Pathogenesis of non-alcoholic fatty liver disease in children and adolescence: From “two hit theory” to “multiple hit model”

Nutrigenomics and Nutrigenetics in Metabolic- (Dysfunction) Associated Fatty Liver Disease: Novel Insights and Future Perspectives

Metabolic- (dysfunction) associated fatty liver disease (MAFLD) represents the predominant hepatopathy and one of the most important systemic, metabolic-related disorders all over the world associated with severe medical and socio-economic repercussions due to its growing prevalence, clinical course (steatohepatitis and/or hepatocellular-carcinoma), and related extra-hepatic comorbidities. To date, no specific medications for the treatment of this condition exist, and the most valid recommendation for patients remains lifestyle change. MAFLD has been associated with metabolic syndrome; its development and progression are widely influenced by the interplay between genetic, environmental, and nutritional factors. Nutrigenetics and nutrigenomics findings suggest nutrition’s capability, by acting on the individual genetic background and modifying the specific epigenetic expression as well, to influence patients’ clinical outcome. Besides, immunity response is emerging as pivotal in this multifactorial scenario, suggesting the interaction between diet, genetics, and immunity as another tangled network that needs to be explored. The present review describes the genetic background contribution to MAFLD onset and worsening, its possibility to be influenced by nutritional habits, and the interplay between nutrients and immunity as one of the most promising research fields of the future in this context.

Association between cumulative childhood blood lead exposure and hepatic steatosis in young Mexican adults

BACKGROUND

Exposure to environmental toxicants may play a role in the pathogenesis of Non Alcoholic Fatty Liver Disease (NAFLD). Cumulative exposure to lead (Pb) has chronic and permanent effects on liver function. Pediatric populations are vulnerable to the toxic effects of Pb, even at low exposure levels. The purpose of the study was to estimate the association between cumulative Pb exposure during childhood and hepatic steatosis biomarkers in young Mexican adults.

METHODS

A subsample of 93 participants from the ELEMENT cohort were included in this study. Childhood blood samples were collected annually from ages 1-4 years and were used to calculate the Cumulative Childhood Blood Lead Levels (CCBLL). Hepatic steatosis during adulthood was defined as an excessive accumulation of hepatic triglycerides (>5%) determined using Magnetic Resonance Imaging (MRI). Liver enzymes were also measured at this time, and elevated liver enzyme levels were defined as ALT (≥30 IU/L), AST (≥30 IU/L), and GGT (≥40 IU/L). Adjusted linear regression models were fit to examine the association between CCBLL (quartiles) and the hepatic steatosis in young adulthood.

RESULTS

In adulthood, the mean age was 21.4 years, 55% were male. The overall prevalence of hepatic steatosis by MRI was 19%. Elevate levels of the enzymes ALT, AST, and GGT were present in 25%, 15%, and 17% of the sample, respectively. We found a positive association between the highest quartile of CCBLL with the steatosis biomarkers of hepatic triglycerides (Q4 vs. Q1: β = 6.07, 95% CI: 1.91-10.21), elevated ALT (Q4 vs. Q1: β = 14.5, 95% CI: 1.39-27.61) and elevated AST (Q4 vs. Q1: β = 7.23, 95% CI: 0.64-13.82). No significant associations were found with GGT.

CONCLUSIONS

Chronic Pb exposure during early childhood is associated with a higher levels of hepatic steatosis biomarkers and hepatocellular injury in young adulthood. More actions should be taken to eliminate sources of Pb during the first years of life.

Role of Endocrine-Disrupting Chemicals in the Pathogenesis of Non-Alcoholic Fatty Liver Disease: A Comprehensive Review

Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disorder, affecting around 25% of the population worldwide. It is a complex disease spectrum, closely linked with other conditions such as obesity, insulin resistance, type 2 diabetes mellitus, and metabolic syndrome, which may increase liver-related mortality. In light of this, numerous efforts have been carried out in recent years in order to clarify its pathogenesis and create new prevention strategies. Currently, the essential role of environmental pollutants in NAFLD development is recognized. Particularly, endocrine-disrupting chemicals (EDCs) have a notable influence. EDCs can be classified as natural (phytoestrogens, genistein, and coumestrol) or synthetic, and the latter ones can be further subdivided into industrial (dioxins, polychlorinated biphenyls, and alkylphenols), agricultural (pesticides, insecticides, herbicides, and fungicides), residential (phthalates, polybrominated biphenyls, and bisphenol A), and pharmaceutical (parabens). Several experimental models have proposed a mechanism involving this group of substances with the disruption of hepatic metabolism, which promotes NAFLD. These include an imbalance between lipid influx/efflux in the liver, mitochondrial dysfunction, liver inflammation, and epigenetic reprogramming. It can be concluded that exposure to EDCs might play a crucial role in NAFLD initiation and evolution. However, further investigations supporting these effects in humans are required.

Worldwide flavor enhancer monosodium glutamate combined with high lipid diet provokes metabolic alterations and systemic anomalies: An overview

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Flavor enhancing high lipid diet acts as silent killer.

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Monosodium glutamate mixed with high lipid diet alters redox-status.

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Monosodium glutamate mixed with high lipid diet induces systemic anomalies.

In this fast-food era, people depend on ready-made foods and engage in minimal physical activities that ultimately change their food habits. Majorities of such foods have harmful effects on human health due to higher percentages of saturated fatty acids, trans-fatty acids, and hydrogenated fats in the form of high lipid diet (HLD). Moreover, food manufacturers add monosodium glutamate (MSG) to enhance the taste and palatability of the HLD. Both MSG and HLD induce the generation of reactive oxygen species (ROS) and thereby alter the redox-homeostasis to cause systemic damage. However, MSG mixed HLD (MH) consumption leads to dyslipidemia, silently develops non-alcoholic fatty liver disease followed by metabolic alterations and systemic anomalies, even malignancies, via modulating different signaling pathways. This comprehensive review formulates health care strategies to create global awareness about the harmful impact of MH on the human body and recommends the daily consumption of more natural foods rich in antioxidants instead of toxic ingredients to counterbalance the MH-induced systemic anomalies.

MiR-484 participates in non-alcoholic fatty liver injury by targeting SIRT1 to mediate cell apoptosis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become a major health threat that is seriously underestimated. Although the pathogenesis of NAFLD is complex, more and more evidence shows that microRNAs (miRNAs) play an important role in regulating the occurrence and development of NAFLD. Whether miR-484 is involved in the occurrence and development of NAFLD remains to be clarified.

AIM

To explore the mechanism of miR-484 in the damage of liver steatosis.

METHODS

A mouse model of NAFLD was established by feeding mice a high-fat diet, and the expression levels of miR-484 and SIRT1 in liver tissues were measured by RT-qPCR and Western blot. A miR-484 knockout NAFLD mouse model was constructed, the degree of steatosis and apoptosis were detected by oil red O staining, HE staining, and TUNEL staining, and the levels of serum ALT and AST were detected. In addition, a cell model of NAFLD was constructed through free fatty acid exposure. The dual luciferase reporter gene assay was first used to verify the direct targeting relationship between miR-484 and SIRT1, then an SIRT1 overexpression model was constructed by transfection with pc-DNA and pc-DNA SIRT1. Oil red O staining was used to detect lipid accumulation and flow cytometry was used to detect cell apoptosis.

RESULTS

In the mouse model of NAFLD, the expression of miR-484 was significantly up-regulated, while the expression of SIRT1 was decreased. The degree of steatosis was reduced and serum ALT and AST levels were significantly reduced in miR-484 knockout mice. In the cell model of NAFLD, miR-484 can directly target SIRT1. In addition, overexpression of SIRT1 significantly decreased the rate of apoptosis and alleviated lipid accumulation in liver cells

CONCLUSION

MiR-484 regulates cell apoptosis by targeting SIRT1 and aggravates lipid accumulation in liver cells, which suggests that miR-484 may be a therapeutic target for NAFLD.

Metabolic Spectrum of Liver Failure in Type 2 Diabetes and Obesity: From NAFLD to NASH to HCC

Liver disease is the spectrum of liver damage ranging from simple steatosis called as nonalcoholic fatty liver disease (NAFLD) to hepatocellular carcinoma (HCC). Clinically, NAFLD and type 2 diabetes coexist. Type 2 diabetes contributes to biological processes driving the severity of NAFLD, the primary cause for development of chronic liver diseases. In the last 20 years, the rate of non-viral NAFLD/NASH-derived HCC has been increasing rapidly. As there are currently no suitable drugs for treatment of NAFLD and NASH, a class of thiazolidinediones (TZDs) drugs for the treatment of type 2 diabetes is sometimes used to improve liver failure despite the risk of side effects. Therefore, diagnosis, prevention, and treatment of the development and progression of NAFLD and NASH are important issues. In this review, we will discuss the pathogenesis of NAFLD/NASH and NAFLD/NASH-derived HCC and the current promising pharmacological therapies of NAFLD/NASH. Further, we will provide insights into "adipose-derived adipokines" and "liver-derived hepatokines" as diagnostic and therapeutic targets from NAFLD to HCC.

