Qianrang Lu, Meiching Ong, Xuewen Yi, Muqiong Xing, Xinyao Tian, Ke Zhang, Ling Lu, Hao Wang, Xiaohan Lin, Jun Fang, Aibo Mu, Jiaying Cao, Jingyu Jiang, Feng Gao, Hongjun Li, Baohong Wang, Qi Ling
Macrophages are central mediators of hepatic inflammation and fibrosis in metabolic-associated steatohepatitis (MASH), yet the mechanisms driving their activation remain unclear. Integration of four human single-nucleus transcriptomic datasets identified Coagulation Factor XIII-A (F13A1)-positive macrophages as the predominant subset in MASH livers, a finding validated in patient samples and murine models. Lipid-stressed hepatocytes induce F13A1 expression through a sphingosine-1-phosphate (S1P)-dependent mechanism. Silencing F13A1 suppressed the pro-inflammatory phenotype and alleviated hepatic injury in vivo. Mechanistically, F13A1 directly interacted with pyruvate kinase M2 (PKM2), promoting its dimerization, a process enhanced by intracellular calcium levels. Dimerized PKM2 translocated into the nucleus and upregulates interleukin-1 beta (IL1B) expression via the PKM2/HIF1A (Hypoxia-inducible factor 1-alpha) axis. In addition, F13A1 enhanced the Warburg effect in macrophages through PKM2-mediated metabolic reprogramming. Pharmacologic activation of PKM2 with DASA-58 abrogated F13A1-driven inflammation, and PEG-PLA micelle-mediated delivery of DASA-58 ameliorated hepatic inflammation in vivo. These findings establish F13A1 as a critical driver of macrophage-mediated inflammation in MASH and highlight the F13A1/PKM2/HIF1A pathway as a promising therapeutic target.