Anti-TNF-alpha antibody attenuates subarachnoid hemorrhage-induced apoptosis in the hypothalamus by inhibiting the activation of Erk

Interleukin-4 Modulates Neuroinflammation by Inducing Phenotypic Transformation of Microglia Following Subarachnoid Hemorrhage

Neuroinflammation, a key pathological feature following subarachnoid hemorrhage (SAH), can be therapeutically targeted by inhibiting microglia M1 polarization and promoting phenotypic transformation to M2 microglia. Interleukin-4 (IL-4) is a pleiotropic cytokine known to its regulation of physiological functions of the central nervous system (CNS) and mediate neuroinflammatory processes. However, its specific role in neuroinflammation and microglia responses following SAH remains unexplored. In this investigation, we established both in vivo and in vitro SAH models and employed a comprehensive array of assessments, including ELISA, neurofunctional profiling, immunofluorescence staining, qRT-PCR, determination of phagocytic capacity, and RNA-Seq analyses. The findings demonstrate an elevated expression of IL-4 within cerebrospinal fluid (CSF) subsequent to SAH. Furthermore, exogenous administration of IL-4 ameliorates post-SAH neurofunctional deficits, attenuates cellular apoptosis, fosters M2 microglia phenotype conversion, and mitigates neuroinflammatory responses. The RNA-Seq analysis signifies that IL-4 governs the modulation of neuroinflammation in microglia within an in vitro SAH model through intricate cascades of signaling pathways, encompassing interactions between cytokines and cytokine receptors. These discoveries not only augment comprehension of the neuropathogenesis associated with post-SAH neuroinflammation but also present novel therapeutic targets for the management thereof.

Veronica persica ameliorates acetaminophen-induced murine hepatotoxicity via attenuating oxidative stress and inflammation

Excess acetaminophen (APAP) commonly causes severe acute liver injury (ALI), characterized by oxidative stress, pro-inflammatory responses, and hepatocyte damage. Veronica persica (VP) is a traditional medicine with antioxidant and anti-inflammatory properties. There is a paucity of information on its medicinal value, especially its potential mechanisms for alleviating ALI. This study aimed to clarify the ameliorative effects and intracellular mechanisms of VP on APAP-induced ALI via attenuating oxidative stress and inflammation. Mice were given VP for 7 days before exposure to APAP (300 mg/kg). The HPLC and radical scavenging assay found that VP contains 12 phenolic acids and 6 flavonoids, as well as show robust antioxidant capacity. In the APAP-induced ALI model, pre-treatment with VP significantly reduces APAP-induced hepatotoxicity by observing improved hepatocyte pathological injury and further confirmed by serum biochemical indicator. Also, the reduction of TUNEL-positive regions and the regulation of Bcl-2-associated X protein indicated that VP attenuates hepatocytotoxicity. Moreover, VP pre-intervention inhibits the formation of liver pro-inflammatory cytokines, the expression of inflammatory response genes, and increases in myeloperoxidase (MPO) in APAP-exposed mice. The elevated reduced glutathione (GSH) levels and decreased oxidative stress markers indicate that VP reduces APAP-promoted oxidative stress. Further study revealed that VP inhibited the phosphorylation of NF-κB/STAT3 cascade, blocked ERK and JNK phosphorylation, and activated AMP-activated protein kinase (AMPK). To sum up, this study demonstrated that VP exists hepatoprotective abilities on APAP-induced ALI, primarily by suppressing the phosphorylation of NF-κB/STAT3 cascade and ERK-JNK and inducing AMPK activation to alleviate oxidative stress and inflammation.

