Impaired SUMOylation of FoxA1 promotes nonalcoholic fatty liver disease through down-regulation of Sirt6.

Abnormal SUMOylation is implicated in non-alcoholic fatty liver disease (NAFLD) progression. Forkhead box protein A1 (FoxA1) has been shown to protect liver from steatosis, which was down-regulated in NAFLD. This study elucidated the role of FoxA1 deSUMOylation in NAFLD. NAFLD models were established in high-fat diet (HFD)-induced mice and palmitate acid (PAL)-treated hepatocytes. Hepatic steatosis was evaluated by biochemical and histological methods. Lipid droplet formation was determined by BODIPY and Oil red O staining. Target molecule levels were analyzed by RT-qPCR, Western blotting, and immunohistochemistry staining. SUMOylation of FoxA1 was determined by Ni-NTA pull-down assay and SUMOylation assay Ultra Kit. Protein interaction and ubiquitination were detected by Co-IP. Gene transcription was assessed by ChIP and dual luciferase reporter assays. Liver FoxA1 knockout mice developed severe liver steatosis, which could be ameliorated by sirtuin 6 (Sirt6) overexpression. Nutritional stresses reduced Sumo2/3-mediated FoxA1 SUMOylation at lysine residue K6, which promoted lipid droplet formation by repressing fatty acid ß-oxidation. Moreover, Sirt6 was a target gene of FoxA1, and Sirt6 transcription activity was restrained by deSUMOylation of FoxA1 at site K6. Furthermore, nutritional stresses-induced deSUMOylation of FoxA1 promoted the ubiquitination and degradation of FoxA1 with assistance of murine double minute 2 (Mdm2). Finally, activating FoxA1 SUMOylation delayed the progression of NAFLD in mice. DeSUMOylation of FoxA1 at K6 promotes FoxA1 degradation and then inhibits Sirt6 transcription, thereby suppressing fatty acid ß-oxidation and facilitating NAFLD development. Our findings suggest that FoxA1 SUMOylation activation might be a promising therapeutic strategy for NAFLD.

Challenges in pediatric inherited/metabolic liver disease: Focus on the disease spectrum, diagnosis and management of relatively common disorders.

The clinical scenario of pediatric liver disease is becoming more intricate due to changes in the disease spectrum, in which an increasing number of inherited/ metabolic liver diseases are reported, while infectious diseases show a decreasing trend. The similar clinical manifestations caused by inherited/metabolic diseases might be under-recognized or misdiagnosed due to nonspecific characteristics. A delayed visit to a doctor due to a lack of symptoms or mild symptoms at an early stage will result in late diagnosis and treatment. Moreover, limited diagnostic approaches, especially liver biopsy, are not easily accepted by pediatric patients, leading to challenges in etiological diagnosis. Liver dysfunction due to inherited/metabolic diseases is often caused by a variety of metabolites, so precision treatment is difficult; symptomatic treatment is a compelling option for inherited disorders.

Poor Outcomes of Patients With NAFLD and Moderate Renal Dysfunction or Short-Term Dialysis Receiving a Liver Transplant Alone.

The outcomes of patients with moderate renal impairment and the impact of liver disease etiology on renal function recovery after liver transplant alone (LTA) are largely unknown. We explored whether NAFLD patients with pre-LTA moderate renal dysfunction (GFR 25-45 ml/min/1.73 m2) may be more susceptible to develop post-LTA severe renal dysfunction (GFR<15 ml/min/1.73 m2) than ALD patients, as well as other overall outcomes. Using the UNOS/OPTN database, we selected patients undergoing liver transplant for NAFLD or ALD (2006-2016), 15,103 of whom received LTA. NAFLD patients with moderate renal dysfunction were more likely to develop subsequent GFR<15 ml/min/1.73 m2 than ALD patients (11.1% vs. 7.38%, p < 0.001). Patients on short-term dialysis pre-LTA (≤12 weeks) were more likely to develop severe renal dysfunction (31.7% vs. 18.1%), especially in NAFLD patients, and were more likely to receive a further kidney transplant (15.3% vs. 3.7%) and had lower survival (48.6% vs. 50.4%) after LTA (p < 0.001 for all). NAFLD was an independent risk factor for post-LTA severe renal dysfunction (HR = 1.2, p = 0.02). NAFLD patients with moderate renal dysfunction and those receiving short-term dialysis prior to LTA are at a higher risk of developing subsequent severe renal dysfunction. Underlying etiology of liver disease may play a role in predicting development and progression of renal failure in patients receiving LTA.

