Propofol administration improves neurological function associated with inhibition of pro-inflammatory cytokines in adult rats after traumatic brain injury

Molecular Toxicology and Pathophysiology of Comorbid Alcohol Use Disorder and Post-Traumatic Stress Disorder Associated with Traumatic Brain Injury

The increasing comorbidity of alcohol use disorder (AUD) and post-traumatic stress disorder (PTSD) associated with traumatic brain injury (TBI) is a serious medical, economic, and social issue. However, the molecular toxicology and pathophysiological mechanisms of comorbid AUD and PTSD are not well understood and the identification of the comorbidity state markers is significantly challenging. This review summarizes the main characteristics of comorbidity between AUD and PTSD (AUD/PTSD) and highlights the significance of a comprehensive understanding of the molecular toxicology and pathophysiological mechanisms of AUD/PTSD, particularly following TBI, with a focus on the role of metabolomics, inflammation, neuroendocrine, signal transduction pathways, and genetic regulation. Instead of a separate disease state, a comprehensive examination of comorbid AUD and PTSD is emphasized by considering additive and synergistic interactions between the two diseases. Finally, we propose several hypotheses of molecular mechanisms for AUD/PTSD and discuss potential future research directions that may provide new insights and translational application opportunities.

Neuro-Inflammation Modulation and Post-Traumatic Brain Injury Lesions: From Bench to Bed-Side

Head trauma is the most common cause of disability in young adults. Known as a silent epidemic, it can cause a mosaic of symptoms, whether neurological (sensory-motor deficits), psychiatric (depressive and anxiety symptoms), or somatic (vertigo, tinnitus, phosphenes). Furthermore, cranial trauma (CT) in children presents several particularities in terms of epidemiology, mechanism, and physiopathology-notably linked to the attack of an immature organ. As in adults, head trauma in children can have lifelong repercussions and can cause social and family isolation, difficulties at school, and, later, socio-professional adversity. Improving management of the pre-hospital and rehabilitation course of these patients reduces secondary morbidity and mortality, but often not without long-term disability. One hypothesized contributor to this process is chronic neuroinflammation, which could accompany primary lesions and facilitate their development into tertiary lesions. Neuroinflammation is a complex process involving different actors such as glial cells (astrocytes, microglia, oligodendrocytes), the permeability of the blood-brain barrier, excitotoxicity, production of oxygen derivatives, cytokine release, tissue damage, and neuronal death. Several studies have investigated the effect of various treatments on the neuroinflammatory response in traumatic brain injury in vitro and in animal and human models. The aim of this review is to examine the various anti-inflammatory therapies that have been implemented.

The Effect of Oral Mucosal Mesenchymal Stem Cells on Pathological and Long-Term Outcomes in Experimental Traumatic Brain Injury

Background

Neuroprotective effects of stem cells have been shown in some neurologic diseases. In this study, the effect of oral mucosal mesenchymal stem cells (OMSCs) on traumatic brain injury (TBI) was evaluated in long term.

Materials and Methods

TBI was induced by Marmarou's method. The number of 2 × 10⁶ OMSCs was intravenously injected 1 and 24 h after the injury. Brain edema and pathological outcome were assessed at 24 h and 21 days after the injury. Besides, long-term neurological, motor, and cognitive outcomes were evaluated at days 3, 7, 14, and 21 after the injury.

Results

OMSCs administration could significantly inhibit microglia proliferation, and reduce brain edema and neuronal damage, at 24 h and 21 days after the injury. Neurological function improvement was observed in the times evaluated in OMSCs group. Cognitive and motor function dysfunction and anxiety-like behavior were prevented especially at 14 and 21 days after the injury in the treatment group.

Conclusion

According to the results of this study, OMSCs administration after TBI reduced brain edema and neuronal damage, improved neurologic outcome, and prevented memory and motor impairments and anxiety-like behavior in long term.

Propofol effects in rodent models of traumatic brain injury: a systematic review

Background

Traumatic brain injury (TBI) causes high mortality and disability worldwide. Animal models have been developed to explore the complex processes in TBI. Propofol is used to manage head injuries during surgical intervention and mechanical ventilation in patients with TBI. Many studies have investigated the neuroprotective effect of propofol on TBI. However, other studies have shown neurotoxic effects.

