Melatonin Alleviates Intracerebral Hemorrhage-Induced Secondary Brain Injury in Rats via Suppressing Apoptosis, Inflammation, Oxidative Stress, DNA Damage, and Mitochondria Injury

Recent developments in delirium after oral and maxillofacial free-flap reconstruction

Postoperative delirium (POD), a common complication following surgery and anesthesia, is particularly prone to occur after reconstruction surgery in the oral and maxillofacial region. The occurrence of POD seriously affects the incidence of postoperative complications, the survival of free flaps, the length of hospital stays, and brings great pain to patients and their families, and even increases perioperative mortality. Currently, a large number of studies have reported on the risk factors for POD after oral and maxillofacial free-flap reconstruction. Multiple independent risk factors have been identified, including age, history of excessive alcohol consumption, and perioperative nutritional status. This review summarizes the relevant literature and hopes to provide insights for the prevention of POD in high-risk patients.

Associations of serum Dickkopf-1 levels with disease severity and 90-day Prognosis after spontaneous intracerebral hemorrhage: results from the prospective cohort study

Dickkopf-1 (DKK-1) may be involved in inflammatory response and secondary brain injury after acute brain injury. We gauged serum DKK-1 levels and further assessed its correlation with disease severity and investigated its predictive value for 90-day prognosis in patients with spontaneous intracerebral hemorrhage (sICH). Serum DKK-1 levels were measured in 128 sICH patients and 128 healthy controls. The severity of sICH was assessed using the Glasgow Coma Scale (GCS) scores and hematoma volumes. Poor prognosis was referred to as a Glasgow Outcome Scale (GOS) score of 1-3 at 90 days after stroke. Multivariate analysis was performed to identify associations of serum DKK-1 levels with disease severity, early neurological deterioration (END) and poor prognosis. Receiver operating characteristic curve (ROC) was built to investigate the prognostic predictive capability. The serum DKK-1 levels of patients were significantly higher than those of controls (median, 4.74 ng/mL versus 1.98 ng/mL; P < 0.001), and were independently correlated with hematoma volumes (ρ = 0.567, P < 0.001; t = 3.444, P = 0.001) and GCS score (ρ = -0.612, P < 0.001; t = -2.048, P = 0.043). Serum DKK-1 significantly differentiated patients at risk of END (area under ROC curve (AUC), 0.850; 95% confidence interval (CI), 0.777-0.907; P < 0.001) and poor prognosis (AUC, 0.830; 95% CI, 0.753-0.890; P < 0.001), which had similar prognostic ability, as compared to GCS scores and hematoma volumes. Subsequent Logistic regression model affirmed that GCS score, hematoma volume, and serum DKK-1 levels were independently associated with END and poor prognosis at 90 days after sICH. The models, which contained them, performed well using ROC curve analysis and calibration curve analysis. Serum DKK-1 levels are markedly associated with disease severity, END and 90-day poor prognosis in sICH. Hence, serum DKK-1 is presumed to be used as a potential prognostic biomarker of sICH.

Transfer of miR-877-3p via extracellular vesicles derived from dental pulp stem cells attenuates neuronal apoptosis and facilitates early neurological functional recovery after cerebral ischemia-reperfusion injury through the Bclaf1/P53 signaling pathway

Cerebral ischemia-reperfusion injury (I/RI) is one of the principal pathogenic factors in the poor prognosis of ischemic stroke, for which current therapeutic options to enhance neurological recovery are notably insufficient. Dental pulp stem cell-derived extracellular vesicles (DPSC-EVs) have promising prospects in stroke treatment and the specific underlying mechanisms have yet to be fully elucidated. The present study observed that DPSC-EVs ameliorated the degree of cerebral edema and infarct volume by reducing the apoptosis of neurons. Furthermore, the miRNA sequencing and functional enrichment analysis identified that miR-877-3p as a key component in DPSC-EVs, contributing to neuroprotection and anti-apoptotic effects. Following target prediction and dual-luciferase assay indicated that miR-877-3p interacted with Bcl-2-associated transcription factor (Bclaf1) to play a function. The miR-877-3p inhibitor or Bclaf1 overexpression reversed the neuroprotective effects of DPSC-EVs. The findings reveal a novel therapeutic pathway where miR-877-3p, transferred via DPSC-EVs, confers neuroprotection against cerebral I/RI, highlighting its potential in promoting neuronal survival and recovery post-ischemia.

Mechanism and treatment of intracerebral hemorrhage focus on mitochondrial permeability transition pore

Intracerebral hemorrhage (ICH) is the second most common subtype of stroke, characterized by high mortality and a poor prognosis. Despite various treatment methods, there has been limited improvement in the prognosis of ICH over the past decades. Therefore, it is imperative to identify a feasible treatment strategy for ICH. Mitochondria are organelles present in most eukaryotic cells and serve as the primary sites for aerobic respiration and energy production. Under unfavorable cellular conditions, mitochondria can induce changes in permeability through the opening of the mitochondrial permeability transition pore (mPTP), ultimately leading to mitochondrial dysfunction and contributing to various diseases. Recent studies have demonstrated that mPTP plays a role in the pathological processes associated with several neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, Huntington's disease, ischemic stroke and ischemia-reperfusion injury, among others. However, there is limited research on mPTP involvement specifically in ICH. Therefore, this study comprehensively examines the pathological processes associated with mPTP in terms of oxidative stress, apoptosis, necrosis, autophagy, ferroptosis, and other related mechanisms to elucidate the potential mechanism underlying mPTP involvement in ICH. This research aims to provide novel insights for the treatment of secondary injury after ICH.

Partners in health and disease: pineal gland and purinergic signalling

In mammal's pineal glands, ATP interacts with the high-affinity P2Y1 and the low-affinity P2X7 receptors. ATP released from sympathetic nerve terminals potentiates noradrenaline-induced serotonin N-acetyltransferase (Snat) transcription, N-acetylserotonin (NAS), and melatonin (MLT) synthesis. Circulating melatonin impairs the expression of adhesion molecules in endothelial cells, blocking the migration of leukocytes. Acute defence response induced by pathogen- and danger/damage-associated molecular patterns (PAMPs and DAMPs) triggers the NF-κB pathway in pinealocytes and blocks the transcription of Snat. Therefore, the darkness hormone is not released, and neutrophils and monocytes migrate to the lesion sites. ATP released in high amounts from apoptotic and death cells was considered a DAMP, and the blockage of P2X7 receptors was tested as a new class of drugs for treating brain damage. However, this is not a simple equation. High ATP injected in a lateral ventricle blocked MLT, but not NAS, synthesis as it impairs the transcription of acetyl serotonin N-methyltransferase. NAS is released in the plasma and the cerebral spinal fluid. NAS also blocks the rolling and adhesion of leukocytes to endothelial cells. Otherwise, it is metabolised specifically in each brain area to provide the requested concentration of MLT as a neuroprotector. As observed in physiological conditions, high extracellular ATP, different from the other DAMPs, reports the environmental light/dark cycle rhythm because NAS substitutes MLT as the nocturnal chemical indicator, the darkness hormone. Thus, blocking the P2X7R should not be considered a universal therapy for improving acute strokes, as MLT and ATP are partners in health and disease.

Edaravone dexborneol regulates γ-aminobutyric acid transaminase in rats with acute intracerebral hemorrhage

OBJECTIVES

Edaravone dexborneol is neuroprotective against ischemic stroke, with free radical-scavenging and anti-inflammatory effects, but its effects in hemorrhagic stroke remain unclear. We evaluated whether edaravone dexborneol has a neuroprotective effect in intracerebral hemorrhage, and its underlying mechanisms.

MATERIALS AND METHODS

Bioinformatics were used to predict the pathway of action of edaravone dexborneol. An intracerebral hemorrhage model was established using type IV collagenase in edaravone dexborneol, intracerebral hemorrhage, Sham, adeno-associated virus + edaravone dexborneol, and adeno-associated virus + intracerebral hemorrhage groups. The modified Neurological Severity Score was used to evaluate neurological function in rats. Brain water content was measured using the dry-wet weight method. Tumor necrosis factor-α, interleukin-1β, inducible nitric oxide synthase, and γ-aminobutyric acid levels were determined by enzyme-linked immunosorbent assay. The expression levels of neurofilament light chain and γ-aminobutyric acid transaminase were determined by western blot. Nissl staining was used to examine neuronal morphology. Cognitive behavior was evaluated using a small-animal treadmill.

RESULTS

Edaravone dexborneol alleviated neurological defects, improved cognitive function, and reduced cerebral edema, neuronal degeneration, and necrosis in rats with cerebral hemorrhage. The expression levels of neurofilament light chain, tumor necrosis factor-α, interleukin-1β, inducible nitric oxide synthase, and γ-aminobutyric acid were decreased, while γ-aminobutyric acid transaminase expression was up-regulated.

CONCLUSIONS

Edaravone dexborneol regulates γ-aminobutyric acid content by acting on the γ-aminobutyric acid transaminase signaling pathway, thus alleviating oxidative stress, neuroinflammation, neuronal degeneration, and death caused by excitatory toxic injury of neurons after intracerebral hemorrhage.

Examining Transcriptomic Alterations in Rat Models of Intracerebral Hemorrhage and Severe Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a life-threatening condition associated with significant morbidity and mortality. This study investigates transcriptomic alterations in rodent models of ICH and severe ICH to shed light on the genetic pathways involved in hemorrhagic brain injury. We performed principal component analysis, revealing distinct principal component segments of normal rats compared to ICH and severe ICH rats. We employed heatmaps and volcano plots to identify differentially expressed genes and utilized bar plots and KEGG pathway analysis to elucidate the molecular pathways involved. We identified a multitude of differentially expressed genes in both the ICH and severe ICH models. Our results revealed 5679 common genes among the normal, ICH, and severe ICH groups in the upregulated genes group, and 1196 common genes in the downregulated genes, respectively. A volcano plot comparing these groups further highlighted common genes, including PDPN, TIMP1, SERPINE1, TUBB6, and CD44. These findings underscore the complex interplay of genes involved in inflammation, oxidative stress, and neuronal damage. Furthermore, pathway enrichment analysis uncovered key signaling pathways, including the TNF signaling pathway, protein processing in the endoplasmic reticulum, MAPK signaling pathway, and Fc gamma R-mediated phagocytosis, implicated in the pathogenesis of ICH.

