Hepatic Encephalopathy: From Metabolic to Neurodegenerative

Oedematic-atrophic astrocytes in hepatic encephalopathy

Hepatic encephalopathy (HE) following acute liver failure (ALF) is considered as a primary toxic astrocytopathy, but in-depth characterisation of astrocytic contribution to the pathogenesis of this disease is far from complete. Using transmission electron microscopy, confocal fluorescent microscopy, and 3D reconstruction, we found complex morphological alterations of cortical astrocytes in mice with azoxymethane-induced ALF and post-mortem cortical tissue of patients at grade IV of HE. In both mice and post-mortem human tissues astrocytic primary branches demonstrated the territory occupied by astrocytes was increased, confirming astrocytic oedema. Astrocytic primary branches demonstrated swelling, while terminal leaflets showed atrophy quantified by the reduced area occupied by astrocytes, decreased number and the length of leaflets, decreased leaflets volume fraction, and altered astrocyte-to-neurone landscape. In mice these morphological changes develop in parallel with decreased expression of proteins critical for astrocytic modelling and function: the water channel aquaporin 4 (AQP4), the phosphorylated leaflet-associated ezrin, and the actin dynamics regulator, profilin 1 (PFN1). Pathological changes in astrocytes develop in parallel, and are likely causally linked to, the HE-linked neurological decline, manifested by a reduction in EEG power and by excessive glutamate in the brain microdialysates. We propose that HE evokes disease-specific remodelling of astrocytes to a "mixed", oedematic/atrophic phenotype. Concurrence of HE-specific phenotype with alterations in the expression of astrocytic proteins are a likely cause of aberrant astrocyte synaptic support resulting in severe, often fatal brain malfunction in HE.

Association between catheter ablation and psychiatric disorder risk in adults with atrial fibrillation: a multi-institutional retrospective cohort study

Background

Given that atrial fibrillation (AF) s associated with a high risk of psychiatric disorders, understanding the potential benefits of catheter ablation is clinically significant. This study was conducted to examine whether catheter ablation can prevent psychiatric disorders in patients with AF.

Methods

A retrospective cohort study was conducted over two years using data from the TriNetX electronic health record network. The study included adults diagnosed with AF and treated with either antiarrhythmic or rate-control medications. Participants were divided into two groups: those who underwent catheter ablation and a control group without ablation. The primary outcome measured was a composite of anxiety, depression, and insomnia occurrence within one to three years post-treatment. Secondary outcomes included individual psychiatric disorders, suicidal ideation or attempts, dementia, cerebral infarction, and atopic dermatitis (as a negative control).

Results

We included 21,019 patients in each matched group. The ablation group demonstrated a lower risk of the primary combined outcome (hazard ratio(HR):0.873, 95% confidence interval (CI) 0.784-0.973, p<0.01), and secondary outcomes including anxiety (HR:0.822, 95% CI:0.700-0.964; p=0.016), depression (HR:0.614, 95% CI:0.508-0.743; p<0.001), suicidal ideation or attempts (HR:0.392, 95% CI:0.165-0.934; p=0.028), dementia (HR:0.569, 95% CI:0.422-0.767; p<0.001), and cerebral infarction (HR:0.704, 95% CI:0.622-0.797; p<0.001) compared to the non-ablation group.

Conclusions

In patients with atrial fibrillation, catheter ablation was associated with a reduced risk of developing psychiatric disorders, including anxiety, depression, insomnia, suicidal ideation or attempt, and dementia, in comparison to those who did not undergo ablation. Clinicians should consider incorporating psychiatric risk factors into their comprehensive patient assessment when evaluating candidates for catheter ablation.

Hepatoprotective and neuroprotective effects of quinacrine against bile duct ligation-induced hepatic encephalopathy in rats: Role of bone morphogenetic proteins signaling

AIMS

This study aimed to assess the potential protective effect of quinacrine, an FDA approved antimalarial drug with reported anti-inflammatory effects, on hepatic encephalopathy (HE) in a bile duct ligation (BDL) experimental model and to investigate the mechanisms responsible for this effect, namely those associated with the liver-brain axis, particularly, bone morphogenetic protein 2 (BMP2) signaling.

MATERIALS AND METHODS

Five groups of rats were selected at random: sham, BDL, (BDL+ quinacrine 5), (BDL+ quinacrine 10), and (quinacrine 10 + sham). Daily Intraperitoneal (I.P.) administration of quinacrine was initiated on the surgery day and continued for 28 days.