The mediating role of AKT/ERK/JNK signaling on the malignant phenotype of microcystin-LR in gastric adenocarcinoma cells

Microcystin-leucine arginine (MC-LR), a widely distributed and highly toxic environmental pollutant, plays crucial roles in cancer malignancy by activating characteristically toxic signaling pathways. Traditional animal-based toxicity evaluation methods have proven insufficient for identifying the specific role of these signaling pathways. Therefore, this study aimed to uncover the regulatory relationship between the toxic pathways and the progression of gastric cancer (GC). The findings provide novel avenues for conducting in vitro toxicity tests based on the investigated pathways. We found that MC-LR promoted the migration and invasion of SGC-7901 cells while simultaneously inhibiting their apoptosis in a dose-dependent manner. This observed cytotoxicity was primarily mediated through the AKT, JNK, and ERK signaling pathways. By using a mediation analysis model, we determined that AKT and ERK exhibited competitive effects in MC-LR-treated GC malignancy, while AKT and JNK acted independently from one another. This study establishes an in vitro toxicity test model of MC-LR based on toxicity-related pathways and underscores the pivotal roles of AKT, ERK, and JNK signaling in MC-LR toxicity. The findings offer a novel, fundamental framework for conducting chemical toxicity risk assessment.

Neurobehavioral Impairments Predict Specific Cerebral Damage in Rat Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a severe form of stroke that can cause unpredictable and diffuse cerebral damage, which is difficult to detect until it becomes irreversible. Therefore, there is a need for a reliable method to identify dysfunctional regions and initiate treatment before permanent damage occurs. Neurobehavioral assessments have been suggested as a possible tool to detect and approximately localize dysfunctional cerebral regions. In this study, we hypothesized that a neurobehavioral assessment battery could be a sensitive and specific method for detecting damage in discrete cerebral regions following SAH. To test this hypothesis, a behavioral battery was employed at multiple time points after SAH induced via an endovascular perforation, and brain damage was confirmed via postmortem histopathological analysis. Our results demonstrate that impairment of sensorimotor function accurately predict damage in the cerebral cortex (AUC 0.905; sensitivity 81.8%; specificity 90.9%) and striatum (AUC 0.913; sensitivity 90.1%; specificity 100%), while impaired novel object recognition is a more accurate indicator of damage to the hippocampus (AUC 0.902; sensitivity 74.1%; specificity 83.3%) than impaired reference memory (AUC 0.746; sensitivity 72.2%; specificity 58.0%). Tests for anxiety-like and depression-like behaviors predict damage to the amygdala (AUC 0.900; sensitivity 77.0%; specificity 81.7%) and thalamus (AUC 0.963; sensitivity 86.3%; specificity 87.8%), respectively. This study suggests that recurring behavioral testing can accurately predict damage in specific brain regions, which could be developed into a clinical battery for early detection of SAH damage in humans, potentially improving early treatment and outcomes.

Systemic Inflammation after Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is one of the most severe neurological disorders, with a high mortality rate and severe disabling functional sequelae. Systemic inflammation following hemorrhagic stroke may play an important role in mediating intracranial and extracranial tissue damage. Previous studies showed that various systemic inflammatory biomarkers might be useful in predicting clinical outcomes. Anti-inflammatory treatment might be a promising therapeutic approach for improving the prognosis of patients with aSAH. This review summarizes the complicated interactions between the nervous system and the immune system.

Neurobehavioral impairments predict specific cerebral damage in rat model of subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a severe form of stroke that can cause unpredictable and diffuse cerebral damage, which is difficult to detect until it becomes irreversible. Therefore, there is a need for a reliable method to identify dysfunctional regions and initiate treatment before permanent damage occurs. Neurobehavioral assessments have been suggested as a possible tool to detect and approximately localize dysfunctional cerebral regions. In this study, we hypothesized that a neurobehavioral assessment battery could be a sensitive and specific early warning for damage in discrete cerebral regions following SAH. To test this hypothesis, a behavioral battery was employed at multiple time points after SAH induced via an endovascular perforation, and brain damage was confirmed via postmortem histopathological analysis. Our results demonstrate that impairment of sensorimotor function accurately predict damage in the cerebral cortex (AUC: 0.905; sensitivity: 81.8%; specificity: 90.9%) and striatum (AUC: 0.913; sensitivity: 90.1%; specificity: 100%), while impaired novel object recognition is a more accurate indicator of damage to the hippocampus (AUC: 0.902; sensitivity: 74.1%; specificity: 83.3%) than impaired reference memory (AUC: 0.746; sensitivity: 72.2%; specificity: 58.0%). Tests for anxiety-like and depression-like behaviors predict damage to the amygdala (AUC: 0.900; sensitivity: 77.0%; specificity: 81.7%) and thalamus (AUC: 0.963; sensitivity: 86.3%; specificity: 87.8%), respectively. This study suggests that recurring behavioral testing can accurately predict damage in specific brain regions, which could be developed into a clinical battery for early detection of SAH damage in humans, potentially improving early treatment and outcomes.

