Acute Alcohol Intoxication Aggravates Brain Injury Caused by Intracerebral Hemorrhage in Rats

Mitigating mitochondrial dysfunction and neuroinflammation by hematoma aspiration in a new surgical model for severe intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is associated with a large hematoma that causes compression, increased intracranial pressure (IICP), midline shift, and brain herniation, and may ultimately lead to death. Urgent surgical removal of the large hematoma can ameliorate these injuries, which would be life-saving, but has not improved clinical outcome. A suitable animal model that mimics the clinically relevant human severe ICH injury requiring surgical hematoma evacuation is urgently needed. Here, we established a novel model of severe ICH in rats allowing aspiration of the hematoma and studying the effects of mitochondrial dysfunction in ICH.

METHODS

Severe ICH was induced by intra-striatal injection of 0.6 U of collagenase in 3 μL sterile saline over 15 min. Aspiration of approximately 75 % of the total hematoma was performed 6 h after induction of severe ICH. The effects of hematoma aspiration on hematoma volume, mortality, oxidative stress, ATP levels, mitochondrial dysfunction, and neurological function were measured in rats.

RESULTS

Severe ICH induction increased hematoma volume, neurological deficits, and mortality. Hematoma aspiration abolished mortality and significantly reduced hematoma volume, and neurological deficits. In addition, hematoma aspiration ameliorated the pronounced mitochondrial dysfunction responsible for the failure of energy production and excessive oxidative stress associated with severe hemorrhagic injury. Hematoma aspiration also modulated mitochondrial biogenesis and mitophagy, thereby promoting mitochondrial homeostasis. Markers of neuroinflammation, including iNOS, MMP9, and MPO, were elevated in severe ICH but attenuated by hematoma aspiration.

CONCLUSION

This study established an animal model of severe ICH and provides valuable insights into the complex pathogenesis of severe ICH. The results showed that hematoma aspiration effectively ameliorates mitochondrial dysfunction, oxidative stress, and neuroinflammation, highlighting its potential as a therapeutic intervention.

Therapeutic Potential of TUBB6 Inhibition for Hematoma Reduction, Microtubule Stabilization, and Neurological Recovery in an In Vivo Model of Intracerebral Hemorrhage

This in vivo study explored the impact of TUBB6 inhibition in intracerebral hemorrhage (ICH), focusing on its effects on hematoma volume, microtubule stability, inflammation, neuronal preservation, and sensorimotor recovery. Sprague-Dawley rats was used to induce ICH by collagenase injection into the right striatum, followed by administration of TUBB6 antisense oligonucleotide (ASO) or Control ASO directly into the hematoma site 3 h post-ICH. Outcomes measured included hematoma volume, microtubule stability (acetylated α-tubulin), levels of inflammatory cytokines, mitogen-activated protein kinase (MAPK) pathway activity, neuronal degeneration (Fluoro-Jade C staining), and cell integrity (Cresyl Violet staining). Functional recovery was assessed using neurological severity scores (mNSS), corner turn, forelimb-placing, and rotarod tests, with body weight tracked for up to 28 days. TUBB6 expression increased with the severity of hemorrhage in the ICH models. TUBB6 ASO significantly reduced hematoma volume at 24- and 72-h post-ICH, restored acetylated α-tubulin levels, suppressed MAPK signaling pathway, and decreased pro-inflammatory markers with increased IL-10. TUBB6 ASO also reduced neuronal degeneration and improved cell viability. In terms of functional outcomes, the TUBB6 ASO + ICH group exhibited reduced mNSS scores, improved body weight maintenance, and better performance on corner turn, forelimb-placing and rotarod tests compared to the Control ASO + ICH group. TUBB6 ASO treatment demonstrated therapeutic potential in a rat model of ICH by reducing hematoma volume, stabilizing microtubules, modulating the MAPK signaling pathway, and mitigating inflammation. It also preserved neuronal integrity and enhanced sensorimotor recovery, suggesting its effectiveness as a therapeutic approach to improve ICH outcomes.

Intracerebral hemorrhage complicated by alcohol use disorder in young males in Chongqing China: Characteristics and long-term outcome

BACKGROUND

The characteristics of patients with intracerebral hemorrhage (ICH) complicated by alcohol use disorders (AUD) are not well understood. Investigating the clinical characteristics and prognosis of this subgroup (AUD-ICH) is necessary.

