Implications of Manganese in Chronic Acquired Hepatocerebral Degeneration

Cellular Pathogenesis of Hepatic Encephalopathy: An Update

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome derived from metabolic disorders due to various liver failures. Clinically, HE is characterized by hyperammonemia, EEG abnormalities, and different degrees of disturbance in sensory, motor, and cognitive functions. The molecular mechanism of HE has not been fully elucidated, although it is generally accepted that HE occurs under the influence of miscellaneous factors, especially the synergistic effect of toxin accumulation and severe metabolism disturbance. This review summarizes the recently discovered cellular mechanisms involved in the pathogenesis of HE. Among the existing hypotheses, ammonia poisoning and the subsequent oxidative/nitrosative stress remain the mainstream theories, and reducing blood ammonia is thus the main strategy for the treatment of HE. Other pathological mechanisms mainly include manganese toxicity, autophagy inhibition, mitochondrial damage, inflammation, and senescence, proposing new avenues for future therapeutic interventions.

Role of hepatitis c virus in hepatocellular carcinoma and neurological disorders: an overview

The hepatitis C virus (HCV) causes serious issues, affecting 71 million people globally. The most common manifestations range from chronic hepatitis to liver cirrhosis, leading to hepatocellular carcinoma. Many mechanisms are known to play an important role in HCV-induced HCC. The interaction of viral proteins with host cells results in oxidative stress damage, liver inflammation, and irregularities in signaling pathways. These results in the activation of oncogenes and metabolic disturbances, liver fibrosis, and angiogenesis. Additionally, some non-coding RNAs (ncRNAs) and toll-like receptors have been identified and play a significant role in HCC development. This virus is also associated with impairment of the central nervous system, resulting in acute or sub-acute encephalopathy and inflammatory disorders. Neurological disorders are associated with the inflammatory responses of many cells, including microglia and astrocytes. Additionally, there are many other extrahepatic manifestations, including neurological disorders such as depression and fatigue, in 50% of infected patients. These manifestations include neuro-invasion, immune-mediated damage, neurotransmitter alterations, sensory-motor polyneuropathy, sensitivity loss, weakness of the leg, and cryoglobulinemia, which significantly results in a reduced quality of life. HCV infection may be improved using an appropriate diagnosis and direct antiviral therapy for sustained virological response. However, the success of therapy depends on the symptoms and organ damage, diagnosis, and therapeutic strategies applied. Some published reports have discussed that HCV is associated with both HCC and neurological disorders. Additionally, it has also been observed that individuals with HCC also develop neurological disorders compared with individuals with HCV alone. This review aims to provide an overview of the latest information about the relationship between HCV-induced HCC and their role in neurological disorders. Additionally, we have also discussed the progress made in the diagnosis, physio-pathological mechanisms, and strong antiviral therapies developed for HCV infection and HCC, as well as the latest advancements made in the study of the neurological disorders associated with HCV infection.

Manganese concentration in patients with encephalopathy following ephedrone use: a narrative review and analysis of case reports

BACKGROUND

Numerous case reports describe manganese encephalopathy in patients using ephedrone (methcathinone). The aim of this narrative review of case reports was to relate manganese ion concentrations in peripheral blood to the reported neurological deficits.

METHODS

International databases, including Thomson (Web of Knowledge), PubMed/Medline, Science Direct, Scopus and Google Scholar were searched for literature items published between 2007 and 2020, in which the authors measured the manganese concentration in patients taking ephedrone.

RESULTS

We identified 39 patients in two case series comprising of twenty-three and twelve patients, respectively, and four case reports meeting inclusion criteria. The study showed that 93% of them had elevated blood manganese concentration in relation to the accepted norm (>219 nmol/L), and the median was 364 nmol/L. The median duration of ephedrone use in individual groups of patients was approximately 48 months, and it did not show a relationship with the manganese concentration in the blood. A greater percentage of the people with manganese concentration higher than 250 nmol/L exhibited more severe gait, speech and handwriting disorders. The median duration of ephedrone withdrawal was a month in the group of people with the highest level of manganese ions (>500 nmol/L).

CONCLUSION

Manganese concentrations did not vary with the duration of ephedrone use.

