Sevoflurane-induced memory impairment in the postnatal developing mouse brain

Novel insights into sevoflurane-induced developmental neurotoxicity mechanisms

Aim: This study explores Sevoflurane (Sevo)-induced neurotoxicity mechanisms in neonates through transcriptome sequencing and models.Methods: Seven-day-old mice were exposed to 3% Sevo, and hippocampal tissue was collected for analysis of differentially expressed lncRNAs and mRNAs compared with normal mice. MiR-152-3p was selected, and the interaction between H19, USP30, and miR-152-3p was explored in BV2 microglial cells and mouse hippocampal neurons.Results: Sevo disrupts mitochondrial autophagy via USP30 upregulation, exacerbating neurotoxicity and activating NLRP1 inflammasome-mediated inflammation.Conclusion: Sevo neurotoxicity is mediated through the H19/miR-152-3p/USP30 axis, implicating microglial regulation of neuronal pyroptosis.

Efficacy of melatonin in alleviating disorders arising from repeated exposure to sevoflurane in males and females of the Wistar rats during preadolescence

Pediatricians use sevoflurane due to its fast action and short recovery time. However, studies have shown that repeated exposure to anesthesia can affect learning and memory. Melatonin, an indole-type neuroendocrine hormone, has significant anti-inflammatory, and neuroprotective properties. Melatonin's impact on cognitive behavior in sevoflurane-anesthetized males and females of the Wistar rats during preadolescence was examined in this research. The cognitive function was evaluated by shuttle box and morris water maze tests, while interleukin-10, Catalase (CAT), Malondialdehyde (MDA), and Tumor Necrosis Factor-α (TNF-α) were evaluated using ELISA kits. The expression levels of the apoptosis-linked proteins, Bax, Bcl-2, and caspase-3, were determined using the western blotting technique. The learning and memory latencies of the rats were more significant in the sevoflurane groups than in the control group; however, the latencies were significantly shorter in the sevoflurane and melatonin groups than in the control group. The levels of MDA, TNF-α, Bax, and caspase-3 were significantly higher in the sevoflurane groups than in the control group. We also found that the levels of CAT and Bcl-2 were significantly reduced in the sevoflurane groups compared to the control group. Increasing levels of CAT, Bcl-2, and decreasing levels of MDA, TNF-α, Bax, and caspase-3 in response to melatonin indicate a possible contribution to the recovery from the sevoflurane impairment. Melatonin shows neuroprotective effects in male and female rats with sevoflurane-induced cognitive impairment. This suggests melatonin could be a valuable treatment for learning and memory deficits resulting from repeated exposure to sevoflurane, possibly by controlling apoptosis, oxidative stress, and inflammation.

Effects of overexpression of Hsp70 in neural stem cells on neurotoxicity and cognitive dysfunction in neonatal mice under sevoflurane exposure

As one of the commonly used inhalation anesthetics in clinical practice, sevoflurane is currently widely applied in surgery for children and the elderly due to its safety and efficacy. However, the neurotoxicity and cognitive impairment induced by sevoflurane exposure cannot be ignored. A recombinant adenovirus with green fluorescent protein-labeled heat shock protein 70 (Hsp70) was constructed and used to infect neural stem cells (NSCs) separated from neonatal mice. Quantitative real-time PCR and Western blot assays were used to evaluate the expression of certain genes. 5‑Ethynyl‑2'‑deoxyuridine staining and cell counting kit assay were used to detect the proliferation and differentiation ability of NSCs. The Morris water maze experiment was used to test the cognitive abilities of mice. Adv-Hsp70 induced the overexpression of Hsp70 in mouse NSCs. Upregulation of Hsp70 promoted the proliferation ability and differentiation of mouse NSCs. NSCs that overexpressed Hsp70 attenuated sevoflurane-induced neurotoxicity and protected cognitive dysfunction in mice under sevoflurane exposure. In summary, our findings demonstrate the potential of overexpression of Hsp70 in NSCs against sevoflurane-induced impairments.

LncRNA Rik-203 Contributes to Sevoflurane Induced Neurotoxicity?

Background: The anesthetics inhibit neural differentiation, induce neuron loss and cognitive impairment in young animals. However, the underlying mechanisms of anesthesia on neural differentiation are unknown. Methods: Embryonic stem cells (ESCs) and mice received sevoflurane anesthesia. RNA sequencing; gene expression of mRNAs, LncRNAs and miRNAs; over-expression and RNA interference of genes; flow cytometry; real-time quantity PCR and Western blot were used in the studies. RNA pull-down assay and PCR were employed to detect any miRNA that attached to Rik-203. The binding of miRNA with mRNA of BDNF was presented by the luciferase assay. Results: Here we found that LncRNA Riken-203(Rik-203) was highly expressed in mice brain and was upregulated during neural differentiation. Sevoflurane decreased the amount of Rik-203 in mice brain. Knockdown of Rik-203 repressed the neural differentiation derived from mouse embryonic stem cell and downregulated the neural progenitor cells markers Sox1 and Nestin. RNA pull-down showed that miR-466l-3p was highly bound to Rik-203. Inhibition of miR-466l-3p restored the neural differentiation repressed by Rik-203 knockdown. Brain derived neurotrophic factor (BDNF), which was downregulated by sevoflurane, was also directly targeted by miR-466l-3p. Overexpression of BDNF restored the neural differentiation repressed by miR-466l-3p and Rik-203 knockdown. Conclusion: Our study suggested that sevoflurane related LncRNARik-203 facilitates neural differentiation by inhibiting miR-466l-3p's ability to reduce BDNF levels.