Levels of serum ceruloplasmin associate with pediatric nonalcoholic fatty liver disease

Obeticholic acid's effect on HDL function in MASH varies by diabetic status

Inflammation and oxidative stress are the key factors in the pathogenesis of both metabolic dysfunction-associated steatohepatitis (MASH) and atherosclerosis. Obeticholic acid (OCA), a farnesoid X receptor (FXR) agonist, improves hepatic inflammation and fibrosis in patients with MASH. However, it also reduces HDL cholesterol, suggesting that OCA may increase cardiovascular disease (CVD) risk in patients with MASH. We assessed HDL cholesterol efflux function, antioxidant (paraoxonase and ceruloplasmin activity), pro-inflammatory index, and particle sizes in a small group of patients with and without diabetes (n = 10/group) at baseline and after 18 months of OCA treatment. Patients on lipid-lowering medications (statins, fibrates) were excluded. At baseline, ferritin levels were higher in patients with MASH without diabetes (336.5 [157.0, 451.0] vs. 83 [36.0, 151.0] ng/mL, p < 0.005). Markers of HDL functions were similar in both groups. OCA therapy significantly improved liver histology and liver enzymes but increased alkaline phosphatase levels in nondiabetic patients with MASH (p < 0.05). However, it did not have any significant effect on cholesterol efflux and the antioxidant paraoxonase functions. In nondiabetics, ceruloplasmin (CP) antioxidant activity decreased (p < 0.005) and the pro-inflammatory index of HDL increased (p < 0.005) due to OCA therapy. In contrast, in diabetics, OCA increased levels of pre-β-HDL-the HDL particles enhanced protective capacity (p = 0.005) with no alteration in HDL functionality. In all patients, serum glucose levels were negatively correlated with OCA-induced change in pro-inflammatory function in HDL (p < 0.001), which was primarily due to diabetes (p = 0.05). These preliminary results suggest a distinct effect of OCA therapy on diabetic and nondiabetic patients with MASH and warrant a future large-scale study.

Elucidating cuproptosis in metabolic dysfunction-associated steatotic liver disease

Emerging research into metabolic dysfunction-associated steatotic liver disease (MASLD) up until January 2024 has highlighted the critical role of cuproptosis, a unique cell death mechanism triggered by copper overload, in the disease's development. This connection offers new insights into MASLD's complex pathogenesis, pointing to copper accumulation as a key factor that disrupts lipid metabolism and insulin sensitivity. The identification of cuproptosis as a significant contributor to MASLD underscores the potential for targeting copper-mediated pathways for novel therapeutic approaches. This promising avenue suggests that managing copper levels could mitigate MASLD progression, offering a fresh perspective on treatment strategies. Further investigations into how cuproptosis influences MASLD are essential for unraveling the detailed mechanisms at play and for identifying effective interventions. The focus on copper's role in liver health opens up the possibility of developing targeted therapies that address the underlying causes of MASLD, moving beyond symptomatic treatment to tackle the root of the problem. The exploration of cuproptosis in the context of MASLD exemplifies the importance of understanding metal homeostasis in metabolic diseases and represents a significant step forward in the quest for more effective treatments. This research direction lights path for innovative MASLD management and reversal.

Lipid dysmetabolism in ceruloplasmin-deficient mice revealed both in vivo and ex vivo by MRI, MRS and NMR analyses

Ceruloplasmin (Cp) is a ferroxidase that plays a role in cellular iron homeostasis and is mainly expressed in the liver and secreted into the blood. Cp is also produced by adipose tissue, which releases it as an adipokine. Although a dysfunctional interaction of iron with the metabolism of lipids has been associated with several metabolic diseases, the role of Cp in adipose tissue metabolism and in the interplay between hepatocytes and adipocytes has been poorly investigated. We previously found that Cp-deficient (CpKO) mice become overweight and demonstrate adipose tissue accumulation together with liver steatosis during aging, suggestive of lipid dysmetabolism. In the present study, we investigated the lipid alterations which occur during aging in adipose tissue and liver of CpKO and wild-type mice both in vivo and ex vivo. During aging of CpKO mice, we observed adipose tissue accumulation and liver lipid deposition, both of which are associated with macrophage infiltration. Liver lipid deposition was characterized by accumulation of triglycerides, fatty acids and ω-3 fatty acids, as well as by a switch from unsaturated to saturated fatty acids, which is characteristic of lipid storage. Liver steatosis was preceded by iron deposition and macrophage infiltration, and this was observed to be already occurring in younger CpKO mice. The accumulation of ω-3 fatty acids, which can only be acquired through diet, was associated with body weight increase in CpKO mice despite food intake being equal to that of wild-type mice, thus underlining the alterations in lipid metabolism/catabolism in Cp-deficient animals.

Involvement of essential trace elements in the pathogenesis of hepatitis C virus‑related chronic liver disease and nonalcoholic steatohepatitis

Essential trace elements are involved in the pathogenesis of chronic liver disease (CLD), which causes hepatic inflammation, steatosis and fibrosis. The present study investigated the roles of essential trace elements in the pathogenesis of hepatitis C virus-related CLD (CLD-C) and nonalcoholic steatohepatitis (NASH), and compared the levels of these trace elements between the two groups. Serum zinc (Zn), selenium (Se), copper (Cu) and ferritin levels were measured in patients with CLD-C (n=66) and NASH (n=26). Subsequently, the correlations between the levels of these essential trace elements in patient sera and the biochemical or pathological parameters of patients with CLD-C and NASH were determined. The results demonstrated that the serum ferritin levels were significantly correlated with serum alanine aminotransferase levels in both the CLD-C and NASH groups. In both groups, the serum Zn and Se levels were significantly associated with serum albumin levels, and inversely associated with the stages of hepatic fibrosis. Furthermore, serum ferritin levels were positively associated, and serum Zn levels were inversely correlated with the grades of hepatic steatosis in patients with CLD-C, whereas serum Se levels were closely associated with the grades of hepatic steatosis only in patients with NASH. In both groups, serum ferritin levels were positively correlated, and serum Zn levels were inversely correlated with homeostasis model for the assessment of insulin resistance (HOMA-IR) values, and serum Se was negatively correlated with the HOMA-IR values in patients with CLD-C only. In conclusion, these results indicated that the involvement of essential trace elements in insulin resistance and hepatic steatosis may differ slightly between patients with CLD-C and those with NASH.

Relationship between dietary intake components and hepatic fibrosis in those with obesity before and 1 year after bariatric surgery

OBJECTIVES

Non-alcoholic fatty liver disease is highly prevalent in the bariatric population but not all patients develop liver fibrosis. Considering that fibrosis may affect clinical outcomes, it is important to assess and treat contributing factors. In this population, it is not clear whether dietary intake is a contributor. The objective was to determine the relationship between dietary intake components and liver fibrosis before and 1 y after Roux-en-Y gastric bypass (RYGB).

