Butorphanol protects PC12 cells against OGD/R-induced inflammation and apoptosis

Preconditioning Exercise Inhibits Neuron Ferroptosis and Ameliorates Brain Ischemia Damage by Skeletal Muscle-Derived Exosomes via Regulating miR-484/ACSL4 Axis

Aims: Although there is evidence that patients with stroke who exercise regularly before stroke have a better prognosis than those who do not exercise, the detailed mechanism remains unclear. Moreover, neuronal death plays a central role in neurological dysfunction caused by ischemic stroke. Thus, we investigated whether exercise could reduce stroke-induced neuronal death and its associated mediators in the current study. Results: Ferroptosis was the most dominant form of programmed cell death in neurons. Preconditioning exercise before stroke improved the neurological function and decreased the infarct area in rats with ischemic stroke. Preconditioning exercise attenuated stroke-induced ferroptosis by reducing lipid peroxidation (LPO) production, upregulating glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), and downregulating acyl-CoA synthetase long-chain family member 4 (ACSL4). High-throughput sequencing and dual luciferase reporter assays revealed that exercise-induced exosomal miR-484 inhibits Acsl4 expression. Moreover, we showed that exercise-induced exosomal miR-484 is mainly derived from skeletal muscle, and the neuroprotective effect of preconditioning exercise is suppressed by inhibiting miR-484 production in skeletal muscle. Innovation: This study suggested that neuronal ferroptosis is the most dominant form of programmed cell death in a hypoxic environment. Moreover, we showed that the ferroptosis pathway is a potential therapeutic target in ischemic stroke and that preconditioning exercise could be an effective antioxidant intervention for cerebral ischemia. Conclusion: Our work revealed that preconditioning exercise before stroke exerts neuroprotective effects against brain ischemia by skeletal muscle-derived exosomal miR-484 via inhibiting ferroptosis.

Butorphanol inhibits ferroptosis to attenuate PC12 cell injury by blocking JNK/p38 signaling

Butorphanol is a synthetic selective opioid receptor antagonist that exhibits substantial analgesic effects. The present study aimed to explore the effects of butorphanol on a neurodegenerative disease cell model and to investigate its specific regulatory mechanism. Cell viability of PC12 cells was assessed using the Cell Counting Kit-8 assay. Oxidative stress levels were measured by the corresponding kits and western blotting of specific protein markers. Apoptosis was determined using the terminal-deoxynucleoitidyl transferase mediated nick end labeling assay and by western blotting. Western blotting was used to analyze the expression levels of c-Jun NH2-terminal kinase (JNK)/p38 signaling pathway-related proteins. Thiobarbituric acid-reactive substances and Fe+2 content were detected using the corresponding assay kits and the expression levels of ferroptosis-associated proteins were assessed by western blotting following the addition of the JNK activator anisomycin (ANI). Oxidative stress and apoptosis were examined with the aforementioned assays following the supplementation of ANI or the ferroptosis inducer erastin (ERA). It was revealed that butorphanol dose-dependently enhanced the viability and suppressed the oxidative stress and apoptosis of H2O2-treated PC12 cells. In addition, butorphanol blocked JNK/p38 signaling and hampered ferroptosis, while this effect was reversed by ANI. ANI or ERA reversed the effects of butorphanol on oxidative stress and apoptosis of H2O2-treated PC12 cells. In summary, butorphanol suppressed ferroptosis by blocking JNK/p38 signaling to impart inhibitory effects on oxidative stress and apoptosis in a neurodegenerative disease cell model.

Nano-Plumber Reshapes Glymphatic-Lymphatic System to Sustain Microenvironment Homeostasis and Improve Long-Term Prognosis after Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Long-term changes in the microenvironment of the brain contribute to the degeneration of neurological function following TBI. However, current research focuses primarily on short-term modulation during the early phases of TBI, not on the critical significance of long-term homeostasis in the brain microenvironment. Notably, dysfunction of the glymphatic-lymphatic system results in the accumulation of danger/damage-associated molecular patterns (DAMPs) in the brain, which is regarded as the leading cause of long-term microenvironmental disturbances following TBI. Here, a nanostructure, Nano-plumber, that co-encapsulates the microenvironment regulator pro-DHA and the lymphatic-specific growth factor VEGF-C is developed, allowing for a sustainable and orderly regulation of the microenvironment to promote long-term neurological recovery. Nano-plumber reverses the injury microenvironment by suppressing microglia and astrocytes activation and maintaining reduced activation via enhanced glymphatic-lymphatic drainage, and significantly improves the neurological function of rodents with TBI. This study demonstrates that glymphatic-lymphatic system reconstruction is essential for enhancing long-term prognosis following TBI, and that the Nano-plumber developed here may serve as a clinically translatable treatment option for TBI.