Objectives

To review systematically the literature regarding the neuroprotective and neurotoxic effects of propofol in rodent models of TBI.

Methods

Data from rodents as models of TBI with propofol as one of the intervention agents, and/or comparing the neuroprotective effects of propofol with the other substances in rodent models of TBI, were obtained from PubMed, EBSCO Host, and ProQuest databases. The PRISMA 2020 statement recommendations were followed and research questions were developed based on PICOS guidelines. Data was extracted from the literature using a standardized Cochrane method.

Results

We analyzed data from 12 articles on physiological changes of experimental animals before and after trauma, the effects of propofol administration, and the observed neurotoxic effects. The effects of propofol administration were observed in terms of changes in traumatic lesion volume, the release of antioxidants and inflammatory factors, and the neurological function of rodent models of TBI.

Conclusion

Propofol has neuroprotective and neurotoxic effects via several mechanisms, and various doses have been used in research to determine its effects. The timing of administration, the dose administered, and the duration of administration contribute to determine the effect of propofol in rodent models of TBI. However, the doses that produce neuroprotective and neurotoxic effects are not yet clear and further research is needed to determine them.

Propofol Alleviates Neuropathic Pain Induced by Chronic Contractile Injury by Regulating the Spinal glun2b-p38mapkepac1 Pathway

BACKGROUND

Propofol acts as an intravenous anesthetic cure which is widely used as a therapy for the craniocerebral injury that comprised surgical anesthesia as well as the sedation done in the intensive care units. Propofol is one of the most commonly used and efficient anesthetics where the painful effects are followed by an injection of propofol. In many cases, patients experience pain followed by anxiety, boredom, fear, and even myocardial ischemia.

OBJECTIVE

This study was performed to investigate the underlying mechanism of propofol and its effect on regulating spinal glun2b-p38mapkepac1 pathways in chronic contractile injury. Material and Methods. Contractile injury was performed by ligation around the nerve of the thigh region postanesthesia. Rats were divided into three groups to analyze the changes like mechanical allodynia by the paw withdrawal threshold and histopathological analysis for assessing cellular degradation. L4-L6 from the spinal dorsal horns were isolated and harvested for studying protein expression, by the method of western blotting and immunofluorescence analysis.

RESULTS

The pain caused due to mechanical allodynia in the paw region was highest at 1 hour postinduction and lasted for three days postinjury. Pain was significantly less in the group receiving propofol when compared with the isoflurane group for the first two hours of injury. In the propofol group, EPAC1, GluN2B, and p38 MAP K were significantly lower.

CONCLUSION

In the rat model of induced chronic contractile injury, postsurgery there was a suppression of the GluN2B-p38MAPK/EPAC1 signaling pathway in the propofol group. As the p38MAPK/EPAC pathway has a significant role in the postoperative hyperalgesia, thus our experiment suggests that propofol has analgesic effects.

Long term neuroprotective effects of acute single dose MK-801treatment against traumatic brain injury in immature rats

Because brain development continues during adolescence, childhood trauma is a major health problem in pediatric ages. It is known traumatic brain injury (TBI) results in damage in hippocampal and cortical areas of the brain and impairs cognitive functions. The study aims to investigate the long-term effects of MK-801 (dizocilpine), an N-methyl d-aspartate (NMDA) receptor antagonist, on hippocampal damage, locomotor activity, and cognitive functions following TBI in immature rats. MK-801 (1 mg/kg) was injected intraperitoneally immediately after TBI. Thirty-seven litters were randomly allocated into three groups at 7 days (P7) of postnatal age: a control group, a trauma group, and an MK-801 treatment group. The control group received no treatment; the trauma group received saline as vehicle control for the MK-801 group and the MK-801 group received a single dose of 1 mg/kg MK-801 immediately after TBI. Hippocampal damage was examined by Hematoxylin-Eosin staining. Brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), NMDA-R, and glial fibrillar acidic protein (GFAP) immunohistochemistry and, BDNF, NGF, and NMDA-R ELISA protein levels were evaluated 125 days after trauma. Histopathological and immunohistochemical evaluations showed that treatment with MK-801 significantly ameliorated the trauma-induced hippocampal neuron loss and increased BDNF, NGF, NMDA-R, GFAP expressions in CA1, CA3, and DG hippocampal regions. Additionally, treatment with MK-801 decreased anxiety and increased hippocampus-dependent memory of animals subjected to brain injury after TBI. These results show that acute treatment of MK-801 has a neuroprotective role against trauma-induced hippocampal neuron loss and associated cognitive impairment in rats.

