Changes in microRNA expression in rat lungs caused by sevoflurane anesthesia: a TaqMan® low-density array study

Initial development and testing of an exhaled microRNA detection strategy for lung cancer case-control discrimination

For detecting field carcinogenesis non-invasively, early technical development and case-control testing of exhaled breath condensate microRNAs was performed. In design, human lung tissue microRNA-seq discovery was reconciled with TCGA and published tumor-discriminant microRNAs, yielding a panel of 24 upregulated microRNAs. The airway origin of exhaled microRNAs was topographically "fingerprinted", using paired EBC, upper and lower airway donor sample sets. A clinic-based case-control study (166 NSCLC cases, 185 controls) was interrogated with the microRNA panel by qualitative RT-PCR. Data were analyzed by logistic regression (LR), and by random-forest (RF) models. Feasibility testing of exhaled microRNA detection, including optimized whole EBC extraction, and RT and qualitative PCR method evaluation, was performed. For sensitivity in this low template setting, intercalating dye-based URT-PCR was superior to fluorescent probe-based PCR (TaqMan). In application, adjusted logistic regression models identified exhaled miR-21, 33b, 212 as overall case-control discriminant. RF analysis of combined clinical + microRNA models showed modest added discrimination capacity (1.1-2.5%) beyond clinical models alone: all subjects 1.1% (p = 8.7e-04)); former smokers 2.5% (p = 3.6e-05); early stage 1.2% (p = 9.0e-03), yielding combined ROC AUC ranging from 0.74 to 0.83. We conclude that exhaled microRNAs are qualitatively measureable, reflect in part lower airway signatures; and when further refined/quantitated, can potentially help to improve lung cancer risk assessment.

Anesthetics and Long Term Cancer Outcomes: May Epigenetics Be the Key for Pancreatic Cancer?

Knowledge shows a divergence of results between preclinical and clinical studies regarding anesthesia and postoperative progression of cancer. While laboratory and animal data from then 2000s onwards raised much enthusiasm in this field of research leading to several clinical investigations worldwide, data from randomized trials seem to have killed off hope for many scientists. However several aspects of the actual knowledge should be reevaluated and there is space for new strategies of investigation. In this paper, we perform a critical review of actual knowledge and propose new research strategies with a special focus on anesthetic management and repurposed anesthetic adjuvants for pancreatic cancer.

Sevoflurane promotes the apoptosis of laryngeal squamous cell carcinoma in-vitro and inhibits its malignant progression via miR-26a/FOXO1 axis

Laryngeal squamous cell carcinoma (LSCC) is a laryngeal malignancy with a high mortality rates, and its treatment remains difficult. Sevoflurane is a surgical anesthesia which has anti-tumor effect. This investigation assessed the effects of LSCC cells treatment with Sevoflurane in vitro and in vivo. Hep-2 and Tu177 cells, human LSCC samples and BALB/C nude mice were used for result assessments. Cell viability, proliferation, migration and invasion were assessed via Cell Count Kit-8, wound healing assay and transwell invasion assay respectively. MiR-26a and FOXO1 expressions was examined by qRT-PCR. FOXO1, E-cadherin, N-cadherin and vimentin activities were examined by Western blotting. Moreover, animal experiments were performed to verify our findings in vitro. Lastly, miR-26a and FOXO1 expression levels in clinical samples were analyzed. According to the results, Sevoflurane decreased LSCC cells’ viability and even stimulated their apoptosis in vitro and in vivo. Moreover, it could reduce the migration, invasion and EMT. Mechanistically, sevoflurane could downregulate miR-26a expression and that miR-26a could negatively modulate FOXO1 activity. Thus, sevoflurane could increase FOXO1 activity. In the clinical samples, miR-26a expression was significantly upregulated, but FOXO1 was remarkably down-regulated and miR-26a expression in LSCC was linked with better prognosis. In conclusion, MiR-26a is increased and FOXO1 is reduced in human LSCC, Sevoflurane inhibits proliferation and mediates apoptosis of LSCC cells. Further, MiR-26a binds FOXO1 directly, and FOXO1 expression is down-regulated by Sevoflurane. Finally, Sevoflurane triggers LSCC cells apoptosis in vivo. Sevoflurane use to target miR-26a/FOXO1 may be a novel alternative for LSCC therapy.

