Metal-induced hepatotoxicity

Heavy metals and cardiovascular health: Uncovering links and health challenges

BACKGROUND

Heavy metals, including lead, mercury, cadmium, and arsenic, along with emerging contaminants, pose significant threats to cardiovascular health. These metals are linked to oxidative stress, endothelial dysfunction, inflammation, and epigenetic alterations, contributing to various cardiovascular diseases.

AIM

This review synthesizes current research on the pathways by which heavy metal exposure affects cardiovascular health, highlighting epidemiological trends, vulnerable populations, and potential preventive strategies.

METHODS

A comprehensive review of molecular mechanisms, epidemiological studies, and public health data was conducted to elucidate the links between heavy metal exposure and cardiovascular health.

RESULTS

Mechanisms of Toxicity: Heavy metals induce oxidative stress and inflammation, impair endothelial function, and disrupt calcium signaling. These effects culminate in hypertension, atherosclerosis, myocardial dysfunction, and other cardiovascular pathologies. Epidemiological Trends: Evidence links even low-level exposures to increased Cardio Vascular Disease risk. Regional trends show elevated risks in areas with significant industrial activity or contaminated water supplies. Vulnerable Populations: Children, the elderly, and individuals in low-income or industrially polluted regions exhibit heightened susceptibility. Preventive Strategies: Regulatory actions, improved water safety, dietary interventions, and community awareness are critical in mitigating exposure and its health impacts.

CONCLUSIONS

Environmental exposure to heavy metals significantly elevates cardiovascular disease risk, particularly among vulnerable groups. Urgent public health measures and further research are needed to address the cumulative and synergistic effects of these toxicants.

Associations between multiple urinary metals and metabolic syndrome: Exploring the mediating role of liver function in Chinese community-dwelling elderly

BACKGROUND

Multiple metals exposure has been revealed to be related to metabolic syndrome (MetS). However, the associations and interactions between multiple metals exposure and MetS are remains controversial, and the potential mechanism of the above-mentioned is still unclear.

METHODS

The associations between urinary metals and the MetS were analyzed by multivariable logistic regression model and restricted cubic spline (RCS). Bayesian kernel machine regression (BKMR) model and quantile-based g-computation (qgcomp) were applied to explore the mixed exposure and interaction effect of metals. Mediation analysis was used to explore the role of liver function.

RESULTS

In the single metal model, multiple metals were significantly associated with MetS. RCS analysis further verified the associations between 8 metals and MetS. BKMR model and qgcomp showed that zinc (Zn), iron (Fe), and tellurium (Te) were the main factors affecting the overall effect. In addition, mediation analysis indicated that serum alanine aminotransferase (ALT) mediated 21.54% and 13.29% in the associations of vanadium (V) and Zn with the risk of MetS, respectively.

CONCLUSIONS

Elevated urinary concentration of Zn, V, Te, copper (Cu), molybdenum (Mo), and thallium (Tl) were related to the increased risk of MetS. Conversely, Fe and selenium (Se) may be protective factors for MetS in mixed exposure. Liver function may play a key role in the association of V and Zn exposure with MetS.

[WITHDRAWN] Serum biomarkers of liver fibrosis identify changes in striatal metabolite levels

The full text of this preprint has been withdrawn by the authors due to author disagreement with the posting of the preprint. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.

MitomiR-1736-3p regulates copper-induced mitochondrial pathway apoptosis by inhibiting AATF in chicken hepatocytes

Copper (Cu) is a toxic heavy metal pollutant. The hepatic toxicity of Cu has attracted widespread attention from researchers. However, its underlying mechanism remains elusive. Mitochondrial microRNAs (mitomiRs) are considered important factors in regulating mitochondrial and cellular functions, and their roles have been implicated in the mechanisms of metal toxicity. Therefore, this research revealed the changes in the mitomiRs expression profile of chicken liver after Cu exposure. It was ultimately determined that mitomiR-1736-3p can be involved in Cu-induced chicken liver damage by targeting AATF. In particular, our investigations have uncovered that exposure to Cu can trigger heightened levels of apoptosis in the hepatic tissue of chickens and primary chicken embryo hepatocytes (CEHs). It is noteworthy that we found upregulation of miR-1736-3p expression can exacerbate Cu-induced cell apoptosis, while inhibition of miR-1736-3p can effectively reduce apoptosis occurrence. Subsequently, we found that Cu-induced cell apoptosis could be restored by overexpressing AATF, while silencing AATF exacerbated the level of apoptosis. Fascinatingly, this change in apoptotic level is directly influenced by AATF on Bax and Bak1, rather than on p53 and Bcl-2. Overall, these findings suggest that the mitomiR-1736-3p/AATF axis mediates the mitochondrial pathway of cell apoptosis potentially involved in Cu-induced chicken liver toxicity.

Fulminant Hepatic Failure With Minimal Alcohol Consumption in a 25-Year-Old Female With Hereditary Hemochromatosis: A Rare Case

Hereditary hemochromatosis (HH) is an inherited disorder in which organ damage and other clinical manifestations are commonly seen in patients with a homozygous mutation involving C282Y of the HFE gene, causing increased iron absorption in the intestine. The liver is the primary site of iron deposition, and excessive iron overload can eventually lead to hepatic cirrhosis. Patients who drink significant amounts of alcohol are more likely to develop cirrhosis, and in females, it is commonly seen after menopause. We describe a young female with hereditary hemochromatosis who developed fulminant hepatic failure with minimal alcohol consumption at age 25.

Transferrin saturation as a surrogate marker for assessment of labile nontransferrin bound iron in chronic liver disease

BACKGROUND

Increased transferrin saturation (TS) and ferritin are common in hereditary hemochromatosis (HH) but also in chronic liver diseases (CLD). Nontransferrin bound iron (NTBI) is believed to be associated with iron-induced cell damage. We aimed to evaluate NTBI in CLD and their relationship with liver damage.

METHODS

Two groups of patients were studied. Group 1 (G1): 94 CLD patients from an Outpatient Hepatology Unit. Group 2 (G2): 36 healthy individuals form a Medical Checkup Clinic. Transferrin iron-binding capacity, TS, ferritin, AST, ALT, and red cell count were performed using standard tests. NTBI was assessed as enhanced labile plasma iron (eLPi). Levels of eLPi less than 0.4 µmol/l were considered within the normal range.