Propofol maintains Th17/Treg cell balance and reduces inflammation in rats with traumatic brain injury via the miR‑145‑3p/NFATc2/NF‑κB axis

Propofol is a commonly used intravenous anesthetic. The aim of the study was to examine the mechanism of propofol in traumatic brain injury (TBI) by regulating interleukin (IL)‑17 activity and maintaining the Th17/Treg balance. A rat model with moderate TBI was established using the weight‑drop method. Rats with TBI were regularly injected with propofol and their brain injuries were monitored. The peripheral blood of rats was collected to measure the Th17/Treg ratio. MicroRNA (miR)‑145‑3p expression was detected in the brain tissues of rats and antagomiR‑145‑3p was injected into the lateral ventricles of their brains to verify the effect of miR‑145‑3p on brain injury. The downstream target of miR‑145‑3p was predicted. The targeting relationship between miR‑145‑3p and nuclear factor of activated T cells c2 (NFATc2) was confirmed. NFATC2 expression and phosphorylation of NF‑κB pathway‑related proteins were measured. Propofol alleviated brain injury in rats with TBI and maintained the Th17/Treg balance. Propofol upregulated miR‑145‑3p expression in rat brains, while the inhibition of miR‑145‑3p reversed the effect of propofol on brain injury. A binding relationship was observed between miR‑145‑3p and NFATc2. Furthermore, propofol decreased the phosphorylation of p65 and IκBα, and inhibited activation of the NF‑κB pathway in the brains of rats with TBI. In conclusion, propofol maintained Th17/Treg balance and reduced inflammation in the rats with TBI via the miR‑145‑3p/NFATc2/NF‑κB axis.

Propofol ameliorates neuropathic pain and neuroinflammation through PPAR γ up-regulation to block Wnt/β-catenin pathway

OBJECTIVE

As an intravenous anesthetic, propofol has been exhibited to provide excellent clinical analgesia. Whether propofol has amelioration property for NP and neuroinflammation remains unexplored. The present study was arranged to probe the role of propofol in the mitigation of NP and neuroinflammation in rats and underlying mechanisms.

METHODS

Rats were randomly classified into the following groups: Model, Sham, Control, Propofol, GW9662, and Saline groups. The radiant heat stimulation was used to measure paw withdrawal latency (PWL), and mechanical stimulation was employed to detect paw withdrawal threshold (PWT). Subsequently, the expression of GFAP was assessed by immunofluorescence to reflect the activation of astrocyte. qRT-PCR and Western blot were utilized for the performance of mRNA and protein expression levels of PPAR γ as well as inflammation factors (TNF-α, IL-1β, and IL-6).

RESULTS

Pentobarbital sodium anesthesia significantly shortened the PWL and PWT, suppressed PPAR γ expression in rats in addition to elevating astrocyte activation and inflammation response. Propofol treatment attenuated the NP of rats as evidenced by restrained astrocyte activation level and inflammation factor levels. Rats treated with propofol had markedly heightened PPAR γ expression. PPAR γ exposure ameliorated NP and inflammation degree, which demonstrated by elevated astrocyte activation and inflammation levels as well as suppressed PWL and PWT in rats injected with PPAR γ inhibitor. Besides, PPAR γ decreased the expression level of β-catenin.

CONCLUSION

Propofol ameliorates NP and neuroinflammation of rats by up-regulating PPAR γ expression to block the Wnt/β-catenin pathway.