The Role of Oxidative Stress in the Progression of Secondary Brain Injury Following Germinal Matrix Hemorrhage

Germinal matrix hemorrhage (GMH) can be a fatal condition responsible for the death of 1.7% of all neonates in the USA. The majority of GMH survivors develop long-term sequalae with debilitating comorbidities. Higher grade GMH is associated with higher mortality rates and higher prevalence of comorbidities. The pathophysiology of GMH can be broken down into two main titles: faulty hemodynamic autoregulation and structural weakness at the level of tissues and cells. Prematurity is the most significant risk factor for GMH, and it predisposes to both major pathophysiological mechanisms of the condition. Secondary brain injury is an important determinant of survival and comorbidities following GMH. Mechanisms of brain injury secondary to GMH include apoptosis, necrosis, neuroinflammation, and oxidative stress. This review will have a special focus on the mechanisms of oxidative stress following GMH, including but not limited to inflammation, mitochondrial reactive oxygen species, glutamate toxicity, and hemoglobin metabolic products. In addition, this review will explore treatment options of GMH, especially targeted therapy.

Genetically predicted hypotaurine levels mediate the relationship between immune cells and intracerebral hemorrhage

The evidence supports a strong link between immune cells and intracerebral hemorrhage (ICH). Nonetheless, the specific cause-and-effect associations between immune cells and ICH remain indeterminate. Here, our primary investigation compared immune cell infiltration in the ICH and sham groups using the GSE24265 dataset. Afterward, we extensively examined the relationship between immune cells and ICH by applying a two-sample Mendelian randomization (MR) analysis to identify the particular immune cells that may be associated with the initiation and advancement of ICH. Nevertheless, the specific processes that regulate the cause-and-effect connection between immune cells and ICH remain unknown. In this study, our objective was to investigate the connections between immune cell characteristics and plasma metabolites, as well as the links between plasma components and ICH. Our investigation uncovered that the levels of hypotaurine play a key role in the advancement of ICH, influencing the ratio of switched memory B cells among lymphocytes. Thus, our findings provide novel insights into the potential biological mechanisms underlying immune cell-mediated ICH.

UBC9-mediated SUMOylation of Lamin B1 enhances DNA-damage-induced nuclear DNA leakage and autophagy after spinal cord injury

Recent studies have shown that nucleophagy can mitigate DNA damage by selectively degrading nuclear components protruding from the nucleus. However, little is known about the role of nucleophagy in neurons after spinal cord injury (SCI). Western blot analysis and immunofluorescence were performed to evaluate the nucleophagy after nuclear DNA damage and leakage in SCI neurons in vivo and NSC34 expression in primary neurons cultured with oxygen-glucose deprivation (OGD) in vitro, as well as the interaction and colocalization of autophagy protein LC3 with nuclear lamina protein Lamin B1. The effect of UBC9, a Small ubiquitin-related modifier (SUMO) E2 ligase, on Lamin B1 SUMOylation and nucleophagy was examined by siRNA transfection or 2-D08 (a small-molecule inhibitor of UBC9), immunoprecipitation, and immunofluorescence. In SCI and OGD injured NSC34 or primary cultured neurons, neuronal nuclear DNA damage induced the SUMOylation of Lamin B1, which was required by the nuclear Lamina accumulation of UBC9. Furthermore, LC3/Atg8, an autophagy-related protein, directly bound to SUMOylated Lamin B1, and delivered Lamin B1 to the lysosome. Knockdown or suppression of UBC9 with siRNA or 2-D08 inhibited SUMOylation of Lamin B1 and subsequent nucleophagy and protected against neuronal death. Upon neuronal DNA damage and leakage after SCI, SUMOylation of Lamin B1 is induced by nuclear Lamina accumulation of UBC9. Furthermore, it promotes LC3-Lamin B1 interaction to trigger nucleophagy that protects against neuronal DNA damage.

Can supplementation of tryptophan in parenteral nutrition increase melatonin and alleviate inflammatory response?

OBJECTIVE

Endogenous melatonin is produced from tryptophan which is an essential amino acid. Besides its role in the regulation of sleep patterns, melatonin has anti-inflammatory effects. In this case-control study, we aimed to compare tryptophan and melatonin levels and their relationship with the inflammatory response, specifically serum interleukin-1, interleukin-6, and c-reactive protein levels following major abdominal surgery in patients with food restriction and who receive parenteral nutritional therapy.

METHODS

We enrolled 40 patients between the ages of 18 and 65 years in the study. We collected blood and urine samples 48 h before the operation and on postoperative days 1, 3, and 5.

RESULTS AND CONCLUSION

The tryptophan levels in the experimental group were higher than in the control group but failed to reach any statistical difference. Melatonin levels were increased in both groups following the surgery compared with preoperative levels. The increase in the experimental group was statistically different 3 days after the surgery. The difference in the level of interleukin-1 between the control and the experimental groups was greatest on postoperative day 3. On postoperative day 3, the interleukin-6 level in the treatment group was slightly higher than in the control group. We did not find any difference in the levels of c-reactive protein between the groups. As a result, the levels of tryptophan and melatonin were increased in the parenteral nutrition group, irrespective of the postoperative inflammatory response.

A mechanism linking ferroptosis and ferritinophagy in melatonin-related improvement of diabetic brain injury

Ferroptosis and ferritinophagy play critical roles in various disease contexts. Herein, we observed that ferroptosis and ferritinophagy were induced both in the brains of mice with diabetes mellitus (DM) and neuronal cells after high glucose (HG) treatment, as evidenced by decreases in GPX4, SLC7A11, and ferritin levels, but increases in NCOA4 levels. Interestingly, melatonin administration ameliorated neuronal damage by inhibiting ferroptosis and ferritinophagy both in vivo and in vitro. At the molecular level, we found that not only the ferroptosis inducer p53 but also the ferritinophagy mediator NCOA4 was the potential target of miR-214-3p, which was downregulated by DM status or HG insult, but was increased after melatonin treatment. However, the inhibitory effects of melatonin on ferroptosis and ferritinophagy were blocked by miR-214-3p downregulation. These findings suggest that melatonin is a potential drug for improving diabetic brain damage by inhibiting p53-mediated ferroptosis and NCOA4-mediated ferritinophagy through regulating miR-214-3p in neurons.

Pathological mechanisms and future therapeutic directions of thrombin in intracerebral hemorrhage: a systematic review

Intracerebral hemorrhage (ICH), a common subtype of hemorrhagic stroke, often causes severe disability or death. ICH induces adverse events that might lead to secondary brain injury (SBI), and there is currently a lack of specific effective treatment strategies. To provide a new direction for SBI treatment post-ICH, the systematic review discussed how thrombin impacts secondary injury after ICH through several potentially deleterious or protective mechanisms. We included 39 studies and evaluated them using SYRCLE's ROB tool. Subsequently, we explored the potential molecular mechanisms of thrombin-mediated effects on SBI post-ICH in terms of inflammation, iron deposition, autophagy, and angiogenesis. Furthermore, we described the effects of thrombin in endothelial cells, astrocytes, pericytes, microglia, and neurons, as well as the harmful and beneficial effects of high and low thrombin concentrations on ICH. Finally, we concluded the current research status of thrombin therapy for ICH, which will provide a basis for the future clinical application of thrombin in the treatment of ICH.

Activating transcription factor 6 alleviates secondary brain injury by increasing cystathionine γ-lyase expression in a rat model of intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) comprises primary and secondary injuries, the latter of which induces increased inflammation and apoptosis and is more severe. Activating transcription factor 6 (ATF6) is a type-II transmembrane protein in the endoplasmic reticulum (ER). ATF6 target genes could improve ER homeostasis, which contributes to cryoprotection. Hence, we predict that ATF6 will have a protective effect on brain tissue after ICH.

METHOD

The ICH rat model was generated through autologous blood injection into the right basal ganglia, the expression of ATF6 after ICH was determined by WB and IF. The expression of ATF6 was effectively controlled by means of intervention, and a series of measures was used to detect cell death, neuroinflammation, brain edema, blood-brain barrier and other indicators after ICH. Finally, the effects on long-term neural function of rats were measured by behavioral means.

RESULT

ATF6 was significantly increased in the ICH-induced brain tissues. Further, ATF6 was found to modulate the expression of cystathionine γ-lyase (CTH) after ICH. Upregulation of ATF6 attenuated neuronal apoptosis and inflammation in ICH rats, along with mitigation of ICH-induced brain edema, blood-brain barrier deterioration, and cognitive behavior defects. Conversely, ATF6 genetic knockdown induced effects counter to those aforementioned.

CONCLUSIONS

This study thereby emphasizes the crucial role of ATF6 in secondary brain injury in response to ICH, indicating that ATF6 upregulation may potentially ameliorate ICH-induced secondary brain injury. Consequently, ATF6 could serve as a promising therapeutic target to alleviate clinical ICH-induced secondary brain injuries.