Inhalational Anesthetics Inhibit Neuroglioma Cell Proliferation and Migration via miR-138, -210 and -335

Inhalational anesthetics was previously reported to suppress glioma cell malignancy but underlying mechanisms remain unclear. The present study aims to investigate the effects of sevoflurane and desflurane on glioma cell malignancy changes via microRNA (miRNA) modulation. The cultured H4 cells were exposed to 3.6% sevoflurane or 10.3% desflurane for 2 h. The miR-138, -210 and -335 expression were determined with qRT-PCR. Cell proliferation and migration were assessed with wound healing assay, Ki67 staining and cell count kit 8 (CCK8) assay with/without miR-138/-210/-335 inhibitor transfections. The miRNA downstream proteins, hypoxia inducible factor-1α (HIF-1α) and matrix metalloproteinase 9 (MMP9), were also determined with immunofluorescent staining. Sevoflurane and desflurane exposure to glioma cells inhibited their proliferation and migration. Sevoflurane exposure increased miR-210 expression whereas desflurane exposure upregulated both miR-138 and miR-335 expressions. The administration of inhibitor of miR-138, -210 or -335 inhibited the suppressing effects of sevoflurane or desflurane on cell proliferation and migration, in line with the HIF-1α and MMP9 expression changes. These data indicated that inhalational anesthetics, sevoflurane and desflurane, inhibited glioma cell malignancy via miRNAs upregulation and their downstream effectors, HIF-1α and MMP9, downregulation. The implication of the current study warrants further study.

Anesthetics may modulate cancer surgical outcome: a possible role of miRNAs regulation

Background

microRNAs (miRNAs) are single-stranded and noncoding RNA molecules that control post-transcriptional gene regulation. miRNAs can be tumor suppressors or oncogenes through various mechanism including cancer cell biology, cell-to-cell communication, and anti-cancer immunity.

Main Body

Anesthetics can affect cell biology through miRNA-mediated regulation of messenger RNA (mRNA). Indeed, sevoflurane was reported to upregulate miR-203 and suppresses breast cancer cell proliferation. Propofol reduces matrix metalloproteinase expression through its impact on miRNAs, leading to anti-cancer microenvironmental changes. Propofol also modifies miRNA expression profile in circulating extracellular vesicles with their subsequent anti-cancer effects via modulating cell-to-cell communication.

Conclusion

Inhalational and intravenous anesthetics can alter cancer cell biology through various cellular signaling pathways induced by miRNAs’ modification. However, this area of research is insufficient and further study is needed to figure out optimal anesthesia regimens for cancer patients.

microRNA-186 in extracellular vesicles from bone marrow mesenchymal stem cells alleviates idiopathic pulmonary fibrosis via interaction with SOX4 and DKK1

Background

Previous reports have identified that human bone marrow mesenchymal stem cell-derived extracellular vesicles (BMSC-EVs) with their cargo microRNAs (miRNAs) are a promising therapeutic approach for the treatment of idiopathic pulmonary fibrosis (IPF). Therefore, we explored whether delivery of microRNA-186 (miR-186), a downregulated miRNA in IPF, by BMSC EVs could interfere with the progression of IPF in a murine model.

Methods

In a co-culture system, we assessed whether BMSC-EVs modulated the activation of fibroblasts. We established a mouse model of PF to evaluate the in vivo therapeutic effects of BMSC-EVs and determined miR-186 expression in BMSC-EVs by polymerase chain reaction. Using a loss-of-function approach, we examined how miR-186 delivered by BMSC-EVs affected fibroblasts. The putative relationship between miR-186 and SRY-related HMG box transcription factor 4 (SOX4) was tested using luciferase assay. Next, we investigated whether EV-miR-186 affected fibroblast activation and PF by targeting SOX4 and its downstream gene, Dickkopf-1 (DKK1).

Results

BMSC-EVs suppressed lung fibroblast activation and delayed IPF progression in mice. miR-186 was downregulated in IPF but enriched in the BMSC-EVs. miR-186 delivered by BMSC-EVs could suppress fibroblast activation. Furthermore, miR-186 reduced the expression of SOX4, a target gene of miR-186, and hence suppressed the expression of DKK1. Finally, EV-delivered miR-186 impaired fibroblast activation and alleviated PF via downregulation of SOX4 and DKK1.