The mechanism and relevant mediators associated with neuronal apoptosis and potential therapeutic targets in subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a dominant cause of death and disability worldwide. A sharp increase in intracranial pressure after SAH leads to a reduction in cerebral perfusion and insufficient blood supply for neurons, which subsequently promotes a series of pathophysiological responses leading to neuronal death. Many previous experimental studies have reported that excitotoxicity, mitochondrial death pathways, the release of free radicals, protein misfolding, apoptosis, necrosis, autophagy, and inflammation are involved solely or in combination in this disorder. Among them, irreversible neuronal apoptosis plays a key role in both short- and long-term prognoses after SAH. Neuronal apoptosis occurs through multiple pathways including extrinsic, mitochondrial, endoplasmic reticulum, p53 and oxidative stress. Meanwhile, a large number of blood contents enter the subarachnoid space after SAH, and the secondary metabolites, including oxygenated hemoglobin and heme, further aggravate the destruction of the blood-brain barrier and vasogenic and cytotoxic brain edema, causing early brain injury and delayed cerebral ischemia, and ultimately increasing neuronal apoptosis. Even there is no clear and effective therapeutic strategy for SAH thus far, but by understanding apoptosis, we might excavate new ideas and approaches, as targeting the upstream and downstream molecules of apoptosis-related pathways shows promise in the treatment of SAH. In this review, we summarize the existing evidence on molecules and related drugs or molecules involved in the apoptotic pathway after SAH, which provides a possible target or new strategy for the treatment of SAH.

New Insights of Early Brain Injury after Subarachnoid Hemorrhage: A Focus on the Caspase Family

Spontaneous subarachnoid hemorrhage (SAH), primarily caused by ruptured intracranial aneurysms, remains a prominent clinical challenge with a high rate of mortality and morbidity worldwide. Accumulating clinical trials aiming at the prevention of cerebral vasospasm (CVS) have failed to improve the clinical outcome of patients with SAH. Therefore, a growing number of studies have shifted focus to the pathophysiological changes that occur during the periods of early brain injury (EBI). New pharmacological agents aiming to alleviate EBI have become a promising direction to improve outcomes after SAH. Caspases belong to a family of cysteine proteases with diverse functions involved in maintaining metabolism, autophagy, tissue differentiation, regeneration, and neural development. Increasing evidence shows that caspases play a critical role in brain pathology after SAH. Therefore, caspase regulation could be a potential target for SAH treatment. Herein, we provide an overview pertaining to the current knowledge on the role of caspases in EBI after SAH, and we discuss the promising therapeutic value of caspase-related agents after SAH.

GPR18 Agonist Resolvin D2 Reduces Early Brain Injury in a Rat Model of Subarachnoid Hemorrhage by Multiple Protective Mechanisms

Early brain injury (EBI) is the early phase of secondary complications arising from subarachnoid hemorrhage (SAH). G protein-coupled receptor 18 (GPR18) can exert neuroprotective effects during ischemia. In this study, we investigated the roles of GPR18 in different brain regions during EBI using a GPR18 agonist, resolvin D2 (RvD2). Location and dynamics of GPR18 expression were assessed by immunohistochemistry and western blotting in a rat model of SAH based on endovascular perforation. RvD2 was given intranasally at 1 h after SAH, and SAH grade, brain water content and behavior were assayed before sacrifice. TUNEL and dihydroethidium staining of the cortex were performed at 24 h after SAH. Selected brain regions were also examined for pathway related proteins using immunofluorescence and Western blotting. We found that GPR18 was expressed in meninges, hypothalamus, cortex and white matter before EBI. After SAH, GPR18 expression was increased in meninges and hypothalamus but decreased in cortex and white matter. RvD2 improved neurological scores and brain edema after SAH. RvD2 attenuated mast cell degranulation and reduced expression of chymase and tryptase expression in the meninges. In the hypothalamus, RvD2 attenuated inflammation, increased expression of proopiomelanocortin and interleukin-10, as well as decreased expression of nerve peptide Y and tumor necrosis factor-α. In cortex, RvD2 alleviated oxidative stress and apoptosis, and protected the blood-brain barrier. RvD2 also ameliorated white matter injury by elevating myelin basic protein and suppressing amyloid precursor protein. Our results suggest that GPR18 may help protect multiple brain regions during EBI, particularly in the cortex and hypothalamus. Upregulating GPR18 by RvD2 may improve neurological functions in different brain regions via multiple mechanisms.