RESULTS

Prevalence of increased iron tests (elevated TS and ferritin) was 14% in G1 and 5.5% in G2 ( P = 0.19). Positive NTBI was found in 12 patients (11 in G1 and 1 in G2). Positivity to NTBI was associated with increased iron tests ( P = 0.03), cirrhosis ( P = 0.03) and AST index (ASTI) ( P = 0.03). NTBI was associated with TS of more than 70% ( P = 0.002) but not to elevated ferritin ( P = 0.74). Variables strongly associated with a positive NTBI in univariate analysis (TS > 70%, cirrhosis and ASTI) were submitted to binary regression analysis. TS of more than 70% was the only independent predictive factor ( P = 0.049; odds ratio, 6.8).

CONCLUSION

NTBI was associated with TS in CLD, but not with ferritin. NTBI testing could be useful for CLD patients with increased iron tests. Alternatively, a TS of more than 70% can be used as a surrogate marker.

MMP2-responsive dual-targeting drug delivery system for valence-controlled arsenic trioxide prodrug delivery against hepatic carcinoma

Arsenic trioxide (ATO) is the active ingredient in traditional Chinese medicine, i.e., Arsenic, which has shown excellent therapeutic effects on hepatocellular carcinoma. However, due to its poor tumor distribution and high toxicity, the mass adoption of ATO in clinical applications has been severely impeded. In this study, matrix metalloproteinase 2 (MMP2)-responsive cleaved cell-penetrating peptide (PF) and folate (FA) co-modified liposome coated calcium arsenate nanoparticles (FA/PF-LP-CaAs) were fabricated based on these two considerations: (1) The tumor microenvironment characterized by overexpressed MMP2 in extracellular matrix and folate receptor on the cell membrane can enhance drug accumulation and accelerate endocytosis; (2) leveraging different toxicity of arsenic in different valence states, i.e., AsV can be reduced to more toxic AsIII by glutathione in tumor cells. Furthermore, FA/PF-LP-CaAs could be responsively degraded by the mild acidic tumor environment, and the degraded product could escape from lysosomes after endocytosis. More importantly, in light of the in vivo biodistribution and pharmacodynamic studies, the vehicle was able to accumulate in the tumor efficiently. Also, it was able to exhibit excellent anti-tumor efficacy with minimized side effects when compared to single-modified counterparts. Thus, the novel strategy based on the tumor microenvironment proposed in this work can enhance the tumor-targeting efficiency and intratumor toxicity.

The molecular and cellular basis of copper dysregulation and its relationship with human pathologies

Copper (Cu) is an essential micronutrient required for the activity of redox-active enzymes involved in critical metabolic reactions, signaling pathways, and biological functions. Transporters and chaperones control Cu ion levels and bioavailability to ensure proper subcellular and systemic Cu distribution. Intensive research has focused on understanding how mammalian cells maintain Cu homeostasis, and how molecular signals coordinate Cu acquisition and storage within organs. In humans, mutations of genes that regulate Cu homeostasis or facilitate interactions with Cu ions lead to numerous pathologic conditions. Malfunctions of the Cu⁺ -transporting ATPases ATP7A and ATP7B cause Menkes disease and Wilson disease, respectively. Additionally, defects in the mitochondrial and cellular distributions and homeostasis of Cu lead to severe neurodegenerative conditions, mitochondrial myopathies, and metabolic diseases. Cu has a dual nature in carcinogenesis as a promotor of tumor growth and an inducer of redox stress in cancer cells. Cu also plays role in cancer treatment as a component of drugs and a regulator of drug sensitivity and uptake. In this review, we provide an overview of the current knowledge of Cu metabolism and transport and its relation to various human pathologies.

Changes in energetic metabolism and lysosomal destruction in the skeletal muscle and cardiac tissues of pigeons (Columba livia f. urbana) from urban areas of the northern Pomeranian region (Poland)

The aim of the present study was to evaluate the biochemical responses of the skeletal muscle and cardiac tissues of the urban pigeon as a bioindicator organism tested in diverse environments (Szpęgawa as a rural environment and Słupsk as an urban environment, Pomeranian Voivodeship, northern Poland), resulting in changes in the level of lipid peroxidation at the initial and final stages of this process and the activities of Krebs cycle enzymes (succinate dehydrogenase, pyruvate dehydrogenase, isocitrate dehydrogenase, and alfa-ketoglutarate dehydrogenase). Szpęgawa village was chosen due to the intensive use of the European motorway A1 with significant traffic and pollution levels. The concentration of Pb was higher in the soil and feathers of pigeons nesting in the polluted areas (Szpęgawa). Our studies have shown that the presence of lead in soil and feathers of the pigeons resulted in the activation of lipid peroxidation, destabilization and increased activity of lysosomal membranes, and activation of mitochondrial enzymes of the Krebs cycle with energy deficiency (reduction of ATP levels) in cardiac and skeletal muscle tissues simultaneously.

Exogenous copper exposure causing clinical wilson disease in a patient with copper deficiency

BACKGROUND

Human Swayback is a disease characterized by acquired copper deficiency which primarily manifests as myeloneuropathy. Common causes include malabsorptive disorders, gastric surgery, total parenteral nutrition and excessive zinc intake. In contrast, copper supplementation should be closely monitored as excessive doses can lead to acute intoxication and in chronic cases, cirrhosis. Copper derangements are rare, however it is important to consider them due to potential severe complications.

CASE PRESENTATION

We present a middle-aged man who had been previously diagnosed with Human Swayback after presenting with various neurological symptoms. The patient was subsequently placed on copper supplementation. A decade later, he was referred to our hospital for liver transplant evaluation due to new diagnosis of decompensated end-stage liver disease after an abdominal surgery. His initial workup was suggestive of Wilson disease-subsequent ATP7B gene was negative. Ultimately, the patient underwent liver transplantation; liver explant was significant for a copper dry weight concentration of 5436 mcg/g.

CONCLUSIONS

Human Swayback is a very rare copper-related disease which deserves awareness due to its potential irreversible health effects in the human body. Additionally, in patients who require copper supplementation, serial levels should be monitored to ensure adequate copper levels.

Hepatotoxicity of copper sulfide nanoparticles towards hepatocyte spheroids using a novel multi-concave agarose chip method

Aim: To explore the hepatotoxicity of copper sulfide nanoparticles (CuSNPs) toward hepatocyte spheroids. Materials & methods: Other than the traditional agarose method to generate hepatocyte spheroids, we developed a multi-concave agarose chip (MCAC) method to investigate changes in hepatocyte viability, morphology, mitochondrial membrane potential, reactive oxygen species and hepatobiliary transporter by CuSNPs. Results: The MCAC method allowed a large number of spheroids to be obtained per sample. CuSNPs showed hepatotoxicity in vitro through a decrease in spheroid viability, albumin/urea production and glycogen deposition. CuSNPs also introduced hepatocyte spheroid injury through alteration of mitochondrial membrane potential and reactive oxygen species, that could be reversed by N-acetyl-l-cysteine. CuSNPs significantly decreased the activity of BSEP transporter by downregulating its mRNA and protein levels. Activity of the MRP2 transporter remained unchanged. Conclusion: We observed the hepatotoxicity of CuSNPs in vitro with associated mechanisms in an advanced 3D culture system.

