Cytotoxicity of propofol in human induced pluripotent stem cell-derived cardiomyocytes

Effects of coenzyme Q10 in a propofol infusion syndrome model of rabbits

Background

Coenzyme Q (CoQ) might be the main site of interaction with propofol on the mitochondrial respiratory chain in the propofol infusion syndrome (PRIS) because of the structural similarity between coenzyme Q10 (CoQ10) and propofol.

Aim

To investigate the effects of CoQ10 on survival and organ injury in a PRIS model in rabbits.

Methods

Sixteen male New Zealand white rabbits were divided into 4 groups: (1) propofol infusion group, (2) propofol infusion and CoQ10, 100 mg/kg was administered intravenously, (3) sevoflurane inhalation was administered, and (4) sevoflurane inhalation and CoQ10, 100 mg/kg intravenously, was administered. Arterial blood gas and biochemical analyses were repeated every 2 h and every 12 h, respectively. Animals that were alive on the 24th hour after anesthesia induction were euthanized. The organ damages were investigated under light and transmission electron microscopy (TEM).

Results

The propofol infusion group had the highest troponin T levels when compared with the other three groups at the 12th hour. The propofol + CoQ10 group had lower troponin T levels when compared with the propofol and sevoflurane groups (P < 0.05). Administration of CoQ10 decreased total liver injury scores and total organ injury scores both in the propofol and sevoflurane groups. The propofol and sevoflurane organ toxicities were attenuated with CoQ10 in liver, gallbladder, urinary bladder, and spleen.

Conclusion

The addition of CoQ10 to propofol and sevoflurane anesthesia prevented the propofol-associated increase in troponin T levels at the 12th hour of infusion and decreased anesthetic-induced total liver and organ injury scores.

Ascorbic acid reduces Ropivacaine-induced myotoxicity in cultured human osteoporotic skeletal muscle cells

BACKGROUND

Osteoporosis is a worldwide health issue. Loss of bone mass is a potential risk factor for fragility fractures, and osteoporotic fractures place a considerable burden on society. Bone and muscle represent a functional unit in which the two tissues are intimately interconnected. Ropivacaine is a potent local anesthetic used in clinical practice for intraoperative anesthesia and postoperative pain management, in particular for hip surgery. When injected, Ropivacaine can diffuse locally through, in particular in surrounding skeletal muscle tissue, causing dose-dependent cytotoxicity, oxidative stress and myogenesis impairment. Based on those evidences, we focused our attention on Ropivacaine-induced cytotoxicity on cultured human myoblasts.

METHODS

Primary human myoblasts and myotubes from healthy subjects, osteoarthritic and osteoporotic patients (OP) were cultured in the presence of Ropivacaine. In some experiments, ascorbic acid (AsA) was added as a potent antioxidant agent. Cell viability and ROS levels were evaluated to investigate the myotoxic activity and Real-Time PCR and Western blot analysis carried out to investigate the expression of proliferation and myogenic markers.

RESULTS

A dose-dependent decrease of cell viability was observed after Ropivacaine exposure in both OP myoblasts and myotubes cultures, whereas those effects were not observed in the presence of Propofol, a general anesthetic. The adding of AsA reduced Ropivacaine negative effects in OP myoblast cultures. In addition, Ropivacaine exposure also increased ROS levels and upregulated Nox4 expression, an enzyme primarily implicated in skeletal muscle ROS generation. AsA treatment counteracted the oxidant activity of Ropivacaine and partially restored the basal condition in cultures. Positive myogenic markers, such as MyoD and Myf5, were downregulated by Ropivacaine exposure, whereas myostatin, a negative regulator of muscle growth and differentiation, was upregulated. The phenotypic deregulation of myogenic controllers in the presence of Ropivacaine was counteracted by AsA treatment.

CONCLUSIONS

Our findings highlight the oxidative stress-mediated myotoxic effect of Ropivacaine on human skeletal muscle tissue cell cultures, and suggest treatment with AsA as valid strategy to mitigate its negative effects and allowing an ameliorated functional skeletal muscle recovery in patients undergoing hip replacement surgery for osteoporotic bone fracture.