METHODS

This study involved young males with ICH who were admitted to our hospital between January 2013 and March 2022. Based on drinking patterns, the included cases were divided into three groups: AUD, occasional drinking, and non-drinking. We compared the clinical characteristics and prognosis of patients in the three groups. The effect of AUD on hematoma expansion and long-term dysfunction was explored by developing regression models. The potential mediating role of hematoma density heterogeneity within the relationship between AUD and hematoma expansion was examined through mediation analysis.

RESULTS

This study included 222 cases of male patients with ICH, with a mean age of 54.16. AUD patients had a higher risk of hematoma expansion and dysfunction compared to occasional drinkers (odds ratio [OR] 2.966, p=0.028 for hematoma expansion; hazard ratio [HR] 2.620, p=0.006 for dysfunction) and non-drinkers (OR 3.505, p=0.011 for hematoma expansion; HR 2.795, P=0.003 for dysfunction). The mediation analysis showed that the indirect effect through hematoma density heterogeneity on the relationship between AUD and hematoma expansion was significant, with a mediated proportion of 19.3%.

CONCLUSIONS

AUD was an independent risk factor for hematoma expansion and long-term dysfunction in young male patients with ICH. Hematoma density heterogeneity partially mediated the relationship between AUD and hematoma expansion.

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 influence of physiological and pathological perturbations on blood-brain barrier function

The blood-brain barrier (BBB) is located at the interface between the vascular system and the brain parenchyma, and is responsible for communication with systemic circulation and peripheral tissues. During life, the BBB can be subjected to a wide range of perturbations or stresses that may be endogenous or exogenous, pathological or therapeutic, or intended or unintended. The risk factors for many diseases of the brain are multifactorial and involve perturbations that may occur simultaneously (e.g., two-hit model for Alzheimer's disease) and result in different outcomes. Therefore, it is important to understand the influence of individual perturbations on BBB function in isolation. Here we review the effects of eight perturbations: mechanical forces, temperature, electromagnetic radiation, hypoxia, endogenous factors, exogenous factors, chemical factors, and pathogens. While some perturbations may result in acute or chronic BBB disruption, many are also exploited for diagnostic or therapeutic purposes. The resultant outcome on BBB function depends on the dose (or magnitude) and duration of the perturbation. Homeostasis may be restored by self-repair, for example, via processes such as proliferation of affected cells or angiogenesis to create new vasculature. Transient or sustained BBB dysfunction may result in acute or pathological symptoms, for example, microhemorrhages or hypoperfusion. In more extreme cases, perturbations may lead to cytotoxicity and cell death, for example, through exposure to cytotoxic plaques.

Alcohol, inflammation, and blood-brain barrier function in health and disease across development

Alcohol is the most commonly used drug of abuse in the world and binge drinking is especially harmful to the brain, though the mechanisms by which alcohol compromises overall brain health remain somewhat elusive. A number of brain diseases and pathological states are accompanied by perturbations in Blood-Brain Barrier (BBB) function, ultimately exacerbating disease progression. The BBB is critical for coordinating activity between the peripheral immune system and the brain. Importantly, BBB integrity is responsive to circulating cytokines and other immune-related signaling molecules, which are powerfully modulated by alcohol exposure. This review will highlight key cellular components of the BBB; discuss mechanisms by which permeability is achieved; offer insight into methodological approaches for assessing BBB integrity; and forecast how alcohol-induced changes in the peripheral and central immune systems might influence BBB function in individuals with a history of binge drinking and ultimately Alcohol Use Disorders (AUD).

Intra-arterial Contrast-enhanced Micro-computed Tomography Can Evaluate Intracranial Status in the Ultra-early Phase of Experimental Subarachnoid Hemorrhage in Rats

The endovascular perforation (EP) model is a common technique for experimental subarachnoid hemorrhage (SAH) in rats, simulating the pathophysiological features observed in the acute phase of SAH. Due to the drawbacks of large variations in the amount of bleeding, the results obtained from this model require severity evaluation. However, no less-invasive procedure could confirm the precise intracranial conditions immediately after establishing the rat EP model. We created a novel method for evaluating SAH immediately after establishing the rat EP model using intra-arterial contrast-enhanced micro-computed tomography (CT). We administered contrast agents continuously via the carotid artery during surgery and performed CT examination immediately after SAH induction. First, bleeding severity was classified by establishing a scoring system based on the CT findings (cSAH scoring system). Subsequently, we determined the actual SAH distribution macroscopically and histologically and compared it with the cSAH scores. Second, we investigated the contrast agent’s neurotoxicity in rats. Finally, we confirmed the correlation between cSAH scores and SAH severity, including neurological status, cerebral vasospasm, and hematoma volume 24 hr after SAH. Intra-arterial contrast-enhanced micro-CT could visualize the distribution of SAH proportionally to the bleeding severity immediately after establishing the EP model. Moreover, the contrast agent administration was determined not to be neurotoxic to rats. The cSAH scoring revealed a significant correlation with the SAH severity in the rat EP model (P <0.01). Thus, our minimally invasive method provided precise information on intracranial status in the ultra-early phase of SAH in rats EP model.