Liver Function of Male Rats Exposed to Manganese at Different Time Points

As an essential trace element in the human body, manganese (Mn) is involved in many important biochemical reactions. However, excessive exposure to manganese can cause multiple systematic damages to the body. This study aims to investigate the effects of manganese exposure on serum hepatic enzymes in male rats at different time points. After adaptive feeding for 7 days, male Sprague-Dawley (SD) rats were injected intraperitoneally with 30 mg/kg MnCl₂·4H₂O once a day for 21 days at zeitgeber time point 2 (ZT2), ZT8, ZT14, and ZT20, respectively. We found that short-term repeated exposure to manganese caused slower body weight gain and increased relative liver and spleen weight index in male rats at different time points. Moreover, serum total bile acid (TBA) increased while aspartate aminotransferase (AST) decreased at ZT2, ZT8, and ZT20. Cholinesterase (ChE) decreased at ZT2 and ZT20, lactic dehydrogenase (LDH) decreased at ZT2, ZT14, and ZT20, and acid phosphatase (ACP) decreased at ZT2 and ZT14. Alkaline phosphatase (ALP) decreased at ZT2, ZT14, and ZT20, but increased at ZT8. Alanine amino transferase (ALT) decreased at ZT2 and ZT20, but increased at ZT8. There was a negative correlation between relative liver weight index with AST, ACP, ALP, and LDH, while a positive correlation with TBA. However, relative spleen weight index had a positive correlation with relative liver weight index and TBA, while a negative correlation with ALT, AST, ACP, ALP, LDH, and ChE. Our study shows that the injury of liver function is caused by short-term repeated manganese exposure at different time points. The time effect should be considered in manganese toxicity evaluation.

Potential Hepatotoxins Found in Herbal Medicinal Products: A Systematic Review

The risk of liver injury associated with the use of herbal medicinal products (HMPs) is well known among physicians caring for patients under a HMP therapy, as documented in case reports or case series and evidenced by using the Roussel Uclaf Causality Assessment Method (RUCAM) to verify a causal relationship. In many cases, however, the quality of HMPs has rarely been considered regarding potential culprits such as contaminants and toxins possibly incriminated as causes for the liver injury. This review aims to comprehensively assemble details of tentative hepatotoxic contaminants and toxins found in HMPs. Based on the origin, harmful agents may be divided according two main sources, namely the phyto-hepatotoxin and the nonphyto-hepatotoxin groups. More specifically, phyto-hepatotoxins are phytochemicals or their metabolites naturally produced by plants or internally in response to plant stress conditions. In contrast, nonphyto-hepatotoxic elements may include contaminants or adulterants occurring during collection, processing and production, are the result of accumulation of toxic heavy metals by the plant itself due to soil pollutions, or represent mycotoxins, herbicidal and pesticidal residues. The phyto-hepatotoxins detected in HMPs are classified into eight major groups consisting of volatile compounds, phytotoxic proteins, glycosides, terpenoid lactones, terpenoids, alkaloids, anthraquinones, and phenolic acids. Nonphyto-hepatotoxins including metals, mycotoxins, and pesticidal and herbicidal residues and tentative mechanisms of toxicity are discussed. In conclusion, although a variety of potential toxic substances may enter the human body through HMP use, the ability of these toxins to trigger human liver injury remains largely unclear.

Do Battlefield Injury-acquired Indwelling Metal Fragments Induce Metal Immunogenicity?

BACKGROUND

A battlefield-related injury results in increased local and systemic innate immune inflammatory responses, resulting in wound-specific complications and an increased incidence of osteoarthritis. However, little is known about whether severe injuries affect long-term systemic homeostasis, for example, immune function. Moreover, it also remains unknown whether battlefield-acquired metal fragments retained over the long term result in residual systemic effects such as altered immune reactivity to metals.

QUESTIONS/PURPOSES

Does a retained metal fragment from a battlefield injury contribute to increased (1) adaptive metal-specific immune responses, (2) systemically elevated metal ion serum levels, and (3) serum immunoglobulin levels compared with combat injuries that did not result in a retained metal fragment?

METHODS

In this pilot study, we analyzed metal-immunogenicity in injured military personnel and noninjured control participants using lymphocyte transformation testing (LTT, lymphocyte proliferation responses to cobalt, chromium and nickel challenge at 0.001, 0.01 and 0.1-mM concentrations in triplicate for each participant), serum metal ion analysis (ICP-mass spectroscopy), and serum immunoglobulin analysis (IgE, IgG, IgA, and IgM ). Military personnel with a battlefield-sustained injury self-recruited without any exclusion for sex, age, degree of injury. Those with battlefield injury resulting in retained metal fragments (INJ-FRAG, n = 20 male, mean time since injury ± SD was 12 ± 10 years) were compared with those with a battlefield injury but without retained metal fragments (INJ-NO-FRAG, n = 12 male, mean time since injury ± SD was 13 ± 12 years). A control group comprised of male noninjured participants was used to compare measured immunogenicity metrics (n = 11, males were selected to match battlefield injury group demographics).

RESULTS

Military participants with sustained metal fragments had increased levels of metal-induced lymphocyte responses. The lymphocyte stimulation index among military participants with metal fragments was higher than in those with nonretained metal fragments (stimulation index = 4.2 ± 6.0 versus stimulation index = 2.1 ± 1.2 (mean difference 2.1 ± 1.4 [95% confidence interval 5.1 to 0.8]; p = 0.07) and an average stimulation index = 2 ± 1 in noninjured controls. Four of 20 participants injured with retained fragments had a lymphocyte proliferation index greater than 2 to cobalt compared with 0 in the group without a retained metal fragment or 0 in the control participants. However, with the numbers available, military personnel with retained metal fragments did not have higher serum metal ion levels than military participants without retained metal fragment-related injuries or control participants. Military personnel with retained metal fragments had lower serum immunoglobulin levels (IgG, IgA, and IgM) than military personnel without retained metal fragments and noninjured controls, except for IgE. Individuals who were metal-reactive positive (that is, a stimulation index > 2) with retained metal fragments had higher median IgE serum levels than participants who metal-reactive with nonmetal injuries (1198 ± 383 IU/mL versus 171 ± 67 IU/mL, mean difference 1027 ± 477 IU/mL [95% CI 2029 to 25]; p = 0.02).