KEY FINDINGS

Results showed that rats that underwent BDL exhibited marked elevation of serum liver enzymes, ammonia, total bilirubin, together with oxidative stress, inflammation, dysregulated farnesoid x receptor (FXR), dysregulated BMP2 signaling and escalated fibrotic markers indicating hepatotoxicity, cholestasis and fibrosis. Besides, neurotoxicity was detected as manifested by cognitive deficits and dysregulation of hippocampal FXR, BMP2 signaling, WNT3A signaling, brain derived neurotrophic factor (BDNF), phospholipase A2 (PLA2) and glial fibrillary acidic protein (GFAP). In contrast, co-treatment with quinacrine mitigated BDL-induced hepatotoxicity, cholestasis, fibrosis, and neurotoxicity. Notably, quinacrine improved learning and memory and restored FXR, BMP2 signaling in the liver and hippocampus. In addition, quinacrine restored hippocampal WNT3A signaling, BDNF, whereas it downregulated expression of hippocampal PLA2 and GFAP.

SIGNIFICANCE

These findings demonstrated implication of BMP2 signaling in the molecular process of BDL-induced HE and proposed that quinacrine has potential hepatoprotective and neuroprotective properties against HE.

Neurological recovery in rats with portocaval anastomosis-induced hepatic encephalopathy treated with leuprolide acetate, a GnRH agonist

Hepatic encephalopathy (HE) is a neuropsychiatric complication of acute liver failure or chronic liver injury. Liver dysfunction impairs ammonia detoxification, allowing it to cross the blood-brain barrier (BBB) and disrupt brain function. The hippocampus becomes a crucial target during elevated ammonia levels, causing spatial memory impairment and decreased learning ability. Leuprolide acetate (LA), a GnRH agonist, has been implicated in neuroprotection and neuroregeneration in several regions of the central nervous system (CNS) including hippocampus. In this study, we aim to evaluate the effects of LA treatment on hippocampus of rats with HE induced by portocaval anastomosis (PCA) trough cognitive tests, histology analysis and expression of neuronal recovery marker proteins, such as neurofilament (NF200) and neurabin II, and astrocyte marker glial fibrillary acidic protein (GFAP). Rats were divided into three groups: SHAM, portocaval anastomosis with saline solution (PCA + SS) and portocaval anastomosis treated with LA (PCA + LA). To evaluate learning and spatial memory elevated T-maze (ETM) and Y-maze test (YMT) were respectively used. Results indicated that LA-treated rats performed significantly better in ETM and YMT than untreated rats. Histological analysis of hippocampus showed increased neuron density, nuclear area, and layer thickness in dentate gyrus of PCA + LA group compared to PCA + SS. Additionally, neurabin II and NF200 expression were higher in LA-treated rats, while GFAP expression was elevated in the PCA + SS group compared to control and PCA + LA groups. In conclusion, LA enhances hippocampal neuron recovery and reduces astrogliosis, suggesting its potential as a therapeutic intervention for attenuating hippocampal damage during HE.

Regulation of autophagy by ST3GAL2-mediated α2-3 sialylated glycosphingolipids in hepatic encephalopathy

In neurological diseases, the regulation of autophagy plays a crucial role in their pathology, particularly the relationship between autophagy and hepatic encephalopathy (HE) which merits detailed investigation. Glycosphingolipids are abundant and broadly functional in the nervous system and are closely associated with autophagy. However, the specific link and mechanisms between glycosphingolipids and autophagy in HE remain unclear. This study aims to explore the impact of glycosphingolipid changes on the autophagy in HE and its potential mechanisms. Utilizing lectin microarrays, we observed elevated expression levels of α2-3 sialylated glycosphingolipid in the brain tissue of HBV transgenic mice and ammonia-induced astrocyte models, suggesting that the increase in α2-3 sialylated glycosphingolipid is related to HE. Further research revealed that the increased expression of α2-3 sialylated glycosphingolipid, mediated by ST3GAL2, affects autophagy by regulating the autophagy initiation complex Vps34-Beclin-1. In summary, our research not only comprehensively reveals the changes in brain glycosphingolipid during HBV-related HE but also elucidates the interactions and regulatory mechanisms between α2-3 sialylated glycosphingolipid and autophagy. This study provides a new perspective on understanding the pathogenesis of HE and offers novel theories and targets for future research and treatment strategies.

Elevated serum neurofilament light chain levels are associated with hepatic encephalopathy in patients with cirrhosis

