Role of CCRL2 in the Pathogenesis of Experimental Autoimmune Myocarditis via P21-Activated Kinase 1/NOD-Like Receptor Protein 3 Pathway

Myocarditis, a severe inflammatory disease, is becoming a worldwide public health concern. This study aims to elucidate the effect of Chemokine (C C motif) receptor-like 2 (CCRL2) in experimental autoimmune myocarditis (EAM) occurrence and its potential regulatory mechanisms.EAM was simulated in a mouse model injected with α-myosin-heavy chain. The changes on EAM were assessed through histological staining of heart tissues, including measuring cardiac troponin I (cTnI), proinflammatory cytokines, transferase-mediated dUTP nick end labeling (TUNEL) assay, and cardiac function. Then, the heart tissues from the EAM mouse model and control groups were analyzed through transcriptome sequencing to identify the differential expressed genes (DEGs) and hub genes related to pyroptosis. Downregulation of CCRL2 further verified the function of CCRL2 on EAM and p21-activated kinase 1/NOD-like receptor protein 3 (PAK/NLRP3) signaling pathways in vivo.The EAM model was constructed successfully, with the heart weight/body weight ratio, serum level of cTnI, and concentrations of proinflammatory cytokines elevation. Moreover, cell apoptosis was also significantly increased. Transcriptome sequencing revealed 696 and 120 upregulated and downregulated DEGs, respectively. After functional enrichment, CCRL2 was selected as a potential target. Then, we verified that CCRL2 knockdown improved cardiac function, alleviated EAM occurrence, and reduced PAK/NLRP3 protein expression.CCRL2 may act as a novel potential treatment target in EAM by regulating the PAK1/NLRP3 pathway.