METHODS

This was a prospective cross-sectional (n = 133) study conducted between 2013 and 2022. In addition, a subgroup of 44 patients were followed for 1 y post-RYGB. Anthropometrics, biochemical measurements, and 3-d food records and liver biopsies were obtained presurgery and, in a subgroup of patients, as for the cohort, 1 y post-RYGB.

RESULTS

In the cross-sectional study, 78.2% were female, with a median age of 48 y and body mass index of 46.8 kg/m2; 33.8% had type 2 diabetes mellitus and 57.1% had metabolic syndrome. In a multivariate analysis, age (odds ratio; 95% CI) (1.076; 1.014-1.141), alanine transaminase (1.068; 1.025-1.112), calorie intake (1.001; 1.000-1.002), and dietary copper (0.127; 0.022-0.752) were independently associated with fibrosis (<0.05). At 1 y post-RYGB, no independent risk factors were associated with persistent fibrosis.

CONCLUSIONS

In bariatric patients before surgery, higher age, alanine transaminase, and total calorie and lower copper intakes were independent risk factors associated with liver fibrosis. These relationships were no longer observed after RYGB, likely due to the effect of surgery on weight and similar postsurgery diet among patients.

Overweight and Obesity Are Positively Associated with Serum Copper Levels in Mexican Schoolchildren

Due to its relationship with oxidative stress and inflammation responses, obesity and its cardiometabolic implications have been related with serum copper (Cu). Hence, we analyzed the association of overweight (OW) and obesity (OB) status and cardiometabolic traits with serum Cu level in Mexican schoolchildren. Anthropometrical data and cardiometabolic traits were analyzed in this cross-sectional study. Serum Cu level was measured by inductively coupled plasma mass spectrometry. The study involved 191 schoolchildren (93 girls and 98 boys) with a mean age of 8.054 ± 1.170 years. Children with OW and OB had higher serum Cu levels than children with normal weight (NW) (mean difference: OW vs NW = 51.85 µg dL^-1, OB vs NW = 47.22 µg dL^-1, p < 0.001). In a multiple linear regression model, OW and OB status were positively associated with serum Cu levels (β_OW = 49.85, 95% confidence interval (95% CI) 35.84-63.87, p < 0.001; β_OB = 44.38, 95% CI 27.70-61.05, p < 0.001). We did not identify any significant association between cardiometabolic traits and serum Cu level. In conclusion, our results show an association of the presence of OW and OB with higher serum Cu levels, for the first time in Mexican schoolchildren. However, further functional studies are needed to better understand the role of Cu in the pathophysiology of obesity.

Recent advances in the application of ionomics in metabolic diseases

Trace elements and minerals play a significant role in human health and diseases. In recent years, ionomics has been rapidly and widely applied to explore the distribution, regulation, and crosstalk of different elements in various physiological and pathological processes. On the basis of multi-elemental analytical techniques and bioinformatics methods, it is possible to elucidate the relationship between the metabolism and homeostasis of diverse elements and common diseases. The current review aims to provide an overview of recent advances in the application of ionomics in metabolic disease research. We mainly focuses on the studies about ionomic or multi-elemental profiling of different biological samples for several major types of metabolic diseases, such as diabetes mellitus, obesity, and metabolic syndrome, which reveal distinct and dynamic patterns of ion contents and their potential benefits in the detection and prognosis of these illnesses. Accumulation of copper, selenium, and environmental toxic metals as well as deficiency of zinc and magnesium appear to be the most significant risk factors for the majority of metabolic diseases, suggesting that imbalance of these elements may be involved in the pathogenesis of these diseases. Moreover, each type of metabolic diseases has shown a relatively unique distribution of ions in biofluids and hair/nails from patients, which might serve as potential indicators for the respective disease. Overall, ionomics not only improves our understanding of the association between elemental dyshomeostasis and the development of metabolic disease but also assists in the identification of new potential diagnostic and prognostic markers in translational medicine.

Ceruloplasmin-Deficient Mice Show Dysregulation of Lipid Metabolism in Liver and Adipose Tissue Reduced by a Protein Replacement

Ceruloplasmin is a ferroxidase that plays a role in iron homeostasis; its deficiency fosters inter alia iron accumulation in the liver, which expresses the soluble form of the protein secreted into the bloodstream. Ceruloplasmin is also secreted by the adipose tissue, but its role in adipocytes has been poorly investigated. We hypothesized that ceruloplasmin might have a role in iron/lipid interplay. We investigated iron/lipid dysmetabolism in the liver and adipose tissue of the ceruloplasmin-deficient mouse (CpKO) model of aceruloplasminemia and evaluated the effectiveness of ceruloplasmin replacement. We found that CpKO mice were overweight, showing adipose tissue accumulation, liver iron deposition and steatosis. In the adipose tissue of CpKO mice, iron homeostasis was not altered. Conversely, the levels of adiponectin and leptin adipokines behaved opposite to the wild-type. Increased macrophage infiltration was observed in adipose tissue and liver of CpKO mice, indicating tissue inflammation. The treatment of CpKO mice with ceruloplasmin limited liver iron accumulation and steatosis without normalizing the expression of iron homeostasis-related proteins. In the CpKO mice, the protein replacement limited macrophage infiltration in both adipose and hepatic tissues reduced the level of serum triglycerides, and partially recovered adipokines levels in the adipose tissue. These results underline the link between iron and lipid dysmetabolism in ceruloplasmin-deficient mice, suggesting that ceruloplasmin in adipose tissue has an anti-inflammatory role rather than a role in iron homeostasis. Furthermore, these data also indicate that ceruloplasmin replacement therapy may be effective at a systemic level.

Mineral metabolism and ferroptosis in non-alcoholic fatty liver diseases

Nonalcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease worldwide. Minerals including iron, copper, zinc, and selenium, fulfil an essential role in various biochemical processes. Moreover, the identification of ferroptosis and cuproptosis further underscores the importance of intracellular mineral homeostasis. However, perturbation of minerals has been frequently reported in patients with NAFLD and related diseases. Interestingly, studies have attempted to establish an association between mineral disorders and NAFLD pathological features, including oxidative stress, mitochondrial dysfunction, inflammatory response, and fibrogenesis. In this review, we aim to provide an overview of the current understanding of mineral metabolism (i.e., absorption, utilization, and transport) and mineral interactions in the pathogenesis of NAFLD. More importantly, this review highlights potential therapeutic strategies, challenges, future directions for targeting mineral metabolism in the treatment of NAFLD.

A Novel Non-Invasive Approach Based on Serum Ceruloplasmin for Identifying Non-Alcoholic Steatohepatitis Patients in the Non-Diabetic Population

Background and Aim

Few non-invasive models were established to identify patients with non-alcoholic steatohepatitis (NASH). Liver biopsy remains the gold standard in the clinic. Decreased serum ceruloplasmin (CP) is reported in patients with non-alcoholic fatty liver disease (NAFLD). We aimed to develop a non-invasive model incorporating CP for identifying NASH from NAFLD without type 2 diabetes mellitus (T2DM).