Airborne Exposure of the Cornea to PM10 Induces Oxidative Stress and Disrupts Nrf2 Mediated Anti-Oxidant Defenses

The purpose of this study is to test the effects of whole-body animal exposure to airborne particulate matter (PM) with an aerodynamic diameter of <10 μm (PM10) in the mouse cornea and in vitro. C57BL/6 mice were exposed to control or 500 µg/m3 PM10 for 2 weeks. In vivo, reduced glutathione (GSH) and malondialdehyde (MDA) were analyzed. RT-PCR and ELISA evaluated levels of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling and inflammatory markers. SKQ1, a novel mitochondrial antioxidant, was applied topically and GSH, MDA and Nrf2 levels were tested. In vitro, cells were treated with PM10 ± SKQ1 and cell viability, MDA, mitochondrial ROS, ATP and Nrf2 protein were tested. In vivo, PM10 vs. control exposure significantly reduced GSH, corneal thickness and increased MDA levels. PM10-exposed corneas showed significantly higher mRNA levels for downstream targets, pro-inflammatory molecules and reduced Nrf2 protein. In PM10-exposed corneas, SKQ1 restored GSH and Nrf2 levels and lowered MDA. In vitro, PM10 reduced cell viability, Nrf2 protein, and ATP, and increased MDA, and mitochondrial ROS; while SKQ1 reversed these effects. Whole-body PM10 exposure triggers oxidative stress, disrupting the Nrf2 pathway. SKQ1 reverses these deleterious effects in vivo and in vitro, suggesting applicability to humans.

Emerging Roles of NDUFS8 Located in Mitochondrial Complex I in Different Diseases

NADH:ubiquinone oxidoreductase core subunit S8 (NDUFS8) is an essential core subunit and component of the iron-sulfur (FeS) fragment of mitochondrial complex I directly involved in the electron transfer process and energy metabolism. Pathogenic variants of the NDUFS8 are relevant to infantile-onset and severe diseases, including Leigh syndrome, cancer, and diabetes mellitus. With over 1000 nuclear genes potentially causing a mitochondrial disorder, the current diagnostic approach requires targeted molecular analysis, guided by a combination of clinical and biochemical features. Currently, there are only several studies on pathogenic variants of the NDUFS8 in Leigh syndrome, and a lack of literature on its precise mechanism in cancer and diabetes mellitus exists. Therefore, NDUFS8-related diseases should be extensively explored and precisely diagnosed at the molecular level with the application of next-generation sequencing technologies. A more distinct comprehension will be needed to shed light on NDUFS8 and its related diseases for further research. In this review, a comprehensive summary of the current knowledge about NDUFS8 structural function, its pathogenic mutations in Leigh syndrome, as well as its underlying roles in cancer and diabetes mellitus is provided, offering potential pathogenesis, progress, and therapeutic target of different diseases. We also put forward some problems and solutions for the following investigations.

Assessing Drug-Induced Mitochondrial Toxicity in Cardiomyocytes: Implications for Preclinical Cardiac Safety Evaluation

Drug-induced cardiotoxicity not only leads to the attrition of drugs during development, but also contributes to the high morbidity and mortality rates of cardiovascular diseases. Comprehensive testing for proarrhythmic risks of drugs has been applied in preclinical cardiac safety assessment for over 15 years. However, other mechanisms of cardiac toxicity have not received such attention. Of them, mitochondrial impairment is a common form of cardiotoxicity and is known to account for over half of cardiovascular adverse-event-related black box warnings imposed by the U.S. Food and Drug Administration. Although it has been studied in great depth, mitochondrial toxicity assessment has not yet been incorporated into routine safety tests for cardiotoxicity at the preclinical stage. This review discusses the main characteristics of mitochondria in cardiomyocytes, drug-induced mitochondrial toxicities, and high-throughput screening strategies for cardiomyocytes, as well as their proposed integration into preclinical safety pharmacology. We emphasize the advantages of using adult human primary cardiomyocytes for the evaluation of mitochondrial morphology and function, and the need for a novel cardiac safety testing platform integrating mitochondrial toxicity and proarrhythmic risk assessments in cardiac safety evaluation.