Protein Network Analysis of the Serum and Their Functional Implication in Patients Subjected to Traumatic Brain Injury

Traumatic brain injury (TBI) often leads to severe neurobehavioral impairment, but the underlying molecular mechanism remains to be elucidated. Here, we collected the sera from 23 patients (aged from 19 to 81 years old, third day after TBI as TBI-third group) subjected to TBI from The First Hospital of Kunming City, and the sera from 22 healthy donors (aged from 18 to 81 years old and as control group). Then, three samples from TBI-third group and three samples from control group were subjected to the protein microarray detection, and bioinformatics analysis. Then, enzyme-linked immunosorbent assay (ELISA) was used to verify significantly altered protein levels. Results showed that, when compared with the control group, all significantly differentially expressed proteins [DEPs, P < 0.05, FDR < 0.05, fold change (FC) > 2] contained 172 molecules in the TBI-third group, in which 65 proteins were upregulated, while 107 proteins were downregulated. The biological processes of these DEPs, mostly happened in the extracellular region and the extracellular region parts, are mainly involved in the regulation of cellular process, signaling and signal transduction, cell communication, response to stimuli, the immune system process and multicellular organismal development. Moreover, the essential molecular functions of them are cytokine activity, growth factor activity and morphogen activity. Additionally, the most significant pathways are enriched in cytokine–cytokine receptor interaction and PI3K-Akt signaling pathways among downregulated proteins, and pathways in cancer and cytokine–cytokine receptor interaction among upregulated proteins. Of these, we focused on the NGF, NT-3, IGF-2, HGF, NPY, CRP, MMP-9, and ICAM-2 with a high number of interactors in Protein–Protein Interaction (PPI) Network indicated by bioinformatics report. Furthermore, using ELISA test, we confirmed that all increase in the levels of NGF, NT-3, IGF-2, HGF, NPY, CRP, MMP-9, and ICAM-2 in the serum from TBI patients. Together, we determined the screened protein expressional profiles in serum for TBI patients, in which the cross-network between inflammatory factors and growth factors may play a crucial role in TBI damage and repair. Our findings could contribute to indication for the diagnosis and treatment of TBI in future translational medicine and clinical practice.

The Effect of Oral Administration of Amantadine on Neurological Outcome of Patients With Diffuse Axonal Injury in ICU

Traumatic brain injury is a major cause of death and disability in adults. This study investigated the effect of oral administration of amantadine on the neurological outcomes of patients with diffuse axonal injury (DAI) in the intensive care unit (ICU). This double-blind clinical trial was conducted in the ICU of Imam Hospital in Urmia. Patients with DAI were intubated and received mechanical ventilation in the ICU. They were divided into 2 groups: patients receiving amantadine (A) and placebo (P). The acquired data were analyzed using SPSS, P < .05 significant level. Findings showed no significant difference between the 2 groups in age and sex. There was no significant difference between the mean Glasgow Coma Scale (GCS) at the time of admission and discharge, and the mean Glasgow Outcome Scale (GOS) of the patients in 2 groups. No significant difference was observed in the duration of mechanical ventilation, hospitalization, and mortality in both groups (P > .05) in ICU. However, there was a significant difference between the mean GCS at the time of admission and discharge and death. Also, significant differences existed between the mean GOS in discharged and deceased patients (P = .001). This study showed no significant difference between the mean GCS at the time of admission and discharge and the mean GOS of the discharged patients and the mortality rate in the 2 groups. However, there were clear statistical differences between these variables in discharged and deceased patients. It is recommended that further studies are conducted with a larger sample size.

Propofol inhibits endogenous formyl peptide-induced neutrophil activation and alleviates lung injury

Critically ill patients have a high risk of sepsis. Various studies have demonstrated that propofol has anti-inflammatory effects that may benefit critically ill patients who require anesthesia. However, the mechanism and therapeutic effect remain incompletely understood. Our previous data suggest that propofol can act as a formyl peptide receptor 1 (FPR1) antagonist. Here, we hypothesize that propofol mitigates sepsis-induced acute lung injury (ALI) by inhibiting mitochondria-derived N-formyl peptide-mediated neutrophil activation. Oxidative stress caused by activated neutrophils is involved in the pathogenesis of ALI. In human neutrophils, propofol competitively reduced the release of superoxide and associated reactive oxygen species induced by fMMYALF, a human mitochondria-derived N-formyl peptide, suggesting that propofol effectively suppresses neutrophilic oxidative stress. In addition, propofol significantly inhibited fMMYALF-induced elastase release, chemotaxis, calcium mobilization, and phosphorylation of protein kinase B and mitogen-activated protein kinases. These results indicate that propofol suppresses neutrophil activation by blocking the interaction between endogenous N-formyl peptide and its receptor, FPR1, thus inhibiting downstream signaling. Furthermore, propofol alleviated alveolar wall disruption, edematous changes, and neutrophil infiltration in lipopolysaccharide-induced ALI in mice. Noticeably, propofol improved the survival of sepsis mice. This study indicates that the anti-neutrophil effects of propofol may benefit critically ill septic patients.