Mitochondrial ferritin upregulation reduced oxidative stress and blood-brain-barrier disruption by maintaining cellular iron homeostasis in a neonatal rat model of germinal matrix hemorrhage

Germinal matrix hemorrhage (GMH) is a devasting neurological disease in premature newborns. After GMH, brain iron overload associated with hemoglobin degradation contributed to oxidative stress, causing disruption of the already vulnerable blood-brain barrier (BBB). Mitochondrial ferritin (FTMT), a novel mitochondrial outer membrane protein, is crucial in maintaining cellular iron homeostasis. We aimed to investigate the effect of FTMT upregulation on oxidative stress and BBB disruption associated with brain iron overload in rats. A total of 222 Sprague-Dawley neonatal rat pups (7 days old) were used to establish a collagenase-induced GMH model and an iron-overload model of intracerebral FeCl2 injection. Deferiprone was administered via gastric lavage 1 h after GMH and given daily until euthanasia. FTMT CRISPR Knockout and adenovirus (Ad)-FTMT were administered intracerebroventricularly 48 h before GMH and FeCl2 injection, respectively. Neurobehavioral tests, immunofluorescence, Western blot, Malondialdehyde measurement, and brain water content were performed to evaluate neurobehavior deficits, oxidative stress, and BBB disruption, respectively. The results demonstrated that brain expressions of iron exporter Ferroportin (FPN) and antioxidant glutathione peroxidase 4 (GPX4) as well as BBB tight junction proteins including Claudin-5 and Zona Occulta (ZO)-1 were found to be decreased at 72 h after GMH. FTMT agonist Deferiprone attenuated oxidative stress and preserved BBB tight junction proteins after GMH. These effects were partially reversed by FTMT CRISPR Knockout. Iron overload by FeCl2 injection resulted in oxidative stress and BBB disruption, which were improved by Ad-FTMT mediated FTMT overexpression. Collectively, FTMT upregulation is neuroprotective against brain injury associated with iron overload. Deferiprone reduced oxidative stress and BBB disruption by maintaining cellular iron homeostasis partially by the upregulating of FTMT after GMH. Deferiprone may be an effective treatment for patients with GMH.

The phosphokinase activity of IRE1ɑ prevents the oxidative stress injury through miR-25/Nox4 pathway after ICH

BACKGROUND

Endoplasmic reticulum (ER) stress and oxidative stress are the major pathologies encountered after intracerebral hemorrhage (ICH). Inositol-requiring enzyme-1 alpha (IRE1α) is the most evolutionarily conserved ER stress sensor, which plays a role in monitoring and responding to the accumulation of unfolded/misfolded proteins in the ER lumen. Recent studies have shown that ER stress is profoundly related to oxidative stress in physiological or pathological conditions. The purpose of this study was to investigate the role of IRE1α in oxidative stress and the potential mechanism.

METHODS

A mouse model of ICH was established by autologous blood injection. The IRE1α phosphokinase inhibitor KIRA6 was administrated intranasally at 1 h after ICH, antagomiR-25 and agomiR-25 were injected intraventricularly at 24 h before ICH. Western blot analysis, RT-qPCR, immunofluorescence staining, hematoma volume, neurobehavioral tests, dihydroethidium (DHE) staining, H2O2 content, brain water content, body weight, Hematoxylin and Eosin (HE) staining, Nissl staining, Morris Water Maze (MWM) and Elevated Plus Maze (EPM) were performed.

RESULTS

Endogenous phosphorylated IRE1α (p-IRE1α), miR-25-3p, and Nox4 were increased in the ICH model. Administration of KIRA6 downregulated miR-25-3p expression, upregulated Nox4 expression, promoted the level of oxidative stress, increased hematoma volume, exacerbated brain edema and neurological deficits, reduced body weight, aggravated spatial learning and memory deficits, and increased anxiety levels. Then antagomiR-25 further upregulated the expression of Nox4, promoted the level of oxidative stress, increased hematoma volume, exacerbated brain edema and neurological deficits, whereas agomiR-25 reversed the effects promoted by KIRA6.

CONCLUSION

The IRE1α phosphokinase activity is involved in the oxidative stress response through miR-25/Nox4 pathway in the mouse ICH brain.

Mogroside V alleviates the heat stress-induced disruption of the porcine oocyte in vitro maturation

Heat stress (HS) is a stressor that negatively affect female reproduction. Specially, oocytes are very sensitive to HS. It has been demonstrated that some active compounds can protect oocyte from HS. We previously found that Mogroside V (MV), extracted from Siraitia grosvenorii (Luo Han Guo), can protect oocyte from many kinds of stresses. However, how MV alleviates HS-induced disruption of oocyte maturation remains unknown. In this study, we treated the HS-induced porcine oocytes with MV to examine their maturation and quality. Our findings demonstrate that MV can effectively alleviate HS-induced porcine oocyte abnormal cumulus cell expansion, decrease of first polar body extrusion rate, spindle assembly and chromosome separation abnormalities, indicating MV attenuates oocyte mature defects. We further observed that MV can effectively alleviate HS-induced cortical granule distribution abnormality and decrease of blastocyst formation rate after parthenogenesis activation. In addition, MV treatment reversed mitochondrial dysfunction and lipid droplet content decrease, reduced reactive oxygen species levels, early apoptosis and DNA damage in porcine oocytes after HS. Collectively, this study suggests that MV can effectively protect porcine oocytes from HS.

ERBB1 alleviates secondary brain injury induced by experimental intracerebral hemorrhage in rats by modulating neuronal death via PLC-γ/PKC pathway

AIMS

Intracerebral hemorrhage (ICH) is a disease with high rates of disability and mortality. The role of epidermal growth factor receptor 1 (ERBB1) in ICH was elucidated in this study.

METHODS

ICH model was constructed by injecting autologous arterial blood into the right basal ganglia. The protein level of ERBB1 was detected by western blot analysis. To up- and downregulation of ERBB1 in rats, intraventricular injection of a lentivirus overexpression vector of ERBB1 and AG1478 (a specific inhibitor of ERBB1) was used. The cell apoptosis, neuronal loss, and pro-inflammatory cytokines were assessed by TUNEL, Nissl staining, and ELISA. Meanwhile, behavioral cognitive impairment of ICH rats was evaluated after ERBB1-targeted interventions.

RESULTS

ERBB1 increased significantly in brain tissue of ICH rats. Overexpression of ERBB1 remarkably reduced cell apoptosis and neuronal loss induced by ICH, as well as pro-inflammatory cytokines and oxidative stress. Meanwhile, the behavioral and cognitive impairment of ICH rats were alleviated after upregulation of ERBB1; however, the secondary brain injury (SBI) was aggravated by AG1478 treatment. Furthermore, the upregulation of PLC-γ and PKC in ICH rats was reversed by AG1478 treatment.

CONCLUSIONS

ERBB1 can improve SBI and has a neuroprotective effect in experimental ICH rats via PLC-γ/PKC pathway.

Mitophagy in intracerebral hemorrhage: a new target for therapeutic intervention

Intracerebral hemorrhage is a life-threatening condition with a high fatality rate and severe sequelae. However, there is currently no treatment available for intracerebral hemorrhage, unlike for other stroke subtypes. Recent studies have indicated that mitochondrial dysfunction and mitophagy likely relate to the pathophysiology of intracerebral hemorrhage. Mitophagy, or selective autophagy of mitochondria, is an essential pathway to preserve mitochondrial homeostasis by clearing up damaged mitochondria. Mitophagy markedly contributes to the reduction of secondary brain injury caused by mitochondrial dysfunction after intracerebral hemorrhage. This review provides an overview of the mitochondrial dysfunction that occurs after intracerebral hemorrhage and the underlying mechanisms regarding how mitophagy regulates it, and discusses the new direction of therapeutic strategies targeting mitophagy for intracerebral hemorrhage, aiming to determine the close connection between mitophagy and intracerebral hemorrhage and identify new therapies to modulate mitophagy after intracerebral hemorrhage. In conclusion, although only a small number of drugs modulating mitophagy in intracerebral hemorrhage have been found thus far, most of which are in the preclinical stage and require further investigation, mitophagy is still a very valid and promising therapeutic target for intracerebral hemorrhage in the long run.

Stromal cell-derived factor-1 downregulation contributes to neuroprotection mediated by CXC chemokine receptor 4 interactions after intracerebral hemorrhage in rats

AIM

Stromal cell-derived factor-1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) have a substantial role in neuronal formation, differentiation, remodeling, and maturation and participate in multiple physiological and pathological events. In this study, we investigated the role of SDF-1/CXCR4 in neural functional injury and neuroprotection after intracerebral hemorrhage (ICH).

METHODS

Western blot, immunofluorescence and immunoprecipitation were used to detect SDF-1/CXCR4 expression and combination respectively after ICH. TUNEL staining, Lactate dehydrogenase assay, Reactive oxygen species assay, and Enzyme-linked immunosorbent assay to study neuronal damage; Brain water content to assay brain edema, Neurological scores to assess short-term neurological deficits. Pharmacological inhibition and genetic intervention of SDF-1/CXCR4 signaling were also used in this study.

RESULTS

ICH induced upregulation of SDF-1/CXCR4 and increased their complex formation, whereas AMD3100 significantly reduced it. The levels of TNF-α and IL-1β were significantly reduced after AMD3100 treatment. Additionally, AMD3100 treatment can alleviate neurobehavioral dysfunction of ICH rats. Conversely, simultaneous SDF-1/CXCR4 overexpression induced the opposite effect. Moreover, immunoprecipitation confirmed that SDF-1/CXCR4 combined to initiate neurodamage effects.

CONCLUSION

This study indicated that inhibition of SDF-1/CXCR4 complex formation can rescue the inflammatory response and alleviate neurobehavioral dysfunction after ICH. SDF-1/CXCR4 may have applications as a therapeutic target after ICH.

Screening of potent RIPK3 inhibitors to attenuate necroptosis and inflammation in mouse traumatic brain injury models

Necroptosis is a type of cell death that occurs when cells are exposed to external stressors such as inflammation, infections, or injury. In necroptosis, cells use a different set of proteins including: receptor-interacting kinase 1 (RIPK1 or RIP1), receptor-interacting kinase 3 (RIPK3 or RIP3) and the phosphorylation of its substrate mixed lineage kinase domain-like protein (MLKL) and pathways to trigger their own death. Mutations in the gene encoding RIPK3 have been associated with many diseases, including neurodegenerative diseases, neuroinflammatory diseases, inflammatory diseases，tumors, and it is being studied as a potential target for inflammatory injury therapy. RIPK3 has also been implicated in the pathology of neuroinflammation following Traumatic brain injury and is currently being explored as a potential therapy. We screened through necroptosis blocking compounds, a library of FDA-approved compounds. We found four compounds:1D6-Foretinib GSK1363089; 15F6-Poziotinib (HM781-36B); 15F9-Dasatinib monohydrate; 15A10-Pexmetinib (ARRY-614); acts as potent inhibitors of necroptosis (Necroptosis Blocking Compounds, NBCs) by blocking the RIPK3 kinase activity. These four compounds effectively block necroptosis induced by death receptor ligands Toll-like receptors as well as viral infections in human, rat and mouse cells. The cellular activation of RIPK3 and MLKL stimulated by necroptosis was strongly inhibited by NBCs. The compounds are promising for targeting RIPK3 kinase activity, thereby preventing necroptosis and inflammatory responses. In our study, we explored the role of NBCs in neuroprotection after traumatic brain injury. It's effectiveness in traumatic brain injury animal models and favorable safety profiles make it a potential candidate for the advances of new therapies for necroptosis-associated neuroinflammatory disorders.