Microglia and Post-Subarachnoid Hemorrhage Vasospasm: Review of Emerging Mechanisms and Treatment Modalities

Vasospasm is a potentially severe complication of subarachnoid hemorrhage. It can be attributed to neuroinflammation and the robust recruitment of microglia. Emerging evidence has linked this sustained inflammation to the development of delayed cerebral ischemia following subarachnoid hemorrhage. In this focused review, we provide an overview of the historical understanding of vasospasm. We then delve into the role of neuroinflammation and the activation of microglia. These activated microglia releases a host of inflammatory cytokines contributing to an influx of peripheral macrophages. This thereby opens a new and innovative treatment strategy to prevent vasospasm. Pre-clinical work has been promising, and the transition to clinical trials is warranted. Finally, some of the key mechanistic targets are outlined with emphasis on translation. This review will serve as a catalyst for researchers and clinicians alike in the quest to improve treatment options for vasospasm.

Rhinacanthin-C but Not -D Extracted from Rhinacanthus nasutus (L.) Kurz Offers Neuroprotection via ERK, CHOP, and LC3B Pathways

Neurodegenerative diseases present an increasing problem as the world’s population ages; thus, the discovery of new drugs that prevent diseases such as Alzheimer’s, and Parkinson’s diseases are vital. In this study, Rhinacanthin-C and -D were isolated from Rhinacanthus nasustus, using ethyl acetate, followed by chromatography to isolate Rhinacanthin-C and -D. Both compounds were confirmed using NMR and ultra-performance-LCMS. Using glutamate toxicity in HT-22 cells, we measured cell viability and apoptosis, ROS build-up, and investigated signaling pathways. We show that Rhinacanthin-C and 2-hydroxy-1,4-naphthoquinone have neuroprotective effects against glutamate-induced apoptosis in HT-22 cells. Furthermore, we see that Rhinacanthin-C resulted in autophagy inhibition and increased ER stress. In contrast, low concentrations of Rhinacanthin-C and 2-hydroxy-1,4-naphthoquinone prevented ER stress and CHOP expression. All concentrations of Rhinacanthin-C prevented ROS production and ERK1/2 phosphorylation. We conclude that, while autophagy is present in HT-22 cells subjected to glutamate toxicity, its inhibition is not necessary for cryoprotection.

Therapeutic effect of and mechanisms underlying the effect of miR-195-5p on subarachnoid hemorrhage-induced vasospasm and brain injury in rats

Objectives

There is much evidence suggesting that inflammation contributes majorly to subarachnoid hemorrhage (SAH)-induced cerebral vasospasm and brain injury. miRNAs have been found to modulate inflammation in several neurological disorders. This study investigated the effect of miR-195-5p on SAH-induced vasospasm and early brain injury in experimental rats.

Methods

Ninety-six Sprague-Dawley male rats were randomly and evenly divided into a control group (no SAH, sham surgery), a SAH only group, a SAH + NC-mimic group, and a SAH + miR-195-5p group. SAH was induced using a single injection of blood into the cisterna magna. Suspensions containing NC-mimic and miR-195-5p were intravenously injected into rat tail 30 mins after SAH was induced. We determined degree of vasospasm by averaging areas of cross-sections the basilar artery 24h after SAH. We measured basilar artery endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κ B), phosphorylated NF-κ B (p-NF-κ B), inhibitor of NF-κ B (Iκ Bα) and phosphorylated-Iκ Bα (p-Iκ Bα). Cell death assay was used to quantify the DNA fragmentation, an indicator of apoptotic cell death, in the cortex, hippocampus, and dentate gyrus. Tumor necrosis factor alpha (TNF-α) levels were measured using sample protein obtained from the cerebral cortex, hippocampus and dentate gyrus.