CONCLUSIONS

We found that males with retained metal fragments after a battlefield-related injury had altered adaptive immune responses compared with battlefield-injured military personnel without indwelling metal fragments. Military participants with a retained metal fragment had an increased proportion of group members and increased average lymphocyte reactivity to common implant metals such as nickel and cobalt. Further studies are needed to determine a causal association between exposure to amounts of retained metal fragments, type of injury, personnel demographics and general immune function/reactivity that may affect personal health or future metal implant performance.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

The interactions between iron and copper in genetic iron overload syndromes and primary copper toxicoses in Japan

Iron and copper are trace elements essential for health, and iron metabolism is tightly regulated by cuproproteins. Clarification of the interactions between iron and copper may provide a better understanding of the pathophysiology and treatment strategy for hemochromatosis, Wilson disease, and related disorders. The hepcidin/ferroportin system was used to classify genetic iron overload syndromes in Japan, and ceruloplasmin and ATP7B were introduced for subtyping Wilson disease into the severe hepatic and classical forms. Interactions between iron and copper were reviewed in these genetic diseases. Iron overload syndromes were classified into pre-hepatic iron loading anemia and aceruloplasminemia, hepatic hemochromatosis, and post-hepatic ferroportin disease. The ATP7B-classical form with hypoceruloplasminemia has primary hepatopathy and late extra-hepatic complications, while the severe hepatic form is free from ATP7B mutation and hypoceruloplasminemia, and silently progresses to liver failure. A large amount of iron and trace copper co-exist in hepatocellular dense bodies of all iron overload syndromes. Cuproprotein induction to stabilize excess iron should be differentiated from copper retention in Wilson disease. The classical form of Wilson disease associated with suppressed hepacidin25 secretion may be double-loaded with copper and iron, and transformed to an iron disease after long-term copper chelation. Iron disease may not be complicated with the severe hepatic form with normal ferroxidase activity. Hepatocellular dense bodies of iron overload syndromes may be loaded with a large amount of iron and trace copper, while the classical Wilson disease may be double-loaded with copper and iron.

Organ-specific regulation of ATP7A abundance is coordinated with systemic copper homeostasis

Copper (Cu) is an essential cofactor for various enzymatic activities including mitochondrial electron transport, iron mobilization, and peptide hormone maturation. Consequently, Cu dysregulation is associated with fatal neonatal disease, liver and cardiac dysfunction, and anemia. While the Cu transporter ATP7A plays a major role in both intestinal Cu mobilization to the periphery and prevention of Cu over-accumulation, it is unclear how regulation of ATP7A contributes to Cu homeostasis in response to systemic Cu fluctuation. Here we show, using Cu-deficient mouse models, that steady-state levels of ATP7A are lower in peripheral tissues (including the heart, spleen, and liver) under Cu deficiency and that subcutaneous administration of Cu to these animals restore normal ATP7A levels in these tissues. Strikingly, ATP7A in the intestine is regulated in the opposite manner - low systemic Cu increases ATP7A while subcutaneous Cu administration decreases ATP7A suggesting that intestine-specific non-autonomous regulation of ATP7A abundance may serve as a key homeostatic control for Cu export into the circulation. Our results support a systemic model for how a single transporter can be inversely regulated in a tissue-specific manner to maintain organismal Cu homeostasis.

Dynamic changes in serum cytokine levels and their clinical significance in predicting acute GVHD

To explore the clinical significance of cytokines and biochemical tests in acute graft-versus-host disease (aGVHD), we detected the concentrations of 8 cytokines and 19 conventional biochemical markers in the sera of aGVHD and non-GVHD patients throughout the process of allogeneic hematopoietic stem cell transplantation and the onset of aGVHD. Predictive models were then established using the 27 indices, and models were verified by a prospective trial. The 27 indices showed significant differences between aGVHD patients and non-GVHD control subjects (two-tailed p<0.05) prior to transplantation and before the onset of aGVHD. Our models, established by binary logistic regression on days +7 and +14, showed a significant absolute capacity of predicting grade 2∼4 aGVHD with positive and negative predictive values of at least 70%. Our data showed that the progression of aGVHD could induce dynamic changes in the levels of serum cytokines and biochemical markers. Because most of these tests were less specific for aGVHD, these changes were easily neglected in clinical work. However, by combining cytokine and biochemical tests, the established prediction model can greatly improve the ability of these biomarkers to predict the development of aGVHD one or two weeks earlier.

Formononetin protects against acetaminophen-induced hepatotoxicity through enhanced NRF2 activity

To examine the effects of formononetin (FMN) on Acetaminophen (APAP)-induced liver injury in vitro and in vivo. Human non-tumor hepatic cells LO2 were pretreated with either vehicle or FMN (20, 40 μM), for 6 h, followed by incubation with or without APAP (10 mM) for 24 h. In an in vivo assay, male BALB/c mice were randomly divided into four groups: (1) control group; (2) APAP group; (3) APAP + FMN (50 mg/Kg); (4) APAP + FMN (100 mg/Kg). The mice in the control and APAP groups were pre-treated with vehicle; the other two groups were pretreated daily with FMN (50, 100 mg/Kg) orally for 7 consecutive days. After the final treatment, acute liver injury was induced in all groups, except the control group, by intraperitoneal (i.p.) injection of 300 mg/Kg APAP. In LO2 cells, APAP exposure decreased the cell viability and glutathione (GSH) content, which were both greatly restored by FMN pretreatment. Overdose of APAP increased hepatic malondialdehyde (MDA) content, serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity in experimental mice. Supplementation with 100 mg/Kg FMN significantly reduced APAP-induced elevated levels of MDA (1.97 ± 0.27 vs 0.55 ± 0.14 nmol/mg protein, p < 0.001), ALT (955.80 ± 209.40 vs 46.90 ± 20.40 IU/L, p < 0.001) and AST (1533.80 ± 244.80 vs 56.70 ± 28.80 IU/L, p < 0.001), and hepatic GSH level (5.54 ± 0.93 vs 8.91 ± 1.11 μmol/mg protein, p < 0.001) was significantly increased. These results were further validated by histopathology and TdT-mediated biotin-dUTP nick-endlabeling (TUNEL) staining, pretreatment with 100 mg/Kg FMN significant decreased APAP-induced hepatocellular damage and cell apoptosis (36.55 ± 3.82 vs 2.58 ± 1.80%, p < 0.001). Concomitantly, FMN stimulated the expression of Nrf2 and antioxidant gene expression in the presence of APAP. These data provide an experimental basis for the use of FMN in the treatment of patients with APAP-induced hepatotoxicity.