Conclusion

In conclusion, miR-186 delivered by BMSC-EVs suppressed SOX4 and DKK1 expression, thereby blocking fibroblast activation and ameliorating IPF, thus presenting a novel therapeutic target for IPF.

MicroRNA Signatures in Plasma of Patients With Venous Thrombosis: A Preliminary Report

BACKGROUND

Venous thromboembolism (VTE) is a frequent and potentially fatal disease, but its pathophysiology is incompletely understood. microRNAs (miR) dysregulate hemostatic proteins and influence thrombotic pathology by posttranscriptional regulation of gene expression. Consensus in defining VTE-related miR clusters and functionally relevant miR has not been reached. We aimed to generate a miR database in patients at high thrombotic risk of VTE and explored their biological functions by seeking information on their messenger RNA targets.

METHODS

By high-throughput screening (Affymetrix miRNA Microarray), we identified 159 miR in venous blood of male patients who had two unprovoked VTE and in age-matched male controls.

RESULTS

Of the 159 miR, 41 were significantly higher expressed in patients compared to controls. Six miR (hsa-miR-6798-3p, hsa-miR-6789-5p hsa-miR-4651, hsa-miR-6765-5p, hsa-miR-6816-5p, hsa-miR-4734) were modulated ≥ 5.0-fold higher. Higher expression levels of 4 of these miR (hsa-miR-6789-5p, hsa-miR-4651, hsa-miR-6765-5p, and hsa-miR-6816-5p; primers were unavailable for hsa-miR-6798-3p and hsa-miR-4734) were confirmed by quantitative real-time polymerase chain reaction in 10 independent patients and 10 control samples. Ingenuity Pathway Analysis identified 23 altered miR including hsa-miR-6789-5p, hsa-miR-4651, hsa-miR-6765-5p and hsa-miR-4734 as the main regulators of messenger RNAs involved in the pathology of VTE. Seven messenger RNA targets including thrombomodulin and four targets related to platelet function had a direct relationship to 4 identified miR.

CONCLUSIONS

We provide evidence of distinct, independently validated miR signatures in patients with VTE and identified a subset of miR as main regulators of messenger RNA involved in disorders related to pathophysiologic processes in venous thrombosis development.

Sevoflurane alleviates LPS‑induced acute lung injury via the microRNA‑27a‑3p/TLR4/MyD88/NF‑κB signaling pathway

Acute lung injury (ALI) is a critical syndrome that is associated with a high morbidity and mortality in patients. Sevoflurane has a lung protective effect in ALI as it reportedly has anti‑inflammatory and apoptotic‑regulating activity. However, the mechanism is still not entirely understood. The aim of the present study was to explore the effects of sevoflurane on lipopolysaccharide (LPS)‑induced ALI in mice and the possible mechanisms involved. The results revealed that sevoflurane treatment improved LPS‑induced lung injury, as evidenced by the reduction in mortality, lung permeability, lung wet/dry ratio and lung histopathological changes in mice. Total cell counts and the production of pro‑inflammatory cytokines [tumor necrosis factor‑α, interleukin (IL)‑1β and IL‑6] in bronchoalveolar fluid were also decreased following treatment with sevoflurane. Additionally, LPS‑triggered apoptosis in lung tissues, which was eliminated by sevoflurane. Furthermore, a miRCURY™ LNA array was employed to screen for differentially expressed microRNAs (miRs/miRNAs). Among these miRNAs, 6 were differentially expressed and were involved in the inflammatory response, but only miR‑27a‑3p (miR‑27a) was regulated by sevoflurane. Subsequently, the present study investigated whether sevoflurane exerts its function through the modulation of miR‑27a. The results demonstrated that the overexpression of miR‑27a via an injection with agomiR‑27a produced similar protections as sevoflurane, while the inhibition of miR‑27a suppressed the lung protective effects of sevoflurane in ALI mice. In addition, the present study identified that miR‑27a inhibited Toll‑like receptor 4 (TLR4) by binding to its 3'‑untranslated region. Western blot analysis demonstrated that sevoflurane may ameliorate the inflammatory response by blocking the miR‑27a/TLR4/MyD88/NF‑κB signaling pathway. The present results indicate that sevoflurane may be a viable therapeutic option in the treatment of patients with ALI.

