Effects of long non-coding RNA NEAT1 on sepsis-induced brain injury in mice via NF-κB

The aim of this study was to investigate the effect of long non-coding ribonucleic acid (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) on sepsis-induced brain injury in mice through nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB).

The mouse model of sepsis was established by cecal ligation and puncture induction. The relative expression levels of NEAT1 and NF-κB in brain tissues of mice in healthy group and sepsis group were determined via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and Western blotting, respectively. Subsequently, the expression of NEAT1 was silenced by transfection of small interfering RNAs (siRNAs). Meanwhile, its effect on NF-κB expression was detected. To further explore the effect of sepsis on brain injury, the content of brain water and the expression levels of apoptosis-related proteins, including B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX), in mice of healthy group, sepsis group, and sepsis + si-NEAT1 group were measured. Furthermore, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were used to detect the proliferation and apoptosis of nerve cells.

The relative expression levels of NEAT1 and NF-κB were significantly increased in the brain tissues of septic mice (p<0.01). Si-NEAT1 transfection significantly decreased the expressions of NEAT1 and NF-κB in brain tissues of septic mice (p<0.05). The content of brain water in mice of sepsis group was evidently increased (p<0.05). However, si-NEAT1 treatment remarkably reduced this content (p<0.05). In addition, sepsis markedly decreased the activity of nerve cells (p<0.05). However, si-NEAT1 could significantly increase the activity of nerve cells in septic mice (p<0.05). Moreover, si-NEAT1 notably decreased the expression of BAX (p<0.05), whereas it increased the expression of Bcl-2 (p<0.05). The results of apoptosis detection revealed that sepsis remarkably promoted the apoptosis of mouse nerve cells (p<0.05). In addition, si-NEAT1 transfection could evidently alleviate the apoptosis of nerve cells in septic mice (p<0.05).

LncRNA NEAT1 promotes brain injury in septic mice by positively regulating NF-κB. However, si-NEAT1 transfection can reduce this injury.