Flame Retardants-Mediated Interferon Signaling in the Pathogenesis of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a growing concern worldwide, affecting 25% of the global population. NAFLD is a multifactorial disease with a broad spectrum of pathology includes steatosis, which gradually progresses to a more severe condition such as nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and eventually leads to hepatic cancer. Several risk factors, including exposure to environmental toxicants, are involved in the development and progression of NAFLD. Environmental factors may promote the development and progression of NAFLD by various biological alterations, including mitochondrial dysfunction, reactive oxygen species production, nuclear receptors dysregulation, and interference in inflammatory and immune-mediated signaling. Moreover, environmental contaminants can influence immune responses by impairing the immune system’s components and, ultimately, disease susceptibility. Flame retardants (FRs) are anthropogenic chemicals or mixtures that are being used to inhibit or delay the spread of fire. FRs have been employed in several household and outdoor products; therefore, human exposure is unavoidable. In this review, we summarized the potential mechanisms of FRs-associated immune and inflammatory signaling and their possible contribution to the development and progression of NAFLD, with an emphasis on FRs-mediated interferon signaling. Knowledge gaps are identified, and emerging pharmacotherapeutic molecules targeting the immune and inflammatory signaling for NAFLD are also discussed.

Non-Alcoholic Fatty Liver Disease in Obese Youth With Insulin Resistance and Type 2 Diabetes

Currently, Non-Alcoholic Fatty Liver Disease (NAFLD) is the most prevalent form of chronic liver disease in children and adolescents worldwide. Simultaneously to the epidemic spreading of childhood obesity, the rate of affected young has dramatically increased in the last decades with an estimated prevalence of NAFLD of 3%-10% in pediatric subjects in the world. The continuous improvement in NAFLD knowledge has significantly defined several risk factors associated to the natural history of this complex liver alteration. Among them, Insulin Resistance (IR) is certainly one of the main features. As well, not surprisingly, abnormal glucose tolerance (prediabetes and diabetes) is highly prevalent among children/adolescents with biopsy-proven NAFLD. In addition, other factors such as genetic, ethnicity, gender, age, puberty and lifestyle might affect the development and progression of hepatic alterations. However, available data are still lacking to confirm whether IR is a risk factor or a consequence of hepatic steatosis. There is also evidence that NAFLD is the hepatic manifestation of Metabolic Syndrome (MetS). In fact, NAFLD often coexist with central obesity, impaired glucose tolerance, dyslipidemia, and hypertension, which represent the main features of MetS. In this Review, main aspects of the natural history and risk factors of the disease are summarized in children and adolescents. In addition, the most relevant scientific evidence about the association between NAFLD and metabolic dysregulation, focusing on clinical, pathogenetic, and histological implication will be provided with some focuses on the main treatment options.

A Comparison of Short- and Long-Term Soy Protein Isolate Intake and Its Ability to Reduce Liver Steatosis in Obese Zucker Rats Through Modifications of Genes Involved in Inflammation and Lipid Transport

Obesity can lead to several health disorders including nonalcoholic fatty liver disease (NAFLD), the aggregation of lipids within hepatocytes, and consequent inflammation of the liver tissue. Previously, we reported that feeding obese Zucker rats with soy protein isolate (SPI) can reduce liver steatosis. To understand how SPI reduced liver steatosis, we conducted global gene expression analysis on liver samples obtained from these rats after short- (8 weeks) and long-term SPI feeding (16 weeks). We compared and contrasted these data using Ingenuity Pathway Analysis (IPA) software. This study focused mainly on target molecules that could be participating in inflammation processes and lipid metabolism that are well-known components of NAFLD. Inflammatory response was predicted to be inhibited in animals fed the SPI diet at both 8 and 16 weeks of experiment. This general prediction was based on negative activation z scores obtained through IPA (z score < -2.0, P < .00001) for eight aspects of immune function/inflammatory response. Lipid metabolism was predicted to be strongly enhanced in rats fed the SPI diet for 16 weeks than for 8 weeks. This prediction was based on positive activation z scores (z scores >2.0, P < .00001) of eight functions involved in lipid transport and metabolism. We observed that the longer the rats were fed the SPI diet, the more beneficial it resulted against NAFLD. Based on our findings, the predicted reductions in inflammatory mechanisms while enhancing lipid transport out of the liver could be the reasons behind the reduction of liver steatosis.

A Positive Relationship between Betel Nut Chewing and Significant Liver Fibrosis in NAFLD Subjects, but Not in Non-NAFLD Ones

Background: Betel nut chewing is associated with oral cancer, cardiovascular disease, liver cirrhosis, and hepatocellular carcinoma (HCC). The aim of this study was to explore the association of betel nut chewing with liver fibrosis in subjects with and without nonalcoholic fatty liver disease (NAFLD). Method: A total of 5967 subjects were enrolled. NAFLD was diagnosed with ultrasonography. Betel nut chewing was classified into non-chewing, ex-chewing, and current chewing, and cumulative dosages were calculated. The aspartate aminotransferase (AST)/platelet ratio index and NAFLD fibrosis scores (NFS) were calculated for evaluation of liver fibrosis. Results: NAFLD increased the associated risk of liver fibrosis in those with (odds ratio (OR): 5.51, 95% confidence interval (CI): 3.09–9.80) and without betel nut chewing (OR: 2.33, 95% CI: 1.64–3.29). In subjects without NAFLD, betel nut chewing was not associated with liver fibrosis (OR: 1.12, 95% CI: 0.44–2.86). In subjects with NAFLD, cumulative betel nut chewing and ex- and current chewing were positively associated with NFS and significant liver fibrosis. Conclusions: In subjects with NAFLD, betel nut chewing, even ex-chewing, was associated with a higher risk of liver fibrosis, where higher cumulative levels were found to increase the risk of significant liver fibrosis. However, the associated risk of liver fibrosis due to betel nut chewing was insignificant in subjects without NAFLD.

LncRNA-Gm9795 promotes inflammation in non-alcoholic steatohepatitis via NF-[Formula: see text]B/JNK pathway by endoplasmic reticulum stress

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a key stage in leading development of non-alcoholic simple fatty liver (NAFL) into cirrhosis and even liver cancer. This study aimed at exploring the lncRNAs expression profile in NASH and the biological function of a novel LncRNA-gm9795.

METHODS

Microarray analysis was performed to compare the expression profiles of lncRNAs in the liver of NASH, NAFLD and normal mice (5 mice for each group). Methionine-choline-deficient Medium (MCD) with Lipopolysaccharide (LPS) or palmitic acid (PA)were used to built NASH cell models. The role and mechanism of LncRNA-gm9795 in NASH were explored by knocking down or over-expressing its expression.

RESULTS

A total of 381 lncRNAs were found to be not only highly expressed in NAFLD, but also is going to go even higher in NASH. A novel LncRNA-gm9795 was significantly highly expressed in liver tissues of NASH animal models and NASH cell models. By staining with Nile red, we found that gm9795 did not affect the fat accumulation of NASH. However, gm9795 in NASH cell models significantly promoted the expression of TNF [Formula: see text], IL-6, IL-1[Formula: see text], the important inflammatory mediators in NASH. At the same time, we found that gm9795 upregulated the key molecules in endoplasmic reticulum stress (ERS), while NF-[Formula: see text]B/JNK pathways were also activated. When ERS activator Thapsigargin (TG) was introduced in cells with Ggm9757 si-RNA, NF-[Formula: see text]B and JNK pathways were activated. Conversely, ERS inhibitor Tauroursodeoxycholic acid (TUDCA) inhibited NF-kB and JNK pathways in cells with gm9795 overexpression plasmid.

CONCLUSION

LncRNA-gm9795 promotes inflammatory response in NASH through NF-kB and JNK pathways by ERS, which might provide theoretical basis for revealing the pathogenesis of NASH and discovering new therapeutic targets.

From Nonalcoholic Fatty Liver Disease (NAFLD) to Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD)-New Terminology in Pediatric Patients as a Step in Good Scientific Direction?

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, which predispose to more serious hepatic conditions. It ranges from simple liver steatosis to nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis, and even end-stage liver disease. Since obesity became one of the most important health concerns wordwide, a considerable increase in the prevalance of NAFLD and other metabolic implications has been observed, both in adults and children. Due to the coexistence of visceral obesity, insulin resistance, dyslipidemia, NAFLD is considered to be the hepatic manifestation of metabolic syndrome (MetS). These relationships between NAFLD and MetS led to the set up in adults of a new term combining both of these conditions, called metabolic dysfunction-associated fatty liver disease (MAFLD). Based on these findings, we propose a set of criteria, which may be useful to diagnose MAFLD in children and adolescents.

Study of Cellular Senescence and Vitamin D Deficiency in Nonalcoholic Fatty Liver Disease and The Potential Protective Effect of Vitamin D Supplementation

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a pathological process characterized by excessive hepatic fatty deposition with possible involvement of vitamin D deficiency and cellular senescence. The aim of this study is to investigate the pathophysiologic role of vitamin D deficiency and cellular senescence in NAFLD development. Moreover, it aims to investigate the potential protective role of vitamin D supplementation.

METHODS

This is an experimental Case/Control study. Forty-five male albino rats were enrolled in this study. Animals were divided into four groups: negative and positive control groups (10 for each group), a model of NAFLD (11) and vitamin D-treated NAFLD groups (14). At the end of the experiment, all rats were subjected to the following investigation; biochemical estimation of serum 25 hydroxycholecalciferol, senescence marker protein-30 (SMP-30), lipid profile and calculation of homeostatic model of insulin resistance (HOMA-IR).

