Animals ; Fatty Liver ; etiology ; genetics ; Humans ; Non-alcoholic Fatty Liver Disease ; Risk Factors

Genetic Predisposition to Disease ; Humans ; Non-alcoholic Fatty Liver Disease ; diagnosis ; genetics ; therapy

Humans ; Genotype ; Non-alcoholic Fatty Liver Disease ; Acyltransferases/genetics* ; Membrane Proteins/genetics*

In recent years, nonalcoholic fatty liver disease (NAFLD) has increased because of the growing prevalence of obesity and overweight in the pediatric population. It has become the most common form of chronic liver diseases in children and the related research on NAFLD is expanded. The "two-hit" and "multiple hit" hypothesis have been widely accepted, and some research has shown that genetic, diet structure and environmental factors appear to play a crucial role in the development of pediatric NAFLD. Though it is expected by researchers, there is not an available satisfactory noninvasive marker for the diagnosis of this disease. Fortunately, some new non-invasive prediction scores for pediatric NAFLD have been developed. There is currently no established special therapy, and lifestyle intervention should be adequate for most cases of NAFLD in children. This article reviews the advances in the current knowledge and ideas concerning pediatric NAFLD, and discusses the diagnosis, perspective therapies and scoring methods for this disease.
Child ; Humans ; Non-alcoholic Fatty Liver Disease ; diagnosis ; etiology ; genetics ; Polymorphism, Single Nucleotide ; Risk Factors

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease whose prevalence has reached global epidemic proportions. Although the disease is relatively benign in the early stages, when severe clinical forms, including nonalcoholic steatohepatitis (NASH), cirrhosis and even hepatocellular carcinoma, occur, they result in worsening the long-term prognosis. A growing body of evidence indicates that NAFLD develops from a complex process in which many factors, including genetic susceptibility and environmental insults, are involved. In this review, we focused on the genetic component of NAFLD, with special emphasis on the role of genetics in the disease pathogenesis and natural history. Insights into the topic of the genetic susceptibility in lean individuals with NAFLD and the potential use of genetic tests in identifying individuals at risk are also discussed.
Carcinoma, Hepatocellular ; Fibrosis ; Genetic Predisposition to Disease* ; Genetics ; Liver Diseases ; Liver Diseases, Alcoholic ; Natural History ; Non-alcoholic Fatty Liver Disease* ; Prevalence ; Prognosis

Non-alcoholic steatohepatitis(NASH) was induced by high-sugar and high-fat diet in mice to investigate the intervention effect of total saponins from Panax japonicus(TSPJ) and explore its possible mechanism. Mice were fed with high-sugar and high-fat diet to establish NASH model, and intervened with different doses of TSPJ(15, 45 mg·kg~(-1)). The animals were fed for 26 weeks. The histomorphology and pathological changes of liver tissues were observed by HE staining. The transcriptional expression levels of miR-199 a-5 p, autophagy related gene 5(ATG5) and inflammatory cytokines interleukin-6(IL-6), interleukin-1β(IL-1β) and tumor necrosis factor α(TNF-α) in mouse liver were measured by quantitative Real-time polymerase chain reaction(qRT-PCR). Western blot was used to detect the expression of autophagy-related proteins ATG5, P62/SQSTM1(P62), and microtubule-associated protein light chain 3(LC3)-I/Ⅱ proteins in mouse liver. The expression of P62 protein was detected by immunofluorescence staining. In order to verify the targeting regulation relationship between miR-199 a-5 p and ATG5, miR mimic/inhibitor NC and miR-199 a-5 p mimic/inhibitor were transfected into Hepa 1-6 cells, and the expression of ATG5 mRNA and protein was detected. pMIR-reportor ATG5-3'UTR luciferase reporter gene plasmid was constructed and co-transfected with miR mimic/inhibitor NC and miR-199 a-5 p mimic/inhibitor into Hepa 1-6 cells to detect luciferase activity. In vivo, HE staining in the model group showed typical fatty degeneration and inflammatory infiltration, with increased expression of miR-199 a-5 p and decreased expression of ATG5 mRNA and protein. The expression of autophagy-associated protein P62 increased significantly, the ratio of LC3Ⅱ/Ⅰ decreased, and the transcriptional expression of inflammatory factors increased significantly. After the intervention by TSPJ, the pathological performance of liver tissue was significantly improved, the expression of miR-199 a-5 p decreased and the expression of ATG5 mRNA and protein increased, the expression of autophagy-associated protein P62 decreased significantly, the ratio of LC3Ⅱ/Ⅰ increased, and the transcriptional expression of inflammatory cytokines IL-6, IL-1β and TNF-α decreased significantly. In vitro, it was found that the expression of ATG5 mRNA and protein and luciferase activity decreased significantly in miR-199 a-5 p overexpression cells, while after inhibition of miR-199 a-5 p expression, the expression level of ATG5 mRNA and protein and luciferase activity increased. The results showed that TSPJ can improve NASH in mice fed with high-sugar and high-fat diet, and its mechanism may be related to the regulation of miR-199 a-5 p/ATG5 signal pathway, the regulation of autophagy activity and the improvement of inflammatory response of NASH.
Animals ; Autophagy ; Autophagy-Related Protein 5 ; Mice ; MicroRNAs/genetics* ; Non-alcoholic Fatty Liver Disease/genetics* ; Panax ; Saponins/pharmacology*

