Identification of MAP3K4 as a novel regulation factor of hepatic lipid metabolism in non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a metabolic disorder with abnormal lipid metabolism. The present study was to identify regulatory genes related to lipid droplets (LDs) abnormal accumulation in NAFLD. METHODS: transcriptomic analysis and bioinformatics analysis (GEO database) were used to identify potential genes in abnormal lipid metabolism of NAFLD. A candidate gene MAP3K4 expression were detected by immunohistochemistry staining in NAFLD and controls. RNA interference and immunoblotting were used to verify the roles of MAP3K4 in the formation of hepatic LDs. RESULTS: A total of 134 candidate genes were screened, including 44 up-regulated genes and 90 down-regulated genes. 29 genes in the protein-protein interaction (PPI) were selected as hub genes, including MAP3K4. The expression levels of MAP3K4 were positively correlated with NAFLD activity score (r = 0.702, p = 0.002). Furthermore, we found a positive correlation of MAP3K4 expression with serum total cholesterol (r = 0.564, p = 0.023), uric acid levels (r = 0.520, p = 0.039), and body mass index (r = 0.574, p = 0.020). Downregulation of MAP3K4 decreased LDs accumulation in HepG2 cells and reduced the expression of CGI-58 and Plin-2 by imbibition of JNK and group IVA cytosolic phospholipase A2 (cPLA2) activation. CONCLUSION: The study revealed a number of regulatory genes related to hepatic lipid metabolism of NAFLD, and demonstrated that MAP3K4 played a pivotal role in the hepatic lipogenesis of NAFLD.

IRX3 plays an important role in the pathogenesis of metabolic-associated fatty liver disease by regulating hepatic lipid metabolism.

Metabolic-associated fatty liver disease (MAFLD) affects approximately a quarter of the global population. Identification of the key genes and pathways involved in hepatic lipid metabolism is of the utmost importance for the diagnosis, treatment, and prevention of MAFLD. In this study, differentially expressed genes were identified through whole-genome transcriptional analysis of liver tissue from MAFLD patients and healthy controls, and a series of lipid metabolism-related molecules and pathways were obtained through pathway analysis. Subsequently, we focused on Iroquois homeobox protein 3 (IRX3), one of 13 transcription factors that were screened from the 331 differentially expressed genes. The transcription factor IRX3 was significantly decreased in the liver tissue of patients with MAFLD when compared with healthy controls. Pearson's correlation analysis showed that the expression levels of IRX3 in liver tissue were negatively correlated with serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, and uric acid levels. The overexpression and interference of IRX3 induced the increased and decreased lipid droplet accumulation in vitro, respectively. Moreover, interference of IRX3 expression increased mitochondrial fragmentation and reduced the activity of the mitochondrial respiratory chain complex IV. In summary, the study demonstrated that IRX3 regulated hepatic lipid metabolism of MAFLD, and also revealed the effect of IRX3 on mitochondria might be an important mechanism by which IRX3 regulated hepatic lipid metabolism of MAFLD.

Risk Factors of Early Allograft Dysfunction in Patients With Hepatitis B Virus-Related Acute-on-Chronic Liver Failure After Deceased Donor Liver Transplant.

OBJECTIVES: Hepatitis B virus-related acute-on-chronic liver failure remains a life-threatening syndrome, and transplant is the definitive treatment. Early allograft dysfunction is a postoperative complication and affects morbidity and mortality. We studied the risk factors associated with early allograft dysfunction in livertransplantrecipients with hepatitis B virus-related acute-on-chronic liver failure. MATERIALS AND METHODS: This single-center retrospective study of early allograft dysfunction is based on data from January 2015 to June 2020 for 323 recipients with hepatitis B virus-related acute-on-chronic liver failure and 445 with only hepatitis B virus infection (control group). Data that correlated with early allograft dysfunction and outcome were analyzed. RESULTS: Incidence of early allograft dysfunction in patients with hepatitis B virus-related acute-on-chronic liver failure was significantly higher versus the control group (39.3% vs 21.1%; P < .001). Transplant recipients with hepatitis B virus-related acute-onchronic liver failure who developed early allograft dysfunction had lower 90-day, 180-day, and 360-day patient survival rates versus patients with no early allograft dysfunction (89.0% vs 98.0%, 82.7% vs 97.5%, and 80.3% vs 96.4%, respectively; P < .001). Pretransplant kidney failure (odds ratio, 2.644; 95% CI, 1.019-6.864; P = .046), pretransplant coagulation failure (odds ratio, 2.162; 95% CI, 1.291-3.621; P = .003), and operative time (odds ratio, 1.005; 95% CI, 1.002-1.008; P = .003) were independent risk factors for early allograft dysfunction in liver transplant recipients with hepatitis B virus-related acute-onchronic liver failure. There was a synergistic effect of early allograft dysfunction and preoperative kidney/coagulation failure on survival rates of liver transplant recipients with hepatitis B virus-related acute-on-chronic liver failure. CONCLUSIONS: Preoperative kidney/coagulation failure and operative time were independent risk factors of early allograft dysfunction in deceased donor liver transplant recipients with hepatitis B virus-related acute-on-chronic liver failure. The combination of early allograft dysfunction and preoperative kidney/coagulation failure was significantly associated with lower survival of these recipients.

