Esketamine is neuroprotective against traumatic brain injury through its modulation of autophagy and oxidative stress via AMPK/mTOR-dependent TFEB nuclear translocation

Esketamine alleviates LPS-induced depression-like behavior by activating Nrf2-mediated anti-inflammatory response in adolescent mice

BACKGROUND

The mechanisms underlying esketamine's therapeutic effects remain elusive. The study aimed to explore the impact of single esketamine treatment on LPS-induced adolescent depressive-like behaviors and the role of Nrf2 regulated neuroinflammatory response in esketamine-produced rapid antidepressant efficacy.

METHODS

Adolescent male C57BL/6J mice were randomly assigned to three groups: control, LPS, and LPS + esketamine (15 mg/kg, i.p.). Depressive-like behaviors were evaluated via the OFT, NFST, and TST. Protein expression of Nrf2 and inflammatory cytokines, including TNF-α, IL-1β, and iNOS in the hippocampus and mPFC, were measured by western blot. Moreover, the Nrf2 inhibitor, ML385, was also applied in the current study. The depressive-like behaviors and the protein expression of Nrf2, TNF-α, IL-1β, and iNOS in mPFC and hippocampus were also measured. Additionally, the plasma's pro-inflammatory cytokines and anti-inflammatory cytokines were assessed using ELISA methods with or without ML385.

RESULTS

A single administration of esketamine treatment alleviated the LPS-induced depressive-like behaviors. Esketamine increased the expression of Nrf2 and reduced the expression of the inflammatory cytokines, including TNF-α, IL-1β, and iNOS, in the mPFC and hippocampus. Notably, pharmacological inhibition of Nrf2 via ML385 administration abrogated the antidepressive-like behaviors and anti-inflammatory effects induced by esketamine. In the periphery, esketamine mitigated the LPS-induced elevation of pro-inflammatory cytokines, and the reduction of anti-inflammatory cytokines, and this effect was reversed by Nrf2 inhibition.

CONCLUSION

Esketamine treatment exerts rapid antidepressant effects and attenuates neuroinflammation in LPS-induced adolescent depressive-like behaviors, potentially through the activation of Nrf2-mediated anti-inflammatory signaling.

AGEING RESEARCH REVIEWS (ARR-D-24-01334R1) Metabolic dysfunction contributes to mood disorders after traumatic brain injury

Traumatic brain injury (TBI) presents significant risks concerning mortality and morbidity. Individuals who suffer from TBI may exhibit mood disorders, including anxiety and depression. Both preclinical and clinical research have established correlations between TBI and disturbances in the metabolism of amino acids, lipids, iron, zinc, and copper, which are implicated in the emergence of mood disorders post-TBI. The purpose of this review is to elucidate the impact of metabolic dysfunction on mood disorders following TBI and to explore potential strategies for mitigating anxiety and depression symptoms. We researched the PubMed and Web of Science databases to delineate the mechanisms by which metabolic dysfunction contributes to mood disorders in the context of TBI. Particular emphasis was placed on the roles of glutamate, kynurenine, lipids, iron, zinc, and copper metabolism. Metabolic dysfunction is linked to mood disorders post-TBI through multiple pathways, encompassing the glutamatergic system, the kynurenine pathway, endocannabinoids, iron deposition, iron-related ferroptosis, zinc deficiency, and copper dysregulation. Furthermore, this review addresses the influence of metabolic dysfunction on mood disorders in the elderly demographic following TBI. Targeting metabolic dysfunction for therapeutic intervention appears promising in alleviating symptoms of anxiety and depression that arise after TBI. While further investigation is warranted to delineate the underlying pathophysiologic mechanisms of mood disorders post-TBI, current evidence underscores the potential contribution of metabolic dysfunction to these conditions. Therefore, rectifying metabolic dysfunction represents a viable and strategic approach to addressing mood disorders following TBI.

Esketamine and neurocognitive disorders in adult surgical patients: a meta-analysis

BACKGROUND

Prior meta-analyses have established the potential of intravenous ketamine in safeguarding against neurocognitive impairment, but the efficacy of intravenous esketamine for the prevention of perioperative neurocognitive disorders (PND) remains uncertain. The primary aim of this meta-analysis was to conduct a comprehensive evaluation of the effects of esketamine on PND in adult surgical patients undergoing general anesthesia.