The Role of Circadian Rhythms in Stroke: A Narrative Review

Stroke, a debilitating condition often leading to long-term disability, poses a substantial global concern and formidable challenge. The increasing incidence of stroke has drawn the attention of medical researchers and neurologists worldwide. Circadian rhythms have emerged as pivotal factors influencing stroke's onset, pathogenesis, treatment, and outcomes. To gain deeper insights into stroke, it is imperative to explore the intricate connection between circadian rhythms and stroke, spanning from molecular mechanisms to pathophysiological processes. Despite existing studies linking circadian rhythm to stroke onset, there remains a paucity of comprehensive reviews exploring its role in pathogenesis, treatment, and prognosis. This review undertakes a narrative analysis of studies investigating the relationship between circadian variation and stroke onset. It delves into the roles of various physiological factors, including blood pressure, coagulation profiles, blood cells, catecholamines, cortisol, and the timing of antihypertensive medication, which contribute to variations in circadian-related stroke risk. At a molecular level, the review elucidates the involvement of melatonin, circadian genes, and glial cells in the pathophysiology. Furthermore, it provides insights into the diverse factors influencing stroke treatment and outcomes within the context of circadian variation. The review underscores the importance of considering circadian rhythms when determining the timing of stroke interventions, emphasizing the necessity for personalized stroke management strategies that incorporate circadian rhythms. It offers valuable insights into potential molecular targets and highlights areas that require further exploration to enhance our understanding of the underlying pathophysiology. In comparison to the published literature, this manuscript distinguishes itself through its coverage of circadian rhythms' impact on stroke across the entire clinical spectrum. It presents a unique synthesis of epidemiological, clinical, molecular, and cellular evidence, underscoring their collective significance.

Multimodal investigation reveals the neuroprotective mechanism of Angong Niuhuang pill for intracerebral hemorrhage: Converging bioinformatics, network pharmacology, and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Angong Niuhuang Pill (ANP) is a traditional Chinese medicine formula that has been used clinically for many years in the treatment of cerebral hemorrhage. It is composed of ingredients such as calculus bovis, moschus, and others. Ancient texts have documented that ANP's multiple components possess properties such as heat-clearing, detoxification, and sedation, which can be effective in treating conditions such as coma and stroke. However, the underlying mechanisms of ANP's potential actions are still under investigation.

AIM OF THE STUDY

ANP is a Chinese medicine widely utilized for the treatment of intracerebral hemorrhage (ICH). However, the precise mechanism underlying the therapeutic effects remains largely elusive. The present study aims to unravel the effects and pharmacological molecular mechanisms of ANP in combatting ICH, employing a comprehensive network pharmacology approach and experimental validation.

MATERIALS AND METHODS

The molecular targets of ANP and ICH were obtained from various databases, followed by the construction of protein-protein interaction (PPI) networks using the STRING database. Further, gene ontology (GO) enrichment and Kyoto encyclopedia of genes and genomes (KEGG) analyses were conducted using the Metascape database and Cytoscape, respectively. Finally, molecular docking was performed. We performed a series of behavioral tests, immunohistochemical staining, TUNEL staining, and Western Blot to verify the effects of ANP.

RESULTS

IL-6, JUN, MMP9, IL-1β, VEGFA were the main candidate targets and were associated with fluid shear stress and atherosclerosis, TNF signaling pathway, etc. It is suggested that the potential mechanism of ANP against ICH may be mainly related to pyroptosis, inflammation. In vivo validation showed that ANP treatment significantly reduced the number of TUNEL-positive cells and ANP inhibited the activation of Iba-1 positive neurons, and suppressed the expression of inflammatory factors and pyroptosis indicators. In addition, ANP improved the cognitive level and motor ability of ICH mice.

CONCLUSION

The results of the study combined with virtual screening and experimental validation showed that ANP has an important contribution in protecting the brain from neuronal damage by regulating the pathways of inflammation and pyroptosis, laying the foundation and innovative ideas for future studies.

Naoxueshu oral liquid promotes hematoma absorption by targeting CD36 in M2 microglia via TLR4/MyD88/NF-κB signaling pathway in rats with intracerebral hemorrhage

ETHNOPHARMACOLOGICAL RELEVANCE

Intracerebral hemorrhage (ICH) is a major public health issue that leads to elevated rates of death and disability and has few proven treatments. Naoxueshu oral liquid (NXS), a TCM patent drug, is widely used in patients with ICH. Although a series of clinical studies have confirmed the efficacy and safety of NXS, the underlying mechanism of hematoma absorption is unclear.

AIM OF THE STUDY

Our work aimed to elucidate the effect and mechanism of NXS on hematoma absorption in rats with ICH.

MATERIALS AND METHODS

Induction of ICH model in the rats with intracerebral injection of collagenase VII, followed by treatment with NXS and Edaravone as a control neuroprotection medication. Neural functional recovery was assessed using mNSS, foot fault test, corner test, forelimb grip-traction test, and adhesive removal test. Hematoma absorption was assessed by the spectrophotometric hemoglobin assay with Drabkin's reagent. The protein expression of CD36, M2 microglia marker (CD206 and YM-1) and TLR4/MyD88/NF-κB pathway related proteins were determined by Western blot and immunofluorescence.

RESULTS

NXS could significantly ameliorate the ICH recovery of neural and locomotor function as well as reduce hemorrhage volume. NXS could increase the expression of CD36 expressed in M2 microglia and promote M2 microglia polarization. Simultaneously, NXS significantly suppressed protein expressions of TLR4, MyD88, and NF-κB following ICH in rats. The results indicated that lipopolysaccharide (LPS), TLR4 specific agonist, could partially reverse the change in ICH rats administrated with NXS.

CONCLUSIONS

NXS promotes hematoma absorption by targeting CD36 expression in M2 microglia via TLR4/MyD88/NF-κB signaling pathway in rats with ICH. Collectively, current research provides a novel theoretical basis for the clinical application of NXS.

Mechanisms and therapeutic targets of mitophagy after intracerebral hemorrhage

Mitochondria are dynamic organelles responsible for cellular energy production. In addition to regulating energy homeostasis, mitochondria are responsible for calcium homeostasis, clearance of damaged organelles, signaling, and cell survival in the context of injury and pathology. In stroke, the mechanisms underlying brain injury secondary to intracerebral hemorrhage are complex and involve cellular hypoxia, oxidative stress, inflammatory responses, and apoptosis. Recent studies have shown that mitochondrial damage and autophagy are essential for neuronal metabolism and functional recovery after intracerebral hemorrhage, and are closely related to inflammatory responses, oxidative stress, apoptosis, and other pathological processes. Because hypoxia and inflammatory responses can cause secondary damage after intracerebral hemorrhage, the restoration of mitochondrial function and timely clearance of damaged mitochondria have neuroprotective effects. Based on studies on mitochondrial autophagy (mitophagy), cellular inflammation, apoptosis, ferroptosis, the BNIP3 autophagy gene, pharmacological and other regulatory approaches, and normobaric oxygen (NBO) therapy, this article further explores the neuroprotective role of mitophagy after intracerebral hemorrhage.

Targeting pyroptosis with nanoparticles to alleviate neuroinflammatory for preventing secondary damage following traumatic brain injury

Posttraumatic neuroinflammation is a key driver of secondary injury after traumatic brain injury (TBI). Pyroptosis, a proinflammatory form of programmed cell death, considerably activates strong neuroinflammation and amplifies the inflammatory response by releasing inflammatory contents. Therefore, treatments targeting pyroptosis may have beneficial effects on the treatment of secondary brain damage after TBI. Here, a cysteine-alanine-glutamine-lysine peptide-modified β-lactoglobulin (β-LG) nanoparticle was constructed to deliver disulfiram (DSF), C-β-LG/DSF, to inhibit pyroptosis and decrease neuroinflammation, thereby preventing TBI-induced secondary injury. In the post-TBI mice model, C-β-LG/DSF selectively targets the injured brain, increases DSF accumulation, and extends the time of the systemic circulation of DSF. C-β-LG/DSF can alleviate brain edema and inflammatory response, inhibit secondary brain injury, promote learning, and improve memory recovery in mice after trauma. Therefore, this study likely provided a potential approach for reducing the secondary spread of TBI.

Palmatine attenuates LPS-induced neuroinflammation through the PI3K/Akt/NF-κB pathway

To investigate the key molecular mechanisms of palmatine for the treatment of neuroinflammation through modulation of a pathway using molecular docking, molecular dynamics (MD) simulation combined with network pharmacology, and animal experiments. Five alkaloid components were obtained from the traditional Chinese medicine Huangteng through literature mining. Molecular docking and MD simulation with acetylcholinesterase were used to screen palmatine. At the animal level, mice were injected with LPS intracerebrally to cause a neuroinflammatory model, and the Morris water maze experiment was performed to examine the learning memory of mice. Anxiety levels were tested using the autonomous activity behavior experiment with the open field and elevated behavior experiments. HE staining and Niss staining were performed on brain tissue sections to observe morphological lesions and apoptosis; serum was examined for inflammatory factors TNF-α, IL-6, and IL-1β; Western blot was performed to detect the protein expression. The expression of PI3K/AKT/NFkB signaling pathway-related proteins was examined by Western blot. The results of network pharmacology showed that the screening of palmatine activation containing the PI3K/Akt/NFkB signaling pathway exerts antineuroinflammatory effects. Results from behavioral experiments showed that Pal enhanced learning memory in model mice, improved anxiety behavior, and significantly improved brain damage caused by neuroinflammation. The results of HE staining and Niss staining of brain tissue sections showed that palmatine could alleviate morphological lesions and nucleus damage in brain tissue. Palmatine improved the levels of serum inflammatory factors TNF-α, IL-6, and IL-1β. SOD, MDA, CAT, ACH, and ACHE in the hippocampus were improved. Western blot results showed that palmatine administration ameliorated LPS-induced neuroinflammation through the PI3K/Akt/NFkB pathway.

