IDDF2023-ABS-0045 Spatiotemporal immune landscape of Mas-driven pro-inflammatory microenvironment with hyperactivated glycolysis in acetaminophen-induced liver injury

Background

Drug-induced liver injury (DILI) is the most common cause of acute liver failure, which requires special attention during the coronavirus disease 2019 epidemic. The inflammatory microenvironment is a critical factor in the progression of DILI, yet the cellular and molecular mechanisms of immune dysregulation are poorly understood. Mas is a G protein-coupled receptor, which could regulate the function of immune cells. Here we aim to explore the changes of the immunometabolic microenvironment during DILI and determine whether Mas plays an important role in liver pathology.

Methods

Multiple cell-specific Mas1-knockout mice were challenged with acetaminophen to clarify the effector cells of Mas. Single-cell RNA sequencing (scRNA-seq), spatial transcriptomics (ST), multiplex Immunohistochemistry (mIHC), flow cytometry and intravital imaging were used to describe the immunometabolic landscape. Cdh5^crePkm^f/+ mice, various mouse primary cells, human blood monocytes and human livers were used to validate the discoveries of bioinformatics analysis.

Results

scRNA-seq, ST and intravital imaging were first used to multidimensionally describe the DILI-imprinted immunometabolic landscape, consisting of CD31⁺MYC⁺CD63⁺endothelial cells (ECs), F4/80⁺MMP12⁺ macrophages (Mψ) and monocytes, which is regulated by the myeloid-Mas signaling (IDDF2023-ABS-0045 Figure 1). Notably, this landscape was visualized by the hour-long intravital imaging in living mice. The deficiency of myeloid-Mas could regulate the function of liver-infiltrating monocytes, and induce the pro-inflammatory phenotype of ECs possibly through metabolic reprogramming, which could enhance glycolysis in adjacent Mψ and regulate their polarization (IDDF2023-ABS-0045 Figure 2). Glycolysis was demonstrated to be the key metabolic pathway for cellular interactions, by using both Cdh5^crePkm^f/+ mice, small-molecule inhibitors and cell co-cultures (IDDF2023-ABS-0045 Figure 3). Moreover, the landscape was perfectly mapped and enriched in DILI patients,which offered good clinical relevance and a diagnostic value (IDDF2023-ABS-0045 Figure 4). Finally, the action of myeloid Mas or inhibition of glycolysis was proven to attenuate liver injury in DILI models.

Conclusions

Myeloid-Mas signaling is critical to regulating the pro-inflammatory and glycolytic microenvironment in the progression of DILI, suggesting that cellular/genetic decoding may enable specific therapeutic interventions for DILI.