METHODS

We searched several electronic databases and clinical trial registries to find relevant trials. Randomized controlled trials of perioperative use of esketamine adjuvant were included in the analysis. The main outcome measured was the risk of postoperative delirium(POD) and postoperative cognitive dysfunction (POCD). Secondary outcomes included the assessment of postoperative cognitive status, pain scores (VAS/NRS), remifentanil consumption and the occurrence of postoperative nausea and vomiting (PONV).

RESULTS

Thirteen studies encompassing procedures such as abdominal, thoracoscopic lung, gastrointestinal, laparoscopic gynecological, spinal surgery, and modified radical mastectomy, were included in the analysis. A cohort comprising 1068 adult patients underwent general anesthesia, with 584 patients assigned to the esketamine group and 484 patients designated to the placebo group. The administration of general anesthesia was augmented by intravenous infusion of esketamine, and a comparative analysis was conducted in relation to alternative pharmacological interventions or a placebo. The application of esketamine during the perioperative period was observed to decrease the risk of POD ( RR 0.46; 95% CI: 0.32, 0.66, p < 0.0001, GRADE = High) and exhibited a protective influence on POCD (RR = 0.50; 95%CI: 0.30, 0.84, p = 0.009, I2 = 0%, GRADE = Moderate). Significant improvements were observed at 4, 24 and 48 h post-surgery when comparing esketamine to a placebo (4 h: SMD -0.78, 95% CI: -1.24, -0.32, p = 0.0009, I2 = 58%, GRADE = Low; 24 h: SMD -0.92, 95% CI: -1.40, -0.44, p = 0.0002, I2 = 86%, GRADE = Low; 48 h: SMD -0.9, 95% CI: -1.68, -0.12, p = 0.02, I2 = 89%, GRADE = Low), and intraoperative remifentanil consumption was significantly reduced in the esketamine group (SMD -0.56; 95%CI: - 0.86, - 0.27, p = 0.0002, I2 = 62%, GRADE = moderate). A notable reduction in the risk of PONV was observed in the esketamine group(RR = 0.64; 95%CI: 0.49, 0.84, p = 0.001, I2 = 0%, GRADE = High).

CONCLUSION

The use of intravenous esketamine as an adjuvant in general anesthesia may represent a potentially beneficial strategy for reducing susceptibility to PND, with potential benefits for preventing POD and POCD. Furthermore, it can decrease intraoperative opioid consumption and alleviate postoperative pain intensity without increasing the incidence of PONV.

TRIAL REGISTRATION

This meta-analysis was registered on PROSPERO (CRD42023453714).

Esketamine alleviates ferroptosis-mediated acute lung injury by modulating the HIF-1α/HO-1 pathway

BACKGROUND

Alveolar epithelial cell (AEC) ferroptosis contributes to the progression of acute lung injury (ALI). Esketamine (ESK) is a new clinical sedative, anesthetic, and analgesic drug that has attracted substantial attention in mental health research because of its antidepressant effects. However, the effects of ESK on ferroptosis-mediated ALI remain unclear.

OBJECTIVE

This study aimed to explore the protective effect of ESK on AEC ferroptosis in ALI and its potential molecular mechanism in vivo and in vitro.

METHODS

The antiferroptotic and anti-inflammatory effects of ESK were assessed in a mouse model of lipopolysaccharide (LPS)-induced ALI. In vitro, the epithelial cell lines MLE-12 and A549 were used to examine the underlying mechanism by which ESK regulates inflammation and ferroptosis.

RESULTS

ESK protected mice against LPS-induced ALI, significantly attenuated pathological changes in the lungs and decreased inflammation and ferroptosis. In vitro, ESK inhibited LPS-induced inflammation and ferroptosis in MLE-12 and A549 cells. Moreover, ferroptosis mediated inflammation in LPS-induced ALI in vivo and in vitro, and ESK decreased the LPS-induced inflammatory response by suppressing ferroptosis. ESK promoted the HIF-1α/HO-1 pathway in LPS-treated AECs and in the lung tissues of mice with LPS-induced ALI. Moreover, pretreatment with ESK and the HIF-1α stabilizer dimethyloxaloylglycine (DMOG) substantially attenuated lung injury and prevented changes in ferroptosis-related biochemical indicators, including glutathione (GSH) depletion, malondialdehyde (MDA) production and glutathione peroxidase 4 (GPX4) downregulation, in untreated LPS-induced mice but not in LPS-induced mice treated with the HO-1 inhibitor zinc protoporphyrin (ZNPP). Similar effects were observed in vitro in HO-1 siRNA-transfected A549 cells after LPS incubation but not in control siRNA-transfected cells.