OBJECTIVETo construct a short hairpin (sh)RNA targeting aquaglyceroporin 9 (AQP9) that effectively silences gene expression in liver cells in order to investigate of the role of AQP9 in nonalcoholic fatty liver disease (NAFLD) pathogenesis using an in vitro cell model system.

METHODSSmall interfering (si)RNAs were designed against the human gene sequences encoding AQP9 (NCBI GenBank Accession No. AB008775) and unrelated control sequences, synthesized, annealed to form double-strands, and inserted into the pGenesil- 1 shRNA-expression plasmid. The silencing effects of the four pshRNA-AQP9 constructs (a-d) and the pshRNA-negative control construct were investigated by transfecting into the L02 human normal liver cell line and detecting expression of AQP9 mRNA and protein (relative to beta-actin) by reverse transcription-PCR and western blotting. The NAFLD cell model was established by treating L02 cells with oleic acid to induce fatty degeneration. After transfecting the NAFLD cell model with various constructs, the effects on NAFLD-related features were investigated by staining with Oil Red O (to detect lipid droplets) and performing enzymatic assays (to quantitate triglyceride (TG), free fatty acid (FFA) and glycerol content). The significance of intergroup differences was assessed by analysis of variance test.

RESULTSOf the four pshRNA-AQP9 constructs, pshRNA-AQP9a produced the most robust silencing effect on AQP9 mRNA (25.1 - 1.2% vs. untransfected: 39.3 +/- 1.7% and pshRNA-negative control: 39.4 +/- 1.5%, P < 0.01) and protein (25.4 - 2.0% vs. untransfected: 35.1 +/- 1.9% and psh-RNA-negative control: 35.6 +/- 2.3%, P < 0.01). Oleic acid-induced L02 cells showed enhanced AQP9 mRNA and protein expression, and increased intracellular content of lipid, TG, FFA, and glycerol, which were significantly reduced by pshRNA-AQP9a transfection (all P <0.05).

CONCLUSIONThe new pshRNA-AQP9a construct can efficiently reduce AQP9 expression in cultured human liver cells and relieve steatosis-related features in an NAFLD cell model, pshRNA-AQP9a represents a novel tool for studying the role ofAQP9 in NAFLD pathogenesis and its potential as a gene therapy strategy.

Aquaporins ; genetics ; Cell Line ; Fatty Liver ; genetics ; Gene Expression ; Genetic Vectors ; Hepatocytes ; metabolism ; Humans ; Non-alcoholic Fatty Liver Disease ; Plasmids ; RNA Interference ; RNA, Messenger ; RNA, Small Interfering

BACKGROUNDMany studies have suggested that cigarette smoking and polymorphisms of resistin and glutathione peroxidase-1 (GPx-1) genes are closely correlated with the pathogenesis of nonalcoholic fatty liver disease (NAFLD). However, few reports have investigated these associations with respect to NAFLD susceptibility. We, therefore, examined the distribution of polymorphisms in GPx-1 and resistin genes in NAFLD patients and healthy controls and analyzed the relationship between these polymorphisms and smoking status.

METHODSNine hundred NAFLD patients and 900 healthy controls were selected, and the genetic polymorphisms of resistin gene promoter-420C/G and GPx-1 gene Pro198Leu were analyzed by polymorphism-polymerase chain reaction (PCR) in DNA extracted from peripheral blood leukocytes. Interactions between the two mutants and the gene-environment interaction with cigarette smoking were also analyzed.

