Variant rs13045 reduces EIF2AK3 expression and inhibits pro-inflammatory cytokine secretion via the MAPK-ERK1/2 pathway in Kawasaki disease.

Abstract

PURPOSE: Kawasaki disease (KD) is an acute systemic vasculitis and a leading cause of acquired heart disease in children in developed countries. This study endeavors to explore the role and underlying mechanisms of EIF2AK3 in KD-related vasculitis, thereby offering novel therapeutic perspectives. METHODS: DNA from 910 KD patients and 848 controls were genotyped for rs13045 using TaqMan® to analyze the association with KD susceptibility. Concurrently, EIF2AK3 expression under KD inflammatory conditions was assessed using qRT-PCR, Western blot, and immunofluorescence. Pro-inflammatory cytokine levels were measured following EIF2AK3 knockdown or overexpression, and RNA sequencing was explored the downstream signaling pathways. For in vivo experiment, a Lactobacillus casei cell wall extract (LCWE)-induced KD mouse model with Eif2ak3 knockdown was established. ELISA and HE staining were used to investigate the degree of vasculitis between Eif2ak3 knockdown and control groups. RESULTS: The EIF2AK3/rs13045 polymorphism was associated with KD susceptibility, with the rs13045 C allele downregulating EIF2AK3. EIF2AK3 expression was increased significantly during KD inflammatory conditions. EIF2AK3 knockdown or pharmacological inhibition (GSK2606414) reduced pro-inflammatory cytokines (IL-1β/IL-6/IL-8/TNF-α) expression, while overexpression of EIF2AK3 elevated them. Mechanistically, EIF2AK3 promoted pro-inflammatory cytokines expression through activation of the MAPK-ERK1/2 pathway. Furthermore, EIF2AK3 downregulation inhibited the endothelial-to-mesenchymal transition (EndoMT), thereby impairing HUVECs migration. These findings were also recapitulated in the KD mouse model. CONCLUSION: EIF2AK3/rs13045 is a novel susceptibility locus for KD in the southern Chinese population. Our findings reveal that EIF2AK3 upregulates pro-inflammatory cytokines, thereby promoting KD-associated vasculitis via the MAPK-ERK1/2 pathway. This discovery suggests EIF2AK3 as a potential therapeutic target for the management of KD.