CONCLUSION

ESK can inhibit ferroptosis-mediated lipid peroxidation by increasing the expression of HIF-1α/HO-1 pathway, highlighting the potential of ESK to treat LPS-induced ALI.

Neuroprotective and neuroregenerative drugs after severe traumatic brain injury : A narrative review from a clinical perspective

Traumatic brain injuries cause enormous individual and socioeconomic burdens. Survivors frequently struggle with motor handicaps as well as impaired cognition and emotion. In addition to the primary mechanical brain damage, complex secondary mechanisms are the main drivers of functional impairment. Many of these pathophysiological mechanisms are now well known: excitotoxic amino acids, breakdown of the blood-brain barrier, neuroinflammation with subsequent damage to cell organelles and membranes, cerebral edema, and apoptotic processes triggering neuronal death; however, paracrine resilience factors may counteract these processes. Specific neuroprotective and neuroregenerative intensive care therapies are few. This review highlights medical approaches aimed at mitigating secondary damage and promoting neurotrophic processes in severe traumatic brain injury. Some pharmacologic attempts that appeared very promising in experimental settings have had disappointing clinical results (progesterone, cyclosporine A, ronopterin, erythropoietin, dexanabinol). Thus, the search for drugs that can effectively limit ongoing posttraumatic neurological damage is ongoing. Some medications appear to be beneficial: N‑methyl-D-aspartate receptor (NMDA) antagonists (esketamine, amantadine, Mg++) reduce excitotoxicity and statins and cerebrolysin are known to counteract neuroinflammation. By supporting the impaired mitochondrial energy supply, oxidative processes are inhibited and neuroregenerative processes, such as neurogenesis, angiogenesis and synaptogenesis are promoted by citicoline and cerebrolysin. First clinical evidence shows an improvement in cognitive and thymopsychic outcomes, underlined by own clinical experience combining different therapeutic approaches. Accordingly, adjuvant treatment with neuroprotective substances appears to be a promising option, although more randomized prospective studies are still needed.

Esketamine Provides Neuroprotection After Intracerebral Hemorrhage in Mice via the NTF3/PI3K/AKT Pathway

BACKGROUND

Esketamine (ESK), a noncompetitive antagonist of N-methyl-D-aspartate (NMDA) receptors, modulates neurotransmitter signaling in the central nervous system. However, the specific mechanisms and therapeutic potential of ESK for intracerebral hemorrhage (ICH) remain unclear. This study aimed to investigate whether ESK promotes nerve repair and improves neurological outcomes in an experimental model of ICH.

METHODS

ICH was induced in mice via collagenase injection into the striatum. Body weight, neurological impairment, and behavioral changes were assessed. ESK administration significantly improved several indicators of ICH. Comprehensive RNA transcriptome sequencing and network pharmacology analyses identified neurotrophin-3 (NTF3) and the PI3K/AKT signaling pathway as targets for ESK treatment. Western blotting and immunofluorescence detected the protein expression levels and cellular localization of NTF3.

RESULTS

After 28 days of adeno-associated virus infection in the mouse striatum, ESK treatment significantly enhanced neuroprotection, indicating the crucial role of NTF3 in ESK-mediated neuroprotection in ICH mice. Inhibition of the PI3K/AKT pathway using the PI3K-specific inhibitor LY294002 significantly attenuated the therapeutic effects of ESK, suggesting that this pathway is involved in ESK-mediated neurorepair in ICH mice.

CONCLUSIONS

ESK treatment significantly improved functional outcomes and demonstrated neuroprotective effects in animal models of ICH. NTF3/PI3K/AKT pathway activation by ESK indicates its therapeutic potential in the treatment of ICH.