Annexin A7 Levels Increase in Rats With Traumatic Brain Injury and Promote Secondary Brain Injury

The incidence of traumatic brain injury (TBI) has been increasing annually. Annexin A7 is a calcium-dependent phospholipid binding protein. It can promote melting of the cell membrane. Recent studies have shown that it plays an important role in atherosclerosis, other cardiovascular diseases, and a variety of tumors. However, few studies of ANXA7 in TBI have been performed. We here observed how ANXA7 changes after TBI and discuss whether brain injury is associated with the use of ANXA7 antagonist intervention. Experimental Results: 1. After TBI, ANXA7 levels were higher than in the sham group, peaking 24 h after TBI. 2. The use of siA7 was found to reduce the expression of A7 in the injured brain tissue, and also brain edema, BBB damage, cell death, and apoptosis relative to the sham group. Conclusion: ANXA7 promotes the development of secondary brain injury (SBI) after TBI.

Lactobacillus johnsonii N6.2 diminishes caspase-1 maturation in the gastrointestinal system of diabetes prone rats

The cells of the gastrointestinal (GI) epithelium are the first to contact the microbiota and food components. As a direct consequence of this, these cells are the first line of defence and key players in priming the immune response. One of the first responses against GI insults is the formation of the inflammasome, a multiprotein complex assembled in response to environmental threats. The formation of the inflammasome regulates caspase-1 by cleaving it into its active form. Once activated, caspase-1 can cleave interleukin-1β (IL-1β), which promotes adaptive and humoral immunity. Some strains, like Lactobacillus johnsonii N6.2, are able to modulate the biosynthesis of important host metabolites mediating inflammation. Of these metabolites are the pro-inflammatory kynurenines. L. johnsonii N6.2 is able to downregulate kynurenines biosynthesis via a redox active mechanism negatively affecting indoleamine 2,3-dioxygenase activity. In this study, we evaluated the effects of L. johnsonii N6.2 combined with the natural antioxidant and anti-inflammatory molecule rosmarinic acid (RA). Inflammasome assembly and the kynurenine pathway were evaluated in GI samples of BioBreeding diabetes-prone (BB-DP) rats. In this work, BB-DP rats were fed daily with RA, L. johnsonii N6.2; or both combined. The transcriptional rate and proteins levels of inflammasome and kynurenine pathway components in ileum tissue were evaluated. Elevated levels of pro-caspase-1 were observed in rats fed with L. johnsonii, while RA had no effect on pro-caspase-1 expression. Western blot assays demonstrated that L. johnsonii fed rats showed lower levels of mature caspase-1, when compared to the other treatments. Furthermore, IL-1β maturation followed a similar pattern across the treatments. Differences were also observed between treatments in expression levels of key enzymes in the kynurenine pathway. These findings support the role of L. johnsonii in modulating the assembly of the inflammasome as well as some steps of the pro-inflammatory kynurenine pathway.

Propofol regulates the expression of TLR4 through miR‑21 in human umbilical vein endothelial cells