Methods

A total of 138 biopsy-proven patients with NAFLD without T2DM were enrolled. The CP ratio was calculated for standardization as the CP value divided by the lower limit of normal. The clinical, anthropometric, biochemical, and histological parameters were compared between the low and high CP ratio groups divided by the median value. Multivariate logistic regression analysis was performed to develop a model for identifying NASH in patients with NAFLD.

Results

The medians of the high (n = 69) and low (n = 69) CP ratio groups were 1.43 (1.28–1.61) and 1.03 (0.94–1.12), respectively. A comparison of the two groups showed that the severity of steatosis, hepatocellular ballooning, inflammation activity, fibrosis, and liver iron deposition decreased along with the CP ratio (p &lt; 0.05). The median CP ratio of patients with NASH was significantly lower than those with NAFL [1.15 (1.01–1.41) vs. 1.33 (1.24–1.54), p = 0.001]. A novel model which consists of the CP ratio, BMI, and aspartate aminotransferase (AST) was developed. The AUCs of the model in discriminating NASH from NAFLD was 0.796 (0.694–0.899) and 0.849 (0.713–0.984) in the training and validation groups, and 0.836 (0.659–1.000), 0.833 (0.705–0.962), and 0.821 (0.612–1.000) in patients with normal serum alanine aminotransferase, AST, and both levels, respectively.

Conclusions

Decreased CP ratio is associated with more severe histological activity, a diagnosis of NASH, and hepatic iron deposition among patients with NAFLD without T2DM. The CP ratio model could be served as a non-invasive approach to identifying patients with NASH, which might reduce the need for liver biopsy.

Nonalcoholic Fatty Liver Disease and the Gut-Liver Axis: Exploring an Undernutrition Perspective

Nonalcoholic fatty liver disease (NAFLD) is a chronic condition affecting one quarter of the global population. Although primarily linked to obesity and metabolic syndrome, undernutrition and the altered (dysbiotic) gut microbiome influence NAFLD progression. Both undernutrition and NAFLD prevalence are predicted to considerably increase, but how the undernourished gut microbiome contributes to hepatic pathophysiology remains far less studied. Here, we present undernutrition conditions with fatty liver features, including kwashiorkor and micronutrient deficiency. We then review the gut microbiota-liver axis, highlighting key pathways linked to NAFLD progression within both overnutrition and undernutrition. To conclude, we identify challenges and collaborative possibilities of emerging multiomic research addressing the pathology and treatment of undernourished NAFLD.

Serum copper, ceruloplasmin, and their relations to metabolic factors in nonalcoholic fatty liver disease: a cross-sectional study

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) characterized by excessive intrahepatic fat accumulation is increasing worldwide. This study aimed to investigate serum copper (Cu) and ceruloplasmin (Cer) levels and their relations to metabolic factors in NAFLD.

METHODS

This cross-sectional study was conducted on 141 subjects with NAFLD diagnosed using abdominal ultrasonography. Personal information, anthropometric measures, glucose and lipid profile, and serum levels of liver enzymes were assessed. Fasting serum levels of Cu and Cer were determined using colorimetry and nephelometry assay, respectively. Odds ratios (ORs) were used to examine the associations of serum Cu and Cer levels with NAFLD risk.

RESULTS

The results on 85 patients with NAFLD and 56 apparently healthy participants showed that all NAFLD cases and 53.6% of the healthy subjects were overweight or obese. More than half of the patients (58.8%) showed mild NAFLD. Age, weight, BMI, lipid profile, uric acid, and ferritin were significantly higher in NAFLD patients than the healthy cases. No significant differences were found in the concentrations of Cu and Cer between the groups. Only 7.4% of the healthy subjects and 2.4% of the patients were Cu deficient (<70 µg/dl). No association was found between the risk of NAFLD and serum Cu [OR: 0.994; 95% confidence interval (CI): 0.981-1.006] and Cer levels (OR: 0.414; 95% CI: 0.001-123.604) after adjusting for the confounders.

CONCLUSION

Our findings revealed no association between Cu deficiency and NAFLD risk. Further human studies with larger sample sizes are required to investigate how Cu and Cer status may affect NAFLD.

Copper-catalyzed dicarbonyl stress in NAFLD mice: protective effects of Oleuropein treatment on liver damage

Background

Nonalcoholic fatty liver disease (NAFLD) or more appropriately, metabolic associated fatty liver disease (MAFLD), is the hepatic manifestation of metabolic syndrome. An imbalance of copper homeostasis has been described in the progression of NAFLD/MAFLD toward NASH/MASH. We were interested in understanding whether the chelating activity of Oleuropein (Ole) was able to improve the copper accumulation and the related pro-oxidant and glycative damage in the liver of mice fed HFD.

Methods

Twelve C57BL/6J mice fed normal diet (ND) or high-fat diet (HFD) for 16 weeks and then thirty two female and male mice fed ND or HFD for 8 weeks adding Ole for the following 8 weeks were studied.

Results

Altered expression of copper-trafficking genes and proteins (CTR1, CTR2, ATP7B, COX17, CCS, and ATOX1) induced imbalance of copper homeostasis combined with an increase in dicarbonyl stress in the liver of HFD fed mice. Interestingly enough, glyoxalase system was improved by Ole administration and the Ole related protective effects differ in the two sexes of mice.

Conclusions

Our study highlights the role of the dicarbonyl stress in the pathogenesis of NAFLD and suggests Ole as a natural copper chelator to prevent the liver damage induced by methyglyoxal pathway derangement.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00641-z.

Hepatic Steatosis in the Mouse Model of Wilson Disease Coincides with a Muted Inflammatory Response

Wilson disease (WND) is caused by inactivation of the copper transporter ATP7B and copper accumulation in tissues. WND presentations vary from liver steatosis to inflammation, fibrosis, and liver failure. Diets influence the liver phenotype in WND, but findings are inconsistent. To better understand the impact of excess calories on liver phenotype in WND, the study compared C57BL/6J Atp7b-/- and C57BL/6J mice fed for 12 weeks with Western diet or normal chow. Serum and liver metabolites, body fat content, liver histology, hepatic proteome, and copper content were analyzed. Wild-type and Atp7b-/- livers showed striking similarities in their responses to Western diet, most notably down-regulation of cholesterol biosynthesis, altered nuclear receptor signaling, and changes in cytoskeleton. Western diet increased body fat content and induced liver steatosis in males and females regardless of genotype; however, the effects were less pronounced in Atp7b-/- mice compared with those in the wild type mice. Although hepatic copper remained elevated in Atp7b-/- mice, liver inflammation was reduced. The diet diminished signaling by Rho GTPases, integrin, IL8, and reversed changes in cell cycle machinery and cytoskeleton. Overall, high calories decreased inflammatory response in favor of steatosis without improving markers of cell viability. Similar changes of cellular pathways during steatosis development in wild-type and Atp7b-/- mice explain histologic overlap between WND and non-alcoholic fatty liver disease despite opposite copper changes in these disorders.