Canine Liver Iron, Copper, and Zinc Concentrations and Association with Histologic Lesions

Concentrations of iron, copper, and zinc were measured in livers of 95 dogs that were suspected of having liver disease. Iron concentrations ranged from 177 to 7,680 ppm (dry weight basis); 54 dogs had iron concentrations greater than the normal concentration of 1,200 ppm. Iron stores were present in Kupffer cells and macrophages but not hepatocytes. The dogs did not have lesions of hemochromatosis. Dogs with high liver iron tended to have high liver copper and inflammatory lesions. High liver copper concentrations usually were associated with hepatocellular necrosis and fibrosis. High liver zinc was found in only 5 animals and was accompanied by histologic inflammatory lesions in one. In humans, increased iron concentration in the liver exacerbates liver damage caused by a variety of insults, and the same may be true for dogs.

Acute Hepatic Phenotype of Wilson Disease: Clinical Features of Acute Episodes and Chronic Lesions Remaining in Survivors

BACKGROUND AND AIMS

Wilson disease (WD) is an inherited disorder of copper metabolism, and an international group for the study of WD (IGSW) has proposed three phenotypes for its initial presentation: acute hepatic, chronic hepatic, and neurologic phenotypes. Characterization of the acute hepatic phenotype may improve our understanding of the disease.

METHODS

Clinical features of 10 WD patients with the acute hepatic phenotype and characteristics of chronic lesions remaining in survivors were assessed by the European Association for the Study of the Liver (EASL) guidelines.

RESULTS

All six patients younger than 30 years had survived an acute episode of hemolytic anemia with residual liver disease of cirrhosis or chronic hepatitis. The acute episode was self-limiting in two of the four patients over the age of 30 years and progressed to acute liver failure in the other two patients. One of the two survivors had residual liver disease of chronic hepatitis, while the other had chronic hepatitis and neurologic disease. Neurologic disease remained in a patient who successfully received a liver transplantation. During acute episodes, serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) changed rapidly along with anemia. Liver-specific ALT levels were age-dependently correlated with hemoglobin (Hb) concentrations. Enzyme reduction was milder for AST than ALT, which resulted in a high AST/ALT ratio in the anemic stage. The anemic stage in two patients transformed to acute liver failure.

CONCLUSIONS

All survivors of an acute episode of the acute hepatic phenotype had residual liver disease or both liver and neurologic diseases. The rapid changes in liver enzymes during the acute episode and the liver and neurologic diseases remaining in survivors may provide a better understanding of WD.

Toxicity of copper on isolated liver mitochondria: impairment at complexes I, II, and IV leads to increased ROS production

Oxidative damage has been implicated in disorders associated with abnormal copper metabolism and also Cu(2+) overloading states. Besides, mitochondria are one of the most important targets for Cu(2+), an essential redox transition metal, induced hepatotoxicity. In this study, we aimed to investigate the mitochondrial toxicity mechanisms on isolated rat liver mitochondria. Rat liver mitochondria in both in vivo and in vitro experiments were obtained by differential ultracentrifugation and the isolated liver mitochondria were then incubated with different concentrations of Cu(2+). Our results showed that Cu(2+) induced a concentration and time-dependent rise in mitochondrial ROS formation, lipid peroxidation, and mitochondrial membrane potential collapse before mitochondrial swelling ensued. Increased disturbance in oxidative phosphorylation was also shown by decreased ATP concentration and decreased ATP/ADP ratio in Cu(2+)-treated isolated mitochondria. In addition, collapse of mitochondrial membrane potential (MMP), mitochondrial swelling, and release of cytochrome c following of Cu(2+) treatment were well inhibited by pretreatment of mitochondria with CsA and BHT. Our results showed that Cu(2+) could interact with respiratory complexes (I, II, and IV). This suggests that Cu(2+)-induced liver toxicity is the result of metal's disruptive effect on liver hepatocyte mitochondrial respiratory chain that is the obvious cause of Cu(2+)-induced ROS formation, lipid peroxidation, mitochondrial membrane potential decline, and cytochrome c expulsion which start cell death signaling.

A dual-emission fluorescence-enhanced probe for imaging copper(ii) ions in lysosomes

We have developed the first example of a fluorescence-enhanced and lysosome-targeted Cu²⁺ probe (Lys-Cu) with unique dual-channel emissions. The newly synthesized fluorescent probe Lys-Cu, which contains two recognition sites with different sensing mechanisms for Cu²⁺, displays fluorescence-enhanced dual-channel emissions with fluorescence response to Cu²⁺ in the lysosome pH environment. Fluorescence imaging shows that Lys-Cu is membrane-permeable and suitable for visualization of Cu²⁺ in lysosomes of living cells by dual-channel imaging.

Reactive oxygen species and cytotoxicity in rainbow trout hepatocytes: effects of medium and incubation time

This study evaluated the effects of exposure medium and culture age on intracellular reactive oxygen species (ROS) development and cytotoxicity in fish hepatocytes following exposure to copper (Cu). ROS was quantified using the fluorescent probes DHR 123 and CM-H2DCFDA following exposure to Cu in Leibovitz' medium (L-15) or Tris-buffered saline (TBS). Similarly, culture age effects were investigated using 1-, 2- and 4-day-old cultured hepatocytes by exposing them to Cu in TBS. The exposure in L-15 resulted in significantly higher ROS compared to TBS using CM-H2DCFDA, but not DHR 123. The age of the primary cultures significantly affected the development of ROS for both probes. None of the exposures caused cytotoxicity in the hepatocytes. The results showed that both factors may affect responses to stressors, and suggested that the use of a simple medium such as TBS may be preferable for some applications. It is also preferable to use 1-day-old primary hepatocyte cultures.

Estimation of copper and iron burden in biological samples of various stages of hepatitis C and liver cirrhosis patients

There is accumulative evidence that the metabolism of iron (Fe) and copper (Cu) is altered in human due to infections, indicating that both elements have roles in pathogenesis and progress of viral diseases. In the present study, the correlation of Cu and Fe was evaluate in biological samples (serum and scalp hair) of hepatitis C (hepatitis C virus (HCV)) patients of both genders at different stages. For comparative study, the scalp hair and serum samples of healthy individuals of same age group (30-50 years) and socioeconomic status were collected. The biological samples were analyzed for Fe and Cu by atomic absorption spectroscopy after microwave-assisted acid digestion. The validity and accuracy of methodology were checked by certified reference materials of same matrixes. The levels of Cu and Fe in biological samples were enhanced in hepatic disorder patients, including acute (after diagnosis test, anti-HCV sero-positive) hepatic fibrosis and liver cirrhosis as compared to healthy referents. The difference was significant (p < 0.01) in the case of liver cirrhotic patients. It was observed that the data of Cu and Fe in referents and patients of both genders had normal distributions. The inter-elemental correlation (r) among Cu vs Fe in serum and scalp hair samples of referents and patients were not significant in both genders (p > 0.1) except in the first stage of HCV (p < 0.1). It was concluded that the increase of Cu and Fe content in human body seems to contribute to the development of cirrhosis in patients with viral hepatitis C.