Engineered DBCO+PD-1 Nanovesicles Carrying 1-MT for Cancer-Targeted Immunotherapy.

Liver cancer cells evade immune surveillance and anticancer response through various pathways, including the programmed death-ligand 1 (PD-L1)/programmed death-1 (PD-1) immune checkpoint axis that exhausts CD8+ T cells. Inhibitors or antibodies of the PD-L1/PD-1 signaling axis are considered promising drugs for cancer immunotherapy and exhibit favorable clinical responses. However, adverse effects, immune tolerance, and delivery barriers of most patients limit the clinical application of PD-L1/PD-1 antibodies. Thus, it is critical to develop a novel delivery strategy to enhance anticancer immunotherapy. In this study, we bioengineered cell membrane-derived nanovesicles (NVs) presenting PD-1 proteins and dibenzocyclooctyne (DBCO) to encapsulate 1-methyltryptophan (1-MT) (DBCO+PD-1@1-MT NVs). DBCO can specifically interact with N-azidoacetylmannosamine-tetraacetylate (Ac4ManN3) labeled onto metabolic cells for targeted killing of cancers. We next explored the effects of DBCO+PD-1@1-MT NVs on anticancer Hepa1-6 cells in vitro and in vivo. Results showed that PD-1@1-MT NVs dramatically inhibited Hepa1-6 proliferation, promoted peripheral blood mononuclear cell (PBMC) expansion, and strengthened anticancer therapy via blockading the PD-1/PD-L1 immune checkpoint axis, owing to the 1-methyltryptophan (1-MT) enhancement of anticancer immunotherapy efficacy through suppressing the activity of indoleamine 2,3-dioxygenase (IDO). Thus, 1-MT was encapsulated into PD-1 NVs to synergistically enhance cancer immunotherapy. Results have shown that PD-1@1-MT NVs obviously attenuated tumor growth, promoting IFN-γ production, increasing the T cells infiltration in tumors and spleens, and improving the survival period of tumor-bearing mice compared to monotherapy. Therefore, we propose a promising delivery strategy of the combination of DBCO+PD-1 NVs and 1-MT for specific and effective cancer-targeted immunotherapy.

LncRNA MEG3 up-regulates SIRT6 by ubiquitinating EZH2 and alleviates nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a global health threat. Here, we presented the significant role of a novel signaling axis comprising long non-coding RNA maternally expressed gene 3 (MEG3), enhancer of zeste homolog 2 (EZH2), and sirtuin 6 (SIRT6) in controlling lipid accumulation, inflammation, and the progression of NAFLD. Mice fed with high-fat diet (HFD) were established as in vitro and in vivo NAFLD models, respectively. Lipid accumulation was measured by oil red O staining and assays for triglycerides or cholesterol. Inflammation was examined by ELISA for pro-inflammatory cytokines. Gene expressions were examined by RT-qPCR or Western blot. Interactions between key signaling molecules were examined by combining expressional analysis, RNA immunoprecipitation, cycloheximide stability assay, co-immunoprecipitation, and chromatin immunoprecipitation. MEG3 level was reduced in FFA-challenged hepatocytes or liver from HFD-fed mice, and the reduction paralleled the severity of NAFLD in clinic. Overexpressing MEG3 suppressed FFA-induced lipid accumulation or inflammation in hepatocytes. By promoting the ubiquitination and degradation of EZH2, MEG3 upregulated SIRT6, an EZH2 target. SIRT6 essentially mediated the protective effects of MEG3 in hepatocytes. Consistently, overexpressing MEG3 alleviated HFD-induced NAFLD in vivo. By controlling the expressions of genes involved in lipid metabolism and inflammation, the MEG3/EZH2/SIRT6 axis significantly suppressed lipid accumulation and inflammation in vitro, and NAFLD development in vivo. Therefore, boosting MEG3 level may benefit the treatment of NAFLD.

