Single-cell RNA-seq Reveals that Methamphetamine Inhibits Liver Immunity with Involvement of Dopamine Receptor D1.

Methamphetamine (METH) is a highly addictive psychostimulant that causes physical and psychological damage and immune system disorder, especially in the liver that contains a significant number of immune cells. Dopamine, a key neurotransmitter in METH addiction and immune regulation, plays a crucial role in this process. Here, we developed a chronic METH administration model and conducted single-cell RNA sequencing (scRNA-seq) to investigate the effect of METH on liver immune cells and involvement of dopamine receptor D1 (DRD1). Our findings reveal that chronic exposure to METH induces immune cell identity shifts from Ifitm3+Macrophage (Mac) and Ccl5+Mac to Cd14+Mac, and from Fyn+CD4+T effector (Teff), CD8+T, and natural killer T cells (NKT) to Fos+CD4+T and Rora+ group 2 innate lymphoid cells (ILC2), along with suppression of multiple functional immune pathways. DRD1 is implicated in regulating certain pathways and identity shifts among the hepatic immune cells. Our results provide valuable insights into development of targeted therapies to mitigate METH-induced immune impairment.