Establishment of a rat model of severe spontaneous intracerebral hemorrhage

Background

Severe intracerebral hemorrhage (ICH) is the most devastating subtype of stroke resulting in high mortality and disability. At present, the development of targeted treatments to minimize the high morbidity and mortality is limited partly due to the lack of a severe ICH animal model. In this study, we aimed to establish an accurate severe ICH model in rats and examine the pathological and physiological changes associated with ICH.

Methods

A rat model of severe ICH model was established by intrastriatal injection of autologous blood using different blood volumes (ICH 100 µL group, ICH 130 µL group, ICH 160 µL group, ICH 170 µL group, and ICH 180 µL group). The mortality was assessed during the 28-day post-ICH period. Short- and long-term neurological deficits were evaluated using the Longa method, foot fault, falling latency, and Morris water maze tests. Brain water content, hematoma volume, hemoglobin content, and magnetic resonance imaging were assessed to determine the extent of brain injury. Immunofluorescence staining was conducted to examine microglial activation and neuronal apoptosis. Hematoxylin and eosin (H&E) staining, lung water content, and western blotting were used to assess lung injury following ICH.

Results

The mortality of ICH rats increased significantly with an increase in autologous blood injection. The 28-day mortality in the 100 µL, 130 µL, 160 µL, 170 µL, and 180 µL ICH groups were 5%, 20%, 40%, 75%, and 100%, respectively. A significantly higher 28-day mortality was observed in the ICH 160 µL group compared to the ICH 100 µL group. The ICH 160 µL group exhibited significantly increased neurological deficits, brain edema, hematoma volume, and hemoglobin content compared to the sham group. Compared with the sham operation group, the activation of microglia and neuronal death in ICH 160 µL rats increased. The use of H&E staining and western blotting demonstrated that disruption of the intra-alveolar structure, alveolar edema, and infiltration of inflammatory cells and cytokines into the lung tissue were more severe in the ICH 160 µL group than the sham group.

Conclusions

A severe ICH model in rats was successfully established using an injection of autologous blood at a volume of 160 µL. This model may provide a valuable tool to examine the pathological mechanisms and potential therapeutic interventions of severe ICH.

Icariin rescues developmental BPA exposure induced spatial memory deficits in rats

Bisphenol A (BPA) has been implicated in cognitive impairment. Icariin is the main active ingredient extracted from Epimedium Herb with protective function of nervous system. However, the potential therapeutic effects of Icariin on spatial memory deficits induced by developmental BPA exposure in Sprague-Dawley rats have not been investigated. This study investigated the therapeutic effect of Icariin (10 mg/kg/day, from postnatal day (PND) 21 to PND 60 by gavage) on spatial memory deficits in rat induced by developmental BPA exposure (1 mg/kg/day, from embryonic to PND 60), demonstrating that Icariin can markedly improve spatial memory in BPA-exposed rat. Furthermore, intra-gastric administration of Icariin could attenuate abnormal hippocampal cell dispersion and loss, improved the dendritic spine density and Nissl bodies. Moreover, Icariin reversed BPA induced reduction of frequency of miniature excitatory postsynaptic currents(mEPSC) and decrease of Vesicular glutamate transporter 1(VGlut1). Collectively, Icariin could effectively rescue BPA-induced spatial memory impairment in male rats by preventing cell loss and reduction of dendritic spines in the hippocampus. In addition, we also found that VGlut1 is a critical target in the repair of BPA-induced spatial memory by Icariin. Thus, Icariin may be a promising therapeutic agent to attenuate BPA-induced spatial memory deficits.

Melatonin Prevents Alcohol- and Metabolic Dysfunction- Associated Steatotic Liver Disease by Mitigating Gut Dysbiosis, Intestinal Barrier Dysfunction, and Endotoxemia

Melatonin (MT) has often been used to support good sleep quality, especially during the COVID-19 pandemic, as many have suffered from stress-related disrupted sleep patterns. It is less known that MT is an antioxidant, anti-inflammatory compound, and modulator of gut barrier dysfunction, which plays a significant role in many disease states. Furthermore, MT is produced at 400-500 times greater concentrations in intestinal enterochromaffin cells, supporting the role of MT in maintaining the functions of the intestines and gut-organ axes. Given this information, the focus of this article is to review the functions of MT and the molecular mechanisms by which it prevents alcohol-associated liver disease (ALD) and metabolic dysfunction-associated steatotic liver disease (MASLD), including its metabolism and interactions with mitochondria to exert its antioxidant and anti-inflammatory activities in the gut-liver axis. We detail various mechanisms by which MT acts as an antioxidant, anti-inflammatory compound, and modulator of intestinal barrier function to prevent the progression of ALD and MASLD via the gut-liver axis, with a focus on how these conditions are modeled in animal studies. Using the mechanisms of MT prevention and animal studies described, we suggest behavioral modifications and several exogenous sources of MT, including food and supplements. Further clinical research should be performed to develop the field of MT in preventing the progression of liver diseases via the gut-liver axis, so we mention a few considerations regarding MT supplementation in the context of clinical trials in order to advance this field of research.

FGF21 alleviates endothelial mitochondrial damage and prevents BBB from disruption after intracranial hemorrhage through a mechanism involving SIRT6

BACKGROUND

Disruption of the BBB is a harmful event after intracranial hemorrhage (ICH), and this disruption contributes to a series of secondary injuries. We hypothesized that FGF21 may have protective effects after intracranial hemorrhage (ICH) and investigated possible underlying molecular mechanisms.

METHODS

Blood samples of ICH patients were collected to determine the relationship between the serum level of FGF21 and the [Formula: see text]GCS%. Wild-type mice, SIRT6flox/flox mice, endothelial-specific SIRT6-homozygous-knockout mice (eSIRT6-/- mice) and cultured human brain microvascular endothelial cells (HCMECs) were used to determine the protective effects of FGF21 on the BBB.

RESULTS

We obtained original clinical evidence from patient data identifying a positive correlation between the serum level of FGF21 and [Formula: see text]GCS%. In mice, we found that FGF21 treatment is capable of alleviating BBB damage, mitigating brain edema, reducing lesion volume and improving neurofunction after ICH. In vitro, after oxyhemoglobin injury, we further explored the protective effects of FGF21 on endothelial cells (ECs), which are a significant component of the BBB. Mitochondria play crucial roles during various types of stress reactions. FGF21 significantly improved mitochondrial biology and function in ECs, as evidenced by alleviated mitochondrial morphology damage, reduced ROS accumulation, and restored ATP production. Moreover, we found that the crucial regulatory mitochondrial factor deacylase sirtuin 6 (SIRT6) played an irreplaceable role in the effects of FGF21. Using endothelial-specific SIRT6-knockout mice, we found that SIRT6 deficiency largely diminished these neuroprotective effects of FGF21. Then, we revealed that FGF21 might promote the expression of SIRT6 via the AMPK-Foxo3a pathway.

CONCLUSIONS

We provide the first evidence that FGF21 is capable of protecting the BBB after ICH by improving SIRT6-mediated mitochondrial homeostasis.

Melatonin alleviates particulate matter-induced liver fibrosis by inhibiting ROS-mediated mitophagy and inflammation via Nrf2 activation

OBJECTIVE

Fine particulate matter (PM2.5) is a source of pollution worldwide, that causes inflammation and liver fibrosis. Melatonin, as the predominant hormone secreted by the pineal gland, can inhibit PM2.5-induced lung injury by activating nuclear factor erythroid 2-related factor 2 (Nrf2) to inhibit ferroptosis. However, the possible role of melatonin in PM2.5-induced liver damage remains unclear.

EXPERIMENTAL APPROACH

In vitro, the effects of melatonin on PM2.5-induced oxidative stress and LX-2 cell activation were examined. In vivo, a PM2.5-induced inflammation and liver fibrosis mouse model was used to evaluate the hepatoprotective effect of melatonin.

RESULTS

In vitro, melatonin induced the expression of Nrf2 and its downstream genes and inhibited PM2.5-induced reactive oxygen species (ROS) production and mitochondrial damage. Melatonin also ameliorated the PM2.5-induced oxidative stress and fibrogenic marker upregulation. However, the antifibrotic effect of melatonin was abolished in siNrf2-treated LX-2 cells. In vivo, we observed mitochondrial abnormalities and mitochondrial fragmentation, which were accompanied by increased PTEN-induced kinase 1 (PINK1) and Parkin expression, in PM2.5-treated mouse hepatocytes. These changes were partially reversed by melatonin. In addition, melatonin activated the Nrf2 signaling pathway and protected against PM2.5-induced oxidative stress. Furthermore, melatonin alleviated inflammation and liver fibrosis. Moreover, Nrf2-KO mice exhibited more severe inflammation and liver fibrosis after PM2.5 exposure than wild-type mice, and the protective effect of melatonin on PM2.5- treated Nrf2-KO mice was greatly compromised.

CONCLUSION

These data suggest that melatonin effectively inhibits PM2.5-induced liver fibrosis by activating Nrf2 and inhibiting ROS-mediated mitophagy and inflammation.