Inhibition of MicroRNA-23 Contributes to the Isoflurane-Mediated Cardioprotection Against Oxidative Stress

Isoflurane is one of the most frequently used volatile anesthetics in clinical practice for inhalational anesthesia. It is widely studied that isoflurane mediates cardioprotection during multiple pathological processes. However, the precise mechanisms have not been fully elucidated. Neonatal cardiomyocytes were isolated and cultured, followed by treatments with isoflurane at 0, 50, 100 or 200 µM. Rat cardiomyoblast cell line, H9c2, was treated with H₂O₂. Expression of miR-23 was measured by qRT-PCR. The cell survival rate of H9c2 in response to H₂O₂ treatments was evaluated by MTT assay. The ROS and GSH/GSSG levels were measured using Superoxide Detection Kit and GSH/GSSG Ratio Detection Assay Kit. In this study, we report an isoflurane-miR-23-antioxidant axis in cardiomyocyte. We observed that miR-23 was suppressed by isoflurane treatments at 50, 100 or 200 µM. Moreover, cardiomyocyte with isoflurane exposure was insensitive to H₂O₂ treatment in vitro. Inhibition of miR-23 protected cardiomyocyte against oxidative stress induced by H₂O₂ treatments at 30, 60, 90 or 120 µM. In addition, overexpression of miR-23 induced ROS generation over twofolds and rendered cardiomyocyte sensitive to H₂O₂ treatments. We demonstrate that miR-23 inhibited intracellular GSH, an antioxidant against oxidative stress. Our results reveal that with isoflurane exposure, overexpression of miR-23 rendered cardiomyocyte sensitive to H₂O₂ treatments at 20, 30, 40, 50 µM. Pretreatments with GSH in miR-23 overexpressing cells rescued the cell death under oxidative stress. In summary, our results illustrate that the isoflurane-mediated protection of cardiomyocytes under oxidative stress is through inhibition of miR-23. This study provides an aspect for the miRNAs-modulated cardiomyocyte sensitivity to oxidative stress, contributing to the development of therapeutic agents.

Circulating microRNAs in head and neck cancer: a scoping review of methods

Circulating microRNAs have been described as head and neck cancer biomarkers in multiple anatomical subsites including the oral cavity, nasopharynx, larynx, salivary glands and the skin. While there is an expanding volume of published literature showing the significance of individual or panels of microRNAs, the clinical validation of candidate biomarkers is lacking. The various methods used to collect, store, process and interpret these microRNAs are likely introducing bias and contributing to the inconsistent results. A systematic scoping review was conducted using PRISMA standards to identify published English literature between 2007 and 2018. Pubmed and EMBASE databases were searched using specific keyword combinations related to head and neck cancer, circulating samples (whole blood, plasma or serum) and microRNA. Following the title and abstract review, two primary authors appraised the articles for their suitability to include in the review based on the detail of methodological descriptions. Thirty suitable articles were identified relating to nasopharyngeal carcinoma, oral cavity, oropharyngeal and laryngeal squamous cell carcinoma as well as primary salivary gland malignancies. Comprehensive methodological analysis identified poor reporting of detailed methodology, variations in collection, storage, pre-processing, RNA isolation and relative quantification including normalisation method. We recommend standardising the pre-processing, RNA isolation, normalisation and relative quantitation steps at biomarker discovery phase. Such standardisation would allow for bias minimisation and effective progression into clinical validation phases.

Volatile anesthetic sevoflurane suppresses lung cancer cells and miRNA interference in lung cancer cells

Purpose

Sevoflurane is widely used in lung cancer surgery. It is well known that volatile anesthetics have a lung-protective effect in lung cancer surgery. However, the association between the inhibition of cancer cells and miRNAs interference remains unknown. Whether sevoflurane can affect some miRNAs in A549 cells has not been reported. The main aim of the present study was to investigate the effect of 3% sevoflurane on A549 cells and assess whether it regulates A549 cells by interfering with miRNA.