Propofol toxicity in the developing mouse heart mitochondria

BACKGROUND

Propofol infusion syndrome (PRIS) is a potentially lethal consequence of long-term propofol administration. Children are vulnerable and cardiac involvement is often prominent and associated with mortality. We aimed to determine the mechanism of propofol toxicity in newborn mice, hypothesizing that propofol would induce discrete defects within immature cardiac mitochondria.

METHODS

Newborn murine cardiac mitochondria were exposed to propofol or intralipid in vitro. Non-exposed mitochondria served as controls. Mitochondrial respiration and membrane potential (ΔΨ) were measured and respiratory chain complex kinetics were determined.

RESULTS

Propofol and intralipid exerted biological activity in isolated mitochondria. Although intralipid effects were a potential confounder, we found that propofol induced a dose-dependent increase in proton leak and caused a defect in substrate oxidation at coenzyme Q (CoQ). These impairments prevented propofol-exposed cardiomyocyte mitochondria from generating an adequate ΔΨ. The addition of the quinone analog, CoQ₀, blocked propofol-induced leak and increased Complex II+III activity.

CONCLUSIONS

Propofol uncoupled immature cardiomyocyte mitochondria by inducing excessive CoQ-sensitive leak and interfered with electron transport at CoQ. The findings provide new insight into the mechanisms of propofol toxicity in the developing heart and may help explain why children are vulnerable to developing PRIS.

IMPACT

Propofol uncouples immature cardiomyocyte mitochondria by inducing excessive coenzyme Q (CoQ)-sensitive proton leak. Propofol also interferes with electron transport at the level of CoQ. These defects provide new insight into propofol toxicity in the developing heart.

Cardiac Glucose and Fatty Acid Transport After Experimental Mono- and Polytrauma

OBJECTIVE

The aim of this study was to define the influence of trauma on cardiac glucose and fatty acid transport. The effects were investigated in vivo in a porcine mono- and polytrauma model and in vitro in human cardiomyocytes, which were treated simultaneously with different inflammatory substances, mimicking posttraumatic inflammatory conditions.

METHODS AND RESULTS

In the porcine fracture- and polytrauma model, blood glucose concentrations were measured by blood gas analysis during an observation period of 72 h. The expression of cardiac glucose and fatty acid transporters in the left ventricle was determined by RT-qPCR and immunofluorescence. Cardiac and hepatic glycogen storage was examined. Furthermore, human cardiomyocytes were exposed to a defined trauma-cocktail and the expression levels of glucose- and fatty acid transporters were determined. Early after polytrauma, hyperglycemia was observed. After 48 and 72 h, pigs with fracture- and polytrauma developed hypoglycemia. The propofol demand significantly increased posttrauma. The hepatic glycogen concentration was reduced 72 h after trauma. Cardiac glucose and fatty acid transporters changed in both trauma models in vivo as well as in vitro in human cardiomyocytes in presence of proinflammatory mediators.

CONCLUSIONS

Monotrauma as well as polytrauma changed the cardiac energy transport by altering the expression of glucose and fatty acid transporters. In vitro data suggest that human cardiomyocytes shift to a state alike myocardial hibernation preferring glucose as primary energy source to maintain cardiac function.