Increasing evidences implicate vital role of neuronal damage in the development of hepatic encephalopathy (HE). Neurofilament light chain (NfL) is the main frame component of neurons and is closely related to axonal radial growth and neuronal structural stability. We hypothesized that NfL as a biomarker of axonal injury may contribute to early diagnosis of HE. This study recruited 101 patients with liver cirrhosis, 10 healthy individuals, and 7 patients with Parkinson's disease. Minimal hepatic encephalopathy (MHE) was diagnosed using psychometric hepatic encephalopathy score. Serum NfL levels were measured by the electrochemiluminescence immunoassay. Serum NfL levels in cirrhotic patients with MHE were significantly higher than cirrhotic patients without MHE, and increased accordingly with the aggravation of HE. Serum NfL levels were associated with psychometric hepatic encephalopathy score, Child-Pugh score, model for end-stage liver disease score, and days of hospitalization. Additionally, serum NfL was an independent predictor of MHE (odds ratio of 1.020 (95% CI 1.005-1.034); P = 0.007). The discriminative abilities of serum NfL were high for identifying MHE (AUC of 0.8134 (95% CI 0.7130-0.9219); P ˂ 0.001) and OHE (AUC of 0.8852 (95% CI 0.8117-0.9587); P ˂ 0.001). Elevated serum NfL levels correlated with the presence of MHE and associated with the severity of HE, are expected to be a biomarker in patients with cirrhosis. Our study suggested that neuronal damage may play a critical role in the development of HE.

Implication of Hypotension in the Pathogenesis of Cognitive Impairment and Brain Injury in Chronic Liver Disease

The incidence of chronic liver disease is on the rise. One of the primary causes of hospital admissions for patients with cirrhosis is hepatic encephalopathy (HE), a debilitating neurological complication. HE is defined as a reversible syndrome, yet there is growing evidence stating that, under certain conditions, HE is associated with permanent neuronal injury and irreversibility. The pathophysiology of HE primarily implicates a strong role for hyperammonemia, but it is believed other pathogenic factors are involved. The fibrotic scarring of the liver during the progression of chronic liver disease (cirrhosis) consequently leads to increased hepatic resistance and circulatory anomalies characterized by portal hypertension, hyperdynamic circulatory state and systemic hypotension. The possible repercussions of these circulatory anomalies on brain perfusion, including impaired cerebral blood flow (CBF) autoregulation, could be implicated in the development of HE and/or permanent brain injury. Furthermore, hypotensive insults incurring during gastrointestinal bleed, infection, or liver transplantation may also trigger or exacerbate brain dysfunction and cell damage. This review will focus on the role of hypotension in the onset of HE as well as in the occurrence of neuronal cell loss in cirrhosis.

Sialyltransferase ST3GAL6 silencing reduces α2,3-sialylated glycans to regulate autophagy by decreasing HSPB8-BAG3 in the brain with hepatic encephalopathy

End-stage liver diseases, such as cirrhosis and liver cancer caused by hepatitis B, are often combined with hepatic encephalopathy (HE); ammonia poisoning is posited as one of its main pathogenesis mechanisms. Ammonia is closely related to autophagy, but the molecular mechanism of ammonia's regulatory effect on autophagy in HE remains unclear. Sialylation is an essential form of glycosylation. In the nervous system, abnormal sialylation affects various physiological processes, such as neural development and synapse formation. ST3 β‍-galactoside α2,‍3-sialyltransferase 6 (ST3GAL6) is one of the significant glycosyltransferases responsible for adding α2,3-linked sialic acid to substrates and generating glycan structures. We found that the expression of ST3GAL6 was upregulated in the brains of mice with HE and in astrocytes after ammonia induction, and the expression levels of α2,3-sialylated glycans and autophagy-related proteins microtubule-associated protein light chain 3 (LC3) and Beclin-1 were upregulated in ammonia-induced astrocytes. These findings suggest that ST3GAL6 is related to autophagy in HE. Therefore, we aimed to determine the regulatory relationship between ST3GAL6 and autophagy. We found that silencing ST3GAL6 and blocking or degrading α2,3-sialylated glycans by way of Maackia amurensis lectin-II (MAL-II) and neuraminidase can inhibit autophagy. In addition, silencing the expression of ST3GAL6 can downregulate the expression of heat shock protein β8 (HSPB8) and Bcl2-associated athanogene 3 (BAG3). Notably, the overexpression of HSPB8 partially restored the reduced autophagy levels caused by silencing ST3GAL6 expression. Our results indicate that ST3GAL6 regulates autophagy through the HSPB8-BAG3 complex.

Lessons on brain edema in HE: from cellular to animal models and clinical studies

Brain edema is considered as a common feature associated with hepatic encephalopathy (HE). However, its central role as cause or consequence of HE and its implication in the development of the neurological alterations linked to HE are still under debate. It is now well accepted that type A and type C HE are biologically and clinically different, leading to different manifestations of brain edema. As a result, the findings on brain edema/swelling in type C HE are variable and sometimes controversial. In the light of the changing natural history of liver disease, better description of the clinical trajectory of cirrhosis and understanding of molecular mechanisms of HE, and the role of brain edema as a central component in the pathogenesis of HE is revisited in the current review. Furthermore, this review highlights the main techniques to measure brain edema and their advantages/disadvantages together with an in-depth description of the main ex-vivo/in-vivo findings using cell cultures, animal models and humans with HE. These findings are instrumental in elucidating the role of brain edema in HE and also in designing new multimodal studies by performing in-vivo combined with ex-vivo experiments for a better characterization of brain edema longitudinally and of its role in HE, especially in type C HE where water content changes are small.