Results

Prior to fixation by perfusion, there were no significant physiological differences among the control and treatment groups. SAH successfully induced vasospasm and early brain injury. MiR-195-5p attenuated vasospasam-induced changes in morphology, reversed SAH-induced elevation of iNOS, p-NF-κ B, NF-κ B, and p-Iκ Bα and reversed SAH-induced suppression of eNOS in the basilar artery. Cell death assay revealed that MiR-195-5p significantly decreased SAH-induced DNA fragmentation (apoptosis) and restored TNF-α level in the dentate gyrus.

Conclusion

In conclusion, MiRNA-195-5p attenuated SAH-induced vasospasm by up-regulating eNOS, down-regulating iNOS and inhibiting the NF-κ B signaling pathway. It also protected neurons by decreasing SAH-induced apoptosis-related cytokine TNF-α expression in the dentate gyrus. Further study is needed to elucidate the detail mechanism underlying miR-195-5p effect on SAH-induced vasospasm and cerebral injury. We believe that MiR-195-5p can potentially be used to manage SAH-induced cerebral vasospasm and brain injury.

Application of patient-centered care using guidelines of the Joint Commission on Accreditation of Healthcare Organizations in patients with acute subarachnoid hemorrhage

OBJECTIVE

This study was designed to explore the feasibility and effectiveness of patient-centered care (PCC) on basis of guidelines of Joint Commission on Accreditation of Healthcare Organizations (JCI) in patients with acute subarachnoid hemorrhage (SAH).

METHODS

A total of 180 SAH patients who received treatment in our hospital were selected as prospective research objects, and were divided into a study group (n=90) and a control group (n=90) by convenience sampling. Patients in the control group received conventional SAH-targeted care, and patients in the study group were additionally nursed with PCC on the basis of conventional SAH-targeted care. The general indicators, including Mini-Mental State Exam (MMSE) scores before and after intervention, activities of daily living (ADL), mental state, general self-efficacy scale (GSES), health knowledge, and incidence of complications were compared between the two groups.

RESULTS

The length of hospital stay, the time in bed, and the expenses of hospitalization in the study group were lower than those of the control group (P<0.05). The scores of MMSE, ADL, GSES, and health knowledge in the study group were higher than those in the control group (P<0.05), and the scores of each dimension of Symptom Checklist-90 (SCL-90) and the incidence of complications in the study group were lower than those in the control group (P<0.05).

CONCLUSION

PCC for SAH patients based on the guidelines of JCI can not only improve the outcomes, cognitive function, self-efficacy, negative emotions and ADL of patients, but also help enhance their awareness of the disease and reduce the incidence of complications.

The role of immune inflammation in aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating disease, which mainly caused by the rupture of an intracranial aneurysm. Clinical trials have demonstrated that cerebral vasospasm (CVS) is not the sole contributor to delayed cerebral ischemia (DCI) and poor outcomes in patients with aSAH. Currently, accumulating evidence suggests that early brain injury (EBI), which occurs within 72 h after the onset of aSAH, lays the foundation for subsequent pathophysiological changes and poor outcomes of patients. The pathological mechanisms of EBI mainly include increased intracranial pressure, oxidative stress, neuroinflammation, blood-brain barrier (BBB) disruption, cerebral edema and cell death. Among them, the brain immune inflammatory responses involve a variety of immune cells and active substances, which play an important role in EBI after aSAH and may be related to DCI and long-term outcomes. Thus, attention should be paid to strategies targeting cerebral immune inflammatory responses. In this review, we discuss the role of immune inflammatory responses in the occurrence and development of aSAH, as well as some inflammatory biomarkers related to CVS, DCI, and aSAH outcomes. In addition, we also summarize the potential therapeutic drugs that target cerebral immune inflammatory responses for patients with aSAH in current research.