Methods

In three percent sevoflurane-pretreated A549 cells, treated for a duration of 30 minutes, the apoptosis rate of A549 cells was evaluated using a flow cytometer. The expression of 6 types of miRNAs associated with non-small cell lung cancer was analyzed by real-time quantitative polymerase chain reaction.

Results

An obvious apoptosis-promoting effect was found in A549 cells, which had been treated with 3% sevoflurane. The expression of several miRNAs that regulate apoptosis was significantly changed compared with the control group.

Conclusion

Three percent sevoflurane can significantly increase the apoptosis rate of A549 cells, which may reduce the spread of cancer cells caused by operation. Sevoflurane disturbed the expression of the miRNAs that regulate apoptosis.

Sevoflurane inhibits cardiac function in pulmonary fibrosis mice through the TLR4 signaling pathway

Pulmonary fibrosis is often concomitant with myocardial injury. We studied sevoflurane's effects on cardiac function and the expression of the TLR4/inducible nitric oxide synthase (iNOS) signaling pathway on a pulmonary fibrosis model. C57BL/6J wild-type (WT) and TLR4-deficient (TLR4^-/-) mice were randomly divided into a control group and a pulmonary fibrosis group. The model of pulmonary fibrosis was induced by treatment with paraquat (PQ; 20 mg/kg). Four weeks after PQ administration, mice were tested for body weight changes, and histopathology and hydroxyproline in lung. Left ventricular function in each group of mice was measured by echocardiogram before and after sevoflurane inhalation. The expression of TLR4 and iNOS protein were analyzed. Pulmonary fibrosis mice were fed lenalidomide (50 mg/kg/day) for three days and cardiac function was assessed before and after sevoflurane inhalation. WT pulmonary fibrosis mice showed pathological damage and excessive deposition of collagen in the lung and heart. Left ventricular function decreased after four weeks of PQ exposure. TLR4^-/- mice were resistant to pulmonary fibrosis like pathological damage and the effect of sevoflurane on heart rate and ejection fraction than that of WT mice. TLR4 and iNOS expression in WT pulmonary fibrosis mice increased significantly after sevoflurane inhalation. Lenalidomide treatment alleviated the effect of sevoflurane on heart rate and ejection fraction in WT pulmonary fibrosis mice. Sevoflurane inhibits cardiac function in pulmonary fibrosis mice through the TLR4/iNOS pathway. Lenalidomide attenuated the sevoflurane's effect on the cardiac function of mice with pulmonary fibrosis.

MicroRNA-27a-3p suppression of peroxisome proliferator-activated receptor-γ contributes to cognitive impairments resulting from sevoflurane treatment

Sevoflurane is the most widely used anaesthetic administered by inhalation. Exposure to sevoflurane in neonatal mice can induce learning deficits and abnormal social behaviours. MicroRNA (miR)-27a-3p, a short, non-coding RNA that functions as a tumour suppressor, is up-regulated after inhalation of anaesthetic, and peroxisome proliferator-activated receptor γ (PPAR-γ) is one of its target genes. The objective of this study was to investigate how the miR-27a-3p-PPAR-γ interaction affects sevoflurane-induced neurotoxicity. A luciferase reporter assay was employed to identify the interaction between miR-27a-3p and PPAR-γ. Primary hippocampal neuron cultures prepared from embryonic day 0 C57BL/6 mice were treated with miR-27a-3p inhibitor or a PPAR-γ agonist to determine the effect of miR-27a-3p and PPAR-γ on sevoflurane-induced cellular damage. Cellular damage was assessed by a flow cytometry assay to detect apoptotic cells, immunofluorescence to detect reactive oxygen species, western blotting to detect NADPH oxidase 1/4 and ELISA to measure inflammatory cytokine levels. In vivo experiments were performed using a sevoflurane-induced anaesthetic mouse model to analyse the effects of miR-27a-3p on neurotoxicity by measuring the number of apoptotic neurons using the Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) method and learning and memory function by employing the Morris water maze test. Our results revealed that PPAR-γ expression was down-regulated by miR-27a-3p following sevoflurane treatment in hippocampal neurons. Down-regulation of miR-27a-3p expression decreased sevoflurane-induced hippocampal neuron apoptosis by decreasing inflammation and oxidative stress-related protein expression through the up-regulation of PPAR-γ. In vivo tests further confirmed that inhibition of miR-27a-3p expression attenuated sevoflurane-induced neuronal apoptosis and learning and memory impairment. Our findings suggest that down-regulation of miR-27a-3p expression ameliorated sevoflurane-induced neurotoxicity and learning and memory impairment through the PPAR-γ signalling pathway. MicroRNA-27a-3p may, therefore, be a potential therapeutic target for preventing or treating sevoflurane-induced neurotoxicity.