Developmental and cardiac toxicities of propofol in zebrafish larvae

Propofol, a commonly used anesthetic, is convenient to use, induces quick effect, enables rapid recovery, and is widely accessible given its stable supply. However, its adverse effects are a concern. Reportedly, propofol exhibits a significant inhibitory effect on the respiratory and circulatory systems. Furthermore, intravenous administration of this drug results in hypotension, rapid heart rate, and respiratory failure. Because many pregnant women are administered propofol during childbirth, it may have a significant negative effect on the development of infants. Propofol can cause considerable developmental neurotoxicity and has known activity on the heart. However, the underling mechanisms of these toxicities remain unclear. In the present study, zebrafish embryos were exposed to propofol at different concentrations (0.05, 0.1, 0.5, 1, 5, 10, and 20 μg/ml) to determine its developmental and cardiac toxicities. Propofol exposure decreased the survival rate and hatchability of zebrafish embryos. Additionally, the embryo malformation rate increased in a concentration-dependent manner. Different types of malformations were observed following propofol administration. The proportion of pericardial cysts increased, whereas the heart rate and size decreased with an increase in propofol concentration. The quantitative reverse-transcription polymerase chain reaction revealed that propofol significantly altered the expression of genes related to cardiac development and functions in zebrafish. Collectively, our findings indicate that propofol exposure induces significant developmental and cardiac toxicities in zebrafish.

Induced pluripotent stem cells as a platform to understand patient-specific responses to opioids and anaesthetics

Recent advances in human induced pluripotent stem cell (iPSC) technology may provide unprecedented opportunities to study patient-specific responses to anaesthetics and opioids. In this review, we will (1) examine the advantages and limitations of iPSC technology, (2) summarize studies using iPSCs that have contributed to our current understanding of anaesthetics and opioid action on the cardiovascular system and central nervous system (CNS), and (3) describe how iPSC technology can be used to further develop personalized analgesic and sedative pharmacotherapies with reduced or minimal detrimental cardiovascular effects.

Downregulation of long noncoding RNA SNHG6 rescued propofol-induced cytotoxicity in human induced pluripotent stem cell-derived cardiomyocytes

Background

Propofol (PPF) overdose is a rare but lethal condition, which may lead to severe cardiac failure. In this study, we established an in vitro PPF-induced cardiac cytotoxicity model, and investigate the functional role of long non-coding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG6).

Methods

Human induced pluripotent stem cell-derived cardiomyocytes (HiPSC-CMs) were exposed to PPF in vitro. PPF-induced cytotoxic effects were measured. PPF-induced SNHG6 expression change in HiPSC-CMs were monitored by qRT-PCR. SNHG6 was downregulated in HiPSC-CMs to examine its role in PPF-induced cardiac cytotoxicity. The expression of competing endogenous RNA (ceRNA) candidate of SNHG6, human microRNA-186-5p (hsa-miR-186-5p) was also investigated in PPF-exposed HiPSC-CMs. Functions of hsa-miR-186-5p were further investigated in PPF-exposed and SNHG6-downregulated HiPSC-CMs.

Results

PPF induced significant cytotoxicity, as well as SNHG6 upregulation in HiPSC-CMs. SNHG6 downregulation had rescuing effects on PPF-induced cardiac cytotoxicity. Dual-luciferase activity assay confirmed that hsa-miR-186-5p was the ceRNA candidate of SNHG6. QRT-PCR showed hsa-miR-186-5p expression was reversely correlated with SNHG6 in PPF-exposed HiPSC-CMs. Suppressing hsa-miR-186-5p reduced the rescuing effects of SNHG6-downregulation on PPF-induced cardiac cytotoxicity.

Conclusions

SNHG6/hsa-miR-186-5p can modulate PPF-induced cardiac cytotoxicity in HiPSC-CMs, and thus may be a future drug target to prevent PPF infusion syndrome.

Gelatin Promotes Cell Retention Within Decellularized Heart Extracellular Matrix Vasculature and Parenchyma

Introduction

Recellularization of organ decellularized extracellular matrix (dECM) offers a potential solution for organ shortage in allograft transplantation. Cell retention rates have ranged from 10 to 54% in varying approaches for reseeding cells in whole organ dECM scaffolds. We aimed to improve recellularization by using soluble gelatin as a cell carrier to deliver endothelial cells to the coronary vasculature and cardiomyocytes to the parenchyma in a whole decellularized rat heart.