Copper exposure association with prevalence of non-alcoholic fatty liver disease and insulin resistance among US adults (NHANES 2011-2014)

BACKGROUND

Excessive copper (Cu) has risky effect on insulin resistance (IR), oxidative stress and inflammation. Instead, some studies reported serum Cu to be protective for non-alcoholic fatty liver disease (NAFLD). The aim of this study was to reevaluate the evidence for a potential risky correlation of serum Cu to NAFLD in large-scale and non-institutionalized American subjects.

METHODS

A cross-sectional study of 3211 subjects was from the National Health and Nutrition Examination Survey (NHANES). Logistic regression and cubic spline-based curve-fitting analyses were used to estimate the independent risky effect of Cu to hepatic steatosis index (HSI), US fatty liver index (USFLI) and NAFLD and their dose-effect relationship. Moreover, this association was analyzed in stratification of HOMA-IR, Metabolic syndrome (MetS) and severity of NAFLD, besides age and gender.

RESULTS

The average level of serum Cu was 18.67 μmol/L and the prevalence of NAFLD was 54.53% and 32.60%, respectively defined by HSI and USFLI. Generally, the level of Cu was higher in females than males. Serum Cu was positively associated with higher HSI, USFLI index and risk of NAFLD. In fully adjusted models, compared with the lowest quartile, the risk of NAFLD increased 97% in the highest quartile of Cu. Interestingly, stratified analysis showed that the risky effect of Cu to NAFLD was more prominent in the middle-aged, females and subjects with improved status of IR (lower HOMA-IR and non-Mets) compared with their counterparts. Moreover, we further found that circulating copper was correlated to severity of NAFLD only in males.

CONCLUSION

Excess serum Cu is significantly associated with risk of NAFLD, which is prominent in females, middle-aged and subjects with improved status of IR, and seems to be related to the severity of NAFLD, additionally. It is necessary to be cautious of the toxic effect of Cu and prospective cohort and mechanism studies are needed to verify the causal effect of Cu to NAFLD.

DISTINCT PHENOTYPE OF NON-ALCOHOLIC FATTY LIVER DISEASE IN PATIENTS WITH LOW LEVELS OF FREE COPPER AND OF CERULOPLASMIN

BACKGROUND

Copper deficiency has been linked to alterations in lipid metabolism and hepatic steatosis. Oxidative stress plays a role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). One of the enzymes that neutralize oxidative stress is Cu/Zn superoxide dismutase, which depends on the availability of adequate amounts of copper.

OBJECTIVE

Correlate the levels of ceruloplasmin and of non-ceruloplasmin-bound copper (NCBC) with clinical, biochemical and histological parameters of non-alcoholic fatty liver disease (NAFLD) patients.

METHODS

Data from 95 consecutively admitted NAFLD patients who underwent liver biopsy composed the groups based on ceruloplasmin levels lower than 25 mg/dL and on negative NCBC. The risk factors for NAFLD in each group were compared.

RESULTS

Body mass index was lower in patients with ceruloplasmin <25 mg/dL (29.1±3.47 vs 32.8±6.24 kg/m2; P=0.005) as were the levels of LDL, HDL and total cholesterol, when compared with their counterparts with ceruloplasmin >25 mg/dL (101±38 vs 116±35 mg/dL, P=0.05; 43±9 vs 51±16 mg/dL, P=0.01; 174±43 vs 197±39 mg/dL, P=0.01, respectively). Mean serum ferritin levels were higher in the ceruloplasmin <25 mg/dL group (343±327 vs 197±190 ng/mL; P=0.02). Otherwise, patients with negative NCBC had higher HOMA-IR (8.2±14.7 vs 4.6±3.7; P=0.03). Age, gender, hypertension and diabetes showed no statistical difference.

CONCLUSION

Patients with NAFLD had different clinical and biochemical markers according to the levels of NCBC and ceruloplasmin.

Current Trends of Essential Trace Elements in Patients with Chronic Liver Diseases

Essential trace elements play crucial roles in the maintenance of health, since they are involved in many metabolic pathways. A deficiency or an excess of some trace elements, including zinc, selenium, iron, and copper, frequently causes these metabolic disorders such as impaired glucose tolerance and dyslipidemia. The liver largely regulates most of the metabolism of trace elements, and accordingly, an impairment of liver functions can result in numerous metabolic disorders. The administration or depletion of these trace elements can improve such metabolic disorders and liver dysfunction. Recent advances in molecular biological techniques have helped to elucidate the putative mechanisms by which liver disorders evoke metabolic abnormalities that are due to deficiencies or excesses of these trace elements. A genome-wide association study revealed that a genetic polymorphism affected the metabolism of a specific trace element. Gut dysbiosis was also responsible for impairment of the metabolism of a trace element. This review focuses on the current trends of four trace elements in chronic liver diseases, including chronic hepatitis, liver cirrhosis, nonalcoholic fatty liver disease, and autoimmune liver diseases. The novel mechanisms by which the trace elements participated in the pathogenesis of the chronic liver diseases are also mentioned.

New mutation of the ceruloplasmin gene in the case of a neurologically asymptomatic patient with microcytic anaemia, obesity and supposed Wilson's disease

BACKGROUND

Aceruloplasminaemia is a very rare autosomal recessive disorder caused by a mutation in the ceruloplasmin gene, which is clinically manifested by damage to the nervous system and retinal degeneration. This classical clinical picture can be preceded by diabetes mellitus and microcytic anaemia, which are considered to be early manifestations of aceruloplasminaemia.

CASE PRESENTATION

In our report, we describe the case of a patient with aceruloplasminaemia detected in an early stage (without clinical symptoms of damage to the nervous system) during the search for the cause of hepatopathy with very low values of serum ceruloplasmin. Molecular genetic examination of the CP gene for ceruloplasmin identified a new variant c.1664G > A (p.Gly555Glu) in the homozygous state, which has not been published in the literature or population frequency databases to date. Throughout the 21-month duration of chelatase treatment, the patient, who is 43 years old, continues to be without neurological and psychiatric symptomatology. We observed a decrease in the serum concentration of ferritin without a reduction in iron deposits in the brain on magnetic resonance imaging.

CONCLUSION

Currently, there is no unequivocal recommendation of an effective treatment for aceruloplasminaemia. Early diagnosis is important in the neurologically asymptomatic stage.