Gastrointestinal cytomegalovirus disease secondary to measles in an immunocompetent infant: A case report.

BACKGROUND: Gastrointestinal cytomegalovirus (CMV) disease occurs commonly in immunocompromised/immunodeficient patients with advanced human immunodeficiency virus infection, neoplasm, solid organ transplantation, hematopoietic stem cell transplantation, or treatment with immunosuppressants, but is rarely reported in association with measles infection. CASE SUMMARY: We describe a case of extensive gastrointestinal CMV disease secondary to measles infection in a 9-mo-old boy who presented with persistent fever and bloody diarrhea. His condition was improved after ganciclovir treatment. Serological analysis of CMV showed negative immunoglobulin (Ig) M and positive IgG. Blood CMV-DNA was 9.26 × 103 copies/mL. The diagnosis of gastrointestinal CMV disease was confirmed by histopathological findings of intranuclear and intracytoplasmic inclusions and Owl's eye inclusion. This case highlights the differential diagnosis and histopathological characteristics of gastrointestinal CMV infection and laboratory tests. CONCLUSION: Extensive gastrointestinal CMV lesions can be induced by the immune suppression secondary to measles infection. Rational, fast, and effective laboratory examinations are essential for suspected patients.

Portal vein thrombosis and renal dysfunction: a national comparative study of liver transplant recipients for NAFLD versus alcoholic cirrhosis.

The prevalence of portal vein thrombosis (PVT), renal dysfunction (RD), and simultaneous PVT/RD in liver transplantation (LT) is poorly understood. We analyzed the prevalence of PVT, RD, simultaneous PVT/RD, and the outcomes of adult recipients of LT for nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) between 2006 and 2016 in the United States. We found that the prevalence of PVT (7.2% â†’ 11.3%), RD (33.8% â†’ 39.2%), and simultaneous PVT/RD (2.4% â†’ 4.5%) has increased significantly over the study period (all P-values <0.05). NAFLD patients had a higher proportion of PVT (14.8% vs. 9.2%), RD (45.0% vs. 42.1%), and simultaneous PVT/RD (6.5% vs. 3.9%; all P-values <0.05). 90-day mortality was 3.8%, 6.3%, 6.8%, and 9.8% for PVT(-)/RD(-), PVT(-)/RD(+), PVT(+)/RD(-), and PVT(+)/RD(+) recipients, respectively (P < 0.01). 5-year survival was 82.1%, 75.5%, 74.8%, and 71.1% for PVT(-)/RD(-), PVT(-)/RD(+), PVT(+)/RD(-), and PVT(+)/RD(+) recipients, respectively (P < 0.05). In conclusion, the prevalence of PVT, RD, and simultaneous PVT/RD has increased among LT recipients, especially for those with NAFLD. The short- and long-term outcomes of recipients with PVT, RD, and simultaneous PVT/RD were inferior to patients without those risk factors irrespective of their indication for LT. No differences in patient outcomes were found between ALD and NAFLD recipients after stratification by risk factors.

Prevention program for the COVID-19 in a children's digestive endoscopy center.

The pneumonia caused by the coronavirus disease-2019 (COVID-19) outbreak in Wuhan, China constitutes a public health emergency of international concern. The gastrointestinal symptoms of vomiting, diarrhea and abdominal pain and the detection of COVID-19 nucleic acid from fecal specimens in a small number of patients suggest the possibility of transmission via the gastrointestinal tract. People of all ages are vulnerable to this virus, including children. Digestive endoscopy is an invasive procedure during which children cannot wear masks; therefore, they have higher risks of exposure to COVID-19, and the digestive endoscopy center is a relatively high-risk area for COVID-19 infection. Based on these factors and in combination with related policies and regulations, a prevention and control program for the COVID-19 pneumonia in a children's digestive endoscopy center was established to prevent the COVID-19 nosocomial infection.

Predictors of outcomes of endoscopic balloon dilatation in strictures after esophageal atresia repair: A retrospective study.