Methods

Rat aortic endothelial cells (RAECs) were perfused over decellularized porcine aorta in low (1%) and high (5%) concentrations of gelatin to assess attachment to a vascular dECM model. After establishing cell viability and proliferation in 1% gelatin, we used 1% gelatin as a carrier to deliver RAECs and neonatal rat cardiomyocytes (NRCMs) to decellularized adult rat hearts. Immediate cell retention in the matrix was quantified, and recellularized hearts were evaluated for visible contractions up to 35 days after recellularization.

Results

We demonstrated that gelatin increased RAEC attachment to decellularized porcine aorta; blocking integrin receptors reversed this effect. In the whole rat heart gelatin (1%) increased retention of both RAECs and NRCMs respectively, compared with the control group (no gelatin). Gelatin was associated with visible contractions of NRCMs within hearts (87% with gelatin vs. 13% control).

Conclusions

Gelatin was an effective cell carrier for increasing cell retention and contraction in dECM. The gelatin-cell-ECM interactions likely mediated by integrin.

A Guide to Understanding "State-of-the-Art" Basic Research Techniques in Anesthesiology

Perioperative medicine is changing from a "protocol-based" approach to a progressively personalized care model. New molecular techniques and comprehensive perioperative medical records allow for detection of patient-specific phenotypes that may better explain, or even predict, a patient's response to perioperative stress and anesthetic care. Basic science technology has significantly evolved in recent years with the advent of powerful approaches that have translational relevance. It is incumbent on us as a primarily clinical specialty to have an in-depth understanding of rapidly evolving underlying basic science techniques to incorporate such approaches into our own research, critically interpret the literature, and improve future anesthesia patient care. This review focuses on 3 important and most likely practice-changing basic science techniques: next-generation sequencing (NGS), clustered regularly interspaced short palindromic repeat (CRISPR) modulations, and inducible pluripotent stem cells (iPSCs). Each technique will be described, potential advantages and limitations discussed, open questions and challenges addressed, and future developments outlined. We hope to provide insight for practicing physicians when confronted with basic science articles and encourage investigators to apply "state-of-the-art" technology to their future experiments.

Astaxanthin improves osteopenia caused by aldehyde-stress resulting from Aldh2 mutation due to impaired osteoblastogenesis

Aldehyde dehydrogenase 2 (ALDH2) plays major roles in aldehyde detoxification and in the catalysis of amino acids. ALDH2∗2, a dominant-negative transgenic expressing aldehyde dehydrogenase 2 (ALDH2) protein, is produced by a single nucleotide polymorphism (rs671) and is involved in the development of osteoporosis and hip fracture with aging. In a previous study, transgenic mice expressing Aldh2∗2(Aldh2∗2 Tg) osteoblastic cells or acetaldehyde -treated MC3T3-E1 showed impaired osteoblastogenesis and caused osteoporosis [1]. In this study, we demonstrated the effects of astaxanthin for differentiation to osteoblasts of MC3T3-E1 by the addition of acetaldehyde and Aldh2∗2 Tg mesenchymal stem cells in bone marrow. Astaxanthin restores the inhibited osteoblastogenesis by acetaldehyde in MC 3T3-E1 and in bone marrow mesenchymal stem cells of Aldh2∗2 Tg mice. Additionally, astaxanthin administration improved femur bone density in Aldh2∗2 Tg mice. Furthermore, astaxanthin improved cell survival and mitochondrial function in acetaldehyde-treated MC 3T3-E1 cells. Our results suggested that astaxanthin had restorative effects on osteoblast formation and provide new insight into the regulation of osteoporosis and suggest a novel strategy to promote bone formation in osteopenic diseases caused by impaired acetaldehyde metabolism.