Lipid and energy metabolism in Wilson disease

Copper accumulation and deficiency are reciprocally connected to lipid metabolism. In Wilson disease (WD), which is caused by a genetic loss of function of the copper-transporting P-type ATPase beta, copper accumulates mainly in the liver and lipid metabolism is dysregulated. The underlying mechanisms linking copper and lipid metabolism in WD are not clear. Copper may impair metabolic machinery by direct binding to protein and lipid structures or by generating reactive oxygen species with consequent damage to cellular organelles vital to energy metabolism. In the liver, copper overload results in mitochondrial impairment, down-regulation of lipid metabolism, and the development of steatosis with an etiology not fully elucidated. Little is known regarding the effect of copper overload on extrahepatic energy homeostasis. This review aims to discuss alterations in hepatic energy metabolism associated with WD, highlights potential mechanisms involved in the development of hepatic and systemic dysregulation of lipid metabolism, and reviews current knowledge on the effects of copper overload on extrahepatic energy metabolism.

Novel predictive models using serum ceruloplasmin levels for hepatic steatosis in patients with chronic hepatitis B infection

AIMS

To evaluate the significance of serum ceruloplasmin (CP) to diagnosis hepatic steatosis (HS) in Chronic hepatitis B (CHB) patients.

METHODS

A total of 360 CHB patients with HS (n = 136) or without HS (n = 224) were included. Relationships between CP and HS degrees were analyzed by Spearman rank correlation. HS-predictive models including CP were constructed using multivariate logistic regression analysis and compared to other HS predicting indexes.

RESULTS

Serum CP were significantly higher in CHB patients with HS than in patients without HS (P < 0.001) and were positively correlated with HS degree (r = 0.487, P < 0.001). The area under the receiver-operating characteristic curves (AUCs) of using CP to predict HS (S ≥ 1), moderate and severe steatosis (S ≥ 2) and severe steatosis (S = 3) were 0.758, 0.794 and 0.883, respectively. Multivariate analysis showed that CP, age, high density lipoprotein (HDL) and hemoglobin were independent predictors of HS, and CP, body mass index and HDL were independent predictors of moderate and severe HS. Two novel indexes for predicting HS of CHB patients were generated. The AUC of HSCHB-1 (for S ≥ 1) and HSCHB-2 (for S ≥ 2) were 0.881 and 0.916 in the training group, and 0.865 and 0.841 in the validation group, respectively. HSCHB-1 was superior to HS index (P < 0.001), fatty liver disease index (P = 0.0043) and steatosis index of patients with hepatitis B virus infection (P = 0.0029) in predicting HS in CHB patients.

CONCLUSIONS

HS of CHB patients was positively associated with serum CP. HSCHB-1 and HSCHB-2 with inclusion of CP are two novel models for predicting HS in CHB patients.

Metabolic dysregulation in the Atp7b-/- Wilson's disease mouse model

Inactivating mutations in the copper transporter Atp7b result in Wilson's disease. The Atp7b-/- mouse develops hallmarks of Wilson's disease. The activity of several nuclear receptors decreased in Atp7b-/- mice, and nuclear receptors are critical for maintaining metabolic homeostasis. Therefore, we anticipated that Atp7b-/- mice would exhibit altered progression of diet-induced obesity, fatty liver, and insulin resistance. Following 10 wk on a chow or Western-type diet (40% kcal fat), parameters of glucose and lipid homeostasis were measured. Hepatic metabolites were measured by liquid chromatography-mass spectrometry and correlated with transcriptomic data. Atp7b-/- mice fed a chow diet presented with blunted body-weight gain over time, had lower fat mass, and were more glucose tolerant than wild type (WT) littermate controls. On the Western diet, Atp7b-/- mice exhibited reduced body weight, adiposity, and hepatic steatosis compared with WT controls. Atp7b-/- mice fed either diet were more insulin sensitive than WT controls; however, fasted Atp7b-/- mice exhibited hypoglycemia after administration of insulin due to an impaired glucose counterregulatory response, as evidenced by reduced hepatic glucose production. Coupling gene expression with metabolomic analyses, we observed striking changes in hepatic metabolic profiles in Atp7b-/- mice, including increases in glycolytic intermediates and components of the tricarboxylic acid cycle. In addition, the active phosphorylated form of AMP kinase was significantly increased in Atp7b-/- mice relative to WT controls. Alterations in hepatic metabolic profiles and nuclear receptor signaling were associated with improved glucose tolerance and insulin sensitivity as well as with impaired fasting glucose production in Atp7b-/- mice.

Obesity is associated with copper elevation in serum and tissues

Copper misbalance has been linked to fat accumulation in animals and experimental systems; however, information about copper homeostasis in human obesity is limited. In this study, the copper status of obese individuals was evaluated by measuring their levels of copper and cuproproteins in serum, adipose and hepatic tissues. The analysis of serum trace elements showed significant positive and element-specific correlation between copper and BMI after controlling for gender, age, and ethnicity. Serum copper also positively correlated with leptin, insulin, and the leptin/BMI ratio. When compared to lean controls, obese patients had elevated circulating cuproproteins, such as semucarbazide-sensitive amine oxidase (SSAO) and ceruloplasmin, and higher SSAO activity and copper levels in visceral fat. Although hepatic steatosis reduces copper levels in the liver, obese patients with no or mild steatosis have higher copper content in the liver compared to lean controls. In conclusion, obese patients evaluated in this study had altered copper status. Strong positive correlations of copper levels with BMI and leptin suggest that copper and/or cuproproteins may be functionally linked to fat accumulation.

Copper Transport and Disease: What Can We Learn from Organoids?

Many metals have biological functions and play important roles in human health. Copper (Cu) is an essential metal that supports normal cellular physiology. Significant research efforts have focused on identifying the molecules and pathways involved in dietary Cu uptake in the digestive tract. The lack of an adequate in vitro model for assessing Cu transport processes in the gut has led to contradictory data and gaps in our understanding of the mechanisms involved in dietary Cu acquisition. The recent development of organoid technology has provided a tractable model system for assessing the detailed mechanistic processes involved in Cu utilization and transport in the context of nutrition. Enteroid (intestinal epithelial organoid)-based studies have identified new links between intestinal Cu metabolism and dietary fat processing. Evidence for a metabolic coupling between the dietary uptake of Cu and uptake of fat (which were previously thought to be independent) is a new and exciting finding that highlights the utility of these three-dimensional primary culture systems. This review has three goals: (a) to critically discuss the roles of key Cu transport enzymes in dietary Cu uptake; (b) to assess the use, utility, and limitations of organoid technology in research into nutritional Cu transport and Cu-based diseases; and (c) to highlight emerging connections between nutritional Cu homeostasis and fat metabolism.