BACKGROUND: Endoscopic balloon dilatation (EBD) has become the first line of therapy for benign esophageal strictures (ESs); however, there are few publications about the predictive factors for the outcomes of this treatment. AIM: To assess the predictive factors for the outcomes of EBD treatment for strictures after esophageal atresia (EA) repair. METHODS: Children with anastomotic ES after thoracoscopic esophageal atresia repair treated by EBD from January 2012 to December 2016 were included. All procedures were performed under tracheal intubation and intravenous anesthesia using a three-grade controlled radial expansion balloon with gastroscopy. Outcomes were recorded and predictors of the outcomes were analyzed. RESULTS: A total of 64 patients were included in this analysis. The rates of response, complications, and recurrence were 96.77%, 8.06%, and 2.33%, respectively. The number of dilatation sessions and complications were significantly higher in patients with a smaller stricture diameter (P = 0.013 and 0.023, respectively) and with more than one stricture (P = 0.014 and 0.004, respectively). The length of the stricture was significantly associated with complications of EBD (P = 0.001). A longer interval between surgery and the first dilatation was related to more sessions and a poorer response (P = 0.017 and 0.024, respectively). CONCLUSION: The diameter, length, and number of strictures are the most important predictive factors for the clinical outcomes of endoscopic balloon dilatation in pediatric ES. The interval between surgery and the first EBD is another factor affecting response and the number of sessions of dilatation.

[Clinical features of cow's milk protein allergy in infants presenting mainly with gastrointestinal symptoms: an analysis of 280 cases].

OBJECTIVE: To investigate the epidemiological and clinical features of cow's milk protein allergy (CMPA) in infants presenting mainly with gastrointestinal symptoms. METHODS: A retrospective analysis was performed for the clinical data of 280 hospitalized infants, who were diagnosed with CMPA presenting mainly with gastrointestinal symptoms. RESULTS: Among the 280 infants, 203 infants(72.5%) were aged of less than 6 months. Major manifestations included diarrhea in 171 infants (61.1%), hematochezia in 149 infants (53.2%), vomiting in 71 infants (25.4%), eczema in 57 infants (20.4%), malnutrition in 42 infants (15%) and constipation in 13 infants (4.6%). Of the 280 infants, 258 (92.1%) had mild-to-moderate CMPA and 22 (7.9%) had severe CMPA. Compared with the mild-to-moderate CMPA group, the severe CMPA group had a significantly higher incidence rate of malnutrition (50.0% vs 12.0%) and a significantly lower incidence rate of hematochezia (22.7% vs 55.8%). The breastfeeding CMPA group had significantly lower incidence rates of malnutrition (10.3% vs 24.6%) and severe CMPA (4.4% vs 18.0%) than the artificial feeding CMPA group, and the artificial feeding CMPA group had a significantly lower incidence rate of hematochezia than the breastfeeding and mixed feeding CMPA groups (37.7% vs 56.6%/59.0%). CONCLUSIONS: CMPA presenting mainly with gastrointestinal symptoms is more common in infants aged of less than 6 months. Diarrhea and hematochezia are the most common manifestations at the time of onset. Most infants have mild-to-moderate allergy. Compared with breastfeeding, artificial feeding is more likely to cause malnutrition and severe CMPA.

[A case of congenital bile acid synthesis disorder type 2 and literature review].

OBJECTIVE: To summarize the clinical features, biochemical change and genetic mutations of a neonate with congenital bile acid synthesis disorder type 2. METHODS: Clinical features, blood biochemical index, gene analysis and treatment of the patient were reviewed. RESULTS: The patient presented with the symptoms of jaundice 3 days after birth but without skin itching. Pale stool was noted. Subsequently, he presented with hepatomegaly, blood coagulation disorders, left cochlear nerve damage, liver cirrhosis and remarkable growth retardation. Serum biochemistries showed that bilirubin and transaminase were elevated, while γ -GT and total bile acid was normal. Abdominal ultrasonography indicated decline of gallbladder contraction. Cholangiography showed normal extra- and intrahepatic bile ducts and patent biliary tract. Liver biopsy showed intrahepatic cholestasis. Gene testing has identified a homozygous mutation in AKR1D1 gene. CONCLUSION: Congenital bile acid synthesis disorder should be suspected when a neonate has presented with jaundice, elevated bilirubin and transaminase, normal or reduced TBA and γ -GT. Genetic testing and urine mass spectrometry analysis can diagnose congenital bile acid synthesis disorder. Early therapy is crucial to patients with congenital bile acid synthesis disorder.