Mechanisms and therapeutic implications of RTA 408, an activator of Nrf2, in subarachnoid hemorrhage-induced delayed cerebral vasospasm and secondary brain injury

Objectives

More and more evidence suggests oxidative stress and inflammation contribute importantly to subarachnoid hemorrhage (SAH)-induced cerebral vasospasm and secondary brain injury. Recent evidence indicates Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) increases the expression of antioxidant genes and decreases the expression of pro-inflammatory genes. This study examines the effects of an activator of Nfr2, RTA 408, on SAH-induced cerebral vasospasm and possible mechanism underlying its effect in a two-hemorrhage rodent model of SAH.

Methods

We randomly assigned 60 Sprague-Dawley male rats (350 to 420g) to five groups twelve rats each: one control group (no SAH), one untreated SAH only group and three RTA-408 treatment groups (SAH+ RTA 408 0.5 mg/kg/day, SAH+RTA 408 1 mg/kg/day and a SAH+RTA 408 1.5 mg/kg/day). The treatment groups were administered RTA 408 by intraperitoneal injection thirty min following first induction of SAH for seven days starting with first hemorrhage. Cerebral vasospasm was determined by averaging the cross-sectional areas of basilar artery 7 days after first SAH. Expressions of Nrf2, NF-κB and iNOS in basilar artery and expressions of Nrf2, HO-1, NQO1 and Cleaved caspase-3 were evaluated. Tissue TNF-alpha was assessed by ELISA using the protein sampled from the dentate gyrus, cerebral cortex, and hippocampus.

Results

Prior to perfusion fixation, there were no significant physiological differences among the control and treated groups. RTA 408 treatment attenuated the morphological changes caused by cerebral vasospasm. It mitigated SAH-induced suppression of Nrf2 and increased expression of NF-κB and iNOS in the basilar artery. In dentate gyrus, it reversed SAH-decreases in Nrf2, HO-1, NQO-1 and cleaved caspase-3 and RTA 408 1.5 mg/kg/day reversed SAH increases in TNF-alpha.

Conclusion

It was concluded that RTA 408 reversal vasospasm was achieved via increases in Nrf2 and decreases in NF-κB and iNOS. It exerted a neuron-protection effect by decreasing the apoptosis-related protein cleaved caspase-3 and decreasing the information cytokine TNF-alpha expression, which it achieved by increasing HO-1 and NQO-1 protein found downstream from Nrf2 and Nrf2. We believe that RTA 408 can potentially be used to manage of cerebral vasospasm and secondary brain injury following SAH.

Mechanisms of neuroinflammation and inflammatory mediators involved in brain injury following subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular disorder. Neuroinflammation is a critical cause of brain injury following SAH in both acute and chronic phases. While accumulating evidence has shown that therapies targeting neuroinflammation exerted beneficial effects in experimental SAH, there is little clinical evidence. One of the factors making neuroinflammation complicated is that inflammatory signaling pathways and mediators act as protective or detrimental responses at different phases. In addition, biomarkers to detect neuroinflammation are little known in clinical settings. In this review, first, we discuss how the inflammatory signaling pathways contribute to brain injury and other secondary pathophysiological changes in SAH. Damage-associated molecular patterns arising from mechanical stress, transient global cerebral ischemia, red blood cell breakdown and delayed cerebral ischemia following SAH trigger to activate pattern recognition receptors (PRRs) such as Toll-like receptors, nucleotide-binding oligomerization domain-like receptors, and receptors for advanced glycation end products. Most of PRRs activate common downstream signaling transcriptional factor nuclear factor-κΒ and mitogen-activated protein kinases, releasing pro-inflammatory mediators and cytokines. Next, we focus on how pro-inflammatory substances play a role during the course of SAH. Finally, we highlight an important inducer of neuroinflammation, matricellular protein (MCP). MCPs are a component of extracellular matrix and exert beneficial and harmful effects through binding to receptors, other matrix proteins, growth factors, and cytokines. Treatment targeting MCPs is being proved efficacious in pre-clinical models for preventing brain injury including neuroinflammation in SAH. In addition, MCPs may be a candidate of biomarkers predicting brain injury following SAH in clinical settings.