[Effect of low-intensity laser-therapy in the correction of encephalopathy in obstructive jaundice]

Hepatic encephalopathy is an early and severe complication of obstructive jaundice and is characterized by occurrence of non-focal and focal neurological manifestations. Different methods of therapy are applied for disorder correction. Low-intensity laser blood irradiation has a pronounced antioxidant and vasoactive effect.

OBJECTIVE

To analyze the results of pharmaceutical treatment and low-intensity laser therapy use in encephalopathy correction in obstructive jaundice of non-neoplastic origin.

MATERIAL AND METHODS

The study was performed at the surgery department in the S.V. Katkov Republican Clinical Hospital (Saransk). The trial included 54 patients with moderate obstructive jaundice of non-neoplastic origin with latent encephalopathy, who were divided into 2 groups: the 1st group (control) consisted of 27 patients receiving standard pharmaceutical treatment; the 2nd group (study) - 27 patients receiving standard treatment and laser therapy (low-intensity laser irradiation in red emission at the cubital vein projection for 15 minutes). A comparative group (norm) included 20 healthy volunteers. All patients underwent biochemical studies (alanine aminotransferase and total bilirubin levels in the blood were assessed) after treatment. Registration of microcirculatory disorders and psychometric testing were conducted to reveal latent hepatic encephalopathy along with the evaluation of liver functional condition.

RESULTS

Correlation analysis showed the association of psychoneurological status improvement with liver functional condition (indicators of microcirculation and biochemical blood analysis were considered) in patients receiving a comprehensive therapy with laser irradiation. Correlation coefficient amounted to 0.87-0.96 (p<0.05).

CONCLUSION

The use of above vascular laser blood irradiation in a comprehensive treatment of moderate obstructive jaundice leads to improvement of liver functional condition (the first barrier organ on the toxin pathway) and to a significant reduction of latent encephalopathy's manifestations. The conducted treatment resulted in a reduction of initially elevated levels of alanine aminotransferase and total bilirubin. Laser therapy has an ability to restore microcirculation that leads to the improvement of psychoneurological status in patients with moderate obstructive jaundice.

Multiple ammonia-induced episodes of hepatic encephalopathy provoke neuronal cell loss in bile-duct ligated rats

Background & Aims

Hepatic encephalopathy (HE) is defined as a reversible syndrome and therefore should resolve following liver transplantation (LT). However, neurological complications have been reported in up to 47% of LT recipients, which have been documented to be associated with a history of overt HE pre-LT. We hypothesise that multiple episodes of HE lead to permanent cell injury and exacerbate neurological dysfunction. Our goal was to evaluate the impact of cumulative HE episodes on neurological status and brain integrity in rats with chronic liver disease.

Methods

Episodes of overt HE (loss of righting reflex) were induced following injection of ammonium acetate in bile duct ligation (BDL) rats (BDL-Ammonia) every 4 days starting at week 3 post-BDL. Neurobehaviour was evaluated after the last episode. Upon sacrifice, plasma ammonia, systemic oxidative stress, and inflammation markers were assessed. Neuronal markers including neuron-specific nuclear antigen and SMI311 (anti-neurofilament marker) and apoptotic markers (cleaved caspase-3, Bax, and Bcl2) were measured. Total antioxidant capacity, oxidative stress marker (4-hydroxynonenal), and proinflammatory cytokines (tumour necrosis factor-alpha and interleukin-1β) were measured in brain (hippocampus, frontal cortex, and cerebellum). Proteomic analysis was conducted in the hippocampus.

Results

In hippocampus of BDL-Ammonia rats, cleaved caspase-3 and Bax/Bcl2 ratio were significantly increased, whereas NeuN and SMI311 were significantly decreased compared with BDL-Vehicle rats. Higher levels of oxidative stress-induced post-translational modified proteins were found in hippocampus of BDL-Ammonia group which were associated with a lower total antioxidant capacity.

Conclusions

Ammonia-induced episodes of overt HE caused neuronal cell injury/death in BDL rats. These results suggest that multiple bouts of HE can be detrimental on the integrity of the brain, translating to irreversibility and hence neurological complications post-LT.

Impact and implications

Hepatic encephalopathy (HE) is defined as a reversible neuropsychiatric syndrome resolving following liver transplantation (LT); however, ∼47% of patients demonstrate neurological impairments after LT, which are associated with a previous history of overt HE pre-LT. Our study indicates that multiple episodes of overt HE can cause permanent neuronal damage which may lead to neurological complications after LT. Nevertheless, preventing the occurrence of overt HE episodes is critical for reducing the risk of irreversible neuronal injury in patients with cirrhosis.

