Isoflurane exposure regulates the cell viability and BDNF expression of astrocytes via upregulation of TREK-1

Neonatal isoflurane exposure in rodents disrupts hippocampal cognitive functions, including learning and memory, and astrocytes may have an important role in this process. However, the molecular mechanisms underlying this disruption are not fully understood. The present study investigated the role of TWIK-related K(+) channel (TREK-1) in isoflurane-induced cognitive impairment. Lentiviruses were used to overexpress or knockdown TREK-1 in astrocytes exposed to increasing concentrations of isoflurane or O(2) for 2 h. Subsequently, the mRNA and protein expression of brain-derived neurotrophic factor (BDNF), caspase-3, Bcl-2-associated X (Bax) and TREK-1 was measured by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. In addition, cell viability was assessed by a 2-(4-Iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt assay. The results demonstrated that, prior to manipulating TREK-1, isoflurane significantly decreased the cell viability and BDNF expression, and increased Bax, caspase-3 and TREK-1 expression was observed. However, TREK-1 overexpression in astrocytes significantly downregulated BDNF expression, and upregulated Bax and caspase-3 expression. Furthermore, lentiviral-mediated short hairpin RNA knockdown of TREK-1 effectively inhibited the isoflurane-induced changes in BDNF, Bax and caspase-3 expression. Taken together, the results of the present study indicate that isoflurane-induced cell damage in astrocytes may be associated with TREK-1-mediated inhibition of BDNF and provide a reference for the safe use of isoflurane anesthesia in infants and children.