Role of drinking water copper in pathogenesis of oral submucous fibrosis: a prospective case control study

Although oral submucous fibrosis (OSMF) is thought to be multifactorial in origin, the chewing of areca nut is thought to be the main cause. Alkaloids and tannins in areca nut are responsible for fibrosis, but recent evidence has suggested that copper ions are also an important mediator, and in a small pilot study we recently found that OSMF was significantly associated with a raised concentration of copper in drinking water. We have further investigated this association in a heterogeneous population in Hyderabad-Karnataka, India, a region with a high incidence of the condition. We evaluated 3 groups, each of 100 patients: those with OSMF who chewed gutkha, those who chewed gutkha but did not have OSMF, and healthy controls who did not chew gutkha. The difference between the groups in the mean concentration of copper in water measured by atomic absorption spectrometry was significant (p<0.001). There were also significant differences between the groups in mean concentrations of serum copper, salivary copper, and ceruloplasmin (p<0.001). Our results confirm that copper in drinking water contributes to the pathogenesis of OSMF, but ingestion of copper is unlikely to be the sole cause.

Selectively sensing first-row transition metal ions through fluorescence enhancement

Fluorescence signaling systems that give enhancement in the presence of first-row transition metal ions are discussed.

Investigation of Alteration in the Levels of Iron and Copper in Scalp Hair Samples of Patients Having Different Types of Viral Hepatitis

The aim of this study was to measure the alterations of copper and iron contents in scalp hair samples of hepatitis A-E patients of both genders, same age group, and socioeconomic status. For comparative study, the scalp hair samples of healthy individuals of the same age and socioeconomic status were collected. The concentrations of copper and iron were measured using an atomic absorption spectrophotometer, after microwave-assisted acid digestion. The validity and accuracy of methodology was checked using a certified reference material. The results of this study showed that the mean values of copper and iron were higher in scalp hair samples of hepatitis patients than those of age-matched control subjects, while the difference was significant in the cases of patients having viral hepatitis B, C, and D as compared to those who have viral hepatitis A and E (p < 0.001). It was concluded that the overload of copper and iron in the human body may cause lipid peroxidation and eventually damage the hepatic system.

Lead, mercury, cadmium, chromium, nickel, copper, zinc, calcium, iron, manganese and chromium (VI) levels in Nigeria and United States of America cement dust

This study was aimed at investigating the relative abundance of heavy metals in cement dust from different cement dust factories in order to predict their possible roles in the severity of cement dust toxicity. The concentrations of total mercury (Hg), copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), manganese (Mn), lead (Pb), iron (Fe) and chromium (VI) (Cr (VI)) levels in cement dust and clinker samples from Nigeria and cement dust sample from the United States of America (USA) were determined using graphite furnace atomic absorption (GFAAS), while Zn and Ca were measured by flame atomic absorption spectrophotometry (FAAS), and Cr (VI) by colorimetric method. Total Cu, Ni and Mn were significantly higher in cement dust sample from USA (p<0.05), also, both total Cr and Cr (VI) were 5.4-26 folds higher in USA cement dust compared with Nigeria cement dust or clinker (p<0.001). Total Cd was higher in both Nigeria cement dust and clinker (p<0.05 and p<0.001), respectively. Mercury was more in both Nigeria cement dust and clinker (p<0.05), while Pb was only significantly higher in clinker from Nigeria (p<0.001). These results show that cement dust contain mixture of metals that are known human carcinogens and also have been implicated in other debilitating health conditions. Additionally, it revealed that metal content concentrations are factory dependent. This study appears to indicate the need for additional human studies relating the toxicity of these metals and their health impacts on cement factory workers.

Evaluation of the possible role of copper ions in drinking water in the pathogenesis of oral submucous fibrosis: a pilot study

We aimed to investigate the concentration of copper ions in drinking water and to assess whether copper has a role in the pathogenesis of oral submucous fibrosis (OSMF). We studied 50 patients with clinically and histologically diagnosed OSMF from the Yadgir district of Karnataka in India. Fifty healthy people matched for age and sex were used as controls. In both groups concentrations of copper ions in serum, saliva, and home drinking water were measured using atomic absorption spectroscopy and intelligent nephelometry technology. Serum ceruloplasmin concentrations were also estimated in both groups. The mean (SD) concentration of copper in the home drinking water of patients with OSMF was significantly higher (764.3 (445.9)μmol/L) than in the controls (305.7 (318.5)μmol/L) (p<0.001). Patients with OSMF also had a significantly higher copper concentrations in serum and saliva, and serum ceruloplasmin than controls (p<0.001). For the first time these data have shown a positive association between copper concentrations in home drinking water and OSMF. It raises the possibility that increased copper in drinking water contributes to the development of OSMF, and adds to that ingested when areca nut is chewed.

Subacute inhalation toxicity assessment of fly ash from industrial waste incinerators

Fly ash from industrial waste incinerators has been a significant concern because of their constituent toxic heavy metals and organic compounds. The objective of this study was to identify the subacute inhalation toxicity of fly ash from industrial waste incinerators, using whole body inhalation exposure chambers. Male and female groups of Sprague-Dawley rats were exposed to fly ash by inhalation of concentrations of 0, 50, 100, 200 mg/m(3), for 6 h/day, 5 days/week for 4 weeks. There was no significant difference in body weight, and relative organ weight to body weight, between the exposure groups and the control group. Hematological examinations revealed a significant increase of monocyte counts in fly ash exposed rats and brown pigment laden macrophage was found in the lungs of rats exposed to high concentration of fly ash. A decrease of blood glucose levels and an increase in glutamate oxaloacetate transaminase activity were observed in fly ash treated rats. There was also a significant increase of lactate dehydrogenase levels in rat blood exposed fly ash. A significant dose-dependent increase of DNA damage was found in lymphocytes, spleen, bronchoalveolar lavage, liver, lung, and thymus of rats exposed to fly ash. In addition, the level of lipid peroxidation was increased in the plasma of rats exposed to a high concentration of fly ash. These results suggest that inhalation of fly ash from industrial waste incinerators can induce histopathologic, hematological, and serum biochemical changes and oxidative damage.

The relationship between copper and steatosis in Wilson's disease

BACKGROUND AND AIMS

The histological similarities seen in Wilson's disease (WD) and non-alcoholic steatohepatitis (NASH) led us to verify possible correlations between glucose and/or lipid and/or iron metabolism alterations and hepatic steatosis in WD patients.

