LPS mediates cuproptosis and inflammation in THP-1 macrophages through HKDC1.

Abstract

Cuproptosis is a recently identified form of copper-driven cell death characterized by the aggregation of acylated proteins and proteotoxic stress in the mitochondrial tricarboxylic acid cycle, which plays a role in inflammation. Recent studies suggest that hexokinase structural domain protein 1 (HKDC1), a fifth hexokinase, is involved in regulating mitochondrial function. However, the role of HKDC1 in cuproptosis and LPS-induced macrophage inflammation remains unclear. Here, we assess macrophage plasticity using CCK8 viability assays and phagocytosis activity experiments in an in vitro inflammatory model of THP-1 cells. We measure the levels of inflammatory factors and cuproptosis-related proteins using western blot analysis and RT-qPCR. Additionally, we examine the expression and localization of the HKDC1 protein using ChIP-qPCR and immunofluorescence staining. We find that LPS promotes the expressions of inflammatory factors and decreases cuproptosis levels in THP-1-derived macrophages while also activating glycolysis and inducing the expression of HKDC1 via the Toll-like receptor 4 (TLR4) receptor. We further demonstrate that HKDC1 knockdown inhibits glycolysis and induces cuproptosis. Mechanistically, we provide the first evidence that LPS promotes the binding of Yin Yang 1 (YY1) to the HKDC1 promoter, thereby regulating HKDC1 transcription. HKDC1 interacts with heat shock cognate B (HSCB) and ferredoxin 1 (FDX1), leading to increased intracellular copper levels and subsequent cuproptosis. HKDC1 knockdown in vivo alleviates acute sepsis by activating copper-dependent cell death pathways. Collectively, our findings suggest that LPS mitigates cuproptosis and promotes inflammation via HKDC1, suggesting a new cuproptosis-dependent anti-inflammatory strategy.