RESULTS

NAFLD group shows a significant increase in glucose, insulin levels, and HOMA- IR compared with both normal controls. This finding indicates the intimate association between insulin resistance and NAFLD pathogenesis. Moreover, it was found that NAFLD group shows a significant decrease in SMP-30 level compared with normal controls. While vitamin D-treated NAFLD group shows significant increased SMP-30 and decrease in HOMA-IR in comparison with nontreated NAFLD group.

CONCLUSION

Vitamin D deficiency and increased cellular senescence are key features of NAFLD. Vitamin D supplementation could play a protective role, which needs further investigation including clinical human study.

Relationship between the risk factors of cardiovascular disease by testing biochemical markers and young men with erectile dysfunction: a case-control study

Background

Erectile dysfunction (ED) shares common risk factors with cardiovascular disease (CVD), such as diabetes mellitus (DM) and dyslipidemia, but the relationship between the risk factors of CVD in biochemical markers and young men with ED age 20–40 years is not fully clarified.

Methods

A total of 289 ED outpatients (20–40 years old) were allocated under ED group, based on patients’ complaints and physical examinations. According to the frequency matching ratio of 1:4, 1,155 male individuals (20–40 years old) without ED were set as control group. All participants were tested for lipid profiles including total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL), blood glucose (BG), homocysteine (HCY), liver function including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and renal function including uric acid (UA) and creatinine (CR). The study was designed to compare the two groups using an established binary logistic regression analysis model. The ED group was then subdivided into a younger ED group (20–30 years old) and an older ED group (31–40 years old) for further comparisons.

Results

After comparison, no obvious differences were found in medians of age, TC, TG, HDL, HCY, UA, and ALT in the two groups. Median LDL, BG, and CR were significantly higher and AST was much lower in the ED group (P<0.01). In binary logistic regression analysis, odds ratios (OR) for LDL, BG, CR, and AST were 1.279, 1.237, 1.026, and 0.978, respectively. The sensitivity value and specificity value were 43.25% and 72.56%, respectively. The medians of LDL, TG, and TC were higher and HDL was much lower in the older ED group, as compared with the younger group (P<0.05). No significant differences were displayed in medians of other biochemical markers in the above comparisons.

Conclusions

Elevated LDL, BG, and CR were related factors of ED in young men. Lipid profile was significantly different between young men with ED aged 20–30 and 31–40 years.

Prolyl endopeptidase disruption reduces hepatic inflammation and oxidative stress in methionine-choline-deficient diet-induced steatohepatitis

AIMS

Prolyl endopeptidase (PREP) is a serine endopeptidase widely distributed in the body, and accumulated evidence suggests that PREP participates in inflammation and oxidative stress. Here, we explored the effect of PREP gene disruption on hepatic inflammation and oxidative stress status in a methionine-choline-deficient (MCD)-induced nonalcoholic steatohepatitis (NASH) model.

MAIN METHODS

PREP gene disruption (PREP^gt) mice and wild-type (WT) littermates were placed on a control or an MCD diet for 4 weeks, respectively. The liver histopathological analysis and the number of inflammatory cells were determined by hematoxylin-eosin (HE) and immunohistochemical staining. Inflammation-associated genes and cytokine levels in liver tissue were evaluated by quantitative PCR and ELISA. The levels of P53, Sesn2, Nrf2, HO-1, and oxidative stress indicators in mice and the palmitic acid (PA)-treated human hepatocellular carcinoma cells (HepG2) were examined by immunoblotting and commercially available kits, respectively.

KEY FINDINGS

We found that PREP expression was upregulated in the MCD-induced NASH model. In addition, PREP disruption alleviated MCD-induced hepatic inflammation accompanied by diminished infiltration of inflammatory cells and secretion of inflammatory mediators. More importantly, the results of this study indicate that targeting PREP can improve oxidative stress status in the liver of MCD-diet mice and PA-exposed HepG2 cells. The effect is most likely mediated by the activation of P53 and its downstream signaling pathways (Sesn2/Nrf2/HO-1).

SIGNIFICANCE

Our results showed that PREP disruption (or inhibition) could decrease oxidative stress and inflammation and improve liver function, indicating that targeting PREP might be a new potential therapeutic option for NAFLD/NASH.

Systemic Overexpression of GDF5 in Adipocytes but Not Hepatocytes Alleviates High-Fat Diet-Induced Nonalcoholic Fatty Liver in Mice

OBJECTIVE

Our recent study demonstrated that growth differentiation factor 5 (GDF5) could promote white adipose tissue thermogenesis and alleviate high-fat diet- (HFD-) induced obesity in fatty acid-binding protein 4- (Fabp4-) GDF5 transgenic mice (TG). Here, we further investigated the effects of systemic overexpression of the GDF5 gene in adipocytes HFD-induced nonalcoholic fatty liver disease (NAFLD).

METHODS

Fabp4-GDF5 TG mice were administered an HFD feeding. NAFLD-related indicators associated with lipid metabolism and inflammation were measured. A GDF5 lentiviral vector was constructed, and the LO2 NAFLD cell model was induced by FFA solution (oleic acid and palmitic acid). The alterations in liver function, liver lipid metabolism, and related inflammatory indicators were analyzed.

RESULTS

The liver weight was significantly reduced in the TG group, which was in accordance with the significantly downregulated expression of TNFα, MCP1, Aim2, and SREBP-1c and significantly upregulated expression of CPT-1α and ACOX2 in TG mouse livers. Compared to that of cells in the FAA-free control group, LO2 cells with in situ overexpression of GDF5 developed lipid droplets after FFA treatment; the levels of triglycerides, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were significantly increased in both the GDF5 lentivirus and control lentivirus groups compared with those of the FAA-free group. Additionally, the levels of FAS, SREBP-1, CPT-1α, and inflammation-associated genes, such as ASC and NLRC4, were unaltered despite GDF5 treatment.

CONCLUSION

Systemic overexpression of GDF5 in adipose tissue in vivo significantly reduced HFD-induced NAFLD liver damage in mice. The overexpression of GDF5 in hepatocytes failed to improve lipid accumulation and inflammation-related reactions induced by mixed fatty acids, suggesting that the protective effect of GDF5 in NAFLD was mainly due to the reduction in adipose tissue and improvements in metabolism. Hence, our study suggests that the management of NAFLD should be targeted to reduce the overall amount of body fat and improve metabolic status before the progression to nonalcoholic steatohepatitis occurs.

Interaction Mechanisms Between Major Depressive Disorder and Non-alcoholic Fatty Liver Disease

Major depressive disorder (MDD), which is highly associated with non-alcoholic fatty liver disease (NAFLD), has complex pathogenic mechanisms. However, a limited number of studies have evaluated the mutual pathomechanisms involved in MDD and NAFLD development. Chronic stress-mediated elevations in glucocorticoid (GC) levels play an important role in the development of MDD-related NAFLD. Elevated GC levels can induce the release of inflammatory factors and changes in gut permeability. Elevated levels of inflammatory factors activate the hypothalamic-pituitary-adrenal (HPA) axis, which further increases the release of GC. At the same time, changes in gut permeability promote the release of inflammatory factors, which results in a vicious circle among the three, causing disease outbreaks. Even though the specific role of the thyroid hormone (TH) in this pathogenesis has not been fully established, it is highly correlated with MDD and NAFLD. Therefore, changing lifestyles and reducing psychological stress levels are necessary measures for preventing MDD-related NAFLD. Among them, GC inhibitors and receptor antagonists may be key in the alleviation of early and mid-term disease progression. However, combination medications may be important in late-stage diseases, but they are associated with various side effects. Traditional Chinese medicines have been shown to be potential therapeutic alternatives for such complex diseases.

Non-Alcoholic Fatty Liver Disease and Hypokalemia in Primary Aldosteronism Among Chinese Population

BACKGROUND

In recent years, evidence that aldosteronism is a risk factor for metabolic disorders has increased. This study was designed to investigate the role of nonalcoholic fatty liver disease (NAFLD) and hypokalemia in primary aldosteronism (PA).

METHODS

A total of 222 patients diagnosed with PA and 222 non-PA patients were included in our study. Demographic data, medical histories, clinical evaluations, complete blood counts, serum biochemical analyses, aldosterone and potassium levels were obtained. Data are presented as the means ± standard deviation (SD). To compare the parameters between cases and controls, Student's t-tests or Mann-Whitney U tests were used for continuous variables, and χ2 tests were used for categorical variables. Pearson correlation analysis was used to define relationships between pairs of parameters. A two-sided P < 0.05 was considered statistically significant. Multivariate logistic regression was performed to assess the independent effects of potassium and other metabolic variables on NAFLD in PA patients.

RESULTS

The diagnosis of NAFLD was more common in PA patients (n=222, 35.1%) than in non-PA subjects (29.7%). PA patients with and without NAFLD had similar metabolic imbalance characteristics. In PA patients with hypokalemia, relatively higher prevalences of NAFLD (44% vs. 27%, P < 0.05) and diabetes mellitus (19.8% vs. 9.9%, P < 0.05) were observed. Hypokalemic PA patients had a worse metabolic status than PA patients without hypokalemia, including higher body mass index (BMI) (25.4 ± 3.4 vs. 24.1 ± 3.9 kg/m², P < 0.05), more severe dyslipidemia as well as insulin resistance, higher serum uric acid levels (354 ± 95 vs. 319 ± 87 μmol/L, P < 0.01) and aggravated inflammation.