RESULTSGenotype frequencies of -420C/G (GG) and Pro198Leu (LL) were significantly higher in NAFLD cases (49.56% and 50.11%, respectively) compared with healthy controls (23.67% and 24.22%, respectively) (P = 0.0069; P = 0.0072). Moreover, the risk of NAFLD with -420C/G (GG) was significantly higher than in controls (odds ratio [OR] =3.1685, 95% confidence interval (CI) =1.9366-5.2073). Individuals carrying Pro198Leu (LL) had a high risk of NAFLD (OR = 3.1424, 95% CI = 1.7951-5.2367). Combined analysis of the polymorphisms showed that the -420C/G (GG)/Pro198Leu (LL) genotype was significantly more common in the NAFLD group than in the control group (39.44% vs. 12.78%, respectively, P = 0.0054), while individuals with -420C/G (GG)/Pro198Leu (LL) had a high risk of NAFLD (OR = 5.0357, 95% CI = 3.1852-7.8106). Moreover, the cigarette smoking rate in the NAFLD group was significantly higher than in the control group (OR = 1.8990, P = 0.0083 in the smoking index (SI) ≤400 subgroup; OR = 5.0937, P = 0.0051 in the SI >400 subgroup), and statistical analysis suggested a positive interaction between cigarette smoking and -420C/G (GG) (γ = 5.6018 in the SI ≤400 subgroup; γ = 4.4770 in the SI >400 subgroup) and Pro198Leu (LL) (γ = 5.7715 in the SI ≤400 subgroup; γ = 4.5985 in the SI >400 subgroup) in increasing the risk of NAFLD.

CONCLUSIONNAFLD risk factors include -420C/G (GG), Pro198Leu (LL) and cigarette smoking, and these three factors have a significant additive effect on NAFLD risk.

Female ; Genetic Predisposition to Disease ; genetics ; Glutathione Peroxidase ; genetics ; Humans ; Male ; Non-alcoholic Fatty Liver Disease ; metabolism ; Polymorphism, Single Nucleotide ; genetics ; Promoter Regions, Genetic ; genetics ; Resistin ; genetics ; Smoking ; genetics

OBJECTIVETo investigate the correlation of the polymorphisms of adiponectin receptor 2 (AdipoR2) gene +33371Gln/;Arg and cytochromes P4502E1 gene Rsa I (CYP2E1-Rsa I) as well as smoking with nonalcoholic fatty liver disease (NAFLD).

METHODSThe polymorphisms of AdipoR2 gene +33371Gln/Arg and CYP2E1-Rsa I were analyzed with PCR technique in peripheral blood leukocytes from 750 NAFLD cases and 750 healthy subjects.

RESULTSThe frequencies of AdipoR2 gene +33371Gln/Arg (A/A) and CYP2E1-Rsa I (c2/c2 ) were 39.20% and 71.73% in NAFLD cases, respectively, significantly higher than those in healthy subjects (21.07% and 43.07%, respectively, P<0.01). The risk of NAFLD increased significantly in subjects carrying +33371Gln/Arg (A/A) (OR=2.4156, 95% CI=1.8164-4.0725) and CYP2E1-Rsa I (c2/c2) (OR=3.3547, 95% CI=1.9182-4.5057). Combined analysis of the polymorphisms showed that the percentage of +33371Gln/Arg (A/A)/CYP2E1-Rsa I (c2/c2) was 32. 67% in NAFLD cases, significantly higher than that in the healthy subjects (6.40%, P<0.01), and subjects carrying both +33371Gln/Arg (A/A) and CYP2E1-Rsa I (c2/c2) had a high risk of NAFLD (OR=9.9264, 95% CI=4.2928-12.4241). The smoking rate was significantly higher in the case group than in the control group (OR=2.5919, 95% CI=1.4194-4. 9527, P<0.01), and statistical analysis suggested an interaction between smoking and +33371Gln/Arg (A/A)/CYP2E1-Rsa I (c2/c2) to increase the risk of NAFLD (OR=34.6764, 95% CI=18.9076-61.5825).

CONCLUSION+33371Gln/Arg (A/A), CYP2E1-Rsa I (c2/c2 ) and smoking are risk factors for NAFLD and coordinately contribute to the occurrence of NAFLD.

Alleles ; Case-Control Studies ; Cytochrome P-450 CYP2E1 ; genetics ; Humans ; Non-alcoholic Fatty Liver Disease ; genetics ; Polymorphism, Genetic ; Receptors, Adiponectin ; genetics ; Risk Factors ; Smoking

Non-alcoholic fatty liver disease (NAFLD) is an epidemic metabolic condition driven by an underlying lipid homeostasis disorder. The lipid droplet (LD), the main organelle involved in neutral lipid storage and hydrolysis, is a potential target for NAFLD therapeutic treatment. In this review, we summarize recent progress elucidating the connections between LD-associated proteins and NAFLD found by genome-wide association studies (GWAS), genomic and proteomic studies. Finally, we discuss a possible mechanism by which the protein 17β-hydroxysteroid dehydrogenase 13 (17β-HSD13) may promote the development of NAFLD.
17-Hydroxysteroid Dehydrogenases ; genetics ; metabolism ; Animals ; Genome-Wide Association Study ; Genomics ; Humans ; Lipid Droplets ; metabolism ; Lipid Metabolism ; genetics ; Non-alcoholic Fatty Liver Disease ; genetics ; metabolism ; Proteomics