Propofol (2,6-diisopropylphenol) is one of the most commonly used intravenous anesthetics. Anesthetics can regulate the inflammatory process; however, the mechanism remains to be fully elucidated. The present study aimed to investigate whether and how propofol affects the inflammatory reaction in human umbilical vein endothelial cells (HUVECs). The expression levels of Toll‑like receptor 4 (TLR4) and cluster of differentiation 14 (CD14) were determined in HUVECs treated with propofol and lipopolysaccharide (LPS) using western blot and reverse transcription‑quantitative polymerase chain reaction analyses. In addition, whether propofol regulated the expression of TLR4 though microRNA (miR)‑21 was examined. The results showed that LPS promoted the expression levels of TLR4, CD14 and tumor necrosis factor α (TNFα), and suppressed the expression of miR‑21 in HUVECs. Propofol suppressed the expression levels of TLR4, CD14 and TNFα, and upregulated the expression of miR‑21 in a concentration‑dependent manner. miR‑21 downregulated the expression of TLR4 at the mRNA and protein levels, whereas the miR‑21 mimic reversed the effect of LPS on the expression of TLR4. In addition, the miR‑21 inhibitor inhibited the downregulatory effect of propofol on the expression of TLR4. TargetScan analysis showed that TLR4 was included in the list of targets of miR‑21. Fluorescent reporter assays showed that the miR‑21 mimic and propofol treatment reduced the fluorescence intensity in cells transfected with a reporter vector containing the wild‑type TLR4 3'‑untranslated region. Taken together, the results of the present study demonstrated that propofol regulated the expression of TLR4 in HUVECs through miR‑21.

Effects of propofol on myocardial ischemia-reperfusion injury in rats with type-2 diabetes mellitus

The current study aimed to examine the effects of propofol on myocardial ischemia-reperfusion injury (MIRI) in rats with type-2 diabetes mellitus (T2DM) and to assess the role of inflammatory mediators. Fifty healthy male adult Sprague-Dawley rats were randomly divided into the sham, ischemia-reperfusion (IR), IR plus low, middle and high-dose (6, 12 and 24 mg/kg/h, intravenous) propofol groups. The rats of all the groups were fed a high-sugar and high-fat diet for 8 weeks and streptozotocin (30 mg/kg, intraperitoneally) was used to establish the T2DM model. Apart from the sham group rats, MIRI was induced by ligating the left anterior descending coronary artery for 30 min, followed by reperfusion for 2 h. Heart rate (HR), left ventricular systolic pressure (LVSP), and the rate of left ventricular pressure increase in early systole (± dp/dt_max) were recorded. Levels of cardiac troponin T (cTnT), nitric oxide (NO), endothelin-1 (ET-1), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were also measured. Myocardial lesions were observed under light microscopy and scanning electron microscopy. Compared with levels prior to arterial occlusion, HR, LVSP, and ± dp/dt_max were significantly reduced (P<0.05) following occlusion for 30 min and reperfusion for 2 h. The administration of propofol ameliorated the cardiac function of rats as reflected by the increase in HR, LVSP and ± dp/dt_max. In addition, the administration of propofol increased the serum NO concentration, and reduced ET-1 and cTnT levels, as well as levels of inflammatory mediators including IL-1β, IL-6 and TNF-α. Thus, propofol exerts protective effects against MIRI in T2DM rats by increasing NO and reducing ET-1 and the inflammatory mediators.

Effect of propofol on microRNA expression in rat primary embryonic neural stem cells

BACKGROUND

Propofol is a widely used intravenous anesthetic that is well-known for its protective effect in various human and animal disease models. However, the effects of propofol on neurogenesis, especially on the development of neural stem cells (NSCs), remains unknown. Related microRNAs may act as important regulators in this process.

METHODS

Published Gene Expression Omnibus (GEO) DataSets related to propofol were selected and re-analyzed to screen neural development-related genes and predict microRNA (miRNA) expression using bioinformatic methods. Screening of the genes and miRNAs was then validated by qRT-PCR analysis of propofol-treated primary embryonic NSCs.

RESULTS

Four differentially expressed mRNAs were identified in the screen and 19 miRNAs were predicted based on a published GEO DataSet. Two of four mRNAs and four of 19 predicted miRNAs were validated by qRT-PCR analysis of propofol-treated NSCs. Rno-miR-19a (Rno, Rattus Norvegicus) and rno-miR-137, and their target gene EGR2, as well as rno-miR-19b-2 and rno-miR-214 and their target gene ARC were found to be closely related to neural developmental processes, including proliferation, differentiation, and maturation of NSCs.

CONCLUSION

Propofol influences miRNA expression; however, further studies are required to elucidate the mechanism underlying the effects of propofol on the four miRNAs and their target genes identified in this study. In particular, the influence of propofol on the entire development process of NSCs remains to be clarified.