GWAS of serum ALT and AST reveals an association of SLC30A10 Thr95Ile with hypermanganesemia symptoms

Understanding mechanisms of hepatocellular damage may lead to new treatments for liver disease, and genome-wide association studies (GWAS) of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) serum activities have proven useful for investigating liver biology. Here we report 100 loci associating with both enzymes, using GWAS across 411,048 subjects in the UK Biobank. The rare missense variant SLC30A10 Thr95Ile (rs188273166) associates with the largest elevation of both enzymes, and this association replicates in the DiscovEHR study. SLC30A10 excretes manganese from the liver to the bile duct, and rare homozygous loss of function causes the syndrome hypermanganesemia with dystonia-1 (HMNDYT1) which involves cirrhosis. Consistent with hematological symptoms of hypermanganesemia, SLC30A10 Thr95Ile carriers have increased hematocrit and risk of iron deficiency anemia. Carriers also have increased risk of extrahepatic bile duct cancer. These results suggest that genetic variation in SLC30A10 adversely affects more individuals than patients with diagnosed HMNDYT1.

Chronic acquired hepatocerebral degeneration presenting with Meige's syndrome and behavioral symptoms fully reversed by liver transplantation

Chronic acquired hepatocerebral degeneration (CAHD) is a rare neurologic syndrome occurring in patients with chronic liver disease, resulting in the combination of movement disorders and cognitive\behavioral changes. Its pathogenesis is debated and the symptoms are poorly responsive to medical therapy. Meige's syndrome is a form of cranial dystonia, considered an idiopathic form of adult onset dystonia. We report a 60-year-old man with HCV-related liver cirrhosis and hepatocarcinoma who developed Meige's syndrome associated with cognitive and behavioral manifestations, unrelated to acute metabolic derangement. CAHD was diagnosed. Liver transplantation reversed the clinical picture and MR abnormalities, reinforcing the idea that CAHD is a potentially reversible syndrome, which may be healed by liver transplantation and should not be considered a contraindication for this operation.

Update on pharmacotherapy of hepatic encephalopathy

Hepatic encephalopathy (HE) is a central nervous system disease caused by serious liver diseases or various portal vein systemic circulation abnormalities. The pathogenesis and pathophysiology of HE have not been fully elucidated yet, and among others, the most important is still the theory of ammonia intoxication proposed in the 1930s. Therefore, reducing blood ammonia is currently the main therapeutic strategy for HE, along with improving nervous system function. Thanks to the clarification of the mechanism underlying ammonia-induced brain cell injury in recent years, researchers have proposed some novel therapeutic targets and related drugs. This work will make a brief summary regarding the update of HE drugs with regard to ammonia reduction, nervous system improvement, and intervention of ammonia toxicity targets.

Manganese, a Likely Cause of 'Parkinson's in Cirrhosis', a Unique Clinical Entity of Acquired Hepatocerebral Degeneration

With idiopathic Parkinson's disease being a common entity, parkinsonism in acquired hepatocerebral degeneration (AHD) in the context of Manganese (Mn) has gained importance in recent years. An insight into the pathomechanisms behind this disease has been put forth. How can Mn as a divalent metal exert its effect in leading to chronic neurodegenerative disorder? Secondary to decreased excretion in liver cirrhosis, Mn significantly alters the striatal dopaminergic system. Management of this debilitating disease also focuses on different aspects where Mn has been involved in the pathogenesis. We have put forth the details behind Mn effects in Parkinson’s, which will be a guide for better understanding and management of this disease.

A literature search was performed using PubMed as a sole database, and all the articles were peer-reviewed. The author tried to follow the PRISMA guidelines. Inclusion criteria were set for 10 years, with most studies with in the last seven years. All types of study designs were included relevant to the topic, clearly delineating the pathomechanisms of Mn in the disease and also its management. After extensive research, through the PubMed database, we found that Parkinson's disease is one of the neurological complications in advanced liver cirrhosis. Mn is an essential element behind its pathogenesis; it works at different cellular levels to promote neurotoxicity. From its influx to its effects on dopamine transporters (DAT), where it disrupts dopamine homeostasis also altering postsynaptic dopamine (D2) receptors, it disrupts mitochondria and the endoplasmic reticulum (ER) promotes oxidative stress and neuroinflammation. Misfolding of alpha-synuclein (α-Syn) is promoted on chronic exposure to Mn where α-Syn from being neuroprotective becomes neurotoxic. It also alters glutaminergic and gabaergic neurotransmission. In a nutshell, the diversity of its effect on nigrostriatal denervation is challenging. The importance of neuroimaging and various approaches to management is also discussed. AHD, an uncommon entity in advanced liver cirrhosis, needs more awareness so that it can be diagnosed earlier and better therapeutic options can be sought. Our study highlighted Mn mechanisms behind this clinical entity, putting forth grounds for a better understanding of this disease. Advanced research targeting Mn for managing this disease will be revolutionary.

