Midazolam prevents sevoflurane-induced death in hippocampal neurons

Sevoflurane-induced POCD-associated exosomes delivered miR-584-5p regulates the growth of human microglia HMC3 cells through targeting BDNF

BACKGROUND

Inhalation of sevoflurane can cause neuronal apoptosis, and cognitive disorders, inducing to the occurrence and progression of post operative cognitive dysfunction (POCD). This study aimed to explore the roles of sevoflurane-induced POCD-associated exosomes on HMC3 cells and its related mechanisms.

METHODS

Exosomes were isolated from the plasma of sevoflurane-induced POCD or non-POCD patients, and were then sent for small RNA sequencing. Real-time quantitative PCR (RT-qPCR) was used to verify the sequencing results, and miR-584-5p was chosen for subsequent study. HMC3 cells were respectively transfected with POCD-derived exosomes and miR-584-5p mimics, and cell viability and apoptosis were measured. Dual-luciferase reporter gene assay was applied to confirm the target of miR-584-5p.

RESULTS

After sequencing, 301 differentially expressed miRNAs were identified, including 184 up-regulated miRNAs and 117 down-regulated miRNAs, and were significantly enriched in 3577 GO terms and 121 KEGG pathways. Due to the high level of miR-584-5p in sevoflurane-treated POCD-derived exosomes, HMC3 cells with miR-584-5p enrichment were successfully established. Compared with the control group, POCD-derived exosomes and miR-584-5p significantly inhibited viability and promoted apoptosis of HMC3 cells (P < 0.05). The IL-1β and TNF-α levels were significantly increased after POCD-derived exosomes and miR-584-5p mimics treatment compared to the control group (P < 0.05). Besides, POCD-derived exosomes and miR-584-5p mimics significantly down-regulated the expression levels of BDNF and p-TrkB, and up-regulated Caspase 3 and IL-1β. Finally, BDNF was confirmed to be the target of miR-584-5p.

CONCLUSIONS

Sevoflurane-induced POCD-associated exosomes delivered miR-584-5p may regulate the growth of HMC3 cells via targeting BDNF.

Minimal effects from a single exposure to sevoflurane in adult male and female Sprague-Dawley rats

Many people undergo procedures requiring general anesthesia each day and adverse cognitive effects have been reported in response to that anesthesia. Postoperative Cognitive Dysfunction (POCD) may occur in as many as 80% of adults during the first post-surgical week and can have lasting effects. Here, the cognitive and motor effects of sevoflurane exposure in Sprague-Dawley rats was examined along with body weights, blood oxygen saturation, heart rate, and body temperature. Male and female rats were exposed to 2.5% sevoflurane or medical grade air for one hour at postnatal day 115. Beginning the following day, rats began a series of behavioral tests examining locomotor activity, motor coordination, novel object recognition, and spatial learning and memory in a water maze. Blood oxygen saturation, heart rate, and body temperature were not affected by the sevoflurane exposure. A slight effect on locomotor activity was detected, but no effects on motor coordination, novel object recognition, or spatial learning and memory were observed. Brain weights following behavioral testing did not differ. The results reported here along with existing literature suggest sevoflurane is largely without effects on later cognition in adult rodents when exposure is of a relatively short duration and at a relatively low concentration.