Factors Prognostic of Survival in Liver Transplant Recipients with Hepatitis B Virus Related Acute-on-Chronic Liver Failure.

Objectives: Factors prognostic of survival in liver transplant (LT) recipients with hepatitis B virus related acute-on-chronic liver failure (HBV-ACLF) remain unclear. This study evaluated risk factors for survival in LT recipients with HBV-ACLF and determined the scoring system optimal for assessing patient prognosis. Methods: This retrospective study included 323 HBV-ACLF related patients undergoing LT, including 112, 146, and 65 patients with HBV-ACLF grades 1, 2, and 3, respectively. Overall survival (OS) was estimated by the Kaplan-Meier method, and factors associated with survival were analysed by multivariate Cox proportional hazards models. Pretransplant prognostic scoring systems were compared by receiver operating characteristic (ROC) curve analysis. Results: The one-year survival rate was significantly lower in HBV-ACLF grade 3 (80.0%) than in grades 1 (93.8%) and 2 (91.8%) recipients (p=0.0063). Cox multivariate analysis showed that age >53 years (hazard ratio (HR) 3.731; 95% confidence interval (CI) 1.640-8.407), WBC count >8.6 × 109/L (HR 4.544; 95% CI 1.140-18.107), HBV-ACLF 3 (HR 2.729; 95% CI 1.050-7.096), and cold ischaemia time >8.5 hours (HR 2.867; 95% CI, 1.38-5.921) were independently prognostic of 1-year survival. Comparisons of pretransplant scoring systems showed that chronic liver failure-consortium ACLF score (CLIF-C ACLFs) was superior to COSSH-ACLF, MELD-Na, and MELD scores in predicting 1-year OS in these patients. Conclusions: Age >53 years, WBC counts >8.6 × 109/L, HBV-ACLF grade 3, and cold ischaemia time >8.5 hours are independently prognostic of OS in LT recipients with HBV-ACLF. CLIF-C ACLFs is superior to other scoring methods in predicting 1-year OS in these patients.

Transcriptomic analysis reveals a novel regulatory factor of ECHDC1 involved in lipid metabolism of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is the highest incidence of chronic liver disease worldwide characterized by lipid accumulation in the liver. The full understanding of the lipogenesis of NAFLD is extreme importance. Here, whole-genome transcriptome analysis was performed on liver tissues of NAFLD patients and healthy controls to identify the differentially expressed genes and find new pathways and target genes related to the lipogenesis of NAFLD. Combined with the Gene Expression Omnibus (GEO) database, we found 86 overlapping genes, many of which are related to lipid metabolism of NAFLD. ECHDC1 is one of 86 overlapping genes, and its role in NAFLD has not been reported. The expression of ECHDC1 was significantly increased in liver tissue of patients with NAFLD than that of healthy controls, and oil Red O intensity was positively correlated with the expression levels of ECHDC1. Inhibition of ECHDC1 expression in HepG2 cells by RNAi significantly reduced intracellular lipid droplet number in vitro. In summary, this study analyzed pathogenic factors related to NAFLD at the whole-genome level and demonstrated that ECHDC1 may be involved in the occurrence and development of NAFLD by regulating hepatic lipid metabolism.

Combined Analysis of Expression Profiles in a Mouse Model and Patients Identified BHMT2 as a New Regulator of Lipid Metabolism in Metabolic-Associated Fatty Liver Disease.

Metabolic associated fatty liver disease (MAFLD) is associated with obesity, type 2 diabetes mellitus, and other metabolic syndromes. Farnesoid X receptor (FXR, NR1H4) plays a prominent role in hepatic lipid metabolism. This study combined the expression of liver genes in FXR knockout (KO) mice and MAFLD patients to identify new pathogenic pathways for MAFLD based on genome-wide transcriptional profiling. In addition, the roles of new target genes in the MAFLD pathogenic pathway were also explored. Two groups of differentially expressed genes were obtained from FXR-KO mice and MAFLD patients by transcriptional analysis of liver tissue samples. The similarities and differences between the two groups of differentially expressed genes were analyzed to identify novel pathogenic pathways and target genes. After the integration analysis of differentially expressed genes, we identified 134 overlapping genes, many of which have been reported to play an important role in lipid metabolism. Our unique analysis method of comparing differential gene expression between FXR-KO mice and patients with MAFLD is useful to identify target genes and pathways that may be strongly implicated in the pathogenesis of MAFLD. The overlapping genes with high specificity were screened using the Gene Expression Omnibus (GEO) database. Through comparison and analysis with the GEO database, we determined that BHMT2 and PKLR could be highly correlated with MAFLD. Clinical data analysis and RNA interference testing in vitro confirmed that BHMT2 may a new regulator of lipid metabolism in MAFLD pathogenesis. These results may provide new ideas for understanding the pathogenesis of MAFLD and thus provide new targets for the treatment of MAFLD.