CONCLUSION

The prevalence of NAFLD was higher in PA patients than in non-PA patients, although the patterns of obesity, dyslipidemia and insulin resistance were similar. Hypokalemic PA patients had a worse metabolic status than normokalemic PA patients. This study provides new insights that can inform further mechanistic studies about metabolic imbalance in patients with aldosteronism.

Efficacy of Weight Reduction on Pediatric Nonalcoholic Fatty Liver Disease: Opportunities to Improve Treatment Outcomes Through Pharmacotherapy

Obesity is the single greatest risk factor for nonalcoholic fatty liver disease (NAFLD). Without intervention, most pediatric patients with NAFLD continue to gain excessive weight, making early, effective weight loss intervention key for disease treatment and prevention of NAFLD progression. Unfortunately, outside of a closely monitored research setting, which is not representative of the real world, lifestyle modification success for weight loss in children is low. Bariatric surgery, though effective, is invasive and can worsen NAFLD postoperatively. Thus, there is an evolving and underutilized role for pharmacotherapy in children, both for weight reduction and NAFLD management. In this perspective article, we provide an overview of the efficacy of weight reduction on pediatric NAFLD treatment, discuss the pros and cons of currently approved pharmacotherapy options, as well as drugs commonly used off-label for weight reduction in children and adolescents. We also highlight gaps in, and opportunities for, streamlining obesity trials to include NAFLD assessment as a valuable, secondary, therapeutic outcome measure, which may aid drug repurposing. Finally, we describe the already available, and emerging, minimally-invasive biomarkers of NAFLD that could offer a safe and convenient alternative to liver biopsy in pediatric obesity and NAFLD trials.

Possible Hepatoprotective Effect of Tocotrienol-Rich Fraction Vitamin E in Non-alcoholic Fatty Liver Disease in Obese Children and Adolescents

Obesity has become a worldwide health concern among the pediatric population. The prevalence of non-alcoholic fatty liver disease (NAFLD) is growing rapidly, alongside the high prevalence of obesity. NAFLD refers to a multifactorial disorder that includes simple steatosis to non-alcoholic steatohepatitis (NASH) with or devoid of fibrosis. NAFLD is regarded as a systemic disorder that influences glucose, lipid, and energy metabolism with hepatic manifestations. A sedentary lifestyle and poor choice of food remain the major contributors to the disease. Prompt and timely diagnosis of NAFLD among overweight children is crucial to prevent the progression of the condition. Yet, there has been no approved pharmacological treatment for NAFLD in adults or children. As indicated by clinical evidence, lifestyle modification plays a vital role as a primary form of therapy for managing and treating NAFLD. Emphasis is on the significance of caloric restriction, particularly macronutrients (fats, carbohydrates, and proteins) in altering the disease consequences. A growing number of studies are now focusing on establishing a link between vitamins and NAFLD. Different types of vitamin supplements have been shown to be effective in treating NAFLD. In this review, we elaborate on the potential role of vitamin E with a high content of tocotrienol as a therapeutic alternative in treating NAFLD in obese children.

Antrodia Cinnamomea Attenuates Non-Alcoholic Steatohepatitis by Suppressing NLRP3 Inflammasome Activation In Vitro and In Vivo

Blockade of the NOD-like receptor protein 3 (NLRP3) inflammasome has been shown to be effective in halting the progression of non-alcoholic steatohepatitis (NASH). Antrodia cinnamomea is a well-known indigenous medicine used by Taiwanese aboriginal tribes. However, its effect on NASH remains unclear. This study aimed to examine the mechanistic insight of Antrodia cinnamomea extract (ACE) in both in vitro and in vivo models of NASH. Murine RAW264.7 macrophages and human hepatocellular carcinoma HepG2 cells were treated with the indicated concentration of ACE 30 minutes prior to stimulation with lipopolysaccharide (LPS) for 24 h. Levels of inflammatory markers, NLRP3 inflammasome, components, and endoplasmic reticulum (ER) stress markers were analyzed by Western blotting. For the in vivo experiments, male C57BL/6 mice weighing 21-25 g were fed a methionine/choline deficient (MCD) diet along with vehicle or ACE (100 mg/kg) for 10 consecutive days. The serum glutamate pyruvate transaminase (SGPT) levels of the mice were measured. The liver tissues from the mice underwent histological analysis (hematoxylin and eosin staining), and the levels of inflammatory markers, NLRP3 inflammasome components, and autophagy-related proteins were evaluated. ACE significantly inhibited NLRP3 inflammasome activation in vitro and in vivo. In addition, ACE attenuated the severity of MCD-induced steatohepatitis, reduced the levels of oxidative stress markers, and ameliorated inflammatory responses, but restored autophagic flux. Based on these findings, Antrodia cinnamomea could be developed into an anti-non-alcoholic fatty liver disease/NASH agent.

MAFLD vs. NAFLD: shared features and potential changes in epidemiology, pathophysiology, diagnosis, and pharmacotherapy

ABSTRACT

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, placing an increasing burden on human health. NAFLD is a complex multifactorial disease involving genetic, metabolic, and environmental factors. It is closely associated with metabolic syndrome, obesity, and type 2 diabetes, of which insulin resistance is the main pathophysiological mechanism. Over the past few decades, investigation of the pathogenesis, diagnosis, and treatments has revealed different aspects of NAFLD, challenging the accuracy of definition and therapeutic strategy for the clinical practice. Recently, experts reach a consensus that NAFLD does not reflect the current knowledge, and metabolic (dysfunction) associated fatty liver disease (MAFLD) is suggested as a more appropriate term. The new definition puts increased emphasis on the important role of metabolic dysfunction in it. Herein, the shared features and potential changes in epidemiology, pathophysiology, diagnosis, and pharmacotherapy of the newly defined MAFLD, as compared with the formerly defined NAFLD, are reviewed for updating our understanding.

Transplantation of brown adipose tissue up-regulates miR-99a to ameliorate liver metabolic disorders in diabetic mice by targeting NOX4

Nonalcoholic fatty liver disease (NAFLD), main cause of liver damage, is inextricably linked to diabetes. However, there is no specific means to improve the pathology of fatty liver in diabetic patients. Brown adipose tissue (BAT) is an important endocrine organ that secretes adipokines and microRNAs (miRNAs) involved in systemic metabolic regulation. To investigate the effects of BAT transplantation on liver lipid metabolism in diabetic mice, we transplanted BAT from male donor mice into diabetic mice induced by streptozotocin (STZ) combined with high-fat diet (HFD). At 10 weeks after transplantation, BAT transplantation significantly decreased the blood glucose and lipid, downregulated FAS, CD36, Scd1, ACCα, NOX2, NOX4, TGF-β1, FN and COL-1, up-regulated Nrf2, reversed the pathological changes of liver and increased the circulating miR-99a in diabetic mice. To verify whether circulating miR-99a improves oxidative stress by targeting inhibition of NOX4, we used 0.4mM palmitic acid (PA) to treat the LO2 cells. The expression of NOX4 protein was significantly decreased after transfection with miR-99a mimic, and increased after transfection with miR-99a inhibitor. Luciferase reporter assay confirmed that miR-99a could target NOX4 mRNA. These findings clarify the role of miR-99a and NOX4 in liver beneficial effect of BAT transplantation in diabetic mice.

The role of hepatic transcription factor cAMP response element-binding protein (CREB) during the development of experimental nonalcoholic fatty liver: a biochemical and histomorphometric study

Background

Several molecular mechanisms contribute to the initiation and progression of nonalcoholic fatty liver disease (NAFLD); however, the exact mechanism is not completely understood. Cyclic adenosine monophosphate (cAMP) is one of the most promising pathways that regulates various cellular functions including lipid and carbohydrate metabolism. cAMP induces gene transcription through phosphorylation of the transcription factor, cAMP response element-binding protein (CREB). The action of cAMP is tightly regulated by its level and repression. Among the repressors, Inducible cAMP Early Repressor (ICER) is the only inducible CRE-binding protein. The present study aimed to evaluate the role of hepatic CREB level in the development of experimental NAFLD model to clarify the pathogenesis of the disease. NAFLD 35 male Wistar rats fed a high fat diet for a period of 14 weeks were studied compared with 35 control rats fed a standard diet. Five fasting rats were sacrificed each 2 weeks intervals for a period of 14 weeks.

Results

NAFLD group revealed a remarkable duration—dependent elevation in cAMP and CREB levels in the liver tissue compared to control group (P value < 0.004, P value < 0.006, respectively). In contrast, ICER gene expression, as a dominant-negative regulator of CREB, was downregulated in the liver of NAFLD group compared to control group. We also demonstrated that CREB levels were positively correlated with liver function tests, and glucose homeostasis parameters.

Conclusions

Our results indicate that cAMP/CREB pathway provides an early signal in the progression to NAFLD representing a noninvasive biomarker that can early detect NAFLD and a promising therapeutic target for the treatment of the disease as well.