METHODS

Thirty-five WD patients (20 females, 15 males, mean age 40.1 ± 5.4 years), and 44 NASH patients (25 females, 19 males, mean age 42.8 ± 6.7 years) were enrolled in the study. BMI, total/HDL/LDL-cholesterol, triglycerides and glucose serum levels were established in all subjects. HOMA index was calculated. Percutaneous liver biopsy with quantitative evaluation of steatosis and copper tissue content was performed in all WD patients and in NASH control group.

RESULTS

Significant difference was seen in baseline serum levels of glucose, HOMA index, total cholesterol, triglycerides, and ferritin between the WD group and NASH group (P<0.05) but steatosis scored was similar between two groups. No correlation between the level of steatosis and metabolic factors studied was highlighted. In WD, hepatic parenchymal copper concentration was 753 ± 65.3 mcg/g dry weight against 54.5 ± 16.9 mcg/g dry weight in NASH patients (P<0.05). Higher liver copper concentrations were seen in patients with severe steatosis compared to those with mild (P=0.004) and moderate, (P=0.038) steatosis. Positive significant correlation between liver copper content and steatosis scores (r=0.87; r(2)=0.76) was observed.

CONCLUSIONS

The hepatic steatosis in WD is not induced by metabolic comorbidities but by the accumulation of copper in the liver tissue. The hypothesise that the metabolic alterations could be co-factors in the pathogenesis of steatosis in these patients cannot be excluded.

Panmasala chewing induces deterioration in oral health and its implications in carcinogenesis

ABSTRACT Panmasala containing tobacco was introduced in the Indian market during the 1970s. Panmasala consists of areca nut (betel nut), catechu, lime, cardamom, spices, and unspecified flavoring agents, etc., with tobacco locally known as gutkha or without tobacco (Plain or sada), and consumed abundantly in India and also other parts of the world, predominantly in South East Asian countries. Available studies demonstrate that the habits of chewing panmasala gutkha or plain by students and adolesescents are on the increase, which may lead to deterioration of oral health and other organ systems. Based on the experimental as well as clinical studies available on panmasala as well as on different components of panmasala, this review suggests that it has the potential in causation of various oral diseases such as Oral Sub Mucosis Fibrosis (OSMF) and leucoplakia which may lead to oral cancer. Studies reviewed on these chewing mixtures also reveal that it is likely to be carcinogenic, as tobacco and areca nut have carcinogenic potential and both have encompassing addictive potential leading to dependence on chewing mixture containing areca nut and tobacco. These mixtures might not only lead to cancer but may also affect other organs of the body, including oral hard tissues in the form of dental attrition and sensitivity. There is a need to consider the potential health hazards associated with the habits of these products, especially oral cancer. More research is needed to find out early changes which could be reversible and also intervention measures through education to desist people in indulging in such habits.

Hemochromatosis gene mutations: prevalence and effects on pegylated-interferon and ribavirin therapy response in chronic hepatitis C in sardinia

BACKGROUND/AIMS

Considerable evidence suggests that iron could be a comorbid factor for liver injury in chronic hepatitis C (CHC). Elevated iron indices are frequently described in CHC and may impact negatively on the course of liver disease and on the response to interferon alfa therapy. The aim of this study was to evaluate the frequency of hemochromatosis gene mutations in Sardinian CHC patients, the association with iron overload and the impact on response to therapy.

METHODS

Sixty-nine CHC patients were enrolled. Iron indices, hepatic and viral parameters were detected. C282Y, H63D and S65C mutations were identified through a PCR. Liver biopsy was performed for hepatic fibrosis evaluation. All patients were treated for 6 months (viral genotype 2/3) or 12 months (viral genotype 1/4) with pegylated-interferon 180 mcg once weekly and ribavirin 1000-1200 mg/daily. Sustained virological response (SVR) was defined as undetectable HCV RNA 24 weeks after the end of treatment.

RESULTS

HFE gene mutation was detected in 29 patients (42%). The presence of HFE mutations was significantly associated with elevated transferrin saturation (P < 0.01). Hepatic fibrosis was more advanced in HFE mutation carriers (χ (2), P = 0.04). Among mutation carriers 27.5% achieved responses at the end of treatment compared with 60% of non-carriers (P = 0.005). Patients with HFE wildtype produced significant SVR compared with patients with HFE mutations (P = 0.03).

CONCLUSIONS

The literature shows discordant results about the prevalence, hepatic distribution and possible therapeutic implications of iron overload in chronic hepatitis C. Our findings shows that HFE gene mutations could favor, synergically with CHC and other genetic or acquired factors, the development of liver damage and could influence the outcome of interferon treatment with higher rate of non-response.

Effect of copper chloride exposure on the membrane potential and cytosolic free calcium in primary cultured chicken hepatocytes

This study was conducted to examine the effects of copper on membrane potential and cytosolic free calcium in isolated primary chicken hepatocytes which were exposed to different concentration of Cu(2+) (0, 10, 50, 100 μM) or a mixture of Cu(2+) and vitamin C (50 and 50 μM, respectively). Viability, membrane potential, and cytosolic free Ca(2+) of monolayer cultured hepatocytes were investigated at the indicated time point. Results showed that, among the different concentrations of Cu(2+) exposure, the viability of hepatocytes treated with 100 μM Cu(2+) was the worst at the 12th and 24th hours. The effects of Cu(2+) on viability and proliferation were time and dose dependent. Further investigation indicated that Cu(2+) exposure significantly enhanced cytosolic free Ca(2+) in hepatocytes, compared to that in control group, at the 24th hour. Meanwhile, membrane potential was noticeably reduced in hepatocytes increasing concentration of Cu(2+). Taking these results together, we have shown that Cu(2+) can cause toxicity to primary chicken hepatocytes in excessive dose and the effect of Cu(2+) exposure on membrane potential is not site specific, which is probably mediated by the changes of cytosolic free Ca(2+).