Moderate Ethanol Pre-treatment Mitigates ICH-Induced Injury via ER Stress Modulation in Rats

Intracerebral hemorrhage (ICH) is a life-threatening type of stroke that disrupts the normal neurological function of the brain. Clinical studies have reported a non-linear J-shaped association between alcohol consumption levels and the occurrence of cerebral stroke. Specifically, alcohol intoxication increases stroke incidence, while moderate alcohol pre-conditioning decreases stroke frequency and improves outcomes. Although alcohol pre-consumption is likely a crucial player in ICH, the underlying mechanism remains unclear. We performed 1-h alcohol pre-conditioning followed by ICH induction in Sprague-Dawley (SD) rats to investigate the role of alcohol pre-conditioning in ICH. Interestingly, behavioral test analysis found that ethanol intoxication (3 g/kg) aggravated ICH-induced neurological deficits, but moderate ethanol pre-conditioning (0.75 g/kg) ameliorated ICH-induced neurological deficits by reducing the oxidative stress and proinflammatory cytokines release. Moreover, we found that moderate ethanol pretreatment improved the striatal endoplasmic reticulum (ER) homeostasis by increasing the chaperone protein expression and reducing oxidative stress and apoptosis caused by ICH. Our findings show that the mechanism regulated by moderate ethanol pre-conditioning might be beneficial for ICH, indicating the importance of ER homeostasis, oxidative stress, and differential cytokines release in ICH.

A Multi-Model Pipeline for Translational Intracerebral Haemorrhage Research

Apart from acute and chronic blood pressure lowering, we have no specific medications to prevent intracerebral haemorrhage (ICH) or improve outcomes once bleeding has occurred. One reason for this may be related to particular limitations associated with the current pre-clinical models of ICH, leading to a failure to translate into the clinic. It would seem that a breakdown in the 'drug development pipeline' currently exists for translational ICH research which needs to be urgently addressed. Here, we review the most commonly used pre-clinical models of ICH and discuss their advantages and disadvantages in the context of translational studies. We propose that to increase our chances of successfully identifying new therapeutics for ICH, a bi-directional, 2- or 3-pronged approach using more than one model species/system could be useful for confirming key pre-clinical observations. Furthermore, we highlight that post-mortem/ex-vivo ICH patient material is a precious and underused resource which could play an essential role in the verification of experimental results prior to consideration for further clinical investigation. Embracing multidisciplinary collaboration between pre-clinical and clinical ICH research groups will be essential to ensure the success of this type of approach in the future.

Exploring blood-brain barrier hyperpermeability and potential biomarkers in traumatic brain injury

Blood-brain barrier breakdown and associated vascular hyperpermeability leads to vasogenic edema in traumatic brain injury (TBI). Tight junctions maintain blood-brain barrier integrity; their disruption in TBI holds significant promise for diagnosis and treatment. A controlled cortical impactor was used for TBI in mouse studies. Blood was collected 1 h after injury and sent for antibody microarray analysis. Twenty human subjects with radiographic evidence of TBI were enrolled and blood collected within 48 h of admission. Control subjects were individuals with nontrauma diagnoses. The subjects were matched by age and gender. Enzyme-linked immunosorbent assays were performed on each TBI and control sample for tight junction-associated proteins (TJPs), inflammatory markers, and S100β. Plasma was used to conduct in vitro monolayer permeability studies with human brain endothelial cells. S100β and the TJP occludin were significantly elevated in TBI plasma in both the murine and human studies. Monolayer permeability studies showed increased hyperpermeability in TBI groups. Plasma from TBI subjects increases microvascular hyperpermeability in vitro. TJPs in the blood may be a potential biomarker for TBI.