Protective effects of trimetazidine and coenzyme Q10 on cisplatin-induced cardiotoxicity by alleviating oxidative stress and mitochondrial dysfunction

Objective:

The objective of this study was to investigate the effects of trimetazidine (TMZ) and coenzyme Q10 (CoQ10) on cisplatin-induced cardiotoxicity in rat cardiomyocytes.

Methods:

Rat cardiomyocytes were isolated and subjected to cisplatin (200 µM) treatment with and without TMZ (200 µM) and CoQ10 (200 mg/L) pretreatment. The cell viability, apoptosis, oxidant and antioxidant indicators, and mitochondrial dysfunction were examined.

Results:

TMZ or CoQ10 significantly attenuated cisplatin-induced cell viability inhibition (p<0.01) and apoptosis (p<0.001), and the combined use of TMZ and CoQ10 pretreatment exerted a pronounced effect compared to the effects of using each of these agents individually (p<0.05). TMZ or CoQ10 inhibited the levels of reactive oxidative species (ROS, p<0.01) and malondialdehyde (MDA, p<0.001 and p<0.01, respectively), elevated the activities of antioxidant enzymes superoxide dismutase (SOD, p<0.01) and catalase (CAT, p<0.01 and p<0.05, respectively), evidently enhanced nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2, p<0.05), alleviated mitochondrial membrane potential (ΔΨm) loss (p<0.05), and down-regulated the release of cytochrome c (cyto-c) into the cytosol (p<0.01) in cisplatin-treated cells. The combined use of TMZ and CoQ10 treatment was more effective than using either agent alone (p<0.01 for ROS, MDA, CAT, and cytosolic cyto-c; p<0.05 for SOD, nuclear Nrf2, and ΔΨm loss).

Conclusion:

TMZ and CoQ10 showed protective effects against cisplatin-induced cardiotoxicity via attenuating oxidative stress.

The Basic Study of the Mechanism of Propofol-Related Infusion Syndrome Using a Murine Skeletal Muscle Injury Model

Background

The pathophysiological mechanism of propofol-related infusion syndrome (PRIS) is believed to be due to the injury to the mitochondrial electron transport chain and the resultant metabolic disorders that are caused by both propofol agents and the lipid solvent. However, the mechanisms and causative factors of PRIS have not been fully elucidated.

Objectives

The aim of this study was to evaluate the possibility of a research model using the culture of differentiated C2C12 cells for fundamental research of PRIS.

Methods

First, differentiated C2C12 cells were cultured accompanied by several concentrations of chemical reagents of 2,6-diisopropylphenol (2,6 DIP) or dimethyl sulfoxide (DMSO) for 60 hours and the cell death rate was examined by trypan blue staining. Second, The cells were incubated with a commercially available propofol reagent or lipid reagent for 48 hours. The supernatant fluid of the cell culture medium was gathered and the numbers of floating cells were measured by cell counter. To investigate the mitochondrial disorder by the propofol preparation, JC-1, an experiment using fluorescent reagent, was performed for the 48 hours with 100 µg/mL propofol incubation.

Results

The rate of cell death was increased with elevating concentrations both of chemical reagents of 2,6 DIP group and dimethyl sulfoxide group. The rates of cell death were significantly higher in the 2,6 DIP group than DMSO group. The numbers of floating cells were increased with elevating concentrations both commercially available propofol reagent and lipid reagent groups. The decreased red/green fluorescence ratio by JC-1 staining in the propofol 100µg/mL group proved an attenuated mitochondrial membrane potential.

Conclusions

The dose-dependent cell damage induced by the propofol reagents and a lipid solvent may provide a proposed model as a basic experimental model for further investigations into PRIS.

Propofol infusion-like syndrome in a dog

An 8-year-old, spayed female Chihuahua mixed breed dog was presented for dyspnea and was subsequently mechanically ventilated. Propofol was utilized as part of the anesthetic protocol. The dog developed rhabdomyolysis, myoglobinuria, cardiac arrhythmias, liver enzyme elevation, and methemoglobinemia. Propofol was discontinued and N-acetylcysteine was administered after which the clinical signs resolved.