Sevoflurane decreases self-renewal capacity and causes c-Jun N-terminal kinase-mediated damage of rat fetal neural stem cells

Increasing studies have demonstrated that sevoflurane can induce neurotoxicity in the developing brains. JNK normally promotes apoptosis. It was hypothesized that sevoflurane affected the proliferation and differentiation of FNSCs and induced cell apoptosis, which caused the learning and memory deficits via JNK pathway. Sevoflurane at a concentration of 1.2% did not induce damage on the FNSCS. However, concentrations of 2.4% and 4.8% decreased the cell viability, as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and increased apoptosis, as shown by flow cytometry. The 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay demonstrated that 4.8% sevoflurane reduced the proliferation of FNSCs. Compared with the control group, the 4.8% sevoflurane group showed a decrease in the proportion of undifferentiated FNSCs at 6-h exposure; 4.8% sevoflurane could increase the p-JNK/JNK ratio. JNK inhibition by the specific inhibitor SP600125 enhanced partially the cell viability. Cumulatively, 4.8% sevoflurane induced significant damage on FNSCs; it decreased cell proliferation and proportion of undifferentiated cells as well. JNK pathway might play a key role in the decrease in survival of FNSCs induced by an inhaled anesthetic. The present findings might raise the possibility that JNK inhibition has therapeutic potential in protecting FNSCs from the adverse effects of the inhaled anesthetic.

Influence of neonatal sevoflurane exposure on nerve development-related microRNAs and behavior of rats

Commonly used anesthetics adversely affect the developing brain, but the mechanisms remain unknown. We previously showed that the expressions of microRNAs (miRNAs) in major organs are affected by anesthetics. Therefore, we used TaqMan low-density array (TLDA) to analyze gene expression in the hippocampus of neonatal rats exposed to sevoflurane and performed behavioral tests after they reached adulthood to evaluate cognitive and memory function. Rat male pups at postnatal day 7 were exposed to 1.9% sevoflurane for 3 h, and the hippocampus-miRNA expression profile on postnatal day 8 was determined. Open field and fear conditioning tests conducted during postnatal weeks 7 and 8 indicated that sevoflurane-exposed rats, but not controls, exhibited anxiety-like disorders. TLDA analysis identified 20 differentially expressed miRNAs, which were not shared between postnatally and maturely sevoflurane-exposed rats. The level of rno-miR-632, which targets brain-derived neurotrophic factor and calcium channel, voltage-dependent, alpha 2/delta subunit 2, increased by 10-fold, indicating that exposure to sevoflurane during early neural development alters hippocampus-miRNA expression and may induce subsequent behavioral disorders.

Circulating microRNAs indicate cardioprotection by sevoflurane inhalation in patients undergoing off-pump coronary artery bypass surgery

In patients undergoing off-pump coronary artery bypass surgery (OPCAB), it is important to attenuate myocardium injury during the surgery. The present study aimed to observe the cardioprotection induced by sevoflurane induction and maintenance compared with propofol intravenous anesthesia, and to detect its potential protection against acute myocardial injury with sensitive biomarkers. In total, 36 patients undergoing OPCAB were randomly assigned into two groups, receiving sevoflurane (n=18) or propofol (n=18) as the induction and maintenance anesthetic agent. The depth of anesthesia in the two groups was kept at a bispectral index value of 40-50. Physiological and hemodynamic parameters were recorded during the surgery. Cardiac troponin-I (cTnI), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH) and two microRNAs (miR-499 and miR-208b) were also measured during and subsequent to surgery. Nno statistically significant differences were observed in the physiological and hemodynamic parameters between the two groups prior to surgery. Following surgery, the cardiac output and stroke volume improved significantly in the sevoflurane group (P<0.05). In addition, patients in the sevoflurane group had lower miR-499 (P<0.05) and miR-208b (P<0.01) levels at 12 h after surgery when compared with the propofol group. However, no significant differences in cTnI, CK-MB and LDH levels were observed following surgery between the two groups. In conclusion, volatile induction and maintenance with sevoflurane resulted in some extent of cardiac function improvement in patients undergoing OPCAB. Cardioprotection by sevoflurane is suggested by reduced cardiac injury compared with propofol, and indicated by the sensitive biomarkers, circulating miR-499 and miR-208b.