The Role of Urocortins in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) causes an accumulation of blood in the brain parenchyma that disrupts the normal neurological function of the brain. Despite extensive clinical trials, no medical or surgical therapy has shown to be effective in managing ICH, resulting in a poor prognosis for the patients. Urocortin (UCN) is a 40-amino-acid endogenous neuropeptide that belongs to the corticotropin-releasing hormone (CRH) family. The effect of UCN is activated by binding to two G-protein coupled receptors, CRH-R1 and CRH-R2, which are expressed in brain neurons and glial cells in various brain regions. Current research has shown that UCN exerts neuroprotective effects in ICH models via anti-inflammatory effects, which generally reduced brain edema and reduced blood-brain barrier disruption. These effects gradually help in the improvement of the neurological outcome, and thus, UCN may be a potential therapeutic target in the treatment of ICH. This review summarizes the data published to date on the role of UCN in ICH and the possible protective mechanisms underlined.

Cerebral Hemorrhage and Alcohol Exposure: A Review

Aims

To investigate the dose–response relationships between alcohol and intracerebral hemorrhage (ICH), the impact of alcohol on the outcome of ICH and possible mechanisms underlying hypertensive ICH (HICH) caused by heavy drinking.

Methods

Literature search from 1985 to August 2019 in the PubMed database.

Results

The relationship between low-middle alcohol consumption and ICH remains controversial for various reasons, whereas chronic heavy drinking increases the incidence of ICH and exerts worse outcome. More attention is needed to clarify the characteristics of chronic alcohol intake and binge drinking. Chronic alcohol abuse tends to elevates blood pressure, resulting in increased occurrence of HICH and exaggerated HICH-contributed brain injury.

Conclusion

It is important to develop strategies to promote reasonable intake categories, prevent alcoholism and thus reduce the risk of ICH.

Astragaloside IV Protects Ethanol-Induced Gastric Mucosal Injury by Preventing Mitochondrial Oxidative Stress and the Activation of Mitochondrial Pathway Apoptosis in Rats

Alcohol consumption affects gastric mucosa by multiple and complex mechanisms depending either by direct contact of ethanol or by indirect biological damage induced by its metabolite acetaldehyde. The present study aims at further investigating the mechanism of ethanol-induced gastric mucosa injury and the protective effect of astragaloside IV (AS-IV) in an aspect of mitochondrial oxidative stress and mitochondrial pathway of apoptosis. Using an array of experimental approaches, we have shown that the development of mitochondrial oxidative stress and associated apoptosis play crucial roles in the pathogenesis of gastric injury induced by ethanol. AS-IV inhibits mitochondrial oxidative stress by scavenging accumulation of malondialdehyde and decreasing the consumption of glutathione. AS-IV also prevents ethanol-induced apoptosis by modulating the activity of caspase-3 and caspase-9, the expression of Bax/Bcl-2, and the release of cytochrome C and apoptosis inducing factor. Moreover, AS-IV reduces ethanol-mediated activation of caspase-8 and breakage of Bid. This study thus indicates that AS-IV prevented ethanol-induced gastric damage by blocking activation of mitochondrial oxidative stress and mitochondrial pathway of apoptosis induced by ethanol in the gastric mucosa.

Neuroimaging in alcohol use disorder: From mouse to man

This article provides an overview of recent advances in understanding the effects of alcohol use disorders (AUD) on the brain from the perspective of magnetic resonance imaging (MRI) research in preclinical models and clinical studies. As a noninvasive investigational tool permitting assessment of morphological, metabolic, and hemodynamic changes over time, MRI offers insight into the dynamic course of alcoholism beginning with initial exposure through periods of binge drinking and escalation, sobriety, and relapse and has been useful in differential diagnosis of neurological diseases associated with AUD. Structural MRI has revealed acute and chronic effects of alcohol on both white and gray matter volumes. MR Spectroscopy, able to quantify brain metabolites in vivo, has shed light on biochemical alterations associated with alcoholism. Diffusion tensor imaging permits microstructural characterization of white matter fiber tracts. Functional MRI has allowed for elucidation of hemodynamic responses at rest and during task engagement. Positron emission tomography, a non-MRI imaging tool, has led to a deeper understanding of alcohol-induced receptor and neurotransmitter changes during various stages of drinking and abstinence. Together, such in vivo imaging tools have expanded our understanding of the dynamic course of alcoholism including evidence for regional specificity of the effects of AUD, hints at mechanisms underlying the shift from casual to compulsive use of alcohol, and profound recovery with sustained abstinence.