Stem cells alleviate OGD/R mediated stress response in PC12 cells following a co-culture: modulation of the apoptotic cascade through BDNF-TrkB signaling

Apoptosis mediated by endoplasmic reticulum (ER) stress plays a crucial role in several neurovascular disorders, including ischemia/reperfusion injury (I/R injury). Previous in vitro and in vivo studies have suggested that following I/R injury, ER stress is vital for mediating CCAT-enhancer-binding protein homologous protein (CHOP) and caspase-12-dependent apoptosis. However, its modulation in the presence of stem cells and the underlying mechanism of cytoprotection remains elusive. In vivo studies from our lab have reported that post-stroke endovascular administration of stem cells renders neuroprotection and regulates apoptosis mediated by ER stress. In the current study, a more robust in vitro validation has been undertaken to decipher the mechanism of stem cell-mediated cytoprotection. Results from our study have shown that oxygen-glucose deprivation/reoxygenation (OGD/R) potentiated ER stress and apoptosis in the pheochromocytoma 12 (PC12) cell line as evident by the increase of protein kinase R (PKR)-like ER kinase (p-PERK), p-Eukaryotic initiation factor 2α subunit (EIF2α), activation transcription factor 4 (ATF4), CHOP, and caspase 12 expressions. Following the co-culture of PC12 cells with MSCs, ER stress was significantly reduced, possibly via modulating the brain-derived neurotrophic factor (BDNF) signaling. Furthermore, inhibition of BDNF by inhibitor K252a abolished the protective effects of BDNF secreted by MSCs following OGD/R. Our study suggests that inhibition of ER stress-associated apoptotic pathway with MSCs co-culture following OGD/R may help to alleviate cellular injury and further substantiate the use of stem cells as a therapeutic modality toward neuroprotection following hypoxic injury or stroke in clinical settings.

Tailored Apoptotic Vesicle Delivery Platform for Inflammatory Regulation and Tissue Repair to Ameliorate Ischemic Stroke

Apoptotic vesicles (ApoVs) hold great promise for inflammatory regulation and tissue repair. However, little effort has been dedicated to developing ApoV-based drug delivery platforms, while the insufficient targeting capability of ApoVs also limits their clinical applications. This work presents a platform architecture that integrates apoptosis induction, drug loading, and functionalized proteome regulation, followed by targeting modification, enabling the creation of an apoptotic vesicle delivery system to treat ischemic stroke. Briefly, α-mangostin (α-M) was utilized to induce mesenchymal stem cell (MSC) apoptosis while being loaded onto MSC-derived ApoVs as an anti-oxidant and anti-inflammatory agent for cerebral ischemia/reperfusion injury. Matrix metalloproteinase activatable cell-penetrating peptide (MAP), a microenvironment-responsive targeting peptide, was modified on the surface of ApoVs to obtain the MAP-functionalized α-M-loaded ApoVs. Such engineered ApoVs targeted the injured ischemic brain after systemic injection and achieved an enhanced neuroprotective activity due to the synergistic effect of ApoVs and α-M. The internal protein payloads of ApoVs, upon α-M activation, were found engaged in regulating immunological response, angiogenesis, and cell proliferation, all of which contributed to the therapeutic effects of ApoVs. The findings provide a universal framework for creating ApoV-based therapeutic drug delivery systems for the amelioration of inflammatory diseases and demonstrate the potential of MSC-derived ApoVs to treat neural injury.

Vitality-Enhanced Dual-Modal Tracking System Reveals the Dynamic Fate of Mesenchymal Stem Cells for Stroke Therapy