D-allose Inhibits TLR4/PI3K/AKT Signaling to Attenuate Neuroinflammation and Neuronal Apoptosis by Inhibiting Gal-3 Following Ischemic Stroke

BACKGROUND

Ischemic stroke (IS) occurs when a blood vessel supplying the brain becomes obstructed, resulting in cerebral ischemia. This type of stroke accounts for approximately 87% of all strokes. Globally, IS leads to high mortality and poor prognosis and is associated with neuroinflammation and neuronal apoptosis. D-allose is a bio-substrate of glucose that is widely expressed in many plants. Our previous study showed that D-allose exerted neuroprotective effects against acute cerebral ischemic/reperfusion (I/R) injury by reducing neuroinflammation. Here, we aimed to clarify the beneficial effects D-allose in suppressing IS-induced neuroinflammation damage, cytotoxicity, neuronal apoptosis and neurological deficits and the underlying mechanism in vitro and in vivo.

METHODS

In vivo, an I/R model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R) in C57BL/6 N mice, and D-allose was given by intraperitoneal injection within 5 min after reperfusion. In vitro, mouse hippocampal neuronal cells (HT-22) with oxygen-glucose deprivation and reperfusion (OGD/R) were established as a cell model of IS. Neurological scores, some cytokines, cytotoxicity and apoptosis in the brain and cell lines were measured. Moreover, Gal-3 short hairpin RNAs, lentiviruses and adeno-associated viruses were used to modulate Gal-3 expression in neurons in vitro and in vivo to reveal the molecular mechanism.

RESULTS

D-allose alleviated cytotoxicity, including cell viability, LDH release and apoptosis, in HT-22 cells after OGD/R, which also alleviated brain injury, as indicated by lesion volume, brain edema, neuronal apoptosis, and neurological functional deficits, in a mouse model of I/R. Moreover, D-allose decreased the release of inflammatory factors, such as IL-1β, IL-6 and TNF-α. Furthermore, the expression of Gal-3 was increased by I/R in wild-type mice and HT-22 cells, and this factor further bound to TLR4, as confirmed by three-dimensional structure prediction and Co-IP. Silencing the Gal-3 gene with shRNAs decreased the activation of TLR4 signaling and alleviated IS-induced neuroinflammation, apoptosis and brain injury. Importantly, the loss of Gal-3 enhanced the D-allose-mediated protection against I/R-induced HT-22 cell injury, inflammatory insults and apoptosis, whereas activation of TLR4 by the selective agonist LPS increased the degree of neuronal injury and abolished the protective effects of D-allose.

CONCLUSIONS

In summary, D-allose plays a crucial role in inhibiting inflammation after IS by suppressing Gal-3/TLR4/PI3K/AKT signaling pathway in vitro and in vivo.

O-GlcNAcylation is essential for therapeutic mitochondrial transplantation

BACKGROUND

Transplantation of mitochondria is increasingly explored as a novel therapy in central nervous system (CNS) injury and disease. However, there are limitations in safety and efficacy because mitochondria are vulnerable in extracellular environments and damaged mitochondria can induce unfavorable danger signals.

METHODS

Mitochondrial O-GlcNAc-modification was amplified by recombinant O-GlcNAc transferase (OGT) and UDP-GlcNAc. O-GlcNAcylated mitochondrial proteins were identified by mass spectrometry and the antiglycation ability of O-GlcNAcylated DJ1 was determined by loss-of-function via mutagenesis. Therapeutic efficacy of O-GlcNAcylated mitochondria was assessed in a mouse model of transient focal cerebral ischemia-reperfusion. To explore translational potential, we evaluated O-GlcNAcylated DJ1 in CSF collected from patients with subarachnoid hemorrhagic stroke (SAH).

RESULTS

We show that isolated mitochondria are susceptible to advanced glycation end product (AGE) modification, and these glycated mitochondria induce the receptor for advanced glycation end product (RAGE)-mediated autophagy and oxidative stress when transferred into neurons. However, modifying mitochondria with O-GlcNAcylation counteracts glycation, diminishes RAGE-mediated effects, and improves viability of mitochondria recipient neurons. In a mouse model of stroke, treatment with extracellular mitochondria modified by O-GlcNAcylation reduces neuronal injury and improves neurologic deficits. In cerebrospinal fluid (CSF) samples from SAH patients, levels of O-GlcNAcylation in extracellular mitochondria correlate with better clinical outcomes.

CONCLUSIONS

These findings suggest that AGE-modification in extracellular mitochondria may induce danger signals, but O-GlcNAcylation can prevent glycation and improve the therapeutic efficacy of transplanted mitochondria in the CNS.

Porous Three-Dimensional Polyurethane Scaffolds Promote Scar-Free Endogenous Regeneration After Acute Brain Hemorrhage

Intracerebral hemorrhage (ICH) is the most lethal subtype of stroke and is associated with significant morbidity and mortality. Despite advances in the clinical treatment of ICH, limited progress has been made regarding endogenous brain regeneration after ICH. Failure of brain regeneration is mainly attributed to the inhibitive regenerative microenvironment caused by secondary injury after ICH. In this study, we investigated a three-dimensional biodegradable waterborne polyurethane (BWPU) scaffold as a tool to promote brain regeneration after ICH. After implantation into the cavity following hematoma evacuation, these implanted scaffolds could act as a reservoir; store a series of necrotic debris, cytokines, and chemokines; and attract microglia/macrophages to their pores. Subsequently, these microglia/macrophages were polarized into the M1-like subtype to eliminate these substances. This process disperses M1-like immune cells and prevents the formation of dense glial scar-free structures after ICH. Inflammatory cells in scaffolds include scar-free secreted growth factors and extracellular matrix (ECM) proteins, and further induce a M2-like immune cells enriched regeneration-predominant microenvironment to promote endogenous brain regeneration with functional recovery. In summary, in this work, we have revealed the potential and mechanism of the BWPU scaffold as a tool to promote endogenous brain tissue regeneration after ICH.

Endothelial TREM-1 receptor regulates the blood-brain barrier integrity after intracerebral hemorrhage in mice via SYK/β-catenin signaling

BACKGROUND

Intracerebral hemorrhage (ICH) is a high mortality and disability stroke subtype. Destruction of the blood-brain barrier (BBB) is a crucial contributor to brain edema and neurological deficit after ICH. Triggering receptor expressed on myeloid cells 1 (TREM-1) has been reported to be expressed in endothelial cells, but its role in ICH remains unclear. This study aims to evaluate the role of TREM-1 on BBB permeability after ICH in mice.

METHODS

Two hundred and forty-two CD1 mice were used in this study. The ICH model was established by collagenase injection. LP17 was administered intranasally at 2 or 8 h after ICH to inhibit TREM-1. To explore the underlying mechanism, SYK activation CRISPR was administered intracerebroventricularly with LP17, and Anti-mouse TREM-1 rat IgG2a (a specific TREM-1 agonist) was injected intracerebroventricularly with R406 (a specific SYK inhibitor) intraperitoneally. Neurobehavioral outcome, brain water content, BBB permeability, and protein expression were evaluated.

RESULTS

The expression level of the TREM-1 receptor increased rapidly as early as 6 h after ICH, and it was mainly expressed on the endotheliocytes in the neurovascular unit. Early and delayed administration of LP17 significantly decreased brain edema and improved neurobehavioral outcomes at 24 h after ICH. LP17 reduced the BBB permeability by increasing β-catenin, claudin-5 and ZO-1 expression. Furthermore, SYK activation CRISPR abolished the beneficial effect of LP17 on the expression of the above junction molecules. Meanwhile, R406 reversed the impact of the TREM-1 activator on the downregulation of β-catenin, claudin-5 and ZO-1 expression.

CONCLUSIONS

This study demonstrated that TREM-1 deteriorated BBB permeability via modulating the expression of interendothelial junction molecules after ICH, and this regulation is partly mediated by the SYK/β-catenin signaling pathway.

Exogenous melatonin enhances the tolerance of tiger nut (Cyperus esculentus L.) via DNA damage repair pathway under heavy metal stress (Cd2+) at the sprout stage

Heavy metal (HM) stress is a non-negligible abiotic stress that seriously restricts crop yield and quality, while the sprout stage is the most sensitive to stress and directly impacts the growth and development of the later stage. Melatonin (N-acetyl-5-methoxytryptamine), as an exogenous additive, enhances stress resistance due to its ability to oxidize and reduce. However, few reports on exogenous melatonin to tiger nuts under HM stress have explored whether exogenous melatonin enhances plants' resistance to heavy metals. Here, "Jisha 2″ was used as material, with a stress concentration of 5 mg/L and 100 μmol/L of CdCl2 to explore whether exogenous melatonin enhances plant resistance and molecular mechanism. The result revealed that stress limits growth, while melatonin alleviated the sprout damage under stress from the phenotypes. Moreover, stress-enhanced reactive oxygen species (ROS) accumulation and membrane lipid peroxidation, while melatonin-increased ROS reduce damage via the analysis of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) and malondialdehyde (MDA) content, hydrogen peroxide (H2O2), superoxide anion (O2-), and Electrolyte leakage (El). Further results indicated that HM leads to DNA damage while exogenous melatonin will repair the damage by analyzing random amplified polymorphic DNA (RAPD), DNA cross-linking, 8-hydroxy-20-deoxyguanine level, and relative density of apurinic sites. Furthermore, gene expression in the DNA-repaired pathway exhibited similar results. These results applied that exogenous melatonin released the hurt caused by HM stress, with DNA repair and ROS balance serving as candidate pathways. This study elucidated the mechanism of melatonin's influence and provided theoretical insights into its application in tiger nuts.