Effects of Esketamine Combined with Dexmedetomidine on Early Postoperative Cognitive Function in Elderly Patients Undergoing Lumbar Spinal Surgery: A Double-Blind Randomized Controlled Clinical Trial

Background

Postoperative cognitive dysfunction (POCD) is a common complication after surgery in elderly patients, and its prevalence can be up to 25.6% at one week after noncardiac surgery. This study mainly evaluates the combined effects of esketamine and dexmedetomidine on the incidence of POCD in elderly patients undergoing lumbar spine surgery and explores the underlying mechanisms.

Methods

A total of 162 elderly patients undergoing lumbar spine surgery were randomized into three groups: esketamine combined with dexmedetomidine group (ED group), esketamine group (E group), and dexmedetomidine group (D group). Primary outcome measures included the incidence of POCD on the first postoperative day. Secondary outcomes included the incidence of POCD on the third postoperative day, first postoperative day serum levels of neuron-specific enolase (NSE) and calcium-binding protein β (S100β), patient visual analog scale (VAS) scores at 2, 24, and 48 hours postoperatively, and the incidence of adverse events.

Results

The incidence of POCD on the first postoperative day was significantly lower in the ED group compared to the E group (P = 0.017), with no significant differences when compared to the D group (P = 0.064). The levels of serum NSE in patients in the ED group on the first postoperative day were significantly lower than those in E group and D group (ED group vs E group, P = 0.028; ED group vs D group, P = 0.048). The results for the S100β were similar to those for the NSE (ED group vs E group, P = 0.005; ED group vs D group, P = 0.011).

Conclusion

The combination of esketamine and dexmedetomidine effectively reduces the incidence of POCD on the first postoperative day in elderly patients undergoing lumbar spine surgery.

Ketamine and Esketamine in Clinical Trials: FDA-Approved and Emerging Indications, Trial Trends With Putative Mechanistic Explanations

Ketamine has a long and very eventful pharmacological history. Its enantiomer, esketamine ((S)-ketamine), was approved by the US Food and Drug Administration (FDA) and EMA for patients with treatment-resistant depression (TRD) in 2019. The number of approved indications for ketamine and esketamine continues to increase, as well as the number of clinical trials. This analysis provides a quantitative overview of the use of ketamine and its enantiomers in clinical trials during 2014-2024. A total of 363 trials were manually assessed from clinicaltrial.gov with the search term "Ketamine." The highest number of trials were found for the FDA-approved indications: anesthesia (~22%) and pain management (~28%) for ketamine and TRD for esketamine (~29%). Clinical trials on TRD for both ketamine and esketamine also comprised a large proportion of these trials, and interestingly, have reached phase III and phase IV status. Combinatorial treatment of psychiatric disorders and non-psychiatric conditions with pharmacological and non-pharmacological combinations (electroconvulsive therapy, psychotherapeutic techniques, virtual reality, and transcranial magnetic stimulation) is prevalent. Sub-anesthetic doses of ketamine may represent novel therapeutic avenues in neuropsychiatric conditions, that is, major depression, schizophrenia, and bipolar disorder, where glutamate excitotoxicity and oxidative stress are likely to be involved. The study suggests that the number of ketamine studies will continue to grow and possible ketamine variants can be approved for treatment of additional indications.

Intricate Role of the Cyclic Guanosine Monophosphate Adenosine Monophosphate Synthase-Stimulator of Interferon Genes (cGAS-STING) Pathway in Traumatic Brain Injury-Generated Neuroinflammation and Neuronal Death

The secondary insult in the aftermath of traumatic brain injury (TBI) causes detrimental and self-perpetuating alteration in cells, resulting in aberrant function and the death of neuronal cells. The secondary insult is mainly driven by activation of the neuroinflammatory pathway. Among several classical pathways, the cGAS-STING pathway, a primary neuroinflammatory route, encompasses the cyclic GMP-AMP synthase (cGAS), stimulator of interferon genes (STING), and downstream signaling adaptor. Recently, the cGAS-STING research domain has gained exponential attention. The aberrant stimulation of cGAS-STING machinery and corresponding neuroinflammation have also been reported after TBI. In addition to the critical contribution to neuroinflammation, the cGAS-STING signaling also provokes neuronal cell death through various cell death mechanisms. This review highlights the structural and molecular mechanisms of the cGAS-STING machinery associated with TBI. We also focus on the intricate relationship and framework between cGAS-STING signaling and cell death mechanisms (autophagy, apoptosis, pyroptosis, ferroptosis, and necroptosis) in the aftermath of TBI. We suggest that the targeting of cGAS-STING signaling may open new therapeutic strategies to combat neuroinflammation and neurodegeneration in TBI.