Oxidative Stress Related to Iron Metabolism in Relapsing Remitting Multiple Sclerosis Patients With Low Disability

Oxidative status may play a role in chronic inflammation and neurodegeneration which are considered critical etiopathogenetic factors in Multiple Sclerosis (MS), both in the early phase of the disease and in the progressive one. The aim of this study is to explore oxidative status related to iron metabolism in peripheral blood of stable Relapsing-Remitting MS with low disability. We studied 60 Relapsing-Remitting MS patients (age 37.2 ± 9.06, EDSS median 1.0), and 40 healthy controls (age 40.3 ± 10.86). We measured total hydroperoxides (dROMs test) and Total Antioxidant Status (TAS), along with the iron metabolism biomarkers: Iron (Fe), ferritin (Ferr), transferrin (Tf), transferrin saturation (Tfsat), and ceruloplasmin (Cp) panel biomarkers [concentration (iCp) and enzymatic activity (eCp), copper (Cu), ceruloplasmin specific activity (eCp:iCp), copper to ceruloplasmin ratio (Cu:Cp), non-ceruloplasmin copper (nCp-Cu)]. We computed also the Cp:Tf ratio as an index of oxidative stress related to iron metabolism. We found lower TAS levels in MS patients than in healthy controls (CTRL) and normal reference level and higher dROMs and Cp:Tf ratio in MS than in healthy controls. Cp and Cu were higher in MS while biomarkers of iron metabolism were not different between patients and controls. Both in controls and MS, dROMs correlated with iCp (CTRL r = 0.821, p < 0.001; MS r = 0.775 p < 0.001) and eCp (CTRL r = 0.734, p < 0.001; MS r = 0.820 p < 0.001). Moreover, only in MS group iCp correlated negatively with Tfsat (r = -0.257, p = 0.047). Dividing MS patients in “untreated” group and “treated” group, we found a significant difference in Fe values [F(2, 97) = 10.136, p < 0.001]; in particular “MS untreated” showed higher mean values (mean = 114.5, SD = 39.37 μg/dL) than CTRL (mean 78.6, SD = 27.55 μg/dL p = 0.001) and “MS treated” (mean = 72.4, SD = 38.08 μg/dL; p < 0.001). Moreover, “MS untreated” showed significantly higher values of Cp:Tf (mean = 10.19, SD = 1.77^∗10^-2; p = 0.015), than CTRL (mean = 9.03, SD = 1.46 ^∗10^-2). These results suggest that chronic oxidative stress is relevant also in the remitting phase of the disease in patients with low disability and short disease duration. Therefore, treatment with antioxidants may be beneficial also in the early stage of the disease to preserve neuronal reserve.

Associations of Insulin Resistance and Glycemia With Liver Enzymes in Hispanic/Latino Youths: Results From the Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth)

BACKGROUND

Associations of insulin resistance and hyperglycemia with a panel of liver enzymes have not been well studied in a young, heterogenous Hispanic/Latino population. We aimed to assess the associations of insulin resistance and glycemia with nonalcoholic fatty liver disease (NAFLD), as measured by liver enzymes and the pediatric NAFLD fibrosis index (PNFI), and whether these associations are modified by body mass index and mediated by inflammation or endothelial dysfunction.

MATERIALS AND METHODS

We conducted a cross-sectional study of 1317 boys and girls aged 8 to 16 years from the Hispanic Community Children's Health Study/Study of Latino Youth. We used Poisson regression to assess the associations of fasting glucose, hemoglobin A1c, and homeostasis model assessment of insulin resistance (HOMA-IR) with elevated alanine aminotransferase (ALT) (>25 U/L in boys, >22 U/L in girls), aspartate aminotransferase (AST) (≥37 U/L), gamma-glutamyl transpeptidase (GGT) (≥17 U/L), and PNFI (≥9; a function of age, waist circumference, and triglyceride level).

RESULTS

HOMA-IR was associated with elevated ALT, AST, GGT, and PNFI [prevalence ratios (95% confidence intervals) for each 1-unit increase in the natural log of HOMA-IR: 1.99 (1.40-2.81), 2.15 (1.12-4.12), 1.70 (1.26-2.30), and 1.98 (1.43-2.74), respectively]. Associations were observed in overweight/obese children, but not in normal weight children (P-interaction=0.04 for AST and P-interaction=0.07 for GGT). After further adjustment for adiponectin, high-sensitivity C-reactive protein, e-selectin, and PAI-1, associations of HOMA-IR with liver enzymes and PNFI were attenuated, but remained statistically significant for AST and PNFI.

CONCLUSION

Insulin resistance was associated with NAFLD in overweight/obese Hispanic/Latino youth, and this association may be partially mediated by inflammation and endothelial dysfunction.

A High-Calorie Diet Aggravates Mitochondrial Dysfunction and Triggers Severe Liver Damage in Wilson Disease Rats

BACKGROUND & AIMS

In Wilson disease, ATP7B mutations impair copper excretion into bile. Hepatic copper accumulation may induce mild to moderate chronic liver damage or even acute liver failure. Etiologic factors for this heterogeneous phenotype remain enigmatic. Liver steatosis is a frequent finding in Wilson disease patients, suggesting that impaired copper homeostasis is linked with liver steatosis. Hepatic mitochondrial function is affected negatively both by copper overload and steatosis. Therefore, we addressed the question of whether a steatosis-promoting high-calorie diet aggravates liver damage in Wilson disease via amplified mitochondrial damage.

METHODS

Control Atp7b+/- and Wilson disease Atp7b-/- rats were fed either a high-calorie diet (HCD) or a normal diet. Copper chelation using the high-affinity peptide methanobactin was used in HCD-fed Atp7b-/- rats to test for therapeutic reversal of mitochondrial copper damage.

RESULTS

In comparison with a normal diet, HCD feeding of Atp7b-/- rats resulted in a markedly earlier onset of clinically apparent hepatic injury. Strongly increased mitochondrial copper accumulation was observed in HCD-fed Atp7b-/- rats, correlating with severe liver injury. Mitochondria presented with massive structural damage, increased H2O2 emergence, and dysfunctional adenosine triphosphate production. Hepatocellular injury presumably was augmented as a result of oxidative stress. Reduction of mitochondrial copper by methanobactin significantly reduced mitochondrial impairment and ameliorated liver damage.

CONCLUSIONS

A high-calorie diet severely aggravates hepatic mitochondrial and hepatocellular damage in Wilson disease rats, causing an earlier onset of the disease and enhanced disease progression.

Copper-Fructose Interactions: A Novel Mechanism in the Pathogenesis of NAFLD

Compelling epidemiologic data support the critical role of dietary fructose in the epidemic of obesity, metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). The metabolic effects of fructose on the development of metabolic syndrome and NAFLD are not completely understood. High fructose intake impairs copper status, and copper-fructose interactions have been well documented in rats. Altered copper-fructose metabolism leads to exacerbated experimental metabolic syndrome and NAFLD. A growing body of evidence has demonstrated that copper levels are low in NAFLD patients. Moreover, hepatic and serum copper levels are inversely correlated with the severity of NAFLD. Thus, high fructose consumption and low copper availability are considered two important risk factors in NAFLD. However, the causal effect of copper-fructose interactions as well as the effects of fructose intake on copper status remain to be evaluated in humans. The aim of this review is to summarize the role of copper-fructose interactions in the pathogenesis of the metabolic syndrome and discuss the potential underlying mechanisms. This review will shed light on the role of copper homeostasis and high fructose intake and point to copper-fructose interactions as novel mechanisms in the fructose induced NAFLD.