Efficacy of resveratrol supplementation on liver enzymes in patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis

OBJECTIVE

Randomized clinical trials (RCTs) examining the effects of resveratrol supplementation on liver enzymes in non-alcoholic fatty liver disease (NAFLD) have reported conflicting results. The aim of this systematic review was to summarize evidence of the effects of resveratrol supplementation on alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels in patients with NAFLD by performing a meta-analysis of RCTs.

METHODS

PubMed, Cochrane Library, Scopus, and Web of Science databases were electronically explored from inception to August 2020 for all relevant studies. Random effect models were used to estimate liver enzymes changes between resveratrol supplementation and control groups by evaluating the weighted mean differences (WMD) with 95 % confidence intervals (CIs).

RESULTS

Five trials with a total of 216 patients were included in the meta-analysis. The pooled results showed that resveratrol supplementation did not result in significant changes in serum ALT (WMD= -2.48 IU/L; 95 % CI: -12.30, 7.34; P = 0.62), and AST (WMD = -2.90 IU/L; 95 % CI: -9.77, 3.98; P = 0.40) concentrations. Subgroup analysis revealed a significant reduction in serum ALT and AST concentrations in the participants with mean age <45 years, and studies with intervention dosage <1000 mg/day. In addition, ALT and AST levels were decreased significantly in studies with duration >12 weeks and participants with BMI < 30 kg/m², respectively.

CONCLUSIONS

The overall results indicated that resveratrol supplementation did not affect liver enzymes in patients with NAFLD. More studies examining the effect of resveratrol supplementation on liver enzymes are needed in the future.

Zucker Lean Rats With Hepatic Steatosis Recapitulate Asymptomatic Metabolic Syndrome and Exhibit Greater Sensitivity to Drug-Induced Liver Injury Compared With Standard Nonclinical Sprague-Dawley Rat Model

Fatty liver disease is a potential risk factor for drug-induced liver injury (DILI). Despite advances in nonclinical in vitro and in vivo models to assess liver injury during drug development, the pharmaceutical industry is still plagued by idiosyncratic DILI. Here, we tested the hypothesis that certain features of asymptomatic metabolic syndrome (namely hepatic steatosis) increase the risk for DILI in certain phenotypes of the human population. Comparison of the Zucker Lean (ZL) and Zucker Fatty rats fed a high fat diet (HFD) revealed that HFD-fed ZL rats developed mild hepatic steatosis with compensatory hyperinsulinemia without increases in liver enzymes. We then challenged steatotic HFD-fed ZL rats and Sprague-Dawley (SD) rats fed normal chow, a nonclinical model widely used in the pharmaceutical industry, with acetaminophen overdose to induce liver injury. Observations in HFD-fed ZL rats included increased liver injury enzymes and greater incidence and severity of hepatic necrosis compared with similarly treated SD rats. The HFD-fed ZL rats also had disproportionately higher hepatic drug accumulation, which was linked with abnormal hepatocellular efflux transporter distribution. Here, we identify ZL rats with HFD-induced hepatic steatosis as a more sensitive nonclinical in vivo test system for modeling DILI compared with SD rats fed normal chow.

Association between the non-HDL-cholesterol to HDL-cholesterol ratio and non-alcoholic fatty liver disease in Chinese children and adolescents: a large single-center cross-sectional study

Background

The non-HDL-cholesterol to HDL-cholesterol (NHDLC/HDLC) ratio is closely related to a variety of dyslipidemia-related diseases. This study examined the relationship between the NHDLC/HDLC ratio and non-alcoholic fatty liver (NAFLD) in children and adolescents.

Methods

This cross-sectional survey included a total of 7759 eligible Chinese children and adolescents (5692 boys and 2067 girls) who received routine medical examinations. The anthropometric and laboratory data of the subjects were collected. NAFLD was diagnosed by liver ultrasonography. Binary logistic regression analysis was performed on the NHDLC/HDLC ratio, NHDLC, HDLC and NAFLD. Receiver operating characteristic (ROC) curve analysis was used to compare the diagnostic significance of the above parameters for NAFLD.

Results

The total prevalence of NAFLD was 4.36%, and the prevalence in boys was higher than that in girls (5.61% vs. 1.9%, P < 0.001). The prevalence of NAFLD was positively correlated with the NHDLC/HDLC ratio (P < 0.001). The binary logistic regression analysis demonstrated that the OR was 8.61 (95% CI, 5.90–12.57, P < 0.001) in tertile 3 (highest NHDLC/HDLC ratio) compared with tertile 1 (lowest NHDLC/HDLC ratio). After adjustment for age, sex, body mass index (BMI), alanine aminotransferase (ALT), uric acid (UA), total bilirubin (TB), fasting plasma glucose (FPG) and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), the OR for tertile 3 (OR = 1.83, 95% CI, 1.04–3.22, P = 0.035) was still significantly higher than that of tertile 1. The area under the curve (AUC) of the NHDLC/HDLC ratio of boys was 0.787, which was significantly greater than NHDLC and HDLC (0.719 and 0.726, P < 0.001). For girls, the AUC of the NHDLC/HDLC ratio was 0.763, which was also significantly greater than NHDLC (0.661, P < 0.001). The cutoff point of the NHDLC/HDLC ratio was 2.475 in boys and 2.695 in girls. In addition, the AUC of the NHDLC/HDLC ratio was 0.761 in subjects with normal ALT levels (ALT ≤40 U/L), which was significantly higher than NHDLC (0.680, P < 0.001) and HDLC (0.724, P = 0.007). For subjects with elevated ALT levels (ALT > 40 U/L), the AUC of the NHDLC/HDLC ratio (0.746) was also significantly greater than NHDLC (0.646, P < 0.001).

Conclusions

The NHDLC/HDLC ratio was positively correlated with NAFLD in Chinese children and adolescents. It may serve as an effective indicator to help identify NAFLD in children and adolescents.

Lower adropin expression is associated with oxidative stress and severity of nonalcoholic fatty liver disease

BACKGROUND & AIMS

Adropin has been reported to be involved in metabolic disorders, including nonalcoholic fatty liver disease (NAFLD). However, the clinical relevance of adropin expression to the histological severity of NAFLD is unclear. This study aimed to investigate adropin expression in biopsy-proven NAFLD patients.

METHODS

This case-control study enrolled a total of 109 participants, including 15 normal histological controls, 26 nonalcoholic fatty liver (NAFL), 21 nonalcoholic steatohepatitis (NASH) subjects and B-ultrasound NAFLD-free normal controls matched to the cases based on age and sex (the case:control ratio was 1:1). Liver biopsies were obtained and histological characteristics were assessed. Primary murine hepatocytes were isolated from C57BL/6J mice and incubated with doses of palmitate to induce oxidative stress.

RESULTS

The serum adropin level in NASH patients was 9.99 ± 5.51 ng/ml, significantly lower than that in B-ultrasound normal controls (22.70 ± 6.32 ng/ml), histological normal controls (21.93 ± 6.63 ng/ml) and NAFL patients (17.82 ± 6.90 ng/ml). Serum adropin levels were negatively correlated with the histological severity of NAFLD. The lower serum adropin level predicted NASH (area under the ROC curve: 87.1%). Adropin expression in serum and liver was also negatively associated with hepatic MDA and serum 8-iso-PGF2α levels. Furthermore, palmitate rather than oleate induced oxidative stress in a dose-dependent manner with a gradient decrease in adropin expression in primary murine hepatocytes. Adropin overexpression or treatment ameliorated palmitate-induced oxidative stress in hepatocytes.

CONCLUSIONS

Circulating adropin was inversely associated with the oxidative stress and histological severity of NAFLD. It may play an important role in the development of NAFLD.

CRISPR-mediated BMP9 ablation promotes liver steatosis via the down-regulation of PPARα expression

Obesity drives the development of nonalcoholic fatty liver disease (NAFLD) characterized by hepatic steatosis. Several bone morphogenetic proteins (BMPs) except BMP9 were reported related to metabolic syndrome. This study demonstrates that liver cytokine BMP9 is decreased in the liver and serum of NAFLD model mice and patients. BMP9 knockdown induces lipid accumulation in Hepa 1-6 cells. BMP9-knockout mice exhibit hepatosteatosis due to down-regulated peroxisome proliferator-activated receptor α (PPARα) expression and reduced fatty acid oxidation. In vitro, recombinant BMP9 treatment attenuates triglyceride accumulation by enhancing PPARα promoter activity via the activation of p-smad. PPARα-specific antagonist GW6471 abolishes the effect of BMP9 knockdown. Furthermore, adeno-associated virus-mediated BMP9 overexpression in mouse liver markedly relieves liver steatosis and obesity-related metabolic syndrome. These findings indicate that BMP9 plays a critical role in regulating hepatic lipid metabolism in a PPARα-dependent manner and may provide a previously unknown insight into NAFLD therapeutic approaches.