Volatile anesthetic sevoflurane ameliorates endotoxin-induced acute lung injury via microRNA modulation in rats

Volatile anesthetics have a lung protective effect in acute lung injury (ALI). Our previous study showed sevoflurane affects the expression of microRNA (miRNA) that control various physiological systems by regulating messenger RNA (mRNA) expression. However, the association between the anti-inflammatory effect of sevoflurane and miRNAs modulation remains unknown. The aim of the present study was to investigate the effect of sevoflurane and the expression of miRNAs in an endotoxin-induced ALI model in rats. Wistar rats were randomly assigned to three groups [lipopolysaccharide (LPS), LPS-sevoflurane and control; n=8/group]. All the rats were mechanically ventilated and intravenously-administered LPS (saline as control). Two hours post-injury, general anaesthesia was performed for 4 h with 2% sevoflurane (LPS-sevoflurane). The LPS and the control groups did not receive anaesthesia. The severity of ALI was evaluated by partial pressure of oxygen/fraction of inspired oxygen and the mRNA expression of inflammatory cytokine. The miRNA expression in lung tissue was analyzed by a reverse transcription-quantitative polymerase chain reaction. LPS caused ALI, evidenced by the impairment of pulmonary function and increased mRNA levels of tumor necrosis factor-α, interleukin-6 and nuclear factor-κB. Sevoflurane improved pulmonary function and inhibited the increased mRNAs. Of the 219 miRNAs detected, 15 and nine miRNAs were significantly changed in the LPS and LPS-sevoflurane group, respectively. In the LPS-sevoflurane group, the expression of several miRNAs that regulate inflammation was significantly changed compared to the LPS group. In conclusion, the present data showed that sevoflurane influences the expression of the miRNAs that regulate inflammation. This result suggests that the changes in miRNA expression are involved in the lung protective mechanisms of volatile anesthetics.

Redox Changes Induced by General Anesthesia in Critically Ill Patients with Multiple Traumas

The critically ill polytrauma patient is a constant challenge for the trauma team due to the complexity of the complications presented. Intense inflammatory response and infections, as well as multiple organ dysfunctions, significantly increase the rate of morbidity and mortality in these patients. Moreover, due to the physiological and biochemical imbalances present in this type of patients, the bioproduction of free radicals is significantly accelerated, thus installing the oxidative stress. In the therapeutic management of such patients, multiple surgical interventions are required and therefore they are being subjected to repeated general anesthesia. In this paper, we want to present the pathophysiological implications of oxidative stress in critically ill patients with multiple traumas and the implications of general anesthesia on the redox mechanisms of the cell. We also want to summarize the antioxidant treatments able to reduce the intensity of oxidative stress by modulating the biochemical activity of some cellular mechanisms.

Effect of Propofol on microRNA Expression Profile in Adipocyte-Derived Adult Stem Cells

MicroRNA (miRNA) pathways have been implicated in stem cell regulation. This study investigated the molecular effects of propofol on adipocyte stem cells (ASCs) by analyzing RNA expression arrays. Human ASCs were isolated by use of a liposuction procedure. ASCs were treated with saline, 50 µM propofol, or 100 µM propofol in culture media for 3 hours. After the isolation of total RNA, the expression of 76 miRNAs was evaluated with peptide nucleic acid-miRNA array analysis through denaturation and hybridization processes. Treatment with 50 µM propofol resulted in significant down-regulation of expression of 18 miRNAs and upregulation of expression of 25 miRNAs; 100 µM propofol resulted in significant downregulation of expression of 14 miRNAs and upregulation of expression of 29 miRNAs. The lowest expression was seen for miR-204, which was 0.07-fold with 50 µM propofol and 0.18-fold with 100 µM propofol. The highest expression was seen for miR-208b, which was 11.23-fold with 50 µM propofol and 11.20-fold with 100 µM propofol. Expression patterns of miRNAs were not significantly different between 50 µM and 100 µM propofol treatment. The results of this study suggest that propofol is involved in altering the miRNA expression level in human ASCs. Additional research is necessary to establish the functional effect of miRNA alteration by propofol.