Non-Excitatory Amino Acids, Melatonin, and Free Radicals: Examining the Role in Stroke and Aging

The aim of this review is to explore the relationship between melatonin, free radicals, and non-excitatory amino acids, and their role in stroke and aging. Melatonin has garnered significant attention in recent years due to its diverse physiological functions and potential therapeutic benefits by reducing oxidative stress, inflammation, and apoptosis. Melatonin has been found to mitigate ischemic brain damage caused by stroke. By scavenging free radicals and reducing oxidative damage, melatonin may help slow down the aging process and protect against age-related cognitive decline. Additionally, non-excitatory amino acids have been shown to possess neuroprotective properties, including antioxidant and anti-inflammatory in stroke and aging-related conditions. They can attenuate oxidative stress, modulate calcium homeostasis, and inhibit apoptosis, thereby safeguarding neurons against damage induced by stroke and aging processes. The intracellular accumulation of certain non-excitatory amino acids could promote harmful effects during hypoxia-ischemia episodes and thus, the blockade of the amino acid transporters involved in the process could be an alternative therapeutic strategy to reduce ischemic damage. On the other hand, the accumulation of free radicals, specifically mitochondrial reactive oxygen and nitrogen species, accelerates cellular senescence and contributes to age-related decline. Recent research suggests a complex interplay between melatonin, free radicals, and non-excitatory amino acids in stroke and aging. The neuroprotective actions of melatonin and non-excitatory amino acids converge on multiple pathways, including the regulation of calcium homeostasis, modulation of apoptosis, and reduction of inflammation. These mechanisms collectively contribute to the preservation of neuronal integrity and functions, making them promising targets for therapeutic interventions in stroke and age-related disorders.

Cleavage of semaphorin 4 C interferes with the neuroprotective effect of the semaphorin 4 C/Plexin B2 pathway on experimental intracerebral hemorrhage in rats

Semaphorin 4 C (SEMA4C) and its cognate receptor Plexin B2 are important regulators of axon guidance and are involved in many neurological diseases, in which SEMA4C acts not only as a ligand ("forward" mode) but also as a signaling receptor ("reverse" mode). However, the role of SEMA4C/Plexin B2 in intracerebral hemorrhage (ICH) remains unclear. In this study, ICH in adult male Sprague-Dawley rats was induced by autologous blood injection in the right basal ganglia. In vitro, cultured primary neurons were subjected to OxyHb to imitate ICH injury. Recombinant SEMA4C (rSEMA4C) and overexpressing lentiviruses encoding full-length SEMA4C or secretory SEMA4C (sSEMA4C) were administered to rats by intraventricular injection. First, we found that elevated levels of sSEMA4C in the cerebrospinal fluid (CSF) of clinical patients were associated with poor prognosis. Both SEMA4C and sSEMA4C were increased in brain tissue around the hematoma after ICH in rats. Overexpression of SEMA4C attenuated neuronal apoptosis, neurosis, and neurologic impairment after ICH. However, treatment with rSEMA4C or sSEMA4C overexpression exacerbated neuronal injury. In addition, when treated with SEMA4C overexpression, the forward mode downstream protein RhoA and the reverse mode downstream ID1/3 transcriptional factors of SEMA4C/Plexin B2 signaling were all activated. Nevertheless, when exposed to rSEMA4C or sSEMA4C overexpression, only the forward mode was activated. Thus, sSEMA4C may be a novel molecular biomarker to predict the prognosis of patients with ICH, and the prevention of SEMA4C cleavage is expected to be a promising therapeutic target.

Histone methyltransferase enzyme enhancer of zeste homolog 2 counteracts ischemic brain injury via H3K27me3-mediated regulation of PI3K/AKT/mTOR signaling pathway

BACKGROUND

Epigenetic histone methylation plays a crucial role in cerebral ischemic injury, particularly in the context of ischemic stroke. However, the complete understanding of regulators involved in histone methylation, such as Enhancer of Zeste Homolog 2 (EZH2), along with their functional effects and underlying mechanisms, remains incomplete.

METHODS

Here, we employed a rat model of MCAO (Middle cerebral artery occlusion) and an OGD (Oxygen-Glucose Deprivation) model of primary cortical neurons to study the role of EZH2 and H3K27me3 in cerebral ischemia-reperfusion injury. The infarct volume was measured through TTC staining, while cell apoptosis was detected using TUNEL staining. The mRNA expression levels were quantified through quantitative real-time polymerase chain reaction (qPCR), whereas protein expressions were evaluated via western blotting and immunofluorescence experiments.

RESULTS

The expression levels of EZH2 and H3K27me3 were upregulated in OGD; these expression levels were further enhanced by GSK-J4 but reduced by EPZ-6438 and AKT inhibitor (LY294002) under OGD conditions. Similar trends were observed for mTOR, AKT, and PI3K while contrasting results were noted for UTX and JMJD3. The phosphorylation levels of mTOR, AKT, and PI3K were activated by OGD, further stimulated by GSK-J4, but inhibited by EPZ-6438 and AKT inhibitor. Inhibition of EZH2 or AKT effectively counteracted OGD-/MCAO-induced cell apoptosis. Additionally, inhibition of EZH2 or AKT mitigated MCAO-induced infarct size and neurological deficit in vivo.

CONCLUSIONS

Collectively, our results demonstrate that EZH2 inhibition exerts a protective effect against ischemic brain injury by modulating the H3K27me3/PI3K/AKT/mTOR signaling pathway. The results provide novel insights into potential therapeutic mechanisms for stroke treatment.

Roles of syntaphilin and armadillo repeat-containing X-linked protein 1 in brain injury after experimental intracerebral hemorrhage

Studies have indicated that neuronal mitochondrial injury may be involved in the brain injury caused by intracerebral hemorrhage (ICH). Syntaphilin (SNPH) is associated with mitochondrial anchoring and Armadillo repeat-containing X-linked protein 1 (Armcx1) is linked to mitochondrial transport. This study aimed to analyze the contribution of SNPH and Armcx1 to the neuronal damage resulting from ICH. Primary cultured neuron cells were exposed to oxygenated hemoglobin to replicate the effects of ICH stimulation, while a mouse model of ICH was established by injecting autoblood into the basal ganglia. Specific SNPH knockout or Armcx1 overexpression in neurons is achieved by stereolocalization injection of adeno-associated virus vectors carrying hsyn specific promoters. First, it was confirmed that there is a correlation between SNPH/Armcx1 and ICH pathology, as evidenced by the rise of SNPH and the decrease of Armcx1 in neurons exposed to ICH both in vitro and in vivo. Second, our research revealed the protective effects of SNPH knockdown and Armcx1 overexpression on brain cell death around the hematoma in mice. In addition, the efficacy of SNPH knockdown and Armcx1 overexpression in improving neurobehavioral deficits was also demonstrated in mouse ICH model. Thus, moderate adjusting the levels of SNPH and Armcx1 may be an effective way to improve the outcome of ICH.

Clinical changes of serum melatonin and ICAM-1 levels in patients with basal ganglia hypertensive intracerebral hemorrhage

Objective

To investigate the clinical changes of serum melatonin and intercellular adhesion molecule-1 (ICAM-1) levels in patients with basal ganglia hypertensive intracerebral hemorrhage (HICH).

Methods

In this retrospective observational study, patients with HICH in Suzhou Hospital of Traditional Chinese and Western Medicine from January 2020 to January 2021 were included as the observation group (n=120), and 120 healthy volunteers who underwent physical examination were included as the control group. According to the Glasgow Coma Scale (GCS), the observation group was divided into four subgroups: normal group (n=27), mild group (n=51), moderate group (n=24), and severe group (n=18). Differences in serum melatonin and ICAM-1 were compared between the observation group and the control group, and between the subgroups. Logistic regression was used to analyze the risk factors of poor prognosis, and the ROC curve was used to analyze the influence of melatonin and ICAM-1 levels on patient prognosis.

Results

Serum melatonin levels were lower in the observation group compared to the control group, while ICAM-1 levels were higher (P<0.05). With the aggravation of brain injury, serum melatonin decreased and ICAM increased (P<0.05). Decreased serum melatonin and increased ICAM-1 were independent risk factors for poor prognosis in patients with HICH. The combined AUC of serum melatonin and ICAM-1 for the detection of poor prognosis in patients with HICH was 0.860, which was higher than that of the two alone (P<0.05).

Conclusions

Low serum melatonin levels and high ICAM-1 levels are associated with poor prognosis in patients with HICH and can be used as predictors of patients' prognosis.

Annao Pingchong decoction alleviate the neurological impairment by attenuating neuroinflammation and apoptosis in intracerebral hemorrhage rats

ETHNOPHARMACOLOGICAL RELEVANCE

Intracerebral hemorrhage (ICH) is a central nervous system disease that causes severe disability or death. Even though Annao Pingchong decoction (ANPCD), a traditional Chinese decoction, has been used clinically to treat ICH in China, its molecular mechanism remains unclear.

AIM OF THE STUDY

To study whether the neuroprotective effect of ANPCD on ICH rats is achieved by alleviating neuroinflammation. This paper mainly explored whether inflammation-related signaling pathways (HMGB1/TLR4/NF-κB P65) plays a role in ANPCD treatment of ICH rats.

MATERIALS AND METHODS

Liquid chromatography-tandem mass spectrometry was used to analyze the chemical composition of ANPCD. ICH models were established by injecting autologous whole blood into the left caudate nucleus of Sprague-Dawley (SD) rats. Modified neurological severity scoring (mNSS) was used to assess the neurological deficits. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were analyzed using enzyme-linked immunosorbent assay (ELISA). Pathological changes in the rat brains were observed using hematoxylin-eosin, Nissl, and TUNEL staining. The protein levels of HMGB1, TLR4, NF-κB p65, B-cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax) were measured by western blotting and immunofluorescence analysis.

RESULTS

Ninety-three ANPCD compounds were identified, including 48 active plasma components. Treatment with ANPCD effectively improved the outcome, as observed by the neurological function scores analysis and brain histopathology. Our results showed that ANPCD exerts its anti-inflammatory effects by significantly downregulating the expression of HMGB1, TLR4, NF-κB p65, TNF-α, IL-1β, and IL-6. ANPCD also exerted anti-apoptotic effects by significantly decreasing the apoptosis rate and Bax/Bcl-2 ratio.

CONCLUSION

We found that ANPCD had neuroprotective effect in clinical work. Here, we also found that the action mechanism of ANPCD might be related to attenuate neuroinflammation and apoptosis. These effects were achieved by inhibiting the expression of HMGB1, TLR4 and NF-κB p65.