Infant cholestasis patient with a novel missense mutation in the AKR1D1 gene successfully treated by early adequate supplementation with chenodeoxycholic acid: A case report and review of the literature.

Steroid 5ß-reductase [aldo-keto reductase family 1 member D1 (AKR1D1)] is essential for bile acid biosynthesis. Bile acid deficiency caused by genetic defects in AKR1D1 leads to life-threatening neonatal hepatitis and cholestasis. There is still limited experience regarding the treatment of this disease. We describe an infant who presented with hyperbilirubinemia and coagulopathy but normal bile acid and γ-glutamyltransferase. Gene analysis was performed using genomic DNA from peripheral lymphocytes from the patient, his parents, and his elder brother. The patient was compound heterozygous for c.919C>T in exon 8 and exhibited a loss of heterozygosity of the AKR1D1 gene, which led to an amino acid substitution of arginine by cysteine at amino acid position 307 (p.R307C). Based on these mutations, the patient was confirmed to have primary 5ß-reductase deficiency. Ursodeoxycholic acid (UDCA) treatment did not have any effect on the patient. However, when we changed to chenodeoxycholic acid (CDCA) treatment, his symptoms and laboratory tests gradually improved. It is therefore crucial to supplement with an adequate dose of CDCA early to improve clinical symptoms and to normalize laboratory tests.

Dynamic oropharyngeal and faecal microbiota during treatment in infants hospitalized for bronchiolitis compared with age-matched healthy subjects.

Bronchiolitis is one of the most severe diseases affecting infants worldwide. An imbalanced oropharynx (OP) microbiota has been reported in infants hospitalized with bronchiolitis; however, the microbiota dynamics in the OP and faeces during therapy remain unexplored. In total, 27 infants who were hospitalized with bronchiolitis were selected for this study, and sampling was conducted before therapy and after clinical recovery. We also recruited 22 age-matched healthy infants for this study. The faecal and OP microbiota diversity in the patients was lower than that in the healthy children. The faecal microbiota (FM) in the diseased children significantly differed from that in the healthy subjects and contained accumulated Bacteroides and Streptococcus. The OP microbiota in both the healthy and diseased infants was dominated by Streptococcus. After the treatment, the FM and OP microbiota in the patients was comparable to that before the treatment. This study may serve as an additional reference for future bronchiolitis studies, and the "risk microbiota model" of clinically recovered infants suggests an increased susceptibility to pathogen intrusion.

Association of MTTP gene variants with pediatric NAFLD: A candidate-gene-based analysis of single nucleotide variations in obese children.

OBJECTIVE: We used targeted next-generation sequencing to investigate whether genetic variants of lipid metabolism-related genes are associated with increased susceptibility to nonalcoholic fatty liver disease (NAFLD) in obese children. METHODS: A cohort of 100 obese children aged 6 to 18 years were divided into NAFLD and non-NAFLD groups and subjected to hepatic ultrasound, anthropometric, and biochemical analyses. We evaluated the association of genetic variants with NAFLD susceptibility by investigating the single nucleotide polymorphisms in each of 36 lipid-metabolism-related genes. The panel genes were assembled for target region sequencing. Correlations between single nucleotide variations, biochemical markers, and clinical phenotypes were analyzed. RESULTS: 97 variants in the 36 target genes per child were uncovered. Twenty-six variants in 16 genes were more prevalent in NAFLD subjects than in in-house controls. The mutation rate of MTTP rs2306986 and SLC6A2 rs3743788 was significantly higher in NAFLD subjects than in non-NAFLD subjects (OR: 3.879; P = 0.004; OR: 6.667, P = 0.005). Logistic regression analysis indicated the MTTP variant rs2306986 was an independent risk factor for NAFLD (OR: 23.468, P = 0.044). CONCLUSIONS: The results of this study, examining a cohort of obese children, suggest that the genetic variation at MTTP rs2306986 was associated with higher susceptibility to NAFLD. This may contribute to the altered lipid metabolism by disruption of assembly and secretion of lipoprotein, leading to reducing fat export from the involved hepatocytes.