Mesenchymal stem cell (MSC) therapy via intravenous transplantation exhibits great potential for brain tissue regeneration, but still faces thorny clinical translation challenges as the unknown dynamic fate leads to the contentious therapeutic mechanism and the poor MSC viability in harsh lesions limits therapeutic efficiency. Here, a vitality-enhanced dual-modal tracking system is designed to improve engraftment efficiency and is utilized to noninvasively explore the fate of intravenous transplanted human umbilical cord-derived MSCs during long-term treatment of ischemic stroke. Such a system is obtained by bioorthogonally conjugating magnetic resonance imaging (MRI) contrast and near-infrared fluorescence (NIRF) imaging nanoparticles to metabolic glycoengineered MSCs with a lipoic acid-containing extracellular antioxidative protective layer. The dynamic fates of MSCs in multi-dimensional space-time evolution are digitally detailed for up to 28 days using MRI and NIRF imaging equipment, and the protective layer greatly shields MSCs from reactive oxygen spices (ROS) degradation, enhances MSC survival, and engraftment efficiency. Additionally, it is observed that the bioengineered MSCs exhibit dynamic intelligent responses corresponding to microenvironment remodeling and exert enhanced therapeutic effects. This dual-modal tracking system enables long-term tracking of MSCs while improving their viability at the lesion sites, which may serve as a valuable tool for expediting the clinical translation of MSC therapy.

Neuroprotective Effect of miR-483-5p Against Cardiac Arrest-Induced Mitochondrial Dysfunction Mediated Through the TNFSF8/AMPK/JNK Signaling Pathway

Substantial morbidity and mortality are associated with postcardiac arrest brain injury (PCABI). MicroRNAs(miRNAs) are essential regulators of neuronal metabolism processes and have been shown to contribute to alleviated neurological injury after cardiac arrest. In this study, we identified miRNAs related to the prognosis of patients with neurological dysfunction after cardiopulmonary resuscitation based on data obtained from the Gene Expression Omnibus (GEO) database. Then, we explored the effects of miR-483-5p on mitochondrial biogenesis, mitochondrial-dependent apoptosis, and oxidative stress levels after ischemia‒reperfusion injury in vitro and in vivo. MiR-483-5p was downregulated in PC12 cells and hippocampal samples compared with that in normal group cells and hippocampi. Overexpression of miR-483-5p increased the viability of PC12 cells after ischemia‒reperfusion injury and reduced the proportion of dead cells. A western blot analysis showed that miR-483-5p increased the protein expression of PCG-1, NRF1, and TFAM and reduced the protein expression of Bax and cleaved caspase 3, inhibiting the release of cytochrome c from mitochondria and alleviating oxidative stress injury by inhibiting the production of ROS and reducing MDA activity. We confirmed that miR-483-5p targeted TNFSF8 to regulate the AMPK/JNK pathway, thereby playing a neuroprotective role after cardiopulmonary resuscitation. Hence, this study provides further insights into strategies for inhibiting neurological impairment after cardiopulmonary resuscitation and suggests a potential therapeutic target for PCABI.

Antioxidant and analgesic potential of butorphanol in dogs undergoing ovariohysterectomy

The aim of this study was to evaluate the postoperative analgesic and antioxidant effects of butorphanol given in the preoperative or early postoperative period. Twenty-seven healthy female dogs undergoing ovariohysterectomy were randomly divided into three groups as before surgery group (BSG, n = 7) received butorphanol 30 min before preanesthetic administration, after surgery group (ASG, n = 10) received butorphanol during the last skin suture and the control group (CG, n = 10) received no butorphanol. Pain was assessed with short form of the Glasgow composite pain scale (CMPS-SF). Serum concentration of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase activities (GPx) were quantified by spectrophotometric methods to assess oxidative stress status. The pain score increased rapidly at 1 h after surgery and then decreased gradually towards to 24 h in all groups. There was no statistical difference among the groups in terms of CMPS-SF scores (P > 0.05). Serum concentration of MDA was lower in ASG than in BSG and CG from 1 h to 24 h after surgery. Serum activity of GPx was higher in ASG than in BSG and CG from 2 h to 24 h (P < 0.05). Serum activity of SOD was higher in ASG than in BSG and CG from 1 h to 24 h after surgery (P < 0.05). Serum SOD activity at different time points in ASG did not differ compared to preoperative level though it decreased significantly from 1 h onwards both in CT and BSG. The results indicate that single butorphanol administration either before or after the operation might not provide sufficient analgesia, however, it seems that it has antioxidant potential and may protect tissues by reducing oxidative stress when administered early postoperative period following ovariohysterectomy.