Astrocytes in human central nervous system diseases: a frontier for new therapies

Astroglia are a broad class of neural parenchymal cells primarily dedicated to homoeostasis and defence of the central nervous system (CNS). Astroglia contribute to the pathophysiology of all neurological and neuropsychiatric disorders in ways that can be either beneficial or detrimental to disorder outcome. Pathophysiological changes in astroglia can be primary or secondary and can result in gain or loss of functions. Astroglia respond to external, non-cell autonomous signals associated with any form of CNS pathology by undergoing complex and variable changes in their structure, molecular expression, and function. In addition, internally driven, cell autonomous changes of astroglial innate properties can lead to CNS pathologies. Astroglial pathophysiology is complex, with different pathophysiological cell states and cell phenotypes that are context-specific and vary with disorder, disorder-stage, comorbidities, age, and sex. Here, we classify astroglial pathophysiology into (i) reactive astrogliosis, (ii) astroglial atrophy with loss of function, (iii) astroglial degeneration and death, and (iv) astrocytopathies characterised by aberrant forms that drive disease. We review astroglial pathophysiology across the spectrum of human CNS diseases and disorders, including neurotrauma, stroke, neuroinfection, autoimmune attack and epilepsy, as well as neurodevelopmental, neurodegenerative, metabolic and neuropsychiatric disorders. Characterising cellular and molecular mechanisms of astroglial pathophysiology represents a new frontier to identify novel therapeutic strategies.

Oxytocin as neuro-hormone and neuro-regulator exert neuroprotective properties: A mechanistic graphical review

BACKGROUND

Neurodegeneration is progressive cell loss in specific neuronal populations, often resulting in clinical consequences with significant medical, societal, and economic implications. Because of its antioxidant, anti-inflammatory, and anti-apoptotic properties, oxytocin has been proposed as a potential neuroprotective and neurobehavioral therapeutic agent, including modulating mood disturbances and cognitive enchantment.

METHODS

Literature searches were conducted using the following databases Web of Science, PubMed, Elsevier Science Direct, Google Scholar, the Core Collection, and Cochrane from January 2000 to February 2023 for articles dealing with oxytocin neuroprotective properties in preventing or treating neurodegenerative disorders and diseases with a focus on oxidative stress, inflammation, and apoptosis/cell death.

RESULTS

The neuroprotective effects of oxytocin appears to be mediated by its anti-inflammatory properties, inhibition of neuro inflammation, activation of several antioxidant enzymes, inhibition of oxidative stress and free radical formation, activation of free radical scavengers, prevent of mitochondrial dysfunction, and inhibition of apoptosis.

CONCLUSION

Oxytocin acts as a neuroprotective agent by preventing neuro-apoptosis, neuro-inflammation, and neuronal oxidative stress, and by restoring mitochondrial function.

Patients who died with steatohepatitis or liver cirrhosis show neuroinflammation and neuronal loss in hippocampus

BACKGROUND

Neuroinflammation in the cerebral cortex of patients who died with liver cirrhosis and neuroinflammation, and neuronal death in the cerebellum of patients who died with steatohepatitis or cirrhosis, were reported. Hippocampal neuroinflammation could contribute to cognitive decline in patients with liver disease, but this has yet to be studied. The study aims were to assess if hippocampus from patients who died with steatohepatitis or cirrhosis showed: (i) glial activation, (ii) altered cytokine content, (iii) immune cell infiltration, (iv) neuronal apoptosis and (v) neuronal loss.

METHODS

Post-mortem hippocampus was obtained from 6 controls, 19 patients with steatohepatitis (SH) and 4 patients with liver cirrhosis. SH patients were divided into SH1 (n = 9), SH2 (n = 6) and SH3 (n = 4) groups depending on disease severity. Glial activation, IL-1β and TNFα content, CD4 lymphocyte and monocyte infiltration, neuronal apoptosis and neuronal loss were analyzed by immunohistochemistry.

RESULTS

Patients who died in SH1 showed astrocyte activation, whereas those who died in SH2 also showed microglial activation, CD4 lymphocyte and monocyte infiltration, neuronal apoptosis and neuronal loss. These changes remained in patients in SH3, who also showed increased IL-1β and TNFα. Patients who died of liver cirrhosis did not show CD4 lymphocyte infiltration, neuronal apoptosis or increase in TNFα, but still showed glial activation, increased IL-1β and neuronal loss.

CONCLUSIONS

Patients with steatohepatitis showed glial activation, immune cell infiltration, apoptosis and neuronal loss. Glial activation and neuronal loss remained in cirrhotic patients. This may explain the irreversibility of some cognitive alterations in hepatic encephalopathy. Cognitive reserve may contribute to different grades of cognitive impairment despite similar neuronal loss.

