Background
Sepsis induces pulmonary P2X7 receptor (P2X7R) expression and P2X7R‐knockout reduced lung inflammation in mice. The present study investigated the expression of circular RNA (circRNA) and mRNA in sepsis‐induced acute lung injury (ALI) treated with a P2X7R antagonist.
Methods
Sepsis was induced by tracheal administration of lipopolysaccharide (LPS), and the mice were then divided into two groups: without [sepsis + dimethyl sulfoxide (DMSO)] or with P2X7R antagonist treatment (sepsis + P2X7A). Sham mice were administrated sterile normal saline. Serum levels of interleukin (IL)‐1β and tumor necrosis factor (TNF)‐α, pathological changes, cell apoptosis and P2X7R expression in lung were assessed, followed by RNA sequencing (RNA‐seq) and bioinformatics analyses. A quantitative reverse transcriptase‐polymerase chain reaction (RT‐qPCR) was used to validate circRNAs and mRNAs.
Results
Compared to the sham group, LPS‐induced sepsis produced obvious pathological changes in lung tissue, as well as increased apoptotic lung cells, serum TNF‐α and IL‐1β levels, and P2X7R expression; P2X7R antagonism significantly ameliorated these changes. RNA‐seq identified many dysregulated circRNAs and mRNAs during sepsis, whereas this changed with P2X7R antagonism. RT‐qPCR confirmed that Mus musculus (mmu)_circ_0001679, mmu_circ_0001212, phospholamban (Pln), cadherin‐2 (Cdh2) and nitrogen permease regulator 3‐like (Nprl3) expression were significantly increased in the sepsis + DMSO group compared to that in the sham group but were decreased in the sepsis + P2X7A group compared to that in the sepsis + DMSO group. The circRNA–microRNA–mRNA coexpression network indicated that mmu_circ_0001679 may regulate Nprl3 and that mmu_circ_0001212 may similarly regulate Pln, Cdh2 and Nprl3 as a competing endogenous RNA.
Conclusions
P2X7R antagonism attenuates sepsis‐induced ALI by inhibiting dysregulated expression of circRNA (circ_0001679, circ_0001212) and mRNA (Pln, Cdh2 and Nprl3).