Simultaneous tracking of autophagy and oxidative stress during stroke with an ICT-TBET integrated ratiometric two-photon platform

Over recent years, fluorescent probes exhibiting simultaneous responses to multiple targets have been developed for in situ, real-time monitoring of cellular metabolism using two photon fluorescence sensing techniques due to numerous advantages including ease of operation, rapid reporting, high resolution, long visualization time and being non-invasive. However, due to interference from different fluorescence channels during simultaneous monitoring of multiple targets and the lack of ratiometric capability amongst the available probes, the accuracy in tracing metabolic processes has been restricted. With this research, using a through-bond energy transfer (TBET) mechanism, we designed a viscosity and peroxynitrite (ONOO^-) mitochondria-targeting two-photon ratiometric fluorescent probe Mito-ONOO. Our results indicated that with decreasing levels of mitochondrial viscosity and increasing levels of ONOO^-, the maximum of the emission wavelength of the probe shifted from 621 nm to 495 nm under 810 nm two-photon excitation. The baselines for the two emission peaks were significantly separated (Δλ = 126 nm), improving the resolution and reliability of bioimaging. Moreover, by ratiometric analysis during oxygen-glucose deprivation/reoxygenation (OGD/R, commonly used to simulate cell ischemia/reperfusion injury), the real-time visualization of the metabolic processes of autophagy and oxidative stress was possible. Our research indicated that during cellular oxygen-glucose deprivation/reoxygenation, cells produce ONOO^-, causing cellular oxidative stress and cellular autophagy after 15 min, as such Mito-ONOO exhibits the potential for the monitoring and diagnosis of stroke, as well as providing insight into potential treatments, and drug design.

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

SET domain containing 7 promotes oxygen-glucose deprivation/reoxygenation-induced PC12 cell inflammation and oxidative stress by regulating Keap1/Nrf2/ARE and NF-κB pathways

Oxidative stress and inflammation are implicated in the pathogenesis of cerebral ischemia-reperfusion (I/R) injury. SETD7 (SET Domain Containing 7) functions as a histone lysine methyltransferase, participates in cardiac lineage commitment, and silence of SETD7 exerts anti-inflammatory or antioxidant capacities. The effect of SETD7 in in vitro cell model of cerebral I/R injury was investigated in this study. Firstly, adrenal pheochromocytoma cell (PC12) was conducted with oxygen-glucose deprivation/reoxygenation (OGD/R) to establish cell model of cerebral I/R injury. OGD/R-enhanced SETD7 expression in PC12 cells. Cell viability of OGD/R-induced PC12 was reduced, while the apoptosis was promoted. Secondly, knockdown of SETD7 reversed the effect of OGD/R on cell viability and apoptosis of PC12. Moreover, OGD/R-induced inflammation in PC12 with decreased interleukin (IL)-10, increased IL-6, IL-1β, tumor necrosis factor-α (TNF-α), and cyclooxygenase 2 (COX-2) were restored by knockdown of SETD7. Thirdly, knockdown of SETD7 attenuated OGD/R-induced decrease of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), as well as increase of malondialdehyde (MDA) and reactive oxygen species (ROS) in PC12. Lastly, OGD/R-induced decrease of NF-κB inhibitor α (IκBα), increase of phosphorylated (p)-p65, p-IκBα, and Keap1 (Kelch-like ECH-associated protein 1) were reversed by silence of SETD7. Silence of SETD7 increased heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2) expression in OGD/R-induced PC12. In conclusion, suppression of SETD7 ameliorated OGD/R-induced inflammation and oxidative stress in PC12 cell through inactivation of NF-κB and activation of Keap1/Nrf2/ARE pathway.

Butorphanol tartrate mitigates cellular senescence against tumor necrosis factor –α (TNF-α) in human HC-A chondrocytes

Aging is an important risk factor for osteoarthritis (OA). Butorphanol is a preoperative sedative and analgesic that possesses anti-inflammatory activity. However, the effect of butorphanol on OA has not been reported. Here we aimed to explore the effect of butorphanol tartrate on the cellular senescence of human chondrocyte-articular (HC-A) cells in response to tumor necrosis factor-α (TNF-α) stimulation. Butorphanol tartrate attenuated the TNF-α-caused cellular senescence of HC-A cells, with decreased positive senescence-associated-β-galactosidase (SA-β-gal) staining and elevated telomerase activity. Butorphanol tartrate prevented TNF-α-caused cell cycle arrest in the G0/G1 phase in HC-A cells and decreased p21 expression. The TNF-α-induced production of interleukin (IL)-6 and IL-8 in HC-A cells were mitigated by butorphanol tartrate. In addition, butorphanol tartrate reduced p-NF-κB p65/total p65 and p-STAT3/STAT3 ratios in HC-A cells cultured with TNF-α. Taken together, butorphanol tartrate protected HC-A cells from TNF-α-caused cellular senescence through inactivation of NF-κB and STAT3. These results imply that butorphanol tartrate might be used as a potential agent for the treatment of aging-related OA.

