Pyrvinium pamoate inhibits the survival of intracellular Mycobacterium tuberculosis through suppression of macrophage ferroptosis.

Tuberculosis is a top killer among infectious diseases. Traditional tuberculosis treatment drugs have serious resistance issues and long treatment courses. Therefore, continuous improvement and new treatment strategies against TB are urgently required. Pyrvinium pamoate is a Food and Drug Administration (FDA) approved anthelminthic drug. Recently we have reported that pyrvinium pamoate can decrease mycobacterial burdens in Mycobacterium tuberculosis (M. tuberculosis)-infected macrophages and mice. However, the mechanism by which pyrvinium pamoate inhibits the survival of intracellular M. tuberculosis remains to be explored. In this study, we discovered that low dose (0.2 μg/mL, less than IC50, half-maximal inhibitory concentration) of pyrvinium pamoate could inhibit the survival of intracellular M. tuberculosis H37Rv/H37Ra growth through suppressing ferroptosis of the infected macrophage. We found that pyrvinium pamoate could bind to casein kinase (CK)1α protein and suppress M. tuberculosis- or RSL3 (a well-known inducer of cell ferroptosis)-induced lipid peroxidation ferroptosis in macrophages through reducing ATF4-xCT-GSH-GPX4 expression and activation of YAP1-ACSL4 and TFRC-Fe3+ pathways. CK1α siRNA or its inhibitor D4476 can reverse above effects by pyrvinium pamoate on the ferroptosis and intracellular M. tuberculosis survival. We unveil a previously unrecognized and multifaceted mechanism by which pyrvinium pamoate, via targeting CK1α, inhibits M. tuberculosis-induced ferroptosis. We propose that pyrvinium pamoate holds great promise as a host-directed therapy (HDT) drug for mycobacterial-induced ferroptosis.