Sp1-Mettl14 Feedback Loop Promotes Ferroptosis in Mycobacterium tuberculosis-Infected Microglia by Activating Acsl4.

Central nervous system tuberculosis (CNS-TB) represents a critical form of extrapulmonary tuberculosis, characterized by high mortality and morbidity. The infection of microglia by Mycobacterium tuberculosis (Mtb) is a crucial factor in the progression of CNS-TB. Ferroptosis plays a significant role in various neurological disorders. However, it remains unclear whether Mtb can induce ferroptosis in microglia and what mechanisms underlie this process. This study demonstrated that Mtb H37Rv infection can induce ferroptosis in microglia, which is characterized by the accumulation of ferrous ions, increased levels of lipid ROS, depletion of glutathione, enhanced lipid peroxidation and reduced expression of Slc7a11 and Gpx4. Additionally, Mtb infection upregulated Sp1 expression, and Sp1 knockdown led to a suppression of ferroptosis induced by Mtb. Mechanistically, we found that Sp1 enhanced the transcription of Mettl14. Subsequently, the N6-methyladenosine modification mediated by Mettl14 stabilized the mRNA of Acsl4, ultimately inducing ferroptosis. Mettl14 also was found to enhance the stability of Sp1 mRNA, establishing a positive regulatory feedback loop. Moreover, knockdown of Acsl4 attenuated Sp1- or Mettl14-mediated ferroptosis in Mtb-infected microglia. Overall, our findings establish a connection between Mtb infection and ferroptosis and delineate a novel mechanism through which H37Rv induces ferroptosis in microglia via the Sp1-Mettl14-Acsl4 axis, offering new insights into the pathogenesis of CNS-TB.