Exploration of the mechanism of luteolin against ischemic stroke based on network pharmacology, molecular docking and experimental verification

Stroke is a leading cause of morbidity and mortality worldwide. As the most common type of stroke cases, treatment effectiveness is still limited despite intensive research. Recently, traditional Chinese medicine has attracted attention because of potential benefits for stroke treatment. Among these, luteolin, a natural plant flavonoid compound, offers neuroprotection following against ischemic stroke, although the specific mechanisms are unknown. Here we used network pharmacology, molecular docking, and experimental verification to explore the mechanisms whereby luteolin can benefit stroke recovery. The pharmacological and molecular properties of luteolin were obtained from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. The potential targets of luteolin and ischemic stroke were collected from interrogating public databases. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed by Funrich and Database for Annotation, Visualization and Integrated Discovery respectively, a luteolin-target-pathway network constructed using Cytoscape, Autodock vina was used for molecular docking simulation with Discovery Studio was used to visualize and analyze the docked conformations. Lastly, we employed an in vitro model of stroke injury to evaluate the effects of luteolin on cell survival and expression of the putative targets. From 95 candidate luteolin target genes, our analysis identified six core targets . KEGG analysis of the candidate targets identified that luteolin provides therapeutic effects on stroke through TNF signaling and other pathways. Our experimental analyses confirmed the conclusions analyzed above. In summary, the molecular and pharmacological mechanisms of luteolin against stroke are indicated in our study from a systematic perspective.

Multiple pathways are responsible to the inhibitory effect of butorphanol on OGD/R-induced apoptosis in AC16 cardiomyocytes

Ischemic heart disease is the leading cause of cardiovascular mortality, which is related to cardiac myocyte apoptosis. Butorphanol is an opioid receptor agonist with potential cardioprotective function. The purpose of this work is to explore the function and mechanism of butorphanol in oxygen and glucose deprivation/reperfusion (OGD/R)-induced cardiomyocyte apoptosis. The overlapping targets of ischemic heart disease and butorphanol were analyzed according to GeneCards, ParmMapper, Cytoscape, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Human cardiomyocyte AC16 cells were incubated with butorphanol and then stimulated with OGD/R. Cell injury was investigated by Cell Counting Kit-8, lactate dehydrogenase (LDH) assay kit, TUNEL staining, caspase-3 activity assay kit, and Western blotting. The proteins in signaling pathways were measured using Western blotting. A total of 93 overlapping targets of ischemic heart disease and butorphanol were obtained. Pathway analysis exhibited that these targets might be involved in multiple signaling pathways. Butorphanol alone showed little cytotoxicity to cardiomyocytes, and it protected against OGD/R-induced viability inhibition, LDH release, cell apoptosis, and increase of caspase-3 activity and expression levels of cleaved caspase-3 and Bim. Butorphanol promoted the activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/forkhead box O (FoxO) and hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) pathways and attenuated the activation of the mitogen-activated protein kinase (MAPK) signaling in OGD/R-treated cardiomyocytes. In conclusion, butorphanol prevents OGD/R-induced cardiomyocyte apoptosis through activating the PI3K/Akt/FoxO and HIF-1α/VEGF pathways and inactivating the MAPK pathway.

Observation of inflammation-induced mitophagy during stroke by a mitochondria-targeting two-photon ratiometric probe

This study reports the development of a new, pH-sensitive, mitochondria-targeting two-photon ratiometric probe (Mito-BNO) for real-time tracking of mitophagy, a process that can be accelerated in brain tissue during stroke. Mito-BNO shows excellent capability for mitochondrial localisation (Pearson's correlation coefficient, r = 0.91), and can also effectively distinguish mitochondria from other subcellular organelles such as lysosomes and the endoplasmic reticulum (r = 0.40 and r = 0.33, respectively). Meanwhile, a rewarding pKa value (5.23 ± 0.03) and the pH reversibility suggest that Mito-BNO can track mitophagy in real time via confocal imaging. Most importantly, the relationship between mitophagy and neuroinflammation during stroke has been successfully demonstrated by evaluating the fluorescence of PC12 cells stained with Mito-BNO during an oxygen-glucose deprivation/reperfusion (OGD/R) process with and without anti-inflammatory treatment. The results indicate that the occurrence of mitophagy during stroke is caused by oxidative stress induced by neuroinflammation. This study will help further understanding stroke pathogenesis, can provide potential new targets for early diagnosis and treatment, and can also help to develop therapeutic drugs for stroke.