Neurologic Manifestations of Gastrointestinal and Nutritional Disorders

OBJECTIVE

A tie between nutritional or gastrointestinal and neurologic disease has been recognized for centuries. Many gastrointestinal disorders are associated with neurologic disease through nutritional, immune-mediated, or degenerative pathophysiologies. This article reviews neurologic disorders in patients with gastrointestinal disease and gastrointestinal manifestations in their own neurologic patients.

LATEST DEVELOPMENTS

Development of new gastric and bariatric surgical procedures and the widespread use of over-the-counter gastric acid-reducing medications continue to create vitamin and nutritional deficiencies despite modern diet and supplementation. Some supplements, such as vitamin A, vitamin B6, and selenium, themselves are now found to cause disease. Recent work has shown extraintestinal and neurologic manifestations of inflammatory bowel disease. Chronic brain damage in liver disease has been recognized, and the opportunity to intervene may exist in the covert beginning stages. The characterization of gluten-related neurologic symptoms and differentiation from those of celiac disease is an evolving body of work.

ESSENTIAL POINTS

Gastrointestinal and neurologic diseases related to common immune-mediated, degenerative, or infectious mechanisms are common and can coexist in the same patient. Furthermore, gastrointestinal disease may cause neurologic complications because of nutritional inadequacies, malabsorption, and hepatic dysfunction. In many cases, the complications are treatable but have subtle or protean presentations. Therefore, the consulting neurologist must be current in knowledge of the growing ties between gastrointestinal and neurologic disease.

Experimental hepatic encephalopathy causes early but sustained glial transcriptional changes

Hepatic encephalopathy (HE) is a common complication of liver cirrhosis, associated with high morbidity and mortality, for which no brain-targeted therapies exist at present. The interplay between hyperammonemia and inflammation is thought to drive HE development. As such, astrocytes, the most important ammonia-metabolizing cells in the brain, and microglia, the main immunomodulatory cells in the brain, have been heavily implicated in HE development. As insight into cellular perturbations driving brain pathology remains largely elusive, we aimed to investigate cell-type specific transcriptomic changes in the HE brain. In the recently established mouse bile duct ligation (BDL) model of HE, we performed RNA-Seq of sorted astrocytes and microglia at 14 and 28 days after induction. This revealed a marked transcriptional response in both cell types which was most pronounced in microglia. In both cell types, pathways related to inflammation and hypoxia, mechanisms commonly implicated in HE, were enriched. Additionally, astrocytes exhibited increased corticoid receptor and oxidative stress signaling, whereas microglial transcriptome changes were linked to immune cell attraction. Accordingly, both monocytes and neutrophils accumulated in the BDL mouse brain. Time-dependent changes were limited in both cell types, suggesting early establishment of a pathological phenotype. While HE is often considered a unique form of encephalopathy, astrocytic and microglial transcriptomes showed significant overlap with previously established gene expression signatures in other neuroinflammatory diseases like septic encephalopathy and stroke, suggesting common pathophysiological mechanisms. Our dataset identifies key molecular mechanisms involved in preclinical HE and provides a valuable resource for development of novel glial-directed therapeutic strategies.

Is metformin neuroprotective against diabetes mellitus-induced neurodegeneration? An updated graphical review of molecular basis

Diabetes mellitus (DM) is a metabolic disease that activates several molecular pathways involved in neurodegenerative disorders. Metformin, an anti-hyperglycemic drug used for treating DM, has the potential to exert a significant neuroprotective role against the detrimental effects of DM. This review discusses recent clinical and laboratory studies investigating the neuroprotective properties of metformin against DM-induced neurodegeneration and the roles of various molecular pathways, including mitochondrial dysfunction, oxidative stress, inflammation, apoptosis, and its related cascades. A literature search was conducted from January 2000 to December 2022 using multiple databases including Web of Science, Wiley, Springer, PubMed, Elsevier Science Direct, Google Scholar, the Core Collection, Scopus, and the Cochrane Library to collect and evaluate peer-reviewed literature regarding the neuroprotective role of metformin against DM-induced neurodegenerative events. The literature search supports the conclusion that metformin is neuroprotective against DM-induced neuronal cell degeneration in both peripheral and central nervous systems, and this effect is likely mediated via modulation of oxidative stress, inflammation, and cell death pathways.