Can You Trust Your Gut? Implicating a Disrupted Intestinal Microbiome in the Progression of NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of disorders, ranging from fatty liver to a more insulin resistant, inflammatory and fibrotic state collectively termed non-alcoholic steatohepatitis (NASH). In the United States, 30%-40% of the adult population has fatty liver and 3%-12% has NASH, making it a major public health concern. Consumption of diets high in fat, obesity and Type II diabetes (T2D) are well-established risk factors; however, there is a growing body of literature suggesting a role for the gut microbiome in the development and progression of NAFLD. The gut microbiota is separated from the body by a monolayer of intestinal epithelial cells (IECs) that line the small intestine and colon. The IEC layer is exposed to luminal contents, participates in selective uptake of nutrients and acts as a barrier to passive paracellular permeability of luminal contents through the expression of tight junctions (TJs) between adjacent IECs. A dysbiotic gut microbiome also leads to decreased gut barrier function by disrupting TJs and the gut vascular barrier (GVB), thus exposing the liver to microbial endotoxins. These endotoxins activate hepatic Toll-like receptors (TLRs), further promoting the progression of fatty liver to a more inflammatory and fibrotic NASH phenotype. This review will summarize major findings pertaining to aforementioned gut-liver interactions and its role in the pathophysiology of NAFLD.

Pediatric nonalcoholic fatty liver disease - a changing diagnostic paradigm

Worldwide, nonalcoholic fatty liver disease (NAFLD) has emerged as the leading cause of chronic liver disease in children and adolescents, but also as a real public health issue. Over the last decades, the increase in the rates of obesity and overweight in children has led to the increase in the worldwide prevalence of pediatric NAFLD. Detection of a hyperechoic appearance of the liver at ultrasounds or elevated levels of transaminases, identified during a routine control in children, suggests NAFLD. The disorder can be diagnosed with either non-invasive strategies or through liver biopsy, which further allows the identification of specific histological aspects, distinct from those found in adults. Since NAFLD is a clinically heterogeneous disease, there is an imperative need to identify noninvasive biomarkers and screening techniques for early diagnosis in children, in order to prevent metabolic and cardiovascular complications later in adulthood. This review emphasizes the main diagnosis tools in pediatric NAFLD, a systemic disorder with multifactorial pathogenesis and varying clinical manifestations.

Lipidomics in Nonalcoholic Fatty Liver Disease: Exploring Serum Lipids as Biomarkers for Pediatric Nonalcoholic Fatty Liver Disease

OBJECTIVES

Disturbances in lipid metabolism play an important role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Using lipidomics, an analytical technique that is used to broadly survey lipid metabolism, we searched for biomarkers in plasma that are correlated with the presence of hepatic steatosis in children with obesity.

METHODS

Lipidomics was performed in plasma samples of 21 children with obesity in whom steatosis was detected using proton magnetic resonance spectroscopy (H-MRS) and were compared with the lipidome of 21 samples of nonsteatotic subjects with obesity.

RESULTS

Forty-two samples were analyzed (57% boys; median age 15 years). A total of 18 lipid classes constituting 839 different lipid species were identified. A statistically significant increase in alkyldiacylglycerol (TG[O]) and phosphatidylethanolamine (PE) species and a significant decrease in alkyl/alkenyl-phosphatidylethanolamine (PE[O]), alkyl/alkenyl-lysophosphatidylethanolamine (LPE[O]) and alkyl/alkenyl-phosphatidylcholine (PC[O]) was observed in children with hepatic steatosis compared with controls. Twelve individual lipid species of 3 lipid classes were significantly increased in steatotic subjects compared with controls.

CONCLUSIONS

In this pilot study, we found statistically significant alterations in 5 major lipid classes and 12 individual lipid species in children with steatosis. These might be potential biomarkers for pediatric NAFLD. Lipidomic studies in larger cohorts of children are needed to determine the diagnostic value of these lipids and determine whether results can be generalized for different age groups and ethnic backgrounds.

Mechanistic study of attenuation of monosodium glutamate mixed high lipid diet induced systemic damage in rats by Coccinia grandis

In the context of failure of treatment for non alcoholic fatty liver disease (NAFLD)-mediated systemic damages, recognition of novel and successful characteristic drug to combat these anomalous situations is earnestly required. The present study is aimed to evaluate protective value of ethanol extract of Coccinia grandis leaves (EECGL), naturally occurring medicinal plant, on NAFLD-mediated systemic damage induced by high lipid diet along with monosodium glutamate (HM)-fed rats. Our study uncovered that EECGL significantly ameliorates HM-induced hyperlipidemia, increased lipogenesis and metabolic disturbances (via up regulation of PPAR-α and PPAR-γ), oxidative stress (via reducing the generation of reactive oxygen species and regulating the redox-homeostasis) and inflammatory response (via regulating the pro-inflammatory and anti-inflammatory factors with concomitant down regulation of NF-kB, iNOS, TNF-α and up regulation of eNOS). Furthermore, EECGL significantly inhibited HM-induced increased population of cells in sub G0/G1 phase, decreased Bcl2 expression and thereby loss of mitochondrial membrane potential with over expression of Bax, p53, p21, activation of caspase 3 and 9 indicated the apoptosis and suppression of cell survival. It is perhaps the first comprehensive study with a mechanistic approach which provides a strong unique strategy for the management of HM-induced systemic damage with effective dose of EECGL.

The Gut Microbiota and Its Metabolites, Novel Targets for Treating and Preventing Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent metabolic disorders worldwide, along with obesity and type 2 diabetes. NAFLD involves a series of liver abnormalities from simple hepatic steatosis to non-alcoholic steatohepatitis, which can ultimately lead to liver cirrhosis and cancer. The gut-liver axis plays an important role in the development of NAFLD, which depends mainly on regulation of the gut microbiota and its bacterial products. These intestinal bacterial species and their metabolites, including bile acids, tryptophan catabolites, and branched-chain amino acids, regulate adipose tissue and intestinal homeostasis and contribute to the pathogenesis of NAFLD/non-alcoholic steatohepatitis. In this review, the current evidence regarding the key role of the gut microbiota and its metabolites in the pathogenesis and development of NAFLD is highlighted, and the advances in the progression and applied prospects of gut microbiota-targeted dietary and exercise therapies is also discussed.

Allele HLA-DQB1*06 reduces fibrosis score in patients with non-alcoholic fatty liver disease

AIM

Human leukocyte antigen (HLA) regions were highlighted as important genetic markers for various liver diseases by hepatology-related genome-wide association studies. Replication studies in non-alcoholic fatty liver disease (NAFLD) are limited and none has investigated the association of HLA alleles with non-alcoholic steatohepatitis (NASH) and other histological characteristics. In the current study, we examined the association of HLA-DQA1 and HLA-DQB1 alleles with NAFLD spectrum and its histological characteristics.

METHODS

Consecutive biopsy-proven NAFLD patients (n = 191) and healthy controls (n = 188) were enrolled and genotyped for HLA-DQA1 and HLA-DQB1 alleles using the sequence-specific oligonucleotide-polymerase chain reaction method.

RESULTS

No association was found between the HLA alleles and NAFLD or NASH in a case-control setting. Nevertheless, among NAFLD patients, the frequency of HLA-DQB1*06 allele was significantly the lowest in NASH with significant fibrosis (10.4%) and approximately similar for NASH without significant fibrosis (22.9%) and NAFL (22.5%) (P = 0.004). It is noteworthy that the association remains significant after correction for multiple comparisons (P_c  = 0.04). Multivariate analysis revealed that HLA-DQB1*06 allele is also associated with fibrosis score (P = 0.001); the result remains significant after correction for multiple comparisons.

CONCLUSION

These findings suggest that HLA-DQB1*06 is associated with lower fibrosis score in NAFLD patients.

β-Glucan ameliorates nonalcoholic steatohepatitis induced by methionine and choline-deficient diet in mice

Nonalcoholic steatohepatitis (NASH) is becoming a huge global health problem. Studies showed that β-glucan displayed potent anti-inflammatory and other multi-beneficial pharmacological properties. Thus, the objective of this study was to investigate the effects of β-glucan on NASH mice induced by the MCD diet. After 8 weeks of β-glucan treatments, results showed that β-glucan effectively decreased the serum ALT and AST levels compared with the MCD model. Besides, histopathological results demonstrated that β-glucan significantly attenuated the fat accumulation, steatosis, and inflammation in the liver compared with that of the MCD group. Furthermore, the ER stress-responsive proteins, including GRP78, p-eiF-2α, and p-JNK, were markedly restrained by β-glucan, while ERp57, p-MAPK, and p-Akt were significantly increased after β-glucan treatment. Collectively, our results suggested that β-glucan beneficially resisted NASH induced by the MCD diet. The ER stress response may be involved in the mechanisms of action of β-glucan. PRACTICAL APPLICATIONS: This study is the first to report the hepatoprotective activity of β-glucan against MCD diet-induced NASH in mice, mainly reflecting its ability to ameliorate hepatic lipid accumulation and inflammation, with the mechanism possibly involving mediating the ER stress signaling pathway. Our results suggest that the β-glucan has good application prospects to be used as a raw material in functional foods for the clinical treatment of NASH.