Brain damage resembling acute necrotizing encephalopathy as a specific manifestation of haemophagocytic lymphohistiocytosis - induced by hypersensitivity.

BACKGROUND: Both haemophagocytic lymphohistiocytosis and acute necrotizing encephalopathy are life-threatening condition. It presents major diagnostic difficulties, since it may have a diversity in clinical picture and with many conditions leading to the same clinical presentation. So it is key important to understand the disorders. CASE PRESENTATION: We report a pediatric case of haemophagocytic lymphohistiocytosis with specific presentation which predominantly featured as acute necrotizing encephalopathy of childhood. We discuss the diagnosis and differential diagnosis, and speculate the etiology of haemophagocytic lymphohistiocytosis is due to hypersensitivity. CONCLUSION: Haemophagocytic lymphohistiocytosis and brain damage in this case may be induced by hypersensitivity, which have good clinical outcome if diagnosed and treated early.

[Clinical features and gene mutations in a patient with multiple aeyl-CoA dehydrogenase deficiency with severe fatty liver].

OBJECTIVE: To analyze the clinical features and gene mutations in an adolescent patient affected with late-onset multiple aeyl-CoA dehydrogenase deficiency (MADD) with severe fatty liver. METHODS: Potential mutations of the ETFDH gene were detected with polymerase chain reaction (PCR) and DNA sequencing. RESULTS: The 13-year-and-10-month girl has presented with weakness without any other special manifestation. Laboratory tests demonstrated an elevation of myocardial enzyme levels, total cholesterol, lactic acid and abnormal serum free fatty acids. H magnetic resonance spectroscopy revealed severe fatty liver. An increase in multiple plasma acyl-carnitines was detected by gas chromatography/mass spectrometry and isobutyrylglycine in urine by screening with tandem mass spectrometry. Genetic analysis demonstrated 2 heterozygous missense mutations c.250G>A (p.Ala84Thr) and c.353G>T (p.Cys118Phe) in the ETFDH gene. The diagnosis of MADD was confirmed. The patient was given large dose of vitamin B2, which resulted in rapid clinical and biochemical improvement. CONCLUSION: A common mutation c.250G>A and a novel mutation c.353G>T in the ETFDH gene were identified in the patient. The pathogenic role of c.353G>T (p.Cys118Phe) deserves further study. Early diagnosis of MADD and appropriate therapy is crucial for the prognosis.

[Analysis of clinical characteristics of hypoxic hepatitis in children].

OBJECTIVE: To explore the etiology and clinical characteristics of hypoxic hepatitis (HH) in children. METHOD: Clinical data of 7 patients with HH in Shenzhen Children's Hospital from January 2011 to March 2014 were retrospectively reviewed. RESULT: Seven cases diagnosed as HH, age from 4 months to 11 years, were admitted to pediatric intensive care unit (PICU), and accounted for 0.32% of patients in PICU during the same period. The primary causes of HH were respiratory failure and cardiac shock caused by severe hand-foot-and-mouth disease, fulminant myocarditis, infant muggy syndrome . Serologic tests for hepatitis B virus, hepatitis C virus, as well as serum antibody and DNA for Epstein-Barr virus and cytomegalovirus were all negative. There was an increase of alanine aminotransferase (ALT) (≥20 time supper limit of normal (ULN), the highest ALT was more than 130 times ULN in all the patients, which was decreased to 2 times ULN from peak within 10 days. There was a significant relationship between ALT and aspartate aminotransferase(AST)in 3 cases(r=1.000, 1.000, and 0.833, respectively, P<0.05), ALT and lactate dehydrogenase (LDH)in 2 cases(r=1.000 and 0.886, respectively, P<0.05), ALT and blood urea nitrogen(BUN)in 1 case(r=1.000, P<0.05), and ALT and creatine kinase(CK)in 1 case(r=0.964, P<0.05). The ALT, AST and LDH returned to normal soon after the primary diseases were controlled. CONCLUSION: Severe heart failure, hypoxemia, shock, etc. are the leading primary diseases causing HH. The sharp increase in ALT, AST and LDH is the typical laboratory manifestion in HH after the onset, which may decline to normal shortly after the treatment, sometimes complicated with reversible change in BUN or CK.