Puerarin enhances TFEB-mediated autophagy and attenuates ROS-induced pyroptosis after ischemic injury of random-pattern skin flaps

BACKGROUND AND AIM

Necrosis of random-pattern flaps restricts their application in clinical practice. Puerarin has come into focus due to its promising therapeutic effects in ischemic diseases. Here, we employed Puerarin and investigated its role and potential mechanisms in flap survival.

EXPERIMENTAL PROCEDURE

The effect of Puerarin on the viability of human umbilical vein endothelial cells (HUVECs) was assessed by CCK-8, EdU staining, migration, and scratch assays. Survival area measurement and laser Doppler blood flow (LDBF) were utilized to assess the viability of ischemic injury flaps. Levels of molecules related to oxidative stress, pyroptosis, autophagy, transcription factor EB (TFEB), and the AMPK-TRPML1-Calcineurin signaling pathway were detected using western blotting, immunofluorescence, dihydroethidium (DHE) staining, RT-qPCR and Elisa.

KEY RESULTS

The findings demonstrated that Puerarin enhanced the survivability of ischemic flaps. Autophagy, oxidative stress, and pyroptosis were implicated in the ability of Puerarin in improving flap survival. Increased autophagic flux and augmented tolerance to oxidative stress contribute to Puerarin's suppression of pyroptosis. Additionally, Puerarin modulated the activity of TFEB through the AMPK-TRPML1-Calcineurin signaling pathway, thereby enhancing autophagic flux.

CONCLUSIONS AND IMPLICATIONS

Puerarin promoted flap survival from ischemic injury through upregulation of TFEB-mediated autophagy and inhibition of oxidative stress. Our findings offered valuable support for the clinical application of Puerarin in the treatment of ischemic diseases, including random-pattern flaps.

Esketamine alleviates hypoxia/reoxygenation injury of cardiomyocytes by regulating TRPV1 expression and inhibiting intracellular Ca2+ concentration

OBJECTIVE

This study aimed to investigate the effect of Esketamine (ESK) on the Hypoxia/Reoxygenation (H/R) injury of cardiomyocytes by regulating TRPV1 and inhibiting the concentration of intracellular Ca2+.

METHODS

The H/R injury model of H9c2 cardiomyocytes was established after 4h hypoxia and 6h reoxygenation. H9c2 cells were treated with different concentrations of ESK or TRPV1 agonist capsaicin (10 μM) or TRPV1 inhibitor capsazepine (1 μM). Cell viability was detected by CCK-8 method, and apoptosis by flow cytometry. Intracellular Ca2+ concentration was evaluated by Fluo-4 AM. LDH, MDA, SOD, and GSH-Px were detected with corresponding commercial kits. TRPV1 and p-TRPV1 proteins were detected by Western blot.

RESULTS

After H/R, H9c2 cell viability decreased, apoptosis increased, intracellular Ca2+ concentration increased, LDH and MDA levels increased, SOD and GSH-Px levels decreased, and p-TRPV1 expression increased. ESK treatment rescued these changes induced by H/R. After up-regulating TRPV1, the protective effect of ESK on H/R injury of H9c2 cells was weakened, while down-regulating TRPV1 could further protect against H/R injury.

CONCLUSION

ESK alleviates H/R injury of cardiomyocytes by regulating TRPV1 expression and inhibiting intracellular Ca2+ concentration.