Hepatoprotective effects and mechanisms of Ixeris denticulate water extract on liver cirrhosis in experimental rat

BACKGROUND

To explore the protective effect and mechanisms of Ixeris denticulate water extract (IDWE) in the development of liver cirrhosis in experimental rat.

METHODS

Sixty rats were randomly divided into five groups: control group, model group and IDWE (2, 4 and 8 g/kg) treatment groups. Alanine transferase (ALT), aspartate transaminase (AST), albumin (ALB), tumor necrosis factor-alpha (TNF-α), Interleukin (IL)-6 and IL-8 in serum and superoxide dismutase (SOD), malondialdehyde (MDA) in liver tissue were evaluated, respectively. The liver index, liver morphology and liver histopathological analysis were detected as a supportive data. The liver protein expression of Bcl-2 and Bax were assessed by western blot, and NF-κB p65 protein expression was determined by immunohistochemistry analysis.

RESULTS

The result showed that a significantly decrease in the levels of serum AST, ALT and serum inflammatory factors TNF-α, IL-6 and IL-8 in IDWE-treated rats. The levels of serum ALB and SOD in liver tissue were markedly increased after IDWE treated, compared with model rats. Furthermore, IDWE-treated group also exhibited a down-regulated protein expression of NF-κB p65 and Bax, up-regulated Bcl-2 protein expression.

CONCLUSIONS

IDWE could effectively alleviate the course of liver cirrhosis in rat model, which may be a potent hepatoprotective agent in clinical therapy in the future.

Atypical neuroimaging findings in patients with acquired hepatocerebral degeneration

BACKGROUND

Acquired hepatocerebral degeneration (AHD) is now widely recognized by physicians. Although hyperintensity in the bilateral globus pallidus in T1-weighted magnetic resonance images (MRIs) are characteristic neuroimaging findings, accumulating reports indicate that atypical neuroimaging findings are not rare. This study aimed to describe the spectrum of atypical neuroimaging findings and related factors in patients with AHD.

METHODS

From February 2017 to January 2019, a retrospective study was conducted of 28 patients with AHD in the Shengjing Hospital of China Medical University. The neurological manifestations, clinical parameters, and biochemical and neuroimaging findings were analyzed.

RESULTS

Among 28 patients, 14 patients were diagnosed with viral hepatitis-caused hepatocirrhosis, which was the most common cause of AHD. Resting tremor, cognitive impairment, and parkinsonian gait were the most common neurologic symptoms. Bilateral globus pallidus T1-weighted hyperintensity was detected in 26 patients (26/28, 92.9%). Ten patients (10/28, 35.7%) were determined to have an atypical neuroimaging finding. Binary logistic regression analysis indicated that age at onset of neurologic symptoms (odds ratio = 1.29, 95% confidence interval [CI] 1.03-1.61; p = 0.030) and Child-Pugh scores (odds ratio = 2.52, 95% CI, 1.01-6.31; p = 0.048) were independently associated with atypical neuroimaging findings in AHD.

CONCLUSION

The clinical manifestations of AHD are diverse; resting tremor, cognitive impairment, and parkinsonian gait were the most common. More than one third of patients had atypical neuroimaging findings. Age at onset of neurologic symptoms and Child-Pugh scores may be important predictors of atypical neuroimaging findings in patients with AHD.

Genetic Disorders of Manganese Metabolism

Purpose of Review

This article provides an overview of the pathogenesis, clinical presentation and treatment of inherited manganese transporter defects.

Recent Findings

Identification of a new group of manganese transportopathies has greatly advanced our understanding of how manganese homeostasis is regulated in vivo. While the manganese efflux transporter SLC30A10 and the uptake transporter SLC39A14 work synergistically to reduce the manganese load, SLC39A8 has an opposing function facilitating manganese uptake into the organism. Bi-allelic mutations in any of these transporter proteins disrupt the manganese equilibrium and lead to neurological disease: Hypermanganesaemia with dystonia 1 (SLC30A10 deficiency) and hypermanganesaemia with dystonia 2 (SLC39A14 deficiency) are characterised by manganese neurotoxicity while SLC39A8 mutations cause a congenital disorder of glycosylation type IIn due to Mn deficiency.

Summary

Inherited manganese transporter defects are an important differential diagnosis of paediatric movement disorders. Manganese blood levels and MRI brain are diagnostic and allow early diagnosis to avoid treatment delay.