Maternal anesthesia via isoflurane or ether differentially affects pre-and postnatal behavior in rat offspring

MicroRNA-424-5p Alleviates Isoflurane Anesthesia-Induced Neurotoxicity in Human Embryonic Stem Cell-Derived Neurons by Targeting FASN

Isoflurane (ISO) is a type of anesthetic that might cause neurotoxicity in children. Although miR-424-5p is considerably downregulated in ISO-treated rat brain samples, its physiological role in ISO-induced neuronal injury in human embryonic stem cell-derived neurons remains unknown (hESC-derived neurons). miR-424-5p expression and fatty acid synthase (FASN) in ISO-treated hESC-derived neurons were tested via qRT-PCR. The amount of protein for Bax, Cleaved-caspase-8, Bcl-2, and FASN was investigated through western blot analysis. The viability and apoptosis of hESC-derived neurons were estimated through cell counting kit-8 assessment and TUNEL assay, accordingly. Superoxide dismutase, glutathione, and malondialdehyde levels were discovered via corresponding kits. The contents of inflammatory factors including interleukin-6 and tumor necrosis factor-α were examined by enzyme-linked immunosorbent assays. The combination between FASN and miR-424-5p was resolute via dual-luciferase reporter assessment. After exposure to ISO, induced neurotoxicity and a decreased miR-424-5p production were identified in hESC-derived neurons. Upregulation of miR-424-5p repressed ISO-induced apoptosis and mitigated ISO-induced inflammatory response and oxidative stress in vitro. FASN expression levels were reduced by elevation of miR-424-5p and upregulated after ISO treatment. Mechanically, FASN was directly targeted by miR-424-5p in hESC-derived neurons. Of note, the miR-424-5p elevation-suppressed neuronal apoptosis, inflammatory response, and oxidative stress were countered by upregulation of FASN.

Effects of Pregnancy Anesthesia on Fetal Nervous System

The effects of general anesthesia on the developing brain remain a great concern in the medical field and even in the public, and most researches in this area focus on infancy and childhood. In recent years, with the continuous development of medical technology, the number of operations during pregnancy is increasing, however, studies on general anesthesia during pregnancy are relatively lacking. The mid-trimester of pregnancy is a critical period, and is regarded as a safe period for surgery, but it is a fragile period for the development of the central nervous system and is particularly sensitive to the impact of the environment. Our research group found that general anesthesia may have adverse effects on fetal neurodevelopment during the mid-trimester. Therefore, in this review, we summarize the characteristics of anesthesia during pregnancy, and the related research of the anesthesia’s impacts on the development of central nervous system were introduced.

Sevoflurane represses the self-renewal ability by regulating miR-7a,7b/Klf4 signalling pathway in mouse embryonic stem cells

Sevoflurane is a frequently-used clinical inhalational anaesthetic and can cause toxicity to embryos during foetal development. Embryonic stem cells (ESCs) are derived from the inner cell mass of blastospheres and can be used as a useful model of early development. Here, we found that sevoflurane significantly influenced self-renewal ability of mESCs on stemness maintenance and cell proliferation. The cell cycle was arrested via G1 phase delay. We further found that sevoflurane upregulated expression of miR-7a,7b to repress self-renewal. Next we performed rescue experiments and found that after adding miR-7a,7b inhibitor into mESCs treated with sevoflurane, its influence on self-renewal could be blocked. Further we identified stemness factor Klf4 as the direct target of miR-7a,7b. Overexpression of Klf4 restored self-renewal ability repressed by miR-7a,7b or sevoflurane. In this work, we determined that sevoflurane repressed self-renewal ability by regulating the miR-7a,7b/Klf4 signalling pathway in mESCs. Our study demonstrated molecular mechanism underlying the side effects of sevoflurane during early development, laying the foundation for studies on safe usage of inhalational anaesthetic during non-obstetric surgery.

Isoflurane inhibits embryonic stem cell self-renewal through retinoic acid receptor

The commonly used inhalation anesthetic isoflurane could permeate rapidly through the placental barrier and induce toxicity to the central nervous system of the developing fetus. However, the effects of isoflurane in utero during early gestation are unknown. We therefore treated pregnant mice with 1.4% isoflurane for 2h per day for three days at day3.5 (E3.5) to day6.5 (E6.5) to investigated the toxicity of isoflurane. Pregnant mice were executed and the fetal mice were weighed and observed. Mouse ESCs (E14) was exposed to 2% isoflurane for 6h. Twenty-four hours later, self-renewal was examined with AP staining. Effects of isoflurane on the expression of RAR-γ were examined using Western blot. As a result, anesthesia with 1.4% isoflurane for 2 hour per day for 3 days reduced fetal growth and development. Isoflurane decreased self-renewal and the expression stemness genes (Nanog, Oct4, Sox2, and Lin28) in mESCs. Vitamin A attenuated the effects of isoflurane inducing self-renewal inhibition. In summary, Anesthesia with 1.4% isoflurane for 2h per day for 3 days reduced fetal growth and development. Moreover, isoflurane inhibits mESCs self-renewal through retinoic acid receptor.

Isoflurane Inhibits Embryonic Stem Cell Self-Renewal and Neural Differentiation Through miR-9/E-cadherin Signaling

The commonly used inhalation anesthetic, isoflurane, can permeate rapidly through the placental barrier and thus cause toxicity to the central nervous system of the developing fetus. In this study, we treated pregnant mice with clinically relevant concentration of isoflurane early on in development (days 3.5-6.5), and then found that the fetus growth was inhibited by isoflurane. We further used the mouse embryonic stem cell (mES cell) to be the early development model to investigate the mechanism of the embryotoxicity of isoflurane and found that isoflurane inhibited self-renewal of mES cells. In addition, neuronal differentiation from the mES cells treated with isoflurane was also inhibited. Overexpression of E-cadherin attenuated the effects of isoflurane on self-renewal and the subsequent neuronal differentiation. We also found that miR-9 can be upregulated by isoflurane. Overexpression of miR-9 inhibited the self-renewal and subsequent neuronal differentiation. E-cadherin was directly targeted by miR-9. Overexpression of E-cadherin can abolish the function of miR-9 or isoflurane on self-renewal and subsequent neuronal differentiation. These data suggested that isoflurane inhibits self-renewal and neuronal differentiation of mES cells, possibly by regulating the miR-9-E-cadherin signaling. The result of the current study may provide a novel idea for preventing the toxicity of inhalation anesthetics in the developing fetal brain in clinical practice when pregnant women accept nonobstetric surgery under inhalation general anesthesia.

Prematurely delivered rats show improved motor coordination during sensory-evoked motor responses compared to age-matched controls

The amount of postnatal experience for perinatal rats was manipulated by delivering pups one day early (postconception day 21; PC21) by cesarean delivery and comparing their motor behavior to age-matched controls on PC22 (the typical day of birth). On PC22, pups were tested on multiple measures of motor coordination: leg extension response (LER), facial wiping, contact righting, and fore- and hindlimb stepping. The LER and facial wiping provided measures of synchronous hind- and forelimb coordination, respectively, and were sensory-evoked. Contact righting also was sensory-evoked and provided a measure of axial coordination. Stepping provided a measure of alternated forelimb and hindlimb coordination and was induced with the serotonin receptor agonist quipazine. Pups that were delivered prematurely and spent an additional day in the postnatal environment showed more bilateral limb coordination during expression of the LER and facial wiping, as well as a more mature righting strategy, compared to controls. These findings suggest that experience around the time of birth shapes motor coordination and the expression of species-typical behavior in the developing rat.