Sevoflurane anesthesia persistently downregulates muscle-specific microRNAs in rat plasma

The volatile anesthetic, sevoflurane, is widely used in surgery. Over the years, there has been a growing interest in the biological effects of sevoflurane on tissue and organ systems and the molecular mechanisms involved. MicroRNAs (miRNAs or miRs) acting as pivotal post‑transcriptional regulators for fine-tuning gene networks are not only expressed intracellularly, but are also secreted into the plasma. However, the sevoflurane‑associated dynamics of circulating miRNAs and the effects of sevoflurane on tissues remain unknown. Thus, the aim of this study was to perform a comprehensive analysis of circulating miRNA levels and compositions in sevoflurane‑anesthetized rats. The rats were allowed to breathe spontaneously under 2% sevoflurane anesthesia for 6 h, and we performed a quantitative polymerase chain reaction (PCR)‑based array analysis of the time-dependent changes in plasma miRNA levels and compositions. Subsequently, we validated the levels of muscle‑specific miRNAs (also known as myomiRNAs; miR-1, miR‑133a, miR-133b and miR-206) of the plasma, heart and skeletal muscle by quantitative PCR following 3 and 6 h of anesthesia, as well as at 1, 3, 7 and 14 days post-anesthesia. Of the 210 miRNAs detected in the rat plasma from the control group (no anesthesia), 161 plasma miRNAs (77%) were transiently downregulated as a result of sevoflurane anesthesia. Although the downregulation of the plasma miRNAs (148 out of the 161 plasma mRNAs; 92%) recovered immediately after anesthesia, the plasma levels of 4 muscle-specific miRNAs were persistently downregulated until 14 days post-anesthesia. In the cardiac and skeletal muscles, the expression levels of the muscle-specific miRNAs were upregulated within 2 weeks post-anesthesia, indicating that the expression levels of the muscle-specific miRNAs in the cardiac and skeletal muscles and their plasma levels are substantially inversely correlated following anesthesia. Our data suggest that sevoflurane predominantly affects cardiac and skeletal muscles and suppresses the release of miRNA from these tissues into the circulation. This new information provides novel insight into the molecular mechanisms of action of the anesthetic, sevoflurane.

Changes in the gene expression levels of microRNAs in the rat hippocampus by sevoflurane and propofol anesthesia

General anesthesia is commonly used in the surgical arena, but little is known regarding its influence at the genomic and molecular levels. MicroRNAs (miRNAs) belong to a new class of non-coding RNA molecules which influence cell biology. In the present study, it was hypothesized that miRNAs alter gene expression levels under general anesthesia. The aim was to compare the miRNA expression profiles in the rat hippocampus in response to anesthesia with representative volatile (sevoflurane) and intravenous (propofol) anesthetics. Wistar Rats were randomly assigned to either a 2.4% sevoflurane, 600 µg/kg/min propofol or control (without anesthetics) group. Total RNA from hippocampal samples which contained miRNA was subjected to quantitative reverse transcription-polymerase chain reaction and Taqman Low-Density Arrays (TLDA). A total of 373 miRNAs are associated with rats and the TLDA analysis revealed that 279 expressed miRNAs (74.8%) were expressed in all three groups. Significant differences in the levels of 33 of the 279 expressed miRNAs (11.8%) were observed among the three groups in response to the anesthetic agents, and when compared with the control group, significant differences were found in 26 of the 279 expressed miRNAs (9.3%). Following sevoflurane anesthesia, the levels of four miRNAs were significantly increased and those of 12 were significantly reduced. By contrast, following propofol anesthesia, the levels of 11 miRNAs were significantly reduced but no miRNAs exhibited significantly elevated levels. One miRNA was common between the two anesthesia groups, whereas 14 miRNAs were significantly differentially expressed. In conclusion, sevoflurane and propofol exerted different effects on miRNA expression in the rat hippocampus.