[Research advances in pediatric nonalcoholic fatty liver disease].

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.

Liver disease in infancy caused by oxysterol 7 α-hydroxylase deficiency: successful treatment with chenodeoxycholic acid.

A child of consanguineous parents of Pakistani origin developed jaundice at 5 weeks and then, at 3 months, irritability, a prolonged prothrombin time, a low albumin, and episodes of hypoglycaemia. Investigation showed an elevated alanine aminotransferase with a normal γ-glutamyl-transpeptidase. Analysis of urine by electrospray ionisation tandem mass spectrometry (ESI-MS/MS) showed that the major peaks were m/z 480 (taurine-conjugated 3ß-hydroxy-5-cholenoic acid) and m/z 453 (sulphated 3ß-hydroxy-5-cholenoic acid). Analysis of plasma by gas chromatography-mass spectrometry (GC-MS) showed increased concentrations of 3ß-hydroxy-5-cholenoic acid, 3ß-hydroxy-5-cholestenoic acid and 27-hydroxycholesterol, indicating oxysterol 7 α-hydroxylase deficiency. The patient was homozygous for a mutation (c.1249C>T) in CYP7B1 that alters a highly conserved residue in oxysterol 7 α-hydroxylase (p.R417C) - previously reported in a family with hereditary spastic paraplegia type 5. On treatment with ursodeoxycholic acid (UDCA), his condition was worsening, but on chenodeoxycholic acid (CDCA), 15 mg/kg/d, he improved rapidly. A biopsy (after 2 weeks on CDCA), showed a giant cell hepatitis, an evolving micronodular cirrhosis, and steatosis. The improvement in liver function on CDCA was associated with a drop in the plasma concentrations and urinary excretions of the 3ß-hydroxy-Δ5 bile acids which are considered hepatotoxic. At age 5 years (on CDCA, 6 mg/kg/d), he was thriving with normal liver function. Neurological development was normal apart from a tendency to trip. Examination revealed pes cavus but no upper motor neuron signs. The findings in this case suggest that CDCA can reduce the activity of cholesterol 27-hydroxylase - the first step in the acidic pathway for bile acid synthesis.

Saturated fatty acid induction of endoplasmic reticulum stress and apoptosis in human liver cells via the PERK/ATF4/CHOP signaling pathway.

Accumulation of saturated fatty acids in the liver can cause nonalcoholic fatty liver disease (NAFLD). This study investigated saturated fatty acid induction of endoplasmic reticulum (ER) stress and apoptosis in human liver cells and the underlying causal mechanism. Human liver L02 and HepG2 cell lines were exposed to the saturated fatty acid sodium palmitate. MTT assay was used for cell viability, flow cytometry and Hoechst 33258 staining for apoptosis, RT-PCR for mRNA expression, and Western blot for protein expression. Silence of PRK-like ER kinase (PERK) expression in liver cells was through transient transfection of PERK shRNA. Treatment of L02 and HepG2 cells with sodium palmitate reduced cell viability through induction of apoptosis. Sodium palmitate also induced ER stress in the cells, indicated by upregulation of PERK phosphorylation and expression of BiP, ATF4, and CHOP proteins. Sodium palmitate had little effect on activating XBP-1, a common target of the other two canonical sensors of ER stress, ATF6, and IRE1. Knockdown of PERK gene expression suppressed the PERK/ATF4/CHOP signaling pathway during sodium palmitate-induced ER stress and significantly inhibited sodium palmitate-induced apoptosis in L02 and HepG2 cells. Saturated fatty acid-induced ER stress and apoptosis in these human liver cells were enacted through the PERK/ATF4/CHOP signaling pathway. Future study is warranted to investigate the role of these proteins in mediating saturated fatty acid-induced NAFLD in animal models.