcl-2 ratio and Cyt c were increased, and caspase-9, -3, and PARP were cleaved. These studies showed that compound 3t could induce apoptosis of A549 cells through the mitochondrial pathway, which was related to the activation of p53 and the generation of ROS. Thus, our results indicate that compound 3t may be used as a promising skeleton for the development of new anti-tumour drugs.