Enriched environment ameliorates learning and memory deficits in hepatic encephalopathy mice by restoration of the structure of dendrites and dendritic spines

Cognitive impairment is one of the most common symptoms of hepatic encephalopathy (HE). However, there is a lack of easily implementable rehabilitation strategies. As an easy-to-implement strategy, numerous studies suggest that enriched environment (EE) can be beneficial for cognitive function. However, the effects of EE on learning and memory, as well as dendritic spines plasticity in HE is still unclear. Accordingly, in the present study, we evaluated the effects of EE on the behavior and dendritic spine morphology in an animal model of HE. Our results showed that HE mice have no movement disorder and anxiety, but they exhibit spatial learning and memory dysfunction. Further analysis revealed that the complexity of the dendrites and the maturity of the dendritic spines are reduced in the hippocampus of HE mice. After 4 weeks of housekeeping in EE, dendritic complexity, and dendritic spine maturity, as well as the spatial learning and memory function of HE mice were restored. In conclusion, exposure to EE can positively influence dendritic spines plasticity in the hippocampus and thereby elicit its beneficial effects on cognitive functions in HE.

Current vision on diagnosis and comprehensive care in hepatic encephalopathy

The first clinical guidelines on hepatic encephalopathy were published in 2009. Almost 14 years since that first publication, numerous advances in the field of diagnosis, treatment, and special condition care have been made. Therefore, as an initiative of the Asociación Mexicana de Gastroenterología A.C., we present a current view of those aspects. The manuscript described herein was formulated by 24 experts that participated in six working groups, analyzing, discussing, and summarizing the following topics: Definition of hepatic encephalopathy; recommended classifications; epidemiologic panorama, worldwide and in Mexico; diagnostic tools; conditions that merit a differential diagnosis; treatment; and primary and secondary prophylaxis. Likewise, these guidelines emphasize the management of certain special conditions, such as hepatic encephalopathy in acute liver failure and acute-on-chronic liver failure, as well as specific care in patients with hepatic encephalopathy, such as the use of medications and types of sedation, describing those that are permitted or recommended, and those that are not.

Residual Amino Acid Imbalance in Rats during Recovery from Acute Thioacetamide-Induced Hepatic Encephalopathy Indicates Incomplete Healing

The delayed consequences of the influence of hepatic encephalopathy (HE) on the metabolism of animals have not been studied enough. We have previously shown that the development of acute HE under the influence of the thioacetamide (TAA) toxin is accompanied by pathological changes in the liver, an imbalance in CoA and acetyl CoA, as well as a number of metabolites of the TCA cycle. This paper discusses the change in the balance of amino acids (AAs) and related metabolites, as well as the activity of glutamine transaminase (GTK) and ω-amidase enzymes in the vital organs of animals 6 days after a single exposure to TAA. The balance of the main AAs in blood plasma, liver, kidney, and brain samples of control (n = 3) and TAA-induced groups (n = 13) of rats that received the toxin at doses of 200, 400, and 600 mg/kg was considered. Despite the apparent physiological recovery of the rats at the time of sampling, a residual imbalance in AA and associated enzymes persisted. The data obtained give an idea of the metabolic trends in the body of rats after their physiological recovery from TAA exposure and may be useful for prognostic purposes when choosing the necessary therapeutic agents.

Impact of Optimizing the Emergency Care Process on the Emergency Effect and Prognosis of Patients with Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a serious complication caused by liver disease and is one of the leading causes of death in patients. Studies have shown that proper emergency care for patients after the occurrence of HE can improve their prognosis and quality of life. Therefore, this study focuses on the effect of optimizing the emergency care process on the effectiveness and prognosis of emergency care for patients with hepatic encephalopathy. In this study, we set 32 patients with HE admitted to receive routine emergency care between May 2020 and March 2021 as the control group and 34 patients with HE admitted to receive optimized emergency care processes between April 2021 and February 2022 as the observation group. The satisfaction of patients' families with this care was assessed using a self-administered nursing satisfaction questionnaire to record the outcome of emergency care, quality of care, and prognosis of patients in the two groups of palliative care. The data collected were analyzed using SPSS17.0 software, and the results showed that the time spent on diagnosis, resuscitation, DTP, and DTT was much lower in the observation group than in the control group, and the scores related to the quality of care, such as ambulance technique, humanistic care, resuscitation efficiency, and resuscitation effect, were all higher than those of the control group, and the satisfaction of the family members in the observation group was also significantly higher than that of the control group (P < 0.05). The success rate of first aid in the observation group was 100.00%, which was higher than 93.72% in the control group, but the difference between the two groups was not significant (P > 0.05). It can be seen that the application of an optimized emergency nursing process in HE patients is effective, which can effectively improve the success rate of HE resuscitation, shorten the resuscitation time and condition diagnosis, improve the resuscitation effect, improve the quality of nursing care, and improve the prognosis of patients to a certain extent.