Penicillamine increases free copper and enhances oxidative stress in the brain of toxic milk mice

Wilson disease (WD) is characterized by the accumulation of copper arising from a mutation in the ATP7B gene. Penicillamine (PA) makes 10–50% of the patients with neurologic symptoms neurologically worse at the early stage of administration. The aim of this study was to determine how the copper metabolism changes and whether the change impairs the brain of toxic milk (tx) mice, an animal model of WD, during the PA administration. The free copper and protein-bound copper concentrations in the serum, cortex and basal ganglia of tx mice with PA administration for 3 days, 10 days and 14 days, respectively, were investigated. The expression of copper transporters, ATP7A and CTR1,was analyzed by real-time quantitative PCR, immunofluorescence and Western blot. Then SOD, MDA and GSH/GSSG were detected to determine whether the oxidative stress changed correspondingly. The results revealed the elevated free copper concentrations in the serum and brain, and declined protein-bound copper concentrations in the brain of tx mice during PA administration. Meanwhile, transiently increased expression of ATP7A and CTR1 was observed generally in the brain parenchyma by immunofluorescence, real-time quantitative PCR and Western blot. Additionally, ATP7A and CTR1 were observed to locate mainly at Golgi apparatus and cellular membrane respectively. Intense staining of ATP7A in the choroid plexus was found in tx mice on the 3rd and 10th day of PA treatment, but rare staining of ATP7A and CTR1 in the blood-brain barrier (BBB). Decreased GSH/GSSG and increased MDA concentrations were also viewed in the cortex and basal ganglia. Our results suggested the elevated free copper concentrations in the brain might lead to the enhanced oxidative stress during PA administration. The increased free copper in the brain might come from the copper mobilized from brain parenchyma cells but not from the serum according to the ATP7A and CTR1 expression analysis.

Decreased serum antioxidant capacity in patients with Wilson disease is associated with neurological symptoms

BACKGROUND & AIMS

Wilson disease (WD) is an inherited disorder of copper disposition caused by an ATP7B transporter gene mutation, leading to copper accumulation in predisposed tissues. In addition to a genetic predisposition, other factors are likely to contribute to its clinical manifestation. The aim of the study was to assess whether oxidative stress affects the phenotypic manifestation of WD.

METHODS

In 56 patients with WD (29 men; 26 with the hepatic form, 22 with the neurologic form, and eight asymptomatic; mean age 38.5 ± 12 years), total serum antioxidant capacity (TAC) and inflammatory parameters (hs-CRP, IL-1β, IL-2, IL-6, IL-10, and TNF-α) were analyzed and related to the clinical manifestation, and mutations of the ATP7B gene. The control group for the TAC and inflammatory parameters consisted of 50 age- and gender-matched healthy individuals.

RESULTS

WD patients had a significantly lower TAC (p < 0.00001), lower IL-10 levels (p = 0.039), as well as both higher IL-1β (p = 0.019) and IL-6 (p = 0.005) levels compared to the control subjects. TNF-α, hs-CRP, and IL-2 did not differ from the controls. Patients with the neurological form of WD had a significantly lower TAC than those with the hepatic form (p < 0.001). In addition, the lower TAC was associated with the severity of the neurological symptoms (p = 0.02). No relationship between the inflammatory parameters and clinical symptoms was found.

CONCLUSIONS

Data from our study suggest that the increased oxidative stress contributes significantly to the clinical manifestation of WD; as a lower TAC is associated with the neurological symptoms in WD patients.

Copper sulfate affects Nile tilapia (Oreochromis niloticus) cardiomyocytes structure and contractile function

Copper sulfate (CuSO(4))is an inorganic chemical product worldwide used as an algaecide and a fungicide in aquaculture and agriculture and being discharged into freshwater environments where it can affect the freshwater fauna, especially fishes. The impact of copper on fish cardiac function was analyzed in two groups of Nile tilapias, Oreochromis niloticus (control group and group exposed to 1 mg l(-1) of CuSO(4) for 96 h). Structural and ultra-structural changes were studied and related to perturbations of the inotropic and chronotropic responses of ventricle strips. Fish of Cu exposed group did not show significant alterations in the medium diameter and in the percentage of collagen in the cardiac myocytes when evaluated through the light microscope. However, the ultrastructural analysis revealed cellular swelling followed by mitochondrial swelling. The myofibrils did not show significant variations among groups. Force contraction was significantly decreased, and rates of time to tension increase (contraction) and decrease (relaxation) were significantly augmented after copper exposure. The results suggest that the copper sulfate impairs the oxidative mitochondrial function and consequently alters the cardiac performance of this species.

Longitudinal analysis of serum miR-122 in a rat model of Wilson's disease

PURPOSE

MicroRNA-122 (miR-122) has recently been shown to represent a novel biomarker of liver disease. However, the presence of serum miR-122 after liver injury was mostly studied at singular time points. The course of serum miR-122 was determined at consecutive time points during the onset of disease.

METHODS

Fulminant hepatitis was induced by a high-copper diet in Long-Evans Cinnamon (LEC) rats that were used as models for Wilson's disease (WD). Levels of serum miR-122, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and liver histology were determined.

RESULTS

Toxic copper given to isolated hepatocytes induced release of miR-122 into the tissue culture medium. Levels of serum miR-122 were highly elevated (21.9 ± 5) in LEC rats after high-copper diet in fulminant hepatitis, whereas healthy rats showed low (<0.6) baseline levels of miR-122. Levels of miR-122 in the serum of LEC rats after high-copper diet continuously increased for about 4 weeks prior to the onset of fulminant hepatitis. In most of the animals (77.8%), significantly increased levels of miR-122 were detected about 2 weeks (13.7 ± 2 days) earlier as compared to hepatitis-associated serum markers ALT, AST, and bilirubin. Analysis of miR-122 in survivors after cell-based therapy of WD demonstrated a rapid decrease of miR-122 levels following hepatocyte transplantation. miR-122 expression in the serum was normalized to baseline levels in most of the (4/5) survivors.

CONCLUSION

Our results suggest that longitudinal analysis of miR-122 allows detection of severe liver disease at an early stage and might be excellently suited to monitor therapy, at least when severe liver disease can be restored as observed after cell-based therapy of WD.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s12072-012-9348-5) contains supplementary material, which is available to authorized users.

Iron overload in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is a major causative agent of chronic liver disease worldwide, but the actual mechanisms responsible for liver injury remain unclear. NAFLD includes a spectrum of clinical entities ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) with possible evolution to cirrhosis and hepatocellular carcinoma. Iron is considered a putative element that interacts with oxygen radicals in inducing liver damage/fibrosis and insulin resistance. The role of hepatic iron in the progression of NASH remains controversial, but in some patients, iron may have a role in the pathogenesis of NASH. Though genetic factors, insulin resistance, dysregulation of iron-regulatory molecules, erythrophagocytosis by Kupffer cells may be responsible for hepatic iron accumulation in NASH, exact mechanisms involved in iron overload remain to be clarified. Iron reduction therapy such as phlebotomy or iron-restricted diet may be promising in patients with NAFLD/NASH to reduce hepatic injury as well as insulin resistance. Larger controlled trials of longer duration are warranted to assess the long-term clinical benefit of phlebotomy and/or iron-restricted diet in NAFLD/NASH.