Brain Magnetic Resonance Imaging of Intracerebral Hemorrhagic Rats after Alcohol Consumption

BACKGROUND

Alcoholism is one of the risk factors for cerebrovascular diseases. Our previous study demonstrated that acute alcohol intoxication enhances brain injury and neurological impairment in rats suffering from intracerebral hemorrhage (ICH). We plan to investigate the effect of chronic alcohol consumption (CAC) in rats with ICH by magnetic resonance imaging (MRI).

METHODS

Sixteen Sprague-Dawley male rats were divided into 2 groups: CAC group (fed with 10% alcohol drinking water for 4 weeks, n = 8), and Control group (plain drinking water, n = 8). ICH was induced by collagenase infusion into the right striata of all rats. Coronal T1-weighted imaging, T2-weighted imaging, T2*-weighted imaging, and diffusion-weighted imaging were generated with a 3.0T MRI scanner to investigate the changes of hemorrhagic volume and edema throughout the injury and recovery stages of ICH in rats.

RESULTS

T2-weighted imaging is ideal for monitoring hematoma volume in rats. The hematoma volume was larger in the CAC group than in the control group (P < .001), however, did not correlate to post-ICH progressive edema formation (P > .7), and neurological impairment (P > .28) between the 2 groups, respectively.

DISCUSSION

Although our findings indicate that CAC induces larger hematoma in rats with ICH, the underlying mechanism should be studied in the future.

Delayed formation of hematomas with ethanol preconditioning in experimental intracerebral hemorrhage rats

OBJECTIVE

Spontaneous intracerebral hemorrhage (ICH) accounts for 10%-15% of all strokes and causes high mortality and morbidity. In the previous study, we demonstrated that ethanol could aggravate the severity of brain injury after ICH by increasing neuroinflammation and oxidative stress. In this study, we further investigate the acute effects of ethanol on brain injury within 24 h after ICH.

MATERIALS AND METHODS

Totally, 66 male Sprague-Dawley rats were assigned randomly into two groups: saline pretreatment before ICH (saline + ICH), and ethanol pretreatment before ICH (ethanol + ICH). Normal saline (10 mL/kg) or ethanol (3 g/kg, in 10 mL/kg normal saline) was administered intraperitoneally 1 h before induction of experimental ICH. Bacterial collagenase VII-S (0.23 U in 1.0 μL sterile saline) was injected into the right striatum to induce ICH in the rats. We evaluated the hematoma expansion, hemodynamic parameters (heart rate and blood pressure), activated partial thromboplastin time (aPTT), prothrombin time (PT), and striatal matrix metallopeptidase 9 (MMP-9) expressions at 3, 6, 9, and 24 h after ICH.

RESULTS

The ethanol + ICH group exhibited decreased hematoma at 3 h after ICH; nevertheless, there was a larger hematoma compared with the saline + ICH group at 9 and 24 h after ICH. The ethanol + ICH group had lower blood pressure at 3, 6, and 9 h post-ICH, but both groups maintained similar heart rates after ICH. There was no significant difference in the aPTT and PT between the two groups. Incremental ethanol concentrations had no influence on collagenase VII-S activity at 120 min in vitro. MMP-9 expression was upregulated in the right striata of the ethanol + ICH group, especially at 3 and 9 h after ICH.

CONCLUSION

Ethanol delayed hematoma formation in the first 3 h due to a hypotensive effect; however, the accelerated growth of hematomas after 9 h may be a sequela of ethanol-induced MMP-9 activation.

Ethanol downregulates N-acyl phosphatidylethanolamine-phospholipase D expression in BV2 microglial cells via epigenetic mechanisms

Excessive ethanol drinking has deleterious effects on the brain. However, the effects of alcohol on microglia, the main mediator of the brain's innate immune response remain poorly understood. On the other hand, the endocannabinoid system plays a fundamental role in regulating microglial reactivity and function. Here we studied the effects of acute ethanol exposure to murine BV2 microglial cells on N-acyl phosphatidylethanolamine-phospholipase D (NAPE-PLD), a major synthesizing enzyme of anandamide and other N-acylethanolamines. We found that ethanol downregulated microglial NAPE-PLD expression by activating cAMP/PKA and ERK1/2. These signaling pathways converged on increased phosphorylation of CREB. Moreover, ethanol induced and increase in histone acetyltransferase activity which led to higher levels of acetylation of histone H3. Taken together, our results suggest that ethanol actions on microglial NAPE-PLD expression might involve epigenetic mechanisms.