Role of Melatonin in Bovine Reproductive Biotechnology

Melatonin has profound antioxidant activity and numerous functions in humans as well as in livestock and poultry. Additionally, melatonin plays an important role in regulating the biological rhythms of animals. Combining melatonin with scientific breeding management has considerable potential for optimizing animal physiological functions, but this idea still faces significant challenges. In this review, we summarized the beneficial effects of melatonin supplementation on physiology and reproductive processes in cattle, including granulosa cells, oocytes, circadian rhythm, stress, inflammation, testicular function, spermatogenesis, and semen cryopreservation. There is much emerging evidence that melatonin can profoundly affect cattle. In the future, we hope that melatonin can not only be applied to cattle, but can also be used to safely and effectively improve the efficiency of animal husbandry.

The impact of sleep quality and its change on the long-term risk of stroke in middle-aged and elderly people: Findings from the English Longitudinal Study of Ageing

OBJECTIVE

This study focused on middle-aged and elderly adults (mean age ≥60 years) in England and aimed to evaluate the impact of sleep quality and change in sleep quality on the long-term risk of stroke.

PATIENTS/METHODS

The current prospective study enrolled 6214 participants without stroke from wave 4 (2008-2009) of the English Longitudinal Study Aging (ELSA) dataset. From the ELSA questionnaires, sleep quality scores were calculated and used to evaluate the sleep quality of each participant. Cox proportional hazards regression models were used to assess the association between sleep status and stroke risk. Restricted cubic spline (RCS) was employed for the relationship between sleep quality score and the risk of stroke.

RESULTS

During the 8-year follow-up, 130 (2.1%) cases of stroke were recorded. Participants with poor baseline sleep quality had a significantly higher long-term risk of stroke compared with those with good sleep quality (hazard ratio [HR] 2.37, 95% confidence intervals [CI] 1.44, 3.91). For the influence of change in sleep quality on stroke risk, worsened sleep quality was associated with a significant increase in the risk of stroke in the good (HR 2.08, 95% CI, 1.02, 4.26) and intermediate sleep quality groups (HR 2.15, 95% CI, 1.16, 3.98). Moreover, improved sleep quality decreased stroke risk among subjects with poor sleep quality (HR 0.31, 95% CI, 0.15, 0.61).

CONCLUSIONS

Poor and worsened sleep quality is associated with an increased risk of stroke. Emphasis should be placed on improving sleep quality in middle-aged and elderly individuals.

Melatonin-Driven NLRP3 Inflammation Inhibition Via Regulation of NF-κB Nucleocytoplasmic Transport: Implications for Postoperative Cognitive Dysfunction

The aseptic inflammatory response of the central nervous system is one of the important causes of neurodegenerative diseases in individuals and is also recognized in postoperative cognitive dysfunction (POCD). Inflammasome is thought to be closely related to brain homeostasis. However, there are few drugs targeting the inflammasome to suppress inflammation in clinical practice. Here, we showed that the neuroinflammatory response mediated by the NLRP3 (NLR family, pyrin domain containing 3) inflammasome was involved in the pathological process of POCD. Melatonin protected mice from nerve damage by inhibiting activation of the NLRP3-caspase-1-interleukin 1 beta (IL-β) pathway and thus reduced the secretion of IL-1β inflammatory factors in microglia. Further research found that melatonin has a potential binding effect with NLRP3 protein, and at the same time could reduce the phosphorylation of nuclear factor kappa-B (NF-κB) and inhibit its nuclear translocation. The underlying mechanism was that melatonin inhibited the expression of acetylation of histone H3 and melatonin attenuated the binding of NF-κb to the NLRP3 promoter region 1-200 bp, where there are two potential binding target sites of NF-κb and NLRP3, namely the sequences 5'-GGGAACCCCC-3' and 5'-GGAAATCCA -3'. Therefore, we confirmed a novel mechanism of action of melatonin in the prevention and treatment of POCD.

Traumatic Brain Injury, Sleep, and Melatonin-Intrinsic Changes with Therapeutic Potential

Traumatic brain injury (TBI) is one of the most prevalent causes of morbidity in the United States and is associated with numerous chronic sequelae long after the point of injury. One of the most common long-term complaints in patients with TBI is sleep dysfunction. It is reported that alterations in melatonin follow TBI and may be linked with various sleep and circadian disorders directly (via cellular signaling) or indirectly (via free radicals and inflammatory signaling). Work over the past two decades has contributed to our understanding of the role of melatonin as a sleep regulator and neuroprotective anti-inflammatory agent. Although there is increasing interest in the treatment of insomnia following TBI, a lack of standardization and rigor in melatonin research has left behind a trail of non-generalizable data and ambiguous treatment recommendations. This narrative review describes the underlying biochemical properties of melatonin as they are relevant to TBI. We also discuss potential benefits and a path forward regarding the therapeutic management of TBI with melatonin treatment, including its role as a neuroprotectant, a somnogen, and a modulator of the circadian rhythm.

Involvement of endoplasmic reticulum stress in trigeminal ganglion corneal neuron injury in dry eye disease

Dry eye disease (DED) is a multifactorial disease with a high prevalence worldwide. Uncomfortable corneal sensations severely affect daily life in DED patients. Hence, corneal neuron injury is a vital pathogenesis in DED. Notably, endoplasmic reticulum stress (ERS) plays a role in peripheral neuron injury. However, the role of ERS in DED corneal neuron injury is still far from being clear. In this study, we established an environmental DED (eDED) model in vivo and a hyperosmotic DED model in vitro. Subsequently, trigeminal ganglion (TG) corneal neurons were retrograde labeled by WGA-Alexa Fluor 555, and fluorescence-activated cell sorting was used to collect targeted corneal neurons for RNA sequencing in mice. Our results revealed that TG corneal neuron injury but not apoptosis in DED. ERS-related genes and proteins were upregulated in TG corneal neurons of the eDED mice. ERS inhibition alleviated TG corneal neuron's ERS-related injury. Therefore, ERS-induced TG corneal neuron injury may be an important pathomechanism and provide a promising therapeutic approach to DED.

Honokiol attenuates mitochondrial fission and cell apoptosis by activating Sirt3 in intracerebral hemorrhage

BACKGROUND

Sirtuin-3 (Sirt3) has been documented to protect against mitochondrial dysfunction and apoptosis. Honokiol (HKL) is a Sirt3 pharmacological activator with reported neuroprotective effects in multiple neurological disorders. The present study aimed to explore the neuroprotective effects of HKL and the role of Sirt3 following intracerebral hemorrhage (ICH).

METHODS

An in vivo ICH model in rats was established by injecting autologous blood into the right basal ganglia. PC12 cells were stimulated with hemin. For the in vivo investigation, the modified Neurological Severity Scores and the Morris water maze test were performed to assess neurological deficits. Hematoxylin-Eosin and Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining were employed to evaluate the histopathology and apoptosis. Immunohistochemical staining was used to investigate the expression of Sirt3. Adenosine triphosphate (ATP) levels were quantified to assess mitochondrial dysfunction. Cell counting kit-8, lactate dehydrogenase assay, and flow cytometry were used to analyze cell vitality and apoptosis in vitro. Immunofluorescence staining was performed to observe mitochondrial morphology and dynamin-related protein 1 (Drp1) localization to mitochondria. Western blot was applied to quantify the expression of Sirt3, Bax, Bcl-2, cleaved-caspase-3, Drp1, phosphorylation of Drp1 at serine-616, and phosphorylation of Drp1 at serine-637 in vivo and in vitro.

RESULTS

HKL treatment alleviated neurological deficits, attenuated the histopathological damage and cell apoptosis, and restored the decreased ATP levels in ICH rats. HKL improved cell survival rate, reduced cell apoptosis, and inhibited mitochondrial fission in PC12 cells. Moreover, both in vivo and in vitro models showed increased phosphorylation of Drp1 at Ser616, and reduced phosphorylation of Drp1 at Ser637. Meanwhile, immunofluorescence co-localization analysis revealed that hemin increased the overlap of Drp1 and mitochondria in PC12 cells. The phosphorylation and mitochondrial translocation of Drp1 were effectively reversed by HKL treatment. Importantly, the selective Sirt3 inhibitor 3-(1H-1,2,3-triazol-4-yl) pyridine suppressed these effects.

CONCLUSION

Our findings demonstrated that HKL ameliorated ICH-induced apoptosis and mitochondrial fission by Sirt3, suggesting that HKL has immense prospects for the treatment of ICH.

Mitochondrial Inhibitor Rotenone Triggers and Enhances Neuronal Ferroptosis Following Intracerebral Hemorrhage

Ferroptosis, a form of regulatory non-apoptotic cell death driven by iron-dependent lipid peroxidation, accounts for more than 80% of the total types of neuronal death in the acute phase of intracerebral hemorrhage (ICH). Mitochondria have essential roles in energy production, macromolecule synthesis, cellular metabolism, and cell death regulation. However, its role in ferroptosis remains unclear and somewhat controversial, especially in ICH. This study aimed to investigate whether damaged mitochondria could trigger and enhance neuronal ferroptosis in ICH. The isobaric tag for relative and absolute quantitation proteomics on human ICH samples suggested that ICH caused significant damage to the mitochondria, which presented ferroptosis-like morphology under electron microscopy. Subsequently, use of the mitochondrial special inhibitor Rotenone (Rot) to induce mitochondrial damage showed that it has significant dose-dependent toxicity on primary neurons. Single Rot administration markedly inhibited neuronal viability, promoted iron accumulation, increased malondialdehyde (MDA) contents, decreased total superoxide dismutase (SOD) activity, and downregulated ferroptosis-related proteins RPL8, COX-2, xCT, ASCL4, and GPX4 in primary neurons. Moreover, Rot enhanced these changes via hemin and autologous blood administration in primary neurons and mice, mimicking the in vitro and in vivo ICH models, respectively. Furthermore, Rot exacerbated the ICH-induced hemorrhagic volumes, brain edema, and neurological deficits in mice. Together, our data revealed that ICH induced significant mitochondrial dysfunction and that mitochondrial inhibitor Rot can trigger and enhance neuronal ferroptosis.