Micronutrients in Nonalcoholic Fatty Liver Disease Pathogenesis

Micronutrients include electrolytes, minerals, vitamins, and carotenoids, and are required in microgram or milligram quantities for cellular metabolism. The liver plays an important role in micronutrient metabolism and this metabolism often is altered in chronic liver diseases. Here, we review how the liver contributes to micronutrient metabolism; how impaired micronutrient metabolism may be involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), a systemic disorder of energy, glucose, and lipid homeostasis; and how insights gained from micronutrient biology have informed NAFLD therapeutics. Finally, we highlight some of the challenges and opportunities that remain with investigating the contribution of micronutrients to NAFLD pathology and suggest strategies to incorporate our understanding into the care of NAFLD patients.

Association of serum ferritin with non-alcoholic fatty liver disease: a meta-analysis

Background

A growing number of studies reported the connection between the level of serum ferritin (SFL) and non-alcoholic fatty liver disease (NAFLD). However, such connection was still disputable. The aim of our meta-analysis was to estimate SFL between the groups as below: patients with NAFLD against control group; non-alcoholic steatohepatitis (NASH) patients against control group; non-alcoholic fatty liver (NAFL) patients against a control group and NASH patients vs NAFL patients.

Methods

We screened the studies in PubMed, EMBASE, the Cochrane Database and the Cochrane Central register controlled trials from the beginning to July 10, 2016 to find the studies indicated the connection between SFL and NAFLD (NAFL and/or NASH). Fourteen published studies which evaluate the SFL in NAFLD patients were selected.

Results

Higher SFL was noticed in NAFLD patients against control group (standardized mean difference [SMD] 1.01; 95% CI 0.89, 1.13), NASH patients against control group (SMD 1.21; 95% CI 1.00, 1.42), NAFL patients against control group (SMD 0.51; 95% CI 0.24, 0.79) and NASH patients against NAFL patients (SMD 0.63; 95% CI 0.52, 0.75). These results remained unaltered actually after the elimination of studies which were focused on paediatric or adolescent populations. Higher SFL was presented in NAFLD patients against the control group (SMD 1.08; 95% CI 0.95, 1.20) in adults and NASH patients against NAFL patients in adults (SMD 0.74; 95% CI 0.62, 0.87). The connection between SFL and NASH against NAFL group in paediatric or adolescent populations was observed inconsistently (SMD 0.10; 95% CI -0.18, 0.38).

Conclusions

The level of SFL was elevated in patients with NAFLD (NAFL and/or NASH) compared with the controls. Compared with NAFL, The level of SFL was increased in NASH. The result remained unaltered actually after the elimination of studies focused on paediatric or adolescent populations.

An exploratory study of BDNF and oxidative stress marker alterations in subacute and chronic stroke patients affected by neuropathic pain

Patients affected by stroke, particularly subacute stroke patients, often complain of neuropathic pain (NP), which may severely impair their quality of life. The aim of this exploratory study was to characterize NP and to investigate whether there is a correlation between NP and serum brain-derived neurotrophic factor (BDNF) and serum markers of oxidative stress. We enrolled 50 patients divided in subacute (< 90 days from stroke onset) and chronic (> 90 and 180 < days from stroke onset). The Barthel Index, Deambulation Index, and Short Form 36 were used to assess the patients' degree of disability and quality of life. Pain-specific tools, namely the Numeric Rating Scale (NRS), Neuropathic Pain Diagnostic questionnaire (DN4), and Neuropathic Pain Symptom Inventory (NPSI), were also used. Serum levels of BDNF and markers of oxidative stress and of metal status were evaluated: copper, iron, transferrin, ferritin, ceruloplasmin concentration (iCp) and activity (eCp), Total Antioxidant status (TAS), Cp/Tf ratio, eCp/iCp ratio, and non-ceruloplasmin bound copper (Non-Cp Cu). We found the highest value of BDNF in subacute with NP (DN4 score ≥ 4). The TAS, Cp/Tf ratio, and eCp/iCp not only fell outside the normal reference range in a high percentage of subacute and chronic patients, but were also found to be related to specific NP symptoms. These preliminary results reveal altered BDNF and oxidative stress indices in subacute stroke patients who complain of NP. These investigative findings may shed more light on the mechanisms underlying NP and consequently lead to a more tailored therapeutic and/or rehabilitation procedure of subacute stroke patients.

Non-Alcoholic Fatty Liver Disease and Nutritional Implications: Special Focus on Copper

Non-alcoholic fatty liver disease (NAFLD) is characterized by excess lipids in hepatocytes, due to excessive fatty acid influx from adipose tissue, de novo hepatic lipogenesis, in addition to excessive dietary fat and carbohydrate intake. Chronic hepatic lipid overload induces mitochondrial oxidative stress and cellular damage leading the development of NAFLD into a more severe liver disease condition, non-alcoholic steato-hepatitis (NASH). In turn, this can progress to cirrhosis and hepatocellular carcinoma (HCC). Among others, copper is one of the main bio-metals required for the preponderance of the enzymes involved in physiological redox reactions, which primarily occurs during mitochondrial respiration. Thus, copper homeostasis could be considered a target point for counteracting the progression of NAFLD. Accordingly, many diseases are correlated to unbalanced copper levels and, actually, some clinical trials are examining the use of copper chelating agents. Currently, no pharmacological interventions are approved for NAFLD, but nutritional and lifestyle modifications are always recommended. Fittingly, antioxidant food agents recognized to improve NAFLD and its complications have been described in the literature to bind copper. Therefore, this review describes the role of nutrition in the development and progression of NAFLD with a particular focus on copper and copper-binding antioxidant compounds against NAFLD.

Clinical implications of understanding the association between oxidative stress and pediatric NAFLD

Oxidative stress is central to the pathogenesis of non-alcoholic steatohepatitis. The reactive oxygen species (ROS) that characterise oxidative stress are generated in several cellular sites and their production is influence by multi-organ interactions. Areas covered: Mitochondrial dysfunction is the main source of ROS in fatty liver and is closely related to endoplasmic reticulum stress. Both are caused by lipotoxicity and together these three factors form a cycle of progressive organelle damage, resulting in sterile inflammation and apoptosis. Adipose tissue inflammation and intestinal dysbiosis provide substrates for ROS formation and trigger immune activation. Obstructive sleep apnea and abnormal divalent metal metabolism may also play a role. Expert commentary: The majority of available high-quality data originates from studies in adults and there are fewer therapeutic trials performed in pediatric cohorts, therefore conclusions are generalised to children. Establishing the role of organelle interactions, and its relationship with oxidative stress in steatohepatitis, is a rapidly evolving area of research.