Heightened Plasma Levels of Transforming Growth Factor Beta (TGF-β) and Increased Degree of Systemic Biochemical Perturbation Characterizes Hepatic Steatosis in Overweight Pediatric Patients: A Cross-Sectional Study

Nonalcoholic Fatty Liver Disease (NAFLD) is a common cause of chronic liver disease in childhood and strongly associated with obesity. Routine biochemical non-invasive tests remain with low accuracy for diagnosis of NAFLD. We performed a cross-sectional study to examine potential associations between anthropometric and biochemical parameters, specially TGF-β, a prognosis marker for hepatic steatosis (HS). Between May and October 2019, seventy-two overweight adolescents were enrolled, of which 36 had hepatic steatosis. Hepatic, lipidic and glycemic profiles, and levels of vitamin D, ferritin and TGF-β were analyzed. Hierarchical cluster and a discriminant model using canonical correlations were employed to depict the overall expression profile of biochemical markers and the biochemical degree of perturbation. Median values of alanine aminotransferase (ALT), gamma glutamyl transpeptidase (GGT), and TGF-β were higher in the adolescents with HS. Values of body mass index (BMI)/age and ALT, but not of TGF-β, were gradually increased proportionally to augmentation of steatosis severity. In a multivariate analysis, TGF-β plasma concentrations were associated with occurrence of hepatic steatosis independent of other covariates. Discriminant analysis confirmed that TGF-β concentrations can identify HS cases. Our data reveal that HS patients exhibit a distinct biosignature of biochemical parameters and imply TGF-β as an important biomarker to evaluate risk of steatosis development.

The Effect of a Family-Based Lifestyle Education Program on Dietary Habits, Hepatic Fat and Adiposity Markers in 8-12-Year-Old Children with Overweight/Obesity

Healthy lifestyle education programs are recommended for obesity prevention and treatment. However, there is no previous information on the effects of these programs on the reduction of hepatic fat percentage. The aims were (i) to examine the effectiveness of a 22-week family-based lifestyle education program on dietary habits, and (ii) to explore the associations of changes in dietary intake with percent hepatic fat reduction and adiposity in children with overweight/obesity. A total of 81 children with overweight/obesity (aged 10.6 ± 1.1 years, 53.1% girls) and their parents attended a 22-week family based healthy lifestyle and psychoeducational program accompanied with (intensive group) or without (control) an exercise program. Hepatic fat (magnetic resonance imaging), adiposity (dual energy X-ray absorptiometry) and dietary habits (two non-consecutive 24 h-recalls) were assessed before and after the intervention. Energy (p < 0.01) fat (p < 0.01) and added sugar (p < 0.03) intake were significantly reduced in both groups at the end of the program, while, in addition, carbohydrates intake (p < 0.04) was reduced exclusively in the control group, and simple sugar (p < 0.05) and cholesterol (p < 0.03) intake was reduced in the exercise group. Fruit (p < 0.03) and low-fat/skimmed dairy consumption (p < 0.02), the adherence to the Mediterranean Diet Quality Index for children and teenagers (KIDMED, p < 0.01) and breakfast quality index (p < 0.03) were significantly higher in both control and intervention groups after the intervention. Moreover, participants in the exercise group increased the adherence to the Dietary Approaches to Stop Hypertension (DASH) diet (p < 0.001), whereas the ratio of evening-morning energy intake was significantly lower exclusively in the control group after the program (p < 0.02). Changes in energy intake were significantly associated with changes in fat mass index (FMI) in the exercise group, whereas changes in sugar-sweetened beverages (SSB) consumption was associated with percent hepatic fat reduction (p < 0.05) in the control group. A 22-week family-based healthy lifestyle program seems to be effective on improving diet quality and health in children with overweight/obesity and these should focus on SSB avoidance and physical activity.

Folic acid attenuates high-fat diet-induced steatohepatitis via deacetylase SIRT1-dependent restoration of PPARα

BACKGROUND

Folic acid has been shown to improve non-alcoholic steatohepatitis (NASH), but its roles in hepatic lipid metabolism, hepatic one-carbon metabolism, and gut microbiota are still unknown.

AIM

To demonstrate the role of folic acid in lipid metabolism and gut microbiota in NASH.

METHODS

Twenty-four Sprague-Dawley rats were assigned into three groups: Chow diet, high-fat diet (HFD), and HFD with folic acid administration. At the end of 16 wk, the liver histology, the expression of hepatic genes related to lipid metabolism, one-carbon metabolism, and gut microbiota structure analysis of fecal samples based on 16S rRNA sequencing were measured to evaluate the effect of folic acid. Palmitic acid-exposed Huh7 cell line was used to evaluate the role of folic acid in hepatic lipid metabolism.

RESULTS

Folic acid treatment attenuated steatosis, lobular inflammation, and hepatocellular ballooning in rats with HFD-induced steatohepatitis. Genes related to lipid de novo lipogenesis, β-oxidation, and lipid uptake were improved in HFD-fed folic acid-treated rats. Furthermore, peroxisome proliferator-activated receptor alpha (PPARα) and silence information regulation factor 1 (SIRT1) were restored by folic acid in HFD-fed rats and palmitic acid-exposed Huh7 cell line. The restoration of PPARα by folic acid was blocked after transfection with SIRT1 siRNA in the Huh7 cell line. Additionally, folic acid administration ameliorated depleted hepatic one-carbon metabolism and restored the diversity of the gut microbiota in rats with HFD-induced steatohepatitis.

CONCLUSION

Folic acid improves hepatic lipid metabolism by upregulating PPARα levels via a SIRT1-dependent mechanism and restores hepatic one-carbon metabolism and diversity of gut microbiota, thereby attenuating HFD-induced NASH in rats.

Association between ratio of γ-glutamyl transpeptidase to high-density lipoprotein cholesterol and prevalence of nonalcoholic fatty liver disease and metabolic syndrome: a cross-sectional study

Background

Metabolic risk factors including obesity, insulin resistance, dyslipidemia, metabolic syndrome (MS), and diabetes are associated with nonalcoholic fatty liver disease (NAFLD). γ-Glutamyl transpeptidase (GGT) and high-density lipoprotein cholesterol (HDL-C) are associated with insulin resistance, dyslipidemia, oxidative stress, and obesity. We investigated the associations between GGT/HDL-C ratio and prevalence of NAFLD in a Chinese population.

Methods

The study included 1,813 NAFLD (526 females, 1,287 males) and 4,513 non-NAFLD (3,077 females, 1,436 males) participants. The diagnosis of NAFLD was based on ultrasonography.

Results

Participants with NAFLD had higher GGT/HDL-C ratio, BMI, WC, TG, TC, and HOMA-IR, but lower HDL-C than participants without NAFLD. GGT/HDL-C ratio was significantly associated with prevalence of NAFLD. Specifically, for each 1 unit increase in GGT/HDL-C ratio, the prevalence of NAFLD will increase by 0.3%. As GGT/HDL-C ratio quartiles increased, prevalence of NAFLD/MS in Q4 (highest GGT/HDL-C ratio quartile) was 6.362/3.968 times higher than that in Q1 (lowest GGT/HDL-C ratio quartile). The AUC [0.799 (0.788-0.810)] for GGT/HDL-C ratio was significantly higher than those for GGT and HDL-C alone.

Conclusions

The present results suggest that GGT/HDL-C ratio can be used as a predictive factor for prevalence of NAFLD after adjustment for confounding variables.

Role of spleen tyrosine kinase in liver diseases

Spleen tyrosine kinase (SYK) is a non-receptor tyrosine kinase expressed in most hematopoietic cells and non-hematopoietic cells and play a crucial role in both immune and non-immune biological responses. SYK mediate diverse cellular responses via an immune-receptor tyrosine-based activation motifs (ITAMs)-dependent signalling pathways, ITAMs-independent and ITAMs-semi-dependent signalling pathways. In liver, SYK expression has been observed in parenchymal (hepatocytes) and non-parenchymal cells (hepatic stellate cells and Kupffer cells), and found to be positively correlated with the disease severity. The implication of SYK pathway has been reported in different liver diseases including liver fibrosis, viral hepatitis, alcoholic liver disease, non-alcoholic steatohepatitis and hepatocellular carcinoma. Antagonism of SYK pathway using kinase inhibitors have shown to attenuate the progression of liver diseases thereby suggesting SYK as a highly promising therapeutic target. This review summarizes the current understanding of SYK and its therapeutic implication in liver diseases.

Effectiveness of phosphatidylcholine in alleviating steatosis in patients with non-alcoholic fatty liver disease and cardiometabolic comorbidities (MANPOWER study)

Objective

The concept of using naturally occurring compounds such as polyenylphosphatidylcholine (PPC) as an adjunctive therapy to treat non-alcoholic fatty liver disease (NAFLD) and alleviate or reverse hepatic steatosis appears a very attractive option for liver protection. We aim to evaluate if PPC adjunctive therapy can effectively improve the ultrasonographic features of NAFLD in routine clinical practice in Russian patients with cardiometabolic comorbidities.

Design

This 24-week, observational, prospective study was carried out in 174 medical sites across 6 federal districts of Russia. A total of 2843 adult patients with newly diagnosed NAFLD, who had a least one of four comorbidities, namely overweight/obesity, hypertension, type 2 diabetes mellitus and hypercholesterolaemia, and who received PPC as an adjunctive treatment to standard care, were enrolled. The assessment of liver ultrasonography was qualitative.

Results

Overall, 2263 (79.6%) patients had at least two metabolic comorbidities associated with NAFLD, and overweight/obesity was the most common comorbidity reported in 2298 (80.8%) patients. Almost all study participants (2837/2843; 99.8%) were prescribed 1.8 g of PPC administered three times daily. At baseline, the most frequently identified abnormalities on ultrasound were liver hyperechogenicity (84.0% of patients) and heterogeneous liver structure (62.9%). At 24 weeks, a significant (p<0.05) improvement in liver echogenicity and in liver structure was observed in 1932/2827 (68.3%) patients (95% CI 66.6% to 70.1%) and in 1207/2827 (42.7%) patients (95% CI 40.9% to 44.5%), respectively. The analysis of ultrasonographic signs by number of comorbidities revealed similar findings—liver echogenicity improved in 67.2%–69.3% and liver structure in 35.6%–45.3% of patients depending on the number of comorbidities.