Heretical thoughts into hepatic encephalopathy

Clinical progress in the development of new diagnostic modalities and therapeutic strategies for the management of patients with hepatic encephalopathy has lagged behind the vast knowledge that has been generated from basic studies. In this article, we critically assess matters that should be revisited, such as definition, classification, diagnosis and grading of hepatic encephalopathy, which are difficult to apply reproducibly using the current criteria. Many lines of investigation have confirmed that hepatic encephalopathy is irreversible in many patients and suggest the need for further studies focussing on mechanisms of neuronal injury and death, to guide future drug development for these patients. The clinical evidence behind using lactulose for all severities of hepatic encephalopathy, which is currently considered the standard of care, is poor and placebo-controlled trials for hepatic encephalopathy should be considered ethically sound. This expert opinion identifies current challenges in hepatic encephalopathy and highlights areas which require further debate and investigation in order to help advance the field both scientifically and clinically.

Hepatic encephalopathy

Hepatic encephalopathy (HE) is a prognostically relevant neuropsychiatric syndrome that occurs in the course of acute or chronic liver disease. Besides ascites and variceal bleeding, it is the most serious complication of decompensated liver cirrhosis. Ammonia and inflammation are major triggers for the appearance of HE, which in patients with liver cirrhosis involves pathophysiologically low-grade cerebral oedema with oxidative/nitrosative stress, inflammation and disturbances of oscillatory networks in the brain. Severity classification and diagnostic approaches regarding mild forms of HE are still a matter of debate. Current medical treatment predominantly involves lactulose and rifaximin following rigorous treatment of so-called known HE precipitating factors. New treatments based on an improved pathophysiological understanding are emerging.

Increased INR Values Predict Accelerating Deterioration and High Short-Term Mortality Among Patients Hospitalized With Cirrhosis or Advanced Fibrosis

Background and Objective: An increase in the international normalized ratio (INR) is associated with increased mortality in patients with cirrhosis and other chronic liver diseases, while little is known about the quantitative relationship. This study aimed to investigate the quantitative relationship between the INR and short-term prognosis among patients hospitalized with cirrhosis or advanced fibrosis and to evaluate the role of the INR as a risk factor for short-term liver transplant (LT)-free mortality in these patients. Patients and Methods: This study prospectively analyzed multicenter cohorts established by the Chinese Acute-on-Chronic Liver Failure (CATCH-LIFE) study. Cox regression was used to describe the relationship between the INR and independent risk factors for short-term LT-free mortality. Forest plots were used in the subgroup analysis. Generalized additive models (GAMs) and splines were used to illustrate the quantitative curve relationship between the INR and the outcome and inflection point on the curve. Results: A total of 2,567 patients with cirrhosis and 924 patients with advanced fibrosis were included in the study. The 90-day LT-free mortality of patients with cirrhosis and advanced fibrosis was 16.7% (428/2,567) and 7.5% (69/924), respectively. In the multivariable Cox regression analysis, the increase in the INR was independently associated with the risk of 90-day LT-free mortality both in patients with cirrhosis (HR, 1.06; 95% CI, 1.04-1.07, p < 0.001) and in patients with advanced fibrosis (HR, 1.09; 95% CI, 1.06-1.12, p < 0.001). An INR of 1.6/1.7 was found to be the starting point of coagulation dysfunction with a rapid increase in mortality in patients with cirrhosis or in patients with advanced fibrosis, respectively. A 28-day LT-free mortality of 15% was associated with an INR value of 2.1 in both cirrhosis and advanced fibrosis patients. Conclusions: This study was the first to quantitatively describe the relationship between the INR and short-term LT-free mortality in patients with cirrhosis or advanced fibrosis. The starting points of INR indicating the rapid increase in mortality and the unified cutoff value of coagulation failure in cirrhosis and advanced fibrosis, will help clinicians accurately recognize early disease deterioration.

The neurogliovascular unit in hepatic encephalopathy

Hepatic encephalopathy (HE) is a neurological complication of hepatic dysfunction and portosystemic shunting. It is highly prevalent in patients with cirrhosis and is associated with poor outcomes. New insights into the role of peripheral origins in HE have led to the development of innovative treatment strategies like faecal microbiota transplantation. However, this broadening of view has not been applied fully to perturbations in the central nervous system. The old paradigm that HE is the clinical manifestation of ammonia-induced astrocyte dysfunction and its secondary neuronal consequences requires updating. In this review, we will use the holistic concept of the neurogliovascular unit to describe central nervous system disturbances in HE, an approach that has proven instrumental in other neurological disorders. We will describe HE as a global dysfunction of the neurogliovascular unit, where blood flow and nutrient supply to the brain, as well as the function of the blood-brain barrier, are impaired. This leads to an accumulation of neurotoxic substances, chief among them ammonia and inflammatory mediators, causing dysfunction of astrocytes and microglia. Finally, glymphatic dysfunction impairs the clearance of these neurotoxins, further aggravating their effect on the brain. Taking a broader view of central nervous system alterations in liver disease could serve as the basis for further research into the specific brain pathophysiology of HE, as well as the development of therapeutic strategies specifically aimed at counteracting the often irreversible central nervous system damage seen in these patients.