The Effect of Pyruvate Kinase M2: Inhibitor(shikonin) on the Function of Mdc in Severe Aplastic Anemia Mouse Model

Severe aplastic anemia (SAA) is a rare disease characterized by severe pancytopenia and bone marrow failure. Over-activated myeloid dendritic cells (mDCs) play an important role in the pathogenesis of SAA. In recent years, the role of pyruvate kinase M2 (PKM2) in DC function and autoimmune response has been gradually recognized. In this study, an immune attack-mediated AA mouse model was constructed by total body irradiation and lymphocyte infusion. The AA model mice showed pancytopenia, decreased ratio of CD4+/CD8+ cells, increased expression of cytotoxic molecules perforin and granzyme in CD8+ cells, increased levels of co-stimulatory molecules CD80 and CD86 in DCs and inadequate Treg number. In-vitro animal experiments confirmed the activation of PKM2 in mDCs, which promoted glycolytic metabolism. High levels of PKM2 in mice contributed to the poor survival rate. Additionally, intervention treatment with shikonin or cyclosporin A in the AA mouse model reduced the expression not only of co-stimulatory molecules CD80 and CD86 in mDCs but also of cytotoxic molecules in CD8+ cells. In conclusion, we confirmed the activation of PKM2 in mDCs in AA mouse models. PKM2 is involved in mDC activation and proliferation, which might contribute to activating the downstream cytotoxic T cells (CTLs). PKM2 is a possible novel target in SAA treatment.