PHLDA1 promotes sevoflurane-induced pyroptosis of neuronal cells in developing rats through TRAF6-mediated activation of Rac1

Abstract

Sevoflurane anesthesia induces neurocognitive impairment and pyroptosis in the developing brain. Pleckstrin homology-like domain, family A, member 1 (PHLDA1) was involved in neuronal apoptosis, oxidative stress and inflammation during ischemic stroke. The role of PHLDA1 in sevoflurane-induced pyroptosis in developing rats was investigated. Firstly, neonatal rats at day 7 was exposed to 2.0% sevoflurane for 6 h to induce neurotoxicity. Pathological analysis showed that sevoflurane anesthesia induced hippocampal injury and reduced the number of neurons. The expression of PHLDA1 was elevated in hippocampus of sevoflurane-treated rats. Secondly, sevoflurane anesthesia-treated neonatal rats were injected with adeno-associated virus serotype (AAV) to mediate knockdown of PHLDA1. Injection with AAV-shPHLDA1 ameliorated sevoflurane-induced hippocampal injury and neurocognitive impairment in rats. Moreover, knockdown of PHLDA1 increased the number of neurons in sevoflurane-treated rats. Silence of PHLDA1 suppressed neuronal apoptosis, and inhibited pyroptosis in sevoflurane-treated rats. Thirdly, PHLDA1 was also elevated in sevoflurane-treated primary neuronal cells. Loss of PHLDA1 also enhanced cell viability and suppressed pyroptosis of sevoflurane-treated primary neuronal cells. Lastly, silence of PHLDA1 reduced protein expression of TRAF6 and p-Rac1 in sevoflurane-treated rats and neuronal cells. Over-expression of TRAF6 attenuated PHLDA1 silence-induced increase of cell viability and decreased pyroptosis in neuronal cells. In conclusion, loss of PHLDA1 protected against sevoflurane-induced pyroptosis in developing rats through inhibition of TRAF6-mediated activation of Rac1.

Keywords: Apoptosis; Neonatal rats; Neurocognitive impairment; PHLDA1; Pyroptosis; Sevoflurane.