Potential Molecular Mechanisms of Alcohol Use Disorder with Non-Coding RNAs and Gut Microbiota for the Development of Superior Therapeutic Application

Many investigations have evaluated the expression of noncoding RNAs (ncRNAs) as well as their related molecular functions and biological machineries in individuals with alcohol dependence. Alcohol dependence may be one of the most prevailing psychological disorders globally, and its pathogenesis is intricate and inadequately comprehended. There is substantial evidence indicating significant links between multiple genetic factors and the development of alcohol dependence. In particular, the critical roles of ncRNAs have been emphasized in the pathology of mental illnesses, probably including alcohol dependence. In the comprehension of the action of ncRNAs and their machineries of modification, furthermore, they have emerged as therapeutic targets for a variety of psychiatric illnesses, including alcohol dependence. It is worth mentioning that the dysregulated expression of ncRNAs has been regularly detected in individuals with alcohol dependence. An in-depth knowledge of the roles of ncRNAs and m6A modification may be valuable for the development of a novel treatment against alcohol dependence. In general, a more profound understanding of the practical roles of ncRNAs might make important contributions to the precise diagnosis and/or actual management of alcohol dependence. Here, in this review, we mostly focused on up-to-date knowledge regarding alterations and/or modifications in the expression of ncRNAs in individuals with alcohol dependence. Then, we present prospects for future research and therapeutic applications with a novel concept of the engram system.

The role and mechanism of esketamine in preventing and treating remifentanil-induced hyperalgesia based on the NMDA receptor-CaMKII pathway

Remifentanil-induced hyperalgesia (RIH) is a common clinical phenomenon that limits the use of opioids in pain management. Esketamine, a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, has been shown to prevent and treat RIH. However, the underlying effect mechanism of esketamine on RIH remains unclear. This study aimed to investigate the role and mechanism of esketamine in preventing and treating RIH based on the NMDA receptor-CaMKIIα pathway. In this study, an experimental animal model was used to determine the therapeutic effect of esketamine on pain elimination. Moreover, the mRNA transcription and protein expression levels of CaMKII and GluN2B were investigated to offer evidence of the protective capability of esketamine in ameliorating RIH. The results demonstrated that esketamine attenuated RIH by inhibiting CaMKII phosphorylation and downstream signaling pathways mediated by the NMDA receptor. Furthermore, ketamine reversed the upregulation of spinal CaMKII induced by remifentanil. These findings suggest that the NMDA receptor-CaMKII pathway plays a critical role in the development of RIH, and ketamine's effect on this pathway may provide a new therapeutic approach for the prevention and treatment of RIH.

Emerging trends and hotspots of Nuclear factor erythroid 2-related factor 2 in nervous system diseases

BACKGROUND

The Nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor has attracted much attention in the context of neurological diseases. However, none of the studies have systematically clarified this field's research hotspots and evolution rules.

AIM

To investigate the research hotspots, evolution patterns, and future research trends in this field in recent years.

METHODS

We conducted a comprehensive literature search in the Web of Science Core Collection database using the following methods: (((((TS=(NFE2 L2)) OR TS=(Nfe2 L2 protein, mouse)) OR TS=(NF-E2-Related Factor 2)) OR TS=(NRF2)) OR TS=(NFE2L2)) OR TS=(Nuclear factor erythroid2-related factor 2) AND (((((((TS=(neurological diseases)) OR TS=(neurological disorder)) OR TS=(brain disorder)) OR TS=(brain injury)) OR TS=(central nervous system disease)) OR TS=(CNS disease)) OR TS=(central nervous system disorder)) OR TS=(CNS disorder) AND Language = English from 2010 to 2022. There are just two forms of literature available: Articles and reviews. Data were processed with the software Cite-Space (version 6.1. R6).

RESULTS

We analyzed 1884 articles from 200 schools in 72 countries/regions. Since 2015, the number of publications in this field has increased rapidly. China has the largest number of publications, but the articles published in the United States have better centrality and H-index. Among the top ten authors with the most published papers, five of them are from China, and the author with the most published papers is Wang Handong. The institution with the most articles was Nanjing University. To their credit, three of the top 10 most cited articles were written by Chinese scholars. The keyword co-occurrence map showed that "oxidative stress", "NRF2", "activation", "expression" and "brain" were the five most frequently used keywords.

CONCLUSION

Research on the role of NRF2 in neurological diseases continues unabated. Researchers in developed countries published more influential papers, while Chinese scholars provided the largest number of articles. There have been numerous studies on the mechanism of NRF2 transcription factor in neurological diseases. NRF2 is also emerging as a potentially effective target for the treatment of neurological diseases. However, despite decades of research, our knowledge of NRF2 transcription factor in nervous system diseases is still limited. Further studies are needed in the future.