Ceruloplasmin, a reliable marker of fibrosis in chronic hepatitis B virus patients with normal or minimally raised alanine aminotransferase

AIM

To develop a non-invasive model to evaluate significant fibrosis and cirrhosis by investigating the association between serum ceruloplasmin (CP) levels and liver fibrosis in chronic hepatitis B (CHB) patients with normal or minimally raised alanine aminotransferase (ALT).

METHODS

Serum samples and liver biopsy were obtained from 193 CHB patients with minimally raised or normal ALT who were randomly divided into a training group (n = 97) and a validation group (n = 96). Liver histology was evaluated by the METAVIR scoring system. Receiver operator characteristic curves were applied to the diagnostic value of CP for measuring liver fibrosis in CHB patients. Spearman rank correlation analyzed the relationship between CP and liver fibrosis. A non-invasive model was set up through multivariate logistic regression analysis.

RESULTS

Serum CP levels individualized various fibrosis stages via area under the curve (AUC) values. Multivariate analysis revealed that CP levels were significantly related to liver cirrhosis. Combining CP with serum GGT levels, a CG model was set up to predict significant fibrosis and liver cirrhosis in CHB patients with normal or minimally raised ALT. The AUC, sensitivity, specificity, positive predictive value, and negative predictive value were 0.84, 83.1%, 78.6%, 39.6%, and 96.5% to predict liver cirrhosis, and 0.789, 80.26%, 68.38%, 62.25%, and 84.21% to predict significant fibrosis. This model expressed a higher AUC than FIB-4 (age, ALT, aspartate aminotransferase, platelets) and GP (globulin, platelets) models to predict significant fibrosis (P = 0.019 and 0.022 respectively) and revealed a dramatically greater AUC than FIB-4 (P = 0.033) to predict liver cirrhosis.

CONCLUSION

The present study showed that CP was independently and negatively associated with liver fibrosis. Furthermore, we developed a novel promising model (CG), based on routine serum markers, for predicting liver fibrosis in CHB patients with normal or minimally raised ALT.

The Potential Role of Iron and Copper in Pediatric Obesity and Nonalcoholic Fatty Liver Disease

Obesity is a rapidly growing health problem and is paralleled by a multitude of comorbidities, including nonalcoholic fatty liver disease (NAFLD). NAFLD has become the most common chronic liver disease in both adults and children. The current understanding of NAFLD is still fragmentary. While simple steatosis is characterized by the interplay between excessive free fatty acid accumulation and hepatic insulin resistance, the progression to NASH has been related to oxidative stress and a proinflammatory state with dysbalanced adipokine, cytokine levels, and endotoxin-mediated immune response. In addition, oxidative stress has been suggested to play a central role for the sequelae leading to NASH. Trace elements are critical in regulatory, immunologic, and antioxidant functions resulting in protection against inflammation and peroxidation and consequently against the known comorbidities of obesity. Disruptions of the metal detoxification processes located in the liver are plausibly related to NAFLD development via oxidative stress. Perturbations of iron and copper (Cu) homeostasis have been shown to contribute to the pathogenesis of NAFLD. This review presents current data from pediatric studies. In addition, data from adult studies are summarized where clinical relevance may be extrapolated to pediatric obesity and NAFLD.

Nutrigenomics analysis reveals that copper deficiency and dietary sucrose up-regulate inflammation, fibrosis and lipogenic pathways in a mature rat model of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) prevalence is increasing worldwide, with the affected US population estimated near 30%. Diet is a recognized risk factor in the NAFLD spectrum, which includes nonalcoholic steatohepatitis (NASH) and fibrosis. Low hepatic copper (Cu) was recently linked to clinical NAFLD/NASH severity. Simple sugar consumption including sucrose and fructose is implicated in NAFLD, while consumption of these macronutrients also decreases liver Cu levels. Though dietary sugar and low Cu are implicated in NAFLD, transcript-level responses that connect diet and pathology are not established. We have developed a mature rat model of NAFLD induced by dietary Cu deficiency, human-relevant high sucrose intake (30% w/w) or both factors in combination. Compared to the control diet with adequate Cu and 10% (w/w) sucrose, rats fed either high-sucrose or low-Cu diet had increased hepatic expression of genes involved in inflammation and fibrogenesis, including hepatic stellate cell activation, while the combination of diet factors also increased ATP citrate lyase and fatty acid synthase gene transcription (fold change > 2, P < 0.02). Low dietary Cu decreased hepatic and serum Cu (P ≤ 0.05), promoted lipid peroxidation and induced NAFLD-like histopathology, while the combined factors also induced fasting hepatic insulin resistance and liver damage. Neither low Cu nor 30% sucrose in the diet led to enhanced weight gain. Taken together, transcript profiles, histological and biochemical data indicate that low Cu and high sucrose promote hepatic gene expression and physiological responses associated with NAFLD and NASH, even in the absence of obesity or severe steatosis.

Novel bioimaging techniques of metals by laser ablation inductively coupled plasma mass spectrometry for diagnosis of fibrotic and cirrhotic liver disorders

Background and Aims

Hereditary disorders associated with metal overload or unwanted toxic accumulation of heavy metals can lead to morbidity and mortality. Patients with hereditary hemochromatosis or Wilson disease for example may develop severe hepatic pathology including fibrosis, cirrhosis or hepatocellular carcinoma. While relevant disease genes are identified and genetic testing is applicable, liver biopsy in combination with metal detecting techniques such as energy-dispersive X-ray spectroscopy (EDX) is still applied for accurate diagnosis of metals. Vice versa, several metals are needed in trace amounts for carrying out vital functions and their deficiency due to rapid growth, pregnancy, excessive blood loss, and insufficient nutritional or digestive uptake results in organic and systemic shortcomings. Established in situ techniques, such as EDX-ray spectroscopy, are not sensitive enough to analyze trace metal distribution and the quantification of metal images is difficult.

Methods

In this study, we developed a quantitative biometal imaging technique of human liver tissue by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in order to compare the distribution of selected metals in cryo-sections of healthy and fibrotic/cirrhotic livers.

Results

Most of the metals are homogeneous distributed within the normal tissue, while they are redirected within fibrotic livers resulting in significant metal deposits. Moreover, total iron and copper concentrations in diseased liver were found about 3-5 times higher than in normal liver samples.

Conclusions

Biometal imaging via LA-ICP-MS is a sensitive innovative diagnostic tool that will impact clinical practice in identification and evaluation of hepatic metal disorders and to detect subtle metal variations during ongoing hepatic fibrogenesis.