Escin protects against acetaminophen-induced liver injury in mice via attenuating inflammatory response and inhibiting ERK signaling pathway

Acetaminophen (APAP) overdose may lead to the formation of oxidative stress, hepatocyte apoptosis and necrosis, and, eventually result in acute liver failure. Escin, a major extracted component of Aesculus hippocastanum, reportedly exerts anti-inflammatory, anti-edematous and anti-oxidant properties. Previous studies have demonstrated these protective effects of A. hippocastanum extracts on ischemia/reperfusion intestinal injury and endotoxin-induced lung injury. In this study, we aimed to evaluate the effect of escin on APAP-induced liver injury in mice. Mice were intraperitoneally administrated with APAP (300 mg/kg) or an equal volume of saline (control), followed by a treatment with various concentrations of escin (0, 0.5, 1, 2 and 4 mg/kg) for 30 min. The animals were sacrificed 16 h following APAP administration for serum and liver tissue assay. Escin treatment attenuated the damage of APAP-induced liver injury in a dose-dependent manner (0.5-4 mg/kg). Escin also attenuated the hepatic myeloperoxidase (MPO) activity and hepatic pro-inflammatory cytokines (i.e., TNF-α, IL-1β, IL-6 and IL-17). Furthermore, escin treatment decreased the hepatic phosphorylation expression of extracellular signal-regulated kinase (ERK). Our data indicates that escin shows protective effects on APAP-induced hepatotoxicity in a dose-dependent manner through anti-inflammatory mechanism and the inhibition of ERK signaling pathway.

Annexin A7 induction of neuronal apoptosis via effect on glutamate release in a rat model of subarachnoid hemorrhage

OBJECTIVE

Glutamate excitotoxicity and neuronal apoptosis are suggested to contribute to early brain injury after subarachnoid hemorrhage (SAH). Annexin A7 (ANXA7) has been shown to regulate glutamate release. However, the role of ANXA7 in early brain injury after SAH has not been illustrated. In this study, we aimed to investigate the effect of ANXA7 knockdown in reducing the severity of early brain injury after SAH, and determine the underlying mechanisms.

METHODS

Endovascular perforation was performed to induce SAH in male Sprague-Dawley rats. ANXA7-siRNA was administered via intraventricular injection 5 days before SAH induction. Neurological test, evaluation of SAH grade, assessment of blood-brain barrier (BBB) permeability, measurement of brain water content, Western blot, double immunofluorescence staining, TUNEL staining, and enzyme-linked immunosorbent assay (ELISA) were performed at 24 hours of SAH induction.

RESULTS

ANXA7 protein expression increased significantly after SAH induction and was seen mainly in neurons. High expression of ANXA7 was associated with poor neurological status. ANXA7 knockdown dramatically ameliorated early brain injury through alleviating BBB disruption and brain edema. Further investigation of the mechanism showed that inhibiting ANXA7 expression can rescue neuronal apoptosis. In addition, ANXA7 knockdown also significantly reduced glutamate release, which was consistent with a significant increase of Bcl-2 expression and decreases of Bax and cleaved caspase-3 expression.

CONCLUSIONS

ANXA7 can induce neuronal apoptosis by affecting glutamate release in rats with SAH. Downregulating the expression of ANXA7 can significantly attenuate early brain injury after SAH. Future therapy targeting ANXA7 may be a promising new choice.

Anti-Cytokine Therapy to Attenuate Ischemic-Reperfusion Associated Brain Injury in the Perinatal Period

Perinatal brain injury is a major cause of morbidity and long-standing disability in newborns. Hypothermia is the only therapy approved to attenuate brain injury in the newborn. However, this treatment is unfortunately only partially neuroprotective and can only be used to treat hypoxic-ischemic encephalopathy in full term infants. Therefore, there is an urgent need for adjunctive therapeutic strategies. Post-ischemic neuro-inflammation is a crucial contributor to the evolution of brain injury in neonates and constitutes a promising therapeutic target. Recently, we demonstrated encouraging neuroprotective capacities of anti-cytokine monoclonal antibodies (mAbs) in an ischemic-reperfusion (I/R) model of brain injury in the ovine fetus. The purpose of this review is to summarize the current knowledge regarding the inflammatory response in the perinatal sheep brain after I/R injury and to review our recent findings regarding the beneficial effects of treatment with anti-cytokine mAbs.