Conclusion

This study showed that PPC adjunctive therapy may be useful in improving the ultrasonographic features of NAFLD in patients with associated cardiometabolic comorbidities. It also supports evidence regarding the role of PPC in the complex management of NAFLD.

Association between neck circumference and non-alcoholic fatty liver disease in Mexican children and adolescents with obesity

Background Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic hepatic disorder in the pediatric population and has grown along with the obesity pandemic in which we live today. Adipose tissue storage in the upper body segment has been positively correlated with visceral adiposity and metabolic disease, which suggests that neck circumference could represent an easily accessible and replicable anthropometric measurement to identify patients with a higher risk of developing NAFLD. The main purpose of this study is to determine if there is an association between neck circumference and NAFLD. The secondary objectives are to establish cutoff values based on gender and puberty staging. Methods We included a sample pediatric population of 112 patients diagnosed with obesity aged between 6 and 18 years. We performed anthropometric and metabolic measurements on every patient, and NAFLD diagnosis was determined with hepatic ultrasound. Results The neck circumference was larger in NAFLD pediatric patients compared to those without NAFLD (p = 0.001). In a multivariate analysis, the neck circumference was associated with NAFLD as an independent risk factor (odds ratio [OR] = 1.172; 95% CI = 1.008-1.362; p = 0.038). Tanner 2-3 = 35 cm and Tanner 4-5 = 38 cm were established as risk cutoff values to develop NAFLD in the male adolescent population. Conclusions There is an association between the neck circumference and NAFLD in pediatric patients with obesity, particularly in the male population.

Curcuma longa and Trigonella foenum graecum-enriched nutrient mixture from germinated Macrotyloma uniflorum and Vigna radiate ameliorate nonalcoholic fatty liver diseases in rats

The prevalence of nonalcoholic fatty liver is increasing due to modern lifestyle. Germinated and dehulled Macrotyloma uniflorum and Vigna radiate were shown to have enhanced nutrients. Curcuma longa and Trigonella foenum graecum were proven hepatoprotective.The supplementation of the nutrient herbal mixture to the MCD diet-induced steatosis shows reduced hepatic fat accumulation and lipid profile, and liver injury markers in serum also reserved in normal. Increased serum albumin in the treatment group indicates that the liver function is enhanced than that of steatosis. The supplementation of the herbal mixture has preserved the hepatic antioxidant. Zymographic analysis of matrix metalloproteinase, western blot determination of α-SMA, and histological evolution (H&E, Sirius red) depicted reduced fibrosis and reveled management of hepatic stellate cells in quiescent form. The present study concludes that the herbal mixture has reduced hepatocyte fat accumulation in steatotic animals, and curtailed the oxidative stress, further it prevents the progression of steatohepatitis. PRACTICAL APPLICATIONS: Fatty liver diseases can be treated by modulating the diet composition such as consuming food rich in the nutrient herbal mixture. In this study, the nutrient mixture was made with dynamic food processing techniques such as germination, dehulling, and milling to augment the nutritional contents. Besides, Macrotyloma uniflorum, Vigna radiate, Curcuma longa, and Trigonella foenum graecum were used to improve the medicinal value and antioxidant. This formulation could target the various stages of NAFLD. This study revealed that the nutrient herbal mixture reduces the steatosis of the liver and curtailed the progression of steatohepatitis from hepatic steatosis. Since the edible foodstuff was used to make the nutrient mixture, it has excellent clinical application.

Cellular endo-lysosomal dysfunction in the pathogenesis of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD), an increasingly devastating human disorder, is characterized by intrahepatic fat accumulation. Although important progress has been made in understanding NAFLD, the fundamental mechanisms involved in the pathogenesis of NAFLD have not been fully explained. The endo-lysosomal trafficking network is central to lipid metabolism, protein degradation and signal transduction, which are involved in a variety of diseases. In recent years, many genes and pathways in the endo-lysosomal trafficking network and involved in lysosomal biogenesis have been associated with the development and progression of NAFLD. Mutations of these genes and impaired signalling lead to dysfunction in multiple steps of the endo-lysosomal network (endocytic trafficking, membrane fusion and lysosomal degradation), resulting in the accumulation of pathogenic proteins. In this review, we will focus on how alterations in these genes and pathways affect endo-lysosomal trafficking as well as the pathophysiology of NAFLD.

Plasma Krebs Cycle Intermediates in Nonalcoholic Fatty Liver Disease

Nonalcoholic liver disease (NAFLD) is manifested with a wide spectrum of clinical symptoms and is closely associated with the metabolic syndrome, inflammation, and mitochondrial dysfunction. Although the mechanism of mitochondrial dysfunction in NAFLD is still not fully elucidated, multiple studies have demonstrated evidence of molecular, biochemical, and biophysical mitochondrial abnormalities in NAFLD. Given the association between NAFLD and mitochondrial dysfunction, the aim of this study is to analyze circulating levels of Krebs cycle intermediates in a cohort of NAFLD-affected individuals and matching healthy controls and to correlate our findings with the liver function metrics. Standard serum biochemistry and Krebs cycle intermediates were analyzed in NAFLD (n = 22) and matched control (n = 67) cohorts. Circulating levels of isocitrate and citrate were significantly (p < 0.05) elevated in the NAFLD cohort of patients. The area under the curve (AUROC) for these two metabolites exhibited a moderate clinical utility. Correlations between plasma Krebs cycle intermediates and standard clinical plasma metrics were explored by Pearson’s correlation coefficient. The data obtained for plasma Krebs cycle intermediates suggest pathophysiological insights that link mitochondrial dysfunction with NAFLD. Our findings reveal that plasma isocitrate and citrate can discriminate between normal and NAFLD cohorts and can be utilized as noninvasive markers of mitochondrial dysfunction in NAFLD. Future studies with large populations at different NAFLD stages are warranted.

Caveolin-1 alleviates lipid accumulation in NAFLD associated with promoting autophagy by inhibiting the Akt/mTOR pathway

Non-alcoholic fatty liver disease (NAFLD) is the most burgeoning chronic liver disease worldwide whose pathogenesis is complex and controversial. Here, we investigated the impact of caveolin-1 (CAV1), a scaffolding protein of caveolae for lipid homeostasis and endocytosis, on the pathogenesis of NAFLD. CAV1 and caveolae play crucial roles in the regulation of autophagy and hepatic energy metabolism. However, it remains unclear whether CAV1 could affect hepatic lipid metabolism by regulating autophagy. In this study, results showed that the expressions of CAV1 and autophagy-related proteins (Beclin1 and LC3-II/Ⅰ) were decreased, while the level of p62 was increased in HFD (high-fat diet) fed mice liver and in A/O (alcohol and oleic acid mixture) treated L02 cells, compared to the corresponding controls. In vivo study, upregulation of CAV1 with CAV1 scaffolding domain peptides (CSD, amino acids 82-101 of caveolin-1) could alleviate lipid accumulation and promote autophagy in NAFLD mice. In vitro study, CAV1 overexpression plasmid and its small interfering RNA were cultured with A/O treated L02 cells respectively. The results also demonstrated that CAV1 reduced lipid accumulation and promoted autophagy in L02 cells. Treatment with chloroquine, an inhibitor of autophagic degradation, abrogated CAV1 plasmid-mediated alleviation of lipid accumulation. Mechanistically, the inhibition of Akt/mTOR pathway was involved in the protective role of CAV1 in autophagy induction and lipid metabolism in NAFLD. Together, these results provided novel perception into the function of CAV1 in liver through autophagy and emphasized its positive role in NAFLD.

Childhood obesity, cardiovascular and liver health: a growing epidemic with age

BACKGROUND

The frequency of childhood obesity has increased over the last 3 decades, and the trend constitutes a worrisome epidemic worldwide. With the raising obesity risk, key aspects to consider are accurate body mass index classification, as well as metabolic and cardiovascular, and hepatic consequences.

DATA SOURCES

The authors performed a systematic literature search in PubMed and EMBASE, using selected key words (obesity, childhood, cardiovascular, liver health). In particular, they focused their search on papers evaluating the impact of obesity on cardiovascular and liver health.

RESULTS

We evaluated the current literature dealing with the impact of excessive body fat accumulation in childhood and across adulthood, as a predisposing factor to cardiovascular and hepatic alterations. We also evaluated the impact of physical and dietary behaviors starting from childhood on cardio-metabolic consequences.

CONCLUSIONS

The epidemic of obesity and obesity-related comorbidities worldwide raises concerns about the impact of early abnormalities during childhood and adolescence. Two key abnormalities in this context include cardiovascular diseases, and nonalcoholic fatty liver disease. Appropriate metabolic screenings and associated comorbidities should start as early as possible in obese children and adolescents. Nevertheless, improving dietary intake and increasing physical activity performance are to date the best therapeutic tools in children to weaken the onset of obesity, cardiovascular diseases, and diabetes risk during adulthood.